ppxscal/embedding_network huggingface dataset:
Interface-based programming assignments and automatic grading of java programs
Authors: Michael T. Helmick
Venue: Proceedings of the 12th annual SIGCSE conference on Innovation and technology in computer science education (2007)

AutoGrader is a framework developed at Miami University for the automatic grading of student programming assignments written in the Java programming language. AutoGrader leverages the abstract concept of interfaces, as implemented by the Java interface language construct, in both the assignment and grading of programming assignments. The use of interfaces reinforces the role of procedural abstraction in object-oriented programming and allows for a common API to all student code. This common API then enables automatic grading of program functionality. AutoGrader provides a simple instructor API and enables the automatic testing of student code through the Java languagefeatures of interfaces and reflection. AutoGrader alsosupports static code analysis using PMD [4] to detect possible bugs, dead code, suboptimal, and overcomplicated code. While AutoGrader is written in and only handles Java programs, this style of automated grading is adaptable to any language that supports (or can mimic) named interfaces and/or abstract functions and that also supports runtime reflection.
On-the-fly model checking for C programs with extended CADP in FMICS-jETI
Authors: Maria del Mar Gallardo, Pedro Merino, Christophe Joubert, David Sanan
Venue: Proceedings of the 12th IEEE International Conference on Engineering Complex Computer Systems (2007)

A current trend in the software engineering community is to integrate different tools in a friendly and powerful development environment for use by final users. This is also the case for tools based on formal methods, which are very valuable for increasing confidence in the reliability of software. This paper contributes to one promising approach to make this integration possible, the project FMICS-JETI. This project aims to obtain an active repository of tools based on formal methods in such a way that users can access and combine all the tools simply by defining a graph with the tools and the files they manage. In particular, the paper explains how two new modules of the well known toolset CADP are added to FMICS-JETI. These new modules, named C.OPEN and ANNOTATOR extend CADP with functions to manage C programs in this toolset.
On the Complexity of Removing Z-Cycles from a Checkpoints and Communication Pattern
Authors: Luca Allulli, Roberto Baldoni, Luigi Laura, Sara Tucci Piergiovanni
Venue: IEEE Transactions on Computers (2007)

Communication-induced checkpointing protocols are mechanisms used to produce checkpoints and communication patterns which enjoy desirable properties, such as No-Z-Cycle (NZC). NZC guarantees that each checkpoint can be part of a global consistent checkpoint. It would be nice to define communication-induced checkpointing protocols that enforce NZC, adding a minimum number of checkpoints to remove all the Z-cycles from the distributed computation. In this paper, we prove that this is impossible by formulating the Minimum Z-Cycle Removal (MinZCR) problem and showing that there are no online competitive protocols for it. Moreover, we prove that the problem of enforcing NZC with an optimal number of checkpoints is difficult even if the whole input instance is known because its decision version is NP-complete. Finally, we also prove that MinZCR is difficult to approximate: it is APX-hard and this implies that no Polynomial Time Approximation Scheme exists for the problem.
Optimal convergence recovery for the Fourier-finite-element approximation of Maxwell's equations in nonsmooth axisymmetric domains
Authors: Boniface Nkemzi
Venue: Applied Numerical Mathematics (2007)

Three-dimensional time-harmonic Maxwell's problems in axisymmetric domains @W@? with edges and conical points on the boundary are treated by means of the Fourier-finite-element method. The Fourier-fem combines the approximating Fourier series expansion of the solution with respect to the rotational angle using trigonometric polynomials of degree N(N->~), with the finite element approximation of the Fourier coefficients on the plane meridian domain @W"a@?R"+^2 of @W@? with mesh size h(h->0). The singular behaviors of the Fourier coefficients near angular points of the domain @W"a are fully described by suitable singular functions and treated numerically by means of the singular function method with the finite element method on graded meshes. It is proved that the rate of convergence of the mixed approximations in H^1(@W@?)^3 is of the order O(h+N^-^1) as known for the classical Fourier-finite-element approximation of problems with regular solutions.
Power supply and power management in Ubicom
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This session views the challenges for power supply and power management with devices and system of ad hoc communication nature. The session highlights some of the design aspects relevant in ubicom and their impact to the whole system design and communication solutions. 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
Cooperative Learning in a manufacturing management course
Authors: J. Sharp
Venue: Proceedings of the 26th Annual Frontiers in Education - Volume 01 (1996)

Cooperative Learning methods were used in a university-level manufacturing management program for students with a technical college preparation. Not only were the exam results improved, diagnostic tests indicated that the students had developed more effective learning and problem solving strategies when compared with similar students who had not learned in an interactive classroom.
SIP mediated services
Authors: G. Reid, F. J. Aparicio, A. L. Low
Venue: BT Technology Journal (2007)

