ppxscal/embedding_network huggingface dataset:
Teaching cooperation and requirements elicitation via a computer-supported cooperative problem solving environment
Authors: K. M. Swigger, R. Brazile, Dongil Shin
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

As the geographical distance among programmers and users continues to grow we are being forced to re-examine the way we teach students to think. This paper suggests that in today's workplace, programmers must be adept at both technical as well as cooperative skills. It also suggests that we must be prepared to teach programmers how to work in collaborative environments that promote users' needs. Towards this end, we built a computer-supported cooperative problem solving environment designed to teach programmers located in different areas how to work together in performing a requirements elicitation task. We believe that requirements elicitation and cooperative skills are highly interrelated and, as such, can be exercised more effectively in a computer-supported cooperative environment. Our special interface encourages cooperative work, and yet monitors both individual and group performance. In order to succeed in this environment, the programmers must learn how to cooperate with each other through a special computer interface. Results from our studies indicate that groups using the interface demonstrate more effective skills than groups who perform the same task face-to-face. Furthermore, the studies show that the competencies relating to group problem description and generation of alternative solutions are the most predictive of successful cooperation.
Understanding Change Requests to Predict Software Impact
Authors: Christopher Ackermann, Mikael Lindvall
Venue: Proceedings of the 30th Annual IEEE/NASA Software Engineering Workshop (2006)

During its lifecycle, software experiences numerous changes that are either due to bug fixes or to the incorporation of new features. Implementing such changes is often more difficult than expected, which frequently leads to underestimation of the associated implementation effort. This paper describes work that aims to understand change impact based on the visualization of the characteristics of change requests using standard diagrams (e.g. UML diagrams). Each diagram depicts different aspects of a software system and can illustrate factors that might drive the implementation effort. Using examples, in which we analyze three change requests, we describe how we determined the characteristics of the change requests. We furthermore discuss how the impact of change requests on diagrams relates to the implementation effort. Our overall goal is to develop a new impact analysis approach that helps determine software change impact based on the use of specific diagrams.
Pseudo-Exhaustive Testing for Software
Authors: D. Richard Kuhn, Vadim Okum
Venue: Proceedings of the 30th Annual IEEE/NASA Software Engineering Workshop (2006)

Pseudo-exhaustive testing uses the empirical observation that, for broad classes of software, a fault is likely triggered by only a few variables interacting. The method takes advantage of two relatively recent advances in software engineering: algorithms for efficiently generating covering arrays to represent software interaction test suites, and automated generation of test oracles using model checking. An experiment with a module of the Traffic Collision Avoidance System (TCAS) illustrates the approach testing pairwise through 6-way interactions. We also outline current and future work applying the test methodology to a large real-world application, the Personal Identity Verification (PIV) smart card.
Parallel space-filling curve generation through sorting: Research Articles
Authors: J. Luitjens, M. Berzins, T. Henderson
Venue: Concurrency and Computation: Practice Experience (2007)

In this paper we consider the scalability of parallel space-filling curve generation as implemented through parallel sorting algorithms. Multiple sorting algorithms are studied and results show that space-filling curves can be generated quickly in parallel on thousands of processors. In addition, performance models are presented that are consistent with measured performance and offer insight into performance on still larger numbers of processors. At large numbers of processors, the scalability of adaptive mesh refined codes depends on the individual components of the adaptive solver. One such component is the dynamic load balancer. In adaptive mesh refined codes, the mesh is constantly changing resulting in load imbalance among the processors requiring a load-balancing phase. The load balancing may occur often, requiring the load balancer to perform quickly. One common method for dynamic load balancing is to use space-filling curves. Space-filling curves, in particular the Hilbert curve, generate good partitions quickly in serial. However, at tens and hundreds of thousands of processors serial generation of space-filling curves will hinder scalability. In order to avoid this issue we have developed a method that generates space-filling curves quickly in parallel by reducing the generation to integer sorting. Copyright &copy; 2007 John Wiley & Sons, Ltd.
Kerberized credential translation: a solution to web access control
Authors: Olga Kornievskaia, Peter Honeyman, Bill Doster, Kevin Coffman
Venue: Proceedings of the 10th conference on USENIX Security Symposium - Volume 10 (2001)

