ppxscal/embedding_network huggingface dataset:
On the positivity step size threshold of Runge-Kutta methods
Authors: Zoltán Horváth
Venue: Applied Numerical Mathematics (2005)

In the first part of this paper we determine the largest step size of Runge-Kutta (RK) methods for which the corresponding numerical approximations are positive (component-wise non-negative) for arbitrary positive initial vector, whenever the underlying initial value problem (IVP) possesses the related positivity preserving property. We prove that step size thresholds for certain classes of positive IVPs guaranteeing positivity that we derived in a former paper are strict for irreducible and non-confluent RK methods. Investigating the strict positivity step size thresholds we can see that these are rather small if at all positive: often they are, roughly speaking, inverse proportional to the Lipschitz constant of the problem.However, for certain (stiff) IVPs with some particular initial vectors, e.g., for some "smooth" vectors in semi-discretized diffusion problems, we experience preservation of positivity with much larger step sizes than the strict positivity step size threshold. To catch this phenomenon, in the second part of the paper we construct positively invariant sets of positive vectors and derive step size thresholds for the discrete version of the positive invariance. The resulting threshold for discrete positive invariance is, roughly speaking, inverse proportional to the one-sided Lipschitz constant only and is shown in good accordance with some displayed computational experiments.
Performance analysis of mobile agents tracking
Authors: Elena Gómez-Martínez, Sergio Ilarri, José Merseguer
Venue: Proceedings of the 6th international workshop on Software and performance (2007)

Mobile agents have arisen as an interesting paradigm to build distributed applications, due to the unparalleled advantages they offer. However, along with the advantages they also present new challenges. One of the most relevant is that it is not easy to ensure efficient communication among agents that move continually from one computer to another.In this paper, we apply SPE techniques to model and analyze, how a mobile agent tracking approach addresses the highly dynamic movement problem in a distributed computing environment.
Formal change impact analyses for emulated control software
Authors: C. J. Fidge
Venue: International Journal on Software Tools for Technology Transfer (STTT) (2006)

Processor emulators are a software tool for allowing legacy computer programs to be executed on a modern processor. In the past emulators have been used in trivial applications such as maintenance of video games. Now, however, processor emulation is being applied to safety-critical control systems, including military avionics. These applications demand utmost guarantees of correctness, but no verification techniques exist for proving that an emulated system preserves the original system&#x2019;s functional and timing properties. Here we show how this can be done by combining concepts previously used for reasoning about real-time program compilation, coupled with an understanding of the new and old software architectures. In particular, we show how both the old and new systems can be given a common semantics, thus allowing their behaviours to be compared directly.
A comparison of sample-path-based simulation-optimization and stochastic decomposition for multi-location transshipment problems
Authors: Lei Zhao, Suvrajeet Sen
Venue: Proceedings of the 38th conference on Winter simulation (2006)

Because of its applicability, as well as its generality, research in the area of simulation-optimization continues to attract significant attention. These methods, most of which rely on the statistically motivated search techniques, are at their best when very little is known about the structure of the function (e.g., function evaluations are treated as "blackbox" function-calls). In some applications such as the one discussed in this paper, objective function values may be obtained through linear/network flow optimization models. In such cases, the objective function may be convex, and in such circumstances, very large instances can be solved using stochastic programming techniques. This paper presents a computational case for using such techniques, whenever applicable.
Business Case for Network Security: Advocacy, Governance, and ROI, The (Network Business)
Authors: Catherine Paquet, Warren Saxe
Venue:  (2004)

