ppxscal/embedding_network huggingface dataset:
Can we refactor conditional compilation into aspects?
Authors: Bram Adams, Wolfgang De Meuter, Herman Tromp, Ahmed E. Hassan
Venue: Proceedings of the 8th ACM international conference on Aspect-oriented software development (2009)

Systems software uses conditional compilation to manage crosscutting concerns in a very fine-grained and efficient way, but at the expense of tangled and scattered conditional code. Refactoring of conditional compilation into aspects gets rid of these issues, but it is not clear yet for which patterns of conditional compilation aspects make sense and whether or not current aspect technology is able to express these patterns. To investigate these two problems, this paper presents a graphical ``preprocessor blueprint'' model which offers a queryable representation of the syntactical interaction of conditional compilation and the source code. A case study on the Parrot VM shows that preprocessor blueprints are able to express and query for the four commonly known patterns of conditional compilation usage, and that they allow to discover seven additional important patterns. By correlating each pattern's potential for refactoring into advice and each pattern's evolution of the number of occurrences, we show that refactoring into advice in the Parrot VM is a good alternative for three of the eleven patterns, whereas for the other patterns trade-offs have to be considered between robustness and fine-grainedness of the advice.
Bialgebraic methods and modal logic in structural operational semantics
Authors: Bartek Klin
Venue: Information and Computation (2009)

Bialgebraic semantics, invented a decade ago by Turi and Plotkin, is an approach to formal reasoning about well-behaved structural operational semantics (SOS). An extension of algebraic and coalgebraic methods, it abstracts from concrete notions of syntax and system behaviour, thus treating various kinds of operational descriptions in a uniform fashion. In this paper, bialgebraic semantics is combined with a coalgebraic approach to modal logic in a novel, general approach to proving the compositionality of process equivalences for languages defined by structural operational semantics. To prove compositionality, one provides a notion of behaviour for logical formulas, and defines an SOS-like specification of modal operators which reflects the original SOS specification of the language. This approach can be used to define SOS congruence formats as well as to prove compositionality for specific languages and equivalences.
Pushback: A hidden Markov model based scheme for energy efficient data transmission in sensor networks
Authors: Sha Liu, Rahul Srivastava, Can Emre Koksal, Prasun Sinha
Venue: Ad Hoc Networks (2009)

In sensor networks, application layer QoS requirements are critical to meet while conserving energy. One of the leading factors for energy wastage is failed transmission attempts due to channel dynamics and interference. Existing techniques are unaware of the channel dynamics and lead to suboptimal channel access patterns. We propose a MAC layer solution called pushback, that appropriately delays packet transmissions to overcome periods of poor channel quality and high interference, while ensuring that the throughput requirement of the node is met. It uses a hidden Markov model (HMM) based channel model that is maintained without any additional signaling overhead. The pushback algorithm is shown to improve the packet success rate by up to 71% and reduce the number of transmissions needed by up to 38% while ensuring the same throughput.
Modelling and Measurement of Active Particle Plasma Chemical Reactions in Water by Pulsed Discharge
Authors: Sheng Lan, Jia-xiang Yang, Jie-ling Jiang
Venue: Proceedings of the 2009 International Conference on Advanced Computer Control (2009)

As the reactions of plasma particles produced by pulse discharge in water are complex, the software CEA2 is employed to simulate and compute the content of each species of product in the plasma channel by converting discharge energy into enthalpy. The respective content of OH and H2O2 is measured by chemical methods in the self-developed reaction device. It is found that experimentally-detected concentrations of OH and H2O2 have the same orders of magnitude with theoretical concentrations given by CEA2 software. The result shows that the calculation here is reasonable and the experimental method here is feasible. The results of calculation and experiment can provide references for further study on organic matters-polluted water treatment by the method of discharge in water.
Description of the HYPERMEDIA ACTS-361 Project: Continuous Audiovisual Market in Europe
Authors: G. Cisneros, P. Fernandez, J. L. Lerma, O. Martinez, J. M. Menendez, J. M. Martinez, J. Bescos, J. Cabrera, A. Orero, J. M. Lopez, J. Chaparro, F. Pascual, L. Torres, L. Lorente, C. Pastor, M. Rodriguez, A. Melguizo, J. Mangas, M. A. Panduro, A. Molina, J. R. Lopez, J. Delgado, J. Fernandez, A. Munoz, S. Vicente, C. Brendes, F. Kozamernik, L. Cacho, G. Alberico, H. Ecija, M. del Rio, J. Salmeron, F. Labrada
Venue: Proceedings of the 1999 IEEE International Conference on Multimedia Computing and Systems - Volume 02 (1999)

