ppxscal/embedding_network huggingface dataset:
Adding connectivity and losing context with ICT: contrasting learning situations from a community of practice perspective
Authors: Patricia Arnold, John D. Smith
Venue: Communities and Technologies (2003)

The promise of information and communication technologies is that it increases connectivity. By providing a spectrum of technologies such as email, web conferencing, telephones, and chat, ICTs bring people who are geographically dispersed together in community. Such communities can provide a new context for learning; at the same time, the social, physical, and technical context of the community's members risks getting lost through computer-mediated communication. Design for online communities, especially design for learning in online environments, tries to find ways of re-inviting participants' contexts, as context has a great bearing on learning, in fact is inextricably linked to learning. In this paper we investigate the complex relationship of context, technologies and community design issues. We present three case studies of online learning communities and analyze the interplay of context and technology for each situation, using a community of practice perspective. Each case balances the demands of time, the need for context, and the demands of practice in a unique way. The insights gained can inform both educational design and design of community technologies.
Doubly-selective channels: estimation, capacity, and space-time coding
Authors: Georgios B. Giannakis
Venue:  (2003)

High data rates give rise to frequency-selective propagation, while carrier frequency-offsets and mobility-induced Doppler shifts introduce time-selectivity in wireless communication links. As the transmission rates and mobility increase, future generations of wireless communication systems will have to cope with critical performance-limiting challenges that originates from propagation channels exhibiting time- and frequency-selectivity (double-selectivity). This research investigation focuses on the basic properties and principles of doubly-selective channels: modeling, estimation, diversity, and capacity. In a nutshell, the research in this dissertation includes: (i) derivation of a basis expansion to model physical doubly-selective channels; (ii) design of linearly coded transmissions with maximum diversity to combat fading of doubly-selective channels; (iii) development of data-aided (training-based) channel estimation and delineation of information-theoretic aspects of doubly-selective propagation with non-coherent receivers; (iv) study of multi-antenna space-time coded transmissions over doubly-selective channels to collect multi-dimensional diversity; and (v) design for multi-antenna systems to achieve full rate and full diversity. The findings impact the basic research, and facilitate the design of mobile wireless systems communicating over interference-rich propagation media.
The Sun Dagger Interactive
Authors: Alan Price
Venue: ACM SIGGRAPH 2003 Sketches Applications (2003)

The Sun Dagger Interactive is a real-time computer simulation of the ancient site on Fajada Butte in Chaco Canyon, New Mexico, and is now part of a permanent exhibit on cultural astronomy at the Adler Planetarium in Chicago. The exhibit opened on March 20, 2002.The Sun Dagger construct is dated over a thousand years old and is believed to mark both the solar year and the nineteen-year lunar cycle. This new computer application allows viewers to explore the ancient site that is no longer accessible to the public.
A top down approach for MAS protocol descriptions
Authors: Joaquín Peña, Rafael Corchuelo, José L. Arjona
Venue: Proceedings of the 2003 ACM symposium on Applied computing (2003)

When the protocol of a complex Multi-Agent System (MAS) needs to be developed, the top-down approach emphasises to start with abstract descriptions that should be refined incrementally until we achieve the detail level necessary to implement it. Unfortunately, there exist a semantic gap in protocol description methodologies because most of them first identify which tasks have to be performed, and then use low level descriptions such as sequences of messages to detail them. In this paper, we propose an approach to bridge this gap. We model MAS protocols using several abstract views of the tasks to be performed, and provide a systematic method to simplify them. Tasks are represented by means of interactions that may be refined into lower-level interactions with the techniques proposed in this paper (simpler interactions are easier to describe and implement using message passing.) Unfortunately, deadlocks may appear due to protocol design mistakes or due to the refinement process. Thus, we also propose an algorithm to ensure that protocols are deadlock free.
Denoising sonographic images of thyroid nodules via singularity detection employing the wavelet transform modulus maxima
Authors: S. Tsantis, D. Cavouras, N. Dimitropoulos, G. Nikiforidis
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

Ultrasound imaging involves signals, which are obtained by coherent summation of echo signals from scatterers in the tissue. This accumulation results in a speckle pattern, which constitutes unwanted noise and causes image degradation. Suppression of speckle-noise is desirable in order to enhance the quality of ultrasonic images and therefore to increase the diagnostic potential of ultrasound examination. In this paper we introduce a denoising technique for medical ultrasound images based on singularity detection through the evolution of the wavelet transform modulus maxima across scales. The algorithm differentiates the image components from the noise by selecting the wavelet transform modulus-maxima that correspond to the image singularities via the Lipschitz exponents. The performance of the proposed algorithm was tested in 145 B-scan thyroid images (pathological and normal) and demonstrated an effective suppression of speckle while preserving resolvable details (edges and boundaries).
RDL: a language for software development
Authors: H. C. Heacox
Venue: ACM SIGPLAN Notices (1979)

