Generating random series with known values of Kendall's tau Kendall's taua offers statistical advantages to the more common Pearson's correlation and both are common in biomedical research. While generating random XY pairs from a known population value of Pearson's correlation is straightforward, the process for generating random sequences for a known value of Kendall's taua is more complicated. Algorithms are presented that yield random numbers from a population with a known expected ?a. They begin with a small set of values that have a known ?. These values are grown to produce an arbitrarily large population that has the same expectation as the smaller set. Two examples are given. One example simulated samples from a population where ?a equaled 0.33 and confidence intervals are produced. A second example illustrates how the algorithm can be used to provide statistical power estimates for research studies using Kendall's ?a.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

kendall's tau
power estimation
statistical methods
simulation methods


Constructing the structure underlying open access practices This article applies a structuralist perspective to examine open access (OA) practices. Anthropologist LSvi-Strauss's culinary triangle model is adopted to streamline a whole OA process from repository content accumulation to OA article consumption. By constructing the conceptual relationship of three OA activities, namely archiving, searching and citation, the article argues that content accumulation constitutes the success of the OA movement. The OA process is perceived as a continuum along which each type of scholar's activity has an impact on, and is also influenced by, other activities. Constructing the structure underlying OA practices will help better recognize the history, present status and future direction of the open access movement.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

digital repositories
electronic journals
open access participation
scholars attitudes and behaviours


Automaton meets algebra: A hybrid paradigm for XML stream processing XML stream applications bring the challenge of efficiently processing queries on sequentially accessible token-based data streams. The automata paradigm is naturally suited for pattern recognition on tokenized XML streams, but requires patches for fulfilling the filtering or restructuring functionalities in the XML query language. In contrast, the algebraic paradigm is a well-established technique for processing self-contained tuples. It however does not traditionally support token inputs. The Raindrop framework is the first to accommodate these two paradigms within one algebraic framework, taking advantage of both. This paper describes the overall framework, highlighting in particular three aspects. First, we describe how the tokens and tuples are modeled in one uniform query processing model. Second, we present the query rewriting that switches computations between these two data models. Third, we discuss strategies for the implementation and synchronization of the operators within the framework. We report experimental results that illustrate the unique optimization opportunities offered by this novel framework. (c) 2005 Elsevier B.V. All rights reserved.

O O B O O O O B I O B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


On the relation between rough set reducts and typical testors This paper studies the relations between rough set reducts and typical testors from the so-called logical combinatorial approach to pattern recognition. Definitions, comments and observations are formally introduced and supported by illustrative examples. Furthermore, some theorems expressing theoretical relations between reducts and typical testors are enunciated and proved. We also discuss several practical applications of these relations that can mutually enrich the development of research and applications in both areas. Although we focus on the relation between the classical concepts of testor and reduct, our study can be expanded to include other types of testors and reducts.

O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O


Difference Expansion Based Reversible Data Hiding Using Two Embedding Directions Current difference-expansion (DE) embedding techniques perform one layer embedding in a difference image. They do not turn to the next difference image for another layer embedding unless the current difference image has no expandable differences left. The obvious disadvantage of these techniques is that image quality may have been severely degraded even before the later layer embedding begins because the previous layer embedding has used up all expandable differences, including those with large magnitude. Based on integer Haar wavelet transform, we propose a new DE embedding algorithm, which utilizes the horizontal as well as vertical difference images for data hiding. We introduce a dynamical expandable difference search and selection mechanism. This mechanism gives even chances to small differences in two difference images and effectively avoids the situation that the largest differences in the first difference image are used up while there is almost no chance to embed in small differences of the second difference image. We also present an improved histogram-based difference selection and shifting scheme, which refines our algorithm and makes it resilient to different types of images. Compared with current algorithms, the proposed algorithm often has better embedding capacity versus image quality performance. The advantage of our algorithm is more obvious near the embedding rate of 0.5 bpp.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

data hiding
integer haar wavelet transform

difference expansion embedding
reversible watermarking


Using visualization for visualization: An ecological interface design approach to inputting data Visualization is experiencing growing use by a diverse community, with continuing improvements in the availability and usability of systems. In spite of these developments the problem of how first to get the data in has received scant attention: the established approach of pre-defined readers and programming aids has changed little in the last two decades. This paper proposes a novel way of inputting data for scientific visualization that employs rapid interaction and visual feedback in order to understand how the data is stored. The approach draws on ideas from the discipline of ecological interface design to extract and control important parameters describing the data, at the same time harnessing our innate human ability to recognize patterns. Crucially, the emphasis is on file format discovery rather than file format description, so the method can therefore still work when nothing is known initially of how the file was originally written, as is often the case with legacy binary data. (C) 2013 Elsevier Ltd. All rights reserved.

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ecological interface design
scientific visualization

file organization
information search
pattern recognition


ATCS: An Adaptive TCP Coding Scheme for Satellite IP Networks In this paper we propose ATCS, a practical TCP protocol coding scheme based on network coding for satellite IP networks. The proposal is specially designed to enhance TCP performance over satellite networks. In our scheme, the source introduces a degree of redundancy and transmits a random linear combination of TCP packets. Since the redundant packets are utilized to mask packet loss over satellite links, the degree of redundancy is determined by the link error rates. Through a simple and effective method, ATCS estimates link error rates in real time and then dynamically adjusts the redundant factor. Consequently, ATCS is adaptable to a wide range of link error rates by coding TCP segments with a flexible redundancy factor. Furthermore, the scheme is compatible with traditional TCP variants. Simulation results indicate that the proposal improves TCP performance considerably.

O O B B O O O B I I O O O O O O O O B O O O O O B I O B I I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O B O O

adaptive
network coding
tcp
satellite ip networks


Human activity recognition from 3D data: A review ? This survey paper summarizes techniques in human activity recognition from 3D data. Focus on recent development in human activity recognition techniques on depth data. Broad categories of algorithms are identified based on the use of features. Pros and cons of the algorithms in each category are analyzed. Possible direction of future research is indicated.

B I I O B I O O O O O O O O O B I I O B I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A note on trapezoidal approximations of fuzzy numbers In this paper, we propose some generalized and new properties of the trapezoidal approximations of fuzzy numbers. First, we claim that the trapezoidal approximation operator is linear with respect to the operations of fuzzy numbers. Second, we show a new property concerning the centroid points of fuzzy numbers. Furthermore, a comment for computing the trapezoidal approximations is provided. Finally, some properties about the distance between a fuzzy number and its trapezoidal approximation are proved. (C) 2006 Elsevier B.V. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O


achieving convergence-free routing using failure-carrying packets Current distributed routing paradigms (such as link-state, distance-vector, and path-vector) involve a convergence process consisting of an iterative exploration of intermediate routes triggered by certain events such as link failures. The convergence process increases router load, introduces outages and transient loops, and slows reaction to failures. We propose a new routing paradigm where the goal is not to reduce the convergence times but rather to eliminate the convergence process completely. To this end, we propose a technique called Failure-Carrying Packets (FCP) that allows data packets to autonomously discover a working path without requiring completely up-to-date state in routers. Our simulations, performed using real-world failure traces and Rocketfuel topologies, show that: (a) the overhead of FCP is very low, (b) unlike traditional link-state routing (such as OSPF), FCP can provide both low loss-rate as well as low control overhead, (c) compared to prior work in backup path pre-computations, FCP provides better routing guarantees under failures despite maintaining lesser state at the routers.

