ppxscal/embedding_network huggingface dataset:
XARK: An extensible framework for automatic recognition of computational kernels
Authors: Manuel Arenaz, Juan Touriño, Ramon Doallo
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (2008)

The recognition of program constructs that are frequently used by software developers is a powerful mechanism for optimizing and parallelizing compilers to improve the performance of the object code. The development of techniques for automatic recognition of computational kernels such as inductions, reductions and array recurrences has been an intensive research area in the scope of compiler technology during the 90's. This article presents a new compiler framework that, unlike previous techniques that focus on specific and isolated kernels, recognizes a comprehensive collection of computational kernels that appear frequently in full-scale real applications. The XARK compiler operates on top of the Gated Single Assignment (GSA) form of a high-level intermediate representation (IR) of the source code. Recognition is carried out through a demand-driven analysis of this high-level IR at two different levels. First, the dependences between the statements that compose the strongly connected components (SCCs) of the data-dependence graph of the GSA form are analyzed. As a result of this intra-SCC analysis, the computational kernels corresponding to the execution of the statements of the SCCs are recognized. Second, the dependences between statements of different SCCs are examined in order to recognize more complex kernels that result from combining simpler kernels in the same code. Overall, the XARK compiler builds a hierarchical representation of the source code as kernels and dependence relationships between those kernels. This article describes in detail the collection of computational kernels recognized by the XARK compiler. Besides, the internals of the recognition algorithms are presented. The design of the algorithms enables to extend the recognition capabilities of XARK to cope with new kernels, and provides an advanced symbolic analysis framework to run other compiler techniques on demand. Finally, extensive experiments showing the effectiveness of XARK for a collection of benchmarks from different application domains are presented. In particular, the SparsKit-II library for the manipulation of sparse matrices, the Perfect benchmarks, the SPEC CPU2000 collection and the PLTMG package for solving elliptic partial differential equations are analyzed in detail.
Buffer Management Policy for Mars Intelligent Proximity Network
Authors: Mahendiran Prathaban, Josephine Kohlenberg
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

Future Mars missions will require effective surface com-munications network supporting exploration activities andscienti®c ®eld data collection. In order to meet the needfor future Mars exploration missions, NASA has come upwith various proximity networks. These proximity networkare relatively small, fairly short-range, often ad hoc, wire-less network typically dedicated to tasks such as transport-ing in site sensing data. This paper enlist the challenges inthese proximity networks in general. We describe proxim-ity network architecture with repeaters to increase the com-munication range of the Mars exploration rovers. We alsodescribe the Mars reply protocol which make the networkautonomous than remotely operated from Earth.In order to achieve data delivery in such challenging net-working environments, researchers have proposed the useof store-carry-and-forward protocols. However, the buffersize in proximity network nodes (Mars rover for example)are unavoidably limited. Thus, ef®cient buffer managementpolicies are necessary to decide which messages should bediscarded, when node buffers are operated close to theircapacity. In this paper, we have proposed buffer manage-ment policy for image data traf®c. Using simulation wehave shown that our buffer management policy providedoptimal delivery ratio in all scenario when compared withother policies.
An auditing protocol for spreadsheet models
Authors: Stephen G. Powell, Kenneth R. Baker, Barry Lawson
Venue: Information and Management (2008)

Errors are prevalent in spreadsheets and can be extremely difficult to find. A number of audits of existing spreadsheets have been reported, but few details have been given about how the audits were performed. We developed and tested a new spreadsheet auditing protocol designed to find errors in operational spreadsheets. Our work showed which auditing procedures, used in what sequence and combination, were most effective across a wide range of spreadsheets. It also provided useful information on the size and complexity of operational spreadsheets, as well as the frequency with which certain types of errors occur.
Interrupt Handlers in Java
Authors: Stephan Korsholm, Martin Schoeberl, Anders P. Ravn
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

An important part of implementing device drivers is to control the interrupt facilities of the hardware platform and to program interrupt handlers. Current methods for handling interrupts in Java use a server thread waiting for the VM to signal an interrupt occurrence. It means that the interrupt is handled at a later time, which has some disadvantages. We present constructs that allow interrupts to be handled directly and not at a later point decided by a scheduler. A desirable feature of our approach is that we do not require a native middelware layer but can handle interrupts entirely with Java code. We have implemented our approach using an interpreter and a Java processor, and give an example demonstrating its use.
On multi-rate fusion for non-linear sampled-data systems: Application to a 6D tracking system
Authors: L. Armesto, J. Tornero, M. Vincze
Venue: Robotics and Autonomous Systems (2008)

