ppxscal/embedding_network huggingface dataset:
Kinematics and inverse dynamics analysis for a general 3-PRS spatial parallel mechanism
Authors: Yangmin Li, Qingsong Xu
Venue: Robotica (2005)

In this paper, the kinematics and inverse dynamics of a novel kind of mechanism called a general 3-PRS parallel mechanism is investigated. In the kinematics study, the inverse kinematics solution is derived in closed form, and the forward kinematics problem is resolved by the Newton iterative method seeking for an on-line solution to this issue. The inverse dynamics analysis is approached with two methods: Lagrangian formulations and principle of virtual work. After deriving the dynamic model by a Lagrangian formulation approach, the simulation results of two introduced examples quantitatively and qualitatively verify the accuracy of the derived dynamic equations. By introducing a simplifying hypothesis, a simplified dynamic model is set up using principle of virtual work, also a computer simulation is performed on this reduced model. The simulation results demonstrate that the simplified dynamic model is reasonable under such kind of assumptions through comparison with the precise model derived from the Lagrangian formulation. The inverse dynamics analysis provides a sound basis to develop controllers for controlling over a general 3-PRS parallel robot.
Numerical approximation of collisional plasmas by high order methods
Authors: Nicolas Crouseilles, Francis Filbet
Venue: Journal of Computational Physics (2004)

In this paper, we investigate the approximation of the solution to the Vlasov equation coupled with the Fokker-Planck-Landau collision operator using a phase space grid. On the one hand, the algorithm is based on the conservation of the flux of particles and the distribution function is reconstructed allowing to control spurious oscillations and preserving positivity and energy. On the other hand, the method preserves the main properties of the collision operators in order to reach the correct stationary state. Several numerical results are presented in one dimension in space and three dimensions in velocity.
Composing schema mappings: second-order dependencies to the rescue
Authors: Ronald Fagin, Phokion G. Kolaitis, Wang-Chiew Tan, Lucian Popa
Venue: Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2004)

A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the target schema). Schema mappings play a key role in numerous areas of database systems, including database design, information integration, and model management. A fundamental problem in this context is composing schema mappings: given two successive schema mappings, derive a schema mapping between the source schema of the first and the target schema of the second that has the same effect as applying successively the two schema mappings.In this paper, we give a rigorous semantics to the composition of schema mappings and investigate the definability and computational complexity of the composition of two schema mappings. We first study the important case of schema mappings in which the specification is given by a finite set of source-to-target tuple-generating dependencies (source-to-target tgds). We show that the composition of a finite set of full source-to-target tgds with a finite set of tgds is always definable by a finite set of source-to-target tgds, but the composition of a finite set of source-to-target tgds with a finite set of full source-to-target tgds may not be definable by any set (finite or infinite) of source-to-target tgds; furthermore, it may not be definable by any formula of least fixed-point logic, and the associated composition query may be NP-complete. After this, we introduce a class of existential second-order formulas with function symbols, which we call second-order tgds, and make a case that they are the "right" language for composing schema mappings. To this effect, we show that the composition of finite sets of source-to-target tgds is always definable by a second-order tgd. Moreover, the composition of second-order tgds is also definable by a second-order tgd. Our second-order tgds allow equalities, even though the "obvious" way to define them does not require equalities. Allowing equalities in second-order tgds turns out to be of the essence, because we show that second-order tgds without equalities are not sufficiently expressive to define even the composition of finite sets of source-to-target tgds. Finally, we show that second-order tgds possess good properties for data exchange. In particular. the chase procedure can be extended to second-order tgds so that it produces polynomial-time computable universal solutions in data exchange settings specified by second-order tgds.
Verification of behavioral descriptions by combining symbolic simulation and automatic reasoning
Authors: Ghiath AL Sammane, Dominique Borrione, Remy Chevallier
Venue: Proceedings of the 15th ACM Great Lakes symposium on VLSI (2005)

We present a property verification method for behavioral descriptions with TheoSim, a tool that combines symbolic simulation and automatic reasoning. The effectiveness of the method is illustrated on the verification of SPSMALL, a memory designed by STMicroelectronics. The proof of correctness was established independently of the memory size.
A Generalized Analytical Framework for SMPT in a Multicode CDMA Wireless System
Authors: Manjunath Krishnam, Martin Reisslein
Venue: Wireless Personal Communications: An International Journal (2004)

