ppxscal/embedding_network huggingface dataset:
Object manipulation in virtual environments: relative size matters
Authors: Yanqing Wang, Christine L. MacKenzie
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

An experiment was conducted to systematically investigate combined effects of controller, cursor and target size on multidimensional object manipulation in a virtual environment. It was found that it was the relative size of controller, cursor and target that significantly affe d object transportation and orientation processes. There were significant interactions between controller size and cursor size as well as between cursor size and target size on the total task completion time, transportation time, orientation time and spatial errors. The same size of controller and cursor improved object manipulation speed, and the same size of cursor and target generally facilitated object manipulation accuracy, regardless of their absolute sizes. Implications of these findings for human-computer interaction design are discussed.
A Fast and High Quality Multilevel Scheme for Partitioning Irregular Graphs
Authors: George Karypis, Vipin Kumar
Venue: SIAM Journal on Scientific Computing (1998)

Recently, a number of researchers have investigated a class of graph partitioning algorithms that reduce the size of the graph by collapsing vertices and edges, partition the smaller graph, and then uncoarsen it to construct a partition for the original graph [Bui and Jones, Proc. of the 6th SIAM Conference on Parallel Processing for Scientific Computing, 1993, 445--452; Hendrickson and Leland, A Multilevel Algorithm for Partitioning Graphs, Tech. report SAND 93-1301, Sandia National Laboratories, Albuquerque, NM, 1993]. From the early work it was clear that multilevel techniques held great promise; however, it was not known if they can be made to consistently produce high quality partitions for graphs arising in a wide range of application domains. We investigate the effectiveness of many different choices for all three phases: coarsening, partition of the coarsest graph, and refinement. In particular, we present a new coarsening heuristic (called heavy-edge heuristic) for which the size of the partition of the coarse graph is within a small factor of the size of the final partition obtained after multilevel refinement. We also present a much faster variation of the Kernighan--Lin (KL) algorithm for refining during uncoarsening. We test our scheme on a large number of graphs arising in various domains including finite element methods, linear programming, VLSI, and transportation. Our experiments show that our scheme produces partitions that are consistently better than those produced by spectral partitioning schemes in substantially smaller time. Also, when our scheme is used to compute fill-reducing orderings for sparse matrices, it produces orderings that have substantially smaller fill than the widely used multiple minimum degree algorithm.
Mathematical Morphology Based on Linear Combined Metric Spaces onZ2 (Part II): Constant Time MorphologicalOperations
Authors: J. L. Díaz De León S., J. H. Sossa-Azuela
Venue: Journal of Mathematical Imaging and Vision (2000)

Mathematical Morphology (MM) is a general method for image processing based on set theory. The two basic morphological operators are dilation and erosion. From these, several non linear filters have been developed, usually with polynomial complexity and this because the two basic operators depend strongly on the definition of the structural element. Most efforts to improve the algorithm's speed for each operator are based on structural element decomposition and/or efficient codification.In this second part, the concepts developed in part I (see D&iacute;az de Le&oacute;n and Sossa Azuela, &ldquo;Mathematical morphology based on linear combined metric spaces on Z^1 (part I): Fast distance transforms,&rdquo; Journal of Mathematical Imaging and Vision, Vol. 12, No. 2, pp. 137&ndash;154, 2000) are used to prove that it is possible to reduce the complexity of the morphological operators to zero complexity (constant time algorithms) for any regular discrete metric space and to eliminate the use of the structural element. In particular, this is done for an infinite family of metric spaces further defined. The use of the distance transformation is proposed for it comprises the information concerning all the discs included in a region to obtain fast morphological operators: erosions, dilations, openings and closings (of zero complexity) for an infinite (countable) family of regular metric spaces. New constant time, in contrast with the polynomial time algorithms, for the computation of these basics operators for any structural element are next derived by using this background. Practical examples showing the efficiency of the proposed algorithms, final comments and present research are also given here.
Performance evaluation of input devices in trajectory-based tasks: an application of the steering law
Authors: Johnny Accot, Shumin Zhai
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Choosing input devices for interactive systems that best suit users needs remains a challenge, especially consid- ering the increasing number of devices available. The choice often has to be made through empirical evalua- tions. The most frequently used evaluation task hitherto is target acquisition, a task that can be accurately modeled by Fitts law. However, todays use of computer input devices has gone beyond target acquisition alone. In particular, we often need to perform trajectory-based tasks, such as drawing, writing, and navigation. This paper illustrates how a recently discovered model, the steering law, can be applied as an evaluation paradigm complementary to Fitts law. We tested five commonly used computer input devices in two steering tasks, one linear and one circular. Results showed that subjects performance with the five devices could be generally classified into three groups in the following order: 1. the tablet and the mouse, 2. the trackpoint, 3. the touch- pad and the trackball. The steering law proved to hold for all five devices with greater than 0.98 correlation. The ability to generalize the experimental results and the limitations of the steering law are also discussed.
Clock rate versus IPC: the end of the road for conventional microarchitectures
Authors: Vikas Agarwal, M. S. Hrishikesh, Stephen W. Keckler, Doug Burger
Venue: ACM SIGARCH Computer Architecture News (2000)

