ppxscal/embedding_network huggingface dataset:
Computational aspects of modular forms and elliptic curves
Authors: Denis Xavier Charles
Venue:  (2005)

In this thesis I investigate certain computational aspects of Modular Forms and Elliptic Curves. The main computational problem in the theory of Modular Forms is the computation of their Fourier coefficients. The first part of the thesis is concerned with the computational complexity of this problem. I show that if we do not fix the modular form, then the problem of computing Fourier coefficients is &sharp; P -hard. Next, in joint work with Eric Bach, we show that if we fix a modular form that is a Hecke eigenform, then computing the Fourier coefficients is at least as hard as factoring RSA moduli. I also provide a new algorithm to compute the Fourier coefficients of any fixed space of cusp forms. This algorithm has a faster asymptotic running time than any previous algorithm for computing Fourier coefficients of these forms. The arithmetic theory of Elliptic Curves has many interesting computational problems. I study two such problems in this thesis. One is the problem of distinguishing elliptic curves with Complex Multiplication from ordinary elliptic curves. I give two algorithms for this problem: one is a randomized polynomial time algorithm and the other is a deterministic polynomial time algorithm. I also show how the randomized polynomial time algorithm can be made to have one-sided error. The other problem that I study is the problem of computing the modular polynomial. The modular polynomial is an object that governs isogenies between elliptic curves. In joint work with Kristin Lauter, we provide a new algorithm to compute the modular polynomial over finite fields. This algorithm also yields an efficient method of generating random isogenies from an elliptic curve over a finite field.
A New Indexing Method for Approximate Search in Text Databases
Authors: Fei Shi, Cread Mefford
Venue: Proceedings of the The Fifth International Conference on Computer and Information Technology (2005)

We present an index structure to support the approximate keyword search in text databases. In an approximate keyword search query, the user presents a query word Q and a tolerance value k (k\geqslant 0), and wishes to find all documents in the database that contain the query word Q or any other word in the vocabulary that matches Q approximately (We say that two words match each other approximately if the edit distance between them does not exceed the tolerance value k. In a typical text database application, a user will choose k = 1, 2, 3, or 4). Our index structure is built on the underlying vocabulary of the text database. The new technique has two principal componentsa new data structure called the V-tree and its partition methods for clustering words in the vocabulary into subgroups. We have implemented our index structure and conducted experiments on real-world data. Our experiments show that even for very large text database, the construction of our index and a search for keywords that match the query word approximately can be done quickly. Our implemntation makes it clear that the V-tree data structure can be easily integrated into existing access structures built on the database such as the inverted index file.
Handwritten Document Segmentation Using Hidden Markov Random Fields
Authors: Stephane Nicolas, Yousri Kessentini, Thierry Paquet, Laurent Heutte
Venue: Proceedings of the Eighth International Conference on Document Analysis and Recognition (2005)

In this paper we present a method based on Hidden Markov Random Fields and 2D dynamic programming image decoding, for segmenting pages of complex handwritten manuscripts such as novelist drafts. After a formal description of the theoretical framework and the principles of the decoding method, we describe the implementation of the model and the decoding method. Then we discuss the results obtained with this approach on the drafts of the French novelist Gustave Flaubert.
Least-Squares Covariance Matrix Adjustment
Authors: Stephen Boyd, Lin Xiao
Venue: SIAM Journal on Matrix Analysis and Applications (2005)

We consider the problem of finding the smallest adjustment to a given symmetric $n \times n$ matrix, as measured by the Euclidean or Frobenius norm, so that it satisfies some given linear equalities and inequalities, and in addition is positive semidefinite. This least-squares covariance adjustment problem is a convex optimization problem, and can be efficiently solved using standard methods when the number of variables (i.e., entries in the matrix) is modest, say, under $1000$. Since the number of variables is $n(n+1)/2$, this corresponds to a limit around $n=45$. Malick [{\it SIAM J. Matrix Anal.\ Appl.,} 26 (2005), pp. 272--284] studies a closely related problem and calls it the semidefinite least-squares problem. In this paper we formulate a dual problem that has no matrix inequality or matrix variables, and a number of (scalar) variables equal to the number of equality and inequality constraints in the original least-squares covariance adjustment problem. This dual problem allows us to solve far larger least-squares covariance adjustment problems than would be possible using standard methods. Assuming a modest number of constraints, problems with $n=1000$ are readily solved by the dual method. The dual method coincides with the dual method proposed by Malick when there are no inequality constraints and can be obtained as an extension of his dual method when there are inequality constraints. Using the dual problem, we show that in many cases the optimal solution is a low rank update of the original matrix. When the original matrix has structure, such as sparsity, this observation allows us to solve very large least-squares covariance adjustment problems.
Simulation models and some applications to maintenance and repair systems
Authors: Zbigniew J. Czajkiewicz, Narendra H. R. Reddy
Venue: ACM SIGSIM Simulation Digest (1985)

