ppxscal/embedding_network huggingface dataset:
Robust subgraphs for trees and paths
Authors: Refael Hassin, Danny Segev
Venue: ACM Transactions on Algorithms (TALG) (2006)

Consider a graph problem which is associated with a parameter, for example, that of finding a longest tour spanning k vertices. The following question is natural: Is there a small subgraph that contains an optimal or near optimal solution for every possible value of the given parameter? Such a subgraph is said to be robust. In this article we consider the problems of finding heavy paths and heavy trees of k edges. In these two cases, we prove surprising bounds on the size of a robust subgraph for a variety of approximation ratios. For both problems, we show that in every complete weighted graph on n vertices there exists a subgraph with approximately &alpha;/1&minus;&alpha;2n edges that contains an &alpha;-approximate solution for every k &equals; 1,&hellip;, n &minus; 1. In the analysis of the tree problem, we also describe a new result regarding balanced decomposition of trees. In addition, we consider variants in which the subgraph itself is restricted to be a path or a tree. For these problems, we describe polynomial time algorithms and corresponding proofs of negative results.
When Computers are Scarce: a Case of Botswana Schools
Authors: Tshepo Batane
Venue: Proceedings of the Fourth IEEE International Workshop on Technology for Education in Developing Countries (2006)

The Insufficient number of computers in school is a major problem plaguing most developing regions. In Botswana, as an effort to improve the quality of education, the government has equipped schools with computers to enhance learning. This paper reports on a study that was done in one secondary school in Botswana to investigate technology use. The researcher visited the school and observed how teachers and students were using computers. Interviews were conducted with the participants to get their views on technology use in their school. The results of the study revealed that the number of computers provided was very small compared to the number of students enrolled. Teachers were willing to use technology in their lessons but their efforts were discouraged by inaccessibility to the computers. The paper also provides some recommendations on how people can best use the limited number of computers they have to make the most from them.
Contory: A Smart Phone Middleware Supporting Multiple Context Provisioning Strategies
Authors: Oriana Riva, Cristiano di Flora
Venue: Proceedings of the 26th IEEE International ConferenceWorkshops on Distributed Computing Systems (2006)

This paper presents Contory, a middleware specifically deployed to support provisioning of context information on mobile devices such as smart phones. Contory integrates multiple strategies for context provisioning, namely internal sensors-based, external infrastructure-based, and distributed provisioning in ad hoc networks. Applications can query Contory about context items of different types, using a declarative query language which features on-demand, periodic, and event-based context queries. Contory allows applications to utilize different provisioning mechanisms depending on resource availability and presence of external infrastructures. This paper illustrates our approach along with its design and implementation on smart phones.
Retrieving process analysis in a parts distribution center: a case study of manual trolley fleet substitution
Authors: Shih Y. Chin, Heráclito L. J. Pontes, Arthur J. V. Porto
Venue: Proceedings of the 37th conference on Winter simulation (2005)

This paper summarizes the results of a simulation study for a Parts Distribution Center (PDC), which contains approximately 30000 items, modeling its retrieving process in simulation software ARENA&reg; 5.0. The collection of the parts is carried out manually by five employees, being supported by manual trolleys. The current problem of PDC is to decide if that manual trolley fleet should be substituted, since the existent ones are unbalanced in comparison with the same market competitors, considering the retrieving process total time effectiveness. The Input data to the model about the fleet is the decision factor. Those data are statistically organized in two levels, according to the design of experiments 2k and the results of each test are obtained from two replications. With these results, managers will be able to evaluate possibilities, compare to the current situation and conclude how viable it is to change the fleet.
Block-based Thiele-like blending rational interpolation
Authors: Qian-Jin Zhao, Jieqing Tan
Venue: Journal of Computational and Applied Mathematics (2006)

Thiele-type continued fraction interpolation may be the favoured nonlinear interpolation in the sense that it is constructed by means of the inverse differences which can be calculated recursively and produce useful intermediate results. However, Thiele's interpolation is in fact a point-based interpolation by which we mean that a new interpolating continued fraction with one more degree of its numerator or denominator polynomial is obtained by adding a tail to the current one, or in other words, this can be reshaped simply by adding a new support point to the current set of support points once at a time. In this paper we introduce so-called block-based inverse differences to extend the point-based Thiele-type interpolation to the block-based Thiele-like blending rational interpolation. The construction process may be outlined as follows: first of all, divide the original set of support points into some subsets (blocks), then construct each block by using whatever interpolation means, linear or rational, and finally assemble these blocks by Thiele's method to shape the whole interpolation scheme. Clearly, many flexible rational interpolation schemes can be obtained in this case including the classical Thiele's continued fraction interpolation as its special case. As an extension, a bivariate analogy is also discussed and numerical examples are given to show the effectiveness of our method.
Stochastic resonance with differential code in feedforward network with intra-layer random connections
Authors: Yuichi Sakumura, Shin Ishii
Venue: Neural Networks (2006)

