ppxscal/embedding_network huggingface dataset:
Data-Driven Visualization and Group Analysis of Multichannel EEG Coherence with Functional Units
Authors: Michael ten Caat, Natasha M. Maurits, Jos. B. T. M. Roerdink
Venue: IEEE Transactions on Visualization and Computer Graphics (2008)

A typical data-driven visualization of electroencephalography (EEG) coherence is a graph layout, with vertices representing electrodes and edges representing significant coherences between electrode signals. A drawback of this layout is its visual clutter for multichannel EEG. To reduce clutter, we define a functional unit (FU) as a data-driven region of interest (ROI). An FU is a spatially connected set of electrodes recording pairwise significantly coherent signals, represented in the coherence graph by a spatially connected clique. Earlier we presented two methods to detect FUs, a maximal clique based (MCB) method and a more efficient watershed based (WB) method. To reduce the potential over-segmentation of the WB method, we introduce here an improved watershed based (IWB) method. The WB and IWB method both are up to a factor of 100,000 faster than the MCB method for a typical multichannel setting with 128 EEG channels, thus making interactive visualization of multichannel EEG coherence possible. We also introduce here two novel group maps for data-driven group analysis as extensions of the IWB method. Finally, we employ an extensive case study to evaluate the IWB FU map and the two new group maps for data-driven group analysis.
A (fairly) simple circuit that (usually) sorts
Authors: T. Leighton, C. G. Plaxton
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

A natural k-round tournament over n=2/sup k/ players is analyzed, and it is demonstrated that the tournament possesses a surprisingly strong ranking property. The ranking property of this tournament is exploited by being used as a building block for efficient parallel sorting algorithms under a variety of different models of computation. Three important applications are provided. First, a sorting circuit of depth 7.44 log n, which sorts all but a superpolynomially small fraction of the n-factorial possible input permutations, is defined. Secondly, a randomized sorting algorithm that runs in O(log n) word steps with very high probability is given for the hypercube and related parallel computers (the butterfly, cube-connected cycles, and shuffle-exchange). Thirdly, a randomized algorithm that runs in O(m+log n)-bit steps with very high probability is given for sorting n O(m)-bit records on an n log n-node butterfly.
Oracle database replay
Authors: Leonidas Galanis, Supiti Buranawatanachoke, Romain Colle, Benoît Dageville, Karl Dias, Jonathan Klein, Stratos Papadomanolakis, Leng Leng Tan, Venkateshwaran Venkataramani, Yujun Wang, Graham Wood
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

This paper presents Oracle Database Replay, a novel approach to testing changes to the relational database management system component of an information system (software upgrades, hardware changes etc). Database Replay makes it possible to subject a test system to a real production system workload, which helps identify all potential problems before implementing the planned changes on the production system. Any interesting workload period of a production database system can be captured with minimal overhead. The captured workload can be used to drive a test system while maintaining the concurrency and load characteristics of the real production workload. Therefore, the test results using database replay can provide very high assurance in determining the impact of changes to a production system before applying these changes. This paper presents the architecture of Database Replay as well as experimental results that demonstrate its usefulness as testing methodology.
The Worst Case Execution Time Tool Challenge 2006
Authors: Jan Gustafsson
Venue: Proceedings of the Second International Symposium on Leveraging Applications of Formal Methods, Verification and Validation (2006)

Worst Case Execution Time (WCET) analysis has a growing importance for real-time systems, to guarantee correct timing, and to be an aid in developing such systems. The WCET tools are currently making their way out to the market, and there are many research groups developing prototype tools using new and better ways of calculating estimates or bounds on the WCET. The purpose of the WCET Tool Challenge is to be able to study, compare and discuss the properties of different WCET tools and approaches, to define common metrics, and to enhance existing WCET benchmarks. The WCET Tool Challenge is designed to find a balance between openness for a wide range of analysis approaches, and specific participation guidelines to provide a level playing field. This should make results transparent and facilitate friendly competition among the participants. This report describes the participating tools as well as the results of the Challenge 2006. There is also an accompanying report by Lili Tan on the external tests of the tools. The WCET Tool Challenge is intended to be an annual event.
Expressive power and abstraction in Essence
Authors: David G. Mitchell, Eugenia Ternovska
Venue: Constraints (2008)

