ppxscal/embedding_network huggingface dataset:
Performance Evaluation of MPI, UPC and OpenMP on Multicore Architectures
Authors: Damián A. Mallón, Guillermo L. Taboada, Carlos Teijeiro, Juan Touriño, Basilio B. Fraguela, Andrés Gómez, Ramón Doallo, J. Carlos Mouriño
Venue: Proceedings of the 16th European PVM/MPI Users' Group Meeting on Recent Advances in Parallel Virtual Machine and Message Passing Interface (2009)

The current trend to multicore architectures underscores the need of parallelism. While new languages and alternatives for supporting more efficiently these systems are proposed, MPI faces this new challenge. Therefore, up-to-date performance evaluations of current options for programming multicore systems are needed. This paper evaluates MPI performance against Unified Parallel C (UPC) and OpenMP on multicore architectures. From the analysis of the results, it can be concluded that MPI is generally the best choice on multicore systems with both shared and hybrid shared/distributed memory, as it takes the highest advantage of data locality, the key factor for performance in these systems. Regarding UPC, although it exploits efficiently the data layout in memory, it suffers from remote shared memory accesses, whereas OpenMP usually lacks efficient data locality support and is restricted to shared memory systems, which limits its scalability.
High-Availability Decentralized Multi-Agent Key Recovery System
Authors: Kanokwan Kanyamee, Chanboon Sathitwiriyawong
Venue: Proceedings of the 2009 Eigth IEEE/ACIS International Conference on Computer and Information Science (2009)

In symmetric cryptography, any two communicating parties share the secret session key. In case it is unavailable or legal investigation of transmitting messages is needed, there should be a mechanism to recover it. The recovery of session key is typically provided by trusted key recovery agents (KRAs). They will recover the session key after receiving the request from those who have the right to use the key. Key recovery can be achieved by either single agent (S-KRA) or multiple agents (M-KRA). M-KRA enhances the security of S-KRA by reducing any risk of falsification and counterfeiting. This paper proposed a high-availability decentralized multi-agent key recovery system without the need of key recovery center (KRC), called HADM-KRS. The proposed method uses simple and flexible principles of secure session key management with appropriated design of key recovery function and the new format of key recovery field (KRF). The system has high availability, ability to detect attacks on group authentication, and can recover session key despite the failure of some KRAs, without the need of KRC. Therefore, the problem of single point of failure of KRC can be avoided. System administrators also have flexibility to manage and choose the number of KRAs to meet security requirements. The system also supports law enforcement and is based on security mechanism using well defined features of Public Key Infrastructure (PKI).
Design Pattern Integration Method for Improving Performance of EJB and Its Applications
Authors: Chen Liyan, Tan Long, An Yi
Venue: Proceedings of the 2009 International Conference on Environmental Science and Information Application Technology - Volume 03 (2009)

This paper analyzes the bottleneck of EJB system performance, proposes an idea of optimizing EJB design pattern to improve the performance, and then give a layered and integrated optimization method based on mixed design patterns. Accordingly, the performance of the application was improved and the system has better flexibility and maintainability. Experiments show the improvement of performance at last.
Onboard Learning of Adaptive Behavior: Biologically Inspired and Formal Methods
Authors: Terry Huntsberger
Venue: Proceedings of the 2009 Advanced Technologies for Enhanced Quality of Life (2009)

Long lifetime autonomous ground vehicles traveling in rough terrain will need a higher level of autonomy with behaviors that must also adapt to declining vehicle health and unknown environmental conditions. For example, the MER (Mars Exploration Rovers) Spirit and Opportunity have both passed 1900 days of life on the Martian surface, with possible extensions to 2200 days and beyond depending on rover health. Changes in navigational planning due to degradation of the drive motors as they pass their lifetime are currently done on Earth for the Spirit rover. This paper reviews biologically inspired and formal methods of adaptive control and presents an algorithm for onboard learning of navigation strategies using adaptive weight learning within a free flow hierarchy (FFH) behavior framework. We also present the results of some field studies. 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
New Linear Cryptanalytic Results of Reduced-Round of CAST-128 and CAST-256
Authors: Meiqin Wang, Xiaoyun Wang, Changhui Hu
Venue: Selected Areas in Cryptography: 15th International Workshop, SAC 2008, Sackville, New Brunswick, Canada, August 14-15, Revised Selected Papers (2009)

