TCP SYN-based DDoS attack on EKG signals monitored via a wireless sensor network Internet distributed denial of service (DDoS) attacks are known to exhaust computing resources of a computer. In many cases, even if the attack is not sufficiently strong to completely crash a computing system, its adverse effects can be devastating for the information being processed on the system. When such information is too critical as an electrocardiogram (EKG) signal, the signal itself becomes vulnerable to such attacks also. In this experimental paper, we evaluate the adverse effects of TCP SYN-based DDoS attacks on EKG signals remotely collected by using wireless sensor networks (WSNs). In lab, we deployed two applications (Serial Forwarder and Oscilloscope GUI) to display the EKG signal on remote monitoring station. Such EKG signal was delivered by a WSN (motes running a modified version of OscilloscopeRF with an analog channel enabled and TOSBase) to collect and send the EKG data. It was found that even though the computing resource of the remote computer running the applications to display the EKG signals was almost exhausted under a DDoS attack, the system was still responding (alive) and displaying the collected EKG signal. However, the normal EKG signal pattern was distorted due to the resource exhaustion caused by the DDoS attack, which in turn made the EKG signal unreliable for medical diagnosis and remote monitoring. In order to understand effect of TCP SYN attack on the EKG signal pattern, the attack was launched at different loads in a controlled lab environment. Finally, an Intrusion Prevention System was deployed in the network to mitigate the adverse effects of attack in the network in an attempt to recover a good EKG signal. Copyright (C) 2011 John Wiley & Sons, Ltd.

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

denial of service attacks
electrocardiogram signals
real-time monitoring
network security


Analog baseband chain of synthetic aperture radar (SAR) receiver An analog baseband chain for a synthetic aperture radar receiver implemented in a 130 nm CMOS technology is presented in this paper. Occupying 0.23 mm(2) of silicon area, the baseband chain consists of a three-stage variable gain amplifier (VGA), a 5th-order gm-C low-pass filter (LPF) and an output buffer. The gain of the chain can be controlled by tuning the control voltages of the VGA and has a range from 25 to 34 dB. 8 dB of the gain is embedded into the LPF. The bandwidth of the LPF is programmable from 100 to 190 MHz by means of capacitor matrices. The chain, which uses a 1.2 V supply voltage, achieves an input-referred noise density of 4 nV/ and an in-band IIP3 of -46 dBV rms.

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

analog baseband chain
synthetic aperture radar receiver
variable gain amplifier
output buffer


Multiple regularization based MRI reconstruction This paper proposes MRI reconstruction based on multiple regularizers. Nonlocal total variation and wavelet are the regularizers used in this work. The Split Bregman method is used to solve the hybrid L1-regularizer. The Split Bregman algorithm makes use of GaussSeidel and Fourier transform methods, it is easily parallelizable and easily coded. The proposed method performs better in terms of reconstruction quality and computational complexity.

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 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

nonlocal total variation
split bregman algorithm

mr image reconstruction
compressed sensing


Physically-motivated dynamical algorithms for the graph isomorphism problem The graph isomorphism problem (GI) plays a central role in the theory of computational complexity and has importance in physics and chemistry as well [1, 2]. No polynomial-time algorithm for solving GI is known. We investigate classical and quantum physics-based polynomial-time algorithms for solving the graph isomorphism problem in which the graph structure is reflected in the behavior of a dynamical system. We show that a classical dynamical algorithm proposed by Gudkov and Nussinov [25] as well as its simplest quantum generalization fail to distinguish pairs of non-isomorphic strongly regular graphs. However, by combining the algorithm of Gudkov and Nussinov with a construction proposed by Rudolph [26] in which one examines a graph describing the dynamics of two particles on the original graph, we find an algorithm that successfully distinguishes all pairs of non-isomorphic strongly regular graphs that we tested with up to 29 vertices.

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 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


on preserving privacy in content-oriented networks The recent literature has hailed the benefits of content-oriented network architectures. However, such designs pose a threat to privacy by revealing a user's content requests. In this paper, we study how to ameliorate privacy in such designs. We present an approach that does not require any special infrastructure or shared secrets between the publishers and consumers of content. In lieu of any informational asymmetry, the approach leverages computational asymmetry by forcing the adversary to perform sizable computations to reconstruct each request. This approach does not provide ideal privacy, but makes it hard for an adversary to effectively monitor the content requests of a large number of users.

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


A survey on fast correlation attacks Fast correlation attacks, pioneered by Meier and Staffelbach in 1988, constitute an important class of attacks on stream ciphers. They exploit a correlation between the keystream and the output of a linear feedback shift register (LFSR) within the cipher. Several factors affect the feasibility of such an attack, e.g., the amount of available keystream and the number of taps in the LFSR. Notably, for a fixed number of taps, the length of the LFSR does not affect the complexity of the attack. When the register does not have a sufficiently small number of taps, however, the attacker will try to find parity check equations of low weight, at which point the length of the register does matter. In this paper, we go through the significant contributions to this field of cryptanalysis, reiterating the various algorithms that have been developed for finding parity check equations and performing the online stage on received keystream. We also suggest some new generalizations of Meier-Staffelbachs original formulations.

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

fast correlation attacks
stream ciphers
cryptanalysis


An investigation of web crawler behavior: characterization and metrics In this paper, we present a characterization study of search-engine crawlers. For the purposes of our work, we use Web-server access logs from five academic sites in three different countries. Based on these logs, we analyze the activity of different crawlers that belong to five search engines: Google, AltaVista, Inktomi, FastSearch and CiteSeer. We compare crawler behavior to the characteristics of the general World-Wide Web traffic and to general characterization studies. We analyze crawler requests to derive insights into the behavior and strategy of crawlers. We propose a set of simple metrics that describe qualitative characteristics of crawler behavior, vis- a -vis a crawler's preference on resources of a particular format, its frequency of visits on a Web site, and the pervasiveness of its visits to a particular site. To the best of our knowledge, this is the first extensive and in depth characterization of search-engine crawlers. Our results and observations provide useful insights into crawler behavior and serve as basis of our ongoing work on the automatic detection of Web crawlers. (c) 2005 Elsevier B.V. All rights reserved.

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


The integer approximation error in mixed-integer optimal control We extend recent work on nonlinear optimal control problems with integer restrictions on some of the control functions (mixed-integer optimal control problems, MIOCP). We improve a theorem (Sager et al. in Math Program 118(1): 109-149, 2009) that states that the solution of a relaxed and convexified problem can be approximated with arbitrary precision by a solution fulfilling the integer requirements. Unlike in previous publications the new proof avoids the usage of the Krein-Milman theorem, which is undesirable as it only states the existence of a solution that may switch infinitely often. We present a constructive way to obtain an integer solution with a guaranteed bound on the performance loss in polynomial time. We prove that this bound depends linearly on the control discretization grid. A numerical benchmark example illustrates the procedure. As a byproduct, we obtain an estimate of the Hausdorff distance between reachable sets. We improve the approximation order to linear grid size instead of the previously known result with order (Hackl in Reachable sets, control sets and their computation, augsburger mathematisch-naturwissenschaftliche schriften. Dr. Bernd Winer, Augsburg, 1996). We are able to include a Special Ordered Set condition which will allow for a transfer of the results to a more general, multi-dimensional and nonlinear case compared to the Theorems in Pietrus and Veliov in (Syst Control Lett 58:395-399, 2009).