Understand the total cost of ownership and return on investment for network security solutions Understand what motivates hackers and how to classify threats Learn how to recognize common vulnerabilities and common types of attacks Examine modern day security systems, devices, and mitigation techniques Integrate policies and personnel with security equipment to effectively lessen security risks Analyze the greater implications of security breaches facing corporations and executives today Understand the governance aspects of network security to help implement a climate of change throughout your organization Learn how to qualify your organization's aversion to risk Quantify the hard costs of attacks versus the cost of security technology investment to determine ROI Learn the essential elements of security policy development and how to continually assess security needs and vulnerabilitiesThe Business Case for Network Security: Advocacy, Governance, and ROI addresses the needs of networking professionals and business executives who seek to assess their organization's risks and objectively quantify both costs and cost savings related to network security technology investments. This book covers the latest topics in network attacks and security. It includes a detailed security-minded examination of return on investment (ROI) and associated financial methodologies that yield both objective and subjective data. The book also introduces and explores the concept of return on prevention (ROP) and discusses the greater implications currently facing corporations, including governance and the fundamental importance of security, for senior executives and the board.Making technical issues accessible, this book presents an overview of security technologies that uses a holistic and objective model to quantify issues such as ROI, total cost of ownership (TCO), and risk tolerance. This book explores capital expenditures and fixed and variable costs, such as maintenance and upgrades, to determine a realistic TCO figure, which in turn is used as the foundation in calculating ROI. The importance of security policies addressing such issues as Internet usage, remote-access usage, and incident reporting is also discussed, acknowledging that the most comprehensive security equipment will not protect an organization if it is poorly configured, implemented, or used. Quick reference sheets and worksheets, included in the appendixes, provide technology reviews and allow financial modeling exercises to be performed easily.An essential IT security-investing tool written from a business management perspective, The Business Case for Network Security: Advocacy, Governance, and ROI helps you determine the effective ROP for your business.This volume is in the Network Business Series offered by Cisco Press®. Books in this series provide IT executives, decision makers, and networking professionals with pertinent information about today's most important technologies and business strategies.
Using diversity of errors for selecting members of a committee classifier
Authors: Matti Aksela, Jorma Laaksonen
Venue: Pattern Recognition (2006)

Diversity of classifiers is generally accepted as being necessary for combining them in a committee. Quantifying diversity of classifiers, however, is difficult as there is no formal definition thereof. Numerous measures have been proposed in literature, but their performance is often know to be suboptimal. Here several common methods are compared with a novel approach focusing on the diversity of the errors made by the member classifiers. Experiments with combining classifiers for handwritten character recognition are presented. The results show that the approach of diversity of errors is beneficial, and that the novel exponential error count measure is capable of consistently finding an effective member classifier set.
Utilization of nonclairvoyant online schedules
Authors: Mohamed Eid Hussein, Uwe Schwiegelshohn
Venue: Theoretical Computer Science (2006)

This paper addresses the analysis of nondelay, nonpreemptive, nonclairvoyant online schedules for independent jobs on m identical machines. In our online model, all jobs are submitted over time. We show that the commonly used makespan criterion is not well suited to describe utilization for this online problem. Therefore, we directly address utilization and determine the maximum deviation from the optimal utilization for the given scheduling problem.
Write Great Code, Volume 2: Thinking Low-Level, Writing High-Level
Authors: Randall Hyde
Venue:  (2006)

The second volume in the Write Great Code series supplies the critical information that today's computer science students don't often get from college and university courses: How to carefully choose their high-level language statements to produce efficient code. Write Great Code, Volume 2: Thinking Low-Level, Writing High-Level, teaches software engineers how compilers translate high-level language statements and data structures into machine code. Armed with this knowledge, a software engineer can make an informed choice concerning the use of those high-level structures to help the compiler produce far better machine code--all without having to give up the productivity and portability benefits of using a high-level language.
Solving the starting problem: device drivers as self-describing artifacts
Authors: Michael F. Spear, Tom Roeder, Orion Hodson, Galen C. Hunt, Steven Levi
Venue: Proceedings of the 1st ACM SIGOPS/EuroSys European Conference on Computer Systems 2006 (2006)

