ppxscal/embedding_network huggingface dataset:
A Systematic Approach to Process Enactment Analysis as Input to Software Process Improvement or Tailoring
Authors: Ming Huo, He Zhang, Ross Jeffery
Venue: Proceedings of the XIII Asia Pacific Software Engineering Conference (2006)

Software process improvement has been a focus of industry for many years. To assist the procedure and implementation of process improvement we provide a software process recovery method based on mining project enactment data. The goal of the method is to uncover the actual process used in order to provide input to improve the quality of a defined software process. The recovered model (or patterns) is at the same level of abstraction as the predefined process model. This provides an easy and clear way to identify the gap between the planned process model and the real enactment. We investigate the enactment of a defined software process from the view of understanding the appropriateness and fitness for purpose of the process model from the viewpoint of the project managers in the context of a small software development organization. We collected data from organizations and applied our method to a pilot case study. The main contribution of our work is to provide a software process model recovery method which supports software process change and improvement.
A peer-to-peer system as an exchange economy
Authors: Christina Aperjis, Ramesh Johari
Venue: Proceeding from the 2006 workshop on Game theory for communications and networks (2006)

We formulate a peer-to-peer system for filesharing as an exchange economy: a price is associated with each file, and users exchange files only when they can afford it. This formulation solves the free-riding problem, since uploading files is a necessary condition for being able to download. However, we do not explicitly introduce a currency; users must upload files in order to earn a budget for downloading. We discuss existence, uniqueness, and dynamic stability of the competitive equilibrium, which is always guaranteed to be Pareto efficient. In addition, a novel aspect of our approach is an allocation mechanism for clearing the market out of equilibrium. We analyze this mechanism when users can anticipate how their actions affect the allocation mechanism (price anticipating behavior). For this regime we characterize the Nash equilibria that will occur, and show that as the number of users increases, the Nash equilibrium rates become approximately Pareto efficient.
Geometry of a Non-Overlapping Multi-Camera Network
Authors: Imran Junejo, Xiaochun Cao, Hassan Foroosh
Venue: Proceedings of the IEEE International Conference on Video and Signal Based Surveillance (2006)

Moving beyond single or stationary camera surveillance systems, we employ an automatically configurable network of non-overlapping cameras. These cameras need not have an overlapping Field of View (FoV) and should be able to move freely in space. In this paper, a practical framework is proposed that determines the geometry of such a dynamic camera network. Assuming each camera in the network is calibrated, it is shown that only one automatically computed vanishing point and a line lying on any plane orthogonal to the vertical direction is sufficient to infer the dynamic network configuration. Our method generalizes previous work which considers restricted camera motions. Using minimal assumptions, we are able to successfully demonstrate promising results on synthetic as well as on real data.
Differential fuzzy filtering for adaptive line enhancement in spread spectrum communications
Authors: Joan Bas, Ana Pérez, Miguel A. Lagunas
Venue: Signal Processing (2006)

This paper presents an estimator/subtractor narrow band interference (NBI) canceller based on fuzzy logic and applied to DS-CDMA systems. The designed fuzzy canceller introduces the slow varying nature of the NBI in its rule base. In this way, we obtain an interference suppressor with the following features: (i) fusion of different NBI models in its rule base; (ii) fast adaptation capability; (iii) low computational burden, and parallel structure; (iv) linguistic mapping between its input and output variables; and (v) non-parametric conditional mean interference estimation. Two criteria have been derived to obtain the ''working region'' of the fuzzy canceller, which has been adapted using a reduced cost recursive least squares (RLS) algorithm. Simulation results show that the fuzzy filter is able to cope with whatever shape of interference in its working region successfully.
Distributed Authorization Using Delegation with Acyclic Paths
Authors: Antonio Lain, Miranda Mowbray
Venue: Proceedings of the 19th IEEE workshop on Computer Security Foundations (2006)

We present a new trust management scheme for distributed authorization which can be easily implemented using X.509-based certificate chains, but does not require globally unique role names. A principal proves that he has authorization for a particular action by demonstrating the existence of an acyclic chain of bindings from a specified principal to himself, where the sequence of labels in the chain matches a template. This template is in an easilycomputed subset of regular path expressions. Our restrictions to acyclic paths and to a subset of path expressions enable us to permit controlled delegation, relax the requirement of global agreement on role names, and provide an intuitive abstraction. We show that some useful security properties can be determined in polynomial time. Our scheme has been used in practice to secure a management framework for distributed components: we give an overview of the implementation.
Computer vision based methods for detecting weeds in lawns
Authors: Ukrit Watchareeruetai, Yoshinori Takeuchi, Tetsuya Matsumoto, Hiroaki Kudo, Noboru Ohnishi
Venue: Machine Vision and Applications (2006)

