ppxscal/embedding_network huggingface dataset:
The Synthesis of Three-Degree-of-Freedom Planar Parallel Mechanisms with Revolute Joints (3-ṞRR) for an Optimal Singularity-Free Workspace
Authors: Marc Arsenault, Roger Boudreau
Venue: Journal of Robotic Systems (2004)

In this paper, a method is presented for the synthesis of 3-<und>R</und>RR planar parallel mechanisms. The method uses a genetic algorithm while considering three different design criteria: the optimization of the mechanism workspace to approach a prescribed workspace, the maximization of the mechanism's dexterity, and the avoidance of singularities inside the mechanism workspace. It is shown that, for a given mechanism, some working modes do not have any corresponding singularity curves located inside the mechanism workspace. Furthermore, a case is presented where, for a given orientation range of the mechanism's end-effector, there are no parallel singularities located inside the workspace. Finally, two methods are described and compared to deal with the nonuniform units of the mechanism's Jacobian matrix during the dexterity computation. &copy; 2004 Wiley Periodicals, Inc.
Efficient implementations of the randomization method with control of the relative error
Authors: Victor Suñé, Juan A. Carrasco
Venue: Computers and Operations Research (2005)

Randomization is a well-known numerical method for the transient analysis of continuous-time Markov chains. The main advantages of the method are numerical stability, well-controlled computation error and ability to specify the computation error in advance. Typical implementations of the method control the truncation error in absolute value, which is not completely satisfactory in some cases. Based on a theoretical result regarding the dependence on the parameter of the Poisson distribution of the relative error introduced when a weighted sum of Poisson probabilities is truncated by the right, in this paper we develop efficient and numerically stable implementations of the randomization method for the computation of two measures on rewarded continuous-time Markov chains with control of the relative error. The numerical stability of those implementations is analyzed using a small example. We also discuss the computational efficiency of the implementations with respect to simpler alternatives.
Fast and Scalable Parallel Matrix Computations on Distributed Memory Systems
Authors: Keqin Li
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

We present fast and scalable parallel computations for a number of important and fundamental matrix problems on distributed memory systems (DMS). These problems include computing the powers, the inverse, the characteristic polynomial, the determinant, the rank, the Krylov matrix, and an LU- and a QR-factorization of a matrix, and solving linear systems of equations. These parallel computations are based on efficient implementations of the fastest sequential matrix multiplication algorithm on DMS. We show that compared with the best known time complexities on PRAM, our parallel matrix computations achieve the same speeds on distributed memory parallel computers (DMPC), and have an extra polylog factor in the time complexities on DMS with hypercubic networks. Furthermore, our parallel matrix computations are fully scalable on DMPC and highly scalable over a wide range of system size on DMS with hypercubic networks. Such fast and scalable parallel matrix computations were not seen before on any distributed memory systems.
Spherical blend skinning: a real-time deformation of articulated models
Authors: Ladislav Kavan, Jiří Žára
Venue: Proceedings of the 2005 symposium on Interactive 3D graphics and games (2005)

Skin deformation based on an underlying skeleton is a common method to animate believable organic models. The most widely used skeletal animation algorithm, linear blend skinning, is also known as skeleton subspace deformation, vertex blending, or enveloping. It runs in real-time even on a low-end hardware but it is also notorious for its failures, such as the collapsing-joints artifacts. We present a new algorithm which removes these shortcomings while maintaining almost the same time and memory complexity as the linear blend skinning. Unlike other approaches, our method works with exactly the same input data as the popular linear version. This minimizes the cost of upgrade from linear to spherical blend skinning in many existing applications: the data structures and models need no change at all. The paper discusses also theoretical properties of rotation interpolation, essential to spherical blend skinning.
Regularizing functions in many-period production optimization models
Authors: Yu. M. Tsodikov, Ya. Yu. Tsodikova
Venue: Automation and Remote Control (2005)

A linear dynamic model for many-period production optimization is designed by linear programming methods. For a large-dimensional model, piecewise-linear regularizing functions are introduced through qualitative information on stocks and flows. An example is given to show the effectiveness of the method for many-period optimization of the operation of a refinery.
Robust Video Communication Based on Source Modeling and Network Congestion Control
Authors: Song Xiao, Chengke Wu, Jechang Jeong
Venue: Proceedings of the 19th International Conference on Advanced Information Networking and Applications - Volume 1 (2005)

