ppxscal/embedding_network huggingface dataset:
An Efficient Bandwidth Reclaim Scheme for the Integrated Transmission of Real-Time and Non-Real-Time Messages on the WLAN
Authors: Junghoon Lee, In-Hye Shin, Gyung-Leen Park, Wang-Cheol Song, Jinhwan Kim, Pankoo Kim, Jiman Hong
Venue: Proceedings of the 7th international conference on Computational Science, Part IV: ICCS 2007 (2007)

This paper proposes and analyzes bandwidth reclaim scheme for IEEE 802.11 WLAN, which may suffer from severe bandwidth waste resulting from not only the variation of transmission rate and message length but also the overallocation to the real-time traffic in compensating for the delay due to the intervention of non-real-time messages. Built on top of the weighted round robin scheduling policy, we address that the polling order rearrangement according to the degree of overallocation can enhance reclaimability of unused network time and that the rearranegable slot has its message pending at the rearranging time. The simulation results show that the proposed scheme is able to reclaim up to 52.3 % of bandwidth waste when the number of streams is 2 and that it also provides stable throughput for utilization of 0.5 through 0.8.
Generic Control Interface for Networked Haptic Virtual Environments
Authors: Priscilla Ramsamy, Adrian Haffegee, Vassil Alexandrov
Venue: Proceedings of the 7th international conference on Computational Science, Part II (2007)

As Virtual Reality pushes the boundaries of the human computer interface new ways of interaction are emerging. One such technology is the integration of haptic interfaces (force-feedback devices) into virtual environments. This modality offers an improved sense of immersion to that achieved when relying only on audio and visual modalities. The paper introduces some of the technical obstacles such as latency and network traffic that need to be overcome for maintaining a high degree of immersion during haptic tasks. The paper describes the advantages of integrating haptic feedback into systems, and presents some of the technical issues inherent in a networked haptic virtual environment. A generic control interface has been developed to seamlessly mesh with existing networked VR development libraries.
Verification of a Hierarchical Generic Mutual Exclusion Algorithm
Authors: Souheib Baarir, Julien Sopena, Fabrice Legond-Aubry
Venue: Proceedings of the 28th IFIP WG 6.1 international conference on Formal Techniques for Networked and Distributed Systems (2008)

In distributed environments, the shared resources access control by mutual exclusion paradigm is a recurrent key problem. To cope with the new constraints implied by recently developed large scale distributed systems like grids, mutual exclusion algorithms become more and more complex and thus much harder to prove and/or verify. In this article, we propose the formal modeling and the verification of a new generic hierarchical approach. This approach is based on the composition of classical already proof checked distributed algorithms. It overcomes some limitations of these classical algorithms by taking into account the network topology latencies and have a high scalability where centralized ones don't. We also have formalized the properties of the mutual exclusion paradigm in order to verify them against our solution. We prove that our compositional approach preserves theses properties under the assumption that all used plain algorithms assert them. This verification by formal method checkers was eased by the efficient use of already proved mutual exclusion algorithms and the reduction of state spaces by exploiting the symmetries.
Topological Semantics and Bisimulations for Intuitionistic Modal Logics and Their Classical Companion Logics
Authors: J. M. Davoren
Venue: Proceedings of the international symposium on Logical Foundations of Computer Science (2007)

We take the well-known intuitionistic modal logic of Fischer Servi with semantics in bi-relational Kripke frames, and give the natural extension to topological Kripke frames. Fischer Servi's two interaction conditions relating the intuitionistic pre-order (or partial-order) with the modal accessibility relation generalise to the requirement that the relation and its inverse be lower semi-continuous with respect to the topology. We then investigate the notion of topological bisimulation relations between topological Kripke frames, as introduced by Aiello and van Benthem, and show that their topology-preserving conditions are equivalent to the properties that the inverse-relation and the relation are lower semi-continuous with respect to the topologies on the two models. Our first main result is that this notion of topological bisimulation yields semantic preservation w.r.t. topological Kripke models for both intuitionistic tense logics, and for their classical companion multi-modal logics in the setting of the Gödel translation. After giving canonical topological Kripke models for the Hilbert-style axiomatizations of the Fischer Servi logic and its classical multi-modal companion logic, we show that the syntactic Gödel translation induces a natural semantic map from the intuitionistic canonical model into the canonical model of the classical companion logic, and this map is itself a topological bisimulation.
Reinforcement Learning in Nonstationary Environment Navigation Tasks
Authors: Terran Lane, Martin Ridens, Scott Stevens
Venue: Proceedings of the 20th conference of the Canadian Society for Computational Studies of Intelligence on Advances in Artificial Intelligence (2007)

