Extending the Contraposition Property of Propositional Logic for Fuzzy Abduction Abduction deals with assumption-based reasoning to explain an observation. In the context of fuzzy reasoning, abduction attempts to determine the membership function of the fuzzy propositions present in the antecedent of a rule when the membership functions for the propositions in the consequent of the rule are given. Currently available models of fuzzy abduction are capable of inferring the membership function of the antecedent clause accurately when the antecedent includes single fuzzy proposition. However, when the antecedent clause of a rule contains multiple fuzzy propositions, these models fail to determine the independent membership function of the individual propositions present in the antecedent. This paper presents a new formulation to handle the above problem by fuzzy extension of the well-known contraposition property of propositional logic. Several interesting properties due to the fuzzy extension of the classical contraposition have been derived. An algorithm for automated abduction using the extended contraposition property has been developed to demonstrate the principle of abduction with rules containing one or more fuzzy propositions in the antecedent/consequent. The time complexity of the proposed fuzzy abduction for a sequence of n-chained rules, where each rule has m fuzzy propositions, is O(mn), considering a uniform cost for composition operation and t-norm computation of the antecedent.

O O B I 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 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 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 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 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

contraposition property
fuzzy abduction
propositional logic

fuzzy logic network (fln)
implication relations


success and failure of audience response systems in the classroom Williams College has been working with audience response systems or "clickers" for three years. Initial experiments with the clickers had mixed results in both performance and faculty enthusiasm for the technology. In the last two years, Williams moved from an infrared system to a radio system that was more portable. After some favorable demos, key faculty tried the technology in their classes. Clicker use spread and is now used in classes as small as 10 students and as large as 180 students. The primary functionality of the system is to collect and present live data collected in the classroom. In its simplest form, faculty could use the system to review student comprehension of content. At Williams though, faculty have used the system in a variety of interesting ways. The system has been used for psychology research, peer instruction, student presentation feedback, and in class discussion. The process of adapting audience response systems to the classroom and the support of faculty using these systems has evolved over time. While some challenges remain, this technology has changed the way some faculty teach at Williams College.

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 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 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 O O O O O O

educational technology
turningpoint
powerpoint
turning technologies
personal response system
audience response system
prs


Branch and price for the vehicle routing problem with discrete split deliveries and time windows The Discrete Split Delivery Vehicle Routing Problem with Time Windows (DSDVRPTW) consists of designing the optimal set of routes to serve, at least cost, a given set of customers while respecting constraints on vehicles capacity and customer time windows. Each customer can be visited by more than one vehicle since each customers demand, discretized in items, can be split in orders, i.e., feasible combinations of items. In this work, we model the DSDVRPTW assuming that all feasible orders are known in advance. Remarkably, service time at customers location depends on the delivered combination of items, which is a modeling feature rarely found in literature. We present a flow-based mixed integer program for the DSDVRPTW, we reformulate it via DantzigWolfe and we apply column generation. The proposed branch-and-price algorithm largely outperforms a commercial solver, as shown by computational experiments on Solomon-based instances. A comparison in terms of complexity between constant service time vs delivery-dependent service time is presented and potential savings are discussed.

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

vehicle routing
split delivery
column generation
branch and price


A multiobjective GIS-based land use planning algorithm We formulate land use optimization in terms of additive and spatial objectives. The optimization model is formulated to link with GIS structures. Objectives of spatial contiguity are represented by measures of proximity. A special purpose genetic algorithm is developed and numerically tested. The approach is applied to a planning problem in The Netherlands.

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

multiple criteria decision making
reference point approach
spatial optimization


Removal of residual layer by liquid transfer imprint lithography using roll-to-roll UV-NIL Residual layer thickness was reduced using RTR-LTIL technique. We controlled the pressure and UV expose during RtR motion. Heating and two rounds of LTIL are effective for obtaining a thin residual layer. Our method produced no-residual-layer transfer of nano structures onto the film.

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

nanoimprint lithography
roll to roll
ultraviolet-cured resin
replica mold


Steepest descent with momentum for quadratic functions is a version of the conjugate gradient method It is pointed out that the so called momentum method, much used in the neural network literature as an acceleration of the backpropagation method, is a stationary version of the conjugate gradient method. Connections with the continuous optimization method known as heavy ball with friction are also made. In both cases, adaptive (dynamic) choices of the so called learning rate and momentum parameters are obtained using a control Liapunov function analysis of the system.

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

backpropagation
steepest descent
momentum
continuous optimization
control liapunov function

conjugate gradient algorithm
convergence
bilinear system


Distributed Quasi-Orthogonal Space-Time Block Code for Four Transmit Antennas with Information Exchange Error Mitigation In this paper, we extend the case of information exchange error mitigation for the distributed orthogonal space-time block code (DOSTBC) for two transmit antennas to distributed quasi-orthogonal space-time block code (DQOSTBC) for four transmit antennas. A rate 1 full-diversity DQOSTBC for four transmit antennas is designed. The code matrix changes according to different information exchange error cases, so full diversity is maintained even if not all information exchange is correct. We also perform analysis of the pairwise error probability. The performance analysis indicates that the proposed rate 1 DQOSTBC outperforms rate 1/2 DOSTBC for four transmit antennas at the same transmission rate, which is confirmed by the simulation results.

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

cooperative communications
distributed coding
diversity product
cyclic redundancy check


Cloud Technologies for Bioinformatics Applications Executing large number of independent jobs or jobs comprising of large number of tasks that perform minimal intertask communication is a common requirement in many domains. Various technologies ranging from classic job schedulers to the latest cloud technologies such as MapReduce can be used to execute these "many-tasks" in parallel. In this paper, we present our experience in applying two cloud technologies Apache Hadoop and Microsoft DryadLINQ to two bioinformatics applications with the above characteristics. The applications are a pairwise Alu sequence alignment application and an Expressed Sequence Tag (EST) sequence assembly program. First, we compare the performance of these cloud technologies using the above applications and also compare them with traditional MPI implementation in one application. Next, we analyze the effect of inhomogeneous data on the scheduling mechanisms of the cloud technologies. Finally, we present a comparison of performance of the cloud technologies under virtual and nonvirtual hardware platforms.

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

distributed programming
parallel systems
programming paradigms


Speed scaling to manage energy and temperature Speed scaling is a power management technique that involves dynamically changing the speed of a processor. We study policies for setting the speed of the processor for both of the goals of minimizing the energy used and the maximum temperature attained. The theoretical study of speed scaling policies to manage energy was initiated in a seminal paper by Yao et al. [1995], and we adopt their setting. We assume that the power required to run at speed s is P(s) = s(alpha) for some constant alpha > 1. We assume a collection of tasks, each with a release time, a deadline, and an arbitrary amount of work that must be done between the release time and the deadline. Yao et al. [1995] gave an offline greedy algorithm YDS to compute the minimum energy schedule. They further proposed two online algorithms Average Rate (AVR) and Optimal Available (OA), and showed that AVR is 2(alpha-1) alpha(alpha)-competitive with respect to energy. We provide a tight alpha(alpha) bound on the competitive ratio of OA with respect to energy. We initiate the study of speed scaling to manage temperature. We assume that the environment has a fixed ambient temperature and that the device cools according to Newton's law of cooling. We observe that the maximum temperature can be approximated within a factor of two by the maximum energy used over any interval of length 1/b, where b is the cooling parameter of the device. We define a speed scaling policy to be cooling-oblivious if it is simultaneously constant-competitive with respect to temperature for all cooling parameters. We then observe that cooling-oblivious algorithms are also constant-competitive with respect to energy, maximum speed and maximum power. We show that YDS is a cooling-oblivious algorithm. In contrast, we show that the online algorithms OA and AVR are not cooling-oblivious. We then propose a new online algorithm that we call BKP. We show that BKP is cooling-oblivious. We further show that BKP is e-competitive with respect to the maximum speed, and that no deterministic online algorithm can have a better competitive ratio. BKP also has a lower competitive ratio for energy than OA for alpha >= 5.

