ppxscal/embedding_network huggingface dataset:
On a class of infinite words with affine factor complexity
Authors: Julien Bernat, Zuzana Masáková, Edita Pelantová
Venue: Theoretical Computer Science (2007)

In this article, we consider the fixed point of a primitive substitution canonically defined by a @b-numeration system. The problem of determination of the factor complexity of such an infinite word has been solved only partially. Here we provide a necessary and sufficient condition on the Renyi expansion of one for having an affine factor complexity map C(n), that is, such that C(n)=an+b for any positive integer n.
Unit testing concurrent software
Authors: William Pugh, Nathaniel Ayewah
Venue: Proceedings of the twenty-second IEEE/ACM international conference on Automated software engineering (2007)

There are many difficulties associated with developing correct multithreaded software, and many of the activities that are simple for single threaded software are exceptionally hard for multithreaded software. One such example is constructing unit tests involving multiple threads. Given, for example, a blocking queue implementation, writing a test case to show that it blocks and unblocks appropriately using existing testing frameworks is exceptionally hard. In this paper, we describe the MultithreadedTC framework which allows the construction of deterministic and repeatable unit tests for concurrent abstractions. This framework is not designed to test for synchronization errors that lead to rare probabilistic faults under concurrent stress. Rather, this framework allows us to demonstrate that code does provide specific concurrent functionality (e.g., a thread attempting to acquire a lock is blocked if another thread has the lock). We describe the framework and provide empirical comparisons against hand-coded tests designed for Sun's Java concurrency utilities library and against previous frameworks that addressed this same issue. The source code for this framework is available under an open source license.
An Effective and Secure Buyer-Seller Watermarking Protocol
Authors: Ibrahim M. Ibrahim, Sherif Hazem Nour El-Din, Abdel Fatah A. Hegazy
Venue: Proceedings of the Third International Symposium on Information Assurance and Security (2007)

Different buyer-seller watermarking protocols have been proposed to address preserving the digital rights of both the buyer and the seller. The previously published protocols have faced one or more of the following major common problems which are customer's rights, copy deterrence, unbinding, conspiracy, buyer's participation in the dispute resolution, protocol's practice applicability and man in the middle attack problems. In this paper an effective and secure buyer-seller watermarking protocol is proposed that encapsulates flexible and yet convenient solution to all of the previously mentioned problems. The security of the proposed protocol is based on the security of the public key infrastructure (PKI). The proposed protocol exploits the existence of the trusted certification authority (CA) to solve the conspiracy problem. Furthermore, the proposed protocol solves the unbinding problem based on a novel idea of generating buyer's dual signature of both the purchase order and the buyer's associated unique watermark.
Split-ST-OFDM: Using split processing to improve the performance of space-time OFDM over digital TV channels
Authors: Richard Demo Souza, João Luiz Rebelatto, Marcelo Eduardo Pellenz, Leonardo Silva Resende
Venue: Computers and Electrical Engineering (2008)

A new space diversity scheme for frequency selective channels is proposed. Split-ST-OFDM makes use of split processing to improve the performance of regular ST-OFDM. The novel approach is shown to be more general than the case where the Hadamard transform is used to explore the multipath diversity inherent to the frequency selective channel. Computer simulations show large gains of the proposed scheme over regular ST-OFDM for the case of terrestrial digital TV channels, at the expense of a very low additional computational complexity.
Performance of SD-Method Compared with OFDM Method
Authors: Rongzhen Jin, Naoki Suehiro, Chenggao Han
Venue: Proceedings of the 7th IEEE International Conference on Computer and Information Technology (2007)

Suehiro, et al. have proposed a new information trans- mission method using the Kronecker product between the rows of DFT matrix and the data sequences called SD- method. OFDM(Orthogonal frequency division multiplex- ing) has developed into a popular scheme for wideband digital communication systems.In this paper,we show that OFDM method is special case of SD-method.Using the SD- method we achieve 2.5times faster transmission speed com- pare with OFDM under same bandwidth,same transmitter power,same multipath environment,and same bit error prob- ability.
A PACA-Based Multicast Routing Algorithm
Authors: Ziqiang Wang, Xia Sun, Dexian Zhang
Venue: Proceedings of the Eighth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing - Volume 02 (2007)

Multicast routing arises in many multimedia communication applications such as videos conference, remote education, CSCW and so on. In order to resolve Qos multicast routing effectively and efficiently, this paper mainly studied the bandwidth-delay- constrained least-cost multicast routing problem, and present a parallel ant colony algorithm (PACA) to solve the problem. The simulation results show that this algorithm is an efficient algorithm.
New integer linear programming approaches for course timetabling
Authors: Natashia Boland, Barry D. Hughes, Liam T. G. Merlot, Peter J. Stuckey
Venue: Computers and Operations Research (2008)

