ppxscal/embedding_network huggingface dataset:
Scaling up the formal verification of Lustre programs with SMT-based techniques
Authors: George Hagen, Cesare Tinelli
Venue: Proceedings of the 2008 International Conference on Formal Methods in Computer-Aided Design (2008)

We present a general approach for verifying safety properties of Lustre programs automatically. Key aspects of the approach are the choice of an expressive first-order logic in which Lustre's semantics is modeled very naturally, the tailoring to this logic of SAT-based k-induction and abstraction techniques, and the use of SMT solvers to reason efficiently in this logic. We discuss initial experimental results showing that our implementation of the approach is highly competitive with existing verification solutions for Lustre.
Satellite network technology
Authors: D. M. Chitre, J. V. Evans
Venue: Space Communications (2000)

Traditionally, fixed satellite services have chiefly been used to support voice communications using capacity allocated to switched circuits, broadcast applications where capacity is allocated to regular TV transmissions, and low speed interactive data applications. Increasingly, however, satellites are being required to serve as high speed links in data networks handling data packets. To function efficiently on terrestrial packet networks (where errors are rare and the delays are short), the protocols, designed in an earlier era, are unsuited to satellite circuits, and considerable work is now underway to try to remedy these shortcomings. This paper reviews the problems encountered when Internet traffic must be carried over satellite and changes being considered and/or implemented in the Transmission Control Protocol/Internet Protocol (TCP/IP) suite to improve its efficient operation over satellites. Also discussed are strategies that can be employed at satellite earth stations to aid in integrating satellite links seamlessly into terrestrial data networks.
Analysis of the interaction between the retinal ON and OFF channels using CNN-UM models
Authors: Róbert Wagner, Al Molnar, Frank S. Werblin
Venue: International Journal of Circuit Theory and Applications (2009)

Quantitative retinal modeling is an important tool for analyzing the circuitry underlying the functional organization of the retina, and developing neuromorphic signal processing for retinal prostheses. The Cellular Neural Network (CNN) is a suitable tool for both purposes due to its structure. Using multilayer CNN models we analyzed two phenomena: First the signal distortion caused by nonlinear synapses and secondly the use of inhibitory interaction between ON and OFF channels. Our simulations show that the ON&ndash;OFF interaction can reduce the signal distortion caused by nonlinear synapses. Copyright &copy; 2008 John Wiley & Sons, Ltd.
Certifying properties of an efficient functional program for computing Gröbner bases
Authors: J. Santiago Jorge, Victor M. Gulias, Jose L. Freire
Venue: Journal of Symbolic Computation (2009)

This paper explores the certification of properties of an efficient functional program in the area of symbolic computation: the calculation of Gröbner basis of a set of multivariate polynomials. Our experience in the development of industrial systems and the certification of some of its relevant properties has led us to use a methodology consisting of functional programs to write the code and the formal verification of fundamental properties. The functional language OBJECTIVE CAML has been chosen to implement the program. To verify the properties two approaches are explored: manual proofs that reason directly over the source code of the algorithms, applying techniques like equational reasoning, and theorem provers that are used as a tool to help us certify a model of the real system. The chosen proof assistant is COQ. Not only will the certification of the software be taken into consideration but also its efficiency. In addition, we present a graphical interface which eases the use of the program.
Long term monitoring of oil spills in European seas
Authors: G. Ferraro, S. Meyer-Roux, O. Muellenhoff, M. Pavliha, J. Svetak, D. Tarchi, K. Topouzelis
Venue: International Journal of Remote Sensing (2009)

Accidental pollution at sea can be reduced but never completely eliminated; however, deliberate illegal discharges from ships can indeed be reduced by the strict enforcement of existing regulations and the control, monitoring and surveillance of maritime traffic. Despite this, operational oil discharges are common and represent the main source of marine pollution from ships. To analyse this problem, the Joint Research Centre (JRC) of the European Commission has focused its attention on the need to monitor in the long term sea-based oil pollution. This research aims, in particular, to map the oil spills, to identify the hot spots and to define the trends in all European seas. For this reason, JRC has collected all relevant data concerning sea-based oil pollution from different actors and archives. For the North and Baltic seas, data from aerial surveillance were used and, for this reason, all oil spills are real and confirmed. Conversely, the data for the Mediterranean and the Black Sea derive from oil spills detected by JRC in low resolution SAR (Synthertic Aperture Radar) satellite images from archives. For the Mediterranean and the Black Sea, these data represent the only source to draw some preliminary conclusions on marine oil pollution. This paper presents for the first time a comprehensive view of the long term monitoring of sea-based oil pollution in all the seas around Europe. The key conclusion of this study is that, if the data analysed are not homogenous, operational pollution in the seas around Europe seems to be slightly decreasing.
A Method for Transforming Workflow Processes to CSS
Authors: Jing Xiao, Guo-qing Wu, Shu Chen
Venue: Proceedings of the 2009 International Conference on Computer Engineering and Technology - Volume 01 (2009)