In this paper, two methods for detecting weeds in lawns using computer vision techniques are proposed. The first is based on an assumption about the differences in statistical values between the weed and grass areas in edge images and using Bayes classifier to discriminate them. The second also uses the differences in texture between both areas in edge images but instead applies only simple morphology operators. Correct weed detection rates range from 77.70 to 82.60% for the first method and from 89.83 to 91.11% for the second method. From the results, the methods show the robustness against lawn color change. In addition, the proposed methods together with a chemical weeding system as well as a non-chemical weeding system based on pulse high voltage discharge are simulated and the efficiency of the overall systems are evaluated theoretically. With a chemical based system, more than 72% of the weeds can be destroyed with a herbicide reduction rate of 90&#x2013;94% for both methods. For the latter weeding system, killed weed rate varies from 58 to 85%.
Economics of online music and consumer behavior
Authors: Marc Fetscherin
Venue: Proceedings of the 8th international conference on Electronic commerce: The new e-commerce: innovations for conquering current barriers, obstacles and limitations to conducting successful business on the internet (2006)

In this paper we first provide a literature review about the economics of online music. Second, we then present an economical model for online music by incorporating various parameters such as the price of a legal download, as well as parameters taking into account the quality and security risk associated with purchasing or copying music form the Internet. Furthermore, we incorporate legal and technological parameters in our model, such as law enforcement and its underlying penalties, as well as rights and usage restrictions enforced through so called Digital Rights Management Systems. We then present the optimal choice for a consumer for purchasing online music with the presence of online piracy. Finally, we discuss three possible scenarios. By using empirical numerical values we establish a link between our model and practical application. Each scenario is discussed in detail and we conclude that content providers should either demand a higher price but not restrict consumers or demand a lower price but restrict consumers more. However, doing both does not seem to motive consumers to purchase online music but rather copying it.
Masking page reference patterns in encryption databases on untrusted storage
Authors: Xi Ma, HweeHwa Pang, Kian-Lee Tan
Venue: Data Knowledge Engineering (2006)

To support ubiquitous computing, the underlying data have to be persistent and available anywhere-anytime. The data thus have to migrate from devices that are local to individual computers, to shared storage volumes that are accessible over open network. This potentially exposes the data to heightened security risks. In particular, the activity on a database exhibits regular page reference patterns that could help attackers learn logical links among physical pages and then launch additional attacks. We propose two countermeasures to mitigate the risk of attacks initiated through analyzing the shared storage server's activity for those page patterns. The first countermeasure relocates data pages according to which page sequences they are in. The second countermeasure enhances the first by randomly prefetching pages from predicted page sequences. We have implemented the two countermeasures in MySQL, and experiment results demonstrate their effectiveness and practicality.
A Methodology for Architectural Design of Concurrent and Distributed Software Systems
Authors: Hassan Reza
Venue: The Journal of Supercomputing (2006)

Concurrent and distributed software applications are complex software systems that exploit highly parallel and distributed infrastructure to improve the quality of systems in cost-effective way. In order to assist the development of affordable concurrent and distributed software systems, a more effective approach of utilizing single-based architectural description languages (ADLs) is needed. In this paper, we describe an architectural modeling framework that can be used for specifying and analyzing distributed and concurrent software applications. Our key contribution is an architectural specification framework that integrates four important concepts: (1) an architectural description language known as syntactic theory (ST), (2) a high level Petri nets modeling language known as Hierarchical Predicate Transition Nets (HPrTNs), (3) a Pattern-Based Refinement Technique (PBRT), and (4) a systematic process for deriving architectural specifications from requirement specifications. Moreover, the method is heterogeneous modeling approach that specifies software architecture of a distributed and concurrent system in a top-down manner. The immediate benefits of our heterogeneous approach include: increased system analyzability, comprehensibility, reusability, and flexibility. We describe a case study to show the applicability of our approach.
Improving fairness of PGMCC: Research Articles
Authors: Hualiang Chen, Zhongxin Liu, Zengqiang Chen, Zhuzhi Yuan
Venue: International Journal of Communication Systems (2006)