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 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

mixed-integer programming
hybrid systems


A directional decomposition heuristic for one-dimensional, non-equidistant machine-cell location problems Machine-cell location (MCL) problems have been major points of interests of many researchers dealing with cell formation and material flow analysis in a manufacturing shop floor. Since the internal configuration of the production line in a cell is the outcome of both machine-group formation and machine-location problems, the locations of these cells along a material-handling track (or transporter path) are of further interests for the refinement of the results. As the processing technology improves and computational capabilities enhance, the scope of this assignment is even more captivated by potential total benefit. In this research, a one-dimensional, non-equidistant MCL problem is considered, where the input of the system starts from the output of a group formation problem. First the bi-directional movements are decomposed into backward and forward gains and these incremental gains are exploited to explore the most potential search procedure in either of the decomposed directions. The solution procedure is simple, but efficient and good with respect to both time and quality of solution. This directional decomposition heuristic generates a relatively good solution as compared to other existing solutions in MCL analysis.

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


Positive solutions of sublinear SturmLiouville problems with changing sign nonlinearity In this paper, the following nonlinear SturmLiouville problem

positive solution
global structure
topological methods


A general heuristic for vehicle routing problems We present a unified heuristic which is able to solve five different variants of the vehicle routing problem: the vehicle routing problem with time windows (VRPTW), the capacitated vehicle routing problem (CVRP), the multi-depot vehicle routing problem (MDVRP), the site-dependent vehicle routing problem (SDVRP) and the open vehicle routing problem (OVRP). All problem variants are transformed into a rich pickup and delivery model and solved using the adaptive large neighborhood search (ALNS) framework presented in Ropke and Pisinger [An adaptive large neighborhood search heuristic for the pickup and delivery problem with time windows. Transportation Science, to appear]. The ALNS framework is an extension of the large neighborhood search framework by Shaw [Using constraint programming and local search methods to solve vehicle routing problems. In: CP-98, Fourth international conference on principles and practice of constraint programming, Lecture notes in computer science, vol. 1520, 1998. p. 41731] with an adaptive layer. This layer adaptively chooses among a number of insertion and removal heuristics to intensify and diversify the search. The presented approach has a number of advantages: it provides solutions of very high quality, the algorithm is robust, and to some extent self-calibrating. Moreover, the unified model allows the dispatcher to mix various variants of VRP problems for individual customers or vehicles. As we believe that the ALNS framework can be applied to a large number of tightly constrained optimization problems, a general description of the framework is given, and it is discussed how the various components can be designed in a particular setting. The paper is concluded with a computational study, in which the five different variants of the vehicle routing problem are considered on standard benchmark tests from the literature. The outcome of the tests is promising as the algorithm is able to improve 183 best known solutions out of 486 benchmark tests. The heuristic has also shown promising results for a large class of vehicle routing problems with backhauls as demonstrated in Ropke and Pisinger [A unified heuristic for a large class of vehicle routing problems with backhauls. European Journal of Operational Research, 2004, to appear].

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

large neighborhood search
vehicle routing problem


Ontology-based Approach to Competence Profile Management Competence management has received much attention during recent years because it contributes to achieving organizational goals and solving problems such as improvement of information flow or competence supply. Many approaches were proposed to modelling competence and using competence models but there is still a lack of research into structures and utilisation of competence profiles in a competence management system. This article addresses this problem by proposing a formal approach to competence profile management. Four project cases are first analysed to elicit requirements of competence profile management, including competence profile operations. After that, an abstract model of competence profile management is formally defined based on the requirements. Finally, an ontology-based implementation of the abstract model is presented including a software architecture of a competence profile management system. The main contribution of this work is formalization of operations on competence profiles and ontology-based implementation of these operations. The proposed implementation architecture can facilitate construction of a competence profile management system.

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

competence management
competence profile
formalisation
ontology-based profile
owl
jena


A modified image representation for bincodes and its manipulations It has been shown that using bincodes (BCs) to represent binary images is storage-saving and easy to be manipulated. Given a set of BCs, this paper presents improved codes, namely, the modified BCs (MBCs) to represent binary images. We first transform the given BCs into a set of logical expressions, then an improved encoding scheme is employed to reduce the storage space required for representing these logical expressions, thus obtaining the MBCs. Given twenty different types of real images, experimental results show that the proposed MBCs has 25% to 28% improvement when compared to BCs. By adopting the level-compact scheme on MBCs, storage space can be reduced further. It is shown that in some cases the storage-saving improvement is more than 50%. Some image manipulations, such as computing geometrical properties and set operations, on the MBCs are also investigated.

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

bintrees
image compression
logical bincodes
spatial data structures


Some experiments with a hybrid model for learning sequential decision making To deal with sequential decision tasks, we present a learning model CLARION, which is a hybrid connectionist model consisting of both localist and distributed representations, based on the two-level approach proposed in our earlier work (Artificial Intelligence, 75(2) (1995) 241-296). The model learns and utilizes procedural and declarative knowledge, tapping into the synergy of the two types of processes. It unifies neural, reinforcement, and symbolic methods to perform on-line, bottom-up learning. Experiments in various situations are reported that shed light on the working of the model. (C) 1998 Elsevier Science Inc. All rights reserved.

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 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

sequential decision making
declarative knowledge

hybrid models
connectionist models
reinforcement learning
cognitive models
procedural knowledge


using uncertainty in reputation methods to enforce cooperation in ad-hoc networks This paper gives an approach to reputation computation that incorporates "uncertainty" based on subjective logic. Uncertainty can arise when a node joins the network and thus has no history, or when a node's behavior changes in a way that is not clearly malicious, but at least suspicious. This uncertainty indicates when a node evaluating the reputation rating of another node should poll its neighbors for recommendations, because its local opinion is not sufficiently well-informed.The uncertainty based algorithm has several parameters and the computed reputation depends on these parameters. To evaluate the effectiveness of the uncertainty based method and to determine the effect of the parameters on the reputation computations, we have implemented a simulation infrastructure for the behavior of ad-hoc networks using the uncertainty based scheme. The simulator can also use other previously proposed mechanisms for reputation computation. The simulator is used to determine optimal parameters for the various schemes and how well each scheme a) ensures cooperative nodes receive service when requested, and b) throttles the ability of free-loading (malicious) nodes to consume service without contributing. The simulations show that the reputation computation that incorporates uncertainty provides superior recognition of "malicious" behavior in a variety of ad-hoc network situations. These initial results are sufficiently promising to motivate continuing study of reputation computations incorporating uncertainty to additional models of malicious behavior and a broader range of network behaviors.

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

cooperation
uncertainty
subjective logic
reputation


Multivoltage Aware Resistive Open Fault Model Resistive open faults (ROFs) represent common interconnect manufacturing defects in VLSI designs causing delay failures and reliability-related concerns. The widespread utilization of multiple supply voltages in contemporary VLSI designs and emerging test methods poses a critical concern as to whether conventional models for resistive opens will still be effective. Conventional models do not explicitly model the VDD effect on fault behavior and detectability. We have empirically observed that a sensitized ROF could exhibit multiple behaviors across its resistance continuum. We also observe that the detectable resistance range versus VDD varies with test speed. We consequently propose a voltage-aware model that divides the full range of open resistances into continuous behavioral intervals and three detectability ranges. The presented model is expected to substantially enhance multivoltage test generation and fault distinction.