Simulation is one of the powerful techniques to study maintenance and repair phenomena. Perhaps the most compelling reason for the adoption of simulation has been the need to realistically model a complex environment. Simulation is quite sophisticated in that it enables various groups, activities, and resource mixes to be modelled. Further failure rates of systems and subsystems, repair times and equipment movement times can all be determined randomly based on input probability distributions. Simulation has a distinct advantage to conduct various trade-off studies like trade-offs between manpower requirements and component reliability and their effect on selection from various means.
Teleautonomy of mobile robots
Authors: Rafael Sandoval-Rodriguez
Venue:  (2005)

This dissertation studies the problem of teleautonomous mobile robots, and is divided into two main areas, namely, the coordination of multiple mobile robots, and the issues introduced by a limited-bandwidth communication channel when this is used to transmit information among the agents. The problem of coordination of multiple agents is addressed first, with a survey of the recent trends in coordination of multiple agents, and a discussion of the proposed architectures. We propose a Internet-Like Protocol (ILP) as a competitive coordination scheme. We provide stability proofs for the protocol, in the presence and absence of propagation time-delays. The applicability of this protocol for the coordination of a group of agents in the completion of formations in the plane is also studied. Bounds for the speed of dynamics in the agents are provided, to guarantee the stability of the formations. A discrete-time version of the protocol is considered, assuming that the protocol is implemented using digital computers. Tuning of the system parameters is analyzed to guarantee monotonic convergence. And finally for this first part, we analyzed the robustness of the protocol to changes in the number of agents participating in formations in the plane. The second part of this dissertation deals with the issues introduced by a communication network. We consider the effects of quantization, saturation, and sampling of signals on the closed-loop performance. Then analyze the effects introduced by a general purpose communication network, when this network is used to transmit the plant's state and control signals. We expose the issues that affect the performance of the system. We propose and test compensation approaches in a physical system, with real Internet traffic. Finally for the second part, we describe experimental mobile robots assembled to evaluate the control algorithms proposed, and to study the effects described above. We used one of these robots in different teleoperation experiments, where the communication channel was the Internet. In these experiments a haptic device was used as the master, while the robot performed as the slave. To perform navigation using visual feedback and local speed regulators along with virtual potential fields for navigation around obstacles.
A Toplogy Based Multi-Classifier System
Authors: Yann Prudent, Abdellatif Ennaji
Venue: Proceedings of the Eighth International Conference on Document Analysis and Recognition (2005)

This paper introduces a new scheme for the general problem of classification task-solving by designing a multiclassifier system. The distribution process respects the data topology in the feature space in order to reach reliable decisions. To this end we use a self-organizing network which give a graph which represent the data topology. During the decision process this graph is used to activate the appropriate classifiers among a set of committee experts. Comparative results are given for a handwritten digit recognition problem.
Sublines of Prime Order Contained in the Set of Internal Points of a Conic
Authors: Michel Lavrauw
Venue: Designs, Codes and Cryptography (2006)

In [2] it was shown that if q ¿ 4n2¿8n+2 then there are no subplanes of order q contained in the set of internal points of a conic in PG(2,qn), q odd, n¿ 3. In this article we improve this bound in the case where q is prime to $q > 2n^2-(4-2\sqrt{3})n+(3-2\sqrt{3})$ , and prove a stronger theorem by considering sublines instead of subplanes. We also explain how one can apply this result to flocks of a quadratic cone in PG(3,qn), ovoids of Q(4,qn), rank two commutative semifields, and eggs in PG(4n¿1,q).
Computational approach to some problems in algebraic analysis
Authors: Alberto Damiano
Venue:  (2006)

This dissertation is the result of my research on the algebraic analysis of linear constant coefficients differential operators, and its computational aspects. It is the natural continuation of the work I initiated with my Laurea Thesis [27] where I studied the computation of the Ext modules using Gr&ouml;bner Bases and their analytical meaning for the function theory of kernels of linear constant coefficient partial differential operators. As the research on Dirac operators developed, new theoretical aspects have emerged and new relations with computer algebra and Gr&ouml;bner Basis theory have been considered. In this dissertation I will provide some background on the algebraic analysis of such operators, and will then summarize the latest results on this topic before proceeding to a detailed exposition of my own results. I will devote particular attention to the use of Gr&ouml;bner Bases and the experiments conducted with some computer algebra software packages such as CoCoA [21], Macaulay2 [44] and Singular [46]. Part of the work is also the CoCoA code I wrote to perform experiments and to implement the algorithms for the explicit calculation of the mathematical objects involved in the Fourier analysis of the operators.
Email in personal information management
Authors: Steve Whittaker, Victoria Bellotti, Jacek Gwizdka
Venue: Communications of the ACM (2006)