In this paper, we proposed a method to transform the workflow processes into CCS, and the workflow process is described in activity network charts. For the first, we used CCS to describe the six basic logical relations of the workflow model, and then based on the basic expressions, we illustrate how to transform the whole workflow model to CCS process expressions.We provide the exact formalization basis for the workflow model, and express its operational semantics in the form of synchronous tree, at last we use the synchronous tree to verify the correctness of the workflow processes.
A Platform Implementation for Real Time Image Processing
Authors: Ching-Hsi Lu, Yu-Sheng Wang, Lei Wang, Hong-Yang Hsu
Venue: Proceedings of the 9th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (2008)

The technologies for image processing are improved evidently since the popularity of modern IA products in the last decade. In order to satisfy the needs on high quality images, higher contrast, higher saturation and higher resolution become the main goals of the researches. This article focuses on how to implement a platform for real time image processing to provide a realistic environment for developing techniques on enhancing image contrast dynamically in real time. A new method for improving the contrast quality of images can be verified by feeding analog images of NTSC television to this platform after digitalized, then perform the functions of enhancing image contrast by FPGA to provide the enhanced result of image contrast. It's different from the simulations made by software that proposed by the past researches, this article proposes a practical hardware real time processing foundation that can be used as a valuable reference of real time image processing.
An improved metric for measuring multi-item multi-level schedule instability under rolling schedules
Authors: Kamil Erkan Kabak, Arslan M. Ornek
Venue: Computers and Industrial Engineering (2009)

Disruptions in material plans due to unrealistic schedules and frequent plan revisions are common symptoms of a phenomenon generally referred to as nervousness or schedule instability in literature. A number of instability measures had been proposed so far. However, none of them deals with instability measurement comprehensively. An appropriate measurement should be able to reflect the degree of changes under rolling schedules, as well as a tool for analyzing the performance of planning systems and nervousness dampening procedures. The intent of this paper is to present a new metric for measuring multi-item multi-level schedule instability under rolling schedules and to compare it with the previous measures in literature. The new metric composed of linear combination of four sub-instability measures separates quantity and timing changes for both scheduled receipts (SRs) and planned orders (PORs). The new metric is tested by a detailed numerical example taken from literature, and results of simulation studies under various experimental factors are presented at the end of the study.
Graph OLAP: Towards Online Analytical Processing on Graphs
Authors: Chen Chen, Xifeng Yan, Feida Zhu, Jiawei Han, Philip S. Yu
Venue: Proceedings of the 2008 Eighth IEEE International Conference on Data Mining (2008)

OLAP (On-Line Analytical Processing) is an important notion in data analysis. Recently, more and more graph or networked data sources come into being. There exists a similar need to deploy graph analysis from different perspectives and with multiple granularities. However, traditional OLAP technology cannot handle such demands because it does not consider the links among individual data tuples. In this paper, we develop a novel graph OLAP framework, which presents a multi-dimensional and multi-level view over graphs. The contributions of this work are two-fold. First, starting from basic definitions, i.e., what are dimensions and measures in the graph OLAP scenario, we develop a conceptual framework for data cubes on graphs. We also look into different semantics of OLAP operations, and classify the framework into two major subcases: informational OLAP and topological OLAP. Then, with more emphasis on informational OLAP (topological OLAP will be covered in a future study due to the lack of space), we show how a graph cube can be materialized by calculating a special kind of measure called aggregated graph and how to implement it efficiently. This includes both full materialization and partial materialization where constraints are enforced to obtain an iceberg cube. We can see that the aggregated graphs, which depend on the graph properties of underlying networks, are much harder to compute than their traditional OLAP counterparts, due to the increased structural complexity of data. Empirical studies show insightful results on real datasets and demonstrate the efficiency of our proposed optimizations.
Dynamic Service Provisioning Using GRIA SLAs
Authors: Mike Boniface, Stephen C. Phillips, Alfonso Sanchez-Macian, Mike Surridge
Venue: Service-Oriented Computing - ICSOC 2007 Workshops: ICSOC 2007, International Workshops, Vienna, Austria, September 17, 2007, Revised Selected Papers (2009)

Service Level Agreements (SLA) include quality of service (QoS) constraints and bounds that have to be honoured by the service provider. To maximise the Service Provider revenue while satisfying the QoS requirements of the agreed SLAs it is important to be able to perform a dynamic distribution of the service provider resources between the services and SLAs. This distribution should be based on the current status and predicted evolution of the QoS characteristics. This paper describes the experiences managing SLA obligations from a service provider perspective in a scenario where dynamic deployment of services can be undertaken. The main issues faced to deal with the management of SLAs in this context are detailed. The adopted solution, based on GRIA (a Service Oriented Architecture framework) is discussed.
A Novel Approach for Web-based Conference Management System
Authors: Pradeep Gurunathan, Seethalakshmi Pandian
Venue: Proceedings of the 2009 International Conference on Computer Engineering and Technology - Volume 02 (2009)