PGM congestion control (pgmcc), a single-rate multicast congestion control scheme, is one of the most promising schemes which aim to solve the problem of multicast fairness with TCP. However, by deep investigation, we find that there exist two inappropriate mechanisms in this scheme, which are the fixed slow start threshold (ssthresh) and the mechanism of changing a group representative (acker). Our experiments have revealed the fact that these mechanisms can lead to the unfairness of pgmcc under some network conditions. In this paper, two new mechanisms have been proposed to replace the original ones. One mechanism is to make the sender adapt the value of ssthresh to the network conditions to mimic the action of TCP, and in order to avoid being more aggressive than TCP, the other one is to make the sender reduce the congestion window by half when the acker changes. Our experiment results, parts of which are discussed in this paper, show that the modified pgmcc can achieve better performance than the original one. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Formal Models in Web Based Contracting
Authors: Jose Machado, Francisco Andrade, Jose Neves, Paulo Novais, Cesar Analide
Venue: Proceedings of the 2006 IEEE/WIC/ACM international conference on Web Intelligence and Intelligent Agent Technology (2006)

Legal principles have some difficulty to deal with software agents celebrating contracts and operating in e-commerce environments without direct human intervention. Autonomous intelligent agents have a control on their own actions and states, supporting or taking effective decisions. Therefore, some qualitative parameters such as trust, reputation and quality of information have to be taken under consideration to evaluate, certify and justify such decisions. Indeed, this paper shows how to construct a dynamic virtual world of complex and interacting entities or agents, organized in terms of Multi-Agent Systems (MAS), that compete against one another in order to solve a particular problem, according to a rigorous selection regime in which its fitness is judged by one criterion alone, a measure of the quality of information of the agent or agents, here understood as evolutionary logic theories. This virtual world could witness the emergence of our first learning, thinking machines, that may cater for some issues on the evolution of formal models of the world in general, and on what is concerned with the objectives set to this work, in contracting, and foray into a vast, untapped technological market.
Tail asymptotics for discrete event systems
Authors: Marc Lelarge
Venue: Proceedings of the 1st international conference on Performance evaluation methodolgies and tools (2006)

In the context of communication networks, the framework of stochastic event graphs allows a modeling of control mechanisms induced by the communication protocol and an analysis of its performances. We concentrate on the logarithmic tail asymptotics of the stationary response time for a class of networks that admit a representation as (max,plus)-linear systems in a random medium. We are able to derive analytic results when the distribution of the holding times are lighttailed. We show that the lack of independence may lead in dimension bigger than one to non-trivial efects in the asymptotics of the sojourn time. We also study in detail a simple queueing network with multipath routing.
An Evaluation of Similarity Coefficients for Software Fault Localization
Authors: Rui Abreu, Peter Zoeteweij, Arjan J. C. van Gemund
Venue: Proceedings of the 12th Pacific Rim International Symposium on Dependable Computing (2006)

Automated diagnosis of software faults can improve the efficiency of the debugging process, and is therefore an important technique for the development of dependable software. In this paper we study different similarity coefficients that are applied in the context of a program spectral approach to software fault localization (single programming mistakes). The coefficients studied are taken from the systems diagnosis / automated debugging tools Pinpoint, Tarantula, and AMPLE, and from the molecular biology domain (the Ochiai coefficient). We evaluate these coefficients on the Siemens Suite of benchmark faults, and assess their effectiveness in terms of the position of the actual fault in the probability ranking of fault candidates produced by the diagnosis technique. Our experiments indicate that the Ochiai coefficient consistently outperforms the coefficients currently used by the tools mentioned. In terms of the amount of code that needs to be inspected, this coefficient improves 5% on average ove
Pseudo roots and the effects of model order overestimation on the ESPRIT algorithm
Authors: S. D. Silverstein
Venue: Proceedings of the Acoustics, Speech, and Signal Processing,1994. on IEEE International Conference - Volume 04 (1994)

The work studies the distribution of the ESPRIT roots in the complex z plane. The real source roots are tightly clustered about their true values, while the pseudo roots corresponding to overestimated non-existing sources are distributed broadly with a definite phase angle bias away from the real source roots. The ESPRIT roots distributions can be coupled with Neyman-Pearson tests for CFAR source detection/system model order estimation. The work includes a mathematical derivation of the asymptotic distribution of the pseudo roots.
Lossless Video Coding Using Lattice Based Distributed Source Coding Techniques
Authors: Mortuza Ali, Manzur Murshed
Venue: Proceedings of the IEEE International Conference on Video and Signal Based Surveillance (2006)

