ppxscal/embedding_network huggingface dataset:
Algorithms for solving the train dispatching problem for general networks
Authors: Maged Dessouky
Venue:  (2006)

Recently, the research community has focused on the problem of efficient movement of freight by rail since there has been a tremendous increase in worldwide container trade. For example, there is an estimation that the Ports of Los Angeles and Long Beach (San Pedro Bay Ports), which are one of the busiest ports in North America, will double their current cargo by year 2020. This raises the demand for freight trains and leads to congestion in rail operation. Several train studies in the past focused on solving the train scheduling problem by simplifying and omitting many realistic characteristics such as trackage configurations or speed restrictions. However, we incorporate these characteristics into our models so we can obtain a solution that can be easily applied to actual railway operations more efficiently. These characteristics include multiple trackage configurations, multiple train types, multiple train lengths, multiple speed limit restrictions, and incorporation of acceleration and deceleration rates. The purpose of this research is to optimize the train travel time for general rail networks. We formulate a nonlinear integer mathematical model with an objective function to minimize the travel time. Since the model is computationally intractable to solve optimally, we present a heuristic based on a genetic algorithm to solve the problem. We benchmark our algorithm against standard procedures for train scheduling. We study both the static and dynamic scheduling problems since each of those problems has their own unique characteristics.
Increased Retention of Early Computer Science and Software Engineering Students Using Pair Programming
Authors: Jeffrey C. Carver, Lisa Henderson, Lulu He, Julia Hodges, Donna Reese
Venue: Proceedings of the 20th Conference on Software Engineering Education & Training (2007)

An important problem faced by many Computer Science and Software Engineering programs is declining enrollment. In an effort to reverse that trend at Mississippi State University, we have instituted pair programming for the laboratory exercises in the introductory programming course. This paper describes a study performed to analyze whether using pair programming would increase retention. An important goal of this study was not only to measure increased retention, but to provide insight into why retention increased or decreased. The results of the study showed that retention significantly increased for those students already majoring in Computer Science, Software Engineering, or Computer Engineering. In addition, survey results indicated that the students viewed many aspects of pair programming to be very beneficial to their learning experience.
A Chained-Directory Cache Choerence Protocol for Multiprocessors
Authors: Soon M. Chung, Longxue Li
Venue: Proceedings of the 1993 International Conference on Parallel Processing - Volume 01 (1993)

In this paper, a chained-directory cache coherence protocol for a shared-memory multiprocessor sys tem is proposed, which uses linked lists to store the informa tion for the coherence maintenance. The proposed scheme uses small memory space and has high scalability, and it requires less memory accesses by distributing the coherence maintenance to caches. We evaluated the performance of the proposed scheme, and compared it with those of two other directory-based schemes; the singly-linked list and the fullmap schemes. The analysis shows that the proposed scheme provides better processor utilization and results in less memory contention.
Transmit adaptive array without user-specific pilot for 3G CDMA
Authors: B. Raghothaman
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

The transmit adaptive array (TxAA) is one of the promising closed-loop downlink diversity schemes being considered for the third generation wireless systems based on code division multiple access (CDMA). The TxAA technique originally proposed, requires a user-specific auxiliary pilot for coherent demodulation. This affects the capacity of the system due to additional power being used by this pilot. The mobile receiver requires additional hardware correlators for demodulating the pilot. Since different channels in spread spectrum systems are distinguished by their spreading sequences, it also uses up an additional Walsh code per user. This paper proposes a decision directed method for demodulation which does not require a user-specific pilot. Our simulations demonstrate that the performance of the technique is comparable to that of the method based on a user specific pilot.
Robust segmentation and representation of foreground key regions in video sequences
Authors: J. R. Hidalgo
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

This paper deals with the extraction and characterization of foreground objects in video sequences. The algorithm first computes the mosaic image representing the background information and then extracts foreground objects. In this last step, the foreground objects are progressively extracted taking into account the reliability of the contour information. This extraction step is based on morphological tools. Finally, the foreground objects are characterized by their shape, texture and motion trajectory. Moreover, some information about the temporal evolution of non rigid objects is also extracted. This feature extraction algorithm is particularly suitable for the indexing, search and retrieval applications.
Driving Component Composition from Early Stages Using Aspect-Oriented Techniques
Authors: Pedro J. Clemente, Juan Hernandez, Fernando Sanchez
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Component-based software engineering is an emerging discipline that is generating tremendous interest due to the development of plug-and-play reusable software. However, component adaptation and later composition still challenges the software engineering community because of the binary nature of software components. Once a binary component is ready to market, its contract cannot be changed in order to be adapted to new contexts or new requirements. Aspect-orientation facilitates software adaptation and evolution by increasing software modularization. In this sense, aspect-oriented mechanisms can obviates contracts to weave new behaviour to an already developed system by means of hooks and behaviour attached to theses hooks. In this paper, a component composition mechanism based on aspect-oriented techniques is presented, which extends typical composition based on interfaces or events. Components and their composition are modeled using UML at early development phases. Our approach is based on model-driven development (MDD), allowing systems to be built from analysis to deployment, automatically generating the required artifacts (such as wrappers or assembly descriptors). This work has been developed using CCM as the component model.
Model-Based Empirical Performance Evaluation Based on Relational Traces
Authors: Marko Boskovic
Venue: Proceedings of the 14th Annual IEEE International Conference and Workshops on the Engineering of Computer-Based Systems (2007)