This paper presents a linear cryptanalysis for reduced round variants of CAST-128 and CAST-256 block ciphers. Compared with the linear relation of round function with the bias 2¿ 17 by J. Nakahara et al., we found the more heavily biased linear approximations for 3 round functions and the highest one is 2¿ 12.91. We can mount the known-plaintext attack on 6-round CAST-128 and the ciphertext-only attack on 4-round CAST-128. Moreover the known-plaintext attack on 24-round CAST-256 with key size 192 and 256 bits has been given, and the ciphertext-only attack on 21-round CAST-256 with key size 192 and 256 bits can be performed. At the same time, we also present the attack on 18-round CAST-256 with key size 128 bits.
Introduction
Authors: Dejan Kostić, Guillaume Pierre, Flavio Junqueira, Peter R. Pietzuch
Venue: Proceedings of the 15th International Euro-Par Conference on Parallel Processing (2009)

In total, fifteen papers were submitted to Topic 8 (including those that were redirected from other Topics), and each paper received four reviews. Five papers were discussed in depth between the chairs. Ultimately, the chairs proposed three papers for acceptance at the PC meeting. The accepted papers tackle a variety of systems and algorithmic problems, with none of the papers tackling some of the "classic" distributed computing topics (e.g., consensus). This was not done as a conscious decision by the chairs; rather, the papers were accepted solely based on quality.
Is presence a technology issue? Some insights from cognitive sciences
Authors: Giuseppe Riva
Venue: Virtual Reality (2009)

The International Society of Presence Research, defines &#x201c;presence&#x201d; (a shortened version of the term &#x201c;telepresence&#x201d;) as a &#x201c;psychological state in which even though part or all of an individual&#x2019;s current experience is generated by and/or filtered through human-made technology, part or all of the individual&#x2019;s perception fails to accurately acknowledge the role of the technology in the experience&#x201d; (ISPR 2000, The concept of presence: explication statement. http://ispr.info/ Accessed 15 Jan 2009). In this article, we will draw on the recent outcomes of cognitive sciences to offer a broader definition of presence, not related to technology only. Specifically, presence is described here as a core neuropsychological phenomenon whose goal is to produce a sense of agency and control: subjects are &#x201c;present&#x201d; if they are able to enact in an external world their intentions. This framework suggests that any environment, virtual or real, does not provide undifferentiated information, ready-made objects equal for everyone. It offers different opportunities and produces presence according to its ability in supporting the users and their intentions. The possible consequences of this approach for the development of presence-inducing virtual environments are also discussed.
The learning context: Influence on learning to program
Authors: Irene Govender
Venue: Computers Education (2009)

In this paper the influence of the learning context is considered when learning to program. For the purposes of this study, the lectures, study process, previous knowledge or teaching experience and tests comprised the learning context. The article argues that students' experiences of the learning context have important implications for teaching and learning. Therefore, the solutions that most students work towards in order to solve a problem are an indication of an essential aspect: the learning context. The study attempts to understand the influence that the learning context has on pre- and in-service teachers learning to program. The participants who took a course in Java programming were asked to keep a journal, which indicated their reflections throughout the course. These reflections together with interview transcripts of some participants were used in the analysis. The instructors of the course were also part of this qualitative study. Activity theory was used as a basis for the analysis. It was found that both the problem and the learning context have a profound effect on students' understanding and performance.
An Agent-Based Simulation Model for Occupant Evacuation under Fire Conditions
Authors: Saili Yi, Jianyong Shi
Venue: Proceedings of the 2009 WRI Global Congress on Intelligent Systems - Volume 01 (2009)

