ppxscal/embedding_network huggingface dataset:
On robust matrix completion with prescribed eigenvalues
Authors: M. T. Chu, F. Diele, I. Sgura
Venue: Future Generation Computer Systems (2003)

Matrix completion with prescribed eigenvalues is a special kind of inverse eigenvalue problems. Thus far, only a handful of specific cases concerning its existence and construction have been studied in the literature. The general problem where the prescribed entries are at arbitrary locations with arbitrary cardinalities proves to be challenging both theoretically and computationally. This paper investigates some continuation techniques by recasting the completion problem as an optimization of the distance between the isospectral matrices with the prescribed eigenvalues and the affine matrices with the prescribed entries. The approach not only offers an avenue to solving the completion problem in its most general setting but also makes it possible to seek a robust solution that is least sensitive to perturbation.
Computer aided engineering for theoretical studies of vehicle active suspension systems
Authors: P. V. Kyratsis, D. A. Panagiotopoulos, D. V. Kakogiannis
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

Active suspension systems offer significant advantages over passive systems. The high power necessary to operate conventional active systems is leading to further investigation for low energy consuming systems.The present work is a theoretical study of a low energy active suspension system. A half vehicle model is developed in order to simulate the active suspension system based on the change of its mechanical lever ratio. The degrees of freedom used are enough to simulate accurately real road conditions, whilst at the same time the models are not very complicated. Due to the horizontal motion of the spring involved, the energy consumption is much lower than in conventional systems, in which actuators are primary suspension elements.Non-linear models are included. These were written in AUTOSIM, which was used to create programs in FORTRAN. The elimination of roll in manoeuvring, by appropriate movement of the actuators, created problems of discomfort and a conflict of these two factors is investigated. When roll is controlled, the control law in order to avoid jacking of the vehicle is defined and different lay-outs are examined. The work is contributing to the good design of a low energy automotive active suspension, mechanically compatible with contemporary systems.
Checkpoint Processing and Recovery: Towards Scalable Large Instruction Window Processors
Authors: Haitham Akkary, Ravi Rajwar, Srikanth T. Srinivasan
Venue: Proceedings of the 36th annual IEEE/ACM International Symposium on Microarchitecture (2003)

Large instruction window processors achieve high performance by exposing large amounts of instruction levelparallelism. However, accessing large hardware structurestypically required to buffer and process such instructionwindow sizes significantly degrade the cycle time. This paper proposes a novel Checkpoint Processing and Recovery(CPR) microarchitecture, and shows how to implement alarge instruction window processor without requiring largestructures thus permitting a high clock frequency.We focus on four critical aspects of a microarchitecture:1) scheduling instructions, 2) recovering from branch mispredicts, 3) buffering a large number of stores and forwarding data from stores to any dependent load, and 4) reclaiming physical registers. While scheduling window size isimportant, we show the performance of large instructionwindows to be more sensitive to the other three design issues. Our CPR proposal incorporates novel microarchitectural schemes for addressing these design issues-a selective checkpoint mechanism for recovering from mispredicts,a hierarchical store queue organization for fast store-loadforwarding, and an effective algorithm for aggressive physical register reclamation. Our proposals allow a processor to realize performance gains due to instruction windowsof thousands of instructions without requiring large cycle-critical hardware structures.
Interview with Alan Kay
Authors: Alan Kay
Venue: Computers in Entertainment (CIE) (2003)