A new method combining source channel coding with source modeling and network congestion control for reliable video transmission over wireless network is proposed in this paper. Based on scene modeling and characteristic analyzing, all layers generated by scalable coding are classified into several types and two queuing are made respectively according to their contribution to network congestion and to the quality of reconstructed video. Then the source rate, protection level and congestion control strategy are dynamically adjusted according to different error status in which the packet loss is caused by network congestion or by unreliable transmission in wireless channel. The simulation results show that our proposed approach can achieve better results than MPEG-4 video source coding with fix rate Turbo coding and than the one which dynamically adjusting source coding and channel coding rates only.
A Meshing Scheme for Efficient Hardware Implementation of Butterfly Subdivision Using Displacement Mapping
Authors: Margarita Amor, Montserrat Boo, Wolfgang Strasser, Johannes Hirche, Michael Doggett
Venue: IEEE Computer Graphics and Applications (2005)

A common bottleneck for high performance graphics systems is the transfer of millions of triangles from the CPU to the graphics pipeline. Displacement mapping is an effective technique for encoding high levels of detail of surface models through the utilization of coarse triangle meshes together with displacement maps. This technique can be employed to reduce the communication requirements between the CPU and the graphics pipeline. In this article we present a new adaptive subdivision scheme in which the curvature of the mesh together with the displacement map information is considered. We also present a hardware architecture for the implementation of this proposal. This hardware is an addition to the standard pipeline in order to achieve a displacement map rendering pipeline. The hardware architecture proposal is regular, with an efficient structure that minimizes data storage and avoids the wait cycles that would be associated with the multiple data accesses required per subdivision. With this method, high quality images are obtained with low communication requirements as only the coarse mesh has to be sent. Moreover, the proposed data management permits reemployment of the information in such a way that each triangle has to be sent only once from the CPU to the graphics pipeline.
Extended regular ternary logic functions and majority functions capable of synthesizing any ternary logic function
Authors: Yoshinori Yamamoto
Venue: Systems and Computers in Japan (2004)

Multiple-valued logic functions using only AND, OR, and NOT as operators are called Kleenean functions. They were actively studied in Japan beginning in the early 1990s. Previously, regular ternary logic functions corresponding to the ambiguous state in which the truth value 1&sol;2 is neither 0 nor 1 were defined in ternary logic; but regular ternary logic functions are equivalent to ternary Kleenean functions. Regular ternary logic functions represent only a small fraction of all ternary logic functions, and only a part of the ternary logic functions can be synthesized. In this paper we define regular ternary logic functions of the zeroth to third kinds by introducing the cyclical operation. We then define majority functions of the zeroth to third kinds, which are a subset of the extended regular ternary logic functions, and show that any ternary logic function can be synthesized by means of these three majority functions. Finally, using a genetic algorithm as the base algorithm, we present a technique for synthesizing any ternary logic function by means of extended ternary majority elements, and give illustrative examples. &copy; 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 35(1): 79&ndash;90, 2004; Published online in Wiley InterScience (). DOI 10.1002&sol;scj.10226
Detecting Overflow Detection
Authors: Vladimir Kotlyar, Mayan Moudgill
Venue: Proceedings of the international conference on Hardware/Software Codesign and System Synthesis: 2004 (2004)

Fixed-point saturating arithmetic is widely used in media and digital signal processing applications. A number of processor architectures provide instructions that implement saturating operations. However, standard high-level languages, such as ANSI C, provide no direct support for saturating arithmetic. Applications written in standard languages have to implement saturating operations in terms of basic twoýs complement operations. In order to provide fast execution of such programs it is important to have an optimizing compiler automatically detect and convert appropriate code fragments to hardware instructions. We present a set of techniques for automatic recognition of saturating arithmetic operations. We show that in most cases the recognition problem is simply one of Boolean circuit equivalence. Given the expense of solving circuit equivalence, we develop a set of practical approximations based on abstract interpretation. Experiments show that our techniques, while reliably recognizing saturating arithmetic, have small compile-time overhead. We also demonstrate that our approach is not limited to saturating arithmetic, but is directly applicable to recognizing other idioms, such as add-with-carry and absolute value.
A Practical Modelling Notation for Secure Distributed Computation
Authors: Yih-Jiun Lee, Peter Henderson
Venue: Proceedings of the 19th International Conference on Advanced Information Networking and Applications - Volume 2 (2005)

