ppxscal/embedding_network huggingface dataset:
Coverage algorithms in GPS-less wireless mobile sensor networks
Authors: Chang Wu Yu, Chun-Hsin Wang, Li Chun Hsu, Kai Jen Cheng
Venue: Proceedings of the International Conference on Mobile Technology, Applications, and Systems (2008)

The coverage problem, being one of fundamental problems in wireless sensor networks, has been received lots of attention. To preserve the coverage of network, some researches suggest moving redundant mobile sensor nodes to uncovered areas for mitigating the problem. Most of previous approaches require location information of sensor nodes to calculate and determine redundant nodes, to detect uncovered areas, and to move those nodes to their pre-determined areas. However, to acquire location information will increase the cost of hardware for deployment, extra computation and communication delay, and additional message overhead and power consumption. In some cases, it becomes difficult to acquire location information. In this work, without exploiting any location and distance information, six distributed algorithms are devised for mitigating the un-coverage problem. The first three distributed algorithms including the neighborhood density detecting algorithm, the random walk algorithm, and the dripping rain algorithm detect uncovered areas, redundant mobile sensor nodes, and direct them to move to cover the uncovered areas, only basing on the number of neighbors of each node and consuming little extra control packets. The expected number of required neighbors and the probability of an arbitrary node being a redundant node are derived theoretically. Moreover, based on the obtained formula, the last three randomized algorithms are developed by modifying the first three algorithms. Simulation results demonstrate that the proposed coverage algorithms can achieve at most 90% coverage rate in a GPS-less sensor network.
Automatic Appropriate Segment Extraction from Shots Based on Learning from Example Videos
Authors: Yousuke Kurihara, Naoko Nitta, Noboru Babaguchi
Venue: Proceedings of the 3rd Pacific Rim Symposium on Advances in Image and Video Technology (2009)

Videos are composed of shots, each of which is recorded continuously by a camera, and video editing can be considered as a process of re-sequencing shots selected from original videos. Shots usually include redundant intervals, which are often edited out by professional editors. Defining the intact interval which is used in the edited video as the appropriate segment and all other intervals of equal length as inappropriate segments, this paper proposes a method for automatically extracting appropriate segments from shots. Since what kinds of characteristics make an interval appropriate to be used in the edited video should be different among shots with different content, the proposed method firstly categorizes shots according to their content with Support Vector Machines. Then, the appropriate segments are extracted based on the temporal patterns of audio and visual features in appropriate and inappropriate segments learned with Hidden Markov Models for each shot category. The effectiveness of the proposed method is verified with experiments.
Using Parallel MultiCore and HPC Systems for Dynamical Visualisation
Authors: Claus-Peter Rückemann
Venue: Proceedings of the 2009 International Conference on Advanced Geographic Information Systems & Web Services (2009)

This paper gives an overview of the current developments for using High Performance Computing (HPC) and Grid Computing resources with Geoscientific Information Systems (GIS) based on the GISIG actmap-project. Focus is on frameworks for the use of computing resources, interfaces for data and application interchange. Using an interface with the Active Source framework, cluster components for Massively Parallel Processing and Symmetric Multi-Processing can beaccessed from within dynamical visualisation and information applicationcomponents. The method of event triggering from within Active Source can be used to exploit the vast computing power of MultiCore parallel systemsfor geoinformation processing, geophysical data analysis,information systems, and e-Science. As various obstacles showed up withimplementing an application-resource workflow, in the future the creationof Web Services for HPC services will be a solution for dedicated issues.For implementation testing the new supercomputer resources HLRN-II(North-German Supercomputing Alliance) have been used. 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
Stabilised weighted linear prediction
Authors: Carlo Magi, Jouni Pohjalainen, Tom Bäckström, Paavo Alku
Venue: Speech Communication (2009)