Information theoretic proof exists to support that independent encoding of distributed sources with a joint decoder by exploiting the correlation among the sources can be as efficient as encoding them jointly. This paper successfully attempts to apply this concept for lossless video coding using lattices to divide the multidimensional integer pixel intensity hyperspace of a block of pixels into a finite number of cosets and encoding each block with its coset index. This radical departure from conventional predictive coding techniques not only offers very low computational complexity by avoiding expensive learning of predictor coefficients but also avoids any coding loss due to rounding of real-valued predictions. On standard test video sequences, this scheme achieved compression within as low as 4.6% of the latest scheme with optimal learning of predictor coefficients. The former, however, outperformed the latter as soon as it started updating the optimal predictor coefficients less frequently to reduce the computational complexity.
Content-based image enhancement in the compressed domain based on multi-scale α-rooting algorithm
Authors: Sangkeun Lee
Venue: Pattern Recognition Letters (2006)

A simple multi-scale image enhancement algorithm for compressing image dynamics and enhancing image details in the discrete cosine transform (DCT) domain is presented. First, an image is separated into illumination and reflectance components. Next, the illumination component is manipulated adaptively for image dynamics by using a content measure. The content measure using the energy distribution of the DCT coefficients is defined directly in each DCT block of an image. Then, the reflectance component is altered by a multi-scale @a-rooting method for enhancing image details based on human visual perception. The main advantage of the proposed algorithm enhances the details in the dark and the bright areas with low computations without boosting noise information and affecting the compressibility of the original image since it performs on the images in the compressed domain. In order to evaluate the proposed scheme, several base-line approaches are described and compared using enhancement quality measures.
The incredible rainbow spitting chicken: teaching traditional programming skills through games programming
Authors: Patricia Haden
Venue: Proceedings of the 8th Austalian conference on Computing education - Volume 52 (2006)

Introductory programming courses must provide sound instruction in basic programming skills while still maintaining a high level of student engagement. At Otago Polytechnic we have recently introduced a second year programming course that teaches traditional core topics in the context of "games programming". While building a variety of computer game applications, students study algorithm design, complex data structures, recursion and class architecture. Early experiences with the course have shown it to be both effective and enjoyable. In this paper we present the rationale and structure of the course, and describe some of the course materials.
Dissertation abstract: geometrical wavelets and their generalizations in digital image coding and processing
Authors: Agnieszka Lisowska
Venue: Machine Graphics Vision International Journal (2005)

Efficient representation of an image plays a crucial role in computer graphics because it forms the foundation for image coding and processing. Recently, it has become evident that separable transforms, e.g., wavelet transformations, are not the best tools for image representation due to their inability to capture line discontinuities present in images in the form of edges. To overcome that problem, a competitive theory of geometrical wavelets has been developed recently.Recent research in psychology of vision and neuropsychology has proven that the amount of information which is gathered by receptors of the retina in the eye is far larger than the dozens of bits per second which are transmitted to the brain from the eye. Additionally, they give us information what kinds of signals are perceived by brain first of all, and which ones are less important. As a result, two practical questions arise. How can we approximate images better, in a more sparse way? And how can we extract, the information which is most important, from the Human Visual System point of viewout of an image in an automatic way? The dissertation has tried to answer both these questions.Thus, firstly, a generalization of wedgelets (the class of geometrical wavelets) to those based on second degree curves has been proposed, and it has been shown that thanks to a better, sparser, approximation of images such wedgelets improve the properties of image coding and processing in comparison with the classical wedgelets. It has been additionally shown that generalized wedgelets give better results in noisy image processing compared to other standard methods.Secondly, a new application of geometrical wavelets to extracting different classes of signals with different importance for perception by human brain has been proposed. With help of such wavelets (especially beamlets), an operator has been defined which extracts such signals automatically in a geometrical multiresolution way. All the results presented in the dissertation appear to improve the results presented so far in literature, which has been confirmed both theoretically and experimentally.
Architectures for scalable and flexible Web personalization services
Authors: Claudia Canali, Sara Casolari, Riccardo Lancellotti
Venue: Proceedings of the First International Workshop on Advanced Architectures and Algorithms for Internet Delivery and Applications (2005)

The complexity of services provided through theWeb is continuously increasing and issues introduced by both heterogeneous client devices and Web content personalization are becoming a major challenge for the Web. The content adaptation operations may be computationally expensive, requiring high efficiency and scalability in the Web architectures. Tailoring Web and multimedia resources to meet the user and client requirements opens two main novel issues in the research area of content adaptation and delivery. First, the characteristics of the content adaptation services have a significant impact on the possible mapping of the services over the nodes of the content adaptation infrastructure. Second, the relationship of the content adaptation system with the content provider has a fundamental impact on the architectural choices in the design of content adaptation systems. In this paper, we propose four novel distributed architectures for the efficient delivery of content adaptation services where the nodes are organized in two levels. We compare the performance of the four architectures to evaluate which architecture is the best and under which conditions the performance gain is more evident.