ppxscal/embedding_network huggingface dataset:
The use of the WWW to support distance learning through NTU
Authors: Douglas D. Dankell,  II, James Hearn
Venue: Proceedings of the 2nd conference on Integrating technology into computer science education (1997)

The teaching of graduate level computer science courses can be a challenging task. The students are confronted with a wealth of complex material with, often, higher expectations by their instructors on their performance. Distance education of students employed full-time presents an interesting and complex challenge. This paper describes the instructional package consisting primarily of a World Wide Web (WWW) site used by the author to aid in educating distance education students enrolled in graduate Artificial Intelligence Concept courses at the University of Florida.
Shape Representation Using a Generalized Potential Field Model
Authors: Narendra Ahuja, Jen-Hui Chuang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

This paper is concerned with efficient derivation of the medial axis transform of a two-dimensional polygonal region. Instead of using the shortest distance to the region border, a potential field model is used for computational efficiency. The region border is assumed to be charged and the valleys of the resulting potential field are used to estimate the axes for the medial axis transform. The potential valleys are found by following force field, thus, avoiding two-dimensional search. The potential field is computed in closed form using the equations of the border segments. The simple Newtonian potential is shown to be inadequate for this purpose. A higher order potential is defined which decays faster with distance than as inverse of distance. It is shown that as the potential order becomes arbitrarily large, the axes approach those computed using the shortest distance to the border. Algorithms are given for the computation of axes, which can run in linear parallel time for part of the axes having initial guesses. Experimental results are presented for a number of examples.
Bounds on Spectra of Codes with Known Dual Distance
Authors: Ilia Krasikov, Simon Litsyn
Venue: Designs, Codes and Cryptography (1998)

We estimate the interval where the distance distribution of a code of length n and of given dual distance is upperbounded by the binomial distribution. The binomial upper bound is shown to be sharp in this range in the sense that for every subinterval of size about &radic;n ln n there exists a spectrum component asymptotically achieving the binomial bound. For self-dual codes we give a better estimate for the interval of binomiality.
Qualitative and Numerical Analysis of Quasi-Static Problems in Elastoplasticity
Authors: Weimin Han, B. Daya Reddy, Gregory C. Schroeder
Venue: SIAM Journal on Numerical Analysis (1997)

The quasi-static problem of elastoplasticity with combined kinematic-isotropic hardening is formulated as a time-dependent variational inequality (VI) of the mixed kind; that is, it is an inequality involving a nondifferentiable functional and is imposed on a subset of a space. This VI differs from the standard parabolic VI in that time derivatives of the unknown variable occur in all of its terms. The problem is shown to possess a unique solution.We consider two types of approximations to the VI corresponding to the quasi-static problem of elastoplasticity: semidiscrete approximations, in which only the spatial domain is discretized, by finite elements; and fully discrete approximations, in which the spatial domain is again discretized by finite elements, and the temporal domain is discretized and the time-derivative appearing in the VI is approximated in an appropriate way.Estimates of the errors inherent in the above two types of approximations, in suitable Sobolev norms, are obtained for the quasi-static problem of elastoplasticity; in particular, these estimates express rates of convergence of successive finite element approximations to the solution of the variational inequality in terms of element size h and, where appropriate, of the time step size k.A major difficulty in solving the problems is caused by the presence of the nondifferentiable terms. We consider some regularization techniques for overcoming the difficulty. Besides the usual convergence estimates, we also provide a posteriori error estimates which enable us to estimate the error by using only the solution of a regularized problem.
3D Pose Estimation by Directly Matching Polyhedral Models to Gray Value Gradients
Authors: Henner Kollnig, Hans-Hellmut Nagel
Venue: International Journal of Computer Vision (1997)

This contribution addresses the problem of pose estimation and tracking of vehicles in image sequences from traffic scenes recorded by a stationary camera. In a new algorithm, the vehicle pose is estimated by directly matching polyhedral vehicle models to image gradients without an edge segment extraction process. The new approach is significantly more robust than approaches that rely on feature extraction since the new approach exploits more information from the image data. We successfully tracked vehicles that were partially occluded by textured objects, e.g., foliage, where a previous approach based on edge segment extraction failed. Moreover, the new pose estimation approach is also used to determine the orientation and position of the road relative to the camera by matching an intersection model directly to image gradients. Results from various experiments with real world traffic scenes are presented.
Admission Policies in Loss Queueing Models with Heterogeneous Arrivals
Authors: E. Carrizosa, E. Conde, M. Munoz-Marquez
Venue: Management Science (1998)