The field of reinforcement learning (RL) has achieved great strides in learning control knowledge from closed-loop interaction with environments. "Classical" RL, based on atomic state space representations, suffers from an inability to adapt to nonstationarities in the target Markov decision process (i.e., environment). Relational RL is widely seen as being a potential solution to this shortcoming. In this paper, we demonstrate a class of "pseudo-relational" learning methods for nonstationary navigational RL domains --- domains in which the location of the goal, or even the structure of the environment, can change over time. Our approach is closely related to deictic representations, which have previously been found to be troublesome for RL. The key insight of this paper is that navigational problems are a highly constrained class of MDP, possessing a strong native topology that relaxes some of the partial observability difficulties arising from deixis. Agents can employ local information that is relevant to their near-term action choices to act effectively. We demonstrate that, unlike an atomic representation, our agents can learn to fluidly adapt to changing goal locations and environment structure.
Patterns and traceability in teaching software architecture
Authors: Holger Gast
Venue: Proceedings of the 6th international symposium on Principles and practice of programming in Java (2008)

Courses on software architecture and software engineering need to explain the role of non-functional properties in software design, and they often use student projects to highlight their interrelations. Despite its critical importance in software development, the property of traceability has so far been mostly neglected. This paper examines the role of traceability for teaching software architecture and describes the objectives and structure of two consecutive courses given by the author at the University of T&uuml;bingen. The courses build on architectural patterns as blueprints for achieving particular non-functional properties. The vehicle for improving traceability is a sequence of small-scale projects, each of which includes the phases of requirements analysis, design, and implementation. This iterative approach allows students to learn from their experiences and to integrate the feedback on their solutions into the next project.
Fast Drug Scheduling Optimization Approach for Cancer Chemotherapy
Authors: Yong Liang, Kwong-Sak Leung, Tony Shu Mok
Venue: Proceedings of the 7th international conference on Computational Science, Part IV: ICCS 2007 (2007)

In this paper, we propose a novel fast evolutionary algorithm -- cycle-wise genetic algorithm (CWGA) based on the theoretical analyses of a drug scheduling mathematical model for cancer chemotherapy. CWGA is more efficient than other existing algorithms to solve the drug scheduling optimization problem. Moreover, its simulation results match well with the clinical treatment experience, and can provide much more drug scheduling policies for a doctor to choose depending on the particular conditions of the patients. CWGA also can be widely used to solve other kinds of the real dynamic systems.
Algebraic theory of minimal nondeterministic finite automata with applications
Authors: Geoffrey Smith
Venue:  (2007)

Since the 1950s, the theory of deterministic and nondeterministic finite automata (DFAs and NFAs, respectively) has been a cornerstone of theoretical computer science. In this dissertation, our main object of study is minimal NFAs. In contrast with minimal DFAs, minimal NFAs are computationally challenging: first, there can be more than one minimal NFA recognizing a given language; second, the problem of converting an NFA to a minimal equivalent NFA is NP-hard, even for NFAs over a unary alphabet. Our study is based on the development of two main theories, inductive bases and partials, which in combination form the foundation for an incremental algorithm, ibas, to find minimal NFAs. An inductive basis is a collection of languages with the property that it can generate (through union) each of the left quotients of its elements. We prove a fundamental characterization theorem which says that a language can be recognized by an n-state NFA if and only if it can be generated by an n-element inductive basis. A partial is an incompletely-specified language. We say that an NFA recognizes a partial if its language extends the partial, meaning that the NFA&rsquo;s behavior is unconstrained on unspecified strings; it follows that a minimal NFA for a partial is also minimal for its language. We therefore direct our attention to minimal NFAs recognizing a given partial. Combining inductive bases and partials, we generalize our characterization theorem, showing that a partial can be recognized by an n-state NFA if and only if it can be generated by an n-element partial inductive basis. We apply our theory to develop and implement ibas, an incremental algorithm that finds minimal partial inductive bases generating a given partial. In the case of unary languages, ibas can often find minimal NFAs of up to 10 states in about an hour of computing time; with brute-force search this would require many trillions of years.
Virus Evolution Strategy for Vehicle Routing Problems with Time Windows
Authors: Hitoshi Kanoh, Souichi Tsukahara
Venue: Proceedings of the 10th international conference on Parallel Problem Solving from Nature: PPSN X (2008)

This paper proposes a new solution to the vehicle routing problem with time windows using an evolution strategy adopting viral infection. The problem belongs to the NP-hard class and is very difficult to solve within practical time limits using systematic optimization techniques. In conventional evolution strategies, a schema with a high degree-of-fitness produced in the process of evolution may not be inherited when the fitness of the individual containing the schema is low. The proposed method preserves the schema as a virus and uses it by the infection operation in successive generations. Experimental results using extended Solomon's benchmark problems with 1000 customers proved that the proposed method is superior to conventional methods in both its rates of searches and the probability of obtaining solutions.
Suboptimal Nonlinear Predictive Control Based on Neural Wiener Models
Authors: Maciej Ławryńczuk
Venue: Proceedings of the 13th international conference on Artificial Intelligence: Methodology, Systems, and Applications (2008)

