ppxscal/embedding_network huggingface dataset:
Spike train statistics and dynamics with synaptic input from any renewal process: A population density approach
Authors: Cheng Ly, Daniel Tranchina
Venue: Neural Computation (2009)

In the probability density function (PDF) approach to neural network modeling, a common simplifying assumption is that the arrival times of elementary postsynaptic events are governed by a Poisson process. This assumption ignores temporal correlations in the input that sometimes have important physiological consequences. We extend PDF methods to models with synaptic event times governed by any modulated renewal process. We focus on the integrate-and-fire neuron with instantaneous synaptic kinetics and a random elementary excitatory postsynaptic potential (EPSP), A. Between presynaptic events, the membrane voltage, v, decays exponentially toward rest, while s, the time since the last synaptic input event, evolves with unit velocity. When a synaptic event arrives, v jumps by A, and s is reset to zero. If v crosses the threshold voltage, an action potential occurs, and v is reset to vreset. The probability per unit time of a synaptic event at time t, given the elapsed time s since the last event, h(s, t), depends on specifics of the renewal process. We study how regularity of the train of synaptic input events affects output spike rate, PDF and coefficient of variation (CV) of the interspike interval, and the autocorrelation function of the output spike train. In the limit of a deterministic, clocklike train of input events, the PDF of the interspike interval converges to a sum of delta functions, with coefficients determined by the PDF for A. The limiting autocorrelation function of the output spike train is a sum of delta functions whose coefficients fall under a damped oscillatory envelope. When the EPSP CV, σA/μA, is equal to 0.45, a CV for the intersynaptic event interval, σT/μT = 0.35, is functionally equivalent to a deterministic periodic train of synaptic input events (CV = 0) with respect to spike statistics. We discuss the relevance to neural network simulations.
Effective performance measurement and analysis of multithreaded applications
Authors: Nathan R. Tallent, John M. Mellor-Crummey
Venue: Proceedings of the 14th ACM SIGPLAN symposium on Principles and practice of parallel programming (2009)

Understanding why the performance of a multithreaded program does not improve linearly with the number of cores in a shared-memory node populated with one or more multicore processors is a problem of growing practical importance. This paper makes three contributions to performance analysis of multithreaded programs. First, we describe how to measure and attribute parallel idleness, namely, where threads are stalled and unable to work. This technique applies broadly to programming models ranging from explicit threading (e.g., Pthreads) to higher-level models such as Cilk and OpenMP. Second, we describe how to measure and attribute parallel overhead -- when a thread is performing miscellaneous work other than executing the user's computation. By employing a combination of compiler support and post-mortem analysis, we incur no measurement cost beyond normal profiling to glean this information. Using idleness and overhead metrics enables one to pinpoint areas of an application where concurrency should be increased (to reduce idleness), decreased (to reduce overhead), or where the present parallelization is hopeless (where idleness and overhead are both high). Third, we describe how to measure and attribute arbitrary performance metrics for high-level multithreaded programming models, such as Cilk. This requires bridging the gap between the expression of logical concurrency in programs and its realization at run-time as it is adaptively partitioned and scheduled onto a pool of threads. We have prototyped these ideas in the context of Rice University's HPCToolkit performance tools. We describe our approach, implementation, and experiences applying this approach to measure and attribute work, idleness, and overhead in executions of Cilk programs.
A technique for operational IT risk management in Latvian monetary and financial institutions
Authors: Andrejs Romanovs, Yuri Merkuryev, Ruslan Klimov, Irina Solovjova
Venue: Proceedings of the 8th conference on Applied computer scince (2008)

The existing operational risk management systems do not always adequately recognize risks connected with informational system application. Conducted analyse of Latvian monetary and financial institutions points on the inadequate level of IT risk management within operational risks management system. Thus, this research considers the problem of IT risks as operational risks subgroup, for which management, IT governance standards and practices should be used. Finally, the paper presents the technique for operational IT risks management system development for use within Latvian monetary and financial institutions.
Scott Kelby's Digital Photography Boxed Set, Volumes 1 and 2, 1 edition
Authors: Scott Kelby
Venue:  (2008)