In this paper we discuss how we can use the session initiation protocol (SIP) to offer advanced services for mobile users over BT's 21st Century Network (21CN). We provide a brief overview of the advantages of using SIP and describe how SIP can play a vital role in today's and future heterogeneous networks, such as BT's 21CN. We demonstrate some advantages of using SIP for handover in these varied networks and we compare it against using other methods for handover, e.g. mobile IP.With the current and anticipated demand for users with multiple devices, we introduce the benefits of using SIP for personal mobility, including the concept of transferring sessions between a user's many and varied devices.We then consider quality of service issues that present themselves when moving frequently between varied, particularly wireless, networks with varying capabilities and congestion. We describe how we have used codec switching to cope with these adverse conditions, and consider the benefits of shifting the control of this adaptation to the network.This work centres on a custom-built test-bed together with our own real-time SIP-based videoconferencing application with codec switching capability. We present this test-bed, and results based on its use.
Linear Upper Bounds for Random Walk on Small Density Random $3$-CNFs
Authors: Mikhail Alekhnovich, Eli Ben-Sasson
Venue: SIAM Journal on Computing (2006)

We analyze the efficiency of the random walk algorithm on random $3$-CNF instances and prove linear upper bounds on the running time of this algorithm for small clause density, less than $1.63$. This is the first subexponential upper bound on the running time of a local improvement algorithm on random instances. Our proof introduces a simple, yet powerful tool for analyzing such algorithms, which may be of further use. This object, called a terminator, is a weighted satisfying assignment. We show that any CNF having a good (small weight) terminator is assured to be solved quickly by the random walk algorithm. This raises the natural question of the terminator threshold which is the maximal clause density for which such assignments exist (with high probability). We use the analysis of the pure literal heuristic presented by Broder, Frieze, and Upfal [Proceedings of the Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, 1993, pp. 322-330] and Luby, Mitzenmacher, and Shokrollahi [Proceedings of the Ninth Annual ACM-SIAM Symposium on Discrete Algorithms, 1998, pp. 364-373] and show that for small clause densities good terminators exist. Thus we show that the pure literal threshold ($\approx$1.63) is a lower bound on the terminator threshold. (We conjecture the terminator threshold to be in fact higher.) One nice property of terminators is that they can be found efficiently via linear programming. This makes tractable the future investigation of the terminator threshold and also provides an efficiently computable certificate for short running time of the simple random walk heuristic.
Electronic auctions with private bids
Authors: Michael Harkavy, J. D. Tygar, Hiroaki Kikuchi
Venue: Proceedings of the 3rd conference on USENIX Workshop on Electronic Commerce - Volume 3 (1998)

Auctions are a fundamental electronic commerce technology. We describe a set of protocols for performing sealed-bid electronic auctions which preserve the privacy of the submitted bids using a form of secure distributed computation. Bids are never revealed to any party, even after the auction is completed. Both first-price and second-price (Vickrey) auctions are supported, and the computational costs of the methods are low enough to allow their use in many real-world auction situations.
Relational Parametricity for Computational Effects
Authors: Rasmus Ejlers Mogelberg, Alex Simpson
Venue: Proceedings of the 22nd Annual IEEE Symposium on Logic in Computer Science (2007)

According to Strachey, a polymorphic program is parametric if it applies a uniform algorithm independently of the type instantiations at which it is applied. The notion of relational parametricity, introduced by Reynolds, is one possible mathematical formulation of this idea. Relational parametricity provides a powerful tool for establishing data abstraction properties, proving equivalences of datatypes, and establishing equalities of programs. Such properties have been well studied in a pure functional setting. Many programs, however, exhibit computational effects. In this paper, we develop a framework for extending the notion of relational parametricity to languages with effects.
Nache: design and implementation of a caching proxy for NFSv4
Authors: Ajay Gulati, Manoj Naik, Renu Tewari
Venue: Proceedings of the 5th USENIX conference on File and Storage Technologies (2007)

In this paper, we present Nache, a caching proxy for NFSv4 that enables a consistent cache of a remote NFS server to be maintained and shared across multiple local NFS clients. Nache leverages the features of NFSv4 to improve the performance of file accesses in a widearea distributed setting by bringing the data closer to the client. Conceptually, Nache acts as an NFS server to the local clients and as an NFS client to the remote server. To provide cache consistency, Nache exploits the read and write delegations support in NFSv4. Nache enables the cache and the delegation to be shared among a set of local clients, thereby reducing conflicts and improving performance. We have implemented Nache in the Linux 2.6 kernel. Using Filebench workloads and other benchmarks, we present the evaluation of Nache and show that it can reduce the NFS operations at the server by 10-50%.
ROI extraction from motion affected MRI images based on fuzzy and active contour models
Authors: C. Weerasinghe
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