The Requirements and Development Language (RDL) is a non-procedural language which permits the user to describe all aspects of software development, from requirements specification through maintenance. RDL statements are used, incrementally, to build an integrated data base containing all data pertinent to the project. From this data base, standard reports can be generated to analyze requirements or design specification, to track problem areas, to produce documentation, to furnish up-to-date status information, and to ensure communication and coordination among all phases of the development process. RDL was developed, and is being used, as an internal tool for Sperry Univac Software Development.This paper describes RDL by discussing the constructs available in the language, and by presenting detailed examples from the area of design specification. In addition, some examples are presented which illustrate the flexibility of the integrated data base and the power of the report-generating facilities of the RDL Processor.
Integrating Fuzziness into OLAP for Multidimensional Fuzzy Association Rules Mining
Authors: Reda Alhajj, Mehmet Kaya
Venue: Proceedings of the Third IEEE International Conference on Data Mining (2003)

This paper contributes to the ongoing research onmultidimensional online association rules mining byproposing a general architecture that utilizes a fuzzy datacube for knowledge discovery. Three different methods areintroduced to mine fuzzy association rules in the constructedfuzzy data cube, namely single dimension, multidimensionaland hybrid association rules mining. Experimental resultsobtained for each of the three methods on the adult data ofthe United States census in 2000 show their effectiveness andapplicability.
Weaving a web
Authors: Ralf Hinze, Johan Jeuring
Venue: Journal of Functional Programming (2001)

Suppose, you want to implement a structured editor for some term type, so that the user can navigate through a given term and perform edit actions on subterms. In this case you are immediately faced with the problem of how to keep track of the cursor movements and the user's edits in a reasonably efficient manner. In a previous pearl, Huet (1997) introduced a simple data structure, the Zipper, that addresses this problem &ndash; we will explain the Zipper briefly in section 2. A drawback of the Zipper is that the type of cursor locations depends on the structure of the term type, i.e. each term type gives rise to a different type of location (unless you are working in an untyped environment). In this pearl, we present an alternative data structure, the web, that serves the same purpose, but that is parametric in the underlying term type. Sections 3&ndash;6 are devoted to the new data structure. Before we unravel the Zipper and explore the web, let us first give a taste of their use.
Test Compression and Hardware Decompression for Scan-Based SoCs
Authors: Francis G. Wolff, Chris Papachristou, David R. McIntyre
Venue: Proceedings of the conference on Design, automation and test in Europe - Volume 1 (2004)

We present a new decompression architecture suitable for embedded cores in SoCs which focuses on improving the download time by avoiding higher internal-to-ATE clock ratios and by exploiting hardware parallelism. The Bounded Huffman compression facilitates decompression hardware tradeoffs. Our technique is scalable in that the downloadable RAM-based decode table and accommodates for different SoC cores with different characteristics such as the number of scan chains and test set data distributions.
Fractal scaling of fractional diffusion processes
Authors: J. R. Leith
Venue: Signal Processing (2003)

The fractal growth of fractional diffusion is analyzed from the viewpoint of the influence of fractional derivative order on scaling exponents. Fractional diffusion is considered here as deterministic with stochastic forcing, and with time and space fractional derivatives defined as the Caputo and Riesz-Feller forms, respectively. Fractal growth, as characterized by a dynamic scaling exponent, z, roughness, α and growth exponent, β, is model-dependent, and we show that the exponents are distinguished by the order of fractional derivatives and the form of stochastic process. Finally, scaling exponents for nonconservative (or uncorrelated) and correlated stochastic processes are found in the lowest-order linear fractional differential equations, and the prospect for construction of stochastic nonlinear fractional diffusion evolution equations is explored here. In application to signal processing, this amounts to modeling dynamic processes (signal evolution, image growth, surface and interface growth, structural growth, etc.) and their equivalence (or approximation) in fractional differencing models of discrete data.
Computer-aided characterization of thyroid nodules by image analysis methods
Authors: S. Tsantis, I. Kalatzis, N. Piliouras, D. Cavouras, N. Dimitropoulos, G. Nikiforidis
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

The assessment of sonographic findings of thyroid nodules in medical praxis is dependent on the examiner's experience and subjective evaluation. Thus, it is obvious that a quantitative method could be of value to diagnosis. This study evaluates the risk factor of malignancy of thyroid nodules by means of an automatic image analysis system designed and implemented in C++ for processing B-mode sonographic images. Precision accuracies of 95% and 93.3% were achieved by means of the Neural Network Multi-layer Perceptron and the Support Vector Machines classifiers respectively. The proposed image analysis system combined with either classifier may be indicative of thyroid nodule's malignancy-risk and may be of value to patient management.
Simple proof of the completeness theorem for second-order classical and intuitionistic logic by reduction to first-order mono-sorted logic
Authors: Karim Nour, Christophe Raffalli
Venue: Theoretical Computer Science (2003)

