ppxscal/embedding_network huggingface dataset:
Interactive presentation: Time-constrained clustering for DSE of clustered VLIW-ASP
Authors: Mario Schölzel
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

In this paper we describe a new time-constrained clustering algorithm. It is coupled with a time-constrained scheduling algorithm and used for Design-Space-Exploration (DSE) of clustered VLIW processors with heterogeneous clusters and heterogeneous functional units. The algorithm enables us to reduce the complexity of the DSE, because the parameters of the VLIW are derived from the clustered schedule of the considered application which is produced during a single compilation step. Several compilations of the same application with different VLIW-parameter settings are not necessary. Our proposed algorithm is integrated into a DSE-Tool in order to explore the best parameters of a clustered VLIW processor for several basic blocks of signal processing applications. The obtained results are compared to the results of Lapinskii's work and show, that, for most benchmarks, we are able to save ports in the register file of each cluster.
An Infrastructure for Indexing and Organizing Best Practices
Authors: Liming Zhu, Mark Staples, Ian Gorton
Venue: Proceedings of the Second International Workshop on Realising Evidence-Based Software Engineering (2007)

Industry best practices are widely held but not necessarily empirically verified software engineering beliefs. Best practices can be documented in distributed web-based public repositories as pattern catalogues or practice libraries. There is a need to systematically index and organize these practices to enable their better practical use and scientific evaluation. In this paper, we propose a semi-automatic approach to index and organise best practices. A central repository acts as an information overlay on top of other pre-existing resources to facilitate organization, navigation, annotation and meta-analysis while maintaining synchronization with those resources. An initial population of the central repository is automated using Yahoo! contextual search services. The collected data is organized using semantic web technologies so that the data can be more easily shared and used for innovative analyses. A prototype has demonstrated the capability of the approach.
Enterprise architecture analysis with extended influence diagrams
Authors: Pontus Johnson, Robert Lagerström, Per Närman, Mårten Simonsson
Venue: Information Systems Frontiers (2007)

The discipline of enterprise architecture advocates the use of models to support decision-making on enterprise-wide information system issues. In order to provide such support, enterprise architecture models should be amenable to analyses of various properties, as e.g. the level of enterprise information security. This paper proposes the use of a formal language to support such analysis. Such a language needs to be able to represent causal relations between, and definitions of, various concepts as well as uncertainty with respect to both concepts and relations. To support decision making properly, the language must also allow the representation of goals and decision alternatives. This paper evaluates a number of languages with respect to these requirements, and selects influence diagrams for further consideration. The influence diagrams are then extended to fully satisfy the requirements. The syntax and semantics of the extended influence diagrams are detailed in the paper, and their use is demonstrated in an example.
Verification of the Capability Exchange Signalling protocol
Authors: Lin Liu, Jonathan Billington
Venue: International Journal on Software Tools for Technology Transfer (STTT) (2007)

The Capability Exchange Signalling (CES) protocol is one of the sub-protocols of recommendation H.245, &#x201c;Control protocol for multimedia communication&#x201d; issued by the International Telecommunication Union. In this paper, we model the CES protocol with Coloured Petri Nets and verify it using state space and language analyses. The results reveal that the CES protocol could fail when the sequence numbers used by the protocol wrap. To solve this problem, we propose a set of changes to the CES protocol. State space and language analyses are then applied to the revised protocol. Verification results suggest that the revised protocol satisfies the desired properties with the errors discovered being eliminated.
Specification-based Test Generation and Optimization Using Model Checking
Authors: Hongwei Zeng, Huaikou Miao, Jing Liu
Venue: Proceedings of the First Joint IEEE/IFIP Symposium on Theoretical Aspects of Software Engineering (2007)

The capability of model checkers to construct counterexamples provides a basis for automated test generation. However, many model checking-based testing approaches just focus on generating test sets with respect to some coverage criteria. Such test sets generally are large and inefficient because of much redundancy. We propose an on-the-fly approach that performs test generation and redundancy elimination by turns. Our approach employs a test-tree to pick out and represent a subset of tests with equal coverage for a test criterion and no redundancy. Along with model checking for a property, a new test sequence is derived from the counterexample and is used to detect redundant properties, and then is winnowed by the testtree as well. We demonstrate the approach by applying some small examples to our prototyped algorithm.
E2EProf: Automated End-to-End Performance Management for Enterprise Systems
Authors: Sandip Agarwala, Fernando Alegre, Karsten Schwan, Jegannathan Mehalingham
Venue: Proceedings of the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (2007)