Simultaneous MAC Packet Transmission (SMPT) has recently been proposed for stabilizing the throughput over wireless links, which is one of the key challenges in providing high-quality wireless multimedia services. SMPT stabilizes the wireless link by transmitting multiple packets on multiple CDMA channels in parallel in response to packet drops due to wireless link errors. These parallel packet transmissions stabilize the link layer throughput, but they also increase the interference level in a given cell of a cellular network or cluster of an ad-hoc network, which in turn reduces the number of traffic flows that can be simultaneously supported in a cell/cluster. We have recently developed an analytical framework for the class of SMPT mechanisms for a simple Bernoulli packet generation process, which does not reflect the oftentimes bursty packet generation processes encountered in real networks. In this paper we develop a generalized analytical framework for SMPT, which accommodates bursty packet traffic (and also non-bursty Bernoulli traffic). This framework expresses the system dynamics in transition probabilities for a Markov chain and calculates the effects of the interference through an iterative approach. The numerical results from our analytical framework and verifying simulations indicate that SMPT provides a significant reduction in packet loss and buffer occupancies (and delay), especially for persistent traffic bursts, in exchange for a reduced number of supported flows. Our analytical framework quantifies these system trade-offs with good accuracy and can thus be employed for resource management.
A clipboard model for Ubiquitous Computing Environments
Authors: Hannah Slay, Bruce Thomas, Rudi Vernik
Venue: Proceedings of the 4th international symposium on Information and communication technologies (2005)

In a traditional computing environment, information can be copied and pasted to the operating system's clipboard. This allows information to be moved between applications, and positions within a given application. Although useful when computers are used independently from each other, this technique does not extend to Ubiquitous Computing Environments (UCEs). Support is required in UCEs to allow information to be copied and pasted between displays, computers, applications and positions within a given application. This paper presents a new clipboard model for UCEs applicable to current ubiquitous workspace technologies.
REUSING SOLUTIONS IN SOFTWARE DESIGN ACTIVITY: AN EMPIRICAL STUDY
Authors: Françoise Dètienne
Venue: ACM SIGCHI Bulletin (1991)

This study is on code reuse in the software design activity. The data analysed in this paper were collected in an experiment1 aimed at studying the activity of design with an object-oriented programming (OOP) language (D eacute;tienne, 1990). Four professional programmers were given two problems to solve and code with an OOP language. The material consisted of two management problems; the task domain was familiar to the subjects. The environment was composed of a basic editor and the 02 system (0. Deux et al., 1989) which is an object-oriented data base system. We collected the subjects-verbalizations, successive versions of programs under development, notes written during the realization of the task, the order in which the different traces of the activity were made, i.e., the order for writing notes and for coding programs with the verbalization recorded simultaneously.
Co-reflection in online learning environments
Authors: Joyce Yukawa
Venue: ACM SIGGROUP Bulletin (2003)

While peer collaboration is the basis for co-learning in many groups, in the classroom the prevailing assumption is that teachers facilitate student learning, through course structure, setting learning tasks and outcomes, presentation, discussion, facilitating small group learning, coaching, and mentoring, among others. Though instructional design models have recognized that learning builds on interactions between learners and their environments (teachers have moved from "sage on the stage" to "guide on the side"), these models tend to focus on individual student learning rather than group learning.
Summary of the Illinois-Toronto OlympiODE test results
Authors: Clifford Addison
Venue: ACM SIGNUM Newsletter (1981)

Late in 1978, the organizers of the 1979 SIGNUM conference on ODE's at Urbana, C. W. Gear, R. D. Skeel and D. S. Watanabe, proposed that an ODE Olympics be held. The plan was to have a competition, open to any code, which would take place prior to the conference. The results of this competition, as well as a discussion on the significance of the results would be used, but the problems would be selected so that some rough assessment of the entries could be made.
Software engineering based on the team software process with a real world project
Authors: Nasser Tadayon
Venue: Journal of Computing Sciences in Colleges (2004)

It can be observed the increasing demand for experienced professionals in development of software. On the other hand we see the decrease of interest in students and decline in student's enrollment in computer science and software engineering in most of the colleges and universities in the United States. The outburst of technology in our society demands software engineers to handle the exponential growth. Software plays very important, if not a critical, role in our daily life. It is one of the most rapidly growing fields in Engineering and technology. As software engineering educators, we bear the obligation of attracting and maintaining the interest of students by exploring and identifying initiatives that excite and draw them to the discipline. One tactical move for undergraduate students to understand the concepts and see themselves in their future role is having a realistic customer with real expectations in a software engineering course. There have been several papers exploring the same idea [1, 2, 6]. In this paper, the instructor describes the process and the structure in building a semi-realistic term project, using an external customer for a sophomore level introductory course in software engineering. The course is designed for relatively small groups of traditional and nontraditional students. The instructor assert his efforts in incorporating teamwork with diverse students as well as the challenging experiences that the students faced while working in the semi-real world industrial environment.
The design of redundant isotropic manipulators with special link parameters
Authors: K. Y. Tsai, Z. W. Wang
Venue: Robotica (2005)

