ppxscal/embedding_network huggingface dataset:
Expanding technological frames towards mediated collaboration: groupware adoption in virtual learning teams
Authors: Pernille Bjørn, Ada Scupola, Brian Fitzgerald
Venue: Scandinavian Journal of Information Systems (2006)

This paper provides an in-depth analysis of the technological and social factors that led to the successful adoption of groupware by a virtual team in a educational setting. Drawing on a theoretical framework based on the concept of technological frames, we conducted an action research study to analyse the chronological sequence of events in groupware adoption. We argue that groupware adoption can be conceptualised as a three-step process of expanding and aligning individual technological frames towards groupware. The first step comprises activities that bring knowledge of new technological opportunities to the participants. The second step involves facilitating the participants to articulate and evaluate their work practices and their use of technology. The third and final step deals with the participants' commitment to, and practical enactment of, groupware technology. The alignment of individual technological frames requires the articulation and re-evaluation of experience with collaborative practice and with the use of technology. One of the key findings is that this activity cannot take place at the outset of groupware adoption.
Exploring the gap between interaction and institutional orders in pragmatic web design
Authors: Mark Aakhus
Venue: Proceedings of the 2nd international conference on Pragmatic web (2007)

This paper explores the call to attend to the communication pragmatics of the pragmatic web by examining instances of institutional talk and internet based support for deliberative communication. The examples map the terrain between the intentional design of communication support and the tacit, often unintentional aspects of communication that shape what is made explicit. Even though there is ever more designed support for communication and increasing capacity to design support, the tacit dimension of communication still plays a role in how people formulate moves in web-based interaction and in what becomes explicit in online interaction. These moves may have subtle but profound consequences for the discourse that emerges from designs intended to augment interaction and reasoning.
Special Feature Computer Graphics: The Human Interface
Authors: W. Myers
Venue: Computer (1980)

New insights, based on the way people learn to use computer graphics, are leading to better designs for the user interface. 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
Mechanism for software tamper resistance: an application of white-box cryptography
Authors: W. Michiels, P. Gorissen
Venue: Proceedings of the 2007 ACM workshop on Digital Rights Management (2007)

In software protection we typically have to deal with the white-box attack model. In this model an attacker is assumed to have full access to the software and full control over its execution. The goal of white-box cryptography is to implement cryptographic algorithms in software such that it is hard for an attacker to extract the key by a white-box attack. Chow et al. present white-box implementations for AES and DES. Based on their ideas, white-box implementations can be derived for other block ciphers as well. In the white-box implementations the key of the underlying block cipher is expanded from several bytes to a collection of lookup tables with a total size in the order of hundreds of kilobytes. In this paper we present a technique that uses a white-box implementation to make software tamper resistant. The technique interprets the binary of software code as lookup tables, which are next incorporated into the collection of lookup tables of a white-box implementation. This makes the code tamper resistant as the dual interpretation implies that a change in the code results in an unintentional change in the white-box implementation. We also indicate in the paper that it is difficult for an attacker to make modifications to the white-box implementation such that its original operation is restored.
Vector Image Segmentation for Content-Based Vector Image Retrieval
Authors: Takahiro Hayashi, Rikio Onai, Koji Abe
Venue: Proceedings of the 7th IEEE International Conference on Computer and Information Technology (2007)

This paper proposes a novel method for vector image segmentation as the first step in developing a content-based vector image retrieval system. Structure of a vector image can be represented as a tree in which each node is assigned each object region in the vector image and each link repre- sents the inclusion relation between two object regions. In order to generate such trees, the method separates object re- gions from background by detecting figures defining bound- ary between object regions and background. The proposed method finds object regions before rasterizing, which is an essential difference from existing object separation meth- ods. We have evaluated the effectiveness of the proposed object separation on 40 test vector images by comparing manual object separation. The experimental results have shown that the proposed method has a high performance which is comparable to manual object separation.
Modeling, optimization and control of rotary traveling-wave oscillator
Authors: Cheng Zhuo, Huafeng Zhang, Rupak Samanta, Jiang Hu, Kangsheng Chen
Venue: Proceedings of the 2007 IEEE/ACM international conference on Computer-aided design (2007)