Run-time conflicts can affect even the most rigorously tested software systems. A reliance on execution-based testing makes it prohibitively costly to test every possible interaction among potentially thousands of programs with complex configurations. In order to reduce configuration problems, detect developer errors, and reduce developer effort, we have created a new first class operating system abstraction, the application abstraction, which enables both online and offline reasoning about programs and their configuration requirements.We have implemented a subset of the application abstraction for device drivers in the Singularity operating system. Programmers use the application abstraction by placing declarative statements about hardware and communication requirements within their code. Our design enables Singularity to learn the input/output and interprocess communication requirements of drivers without executing driver code. By reasoning about this information within the domain of Singularity's strong software isolation architecture, the installer can execute a subset the system's resource management algorithm at install time to verify that a new driver will not conflict with existing software. This abstract representation also allows the system to run the full algorithm at driver start time to ensure that there are never resource conflicts between executing drivers, and that drivers never use undeclared resources.
Underlying issues associated with validation and verification of dynamic data driven simulation
Authors: John G. Michopoulos, Samuel G. Lambrakos
Venue: Proceedings of the 38th conference on Winter simulation (2006)

This paper presents a brief exposition of three underempha-sized issues concerning modeling and simulation as they relate to Dynamic Data Driven Application Systems. One issue concerns the fact that conventional procedures for validation of data-driven models and simulations are unnecessary as they intrinsically contain validation in that they have been constructed according to acquired data. Another issue concerns the inherent coupling between the experimental frame used to measure system response and the system itself. This coupling can lead to an unrealistic simulation of the system in that the data contains the interaction of the system with the experimental frame. The final issue concerns the inherent pluralism of parametric representation and of potential mappings from data space into model space. This inherent pluralism imposes the need for optimal model and data space navigation procedures that are structured for appropriate sampling of data space and specification of faithful model parameterizations.
Simulation assisted optimozation and real-time control aspects of flexible production systems subject to disturbances
Authors: Wilhelm Dangelmaier, Kiran R Mahajan, Thomas Seeger, Benjamin Klöpper, Mark Aufenanger
Venue: Proceedings of the 38th conference on Winter simulation (2006)

Several types of production systems have been studied and researched in the past using either simulation and\or optimization methods. In this paper we describe the design and development of a simulation assisted predictive-reactive system for scheduling and rescheduling a typical flexible production system configuration. Aspects like the combined use of simulation and optimization to solve complex scheduling and rescheduling tasks are described in view of system stability and some of the broader production system elements like buffer sizing and material handling equipment. Results show that combining simulation and optimization for predictive scheduling resulted in better and valid performance measures for a typical example. Results also show that some newly addressed aspects of stability and real-time control can be handled efficiently using a combination of simulation and optimization. Our discussions only bolster the claim that simulation is an indispensable tool in managing complex production systems.
A graph-based, multi-resolution algorithm for tracking objects in presence of occlusions
Authors: Donatello Conte, Pasquale Foggia, Jean-Michel Jolion, Mario Vento
Venue: Pattern Recognition (2006)

One of the main difficult problem in video analysis is to track moving objects during a video sequence, especially in presence of occlusions. Unfortunately, almost all the different approaches work on a pixel-by-pixel basis, yielding them unusable in real-time situations as well as not much expressive at a semantic level of the video. We present in this paper a novel method of tracking objects through occlusions that exploits the wealth of information due to the spatial coherence between pixels, using a graph-based, multi-resolution representation of the moving regions. The experimental results show that the approach is promising.
Challenges for modeling and simulation methods in systems biology
Authors: Herbert M. Sauro, David Harel, Marta Kwiatkowska, Clifford A. Shaffer, Adelinde M. Uhrmacher, Michael Hucka, Pedro Mendes, Lena Strömback, John J. Tyson
Venue: Proceedings of the 38th conference on Winter simulation (2006)

Systems Biology is aimed at analyzing the behavior and interrelationships of biological systems and is characterized by combining experimentation, theory, and computation. Dedicated to exploring current challenges, the panel brings together people from a variety of disciplines whose perspectives illuminate diverse facets of Systems Biology and the challenges for modeling and simulation methods.
Clustering in video data: Dealing with heterogeneous semantics of features
Authors: Gaurav Harit, Santanu Chaudhury
Venue: Pattern Recognition (2006)