We examined stochastic resonance with a differential coding scheme using a multilayer feedforward neural network which is composed of intra-layer connections. We show that the network, with random synaptic connections in each layer, encodes an input signal into a spike coherence that represents temporal differences among the inputs. We also demonstrate that both internal and external noise enhance the detection of weak signals. Finally, we discuss how the feedforward network with intra-layer random connections is similar to a membrane in its sensitivity to and amplification of a change in stimulus and suggest that the intensity of internal noise may be tuned in a real brain.
Science, engineering, and statistics: Research Articles
Authors: T. P. Davis
Venue: Applied Stochastic Models in Business and Industry (2006)

Symmetry and parsimony, together with unification through synthesis are important principles that govern the character of physical law. We show how these principles can be applied to engineering to develop an approach to reliability, and engineering in general, that centres on the identification, detection, and avoidance of failure modes through design. A definition of reliability, not presented in terms of probability, but rather based on physics, geometry, and the properties of materials, will be emphasized to support this approach. We will also show how the nature of the inductive&ndash;deductive learning cycle provides the framework for statistical science to be embedded into engineering practice, with particular regard to improving reliability through failure mode avoidance. Copyright &copy; 2006 John Wiley & Sons, Ltd.
Identifying User Requirements for a Mobile Terminal Centric Ubiquitous Computing Architecture
Authors: Eija Kaasinen, Marketta Niemela, Timo Tuomisto, Pasi Valkkynen, Vladimir Ermolov
Venue: Proceedings of the International Workshop on System Support for Future Mobile Computing Applications (2006)

System level solutions affect many properties of ubiquitous applications and thus also user experience. That is why user point of view should guide the design of mobile architectures although the users will see them indirectly, via the applications. This paper describes our approach in identifying user requirements for a ubiquitous computing architecture that facilitates mobile applications sensing their environment. The sensing is based on wireless connectivity to tags and sensors in the environment. We illustrated a representative set of future applications as scenarios and proof-of-concepts and evaluated them with potential users. Scenarios were analyzed to identify generic use cases and to understand the implications of the user feedback on the architecture. Our experiences show that user requirements for system level solutions can be identified with this approach. We identified several requirements for the architecture dealing with user interaction, wireless measurements, contextawareness, taking applications into use and ethical issues.
In-network fault tolerance in networked sensor systems
Authors: Iman Saleh, Adnan Agbaria, Mohamed Eltoweissy
Venue: Proceedings of the 2006 workshop on Dependability issues in wireless ad hoc networks and sensor networks (2006)

Networked sensor systems (NSS) have the potential of significantly enhancing our ability to monitor and interact with our physical environment. For example, numerous tiny sensors may be spread all over a forest to reveal the forest's life and events in detail along the time-space continuum. Critical to the success of NSS is the reliable collection and dissemination of data while conserving sensors' limited resources, in particular energy. In this paper, we propose a novel scheme that provides fault-tolerant data collection and dissemination through data checkpointing and recovery. We assume that the data is periodically reported from a sink node to the end users. Based on a model-based simulation, we show that our scheme is highly resilient to sensor and sink failure. It also leads to enhanced NSS lifetime and data collection with minimal overhead.
Branch predictor guided instruction decoding
Authors: Oliverio J. Santana, Ayose Falcón, Alex Ramirez, Mateo Valero
Venue: Proceedings of the 15th international conference on Parallel architectures and compilation techniques (2006)

Fast instruction decoding is a challenge for the design of CISC microprocessors. A well-known solution to overcome this problem is using a trace cache. It stores and fetches already decoded instructions, avoiding the need for decoding them again. However, implementing a trace cache involves an important increase in the fetch architecture complexity.In this paper, we propose a novel decoding architecture that reduces the fetch engine implementation cost. Instead of using a special-purpose buffer like the trace cache, our proposal stores frequently decoded instructions in the memory hierarchy. The address where the decoded instructions are stored is kept in the branch prediction mechanism, enabling it to guide our decoding architecture. This makes it possible for the processor front-end to fetch already decoded instructions from memory instead of the original nondecoded instructions. Our results show that an 8-wide superscalar processor achieves an average 14% performance improvement by using our decoding architecture. This improvement is comparable to the one achieved by using the more complex trace cache, while requiring 16% less chip area and 21% less energy consumption in the fetch architecture.
Explor@Graph the Representation Power of Adaptive Conceptual Graphs
Authors: Aude Dufresne
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