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

algorithms
speed scaling
power management


Development of an expert selection system to choose ideal cities for medical service ventures For ensuring the successful implementation of medical service investments, here an expert selection system of how ventures can better evaluate and select a favorable city to invest before that implementation has been developed. However, selecting in ideas city is a kind of multiple criteria decision-making (MCDM) problem requiring to consider a large number of complex factors that are based on the independence assumption. The analytic network process (ANP) is a relativly new MCDM method which can deal with all kinds of dependences systematically. With the advantages of ANP in hand, in this paper, we develop an effective method based oil the ANP combined with the technique for order preference by similarity to ideal solution (TOPSIS) to help medical service inventors who need to evaluate and select proper city. Additionally, an empirical study is presented to illustrate the application of the proposed method. (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 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 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 O O O O O O O O O O O O O O O O O O O O O

medical service venture
analytic network process (anp)


Explication and semantic querying of enterprise information systems Many researches show that the ability of independent, heterogeneous enterprises information systems to interoperate is related to the challenges of making their semantics explicit and formal, so that the messages are not merely exchanged, but interpreted, without ambiguity. In this paper, we present an approach to overcome those challenges by developing a method for explication of the systems implicit semantics. We define and implement the method for the generation of local ontologies, based on the databases of their systems. In addition, we describe an associated method for the translation between semantic and SQL queries, a process in which implicit semantics of the EISs databases and explicit semantics of the local ontologies become interrelated. Both methods are demonstrated in the case of creating the local ontology and the semantic querying of OpenERP Enterprise Resource Planning system, for the benefit of the collaborative supply chain planning.

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

systems interoperability
database semantics
enterprise information system


POINT SET DISTANCE AND ORTHOGONAL RANGE PROBLEMS WITH DEPENDENT GEOMETRIC UNCERTAINTIES Classical computational geometry algorithms handle geometric constructs whose shapes and locations are exact. However, many real-world applications require modeling and computing with geometric uncertainties, which are often coupled and mutually dependent. In this paper we address the relative position of points, point set distance problems, and orthogonal range queries in the plane in the presence of geometric uncertainty. The uncertainty can be in the locations of the points, in the query range, or both, and is possibly coupled. Point coordinates and range uncertainties are modeled with the Linear Parametric Geometric Uncertainty Model (LPGUM), a general and computationally efficient worst-case, first-order linear approximation of geometric uncertainty that supports dependence among uncertainties. We present efficient algorithms for relative points orientation, minimum and maximum pairwise distance, closest pair, diameter, and efficient algorithms for uncertain range queries: uncertain range/nominal points, nominal range/uncertain points, uncertain range/uncertain points, with independent/dependent uncertainties. In most cases, the added complexity is sub-quadratic in the number of parameters and points, with higher complexities for dependent point uncertainties.

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

imprecise points
dependent point location uncertainty
uncertain point set distance problems
uncertain relative positioning
uncertain orthogonal range query


protecting representation with effect encapsulation Representation exposure is a well-known problem in the object-oriented realm. Object encapsulation mechanisms have established a tradition for solving this problem based on a principle of reference containment. This paper proposes a novel type system which is based on a different principle, we call effect encapsulation , which confines side effects, rather than object references, according to an ownership structure. Compared to object encapsulation, effect encapsulation liberates us from the restriction on object referenceability and offers more flexibility. In this paper, we show that effect encapsulation can be statically type checked.

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

type system
structure
encapsulation
ownership
object
representation exposure
flexibility
representation
paper
effect

ownership types
types
effect systems
object encapsulation
object-oriented
container


efficient fault tolerant algorithms for resource allocation in distributed systems Solutions to resource allocation problems in distributed systems are examined with respect to the measures of response time, message complexity , and failure locality . Response time measures the time it takes for an algorithm to respond to the requests of a process, message complexity measures the number of messages sent and received by a process, and failure locality characterizes the size of the network that is affected by the failure of a single process. An algorithm that achieves a constant failure locality of four along with a quadratic response time and a quadratic message complexity is presented.

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

network
resource allocation
size
message
response time
process
complexity
algorithm
distributed systems
locality
failure

measurement
efficiency
timing
fault tolerance


C-4: A Real-Time Object Detection Framework A real-time and accurate object detection framework, C-4, is proposed in this paper. C-4 achieves 20 fps speed and the state-of-the-art detection accuracy, using only one processing thread without resorting to special hardware such as GPU. The real-time accurate object detection is made possible by two contributions. First, we conjecture (with supporting experiments) that contour is what we should capture and signs of comparisons among neighboring pixels are the key information to capture contour cues. Second, we show that the CENTRIST visual descriptor is suitable for contour based object detection, because it encodes the sign information and can implicitly represent the global contour. When CENTRIST and linear classifier are used, we propose a computational method that does not need to explicitly generate feature vectors. It involves no image preprocessing or feature vector normalization, and only requires O(1) steps to test an image patch. C-4 is also friendly to further hardware acceleration. It has been applied to detect objects such as pedestrians, faces, and cars on benchmark data sets. It has comparable detection accuracy with state-of-the-art methods, and has a clear advantage in detection speed.

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 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 O B I 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


the structure of cedar This paper presents an overview of the Cedar programming environment, focusing primarily on its overall structure: the major components of Cedar and the way they are organized. Cedar supports the development of programs written in a single programming language, also called Cedar. We will emphasize the extent to which the Cedar language, with runtime support, has influenced the organization, comprehensibility, and stability of Cedar. Produced in the Computer Science Laboratory (CSL) at the Xerox Palo Alto Research Center, Cedar is a research environment supporting the development and use of experimental programs, emphasizing office information and personal information management applications. Although it was clear that some unsolved problems would be addressed, the intent was to combine well-understood methods and technologies to exploit a new generation of high-performance personal computers, including the Xerox 1132 (Dorado) and Xerox 1108 (Dandelion).

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

applications
generation
use
personal information management
intent
paper
programming environment
runtime
computer science
stability
organization
research
structure
technologies
exploit
language
support
laboratory

developer
high-performance
informal
component
program
method
experimentation
environments
personal computer
comprehension
programming language


Fast Flip-Chip Pin-Out Designation Respin for Package-Board Codesign Deep submicrometer effects drive the complication in designing chips, as well as in package designs and communications between package and board. As a result, the iterative interface design has been a time-consuming process. This paper proposes a novel and efficient approach to designating pin-out, which is a package ball chart describing pin locations for flip-chip BGA package when designing chipsets. The proposed approach can not only automate the assignment of more than 200 input/output (I/O) pins on package, but also precisely evaluate package size which accommodates all pins with almost no void pin positions, as good as the one from manual design. Furthermore, the practical experience and techniques in designing such interface has been accounted for, including signal integrity, power delivery and routability. This efficient pin-out designation and package size estimation by pin-block design and floorplanning provides much faster turn around time, thus enormous improvement in meeting design schedule. Our pin-block design contains two major parts. First, we have pin-block construction to locate signal pins within a block along the specific patterns. Six pin patterns are proposed as templates which are automatically generated according to the user-defined constraints. Second, we have pin-blocks grouping to group all pin-blocks into package boundaries. Two alternative pin-blocks grouping strategies are provided for various applications such as chipset and field-programmable gate array (FPGA). The results on two real cases show that our methodology is effective in achieving almost the same dimensions in package size, compared with manual design in weeks, while simultaneously considering critical issues and package size migration in package-board codesign.