The doubling of microprocessor performance every three years has been the result of two factors: more transistors per chip and superlinear scali ng of the processor clock with technology generation. Our results show that, due to both diminishing improvements in clock rates and poor wire scaling as semiconductor devices shrink, the achievable performance growth of conventional microarchitectures will slow substantially. In this paper, we describe technology-driven models for wire capacitance, wire delay, and microarchitectural component delay. Using the results of these models, we measure the simulated performance&mdash;estimating both clock rate and IPC &mdash;of an aggressive out-of-order microarchitecture as it is scaled from a 250nm technology to a 35nm technology. We perform this analysis for three clock scaling targets and two microarchitecture scaling strategies: pipeline scaling and capacity scaling. We find that no scaling strategy permits annual performance improvements of better than 12.5%, which is far worse than the annual 50-60% to which we have grown accustomed.
Architecture and Performance of a Multimedia Conference System
Authors: Anna A. Hać, Dongchen A. Lu
Venue: International Journal of Network Management (1996)

A new architecture for the multimedia conference system is proposed and evaluated. This system can be used in a wide variety of cooperative work environments such as distributed software development, joint authoring, and group decision support.
Why don't we get more (self?) respect: the positive impact of software engineering research upon practice
Authors: Barry W. Boehm, Mike Evangelist, Volker Gruhn, Jeff Kramer, Edward F. Miller,  Jr.
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

Software vendors rarely acknowledge their debt to research, indeed often are unaware of it, and rarely even appreciate the importance of such acknowledgement. The long lead times, and tortuous adoption paths, for software engineering research contributions also cloud perception of the actual source of popularly adopted software engineering technologies.Whatever the reasons, this panel proposes to address the problem of lack of appreciation of software engineering research by presenting evidence of the ways in which the work of the community has had tangible, and often substantial, impact. The case studies we will trace include: the growth of software design and architecture from the early work of Parnas, Jackson, et al.,. the growth of software testing and analysis technology from the early work of Howden, Miller, et. al., and the growth of software measurement from the work of Boehm and others.It is hoped that this panel will prove to be the springboard for a larger community effort to document in a scholarly and articulate way the successes and impacts of our community. It is hoped that this documentation will lead to improved self-image, greater respect from other communities, and a more favorable attitude from funding sources. Part of the panel discussion will focus on how to achieve these goals.
Implications of proxy caching for provisioning networks and servers
Authors: Mohammad S. Raunak, Prashant Shenoy, Pawan Goyal, Krithi Ramamritham
Venue: Proceedings of the 2000 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2000)

In this paper, we examine the potential benefits of web proxy caches in improving the effective capacity of servers and networks. Since networks and servers are typically provisioned based on a high percentile of the load, we focus on the effects of proxy caching on the tail of the load distribution. We find that, unlike their substantial impact on the average load, proxies have a diminished impact on the tail of the load distribution. The exact reduction in the tail and the corresponding capacity savings depend on the percentile of the load distribution chosen for provisioning networks and servers&mdash;the higher the percentile, the smaller the savings. In particular, compared to over a 50% reduction in the average load, the savings in network and server capacity is only 20-35% for the 99th percentile of the load distribution. We also find that while proxies can be somewhat useful in smoothing out some of the burstiness in web workloads; the resulting workload continues, however, to exhibit substantial burstiness and a heavy-tailed nature. We identify large objects with poor locality to be the limiting factor that diminishes the impact of proxies on the tail of load distribution. We conclude that, while proxies are immensely useful to users due to the reduction in the average response time, they are less effective in improving the capacities of networks and servers.
A stochastic assignment model for extraurban transit networks
Authors: Umberto Crisalli, Domenico Iannó
Venue: Advances in intelligent systems (1997)