In this paper we consider a loss system where the arrivals can be classified into different groups according to their arrival rate and expected service time. While the standard admission policy consists of rejecting only those customers who arrive when all servers are busy, we address the problem of finding the optimal static admission policy (with respect to a given reward structure) when customers can be discriminated according to the group they belong to, thus customers of some groups might be automatically rejected (even if some servers remain idle) in order to enhance the global efficiency of the system. The optimality of a c&#956;-rule is shown, from which finite-time algorithms for the one- and two-server cases are derived.
Incorporating financial and ergonomic considerations into models of manufacturing systems
Authors: Henry Herper, Thomas Kagerl, Dietrich Ziems
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This contribution describes a modular concept by which simulation results can be post-run interpreted under different aspects (multifunctional interpretation). The extension of classic simulation models for materials flow systems and manufacturing systems by economic, ecological and environmental aspects as well as the advantages and limits of this approach are discussed in this paper. A gear manufacturing was chosen as an example to demonstrate the application of a multifunctional interpretation.
Functional programming with graphs
Authors: Martin Erwig
Venue: ACM SIGPLAN Notices (1997)

Graph algorithms expressed in functional languages often suffer from their inherited imperative, state-based style. In particular, this impedes formal program manipulation. We show how to model persistent graphs in functional languages by graph constructors. This provides a decompositional view of graphs which is very close to that of data types and leads to a "more fictional" formulation of graph algorithms. Graph constructors enable the definition of general fold operations for graphs. We present a promotion theorem for one of these folds that allows program fusion and the elimination of intermediate results. Fusion is not restricted to the elimination of tree-like structures, and we prove another theorem that facilitates the elimination of intermediate graphs. We describe an ML-implementation of persistent graphs which efficiently supports the presented fold operators. For example, depth-first-search expressed by a fold over a functional graph has the same complexity as the corresponding imperative algorithm.
An Algorithm for the Learning of Weights in Discrimination Functions Using a Priori Constraints
Authors: Norbert Krüger
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

We introduce a learning algorithm for the weights in a very common class of discrimination functions usually called "weighted average." The learning algorithm can reduce the number of free variables by simple but effective a priori criteria about significant features. Here we apply our algorithm to three tasks of different dimensionality all concerned with face recognition.
Generational garbage collection and the radioactive decay model
Authors: William D. Clinger, Lars T. Hansen
Venue: Proceedings of the ACM SIGPLAN 1997 conference on Programming language design and implementation (1997)

If a fixed exponentially decreasing probability distribution function is used to model every object's lifetime, then the age of an object gives no information about its future life expectancy. This radioactive decay model implies there can be no rational basis for deciding which live objects should be promoted to another generation. Yet there remains a rational basis for deciding how many objects to promote, when to collect garbage, and which generations to collect.Analysis of the model leads to a new kind of generational garbage collector whose effectiveness does not depend upon heuristics that predict which objects will live longer than others.This result provides insight into the computational advantages of generational garbage collection, with implications for the management of objects whose life expectancies are difficult to predict.
Processor-Ring Communication: A Tight Asymptotic Bound on Packet Waiting Times
Authors: E. G. Coffman,  Jr., Nabil Kahale, F. T. Leighton
Venue: SIAM Journal on Computing (1998)

We consider N processors communicating unidirectionally over a closed transmission channel, or ring. Each message is assembled into a fixed-length packet. Packets to be sent are generated at random times by the processors, and the transit times spent by packets on the ring are also random. Packets being forwarded, i.e., packets already on the ring, have priority over waiting packets. The objective of this paper is to analyze packet waiting times under a greedy policy within a discrete Markov model that retains the overall structure of a practical system but is simple enough so that explicit results can be proved. Independent, identical Bernoulli processes model message generation at the processors, and independently and identically distributed (i.i.d.) geometric random variables model the transit times. Our emphasis is on asymptotic behavior for large ring sizes, $N$, when the respective rate parameters have the scaling $\lambda /N$ and $\mu /N$. Our main result shows that, if the traffic intensity is fixed at $\rho = \lambda / \mu
Towards reuse of verified Ada software
Authors: Geoffrey R. Hird
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

Reuse of software, and formal verification, are two important problems of software engineering. A great deal of effort has been expended on each these two problems separately, but with limited success. The two problems are in fact related, and attacking them jointly holds promise of progress on both fronts. On the one hand, reuse leverages the cost of verification. On the other, verification captures essential information which is needed when adapting code for reuse. We describe techniques for minimizing the reverification needs of modified programs. We also describe a model for verification libraries, which minimizes the need for reverification across the library when any unit is altered.
Optical interference produced by artificial light
Authors: Adriano J. C. Moreira, Rui T. Valadas, A. M. de Oliveira Duarte
Venue: Wireless Networks (1997)