Kerberos, a widely used network authentication mechanism, is integrated into numerous applications: UNIX and Windows 2000 login, AFS, Telnet, and SSH to name a few. Yet, Web applications rely on SSL to estabilish authenticated and secure connections. SSL Provides strong authentication by using certificates and public key challenge response authentication. The expansion of the Internet requires each system to leverage the strength of the other, which suggets the importance of interoperability between them. This paper descirbes the design, implentation, and performance of a system that provides controlled access to Kerberized services through a browser. This system provides a singole sign-on that produces both Kerberos and public key credentials. The Web server uses a plugin that translates public key credentials to Kerberos credentials. The Web server's subsequent authenticated actions taken on a user's behalf are limited in time and scope. Performance measurements show how the overhead introduced by credential trnslation is amortized over the login session.
Efficient and effective searching in unstructured file-sharing peer-to-peer networks
Authors: Jie Wu
Venue:  (2006)

Peer-to-peer (P2P) networking has been receiving increasing attention from the research community recently. How to conduct efficient and effective searching in such networks has been a challenging research topic. This dissertation focuses on unstructured file-sharing peer-to-peer networks. Three novel searching schemes are proposed, implemented, and evaluated. In the first scheme named ISRL (Intelligent Search by Reinforcement Learning), we propose to systematically learn the best route to desired files through reinforcement learning when topology adaptation is impossible or infeasible. To discover the best path to desired files, ISRL not only explores new paths by forwarding queries to randomly chosen neighbors, but also exploits the paths that have been discovered for reducing the cumulative query cost. Three models of ISRL are put forwarded: a basic version for finding one desired file, MP-ISRL (MP stands for Multiple-Path ISRL) for finding at least k files, and C-ISRL (C refers to Clustering) for reducing maintenance overhead through clustering when there are many queries. ISRL outperforms existing searching approaches in unstructured peer-to-peer networks by achieving similar query quality with lower cumulative query cost. The experimental results confirm the performance improvement of ISRL. The second approach, HS-SDBF (Hint-based Searching by Scope Decay Bloom Filter), addresses the issue of effective and efficient hint propagation. We design a new data structure called SDBF (Scope Decay Bloom Filter) to represent and advertise probabilistic hints. Compared to existing proactive schemes, HS-SDBF can answer many more queries successfully at a lower amortized cost considering both the query traffic and hint propagation traffic. Both the analytic and the experimental results support the performance improvement of our protocol. The third algorithm, hybrid search, seeks to combine the benefits of both forwarding and non-forwarding searching schemes. In this approach, a querying source directly probes its own extended neighbors and forwards a query to a subset of its extended neighbors and guides these neighbors to probe their own extended neighbors on its behalf. The hybrid search is able to adapt query execution to the popularity of desired files without generating too much state maintenance overhead because of the 1-hop forwarding inherent in the approach. It achieves a higher query efficiency than the forwarding scheme and a better success rate than the non-forwarding approach. To the best of our knowledge, this work is the first attempt to integrate forwarding and non-forwarding schemes. Simulation results demonstrate the effectiveness of the hybrid search.
Least squares based decoding for BCH codes in image applications
Authors: N. Rozic
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

BCH codes in the frequency domain provide robust channel coding for image channel coding applications. The underlying problem of estimation of real/complex sinusoids in white additive noise may be formulated and solved in different ways. The standard approach is based on the least squares method and Berlekamp-Massey algorithm (BMA). In this paper we compare the performance of the BMA with other LS based algorithms including: minimum norm solution based algorithm (MNS), forward-backward linear prediction based algorithm (FBLP) and singular-value decomposition based minimum norm algorithm (SVD-MNA). Results of computer experiments show that the introduction of minimum norm solution, foward-backward prediction and the SVD decomposition may significantly improve the performance of the decoder in the case of the relatively low SNR. In selecting between the proposed algorithms a performance/complexity trade-off has to be considered.
The Reality of Libraries
Authors: Daniel Ratiu, Jan Jurjens
Venue: Proceedings of the 11th European Conference on Software Maintenance and Reengineering (2007)

Libraries provide implementation for the concepts of a particular domain. When programmers use a library, they do not work any more with the real-world concepts but with their implementation available within the used library. From this point of view, libraries represent the "reality" at which the programmers have to adapt. Ideally, in order to be easy to use, the implementation of concepts in libraries should accurately mirror the concepts and their relations from the real world. Unfortunately, this is not always realised and this results in a bias between the real-world concepts and their implementation. Depending on the kind of the bias, the users can adapt themselves or not to the library's "reality". In this paper we propose a method to describe and evaluate the bias of the library implementation of real-world concepts expressed within an ontology. We use our method to describe several primitive bias classes in a formal framework and to discuss how can they affect the library's users. We present our results with the help of bias examples which we (semi-)automatically identified in the Java standard library.
Efficient Arguments without Short PCPs
Authors: Yuval Ishai, Eyal Kushilevitz, Rafail Ostrovsky
Venue: Proceedings of the Twenty-Second Annual IEEE Conference on Computational Complexity (2007)