Empirical performance evaluation is the process of measuring and calculating performance metrics of deployed software systems. It is a part of performance validation during testing of a software system. The topic of this thesis is an approach for the empirical performance evaluation in the context of model-driven engineering. The hypothesis which will be examined is whether concepts of the temporal databases theory can be used as a general way for empirical performance evaluation of model-driven developed software.
deal.II&mdash;A general-purpose object-oriented finite element library
Authors: W. Bangerth, R. Hartmann, G. Kanschat
Venue: ACM Transactions on Mathematical Software (TOMS) (2007)

An overview of the software design and data abstraction decisions chosen for deal.II, a general purpose finite element library written in C&plus;&plus;, is given. The library uses advanced object-oriented and data encapsulation techniques to break finite element implementations into smaller blocks that can be arranged to fit users requirements. Through this approach, deal.II supports a large number of different applications covering a wide range of scientific areas, programming methodologies, and application-specific algorithms, without imposing a rigid framework into which they have to fit. A judicious use of programming techniques allows us to avoid the computational costs frequently associated with abstract object-oriented class libraries. The paper presents a detailed description of the abstractions chosen for defining geometric information of meshes and the handling of degrees of freedom associated with finite element spaces, as well as of linear algebra, input/output capabilities and of interfaces to other software, such as visualization tools. Finally, some results obtained with applications built atop deal.II are shown to demonstrate the powerful capabilities of this toolbox.
WEAVER codes: highly fault tolerant erasure codes for storage systems
Authors: James Lee Hafner
Venue: Proceedings of the 4th conference on USENIX Conference on File and Storage Technologies - Volume 4 (2005)

We present the WEAVER codes, new families of simple highly fault tolerant XOR-based erasure codes for storage systems (with fault tolerance up to 12). The design features of WEAVER codes are (a) placement of data and parity blocks on the same strip, (b) constrained parity in-degree and (c) balance and symmetry. These codes are in general not maximum distance separable (MDS) but have optimal storage efficiency among all codes with constrained parity in-degree. Though applicable to RAID controller systems, the WEAVER codes are probably best suited in dRAID systems (distributed Redundant Arrangement of Independent Devices). We discuss the advantages these codes have over many other erasure codes for storage systems.
Adaptive data placement for wide-area sensing services
Authors: Suman Nath, Phillip B. Gibbons, Srinivasan Seshan
Venue: Proceedings of the 4th conference on USENIX Conference on File and Storage Technologies - Volume 4 (2005)

Wide-area sensing services enable users to query data collected from multitudes of widely distributed sensors. In this paper, we consider the novel distributed database workload characteristics of these services, and present IDP, an online, adaptive data placement and replication system tailored to this workload. Given a hierarchical database, IDP automatically partitions it among a set of networked hosts, and replicates portions of it. IDP makes decisions based on measurements of access locality within the database, read and write load for individual objects within the database, proximity between queriers and potential replicas, and total load on hosts participating in the database. Our evaluation of IDP under real and synthetic workloads, including flash crowds of queriers, demonstrates that in comparison with previously-studied replica placement techniques, IDP reduces average response times for user queries by up to a factor of 3 and reduces network traffic for queries, updates, and data movements by up to an order of magnitude.
A software test program generator for verifying system-on-chips
Authors: A. Cheng, Cheng-Chew Lim, A. Parashkevov
Venue: Proceedings of the High-Level Design Validation and Test Workshop, 2005. on Tenth IEEE International (2005)