Wireless infrared transmission systems for indoor use are affected by noise and interference induced by natural and artificial ambient light. This paper presents a characterisation (through extensive measurements) of the interference produced by artificial light and proposes a simple model to describe it. These measurements show that artificial light can introduce significant in-band components for systems operating at bit rates up to several Mbit/s. Therefore it is essential to include it as part of the optical wireless indoor channel. The measurements show that fluorescent lamps driven by solid state ballasts produce the wider band interfering signals, and are then expected to be the more important source of degradation in optical wireless systems.
Discretisation in Lazy Learning Algorithms
Authors: Kai Ming Ting
Venue: Artificial Intelligence Review (1997)

This paper adopts the idea of discretising continuous attributes (Fayyad and Irani 1993) and applies it to lazy learning algorithms (Aha 1990; Aha, Kibler and Albert 1991). This approach converts continuous attributes into nominal attributes at the outset. We investigate the effects of this approach on the performance of lazy learning algorithms and examine it empirically using both real-world and artificial data to characterise the benefits of discretisation in lazy learning algorithms. Specifically, we have showed that discretisation achieves an effect of noise reduction and increases lazy learning algorithms&lsquo; tolerance for irrelevant continuous attributes. The proposed approach constrains the representation space in lazy learning algorithms to hyper-rectangular regions that are orthogonal to the attribute axes. Our generally better results obtained using a more restricted representation language indicate that employing a powerful representation language in a learning algorithm is not always the best choice as it can lead to a loss of accuracy.
The Synchronous Approach to Designing Reactive Systems
Authors: Axel Poigné, Matthew Morley, Olivier Maffeïs, Leszek Holenderski, Reinhard Budde
Venue: Formal Methods in System Design (1998)

Synchronous programming is available through several formally defined languages having very different characteristics: Esterel is imperative, while Lustre and Signal are declarative in style; Statecharts and Argos are graphical languages that allow one to program by constructing hierarchical automata. Our motivation for taking the synchronous design paradigm further, integrating imperative, declarative (or dataflow), and graphical programming styles, is that real systems typically have components that match each of these profiles. This paper motivates our interest in the mixed language programming of embedded software around a number of examples, and sketches the semantical foundation of the Synchronie toolset which ensures a coherent computational model. This toolset supports a design trajectory that incorporates rapid prototyping and systematic testing for early design validation, an object oriented development methodology for long term software management, and formal verification at the level of automatically generated object code.
Software engineering as a radical novelty: the Air Force Ada experience
Authors: Richard R. Gross, David A. Umphress
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

&ldquo;It takes &hellip;15 to 20 years to mature a [software] technology to the point that it can be popularized and disseminated to the community at large&rdquo; [10]. Education typically bears a large share of the blame. This paper critically examines education's role in the U.S. Air Force's 1980s insertion of Ada and Ada software engineering. It concludes that our principal error in the process was a failure to define &ldquo;education&rdquo; in a broad enough sense, to consider the educational needs of the corporate Air Force (&ldquo;institutional education&rdquo;) as well as those of the individuals in it. Lessons learned are summarized for application to future technology insertion efforts.
Soft systems methodology and simulation modeling
Authors: Brian Lehaney, Ray J. Paul
Venue: Proceedings of the 28th conference on Winter simulation (1996)

Simulation is both popular and powerful, but reportage of simulation case studies indicates that in many cases process is treated cursorily, and end-user-acceptance of final models is not forthcoming. Whilst texts often proclaim the importance of process, this is usually left to the discretion of the modeler, A range of problem structuring (or soft) methodologies have been developed to address process issues. However, these can be both slow and unwieldy. This paper outlines a case which utilises the principles of soft methodologies in a relatively quick and dirty approach to process.
NDC++: an approach to concurrent extension of C++
Authors: Jiajun Chen, Guoliang Zheng
Venue: ACM SIGPLAN Notices (1997)

In this paper, we present an approach to extending C++ with the capability of describing concurrent computation. The concurrent object-oriented model we adopt consists of a group of concurrent objects which may have bodies. When a concurrent object is created, its body begins to run. Inter-object communication uses the synchronous message passing and the internal concurrency of object is permitted. Concurrency control is distributed among each method's activation condition in an object. We also provide a policy to transform the classes defined in the extended C++ into C++ classes. The implementation is based on the multithreading and synchronization facilities supported in some multitasking operating systems such as Windows 95.
Achievable bounds on signal transition activity
Authors: Sumant Ramprasad, Naresh R. Shanbhag, Ibrahim N. Hajj
Venue: Proceedings of the 1997 IEEE/ACM international conference on Computer-aided design (1997)