The legendary Alan Kay and Roy E. Disney have graciously appeared on camera for interviews and joined the ACM Computers in Entertainment magazine's editorial board. Alan and Roy are two of the nicest people to talk to and work with. Alan talked about soft fun versus hard fun, and his research on Squeak for enhancing and amplifying learning in children's education. Roy told us about educators versus entertainers, and his views on traditional and CGI animations. The video clips of the interviews are available at http://www.acm.org/pubs/cie/oct2003/index.htmlAlan Kay, HP Fellow and President of Viewpoints Research Institute, is best known for the idea of personal computing the conception of the intimate laptop computer, and the inventions of the now ubiquitous overlapping-window interface and modern object-oriented programming. His deep interests in children and education were the catalyst for these ideas, and they continue to be a major source of inspiration. In the past, Alan has been a Xerox Fellow, Chief Scientist of Atari, Apple Fellow, and Disney Fellow. More information is available at http://www.squeakland.org/community/biography/alanbio.html and http://www.viewpointsresearch.org/alan.html
Displacement Following of Hidden Objects in a Video Sequence
Authors: Olivia Sanchez, Françoise Dibos
Venue: International Journal of Computer Vision (2004)

In a video sequence, computing the motion of an object requires the continuity of the apparent velocity field. This property does not hold when the object is hidden by an occlusion during its motion. The minimization of an energy functional leads to a simple algorithm which allows the recovery of the most likely trajectory of the occluded object from optical flow data at the border of the occlusion. Optical flow used for developing our method is an improvement on any variational technique of computing it. This improvement is based on a multichannel segmentation.
Describing Data on the Grid
Authors: Martin Westhead, Ted Wen, Robert Carroll
Venue: Proceedings of the 4th International Workshop on Grid Computing (2003)

The development of standards for describing format,structure and semantic content of data is essential for itsautomatic manipulation within a grid. This paperdescribes two related pieces of work that aim to addressthis need. BinX is a language with supporting tools andlibrary for describing binary data, developed as part ofthe eDIKT project at the National eScience Centre. TheData Format Description Language (DFDL) is a GlobalGrid Forum working group which draws on the BinXwork and aims to develop an extensible standard fordescribing these features of data formats.
Further towards a taxonomy of agent-based simulation models in environmental management
Authors: M. Hare, P. Deadman
Venue: Mathematics and Computers in Simulation (2004)

Agent-based simulation (ABS) is being increasingly used in environmental management. However, the efficient and effective use of ABS for environmental modelling is hindered by the fact that there is no fixed and clear definition of what an ABS is or even what an agent should be. Terminology has proliferated and definitions of agency have been drawn from an application area (Distributed Artificial Intelligence) which is not wholly relevant to the task of environmental simulation. This situation leaves modellers with little practical support for clearly identifying ABS techniques and how to implement them.This paper is intended to provide an overview of agent-based simulation in environmental modelling so that modellers can link their requirements to the current state of the art in the techniques that are currently used to satisfy them. Terminology is clarified and then simplified to two key existing terms, agent-based modelling and multi-agent simulation, which represent subtly different approaches to ABS, reflected in their respective artificial life (A-life) and distributed artificial intelligence roots. A representative set of case studies are reviewed, from which a classification scheme is developed as a stepping-stone to developing a taxonomy. The taxonomy can then be used by modellers to match ABS techniques to their requirements.
Approximation Algorithms for the Class Cover Problem
Authors: Adam H. Cannon, Lenore J. Cowen
Venue: Annals of Mathematics and Artificial Intelligence (2004)

We introduce the class cover problem, a variant of disk cover with forbidden regions, with applications to classification and facility location problems. We prove similar hardness results to disk cover. We then present a polynomial-time approximation algorithm for class cover that performs within a ln&thinsp;n+1 factor of optimal, which is nearly tight under standard hardness assumptions. In the special case that the points lie in a d-dimensional space with Euclidean norm, for some fixed constant d, we obtain a polynomial time approximation scheme.
Behavioural Bitwise Scheduling Based on Computational Effort Balancing
Authors: M. C. Molina, R. Ruiz-Sautua, J. M. Mendías, R. Hermida
Venue: Proceedings of the conference on Design, automation and test in Europe - Volume 1 (2004)