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

open resistance intervals
resistive open faults (rofs)
small delay faults
voltage-aware modeling


Fat Hoffman graphs with smallest eigenvalue greater than ?3 In this paper, we give a combinatorial characterization of the special graphs of fat Hoffman graphs containing K1,2 K 1 , 2 with smallest eigenvalue greater than ?3, where K1,2 K 1 , 2 is the Hoffman graph having one slim vertex and two fat vertices.

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

graph eigenvalue
line graph
block graph
signed graph


Molecular field feature extraction and analysis with level set method ? In this paper, we exploit the level set methods to extract and analyze the feature of macromolecular field. For the 3D volume data of the field, we propose a novel variational formulation of the geometric active contour, which is composed of an external energy to drive the active contour, and an internal energy which penalizes the level set function adaptively to avoid periodically re-initializing. We adjust the parameters of each component and examine their influences in the whole process. Our approach provides an intuitive way to study spatial relationships of the segmented regions. Compared with the traditional level set frameworks, our approach is more accurate and efficient on the feature extraction regarding the HIV-1 protease molecular field and the DPS protein molecular field. During the exploration, we successfully found the escape route of water molecules hidden in the HIV-1 protease and the internal cavity of the DPS protein for the iron atom's entry and deposition. Both of these results support the experimental results given by chemists and biologists.

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

molecular field
level set method
feature extraction
variational formulation
parameters
spatial relationships
dps protein


efficient multiple-click models in web search Many tasks that leverage web search users' implicit feedback rely on a proper and unbiased interpretation of user clicks. Previous eye-tracking experiments and studies on explaining position-bias of user clicks provide a spectrum of hypotheses and models on how an average user examines and possibly clicks web documents returned by a search engine with respect to the submitted query. In this paper, we attempt to close the gap between previous work, which studied how to model a single click, and the reality that multiple clicks on web documents in a single result page are not uncommon. Specifically, we present two multiple-click models: the independent click model (ICM) which is reformulated from previous work, and the dependent click model (DCM) which takes into consideration dependencies between multiple clicks. Both models can be efficiently learned with linear time and space complexities. More importantly, they can be incrementally updated as new click logs flow in. These are well-demanded properties in reality. We systematically evaluate the two models on click logs obtained in July 2008 from a major commercial search engine. The data set, after preprocessing, contains over 110 thousand distinct queries and 8.8 million query sessions. Extensive experimental studies demonstrate the gain of modeling multiple clicks and their dependencies. Finally, we note that since our experimental setup does not rely on tweaking search result rankings, it can be easily adopted by future studies.

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

implicit feedback
web
model
paper
user
search
dependencies
users
space
interpretation
data
flow
demonstrate
queries
future
query

statistical models
paging
efficiency
experience
timing
bias
evaluation
posit
eye tracking
experimentation
search engine
click log analysis
web search
documentation


CURD: Controllable reactive jamming detection in underwater sensor networks ? Underwater sensor networks (UWSNs) are vulnerable to jamming attacks. Controllable reactive jamming is a kind of realistic and very harmful jamming attack. A reactive jammer controls the probability of jamming and the duration of the jam signal, in order to maintain high vulnerability with low detection probability. The existing works on reactive jamming detection are focused on terrestrial wireless sensor networks (TWSNs), and are limited in their ability to (a) detect jamming correctly, (b) distinguish between the corrupted and uncorrupted parts of a packet, and (c) be adaptive with the dynamic environment. In this paper, we develop a non-parametric cumulative sum (CUSUM)-test and weak estimation learning automata (WELA)-based scheme, named CURD, for controllable reactive jamming detection. In the proposed scheme, the CUSUM-test allows to quickly find the abrupt changes in bits without any a priori knowledge about the adversary, and the learning scheme helps in absorbing the impact of the dynamism in the environment. Unlike the existing works on this issue, we introduce the concept of partial-packet (PP) for analyzing a packet in different fragments (i.e., PPs) to identify packet corruption in few bits. We develop a Markov chain-based analytical model for theoretical analysis of the proposed scheme, CURD, under the consideration of a single controllable reactive jammer. We evaluate the performance of CURD through simulation studies in a UWSN environment. Results show that the proposed scheme is capable of accurately detecting reactive jamming in UWSNs, and outperforms the benchmark scheme considered in the study.

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

reactive jamming
weak estimation learning
cumulative sum


modlisp This paper discusses the design and implementation of MODLISP, a LISP-like language enhanced with the idea of MODes. This extension permits, but does not require, the user to declare the types of various variables, and to compile functions with the arguments declared to be of a particular type. It is possible to declare several functions of the same name, with arguments of different type (e.g. PLUS could be declared for Integer arguments, or Rational, or Real, or even Polynomial arguments) and the system will apply the correct function for the types of the arguments. The MODLISP language differs from other abstract data type languages such as CLU [Liskov & Zilles, 1974; Liskov et al, 1977] and Russell [Donahue,1977] in that it allows dynamic construction of new parametrised data types and possesses a unified semantics covering interpreted and compiled code, which can call one another at will. In short, it is LISP-like.

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

abstract data type
polynomial
code
dynamic
language
design
types
implementation
data
paper
user

variability lisp systems semantic functional extensibility argument


Strengths and barriers behind the successful agile deploymentinsights from the three software intensive companies in Finland The number of success stories being reported concerning agile software development has led to an increase in interest among industries and research communities. The purpose of this paper is to identify strengths and barriers for successful agile deployment in the software companies. This knowledge can benefit software companies planning their current strategy for agile deployment. Analysis of 57 developers, architects, project managers, customers, quality managers, and line and product managers in three case companies identifies 71 strengths and 169 barriers of agile deployment. The analysis revealed the importance of management providing the necessary goals and support for agile development. It also indicated the significance of defining a tailored process model and giving developers the freedom to improve their own agile development process continuously during agile deployment. The identified barriers, strengths and recommendations can be used as a checklist for planning and/or monitoring the effectiveness of agile deployment in software companies. By identifying the barriers and strengths of agile deployment, the paper deepens understanding of this highly relevant but relatively under-researched phenomenon and contributes to the literature on agile deployment and software process improvement.

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

improving agile development
success factors for agile deployment
software process improvement (spi)


Preliminary evaluation of an MRI-based technique for displaying and quantifying bony deformities in cam-type femoroacetabular impingement Characterizing aspheric deformities of the femoral headneck junction in cam-type femoroacetabular impingement (FAI) requires representing the location, size, or extent of the bony lesion. The objectives of this work are to (1) assess the feasibility of creating 3D models of cam deformities from MRI sets, (2) present a standardized 2D visualization of the lesion, and (3) present and evaluate the potential utility of summary metrics in distinguishing between FAI patients and control subjects.

