ppxscal/embedding_network huggingface dataset:
A class of discrete distributions arising from difference of two random variables
Authors: S. H. Ong, K. Shimizu, Choung Min Ng
Venue: Computational Statistics Data Analysis (2008)

This paper considers a class of distributions arising from the difference of two discrete random variables belonging to the Panjer family of distributions. Some distributional properties and computation of probabilities are discussed. Goodness of fit and tests of hypotheses involving the likelihood ratio, score and Wald tests have been considered. As an illustration, an application to paired count data is given.
Index compression is good, especially for random access
Authors: Stefan Büttcher, Charles L. A. Clarke
Venue: Proceedings of the sixteenth ACM conference on Conference on information and knowledge management (2007)

Index compression techniques are known to substantially decrease the storage requirements of a text retrieval system. As a side-effect, they may increase its retrieval performance by reducing disk I/O overhead. Despite this advantage, developers sometimes choose to store index data in uncompressed form, in order to not obstruct random access into each index term's postings list. In this paper, we show that index compression does not harm random access performance. In fact, we demonstrate that, in some cases, random access into a term's postings list may be realized more efficiently if the list is stored in compressed form instead of uncompressed. This is regardless of whether the index is stored on disk or in main memory, since both types of storage - hard drives and RAM - do not support efficient random access in the first place.
A Lightweight Model for End Users' Data: Progress and Future Work
Authors: Christopher Scaffidi
Venue: Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing (2007)

To understand the software needs of information workers, we conducted a contextual inquiry, revealing that end users' tasks often involve categories of short, human-readable, multi-format data such as phone numbers, state names, and product identifiers [6]. In many tasks, workers copied and pasted data between web forms, often with intervening reformatting. At some points in tasks, users came upon data with questionable validity, prompting them to double-check values (which they sometimes used anyway). One task involved copying data from multiple sources into a spreadsheet, then manually reformatting the data into a common format and manually identifying and removing duplicates.
Thermoplastic Holographic Recording of Binary Patterns in PLZT Line Composer
Authors: C. D. Butter
Venue: IEEE Transactions on Computers (1975)

Binary patterns electrically set into a 12 element PLZT line composer have been recorded on a thermoplastic-photoconductor recording medium as Fourier transform (FT) holograms. A short description of the line composer, thermoplastic-photoconductive recording medium and optical system is given as background information for the experimental results. The reconstructed patterns show contrast ratios of 40:1.
Improved centroids estimation for the nearest shrunken centroid classifier
Authors: Sijian Wang, Ji Zhu
Venue: Bioinformatics (2007)

Motivation: The nearest shrunken centroid (NSC) method has been successfully applied in many DNA-microarray classification problems. The NSC uses ‘shrunken’ centroids as prototypes for each class and identifies subsets of genes that best characterize each class. Classification is then made to the nearest (shrunken) centroid. The NSC is very easy to implement and very easy to interpret, however, it has drawbacks. Results: We show that the NSC method can be interpreted in the framework of LASSO regression. Based on that, we consider two new methods, adaptive L∞-norm penalized NSC (ALP-NSC) and adaptive hierarchically penalized NSC (AHP-NSC), with two different penalty functions for microarray classification, which improve over the NSC. Unlike the L1-norm penalty used in LASSO, the penalty terms that we consider make use of the fact that parameters belonging to one gene should be treated as a natural group. Numerical results indicate that the two new methods tend to remove irrelevant genes more effectively and provide better classification results than the L1-norm approach. Availability: R code for the ALP-NSC and the AHP-NSC algorithms are available from authors upon request. Contact: jizhu@umich.edu Supplementary information: Supplementary data are available at Bioinformatics online.
What's the difference, still? a follow up methodological review of the distance education research
Authors: Justus J. Randolph
Venue: Informatics in education (2007)

A high quality review of the distance learning literature from 1992-1999 concluded that most of the research on distance learning had serious methodological flaws. This paper presents the results of a small-scale replication of that review. A sample of 66 articles was drawn from three leading distance education journals. Those articles were categorized by study type, and the experimental or quasi-experimental articles were analyzed in terms of their research methodologies. The results indicated that the sample of post-1999 articles had the same methodological flaws as the sample of pre-1999 articles: most participants were not randomly selected, extraneous variables and reactive effects were not controlled for, and the validity and reliability of measures were not reported.
Thematic Role Based Generation of UML Models from Real World Requirements
Authors: Tom Gelhausen, Walter F. Tichy
Venue: Proceedings of the International Conference on Semantic Computing (2007)