Egomotion estimation, e.g. for robot navigation or augmented reality applications, requires the fusion of non-linear sampled-data system with different sensors. An example is to fuse the complimentary characteristics of visual and inertial sensors. Existing approaches either use Kalman filters in conventionally sampled systems or use Particle filters to accommodate the uncertainty of motion models. This paper introduces an approach that models multi-rate non-linear systems to exploit the characteristics of both sensors, assuming synchronicity and periodicity of measurements. The final contribution of this paper is an in-depth analysis and performance comparison of the Extended Kalman filter, the Unscented Kalman filter and three particle filters (Bootstrap, Extended and Unscented). While there is large debate over the pros and cons of these two approaches, this work shows the following results for fusing visual and inertial data in 6 DOF (position and orientation) in a tracking application: the Bootstrap Particle filter gives higher estimation error than Extended and Unscented Particle filters, which give very similar results than Extended and Unscented Kalman filters, but with considerable higher computational burden.
On the "log rank"-conjecture in communication complexity
Authors: R. Raz
Venue: Proceedings of the 1993 IEEE 34th Annual Foundations of Computer Science (1993)

We show the existence of a non-constant gap between the communication complexity of a function and the logarithm of the rank of its input matrix. We consider the following problem: each of two players gets a perfect matching between two n-element sets of vertices. Their goal is to decide whether or not the union of the two matchings forms a Hamiltonian cycle. We prove: (1) The rank of the input matrix over the reals for this problem is 2/sup O(n)/. (2) The non-deterministic communication complexity of the problem is /spl Omega/(n log log n). Our result also supplies a superpolynomial gap between the chromatic number of a graph and the rank of its adjacency matrix. Another conclusion from the second result is an /spl Omega/(n log log n). Lower bound for the graph connectivity problem in the non-deterministic case. We make use of the theory of group representations for the first result. The second result is proved by an information theoretic argument.
A low-cost hybrid coordinated checkpointing protocol for mobile distributed systems
Authors: Parveen Kumar
Venue: Mobile Information Systems (2008)

Mobile distributed systems raise new issues such as mobility, low bandwidth of wireless channels, disconnections, limited battery power and lack of reliable stable storage on mobile nodes. In minimum-process coordinated checkpointing, some processes may not checkpoint for several checkpoint initiations. In the case of a recovery after a fault, such processes may rollback to far earlier checkpointed state and thus may cause greater loss of computation. In all-process coordinated checkpointing, the recovery line is advanced for all processes but the checkpointing overhead may be exceedingly high. To optimize both matrices, the checkpointing overhead and the loss of computation on recovery, we propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. Thus, the Mobile nodes with low activity or in doze mode operation may not be disturbed in the case of minimum-process checkpointing and the recovery line is advanced for each process after an all-process checkpoint. Additionally, we try to minimize the information piggybacked onto each computation message. For minimum-process checkpointing, we design a blocking algorithm, where no useless checkpoints are taken and an effort has been made to optimize the blocking of processes. We propose to delay selective messages at the receiver end. By doing so, processes are allowed to perform their normal computation, send messages and partially receive them during their blocking period. The proposed minimum-process blocking algorithm forces zero useless checkpoints at the cost of very small blocking.
CoWSAMI: Interface-aware context gathering in ambient intelligence environments
Authors: Dionysis Athanasopoulos, Apostolos V. Zarras, Valerie Issarny, Evaggelia Pitoura, Panos Vassiliadis
Venue: Pervasive and Mobile Computing (2008)

In this paper we present CoWSAMI, a middleware infrastructure that enables context awareness in open ambient intelligence environments, consisting of mobile users and context sources that become dynamically available as the users move from one location to another. A central requirement in such dynamic scenarios is to be able to integrate new context sources and users at run-time. CoWSAMI exploits a novel approach towards this goal. The proposed approach is based on utilizing Web services as interfaces to context sources and dynamically updatable relational views for storing, aggregating and interpreting context. Context rules are employed to provide mappings that specify how to populate context relations, with respect to the different context sources that become dynamically available. An underlying context sources discovery mechanism is utilized to maintain context information up to date as context sources, and users get dynamically involved.
Performance evaluation of deadline-based and laxity-based scheduling algorithms in real-time multiprocessor environments
Authors: Vahid Salmani, Mahmoud Naghibzadeh, Amirhossein Taherinia, Malihe Bahekmat, Sedigheh Khajouie Nejad
Venue: Proceedings of the 6th WSEAS International Conference on Systems Theory & Scientific Computation (2006)