Design verification is crucial for successful systems-on-chips (SoCs). However, validating and proving the correctness of SoCs is often a bottleneck in the design project. This paper presents a technique to test the SoC at the system level using software application based programs. Our software application level verification methodology (SALVEM) employs test programs composed of dynamic sequences of software code segments. The SALVEM system implements a test generator to create these software test programs automatically. Experiments were conducted applying SALVEM tests to the Altera Nios SoC. A feedback verification flow is also feasible in our SALVEM system. SALVEM test runs are analyzed to direct the test generator toward important SoC scenarios.
Reasoning about Nonblocking Concurrency using Reduction
Authors: Lindsay Groves
Venue: Proceedings of the 12th IEEE International Conference on Engineering Complex Computer Systems (2007)

Reduction methods developed by Lipton, Lamport, Cohen, and others, allow one to reason about concurrent programs at various levels of atomicity. An action which is considered to be atomic at one level may be implemented by more complex code at the next level. We can show that certain properties of the program are preserved by first showing that the property holds when the expanded code is executed sequentially, and then showing that any execution in which this code is executed concurrently with other processes is equivalent to an execution in which the expanded code is executed without interruption. Existing reduction methods are aimed at traditional approaches to concurrency which prevent interference between concurrent processes using mechanisms such as locks or semaphores. In this paper, we show that these reduction methods can be adapted to reason about nonblocking algorithms, which are designed to operate correctly in the presence of interference, rather than to avoid interference. These algorithms typically use strong synchronisation primitives, such as Load Linked/Store Conditional or Compare and Swap, to detect that interference has occurred and in that case retry their operations. We show that reduction can be used with such algorithms, and illustrate this approach with examples based on shared counters and stacks.
The object binary interface: C++ objects for evolvable shared class libraries
Authors: Theodore C. Goldstein, Alan D. Sloane
Venue: Proceedings of the 6th conference on USENIX Sixth C++ Technical Conference - Volume 6 (1994)

Object-oriented design and object-oriented languages support the development of independent software components such as class libraries. When using such components, versioning becomes a key issue. While various ad-hoc techniques and coding idioms have been used to provide versioning, all of these techniques have deficiencies - ambiguity, the necessity of recompilation or re-coding, or the loss of binary compatibility of programs. Components from different software vendors are versioned at different times. Maintaining compatibility between versions must be consciously engineered. New technologies such as distributed objects further complicate libraries by requiring multiple implementations of a type simultaneously in a program. This paper describes a new C++ object model called the Shared Object Model for C++ users and a new implementation model called the Object Binary Interface for C++ implementors.These techniques provide a mechanism for allowing multiple implementations of an object in a program. Early analysis of this approach has shown it to have performance broadly comparable to conventional implementations.
About yes&#x002F;no queries against possibilistic databases: Research Articles
Authors: Patrick Bosc, Olivier Pivert
Venue: International Journal of Intelligent Systems (2007)

This article is concerned with the handling of imprecise information in databases. The need for dealing with imprecise data is more and more acknowledged in order to cope with real data, even if commercial systems are most of the time unable to manage them. Here, the possibilistic setting is taken into consideration because it is less demanding than the probabilistic one. Then, any imprecise piece of information is modeled as a possibility distribution intended for constraining the more or less acceptable values. Such a possibilistic database has a natural interpretation in terms of a set of regular databases, which provides the basic gateway to interpret queries. However, if this approach is sound, it is not realistic, and it is necessary to consider restricted queries for which a calculus grounded on the possibilistic database, that is, where the operators work directly on possibilistic relations, is feasible. Extended yes&#x002F;no queries are dealt with here, where their general form is: &ldquo;to what extent is it possible and certain that tuple t (given) belongs to the answer to Q,&rdquo; where Q is an algebraic relational query. A strategy for processing such queries efficiently is proposed under some assumptions as to the operators appearing in Q. &copy; 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 691&ndash;721, 2007.
Evolutionary benefits of evolvable component integration
Authors: David Malkin, R. Beau Lotto
Venue: Proceedings of the 2007 GECCO conference companion on Genetic and evolutionary computation (2007)

A system composed of multiple interacting components is capable of responding to contextual information and producing a higher range of non-linear responses to stimuli compared to modular systems with a low degree of component interaction. However, the fitness landscape of highly integrated systems is more rugged indicating that such systems are likely to be less evolvable. In this work we use an artificial life simulation to investigate whether the evolvability of highly integrated systems can be improved if thelevel of integration between the system's components is underevolutionary control. When evolving our multi-component system we discover that the level of integration very quickly falls to virtually zero reducing the ruggedness of the landscape and making it nearly neutral. This allows the evolving population to explore the genome space without getting stuck on local optima. The components then integrate and the evolving population settles on the global optimum. This work is unique because the presented problem requires the evolving system to be fully integrated in order to solve it and as such the decreased ruggedness and near neutrality are not a permanent feature of the landscape but rather a property which is temporarily manipulated and exploited by the evolving population.
Nuisance free recognition of hand postures over a tabletop display
Authors: João Carreira, Paulo Peixoto
Venue: Proceedings of the HCSNet workshop on Use of vision in human-computer interaction - Volume 56 (2006)