This paper proposes a general method to develop n-DOF serial isotropic manipulators. The parameters of 6-DOF isotropy generators are used as the initial values in a numerical method to obtain redundant isotropic generators. Additional constraint equations are then added, with the parameters of the obtained generators as initial values, to obtain the isotropy generators with special parameters. Each generator can be developed into many isotropic designs with special or desired link parameters. Two different approaches for developing isotropic manipulators are also investigated.
Dynamic Thread for Real-Time Knot-Tying
Authors: F. Wang, E. Burdet, A. Dhanik, T. Poston, C. L. Teo
Venue: Proceedings of the First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2005)

Real-time simulation of knot-tying with visual and force feedback is essential to VR surgery training. We present a physics-based simulator that enables realistic knot tying at haptic speed. The virtual thread obeys Newtonýs laws and behaves naturally. The model covers mechanical properties of real thread such as stretching, compressing, bending and twisting, contact forces with self and the environment, and gravity. Its structure has essential advantages over geometrically based approaches.
An application of pruning in the design of neural networks for real time flood forecasting
Authors: Giorgio Corani, Giorgio Guariso
Venue: Neural Computing and Applications (2005)

We propose the application of pruning in the design of neural networks for hydrological prediction. The basic idea of pruning algorithms, which have not been used in water resources problems yet, is to start from a network which is larger than necessary, and then remove the parameters that are less influential one at a time, designing a much more parameter-parsimonious model. We compare pruned and complete predictors on two quite different Italian catchments. Remarkably, pruned models may provide better generalization than fully connected ones, thus improving the quality of the forecast. Besides the performance issues, pruning is useful to provide evidence of inputs relevance, removing measuring stations identified as redundant (30&#x2013;40% in our case studies) from the input set. This is a desirable property in the system exercise since data may not be available in extreme situations such as floods; the smaller the set of measuring stations the model depends on, the lower the probability of system downtimes due to missing data. Furthermore, the Authority in charge of the forecast system may decide for real-time operations just to link the gauges of the pruned predictor, thus saving costs considerably, a critical issue in developing countries.
Moral Theories for Autonomous Software Agents
Authors: Richard Lucas
Venue: ACM SIGCAS Computers and Society (2004)

It is commonplace that computers are intruding, in an active way, ever more into our lives. This incursion ought to lead to us thinking about the role of responsibility that attaches to the actions that result. After all, we think about responsibility when people act. The leading researchers in the field responsible for producing software that intrude so (that is, intrude actively) call the fruits of their labour Autonomous Software Agents (ASAs). So, is it desirable or even possible for these ASAs to be morally responsible? 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
Nonlinear diffusion filtering on extended neighborhood
Authors: Danny Barash
Venue: Applied Numerical Mathematics (2005)

A generalization to the nonlinear diffusion of digital images is proposed, taking into account an extended neighborhood as a prolongation to information derived from local, nearest-neighboring pixels. Traditionally, each iteration in nonlinear diffusion filtering is performed on a 3 × 3 window. While several iterations can propagate this local information to pixels which are further away from the center of the window, it clearly presents a limitation in some applications as compared to non-PDE based filtering approaches in which the window is larger than 3 × 3. Here, an extension is presented to describe the nonlinear diffusion equation for larger windows, thus overcoming this limitation.
Securely Replicated Web Documents
Authors: Bogdan C. Popescu, Maarten van Steen, Bruno Crispo, Andrew S. Tanenbaum, Jan Sacha, Ihor Kuz
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

In order to achieve better scalability and reduce latency in handling user requests, many Web applications make extensive use of data replication through caches and Content Delivery Networks. However, in such scenarios data is often placed on untrusted hosts. As a result, existing replication mechanisms open a wide class vulnerabilities, ranging from denial of service to content masquerading. In this paper we present an architecture that combines data content, replication strategies and security in one unified object model and offers integrity guarantees for Web documents replicated on non secure servers.
Facial Expression Recognition Based on Gabor Wavelet Transformation and Elastic Templates Matching
Authors: Yong-zhao Zhan, Jing-fu Ye, De-jiao Niu, Peng Cao
Venue: Proceedings of the Third International Conference on Image and Graphics (2004)