We present a simpler way than usual to deduce the completeness theorem for the second-order classical logic from the first-order one. We also extend our method to the case of second-order intuitionistic logic.
Experiences in the Inspection Process Characterization Techniques
Authors: Viswanathan Narayana, Rajashekara Swamy
Venue: Proceedings of the Third International Conference on Quality Software (2003)

Implementation of a disciplined engineering approach to software development requires the existence of an adequatesupporting measurement & analysis system. Due to demands for increased efficiency and effectiveness of software processes,measurement models need to be created to characterize and describe the various processes usefully. The data derived fromthese models should then be analyzed quantitatively to assess the effects of new techniques and methodologies. In recenttimes, statistical and process thinking principles have led software organizations to appreciate the value of applyingStatistical Process Control techniques. As part of the journey towards SW-CMM® Level 5 at the Motorola Malaysia SoftwareCenter, which the center achieved in October 2001, considerable effort was spent on exploring SPC techniques to establishprocess control while focusing on the Quantitative Process Management KPA of the SW-CMM®. This paper discusses theevolutionary learning experiences, results and lessons learnt by the center in establishing appropriate analysis techniquesusing statistical and other derivative techniques. The paper discusses the history of analysis techniques that were exploredwith specific focus on characterizing the inspection process. Future plans to enhance existing techniques and to broaden thescope to cover analysis of other software processes are also discussed.
A model for the implementation of software process improvement: A pilot study
Authors: Mahmood Niazi, David Wilson, Didar Zowghi
Venue: Proceedings of the Third International Conference on Quality Software (2003)

Little attention has been paid in the literature on "how toimplement" software process improvement (SPI) whichhas resulted in limited success for many SPI efforts. In thispaper we report on our recent empirical study whichexplored the experiences and perceptions of practitionersabout SPI implementation. We visited 11 companies andconducted 14 in-depth interviews. Using the differentexperiences and opinions of practitioners regarding SPIimplementation, we have developed a model for theimplementation of SPI programmes. This model has sixphases - awareness, learning, pilot implementation, SPIimplementation action plan, implementation across theorganization and maintenance - and provides advice topractitioners in effectively implementing SPI programmes.
Image Sharpening by Flows Based on Triple Well Potentials
Authors: Guy Gilboa, Nir Sochen, Yehoshua Y. Zeevi
Venue: Journal of Mathematical Imaging and Vision (2004)

Image sharpening in the presence of noise is formulated as a non-convex variational problem. The energy functional incorporates a gradient-dependent potential, a convex fidelity criterion and a high order convex regularizing term. The first term attains local minima at zero and some high gradient magnitude, thus forming a triple well-shaped potential (in the one-dimensional case). The energy minimization flow results in sharpening of the dominant edges, while most noisy fluctuations are filtered out.
Certificate-based authorization policy in a PKI environment
Authors: Mary R. Thompson, Abdelilah Essiari, Srilekha Mudumbai
Venue: ACM Transactions on Information and System Security (TISSEC) (2003)

The major emphasis of public key infrastructure has been to provide a cryptographically secure means of authenticating identities. However, procedures for authorizing the holders of these identities to perform specific actions still need additional research and development. While there are a number of proposed standards for authorization structures and protocols such as KeyNote, SPKI, and SAML based on X.509 or other key-based identities, none have been widely adopted. As part of an effort to use X.509 identities to provide authorization in highly distributed environments, we have developed and deployed an authorization service based on X.509 identified users and access policy contained in certificates signed by X.509 identified stakeholders. The major goal of this system, called Akenti, is to produce a usable authorization system for an environment consisting of distributed resources used by geographically and administratively distributed users. Akenti assumes communication between users and resources over a secure protocol such as transport layer security (TLS) to provide mutual authentication with X.509 certificates. This paper explains the authorization model and policy language used by Akenti, and how we have implemented an Apache authorization module to provide Akenti authorization.
A unified framework for model-based clustering
Authors: Shi Zhong, Joydeep Ghosh
Venue: The Journal of Machine Learning Research (2003)