A new method for extracting the boundary of the region of interest (ROI) from motion affected magnetic resonance images (MRI) is presented. An image pre-processing stage is included to suppress prominent ghost artifacts and excessive blurring in the background, in order to facilitate the contour extraction algorithm. The pre-processing stage consists of a novel fuzzy model, incorporating a technique of hierarchical view by view image reconstruction. The contour extraction is performed using an intelligent, attractable active contour model (snakes), which is capable of driving any initial guess in the area of the evolving estimate towards the desired contour, and fitting in to the object without any overrun. The proposed method has been applied to spin echo MRI images affected by rotational motion, producing good results.
Self-stabilized adaptive allpass filters for phase equalization and approximation
Authors: X. Sun
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

In this paper, we present a simple adaptive filtering solution to general phase equalization and phase modeling tasks. Our proposed algorithm maintains approximate allpass constraints on the coefficients of an adaptive FIR filter in a self-stabilized manner. An analysis of an idealized IIR version of the technique shows that it converges to a unique stationary point corresponding to the optimal phase relationship between the processed signals. The relationship between the mean-squared error of the estimated phase response and the mean-squared error of the filter coefficients is also derived. Simulations verify that the proposed algorithm performs accurate phase equalization and approximation of unknown systems even in low signal-to-noise ratio conditions.
Parallelization of DC Analysis through Multiport Decomposition
Authors: Gaurav Trivedi, Madhav P. Desai, H. Narayanan
Venue: Proceedings of the 20th International Conference on VLSI Design held jointly with 6th International Conference: Embedded Systems (2007)

Physical problems offer scope for macro level parallelization of solution by their essential structure. For parallelization of electrical network simulation, the most natural structure based method is that of Multiport Decomposition. In this paper this method is used for the simulation of electrical networks consisting of resistances, voltage and current sources using a distributed cluster of weakly coupled processors. At the two levels in which equations are solved in this method we have used sparse LU for both levels in the first scheme and sparse LU in the inner level and Conjugate Gradient in the outer level in the second scheme. Results are presented for planar networks, for the cases where the number of slave processors are 1 and 2, and for circuit sizes upto 8.2 million nodes and 16.4 million edges using 8 slave processors. We use a cluster of Pentium IV processors linked through a 10/100MBPS Ethernet switch.
Using Decision Trees for Knowledge-Assisted Topologically Structured Data Analysis
Authors: C. Simon, J. Meessen, D. Tzovaras, C. De Vleeschouwer
Venue: Proceedings of the Eight International Workshop on Image Analysis for Multimedia Interactive Services (2007)

Supervised learning of an ensemble of randomized trees is considered to recognize classes of events in topologically structured data (e.g. images or time series). We are primarily interested in classification problems that are characterized by severe scarcity of the training samples. The main idea of our paper consists in favoring the selection of attributes that are known to efficiently discriminate the minority class in those nodes of the tree that are close to the leaves and where classes are represented by a small number of training examples. In practice, the knowledge about the ability of an attribute to discriminate the classes represented in a particular node is either provided by an expert or inferred based on a pre-analysis of the entire initial training set. The experimental validation of our approach considers sign language and human behavior recognition. It reveals that the proposed knowledgeassisted tree induction mechanism efficiently compensates for the shortage of the training samples, and significantly improves the tree classifier accuracy in such scenarios.
Blind CDMA detection and equalization using linearly constrained CMA
Authors: L. Li
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

A linearly constrained constant modulus algorithm (CMA) for CDMA detection and equalization is proposed in this paper. Multipath propagation is assumed and only the code sequence of a particular desired user is known. The new algorithm overcomes the shortcoming that the unconstrained CMA cannot lock to the desired user, and yields better performance compared to the existing constrained minimum output energy method.
On general convergence in extracting radicals via a fundamental family of iteration functions
Authors: Yi Jin, Bahman Kalantari
Venue: Journal of Computational and Applied Mathematics (2007)

Newton's method is well-known to be generally convergent for solving x^n-c=0. In this paper, we first extend this result to the next two members of an infinite family of high order methods referred to here as the Basic Family which starts with Newton's method. While computing roots of unity numerically is a trivial task, studying the general convergence of the Basic Family in this simple case is an important first step toward the understanding of the global behavior of this fundamental family. With the aid of polynomiography, techniques for the visualization of polynomial root-finding, we further conjecture the general convergence of all members of the Basic Family when extracting radicals. Using the computer algebra system Maple, we obtain some partial results toward the proof of our conjecture.
Exact decoding for jointly labeling and chunking sequences
Authors: Nobuyuki Shimizu, Andrew Haas
Venue: Proceedings of the COLING/ACL on Main conference poster sessions (2006)