In order to achieve subject-independent facial expression recognition and obtain robustness against illumination variety and image deformation, facial expression recognition methods based on Gabor wavelet transformation and elastic templates matching are presented in this paper. Firstly, given a still image containing facial expression information, preprocessors are executed. Secondly, Gabor wavelets are adopted to extract expression features. Then the elastic graph for expression features is constructed. Finally, elastic templates matching algorithm is used to recognize facial expression. Experiments show that expression features can be extracted effectively by Gabor wavelet transformation and high recognition rate can be obtained using elastic templates matching algorithm.
An overview of model driven architecture &reg; (MDA&reg;): invited talk abstract
Authors: Michael Rosen
Venue: Proceedings of the 5th international workshop on Software and performance (2005)

This talk provides an overview of Model Driven Architecture (MDA). It outlines the economic drivers of MDA, gives a broad outline of the scope of MDA, and projects the future of MDA.
An affordable multispectral imaging system for the digital museum
Authors: Gianluca Novati, Paolo Pellegri, Raimondo Schettini
Venue: International Journal on Digital Libraries (2005)

The use of multispectral imaging for the acquisition of the image content of a digital museum is proposed. The advantages of multispectral imaging over &#x201c;traditional&#x201d; RGB imaging are explained, and the two existing approaches to multispectral acquisition, based on narrowband and wideband sensors respectively, are detailed. The characteristics of wideband multispectral acquisition systems in view of their possible large-scale use for digital museum content acquisition are then discussed, and an example system assembled by the authors and tested in acquisitions of real artifacts is introduced. Finally, it is shown that multispectral representations collected with such systems can be used for several purposes, including reproduction with current and future devices and support for monitoring and restoration, making them a natural choice for master copies in cultural institutions&#x2019; archives.
Effects of introducing survival behaviours into automated negotiators specified in an environmental and behavioural framework
Authors: Peter Henderson, Stephen Crouch, Robert John Walters, Qinglai Ni
Venue: Journal of Systems and Software (2005)

With the rise of distributed e-commerce in recent years, demand for automated negotiation has increased. In turn, this has engendered a demand for ever more complex algorithms to conduct these negotiations. As the complexity of these algorithms increases, our ability to reason about and predict their behaviour in an ever larger and more diverse negotiation environment decreases. In addition, with the proliferation of internet-based negotiation, any algorithm also has to contend with potential reliability issues in the underlying message-passing infrastructure. These factors can create problems for building these algorithms, which need to incorporate methods for survival as well as negotiation.This paper proposes a simple yet effective framework for integrating survivability into negotiators, so they are better able to withstand imperfections in their environment. An overview of this framework is given, with two examples of how negotiation behaviour can be specified within this framework. Results of an experiment which is based on these negotiation algorithms are provided. These results show how the stability of a negotiation community is affected by incorporating an example survival behaviour into negotiators operating in an environment developed to support this framework.
A globally convergent learning algorithm for PCA neural networks
Authors: Mao Ye, Zhang Yi, JianCheng Lv
Venue: Neural Computing and Applications (2005)

Principal component analysis (PCA) by neural networks is one of the most frequently used feature extracting methods. To process huge data sets, many learning algorithms based on neural networks for PCA have been proposed. However, traditional algorithms are not globally convergent. In this paper, a new PCA learning algorithm based on cascade recursive least square (CRLS) neural network is proposed. This algorithm can guarantee the network weight vector converges to an eigenvector associated with the largest eigenvalue of the input covariance matrix globally. A rigorous mathematical proof is given. Simulation results show the effectiveness of the algorithm.
Visions for ICT, Ethics and the Practice of Teachers
Authors: Yngve Troye Nordkvelle, John Olson
Venue: Education and Information Technologies (2005)

The "failure" of educational computing is often attributed to deficiencies of practice: resisting teachers and lack of will, competence and sincerity on behalf of the teaching profession. But the complexity of school life and teachers' work has been underestimated by the entrepreneurs of educational computing. Theoretically there is a need to approach this area from a different angle. We will suggest there is a need to reframe the issue of ICT in schools with educational policy and discourse with education, rather than with technology in mind. In order to reach that goal there is a need to inculcate "technology" as an ordinary part of teachers' vocabulary about their own work and as a part of their professional ethos. Teachers need to examine the moral values inherent in their practices and use those values as bases for debate. Not taking up these issues and instead adopting defensive stances is dangerous to the profession. The danger is that defensiveness can be seen by others outside the school as rigidity and play into the hands of those who are impatient with teachers. It would serve teachers well if they had a more robust ability to communicate the nature of the difficulties they face and how they deal with them.
On structured programming in FORTRAN
Authors: S. Charmonman, J. L. Wagener
Venue: ACM SIGNUM Newsletter (1975)

A modification is suggested to improve Hull's format of structured programming in FORTRAN. In addition a FORTRAN versions of Dijkstra's IF-FI and DO-OD constructs is presented, with examples of program segments written in this form.