This paper is concerned with a computationally efficient (suboptimal) nonlinear Model Predictive Control (MPC) algorithm based on neural Wiener models. The model contains a linear dynamic part in series with a steady-state nonlinear part which is realised by a neural network. The model is linearised on-line, as a result the nonlinear MPC algorithm needs solving a quadratic programming problem. The algorithm gives control performance similar to that obtained in nonlinear MPC, which hinges on non-convex optimisation. In order to demonstrate accuracy and computational efficiency of the considered MPC algorithm, a polymerisation reactor is studied.
Optimal capacitor placement for electric distribution systems
Authors: Ching-Tzong Su, Ji-Jen Wong, Cheng-Yi Lin
Venue: Proceedings of the 10th WSEAS International Conference on Automatic Control, Modelling & Simulation (2008)

This paper proposes a study of reactive power compensation for electric distribution systems to find out the optimal capacitive compensation location and size for reducing power loss and improving bus voltage profile. The most commonly used reactive power sources for compensation in distribution systems are capacitor banks. A new method-evolutionary simulated annealing, with evolution strategies embedded in the simulation annealing, is employed to solve a 36-bus distribution system composed of radial-type and loop-type circuits, to search for the optimal capacitor placement solutions.
Diagnosis of structural integrity using the nonlinear vibration technique
Authors: Leopa Adrian
Venue: Proceedings of the 9th WSEAS International Conference on Acoustics & Music: Theory & Applications (2008)

This paper refers to a study based on theoretical and experimental data regarding the impact of the vibration came from technological equipment functioning with intensive and various activities, environmental propagated (human and building). The aim of the presented work was to investigate the possibility of using hangs in the non-linear vibration characteristics to detect damage in mechanical structure. The nonlinearities were detected by examining the changes in time and frequency response, during period of time.
A Comprehensive Approach for Situation-Awareness Based on Sensing and Reasoning about Context
Authors: Thomas Springer, Patrick Wustmann, Iris Braun, Waltenegus Dargie, Michael Berger
Venue: Proceedings of the 5th international conference on Ubiquitous Intelligence and Computing (2008)

Research in Ubiquitous Computing and Ambience Intelligence aims at creating systems able to interact in an intelligent way with the environment, especially the user. To be aware of and to react on the current situation usually a complex set of features describing particular aspects of the environmental state has to be captured and processed. Currently, no standard mechanisms are available to model and reason about complex situations. In this paper, we describe a comprehensive approach for situation-awareness which covers the whole process of context capturing, context abstraction and decision making. Our solution comprises an ontology-based description of the sensing and reasoning environment, the management of sensing devices and reasoning components and the integration of these components into applications for decision making. These technological components are embedded into an conceptual architecture and generic framework which enable an easy and flexible development of situation-aware systems. We illustrate the use of our approach based on a meeting room scenario.
Bridging UMTS and multicast routing in ns-2
Authors: Antonios Alexiou, Christos Bouras, Andreas Papazois
Venue: Proceedings of the 1st international conference on Simulation tools and techniques for communications, networks and systems & workshops (2008)

In this paper, we present the design and the implementation of a novel scheme for the multicast transmission of data over Universal Mobile Telecommunications System (UMTS) networks. The proposed scheme is implemented as an ns-2 network simulator module which can be employed to investigate various aspects of UMTS multicast. Apart from the normal multicast transmission over UMTS, we consider the handling of exceptional cases induced by user mobility scenarios. The proposed scheme is in accordance with the current specifications of the Multimedia Multicast/Broadcast Service (MBMS) defined by the 3rd Generation Partnership Project (3GPP) and introduces minor modifications in the UMTS architecture and the mobility management mechanisms. The performance of the proposed scheme is validated and analyzed through simulation experiments. Finally, the simulation results are presented along with their analysis.
Distributed, Play-Based Coordination for Robot Teams in Dynamic Environments
Authors: Colin Mcmillen, Manuela Veloso
Venue: RoboCup 2006: Robot Soccer World Cup X (2006)

We present refinements to our previous work on team communication and multi-robot world modeling in the RoboCup legged league. These refinements put high priority on the communication of task-relevant data. We also build upon past results within the simulation and the small-size leagues and contribute a distributed, play-based role assignment algorithm. This algorithm allows the robots to autonomously adapt their strategy based on the current state of the environment, the game, and the behavior of opponents. The improvements discussed in this paper were used by CMDash in the RoboCup 2005 international competition.
Evaluating the performance of DCOP algorithms in a real world, dynamic problem
Authors: Robert Junges, Ana L. C. Bazzan
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 2 (2008)