O O B O O O O B B O O O O O O O O O B B O O O O B O O O O O O O O O O O O B B O B O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O B B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B B O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O

convergence traces router topologies data process routing distributed control failure exploration

distance
vectorization
simulation
protocols
event
internet routing
linking
iter


enhancing recommendation diversity with organization interfaces Research increasingly indicates that accuracy cannot be the sole criteria in creating a satisfying recommender from the users' point of view. Other criteria, such as diversity, are emerging as important characteristics for consideration as well. In this paper, we try to address the problem of augmenting users' perception of recommendation diversity by applying an organization interface design method to the commonly used list interface. An in-depth user study was conducted to compare an organization interface with a standard list interface. Our results show that the organization interface indeed effectively increased users' perceived diversity of recommendations, especially perceived categorical diversity. Furthermore, 65\% of users preferred the organization interface, versus 20\% for the list interface. 70\% of users thought the organization interface is better at helping them perceive recommendation diversity versus only 15\% for the list interface.

O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O B O O B I O O O O O O B O O O O B O O O O O O B O O O O O B O O O O O B O O O O O O O B O O O O O B O O O O O O B O O O O O O O B O O O O O O B


A Sensor Network Protocol for Automatic Meter Reading in an Apartment Building A wireless sensor network for automatic meter reading needs to satisfy two contradicting requirements, i.e. long lifetime and prompt detection and notification of emergency. We propose a sensor network protocol for this purpose, in which sensor nodes operate on a low duty cycle while the latency of transmission is guaranteed to be less than it certain bound. In this protocol, each node is assigned a time slot in which it receives messages from other nodes. To accomplish slot assignment where nodes further from a BS are assigned earlier time slots for a packet to be transmitted to the BS in one cycle, we propose a slot assignment function with which a node can determine its own slot in a distributed way. We explore several slot assignment functions to find one which gives low and homogeneous contention over a grid network. The simulation results show that our protocol performs well close to the optimal case.

O O O O O B I I O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

sensor networks
sleep schedule
urgent information


a novel fitting algorithm using the icp and the particle filters for robust 3d human body motion tracking This paper proposes a novel fitting algorithm using the iterative closest point (ICP) registration algorithm and the particle filters for robust 3D human body motion tracking. We use the ICP registration algorithm that fits the 3D human body model to the 3D articulation data in a hierarchical manner. However, it often can not fit under the rapidly moving human body motion. To solve this problem, we combine the modified particle filter with the ICP algorithm. It can search the most appropriate motion parameters by using the observation model based on the surface normal vector and the binary valued function and the state transitional model based on the motion history information. Experimental results show that the proposed combined fitting algorithm provides accurate fitting performance and high convergence rate.

O O O O O O B O O O O O O O B I I I O O O O O O O O O O O O B O O O O O O O O O B I I I O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

particle filter
human body motion tracking
icp


A nonparametric regression model for virtual humans generation In this paper, we propose a novel nonparametric regression model to generate virtual humans from still images for the applications of next generation environments (NG). This model automatically synthesizes deformed shapes of characters by using kernel regression with elliptic radial basis functions (ERBFs) and locally weighted regression (LOESS). Kernel regression with ERBFs is used for representing the deformed character shapes and creating lively animated talking faces. For preserving patterns within the shapes, LOESS is applied to fit the details with local control. The results show that our method effectively simulates plausible movements for character animation, including body movement simulation, novel views synthesis, and expressive facial animation synchronized with input speech. Therefore, the proposed model is especially suitable for intelligent multimedia applications in virtual humans generation.

O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

nonparametric regression
elliptic radial basis functions
locally weighted regression

image deformation
functional approximation


application of partial-order methods for the verification of closed-loop sdl systems This article is concerned with the verification of closed-loop asynchronous reactive systems. Such systems, specified for instance with the industrial SDL (Specification and Description Language) language, communicate with their environment through buffers which memorize occurrences of events. Such a communication mechanism is quite interesting for specifying systems connected to several asynchronous external actors. However, it leads to a verification model possibly composed of a huge number of states (due to the state-space of the buffers). This article shows how this combinatorial explosion could be reduced by specifying the environment of the system to be verified, and by using partial-orders methods both on the system and its environment. After presenting the formal modeling languages SDL (for the reactive system) and CDL Context Description Language (for its environment), the main points of our work are two-fold: (1) we define an independence relation between input events for a given specification where S is the specification of the system (in SDL), C is the behavior of its external environment (in CDL), and ϕ the property to verify. The key point is that this independence relation is separately computed on S, C and ϕ, without building the global synchronization product of the system; (2) we apply the Mazurkiewicz theory for defining the set of scenarios (sequences of input events) which exactly covers the environment C and which is sufficient for verifying ϕ on S . We finally show on two industrial case-studies that this approach leads to an interesting reduction in verification time.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

asynchronous systems verification
partial-order methods


On the search of workstations arrangement in pull production systems This research presents a model to determine the workstation arrangement and kanban number for pull production systems. Several practical production line characters are considered, and evolutionary algorithms are utilized to obtain the optimal/near-optimal result. The proposed system is a flow-shop, pull production line with N unreliable workstations and N - 1 inter-stage buffers. Workstations may be allocated to any stage in the production line and have a different processing rate at each stage. Workstations will breakdown/recover at fixed rates, and the operating-breakdown-recovery process is formulated as a Markov process in this model. The size of the inter-stage buffers varies according to the arrangements of workstations. A model is established on the objective of minimizing the total production cost per item of the finished product. The costs considered in the system contain the allocation of workstations, operations, inventory, and production shortage costs. An evolutionary algorithm, genetic algorithm, is used to obtain the allocation of workstations in the production line. (C) 2007 Elsevier Ltd. All rights reserved.

O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O

evolutionary algorithm
workstation arrangement

pull production system
unreliable machine


Dynamic analysis of an automobile assembly line considering starving and blocking Dynamic analysis considering starving and blocking of machines in networks of closed loops has a great importance in most automobile assembly lines. In this work, an actual automobile assembly line is modelled as a network of closed loops of machines and intermediate buffers formed by conveyors. As a consequence of it, machines can work in both, stationary or transitory regimes. The influence of the working regimes of the machines or the proportion of four-door cars between the doors disassembly and assembly stations on the starving and blocking transmission from the main assembly line has been analyzed. These factors have not been considered yet by the existing literature and they have a great significance in the performance of this kind of manufacturing systems.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I

manufacturing systems
automobile assembly lines


Dynamic programming in a heuristically confined state space: a stochastic resource-constrained project scheduling application The resource-constrained project scheduling problem (RCPSP) is a significant challenge in highly regulated industries, such as pharmaceuticals and agrochemicals, where a large number of candidate new products must undergo a set of tests for certification. We propose a novel way of addressing the uncertainties in the RCPSP including the uncertainties in task durations and costs, as well as uncertainties in the results of tasks (success or failure) by using a discrete time Markov chain, which enables us to model probabilistic correlation of the uncertain parameters. The resulting stochastic optimization problem can be solved by using dynamic programming, but the computational load renders this impractical. Instead, we develop a new way to combine heuristic solutions through dynamic programming in the state space that the heuristics generate. The proposed approach is tested on a simplified version of RCPSP that has a fairly complicated stochastic nature, with 1,214,693,756 possible parameter realizations (scenarios), and involves five projects and 17 tasks. As a result, an on-line policy is obtained, which can use the information states in on-line decision making and improve the heuristics rather than a fixed solution obtained by the previous mathematical programming (MILP) problem formulations. (C) 2003 Elsevier Ltd. All rights reserved.