Email's conduit function means the inbox, folders, search, and sort are used to support core PIM functions of task management, personal archiving, and contact management.
Authentication interface evaluation and design for mobile devices
Authors: Benjamin J. Halpert
Venue: Proceedings of the 2nd annual conference on Information security curriculum development (2005)

The design of mobile device interfaces is an area that has started to be addressed in the human computer interaction (HCI) community during the past few years. While previous work on handheld interface design has focused on overall usability aspects, security related design issues have only been minimally addressed. An example of a security interface is an authentication interface as used by electronic commerce (e-commerce) web sites. The paper opens with a review of prior research on secure interface design. Results of a usability evaluation targeting authentication interfaces as accessed on mobile devices is presented. To illustrate design aspects of an authentication interface, a discussion of the eBay authentication interface is then discussed. Recommended guidelines are proposed for designing authentication interfaces as accessed via mobile devices.
The impact of collaborative computer software on the enhancement of learning in a secondary science course
Authors: Timothy Paul
Venue:  (2005)

This qualitative study examines the impact of the use of collaborative computer software on the enhancement of learning in three high school biology classes. Current research has suggested that collaborative teaching methods can increase student achievement in the study of science and can create in students a more positive attitude toward the study of science. Research further indicates that computer supported collaborative learning (CSCL) can also promote higher achievement in science and a more positive attitude in students studying science. This study focused primarily on gaining a better understanding of how CSCL can affect student attitudes toward learning biology and how teachers change their attitudes toward CSCL and their curriculum and assessment practices to accommodate CSCL. An additional focus of the study was to examine whether CSCL could significantly enhance student achievement. In this study three groups of five students each participated in weekly CSCL sessions (using Groove collaborative software) for one semester). Questionnaires were administered to both project participants and comparison groups to compare student attitudes toward the study of biology. Teacher attitudes toward changing their curriculum and assessment practices for students involved in CSCL projects were determined from both the researcher's notes of biweekly teacher meetings and teacher reflection papers. The principal findings of this research are: (1) students who engaged in CSCL enjoyed their study of biology more than their comparison group students, (2) students who engaged in CSCL had generally higher (though not statistically significant) achievement in biology than comparison students, (3) teachers significantly changed their mode of instruction from teacher centered to student centered learning, (4) teachers significantly changed their assessment practices to accommodate CSCL students. This study suggests that the use of CSCL can improve student attitude and achievement in the study of biology at the secondary level. In addition, it confirms that teachers involved in CSCL will need to change both their curriculum and assessment practices to accommodate CSCL students.
"smart" sensors for civil infrastructure systems
Authors: Manuel E. Ruiz-Sandoval
Venue:  (2004)

&ldquo;Smart&rdquo; sensors with embedded microprocessors and wireless communication links have the potential to change fundamentally the way civil infrastructure systems are monitored, controlled, and maintained. A 2002 National Research Council report noted that the use of networked systems of embedded computers and sensors throughout society could well dwarf all previous milestones in the information revolution. Structural health monitoring and control systems (SHM/C) represent one of the primary applications for new sensor technologies. This dissertation explores the use of the smart sensor technology for the SHM/C of civil infrastructure. Following a brief introduction to smart sensor technology, a literature review of the devices developed to date is presented. The research herein concentrates on the Mote platform developed at the University of California at Berkeley. This platform offers for the first time an open software/hardware environment for a broad range of smart sensing research. The suitability of the accelerometer on the existing Berkeley-platform for civil engineering applications is then investigated. A new sensor board (called Tadeo) is developed that has a high sensitivity accelerometer, a microphone, a thermistor, and photo resistor. The accelerometer employed overcomes many of the deficiencies of the sensor on the available boards. However, a number of the challenges still remaining are identified. An agent-based paradigm is proposed that supports implementation of SHM/C algorithms on networks of smart sensors. Because traditional algorithms for SHM/C assume that data is centrally processed, they cannot be implemented directly in the distributed computing environment employed by smart sensors. To demonstrate the efficacy of this approach, a reference implementation of the agent-based framework is provided for a SHM system employing the AR-ARX algorithm. Numerical examples indicate that the framework is effective. This initial research demonstrates the feasibility of using smart sensors for SHM of civil infrastructure. A new sensor board is developed and shown to meet the needs of the application. An agent-based framework for smart sensing is proposed and shown to perform well. This research begins to lay the foundation from which the many opportunities offered by smart sensing technology can be pursued.
A Symbolic Query-by-Example Framework for the Image Retrieval Signal/Semantic Integration
Authors: Mohammed Belkhatir
Venue: Proceedings of the 17th IEEE International Conference on Tools with Artificial Intelligence (2005)

