ppxscal/embedding_network huggingface dataset:
Out-of-Core and Pipeline Techniques for Wavefront Algorithms
Authors: Eddy Caron, Frederic Desprez, Frederic Suter
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

Several numerical computation algorithms exhibit dependences that lead to a wavefront of the computation. Depending on the data distribution chosen, pipelining communication and computation can be the only way to avoid a sequential execution of the parallel code. The computation grain has to be wisely chosen to obtain at the same time a maximum parallelism and a small communication overhead. On the other hand, when the size of data exceeds the memory capacity of the target platform, data have to be stored on disk. The concept of out-of-core computation aims at minimizing the impact of the I/O needed to compute on such data. It has been applied successfully on several linear algebra applications. In this paper we apply out-of-core techniques to wavefront algorithms. The originality of our approach is to overlap computation, communication, and I/O. An original strategy is proposed using several memory blocks accessed in a cyclic way. The resulting pipeline algorithm achieves a saturation of the disk resource which is the bottleneck in out-of-core algorithms.
Audio-haptic feedback in mobile phones
Authors: Angela Chang, Conor O'Sullivan
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

A new breed of mobile phones has been designed to enable concurrent vibration and audio stimulation, or audio-haptics. This paper aims to share techniques for creating and optimizing audio-haptic effects to enhance the user interface.The authors present audio manipulation techniques specific to the multifunction transducer (MFT) technology. In particular two techniques, the Haptic Inheritance and Synthesis and Matching methods are discussed. These two methods of haptic media generation allow simple creation of vibration content, and also allow for compatibility with non-haptic mobile devices.The authors present preliminary results of an evaluation of 42 participants comparing audio-based haptic user interface (UI) feedback with audio-only feedback. The results show that users were receptive to audio-haptic UI feedback. The results also suggest that audio-haptics seems to enhance the perception of audio quality.
Designing interactivity for the specific context of designerly collaborations
Authors: Eli Blevis, Youn-Kyung Lim, Muzaffer Ozakca, Shweta Aneja
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

We report on one of several exploratory, formulative studies that we conducted to help inform the thoughtful use of mixed physical and digital interactivity in a wiki-based system targeted at design collaborations. This study had two parts, both involving bar-coded cards, a bar-code scanner, and a projector. One part emphasized a creative, synthesis-oriented design activity. The other part emphasized a decision-making design activity.We learned that our method of designing the physical cards and the variance in the types of information we included on the cards significantly affected the collaborative behaviors. We also learned that the extension of interactivity from the digital to the physical world and back again successfully scaffolded both creative and decision-making activities in our context, although with some very notable differences in interactive behaviors between the specific activities. This latter point notwithstanding, we learned that allowing high-resolution, small size physical cards to be arrayed and manipulated on a shared surface matters much more for the purposes of scaffolding the collaborative activities than the ability to scan and project large-size, low-resolution facsimiles of the same information, in specific contexts of collaborative story-creation and decision making.
Efficient and Safe Global Constraints for Handling Numerical Constraint Systems
Authors: Yahia Lebbah, Claude Michel, Michel Rueher, David Daney, Jean-Pierre Merlet
Venue: SIAM Journal on Numerical Analysis (2004)

Numerical constraint systems are often handled by branch and prune algorithms that combine splitting techniques, local consistencies, and interval methods. This paper first recalls the principles of {\tt Quad}, a global constraint that works on a tight and safe linear relaxation of quadratic subsystems of constraints. Then, it introduces a generalization of {\tt Quad} to polynomial constraint systems. It also introduces a method to get safe linear relaxations and shows how to compute safe bounds of the variables of the linear constraint system. Different linearization techniques are investigated to limit the number of generated constraints. {\tt QuadSolver}, a new branch and prune algorithm that combines {\tt Quad}, local consistencies, and interval methods, is introduced. {\tt QuadSolver} has been evaluated on a variety of benchmarks from kinematics, mechanics, and robotics. On these benchmarks, it outperforms classical interval methods as well as constraint satisfaction problem solvers and it compares well with state-of-the-art optimization solvers.
ZP+: correct Z-pass stencil shadows
Authors: Samuel Hornus, Jared Hoberock, Sylvain Lefebvre, John Hart
Venue: Proceedings of the 2005 symposium on Interactive 3D graphics and games (2005)