Development of languages for specifying or modelling problems is an important direction in constraint modelling. To provide greater abstraction and modelling convenience, these languages are becoming more syntactically rich, leading to a variety of questions about their expressive power. In this paper, we consider the expressiveness of Essence, a specification language with a rich variety of syntactic features. We identify natural fragments of Essence that capture the complexity classes P, NP, all levels $\Sigma_i^p$ of the polynomial-time hierarchy, and all levels k-NEXP of the nondeterministic exponential-time hierarchy. The union of these classes is the very large complexity class ELEMENTARY. One goal is to begin to understand which features play a role in the high expressive power of the language and which are purely features of convenience. We also discuss the formalization of arithmetic in Essence and related languages, a notion of capturing NP-search which is slightly different than that of capturing NP, and a conjectured limit to the expressive power of Essence. Our study is an application of descriptive complexity theory, and illustrates the value of taking a logic-based view of modelling and specification languages.
Peer-to-peer autonomic location based services
Authors: Peter Leong, Senthil Sukumar, Valencia Lee
Venue: Proceedings of the 4th international conference on mobile technology, applications, and systems and the 1st international symposium on Computer human interaction in mobile technology (2007)

In this paper, we describe a new approach towards creating location-based services with autonomic characteristics. Location based services is gaining acceptance in many applications that require the geographical context of the user. Examples of these include mobile advertisements, events announcements, news feeds, and information guides. Peer-to-peer systems are suited to dynamic mobile systems because the loose association between the mobile clients fits naturally with the P2P network; and additionally P2P architecture allows each service client machine to act also as a service provider. However, most present P2P systems had been designed with a fixed infrastructure rather than a wireless or mobile infrastructure. This paper proposes an intelligent location context-aware peer-to-peer multiagent system that could be used to address the dynamic requirements of a mobile infrastructure and hence provide reliable autonomic location-based services environment.
A sidelobes suppression technique for spectra discontinuous HF radar signal
Authors: Dongpo Zhang, Xingzhao Liu
Venue: Proceedings of the 2nd WSEAS International Conference on Electronics, Control and Signal Processing (2003)

Over-the-Horizon High Frequency (OTH-HF) radars operate in HF (High Frequency) band, it is quite difficult to find clear frequency band for radar system requirements in this band due to heavy interferences. To adopt discontinuous spectra waveform can mitigate the interferences influence, as a result it gives rise to high range sidelobes and thus a low signal dynamic range, this kind of sidelobes can not be suppressed by traditional spectral weighting. In this paper we introduce a new signal processing technique based on frequency extrapolation to lower the sidelobes associated with discontinuous spectra signals. Simulation results show significant range sidelobe reduction using this new algorithm.
Lessons Learned from Implementing WS-Coordination and WS-AtomicTransaction
Authors: Ivan Silva Neto, Francisco Reverbel
Venue: Proceedings of the Seventh IEEE/ACIS International Conference on Computer and Information Science (icis 2008) (2008)

This paper presents the design and implementation of a transaction service that complies with the WS-Coordination and WS-AtomicTransaction standards. Such service builds upon XActor, a distributed transaction manager that supports an open-ended set of transports, and enhances it with full support for atomic transactions over Web services. The paper summarizes the main lessons we learned from implementing those standards. It also identifies weaknesses in the WS-AtomicTransaction specification and presents advice for implementors of any systems based upon WS-Coordination.
FaCSim: a fast and cycle-accurate architecture simulator for embedded systems
Authors: Jaejin Lee, Junghyun Kim, Choonki Jang, Seungkyun Kim, Bernhard Egger, Kwangsub Kim, SangYong Han
Venue: Proceedings of the 2008 ACM SIGPLAN-SIGBED conference on Languages, compilers, and tools for embedded systems (2008)

There have been strong demands for a fast and cycle-accurate virtual platforms in the embedded systems area where developers can do meaningful software development including performance debugging in the context of the entire platform. In this paper, we describe the design and implementation of a fast and cycle-accurate architecture simulator called FaCSim as a first step towards such a virtual platform. FacSim accurately models the ARM9E-S processor core and ARM926EJ-S processor's memory subsystem. It accurately simulates exceptions and interrupts to enable whole-system simulation including the OS. Since it is implemented in a modular manner in C++, it can be easily extended with other system components by subclassing or adding new classes. FaCSim is based on an interpretive simulation technique to provide flexibility, yet achieving high speed. It enables fast cycle-accurate architecture simulation by means of three mechanisms. First, it computes elapsed cycles in each pipeline stage as a chunk and incrementally adds it up to advance the core clock instead of performing cycle-by-cycle simulation. Second, it uses a basic-block cache that caches decoded instructions at the basic-block level. Finally, it is parallelized to exploit multicore systems that are available everywhere these days. Using 21 applications from the EEMBC benchmark suite, FaCSim's accuracy is validated against the ARM926EJ-S development board from ARM, and is accurate in a ±7% error margin. Due to basic-block level caching and parallelization, FaCSim is, on average, more than three times faster than ARMulator and more than six times faster than SimpleScalar.
Biological Boundaries and Biological Age: Solutions of Variational Problems
Authors: Jacques Demongeot
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