In this paper, an agent-based simulation model is presented to simulate occupant evacuation in fire environment. Based on the agent technology, a computer program is developed to simulate and analyze the egress progress in large public buildings. Through simulation, the occupant behaviors and fire safety performance of different architecture plans can be investigated and analyzed in case of emergency. A CFD (Computational Fluid Dynamics) model is integrated into the model to simulate fire scenarios. By coupling with the fire scenario simulated by CFD technology, the computer simulation program may represent the overall and dynamic process of occupants’ evacuation under fire expansion, and the mutual relationship between occupants’ safety and fire hazard. A case study was presented to indicate that the model can be applied to evaluate the fire safety and evacuation efficiency of large public buildings.
An Improved Approximation Bound for Spanning Star Forest and Color Saving
Authors: Stavros Athanassopoulos, Ioannis Caragiannis, Christos Kaklamanis, Maria Kyropoulou
Venue: Proceedings of the 34th International Symposium on Mathematical Foundations of Computer Science 2009 (2009)

We present a simple algorithm for the maximum spanning star forest problem. We take advantage of the fact that the problem is a special case of complementary set cover and we adapt an algorithm of Duh and Fürer in order to solve it. We prove that this algorithm computes 193/240 ≈ 0.804-approximate spanning star forests; this result improves a previous lower bound of 0.71 by Chen et al. Although the algorithm is purely combinatorial, our analysis defines a linear program that uses a parameter f and which is feasible for values of the parameter f not smaller than the approximation ratio of the algorithm. The analysis is tight and, interestingly, it also applies to complementary versions of set cover such as color saving; it yields the same approximation guarantee of 193/240 that marginally improves the previously known upper bound of Duh and Fürer. We also show that, in general, a natural class of local search algorithms do not provide better than 1/2-approximate spanning star forests.
Parameterized Complexity Classes under Logical Reductions
Authors: Anuj Dawar, Yuguo He
Venue: Proceedings of the 34th International Symposium on Mathematical Foundations of Computer Science 2009 (2009)

The parameterized complexity classes of the W-hierarchy are usually defined as the problems reducible to certain natural complete problems by means of fixed-parameter tractable (fpt) reductions. We investigate whether the classes can be characterised by means of weaker, logical reductions. We show that each class W[t] has complete problems under slicewise bounded-variable first-order reductions. These are a natural weakening of slicewise bounded-variable LFP reductions which, by a result of Flum and Grohe, are known to be equivalent to fpt-reductions. If we relax the restriction on having a bounded number of variables, we obtain reductions that are too strong and, on the other hand, if we consider slicewise quantifier-free first-order reductions, they are considerably weaker. These last two results are established by considering the characterisation of W[t] as the closure of a class of Fagin-definability problems under fpt-reductions. We show that replacing these by slicewise first-order reductions yields a hierarchy that collapses, while allowing only quantifier-free first-order reductions yields a hierarchy that is provably strict.
VLSI Architecture for Fast Memetic Vector Quantizer Design on Reconfigurable Hardware
Authors: Sheng-Kai Weng, Chien-Min Ou, Wen-Jyi Hwang
Venue: Proceedings of the 9th International Conference on Algorithms and Architectures for Parallel Processing (2009)

A novel hardware architecture for memetic vector quantizer (VQ) design is presented in this paper. The architecture uses steady-state genetic algorithm (GA) for global search, and C-means algorithm for local refinement. It adopts a shift register based circuit for accelerating mutation and crossover operations for steady state GA operations. It also uses a pipeline architecture for the hardware implementation of C-means algorithm. The proposed architecture has been embedded in a softcore CPU for physical performance measurement. Experimental results show that the proposed architecture is an effective alternative for VQ optimization attaining both high performance and low computational time.
Consistency Checking for LSC Specifications
Authors: Hai-Feng Guo, Wen Zheng, Mahadevan Subramaniam
Venue: Proceedings of the 2009 Third IEEE International Symposium on Theoretical Aspects of Software Engineering (2009)