Mobile code computation has lead to a new paradigm of distributed computation. A mobile process can move from site to site and interact with the resources as a local process. To prevent the misuse resources, authentication and authorization need to be dealt with. Many modeling languages have been proposed to model distributed computation; Ambient Calculus [1] is one of them. Ambient Calculus, a type of process calculus, can be used to model boundary crossing activities in a mathematical notation. SJAN, a modeling language, extends the basic idea of Ambient Calculus, but it has a simple notation, design and representation. SJAN can be verified by J-Ambient, a JAVA implementation, to certify the correctness of the model. In this paper, we will introduce SJAN notation and J-Ambient. SJAN can be also used to model grid computation and provides the security consideration. Thus, finally, we will address several security scenarios in SJAN to show its functionality.
On the Possibility of Consensus in Asynchronous Systems with Finite Average Response Times
Authors: Christof Fetzer, Ulrich Schmid, Martin Susskraut
Venue: Proceedings of the 25th IEEE International Conference on Distributed Computing Systems (2005)

It has long been known that the consensus problem cannot be solved deterministically in completely asynchronous distributed systems, i.e., systems (1) without assumptions on communication delays and relative speed of processes and (2) without access to real-time clocks. In this paper1 wedefine a new asynchronous system model: Instead of assuming reliable channelswith finite transmission delays, we assume stubborn channels with a finite average response time (if neither the sender nor the receiver crashes), and we assume that there exists some unknown physical bound on how fast an integer can be incremented. Note that there is no limit on how slow a program can be executed or how fast other statements can be executed. Also, there exists no upper or lower bound on the transmission delay of messages or the relative speed of processes. The are no additional assumptions about clocks, failure detectors, etc. that would aid in solving consensus either. We show that consensus can nevertheless be solved deterministically in this asynchronous system model.
Catenation and specialization for Tcl virtual machine performance
Authors: Benjamin Vitale, Tarek S. Abdelrahman
Venue: Proceedings of the 2004 workshop on Interpreters, virtual machines and emulators (2004)

We present techniques for eliminating dispatch overhead in a virtual machine interpreter using a lightweight just-in-time native-code compilation. In the context of the Tcl VM, we convert bytecodes to native Sparc code, by concatenating the native instructions used by the VM to implement each bytecode instruction. We thus eliminate the dispatch loop. Furthermore, immediate arguments of bytecode instructions are substituted into the native code using runtime specialization. Native code output from the C compiler is not amenable to relocation by copying; fix-up of the code is required for correct execution. The dynamic instruction count improvement from eliding dispatch depends on the length in native instructions of each bytecode opcode implementation. These are relatively long in Tcl, but dispatch is still a significant overhead. However, their length also causes our technique to overflow the instruction cache. Furthermore, our native compilation consumes runtime. Some benchmarks run up to three times faster, but roughly half slow down, or exhibit little change.
Dynamic Discovery and Coordination of Agent-Based Semantic Web Services
Authors: Katia Sycara, Massimo Paolucci, Julien Soudry, Naveen Srinivasan
Venue: IEEE Internet Computing (2004)

Matchmaking and brokering are multiagent coordination mechanisms for Web services. Both have performance trade-offs, but the OWL ontology for semantic Web services (OWL-S) can handle extensions that address some of the shortcomings. In this article, the authors focus on the broker, which they analyze to explore its interaction protocol and the reasoning tasks it has to accomplish. The authors also describe OWL-S's exec extensions, detail their implementation's basic features, and explain how these features address the broker's reasoning problems.
A model of contextual effect on reproduced extents in recall tasks: the issue of the imputed motion hypothesis
Authors: Jean-Christophe Sarrazin, Arnaud Tonnelier, Frederic Alexandre
Venue: Biological Cybernetics (2005)

In this article the fundamental question of space and time dependencies in the reproduction of spatial or temporal extents is studied. The functional dependence of spatial responses on the temporal context and the corresponding dependence of temporal responses on spatial context are reported as the tau and kappa effects, respectively. A common explanation suggested that the participant imputes motion to discontinuous displays. Using a mathematical model we explore the imputed velocity hypothesis and provide a globally fit model that addresses the question of sequences modelling. Our model accounts for observed data in the tau experiment. The accuracy of the model is improved introducing a new hypothesis based on small velocity variations. On the other hand, results show that the imputed velocity hypothesis fails to reproduce the kappa effect. This result definitively shows that both effects are not symmetric.
Considering expected utility of future bidding options in bundle purchasing with multiple auctions
Authors: Scott Buffett
Venue: Proceedings of the 6th international conference on Electronic commerce (2004)