We present a novel algorithm for the rendering of hard shadows cast by a point light source. The well-known Z-pass method for rasterizing shadow volumes is not always correct. Our algorithm, which we call ZP+, elegantly corrects Z-pass defects. ZP+ takes advantage of triangle strips and the fast culling capabilities of graphics hardware not available to conventional robust methods like Z-fail. While Z-fail can be up to 80% slower than Z-pass, our new method ZP+ is typically less than 10% slower than Z-pass. Finally, we compare the three methods. When a scene is geometry-bound, ZP+ is always faster than Z-fail. We also explain why, in some situations, Z-pass (hence ZP+) is surprisingly slower than Z-fail on more recent graphics hardware.
Improving an Upper Bound on the Stability Number of a Graph
Authors: Carlos J. Luz
Venue: Journal of Global Optimization (2005)

In previous works an upper bound on the stability number of a graph based on quadratic programming was introduced and several of its properties were given. The graphs for which this bound is attained has been known as graphs with convex-QP stability number. This paper proposes a new upper bound on the stability number whose determination is also done by quadratic programming. It is proved that the new bound improves the above mentioned bound and several computational tests asserting its interest for large graphs are presented. In addition a necessary and sufficient condition for a graph to attain the new bound is proved. As a consequence a graph with convex-QP stability number also attains the new bound. On the other hand it is shown the existence of graphs attaining the new bound that do not belong to the class of graphs with convex-QP stability number. This allows to assert that the class of graphs with convex-QP stability number is strictly included in the class of graphs that attain the introduced bound. Some conclusions and lines for future work finalize the paper.
Compiler Support for Exploiting Coarse-Grained Pipelined Parallelism
Authors: Wei Du, Renato Ferreira, Gagan Agrawal
Venue: Proceedings of the 2003 ACM/IEEE conference on Supercomputing (2003)

The emergence of grid and a new class of data-driven applications is making a new form of parallelism desirable, which we refer to as coarse-grained pipelined parallelism. This paper reports on a compilation system developed to exploit this form of parallelism. We use a dialect of Java that exposes both pipelined and data parallelism to the compiler. Our compiler is responsible for selecting a set of candidate filter boundaries, determining the volume of communication required if a particular boundary is chosen, performing the decomposition, and generating code. We have developed a one-pass algorithm for determining the required communication between consecutive filters. We have developed a cost model for estimating the execution time for a given decomposition, and a dynamic programming algorithm for performing the decomposition. Detailed evaluation of our current compiler using four data-driven applications demonstrate the feasibility of our approach.
Exploiting UML dynamic object modeling for the visualization of C++ programs
Authors: Brian A. Malloy, James F. Power
Venue: Proceedings of the 2005 ACM symposium on Software visualization (2005)

In this paper we present an approach to modeling and visualizing the dynamic interactions among objects in a C++ application. We exploit UML diagrams to expressively visualize both the static and dynamic properties of the application. We make use of a class diagram and call graph of the application to select the parts of the application to be modeled, thereby reducing the number of objects and methods under consideration with a concomitant reduction in the cognitive burden on the user of our system. We use aspects to insert probes into the application to enable profiling of the interactions of objects and methods and we visualize these interactions by providing sequence and communication diagrams for the parts of the program under consideration. We complement our static selectors with dynamic selectors that enable the user to further filter objects and methods from the sequence and communication diagrams, further enhancing the cognitive economy of our system. A key feature of our approach is the provision for dynamic interaction with both the profiler and the application. Interaction with the profiler enables filtering of methods and objects. Interaction with the application enables the user to supply input to the application to provide direction and enhance comprehension or debugging.
SQL DOM: compile time checking of dynamic SQL statements
Authors: Russell A. McClure, Ingolf H. Krüger
Venue: Proceedings of the 27th international conference on Software engineering (2005)