Rotary traveling-wave oscillator (RTWO) is a recently proposed transmission-line approach for multi-gigahertz rate clock generation. RTWO has the characteristics of both conventional LC tank oscillator and ring oscillator. Thus, it is difficult to be analyzed by a general-purpose method. This paper presents a systematic and efficient method for RTWO modeling and optimization. Equations for frequency, power dissipation, die area, loop gain and phase noise are formulated in posynomial forms. The resulting optimization problem is relaxed to be a Geometric Programming (GP) and can be efficiently solved with a convex optimization solver. A novel scheme to control the rotation direction is also suggested for skew control. Experimental results show that our method can rapidly compute the globally optimal trade-off and reduce the power by up to 85% for a 11.8 GHz RTWO design. Compared to a recently reported low-power methodology, the proposed design scheme can save about 50% of die area and achieve lower power dissipation as well as faster rise/fall time.
How to Obtain Fair Managerial Decisions in Sugar Cane Harvest Using NSGA-II
Authors: Diogo Ferreira Pacheco, Tarcisio Daniel P. Lucas, Fernando B. de Lima Neto
Venue: Proceedings of the 7th International Conference on Hybrid Intelligent Systems (2007)

The world's demand for sugar and particularly for renewable fuels such as ethanol requires an increase in production in sugar mills. The use of artificial neural networks (ANN) posed as a predictive core associated with the algorithm NSGA-II aims at helping decision makers to optimize the multi-objective harvest problem. This paper presents two approaches and the good results achieved as compared with other classical techniques.
Molecular complexes at a glance
Authors: Katrin Stierand, Patrick C. Maaß, Matthias Rarey
Venue: Bioinformatics (2006)

Motivation: In this paper a new algorithmic approach is presented, which automatically generates structure diagrams of molecular complexes. A complex diagram contains the ligand, the amino acids of the protein interacting with the ligand and the hydrophilic interactions schematized as dashed lines between the corresponding atoms. The algorithm is based on a combinatorial optimization strategy which solves parts of the layout problem non-heuristically. The depicted molecules are represented as structure diagrams according to the chemical nomenclature. Due to the frequent usage of complex diagrams in the scientific literature as well as in text books dealing with structural biology, biochemistry and medicinal chemistry, the new algorithm is a key element for computer applications in these areas. Results: The method was implemented in the new software tool PoseView. It was tested on a representative dataset containing 305 protein–ligand complexes in total from the Brookhaven Protein Data Bank. PoseView was able to find collision-free layouts for more than three quarters of all complexes. In the following the layout generation algorithm is presented and, additional to the statistical results, representative test cases demonstrating the challenges of the layout generation will be discussed. Availability: The method is available as a webservice at Contact: rarey@zbh.uni-hamburg.de
Review: A comparative study of deformable contour methods on medical image segmentation
Authors: Lei He, Zhigang Peng, Bryan Everding, Xun Wang, Chia Y. Han, Kenneth L. Weiss, William G. Wee
Venue: Image and Vision Computing (2008)

A comparative study to review eight different deformable contour methods (DCMs) of snakes and level set methods applied to the medical image segmentation is presented. These DCMs are now applied extensively in industrial and medical image applications. The segmentation task that is required for biomedical applications is usually not simple. Critical issues for any practical application of DCMs include complex procedures, multiple parameter selection, and sensitive initial contour location. Guidance on the usage of these methods will be helpful for users, especially those unfamiliar with DCMs, to select suitable approaches in different conditions. This study is to provide such guidance by addressing the critical considerations on a common image test set. The test set of selected images offers different and typical difficult problems encountered in biomedical image segmentation. The studied DCMs are compared using both qualitative and quantitative measures and the comparative results highlight both the strengths and limitations of these methods. The lessons learned from this medical segmentation comparison can also be translated to other image segmentation domains.
Situation Awareness Unified Process
Authors: Vikram Sorathia, Anutosh Maitra
Venue: Proceedings of the International Conference on Software Engineering Advances (2007)

This paper identifies the process for developing information system for Situation Awareness application domain and identifies novel process artifacts that need to be introduced along with existing approaches. Appropriately engineered method is an important requirement for successful implementation of any software system targeted at situation awareness. When it comes to Information System Development (ISD) for dynamic organizations, the method engineering plays even more critical role. The existing approaches for architectural description, method composition and process guidance are derived based on experiences from successful past implementations. Yet, how existing team utilizes the experience is the determining factor for its efficient use. Today's organization, where one information system is the result of continuous efforts of multiple teams forming a virtual organization, calls for extending the approaches to get proper benefit from Method Engineering.
Linear Features Extraction From Remote Sensing Image Based on Wedgelet Decomposition
Authors: Ruiqing Niu, Xiaoming Mei, Liang-pei Zhang, Ping-xiang Li
Venue: Proceedings of the Fourth International Conference on Image and Graphics (2007)