The Explor@Graph system is an open environment to design learning scenarios as conceptual structures, linked to resources, discussion forums and support.
Analyzing printed circuit board assembly lines using a PCB assembly template
Authors: Pradip D. Jadhav, Jeffrey S. Smith
Venue: Proceedings of the 37th conference on Winter simulation (2005)

PCB assembly lines are characterized by asynchronous transfer of parts resulting from variability in terms of random processing, failure, repair, exhaust, and replenishment times. The throughput for such manufacturing systems depends upon simultaneous availability of resources; namely, machines, material, and operators. Further, random breakdowns along with the capacitated buffers cause blocking and starving which affects the throughput. Analytical models for such system require simplifying assumptions, hence simulation modeling is the popular choice. For simulation models to be successful, capturing the impact of operator interference is important. This paper describes a methodology developed for simulation modeling and analysis of PCB manufacturing lines, capturing the complex interactions between its components. A custom-developed PCB assembly template is used for modeling purposes. Though the analysis described in this paper pertains to PCB assembly lines, it is equally applicable to general class of serial production lines with capacitated buffers.
The dynamics of multinational capital structure and macroeconomic conditions
Authors: Samuel Frimpong Boateng
Venue: Proceedings of the 37th conference on Winter simulation (2005)

Using a panel data methodology on a sample of 712 multinational corporations, we model capital structure changes in a non-linear fashion and compare the speed of capital structure adjustment with that of aggregate macroeconomic issues by using three types of leverage - short-term debt, long-term debt, and total debt. It is determined, macroeconomic factors are more useful in the adjustment process of capital structure than in deciding explicit debt values. A relationship between the speed of capital structure adjustment and the rate of aggregate macroeconomic changes is found. By using a nonlinear approach in conjunction with the Monte Carlo simulation model we unravel and correct the shortcomings inherent in the conventional approach to linear static capital structure investigations. The results support the hypothesis that MNCs use more shortterm debt in their capital structure and draws some allusions from the behavioral pattern of managers in reacting to short-run contemporaneous macroeconomic changes. 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
GriCoL: A Language for Scientific Grids
Authors: Natalia Currle-Linde, Panagiotis Adamidis, Michael Resch, Fabian Bos, Jurgen Pleiss
Venue: Proceedings of the Second IEEE International Conference on e-Science and Grid Computing (2006)

The development of the Grid has opened new possibilities for scientists and engineers to execute large-scale modeling experiments. This has stimulated the generation and development of tools for the creation and management of complex computing experiments in the Grid. Among these, tools for the automation of the programming of experiments play a significant role. In this paper we present GriCoL, which we propose as a simple and efficient language for the description of complex Grid experiments. We also describe the environment within which GriCoL works, namely the Science Experimental Grid Laboratory (SEGL) system for designing and executing complex experiments. As an illustration, the paper includes the description of a biochemical experiment using Molecular Dynamics simulations.
A Scalable De-centralized Multicast Key Management Scheme
Authors: Xu Yanyan, Xu Zhengquan, Chen Xi, Yu Zhanwu
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 1 (2006)

Key management is an important part of secure multicast. Among the representative solutions to the multicast key management, the de-centralized scheme inherits the merits of others. In this paper, we present a scalable de-centralized multicast key management scheme, introduce the main idea and analyze its advantages and disadvantages. We construct a core tree in the group member at first, whose nodes sharing a DEK and then constituting one key management level. The core node and other members in the same region form another key management level. When the member in the subgroup changes, only local sub-tree re-key. If the member in the core tree changes, the DEK of the core tree is updated. Thus the overhead of re-key decreases. When data are transmitted between different subgroups, the nodes in the core tree decrypt/encrypt data only once before switch it to local subgroup members, thus the cost of data transmission is decreased. When the size of group becomes large, we use batch re-key scheme to alleviate the cost of rekey further. The scheme has highly robustness, good scalability and lower cost.
Performance of Sniff and Embark MAC Protocol for Real-Time Traffic in Wireless LANs
Authors: Aditya Dhananjay, Debabrata Das
Venue: Proceedings of the 9th International Conference on Information Technology (2006)