Most object oriented applications that involve persistent data interact with a relational database. The most common interaction mechanism is a call level interface (CLI) such as ODBC or JDBC. While there are many advantages to using a CLI -- expressive power and performance being two of the most key -- there are also drawbacks. Applications communicate through a CLI by constructing strings that contain SQL statements. These SQL statements are only checked for correctness at runtime, tend to be fragile and are vulnerable to SQL injection attacks. To solve these and other problems, we present the SQL DOM: a set of classes that are strongly-typed to a database schema. Instead of string manipulation, these classes are used to generate SQL statements. We show how to extract the SQL DOM automatically from an existing database schema, demonstrate its applicability to solve the mentioned problems, and evaluate its performance.
Constructive role of noise in signal detection from parallel arrays of quantizers
Authors: David Rousseau, François Chapeau-Blondeau
Venue: Signal Processing (2005)

A noisy input signal is observed by means of a parallel array of one-bit threshold quantizers, in which all the quantizer outputs are added to produce the array output. This parsimonious signal representation is used to implement an optimal detection from the output of the array. Such conditions can be relevant for fast real-time processing in large-scale sensor networks. We demonstrate that, even for suprathreshold input signals, the presence of independent noises added to the thresholds in the array, can lead to a better performance in the optimal detection. We relate these results to the phenomenon of suprathreshold stochastic resonance, by which nonlinear transmission or processing of signals with arbitrary amplitude can be improved by added noises in arrays.
It's our job to care for SE
Authors: Michael Wing
Venue: ACM SIGSOFT Software Engineering Notes (2005)

I want software engineering to become a great and enduring profession. Alas, this topic is too large for one essay, so here I focus on the notion that "it is our job to care for SE." This can be restated as "we must be true to ourselves" or "success" comes from within" or "we are responsible for our own success." I believe that most of what I write here is obvious, but I believe it warrants a closer look and I want to say it clearly.
Roaming and service management in public wireless networks using an innovative policy management architecture
Authors: Idir Fodil, Guy Pujolle
Venue: International Journal of Network Management (2005)

Nowadays, public wireless local area networks (WLANs), commonly called hotspots, are being largely deployed by WISPs (Wireless Internet Service Providers) as a means of offering ubiquitous Internet access to their customers. Although a substantial number of solutions have been proposed to improve security, mobility and quality of service on the wireless area, access network management which is mandatory remains a very significant concern.This paper describes RSM-WISP, a new management architecture designed for WISPs to facilitate the implementation and management of the services they offer at the access side of the WLAN, and to manage roaming contracts between WISPs. Our architecture is based upon the policy-based management principles as introduced by the IETF, combined with more intelligence at the network edge. RSM-WISP adopts an architecture that is composed of two elements: a WISP management center (MC) that deploys policies and monitors all the WLANs, and a programmable access router (CPE) located in each WLAN. The CPE ensures service enforcement, service differentiation (access to different service levels) and guarantee, user access management, and dynamic WLAN adaptation according to the user's SLA (service level agreement). It also permits automatic service updates according to the user's requirements. Concerning roaming management, this is achieved on the CPE through multiple service provider support capabilities. This approach provides WISPs with a simple, flexible and scalable solution that allows easy service deployment and management at the access. This management architecture has been implemented, tested and validated on the 6WINDGate routers.
Recognizing and Modelling Non-Rigid Human Body Actions in Space-Time
Authors: Xin Lu, Shunichiro Oe
Venue: Proceedings of the Third International Conference on Image and Graphics (2004)