With over 400 of the most closely guarded photographic tricks of the trade, this boxed setconsisting of The Digital Photography Book, volume 1 and The Digital Photography Book, volume 2is the ultimate resource for anyone who wants to shoot dramatically better-looking, sharper, more colorful, more professional-looking photos every time.Scott Kelby, the man who changed the digital darkroom forever with his ground-breaking, bestselling The Photoshop Book for Digital Photographers, now tackles the most important side of digital photographyhow to take professional-quality shots using the same tricks todays top digital pros use (and its easier than you think).These arent books of theory, full of confusing jargon and detailed concepts. These are books on which button to push, which setting to use, and when to use it. Each page covers a single concept on how to make your photography better. Every time you turn the page, youll learn another pro setting, tool, or trick to transform your work from snapshots into gallery prints. If youre tired of shots that look okay, and if youre tired of looking in photography magazines and thinking, Why dont my shots look like that? then these are the books for you.
Improving the responsiveness of internet services with automatic cache placement
Authors: Alexander Rasmussen, Emre Kiciman, Benjamin Livshits, Madanlal Musuvathi
Venue: Proceedings of the 4th ACM European conference on Computer systems (2009)

The backends of today's Internet services rely heavily on caching at various layers both to provide faster service to common requests and to reduce load on back-end components. Cache placement is especially challenging given the diversity of workloads handled by widely deployed Internet services. This paper presents TOOL, an analysis technique that automatically optimizes cache placement. Our experiments have shown that near-optimal cache placements vary significantly based on input distribution.
Looking for Great Ideas: Analyzing the Innovation Jam
Authors: Wojciech Gryc, Mary Helander, Rick Lawrence, Yan Liu, Claudia Perlich, Chandan Reddy, Saharon Rosset
Venue: Advances in Web Mining and Web Usage Analysis: 9th International Workshop on Knowledge Discovery on the Web, WebKDD 2007, and 1st International Workshop on Social Networks Analysis, SNA-KDD 2007, San Jose, CA, USA, August 12-15, 2007. Revised Papers (2009)

In 2006, IBM hosted the Innovation Jam with the objective of identifying innovative and promising "Big Ideas" through a moderated on-line discussion among IBM worldwide employees and external contributors. We describe the data available and investigate several analytical approaches to address the challenge of understanding "how innovation happens". Specifically, we examine whether it is possible to identify characteristics of such discussions that are more likely to lead to innovative ideas as identified by the Jam organizers. We demonstrate the social network structure of data and its time dependence, and discuss the results of both supervised and unsupervised learning applied to this data.
Decoupling capacitance allocation for timing with statistical noise model and timing analysis
Authors: Takashi Enami, Masanori Hashimoto, Takashi Sato
Venue: Proceedings of the 2008 IEEE/ACM International Conference on Computer-Aided Design (2008)

This paper presents an allocation method of decoupling capacitance that explicitly considers timing. We have found and focused that decap does not necessarily improve a gate delay at all the switching timing within a cycle, and devised an efficient sensitivity calculation of timing to decap for decap allocation. The proposed method, which is based on a statistical noise modeling and timing analysis, accelerates the sensitivity calculation with an approximation and adjoint sensitivity analysis. Experimental results show that the decap allocation based on the sensitivity analysis efficiently optimizes the worst-case circuit delay within a given decap budget. Compared to the maximum decap placement, the delay improvement due to decap increases by 5% even while the total amount of decap is reduced to 40%.
A topological order for a rectangular three dimensional bin packing problem
Authors: Marinescu Daniela, Iacob Paul, Baicoianu Alexandra
Venue: Proceedings of the 12th WSEAS international conference on Computers (2008)

This paper extends the previous work [9] regarding the two dimensional covering problem to a rectangular three dimensional bin packing problem, where a bin is packed with a set of rectangular boxes, without gaps or overlapping. Our objective is to determine an order of the loading the boxes in the bin so that a box is packed in the bin only if there are no empty spaces down to this box and the origin of the box is in a fixed position. We define a graph representation, similarly with [10, 11], of the packing model so that to obtain an acyclic graph. Starting from this graph it is possible to obtain a topological order of the boxes. At the end we present a kind of topological sorting algorithm for this problem, of linear complexity.
Secret Sharing and Non-Shannon Information Inequalities
Authors: Amos Beimel, Ilan Orlov
Venue: Proceedings of the 6th Theory of Cryptography Conference on Theory of Cryptography (2009)

The known secret-sharing schemes for most access structures are not efficient; even for a one-bit secret the length of the shares in the schemes is 2 O(n), where n is the number of participants in the access structure. It is a long standing open problem to improve these schemes or prove that they cannot be improved. The best known lower bound is by Csirmaz (J. Cryptology 97), who proved that there exist access structures with n participants such that the size of the share of at least one party is n/logn times the secret size. Csirmaz's proof uses Shannon information inequalities, which were the only information inequalities known when Csirmaz published his result. On the negative side, Csirmaz proved that by only using Shannon information inequalities one cannot prove a lower bound of ¿(n) on the share size. In the last decade, a sequence of non-Shannon information inequalities were discovered. This raises the hope that these inequalities can help in improving the lower bounds beyond n. However, in this paper we show that all the inequalities known to date cannot prove a lower bound of ¿(n) on the share size.
On the modelling and controller design for the outpouring phase of the pouring process
Authors: M. P. Tzamtzi, F. N. Koumboulis, M. G. Skarpetis
Venue: WSEAS Transactions on Systems and Control (2009)