Weighted linear prediction (WLP) is a method to compute all-pole models of speech by applying temporal weighting of the square of the residual signal. By using short-time energy (STE) as a weighting function, this algorithm was originally proposed as an improved linear predictive (LP) method based on emphasising those samples that fit the underlying speech production model well. The original formulation of WLP, however, did not guarantee stability of all-pole models. Therefore, the current work revisits the concept of WLP by introducing a modified short-time energy function leading always to stable all-pole models. This new method, stabilised weighted linear prediction (SWLP), is shown to yield all-pole models whose general performance can be adjusted by properly choosing the length of the STE window, a parameter denoted by M. The study compares the performances of SWLP, minimum variance distortionless response (MVDR), and conventional LP in spectral modelling of speech corrupted by additive noise. The comparisons were performed by computing, for each method, the logarithmic spectral differences between the all-pole spectra extracted from clean and noisy speech in different segmental signal-to-noise ratio (SNR) categories. The results showed that the proposed SWLP algorithm was the most robust method against zero-mean Gaussian noise and the robustness was largest for SWLP with a small M-value. These findings were corroborated by a small listening test in which the majority of the listeners assessed the quality of impulse-train-excited SWLP filters, extracted from noisy speech, to be perceptually closer to original clean speech than the corresponding all-pole responses computed by MVDR. Finally, SWLP was compared to other short-time spectral estimation methods (FFT, LP, MVDR) in isolated word recognition experiments. Recognition accuracy obtained by SWLP, in comparison to other short-time spectral estimation methods, improved already at moderate segmental SNR values for sounds corrupted by zero-mean Gaussian noise. For realistic factory noise of low pass characteristics, the SWLP method improved the recognition results at segmental SNR levels below 0dB.
A hybrid fuzzy-statistical clustering approach for estimating the time of changes in fixed and variable sampling control charts
Authors: Adel Alaeddini, Mehdi Ghazanfari, Majid Amin Nayeri
Venue: Information Sciences: an International Journal (2009)

Control charts are the most popular Statistical Process Control (SPC) tools used to monitor process changes. When a control chart produces an out-of-control signal, it means that the process has changed. However, control chart signals do not indicate the real time of the process changes, which is essential for identifying and removing assignable causes and ultimately improving the process. Identifying the real time of the process change is known as change-point estimation problem. Most of the traditional change-point methods are based on maximum likelihood estimators (MLE) which need strict statistical assumptions. In this paper, first, we introduce clustering as a potential tool for change-point estimation. Next, we discuss the challenges of employing clustering methods for change-point estimation. Afterwards, based on the concepts of fuzzy clustering and statistical methods, we develop a novel hybrid approach which is able to effectively estimate change-points in processes with either fixed or variable sample size. Using extensive simulation studies, we also show that the proposed approach performs considerably well in all considered conditions in comparison to powerful statistical methods and popular fuzzy clustering techniques. The proposed approach can be employed for processes with either normal or non-normal distributions. It is also applicable to both phase-I and phase-II. Finally, it can estimate the true values of both in- and out-of-control states' parameters.
K-6 outreach using "Computer Science Unplugged"
Authors: Joan M. Lucas
Venue: Journal of Computing Sciences in Colleges (2009)

The Computer Science discipline continues to struggle with low enrollment. To reverse this trend we need to engage students in the excitement of this field as early as possible in their educational careers. To this end, a series of activities aimed towards grade school children has been developed by Tim Bell, et al. of the University of Christchurch, New Zealand. Known collectively as "Computer Science Unplugged" (csunplugged.org), these activities illustrate the fundamentals of computer science without requiring a computer or any other equipment beyond paper, pencils, cards, string, chalk, whiteboard markers, balls or similar common-place items. By eliminating the details of particular computer systems, the great ideas behind computer science can be brought into the open. These activities demonstrate some of the key concepts of computing such as data encoding, data compression, error detection, sorting, routing and deadlock, intractability, cryptography and artificial intelligence. The activities are structured to allow students to discover answers for themselves, rather than just being given solutions or algorithms to follow. These modules can be freely downloaded and have been used and refined over 15 years around the world. The activities are stand-alone modules, so they can be used independently for enrichment in curricula, or as a series. This tutorial will describe the basic philosophy of Computer Science Unplugged. We will briefly outline several of these activities and then the participants will actually perform several other activities so that they can actually engage in the active learning process. Finally, the tutorial will conclude with a summary of the presenter's experience bringing these activities into an elementary school and some of the implementation issues that arise.
On rewriting XPath queries using views
Authors: Foto Afrati, Rada Chirkova, Manolis Gergatsoulis, Benny Kimelfeld, Vassia Pavlaki, Yehoshua Sagiv
Venue: Proceedings of the 12th International Conference on Extending Database Technology: Advances in Database Technology (2009)

The problem of rewriting a query using a materialized view is studied for a well known fragment of XPath that includes the following three constructs: wildcards, descendant edges and branches. In earlier work, determining the existence of a rewriting was shown to be coNP-hard, but no tight complexity bound was given. While it was argued that &Sigma;3p is an upper bound, the proof was based on results that have recently been refuted. Consequently, the exact complexity (and even decidability) of this basic problem has been unknown, and there have been no practical rewriting algorithms if the query and the view use all the three constructs mentioned above. It is shown that under fairly general conditions, there are only two candidates for rewriting and hence, the problem can be practically solved by two containment tests. In particular, under these conditions, determining the existence of a rewriting is coNP-complete. The proofs utilize various novel techniques for reasoning about XPath patterns. For the general case, the exact complexity remains unknown, but it is shown that the problem is decidable.
Spatial Calculus of Looping Sequences
Authors: Roberto Barbuti, Andrea Maggiolo--Schettini, Paolo Milazzo, Giovanni Pardini
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2009)