This paper presents a new method to recognize and restructure the human motions in space-time using the tracking information of human joints. A specific posture can be recognized in actual frame by finding the correspondence between actual frame and key frame. Within key frame prototype information has been extracted to represent defined posture (one step of action). By recognizing some personýs postures in order, it is possible to map body locations from the key frames to actual frames in long video sequence and confirm the posture-sequence (action). The proposed method is tolerant to substantial deformation between image and prototype and recognizes qualitatively similar joints moving traces that compose human action. The proposed method is achieved by using a KLT feature tracker approach to track joints in key frames and actual frames. Then, the factorized sampling method is applied to replace one tracker with tracker-set to enhance the joints tracking accuracy. The experiments results demonstrate that accuracy and efficiency of recognizing non-rigid human actions.
Progressive skyline computation in database systems
Authors: Dimitris Papadias, Yufei Tao, Greg Fu, Bernhard Seeger
Venue: ACM Transactions on Database Systems (TODS) (2005)

The skyline of a d-dimensional dataset contains the points that are not dominated by any other point on all dimensions. Skyline computation has recently received considerable attention in the database community, especially for progressive methods that can quickly return the initial results without reading the entire database. All the existing algorithms, however, have some serious shortcomings which limit their applicability in practice. In this article we develop branch-and-bound skyline (BBS), an algorithm based on nearest-neighbor search, which is I/O optimal, that is, it performs a single access only to those nodes that may contain skyline points. BBS is simple to implement and supports all types of progressive processing (e.g., user preferences, arbitrary dimensionality, etc). Furthermore, we propose several interesting variations of skyline computation, and show how BBS can be applied for their efficient processing.
A New Approach for High Performance Computing Systems with Various Checkpointing Schemes
Authors: Gyung-Leen Park, Hee Youn Yong
Venue: The Journal of Supercomputing (2005)

Roll-forward recovery schemes were proposed to enhance the performance of fault tolerant systems employing checkpointing approach. In the roll-forward schemes, multiple processors are used for simultaneous roll-forward and validation processing. This paper proposes the sample comparison approach along with the checkpointing, which further improves the performance by reducing the overhead imposed by the checkpointing. We also develop general analytical models for estimating the availability, which are applicable for any checkpointing scheme. Performance comparisons reveal that the availabilities of the checkpointing schemes with sample comparison are higher than those of the schemes without it, while the required checkpoint interval is larger.
Obol: integrating language and meaning in bio-ontologies: Conference Papers
Authors: Christopher J. Mungall
Venue: Comparative and Functional Genomics (2004)

Ontologies are intended to capture and formalize a domain of knowledge. The ontologies comprising the Open Biological Ontologies (OBO) project, which includes the Gene Ontology (GO), are formalizations of various domains of biological knowledge. Ontologies within OBO typically lack computable definitions that serve to differentiate a term from other similar terms. The computer is unable to determine the meaning of a term, which presents problems for tools such as automated reasoners. Reasoners can be of enormous benefit in managing a complex ontology. OBO term names frequently implicitly encode the kind of definitions that can be used by computational tools, such as automated reasoners. The definitions encoded in the names are not easily amenable to computation, because the names are ostensibly natural language phrases designed for human users. These names are highly regular in their grammar, and can thus be treated as valid sentences in some formal or computable language. With a description of the rules underlying this formal language, term names can be parsed to derive computable definitions, which can then be reasoned over. This paper describes the effort to elucidate that language, called Obol, and the attempts to reason over the resulting definitions. The current implementation finds unique non-trivial definitions for around half of the terms in the GO, and has been used to find 223 missing relationships, which have since been added to the ontology. Obol has utility as an ontology maintenance tool, and as a means of generating computable definitions for a whole ontology.The software is available under an open-source license from: . Supplementary material for this article can be found at: Copyright &copy; 2004 John Wiley & Sons, Ltd.
Panconnectivity, fault-tolerant hamiltonicity and hamiltonian-connectivity in alternating group graphs
Authors: Jou-Ming Chang, Jinn-Shyong Yang, Yue-Li Wang, Yuwen Cheng
Venue: Networks (2004)