Transitions on high capacitance busses in VLSI systems result in considerable system power dissipation. Therefore, various coding schemes have been proposed in the literature to encode the input signal in order to reduce the number of transitions. In this paper we derive achievable lower and upper bounds on the expected signal transition activity. These bounds are derived via an information-theoretic approach in which symbols generated by a source (possibly correlated) with entropy rate H are coded with an average of R bits/symbol. These results are applied to, 1.) determine the activity reducing efficiency of different coding algorithms such as Entropy coding, Transition coding, and Bus-Invert coding, 2.) bound the error in entropy-based power estimation schemes, and 3.) determine the lower-bound on the power-delay product. Two examples are provided where transition activity within 4% and 8% of the lower bound is achieved when blocks of 8 and 13 symbols respectively are coded at a time.
Lazy Acquisition of Place Knowledge
Authors: Pat Langley, Karl Pfleger, Mehran Sahami
Venue: Artificial Intelligence Review (1997)

In this paper we define the task of place learning and describe one approach to this problem. Our framework represents distinct places as evidence grids, a probabilistic description of occupancy. Place recognition relies on nearest neighbor classification, augmented by a registration process to correct for translational differences between the two grids. The learning mechanism is lazy in that it involves the simple storage of inferred evidence grids. Experimental studies with physical and simulated robots suggest that this approach improves place recognition with experience, that it can handle significant sensor noise, that it benefits from improved quality in stored cases, and that it scales well to environments with many distinct places. Additional studies suggest that using historical information about the robot&lsquo;s path through the environment can actually reduce recognition accuracy. Previous researchers have studied evidence grids and place learning, but they have not combined these two powerful concepts, nor have they used systematic experimentation to evaluate their methods&lsquo; abilities.
Simulation system for real-time planning, scheduling, and control
Authors: Glenn R. Drake, Jeffrey S. Smith
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This paper introduces a framework for on-line simulation systems in the operational planning, scheduling, and control of manufacturing systems. Five basic concepts for software design of an on-line simulation system are identified and an example simulator is illustrated.
Assembly System Design: a Branch and Cut Approach
Authors: Anulark Pinnoi, Wilbert E. Wilhelm
Venue: Management Science (1998)

This paper addresses the single-product assembly system design problem (ASDP), which seeks to minimize total cost by optimally integrating design (selecting the machine type to locate at each activated station) and operating issues (assigning tasks to observe precedence relationships and cycle time restrictions). We propose an effective branch-and-cut approach for solving single-product ASDPs, adapting inequalities known to be valid for embedded line balancing structures to form inequalities that are valid for the ASDP. The implementation alsoinvolves a specialized preprocessor, a heuristic, separation procedures, and an enumeration scheme. Computational tests establish benchmark results for this first implementation of cutting planes for solving the ASDP.
Modeling formalisms for dynamic structure systems
Authors: Fernando J. Barros
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1997)

We present a new concept for a system network to represent systems that are able to undergo structural change. Change in structure is defined in general terms, and includes the addition and deletion of systems and the modification of the relations among components. The structure of a system network is stored in the network executive. Any change in structure-related information is mapped into modifications in the network structure.Based on these concepts, we derive three new system specifications that provide a shorthand notation to specify classes of dynamic structure systems. These new formalisms are: dynamic structure discrete time system, dynamic structure differential equation specified systems, and dynamic structure discrete event system specification. We demonstrate that these formalisms are closed under coupling, making hierarchical model construction possible. formalisms are described using set theoretic notation and general systems theory concepts.
Sometimes Travelling is Easy: The Master Tour Problem
Authors: Vladimir G. Deuineko, Rüdiger Rudolf, Gerhard J. Woeginger
Venue: SIAM Journal on Discrete Mathematics (1998)

In 1975, Kalmanson proved that if the distance matrix in the travelling salesman problem (TSP) fulfills certain combinatorial conditions (that are nowadays called the Kalmanson conditions) then the TSP is solvable in polynomial time [Canad. J. Math., 27 (1995), pp. 1000--1010].We deal with the problem of deciding, for a given instance of the TSP, whether there is a renumbering of the cities such that the corresponding renumbered distance matrix fulfills the Kalmanson conditions. Two results are derived: first, it is shown that---in case it exists---such a renumbering can be found in polynomial time. Secondly, it is proved that such a renumbering exists if and only if the instance possesses the so-called master tour property. A recently posed question by Papadimitriou is thereby answered in the negative.