If we consider the chronologic age of an organism, it is often unable to give useful information about its stage in the development or aging processes. Then we propose here to use a biological age essentially determined by the number of used mitoses before the Hayflick's limit for the tissues of the critical organs (in the sense where their loss causes the death of the whole organism) of a living being. We propose a definition of the biological age of an organ based on the Hayflick's limit and on a desynchronization index (the cell entropy) of its tissues.
Sample-based learning and search with permanent and transient memories
Authors: David Silver, Richard S. Sutton, Martin Müller
Venue: Proceedings of the 25th international conference on Machine learning (2008)

We present a reinforcement learning architecture, Dyna-2, that encompasses both sample-based learning and sample-based search, and that generalises across states during both learning and search. We apply Dyna-2 to high performance Computer Go. In this domain the most successful planning methods are based on sample-based search algorithms, such as UCT, in which states are treated individually, and the most successful learning methods are based on temporal-difference learning algorithms, such as Sarsa, in which linear function approximation is used. In both cases, an estimate of the value function is formed, but in the first case it is transient, computed and then discarded after each move, whereas in the second case it is more permanent, slowly accumulating over many moves and games. The idea of Dyna-2 is for the transient planning memory and the permanent learning memory to remain separate, but for both to be based on linear function approximation and both to be updated by Sarsa. To apply Dyna-2 to 9x9 Computer Go, we use a million binary features in the function approximator, based on templates matching small fragments of the board. Using only the transient memory, Dyna-2 performed at least as well as UCT. Using both memories combined, it significantly outperformed UCT. Our program based on Dyna-2 achieved a higher rating on the Computer Go Online Server than any handcrafted or traditional search based program.
A local greedy scheduling scheme with provable performance guarantee
Authors: Changhee Joo
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

In recent years, there have been many efforts to develop low-complexity scheduling schemes that can approximate optimal performance in multi-hop wireless networks. A centralized sub-optimal scheduling policy, called Greedy Maximal Scheduling (GMS) is a good candidate because it achieves high throughput. However, its distributed realization requires O(|V|) complexity, which becomes a major obstacle for practical implementation, where |V| is the number of nodes in the network. In this paper, we develop a simple distributed scheduling policy for multi-hop wireless networks. It achieves O(log |V|) complexity by relaxing the global ordering requirement of GMS. Instead, it deterministically schedules only links that have the largest queue length among their local neighbors. We show that, it still guarantees a fraction of the optimal performance, which is no smaller than GMS. We also further improve its performance and address some important implementation issues. The simulation results confirm that the new scheduling scheme achieves the performance equivalent of GMS and significantly outperforms state-of-the-art distributed random access scheduling policies.
The optimized bridge-leg power switch
Authors: K. H. Edelmoser, H. Ertl, F. C. Zach
Venue: Proceedings of the 9th International Conference on Circuits (2005)

Modern power electronic equipment (inverters, converters, switching mode amplifiers, etc.) mostly are based on switching technique realized by MOSFETs or IGBTs. The requirement of higher output signal quality, reduced size and weight as well as improved power density forces the design engineer to increase the switching frequency into the range of up to several hundred kilohertz, which only can be realized using optimized MOSFET topologies. Nevertheless, all these solutions deal with the disadvantage of the 'weak' body diode of these components. To overcome this drawback, several solutions have been presented in the past. In this paper a novel method is presented which helps to avoid the known disadvantages of the body diode (reverse recovery current, recovery time). The application of an external switching diode (e.g. based on SiC-technology) permits switching frequency increased by a factor of more than two without additional losses.
Automatic variable order selection for polynomial system solving (abstract only)
Authors: John P. May, Mark Giesbrecht, Daniel Roche, Marc Moreno Maza, Yuzhen Xie
Venue: ACM Communications in Computer Algebra (2008)

The goal of a general purpose solver is to allow a user to compute the solutions of a system of equations with minimal interactions. Modern tools for polynomial system solving, namely triangular decomposition and Groebner basis computation, can be highly sensitive to the ordering of the variables. Our goal is to examine the structure of a given system and use it to compute a variable ordering that will cause the solving algorithm to complete quickly (or alternately, to give compact output). We explore methods based on the dependency graph of coincident variables and terms between the equations. Desirable orderings are gleaned from connected components and other topological properties of these graphs, under different weighting schemes. We present experimental results suggesting that these methods work well in practice.
Confidence intervals for marginal parameters under fractional linear regression imputation for missing data
Authors: Yongsong Qin, J. N. K. Rao, Qunshu Ren
Venue: Journal of Multivariate Analysis (2008)