Distributed systems are becoming increasingly complex, caused by the prevalent use of web services, multi-tier architectures, and grid computing, where dynamic sets of components interact with each other across distributed and heterogeneous computing infrastructures. For these applications to be able to predictably and efficiently deliver services to end users, it is therefore, critical to understand and control their runtime behavior. In a datacenter environment, for instance, understanding the end-to-end dynamic behavior of certain IT subsystems, from the time requests are made to when responses are generated and finally, received, is a key prerequisite for improving application response, to provide required levels of performance, or to meet service level agreements (SLAs). The E2EProf toolkit enables the efficient and nonintrusive capture and analysis of end-to-end program behavior for complex enterprise applications. E2EProf permits an enterprise to recognize and analyze performance problems when they occur -- online, to take corrective actions as soon as possible and wherever necessary along the paths currently taken by user requests -- end-to-end, and to do so without the need to instrument applications -- nonintrusively. Online analysis exploits a novel signal analysis algorithm, termed pathmap, which dynamically detects the causal paths taken by client requests through application and backend servers and annotates these paths with endto- end latencies and with the contributions to these latencies from different path components. Thus, with pathmap, it is possible to dynamically identify the bottlenecks present in selected servers or services and to detect the abnormal or unusual performance behaviors indicative of potential problems or overloads. Pathmap and the E2EProf toolkit successfully detect causal request paths and associated performance bottlenecks in the RUBiS ebay-like multi-tier web application and in one of the datacenter of our industry partner, Delta Air Lines.
On the convergence of Newton's method for monotone systems of polynomial equations
Authors: Stefan Kiefer, Michael Luttenberger, Javier Esparza
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

Monotone systems of polynomial equations (MSPEs) are systems of fixed-point equations X1 = f1(X1, ..., Xn), ..., Xn = fn(X1, ..., Xn) where each fi is a polynomial with positive real coefficients. The question of computing the least non-negative solution of a given MSPE X = f(X) arises naturally in the analysis of stochastic context-free grammars, recursive Markov chains, and probabilistic pushdown automata. While the Kleene sequence f(0), f(f(0)), ... always converges to the least solution mu.f, if it exists, the number of iterations needed to compute the first i bits of mu.f may grow exponentially in i.Etessami and Yannakakis have recently adapted Newton's iterative method to MSPEs and proved that the Newton sequence converges at least as fast as the Kleene sequence and exponentially faster in many cases.They conjecture that, given an MSPE of size m, the number of Newton iterations needed to obtain i accurate bits of mu.f grows polynomially in i and m. In this paper we show that the number of iterations grows linearly in i for strongly connected MSPEs and may grow exponentially in m for general MSPEs.
Adaptive blind separation of convolutive mixtures
Authors: N. Delfosse
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 05 (1996)

In this paper, the blind separation of convolutive mixtures is addressed. Provided that there are more sensors than sources, it can be solved using almost only the second order statistics of the observed signal, through a three-step method (analysis, instantaneous separation and synthesis). A decomposed and normalized lattice synthesis filter is introduced. It solves the problem of singularity, and it is stable for any choice of its parameters. It can be adaptively computed via a least squares lattice (LSL) algorithm, as shown by the simulation results.
Asynchronous Data Path Models
Authors: Danil Sokolov, Ivan Poliakov, Alex Yakovlev
Venue: Proceedings of the Seventh International Conference on Application of Concurrency to System Design (2007)

A token-based model for asynchronous data path is formally defined and three token game semantics, spread token, antitoken and counterflow, are introduced. These semantics are studied and their advantages and drawbacks are highlighted. For analysis and comparison a software tool is developed which integrates these models into a consistent framework. The models are verified by mapping them into Petri nets and employing the existing model checking tools.
The GNOME canvas: a generic engine for structured graphics
Authors: Federico Mena-Quintero, Raph Levien
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

The GNOME canvas is a generic engine for structured graphics that offers a rich imaging model, high performance rendering, and a powerful high-level API. Application programmers can use the canvas to create interactive graphics displays easily. Many GNOME applications use the canvas as their main display engine, some of them using the basic functionality provided by the canvas, and others by extending it for their particular needs. This paper describes the architecture of the canvas in detail and examines the way it is used in several GNOME applications.
On visual quality of optimal 3D sampling and reconstruction
Authors: Tai Meng, Benjamin Smith, Alireza Entezari, Arthur E. Kirkpatrick, Daniel Weiskopf, Leila Kalantari, Torsten Möller
Venue: Proceedings of Graphics Interface 2007 (2007)