Conventional synthesis algorithms schedule multiple precision specifications by balancing the number of operations of every different type and width executed per cycle. However, totally balanced schedules are not always possible and therefore some hardware waste appears. Inthis paper a heuristic scheduling algorithm to minimize this hardware waste is presented. It successively transforms specification operations into sets of smaller ones until the most uniform distribution of the computational effort of operations among cycles is reached. In the schedules proposed some operations are executed during a set of non- consecutive cycles.
Effective features of algorithm visualizations
Authors: Purvi Saraiya, Clifford A. Shaffer, D. Scott McCrickard, Chris North
Venue: Proceedings of the 35th SIGCSE technical symposium on Computer science education (2004)

Many algorithm visualizations have been created, but little is known about which features are most important to their success. We believe that pedagogically useful visualizations exhibit certain features that hold across a wide range of visualization styles and content. We began our efforts to identify these features with a review that attempted to identify an initial set of candidates. We then ran two experiments that attempted to identify the effectiveness for a subset of features from the list. We identified a small number of features for algorithm visualizations that seem to have a significant impact on their pedagogical effectiveness, and found that several others appear to have little impact. The single most important feature studied is the ability to directly control the pace of the visualization. An algorithm visualization having a minimum of distracting features, and which focuses on the logical steps of an algorithm, appears to be best for procedural understanding of the algorithm. Providing a good example for the visualization to operate on proved significantly more effective than letting students construct their own data sets. Finally, a pseudocode display, a series of questions to guide exploration of the algorithm, or the ability to back up within the visualization did not show a significant effect on learning.
BiST Model for IC RF-Transceiver Front-End
Authors: Jerzy Dabrowski
Venue: Proceedings of the 18th IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems (2003)

In this paper a BiST technique for RF transceiver front-end is presented. The test is aimed atspot defects typical of mass production in CMOS process. The loop-back approach is used todetect the faults modeled as resistive breaks or bridges. The resulting impairments in gain, noise figure or selectivity of the RF blocks are considered functional-level faults, and as suchare subjected to test with PRBS stimulus and BER as the response at base-band. The extra test circuitry is limited and the on-chip resources are used to set-up the BiST. A model of GSMtransceiver with BiST is investigated to verify the proposed approach.
Haptic Virtual Environment Performance over IP Networks: A Case Study
Authors: Rima Tfaily Souayed, Dominique Gaiti, Guy Pujolle, Wai Yu, Qiang Gu, Alan Marshall
Venue: Proceedings of the Seventh IEEE International Symposium on Distributed Simulation and Real-Time Applications (2003)

This paper reports on the quality of service (QoS) requirements and the performance of Virtual Environment (VE) Applications deployed in IP networks. We are interested specifically in systems that support communication with end-user through force feedback devices known as haptic interfaces. Little is known about networked haptic interfaces in VE. Our goal is to understand such application QoS requirements as well as the effect of other traffic when they co-exist in the same network. In this paper, we compare the peer-to-peer model with the client-server model. Our motivation is to deploy Distributed Haptic VE applications (DHVE) over a network connecting two departments of Queen's university of Belfast. This deployment will be used for educational purposes and for implementing further research in this area, and will be evaluated by end-users; hence, the essential realisation of network-based DHVE under realistic network conditions. A set of experiments was conducted to achieve this aim and their results are presented in this paper.
S-MEP: A Planner for Numeric Goals
Authors: Javier Sanchez, Amol Dattatraya Mali
Venue: Proceedings of the 15th IEEE International Conference on Tools with Artificial Intelligence (2003)