This paper presents an algorithm for decision-making in multiple open ascending-price (English) auctions where the buyer needs to procure a complete bundle of complementary products. When making bidding decisions, the utility of each choice is determined by considering the buyer's expected utility of future consequential decisions. The problem is modeled as a Markov decision process (MDP), and the value iteration method of dynamic programming is used to determine the value of bidding/not bidding in each state. To ease the computational burden, three state-reducing techniques are employed. When tested against adaptations of two methods from the literature, results show that the algorithm works significantly better when sufficient information on the progress of other concurrently running auctions will be available when future bidding decisions are made.
Multiscale simulations of copper electrodeposition onto a resistive substrate
Authors: Timothy O. Drews, Sriram Krishnan, Jay C. Alameda,  Jr., Dennis Gannon, Richard D. Braatz, Richard C. Alkire
Venue: IBM Journal of Research and Development (2005)

During the initial stages of copper electrodeposition onto a thin seed layer, a nonuniform potential distribution arises, resulting in local variations in growth rate and deposit morphology. Early stages of morphology evolution during copper electrodeposition are of practical importance but have not been well studied. Here, a new multiscale approach is developed for numerical simulation of the effect of a macroscopic potential distribution along a seed layer on microscopic local roughness evolution. The key contribution is a generic method for coupling multiple computer codes, and the demonstration of its use. The macroscopic code passes the local potential at ten points along the seed layer to ten kinetic Monte Carlo codes, each of which simulates additive-free copper electrodeposition and roughness evolution on an initially flat surface. Periodically, each Monte Carlo code computes the local film thickness and passes it back to the resistance code, which updates the potential distribution for the next iteration. Results are obtained for a wide range of parameter space including both constant-potential and constant-current operation. A confirmation procedure was developed to verify that the multiscale approach (using small Monte Carlo simulation domains with periodic boundary conditions) does not significantly alter the physical accuracy of the simulations.
Examining the masculinity and femininity of critical attributes necessary to succeed in IT
Authors: K. D. Joshi, Kristine Kuhn
Venue: Proceedings of the 2005 ACM SIGMIS CPR conference on Computer personnel research (2005)

Some research findings show that women are even more likely than men to leave the information technology (IT) field and gender segregation in the types of jobs held within the broad field of IT is marked, with women especially rare in the higher paid job categories. Therefore, this study examines whether the gender segregation and turnover of women in IT, in part, shaped by the perception that the desired characteristics of IT workers that are necessary to be successful in IT occupations fit men more so than women. Research is being conducted at two organizations: a large international consulting firm and a Fortune 500 information technology company, limited to IT employees and stakeholders in the Northwest. This study is being conducted in two phases. The first phase activities involve focus group sessions and interviews at the participating organizations. In the second phase, a web-based company-specific survey will be developed and administered to a large sample of employees and stakeholders in each organization.
An Ear-Decomposition Based Approach for Survivable Routing in WDM Networks
Authors: SingLing Lee, Jung-Chun Liu, YuChing Chen
Venue: Proceedings of the 19th International Conference on Advanced Information Networking and Applications - Volume 1 (2005)

In WDM-based network, a single fiber abortion may cause many logical lightpaths failures such that embedded logical topology of a WDM network may become disconnected. And a hung amount of data of a single link carried is lost by this link errors. For this reason, we propose anefficient survivable routing approach, which is based on the the technique of ear-decomposition, to create protected routing of the embedded logical topology that can withstand a physical link failure. Our approach divides the logical topology into several ears, and restricts the lightpaths of the same ear are routed by using disjoint physical links. To solve the survivable problem is NP-complete and we formulate the survivable routing problem as an ILP problem based on the results of ear decomposition. And our experiments has shown that the solution generated from our ILP achieves the following two results: (1) a high performance in terms of the survivable routing and (2) a better performance than previous research results for the balance of traffic loads.
Higher-Order Image Statistics for Unsupervised, Information-Theoretic, Adaptive, Image Filtering
Authors: Suyash P. Awate, Ross T. Whitaker
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 2 - Volume 02 (2005)

The restoration of images is an important and widely studied problem in computer vision and image processing. Various image filtering strategies have been effective, but invariably make strong assumptions about the properties of the signal and/or degradation. Therefore, these methods typically lack the generality to be easily applied to new applications or diverse image collections. This paper describes a novel unsupervised, information-theoretic, adaptive filter (UINTA) that improves the predictability of pixel intensities from their neighborhoods by decreasing the joint entropy between them. Thus UINTA automatically discovers the statistical properties of the signal and can thereby restore a wide spectrum of images and applications. This paper describes the formulation required to minimize the joint entropy measure, presents several important practical considerations in estimating image-region statistics, and then presents results on both real and synthetic data.