Model-driven development depends on good initial models. Creating these models by hand is a challenging task, because of complex specification documents and change requests. We propose a new internal representation based on thematic roles, especially designed for (but not limited to) requirements documents. The representation can be generated automatically out of annotated real-world specification text and can be used to generate UML models based on graph rewriting rules.
Necessary optimality conditions for bilevel set optimization problems
Authors: S. Dempe, N. Gadhi
Venue: Journal of Global Optimization (2007)

Bilevel programming problems are hierarchical optimization problems where in the upper level problem a function is minimized subject to the graph of the solution set mapping of the lower level problem. In this paper necessary optimality conditions for such problems are derived using the notion of a convexificator by Luc and Jeyakumar. Convexificators are subsets of many other generalized derivatives. Hence, our optimality conditions are stronger than those using e.g., the generalized derivative due to Clarke or Michel-Penot. Using a certain regularity condition Karush-Kuhn-Tucker conditions are obtained.
An approach for low sidelobe beamforming in uniform concentric circular arrays
Authors: Yasser Attia Albagory, Moawad Dessouky, Hamdy Sharshar
Venue: Wireless Personal Communications: An International Journal (2007)

In this paper, a new tapered beamforming function for sidelobe reduction in the uniform concentric circular arrays (UCCA) is proposed. This technique is based on tapering the current amplitudes of the rings in the array, where all elements in an individual ring are weighted in amplitude by the same value and the weight values of different rings are determined by a function that has a normalized-gaussian probability density function variation. This novel tapering window is optimized in its parameters to have the lowest possible sidelobe level that may reach 43 dB below the main lobe and these optimum weights are found to be function of the number of elements of the innermost ring and the number of rings in the array. The proposed tapering window can be modified to compensate the gain reduction due to tapering when compared with the uniform feeding case.
Fully distributed service configuration management
Authors: Paul Murray, Patrick Goldsack
Venue: Proceedings of the 3rd workshop on on Hot Topics in System Dependability (2007)

Configuration management in today's data centers is largely a human activity. Where automation does exist it is usually implemented by centralized management tools that coordinate configuration actions across the entire infrastructure and applications. These systems are limited in scale, reliability, and security. We propose that dependable service configuration management is more naturally implemented by a loose federation of fully distributed and self discovering management systems that interact through controlled information exchange.
Stemming Indonesian: A confix-stripping approach
Authors: Mirna Adriani, Jelita Asian, Bobby Nazief, S. M.M. Tahaghoghi, Hugh E. Williams
Venue: ACM Transactions on Asian Language Information Processing (TALIP) (2007)

Stemming words to (usually) remove suffixes has applications in text search, machine translation, document summarization, and text classification. For example, English stemming reduces the words "computer," "computing," "computation," and "computability" to their common morphological root, "comput-." In text search, this permits a search for "computers" to find documents containing all words with the stem "comput-." In the Indonesian language, stemming is of crucial importance: words have prefixes, suffixes, infixes, and confixes that make matching related words difficult. This work surveys existing techniques for stemming Indonesian words to their morphological roots, presents our novel and highly accurate CS algorithm, and explores the effectiveness of stemming in the context of general-purpose text information retrieval through ad hoc queries.
Natural scenes categorization by hierarchical extraction of typicality patterns
Authors: A. Perina, M. Cristani, V. Murino
Venue: Proceedings of the 14th International Conference on Image Analysis and Processing (2007)

Natural scene categorization of images represents a very useful task for automatic image analysis systems in a wide variety of applications. In the literature, several methods have been proposed facing this issue with excellent results. Typically, features of several types are clustered so as to generate a vocabulary able to efficiently represent the considered image collection. This vocabulary is formed by a discrete set of visual codewords whose co-occurrence or composition allows to classify the scene category. A common drawback of these methods is that features are usually extracted from the whole image, actually disregarding whether they derive from the scene to be classified or other objects, independent from the scene, eventually present in it. As quoted by perceptual studies, features regarding objects present in an image are not useful to scene categorization, indeed bringing an important source of clutter, in dependence of their size. In this paper, a novel, multiscale, statistical approach for image representation aimed at scene categorization is presented. The method is able to select, at different scales, sets of features that represent exclusively the scene disregarding other non-characteristic, clutter, elements. The proposed procedure, based on a generative model, is then able to produce a robust representation scheme useful for image classification. The obtained results are very convincing and prove the goodness of the approach even by just considering simple features like local color image histograms.
Evolutionary divide and conquer (i): A novel genetic approach to the tsp
Authors: Christine L. Valenzuela, Antonia J. Jones
Venue: Evolutionary Computation (1993)