Item nonresponse occurs frequently in sample surveys and other applications. Imputation is commonly used to fill in the missing item values in a random sample {Y"i;i=1,...,n}. Fractional linear regression imputation, based on the model Y"i=X"i^'@b+@n"0(X"i)@e"i with independent zero mean errors @e"i, is used to create one or more imputed values in the data file for each missing item Y"i, where {X"i,i=1,...,n}, is observed completely. Asymptotic normality of the imputed estimators of the mean @m=E(Y), distribution function @q=F(y) for a given y, and qth quantile @q"q=F^-^1(q),0
Instance weighting versus threshold adjusting for cost-sensitive classification
Authors: Huimin Zhao
Venue: Knowledge and Information Systems (2008)

In real-world classification problems, different types of misclassification errors often have asymmetric costs, thus demanding cost-sensitive learning methods that attempt to minimize average misclassification cost rather than plain error rate. Instance weighting and post hoc threshold adjusting are two major approaches to cost-sensitive classifier learning. This paper compares the effects of these two approaches on several standard, off-the-shelf classification methods. The comparison indicates that the two approaches lead to similar results for some classification methods, such as Na&#x00ef;ve Bayes, logistic regression, and backpropagation neural network, but very different results for other methods, such as decision tree, decision table, and decision rule learners. The findings from this research have important implications on the selection of the cost-sensitive classifier learning approach as well as on the interpretation of a recently published finding about the relative performance of Na&#x00ef;ve Bayes and decision trees.
LINQ for Visual C# 2005
Authors: Fabio Claudio Ferracchiati
Venue:  (2007)

C# programmers of every level need to learn about LINQ (Language-Integrated Query), Microsofts breakthrough technology for simplifying and unifying data access from any data source. With LINQ you can write more elegant and flexible code, not just to access databases and files, but also to manipulate data structures and XML. LINQ for Visual C# 2005 is a short yet comprehensive guide to the major features of LINQ. It thoroughly covers LINQ to Objects, LINQ to SQL, LINQ to DataSet, and LINQ to XML. It also details significant enhancements to the next versions of C#, .NET, and ADO.NET. The book also includes plenty of working examples to demonstrate LINQ in action. There is no better source than this book for getting a head start on the future of these technologies.
Mesh representation of simply connected 3D objects visualization of melting phenomena
Authors: Dominik Szajerman
Venue: Machine Graphics Vision International Journal (2006)

This paper discusses some aspects of the physics approach to simulation of the melting phenomena: energy distribution in a volumetric model, substance vaporization and their relation to geometric properties of a model. A new simulation method for melting objects is presented. The method consists in mesh deformations which allow simulation of melting phenomena with preservation of visual effects similar to those achieved in the volumetric approach. Moreover, a few examples of melted models are included to show visual effects achievable with the help of the method. Meshes used with the method should be simply connected sets. This means there are no holes in them, and that they constitute a single object through the whole simulation process. Furthermore, a new method for determining whether a point is situated inside a given polygon is shown.
Implementing Influence Analysis Using Parameterised Boolean Equation Systems
Authors: María del Mar Gallardo, Christophe Joubert, Pedro Merino
Venue: Proceedings of the Second International Symposium on Leveraging Applications of Formal Methods, Verification and Validation (2006)

The well-known problem of state space explosion in model checking is even more critical when applying this technique to programming languages, mainly due to the presence of complex data structures. One recent and promising approach to deal with this problem is the construction of an abstract and correct representation of the global program state allowing to match visited states during program model exploration. In particular, one powerful method to implement abstract matching is to fill the state vector with a minimal amount of relevant variables for each program point. In this paper, we combine the on-the-fly model checking approach (incremental construction of the program state space) and the static analysis method called influence analysis (extraction of significant variables for each program point) in order to automatically construct an abstract matching function. Firstly, we describe the problem as an alternation-free value-based µ-calculus formula, whose validity can be checked on the program model expressed as a labeled transition system (LTS). Secondly, we translate the analysis into the local resolution of a parameterised boolean equation system (P BES), whose representation enables a more efficient construction of the resulting abstract matching function Finally, we show how our proposal has been elegantly integrated into C ADP, a generic framework for both the design and analysis of distributed systems and the development of verification tools.
A newbie's guide to eclipse APIs
Authors: Reid Holmes, Robert J. Walker
Venue: Proceedings of the 2008 international working conference on Mining software repositories (2008)

Eclipse has evolved from a fledgling Java IDE into a mature software ecosystem. One of the greatest benefits Eclipse provides developers is flexibility; however, this is not without cost. New Eclipse developers often find the framework to be large and confusing. Determining which parts of the framework they should be using can be a difficult task as Eclipse documentation tends to be either very high-level, focusing on the design of the framework, or low-level, focusing on specific APIs. We have developed a tool called PopCon that provides a bridge between high-level design documentation and low-level API documentation by statically analyzing a framework and several of its clients and providing a ranked list of the relative popularity of its APIs. We have applied PopCon to the Eclipse framework for this challenge to help newbie Eclipse developers identify some of the most relevant APIs for their tasks.