Current constructions of efficient argument systems combine a short (polynomial size) PCP with a cryptographic hashing technique. We suggest an alternative approach for this problem that allows to simplify the underlying PCP machinery using a stronger cryptographic technique. More concretely, we present a direct method for compiling an exponentially long PCP which is succinctly described by a linear oracle function \pi : F^n \to F into an argument system in which the verifier sends to the prover O(n) encrypted field elements and receives O(1) encryptions in return. This compiler can be based on an arbitrary homomorphic encryption scheme. Applying our general compiler to the exponential size Hadamard code based PCP of Arora et al. (JACM 1998) yields a simple argument system for NP in which the communication from the prover to the verifier only includes a constant number of short encryptions. The main tool we use is a new cryptographic primitive which allows to efficiently commit to a linear function and later open the output of the function on an arbitrary vector. Our efficient implementation of this primitive is independently motivated by cryptographic applications.
Mesh shape-quality optimization using the inverse mean-ratio metric
Authors: Todd Munson
Venue: Mathematical Programming: Series A and B (2007)

Meshes containing elements with bad quality can result in poorly conditioned systems of equations that must be solved when using a discretization method, such as the finite-element method, for solving a partial differential equation. Moreover, such meshes can lead to poor accuracy in the approximate solution computed. In this paper, we present a nonlinear fractional program that relocates the vertex coordinates of a given mesh to optimize the average element shape quality as measured by the inverse mean-ratio metric. To solve the resulting large-scale optimization problems, we apply an efficient implementation of an inexact Newton algorithm that uses the conjugate gradient method with a block Jacobi preconditioner to compute the direction. We show that the block Jacobi preconditioner is positive definite by proving a general theorem concerning the convexity of fractional functions, applying this result to components of the inverse mean-ratio metric, and showing that each block in the preconditioner is invertible. Numerical results obtained with this special-purpose code on several test meshes are presented and used to quantify the impact on solution time and memory requirements of using a modeling language and general-purpose algorithm to solve these problems.
SockMi: a solution for migrating TCP/IP connections
Authors: Massimo Bernaschi, Francesco Casadei, Paolo Tassotti
Venue: Proceedings of the 15th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (2007)

SockMi is a solution for the migration of TCP/IP connections between Linux systems. Only the migrating peer of the connection needs to reside on a Linux system. The migration is completely transparent to the other peer that can reside on a system running any operating system. Our solution does not require changes to existing Linux kernel data structures and algorithms and can be activated in any phase of the connection. Both 2.4 and 2.6 versions of the Linux kernel are supported.
How Do Mobile Phones Fail? A Failure Data Analysis of Symbian OS Smart Phones
Authors: Marcello Cinque, Domenico Cotroneo, Zbigniew Kalbarczyk, Ravishankar K. Iyer
Venue: Proceedings of the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (2007)

While the new generation of hand-held devices, e.g., smart phones, support a rich set of applications, growing complexity of the hardware and runtime environment makes the devices susceptible to accidental errors and malicious attacks. Despite these concerns, very few studies have looked into the dependability of mobile phones. This paper presents measurement-based failure characterization of mobile phones. The analysis starts with a high level failure characterization of mobile phones based on data from publicly available web forums, where users post information on their experiences in using hand-held devices. This initial analysis is then used to guide the development of a failure data logger for collecting failure-related information on SymbianOS-based smart phones. Failure data is collected from 25 phones (in Italy and USA) over the period of 14 months. Key findings indicate that: (i) the majority of kernel exceptions are due to memory access violation errors (56%) and heap management problems (18%), and (ii) on average users experience a failure (freeze or self shutdown) every 11 days. While the study provide valuable insight into the failure sensitivity of smart-phones, more data and further analysis are needed before generalizing the results.
The use of syllable phonotactics for word hypothesization
Authors: R. De Mori
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

A search technique incorporating the automatic modeling of lexical variability is introduced for medium or large-vocabulary speaker-independent speech recognition. Current state-of-art systems depend on being able to model the entire language based on acoustic features and the constraints of syntax or inter-word probabilities. These methods often fail in the presence of multiple speakers, new vocabulary, noise, and spontaneous speech phenomena. A new approach for word hypothesization is proposed, based on an acoustic-phonetic unit called the pseudo-syllable segment. An algorithm is described for transforming a sequence of syllables into words. Techniques are suggested for controlling the accuracy of the syllabic hypothesis set, and learning the phonotactics of syllables automatically in a statistical framework.
Evaluation of a 3-D visual programming environment in an introductory course of object-oriented programming
Authors: K. Nagaoka
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 01 (2000)

