ppxscal/embedding_network huggingface dataset:
Programming mobile intelligent agents: An operational semantics
Authors: A. Suna, A. El Fallah Seghrouchni
Venue: Web Intelligence and Agent Systems (2007)

This paper presents the operational semantics of an agent-oriented programming language called CLAIM. CLAIM allows to design multi-agent systems that support both stationary and mobile agents, endowed with cognitive capabilities and able to communicate. The semantics takes into account agents' reasoning, mobility, communication and concurrence, and contains a set of reduction rules between coherent states of a program. The operational semantics is a first step towards the formal verification of agent-based programs written in CLAIM. The reduction rules are illustrated on a case study.
Efficiently inverting bijections given by straight line programs
Authors: C. Sturtivant
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

Let K be any field, and let F: K/sup n/ to K/sup n/ be a bijection with the property that both F and F/sup -1/ are computable using only arithmetic operations from K. Motivated by cryptographic considerations, the authors concern themselves with the relationship between the arithmetic complexity of F and the arithmetic complexity of F/sup -1/. They give strong relations between the complexity of F and F/sup -1/ when F is an automorphism in the sense of algebraic geometry (i.e. a formal bijection defined by n polynomials in n variables with a formal inverse of the same form). These constitute all such bijections in the case in which K is infinite. The authors show that at polynomially bounded degree, if an automorphism F has a polynomial-size arithmetic circuit, then F/sup -1/ has a polynomial-size arithmetic circuit. Furthermore, this result is uniform in the sense that there is an efficient algorithm for finding such a circuit for F/sup -1/, given such a circuit for F. This algorithm can also be used to check whether a circuit defines an automorphism F. If K is the Boolean field GF(2), then a circuit defining a bijection does not necessarily define an automorphism. However, it is shown in this case that, given any K/sup n/ to K/sup n/ bijection, there always exists an automorphism defining that bijection. This is not generally true for an arbitrary finite field.
Design of low-power short-distance opto-electronic transceiver front-ends with scalable supply voltages and frequencies
Authors: Xuning Chen, Gu-Yeon Wei, Li-Shiuan Peh
Venue: Proceeding of the 13th international symposium on Low power electronics and design (2008)

The need for low-power I/Os is widely recognized, as I/Os take up a significant portion of total chip power. In recent years, researchers have pointed to the potential system-level power savings that can be realized if dynamic voltage scalable I/Os are available. However, substantial challenges remain in building such links. This paper presents the design and implementation details of opto-electronic transceiver front-end blocks where supply voltage can scale from 1.2V to 0.6V with almost linearly scalable bandwidth from 8Gb/s to 4Gb/s, and power consumption from 36mW to 5mW in a 130nm CMOS process. To the best of our knowledge, this is the first circuit demonstration of voltage-scalable optical links. It demonstrates the feasibility of dynamic voltage scalable optical I/Os.
Analysis-adjustment-synthesis networks
Authors: I-Cheng Yeh
Venue: Connection Science (2007)

This paper presents a novel neural network architecture, analysis-adjustment-synthesis network (AASN), and tests its efficiency and accuracy in modelling non-linear function and classification. The AASN is a composite of three sub-networks: analysis sub-network; adjustment sub-network; and synthesis sub-network. The analysis sub-network is a one-layered network that spreads the input values into a layer of 'spread input neurons'. This synthesis sub-network is a one-layered network that spreads the output values back into a layer of 'spread output neurons'. The adjustment sub-network, between the analysis sub-network and the synthesis sub-network, is a standard multi-layered network that operates as the learning mechanism. After training the adjustment sub-network in recalling phase, the synthesis sub-network receives the output values of spread output neurons and synthesizes them into output values with a weighted-average computation. The weights in the weighted-average computation are deduced from the method of Lagrange multipliers. The approach is tested using four function mapping problems and one classification problem. The results show that combining the analysis sub-network and the synthesis sub-network with a multi-layered network can significantly improve a network's efficiency and accuracy.
HMD calibration and its effects on distance judgments
Authors: Scott A. Kuhl, William B. Thompson, Sarah H. Creem-Regehr
Venue: Proceedings of the 5th symposium on Applied perception in graphics and visualization (2008)