The most complete form of academic timetabling problem is the population and course timetabling problem. In this problem, there may be multiple classes of each subject, and the decision on which students are to constitute each class is made in concert with the decision on the timetable for each class. In order to solve this problem, it is normally simplified or decomposed in some fashion. One simplification commonly used in practice is known as blocking: it is assumed that the classes can be partitioned into sets of classes (or blocks) that will be timetabled in parallel. This restricts clashing to occur only between classes in the same block, and essentially removes the timetabling aspect of the problem, which can be carried out once the blocks are constituted and the classes populated. The problem of constituting the blocks and populating the classes, known as the course blocking and population problem, is nevertheless a challenging problem, and provides the focus of this paper. We demonstrate, using data provided by a local high school, that integer linear programming approaches can solve the problem in a matter of seconds. Key features include remodelling to remove symmetry caused by students with identical subject selection, and the observation that in practice, only integrality of the block composition variables needs to be enforced; the class population aspects of the model have strong integrality properties.
A noise resilient variable step-size LMS algorithm
Authors: Márcio Holsbach Costa, José Carlos Moreira Bermudez
Venue: Signal Processing (2008)

This work presents a modified version of the variable step size (VSS) least mean square (LMS) algorithm originally proposed by Kwong and Johnston [IEEE Trans. Signal Process. 40(7) (July 1992) 1633-1642]. The performance of the new algorithm, called noise resilient variable step size (NRVSS), is less sensitive than VSS to the power of the measurement noise. Its implementation requires only a very small increase in the computational complexity. Analytical models are derived for both NRVSS and VSS algorithms for Gaussian signals and small step-size fluctuations. Simulation results show that the NRVSS algorithm has approximately the same transient behavior as VSS but leads to lower steady-state excess mean-square errors as the signal-to-noise ratio (SNR) decreases. The NRVSS algorithm is specially indicated for adaptive interference reduction in biomedical applications.
A Novel Double-Data-Rate AES Architecture Resistant against Fault Injection
Authors: P. Maistri, P. Vanhauwaert, R. Leveugle
Venue: Proceedings of the Workshop on Fault Diagnosis and Tolerance in Cryptography (2007)

Several techniques have been proposed for encryption blocks in order to provide protection against faults. These techniques usually exploit some form of redundancy, e.g. by means of error detection codes. However, protection schemes that offer an acceptable error detection rate are in general expensive, while temporal redundancy heavily affects the throughput. In this paper, we propose a new design solution that exploits temporal redundancy by DDR techniques without affecting adversely the throughput at lower clock frequencies. We will also show that the overall costs can be comparable to other solutions recently proposed.
What is a "Distributed" Data Processing System?
Authors: P. H. Enslow
Venue: Computer (1978)

Words have only one purpose in a technical context-the transmission of information. When they fail to do that, they lead to confusion and misunderstanding. "Distributed data processing" and "distributed processing" are two phrases which illustrate that axiom. Like many other words in the lexicon of the computer professional, these have become cliches through over-use, losing much of their original meaning in the process. This paper is an attempt to reverse that trend.
Software product release planning through optimization and what-if analysis
Authors: Marjan van den Akker, Sjaak Brinkkemper, Guido Diepen, Johan Versendaal
Venue: Information and Software Technology (2008)

We present a mathematical formalization of release planning with a corresponding optimization tool that supports product and project managers during release planning. The tool is based on integer linear programming and assumes that an optimal set of requirements is the set with maximal projected revenue against available resources. The input for the optimization is twofold. The first type of input data concerns the list of candidate requirements, estimated revenues, and resources needed. Second, managerial steering mechanisms enable what-if analysis in the optimization environment. Experiments based on real-life data made a sound case for the applicability of our approach.
The Oregon Report Computer System Organization: Problems of the 1980's
Authors: H. Apfelbaum
Venue: Computer (1978)

Soon, system architects will treat all system components- hardware as well as software, user interfaces as well as data bases-as structural or architectural elements.
An Accurate Analysis of Microprocessor Design Verification
Authors: Haihua Shen, Heng Zhang
Venue: Proceedings of the 16th Asian Test Symposium (2007)

Comparing with the passion for verification technical innovations, the practical verification experiences especially the bug reports and analyses rarely appear in public research. It is very important to analyze the practical bug reports for feedback on the future verification. Thanks to the sufficient design scale of our microprocessor and efficient verification environment we developed, we are able to present in this paper an extensive analysis of the effects of bugs on different design stages and different microarchitectures. The analysis approaches and results are valuable for estimating the distribution of bugs in a microprocessor design and preventing the project from verification bottlenecks.
Sycophant: An API for Research in Context-Aware User Interfaces
Authors: Anil Shankar, Juan Quiroz, Sergiu M. Dascalu, Sushil J. Louis, Monica N. Nicolescu
Venue: Proceedings of the International Conference on Software Engineering Advances (2007)