HYPERMEDIA (AC361) is a project actually running under the ACTS Programme of the European Commission. It started June 1st, 1998 and will extend for 2 years. Actually, there is an open market framework to deploy interactive telecommunication services dealing with browsing, handling, and delivery of continuous information media: Communication and Media Corporations compete to offer the best services to their final users. HYPERMEDIA will show a complete pilot solution for service provisioning within this Continuous Audiovisual Market attending to all its aspects (metadata, video indexing tools for content based metadata generation, database and network architectures, Intellectual Property Rights services), evaluated on the basis of a realistic trial implemented in the project. HYPERMEDIA will make a follow up and will contribute to standardisation efforts on content based metadata such as MPEG-7. There is an important challenge to avoid being overtaken by products of the marketplace and research advances during the execution of the project.
Encoding Subsystem Codes with and without Noisy Gauge Qubits
Authors: Pradeep Kiran Sarvepalli, Andreas Klappenecker
Venue: Proceedings of the 2009 Third International Conference on Quantum, Nano and Micro Technologies (2009)

In this paper, we investigate a rather neglected aspect of subsystem codes viz. that of encoding. We show that encoding of subsystem codes can be reduced to encoding of a related stabilizer code making it possible to use the known results on encoding of stabilizer codes. Along the way we also show how Clifford codes can be encoded. These encoding schemes can tolerate initialization errors on the gauge qubits. This tolerance can be traded for reduced encoding complexity.
Differential quadrature solution of nonlinear reaction-diffusion equation with relaxation-type time integration
Authors: G. Meral, M. Tezer-Sezgin
Venue: International Journal of Computer Mathematics (2009)

This paper presents the combined application of differential quadrature method (DQM) and finite-difference method (FDM) with a relaxation parameter to nonlinear reaction-diffusion equation in one and two dimensions. The polynomial-based DQM is employed to discretize the spatial partial derivatives by using Gauss-Chebyshev-Lobatto points. The resulting system of ordinary differential equations is solved, discretizating the time derivative by an explicit FDM. A relaxation parameter is used to position the solution from the two time levels, aiming to increase the convergence rate with a moderate time step to the steady state and also to obtain stable solution. Numerical experiments are given to illustrate the scheme for one-dimensional Fisher-type problems and also for two-dimensional reaction-diffusion boundary-value problems. The agreement of the solution with the exact solution is very good in two-dimensional case while some other numerical schemes may result in some unwanted oscillations in the computed solution. Optimal value of the relaxation parameter is obtained numerically to prevent the use of very small time steps and to achieve stable solutions. The DQM with a relaxation-type finite-difference time integration scheme exhibits superior accuracy at large time values for the problems tending towards a steady state.
Phrase based browsing for simulation traces of network protocols
Authors: Nathan J. Schmidt, Peter Kemper
Venue: Proceedings of the 40th Conference on Winter Simulation (2008)

Most discrete event simulation frameworks are able to output simulation runs as a trace. The Network Simulator 2 (NS2) is a prominent example that does so to decouple generation of dynamic behavior from its evaluation. If a modeler is interested in the specific details and confronted with lengthy traces from simulation runs, support is needed to identify relevant pieces of information. In this paper, we present a new phrase-based browser that has its roots in information retrieval, language acquisition and text compression which is refined to work with trace data derived from simulation models. The browser is a new navigation feature of Traviando, a trace visualizer and analyzer for simulation traces. The browsing technique allows a modeler to investigate particular patterns seen in a trace, that may be of interest due to their frequent or rare occurrence. We demonstrate how this approach applies to traces generated with NS2.
Efficient Learning of Finite Mixture Densities Using Mutual Information
Authors: Padmini Jaikumar, Abhishek Singh, Suman K. Mitra
Venue: Proceedings of the 2009 Seventh International Conference on Advances in Pattern Recognition (2009)

This paper presents a technique of determining the optimum number of components in a mixture model. A count of the number of local maxima in the density of the data is first used to obtain a rough guess of the actual number of components. Mutual Information criteria are then used to judge if components need to be added or removed in order to reach the optimum number. An incremental K-means algorithm is used to add components to the mixture model if required. An obvious advantage of the proposed method is in terms of computational time, as a good guess of the optimum number of components is quickly obtained. The technique has been successfully tested on a variety of univariate as well as bivariate simulated data and the Iris dataset.
Facsimile image coding
Authors: Joan L. Mitchell
Venue: Proceedings of the May 19-22, 1980, national computer conference (1980)

Facsimile image coding has recently received a lot of attention because of the standardization work being done in this area by the International Telegraph and Telephone Consultative Committee (CCITT). In November, 1977, CCITT Study Group XIV standardized a one-dimensional data compression scheme for facsimile images. Two years later this standard was incorporated in a recommended two-dimensional coding scheme.
Tracking performance and average error analysis of GPS discriminators in multipath
Authors: Liyu Liu, Moeness G. Amin
Venue: Signal Processing (2009)