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

hip
alpha angle
computer-assisted diagnosis
magnetic resonance imaging


Generating G(n) parametric blending surfaces based on partial reparameterization of base surfaces A method for generating parametric G(n) blending surfaces based on reparameterization of partial surface patches of the base surfaces is presented. In the method, partial regions, called repararneterized local base surfaces, near the contact curves on both base surfaces are reparameterized first. Then a parametric G(n) blending surface is generated by a linear combination of the two reparanieterized local base surface patches by using Erich Hartmann's method. Here, contact curves can be arbitrarily defined by users according to practical requirements. Some methods for determining the reparameterized local base surfaces are given, and thereafter the influences of the repararneterized local base surfaces on the blending surface are discussed in detail. In addition, in order to achieve the fairness of the blending surface, a shape optimization method for minimizing the strain energy of the surface is proposed. Finally, some examples, including a G(2) blending surface generated with the method between an aerofoil and a missile body, are given to demonstrate the effectiveness of the proposed approach. (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 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 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 B I O 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

blending surface
base surface
linear combination
shape optimization

reparameterized local base surface
contact curve


A Tool Suite to Enable Web designers, Web Application developers and End-Users to Handle Semantic Data Current web application development requires highly qualified staff, dealing with an extensive number of architectures and technologies. When these applications incorporate semantic data, the list of skill requirements becomes even larger, leading to a high adoption barrier for the development of semantically enabled Web applications. This paper describes VPOET, a tool focused mainly on two types of users: web designers and web application developers. By using this tool, web designers do not need specific skills in semantic web technologies to create web templates to handle semantic data. Web application developers incorporate those templates into their web applications, by means of a simple mechanism based in HTTP messages. End-users can use these templates through a Google Gadget. As web designers play a key role in the system, an experimental evaluation has been conducted, showing that VPOET provides good usability features for a representative group of web designers in a wide range of competencies in client-side technologies, ranging from amateur HTML developers to professional web designers.

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

semantic data
semantically enabled web applications
vpoet
web application development
web applications


Case-based reasoning for matching SmartHouse technology to people's needs SmartHouse technology offers devices that help the elderly and people with disabilities to live independently in their homes. This paper presents our experiences from a pilot project applying case-based reasoning techniques to match the needs of the elderly and those with disabilities to SmartHouse technology. The SmartHouse problem is decomposed into sub-tasks, and generalised concepts added for each sub-task. This decomposition and generalisation enables multiple case reuse employing a standard decision tree index based iterative retrieval strategy. Documented real situations are used to create a small case base. An initial prototype is evaluated empirically using leave-one-out testing, and separately with the domain expert on newly created test cases. Results show that system generated solutions to be comparable to those of a domain expert. Importantly, the iterative retrieval strategy employing multiple indices generated solutions that were significantly better compared to a one-shot retrieval without indices.

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

case-based reasoning
smarthouse technology smarthouse
multiple indexed retrieval
concept generalisation


SLA-based operations of massively multiplayer online games in clouds Successful massively multiplayer online games (MMOGs) have today millions of registered users and hundreds of thousands of active concurrent players. To be able to guarantee quality of service (QoS) to a highly variable number of concurrent users, game operators statically over-provision a large infrastructure capable of sustaining the game peak load, even though a large portion of the resources is unused most of the time. To address this problem, we introduce in this work a new MMOG ecosystem for hosting and provisioning of MMOGs which effectively splits the traditional monolithic MMOG companies into three main service providers: game providers, game operators, and resource providers. Their interaction is regulated through comprehensive service level agreements (SLA) that establish the price, terms of operation, and compensation for service violations. In our model, game operators efficiently provision resources for MMOGs from multiple cloud providers, based on dynamic load forecasts, and ensure proper game operation that maintains the required QoS to all clients under varying resource availability. Game providers manage multiple distributed MMOGs for which they lease services under strict operational SLAs from game operators to satisfy all client requests. These three self-standing, smaller, more agile service providers enable access to the MMOG market for the small and medium enterprises, and to the current commercial cloud providers. We evaluate, through simulations based on real-life MMOG traces and commercial cloud SLAs, the impact of resource availability on the QoS offered to the MMOG clients. We find that our model can mitigate the negative effects of resource failures within four minutes and that MMOG server consolidation can accentuate the negative effects of failures in a resource-scarce environment. We further investigate different methods of ranking MMOG operational offers with either single or multiple (competing) MMOG providers. Our results show that compensations for SLA faults in the offer selection process can lead up to 1116% gain in the game providers income. We also demonstrate that adequate ranking of offers can lead to MMOG operational cost reductions from 20 up to 60%.

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


Virtual Private Social Networks and a Facebook Implementation The popularity of Social Networking Sites (SNS) is growing rapidly, with the largest sites serving hundreds of millions of users and their private information. The privacy settings of these SNSs do not allow the user to avoid sharing some information (e. g., name and profile picture) with all the other users. Also, no matter the privacy settings, this information is always shared with the SNS (that could sell this information or be hacked). To mitigate these threats, we recently introduced the concept of Virtual Private Social Networks (VPSNs). In this work we propose the first complete architecture and implementation of VPSNs for Facebook. In particular, we address an important problem left unexplored in our previous research-that is the automatic propagation of updated profiles to all the members of the same VPSN. Furthermore, we made an in-depth study on performance and implemented several optimization to reduce the impact of VPSN on user experience. The proposed solution is lightweight, completely distributed, does not depend on the collaboration from Facebook, does not have a central point of failure, it offers (with some limitations) the same functionality as Facebook, and apart from some simple settings, the solution is almost transparent to the user. Thorough experiments, with an extended set of parameters, we have confirmed the feasibility of the proposal and have shown a very limited time-overhead experienced by the user while browsing Facebook pages.

B I I 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 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 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 private social networks
social networking sites

security
internet and privacy
facebook privacy


Multi-hop Clustering Based on Neighborhood Benchmark in Mobile Ad-hoc Networks Large-scale mobile ad-hoc networks require flexible and stable clustered network structure for efficient data collection and dissemination. In this paper, a technique is presented to construct multi-hop clusters with balanced sizes, based on the neighborhood benchmark (NB) to quantify the connectivity and link stability of mobile nodes. By exploiting autonomous clusterhead selection and a specialized handshake process with the clusterheads, the nodes with highest NB scores are selected as clusterheads and all the clusters constructed are connected. The deviation of cluster sizes is kept small using a partial probability-based approach. Our technique generates highly stable multi-hop clusters with low overhead, and provides the flexibility of controlling the cluster radius adaptively for various network applications.

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 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

mobile ad-hoc networks
multi-hop clusters


Multilevel symmetry-constraint generation for retargeting large analog layouts The strong impact of layout intricacies on analog-circuit performance poses great challenges to analog layout automation. Recently, template-based methods have been shown to be effective in reuse-centric layout automation for CMOS analog blocks such as operational amplifiers. The layout-retargeting method first creates a template by extracting a set of constraints from an existing layout representation. From this template, new layouts are then generated corresponding to new technology processes and new device. specifications. For large analog layouts, however, this method results in an unmanageable template due to a tremendous increase in the number of constraints, especially those emerging from layout symmetries. In this paper, we present a new method of multilevel symmetry-constraint generation by utilizing the inherent circuit structure and hierarchy information from the extracted nedist. The method has been implemented in a layout-retargeting system called Intellectual Property Reuse-based Analog IC Layout (IPRAIL) and demonstrated 18 times reduction in the number of symmetry constraints required for retargeting an analog-to-digital converter layout. This enables our retargeting engine to successfully handle the complexities associated with large analog layouts. While manual relayout is known to take weeks, our layout-retargeting tool generates the target layout in hours and achieves comparable electrical performance.

