ppxscal/embedding_network huggingface dataset:
Contention awareness and fault-tolerant scheduling for precedence constrained tasks in heterogeneous systems
Authors: Anne Benoit, Mourad Hakem, Yves Robert
Venue: Parallel Computing (2009)

Heterogeneous distributed systems are widely deployed for executing computationally intensive parallel applications with diverse computing needs. Such environments require effective scheduling strategies that take into account both algorithmic and architectural characteristics. Unfortunately, most of the scheduling algorithms developed for such systems rely on a simple platform model where communication contention is not taken into account. In addition, it is generally assumed that processors are completely safe. To schedule precedence graphs in a more realistic framework, we introduce first an efficient fault-tolerant scheduling algorithm that is both contention-aware and capable of supporting an arbitrary number of fail-silent (fail-stop) processor failures. Next, we derive a more complex heuristic that departs from the main principle of the first algorithm. Instead of considering a single task (one with highest priority) and assigning all its replicas to the currently best available resources, we consider a chunk of ready tasks, and assign all their replicas in the same decision making procedure. This leads to a better load balance of processors and communication links. We focus on a bi-criteria approach, where we aim at minimizing the total execution time, or latency, given a fixed number of failures supported in the system. Our algorithms have a low time complexity, and drastically reduce the number of additional communications induced by the replication mechanism. Experimental results fully demonstrate the usefulness of the proposed algorithms, which lead to efficient execution schemes while guaranteeing a prescribed level of fault-tolerance.
The design of an asynchronous web-based project review system to support studio-based learning in computing education
Authors: Anukrati Agrawal, Christopher D. Hundhausen
Venue: Proceedings of the 2008 IEEE Symposium on Visual Languages and Human-Centric Computing (2008)

Learning computer science is no longer simply a matter of learning computer programming. Indeed, modern day computing jobs demand design, communication and collaborative skills as well. In order to address this need and make computing education more engaging, motivating, and community-oriented, we have been exploring a “studio based” approach in which students (a) construct computational solutions to problems that have many possible solution strategies, and then (b) present their solutions to their peers and instructors for feedback and discussion. In the fall of 2007, we implemented this approach in a pre-CS1course by requiring students to present their solutions to five course programming projects in face-to-face review sessions. Interview and observational data collected in this course pointed out several practical and logistical problems surrounding the face-to-face review sessions that diminished their educational effectiveness. To address these problems, we describe the preliminary design of a novel asynchronous web-based project review system to support and augment face-to-face studio-based review sessions.
AudiCom: A Video Analysis System for Auditing Commercial Broadcasts
Authors: Juan Maria Sanchez, Xavier Binefa
Venue: Proceedings of the 1999 IEEE International Conference on Multimedia Computing and Systems - Volume 02 (1999)

Commercials are very important in nowadays' TV broadcasts. Many enterprises invest large amounts of money in TV publicity and governments dictate pertinent regulations to preserve consumer's rights. AudiCom is a system that detects the broadcast of previously learned commercials and collects some interesting information about them. It is based on a new scene break detection operator that relies on the colors around the edges of the frames, and on the compaction of the information contained in the different shots that constitute the commercials. This compaction is obtained using principal component analysis (PCA) of the color histogram of a representative frame of every shot.
Compiler-assisted dynamic scheduling for effective parallelization of loop nests on multicore processors
Authors: Muthu Manikandan Baskaran, Nagavijayalakshmi Vydyanathan, Uday Kumar Reddy Bondhugula, J. Ramanujam, Atanas Rountev, P. Sadayappan
Venue: Proceedings of the 14th ACM SIGPLAN symposium on Principles and practice of parallel programming (2009)

Recent advances in polyhedral compilation technology have made it feasible to automatically transform affine sequential loop nests for tiled parallel execution on multi-core processors. However, for multi-statement input programs with statements of different dimensionalities, such as Cholesky or LU decomposition, the parallel tiled code generated by existing automatic parallelization approaches may suffer from significant load imbalance, resulting in poor scalability on multi-core systems. In this paper, we develop a completely automatic parallelization approach for transforming input affine sequential codes into efficient parallel codes that can be executed on a multi-core system in a load-balanced manner. In our approach, we employ a compile-time technique that enables dynamic extraction of inter-tile dependences at run-time, and dynamic scheduling of the parallel tiles on the processor cores for improved scalable execution. Our approach obviates the need for programmer intervention and re-writing of existing algorithms for efficient parallel execution on multi-cores. We demonstrate the usefulness of our approach through comparisons using linear algebra computations: LU and Cholesky decomposition.
Finding a Simple Polytope from Its Graph in&#x00a0;Polynomial Time
Authors: Eric J. Friedman
Venue: Discrete Computational Geometry (2009)