Jwo et al. &lsqb;Networks 23 &lpar;1993&rpar; 315&ndash;326&rsqb; introduced the alternating group graph as an interconnection network topology for computing systems. They showed that the proposed structure has many advantages over n-cubes and star graphs. For example, all alternating group graphs are hamiltonian-connected &lpar;i.e., every pair of vertices in the graph are connected by a hamiltonian path&rpar; and pancyclic &lpar;i.e., the graph can embed cycles with arbitrary length with dilation 1&rpar;. In this article, we give a stronger result: all alternating group graphs are panconnected, that is, every two vertices x and y in the graph are connected by a path of length k for each k satisfying d&lpar;x, y&rpar; &le; k &le; &verbar;V&verbar; - 1, where d&lpar;x, y&rpar; denotes the distance between x and y, and &verbar;V&verbar; is the number of vertices in the graph. Moreover, we show that the r-dimensional alternating group graph AGr, r &ge; 4, is &lpar;r - 3&rpar;-vertex fault-tolerant Hamiltonian-connected and &lpar;r - 2&rpar;-vertex fault-tolerant hamiltonian. The latter result can be viewed as complementary to the recent work of Lo and Chen &lsqb;IEEE Trans. Parallel and Distributed Systems 12 &lpar;2001&rpar; 209&ndash;222&rsqb;, which studies the fault-tolerant hamiltonicity in faulty arrangement graphs. &copy; 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44&lpar;4&rpar;, 302&ndash;310 2004
Sampling design for weak signal detection in SIRP noise
Authors: Chao-Tang Yu
Venue: Signal Processing (2005)

In this paper, we present a sampling design for weak signal detection in additive spherically invariant random process (SIRP) noise. Our approach for the design of sampling schemes is based on the class of Ali-Silvey distance measures. A design objective function for this problem is developed. This objective function is maximized to obtain the sampling scheme for the detection problem under consideration. Two examples are presented to illustrate our sampling design. Numerical results show that our sampling design outperforms the uniform sampling. It is also numerically shown that the sampling design is insensitive to the statistics (the characteristic probability density function) of the SIRP noise samples.
A novel method to represent speech signals
Authors: Rafet Akdeniz, Siddik Yarman
Venue: Signal Processing (2005)

In this work, speech signals are modeled by means of the so-called pre-defined "signature functions". The pre-defined signature functions are generated using the statistical properties of the speech signals. It has been exhibited that, with a few basic signature functions, any speech signal can be generated within a tolerable error.
An integrated experimental environment for distributed systems and networks
Authors: Brian White, Jay Lepreau, Leigh Stoller, Robert Ricci, Shashi Guruprasad, Mac Newbold, Mike Hibler, Chad Barb, Abhijeet Joglekar
Venue: Proceedings of the 5th symposium on Operating systems design and implementationDue to copyright restrictions we are not able to make the PDFs for this conference available for downloading (2002)

Three experimental environments traditionally support network and distributed systems research: network emulators, network simulators, and live networks. The continued use of multiple approaches highlights both the value and inadequacy of each. Netbed, a descendant of Emulab, provides an experimentation facility that integrates these approaches, allowing researchers to configure and access networks composed of emulated, simulated, and wide-area nodes and links. Netbed's primary goals are ease of use, control, and realism, achieved through consistent use of virtualization and abstraction.By providing operating system-like services, such as resource allocation and scheduling, and by virtualizing heterogeneous resources, Netbed acts as a virtual machine for network experimentation. This paper presents Netbed's overall design and implementation and demonstrates its ability to improve experimental automation and efficiency. These, in turn, lead to new methods of experimentation, including automated parameter-space studies within emulation and straightforward comparisons of simulated, emulated, and wide-area scenarios.