Planning for numeric goals is an important problem. Only one of the many participants from the 2002 international planning competition (Metric-FF) can effectively handle problems containing numeric goal expressions. We report on planner S-MEP (Sequential More Expressive Planner) in this paper. S-MEP handles non-linear as well as linear expressions in preconditions, effects and goal. Metric-FF handles only linear expressions. Metric-FF ignores decrease effects of actions while computing the heuristic information. S-MEP considers decrease effects of actions while computing heuristic information. We report on empirical evaluation of S-MEP and its comparison with two versions of Metric-FF on 400 problems from linear Jugs domain, 120 problems from linear Short-Move-Karel domain and 120 problems from linear Long-Move-Karel domain. Karel domains are robotic transportation domains and Jugs domain is a fluid transfer domain. S-MEP solves many problems that neither version of Metric-FF can solve.
Computer science and the arts: some multi-disciplinary teaching collaborations
Authors: J. R. Parker, Katrin Becker, Douglas McCullough
Venue: Proceedings of the 8th annual conference on Innovation and technology in computer science education (2003)

We explain the need for formal collaboration between students in the arts and computer science students, and argue that this should be encouraged at an early stage of their education. Two specific courses that foster this sort of cooperation are described.
Dynamic Integrated Scheduling of Hard Real-Time, Soft Real-Time and Non-Real-Time Processes
Authors: Scott A. Brandt, Scott Banachowski, Caixue Lin, Timothy Bisson
Venue: Proceedings of the 24th IEEE International Real-Time Systems Symposium (2003)

Real-time systems are growing in complexity and real-timeand soft real-time applications are becoming commonin general-purpose computing environments. Thus, there isa growing need for scheduling solutions that simultaneouslysupport processes with a variety of different timeliness constraints.Toward this goal we have developed the ResourceAllocation/Dispatching (RAD) integrated scheduling modeland the Rate-Based Earliest Deadline (RBED) integratedmulti-class real-time scheduler based on this model. Wepresent RAD and the RBED scheduler and formally provethe correctness of the operations that RBED employs. Wethen describe our implementation of RBED and present resultsdemonstrating how RBED simultaneously and seamlesslysupports hard real-time, soft real-time, and best-effortprocesses.
Channel dependent types for higher-order mobile processes
Authors: Nobuko Yoshida
Venue: ACM SIGPLAN Notices (2004)

This paper introduces a new expressive theory of types for the higher-order π-calculus and demonstrates its applicability via two security analyses for higher-order code mobility. The new theory significantly improves our previous one presented in [55] by the use of channel dependent/existential types. New dependent types control dynamic change of process accessibility via channel passing, while existential types guarantee safe scope-extrusion in higher-order process passing. This solves an open issue in [55], leading to significant enlargement of original typability. The resulting typing system is coherently integrated with the linear/affine typing disciplines as well as state, concurrency and distribution [53, 5, 56, 22], allowing precise analysis of software behaviour with higher-order mobility. As illustration of the usage of the typed calculus, two basic security concerns for mobile computation, secrecy for data confidentiality and rôle-based access control for authorised resources, are analysed in a uniform type-based framework, leading to the noninterference theorem and authority-error freedom in the presence of higher-order code mobility.
Information extraction from case law and retrieval of prior cases
Authors: Peter Jackson, Khalid Al-Kofahi, Alex Tyrrell, Arun Vachher
Venue: Artificial Intelligence (2003)

We describe an information extraction and retrieval system, called History Assistant, which extracts rulings from court opinions and retrieves relevant prior cases from a citator database. The technology employed is similar to that adopted in the Message Understanding Conferences, but attempts a fuller parse in order to distinguish current rulings from previous rulings reported in a case. In addition, we employ a combination of information retrieval and machine learning techniques to link each new case to related documents that it may impact. We present experimental results, in terms of precision and recall, for all tasks performed by the extraction and linking programs. Part of the finished system has been deemed worthy of further development into a computer-assisted database update tool to help editors assimilate historical relationships between cases into a concordance of court decisions, called a citator.
The emerging need for e-commerce accepted practice (ECAP)
Authors: G. Erwin, S. Singh
Venue: The economic and social impacts of e-commerce (2003)