We show that one can compute the combinatorial facets of a simple polytope from its graph in polynomial time. Our proof relies on a primal-dual characterization (by Joswig, Kaibel, and K&#x00f6;rner in Israel J. Math. 129:109&#x2013;118, 2002) and a linear program, with an exponential number of constraints, which can be used to construct the solution and can be solved in polynomial time. We show that this allows one to characterize the face lattice of the polytope, via a simple face recognition algorithm. In addition, we use this linear program to construct several interesting polynomial-time computable sets of graphs which may be of independent interest.
Towards a Universal Friendly P2P Media Streaming Application: An Evaluation Framework
Authors: Zhijia Chen, Hao Yin, Chuang Lin, Fenlin Wu, Xuening Liu
Venue: Proceedings of the 9th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (2008)

Network-oblivious P2P applications have produced high cross-ISP traffics and led to serious disruption to ISP economics. While end users are concerned with quality, Internet Content Provider (ICP) cares more about service scale and ISP focuses on operating cost. Thus this paper provides a framework of evaluating the P2P streaming application performance from perspectives of all entities involved, i.e ISP, ICP and end users. Based on the analytical study, we propose potential solutions to define unprecedented friendly and cost-effective P2P streaming application to achieve the ideal philosophy of "More Users =Better performance + Lower cost".
Fast problem-size-independent parallel prefix circuits
Authors: Yen-Chun Lin, Li-Ling Hung
Venue: Journal of Parallel and Distributed Computing (2009)

A family of parallel algorithms solving the prefix problem on the combinational circuit model is presented. These prefix circuits are waist-size optimal with waist 1 (WSO-1). They are not only building blocks for constructing fast depth-size optimal prefix circuits, but also themselves fast problem-size-independent prefix circuits. When the problem size is greater than the circuit width, the presented prefix circuits may very much faster than any other prefix circuits of the same width, especially when the problem size is greater than or equal to twice the circuit width. The new prefix circuits are compared analytically with other representative prefix circuits to show how fast they are. They have the minimum depth and are the fastest among all WSO-1 prefix circuits of the same width and fan-out. Thus, they are better building blocks than other WSO-1 circuits for constructing fast depth-size optimal prefix circuits with the same fan-out.
A Modified Adaptive Algorithm for Formant Bandwidth in Whisper Conversion
Authors: Gang Lv, Heming Zhao
Venue: Proceedings of the 2009 International Asia Conference on Informatics in Control, Automation and Robotics (2009)

The whisper conversion technology is to transform undistinguished whispers with lower SNR into clear normal speech, and it has important application prospect in mobile communication. Because the whisper speech is stirred by the yawp source, its formant position shifts and its bandwidth increases, which induces the problem of formant combination occurs in the whisper conversion. By analyzing the power spectrum, in this article, we proposed a modified adaptive algorithm for formant bandwidth. Based on the rule that the pole power does not change, the algorithm has resolved the problem of formant combination by modifying the formant bandwidth of whisper before implementing formant conversion. The experimental results with six Chinese mandarin monophthong phoneme conversions proved the validity of the algorithm.
Usability is the best policy: public policy and the lived experience of transport systems in London
Authors: Philip Inglesant, M. Angela Sasse
Venue: Proceedings of the 21st British CHI Group Annual Conference on HCI 2007: People and Computers XXI: HCI...but not as we know it - Volume 1 (2007)

This paper explores the relations between public policy and usability in lived experience, drawing on 3 case studies in one important area of urban policy, transport. For these studies, discourse from interviews and focus groups with a total of 120 participants, and a written corpus of over 80 documents, were collected and analyzed, together with interviews with 25 key staff and observations of user interactions both in the laboratory and in situ. The resulting rich dataset presents a new perspective on e-government systems in use. The results show that usability must be prioritised at the policy design stage; it cannot be left to implementation. Failure to do so is experienced by users in systems which fail to work together to meet their needs. Negative experiences, in turn, may lead to loss of trust and legitimacy, and detract from public value and community well-being. These findings, therefore, provide lessons from HCI insights for both public policy-makers and implementers of e-government systems. The paper concludes by suggesting some HCI methods for pre-venting usability problems in e-government systems, by involving users in design in order to understand their lived experiences around the ecology of the systems.
Layered Diffusion-based Coverage Control in Wireless Sensor Networks
Authors: Bang Wang, Cheng Fu, Hock Beng Lim
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2009)