This paper proposes a new approach to shape classification that is well suited to the specific challenges of vision-based hand posture recognition in a multi-user tabletop collaboration scenario. We use a representation of the 2-D hand silhouette where in-plane rotation and mirror symmetry appear as particular cases of permutations, and then show how to take advantage of this pattern to develop an efficient version of the permutation invariant SVM. Invariance to these transformations is very important because the users stand around the table, and a video camera captures the scene from the top. We also report experimental results that compare this approach favorably over common classification approaches, under the stated requirements.
Adaptive particle swarm optimization: detection and response to dynamic systems
Authors: Xiaohui Hu, R. C. Eberhart
Venue: Proceedings of the Evolutionary Computation on 2002. CEC '02. Proceedings of the 2002 Congress - Volume 02 (2002)

This paper introduces an adaptive PSO, which automatically tracks various changes in a dynamic system. Different environment detection and response techniques are tested on the parabolic and Rosenbrock benchmark functions, and re-randomization is introduced to respond to the dynamic changes. Performance on the benchmark functions with various severities is analyzed.
Generating Families of Business Components from Metamodel Hierarchies
Authors: Markus Aleksy, Michael Schwind, Ralf Gitzel
Venue: Proceedings of the First International Conference on Complex, Intelligent and Software Intensive Systems (2007)

Model-Driven Software Development (MDSD) has gained acceptance in the software development industry over the last few years. Current approaches to MDSD favor targeting particular domains over general-purpose modeling and code generation solutions. The OMEGA toolset provides an infrastructure for the rapid development of domain-specific modeling and code generation facilities. It is based on the concept of metamodel hierarchies. In this paper we propose an extension to the OMEGA approach that is targeted at enabling the evolutionary development of families of business components by introducing additional model types. The paper provides an overview of the OMEGA approach and describes the integration of family and feature models as configuration data to the OMEGA code generator and the expected benefits. A short outlook at the end of the paper outlines future work on this matter.
Transformation for Refining Unraveled Conditional Term Rewriting Systems
Authors: Naoki Nishida, Tomohiro Mizutani, Masahiko Sakai
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2007)

Unravelings, transformations from conditional term rewriting systems (CTRSs, for short) into unconditional term rewriting systems, are valuable for analyzing properties of CTRSs. In order to completely simulate rewrite sequences of CTRSs, the restriction by a particular context-sensitive and membership condition that is determined by extra function symbols introduced due to the unravelings, must be imposed on the rewrite relations of the unraveled CTRSs. In this paper, in order to weaken the context-sensitive and membership condition, we propose a transformation applied to the unraveled CTRSs, that reduces the number of the extra symbols. In the transformation, updating the context-sensitive condition properly, we remove the extra symbols that satisfy a certain condition. If the transformation succeeds in removing all of the extra symbols, we obtain the TRSs that are computationally equivalent with the original CTRSs.
How Accurately Do Engineers Predict Software Maintenance Tasks?
Authors: Les Hatton
Venue: Computer (2007)

Previous research shows considerable overlap among perfective, corrective, and adaptivemaintenance tasks in software development projects. A case study involving two recentproducts provides further empirical evidence of this distribution and sheds light on how wellprogrammers estimate both the type of maintenance necessary and the duration with somesignificant surprises.
Computing Geographical Reality with Animated Map Language
Authors: Hong Shu, Cuihong Qi, Geoffrey Edwards
Venue: Proceedings of the 16th International Conference on Artificial Reality and Telexistence--Workshops (2006)

This paper has presented our ideas of computing geographical reality with animated map language. Inherently, geographical reality is considered as an integration of physical, cognitive, and computational geographical worlds. An animated map is the result of animated mapping of time-varying geographic phenomena. Alternatively, the animated map is a computational reality of geographical world or an augmented part of existing geographical reality. More, the animated map results from the interaction of humans and the computers on geographical world. Again, the animated map is a visual medium of geographical spatio-temporal information communication between map makers and map users. In terms of valid time involvement, we distinguish two types of animated maps, i.e., temporal and atemporal animated maps. We consider an animated map as a composite map symbol of atomic map symbols. The design of dynamic map symbols is grounded on the theory of visual variables. The syntax of animated map language is a group of rules of visual variables applied to geographical data. To some extent, the organization rules of map symbols are projections of geographical spatio-temporal data structural relationships. In particular, an experiment of population change mapping is used to exemplify our ideas of animated map design.