O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O

markov chain
project scheduling
heuristics

stochastic dynamic programming
combinatorial optimization


Flexibility-based large increment method for analysis of elastic-perfectly plastic beam structures This paper presents the derivation and implementation of a flexibility-based large increment method (LIM) for solving nonlinear structural problems. The finite element displacement and force approaches have been developed for solving nonlinear structural problem. The displacement-based finite element method requires a step-by-step approach for material nonlinear analysis that depends on flow theory. Furthermore, significant mesh refinement is often required in plastic zones. The main advantage of the LIM is that it separates the usage of the three-system equation into two stages, global linear stage and local nonlinear stage. Here LIM formulations are developed for two-dimensional beam elements controlled by an elastic-fully plastic material model. These new formulations are demonstrated using simple nonlinear problems and the results are compared to those obtained from the displacement method. The examples highlight the accuracy and the computational efficiency of the flexibility-based large increment method for this class of structural problems. (c) 2005 Elsevier Ltd. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O

large increment method (lim)
step-by-step
generalized inverse
fully-plastic
beam element


Dynamically generated models for medical decision support systems Doctors applying mechanical ventilation need to find the best balance between benefit and risk for the patient. Mathematical models simulating patient's reactions to alterations in the ventilation regime may be employed. A framework is introduced that is able to dynamically combine mathematical models from different model families to form a complex interacting model system. Each of these families consists of submodels differing in complexity of dynamics formulation or anatomical/geometrical resolution. The interaction of model systems reveals qualitatively varying results depending on the complexity of the involved models. Realistic overlaying of respiratory and cardiovascular rhythms can be detected in blood gas concentrations.

O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

mathematical modeling
lung protective ventilation
respiratory mechanics
gas exchange
cardiovascular dynamics


Introductory programming languages at Australian universities at the beginning of the twenty first century Introductory programming instructors in Australian universities are choosing the programming language they teach primarily based on a perception of industry demand. This paper examines if this perception is justifiable, and offers instructors of all programming languages an insight into the issue of academic and industry balance, now and into the future.

O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O

programming languages
introductory programming

industry demand acm computing classification system: d.3.0


Enterprise systems, knowledge transfer and power users There are few studies of knowledge transfer (KT) between groups with dissimilar purposes and dissimilar practices, which is the situation when transferring knowledge from an enterprise systems (ES) developer team to the users of the new ES. To support such KT, organizations identify a group of power users to work with the ES team and then to help other users integrate the new system into their operations. That KT process still encounters barriers. In a comparative case study of four such KT situations at two different companies we identify the critical barriers, and empirically uncover two new KT mechanisms that are effective for addressing the KT barriers in the ES context.

B I B I O B I O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

enterprise systems
power users
knowledge transfer
case study


Motion planning for haptic guidance Haptic devices allow a user to feel either reaction forces from virtual interactions or reaction forces reflected from a remote site during a bilateral teleoperation task. Also, guiding forces can be exerted to train the user in the performance of a virtual task or to assist him/her to safely teleoperate a robot. The generation of guiding forces relies on the existence of a motion plan that provides the direction to be followed to reach the goal from any free configuration of the configuration space (C-space). This paper proposes a method to obtain such a plan that interleaves a sampling-based exploration of C-space with an efficient computation of harmonic functions. A deterministic sampling sequence (with a bias based on harmonic function values) is used to obtain a hierarchical cell decomposition model of C-space. A harmonic function is iteratively computed over the partially known model using a novel approach. The harmonic function is the navigation function used as motion plan. The approach has been implemented in a planner (called the Kautham planner) that, given an initial and a goal configuration, provides: (a) a channel of cells connecting the cell that contains the initial configuration with the cell that contains the goal configuration; (b) two harmonic functions over the whole C-space, one that guides motions towards the channel and another that guides motions within the channel towards the goal; and (c) a path computed over a roadmap built with the free samples of the channel. The harmonic functions and the solution path are then used to generate the guiding forces for the haptic device. The planning approach is illustrated with examples on 2D and 3D workspaces.

O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O

haptic guidance
deterministic sampling
harmonic functions

feedback motion planning
sampling-based methods


Exploiting path diversity in the link layer in wireless ad hoc networks We develop an anycast mechanism at the link layer for wireless ad hoc networks. The goal is to exploit path diversity in the link layer by choosing the best next hop to forward packets when multiple next hop choices are available. Such choices can come from a multipath routing protocol, for example. This technique can reduce transmission retries and packet drop probabilities in the face of channel fading. We develop an anycast extension of the IEEE 802.11 MAC layer based on this idea. We implement the protocol in an experimental proof-of-concept testbed using the Berkeley motes platform and S-MAC protocol stack. We also implement it in the popular ns-2 simulator and experiment with the AOMDV multipath routing protocol and Ricean fading channels. We show that anycast performs significantly better than 802.11 in terms of packet delivery, particularly when the path length or effect of fading is large. Further we experiment with anycast in networks that use multiple channels and those that use directional antennas for transmission. In these networks, deafness and hidden terminal problems are the main source of packet loss. We implemented anycast as extension of 802.11 like protocols that were proposed for these special networks. We are able to show that anycast is capable of enhancing the performance of these protocols by simply making use of the path diversity whenever it is available.

O O O O O O O O O B I I O O O B O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O

multichannel
directional antenna
interlayer-interaction


Bayesian analysis of finite mixtures of multinomial and negative-multinomial distributions The Bayesian implementation of finite mixtures of distributions has been an area of considerable interest within the literature. Computational advances on approximation techniques such as Markov chain Monte Carlo (MCMC) methods have been a keystone to Bayesian analysis of mixture models. This paper deals with the Bayesian analysis of finite mixtures of two particular types of multidimensional distributions: the multinomial and the negative-multinomial ones. A unified framework addressing the main topics in a Bayesian analysis is developed for the case with a known number of component distributions. In particular, theoretical results and algorithms to solve the label-switching problem are provided. An illustrative example is presented to show that the proposed techniques are easily applied in practice.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

bayesian inference
finite mixture
gibbs sampling
label-switching
multinomial distribution
negative-multinomial distribution


AMPH-IMA97: a hypercard program to determine the name of an amphibole from electron microprobe and wet chemical analyses In 1997, the International Mineralogical Association (IMA) revised the amphibole naming scheme making it necessary to amend the previous EMP-AMPH Macintosh program to the new rules. The ANIPH-IMA97 program allows single input or automatic input of as many amphibole analyses as are available following a set input format. There are three options for calculation scheme of amphibole analysis: (1) complete chemical analyses can be calculated to 24(O, OH, F, Cl); (2) analyses with determined FeO and Fe(2)O(3) but without H(2)O can be calculated to 23(O) and (3) electron microprobe analyses with only total Fe determined and without H(2)O can be calculated to 23(O) with IMA97-recommended normalization for Fe(3+) and Fe(2+) values. To test the program, over 500 analyses were calculated using the three options. The first comprehensive test of the third option successfully estimated Fe(2+) (R(2) = 0.88), but became less successful for Fe(3+) (R(2) = 0.42) estimation. Problems in the normalization of Mn(3+)- and Mn(2+)-bearing amphiboles and in the IMA97 sodic amphibole classification procedure emerged for Mn-rich amphiboles. This necessitated the proposal and implementation with the program of a simplified sodic amphibole classification scheme. A new coloured amphibole classification chart accompanies the program. (C) 2001 Elsevier Science Ltd. All rights reserved.