Most head-mounted displays (HMDs) suffer from substantial optical distortion, and vendor-supplied specifications for field-of-view often are at variance with reality. Such displays do not present perspective-related visual cues in a geometrically correct manner, which has the potential to affect applications of HMDs which depend on precise spatial perception. This paper provides empirical evidence for the degree to which these resulting distortions affect one type of spatial judgment in virtual environments. We show that minification in the HMD that would occur from an overstated HMD field of view results in a significant change in distance judgments. Incorrectly calibrated pitch and pincushion distortion, however, did not cause statistically significant changes in distance judgments for the degree of distortions examined. While the means for determining the optical distortion of display systems are well known, they are often not used in non-see-through HMDs due to problems in measuring and correcting for distortion. As a result, we also provide practical guidelines for creating geometrically calibrated systems.
Experimental and numerical characterization of a membrane material for orthotropic steel deck bridges: Part 2
Authors: X. Liu, T. O. Medani, A. Scarpas, M. Huurman, A. A. A. Molenaar
Venue: Finite Elements in Analysis and Design (2008)

Preliminary analyses have shown that membrane materials, connecting mastic asphalt surfacings to plates of orthotropic steel deck bridges, play an extremely important role in determining the structural response of these types of bridges. This necessitates search for a realistic representation of the behaviour of membrane materials. For this purpose, an extensive experimental program was carried out, and a nonlinear constitutive model was developed to describe the behaviour of membrane materials. This is the second part of two papers on characterization of the behaviour of a bituminous-based membrane material in an orthotropic steel deck bridge. In this paper, the details of the constitutive model will be discussed. Furthermore, an unconditionally stable, implicit Euler backward algorithm for the integration of the constitutive equations will be presented in details. Comparisons of model predictions and laboratory measurements at different temperatures, deformation rates and confining stresses are presented. Some numerical examples, in which various aspects of the finite elements response of a 3D orthotropic steel deck bridge subjected to stationary and moving loads, are presented. The importance of the damage distribution on the membrane material is demonstrated as well as the role of other influencing factors, such as loading speed and temperature.
Complex Price Dynamics in a Financial Market with Imitation
Authors: Ilaria Foroni, Anna Agliari
Venue: Computational Economics (2008)

In this work a simple financial model with fundamentalists and imitators is being considered. In order to describe the price dynamics of the heterogeneous stock market, a synergetic approach is used and some global bifurcations arising in the model are being studied. It is shown that the fundamental equilibrium point P* may be destabilized through a subcritical Neimark---Sacker bifurcation and that two invariant closed curves, one attracting and one repelling, appear when P* is still stable. This particular bifurcation scenario allows us to show some noticeable features of the market that emerge when the imitation effect is emphasized. Among these features are, for instance, the volatility clusters associated with the presence of multistability (i.e. coexistence of attractors) and the hysteresis phenomenon.
Angle-based space partitioning for efficient parallel skyline computation
Authors: Akrivi Vlachou, Christos Doulkeridis, Yannis Kotidis
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Recently, skyline queries have attracted much attention in the database research community. Space partitioning techniques, such as recursive division of the data space, have been used for skyline query processing in centralized, parallel and distributed settings. Unfortunately, such grid-based partitioning is not suitable in the case of a parallel skyline query, where allpartitions are examined at the same time, since many data partitions do not contribute to the overall skyline set, resulting in a lot of redundant processing. In this paper we propose a novel angle-based space partitioning scheme using the hyperspherical coordinates of the data points. We demonstrate both formally as well as through an exhaustive set of experiments that this new scheme is very suitable for skyline query processing in a parallel share-nothing architecture. The intuition of our partitioning technique is that the skyline points are equally spread to all partitions. We also show that partitioning the data according to the hyperspherical coordinates manages to increase the average pruning power of points within a partition. Our novel partitioning scheme alleviates most of the problems of traditional grid partitioning techniques, thus managing to reduce the response time and share the computational workload more fairly. As demonstrated by our experimental study, our technique outperforms grid partitioning in all cases, thus becoming an efficient and scalable solution for skyline query processing in parallel environments.
History Based Adaptive Backoff (HBAB) IEEE 802.11 MAC Protocol
Authors: Qassim Nasir, Maali Albalt
Venue: Proceedings of the Communication Networks and Services Research Conference (2008)

A Mobile Ad Hoc Network (MANET) is a collection of mobile nodes interconnected by wireless media. Several protocols have been proposed to manage multiple access to the shared wireless medium in MANETs, with the IEEE 802.11 being the most implemented protocol. In this work, a History-Based Adaptive Backoff (HBAB) MAC Protocol is proposed to provide a better QoS performance. HBAB modifies the original IEEE 802.11 Binary Exponential Backoff (BEB) algorithm (which is used to control the contention window in the case of collisions) to reflect the network status and condition. Inspired by the adaptive delta modulation scheme that is used in communications, HBAB considers the history of past trials for transmission. Simulations show a significant improvement in performance measures (around 15% in packet delivery fraction and up to 50% in average packet delay) with using HBAB compared to the original backoff algorithm of IEEE 802.11.
On the computational complexity and effectiveness of N-hub shortest-path routing
Authors: Reuven Cohen, Gabi Nakibly
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