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

package-board codesign
pin-block floorplanning
pin-out designation


Government regulation through voluntary cooperation: A follow-up study of the strategic impact of information technology A follow-up study of Australian tax agents' attitudes towards the Electronic Lodgement Service introduced by the Australian Taxation Office (ATO) found that perceptions of improved cooperation had declined. Despite further improvements at the level of routine transactions and a strong increase in perceptions that the benefits of the new system offset the costs to agents, divergent goals and greater agent uncertainty about how the ATO would use its monitoring capacity and regulatory authority appear to have restricted the system's positive contributions to regulatory strategy.

B I O B I 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

government regulation
voluntary cooperation
information technology


Reducing simulation models for scheduling manufacturing facilities Within the framework of the application of their industrial management system, companies compile a Master Production Schedule (MPS). However, once the MPS is released, daily events may require it to be brought into question. The use of reduced models within the framework of flow dynamic simulation enables quick decision-making while maximizing the use of resources and minimizing risk. The article shows the advantage of model reduction and how we arrive at it. Afterwards we develop an analysis of the influence of the model factors by highlighting the differences between the simulation results and MPS. Finally we show the circumstances in which the flow dynamic simulation with reduced models is relevant.

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


reinforcement learning with utility-aware agents for market-based resource allocation In this paper we propose and investigate the use of Reinforcement Learning in a market-based resource allocation mechanism called Iterative Price Adjustment. Under standard assumptions, this mechanism uses demand functions that do not allow the agents to have preferences over the attributes of the allocation, e.g. the price of the resources. To address this limitation, we study the case where the agent's preferences in the resource allocation are described by utility functions and they learn the demand functions given their utility functions. The approach has been evaluated with extensive experiments.

B I 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


Virtual Hydraulic Experiments in Courseware: 2D Virtual Circuits and 3D Virtual Equipments The process of developing two types of virtual hydraulic experiment supporting animations used in courseware are described: (1) schematic diagram-based 2D virtual hydraulic circuits using Flash, and (2) VRML-based 3D virtual hydraulic equipments. The effects and students' attitudes on the two approaches are surveyed and analyzed. (c) 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 315-326, 2011; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20313

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 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

virtual hydraulic circuit/equipment
virtual experiment
vrml


a scalable and energy-efficient hybrid-based mac protocol for wireless sensor networks The problem of MAC protocol design for wireless sensor networks poses many challenges such as energy constraint resources, strict wireless bandwidth, channel utilization & etc. These challenges make handling changes in network topology and network scalability a major issue. In this paper we present a new scalable and energy efficient hybrid-based MAC protocol for wireless sensor networks, abbreviated as SEHM. The protocol saves energy by reducing energy consumption due to idle listening and signal interference. Idle listening is reduced by making idle nodes and all nodes that have no data to send to switch early to sleep state. Signal interference is limited through using time division based medium access. Scalability of our approach is achieved through dividing the sensor network into clusters. Clusters are dynamically formed as all nodes in the sensor network are allowed to content for the position of a cluster head, to finally elect suitable cluster heads. The performance of our protocol is studied and analyzed by means of computer simulations, and we show that our approach outperforms S-MAC protocol in terms of energy consumption and packet delivery rate.

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

sensor networks
mac protocol
scalability


OptiPa, an essential primer to develop models in the postharvest area This research note describes a software tool to develop and calibrate mathematical models in the area of postharvest biology and technology. Historically this has been the territory of mathematicians and statisticians. However, as the applied researchers are the ones holding most of the expertise regarding postharvest product physiology there is a need to stimulate these researchers to develop their own physiology based models. Therefore, OptiPa was developed to calibrate a given mathematical model by estimating values for its parameters using experimental data. The main contribution of OptiPa lies in its ability to quickly screen potential models on their fitness to describe and predict the experimental data. OptiPa discerns itself from other available optimisation tools through its built-in functionality to classify model parameters following user defined grouping criteria.

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

modelling
model calibration
parameter estimation


The Unfolded Protein Response Is Involved in the Pathology of Alzheimer's Disease The endoplasmic reticulum (ER) performs the synthesis, posttranslational modification, and proper folding of proteins. A variety of conditions can be ER stress, causing the accumulation of unfolding or misfolding proteins in the ER. Eukaryotic cells have three different mechanisms for dealing with an accumulation of unfolded proteins in the ER known as the unfolded protein response (UPR)

O O O O O O O O O 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

unfolded protein response (upr)
endoplasmic reticulum (er)
amyloid-? peptide (a?)
familial alzheimer's disease (fad)
ps1


Performance modelling of pipelined circuit switching in hypercubes with hot spot traffic Pipelined Circuit Switching (PCS) has been suggested as an efficient switching method for supporting interprocessor communication in multicomputer networks due to its ability to preserve both communication performance and fault-tolerant demands in these networks. A number of studies have demonstrated that PCS can exhibit superior performance characteristics over Wormhole Switching (WS) under uniform traffic. However, the performance properties of PCS have not yet been thoroughly investigated in the presence of non-uniform traffic. Analytical model of PCS for common networks (e.g., hypercube) under the uniform traffic pattern has been reported in the literature. A non-uniform traffic model that has attracted much attention is the hot spot model which leads to extreme network congestion resulting in serious performance degradation due to the tree saturation phenomenon in the network. An analytical model for WS with hot spot traffic has been reported in the literature. However, to the best of our knowledge, there has not been reported any analytical model for PCS augmented with virtual channels in the presence of hot spot traffic. This paper proposes a model for this switching mechanism using new methods to calculate the probability of message header blocking and hot spot rates on channels. The model makes latency predictions that are in good agreement with those obtained through simulation experiments. An extensive performance comparison using the new analytical model reveals that PCS performs the same or in some occasions worse than WS in the presence of hot spot traffic.

B I 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 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 B 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 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 B I I

virtual channels
hot spot traffic
performance modelling
simulation

multicomputers
interconnection networks
routing algorithms
adaptive routing
message latency


Designing needs statements in a systematic iterative way Designing specifications for technically advanced instructional products, such as e-learning, simulations or simulators requires different kinds of expertise. The SLIM method proposes to involve all stakeholders from the beginning in a series of workshops under the guidance of experienced instructional designers. These instructional designers ensure that specifications are designed in a systematic, iterative, way based on instructional design and development models. The workshop participants, however, bring in all the necessary information and they take all the decisions. The SLIM method is geared towards the first phase of the instructional design process: designing a needs statement in the form of a first set of global user requirements. It has been used in eight case studies. The results of these case studies have led to improvements to the method and suggestions for further research. (C) 2008 Elsevier Ltd. All rights reserved.