Experiments with genetic algorithms using permutation operators applied to the traveling salesman problem (TSP) tend to suggest that these algorithms fail in two respects when applied to very large problems: they scale rather poorly as the number of cities n increases, and the solution quality degrades rapidly. We propose an alternative approach for genetic algorithms applied to hard combinatoric search which we call Evolutionary Divide and Conquer (EDAC). This method has potential for any search problem in which knowledge of good solutions for subproblems can be exploited to improve the solution of the problem itself. The idea is to use the genetic algorithm to explore the space of problem subdivisions rather than the space of solutions themselves. We give some preliminary results of this method applied to the geometric TSP.
Construct Metadata Based on Change Model Using for Component-Based Software Regression Testing
Authors: Liangli Ma, Fuliang Guo
Venue: Proceedings of the Fourth International Conference on Fuzzy Systems and Knowledge Discovery - Volume 01 (2007)

Component metadata is one of the most effective methods to improve the testability of component-based software. In this paper, we give definition of a component and summarize all possible changes of component. All these changes are further classified into two types and described as a two-tuple. Then a change model is constructed. We present the conceptions of mapping mechanism to implement changes within component mapping to interface changes of component. And we introduce the conceptions of present change-interface mapping graph(C-IMG), change-interface dependency relationship(C-IDR), method dependency graph (MDG) and component interface model(CIM) to describe the mapping mechanism. Furthermore, a relative mapping algorithm is given based on the above mapping mechanism. In the following, we apply above model research to component RegisterStuGrade developed by ourselves and compare with regression testing technique without metadata and Orso method in regression testing cases number and running time to verify the validity of our method.
Disease-specific genomic analysis
Authors: Monica Nicolau, Robert Tibshirani, Anne-Lise Børresen-Dale, Stefanie S. Jeffrey
Venue: Bioinformatics (2007)

Motivation: Genomic high-throughput technology generates massive data, providing opportunities to understand countless facets of the functioning genome. It also raises profound issues in identifying data relevant to the biology being studied. Results: We introduce a method for the analysis of pathologic biology that unravels the disease characteristics of high dimensional data. The method, disease-specific genomic analysis (DSGA), is intended to precede standard techniques like clustering or class prediction, and enhance their performance and ability to detect disease. DSGA measures the extent to which the disease deviates from a continuous range of normal phenotypes, and isolates the aberrant component of data. In several microarray cancer datasets, we show that DSGA outperforms standard methods. We then use DSGA to highlight a novel subdivision of an important class of genes in breast cancer, the estrogen receptor (ER) cluster. We also identify new markers distinguishing ductal and lobular breast cancers. Although our examples focus on microarrays, DSGA generalizes to any high dimensional genomic/proteomic data. Contact: ssj@standford.edu Supplementary information: Supplementary data are available at Bioinformatics online.
Mathematical Model for Multiobjective Synthesis of NoC Architectures
Authors: Ben A. Abderazek, Mushfiquzzaman Akanda, Tsutomu Yoshinaga, Masahiro Sowa
Venue: Proceedings of the 2007 International Conference on Parallel Processing Workshops (2007)

Network-on-Chip (NoC) interconnections have been proposed to overcome the problems associated with long wires used in chip wide communications. They support asynchronous transfer of communication between cores within multicore systems-on-chips (MCSoCs). The design of such architectures is crucial for achieving high performance and energy efficient systems. However, the effectiveness of NoC based design depends on the adopted design methodology. Automatic design approach is highly desirable to increase system design productivity. This paper presents a new mathematical formulation for synthesizing application specific NoC architectures, such that the performance constraints are satisfied and the communication power consumption is minimized.
On an online random k-SAT model
Authors: David Kravitz
Venue: Random Structures Algorithms (2008)

Given n Boolean variables x1,&hellip;,xn, a k-clause is a disjunction of k literals, where a literal is a variable or its negation. Suppose random k-clauses are generated one at a time and an online algorithm accepts or rejects each clause as it is generated. Our goal is to accept as many randomly generated k-clauses as possible with the condition that it must be possible to satisfy every clause that is accepted. When cn random k-clauses on n variables are given, a natural online algorithm known as Online-Lazy accepts an expected (1 - ${{1}\over {2^{k}}}$)cn + akn clauses for some constant ak. If these clauses are given offline, it is possible to do much better, (1 - ${{1}\over {2^{k}}}$)cn + &Omega;($\sqrt{c}$)n can be accepted whp. The question of closing the gap between ak and &Omega;($\sqrt{c}$) for the online version remained open. This article shows that for any k &ge; 1, any online algorithm will accept less than (1 - ${{1}\over {2^{k}}}$)cn + (ln 2)n k-clauses whp, closing the gap between the constant and &Omega;($\sqrt{c}$). Furthermore we show that this bound is asymptotically tight as k &rarr; &infin;. &copy; 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Stories with emotions and conflicts drive development of better interactions in industrial software projects
Authors: Georg Strom
Venue: Proceedings of the 19th Australasian conference on Computer-Human Interaction: Entertaining User Interfaces (2007)