In this paper, we propose Sniff and Embark (SNE) protocol, a novel frame sniffing and token passing based approach to provide QoS in WLANs. Our simulations show that SNE performs significantly better than EDCF over the performance metrics - delay, jitter and timeconstrained frame drop ratio.
Dynamic Service Composition and Selection through an Agent Interaction Protocol
Authors: Yasmine Charif-Djebbar, Nicolas Sabouret
Venue: Proceedings of the 2006 IEEE/WIC/ACM international conference on Web Intelligence and Intelligent Agent Technology (2006)

This paper addresses the dynamic service selection and composition issues for the satisfaction of user requirements. We propose an approach in which agents perform service composition through unplanned interactions. In our architecture, agents offer semantic web services and are capable of reasoning about their services' functionalities. These agents are provided with an interaction protocol that allows them, through dialogue games, to select and compose appropriate services' functionalities in order to fulfill a complex set of requirements specified by a user.
Virtual environments for social skills training: comments from two adolescents with autistic spectrum disorder
Authors: Sarah Parsons, Anne Leonard, Peter Mitchell
Venue: Computers Education (2006)

Previous research has shown that computer-based tasks can motivate people with autism and encourage learning. As a computer-based medium, Virtual Environments (VEs) offer a potentially useful tool for social skills training for people with autistic spectrum disorders (ASDs). However, there are some concerns over whether people with ASDs can understand, use and interpret the technology appropriately. This paper adopts a qualitative case-study approach to report observations of, and comments from, two adolescent boys with ASDs, gathered during a series of sessions using a virtual café and bus environment. Although there were signs of repetitive behaviours, literal interpretation of the scenes, and that the VEs were treated as not having real-world relevance, these were not the dominant modes of responding. Instead, participants seemed to interpret the scenes meaningfully and appreciated the opportunities to discuss appropriate social responses with a facilitator sitting alongside. They enjoyed using the VEs and provided specific examples of how the VEs had helped, or could help, them in the real world. This gives encouraging support for the idea that VEs can be used and interpreted meaningfully by at least some students with ASDs. The paper concludes with some considerations for the future development of VEs for members of this population.
Training a reciprocal-sigmoid classifier by feature scaling-space
Authors: Kar-Ann Toh
Venue: Machine Learning (2006)

This paper presents a reciprocal-sigmoid model for pattern classification. This proposed classifier can be considered as a ¿-machine since it preserves the theoretical advantage of linear machines where the weight parameters can be estimated in a single step. The model can also be considered as an approximation to logistic regression under the framework of Generalized Linear Models. While inheriting the necessary classification capability from logistic regression, the problems of local minima and tedious recursive search no longer exist in the proposed formulation. To handle possible over-fitting when using high order models, the classifier is trained using multiple samples of uniformly scaled pattern features. Empirically, the classifier is evaluated using a benchmark synthetic data from random sampling runs for initial statistical evidence regarding its classification accuracy and computational efficiency. Additional experiments based on ten runs of 10-fold cross validations on 40 data sets further support the effectiveness of the reciprocal-sigmoid model, where its classification accuracy is seen to be comparable to several top classifiers in the literature. Main reasons for the good performance are attributed to effective use of reciprocal sigmoid for embedding nonlinearities and effective use of bundled feature sets for smoothing the training error hyper-surface.
Task-Dependent Modulation of Regions in the Left Inferior Frontal Cortex during Semantic Processing
Authors: A. L. Roskies, J. A. Fiez, D. A. Balota, M. E. Raichle, S. E. Petersen
Venue: Journal of Cognitive Neuroscience (2001)

To distinguish areas involved in the processing of word meaning (semantics) from other regions involved in lexical processing more generally, subjects were scanned with positron emission tomography (PET) while performing lexical tasks, three of which required varying degrees of semantic analysis and one that required phonological analysis. Three closely apposed regions in the left inferior frontal cortex and one in the right cerebellum were significantly active above baseline in the semantic tasks, but not in the nonsemantic task. The activity in two of the frontal regions was modulated by the difficulty of the semantic judgment. Other regions, including some in the left temporal cortex and the cerebellum, were active across all four language tasks. Thus, in addition to a number of regions known to be active during language processing, regions in the left inferior frontal cortex were specifically recruited during semantic processing in a task-dependent manner. A region in the right cerebellum may be functionally related to those in the left inferior frontal cortex. Discussion focuses on the implications of these results for current views regarding neural substrates of semantic processing.