With the rapid expansion of the Internet and constant technological advances, it is clear that e-commerce will reshape methods of the business world. Government, large corporations, medium and small business now have to conduct their electronic activities in an accountable, transparent and well-structured way. Unlike traditional business recording, such as accounting, with Generally Accepted Accounting Practice (GAAP), no guidelines or frameworks exist that recognize e-commerce issues.
Packet Classification Using Extended TCAMs
Authors: Ed Spitznagel, David Taylor, Jonathan Turner
Venue: Proceedings of the 11th IEEE International Conference on Network Protocols (2003)

CAMs are the most popular practical method for implementing packet classification in high performance routers. Their principal drawbacks are high power consumption and inefficient representation of filters with port ranges. A recent paper [11] showed how partitioned TCAMs can be used to implement IP route lookup with dramatically lower power consumption. We extend the ideas in [11] to address the more challenging problem of general packet classification. We describe two extensions to the standard TCAM architecture. The first organizes the TCAM as a two level hierarchy in which an index block is used to enable/disable the querying of the main storage blocks. The second incorporates circuits for range comparisons directly within the TCAM memory array. Extended TCAMs can deliver high performance (100 million lookups per second) for large filter sets (100,000 filters), while reducing power consumption by a factor of ten and improving space efficiency by a factor of three.
Visualizing concept drift
Authors: Kevin B. Pratt, Gleb Tschapek
Venue: Proceedings of the ninth ACM SIGKDD international conference on Knowledge discovery and data mining (2003)

We describe a visualization technique that uses brushed, parallel histograms to aid in understanding concept drift in multidimensional problem spaces. This technique illustrates the relationship between changes in distributions of multiple antecedent feature values and the outcome distribution. We can also observe effects on the relative utilization of predictive rules. Our parallel histogram technique solves the over-plotting difficulty of parallel coordinate graphs and the difficulty of comparing distributions of brushed and original data. We demonstrate our technique's usefulness in understanding concept drifts in power demand and stock investment returns.
Constructing Web search queries from the user's information need expressed in a natural language
Authors: Jacob Shapiro, Isak Taksa
Venue: Proceedings of the 2003 ACM symposium on Applied computing (2003)

This paper focuses on improving the quality of information retrieval on the Web through the use of long queries. Long queries allow use of natural language and provide for a more complete description of the user's information need. We propose and analyze several novel algorithms dealing with long query information retrieval on the Web. These algorithms include selecting of search terms, constructing multiple query formulations, merging and ranking search results. We developed a meta-search engine, incorporating the proposed algorithms, and conducted a series of experiments to evaluate the performance of various algorithms. We also compared search results of the new engine with the results of popular search engines on the Web. These experiments clearly demonstrate that using long queries in the Web environment is practical and can substantially improve the quality of information retrieval.
Aspen language specifications
Authors: Thomas R. Wilcox
Venue: ACM SIGPLAN Notices (1977)

ASPEN is a "toy" language that has been designed for use in the teaching of compiler construction and is therefore a curious amalgam of highly refined language features that manage to barely cover the full spectrum of algorithmic languages. One selection statement is made to do the work of IF-THEN-ELSE and CASE, but with certain severe restrictions on the conditions that may be written. on the other hand, iterations must be written as a primitive infinite loop with explicit conditional exits.Only floating point (REAL) arithmetic is supported, and although strings are present, their only practical use is restricted to the labeling of output. Both array and record aggregates are defined, but both are reduced to n-tuples of fixed-length words that are referenced through pointers: each word contains either a REAL value or a pointer to another n-tuple or string. All pointers are strongly typed.The user is permitted to define his own types, but no coercions between types are predefined. Type definitions are implemented in the same manner as functions and procedures with all parameter passing being done by value. The uniformity of data structuring permits efficient implementation of simple parametric types and polymorphic procedures.Using two stacks at runtime, instead of one, a degree of dynamic storage allocation is possible, but without the need for a heap and garbage collection. The "dangling reference" problem is <u>not</u> avoided, however. Finally, an encapsulation mechanism that allows controlled permeation of names through a program is provided to support data abstraction and information hiding, although separate compilation is not supported.