An earlier study shows that stories with dialogue, emotions and conflicts -- similar to fiction writing -- give a better understanding of user needs and the situations in which an interface is used when compared to conventional scenarios. This paper describes how stories with emotions and conflicts were accepted as inputs to the definition of requirements in two industrial software projects, and how managers regarded stories as more credible than concise reports. The paper describes how it is possible to use stories with emotions and conflicts in industrial software projects, characteristics of the most useful stories, and how stories can be used to facilitate a dialogue between users and developers.
Cache-conscious radix-decluster projections
Authors: Stefan Manegold, Peter Boncz, Niels Nes, Martin Kersten
Venue: Proceedings of the Thirtieth international conference on Very large data bases - Volume 30 (2004)

As CPUs become more powerful with Moore's law and memory latencies stay constant, the impact of the memory access performance bottleneck continues to grow on relational operators like join, which can exhibit random access on a memory region larger than the hardware caches. While cache-conscious variants for various relational algorithms have been described, previous work has mostly ignored (the cost of) projection columns. However, real-life joins almost always come with projections, such that proper projection column manipulation should be an integral part of any generic join algorithm. In this paper, we analyze cache-conscious hash-join algorithms including projections on two storage schemes: N-ary Storage Model (NSM) and Decomposition Storage Model (DSM). It turns out, that the strategy of first executing the join and only afterwards dealing with the projection columns (i.e., post-projection) on DSM, in combination with a new finely tunable algorithm called Radix-Decluster, outperforms all previously reported projection strategies. To make this result generally applicable, we also outline how DSM Radix-Decluster can be integrated in a NSM-based RDBMS using projection indices.
Fast nGram-based string search over data encoded using algebraic signatures
Authors: Witold Litwin, Riad Mokadem, Philippe Rigaux, Thomas Schwarz
Venue: Proceedings of the 33rd international conference on Very large data bases (2007)

We propose a novel string search algorithm for data stored once and read many times. Our search method combines the sublinear traversal of the record (as in Boyer Moore or Knuth-Morris-Pratt) with the agglomeration of parts of the record and search pattern into a single character -- the algebraic signature -- in the manner of Karp-Rabin. Our experiments show that our algorithm is up to seventy times faster for DNA data, up to eleven times faster for ASCII, and up to a six times faster for XML documents compared with an implementation of Boyer-Moore. To obtain this speed-up, we store records in encoded form, where each original character is replaced with an algebraic signature. Our method applies to records stored in databases in general and to distributed implementations of a Database As Service (DAS) in particular. Clients send records for insertion and search patterns already in encoded form and servers never operate on records in clear text. No one at a node can involuntarily discover the content of the stored data.
On the Higher Order Difference Equation x_{n+1} = (x_{n-k+1})/(-1+x_{n}x_{n-1}...x_{n-k+1})
Authors: L. Y. Wang, D. C. Zhang, X. Y. Zeng
Venue: Proceedings of the Eighth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing - Volume 02 (2007)

In this paper, we investigate the solutions of the higher order difference equationx_n+1 = \frac{{x_{n - k + 1} }} {{ - 1 + x_n x_n\cdot\cdot\cdot x_{n - k + 1} }} for n = 0,1,... where k \in {1,2,...} and x_{-k+1}, ..., x_0 are the real numbers such that x_{-k+1}...x_0 \ne 1.
Realism in Computer Graphics: A Survey
Authors: John Amanatides
Venue: IEEE Computer Graphics and Applications (1987)

This article surveys most of the major issues to be dealt with when generating realistic images, and covers papers up to December 1985. It begins with an overview of the rendering process and a quick review of visible-surface-determination algorithms. Then, in more detail, it discusses shading, antialiasing, texture mapping, shadows, and optical effects and closes witha discussion of modeling primitives.
Apex: An Experiment in the Automated Creation of Pictorial Explanations
Authors: Steven feiner
Venue: IEEE Computer Graphics and Applications (1985)

How might we automate the design of pictures that are intended to show the viewer how to perform a series of tasks?
Combining personalisation and adaptation in game-based learning systems
Authors: Franziska Spring, Tsuyoshi Ito
Venue: Proceedings of the sixth conference on IASTED International Conference Web-Based Education - Volume 2 (2007)

This paper deals with adaptation and personalisation of a learning environment in digital learning games for adults. There is a great demand for research that considers the learner-centred approach in learning games. Learners should be able to determine their personal learning goals with a learning environment that supports them according to their individual learner's characteristics. The main focus of this paper lies in the design of an adaptive learning game that combines adaptation and personalisation. This system will be illustrated on the basis of the learning game "Virtual Team Collaborator". It teaches social skills for group work and project management. Finally it is shown how to build up the individual learning paths that result from personalised choices.