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 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 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

analog integrated circuit (ic)
device matching


Intelligent topology analyzer for improved plant operation Purpose - This paper aims to provide a design of intelligent model-based topology analyzer that can be used to improve plant operation. Design/methodology/approach - POOM process modeling methodology is proposed to model and partition plant topology so that plant operation can be designed in effective manner as mapped to plant topology partitions. Plant topology is divided into areas based on the operation required and material flow and isolation paths are identified automatically using intelligent algorithm. Findings - It is possible to define hierarchical plant structure (topology) partitions that can be mapped to plant operation levels, which are described by ANSI/ISA-S88. In addition, the use of design knowledge can be useful to define conceptual partitions such as Block, which is essential to link design and operation knowledge. Plant operation (jobs) can be flexibly defined in view of plant structure partitions in terms of resources (materials, plant structural areas) required and operation scheduling. Research limitations/implications - It is important to link to production scheduling to ensure effective use of topology partitions in real time based on available resources. The proposed approach can be improved via the integration with intelligent production scheduling. Practical implications - Production and manufacturing plants will be able to use the proposed approach to design and validate plant operation and to improve plant maintenance while reducing operation risks by identifying plant structures required for each operation task. The proposed technique can be helpful to engineers and R&D members to consider in their design and investigation for process safety, risk management, and plant operation and management. Originality/value - The idea of topology analysis is quite new where it is usually implemented using search algorithms without considering domain knowledge and operation structures. This paper proposes a valuable technique to link plant structure with plant operation hierarchies, which is important for design and engineering practices and R&D activities for plant operation.

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

plant efficiency
operating systems
process management
modelling


Design and implementation of fuzzy sliding mode controllers for generalized projective synchronization of chaos horizontal platform systems This paper presents robust chattering-free fuzzy sliding mode control (FSMC) as a way to achieve generalized projective synchronization (GPS) of two horizontal chaos platform vibration systems with system uncertainty and external disturbance. An appropriate sliding surface is acquired through an SMC design such that the error state trajectories of a masterslave system will reach such a sliding surface and approaches to the origin. Based on the Lyapunov stability theory, we address the design schemes of integration fuzzy sliding mode control, where the reaching law is proposed by a set of linguistic rules and the control input is chattering free. As a consequence, the system is simulated and experimented to demonstrate that the error state tends to be stabilized and the chattering problem can be thus resolved, implying that the slave horizontal platform system (HPS) is GPS with the master HPS.

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

horizontal platform vibration system
chaos system
lyapunov stability theorem


GLOBAL SCHISTOSOMIASIS DATABASE - PRACTICAL CONSIDERATIONS IN THE DESIGN OF A USER-FRIENDLY DATABASE A computerized database for monitoring global schistosomiasis data is discussed. The potential target users include schistosomiasis program managers, Ministries of Health of endemic countries, consultants, and WHO Regional Offices. The concept behind the design of the database structure, the user interface and the query interface is addressed along with a brief description of the hardware and software used. The database, holding information on 76 schistosomiasis endemic countries around the world, has been tested in the WHO Regional Offices with positive results.

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


An approach for modelling concrete spalling in finite strains A new approach for modelling concrete spalling process is here proposed, taking into account a fully nonlinear-displacement/strain theory able to catch complex interactions between pressure, thermal and mechanical fields. The micro-structural modelling of concrete under fire conditions is derived from a mechanical and thermodynamic consistent theory and it is strictly related to a self-consistent, carefully extracted set of experimental data, in order to make a correct validation and calibration of the numerical F.E. procedures and codes. Even if appearing as a first but successful example, it is shown that a procedure accounting for coupled material and geometric nonlinearities is able to attain valuable and realistic numerical results concerning spalling process in concrete. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved.

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

concrete spatting
micro-structural modelling


on feasible numbers (preliminary version) We study complexity problems associated with generation and manipulation of integers. We show that many such questions may be formulated as problems about random access machines (RAMs), and recent results about RAMs with special instructions sets can be used to give estimates about the complexity of the manipulations. Finally we settle an open problem about RAMs (which becomes more interesting in this setting), namely the power of unrestricted vector machines, studied in [5] [6] [2]. We prove that allowing arbitrary shifts (instead of bounded shifts) gives at most a polynomial reduction in the time necessary to recognize languages by vector machines, thus solving the main problem left unanswered by the papers of Pratt and Stockmeyer [5], [6] and Hartmanis and Simon [2], [3]. Equivalently, it is possible to compare two integers, each obtained by a sequence of at most n operations of shift, sum, and boolean vector operations, within tape polynomial in n.

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

generation
polynomial
random access
reduction
version
power
complexity
manipulation
sequence

vectorization association language instruction operability timing paper


Double recurrent interaction V1V2V4 based neural architecture for color natural scene boundary detection and surface perception Bio-inspired neural architecture for natural scene boundary detection. Double feedback among V1, V2 and V4 cortical areas and chromatic diffusion. Results quantified using F-measure from the Berkeley segmentation benchmark. Parallel implementations on GPU: CUDA(R) and Matlab(R). Neural architecture performance and results compatible with real applications.

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

neural networks
color image processing
bio-inspired models
cuda


conflict resolution with argumentation dialogues Conflicts exist in multi-agent systems for a number of reasons: agents have different interests and desires; agents hold different beliefs; agents make different assumptions. To resolve conflicts, agents need to better convey information to each other and facilitate fair negotiations yielding jointly agreeable outcomes. We present a two-agent, dialogical conflict resolution scheme developed with the Assumption-Based Argumentation (ABA) framework.

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


from behaviour to innovation at nortel networks In this paper we outline the role of Design Interpretive in Nortel Networks. In particular, we describe our approach to designing innovative product concepts derived from observation of human behaviour.

O O 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 O O O O O O O

telecommunications
interaction design
usability
value qualification
product design
rapid prototyping
human factors


On the thermal stability of physically-vapor-deposited diffusion barriers in 3D Through-Silicon Vias during IC processing ? Barrier reliability in 3D through-Si via (TSV) Cu interconnections requires particular attention as these structures come very close to the active devices and Cu diffusion into the silicon substrate would significantly affect device performance. This work focuses on a via-middle process flow, which implies processing of the 3D-TSV after the front-end-of-line (FEOL) process, but before the back-end-of-line (BEOL) interconnect process. This results in several high temperature processing steps after TSV fabrication, including a final device wafer sintering step, generally in the 400C range. Thus, it becomes essential to study the stability of the TSV Cu-barrier at these temperatures to ensure a reliable integration of 3D TSV in CMOS wafers. TSV aspect ratios can vary as function of the integration scheme, for instance in a via-last or via-middle flow, and thus barrier continuity requires conformality which guarantees the presence of a diffusion barrier until the bottom of the TSV. Target conformality can either be obtained by PVD, typically for TSV A.R.?10:1. We report on the thermal stability of Ta, and Ti barriers and we show that 5nm PVD Ta barriers are thermally stable, while PVD Ti-barriers require thicknesses above 5nm to guarantee their thermal stability.

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

diffusion barrier
reliability
thermal stability

3d integration
physical-vapor deposition
through-silicon via (tsv)


Seismic depth migration with pseudo-screen propagator The generalized screen propagator (GSP) is a fast and accurate method for computing wave propagation in laterally varying velocity media. The method solves the acoustic one-way wave equation by shuffling FFTs between frequency-space and frequency-wavenumber domain. The velocity model is decomposed into a vertically varying reference velocity and a laterally varying perturbation. Downward continuation of the wavefield is performed with a phase shift in a background medium followed by a correction that accommodates the lateral velocity variations. All frequencies of interest are migrated and summed to produce an image at each depth level. The screen propagators are applicable to both poststack and prestack depth migrations. We illustrate the method with the SEG-EAGE salt model and Marmousi data set. The image results show that the pseudo-screen propagator is a big improvement over the phase-screen propagator for steeply dipping events in strong-contrast heterogeneous media.