We propose in this paper to enhance the performance of the S.I.R. [2,3,4] (Signal/semantic integration for Image Retrieval) image indexing and retrieval architecture through the integration of a query-by-example framework based on high-level image descriptions instead of their extracted low-level features. This framework features a multi-facetted conceptual model which integrates visual semantics as well as symbolic color and texture characterizations and operates on image objects (abstractions of visual entities within a physical image) in an attempt to perform querying operations beyond trivial low-level processes and region-based frameworks. Also, it manipulates a rich query language, consisting of both boolean and quantification operators, which therefore leads to optimized user interaction and increased retrieval performance. Experimental results on a test collection of 2500 color personal photographs show that our approach gives better results in terms of recall and precision measures than state-of-the-art frameworks loosely coupling keyword-based query modules and relevance feedback processes operating on low-level features.
The role of statistical methodology in simulation
Authors: Jack P. C. Kleijnen
Venue: ACM SIGSIM Simulation Digest (1978)

In practice, a most popular method to study complex systems is simulation. However, a major practical drawback of simulation is its <u>ad hoc</u> character. After spending much mental effort and computer time to develop, program, and run a computer simulation, strictly speaking, the results are valid only for the specific parameter values and structural relationships of the executed simulation program (or programs). Changing a parameter or relationship means that the simulation program has to be run again. Yet, such changes are necessary to answer "what if" questions, to find optimal system configurations and, not to be forgotten, to establish the sensitivity of the conclusions to specific model assumptions.
Interaction Protocols as Design Abstractions for Business Processes
Authors: Nirmit Desai, Ashok U. Mallya, Amit K. Chopra, Munindar P. Singh
Venue: IEEE Transactions on Software Engineering (2005)

Business process modeling and enactment are notoriously complex, especially in open settings, where business partners are autonomous, requirements must be continually finessed, and exceptions frequently arise because of real-world or organizational problems. Traditional approaches, which attempt to capture processes as monolithic flows, have proven inadequate in addressing these challenges. We propose (business) protocols as components for developing business processes. A protocol is an abstract, modular, publishable specification of an interaction among different roles to be played by different participants. When instantiated with the participants' internal policies, protocols yield concrete business processes. Protocols are reusable and refinable, thus simplifying business process design. We show how protocols and their composition are theoretically founded in the \pi-calculus.
Efficient Exact Spare Allocation via Boolean Satisfiability
Authors: Fang Yu, Chung-Hung Tsai, Yao-Wen Huang, D. T. Lee, Hung-Yau Lin, Sy-Yen Kuo
Venue: Proceedings of the 20th IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems (2005)

Fabricating large memory and processor arrays is subject to physical failures resulting in yield degradation. The strategy of incorporating spare rows and columns to obtain reasonable production yields was first proposed in the 1970s, and continues to play an important role in recent VLSI developments. The spare allocation problem (SAP) in general is known to be intractable, an efficient exact spare allocation algorithm has great value. We propose a new Boolean encoding of SAP and a new SAT-based exact algorithm SATRepair. We used a realistic fault distribution model to compare SATRepair¿s performances against those of BDDRepair and several algorithms found in the literature. We found that a) our Boolean encoding of SAP facilitates the development of efficient exact SAP algorithms, and b) our SAT-based algorithm outperforms previous algorithms, especially for large problems.
Computer-Assisted and Customer-Oriented Requirements Elicitation
Authors: K. Li,  R. G. Dewar, R. J. Pooley
Venue: Proceedings of the 13th IEEE International Conference on Requirements Engineering (2005)

In requirements elicitation, there is almost always a need for the participation of stakeholders (e.g. domain experts, customers and end-users) to help requirements engineers to uncover requirements. This need leads to the problem of how the stakeholders can communicate their needs effectively, but if one addresses existing work on such communication related issues, a wide diversity of techniques is proposed to support better description and understanding, all based on face-toface communication with stakeholders [1]. The humancentred nature of these approaches creates a considerable difficulty in attempting automation of requirements elicitation. Furthermore, stakeholders often lack relevant domain and system knowledge. Modelling techniques are typically applied to analyse the domain-specific data, using the chosen modelling concepts.
Review of "Working effectively with legacy code by Michael Feathers", Prentice Hall PTR, 2004, $44.99 ISBN: 0131177052
Authors: Fernando Berzal
Venue: Queue (2005)

Karl Kopper, No Starch Press, 2005, $49.95 ISBN: 1593270364 Have you ever wanted to build a highly available cluster? This book shows you how to do it, using commodity hardware and free software. Author Karl Kopper has worked with distributed computing environments on a number of platforms; he uses the cluster he successfully deployed at a food distribution company as the basis for the examples in the book.