In the last few years, several Web-based conference management systems have been developed and used by many international conferences. However, almost all of them were built on stand-alone Web servers. Their fault tolerance, scalability and ability of responding to dispersed users are limited. Aimed at addressing these problems, this paper presents a novel approach for webbased conference management system, whose fault tolerance, scalability and ability of responding to dispersed users are greatly enhanced by Service Oriented Architecture, that aims to achieve interoperability of remotely or locally located homogeneous and heterogeneous applications byutilizing reusable service logic.
Optimising Java RMI programs by communication restructuring
Authors: Kwok Cheung Yeung, Paul H. J. Kelly
Venue: Proceedings of the ACM/IFIP/USENIX 2003 International Conference on Middleware (2003)

We present an automated run-time optimisation framework that can improve the performance of distributed applications written using Java RMI whilst preserving its semantics. Java classes are modified at load-time in order to intercept RMI calls as they occur. RMI calls are not executed immediately, but are delayed for as long as possible. When a dependence forces execution of the delayed calls, the aggregated calls are sent over to the remote server to be executed in one step. This reduces network overhead and the quantity of data sent, since data can be shared between calls. The sequence of calls may be cached on the server side along with any known constants in order to speed up future calls. A remote server may also make RMI calls to another remote server on behalf of the client if necessary. Our results show that the techniques can speed up distributed programs significantly, especially when operating across slower networks. We also discuss some of the challenges involved in maintaining program semantics, and show how the approach can be used for more ambitious optimisations in the future.
Concurrency coordination in a locally distributed database system
Authors: Gruia-Catalin Roman
Venue: Proceedings of the May 19-22, 1980, national computer conference (1980)

A database is called internally consistent (or just consistent) with respect to a given set of invariant properties if, in the absence of any database activity, the above said invariants hold true. These properties reflect relations among objects of the application domain and characterize its semantic consistency (e.g., 'last name appears first on all government forms'). Because a single database may support many different applications, these relations are generally assumed to be known solely by the database user and not by the database designer. The very definition of a transaction (a sequence of primitive database activities which, when acting alone, preserves, as a whole, all invariants) is in recognition of the fact that it is the user's duty to guarantee the integrity of the data he manipulates.
JMT: performance engineering tools for system modeling
Authors: Marco Bertoli, Giuliano Casale, Giuseppe Serazzi
Venue: ACM SIGMETRICS Performance Evaluation Review (2009)

We present the Java Modelling Tools (JMT) suite, an integrated framework of Java tools for performance evaluation of computer systems using queueing models. The suite offers a rich user interface that simplifies the definition of performance models by means of wizard dialogs and of a graphical design workspace. The performance evaluation features of JMT span a wide range of state-of-the-art methodologies including discrete-event simulation, mean value analysis of product-form networks, analytical identification of bottleneck resources in multiclass environments, and workload characterization with fuzzy clustering. The discrete-event simulator supports several advanced modeling features such as finite capacity regions, load-dependent service times, bursty processes, fork-and-join nodes, and implements spectral estimation for analysis of simulative results. The suite is open-source, released under the GNU general public license (GPL), and it is available for free download at: http://jmt.sourceforge.net.
Exploration of distributional models for a novel intensity-dependent normalization procedure in censored gene expression data
Authors: Nicola Lama, Patrizia Boracchi, Elia Biganzoli
Venue: Computational Statistics Data Analysis (2009)

Current gene intensity-dependent normalization methods, based on regression smoothing techniques, usually approach the two problems of reducing location bias and data rescaling without taking into account the censoring that is characteristic of certain gene expressions, produced by experimental measurement constraints or by previous normalization steps. Moreover, control of normalization procedures for balancing bias versus variance is often left to the user's experience. An approximate maximum likelihood procedure for fitting a model smoothing the dependences of log-fold gene expression differences on average gene intensities is presented. Central tendency and scaling factor are modeled by means of the B-spline smoothing technique. As an alternative to the outlier theory and robust methods, the approach presented looks for suitable distributional models, possibly generalizing the classical Gaussian and Laplacian assumptions, controlling for different types of censoring. The Bayesian information criterion is adopted for model selection. Distributional assumptions are tested using goodness-of-fit statistics and Monte Carlo evaluation. Randomization quantiles are proposed to produce normally distributed adjusted data. Three publicly available data sets are analyzed for demonstration purposes. Student's t error models reveal best performances in all of the data sets considered. More validating evidence is needed to evaluate the Asymmetric Laplace distribution, which showed interesting results in one data set.
Checking timed B&uuml;chi automata emptiness on simulation graphs
Authors: Stavros Tripakis
Venue: ACM Transactions on Computational Logic (TOCL) (2009)

