ppxscal/embedding_network huggingface dataset:
A descriptive study of the yearly activities of instructional technology support personnel in selected public school systems of tennessee, academic year 2001--2002
Authors: Michael John Ward
Venue:  (2003)

This descriptive study involved the exploration of the annual activities of a selected subset of the technical support staff and technical coordinators within the Tennessee public school systems. The study focused on how the technical support personnel's allocation of time for general support and computer-related support varied by the factors of supported student population, experience, education, gender, and salary.The population of the study was defined by an existing electronic mailing (email) list used to provide an informal method of communication between the participants. The data for this study was obtained through the use of an on-line questionnaire with the participants being notified of its location via email. From the study population of 192 individuals, 136 valid questionnaire responses were received. Once the data had been collected, One-way Analysis of Variance (ANOVA) procedures were used to determine if statistically significant differences existed for each of the independent variables of supported student population, experience, education, gender, and salary. Categorizing the activities within general support, computer-related support, and methods of support provided the dependent variables for the ANOVA procedures. Where statistically significant differences occurred, the Tukey post-hoc was used to determine the amount of difference and its direction. A variety of descriptive statistics were also generated.The largest portion (43%) of the average participant's time during the school year was spent supporting computer-related technologies, and most of this time was spent supporting existing technologies. Salary and experience have the greatest effect upon the duties of technical support personnel. As salary or years of experience increased, so too did the amount of time per year spent on administrative functions. Conversely, the lower one's salary or years of experience, the greater the chance of performing computer-related support. Gender had little impact upon the allocation of time spent providing support though minor differences existed in the methods of providing that support. While support via email was almost as important as support via telephone, in most instances, the participant visited the area in which support was needed.
The dream of a common language: the search for simplicity and stability in computer science education
Authors: Eric Roberts
Venue: Proceedings of the 35th SIGCSE technical symposium on Computer science education (2004)

In recent years, the languages, paradigms, and tools used to teach computer science have become increasingly complex. This added complexity puts pressure on designers of introductory courses, who must cover more material in an already overcrowded syllabus. The problem of complexity is exacerbated by the fact that languages and tools change quickly, which leads to profound instability in the manner in which computer science is taught. The situation has reached a point where it is difficult for individual computer science teachers to keep up. This paper examines the factors that promote complexity and instability in computer science. It then goes on to argue that we, as educators, must take responsibility for breaking this cycle of rapid obsolescence by developing a stable and effective collection of Java-based teaching resources that will meet the needs of the computer science education community. Such an initiative is already in progress under the direction of a special task force appointed by the ACM Education Board. The charter and current plans for that task force are being presented in a special session at this symposium.
Excluding Minors in Nonplanar Graphs of Girth at Least Five
Authors: Robin Thomas, Jan McDonald Thomson
Venue: Combinatorics, Probability and Computing (2000)

A graph G is quasi 4-connected if it is simple, 3-connected, has at least five vertices, and for every partition (A, B, C) of V(G) either &#x2223;C&#x2223; &ge; 4, or G has an edge with one end in A and the other end in B, or one of A,B has at most one vertex. We show that any quasi 4-connected nonplanar graph with minimum degree at least three and no cycle of length less than five has a minor isomorphic to P&minus;10, the Petersen graph with one edge deleted. We deduce the following weakening of Tutte's Four Flow Conjecture: every 2-edge-connected graph with no minor isomorphic to P&minus;10 has a nowhere-zero 4-flow. This extends a result of Kilakos and Shepherd who proved the same for 3-regular graphs.
A is for apple
Authors: David A. Clark
Venue: ACM SIGGRAPH 2003 Web Graphics (2003)

'A is for Apple' is an interactive web artwork by David Clark. It was produced in collaboration with web designers Rob Whynot, Randy Knott, and Ron Gervais. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Discretized marching cubes
Authors: C. Montani, R. Scateni, R. Scopigno
Venue: Proceedings of the conference on Visualization '94 (1994)

Since the introduction of standard techniques for isosurface extraction from volumetric datasets, one of the hardest problems has been to reduce the number of triangles (or polygons) generated.This paper presents an algorithm that considerably reduces the number of polygons generated by a Marching Cubes-like scheme without excessively increasing the overall computational complexity. The algorithm assumes discretization of the dataset space and replaces cell edge interpolation by midpoint selection. Under these assumptions, the extracted surfaces are composed of polygons lying within a finite number of incidences, thus allowing simple merging of the output facets into large coplanar polygons.An experimental evaluation of the proposed approach on datasets related to biomedical imaging and chemical modelling is reported.
Abstractions from proofs
Authors: Thomas A. Henzinger, Ranjit Jhala, Rupak Majumdar, Kenneth L. McMillan
Venue: ACM SIGPLAN Notices (2004)