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 O O O O O

authoring tools and methods
interdisciplinary projects
media in education


a parallel language and its compilation to multiprocessor machines or vlsi A language Crystal and its compiler for parallel programming is presented. The goal of Crystal is to help programmers in seeking efficient parallel implementations of an algorithm, and managing the complexity that might arise in dealing with hundreds of thousands of autonomous parallel processes. In Crystal, a program consists of a system of recursion equations and is interpreted as a parallel system. Crystal views a large complex system as consisting of a hierarchy of parallel sub-systems, built upon a set of Crystal programs by composition and abstraction. There is no mention of explicit communications in a Crystal program. The Crystal compiler automatically incorporates pipelining into programs, and generates a parallel program that is optimal with respect to an algorithm. Each optimizing compiler, targeted for a particular machine, determines the appropriate granular size of parallelism and attains a balance between computations and communications. Based on the language, a unified theory for understanding and generating any systolic design has been devised and it constitues a part of the compiler.

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

help
optimizing compiler
recursion
design
theory
program
views
abstraction
parallel
size
language
compilation
complexity
algorithm
multiprocessor

communication
understandability
efficiency
pipeline
complex systems
hierarchies
autonomic
compositing
management
systems
optimality
parallel programming
implementation
process
programmer


A diffusion approximation model for managing cash in firms: An alternative approach to the MillerOrr model This article considers a cash management problem of a typical business firm in a two-asset setting, namely, the firm's cash balance and a portfolio of assets such as treasury bills, commercial papers, etc. From time to time, firms will have to transfer money from one asset account to the other by selling or buying securities to bring the cash balance to a suitable level (return point). These transactions are made when the cash balance reaches the lower or the upper control limits set by the firm. We use the diffusion approximation technique to obtain the probability density function of the daily cash balance and the optimal values for the return point and the upper control limit which minimize the daily cost of managing the cash. Numerical results show that the proposed model is superior to the original model proposed by Miller and Orr in 1966 known as the MillerOrr model. The proposal can be regarded as a more generalized model which relaxes most of the restrictive assumptions made in the MillerOrr model.

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

cash balance
cash management
millerorr model
diffusion approximation


An optimal timing model of water reallocation and reservoir construction Growth of the users base often reduces the efficiency of existing water allocation policies and causes new water supplies to cost more than the value of water in existing use. Historically, water management authorities have shown a bias toward undertaking of new supply projects and delay of necessary reallocations. This study provides an analysis of the timing and adjustments associated with construction of new reservoirs and reallocation of existing supplies. A dynamic model yields simultaneously the optimal construction timing of new projects and guidelines for reallocation of existing supplies. A number of sensitivity results provide additional insights.

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

optimization theory
systems dynamics
facilities planning and design
natural resources


Ranking spaces for predicting human movement in an urban environment A city can be topologically represented as a connectivity graph, consisting of nodes representing individual spaces and links if the corresponding spaces are intersected. It turns out in the space syntax literature that some defined topological metrics can capture human movement rates in individual spaces. In other words, the topological metrics are significantly correlated to human movement rates, and individual spaces can be ranked by the metrics for predicting human movement. However, this correlation has never been well justified. In this paper, we study the same issue by applying the weighted PageRank algorithm to the connectivity graph or space-space topology for ranking the individual spaces, and find surprisingly that: (1) the PageRank scores are better correlated to human movement rates than the space syntax metrics, and (2) the underlying space-space topology demonstrates small world and scale free properties. The findings provide a novel justification as to why space syntax, or topological analysis in general, can be used to predict human movement. We further conjecture that this kind of analysis is no more than predicting a drunkard's walking on a small world and scale free network.

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

space syntax
small world
scale free
human movement
pagerank


Bioinformatics analysis of transcriptional regulation of circadian genes in rat liver The circadian clock is a critical regulator of biological functions controlling behavioral, physiological and biochemical processes. Because the liver is the primary regulator of metabolites within the mammalian body and the disruption of circadian rhythms in liver is associated with severe illness, circadian regulators would play a strong role in maintaining liver function. However, the regulatory structure that governs circadian dynamics within the liver at a transcriptional level remains unknown. To explore this aspect, we analyzed hepatic transcriptional dynamics in Sprague-Dawley rats over a period of 24 hours to assess the genome-wide responses.

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

circadian rhythm
microarray analysis
gene expression
consensus clustering
promoter analysis
transcription factor
circadian regulation


A Learning Model of Information Technology Outsourcing: Normative Implications We use an economic learning model to examine how knowledge parameters characterizing a sourcing relationship between it vendor and it client interact with production costs and coordination costs to affect the business value of alternative outsourcing strategies. This Information is then used to determine a fit-in's optimal rate of information technology (IT) Outsourcing. We find that the optimal Outsourcing rate is dependent oil the ability of the Outsourcing client to acquire production Knowledge front its outsourcing vendor and to retain its internal coordination knowledge despite losses of fundamental production skills due to Outsourcing. Specifically, when the Client is unable to acquire sufficient production knowledge from the external vendor, the client's optimal Outsourcing decision is to engage in either one of two extreme strategies-total insourcing or total outsourcing-depending on the rate at which the client's coordination knowledge depreciates. On the other hand, when the client is able to acquire a substantial amount of production knowledge from the external vendor, the firm's optimal decision is to outsource only a portion of its IT services, where the proportion depends on the rate at which the client's coordination knowledge depreciates.

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

coordination
it outsourcing
knowledge
outsourcing
production costs

economic analysis
modeling
organizational learning
vendor-client relationship


Comparison of Phase-Shift and Step Wave Modulation Technique applied to Symmetrical Cascaded Multilevel Inverter This paper presents a comparison between the phase-shift and the step wave modulation techniques applied to symmetrical cascaded multilevel inverter. Initially, the phase-shift modulation and a simple method to determine the switching angles used to generate a step pulse waveform are presented. Performance indices as harmonic spectrum, total harmonic distortion, common mode voltage, power losses in semiconductors devices and first/second distortion factors are analyzed to demonstrate the performance of these modulation techniques. The modulation strategy that presents more advantages is implemented in FPGA and the experimental results are 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 B I O O O O O O O O O O O O O O

adjustable speed drive
multilevel converters


Integration of workflow management and simulation Addressed in this paper is a method of integrating a workflow system and simulation technology. It is often conceived that workflow systems are a major tool to support BPR. A key to apply the workflow systems to BPR is how to analyse and evaluate the performance of newly designed processes in advance. A simulation module, called WFSIM, has been developed and interfaced with a workflow system to better support the BPR capability. We demonstrate the workability of translating from a workflow model to a simulation language. (C) 1999 Elsevier Science Ltd. All rights reserved.

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

workflow management system
process definition language and model


A practical Random Network Coding scheme for data distribution on peer-to-peer networks using rateless codes ? In this paper, we propose a practical Random Network Coding (RNC) scheme for data distribution in a peer-to-peer (P2P) overlay network. The use of RNC incurs a significant computational cost that, till present, has limited its deployment in practical applications. In this study, it is shown that RNC complexity can be lowered by using Luby Transform (LT) codes to pre-encode the data and by letting intermediate nodes use RNC in a low-order Galois Field, i.e. GF(2). Moreover, we exploit a recently proposed variant of the Gaussian Elimination algorithm (OFG) to improve further both the creation of random combinations for RNC and the final decoding of the content. Our analysis is based on both analytical modeling and simulations over P2P overlay networks generated from random graphs and real snapshots of the PPLive streaming application. The results point out that using LT codes and RNC in GF(2) one is able to significantly improve the overall performance in terms of both delay and bandwidth utilization at a reasonable computational cost. Finally, the RNC strategies we propose do not require any prior knowledge of the overlay network topology thus making them very general.