Live sequence charts (LSCs) have been proposed as an inter-object scenario-based specification and visual programming language. In this paper, we introduce a high level computational semantics of LSCs, in the form of a PLAY-tree, to show how a running LSC affects the system behaviors in response to a set of external events. Given a nonempty regular language of external events,the consistency of an LSC specification is defined as whether there exists a corresponding PLAY-tree with all success branches; in case of inconsistency, failure traces can be obtained through failure branches of the PLAY-tree. We also present an algorithm using a memoized depth-first search strategy and an implementation framework in logic programming for consistency checking of LSCs.
Assessment for Attending and Responding Stages of Affective Teaching Goal in Distance Learning Based on Fuzzy Fusion
Authors: Kuo-An Hwang, Chia-Hao Yang, Chuan-Ren Wang
Venue: Proceedings of the 2009 International Forum on Information Technology and Applications - Volume 03 (2009)

Distance learning is a learning style that can overcome the limitation of time and space. Because of the distance, teachers can not assess the achievement of Affective Domain teaching goal. If teachers can know the student's affective state through the learning system, they can overcome the difficult. The research applies the image recognition technologies to capture the face images of students and analyzes their participation in discussion to evaluate the student's affective state by Fuzzy Integral. Finally, teachers can assess the student's achievement in Affective Domain teaching goal.
Analysis of Steady Thermal Stress in a ZrO2/FGM/Ti-6Al-4V Composite ECBF Plate with Temperature-Dependent Material Properties by NFEM
Authors: Yangjian Xu, Daihui Tu
Venue: Proceedings of the 2009 WASE International Conference on Information Engineering - Volume 02 (2009)

A NFE model is constructed to analyze the heating steady thermal stress in a ZrO2/FGM/Ti-6Al-4V composite ECBF plate considered temperature dependency. From numerical calculation, when T0=300K Ta=670 and Tb=1 070K, the stress distributions in the plate were obtained. The results are as follows. The change of the FGM layer thickness is little effect on the stress in metal layer. Compared with M=0.1, when M=10, the stress difference on the ceramic surface is 133.9MPa, and the tensile stress at the interface between FGM and ceramic layers reduces by 52.3%. Compared with A=3.99, when A=0, the tensile stress on the ceramic surface reduces by 96.2%. When T0=300K, Ta=700K, compared with Tb=1 800K, when Tb=1 050K, the tensile stress in the plate reduces by 84.1%, and the maximum stress difference on the surface of ceramics is 1610.8MPa. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of ZrO2/FGM/Ti-6Al-4V composite ECBF plate is very gentle and smooth. The stress in graded three-layered composite plate considered temperature dependency becomes small obviously, and the maximum tensile stress on the metal surface reduces by 30.1%, and the maximum compressive stress on the ceramic surface reduces by 9.49%. The results provide the foundations of theoretical calculation for the design and application of the composite plate.
Lexical Markup Framework (LMF) for NLP multilingual resources
Authors: Gil Francopoulo, Nuria Bel, Monte George, Nicoletta Calzolari, Monica Monachini, Mandy Pet, Claudia Soria
Venue: Proceedings of the Workshop on Multilingual Language Resources and Interoperability (2006)

Optimizing the production, maintenance and extension of lexical resources is one the crucial aspects impacting Natural Language Processing (NLP). A second aspect involves optimizing the process leading to their integration in applications. With this respect, we believe that the production of a consensual specification on multilingual lexicons can be a useful aid for the various NLP actors. Within ISO, one purpose of LMF (ISO-24613) is to define a standard for lexicons that covers multilingual data.
The Weighted Coupon Collector's Problem and Applications
Authors: Petra Berenbrink, Thomas Sauerwald
Venue: Proceedings of the 15th Annual International Conference on Computing and Combinatorics (2009)