Signal multipath in GPS leads to undesirable tracking errors and inaccurate ranging information. The extent of the tracking error in compromising the receiver performance depends on the multipath amplitude, delay, and phase relative to the direct path. The coherent discriminator and the noncoherent early-minus-late power discriminator offer different tracking accuracy and sensitivity to multipath parameters. In this paper, we develop analyses of the effect of multipath carrier phase offset on GPS tracking error bounds as well as statistical average error values. Although the two receiver discriminators share the same performance bounds, they differ in their response to the multipath within these bounds. The analytical expressions for this response provide the framework to assess the average performance of the two discriminators over the multipath phase distribution and other important propagation channel variables.
A Novel Backoff Algorithm Based on the Tradeoff of Efficiency and Fairness for Ad hoc Networks
Authors: Hai-Xia Cui, Gang Wei
Venue: Proceedings of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 02 (2009)

Since the wireless medium is a scarce resource, design of efficient medium access control (MAC) protocols with both high throughput and high fairness is significantly important for distributed ad hoc networks. Many current MAC protocols use an exponential backoff mechanism. In that mechanism, a node picks a random backoff time uniformly in an interval that doubles in size after a collision or decreases to the minimum value after a successful transmission. It can cause unfairness problem to some nodes. In this paper, we propose a novel and efficient contention-based backoff mechanism for wireless ad hoc networks, namely, the adaptive efficiency-fairness tradeoff (AEFT) backoff algorithm, which provides not only a higher throughput and a larger fairness index, but also a tradeoff between efficiency and fairness. We increase the contention window when the channel is busy, and use an adaptive window to fast decrease the backoff time when the channel is idle by fair scheduling. The fair scheduling mainly adopts maximum successive transmission and collision limit to finish the fairness.
Force Versus Majority: A Comparison in Convention Emergence Efficiency
Authors: Paulo Urbano, João Balsa, Luis Antunes, Luis Moniz
Venue: Coordination, Organizations, Institutions and Norms in Agent Systems IV: COIN 2008 International Workshops, COIN@AAMAS 2008, Estoril, Portugal, May 12, 2008. COIN@AAAI 2008, Chicago, USA, July 14, 2008. Revised Selected Papers (2009)

In open societies such as multi-agent systems, it is important that coordination among the several actors is achieved efficiently. One economical way of capturing that aspiration is consensus: social conventions and lexicons are good examples of coordinating systems, where uniformity promotes shared expectations of behavior and shared meanings. We are particularly interested in consensus that is achieved without any central control or ruling, through decentralized mechanisms that prove to be effective, efficient, and robust. The nature of interactions and also the nature of society configurations may promote or inhibit consensual emergence. Traditionally, preference to adopt the most seen choices (the majority option) has dominated the emergence convention research in multi-agents, being analyzed along different social topologies.Recently, we have introduced a different type of interaction, based on force, where force is not defined a priori but evolves dynamically. We compare the Majority class of choice update against Force based interactions, along three dimensions: types of encounters, rules of interaction and network topologies. Our experiments show that interactions based on Force are significantly more efficient (fewer encounters) for group decision making.
Minimizing the energy cost of throughput in a linear pipeline by opportunistic time borrowing
Authors: Mohammad Ghasemazar, Massoud Pedram
Venue: Proceedings of the 2008 IEEE/ACM International Conference on Computer-Aided Design (2008)

In this paper, we present a technique to optimize the energy-delay product of a synchronous linear pipeline circuit with dynamic error detection and correction capability running. The technique dynamically adjusts the supply voltage level and clock frequency of the design by exploiting slacks that are present in various stages of the pipeline. The key enabler is the utilization of soft-edge flip-flops to allow time borrowing between consecutive stages of the pipeline in order to provide the timing-critical stages with more time to complete their computations resulting in lower error probability. This raises the effective throughput of the pipeline for a fixed energy consumption level, or alternatively, lowers the energy consumption for the same effective throughput. We formulate the problem of optimally selecting the transparency window sizes of the soft-edge flip-flops and the frequency level of the pipeline circuit at different voltage levels so as to optimize the energy cost of the achieved throughput. Experimental results show the efficacy of the problem formulation and solution technique.
A Semantic Web-Based Architecture to Support Product Data Management Systems
Authors: Marcela Vegetti, Luis Larrateguy, Silvio Gonnet, Horacio Leone
Venue: Proceedings of the 2008 Latin American Web Conference (2008)

The distributed, dynamic and disparate nature of the information in supply chains is a major obstacle to gather the dispersed information required for the function of an enterprise. This obstacle affects the product data management’s functionality and capability. However, the recent advance in Semantic Web technologies gives the opportunity to overcome it. This contribution proposes a Semantic Web-based architecture that supports the formulation of queries about the structure of products whose components are manufactured by different nodes of a supply chain that apply the concept of collaborative product development. The integration of different sources of information is achieved by means of a common vocabulary defined by an ontology, but locally keeping data management in each node of the supply chain.
The Research and Scheme of J2EE Based Access Decision Services
Authors: Fangzhou Zhang, Dan Wang, Linlin Zhang
Venue: Proceedings of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 03 (2009)