O O B I I 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 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 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


Use of ebRIM-based CSW with sensor observation services for registry and discovery of remote-sensing observations Recent advances in Sensor Web geospatial data capture, such as high-resolution in satellite imagery and Web-ready data processing and modeling technologies, have led to the generation of large numbers of datasets from real-time or near real-time observations and measurements. Finding which sensor or data complies with criteria such as specific times, locations, and scales has become a bottleneck for Sensor Web-based applications, especially remote-sensing observations. In this paper, an architecture for use of the integration Sensor Observation Service (SOS) with the Open Geospatial Consortium (OGC) Catalogue Service-Web profile (CSW) is put forward. The architecture consists of a distributed geospatial sensor observation service, a geospatial catalogue service based on the ebXML Registry Information Model (ebRIM), SOS search and registry middleware, and a geospatial sensor portal. The SOS search and registry middleware finds the potential SOS, generating data granule information and inserting the records into CSW. The contents and sequence of the services, the available observations, and the metadata of the observations registry are described. A prototype system is designed and implemented using the service middleware technology and a standard interface and protocol. The feasibility and the response time of registry and retrieval of observations are evaluated using a realistic Earth Observing-1 (EO-1) SOS scenario. Extracting information from SOS requires the same execution time as record generation for CSW. The average data retrieval response time in SOS+CSW mode is 17.6% of that of the SOS-alone mode. The proposed architecture has the more advantages of SOS search and observation data retrieval than the existing sensor Web enabled systems.

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

sensor web
sensor observation service
csw
registry


Meta-programming through typeful code representation By allowing the programmer to write code that can generate code at run-time, meta-programming offers a powerful approach to program construction. For instance, meta-programming can often be employed to enhance program efficiency and facilitate the construction of generic programs. However, meta-programming, especially in an untyped setting, is notoriously error-prone. In this paper, we aim at making meta-programming less error-prone by providing a type system to facilitate the construction of correct meta-programs. We first introduce some code constructors for constructing typeful code representation in which program variables are replaced with deBruijn indices, and then formally demonstrate how such typeful code representation can be used to support meta-programming. The main contribution of the paper lies in recognition and then formalization of a novel approach to typed meta-programming that is practical, general and flexible.

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 B I I 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

meta-programming
multi-level staged programming


Mixed-norm sparse representation for multi view face recognition We introduce a novel mixed-norm that takes a trade-off between ?1-norm ? 1 - norm and ?2,1-norm ? 2 , 1 - norm . We use ?1-norm ? 1 - norm norm on the loss function to achieve a robust solution. We derive a simple and provably convergent algorithm based on the alternative directions method of multipliers framework. Extensive experiments have been done to demonstrate the performance of the proposed method.

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

joint dynamic sparse representation classification


software control systems for parallel simulation Parallel simulations using optimistic synchronization strategies such as Time Warp, operate with no regard to global synchronization since this results in greater parallelism and lower synchronization cost. However, like virtual memory, the parallel simulators may end up thrashing instead of performing useful work. The complication in using a Time Warp simulator is then to configure it suitably for good performance and avoid thrashing. Unfortunately, the optimal configuration is not generally static among different applications or even throughout an entire run of a single application. Thus, online feedback control systems are deployed to govern the adjustment of input parameters in our Time Warp simulation kernel. The design and implementation of effective feedback control systems can be difficult; the extra processing is pure overhead that must be absorbed by any performance gains delivered. The problem is further complicated when attempting to build a simulation kernel that is designed efficiently to operate with many different applications. In this paper, we introduce a control-centric architecture that is used to monitor and manage different parts of a Time Warp simulator. Specifically, we extend concepts from control theory such as adaptive control and stability, to better understand and design hierarchically-distributed run-time control systems for Time Warp based parallel simulation.

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 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 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 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 B I O O O

distributed simulation
run-time control
parallel discrete-event simulation


Bayesian computation: a summary of the current state, and samples backwards and forwards Recent decades have seen enormous improvements in computational inference for statistical models; there have been competitive continual enhancements in a wide range of computational tools. In Bayesian inference, first and foremost, MCMC techniques have continued to evolve, moving from random walk proposals to Langevin drift, to Hamiltonian Monte Carlo, and so on, with both theoretical and algorithmic innovations opening new opportunities to practitioners. However, this impressive evolution in capacity is confronted by an even steeper increase in the complexity of the datasets to be addressed. The difficulties of modelling and then handling ever more complex datasets most likely call for a new type of tool for computational inference that dramatically reduces the dimension and size of the raw data while capturing its essential aspects. Approximate models and algorithms may thus be at the core of the next computational revolution.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 analysis
mcmc algorithms
abc techniques
optimisation


exploration of query context for information retrieval A number of existing information retrieval systems propose the notion of query context to combine the knowledge of query and user into retrieval to reveal the most exact description of user's information needs. In this paper we interpret query context as a document consisting of sentences related to the current query. This kind of query context is used to re-estimate the relevance probabilities of top-ranked documents and then re-rank top-ranked documents. The experiments show that the proposed context-based approach for information retrieval can greatly improved relevance of search results.

O O B I O B I 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 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 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


Using Social Network Analysis to Analyze Relationships Among IS Journals Social network analysis (SNA) offers a richer and more objective way of examining individual journal influence and relationships among journals than studies based on individual perceptions, since it avoids personal biases. This article demonstrates how SNA can be used to study the nature of the IS discipline, by presenting results from an exploratory SNA of 125 previously ranked journals from IS and allied disciplines. While many of the most prominent journals in the network are still associated with IS's foundational disciplines, we identify several IS journals that play important roles in disseminating information throughout different subcomponents of the network. We also identify related groups of journals based not only on patterns of information flow, but also on similarity in citation patterns. This enables us to identify the core set of journals that is important for "pure IS" research, as well as other subsets of journals that are important for specialty areas of interest. Overall, results indicate that the IS discipline is still somewhat fragmented and is still a net receiver, as opposed to a net provider, of information from allied disciplines. Like other forms of analysis, SNA is not entirely free from biases. However, these biases can be systematically researched in order to develop an improved, consistent tool with which to examine the IS field via citations among member journals. Thus, while many challenges remain in applying SNA techniques to the study of IS journals, the opportunity to track trends in the discipline over time, with a larger basket of journals, suggests a number of valuable future applications of SNA for understanding the IS publication system.

O B I I 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 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

journal citation networks
is journal rankings
reference disciplines


A method for dealing with inconsistencies in pairwise comparisons The Pairwise Comparison method is a powerful inference tool for assessing the relative importance of a set of items. Formally, its objective is to make compatible decision maker's assignments (paired comparison) with properties needed for obtaining an overall rank. In this paper, we propose a distance-based framework for analysing this kind of compatibility. In this context, Goal Programming is proposed as an attractive and flexible tool.

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 B I O O O O O O O O


Application of finite elementfinite difference method to the determination of transient temperature field in functionally graded materials A finite element/finite difference method (FEM/FDM) is developed to solve the time-dependent temperature field in non-homogeneous materials such as functionally graded materials. The method uses the finite element space discretization to obtain a first-order system of differential equations, which is solved by employing finite difference scheme to resolve the time-dependent response. A computation code is developed in the programming environment MATLAB. Temperature-dependent material properties are taken into account in the program.