Scheduling algorithms play an important role in design of real-time systems. Owing to high processing power and low price of multiprocessors, real-time scheduling in such systems is more interesting; however, more complicated. Its complication is due to the fact that multiprocessors are composed of a number of processors that require more complex strategies in order to maintain the system's performance over a desirable level. Earliest Deadline First (EDF) and Least Laxity First (LLF) are two well-known and extensively applied dynamic scheduling algorithms which have been proved to be optimal on uniprocessor systems. However, neither of these algorithms is shown to be optimal on multiprocessors. Up until now, many researches have been done on aforementioned algorithms, but to the best of our knowledge, none of which has compared the efficiency of the two algorithms under similar conditions. Perhaps the main reason is that LLF algorithm is fully dynamic and impractical to implement. In this research, we have used a practical version of LLF which is called the Modified Least Laxity First (MLLF) algorithm instead of the traditional LLF and have compared its performance with the EDF algorithm. The MLLF is a job-level dynamic and optimal strategy on uniprocessor systems, similar to the EDF algorithm. We have comprehensively investigated the performance of EDF and MLLF from many different aspects.
Tablet PC to Support Collaborative Learning: An Empirical Study of English Vocabulary Learning
Authors: Chiu-Pin Lin, Kuo-Ping Liu, Jitti Niramitranon
Venue: Proceedings of the Fifth IEEE International Conference on Wireless, Mobile, and Ubiquitous Technology in Education (2008)

Compared to typing, ink can be more expressive of important ideas. Hand-drawn sketch is likely more expressive of the key concepts one wishes to communicate than a neat, chiseled presentation would have been [1]. The aim of this study is to deploy computer supported collaborative learning scenario by means of using Tablet PC with Group Scribbles (GS), a collection of software designed to facilitate students engaging in collaborative learning in English vocabulary activities. The outcomes after the completion of learning activities showed this Tablet PC enhanced instructional design indeed arouses students’ motivations and improves students’ mutual interactions.
Generalized reflexive solutions of the matrix equation AXB=D and an associated optimal approximation problem
Authors: Yongxin Yuan, Hua Dai
Venue: Computers Mathematics with Applications (2008)

Let R@?C^m^x^m and S@?C^n^x^n be nontrivial unitary involutions, i.e., R^H=R=R^-^1I"n. We say that G@?C^m^x^n is a generalized reflexive matrix if RGS=G. The set of all mxn generalized reflexive matrices is denoted by GRC^m^x^n. In this paper, a sufficient and necessary condition for the matrix equation AXB=D, where A@?C^p^x^m,B@?C^n^x^q and D@?C^p^x^q, to have a solution X@?GRC^m^x^n is established, and if it exists, a representation of the solution set S"X is given. An optimal approximation between a given matrix X@?@?C^m^x^n and the affine subspace S"X is discussed, an explicit formula for the unique optimal approximation solution is presented, and a numerical example is provided.
*Miner: A Suit of Classifiers for Spatial, Temporal, Ancillary, and Remote Sensing Data Mining
Authors: Ranga Raju Vatsavai, Shashi Shekhar, Thomas E. Burk, Budhendra Bhaduri
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

Thematic classification of multi-spectral remotely sensed imagery for large geographic regions requires complex algorithms and feature selection techniques. Traditional statistical classifiers rely exclusively on spectral characteristics, but thematic classes are often spectrally overlapping. The spectral response distributions of thematic classes are dependent on many factors including terrain, slope, aspect, soil type, and atmospheric conditions present during the image acquisition. With the availability of geo-spatial databases, it is possible to exploit the knowledge derived from these ancillary geo-spatial databases to improve the classification accuracies. However, it is not easy to incorporate this additional knowledge into traditional statistical classification methods. On the other hand, knowledge-based and neural network classifiers can readily incorporate these spatial databases, but these systems are often complex to train and their accuracy is only slightly better than statistical classifiers. In this paper we present a new suit of classifiers developed through NASA funding, which addresses many of these problems and provide a framework for mining multi-spectral and temporal remote sensing images guided by geo-spatial databases.
Optimizing workflow data footprint
Authors: Gurmeet Singh, Karan Vahi, Arun Ramakrishnan, Gaurang Mehta, Ewa Deelman, Henan Zhao, Rizos Sakellariou, Kent Blackburn, Duncan Brown, Stephen Fairhurst, David Meyers, G. Bruce Berriman, John Good, Daniel S. Katz
Venue: Scientific Programming (2007)

In this paper we examine the issue of optimizing disk usage and scheduling large-scale scientific workflows onto distributed resources where the workflows are data-intensive, requiring large amounts of data storage, and the resources have limited storage resources. Our approach is two-fold: we minimize the amount of space a workflow requires during execution by removing data files at runtime when they are no longer needed and we demonstrate that workflows may have to be restructured to reduce the overall data footprint of the workflow. We show the results of our data management and workflow restructuring solutions using a Laser Interferometer Gravitational-Wave Observatory (LIGO) application and an astronomy application, Montage, running on a large-scale production grid-the Open Science Grid. We show that although reducing the data footprint of Montage by 48% can be achieved with dynamic data cleanup techniques, LIGO Scientific Collaboration workflows require additional restructuring to achieve a 56% reduction in data space usage. We also examine the cost of the workflow restructuring in terms of the application's runtime.
Transformation Matrix System for Reducing the Computational Complexity of Wireless Multi-User Receivers for DS-CDMA Systems
Authors: Syed S. Rizvi, Aasia Riasat, Khaled M. Elleithy
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