Linear feature extraction is an important problem for remote sensing image processing, and it is very difficult to extract those linear features embedded in strong noise or when the SNR (signal to noise) is low like the complicated environment of remote sensing image. In this paper, an algorithm based on wedgelet decomposition is proposed to extract linear features from remote sensing image. Firstly, beamlets can be generated by recursive dyadic partitioning, vertex marking and connecting in different scales, and beamlet transform is implemented as one important parameter to generate edge map of linear feature. Secondly, each dyadic square is split into two wedgelet segments, and wedgelet decomposition is implemented as the other important parameter to generate edge map of linear feature. The propose method can detect lines with any orientation, location and length in different scales. Experimental results show that the proposed method can extract linear features accurately from remote sensing image. It can be suited to remote sensing image processing and in practice it has surprisingly powerful and apparently unprecedented capabilities.
Testing Reversible One-Dimensional QCA Arrays for Multiple F
Authors: J. Huang, X. Ma, C. Metra, F. Lombardi
Venue: Proceedings of the 22nd IEEE International Symposium on Defect and Fault-Tolerance in VLSI Systems (2007)

Reversible logic design is a well-known paradigm in digital computation. In this paper, Quantum-dot Cellular Automata (QCA) is investigated for testable implementations of reversible logic in array systems. C-testability of a 1D array is investigated for multiple cell faults. It has been shown that fault masking is possible in the presence of multiple faults [9]. A technique for achieving C-testability of 1D array is introduced by adding lines for controllability and observability. Rules for choosing lines for controllability and observability are proposed. Examples using the QCA reversible logic gates proposed in [9] are presented.
Improving the Agent Based Software Development Process
Authors: PRABHAT RANJAN, A. K. MISRA
Venue: Proceedings of the International Conference on Software Engineering Advances (2007)

Agent oriented software development is generally motivated by the need of open and adaptive systems develpoment that continuously change and evolve to meet new requirements. In this paper, we propose model-based technique that provides a specific model for the type of information to be gathered and uses this model to drive the domain specific analysis process. In the proposed agent-based system, the focus is on a clear separtion between the requirement gathering and analysis phases. The analysis methodology splits the analysis phase into the user_centric analysis and the system_centric analysis phases. Optimization of the system performance by exploiting the relationships and dependencies among roles and mapping criteria between roles to agents has also been proposed. The Gaia and ROADMAP models have been used as a fundamental ingredient to the new proposed agentbased modeling method.
Dynamic Data Replication based on Local Optimization Principle in Data Grid
Authors: Yulai Yuan, Yongwei Wu, Guangwen Yang, Feng Yu
Venue: Proceedings of the Sixth International Conference on Grid and Cooperative Computing (2007)

Efficient data access is one way of improving the performance of the Data Grid. In order to speed up the data access and reduce bandwidth consumption, Data Grid replicates essential data in multiple locations. This paper studies data replication strategy in Data Grid, taking into account two important issues which bound the replication: storage capability of different nodes and the bandwidth between these nodes. We propose a new dynamic replication strategy based on the principle of local optimization. The Data Grid can achieve the global data access optimization through the interaction of the local optimization in the local optimization areas.
Self-Reconfigurable Embedded Systems on Low-Cost FPGAs
Authors: Ivan Gonzalez, Estanislao Aguayo, Sergio Lopez-Buedo
Venue: IEEE Micro (2007)

Hardware acceleration significantly increases the performance of embedded systems built on programmable logic. Allowing a FPGA-based MicroBlaze processor to self-select the coprocessors it uses can help reduce area requirements and increase a system's versatility. With a simple hardware arrangement, requiring only a few external connections and no additional components, low-cost FPGAs such as Xilinx's Spartan-3 can become self-reconfigurable platforms.
Image interpolation using interpolative classified vector quantization
Authors: Sung-Ho Hong, Rae-Hong Park, Seungjoon Yang, Jun-Yong Kim
Venue: Image and Vision Computing (2008)

According to advances in digital imaging technology, interest in high-resolution (HR) images has been increased. Various methods that convert low-resolution (LR) images to HR ones have been presented. In this paper, to reduce the computational load we propose a vector quantization (VQ) based algorithm that reconstructs an interpolation image by adding to an initially interpolated image high-frequency components predicted from training with a number of example image sets. The proposed interpolative classified VQ (ICVQ) algorithm combines interpolative VQ with classified VQ. With a number of (LR and HR) example image sets, we construct two types of (LR and HR) codebooks. Comparative experiments with three conventional image interpolation algorithms show that the proposed interpolation algorithms using ICVQ effectively preserve edges to which the human visual system is sensitive. The proposed algorithm can be applicable to various image- and video-based applications such as digital camera and digital television.
View-dependent mesh streaming using multi-chart geometry images
Authors: Bin Sheng, Enhua Wu
Venue: Proceedings of the 2007 ACM symposium on Virtual reality software and technology (2007)