Performance of TCP connections in high-speed wide-area ATM networks is of great importance due to the widespread use of the TCT/IP protocol for data transfers and the increasing deployment of ATM networks. ATM technology promises substantial gains by allowing the available link bandwidth to be efficiently used by a mix of audio, video, and data traffic. However, certain features of ATM technology lead to a substantial degradation of TCP connection throughput under congestion conditions. The poor performance of TCP has been observed in a number of recent studies [7] and a number of remedies have been proposed [1, 8], but most of the additional mechanisms proposed to improve TCP performance in ATM networks require substantial complication of the ATM switches.
Design of a set-top box system on a chip (abstract only)
Authors: Eric Foster
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

This presentation will review system-level issues associated with integrating the major blocks of a Set-Top Box onto a single die. In addition to the challenges of merging several powerful functions into a single chip, the goal of integration is to yield a composite design that is not only more cost effective but also provides more function than the sum of discrete parts. This is accomplished through consolidated and shared memory, improved system bandwidth and efficiency, and additional inter-macro signals to facilitate improved communication.
Optimal Nonlinear Income Taxation with a Two-Dimensional Population;A Computational Approach
Authors: Ritva Tarkiainen, Matti Tuomala
Venue: Computational Economics (1999)

We consider the optimal income tax problem when income differences are due to differences in abilities and in preferences between consumption and leisure among individuals. We model this problem as an optimal control problem and develop a numerical method for solving it. The method is based on the expansion of state and control variables in Lagrange series and on a spectral collocation method for approximating state equations. In this way the optimal control problem is reduced to a parameter optimization problem. The problem is difficult to solve, but we managed to do so with some limitations. On the basis of our calculations we conclude that the tax system in the two-dimensional case is more redistributive compared to that obtained from the one-dimensional model.
Quality and Competition
Authors: Rajiv D. Banker, Inder Khosla, Kingshuk K. Sinha
Venue: Management Science (1998)

In recent years, the practitioner literature in operations management has seen a dramatic surge in articles on quality management. It reflects the increased emphasis on quality by U.S. firms, which has been attributed largely to increased competition faced by them. The question of how quality is influenced by competitive intensity, however, has not received much attention, either in the practitioner or the academic research literatures. The notion of competitive intensity itself has not been defined precisely. In this paper, we develop formal models of oligopolistic competition to investigate whether equilibrium levels of quality increase as competition intensifies. We consider three different competitive settings: (i) asymmetric duopolistic competition where the dominant firm's intrinsic demand potential decreases; (ii) a symmetric duopoly where the firms are precluded from cooperating in setting quality levels; and (iii) symmetric oligopolistic competition where the number of firms increases. We find that the relation between equilibrium quality and competitive intensity depends on what is understood by increased competition and, in addition, the relation is contingent on the values of parameters describing the cost and demand structure for the industry.
Optimal smoothing schedules for real-time streams (extended abstract)
Authors: Yishay Mansour, Boaz Patt-Shamir, Ofer Lapid
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

We consider the problem of smoothing real-time streams (such as video streams), where the goal is to reproduce a variable-bandwidth stream remotely, while minimizing bandwidth cost, space overhead, and playback delay. We focus on lossy schedules, where some bytes may be dropped due to limited bandwidth or space. We present the following results. First, we determine the optimal tradeoff between buffer space, queuing delay, and link bandwidth for lossy smoothing schedules. Specifically, this means that if one of these parameters is under our control, we can precisely calculate the optimal value which minimizes data loss while avoiding resource wastage. The tradeoff is accomplished by a simple generic algorithm, that allows one some freedom in choosing which data to discard. This algorithm is very easy to implement both at the server and at the client, and it enjoys the nice property that only the server decides which data to discard, and the client needs only to reconstruct the stream. In a second set of results we study the case where different parts of the data have different importance, modeled by assigning a real &ldquo;weight&rdquo; to each byte in the stream. For this setting we use competitive analysis, i.e., we compare the weight delivered by on-line algorithms to the weight of an optimal off-line schedule using the same resources. We prove that a natural greedy algorithm is 4-competitive. We also prove a lower bound of 1.25 on the competitive ratio of any deterministic on-line algorithm. Finally, we give a few experimental results which show that smoothing is extremely effective in practice, and that the greedy algorithm performs very well in the weighted case.
Theoretical Analysis and Improved Decision Criteria for the n-Tuple Classifier
Authors: Thomas Martini Jørgensen, Christian Linneberg
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1999)