Model-based clustering techniques have been widely used and have shown promising results in many applications involving complex data. This paper presents a unified framework for probabilistic model-based clustering based on a bipartite graph view of data and models that highlights the commonalities and differences among existing model-based clustering algorithms. In this view, clusters are represented as probabilistic models in a model space that is conceptually separate from the data space. For partitional clustering, the view is conceptually similar to the Expectation-Maximization (EM) algorithm. For hierarchical clustering, the graph-based view helps to visualize critical/important distinctions between similarity-based approaches and model-based approaches. The framework also suggests several useful variations of existing clustering algorithms. Two new variations---balanced model-based clustering and hybrid model-based clustering---are discussed and empirically evaluated on a variety of data types.
Compilation and equivalence of imperative objects
Authors: Andrew D. Gordon, Paul D. Hankin, Søren B. Lassen
Venue: Journal of Functional Programming (1999)

We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling object-oriented languages. We present both a big-step and a small-step substitution-based operational semantics for the calculus. Our first two results are theorems asserting the equivalence of our substitution-based semantics with a closure-based semantics like that given by Abadi and Cardelli. Our third result is a direct proof of the correctness of compilation to a stack-based abstract machine via a small-step decompilation algorithm. Our fourth result is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU equivalence; the latter provides a tractable means of establishing operational equivalences. Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving method offsets. This is the first study of correctness of an object-oriented abstract machine, and of operational equivalence for the imperative object calculus.
Exponential fitted Runge--Kutta methods of collocation type: fixed or variable knot points?
Authors: G. Vanden Berghe, M. Van Daele, H. Vande Vyver
Venue: Journal of Computational and Applied Mathematics (2003)

Two different classes of exponential fitted Runge-Kutta collocation methods are considered: methods with fixed points and methods with frequency-dependent points. For both cases we have obtained extensions of the classical two-stage Gauss, RadauIIA and LobattoIIIA methods. Numerical examples reveal important differences between both approaches.
Music thumbnailing via structural analysis
Authors: Wei Chai, Barry Vercoe
Venue: Proceedings of the eleventh ACM international conference on Multimedia (2003)

Music thumbnailing (or music summarization) aims at finding the most representative part of a song, which can be used for web browsing, web searching and music recommendation. Three strategies are proposed in this paper for automatically generating the thumbnails of music. All the strategies are based on the results of music structural analysis, which identifies the recurrent structure of musical signals. Instead of being evaluated subjectively, the generated thumbnails are evaluated by several criteria, mainly based on previous human experiments on music thumbnailing and the properties of thumbnails used for commercial web sites. Additionally, the performance of the structural analysis is demonstrated visually using figures for qualitative evaluation, and by three novel structural similarity metrics for quantitative evaluation. The preliminary results obtained using a corpus of Beatles' songs demonstrate the promise of our method and suggest that different thumbnailing strategies might be proper for different applications.
A Social Capital Approach to IT Relationship Management Evaluation
Authors: Tally Hatzakis
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 8 - Volume 8 (2004)

In spite of the increasing adoption of IT relationship management as an intervention strategy for improving business -- IT relationships, researchers have so far paid little attention to evaluating its impact on organisations. This paper proposes that the impact of IT relationship management on organisations be evaluated by changes in the social capital between business and IT that result in improved productivity. It develops an evaluation framework for measuring the impact of IT relationship management on social capital and tests it in the context of a large financial institution. Findings suggest that Relationship Management has (a) diminished the immediacy, but extended mediated participation, (b) increased the levels of trust and reciprocity between themselves and business people but not between business and other IT representatives, but (c) considerably increased communication levels and mutual understanding. The work concludes that whilst Relationship Management interventions have brought satisfaction with the efficiency and effectiveness of work coordination processes, the sustainability of the impact of Relationship Management interventions on organisations is questionable. Implications for IT relationship management practice and recommendations for best practice development are highlighted.
Human Capital and Institutional Determinants of Information Technology Compensation: Modeling Multilevel and Cross-Level Interactions
Authors: Soon Ang, Sandra Slaughter, Kok Yee Ng
Venue: Management Science (2002)

Compensation is critical in attracting and retaining information technology (IT) professionals. However, there has been very little research on IT compensation. Juxtaposing theories of compensation that focus on human capital endowments and labor market segmentation, we hypothesize multilevel and cross-level determinants of compensation. We use hierarchical linear modeling to analyze archival salary data for 1,576 IT professionals across 39 institutions. Results indicate that compensation is directly determined by human capital endowments of education and experience. Institutional differentials do not directly drive compensation, but instead moderate the relationship of human capital endowments to compensation. Large institutions pay more than small institutions to IT professionals with more education, while small institutions pay more than large institutions to IT professionals with less education. Not-for-profit institutions pay more than for-profits to IT professionals with more or IT-specific education. Further, information-intensive institutions pay more than non information-intensive institutions to IT professionals with more or IT-specific education. We interpret these results in the context of institutional rigidity, core competencies, and labor shortages in the IT labor market.