Many mesh streaming algorithms have focused on the transmission order of the polygon data with respect to the current viewpoint. In contrast to the conventional progressive streaming where the resolution of a model changes in the geometry space, we present an new approach which firstly partitions a mesh into several patches, then converts these patch into multi-chart geometry images(MCGIM). After all the MCGIM and normal map atlas are obtained by regular re-sampling, we could construct the regular quadtree-based hierarchical representation based on MCGIM. Experimental results have shown the effectiveness of our approach where one server streams the MCGIM texture atlas to the clients.
Localization for indoor wireless networks using minimum intersection areas of iso-RSS lines
Authors: Begumhan Turgut, Richard P. Martin
Venue: Proceedings of the 32nd IEEE Conference on Local Computer Networks (2007)

We present a new method for localization in wireless networks based on the measurement of the received signal strength (RSS) from multiple access points in an indoor setting. Our approach starts by learning a smoothed RSS surface for each of the access points from a set of training data. We then extract the isometric lines of the RSS surface (iso-RSS lines) for each access point. To perform the localization, the user measures the incoming signal strength of each access point and identifies the corresponding iso-RSS line. Ideally, the exact location would be the common intersection point of these lines. However, noise and measurement imperfections make the lines not intersect in a single point. We search for the smallest rectangular area which is intersected by all the selected iso-RSS lines. This rectangle is interpreted as the most likely location of the user; the area of the rectangle is an estimate of the localization error. We describe an efficient method for finding the minimal intersection area based on recursive grid partitioning. Through experiments over multiple indoor data sets we show that our approach provides a better localization accuracy than existing localization algorithms.
Fibrations and universal view updatability
Authors: Michael Johnson, Robert Rosebrugh
Venue: Theoretical Computer Science (2007)

Maintainability and modifiability of information system software can be enhanced by the provision of comprehensive support for views, since view support allows application programs to continue to operate unchanged when the underlying information system is modified. Supporting views depend upon a solution to the view update problem. This paper presents a new treatment of view updates for formally specified semantic data models based on the category theoretic sketch data model. The sketch data model has been the basis of a number of successful major information system consultancies. We define view updates by a universal property in models of the formal specification, and explain why this indeed gives a complete and correct treatment of view updatability, including a solution to the view update problem. However, a definition of updatability which is based on models causes some inconvenience in applications, so we prove that in a variety of circumstances updatability is guaranteed independently of the current model. This is done first with a very general criterion, and then for some specific cases relevant to applications. We include some details about the sketch data model, noting that it involves extensions of algebraic data specification techniques.
Security policy analysis using deductive spreadsheets
Authors: Anu Singh, C. R. Ramakrishnan, I. V. Ramakrishnan, Scott D. Stoller, David S. Warren
Venue: Proceedings of the 2007 ACM workshop on Formal methods in security engineering (2007)

As security policies get larger and more complex, analysis tools that help users understand and validate security policies are becoming more important.This paper explores the use of deductive spreadsheets for security policy analysis.Deductive spreadsheets combine the power ofdeductive rules (for specifying policies and analyses) with the usability of spreadsheets.This approach is introduced with a simple example of analyzing information flow allowed by RBAC policies and then applied in two case studies: analysis of computer system configurations and analysisof Security-Enhanced Linux access control policies.
Electronic Disks
Authors: J. H. Wensley
Venue: Computer (1975)

The term electronic disks has become associated with memory systems that are electronic devices-i.e., not involving mechanical movement, but possessing memory capacities and cost per bit which compete with rotating memories. Many technologies are being investigated that have the potential of being used for electronic disks. These include charge-coupled devices (CCD), magnetic bubbles, domain tip (DOT), and electron beam addressed memories (EBAM).
Dynamic behavior of DCT and DDT formulations for the Sanger neural network
Authors: J. Andrés Berzal, Pedro J. Zufiria
Venue: Neurocomputing (2007)

In this paper, the behavior of the Sanger hebbian artificial neural networks is analyzed. Hebbian networks are employed to implement principal component analysis (PCA), and several improvements over the original model due to Oja have been developed in the last two decades. Among them, Sanger model is designed to directly provide the eigenvectors of the correlation matrix. The behavior of these models has been traditionally considered on a deterministic continuous-time (DCT) formulation whose validity is justified under some hypotheses on the specific asymptotic behavior of the learning gain. In practical applications, these assumptions cannot be guaranteed. This paper addresses a comparative study with a deterministic discrete-time (DDT) formulation that characterizes the average evolution of the net, preserving the discrete-time form of the original network and gathering a more realistic behavior of the learning gain. The results thoroughly characterize the relationship between the learning gain and the eigenvalue structure of the correlation matrix.