Timed automata [Alur and Dill 1994] comprise a popular model for describing real-time and embedded systems and reasoning formally about them. Efficient model-checking algorithms have been developed and implemented in tools such as Kronos [Daws et al. 1996] or Uppaal [Larsen et al. 1997] for checking safety properties on this model, which amounts to reachability. These algorithms use the so-called zone-closed simulation graph, a finite graph that admits efficient representation and has been recently shown to preserve reachability [Bouyer 2004]. Building upon Bouyer [2004] and our previous work [Bouajjani et al. 1997; Tripakis et al. 2005], we show that this graph can also be used for checking liveness properties, in particular, emptiness of timed B&uuml;chi automata.
Linear filtering in DCT IV/DST IV and MDCT/MDST domain
Authors: K. Suresh, T. V. Sreenivas
Venue: Signal Processing (2009)

In this paper, expressions for convolution multiplication properties of DCT IV and DST IV are derived starting from equivalent DFT representations. Using these expressions methods for implementing linear filtering through block convolution in the DCT IV and DST IV domain are proposed. Techniques developed for DCT IV and DST IV are further extended to MDCT and MDST where the filter implementation is near exact for symmetric filters and approximate for non-symmetric filters. No additional overlapping is required for implementing the symmetric filtering in the MDCT domain and hence the proposed algorithm is computationally competitive with DFT based systems. Moreover, inherent 50% overlap between the adjacent frames used for MDCT/MDST domain reduces the blocking artifacts due to block processing or quantization. The techniques are computationally efficient for symmetric filters and provides a new alternative to DFT based convolution.
Design and simulation of a normally closed glucose sensitive hydrogel based microvalve
Authors: Masoomeh Tehranirokh, Burhanuddin Yeop Majlis, Badariah Bais
Venue: Microsystem Technologies (2009)

In drug delivery systems microvalves are the key components that have been developed for active control of drugs. In this research a normally closed microvalve with a glucose sensitive hydrogel actuating system is designed and simulated. Swelling of the hydrogel forces a silicone rubber membrane to deflect and causes the valve to be opened. The component of the valve that can be opened because of the hydrogel pressure is a silicon nitride cantilever beam which is sealed with a parylene layer. Simulations have been done by FEM analysis and the results show that membrane deflection is large enough to enable the valve to be opened and the fluid to flow through the microchannel. For both rectangular and trapezoidal microchannels with various hydraulic diameters, output flow rates less than 50&#x00a0;&#x03bc;l/min to several hundreds of &#x03bc;l/min can be achieved. Final design has been optimized for the opening point of microvalve at glucose concentration of 15&#x00a0;mM. Overall investigation has been done for a microvalve with specific dimensions and with 4&#x00a0;kPa input pressure the output flow rate of 100&#x00a0;&#x03bc;l/min has been generated which is in the desired range.
Norm negotiation in online multi-player games
Authors: Guido Boella, Patrice Caire, Leendert van der Torre
Venue: Knowledge and Information Systems (2009)

In this paper, we introduce an agent communication protocol and speech acts for norm negotiation. The protocol creates individual or contractual obligations to fulfill goals of the agents based on the so-called social delegation cycle. First, agents communicate their individual goals and powers. Second, they propose social goals which can be accepted or rejected by other agents. Third, they propose obligations and sanctions to achieve the social goal, which can again be accepted or rejected. Finally, the agents accept the new norm by indicating which of their communicated individual goals the norm achieves. The semantics of the speech acts is based on a commitment to public mental attitudes. The norm negotiation model is illustrated by an example of norm negotiation in multi-player online gaming.
A Quality of Service Assessment Technique for Large-Scale Management of Multimedia Flows
Authors: J. L. García-Dorado, J. Aracil, J. A. Hernández, S. Lopez-Buedo, J. E. Vergara, P. Reviriego, G. Huecas, S. Pavón, J. Quemada
Venue: Proceedings of the 10th IFIP/IEEE International Conference on Management of Multimedia and Mobile Networks and Services: Real-Time Mobile Multimedia Services (2008)

This paper presents the concept and preliminary experiments of a system for assessing on the Quality of Service of multimedia flows. The goal is to devise a mechanism that allows a service provider to take action whenever poor quality of service is detected in the delivery of multimedia flows. Such procedure is fully automatic since it is based on a goodness-of-fit test between source and destination packet interarrival histograms. If the null hypothesis of the test is accepted the flow is marked as in good standing, otherwise it is marked as anomalous and the network management system should take action in response. The proposed technique is analyzed in terms of hardware complexity and bandwidth consumption. The results show this technique is feasible and easily deployable at a minimum hardware and bandwidth expense.