In the classical coupon collector's problem n coupons are given. In every step one of the n coupons is drawn uniformly at random (with replacement) and the goal is to obtain a copy of all the coupons. It is a well-known fact that in expectation $n \sum_{k=1}^n 1/k \approx n \ln n$ steps are needed to obtain all coupons.In this paper we show two results. First we revisit the weighted coupon collector case where in each step every coupon i is drawn with probability p i . Let p = (p 1,..., p n ). In this setting exact but complicated bounds are known for ${\mathbf{E}}[{ \mathcal{C} ({\mathbf{p}})] }$, which is the expected time to obtain all n coupons. Here we suggest the following rather simple way to approximate ${\mathbf{E}}[{ \mathcal{C} ({\mathbf{p}})] }$. Assume p 1 ≤ p 2 ≤ ¿ ≤ p n and take $\sum_{i=1}^n 1/(i p_i)$ as an approximation. We prove that, rather unexpectedly, this expression approximates $\operatorname{\mathbf{E}}\left[ \mathcal{C} ({\mathbf{p}}) \right]$ by a factor of ¿(loglogn). We also present an extension that achieves an approximation factor of ${\mathcal{O}}(\log \log \log n)$.In the second part of the paper we derive some combinatorial properties of the coupon collecting processes. We apply these properties to show results for the following simple randomized broadcast algorithm. A graph G is given and one node is initially informed. In each round, every informed node chooses a random neighbor and informs it. We restrict G to the class of trees and we show that the expected broadcast time is maximized if and only if G is the star graph. Besides being the first rigorous extremal result, our finding nicely contrasts with a previous result by Brightwell and Winkler [2] showing that for the star graph the cover time of a random walk is minimized among all trees.
Gem #63: the effect of pragma suppress
Authors: Gary Dismukes
Venue: ACM SIGAda Ada Letters (2009)

The features of Ada have generally been designed to prevent violating the properties of data types, enforced either by compile-time rules or, in the case of dynamic properties, by using run-time checks. Ada allows run-time checks to be suppressed, but not with the intent of allowing programmers to subvert the type system.
The present use of statistics in the evaluation of NLP parsers
Authors: J. Entwisle, D. M. W. Powers
Venue: Proceedings of the Joint Conferences on New Methods in Language Processing and Computational Natural Language Learning (1998)

We are concerned that the quality of results produced by an NLP parser bears little, if any, relation to the percentage-results claimed by the various NLP parser-systems presently available for use. To illustrate this problem, we examine one readily available NLP tagging and parsing system, the ENGCG parser; and one tagger, the Brill tagger. We note responses to both artificially generated and naturally occurring text. The percentage assessments are methodologically flawed, and should be taken with a grain of salt; instead, assessment of the performance of an NLP parser should be effected by a user, and solely from a consideration of the resulting parses of exactly the input which an NLP user decides to contribute for such an assessment. Careful attention to input of whatever corpus the user decides on, is presently the only suitable qualifying test of parsing ability. The parsers available are none of them perfectible yet, despite apparent yields now quoted at 99%+. We consider the impact of Zipf's argument of 'least effort' on percentage assessment; and we open a discussion on estimating the relative complexities of corpora.
Understanding Users in Context: An In-Depth Introduction to Fieldwork for User Centered Design
Authors: Susan M. Dray, David A. Siegel
Venue: Proceedings of the 12th IFIP TC 13 International Conference on Human-Computer Interaction: Part II (2009)

There is increased awareness of the need for design to be driven by deep understanding of users, their activity patterns, processes, needs and external influences---understanding that can only be gained by studying user behavior in the user's context. This requires understanding of how to plan and carry out observational studies of users, which is a new skill for many. In addition, fieldwork is bigger than any one methodology. Therefore, in this tutorial, we will take a fresh and deeper look at fundamental principles, teach a range of techniques, and examine important issues on which methods differ.
Answering the question you wish they had asked: the impact of paraphrasing for question answering
Authors: Pablo Ariel Duboue, Jennifer Chu-Carroll
Venue: Proceedings of the Human Language Technology Conference of the NAACL, Companion Volume: Short Papers on XX (2006)

State-of-the-art Question Answering (QA) systems are very sensitive to variations in the phrasing of an information need. Finding the preferred language for such a need is a valuable task. We investigate that claim by adopting a simple MT-based paraphrasing technique and evaluating QA system performance on paraphrased questions. We found a potential increase of 35% in MRR with respect to the original question.