This paper presents a user study of the visual quality of an imaging pipeline employing the optimal body-centered cubic (BCC) sampling lattice. We provide perceptual evidence supporting the theoretical expectation that sampling and reconstruction on the BCC lattice offer superior imaging quality over the traditionally popular Cartesian cubic (CC) sampling lattice. We asked 12 participants to choose the better of two images: one image rendered from data sampled on the CC lattice and one image that is rendered from data sampled on the BCC lattice. We used both synthetic and CT volumetric data, and confirm that the theoretical advantages of BCC sampling carry over to the perceived quality of rendered images. Using 25% to 35% fewer samples, BCC sampled data result in images that exhibit comparable visual quality to their CC counterparts.
Access Control Policy Combinations for the Grid Using the Policy Machine
Authors: Vincent C. Hu, David F. Ferraiolo, Karen Scarfone
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

Many researchers have tackled the architecture and requirements aspects of grid security, concentrating on the authentication or authorization mediation instead of authorization techniques, especially the topic of policy combination. Policy combination is an essential requirement of grid, not only because of the required remote (or global) vs. local interaction between grid members, but also the dynamic scalability nature of handling the joining and leaving of grid membership. However, evolving from the general security requirements of grid, the independency of a grid member's access control system is critical and needs to be maintained when the access decision is determined by the combination of global and local access control policies. The Policy Machine (PM) provides features which not only can meet the significant independency requirement but also have better performance, easier management, and more straightforward policy expression than most of the popular policy combination techniques for grid.
Investigating Factors Affecting the Adoption of Electronic Toll Collection: A Transaction Cost Economics Perspective
Authors: Chun-Der Chen, Yi-Wen Fan, Cheng-Kiang Farn
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

In order to reduce the number of vehicles stuck in congestion, especially for stop-and-go traffic at toll plazas, the establishment of electronic toll collection (ETC) system has been a hot issue and dominant trend in many countries. However, despite the potential benefits for motorists, the utilization rate of vehicles has been lower than expected in Taiwan during the introduction stage. Drawing from the transaction cost economics (TCE) perspective, the objective of this study is to advance our understanding in the effects of transaction attributes (uncertainty, asset specificity, and transaction frequency) on the intention of ETC system adoption. Through empirical data collection and analysis from highway motorists who had not installed on-board unit (OBU) for ETC service in Taiwan, we found that uncertainty and asset specificity indeed positively engender motorist's perceived risk. Moreover, results also reveals that perceived risk negatively influences the intention of ETC system adoption, and transaction frequency positively affects the intention for adopting ETC system. Implications for practitioners and researchers and suggestions for future research are also addressed in this study.
Implementing optimized distributed data sharing using scoped behaviour and a class library
Authors: Paul Lu
Venue: Proceedings of the 3rd conference on USENIX Conference on Object-Oriented Technologies (COOTS) - Volume 3 (1997)

Sometimes, it is desirable to alter or optimize the behaviour of an object according to the needs of a specific portion of the source code (i.e., context), such as a particular loop or phase. One technique to support this form of optimization flexibility is a novel approach called scoped behaviour. Scoped behaviour allows the programmer to incrementally tune applications on a per-object and per-context basis within standard C++. We explore the use of scoped behaviour in the implementation of the Aurora distributed shared data (DSD) system. In Aurora, the programmer uses scoped behaviour as the interface to various data sharing optimizations. We detail howa class library implements the basic data sharing functionality and how scoped behaviour co-ordinates the compile-time and run-time interaction between classes to implement the optimizations. We also explore how the library can be expanded with new classes and new optimization behaviours. The good performance of Aurora suggests that using scoped behaviour and a class library is a viable approach for supporting this form of optimization flexibility.
Design of Dyad Game for Developing Fluency in Multiplication Facts
Authors: Charles Y. C. Yeh, Calvin C. Y. Liao, Jen-Hang Wang, Tak-Wai Chan
Venue: Proceedings of the The First IEEE International Workshop on Digital Game and Intelligent Toy Enhanced Learning (2007)

In elementary arithmetic, after acquiring the concept and basic procedures of multiplication, fluency in multiplication facts in the Times Table then becomes the basis for computing more complex multiplications, for example, multiplying two 2-digit numbers. A dyad game in one-to-one technology enhanced classroom environment, called Honeycomb, is designed for developing the fluency of multiplication facts through utterance memorization and retrieval. Honeycomb is a drill-and-practice game for enhancing students' multiplication facts retrieval.
Matching pursuit algorithms with applications in wireless communication systems
Authors: Gunes Karabulut
Venue:  (2006)