The success of model checking for large programs depends crucially on the ability to efficiently construct parsimonious abstractions. A predicate abstraction is parsimonious if at each control location, it specifies only relationships between current values of variables, and only those which are required for proving correctness. Previous methods for automatically refining predicate abstractions until sufficient precision is obtained do not systematically construct parsimonious abstractions: predicates usually contain symbolic variables, and are added heuristically and often uniformly to many or all control locations at once. We use Craig interpolation to efficiently construct, from a given abstract error trace which cannot be concretized, a parsominous abstraction that removes the trace. At each location of the trace, we infer the relevant predicates as an interpolant between the two formulas that define the past and the future segment of the trace. Each interpolant is a relationship between current values of program variables, and is relevant only at that particular program location. It can be found by a linear scan of the proof of infeasibility of the trace.We develop our method for programs with arithmetic and pointer expressions, and call-by-value function calls. For function calls, Craig interpolation offers a systematic way of generating relevant predicates that contain only the local variables of the function and the values of the formal parameters when the function was called. We have extended our model checker Blast with predicate discovery by Craig interpolation, and applied it successfully to C programs with more than 130,000 lines of code, which was not possible with approaches that build less parsimonious abstractions.
Introducing Uncertainty into Pattern Discovery in Temporal Event Sequences
Authors: Xingzhi Sun, Maria E. Orlowska, Xue Li
Venue: Proceedings of the Third IEEE International Conference on Data Mining (2003)

Pattern discovery in temporal event sequences is of greatimportance in many application domains, such as telecommunicationnetwork fault analysis. In reality, not every typeof event has an accurate timestamp. Some of them, definedas inaccurate events in this paper, may only have an intervalas possible time of occurrence. The existence of inaccurateevents may cause uncertainty in event ordering. Thetraditional support model cannot deal with this uncertainty,which would cause some interesting patterns to be missing.In this paper, a new concept, precise support, is introducedto evaluate the probability of a pattern contained in a sequence.Based on this new metric, we define the uncertaintymodel and present an algorithm to discover interesting patternsin the sequence database that has one type of inaccurateevent. In our model, the number of types of inaccurateevents can be extended to k readily, however, at a cost ofincreasing computational complexity.
Solving Karush--Kuhn--Tucker Systems via the Trust Region and the Conjugate Gradient Methods
Authors: Houduo Qi, Liqun Qi, Defeng Sun
Venue: SIAM Journal on Optimization (2003)

A popular approach to solving the Karush--Kuhn--Tucker (KKT) system, mainly arising from the variational inequality problem, is to reformulate it as a constrained minimization problem with simple bounds. In this paper, we propose a trust region method for solving the reformulation problem with the trust region subproblems being solved by the truncated conjugate gradient (CG) method, which is cost effective. Other advantages of the proposed method over existing ones include the fact that a good approximated solution to the trust region subproblem can be found by the truncated CG method and is judged in a simple way; also, the working matrix in each iteration is H, instead of the condensed HTH, where H is a matrix element of the generalized Jacobian of the function used in the reformulation. As a matter of fact, the matrix used is of reduced dimension. We pay extra attention to ensure the success of the truncated CG method as well as the feasibility of the iterates with respect to the simple constraints. Another feature of the proposed method is that we allow the merit function value to be increased at some iterations to speed up the convergence. Global and superlinear/quadratic convergence is shown under standard assumptions. Numerical results are reported on a subset of problems from the MCPLIB collection [S. P. Dirkse and M. C. Ferris, Optim. Methods Softw., 5 (1995), pp. 319--345].
Apply agent to build grid service management
Authors: Li Chunlin, Li Layuan
Venue: Journal of Network and Computer Applications (2003)

This paper presents an Agent-based Grid Service Management, which applies the concept of agents to computational grid. All entities in the Grid environment including computing resources and services can be represented as agents. Each entity is registered with a Grid Service Manager. A Grid service can be a service agent that provides the actual grid service to the other grid member. Grid members communicate with each other by communication space that is an implementation of tuple space. The design of three grid protocols for grid resource management is given. They are Grid Service Discovery Protocol, Grid Service Subscription Protocol and Grid Service Access Protocol. Grid service Subscription Protocol allows user/requestor agents to dynamically subscribe some grid services for a finite time period. A grid service can be subscribed before it can be configured or used by the user/requestor agent. A basic performance evaluation is given. Finally, some conclusions are given.
Bounds on the List-Decoding Radius of Reed-Solomon Codes
Authors: Gitit Ruckenstein, Ron M. Roth
Venue: SIAM Journal on Discrete Mathematics (2004)