O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O


Tool support for hardware/software co-design of communication protocols An important aspect in providing high performance distributed systems such as multimedia systems is the combined use of hardware and software in the end systems. System design techniques should allow hardware/software (HW/SW) co-design to integrate both means of implementation. Zn this paper, we show how the standardized formal language Estelle can be used to facilitate co-design. The system to be developed will first be designed in Estelle. At the point of time of final decision on which parts to implement in software and which in hardware, the original specification will be split into several partial specifications, The software parts are translated into C code, while the hardware parts are translated into VHDL code for further analysis and development. We present a tool environment that supports the protocol developer in the design and implementation process. An example shows the usefulness of the tool environment. (C) 2000 Elsevier Science B.V. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O


aesthetic measure of alignment and regularity To be effective as communications or sales tools, documents that are personalized and customized for each customer must be visually appealing and aesthetically pleasing. Producing perhaps millions of unique versions of essentially the same document not only presents challenges to the printing process but also disrupts the standard quality control procedures. The quality of the alignment in each document can easily distinguish professionally looking documents from amateur designs and some computer generated layouts. A multicomponent measure of document alignment and regularity, derived directly from designer knowledge, is developed and presented in computable form. The measure includes: edge quality, page connectivity, grid regularity and alignment statistics. It is clear that these components may have different levels of importance, relevance and acceptability for various document types and classes, thus the proposed measure should always be evaluated against the requirements of the desired class of documents.

O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

aesthetic rules
automatic layout evaluation
designer grid
the hough transform


Surface Reconstruction from Partially Structured Noisy Cloud of Points Using B-Splines This paper presents a new approach how to reconstruct a parametric surface from a partially structured and noisy cloud of points representing surface that has a centre-line, such that all perpendicular rays to that line intersects with a surface not more than once. Presented algorithm analyses partially structured cloud of points, generated by point based 3D scanner and calculates parameters to build a non-uniform B-spline 3D mesh.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

3d surface reconstruction
non-uniform b-spline
parametric surfaces
3d scanning and visualization
point cloud approximation


ranking of wireless access networks for providing qos in heterogeneous environment How to select a proper access network for providing Quality of Service (QoS) in a heterogeneous environment is a unsolved question. This paper introduces a novel ranking algorithm to evaluate the QoS in heterogeneous networks by posing the problem as a multi-objective optimization problem. We focus on a multi-provider environment, including issues like administration domain, access technology, terminal, and application.

O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B I O O O B O B I O O O O O O O O O O O O O O O O O O O O O O O O O

qos
ranking algorithm
heterogeneous networks


a joint power/performance optimization algorithm for multiprocessor systems using a period graph construct A critical challenge in synthesis techniques for iterative applications is the efficient analysis of performance in the presence of communication resource contention. To address this challenge, we introduce the concept of the period graph. The period graph is constructed from the output of a simulation of the system, with idle states included in the graph, and its maximum cycle mean is used to estimate overall system throughput. As an example of the utility of the period graph, we demonstrate its use in a joint power/performance optimization solution that uses either a nested genetic algorithm, or a simulated annealing algorithm. We analyze the fidelity of this estimator, and quantify the speedup and optimization accuracy obtained compared to simulation.

O O O O B O B B O O O B O O O B O B O O O B O O O B O B O O B O B B B O O O B O O O B O O O B O O B O O O O O O O B O O O O O O O O O B O O O O B O O O O O O B O O O O O B O O O B O B O B O O O O O O O O O O O B I O O B I B O O O O O O O O O O B O O B O O O B

communication
challenge
speedup
applications
use
simulation
analysis
performance
concept
presence
throughput
simulated annealing
genetic algorithm
contention
accuracy
systems
mean
demonstrate
graph
synthesis
algorithm
utility
multiprocessor
resource

estimates
examples
efficiency
addressing
optimality
power
critic
iter
performance optimization


Variations and Commonalities in Processes of Collaboration: The Need for Multi-Site Workplace Studies Workplace studies have made a major contribution to the field of CSCW, drawing attention to subtle practices that enable effective collaboration. However, workplace studies typically focus on a single setting, making it difficult to assess the generalisability of the findings. Through a multi-site workplace study, we explore a specific collaborative process, that of the handover which occurs when a patient is transferred from one hospital or ward to another. The study demonstrates that the term handover captures a variety of collaborative practices that vary in both their form and content, reflecting aspects of the setting in which they occur. Multi-site workplace studies are shown to be essential for CSCW, not only generating findings that have relevance beyond a single setting but also focusing attention on aspects of work practice that may otherwise go unnoticed.

O O O O O O O O O O O B I B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Asynchronous evolutionary shape optimization based on high-quality surrogates: application to an air-conditioning duct Multi-processor HPC tools have become commonplace in industry and research today. Evolutionary algorithms may be elegantly parallelized by broadcasting a whole population of designs to an array of processors in a computing cluster or grid. However, issues arise due to synchronization barriers: subsequent iterations have to wait for the successful execution of all jobs of the previous generation. When other users load a cluster or a grid, individual tasks may be delayed and some of them may never complete, slowing down and eventually blocking the optimization process. In this paper, we extend the recent Futures concept permitting the algorithm to circumvent such situations. The idea is to set the default values to the cost function values calculated using a high-quality surrogate model, progressively improving when exact numerical results are received. While waiting for the exact result, the algorithm continues using the approximation and when the data finally arrives, the surrogate model is updated. At convergence, the final result is not only an optimized set of designs, but also a surrogate model that is precise within the neighborhood of the optimal solution. We illustrate this approach with the cluster optimization of an A/C duct of a passenger car, using a refined CFD legacy software model along with an adaptive meta-model based on Proper Orthogonal Decomposition (POD) and diffuse approximation.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

parallel computing
genetic algorithms
ask&tell
fluid mechanics


Coverage breach problems in bandwidth-constrained sensor networks Recent research in sensor networks highlights the low-power mode operation of sensor networks. In wireless sensor networks, network lifetime can be extended by organizing sensors into mutually exclusive subsets and alternatively activating each subset. Coverage breach occurs when a subset fails to cover all the targets. In bandwidth-constrained sensor networks, coverage breach is more likely to happen because when active sensors periodically send data to the base station, contention for channel access must be considered. Channel bandwidth imposes a limit on the cardinality of each subset. To make efficient use of both energy and bandwidth with minimum coverage breach requires optimal arrangement of sensor nodes. This article addresses three coverage breach problems related to the low-power operation of wireless sensor networks where channel bandwidth is limited. The three coverage breach problems are formulated using integer linear programming models. A greedy approximation algorithm and a heuristic based on the LP-relaxation method are proposed. Effects of changing different network resources on sensor network coverage are studied through simulations. One consistent result is that when the number of sensors increases, network lifetime can be improved without loss of network coverage only if there is no bandwidth constraint; with bandwidth constraints, network lifetime may be improved further at the cost of coverage breach.