The Calculus of Looping Sequences (CLS) enables the description of biological systems and of their evolution. This paper presents the Spatial CLS, an extension of CLS that allows the description of the position of biological elements, and of the space they take up in a 2D/3D space. The elements may move autonomously during the passage of time, and may interact when constraints on their positions are satisfied. The space occupied by each element is modeled as a hard sphere, hence space conflicts may arise during system evolution. These conflicts are resolved by an appropriate algorithm, which rearranges the position of the elements by assuming that they push each other when they are too close. Moreover, rewrite rules are endowed with a parameter describing their reaction rate. The aim of Spatial CLS is to enable a more accurate description of those biological processes whose behaviour depends on the exact position of the elements. As example applications of the calculus, we present a model of cell proliferation, and a model of the quorum sensing process in Pseudomonas aeruginosa.
Factor congruences in BCK-algebras
Authors: Manuel Abad, J. Patricio D&#x00ed;az Varela
Venue: Soft Computing - A Fusion of Foundations, Methodologies and Applications (2009)

In this paper, we characterize factor congruences in the quasivariety of BCK-algebras. As an application we prove that the free algebra over an infinite set of generators is indecomposable in any subvariety of BCK-algebras. We also study the decomposability of free algebras in the variety of hoop residuation algebras and its subvarieties. We prove that free algebras in a non k-potent subvariety of are indecomposable while finitely generated free algebras in k-potent subvarieties have a unique non-trivial decomposition into a direct product of two factors, and one of them is the two-element implication algebra.
A short guide to modulated light
Authors: Florian Echtler, Tobias Sielhorst, Manuel Huber, Gudrun Klinker
Venue: Proceedings of the 3rd International Conference on Tangible and Embedded Interaction (2009)

Many types of tangible interaction systems, such as interactive surfaces and gesture-based interfaces, are based on various kinds of optical tracking, using infrared illuminators and cameras. One drawback of these setups is that they suffer from problems common to optical trackers, such as sensitivity to stray environment light from artificial and natural sources. In this paper, we present a method to significantly enhance tracking robustness for those systems which employ active illumination. Through addition of a small electronic circuit which modulates the LEDs used to illuminate the scene, contrast can be significantly increased.
Qualitative fusion of normalised scores in multimodal biometrics
Authors: Fawaz Alsaade, Aladdin Ariyaeeinia, Amit Malegaonkar, Surosh Pillay
Venue: Pattern Recognition Letters (2009)

A new approach to enhancing the accuracy of multimodal biometrics is investigated. The proposed approach, which involves combining score normalisation and qualitative-based fusion, is shown to considerably improve the accuracy of multimodal biometrics under different data conditions.
Matchin: eliciting user preferences with an online game
Authors: Severin Hacker, Luis von Ahn
Venue: Proceedings of the 27th international conference on Human factors in computing systems (2009)

Eliciting user preferences for large datasets and creating rankings based on these preferences has many practical applications in community-based sites. This paper gives a new method to elicit user preferences that does not ask users to tell what they prefer, but rather what a random person would prefer, and rewards them if their prediction is correct. We provide an implementation of our method as a two-player game in which each player is shown two images and asked to click on the image their partner would prefer. The game has proven to be enjoyable, has attracted tens of thousands of people and has already collected millions of judgments. We compare several algorithms for combining these relative judgments between pairs of images into a total ordering of all images and present a new algorithm to perform collaborative filtering on pair-wise relative judgments. In addition, we show how merely observing user preferences on a specially chosen set of images can predict a user's gender with high probability.
Direct send compositing for parallel sort-last rendering
Authors: Stefan Eilemann, Renato Pajarola
Venue: ACM SIGGRAPH ASIA 2008 courses (2008)

In contrast to sort-first, sort-last parallel rendering has the distinct advantage that the task division for parallel geometry processing and rasterization is simple, and can easily be incorporated into most visualization systems. However, the efficient final depth-compositing for polygonal data, or alpha-blending for volume data of partial rendering results is the key to achieve scalability in sort-last parallel rendering. In this paper, we demonstrate the efficiency as well as flexibility of the direct send sort-last compositing algorithm, and compare it to existing approaches, both in a theoretical analysis and in an experimental setting.
A Replica Replacement Algorithm Based on Value-Cost Prediction
Authors: Tian Tian, Junzhou Luo, Zhiang Wu
Venue: Computer Supported Cooperative Work in Design IV: 11th International Conference, CSCWD 2007, Melbourne, Australia, April 26-28, 2007. Revised Selected Papers (2008)