The present work contributes towards modeling and control of the outpouring phase of a pouring process, where the liquid container is carried by a robotic manipulator. The dynamics of the liquid motion are approximated by the well-known pendulum-type model, where the length and the mass of the pendulum vary with time due to liquid outpouring. The dynamics of the liquid transfer structure, including the carrying manipulator, the container and the liquid, are approximated by the dynamics of a robotic structure that incorporates virtual prismatic joints and corresponding weightless links to represent variations of the liquid level and corresponding variations of the pendulum length within the tank. The performance of a two stage control design scheme on the control of liquid outpouring and the suppression of liquid sloshing during the outpouring phase of the pouring process is studied for the derived model using simulation results. The designed scheme combines a partial inverse dynamics controller with a PID controller, tuned with the use of a "metaheuristic" search algorithm. Both controllers have been designed for a nominal model, ignoring the loss of liquid's mass due to outpouring.
Bridging digital divide: role of telecommunication sector
Authors: Muhammed Azam
Venue: Proceedings of the 2nd International Conference on Theory and Practice of Electronic Governance (2008)

Information and Communication Technology (ICT) enables socio-economic development in numerous countries. ICT revolution is swiftly spreading across boundaries. However, the vast majority of the world still seems to remain oblivious to connectivity and its vital role towards helping in providing faster economic progress. Still today, developing countries regard this field of technology as too expensive to expand. Therefore, we are compelled to believe that a more affordable solution is needed. ICT is relatively less expensive technology and so would solve many of the problems of the poor regions; especially in rural villages. Its expansion may have far-reaching effects on reducing poverty and Bridging the Digital Divide, like cell phones which creates a way through to bring an end to this technological gap. The aim of this paper is to explore the role of the telecommunication sector for bridging the so-called digital divide.
SAP CRM Middleware Optimization Guide, 1st edition
Authors: Juliane Bode, Stephan Golze, Thomas Schrder
Venue:  (2008)

Now you can proactively avoid administration problems with CRM Middleware - whether they be performance losses or even complete system freezes - using this comprehensive book, based on the extensive experience of SAP Active Global Support. You'll learn the basics of data processing in the Middleware (input processing, validation, output processing) and get concrete troubleshooting advice. Plus, uncover a vast array of optimization options for all critical parts of the Middleware, as well as practical instruction on how to avoid system freezes and on how to handle those freezes once they've occurred. Based on CRM Release 5.0, this book is also highly useful for those still working with the older Release 4.0. In addition, wherever possible, the authors also provide you with sneak previews of the upcoming release 6.0 as well. Highlights Input processing and validation Output processing BDoc modelling and storage Groupware integration Exchanging your own data Replication & Realignment XML Reorganizing the Middleware Mass changes Roadmaps for analyzing the Middleware
Evaluation of memory performance on the cell BE with the SARC programming model
Authors: Roger Ferrer, Marc González, Federico Silla, Xavier Martorell, Eduard Ayguadé
Venue: Proceedings of the 9th workshop on MEmory performance: DEaling with Applications, systems and architecture (2008)

With the advent of multicore architectures, especially with the heterogeneous ones, both computational and memory top performance are difficult to obtain using traditional programming models. Usually, programmers have to fully reorganize the code and data of their applications in order to maximize resource usage, and work with the low-level interfaces offered by the vendor-provided SDKs, to obtain high computational and memory performances. In this paper, we present the evaluation of the SARC programming model on the Cell BE architecture, with respect to memory performance. We show how we have annotated the HPL STREAM and RandomAccess applications, and the memory bandwidth obtained. Results indicate that the programming model provides good productivity and competitive performance on this kind of architectures.
Illuminac: simultaneous naming and configuration for workspace lighting control
Authors: Ana Ramírez Chang, John Canny
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2009)

We explore natural and calm interfaces for configuring ubiquitous computing environments. A natural interface should enable the user to name a desired configuration and have the system enact that configuration. Users should be able to use familiar names for configurations without learning, which implies the mapping from names to configurations is many-to-one. Instead of users learning the environment's command language, the system simultaneously learns common configurations and infers the keywords that are most salient to them. We call this the SNAC problem (Simultaneous Naming and Configuration). As a case study, we design a speech interface for workspace lighting control on a large array of individually-controllable lights. We present an approach to the SNAC problem and demonstrate its applicability through an evaluation of our system, Illuminac.
Experiences with Handheld Augmented Reality
Authors: Dieter Schmalstieg, Daniel Wagner
Venue: Proceedings of the 2007 6th IEEE and ACM International Symposium on Mixed and Augmented Reality (2007)