Access control is an effective method to deal with internet attacks. It has problems in some application fields, such as bigger granularity, not easy to assure the consistency of authority policies and so on. The paper proposed the model of J2EE Based Access Decision Services --- JRADS according to the comprehensive application of J2EE in the distributed environment. It separated the authority logic of application level from the application logic so that to solve the access control problem of distributed application sources better. First, the paper showed the interface between application systems and JRADS. Then it designed the logic components of JRADS. Next, it designed the main functional elements, supervisory elements and their corresponding assistant components. Finally, the paper realized the interface and its method of the JRADS model. It has obtained the anticipatory effects by deployment and application in the basic condition platform of national science and technology.
Specifying target resources in a machine independent higher level language
Authors: Scott Davidson, Bruce D. Shriver
Venue: Proceedings of the May 4-7, 1981, national computer conference (1981)

Each Higher Level Language (HLL) defines a virtual machine. A compiler for a HLL translates a program written for this virtual machine into a program for a lower level target virtual machine, which could be at the operating system, machine language, microcode, or other level. The space and time needed to run the compiled program are influenced by the difference between the functionality and semantics of the source and target virtual machines (semantic gap). As part of the translation process, a compiler binds source language constructs to target language constructs. For example, a variable in a program will be bound to a memory location, and an operator in a program (such as Plus) will be bound to a target machine functional unit (such as an Adder).
Modeling interaction join point adaptations independent of pointcut models using UML stereotypes
Authors: Mariam Nainan
Venue: Proceedings of the 13th workshop on Aspect-oriented modeling (2009)

Several approaches to aspect-oriented modeling of interactions are based on modeling pointcuts that select join points (pointcut models) and modeling adaptations needed at those join points (adaptation models). A common limitation of most of these approaches is that they couple the two models together because identifiers in adaptation models reference those in pointcut models or the same type of diagram is used to represent both models. If it is possible to use pointcut and adaptation models independently of each other, aspect-oriented modeling would be more flexible because, for example, a diagram type can be chosen based on its appropriateness in expressing the model instead of having to consistently use the same type of diagram. This paper proposes a technique for creating interaction adaptation models that are independent of the pointcut models used to capture join points. The technique uses Unified Modeling Language profiles and stereotypes. Examples are also given of how the profile is used to define a generic adaptation model and how the generic model is specialized.
An Efficient Searching Algorithm for Approximate Nearest Neighbor Queries in High Dimensions
Authors: Sakti Pramanik, Scott Alexander, Jinhua Li
Venue: Proceedings of the IEEE International Conference on Multimedia Computing and Systems - Volume 2 (1999)

In this paper, we present an approximate nearest neighbor search algorithm that use heuristics to decide whether or not to access a node in the index tree based on three interesting data distribution properties. We demonstrate that the proposed algorithm significantly reduces the number of nodes accessed over the algorithms that have been proposed in earlier works. Also, it will be demonstrated in this paper that the proposed algorithm can retain close to 100% of the K nearest neighbors in most cases.
Scalable synchronous queues
Authors: William N. Scherer,  III, Doug Lea, Michael L. Scott
Venue: Communications of the ACM (2009)

In a thread-safe concurrent queue, consumers typically wait for producers to make data available. In a synchronous queue, producers similarly wait for consumers to take the data. We present two new nonblocking, contention-free synchronous queues that achieve high performance through a form of dualism: The underlying data structure may hold both data and, symmetrically, requests. We present performance results on 16-processor SPARC and 4-processor Opteron machines. We compare our algorithms to commonly used alternatives from the literature and from the Java SE 5.0 class java.util.concurrent.SynchronousQueue both directly in synthetic microbenchmarks and indirectly as the core of Java's ThreadPoolExecutor mechanism. Our new algorithms consistently outperform the Java SE 5.0 SynchronousQueue by factors of three in unfair mode and 14 in fair mode; this translates to factors of two and ten for the ThreadPoolExecutor. Our synchronous queues have been adopted for inclusion in Java 6.
A formalism for reasoning about UML activity diagrams
Authors: Vitus S. W. Lam
Venue: Nordic Journal of Computing (2007)

The major problem of UML activity diagrams is the lack of a rigorous approach for verifying the correctness of a model. In this paper, we examine how activity diagrams defined in UML 2.0 standard are formally analyzed using NuSMV model checker. A model represented as activity diagrams is first transformed into NuSMV input language and then verified that a set of system specifications is satisfied using NuSMV.