Data Grid is a new kind of data management infrastructure. To improve access efficiency, large amounts of data on Data Grids need to be replicated in the form of replicas at distributed sites. Due to the limited storage capacity, a good replica replacement algorithm is needed. This paper proposes a replica replacement algorithm based on value-cost prediction, which achieves a good balance between value and cost. The algorithm predicts replica value to select replicas that will be replaced in the first stage, and predicts the bandwidth to make replacement cost as low as possible in the second stage. Simulation shows that compared with traditional replacement algorithms our replica replacement algorithm contributes to better grid performance.
Multi-linear formulas for permanent and determinant are of super-polynomial size
Authors: Ran Raz
Venue: Journal of the ACM (JACM) (2009)

An arithmetic formula is multilinear if the polynomial computed by each of its subformulas is multilinear. We prove that any multilinear arithmetic formula for the permanent or the determinant of an n &times; n matrix is of size super-polynomial in n. Previously, super-polynomial lower bounds were not known (for any explicit function) even for the special case of multilinear formulas of constant depth.
The pintos instructional operating system kernel
Authors: Ben Pfaff, Anthony Romano, Godmar Back
Venue: Proceedings of the 40th ACM technical symposium on Computer science education (2009)

Pintos is an instructional operating system, complete with documentation and ready-made, modular projects that introduce students to the principles of multi-programming, scheduling, virtual memory, and filesystems. By allowing students to run their work product on actual hardware, while simultaneously benefiting from debugging and dynamic analysis tools provided in simulated and emulated environments, Pintos increases student engagement. Unlike tailored versions of commercial or open source OS such as Linux, Pintos is designed from the ground up from an educational perspective. It has been used by multiple institutions for a number of years and is available for wider use.
Resource Negotiation for Collaborative Multimedia Presentations
Authors: B. Prabhakaran
Venue: Proceedings of the 1999 IEEE International Conference on Multimedia Computing and Systems - Volume 02 (1999)

Distributed multimedia documents systems, distributed video servers are examples of multimedia presentations involving collaboration among multiple information sources. In such applications, objects have to be retrieved from their sources and presented to users according to specified temporal relationships. Objects retrieval in these collaborative applications is influenced by their presentation times, durations, and network throughput available to their sources. Replication of objects amongst the set of collaborating systems gives a choice for object retrieval. In this paper, we present a graph-search based algorithm for computing and negotiating throughput requirements of collaborating multimedia presentations with replicated objects. This algorithm optimizes the number of cached objects (that have already been played) for handling operations like reverse presentation.
Legislators and constituents: Examining demographics and online communication tools
Authors: Amber J. Narro, Charles Mayo, Alison F. Miller
Venue: Information Polity (2008)

This study focuses on legislators' homepages as a political communication channel for constituents to remain informed of state legislative decisions and actions, as well as legislative issues. Included in this research is an examination of whether state legislators in the United States offer Internet tools and online relationship-building strategies as a means of political communication. Regression analysis of results from the content analysis of state legislators' official homepages (provided by their respective state legislatures) led the researchers to find for the most part, there is still a digital divide when considering the tools available on the legislative homepages that offer constituent relationship-building strategies as well as Internet tools. Constituents in some districts are able to utilize more Internet tools than those who live in others. Age, race and education of the legislators predicted more availability of tools of communication on homepages. Race, income and education of the constituents also predicted that more communication tools were available on legislators' homepages. The results suggest that even when considering the mountain of information available online, there are still some population segments that have online access to specific information relevant to their own districts and some who do not.
Integrated dynamic and simulation model on coupled closed-loop workstation capacity controls in a multi-workstation production system
Authors: Tao Wu, Leyuan Shi, Benjamin Quirt, N. A. Duffie
Venue: Proceedings of the 40th Conference on Winter Simulation (2008)

In this paper, a dynamic model coupled with a simulation model is introduced to control a multi-workstation production system such that a given performance measure is achieved. In particular, we consider closed loop capacity controls for regulating WIP (Work-in-Process) at individual workstation. The capacity adjustments are consisted of both compensation for local disturbances and predictive control of downstream effects of capacity adjustments make up-stream in the system. Using real data collected from an industrial production system, we are able to demonstrate that our hybrid dynamic and simulation framework can effectively predict lead times associated with each workstation and thus to correctly plan production using a static capacity control system.