Techniques are presented for computing upper and lower bounds on the number of errors that can be corrected by list decoders for general block codes and, specifically, for Reed--Solomon (RS) codes. The list decoder of Guruswami and Sudan implies such a lower bound (referred to here as the GS bound) for RS codes. It is shown that this lower bound, given by means of the code's length, the minimum Hamming distance, and the maximal allowed list size, in fact applies to all block codes. Ranges of code parameters are identified where the GS bound is tight for worst-case RS codes, in which case the list decoder of Guruswami and Sudan provably corrects the largest possible number of errors.On the other hand, ranges of parameters are provided for which the GS lower bound can be strictly improved. In some cases the improvement applies to all block codes with a given minimum Hamming distance, while in others it applies only to RS codes.
An investigation of TCP throughput variation for SIP traffic
Authors: Meredith Lulling, John Vaughan
Venue: Proceedings of the 1st international symposium on Information and communication technologies (2003)

This paper compares the performance of different TCP variants, specifically Reno, Vegas and Sack, when used to transport SIP signalling traffic, in both a homogeneous and heterogenous competition environment. Throughput achieved by the relevant TCP connection is used as a basis for this comparison and analysis.
Least-squares policy iteration
Authors: Michail G. Lagoudakis, Ronald Parr
Venue: The Journal of Machine Learning Research (2003)

We propose a new approach to reinforcement learning for control problems which combines value-function approximation with linear architectures and approximate policy iteration. This new approach is motivated by the least-squares temporal-difference learning algorithm (LSTD) for prediction problems, which is known for its efficient use of sample experiences compared to pure temporal-difference algorithms. Heretofore, LSTD has not had a straightforward application to control problems mainly because LSTD learns the state value function of a fixed policy which cannot be used for action selection and control without a model of the underlying process. Our new algorithm, least-squares policy iteration (LSPI), learns the state-action value function which allows for action selection without a model and for incremental policy improvement within a policy-iteration framework. LSPI is a model-free, off-policy method which can use efficiently (and reuse in each iteration) sample experiences collected in any manner. By separating the sample collection method, the choice of the linear approximation architecture, and the solution method, LSPI allows for focused attention on the distinct elements that contribute to practical reinforcement learning. LSPI is tested on the simple task of balancing an inverted pendulum and the harder task of balancing and riding a bicycle to a target location. In both cases, LSPI learns to control the pendulum or the bicycle by merely observing a relatively small number of trials where actions are selected randomly. LSPI is also compared against Q-learning (both with and without experience replay) using the same value function architecture. While LSPI achieves good performance fairly consistently on the difficult bicycle task, Q-learning variants were rarely able to balance for more than a small fraction of the time needed to reach the target location.
Diagnostics for conditional heteroscedasticity models: some simulation results
Authors: Albert K. Tsui
Venue: Mathematics and Computers in Simulation (2004)

In this paper, we study the size and power of various diagnostic statistics for univariate conditional heteroscedasticity models. These test statistics include the residual-based tests recently derived by Tse, Li and Mak, and Wooldridge, respectively. Monte-Carlo experiments with 1000 replications are conducted to generate conditional variances which follow the autoregressive conditional heteroscedasticity (ARCH)/GARCH processes. We use quasi-maximum likelihood estimation (MLE) method to obtain estimates of parameters under different ARCH/generalized ARCH (GARCH) models. It is found that the Tse and Li-Mak diagnostics are more powerful.
Fair and robust circle splines
Authors: Carlo H. Séquin, Kiha Lee
Venue: ACM SIGGRAPH 2003 Sketches Applications (2003)

For many applications, such as aesthetic designs or camera paths, nicely rounded, smooth, interpolatory paths -- free of cusps and abrupt hairpin turns -- are most important. Such curves can be obtained from globally optimized minimum variation curves (MVC) [Moreton and S&eacute;quin 1992], but at high computational costs. We present a blending scheme between circles that robustly produces equally good-looking G2-continuous curves through very challenging sets of interpolation points. One basic method produces such curves in the plane, on a sphere, and in 3D space.
Applying Scheduling by Edge Reversal to Constraint Partitioning
Authors: Marluce Rodrigues Pereira, Patrícia Kayser Vargas, Felipe M. G. França, Maria Clicia Stelling de Castro, Inês de Castro Dutra
Venue: Proceedings of the 15th Symposium on Computer Architecture and High Performance Computing (2003)