In this paper, we study the computational complexity and effectiveness of a concept we term "N-hub Shortest-Path Routing" in IP networks. N-hub Shortest-Path Routing allows the ingress node of a routing domain to determine up to N intermediate nodes ("hubs") through which a packet will pass before reaching its final destination. This facilitates better utilization of the network resources, while allowing the network routers to continue to employ the simple and well-known shortest-path routing paradigm. Although this concept has been proposed in the past, this paper is the first to investigate it in depth. We apply N-hub Shortest-Path Routing to the problem of minimizing the maximum load in the network. We show that the resulting routing problem is NP-complete and hard to approximate. However, we propose efficient algorithms for solving it both in the online and the offline contexts. Our results show that N-hub Shortest-Path Routing can increase network utilization significantly even for N = 1. Hence, this routing paradigm should be considered as a powerful mechanism for future datagram routing in the Internet.
Distributed Databases in Dynamic R-Tree for Vehicle Information Systems
Authors: Yusuke Murase, Ailixier Aikebaier, Tomoya Enokido, Makoto Takizawa
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

Information and communication systems for vehicles aregetting significant like ETC (Electronic Toll Collection) andcar navigation systems. In the next generation navigationsystems, each vehicle can not only receive various types ofinformation like maps and traffic but also obtain traffic informationaround the vehicle by using the sensors and sendthem to a navigation center. It is critical to discuss howto store information collected by vehicles in databases andhow vehicles access the information in the database in thepresence of a huge number of vehicles on roads. In thispaper, we propose an enhanced dynamic R-tree (EDR-tree)scheme to store and retrieve traffic data collected by vehiclesin dynamic distributed database systems. In distributedtree-structured indexes like R-tree and B-tree, the root nodeand nodes at upper layers easily get performance bottleneckand points of failure since every query request is transferredfrom root to leaf node. In this paper, we propose a new treestructuredscheme named EDR-tree to store data. A road isrealized as a sequence of road units. A geographical spaceof roads is separated into area units where road units arestored. An area unit is stored in a leaf node and there isa tree-structured index on the leaf nodes like B+-tree andR-tree. Each vehicle first makes an access to a leaf node,not the root, which has information of a road unit where thevehicle is currently moving. Then, a query request is efficientlyand reliably delivered to a target node by using notonly parent-child links but also enhancing links, sibling andadjacent links. We evaluate the EDR-tree in terms of searchtime and insertion time.
Real-time editing and relighting of homogeneous translucent materials
Authors: Rui Wang-erb, Ewen Cheslack-Postava, Rui Wang, David Luebke, Qianyong Chen, Wei Hua, Qunsheng Peng, Hujun Bao
Venue: The Visual Computer: International Journal of Computer Graphics (2008)

Existing techniques for fast, high-quality rendering of translucent materials often fix BSSRDF parameters at precomputation time. We present a novel method for accurate rendering and relighting of translucent materials that also enables real-time editing and manipulation of homogeneous diffuse BSSRDFs. We first apply PCA analysis on diffuse multiple scattering to derive a compact basis set, consisting of only twelve 1D functions. We discovered that this small basis set is accurate enough to approximate a general diffuse scattering profile. For each basis, we then precompute light transport data representing the translucent transfer from a set of local illumination samples to each rendered vertex. This local transfer model allows our system to integrate a variety of lighting models in a single framework, including environment lighting, local area lights, and point lights. To reduce the PRT data size, we compress both the illumination and spatial dimensions using efficient nonlinear wavelets. To edit material properties in real-time, a user-defined diffuse BSSRDF is dynamically projected onto our precomputed basis set, and is then multiplied with the translucent transfer information on the fly. Using our system, we demonstrate realistic, real-time translucent material editing and relighting effects under a variety of complex, dynamic lighting scenarios.
Approaches of quality outputs from the business systems
Authors: Karel Naiman, Hana Kopackova, Stanislava Simonova, Renata Bilkova
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

An information system can be described as a set of interrelated information technologies that work together to process, store, retrieve, collect, and distribute information. Information systems reside at various levels and within almost all functional areas within an organization. Users of business system are both common end users and top-level decision makers. Quality of outputs is based on the reporting tools as well as on the abilities of people to understand them and work with them. Strong and powerful way how to present the data without high level user knowledge is discussed.
LearnPADS: automatic tool generation from ad hoc data
Authors: Kathleen Fisher, David Walker, Kenny Q. Zhu
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