Research in context-aware user interfaces aims to improve human-computer interaction by providing more effective, smarter and user-friendlier solutions for computer applications. Currently, software available for performing such research and developing context-aware interfaces is very limited both in scope and possibilities of extension. Sycophant was designed with two objectives in mind: first, to allow easy insertion of new features and capabilities needed for conducting research and, second, to provide a reusable, readily available programming resource for developing new context-aware interactive software applications. Available as open source software, Sycophant's API and the calendaring application we created using it are presented in this paper in terms of functional capabilities, high level architecture, detailed design, and results of use. Procedural steps for developing new context-aware user interfaces using our API are also described in the paper.
Integrating Memory Compression and Decompression with Coherence Protocols in Distributed Shared Memory Multiprocessors
Authors: Lakshmana Rao Vittanala, Mainak Chaudhuri
Venue: Proceedings of the 2007 International Conference on Parallel Processing (2007)

Ever-increasing memory footprint of applications and increasing mainstream popularity of shared memory parallel computing motivate us to explore memory compression potential in distributed shared memory (DSM) multiprocessors. This paper for the first time integrates on-the-fly cache block compression/decompression algorithms in the cache coherence protocols by leveraging the directory structure already present in these scalable machines. Our proposal is unique in the sense that instead of employing custom compression/ decompression hardware, we use a simple on-die protocol processing core in dual-core nodes for running our directory-based coherence protocol suitably extended with compression/decompression algorithms. We design a low-overhead compression scheme based on frequent patterns and zero runs present in the evicted dirty L2 cache blocks. Our compression algorithm examines the first eight bytes of an evicted dirty L2 block arriving at the home memory controller and speculates which compression scheme to invoke for the rest of the block. Our customized algorithm for handling completely zero cache blocks helps hide a significant amount of memory access latency. Our simulationbased experiments on a 16-node DSM multiprocessor with seven scientific computing applications show that our best design achieves, on average, 16% to 73% storage saving per evicted dirty L2 cache block for four out of the seven applications at the expense of at most 15% increased parallel execution time.
Buffering accesses to memory-resident index structures
Authors: Jingren Zhou, Kenneth A. Ross
Venue: Proceedings of the 29th international conference on Very large data bases - Volume 29 (2003)

Recent studies have shown that cache-conscious indexes outperform conventional main memory indexes. Cache-conscious indexes focus on better utilization of each cache line for improving search performance of a single lookup. None has exploited cache spatial and temporal locality between consecutive lookups. We show that conventional indexes, even "cache-conscious" ones, suffer from significant cache thrashing between accesses. Such thrashing can impact the performance of applications such as stream processing and query operations such as index-nested-loops join. We propose techniques to buffer accesses to memory-resident tree-structured indexes to avoid cache thrashing. We study several alternative designs of the buffering technique, including whether to use fixed-size or variable-sized buffers, whether to buffer at each tree level or only at some of the levels, how to support bulk access while there are concurrent updates happening to the index, and how to preserve the order of the incoming lookups in the output results. Our methods improve cache performance for both cache-conscious and conventional index structures. Our experiments show that buffering techniques enable a probe throughput that is two to three times higher than traditional methods.
A fuzzy constraint satisfaction problem in the wine industry
Authors: Régis Sabbadin, Didier Dubois, Henri Prade, Pierre Grenier
Venue: Journal of Intelligent Fuzzy Systems: Applications in Engineering and Technology (1998)

The paper reports on a real case study coming from wine industry, which is an example of linear constraint satisfaction problem, where the constraints are flexible, may have different levels of priority or involve ill-known (imprecise or fuzzy) parameters. Fuzzy sets and possibility theory offer a unified framework that allows for the modelling of i) preferences between different ways of satisfying a flexible constraint, of ii) uncertainty pervading data, and of iii) priority among constraints. Indeed, actual constraints are often flexible and their satisfaction a matter of degree. That is why they are conveniently described by fuzzy sets. Uncertain pieces of data can be represented by means of possibility distributions, and the level of priority of a constraint can be viewed as the maximum degree of acceptability of a solution that violates this constraint. In the following the fuzzy set-based approach to the handling of soft and uncertain constraints is presented and its interest is illustrated on the case study.
Intelligent Active Queue Management Predictive Controller using Neural Networks
Authors: R. Alasem, M. A. Hossain, I. Awan
Venue: Proceedings of the The 2007 International Conference on Next Generation Mobile Applications, Services and Technologies (2007)