O O O O O O O O O O B 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 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

transient temperature
functionally graded materials

finite element method
finite difference method


Fully dynamic maintenance of k-connectivity in parallel Given a graph G = (V, E) with n vertices and m edges, the k-connectivity of G denotes either the k-edge connectivity or the k-vertex connectivity of G. In this paper, we deal with the fully dynamic maintenance of k-connectivity of G in the parallel setting for k = 2,3. We study the problem of maintaining k-edge/vertex connected components of a graph undergoing repeatedly dynamic updates, such as edge insertions and deletions, and answering the query of whether two vertices are included in the same k-edge/vertex connected component. Our major results are the following: 1) An NC algorithm for the 2-edge connectivity problem is proposed, which runs in O(log n log(m/n)) time using O(n(3/4)) processors per update and query. 2) It is shown that the biconnectivity problem can be solved in O(log(2) n) time using O(n alpha (2n, n)/ log n) processors per update and O(1) time with a single processor per query or in O(log n log (m)/(n)) time using O(n alpha (2n, n)/ log n) processors per update and O(log n) time using O(n alpha (2n, n) / log n) processors per query, where alpha(.,.) is the inverse of Ackermann's function. 3) An NC algorithm for the triconnectivity problem is also derived, which takes O(log n log (m)/(n) + log n log log n/alpha (3n, n)) time using O(n alpha (3n, n)/log n) processors per update and O(1) time with a single processor per query. 4) An NC algorithm for the 3-edge connectivity problem Is obtained, which has the same time and processor complexities as the algorithm for the triconnectivity problem. To the best of our knowledge, the proposed algorithms are the first NC algorithms for the problems using O(n) processors in contrast to Omega (m) processors for solving them from scratch, In particular, the proposed NC algorithm for the 2-edge connectivity problem uses only O(n(3/4)) processors. Ali the proposed algorithms run on a CRCW PRAM.

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

2-edge/vertex connectivity
3-edge/vertex connectivity
dynamic data structures
parallel algorithm design and analysis
graph problems


Comparison of Multimedia Delivery Scenarios Using Parallel Wireless Links and Path Diversity Several scenarios to deliver multimedia streams in wireless multi-hop networks, as in the wireless metropolitan area network (WMAN) environment, are considered and examined. Those scenarios considered in this paper are not new but they are examined in a new environment where the system is benefited from path diversity and cooperative diversity. By simulation, we examine those scenarios in an orthogonal frequency-division multiple access (OFDMA)-based wireless network. The simulation results demonstrate how much path diversity and cooperative diversity improve the performance in average sense. We also discuss open research issues on resource utilization in emerging wireless networks.

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

resource allocation
ofdma
multihop network


Mutations in the Human Proopiomelanocortin Gene The melanocortin peptides and their receptors represent one of the most complex systems in human endocrinology. Hormonal regulation includes pigmentation, weight maintenance, adrenal function, and exocrine gland secretion via endocrine, paracrine, autocrine, and neurocrine action of melanocortin peptides at five different but homologous melanocortin receptors. Genetic relevance of the melanocortin system for human physiology was initially shown by mutations in the different melanocortin receptor genes, first described in the melanocortin-2 receptor gene in 1993 as one reason for congenital hypocortisolism. Because all ligands within the melanocortin systems are derived from one single precursor hormone, proopiomelanocortin (POMC), a genetic defect in the POMC gene could have been expected to affect all functional components of the melanocortin system. Accordingly, patients with a complete defect of the POMC gene product due to homozygous or compound heterozygous loss of function mutations were shown to be affected mainly by red hair, early-onset obesity, and congenital hypocortisolism. No further obvious clinical problems were described in these patients, suggesting that no additional function of the melanocortin system has escaped recognition. However, whether partial loss of function mutations in the POMC gene might lead to more circumscribed phenotypes, especially common obesity, remains an open question.

O 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 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 B O O O O

adrenocorticotropin-stimulating hormone (acth) deficiency


the tree width of auxiliary storage We propose a generalization of results on the decidability of emptiness for several restricted classes of sequential and distributed automata with auxiliary storage (stacks, queues) that have recently been proved. Our generalization relies on reducing emptiness of these automata to finite-state graph automata (without storage) restricted to monadic second-order (MSO) definable graphs of bounded tree-width, where the graph structure encodes the mechanism provided by the auxiliary storage. Our results outline a uniform mechanism to derive emptiness algorithms for automata, explaining and simplifying several existing results, as well as proving new decidability results.

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

bounded tree-width
decision procedures
model checking


Soft memberships for spectral clustering, with application to permeable language distinction Recently, a large amount of work has been devoted to the study of spectral clusteringa powerful unsupervised classification method. This paper brings contributions to both its foundations, and its applications to text classification. Departing from the mainstream, concerned with hard membership, we study the extension of spectral clustering to soft membership (probabilistic, EM style) assignments. One of its key features is to avoid the complexity gap of hard membership. We apply this theory to a challenging problem, text clustering for languages having permeable borders, via a novel construction of Markov chains from corpora. Experiments with a readily available code clearly display the potential of the method, which brings a visually appealing soft distinction of languages that may define altogether a whole corpus.

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 B I 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

spectral clustering
soft membership
text classification


Implementation and evaluation of directory hints in CC-NUMA multiprocessors ? Directory hints (DHs) help a node in a cache coherent non-uniform memory (CC-NUMA) shared memory multiprocessor to keep track of where valid copies of a memory block may reside. With this information the node can fetch the block directly from those nodes on a read miss (RM). In this way the number of network transactions to serve the miss may be reduced and the expensive directory lookup operation may be removed from the critical path. In this paper, we discuss the issues involved in implementing the DH scheme on a CC-NUMA shared memory multiprocessor and examine one such implementation, which employs a small and fast cache to store the hints. Our simulation results show that the DH scheme can effectively reduce the read stall time. Also its performance is very competitive compared with a more expensive implementation which uses a large level-three cache. A drawback of the scheme is that it will introduce extra network traffic. We believe that the state-of-the-art interconnection networks, such as those built upon the SGI Spider [M. Galles, Scalable pipelined interconnect for distributed endpoint routing: the SGI SPIDER chip, in: Proc. Internat. Symp. on High Performance Interconnects (Hot Interconnects 4), 1996] and the Intel Cavallino [J. Carbonaro, F. Verhoorn, Cavallino: the TeraFlops router and Nic, in: Proc. Internat. Symp. on High Performance Interconnects (Hot Interconnects 4), 1996] chips, provide the opportunity to make the DH scheme feasible even with the slower network such as the one built by Myrinet switches (N.J. Boden et al., Myrinet: a gigabit-per-second local area network, in: IEEE Micro, 1995, p. 29).

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

cc-numa multiprocessor
remote read latency
interconnection network
performance evaluation


Algorithms for solving linear systems over cyclotomic fields We consider the problem of solving a linear system Ax = b over a cyclotomic field. Cyclotomic fields are special in that we can easily find a prime p for which the minimal polynomial m(z) for the field factors into a product of distinct linear factors. This makes it possible to develop fast modular algorithms. We give two output sensitive modular algorithms, one using multiple primes and Chinese remaindering, the other using linear p-adic lifting. Both use rational reconstruction to recover the rational coefficients in the solution vector. We also give a third algorithm which computes the solutions as ratios of two determinants modulo m(z) using Chinese remaindering only. Because this representation is d = deg m(z) times more compact in general, we can compute it the fastest. We have implemented the algorithms in Maple. Our benchmarks show that the third method is fastest on random inputs, but on real inputs arising from problems in computational group theory, the first two methods are faster because the solutions have small rational coefficients. (C) 2010 Elsevier Ltd. All rights reserved.