In this demonstration, we will present LEARNPADS, a fully automatic system for generating ad hoc data processing tools. When presented with a collection of ad hoc data, the system (1) analyzes the data, (2) infers a PADS [4, 5] description, (3) generates parser, printer, validation and traversal libraries and (4) links these libraries with format-independent tool suites to form stand-alone applications. These applications provide statistical analysis, XML conversion, CSV conversion, the ability to query with the Galax XQuery engine [3], and the ability to graph selected data elements, all directly from ASCII ad hoc data without human intervention. SIGMOD attendees will see both the user experience with LEARNPADS and the internals of the multi-phase inference algorithm which lies at the heart of the system.
CandidTree: visualizing structural uncertainty in similar hierarchies
Authors: Bongshin Lee, George G. Robertson, Mary Czerwinski, Cynthia Sims Parr
Venue: Information Visualization (2007)

Most visualization systems fail to convey uncertainty within data. To provide a way to show uncertainty in similar hierarchies, we interpreted the differences between two tree structures as uncertainty. We developed a new interactive visualization system called CandidTree that merges two trees into one and visualizes two types of structural uncertainty: location and sub-tree structure uncertainty. Since CandidTree can visualize the differences between two tree structures, we conducted a series of user studies with tree-comparison tasks. First a usability study was conducted to identify major usability issues and evaluate how our system works. Another qualitative user study was conducted to see if biologists, who regularly work with hierarchically organized names, are able to use CandidTree, and to assess the 'uncertainty' metric we used. A controlled experiment with software engineers was conducted to compare CandidTree with WinDiff, a traditional files and folders comparison tool. The results showed that users performed better with CandidTree. Furthermore, CandidTree received better satisfaction ratings and all users preferred CandidTree to WinDiff.
Proceedings of the 2007 workshop on Massive datasets
Venue: International Conference on Multimodal Interfaces (2007)

This workshop was intended to encourage work and discussion on the topic of analysis, visualization, and manipulation of long-term data sets recorded from large-scale sensor networks. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Interactive global illumination based on coherent surface shadow maps
Authors: Tobias Ritschel, Thorsten Grosch, Jan Kautz, Hans-Peter Seidel
Venue: Proceedings of graphics interface 2008 (2008)

Interactive rendering of global illumination effects is a challenging problem. While precomputed radiance transfer (PRT) is able to render such effects in real time the geometry is generally assumed static. This work proposes to replace the precomputed lighting response used in PRT by precomputed depth. Precomputing depth has the same cost as precomputing visibility, but allows visibility tests for moving objects at runtime using simple shadow mapping. For this purpose, a compression scheme for a high number of coherent surface shadow maps (CSSMs) covering the entire scene surface is developed. CSSMs allow visibility tests between all surface points against all points in the scene. We demonstrate the effectiveness of CSSM-based visibility using a novel combination of the lightcuts algorithm and hierarchical radiosity, which can be efficiently implemented on the GPU. We demonstrate interactive n-bounce diffuse global illumination, with a final glossy bounce and many high frequency effects: general BRDFs, texture and normal maps, and local or distant lighting of arbitrary shape and distribution -- all evaluated per-pixel. Furthermore, all parameters can vary freely over time -- the only requirement is rigid geometry.
Integrated genetic algorithm and goal programming for network topology design problem with multiple objectives and multiple criteria
Authors: Chen-Shu Wang, Ching-Ter Chang
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

Network topology design (NTD) with multiple objectives has been presented by many researchers. However, no work in the literature has addressed this issue with both multiple objectives and multiple criteria. In order to suit real-world situations, this paper presents a new idea integrating genetic algorithm and goal programming to establish a model for solving the NTD problem with multiple objectives and multiple criteria taken into consideration. In addition, the proposed model can also solve both construct and extend network topology problems under shared risk link group (SRLG) constraints. Finally, illustrative examples are included to demonstrate the superiority and usefulness of the proposed method.
Problem frames for intelligent building services: a suitability study
Authors: Milan Hlousek
Venue: Proceedings of the 3rd international workshop on Applications and advances of problem frames (2008)

In this paper, we explore suitability of the Problem Frames framework for intelligent building software requirements gathering. The research was conducted through a pilot application presented to intelligent building specialists, with a follow-up survey investigating views of the fitness of purpose of the framework to the task, and willingness to use it in the future.