Signal decomposition finds its applications in a wide range of areas. The problem of basis selection for signal decomposition consists of determining a small, possibly smallest, subset of vectors chosen from a large redundant set of vectors to match the given data. However, it is shown that finding the sparsest solution to linear systems is a nondeterministic polynomial time (NP) hard problem and requires combinatorial search. For a simpler solution, greedy heuristic algorithms, namely matching pursuit (MP) algorithms are proposed. These algorithms require sequential selection of basis vectors from a set of vectors, termed as dictionary. This dictionary can be undercomplete, overcomplete or complete, depending on the number of basis vectors it contains. The contributions of this dissertation are composed of two complementary parts. In the first part, the limitations of the MP based algorithms are considered. Combination of orthogonal matching pursuit (OMP) algorithm with tree-based combinatorial search techniques is proposed in order to overcome the limitations of the greedy heuristic algorithms. A novel flexible tree-search based OMP (FTB-OMP) algorithm is introduced for sparse signal representations. The algorithm provides some design parameters, giving flexibility to establish a tradeoff between performance and complexity. The efficiency is achieved by using a correlation based pruning in the search tree, and reducing the number of leaves as the depth of nodes increases. It must be noted that this algorithm can be applied to any kind of detection problem that can be modeled as a set of linear equations. In the second part of the dissertation, parameter estimation problems related to wireless communications are considered. These problems are channel estimation, direction of arrival (DOA) estimation and multi-user detection (MUD). These problems are modeled with different types of dictionaries due to their physical characteristics. The channel estimation problem is modeled with undercomplete dictionary. DOA estimation and MUD have overcomplete and complete dictionary models, respectively. It is shown that the family of MP algorithms, especially FTB-OMP, provides a low complexity solution for parameter detection problems with different types of dictionaries. These algorithms provide a practical solution for detection and estimation problems that are widely encountered in wireless communications.
A fully-integrated 5 Gbit/s CMOS clock and data recovery circuit
Authors: Tan Kok-Siang, Mohd-Shahiman Sulaiman, Mamun Reaz, Chuah Hean-Teik, Manoj Sachdev
Venue: Analog Integrated Circuits and Signal Processing (2007)

A fully-integrated 5 Gb/s PLL-based clock and data recovery circuit based on a linear half-rate phase detector (PD) architecture is presented. Data retiming performed by the linear PD provides practically no systematic offset for the operating frequency of interest. The circuit was designed in a 0.18 μm CMOS process and occupies an active area of 0.2 × 0.32 mm2. The CDR exhibits an RMS jitter of ± 1.2 ps and a peak-to-peak jitter of 5 ps. The power dissipation is 97 mW from a 1.8 V supply.
Multi-channel Busy-tone Multiple Access for Scalable Wireless Mesh Network
Authors: Hairong Zhou, Chihsiang Yeh, Hussein T. Mouftah
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

This paper proposes a multi-channel medium access control (MAC) protocol for wireless mesh networks (WMNs) by using busy tones to prevent data packet collisions at data channels. Multi-channel MAC schemes can achieve higher network throughput than single channel MAC schemes in multihop wireless networks. It is especially appealing to exploit multiple channels in WMNs which has high capacity requirement to support backbone multimedia applications. Most previously proposed MAC protocols make use of the RTS/CTS mechanism to deal with data packet collisions caused by exposed/hidden terminal problems in multihop environment. However, when multiple channels are used for data transmissions, the RTS/CTS mechanism can no longer handle the exposed/hidden terminal successfully. By investigating the special features of WMN architecture, we apply the busy tone solution into the medium access control mechanism for WMNs, in which mesh nodes have no limit on power consumption. In this paper, we clearly presented the idea and operation of our proposed multi-channel MAC protocol for WMNs. Comprehensive simulation is underway to compare the performance of our proposed mechanism with that of other RTS/CTS-based multi-channel MAC protocols.
Cellular universal IP for nested network mobility
Authors: Patrick P. Lam, Soung C. Liew, Jack Y. B. Lee
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2007)

In recent years, network mobility (NEMO) has been studied extensively due to its potential applications in military and public transportation. NEMO basic support protocol (NBSP), the current de facto NEMO standard based on mobile IPv6, can be readily deployed using the existing mobile IPv6 infrastructure. However, NBSP's root in mobile IPv6, such as the need of care-of address (CoA) and tunneling, results in substantial performance overhead, generally known as route sub-optimality, in nested NEMO environments. This paper tackles this problem by proposing a scheme based on cellular universal IP (CUIP) to eliminate the need for CoA and tunneling in supporting nested network mobility. Using quantitative analysis, we show that the proposed scheme outperforms the existing nested NEMO schemes by multiple folds in terms of bandwidth overhead. We also show how IP fragmentation negatively impacts route optimality, and that the proposed scheme is inherently superior to the existing schemes in this regard. More importantly, while the scalability of the existing schemes generally deteriorates with the network size, the complexity of our proposed scheme is independent of the network size and thus is far more scalable. Our results show that the proposed scheme is particularly suitable for nested NEMO networks formed by mobile routers with random and ad hoc movement patterns.