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

linear systems
modular algorithms
cyclotomic fields


Probabilities on Sentences in an Expressive Logic Automated reasoning about uncertain knowledge has many applications. One difficulty when developing such systems is the lack of a completely satisfactory integration of logic and probability. We address this problem directly. Expressive languages like higher-order logic are ideally suited for representing and reasoning about structured knowledge. Uncertain knowledge can be modeled by using graded probabilities rather than binary truth values. The main technical problem studied in this paper is the following: Given a set of sentences, each having some probability of being true, what probability should be ascribed to other (query) sentences? A natural wish-list, among others, is that the probability distribution (i) is consistent with the knowledge base, (ii) allows for a consistent inference procedure and in particular (iii) reduces to deductive logic in the limit of probabilities being 0 and 1, (iv) allows (Bayesian) inductive reasoning and (v) learning in the limit and in particular (vi) allows confirmation of universally quantified hypotheses/sentences. We translate this wish-list into technical requirements for a prior probability and show that probabilities satisfying all our criteria exist. We also give explicit constructions and several general characterizations of probabilities that satisfy some or all of the criteria and various (counter)examples. We also derive necessary and sufficient conditions for extending beliefs about finitely many sentences to suitable probabilities over all sentences, and in particular least dogmatic or least biased ones. We conclude with a brief outlook on how the developed theory might be used and approximated in autonomous reasoning agents. Our theory is a step towards a globally consistent and empirically satisfactory unification of probability and logic. (C) 2013 Elsevier B.V. All rights reserved.

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

higher-order logic
probability on sentences
gaifman
cournot
induction
entropy


algebraic approach to optimal clone selection applied in metagenomic projects Due to the wide diversity of unknown organisms in the environment, 99\% of them cannot be grown in traditional culture medium in laboratories. Therefore, metagenomics projects are proposed to study microbial communities present in the environment, from molecular techniques, especially the sequencing. Thereby, for the coming years it is expected an accumulation of sequences produced by these projects. Thus, the sequences produced by genomics and metagenomics projects present several challenges for the treatment, storing and analysis such as: the search for clones containing genes of interest. This work presents the OCI Metagenomics, which allows defines and manages dynamically the rules of clone selection in metagenomic libraries, thought an algebraic approach based on process algebra. Furthermore, a web interface was developed to allow researchers to easily create and execute their own rules to select clones in genomic sequence database. This software has been tested in metagenomic cosmid library and it was able to select clones containing genes of interest.

O O O O O O O O O O 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 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 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


Direct measurement of interfacial structure in epitaxial Gd2O3 on GaAs (001) using scanning tunneling microscopy The epitaxial growth of Gd2O3 on GaAs (001) has given a low interfacial density of states, resulting in the demonstration of the first inversion-channel GaAs metal-oxide-semiconductor field-effect transistor. Motivated by the significance of this discovery, in this work, cross-sectional scanning tunneling microscopy is employed herein to obtain precise structural and electronic information on these epitaxial films and interfaces. At the interface, the interfacial stacking of Gd2O3 films is directly correlated with the stacking sequence of the substrate GaAs. Additionally, from the local electronic states across the gate oxides, the spatial extent of the GaAs wavefunctions into the oxide dielectric may suggest a minimum Gd2O3 thickness to be of bulk properties.

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

gaas
gd2o3
scanning tunneling microscopy
interfacial stacking
electronic information


Stack and queue layouts of directed acyclic graphs: Part I Stack layouts and queue layouts of undirected graphs have been used to model problems in fault-tolerant computing and in parallel process scheduling. However, problems in parallel process scheduling are more accurately modeled by stack and queue layouts of directed acyclic graphs (dags). A stack layout of a dag is similar to a stack layout of an undirected graph, with the additional requirement that the nodes of the dag be in some topological order. A queue layout is defined in an analogous manner. The stacknumber (queuenumber) of a dag is the smallest number of stacks (queues) required for its stack layout (queue layout). In this paper, bounds are established on the stacknumber and queuenumber of two classes of dags: tree dags and unicyclic dags. In particular, any tree dag can be laid out in 1 stack and in at most 2 queues; and any unicyclic dag can be laid out in at most 2 stacks and in at most 2 queues. Forbidden subgraph characterizations of 1-queue tree dags and 1-queue cycle dags are also presented. Part II of this paper presents algorithmic results-in particular, linear time algorithms for recognizing 1-stack dags and 1-queue dags and proof of NP-completeness for the problem of recognizing a 4-queue dag and the problem of recognizing a 9-stack dag.

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

stack layout
queue layout
directed acyclic graphs
dags
forbidden subgraph


exploiting gradient information in numerical multi--objective evolutionary optimization Various multi--objective evolutionary algorithms (MOEAs) have obtained promising results on various numerical multi--objective optimization problems. The combination with gradient--based local search operators has however been limited to only a few studies. In the single--objective case it is known that the additional use of gradient information can be beneficial. In this paper we provide an analytical parametric description of the set of all non--dominated (i.e. most promising) directions in which a solution can be moved such that its objectives either improve or remain the same. Moreover, the parameters describing this set can be computed efficiently using only the gradients of the individual objectives. We use this result to hybridize an existing MOEA with a local search operator that moves a solution in a randomly chosen non--dominated improving direction. We test the resulting algorithm on a few well--known benchmark problems and compare the results with the same MOEA without local search and the same MOEA with gradient--based techniques that use only one objective at a time. The results indicate that exploiting gradient information based on the non--dominated improving directions is superior to using the gradients of the objectives separately and that it can furthermore improve the result of MOEAs in which no local search is used, given enough evaluations.

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 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 O

multi--objective optimization
numerical optimization
memetic algorithms


Keypoint descriptor fusion with DempsterShafer theory ? Novel approach fusing information from multiple keypoint descriptors using the DempsterShafer Theory of evidence. Descriptors matches are transformed in evidence distributions assigning a confidence factor using Shannon's entropy. Results on the Oxford keypoint dataset show improvements of up to 10% compared to the best keypoint descriptor.

O O O O B 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


Improvement to the second-order rational functions approximation for hysteresis cycles of magnetic materials Purpose - The purpose of this paper is to introduce a simplified method, based on an improvement to the actual second-order approximation to magnetic hysteresis curves, to calculate an estimation of quasi-static hysteresis loops of ferromagnetic materials. Design/methodology/approach - The addition of a new dB(B) function is proposed to second-order rational approximation for the upward and downward magnetic quasi-static hysteresis loop. The new semi-empirical approach is tested with typical cycles of commercial Ni-ferrites (ferroxcube) and Ni standards using a vibrating sample magnetometer (VSM). Findings - The model is simple and a fast tool to reproduce with reasonable accuracy the hysteresis loops based on appropriate parameters of materials under analysis. The proposed extension to the Rivas model has reduced the maximum difference between experimental and modeled values from 19 to 0.08 per cent in the approximation to different hysteresis cycles of the magnetic materials studied here. Originality/value - This paper presents an improvement to second-order rational functions approach for fitting of hysteresis loops with simple added functions.