B O O O O B I O O O B I O O O O O O B I O O B I B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B I B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O B I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B I O O O O O O O B O O O O O O O O O O B I O O O O O O O O B O

sensor networks
network lifetime
coverage

algorithms
theory
performance
coverage breach
scheduling
energy efficiency


RCare: Extending Secure Health Care to Rural Area Using VANETs In this paper, we propose a delay-tolerant secure long-term health care scheme, RCare, for collecting patients sensitive personal health information (PHI). Specifically, to minimize the overall health care cost, RCare provides network connectivity to rural areas using conventional transportation vehicles (e.g., cars, buses) as relay nodes. These vehicles are expected to store, carry, and forward the PHI to the health-service-provider located mostly at the city area following an opportunistic routing. RCare improves network performance by providing incentive to the cooperative vehicles, and encompasses identity based cryptography to ensure security and privacy of the PHI during the routing period by using short digital signature and pseudo-identity. Network fairness and resistance to different possible attacks are also ensured by RCare. Extensive security and performance analyses demonstrate that RCare is able to achieve desired security requirements with effectiveness in terms of high delivery ratio with acceptable communication delay.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

rural care
ehealth
vehicular adhoc networks
delay tolerant networks


Centralized IDS Based on Misuse Detection for Cluster-Based Wireless Sensors Networks Despite of their energy efficiency, most of WSNs cluster-based routing protocols are vulnerable to security threats. Selective forwarding and black hole attacks are ranked among the most devastating attacks which they target this class of routing protocols. In this paper, a new centralized intrusion detection system is proposed to detect selective forwarding and black hole attacks in cluster-based wireless sensors networks. The main idea is the use of a centralized detection approach, where the base station decides on potential intrusions based on control packets sent from the cluster heads. The proposed intrusion detection technique is simple and energy efficient, it is thus suitable for sensor nodes with resource constrained. The simulation results confirm the expected performance of the proposed IDS in terms of security and energy efficiency.

O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O B I I I O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

selective forwarding
black hole
centralized intrusion detection system
misuse detection

wireless sensor network
cluster-based routing protocols


STUDY OF A VOICE ACTIVITY DETECTOR AND ITS INFLUENCE ON A NOISE-REDUCTION SYSTEM Some noise reduction processings, such as spectral subtraction techniques, require the learning of noise characteristics. In consequence, a Voice Activity Detector (VAD) is needed to determine noise and speech sequences. In this paper, in the case of spatially uncorrelated (or slightly correlated) noises, we introduce a new technique based on the coherence function which is used to determine a speech/noise classification algorithm. We combine it with a noise reduction technique based on the spectral subtraction and evaluate its influence. We report on results obtained on the performance of the algorithm and conclude that they are quite comparable to those obtained using a manual labelling.

O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Assisted Reproductive Technologies in Europe Encompass Diverse and Complex Ethical Viewpoints: Issues to Be Considered in Reporting Research in Human Reproduction Abstract: The many dimensions of the field of reproduction (clinical, scientific, social, ethical, legal) must be addressed by those with editorial responsibility for the major journals in the field. As the editorial team of the leading reproductive journal Human Reproduction, we have evolved processes that attempt to ensure a transparent but robust approach to complexities whose impact varies across international boundaries.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

assisted reproduction
reproductive ethics
publication ethics
reproductive biology
stem cells
cloning


conditional hardness of precedence constrained scheduling on identical machines Already in 1966, Graham showed that a simple procedure called list scheduling yields a 2-approximation algorithm for the central problem of scheduling precedence constrained jobs on identical machines to minimize makespan. Till this date it has remained the best algorithm and whether it can or cannot be improved has become a major open problem in scheduling theory. We address this problem by establishing a quite surprising relation between the approximability of the considered problem and that of scheduling precedence constrained jobs on a single machine to minimize weighted completion time. More specifically, we prove that if the single machine problem is hard to approximate within a factor of 2-? then the considered parallel machine problem, even in the case of unit processing times, is hard to approximate within a factor of 2-?, where ? tends to 0 as ? tends to 0. Combining this with Bansal & Khot's recent hardness result for the single machine problem gives that it is NP-hard to improve upon the approximation ratio obtained by Graham, assuming a new variant of the unique games conjecture.

O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O


An evolutionary navigator for autonomous agents on unknown large-scale environments Computation of a collision-free path for a movable object among obstacles is an important problem in the fields of robotics. In previous research we have introduced an evolutionary algorithm for a robot moving on a known map considering a 4-connected grid model, and we have obtained encouraging results. In this paper, we focus our attention on a more complex motion planning problem: An autonomous agent with a limited sensor capability which is moving in a completely unknown large-scale environment. We introduce an evolutionary approach that has shown some adaptation abilities due to its constant update of its environment knowledge, and replanning only when it is strictly required. We compare our approach for various map sizes to a very well-known evolutionary algorithm and to the complete approach D* Lite. Our algorithm outperforms them in both CPU time and in the number of re-plannings.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Simulation of the energy absorption and the resist development at sub-150nm ion lithography The simulation tools for sub-150nm ion beam lithography require more adequate models of the ion scattering, the energy losses and the development process. Accumulation and analysis of calculated results and physical parameters included in the models permit deeper understanding of the processes, comparison with experimental data and optimization of the simulation tools. Ion lithography of poly-methyl methacrylate of thickness up to 400nm is studied. From the detailed simulation study, significant information on the energy losses, ranges and moments of the space distributions for different ions is obtained. It is concluded that the exposure with He ions with energies from 60 to 100keV is favorable for sub-150nm region. The presented energy absorption data confirm the importance of the electronic losses and the negligible effect of the nuclear losses on the local resist modification. Using simulation tools, accurate prediction of final resist profiles (after development) and analysis of obtained results at different process parameters of sub-150nm structures is performed.

O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ion penetration range
electronic and nuclear losses
developed resist profiles


Biometric recognition using 3D ear shape Previous works have shown that the ear is a promising candidate for biometric identification. However, in prior work, the preprocessing of ear images has had manual steps and algorithms have not necessarily handled problems caused by hair and earrings. We present a complete system for ear biometrics, including automated segmentation of the ear in a profile view image and 3D shape matching for recognition. We evaluated this system with the largest experimental study to date in ear biometrics, achieving a rank-one recognition rate of 97.8 percent for an identification scenario and an equal error rate of 1.2 percent for a verification scenario on a database of 415 subjects and 1,386 total probes.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ear biometrics
skin detection
curvature estimation
active contour
iterative closest point


Application of neuro-fuzzy scheme to investigate the winding insulation paper deterioration in oil-immersed power transformer Neuro-fuzzy scheme to investigate the winding insulation paper (WIP) deterioration. To investigate the deterioration condition of the WIP in oil-immerged power transformer. New technique also diagnoses those samples which are out of IEEE and IEC standard range. Testing results are better as compare to IEEE and IEC methods.

O O O O O O O O B I O O O O B O O O O O O B I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O

dissolved gas analysis (dga)
fuzzy-logic
artificial neural network (ann)
pnn


Students' navigation patterns in the interaction with a mechanics hypermedia program This study investigates the interaction of a group of freshmen enrolled in a Pre Service Physics Teacher Training Course with a mechanics hypermedia program. Data were obtained to discuss hypertextual navigation guided by the following questions: (i) How can the students' navigation in this hypermedia program be characterized? (ii) How does this relate to their prior knowledge in mechanics? The sequence analysis of the events collected from the log files was used to characterize students' navigation and a mechanics test assessed students' prior knowledge. The inspection of students' navigation graphs made it possible to associate the structure of navigation to prior knowledge in mechanics. Three patterns of navigation are proposed associated to different levels of students' prior knowledge and to different roles performed by the program. In the organized navigation, the student who best performed in the pre test seemed to be reviewing content he already knew, using the system as a database. In the conceptual navigation the students who presented difficulties in the pre test spent different times in the pages as they were addressing conceptual difficulties, using the system as a support for learning. The students who scored the lowest in the test performed a disoriented navigation, spending much less than the adequate time to interact meaningfully with the content. The role that previous knowledge in mechanics plays in these patterns of navigation was related to the function that Ausubel's subsumers perform in learning. The results indicate that hypertextual navigation can provide information about students' conditions to engage in meaningful learning, which could be used to help the teacher personalize instruction. (C) 2007 Elsevier Ltd. All rights reserved.