The anticipated behavior of the n-tuple classification system is that it gives the highest output score for the class to which the input example actually belongs. By performing a theoretical analysis of how the output scores are related to the underlying probability distributions of the data, this paper shows that this in general is not to be expected. The theoretical results are able to explain the behavior that is observed in experimental studies. The theoretical analysis also give valuable insight into how the n-tuple classifier can be improved to deal with skewed training priors, which until now have been a hard problem for the architecture to tackle. It is shown that by relating an output score to the probability that a given class generates the data makes it possible to design the n-tuple net to operate as a close approximation to the Bayes estimator. It is specifically illustrated that this approximation can be obtained by modifying the decision criteria. In real cases, the underlying example distributions are unknown and accordingly the optimum way to treat the output scores cannot be calculated theoretically. However, it is shown that the feasibility of performing leave-one-out cross-validation tests in n-tuple networks makes it possible to obtain proper processing of the scores in such cases.
What is the cost of delay insensitivity?
Authors: Hiroshi Saito, Alex Kondratyev, Jordi Cortadella, Luciano Lavagno, Alexander Yakovlev
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

Deep submicron technology calls for new design techniques, in which wire and gate delays are accounted to have equal or nearly equal effect on circuit behaviour. Asynchronous speed-independent (SI) circuits, whose behaviour is only robust to gate delay variations, may be too optimistic. On the other hand, building circuits totally delay-insensitive (DI), for both gates and wires, is impractical. The paper presents an approach for automated synthesis of globally DI and locally SI circuits. It is based on order relaxation, a simple graphical transformation of a circuit's behavioural specification, for which Signal Transition Graph, an interpreted Petri net, is used. The method is successfully tested on a set of benchmarks and a realistic design example. It proves effective showing average cost of DI interfacing at about 40% for area and 20% for speed.
A role-based access control model and reference implementation within a corporate intranet
Authors: David F. Ferraiolo, John F. Barkley, D. Richard Kuhn
Venue: ACM Transactions on Information and System Security (TISSEC) (1999)

This paper describes NIST's enhanced RBAC model and our approach to designing and implementing RBAC features for networked Web servers. The RBAC model formalized in this paper is based on the properties that were first described in Ferraiolo and Kuhn [1992] and Ferraiolo et al. [1995], with adjustments resulting from experience gained by prototype implementations, market analysis, and observations made by Jansen [1988] and Hoffman [1996]. The implementation of RBAC for the Web (RBAC/Web) provides an alternative to the conventional means of administering and enforcing authorization policy on a server-by-server basis. RBAC/Web provides administrators with a means of managing authorization data at the enterprise level, in a manner consistent with the current set of laws, regulations, and practices.
Minimizing time-space cost for database version control
Authors: Lin Yu, Daniel J. Rosenkrantz
Venue: Proceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1988)

We introduce the concept of a version graph to model the problem of minimising the space and version regeneration cost for database version control. We show that, in general, this problem and several of its variations are NP-complete. Motivated by the practical importance of these problems, we develop several heuristics and obtain worst-case guarantees on their performance. We also present linear time algorithms for problems characterized by special classes of version graphs.
An axiomatic treatment of three qualitative decision criteria
Authors: Ronen I. Brafman, Moshe Tennenholtz
Venue: Journal of the ACM (JACM) (2000)

The need for computationally efficient decision-making techniques together with the desire to simplify the processes of knowledge acquisition and agent specification have led various researchers in artificial intelligence to examine qualitative decision tools. However, the adequacy of such tools is not clear. This paper investigates the foundations of maximin, minmax regret, and competitive ratio, three central qualitative decision criteria, by characterizing those behaviors that could result from their use. This characterizaton provides two important insights: (1)under what conditions can we employ an agent model based on these basic qualitative decision criteria, and (2) how &ldquo;rational&rdquo; are these decision procedures. For the competitive ratio criterion in particular, this latter issue is of central importance to our understanding of current work on on-line algorithms. Our main result is a constructive representation theorem that uses two choice axioms to characterize maximin, minmax regret, and competitive ratio.
Planning information networks: the scope and the customer issues
Authors: Saad Haj Bakry, Abdullah Haj Al-Dhelaan
Venue: International Journal of Network Management (1999)

This article addresses the planning of information networks with emphasis on the common principles used, and on the scope and customer issues. Copyright &copy; 1999 John Wiley Sons, Ltd.