Network congestion control, due to increasing number of Internet services with various quality of service (QoS) demands, has become the focus of current research. In this paper, a novel scheme of adaptive Smith Predictor (SP) controller using Neural Network for active queue management (NNAQM) is presented. Smith predictor is used to overcome the disadvantages such as influence of time delay, in particular, when it becomes significant in large TCP/IP networks. In this investigation, the well known Back-Propagation (BP) algorithm is used to train weights of the neural networks of the proposed design. Finally, a simulation platform is developed, tested and validated to demonstrate the merits of the scheme through a set of experiments.
Particle Swarm Optimization with Adaptive Parameters
Authors: Dongyong Yang, Jinyin Chen, Naofumi Matsumoto
Venue: Proceedings of the Eighth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing - Volume 01 (2007)

Particle swarm optimization is an effective evolution algorithm for global optimizing. Based on analysis of particle movements during evolution, parameter p is brought up to control the value of C1 and C2, which effects convergence rate of PSO. Aiming at solving different problems, corresponding p is adopted to improve performance. Particle confidence coefficient q is applied to weigh proper emphasize on itself best solution and global solution. Adaptive value of q is introduced to PSO to satisfy specific situation for each particle. Finally, performance of PSO with parameters p and q is testified by optimizing benchmark functions.
A study on the scalability of non-preferred hand mode manipulation
Authors: Jaime Ruiz, Edward Lank
Venue: Proceedings of the 9th international conference on Multimodal interfaces (2007)

In pen-tablet input devices modes allow overloading of the electronic stylus. In the case of two modes, switching modes with the non-preferred hand is most effective [12]. Further, allowing temporal overlap of mode switch and pen action boosts speed [11]. We examine the effect of increasing the number of interface modes accessible via non-preferred hand mode switching on task performance in pen-tablet interfaces. We demonstrate that the temporal benefit of overlapping mode-selection and pen action for the two mode case is preserved as the number of modes increases. This benefit is the result of both concurrent action of the hands, and reduced planning time for the overall task. Finally, while allowing bimanual overlap is still faster it takes longer to switch modes as the number of modes increases. Improved understanding of the temporal costs presented assists in the design of pen-tablet interfaces with larger sets of interface modes.
SVSb: simple and visual storyboards: developing a visualisation method for depicting user scenarios
Authors: Niina Kantola, Timo Jokela
Venue: Proceedings of the 19th Australasian conference on Computer-Human Interaction: Entertaining User Interfaces (2007)

Presenting scenarios, or user tasks, in the form of storyboards is a common technique in the field of HCI. A storyboarding approach, called SVSb ('simple and visual storyboards'), is proposed. The aim is to create storyboards that are simple and easy to construct and modify, but still communicative and descriptive enough. The storyboards include elements such as context, user, user goals, plans, evaluation, user actions and system events. The rationale of SVSb and experiences on using the approach in a case project are described.
Automatic Information Retrieval
Authors: G. Salton
Venue: Computer (1980)

Advances such as specialized parallel hardware and new algorithms for text searching will improve the effectiveness of information retrieval systems.
The Open Channel
Authors: C. McCabe
Venue: Computer (1980)

The Open Channel is exactly what the name implies: a forum for the free exchange of technical ideas. Try to hold your contributions to one page maximum in the final magazine format (about 1000 words). 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
A Classifier Design Technique for Discrete Variable Pattern Recognition Problems
Authors: J. C. Stoffel
Venue: IEEE Transactions on Computers (1974)

This paper presents a new computerized technique to aid the designers of pattern classifiers when the measurement variables are discrete and the values form a simple nominal scale (no inherent metric). A theory of "prime events" which applies to patterns with measurements of this type is presented. A procedure for applying the theory of "prime events" and an analysis of the "prime event estimates" is given. To manifest additional characteristics of this technique, an example optical character recognition (OCR) application is discussed.
A domain specific language and methodology for control systems GUI specification, verification and prototyping
Authors: Matteo Risoldi, Didier Buchs
Venue: Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing (2007)

A work-in-progress domain-specific language and methodology for modeling complex control systems GUIs is presented. MDA techniques are applied for language design and verification, simulation and prototyping.
Removing Shading Distortions in Camera-based Document Images Using Inpainting and Surface Fitting With Radial Basis Functions
Authors: Li Zhang, Andy M. Yip, Chew Lim Tan
Venue: Proceedings of the Ninth International Conference on Document Analysis and Recognition - Volume 02 (2007)

Shading distortions are often perceived in geometrically distorted document images due to the change of surface normal with respect to the illumination direction. Such distortions are undesirable because they hamper OCR performance tremendously even when the geometric distortions are corrected. In this paper, we propose an effective method that removes shading distortions in images of documents with various geometric shapes based on the notion of intrinsic images. We first try to derive the shading image using an inpainting technique with an automatic mask generation routine and then apply a surface fitting procedure with radial basis functions to remove pepper noises in the inpainted image and return a smooth shading image. Once the shading image is extracted, the reflectance image can be obtained automatically. Experiments on a wide range of distorted document images demonstrate a robust performance. Moreover, we also show its potential applications to the restoration of historical handwritten documents.