O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O B O O O O O O O O O B O B I O O O O O B O O O O O O O O B I O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Salt-and-pepper noise removal by median-type noise detectors and detail-preserving regularization This paper proposes a two-phase scheme for removing salt-and-pepper impulse noise. In the first phase, an adaptive median filter is used to identify pixels which are likely to be contaminated by noise (noise candidates). In the second phase, the image is restored using a specialized regularization method that applies only to those selected noise candidates. In terms of edge preservation and noise suppression, our restored images show a significant improvement compared to those restored by using just nonlinear filters or regularization methods only. Our scheme can remove salt-and-pepper-noise with a noise level as high as 90%.

O O O O O O O O O O O O O O O O O O O B I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


evolutionary algorithms and matroid optimization problems We analyze the performance of evolutionary algorithms on various matroid optimization problems thatencompass a vast number of efficiently solvable as well as NP-hard combinatorial optimizationproblems (including many well-known examples such as minimum spanning tree and maximum bipartitematching). We obtain very promising bounds on the expected running time and quality of the computedsolution. Our results establish a better theoretical understanding of why randomized searchheuristics yield empirically good results for many real-world optimization problems.

B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

matroid intersection
minimum weight basis
matroids
randomized search heuristics


Automatically conflating road vector data with orthoimagery Recent growth of the geospatial information on the web has made it possible to easily access a wide variety of spatial data. The ability to combine various sets of geospatial data into a single composite dataset has been one of central issues of modern geographic information processing. By conflating diverse spatial datasets, one can support a rich set of queries that could have not been answered given any of these sets in isolation. However, automatically conflating geospatial data from different data sources remains a challenging task. This is because geospatial data obtained from various data sources may have different projections, different accuracy levels and different formats (e.g., raster or vector format), thus resulting in various positional inconsistencies. Most of the existing algorithms only deal with vector to vector data conflation or require human intervention to accomplish vector data to imagery conflation. In this paper, we describe a novel geospatial data fusion approach, named AMS-Conflation, which achieves automatic vector to imagery conflation. We describe an efficient technique to automatically generate control point pairs from the orthoimagery and vector data by exploiting the information from the vector data to perform localized image processing on the orthoimagery. We also evaluate a filtering technique to automatically eliminate inaccurate pairs from the generated control points. We show that these conflation techniques can automatically align the roads in orthoimagery, such that 75% of the conflated roads are within 3.6 meters from the real road axes compared to 35% for the original vector data for partial areas of the county of St. Louis, MO.

O O O B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I B O O O O O O B I O O B O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O B O B I O O O O O O B I O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O

conflation
fusion
vector data
orthoimagery


Computational dose predictions for combined treatment of hemofiltration with weekly hemodialysis Hemodialysis (HD) has sufficient efficacy as a conventional diffusive treatment for removing small molecules, whereas hemofiltration (HF), which is a convective treatment, has an improved the clearance of intermediate-sized molecules. This paper reports a combined treatment (CT) which combines the diffusive and convective efficacies of HF several times weekly with HD weekly. CT modalities with various schedules and prescriptions are described mathematically using a variable-volume two-compartment kinetics model, and the kinetic parameters were obtained from previous clinical reports and a hemodialysis-related database. The blood concentration profiles of the three waste molecules for 52 weeks were calculated in order to compare the capability of removing small and intermediate-sized molecules to those of other renal treatments. The results by a computer simulation show that CT can reduce the frequency of sessions and the volume of replacement fluid compared with daily convective treatment, and achieve the adequate treatment efficiency with both small and intermediate-sized molecules for chronic renal failure patients.

O O O O B I O B O O B B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

hemodialysis
hemofiltration
combined treatment
kinetics model


Preprocessing DEA We collect, organize, analyze, implement, test, and compare a comprehensive list of ideas for preprocessors for entity classification in DEA. We limit our focus to procedures that do not involve solving LPs. The procedures are adaptations from previous work in DEA and in computational geometry. The result is five preprocessing methods three of which are new for DEA. Testing shows that preprocessors have the potential to classify a large number of DMUs economically making them an important computational tool especially in large scale applications. This is a comprehensive study of preprocessing in DEA. The purpose is to provide tools that will reduce the computational burden of DEA studies especially in large scale applications.

O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O


Connecting Congregations Technology Resources Influence Parish Nurse Practice This descriptive pilot study evaluated the influence of health resource information education and the use of Web-based communication technology on the professional practice of the parish nurse in the congregational setting. Five parish nurse participants from varied denominations in rural and nonrural Virginia received a laptop computer, printer, video projector, and webcam along with high-speed Internet access in each congregational setting. The nurses attended two group education sessions that incorporated computer applications and training in accessing and using quality health information resources and communication applications such as a group "chat" software and webcam to communicate with others through high-speed Internet access. Qualitative analysis from semistructured interviews of nurses confirmed that participants found the project to be beneficial in terms of awareness, education, and applicability of technology use in parish nurse practice. Quantitative data from preproject and postproject surveys found significant differences in nurses' abilities and confidence with technology use and application. Findings showed that the knowledge and experience gained from this study enhanced parish nurse practice and confidence in using technology for communication, health education, and counseling.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

computer-mediated communication
computer user training
parish nursing


Convergence analysis and detection of singularities within a boundary meshless method based on Taylor series We study a meshless method based on Taylor series approximation. This method solves quasi-exactly the Partial Differential Equation (PDE) in the domain. The boundary conditions are applied by using a least square method as proposed by Zhang et al. (2001 [3]), for stabilising collocation method. After showing accuracy and efficiency of the technique, we analyse the convergence of the series. In this aim, we introduce techniques as Domb Sykes plot, Hadamard criterion or Darboux criterion. This analysis leads to the radius of convergence and to the location and the nature of the singularities of the sought solution.

O O O O O O O O O B I O O B I O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

meshless method
collocation
taylor series


Demonstration of Data and Control Plane for Optical Multicast at 100 and 200 Gb/s With and Without Frequency Conversion Emerging services, such as high-definition Internet Protocol TV (IP-TV) or data center migration, are going to increase the amount of multicast traffic in the Internet. The support of multicast directly in the optical domain, instead of at the IP layer, is a target for reducing the amount of optical-electronic-optical conversions (thus, the network operational and capital expenditure) and energy consumption. In parallel, flex-grid technology (e. g., bandwidth variable wavelength selective switches) is emerging as a candidate solution to be adopted in future optical transport networks given its capacity of improving spectrum efficiency. This paper is focused on optical multicast in flex-grid optical networks and on its control through the Path Computation Element (PCE). First, we present two node architectures supporting optical multicast. The first node architecture achieves optical multicast through passive light split and requires that the multicast connection satisfies the spectrum continuity constraint. The second node architecture achieves optical multicast with frequency conversion. In particular, a specific implementation of the second architecture is proposed in this paper exploiting a periodically poled lithium niobate (PPLN) waveguide. Then, a PCE architecture to control optical multicast (with and without frequency conversion) is proposed. Optical multicasting, based on the proposed node architectures, at 100 and 200 Gb/s is experimentally demonstrated in a flex-grid network testbed. In particular, multicasting is demonstrated with 112 Gb/s polarization multiplexing 16 quadrature amplitude modulation (PM-16QAM) and polarization multiplexing quadrature phase shift keying (PM-QPSK), and with 224 Gb/s PM-16QAM considering the light-split node architecture. Moreover, optical multicast with two frequency conversions, achieved in a single PPLN device, is demonstrated for the first time with a 224 Gb/s PM-16QAM signal. The testbed also includes the PCE, which is extended to control optical multicast in flex-grid optical networks.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