There are two decoding algorithms essential to the area of natural language processing. One is the Viterbi algorithm for linear-chain models, such as HMMs or CRFs. The other is the CKY algorithm for probabilistic context free grammars. However, tasks such as noun phrase chunking and relation extraction seem to fall between the two, neither of them being the best fit. Ideally we would like to model entities and relations, with two layers of labels. We present a tractable algorithm for exact inference over two layers of labels and chunks with time complexity O(n2), and provide empirical results comparing our model with linear-chain models.
Filter-and-sum beamformer with adjustable filter characteristics
Authors: M. Kajala
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

We introduce a polynomial filter structure for filter-and-sum beamforming applied to a microphone array application. The structure is a multidimensional extension of the well known Farrow structure, which has mainly been used for fractional delay filtering and interpolation of I-D signals. The proposed method enables an easy, smooth and efficient control of the beamforming filter characteristics by adjusting only a single control variable, e.g., for dynamic beam steering. The optimization method for polynomial beamforming filter design is presented and illustrated with simulations of beamforming filter characteristics. The design example is given for a linear array of four omni-directional microphones and a polynomial FIR filter with 20-tap delay lines.
Where to Now? Generating Visions for mBusiness from the Drivers of Use
Authors: Jennie Carroll
Venue: Proceedings of the International Conference on the Management of Mobile Business (2007)

Harnessing the potential of mBusiness has proved significantly more difficult that initially expected. Despite high rates of diffusion and acceptance of mobile devices, there has only been modest uptake of mobile content services. Many of the early visions of mBusiness focused on the capabilities of technology whereas commercial success depends on the value derived from the application of technology by customers or users. This paper outlines an alternative approach to setting visions that is grounded in understanding of users' appropriation of technology. The approach is illustrated through analysis of the drivers of mobile content services. Some of the implications of applying this approach are outlined and future areas for research are indicated.
Open multimedia application platform: enabling multimedia applications in third generation wireless terminals through a combined RISC/DSP architecture
Authors: J. Chaoui
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 200. on IEEE International Conference - Volume 02 (2001)

Describes how multimedia applications will be enabled in 3G wireless terminals thanks to the efficiency of the DSP core embedded in the TI Open Multimedia Application Platform (OMAP). The OMAP H/W architecture is described, with an emphasis on how multimedia applications (video, audio, speech) will benefit from this advanced architecture. The paper also depicts the advantages provided by a combined RISC/DSP architecture, compared to a single RISC architecture, for 3G multimedia mobile applications.
Concept Analysis andWeb Clustering using Combinatorial Topology
Authors: Tsau Young (T. Y. ). Lin, Albert Sutojo, Jean-David Hsu
Venue: Proceedings of the Sixth IEEE International Conference on Data Mining - Workshops (2006)

The collection of the concepts that are discussed in a document set can be represented by a geometric structure, called simplical complex, of combinatorial topology. A simplex is a high-frequency keywordset that co-occurs closely which, we believe, carries a concept in the document set. The collection of all these simplexes that forms the simplical complex represents the structure of these concepts. Based on the topological structure of this complex, the documents are clustered. Several clustering schemes are presented. Our initial experiments, as expected, do support the theory.
Algorithms for joint estimation of attenuation and emission images in PET
Authors: H. Erdogan
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

In positron emission tomography (PET), positron emission from radiolabeled compounds yields two high energy photons emitted in opposing directions. However, often the photons are not detected due to attenuation within the patient. This attenuation is nonuniform and must be corrected to obtain quantitatively accurate emission images. To measure attenuation effects, one typically acquires a PET transmission scan before or after the injection of radiotracer. In commercially available PET scanners, image reconstruction is performed sequentially in two steps regardless of the reconstruction method: 1. Attenuation correction factor computation (ACF) from transmission scans, 2. Emission image reconstruction using the computed ACFs. This two-step reconstruction scheme does not use all the information in the transmission and emission scans. Postinjection transmission scans contain emission contamination that includes information about emission parameters. Similarly, emission scans contain information about the attenuating medium. To use all the available information, we propose a joint estimation approach that estimates the attenuation map and the emission image simultaneously from these two scans. The penalized-likelihood objective function is nonconvex for this problem. We propose an algorithm based on paraboloidal surrogates that alternates between updating emission and attenuation parameters and is guaranteed to monotonically decrease the objective function.