Scheduling by Edge Reversal (SER) is a fully distributed scheduling mechanism based on the manipulation of acyclic orientations of a graph. This work uses SER to perform constraint partitioning of Constraint Satisfaction Problems (CSP). In order to apply the SER mechanism, the graph representing the constraints must receive an acyclic orientation. Since obtaining an optimal acyclic orientation is an NP-hard problem, this work studies three non-deterministicstrategies known in the literature: Alg-Neigh, Alg-Edges, and Alg-Colour. We implemented the three algorithms and the SER scheduling mechanism, applying them to the CSP constraint networks generated from 3 applications. Our results show that SER has a great potential to perform a good partitioning of the constraint graphs.
A secure adaptive network processor
Authors: Scott Jeffery Harper
Venue:  (2003)

Network processors are becoming a predominant feature in the field of network hardware. As new network protocols emerge and data speeds increase, contemporary general-purpose network processors are entering their second generation and academic research is being actively conducted into new techniques for the design and implementation of these systems. At the same time, systems ranging from secured military communications equipment to consumer devices are being updated to provide network connectivity. Many of these devices require, or would benefit from, the inclusion of device security in addition to data security. Whether it is a top-secret encryption scheme that must be concealed or a personal device that needs protection against unauthorized use, security of the device itself is becoming an important factor in system design. Unfortunately, current network processor solutions were not developed with device security in mind. A secure adaptive network processor can provide the means to fill this gap while continuing to provide full support for emerging communication protocols. This dissertation describes the concept and structure of one such device. Analysis of the hardware security provided by the proposed device is provided to highlight strengths and weaknesses, while a prototype system is developed to allow it to be embedded into practical applications for investigation. Two such applications are developed, using the device to provide support for both a secure network edge device and a user-adaptable network gateway. Results of these experiments indicate that the proposed device is useful both as a hardware security measure and as a basis for user adaptation of information-handling systems.
A software framework for efficient system-level performance evaluation of embedded systems
Authors: Joseph E. Coffland, Andy D. Pimentel
Venue: Proceedings of the 2003 ACM symposium on Applied computing (2003)

The Sesame environment provides modeling and simulation methods and tools for the efficient design space exploration of heterogeneous embedded multimedia systems. In this paper we describe the Sesame software system and demonstrate its capabilities using several examples. We show that Sesame significantly reduces model construction time through the use of modeling component libraries, hierarchy, and advanced model structure description features.
Enabling large-scale wireless broadband: the case for TAPs
Authors: R. Karrer, A. Sabharwal, E. Knightly
Venue: ACM SIGCOMM Computer Communication Review (2004)

The vision is tantalizing: a high-performance, scalable, and widely deployed wireless Internet that facilitates services ranging from radically new and unforeseen applications to true wireless "broadband" to residences and public spaces at rates of 10s of Mb/sec. However, while high-speed wireless access is easy to achieve in an enterprise network via low-cost IEEE 802.11 (WiFi) access points, wireless technology in public spaces is in its infancy. "Hot spots" provide high-speed wireless access, but do so in very few isolated "islands" at immense costs. Likewise, while fixed wireless (e.g. LMDS) and 3G can provide ubiquitous coverage and 3G can support mobility, throughputs can often be two orders of magnitude slower than WiFi.In this paper, we formulate the challenges of building a high-performance, scalable and widely deployed wireless Internet along 10 premises. We make the case for the requirement of a fundamental new architecture based on beamforming antennas deployed on fixed, wire-powered Transit Access Points (TAPs) that form a multi-hopping wireless backbone with a limited number of wired ingress/egress points. To address scalability, deployability, and performance challenges we present distributed, opportunistic and coordinated resource management problems and a novel "network is the channel" framework that searches for fundamental information-theoretic tradeoffs between protocol overhead and capacity.
A Peer-to-Peer Approach to Web Service Discovery
Authors: Cristina Schmidt, Manish Parashar
Venue: World Wide Web (2004)

Web Services are emerging as a dominant paradigm for constructing and composing distributed business applications and enabling enterprise-wide interoperability. A critical factor to the overall utility of Web Services is a scalable, flexible and robust discovery mechanism. This paper presents a Peer-to-Peer (P2P) indexing system and associated P2P storage that supports large-scale, decentralized, real-time search capabilities. The presented system supports complex queries containing partial keywords and wildcards. Furthermore, it guarantees that all existing data elements matching a query will be found with bounded costs in terms of number of messages and number of nodes involved. The key innovation is a dimension reducing indexing scheme that effectively maps the multidimensional information space to physical peers. The design and an experimental evaluation of the system are presented.