Coverage is an important performance metric for many applications, such as surveillance in wireless sensor networks. Coverage control is used to select as few active nodes as possible from all deployed sensor nodes, such that sufficient coverage of the monitored area can be guaranteed while reducing the energy consumption of each individual sensor node to prolong the network lifetime. This paper classifies three types of coverage control protocols based on the available information about nodes' distances or locations, and reviews several representative protocols for each type. We also propose a new distributed and localized coverage control protocol, called Layered Diffusion-based Coverage Control (LDCC). The LDCC protocol does not require information about the node location coordinates when selecting active nodes. Instead, it exploits hop count information, which is easily obtained in a WSN, to select active sensor nodes. Furthermore, the LDCC protocol is very simple and does not require any sophisticated computation such as distance or covered area computation. Our simulation results show that the LDCC protocol achieves a high coverage ratio while incurring very low message overhead compared with other existing protocols. Furthermore, simulation results suggest that in a large-scale sensor network with medium to large localization errors, LDCC performs even better than location-based coverage control protocols.
Design of Objects Sharing Mechanism with Security Domain in Java Smart Card
Authors: Yixin Xu, Qishan Zhang
Venue: Proceedings of the 2009 International Conference on Electronic Computer Technology (2009)

This paper presents a medium attack to current shareable interface object mechanism. This method can invoke the shareable interface service functions without triggering the security checks in the Applet. Then a trust model is used to clarify the relationship of the inter-applet shareable objects. According to the constraint of trust transfer we infer that a global security policy of card is necessary to prevent the unauthorized information flow in addition to the applet level access controls. Finally we design an implementation of the global security mechanism based on the security domain in the card.
Capacity management and equilibrium for proportional QoS
Authors: Ishai Menache, Nahum Shimkin
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

Differentiated services architectures are scalable solutions for providing class-based Quality of Service (QoS) over packet switched networks. While qualitative attributes of the offered service classes are often well defined, the actual differentiation between classes is left as an open issue. We address here the proportional QoS model, which aims at maintaining pre-defined ratios between the service class delays (or related congestion measures). In particular, we consider capacity assignment among service classes as the means for attaining this design objective. Starting with a detailed analysis for the single hop model, we first obtain the required capacity assignment for fixed flow rates. We then analyze the scheme under a reactive scenario, in which self-optimizing users may choose their service class in response to capacity modifications. We demonstrate the existence and uniqueness of the equilibrium in which the required ratios are maintained, and address the efficient computation of the optimal capacities. We further provide dynamic schemes for capacity adjustment, and consider the incorporation of pricing and congestion control to enforce absolute performance bounds on top of the proportional ones. Finally, we extend our basic results to networks with general topology.
Area optimisation for field-programmable gate arrays in SystemC hardware compilation
Authors: Johan Ditmar, Steve McKeever, Alex Wilson
Venue: International Journal of Reconfigurable Computing (2008)

This paper discusses a pair of synthesis algorithms that optimise a SystemC design to minimise area when targeting FPGAs. Each can significantly improve the synthesis of a high-level language construct, thus allowing a designer to concentrate more on an algorithm description and less on hardware-specific implementation details. The first algorithm is a source-level transformation implementing function exlining--where a separate block of hardware implements a function and is shared between multiple calls to the function. The second is a novel algorithm for mapping arrays to memories which involves assigning array accesses to memory ports such that no port is ever accessed more than once in a clock cycle. This algorithm assigns accesses to read/write only ports and read-write ports concurrently, solving the assignment problem more efficiently for a wider range of memories compared to existing methods. Both optimisations operate on a high-level program representation and have been implemented in a commercial SystemC compiler. Experiments show that in suitable circumstances these techniques result in significant reductions in logic utilisation for FPGAs.
Graph memory development in a robot control architecture
Authors: Patrick McDowell, Cris Koutsougeras
Venue: Journal of Computing Sciences in Colleges (2009)

The objective of this work is to develop a robot control architecture that detects and adapts to changing conditions without relying on a-priori information or human-in-the-loop calibration and setup. The focus of this work is the integration of memory based learning algorithms with coordinated observer and exploration modules through the use of a common graph based situational memory
Nonlinear dimensionality reduction with relative distance comparison
Authors: Chunxia Zhang, Shiming Xiang, Feiping Nie, Yangqiu Song
Venue: Neurocomputing (2009)

This paper proposes a new algorithm for nonlinear dimensionality reduction. Our basic idea is to explore and exploit the local geometry of the manifold with relative distance comparisons. All such comparisons derived from local neighborhoods are enumerated to constrain the manifold to be learned. The task is formulated as a problem of quadratically constrained quadratic programming (QCQP). However, such a QCQP problem is not convex. We relax it to be a problem of semi-definite programming (SDP), from which a globally optimal embedding is obtained. Experimental results illustrate the validity of our algorithm.
Techniques for estimating the state-of-charge of lead acid batteries in electric vehicles
Authors: Ying-Shing Shiao, Ding-Tsair Su, Chen-Tsai Ko, Rong-Wen Hung
Venue: Proceedings of the 8th conference on Systems theory and scientific computation (2008)