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

magnetism
magnetic measurement
physical properties of materials
ferrous metals


DYLEMA: Using walking robots for landmine detection and location Detection and removal of antipersonnel landmines is an important worldwide concern. A huge number of landmines has been deployed over the last twenty years, and demining will take several more decades, even if no more mines were deployed in future. An adequate mine-clearance rate can only be achieved by using new technologies such as improved sensors, efficient manipulators and mobile robots. This paper presents some basic ideas on the configuration of a mobile system for detecting and locating antipersonnel landmines efficiently and effectively. The paper describes the main features of the overall system, which consists of a sensor head that can detect certain landmine types, a manipulator to move the sensor head over large areas, a locating system based on a global-positioning system, a remote supervisor computer and a legged robot used as the subsystems' carrier. The whole system has been configured to work in a semi-autonomous mode with a view also to robot mobility and energy efficiency.

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

dylema
walking robots
landmine detection


AT-free graphs: linear bounds for the oriented diameter ? Let G be a bridgeless connected undirected (b.c.u.) graph. The oriented diameter of G, OD(G), is given by , where diam(H) is the maximum length computed over the lengths of all the shortest directed paths in H. This work starts with a result stating that, for every b.c.u. graph G, its oriented diameter OD(G) and its domination number ?(G) are linearly related as follows: OD(G)?9?(G)?5. Sinceas shown by Corneil et al. (SIAM J. Discrete Math. 10 (1997) 399) ?(G)?diam(G) for every AT-free graph G, it follows that OD(G)?9diam(G)?5 for every b.c.u. AT-free graph G. Our main result is the improvement of the previous linear upper bound. We show that OD(G)?2diam(G)+11 for every b.c.u. AT-free graph G. For some subclasses we obtain better bounds: for every interval b.c.u. graph G, and for every 2-connected interval b.c.u. graph G. We prove that, for the class of b.c.u. AT-free graphs and its previously mentioned subclasses, all our bounds are optimal (up to additive constants).

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


Nonlinear Multi-Error Correction Codes for Reliable MLC NAND Flash Memories Multi-level cell (MLC) NAND flash memories are popular storage media because of their power efficiency and large storage density. Conventional reliable MLC NAND flash memories based on BCH codes or Reed-Solomon (RS) codes have a large number of undetectable and miscorrected errors. Moreover, standard decoders for BCH and RS codes cannot be easily modified to correct errors beyond their error correcting capability t = [(d - 1/2)], where is the Hamming distance of the code. In this paper, we propose two general constructions of nonlinear multi-error correcting codes based on concatenations or generalized from Vasil'ev codes. The proposed constructions can generate nonlinear bit-error correcting or digit-error correcting codes with very few or even no errors undetected or miscorrected for all codewords. Moreover, codes generated by the generalized Vasil'ev construction can correct some errors with multiplicities larger than t without any extra overhead in area, latency, and power consumption compared to schemes where only errors with multiplicity up to t are corrected. The design of reliable MLC NAND flash architectures can be based on the proposed nonlinear multi-error correcting codes. The reliability, area overhead and the penalty in latency and power consumption of the architectures based on the proposed codes are compared to architectures based on BCH codes and RS codes. The results show that using the proposed nonlinear error correcting codes for the protection of MLC NAND flash memories can reduce the number of errors undetected or miscorrected for all codewords to be almost 0 at the cost of less than 20% increase in power and area compared to architectures based on BCH codes and RS codes.

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

multi-error correcting codes
nonlinear codes
reliable memory


Diffeomorphic real-analytic maps and the Jacobian conjecture It is shown that if the real-analytic map f(x) : R-2 --> R-2 has a Jacobian matrix whose eigenvalues are always both one, then the map is a diffeomorphism. An explicit form of the inverse is given. The proof relies on a result which says that the only global solutions to the quasi-linear partial differential equation (cos u)u(x) - (sin u)u(y) = 0 are constant functions. The main result is put into a context concerning the Jacobian Conjecture. (C) 2000 Elsevier Science Ltd. All rights reserved.

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

polymorphisms
injectivity
markus-yamabe conjecture


One iteration CHC algorithm for learning Bayesian networks: an effective and efficient algorithm for high dimensional problems It is well known that learning Bayesian networks from data is an NP-hard problem. For this reason, usually metaheuristics or approximate algorithms have been used to provide a good solution. In particular, the family of hill climbing algorithms has a key role in this scenario because of its good trade-off between computational demand and the quality of the learned models. In addition, these algorithms have several good theoretical properties. In spite of these characteristics of quality and efficiency, when it comes to dealing with high-dimensional datasets, they can be improved upon, and this is the goal of this paper. Recent papers have tackled this problem, usually by dividing the learning task into two or more iterations or phases. The first phase aims to constrain the search space, and, once the space is pruned, the second one consists of a (local) search in this constrained search space. Normally, the first iteration is the one with the highest computational complexity. One such algorithm is constrained hill climbing (CHC), which in its initial iteration not only progressively constrains the search space, but also learns good quality Bayesian networks. A second iteration, or even more, is used in order to improve these networks and also to ensure the good theoretical properties exhibited by the classical hill climbing algorithm. In this latter algorithm we can see that the first iteration is extremely fast when compared to similar algorithms, but the performance decays over the rest of the iterations with respect to the saved CPU time. In this paper, we present an improvement on this CHC algorithm, in which, to put it, briefly, we avoid the last iteration while still obtaining the same theoretical properties. Furthermore, we experimentally test the proposed algorithms over a set of different domains, some of them quite large (more than 1,000 variables), in order to study their behavior in practice.

O O O O O O B I 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 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 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

machine learning
score-based learning
scalability


network defense strategies for maximization of network survivability The Internet has brought about several threats of information security to individuals and cooperates. It is difficult to keep a network completely safe because cyber attackers can launch attacks through networks without limitations of time and space. As a result, it is an important and critical issue be able to efficiently evaluate network survivability. In this paper, an innovative metric called the Degree of Disconnectivity (DOD) is proposed, which is used to evaluate the damage level of the network. A network attack-defense scenario is also considered in this problem, in which the attack and defense actions are composed by many rounds with each round containing two stages. In the first stage, defenders deploy limited resources on the nodes resulting in attackers needing to increase attack costs to compromise the nodes. In the second stage, the attacker uses his limited budget to launch attacks, trying to maximize the damage of the network. The Lagrangean Relaxation Method is applied to obtain optimal solutions for the problem.

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

lagrangean relaxation
degree of disconnectivity

network attack and defense
resource allocation
information system survivability
optimization
mathematical programming


Threshold configuration and routing optimization for PCN-based resilient admission control Pre-Congestion Notification (PCN) in IP networks uses packet metering and marking within a PCN domain to notify its egress nodes whether link-specific admissible or supportable rate thresholds have been exceeded by high-priority traffic. Based on this information simple admission control and flow termination is implemented. The latter is a new now control function and useful in case of overload through high priority traffic which can occur in spite of admission control, e.g., when traffic is rerouted in failure cases. Resilient admission control admits only so much traffic that admitted traffic can be rerouted without causing congestion on backup paths in case of a likely failures, e.g., single link failures. We propose algorithms to configure the link-specific PCN rate thresholds Such that resources are utilized efficiently and fairly by competing traffic aggregates while meeting resilience constraints. This is done for the single and dual marking PCN architecture whereby the single marking case is more demanding since it requires that the supportable rate is a fixed multiple of the admissible rate on all links within a single PCN domain. Furthermore, we derive objective functions to optimize the underlying routing system for both cases. Our performance results for various network types show that the dual marking PCN architecture leads to significantly better resource efficiency than the single marking PCN architecture. (C) 2009 Elsevier B.V. All rights reserved.

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 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 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 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

routing optimization
resilience
admission control