Complete algorithms have been proposed to solve problems modelled as distributed constraint optimization (DCOP). However, there are only few attempts to address real world scenarios using this formalism, mainly because of the complexity associated with those algorithms. In the present work we compare three complete algorithms for DCOP, aiming at studying how they perform in complex and dynamic scenarios of increasing sizes. In order to assess their performance we measure not only standard quantities such as number of cycles to arrive to a solution, size and quantity of exchanged messages, but also computing time and quality of the solution which is related to the particular domain we use. This study can shed light in the issues of how the algorithms perform when applied to problems other than those reported in the literature (graph coloring, meeting scheduling, and distributed sensor network).
Virtual Humans: From Researcher's Fascination to Mass-Market Technology
Authors: Igor S. Pandzic
Venue: Proceedings of the 12th international conference on Knowledge-Based Intelligent Information and Engineering Systems, Part I (2008)

The talk will give a snapshot of virtual humans research and their applications. The fundamental driving force of scientific progress is the researchers' fascination and deep passion for their research topic. In few fields is this so obvious as in virtual humans: what can be more fascinating than trying to reproduce the image of ourselves - walking, talking, communicating, intelligent human-like beings. It is therefore no wonder that efforts in this direction have been going on since decades. So what do we have to show after all this work? In terms of graphics and animation, some of today's virtual characters are quite amazing. However, high levels of expressivity and naturalness require huge amounts of manual work, so fully autonomous real-time characters lag far behind such creations. When it comes to perception, most of today's virtual humans are blind (i.e. computer vision or other sensors are used only in a small number of systems), hard of hearing (i.e. speech recognition is unreliable) and the other senses are barely explored, if at all. While natural language processing, dialog systems and theory of mind have all made progress, it is fair to say that cognitive and conversational capabilities of intelligent virtual agents are nowhere near those of real people. All things considered, while huge progress has been made, there is a tremendous amount of work still in front of us on the road to truly interactive and believable virtual humans. At the same time, we have reached the stage of development where numerous applications for virtual people are springing up. In parallel with the research work, we are witnessing an increased entrepreneurial activity in this field in the recent years. Beyond movies and games, virtual humans are appearing as tutors, advisors, receptionists, personal avatars or companions in a whole array of application fields including health care, finance, retail, communications, entertainment and others.
Using Image Stimuli to Drive fMRI Analysis
Authors: David R. Hardoon, Janaina Mourão-Miranda, Michael Brammer, John Shawe-Taylor
Venue: Neural Information Processing: 14th International Conference, ICONIP 2007, Kitakyushu, Japan, November 13-16, 2007, Revised Selected Papers, Part I (2007)

We introduce a new unsupervised fMRI analysis method based on Kernel Canonical Correlation Analysis which differs from the class of supervised learning methods that are increasingly being employed in fMRI data analysis. Whereas SVM associates properties of the imaging data with simple specific categorical labels, KCCA replaces these simple labels with a label vector for each stimulus containing details of the features of that stimulus. We have compared KCCA and SVM analyses of an fMRI data set involving responses to emotionally salient stimuli. This involved first training the algorithm ( SVM, KCCA) on a subset of fMRI data and the corresponding labels/label vectors, then testing the algorithms on data withheld from the original training phase. The classification accuracies of SVM and KCCA proved to be very similar. However, the most important result arising from this study is that KCCA in able in part to extract many of the brain regions that SVM identifies as the most important in task discrimination blind to the categorical task labels.
An experimental study of different approaches to solve the market equilibrium problem
Authors: Bruno Codenotti, Benton Mccune, Sriram Pemmaraju, Rajiv Raman, Kasturi Varadarajan
Venue: Journal of Experimental Algorithmics (JEA) (2008)

Over the last few years, the problem of computing market equilibrium prices for exchange economies has received much attention in the theoretical computer science community. Such activity led to a flurry of polynomial time algorithms for various restricted, yet significant, settings. The most important restrictions arise either when the traders' utility functions satisfy a property known as gross substitutability or when the initial endowments are proportional (the Fisher model). In this paper, we experimentally compare the performance of some of these recent algorithms against that of the most used software packages. In particular, we evaluate the following approaches: (1) the solver PATH, available under GAMS/MPSGE, a popular tool for computing market equilibrium prices; (2) a discrete version of a simple iterative price update scheme called t&acirc;tonnement; (3) a discrete version of the welfare adjustment process; (4) convex feasibility programs that characterize the equilibrium in some special cases. We analyze the performance of these approaches on models of exchange economies where the consumers are equipped with utility functions, which are widely used in real world applications. The outcomes of our experiments consistently show that many market settings allow for an efficient computation of the equilibrium, well beyond the restrictions under which the theory provides polynomial time guarantees. For some of the approaches, we also identify models where they are are prone to failure.