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

depth migration
generalized screen propagator

pseudo-screen propagator
phase-screen propagator


Reliability and performance-based design by artificial neural network Whilst conventional approach in structural design is based on reliability-calibrated factored design formula, performance-based design customizes a solution to the specific circumstance. In this work, an artificial neural network approach is employed to determine implicit limit state functions for reliability evaluations in performance-based design and to optimally evaluate a set of design variables under specified performance criteria and corresponding desired reliability levels in design. Case examples are shown for reliability design. Through the establishment of the response and reliability databases, for specified target reliabilities, structural response computations are integrated with the evaluation of design parameters and design can be accomplished. By employing this methodology, with the same performance requirements, pertinent design parameters can be altered in order to evaluate feasible design alternatives, to explore the usage of various structural materials and to define required material quality control.

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

performance-based design
structural reliability


A probabilistic model for sub-carrier allocation in OFDMA systems Orthogonal frequency division multiple-access technique showed a successful utilization of channel features. It implements an orthogonal sub-carrier space to be shared among different users. The management of these sub-carriers in both power and frequency allocation is reflected on the systems performance as better utilization of bandwidth, and hence, better capacity is obtained. Sub-carrier allocation is used to avoid deep fading that might occur at some users locations but not at other users locations. In this paper, we devise an algorithm based on probabilistic model for sub-carrier allocation to avoid deep fading in some users signals. By controlling the sub-carrier allocation for each user, we can create a full rank channel for each user and hence, provide maximum capacity for the system. Simulation results showed that using the devised algorithm will avoid deep fading and utilize the bandwidth up to 40% more than localized allocation strategies.

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

lte
lofdma
dofdma
mimo
outage and capacity


Spiral packing We present a simple method for creating artistic space-filling designs based on spiral packings. Connected spiral sets are generated by successively branching child spirals from parent spirals, constrained to fit nearby neighbors in their environment. The underlying geometry is discussed in detail and a number of color examples generated by the algorithm are given.

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

archimedes spiral
apollonian circle packing
fractal
art


The state of the art in flow visualization: dense and texture-based techniques Flow visualization has been a very attractive component of scientific visualization research for a long time. Usually very large multivariate datasets require processing. These datasets often consist of a large number of sample locations and several time steps. The steadily increasing performance of computers has recently become a driving factor for a reemergence in flow visualization research, especially in texture-based techniques. In this paper, dense, texture-based flow visualization techniques are discussed. This class of techniques attempts to provide a complete, dense representation of the flow field with high spatio-temporal coherency. An attempt of categorizing closely related solutions is incorporated and presented. Fundamentals are shortly addressed as well as advantages and disadvantages of the methods.

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

flow visualization
vector field visualization
texture-based flow visualization


0.8 V bulk-driven operational amplifier A low-voltage bulk-driven CMOS operational amplifier is proposed in this paper. The inherent small transconductance of the bulk-driven devices is enlarged using a positive feedback, improving also the noise performance. The amplifier is designed using standard 0.18 mu m n-well CMOS process. Although the amplifier is optimized for 0.8 V supply voltage, it is also capable to operate under supply voltage of 0.7 V. The amplifier consumes 130 mu A, performing 56 dB open-loop gain, 154 nV/root Hz input-referred spot noise at 100 kHz, 80 dB CMRR at 100 kHz and IIP3 equal to -4.7 dBV.

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

analog vlsi
low-voltage
amplifiers
bulk-driven transistor


An extended Branch-and-Bound algorithm for fuzzy linear bilevel programming This paper presents an extended Branch-and-Bound algorithm for solving fuzzy linear bilevel programming problems. In a fuzzy bilevel programming model, the leader attempts to optimize his/her fuzzy objective with a consideration of overall satisfaction, and the follower tries to find an optimized strategy, under himself fuzzy objective, according to each of possible decisions made by the leader. This paper first proposes a new solution concept for fuzzy linear bilevel programming. It then presents a fuzzy number based extended Branch-and-bound algorithm for solving fuzzy linear bilevel programming problems.

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

branch-and-bound algorithm
fuzzy sets
fuzzy optimization
decision making


Two higher order hybrid-Trefftz elements for thin plate bending analysis Two higher-order hybrid-Trefftz elements are proposed. To formulate these elements, the hybrid-Trefftz method is employed. In this study, two independent fields are introduced. The findings demonstrate the high accuracy of the proposed elements in analyzing the thin bending plates.

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

finite element
hybrid-trefftz formulation
thin bending plate
quadrilateral element
triangular element


On the amount of minimal pairs of convex sets In this paper, we determine the cardinality of various subsets of the family of all minimal pairs of compact convex subsets of n (Theorems 2.1 and 2.8). Furthermore, we express minimality properties of a pair of closed bounded convex sets in set-theoretical terms (Theorem 3.3).

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

convex analysis
minimal pairs of compact convex sets


Parametric study of a Mach 1.3 cold jet excited by the flapping mode using plasma actuators This paper describes an investigation into numerical and physical parameters influencing an ideally-expanded Mach 1.3 jet excited by the m = +/- 1 flapping mode. The nozzle exit properties of the perfectly expanded jet include rho(jet) = 1.576 kg/(m(3)), T-jet = 224 K, Re = 1.1 x 10(6), and T-0jet = T-ambient = 300 K. The excitation is imposed by eight Localized Arc Filament Plasma Actuators (LAFPA) placed around the periphery of the circular nozzle exit. The reference controlled case considers the most amplified (jet column mode) frequency corresponding to a Strouhal number of 0.3 based on the diameter of the nozzle and jet velocity, with an actuator-imposed temperature of 1500 K and a duty cycle of 20%. Relative to this reference, the effects of changing frequency, duty cycle and actuator model temperature are explored and results are compared with experimental data where available. The results are analyzed with several different quantitative and qualitative metrics, including time-averaged centerline decay and jet half-width as well as phase-averaged coherent structures. Raising the frequency affects the dynamics in several ways; the number of features observed in the phase-averaged data increases and the rate of decay of the centerline velocity is reduced. The alternating vortex ring interactions observed in the reference case are not distinct but are rather replaced by smaller structures, trends which are also observed in experiment. Lowering the Strouhal number increases mixing until a reversal occurs at St = 0.1. The higher duty cycle exhibits strengthened coherent structures and slightly higher jet growth along the flapping plane, but the overall dynamics remain the same. The response of the jet is relatively insensitive to actuator temperature model within reasonable limits. The latter two studies, with different duty cycles and actuator temperatures, are consistent with previous analyses demonstrating that instability manipulation, rather than heat deposition is the primary mechanism of control. (C) 2013 Elsevier Ltd. All rights reserved.