broadcasting
elastic networks
flex-grid
high rates


Understanding the triaging and fixing processes of long lived bugs Bug fixing is an integral part of software development and maintenance. A large number of bugs often indicate poor software quality, since buggy behavior not only causes failures that may be costly but also has a detrimental effect on the users overall experience with the software product. The impact of long lived bugs can be even more critical since experiencing the same bug version after version can be particularly frustrating for user. While there are many studies that investigate factors affecting bug fixing time for entire bug repositories, to the best of our knowledge, none of these studies investigates the extent and reasons of long lived bugs. In this paper, we investigate the triaging and fixing processes of long lived bugs so that we can identify the reasons for delay and improve the overall bug fixing process. We mine the bug repositories of popular open source projects, and analyze long lived bugs from five different perspectives: their proportion, severity, assignment, reasons, as well as the nature of fixes. Our study on seven open-source projects shows that there are a considerable number of long lived bugs in each system and over 90% of them adversely affect the users experience. The reasons for these long lived bugs are diverse including long assignment time, not understanding their importance in advance, etc. However, many bug-fixes were delayed without any specific reasons. Furthermore, 40% of long lived bugs need only small fixes. Our overall results suggest that a significant number of long lived bugs may be minimized through careful triaging and prioritization if developers could predict their severity, change effort, and change impact in advance. We believe our results will help both developers and researchers better to understand factors behind delays, improve the overall bug fixing process, and investigate analytical approaches for prioritizing bugs based on bug severity as well as expected bug fixing effort.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

bug tracking
bug triaging
bug survival time


Level-of-detail for data analysis and exploration: A historical overview and some new perspectives Level-of-detail (LOD) techniques have been studied for many years in computer graphics. Research in this area has reached maturity and several effective tools in LOD modeling are now available. However, most models and tools proposed in the literature are oriented to rendering. This is just one among many tasks that LOD should support in the context of applications involving geometric meshes of large size. Our approach to the research on LOD has always been to develop models and data structures that can support a range of spatial queries, rather than being optimized for rendering. Here, we present a historical overview, by highlighting the impact of this approach in the design of LOD models and data structures, and we briefly describe our current research, outlining new challenges in which LOD finds important applications.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A new similarity measure for nonlocal filtering in the presence of multiplicative noise A new similarity measure and nonlocal filters for images corrupted by multiplicative noise are presented. The considered filters are generalizations of the nonlocal means filter of Buades et al., which is known to be well suited for removing additive Gaussian noise. To adapt this filter to different noise models, the involved patch comparison has first of all to be performed by a suitable noise dependent similarity measure. For this purpose, a recently proposed probabilistic measure for general noise models by Deledalle et al. is studied. This measure is analyzed in the context of conditional density functions and its properties are examined for data corrupted by additive and multiplicative noise. Since it turns out to have unfavorable properties for multiplicative noise, a new similarity measure is deduced consisting of a probability density function specially chosen for this type of noise. The properties of this new measure are studied theoretically as well as by numerical experiments. To finally obtain nonlocal filters, a weighted maximum likelihood estimation framework is applied, which also incorporates the noise statistics. Moreover, the weights occurring in these filters are defined using the new similarity measure and different adaptations are proposed to further improve the results. Finally, restoration results for images corrupted by multiplicative Gamma and Rayleigh noise are presented to demonstrate the very good performance of these nonlocal filters.

O O O O O B I O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiplicative noise
conditional density functions
maximum likelihood estimation
nonlocal filtering


Similarity search in sensor networks using semantic-based caching Sensor networks build temporary wireless connections in environments where the stationary infrastructures are either destroyed or too expensive to construct. Most of the previous research in sensor networks focuses on routing protocols that adapt to the dynamic network topologies, and not much work has been done on data accessing. One important data accessing application is similarity search, which provides the foundation of content-based retrieval. Many traditional similarity search algorithms are based on centralized or flooding mechanisms, which are not effective in wireless sensor network environments due to the multiple limitations such as bandwidth and power. In this paper we tackle the problem of similarity search by using semantic-based caching to reflect the data content distribution in the network. The basic idea is analyzing the cached results of earlier queries and trying to resolve the later queries within a small collection of content-related mobile nodes. Based on a Hilbert space-filling curve, the data points in a multi-dimensional semantic space are described as a linear representation. These data points are further cached to facilitate query processing. Through extensive simulations, we show that our method can perform similarity search with improved performance in terms of search cost and response time.

B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O


future of home media In the future, the television set at home will be a key device for providing integrated information services through broadcasting, communication and storage media. In this environment, users will be able to receive any type of information, e. g., HDTV programs, in real-time and whenever s/he wants. Moreover, the advent of advanced mobile terminals means that this new environment will eventually expand to anywhere outside the home. In this speech, I will introduce the services in the future and some topics of the technologies being developed by the NHK Science and Technical Research Laboratories (STRL) to achieve such services.

O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

vod
conditional access system
agent
metadata extraction


webwork for programming fundamentals WeBWorK is a web-based assessment tool developed at the University of Rochester to generate, deliver, and automatically grade homework problems and distribute their solutions. Sharing the market with similar systems, WeBWorK differs in that it is free and open-source. It provides an advanced processing of mathematical formulae and a high-level of problem randomization. Although it was used initially used in mathematics and physics, we are working on extending and adapting WeBWorK for programming fundamentals and computer science.

B O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O

active learning
web-based assessment tool


A note on the correlation of fuzzy numbers by expected interval In this paper, we propose a method to calculate the correlation coefficient of fuzzy numbers by means of "expected interval" (see [8], [9]). This value obtained from our formula tell us not only the strength of relationship between the fuzzy numbers, but also whether the fuzzy numbers are positively or negatively related. This approach looks better than previous methods which only evaluate the strength of the relation. Furthermore, we extend the "expected interval" method to interval-valued fuzzy numbers. The value of the correlation coefficient between interval-valued fuzzy numbers lies in the interval [- 1, 1], as computed from our formula.

O O O O O O O O O B I O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O

correlation coefficient
expected interval

fuzzy number
interval-valued fuzzy number


Cooperating distributed systems of restarting automata Here we introduce cooperating distributed systems of restarting automata and establish that in mode = 1 they correspond to the non-forgetting restarting automaton.

O O O O O O O O O O O O O O O O O O O O O O O O O O O B I


A scalable algorithm for extraction and clustering of event-related pictures The event detection problem, which is closely related to clustering, has gained a lot of attentions within event detection for textual documents. However, although image clustering is a problem that has been treated extensively in both Content-Based Image Retrieval (CBIR) and Text-Based Image Retrieval (TBIR) systems, event detection within image management is a relatively new area. Having this in mind, we propose a novel approach for event extraction and clustering of images, taking into account textual annotations, time and geographical positions. Our goal is to develop a clustering method based on the fact that an image may belong to an event cluster. Here, we stress the necessity of having an event clustering and cluster extraction algorithm that are both scalable and allow online applications. To achieve this, we extend a well-known clustering algorithm called Suffix Tree Clustering (STC), originally developed to cluster text documents using document snippets. The idea is that we consider an image along with its annotation as a document. Further, we extend it to also include time and geographical position so that we can capture the contextual information from each image during the clustering process. This has appeared to be particularly useful on images gathered from online photo-sharing applications such as Flickr. Hence, our STC-based approach is aimed at dealing with the challenges induced by capturing contextual information from Flickr images and extracting related events. We evaluate our algorithm using different annotated datasets mainly gathered from Flickr. As part of this evaluation we investigate the effects of using different parameters, such as time and space granularities, and compare these effects. In addition, we evaluate the performance of our algorithm with respect to mining events from image collections. Our experimental results clearly demonstrate the effectiveness of our STC-based algorithm in extracting and clustering events.