This paper presents a new transformation matrix system for reducing the computational complexity of multiuser receiver. The proposed system observes the coordinates of the constellation diagram to determine the location of the transformation points. Since most of the decisions are correct, we can reduce the number of required computations by using the transformation matrixes only on those coordinates which are most likely to lead to an incorrect decision. Our results show that the proposed system successfully reduces the computational complexity of an optimal multiuser receiver. The complexity of the proposed system is not polynomial in the number of users, but it still gives comparatively reduced complexity.
Incorporating free-form features in aesthetic and engineering product design: State-of-the-art report
Authors: J. -P. Pernot, B. Falcidieno, F. Giannini, J. -C. Léon
Venue: Computers in Industry (2008)

The use of free-form shapes has become mainstream to design complex products that have to fulfil engineering requirements as well as aesthetic criteria. Even if today's CAD systems can easily represent free-form shapes by means of NURBS surfaces, their definition and modification still require a deep knowledge and a great skill in the manipulation of the underlying mathematical models. The implemented free-form shapes design operators are time consuming and do not enable fast modifications. To overcome these limits, some researches have been undertaken to try to adapt the feature concept, successfully adopted for the design of regular shapes, in the free-form domain. It gives rise to a set of free-form features modelling strategies. This paper gathers together the state-of-the-art of these advances. The various approaches are depicted and compared with respect to a very precise set of criteria expressing the needs in aesthetic and engineering designs. The limits and future trends are presented.
Differential evolution with dynamic stochastic selection for constrained optimization
Authors: Min Zhang, Wenjian Luo, Xufa Wang
Venue: Information Sciences: an International Journal (2008)

How much attention should be paid to the promising infeasible solutions during the evolution process is investigated in this paper. Stochastic ranking has been demonstrated as an effective technique for constrained optimization. In stochastic ranking, the comparison probability will affect the position of feasible solution after ranking, and the quality of the final solutions. In this paper, the dynamic stochastic selection (DSS) is put forward within the framework of multimember differential evolution. Firstly, a simple version named DSS-MDE is given, where the comparison probability decreases linearly. The algorithm DSS-MDE has been compared with two state-of-the-art evolution strategies and three competitive differential evolution algorithms for constrained optimization on 13 common benchmark functions. DSS-MDE is also evaluated on four well-studied engineering design examples, and the experimental results are significantly better than current available results. Secondly, other dynamic settings of the comparison probability for DSS-MDE are also designed and tested. From the experimental results, DSS-MDE is effective for constrained optimization. Finally, DSS-MDE with a square root adjusted comparison probability is evaluated on the 22 benchmark functions in CEC'06, and the experimental results on most functions are competitive.
A method to eliminate riding waves appearing in the empirical AM/FM demodulation
Authors: Zhijing Yang, Lihua Yang, Chunmei Qing, Daren Huang
Venue: Digital Signal Processing (2008)

Empirical mode decomposition can decompose a complicated signal into a sum of finite intrinsic mode functions whose instantaneous frequencies computed by the analytic signal method give a physically meaningful characterization of the signal. However, it is found that computing the instantaneous frequency of an intrinsic mode function through the Hilbert transform may produce some ridiculous results. Recently, an empirical AM/FM (amplitude and frequency modulation) demodulation for computing the instantaneous frequency of an intrinsic mode function has been proposed by Huang and his coworkers. This method totally eschews the Hilbert transform and can compute the instantaneous frequency of an intrinsic mode function very accurately. However, this paper will show that the empirical FM part extracted through the empirical AM/FM demodulation may contain riding waves and is no longer an intrinsic mode function. That will make the instantaneous frequency nonsensical. To overcome this drawback, an improved method, called riding wave turnover-empirical AM/FM demodulation, is proposed in this paper. Experiments show very positive results.
Un syst&egrave;me d'apprentissage pervasif int&eacute;grant des activit&eacute;s de travail et de formation
Authors: Cuong Pham-Nguyen, Serge Garlatti
Venue: Proceedings of the 4th French-speaking conference on Mobility and ubiquity computing (2008)

In the p-LearNet project, we are interested in TEL systems integrating context-aware corporate learning and working activities for e-retail (shops and hypermarkets). The main issues of the p-LearNet project are: work-integrated learning and customer learning support whatever the place, the time, the organisational and technological contexts of the individual or collective learning and working processes. We propose an adaptive and context-aware model of scenario for a pervasive learning system. This model enables us to choose how to achieve activities according to the current situation. The scenario model is based on a hierarchical task model having the task/method paradigm - methods define how to achieve a task, a task represents an activity. The context-aware adaptation process selects the relevant methods according to the current situation.