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


A computer-enabled solution procedure for food wholesalers' distribution decision in cities with a circular transportation infrastructure This paper addresses the food distribution decision from a wholesaler's perspective. as the wholesalers are often faced with thorny issues such as when, where, how to deliver products at the lowest costs to best satisfy the retailers' changing needs. This research relies on a distribution problem encountered at Northern Grocery Company in Beijing as an example to develop a two-stage solution procedure and subsequent computer-enabled programs for identifying efficient vehicle routing alternatives. The solution process, which integrates heuristic search algorithms and an integer programming model, can be applied to a wide range of distribution problems with specified route durations and a circular transportation network structure as exemplified by City of Beijing. (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 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

optimization
vehicle routing problem
heuristic search technique
computer applications


A multi-view approach for requirements analysis using goal and scenario As systems get complex, requirements elicitation and analysis are becoming increasingly difficult and important in software development. Even though various analysis methods have been proposed, including scenario-based analysis, goal-based analysis, combining goal with scenario and use case-driven analysis - each method has its own strengths and weaknesses and do not support requirements elicitation and analysis efficiently. This paper proposes a multi-view approach to analyze the requirements of complex software systems. The multi-view approach comprises four views, which incorporate many factors that are part of existing methods. This paper discusses the need for these four views, the activities that are part of each view and how they are carried out. As a proof of concept, we apply the multi-view approach to an automatic teller machine system development.

O O 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 B


Local gapped subforest alignment and its application in finding RNA structural motifs RNA molecules whose secondary structures contain similar substructures often have similar functions. Therefore, an important task in the study of RNA is to develop methods for discovering substructures in RNA secondary structures that occur frequently (also referred to as motifs). In this paper, we consider the problem of computing an optimal local alignment of two given labeled ordered forests F-1 and F-2. This problem asks for a substructure of F-1 and a substructure of F-2 that exhibit a high similarity. Since an RNA molecule's secondary structure can be represented as a labeled ordered forest, the problem we study has a direct application to finding potential motifs. We generalize the previously studied concept of a closed subforest to a gapped subforest and present the first algorithm for computing the optimal local gapped subforest alignment of F-1 and F-2. We also show that our technique can improve the time and space complexity of the previously most efficient algorithm for optimal local closed subforest alignment. Furthermore, we prove that a special case of our local gapped subforest alignment problem is equivalent to a problem known in the literature as the local sequence-structure alignment problem (lssa) and modify our main algorithm to obtain a much faster algorithm for lssa than the one previously proposed. An implementation of our algorithm is available at www.comp.nus.edu.sg/similar to bioinfo/LGSFAligner/. Its running time is significantly faster than the original lssa program.

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 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 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

local forest alignment
rna secondary structure
local sequence-structure motif
dynamic programming


Nonlinear regularization techniques for seismic tomography The effects of several nonlinear regularization techniques are discussed in the framework of 3D seismic tomography. Traditional, linear, ?2 ? 2 penalties are compared to so-called sparsity promoting ?1 ? 1 and ?0 ? 0 penalties, and a total variation penalty. Which of these algorithms is judged optimal depends on the specific requirements of the scientific experiment. If the correct reproduction of model amplitudes is important, classical damping towards a smooth model using an ?2 ? 2 norm works almost as well as minimizing the total variation but is much more efficient. If gradients (edges of anomalies) should be resolved with a minimum of distortion, we prefer ?1 ? 1 damping of Daubechies-4 wavelet coefficients. It has the additional advantage of yielding a noiseless reconstruction, contrary to simple ?2 ? 2 minimization (Tikhonov regularization) which should be avoided. In some of our examples, the ?0 ? 0 method produced notable artifacts. In addition we show how nonlinear ?1 ? 1 methods for finding sparse models can be competitive in speed with the widely used ?2 ? 2 methods, certainly under noisy conditions, so that there is no need to shun ?1 ? 1 penalizations.

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


comparing random data allocation and data striping in multimedia servers We compare performance of a multimedia storage server based on a random data allocation layout and block replication with traditional data striping techniques. Data striping techniques in multimedia servers are often designed for restricted workloads, e.g. sequential access patterns with CBR (constant bit rate) requirements. On the other hand, a system based on random data allocation can support virtually any type of multimedia application, including VBR (variable bit rate) video or audio, and interactive applications with unpredictable access patterns, such as 3D interactive virtual worlds, interactive scientific visualizations, etc. Surprisingly, our results show that system performance with random data allocation is competitive and sometimes even outperforms traditional data striping techniques, for the workloads for which data striping is designed to work best; i.e. streams with sequential access patterns and CBR requirements. Due to its superiority in supporting general workloads and competitive system performance, we believe that random data allocation will be the scheme of choice for next generation multimedia servers.

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

requirements
generation
video
replication
performance
layout
general
access
audio
interactive applications
storage
multimedia
data
support
3d
server
scheme
allocation

competition
randomization
virtual world
pattern
interaction
variability
systems
scientific visualiztion
multimedia application
blocking


Local Dimensionality Reduction for Non-Parametric Regression Locally-weighted regression is a computationally-efficient technique for non-linear regression. However, for high-dimensional data, this technique becomes numerically brittle and computationally too expensive if many local models need to be maintained simultaneously. Thus, local linear dimensionality reduction combined with locally-weighted regression seems to be a promising solution. In this context, we review linear dimensionality-reduction methods, compare their performance on non-parametric locally-linear regression, and discuss their ability to extend to incremental learning. The considered methods belong to the following three groups: (1) reducing dimensionality only on the input data, (2) modeling the joint input-output data distribution, and (3) optimizing the correlation between projection directions and output data. Group 1 contains principal component regression (PCR); group 2 contains principal component analysis (PCA) in joint input and output space, factor analysis, and probabilistic PCA; and group 3 contains reduced rank regression (RRR) and partial least squares (PLS) regression. Among the tested methods, only group 3 managed to achieve robust performance even for a non-optimal number of components (factors or projection directions). In contrast, group 1 and 2 failed for fewer components since these methods rely on the correct estimate of the true intrinsic dimensionality. In group 3, PLS is the only method for which a computationally-efficient incremental implementation exists. Thus, PLS appears to be ideally suited as a building block for a locally-weighted regressor in which projection directions are incrementally added on the fly.

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

correlation
dimensionality reduction
factor analysis
incremental learning
partial least squares
principal component analysis
principal component regression

kernel function
locally-weighted regression
reduced-rank regression


A new optimization approach for mass-spring models parameterization Mass-spring models (MSM) are frequently used to model deformable objects for computer graphics applications due to their simplicity and computational efficiency. However, the model parameters are not related to the constitutive laws of elastic material in an obvious way. The MSM parameters computation from a model based on continuum mechanics is a possibility to address this problem. Therefore, in this paper we propose a new method to derive MSM parameters using a data-driven strategy with a new objective function based on the model acceleration so that the MSM and the reference model behave similarly. The proposed methodology does not depend on reference model, mesh topology or static equilibrium configuration. We validate the methodology for deriving MSM systems using finite element method (FEM) and MSM itself as reference models. The obtained results are compared with related works. We also discuss its robustness against different discretizations and material properties.

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

mass-spring model
mass-spring parameterization
deformable object models
physically based modeling
elasticity theory


Efficient query expansion with auxiliary data structures Query expansion is a well-known method for improving average effectiveness in information retrieval. The most effective query expansion methods rely on retrieving documents which are used as a source of expansion terms. Retrieving those documents is costly. We examine the bottlenecks of a conventional approach and investigate alternative methods aimed at reducing query evaluation time. We propose a new method that draws candidate terms from brief document summaries that are held in memory for each document. While approximately maintaining the effectiveness of the conventional approach, this method significantly reduces the time required for query expansion by a factor of 510.