A newly developed visual programming environment has been evaluated. It allows students to visualize and manipulate programs in 3D representation. That visual programming environment is expected to enhance motivation to programming, understanding of programs, and efficiency of programming education. An experiment was conducted to evaluate the newly developed programming environment. The experiment included lectures, exercises of programming, achievement tests, video recordings, monitoring of keyboard and mouse activities and questionnaires.
Stability analysis of a new model for floating caliper disk brake
Authors: T. Jearsiripongkul, G. Chakraborty, P. Hagedorn
Venue: Integrated Computer-Aided Engineering (2004)

The customers' demand for ride comfort has led the automotive industries to look for various ways to reduce and control the brake noise. Intensive research on brake squeal (high frequency noise between 1-5 kHz) has been carried out. A large variety of mathematical-mechanical models has been developed, studying various instability phenomena. The squeal is ascribed mainly to three reasons, alternative stick and slip motion between pad and disk [3,8], static instability due to excessive braking force [7], and dynamic instability arising from the friction force [1,2,4,5,6,9,10,11,12,13]. In this paper, a new model to study the onset of dynamic instability in a floating caliper disk brake is presented. Linearized equations of motion about equilibrium positions are derived assuming a constant braking force. The equations are subsequently discretized using Galerkin's method. The eigenvalue problem is then solved to detect the onset of instability.
Integrating composition in math, science and engineering courses
Authors: V. M. Johnson
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

Most mathematics, science and engineering classrooms rarely give students opportunities to write other than traditional note-taking and laboratory report-writing. New ways of writing in these classrooms should be investigated and, if appropriate with learning objectives, implemented. This research focuses specifically on the possibility of integrating writing-to-learn assignments into an undergraduate physics course. 63 undergraduate physics students were involved in this study. 50 males and 13 females participated. There were 2 Asians, 2 African-Americans, 49 Caucasians, 2 Hispanics, 2 Indians, and 6 who did not indicate ethnicity. 13 majors were also represented. The students were given a list of studying techniques and asked to mark which ones they currently used and which ones they do not use but would use if it was proven beneficial. The students were asked to choose among drawing diagrams, reading the text, rewriting concepts in their own words, study groups and working problems. Of the current techniques surveyed, writing was the least used but was the most likely to be used if they were convinced of its benefits.
An accurate nonuniform fourier transform for SPRITE magnetic resonance imaging data
Authors: J. Rioux, M. Halse, E. Aubanel, B. J. Balcom, J. Kaffanke, S. Romanzetti, T. Dierkes, N. J. Shah
Venue: ACM Transactions on Mathematical Software (TOMS) (2007)

A new algorithm is proposed for computing the discrete Fourier Transform (DFT) of purely phase encoded data acquired during Magnetic Resonance Imaging (MRI) experiments. These experiments use the SPRITE (Single Point Ramped Imaging with T1 Enhancement) method and multiple-point acquisition, sampling data in a nonuniform manner that prohibits reconstruction by fast Fourier transform. The chirp z-transform algorithm of Rabiner, Schafer, and Rader can be combined with phase corrections to compute the DFT of this data to extremely high accuracy. This algorithm outperforms the interpolation methods that are traditionally used to process nonuniform data, both in terms of execution time and in terms of accuracy as compared to the DFT.
On the beat!: timing and tension for dynamic characters
Authors: Brian Allen, Derek Chu, Ari Shapiro, Petros Faloutsos
Venue: Proceedings of the 2007 ACM SIGGRAPH/Eurographics symposium on Computer animation (2007)

Dynamic simulation is a promising complement to kinematic motion synthesis, particularly in cases where simulated characters need to respond to unpredictable interactions. Moving beyond simple rag-doll effects, though, requires dynamic control. The main issue with dynamic control is that there are no standardized techniques that allow an animator to precisely specify the timing of the motion while still providing natural response to external disturbances. The few proposed techniques that address this problem are based on heuristically or manually tuning proportional-derivative (PD) control parameters and do not generalize easily. We propose an approach to dynamic character control that is able to honor timing constraints, to provide natural-looking motion and to allow for realistic response to perturbations. Our approach uses traditional PD control to interpolate between key-frames. The key innovation is that the parameters of the PD controllers are computed for each joint analytically. By continuously updating these parameters over time, the controller is able to respond naturally to both external perturbations and changes in the state of the character.