This paper proposes a method for estimating state-of-charge of lead acid batteries in electric vehicles. The electrochemistry theorems are used to design the algorithms to measure the resistance variations of electrode reaction, to estimate the internal energy loss, and to calculate the electrolyte specific gravity in batteries. The proposed algorithms can accuracy computes the resistance variation caused by electrolyte concentration changes. A SOC indicator is designed and implemented based on a digital signal processor. Several experiments were conducted on different procedures to obtain the resistance profiles of charging and discharging. By using the results, the accuracies are investigated that validate the performances of the capacitance estimation and residue energy measurement.
Why things are so bad for the computer-naive user
Authors: William C. Mann
Venue: Proceedings of the May 19-22, 1975, national computer conference and exposition (1975)

This paper is about people's use of computers to get work done. Computers are tools that operate on symbols. Unlike many other tools, such as eggbeaters, telephones and automobiles, most people in our culture seem to regard computers as alien, mysterious and inherently difficult to use. While some of this view is based on mere hearsay, it is nonetheless held by many who have had some experience with computer systems.
Low-threshold ZnSe microdisk laser based on fluorine impurity bound-exciton transitions
Authors: A. Pawlis, M. Panfilova, K. Sanaka, T. D. Ladd, D. J. As, K. Lischka, Y. Yamamoto
Venue: Microelectronics Journal (2009)

Impurity states in semiconductors, in which two long-lived ground states can be optically coupled to a single excited state, provide a powerful mechanism for applications including lasing without inversion, electromagnetically induced transparency, and optically addressable quantum memory for quantum information processing. We report low-threshold lasing from fluorine-doped ZnMgSe/ZnSe quantum wells in microdisk cavities. The lasing mechanism was studied by power-dependent photoluminescence spectroscopy. Lasing thresholds lower than 50Wcm^-^2 were observed and the fraction of spontaneous emission contributed to the lasing modes was about @b=0.03-0.1.
Multi-finger interactions with papers on augmented tabletops
Authors: Son Do-Lenh, Frédéric Kaplan, Akshit Sharma, Pierre Dillenbourg
Venue: Proceedings of the 3rd International Conference on Tangible and Embedded Interaction (2009)

Although many augmented tabletop systems have shown the potential and usability of finger-based interactions and paper-based interfaces, they have mainly dealt with each of them separately. In this paper, we introduce a novel method aimed to improve human natural interactions on augmented tabletop systems, which enables multiple users to use both fingertips and physical papers as mediums for interaction. This method uses computer vision techniques to detect multi-fingertips both over and touching the surface in real-time regardless of their orientations. Fingertip and touch positions would then be used in combination with paper tracking to provide a richer set of interaction gestures that the users can perform in collaborative scenarios.
Generating unambiguous URL clusters from web search
Authors: G. Smith, T. Brailsford, C. Donner, D. Hooijmaijers, M. Truran, J. Goulding, H. Ashman
Venue: Proceedings of the 2009 workshop on Web Search Click Data (2009)

This paper reports on the generation of unambiguous clusters of URLs from clickthrough data from the MSN search query log excerpt (the RFP 2006 dataset). Selections (clickthroughs) by a single user from a single query can be assumed to have some mutual semantic relevance, and the URLs coselected in this way can be aggregated to form single-sense clusters. When the graphs for a single term separate into distinct clusters, the semantics of the distinct clusters can be interpreted as disambiguated aggregations of URLs. This principle had been tested on smaller and more constrained datasets previously, and this paper reports on findings from applying a method based on the principle to the RFP 2006 dataset. This paper evaluates the proposed coselection method for generating single-sense clusters against two other methods, with varying parameters. The evaluation is done both with a human evaluation to determine the quality of the clusters generated by the different methods, and by a simple "edit distance" analysis to determine the content difference of the methods. The main questions addressed are i) whether it is feasible to generate single-sense / sense-coherent clusters, and ii) whether, in a closed world, it would be feasible to discover ambiguous terms. The experimentation showed that sense-coherent clusters were found and further indicated that ambiguous terms could be detected from observing small overlap between large clusters.
A High-Speed Two-Parallel Radix-24 FFT/IFFT Processor for MB-OFDM UWB Systems
Authors: Jeesung Lee, Hanho Lee
Venue: IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (2008)

This paper presents a novel high-speed, low-complexity two-parallel 128-point radix-24 FFT/IFFT processor for MB-OFDM ultrawideband (UWB) systems. The proposed high-speed, low-complexity FFT architecture can provide a higher throughput rate and low hardware complexity by using a two-parallel data-path scheme and a single-path delay-feedback (SDF) structure. The radix-24 FFT algorithm is also realized in our processor to reduce the number of complex multiplications. The proposed FFT/IFFT processor has been designed and implemented with 0.18-μm CMOS technology in a supply voltage of 1.8 V. The proposed two-parallel FFT/IFFT processor has a throughput rate of up to 900 Msample/s at 450 MHz while requiring much smaller hardware complexity and low power consumption.