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

efficiency
document surrogates
query associations


limitations of special-purpose instructions for similarity measurements in media simd extensions Microprocessor vendors have provided special-purpose instructions such as psadbw and pdist to accelerate the sum-of-absolute differences (SAD) similarity measurement. The usefulness of these special-purpose instructions is limited except for the motion estimation kernel. This has several drawbacks. First, if the SAD becomes obsolete because a different similarity metric is going to be employed, then those special-purpose instructions are no longer useful. Second, these special instructions process 8-bit subwords only. This precision is not su cient for some kernels such as motion estimation in the transform domain. In addition, when employing other n -way parallel SIMD instructions to implement the SAD and sum-of-squared differences (SSD),the obtained speedup is much less than n . This is because there is a mismatch between the storage and the computational format. In this paper, we design and evaluate a variety of SIMD instructions for different data types. We synthesize special-purpose instructions using a few general-purpose SIMD instructions. In addition, we employ the extended subwords technique to avoid conversion overhead and to increase parallelism. In this technique there are four extra bits for every byte of register. The results show that using different SIMD instructions and extended subwords achieve a speedup ranging from 10.39 to 14.57 over C performance for SAD, SSD with interpolation, and SSD functions in the motion estimation kernel. While, MMX achieves a speedup ranging from 4.61 to 7.42. Additionally,the proposed SIMD instructions improve the performance of similarity measurement for image histograms by a factor ranging from 8.69 (1-way)to 11.70 (4-way) over C.While for MMX speedup is between 2.90 (1-way) and 4.33 (4-way).

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


The powerset operator on abstract interpretations In the context of the standard Cousot and Cousot framework, refinement operators that systematically produce more precise abstract interpretations from simpler ones are useful. We present a theoretical study of one such operator: the powerset. For any given abstract interpretation, i.e. an abstract domain equipped with corresponding abstract operations, the powerset operator yields a new abstract interpretation, where the abstract domain is (very close to) the powerset of the original one and the operations are accordingly extended. It turns out that the refined powerset domain is able to represent in the best possible way the concrete disjunction. Conditions that guarantee the correctness of the powerset operator are given, and the relationship, with respect to the precision, between any abstract interpretation and its powerset is studied. The general theory is applied to the well-known abstract interpretation POS, typically used for ground-dependency analysis of logic languages. We show that the powerset P(POS) is strictly more precise than POS both at the domain and operations level. Furthermore, the standard bottom-up abstract semantics of logic programs based on POS and P(POS) are compared by exhibiting a completeness relationship between them, i.e. the first semantics can be obtained by abstracting back the second one. (C) 1999 Elsevier Science B.V. All rights reserved.

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

abstract interpretation
powerset operator

logic program ground-dependency analysis


Collusion in peer-to-peer systems ? P2P systems are used to provide distributed storage, file sharing, video streaming, distributed gaming, and other applications based on the collaboration of participating peers and on the observation that sharing resources used sporadically leads to huge savings. The operation of a P2P system, as well as its sheer survival, however, is open to many kinds of attacks, which are tough to fight due to both the decentralized nature of P2P applications, and the lack, in some of them, of a central authority, or of a well-defined structure, or both. Particularly, as P2P systems require the active collaboration of the participants beyond their selfish interest, many systems include methods designed to lure the most resourceful users into broader participation, to provide an overall better service. The methods devised to attract the contribution of users are unfortunately vulnerable to a particular class of attacks: collusion. Collusion is broadly defined as any malicious coordinated behavior of a group of users aimed at gaining undeserved benefits, or at damaging (some) well behaved users. In this paper, we survey the literature on P2P systems security with specific attention to collusion, to find out how they resist to such attacks and what solutions can be used, e.g., game theory, to further counter this problem and give P2P systems the possibility of developing into full fledged services of the future Internet.

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


Towards healthcare business intelligence in long-term care: An explorative case study in the Netherlands Long-term care in the Netherlands costs doubled to 27billion in the last decade. Customer experience is the number one information need but no data are available. Staffing wrt Care Intensity Packages (ZZP) is the most important indicator. For 68.9% of the clients with a risk of depression, there is no adequate follow-up. A falling risk of 90.63% results from a combined incontinence and medication risk.

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

knowledge discovery
data mining
crisp-dm
long-term care


Transient stability prediction based on apparent impedance trajectory recorded by PMUs Predicted transient stability using apparent impedance trajectory recorded by PMUs. Optimized locations for PMU placement for transient stability analysis. Classification of disturbances and diverse operating conditions using PMU data.

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

apparent impedance trajectory
transient stability

classification and regression tree (cart)


a proposal for unifying mobility with multi-homing, nat, & security Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being separate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Meanwhile, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have postulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a separate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.

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


Design issues in fuzzy case-based reasoning This paper focuses on the aspect of case representation in case-based reasoning systems. We introduce an augmentation in which each case is weighted individually over an independent set of properties. In addition, we encourage the use of fuzzy-valued properties, and show their incorporation in this representation. Combining these two characteristics, we receive the framework for a versatile Fuzzy CBR system. (C) 2001 Elsevier Science B.V. All rights reserved.

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

similarity measures
fuzzy case-based reasoning
fuzzy matching algorithms


design of spatially aware graspable displays We propose spatially aware portable displays which use movement in real physical space to control navigation in the digital information space within. This paper describes two interface design studies which use physical models, such as friction and gravity, in relating the movement of the display to the movement of information on the display surface. In combining input and output aspects of the interface into a single object, we can improve control and provide a meaningful relationship between the interface and the body of the user.

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

use movement input design object paper navigation control user space physical display surface

portability
interfaces
physical model
interface design
informal
combinational
industrial design
digitize
interaction design
aspect
relationships
3d interfaces
lego


SINGINT: Automatic numerical integration of singular integrands We explore the combination of deterministic and Monte Carlo methods to facilitate efficient automatic numerical computation of multidimensional integrals with singular integrands. Two adaptive algorithms are presented that employ recursion and are runtime and memory optimized, respectively. SINGINT, a C implementation of the algorithms, is introduced and its utilization in the calculation of particle scattering amplitudes is exemplified. (C) 2003 Elsevier Science B.V. 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 B I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

adaptive numerical integration
multidimensional quadrature
integration rules
monte carlo integration


Multi-installment divisible load processing in heterogeneous distributed systems Divisible loads are parallel applications with fine granularity and negligible data dependencies. Such computations can be divided into parts of arbitrary sizes and processed independently in parallel. The load distribution process incurs considerable communication delays. To reduce processor waiting time during the computation initialization phase, the load is distributed in multiple small installments rather than in one big chunk. In this paper we analyze multi-installment divisible load processing in heterogeneous distributed systems. Scheduling divisible loads in heterogeneous systems is hard because the sizes of the installments should be adjusted to the communication and computation capabilities of the system. We show that ignoring heterogeneity of the distributed system may result in arbitrarily bad solutions. Two algorithms are proposed to gear the load chunk sizes to different communication and computation speeds: an optimization branch-and-bound algorithm and a heuristic based on a genetic search method. The running times of both methods and the quality of the solutions are compared. Then, we use these algorithms to study the features of the multi-installment divisible load scheduling problem. We demonstrate that it has both combinatorial and algebraic nature, and that optimum solutions are harder to find with the growing heterogeneity of the system. Copyright (c) 2007 John Wiley & Sons, Ltd.

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 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

scheduling and load balancing
multi-installment processing
combinatorial optimization algorithms