O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

event detection
image clustering
suffix tree


Multilayer Traffic Network Optimized by Multiobjective Genetic Clustering Algorithm This paper introduces a multilayer traffic network model and traffic network clustering method for solving the route selection problem (RSP) in car navigation system (CNS). The purpose of the proposed method is to reduce the computation time of route selection substantially with acceptable loss of accuracy by preprocessing the large size traffic network into new network form. The proposed approach further preprocesses the traffic network than the traditional hierarchical network method by clustering method. The traffic network clustering considers two criteria. We specify a genetic clustering algorithm for traffic network clustering and use NSGA-II for calculating the multiple objective Pareto optimal set. The proposed method can overcome the size limitations when solving route selection in CNS. Solutions provided by the proposed algorithm are compared with the optimal solutions to analyze and quantify the loss of accuracy.

O O O O O O O B O O O O O O O O O O O O B O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O B O O O O B O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O


Comparison of ANFIS and NN modelsWith a study in critical buckling load estimation The investigation of the effects of cracks or similar weaknesses on the load carrying capacity of structural elements such as columns, beams and shells is an important problem in civil, mechanical, earthquake and aerospace engineering. In this paper, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) model have been successfully used for the buckling analysis of slender prismatic columns with a single non-propagating open edge crack subjected to axial loads. The main focus of this work has been to study the feasibility of using ANFIS and neural network (NN) trained with the non-dimensional crack depth and the non-dimensional crack location parameters to predict the critical buckling load of fixed-free, pinned-pinned, fixed-pinned and fixed-fixed supported, axially loaded compression rods. A comparative study is made using the neural nets and neuro-fuzzy techniques. Statistic measures were used to evaluate the performance of the models. Based on comparison of the results it is found that the proposed ANFIS architecture with Gaussian membership function is found to perform better than the multilayer feed forward ANN learning by backpropagation algorithm. The final results show that especially the ANFIS modeling may constitute an efficient tool for elastic buckling analysis of edge cracked columns. Architectures of the ANFIS and NN established in the current study perform sufficiently in the estimation of critical buckling loads, and particularly the ANFIS estimates closely follow the actual values for the whole data sets. These model architectures can be used as a non-destructive procedure for health monitoring of structural elements.

O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I I O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

slender prismatic columns
buckling
open edge crack

stability
neural networks
neuro-fuzzy modeling


Channel Power Excursions From Single-Step Channel Provisioning Steady-state power excursions arising from channel-addition wavelength-switching events are measured as a function of spectral configuration and amplifier settings in an erbium-doped-fiber-amplifier- (EDFA-) based reconfigurable optical add-drop multiplexer network, and they exhibit a maximum excursion of 4.5 dB after four spans of 40 km standard single-mode fiber and 5 EDFAs. A simple model is introduced to explain the power-coupling phenomena responsible for the power excursions. The results show that the maximum excursion is determined by the maximum mean gain difference between the existing and added channels and does not necessarily correspond to the maximum number of channels or input power change.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

communication system control
optical amplifiers
optical switches


Easing the smart home: Semi-automatic adaptation in perceptive environments This paper analyses the requirements of automation and adaptation in the so called perceptive environments. These environments are places with the ability of perceiving the context through sensors and other mechanisms. Focusing on personal/home environments, we present a first approach and prototype to semi-automatic adaptation of Perceptive Environments through a system of rule-based, configurable and modular agents, which are able to explain their behaviors and to adapt to the changing habits of the users. This prototype has been implemented over a real environment: a living room equipped with ambient intelligence capabilities. The core of the system relies on a set of modular agents equipped with rules. Those rules are composed of triggers, conditions and actions that enable them to express desired behaviors of the environment as well as to infer high-level context from low level context. One of the main objectives of the system is to leverage the control of the user over his/her own environment, making it easy to create powerful and personal behaviors without expert assistance. In this sense this work follows Greenberg's thought of making "simple ideas simple to be done" [Greenberg 07].

O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ubiquitous computing
automatic adaptation
natural programming


Tolerance spaces: Origins, theoretical aspects and applications This article considers the origins, theoretical aspects and applications of tolerance spaces. In terms of the origin of tolerance spaces, this article calls attention to the seminal work by J.H. Poincar (18541912) and E.C. Zeeman (1925) on establishing the foundations for tolerance spaces. During the period from 1895 to 1912, Poincar introduced sets of sensations and sequences of almost the same sensations as a means of characterizing the physical spectrum. The perception of physical objects that are almost the same leads to a tolerance space view of visual perception as well as other forms of perception such as touch and sound. Roughly 60years later (in 1962), Zeeman formally introduced the notion of a tolerance space as a useful means of investigating a geometry of visual perception. In addition to the general theory of tolerance spaces, this article also carries forward earlier work on perceptual tolerance relations and considers the resemblance (nearness) between tolerance spaces. From an information systems point of view, it can be observed that tolerance spaces have proved to be fruitful in a number of research areas. Evidence of the utility of tolerance spaces in information systems can be seen in the introduction of tolerance rough sets, tolerance approximation spaces, and tolerance near sets. The contribution of this article is an overview of tolerance spaces considered in the context of visual perception and a presentation of a formal basis for the study of perceptual tolerance spaces.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O

physical spectrum
resemblance
tolerance space
visual perception


The complexity of Boolean constraint satisfaction local search problems The class of generalized satisfiability problems, first introduced by Schaefer in 1978, presents a uniform way of studying the complexity of Boolean constraint satisfaction problems with respect to the nature of constraints allowed in the input. We investigate the complexity of local search for this class of problems. We prove a dichotomy result: any generalized satisfiability local search problem is either in P or PLS-complete. In the meantime our study contributes to a better understanding of the complexity class PLS through the identification of an appropriate tool that captures reducibility among Boolean constraint satisfaction local search problems: sensitive implementation.

O B O O O O B I O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O B I O O O O O O O O O O O O B B I O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O B I O O O

satisfiability
local search
complexity
pls


Hydraulic conductivity estimation in partially saturated soils using the adjoint method An iterative algorithm based on the adjoint method for the estimation of the saturated hydraulic conductivity k in a partially saturated soil Q is proposed. Groundwater flow in Q is assumed to be described by Richards equation. The optimization problem minimizes the L2-error between the pressure head values p(k,x,t) calculated as the solution of a direct problem and the measured values of the pressure head at discrete points inside the domain Q. The exact gradient of the cost functional is obtained by solving an appropriate adjoint problem, which is derived from the equations of the Gteaux derivatives of the pressure head with respect to the parameter k. A finite element procedure is used to obtain approximate solutions of the direct and adjoint problems and the Gteaux derivatives. A discrete form of the expression of the gradient of the cost functional at the continuous level is used inside a nonlinear conjugate gradient iteration to solve the optimization problem. A numerical example showing the implementation of the algorithm to estimate the saturated hydraulic conductivity k(x) during an hypothetical infiltration experiment in a heterogeneous soil is also presented.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

inverse problems
adjoint methods
finite elements