In this paper, we present Studierstube ES, a framework for the development of handheld Augmented Reality. The applications run self-contained on handheld computers and smartphones with Windows CE. A detailed description of the performance critical tracking and rendering components are given. We also report on the implementation of a client-server architecture for multi-user applications, and a game engine for location based museum games that has been built on top of this infrastructure. Details on two games that were created, permanently deployed and evaluated in two Austrian museums illustrate the practical value of the framework and lessons learned from using it.
Gaussian proposal density using moment matching in SMC methods
Authors: S. Saha, P. K. Mandal, Y. Boers, H. Driessen, A. Bagchi
Venue: Statistics and Computing (2009)

In this article we introduce a new Gaussian proposal distribution to be used in conjunction with the sequential Monte Carlo (SMC) method for solving non-linear filtering problems. The proposal, in line with the recent trend, incorporates the current observation. The introduced proposal is characterized by the exact moments obtained from the dynamical system. This is in contrast with recent works where the moments are approximated either numerically or by linearizing the observation model. We show further that the newly introduced proposal performs better than other similar proposal functions which also incorporate both state and observations.
UWB-based sensor networks for localization in mining environments
Authors: Abdellah Chehri, Paul Fortier, Pierre Martin Tardif
Venue: Ad Hoc Networks (2009)

Wireless sensor networks (WSN) have attached a great attention in the last few years. WSN offer several advantages over the traditional sensor networks, such as elimination of costly wires, security and larger area coverage. In the last few years, there has been great interest commercial applications based on Ultra Wideband (UWB). It has potentially low complexity, low cost and an excellent time domain resolution which facilitates location and tracking applications. Therefore, UWB provide a good combination of high performance with low complexity for WSN applications. Localization has attracted considerable attention in many fields. Accurate estimation of an individual location can be a difficult task, producing ambiguous results particularly in harsh environment. In this paper, we focus on feasibility study (via simulation and measurements) of using UWB based-WNS as future solution for localization in underground mines.
Letters: On the bias of batch Bellman residual minimisation
Authors: Daniel Schneegass
Venue: Neurocomputing (2009)

This letter addresses the problem of Bellman residual minimisation in reinforcement learning for the model-free batch case. We prove the simple, but not necessarily obvious result, that no unbiased estimate of the Bellman residual exists for a single trajectory of observations. We further pick up the recent suggestion of Antos et al. [Learning near-optimal policies with Bellman-residual minimisation based fitted policy iteration and a single sample path, in: COLT, 2006, pp. 574-588] for approximative Bellman residual minimisation and discuss its properties concerning consistency, biasedness, and optimality. We finally give a suggestion to improve the optimality.
Classification and evaluation of timed running schemas for workflow based on process mining
Authors: Hua Duan, Qingtian Zeng, Huaiqing Wang, Sherry X. Sun, Dongming Xu
Venue: Journal of Systems and Software (2009)

The system running logs of a workflow contain much information about the behavior and logical structure between activities. In this paper, a mining approach is proposed to discover the structural and temporal model for a workflow from its timed running logs. The mining results are represented in the formalized form of Petri nets extended with two timing factors that allows validation or verification the actual behaviors, especially the temporal constraints between activities. According to the reachability graph of the extended Petri net model mined, all running schemas of a workflow can be generated, which defines the temporal constraints between running activities. By calculating the earliest and latest start time of each activity, the earliest starting and latest existing time of each state in the running schema can be determined. Based on the temporal relations between the timing factors of each running state, the running schemas can be classified into six classes. The effects of the six classes of running schemas on the implementation of the whole workflow are evaluated so as to obtain the best one that can ensure the workflow is finished in the shortest time. The standards for the ideal, reliable and favorable running schemas and their existence conditions are discussed, which can be used to evaluate the running logs and control the future running of a workflow.
For a science of group interaction
Authors: Gerry Stahl
Venue: Proceedings of the ACM 2009 international conference on Supporting group work (2009)

As a foundation for the design of groupware, we need a new science of group interaction, a systematic description of the processes at the group level of description that may contribute to problem solving, knowledge building and other cognitive tasks undertaken by small groups collaborating synchronously over networked computers. A scientific investigation of the knowledge-building interactions of online teams involves explorations along multiple dimensions: (a) designing a testbed to support interaction within teams, (b) analyzing how interaction takes place within this setting and (c) describing how the teams achieve their tasks. This paper discusses how a current CSCL project designed a groupware environment in which this could take place and be studied; it reviews how the project approached the rigorous study of what took place there; and it reflects on the nature of group interaction as an object for a new science.