Unsupervised clustering is an important tool to analyze video data. Selection of an appropriate clustering scheme is governed by the suitability of the clusters it produces. It is difficult to formulate cluster suitability criteria for a domain where different feature attributes have different meanings. We propose a novel clustering strategy, tailored towards the specific requirements of clustering in video data. Our clustering methodology decouples clustering along different feature components. Our scheme chooses the clustering model so as to meet the requirements of clustering in video data. The clusters obtained from our scheme reasonably model the homogeneous color regions in a video scene in both space and time. The space-time clusters obtained by our clustering methodology can be subsequently grouped together to compose meaningful objects. Experimental comparison of our results with existing clustering techniques clearly show that our scheme takes care of many of the problems with traditional clustering schemes applied to the heterogeneous feature space of video.
A prediction error-based hypothesis testing method for sensor data acquisition
Authors: Tarik Arici, Toygar Akgun, Yucel Altunbasak
Venue: ACM Transactions on Sensor Networks (TOSN) (2006)

We present a statistical method that uses prediction modeling to decrease the temporally redundant data transmitted back to the sink. The major novelties are fourfold: First, a prediction model is fit to the sensor data. Second, prediction error is utilized to adaptively update the model parameters using hypothesis testing. Third, a data transformation is proposed to bring the sensor sample series closer to weak stationarity. Finally, an efficient implementation is presented. We show that our proposed preDiction eRror bASed hypoThesis testInG (DRASTIG) method achieves low energy dissipation while keeping the prediction errors at user-defined tolerable magnitudes based on real data experiments.
Using IBM Lto Ultrium With Open Systems (Ibm Redbooks.)
Authors: Charlotte Brooks
Venue:  (2003)

How to set up Ultrium tape drives and libraries in multiple open environments Integration with popular backup applications New: LTO 2 drives and libraries This IBM Redbook follows on from The IBM Ultrium Tape Libraries Guide, SG24-5946, and will help you plan, install, and configure IBM Ultrium LTO tape drives and libraries in UNIX environments. It focuses on the setup and customization of these drives and libraries in both direct-attached SCSI and SAN configurations for the AIX, Solaris, and HP-UX operating systems. The first part of the book describes how to attach and configure the drives and libraries, and covers basic installation and administration. The second part documents how to use these products with popular data backup applications: IBM Tivoli Storage Manager, VERITAS NetBackup DataCenter, and Legato NetWorker. This redbook will help IBM personnel, Business Partners, and customers to better understand and implement the IBM Ultrium LTO product line in UNIX environments. We assume that the reader is familiar with tape drives and libraries and understands basic SAN concepts and technologies. The second edition of this book includes information on the second generation LTO products.
MCSE 70-294 Exam Prep: Planning, Implementing, and Maintaining a Microsoft Windows Server 2003 Active Directory Infrastructure (2nd Edition) (Exam Prep)
Authors: Donald Poulton
Venue:  (2006)

MCSE Planning, Implementing, and Maintaining a Microsoft® Windows Server™ 2003 Active Directory Infrastructureï¾ Exam 70-294Your Complete Certification Solution!The Smart Way to Study™In This Book You'll Learn How To: Understand the impact of the latest improvements in Windows Server™ 2003 on Active Directory, including Service Pack 1 (SP1) and Release 2 (R2) Plan an Active Directory infrastructure, including forests, trees, domains, organizational units (OUs), sites, global catalogs, and operations masters Install Active Directory domain controllers in forest roots, child domains, and additional domain controllers Plan and implement trust relationships within and between Active Directory forests, Windows NT 4.0 domains, and Kerberos realms Configure Active Directory sites, including site boundaries, links, link bridges, and replications Manage, monitor, maintain, and restore the Active Directory infrastructure Plan and implement user and group strategies, including security and distribution groups, organizational unit structures, and user authentication strategies Plan the application of Group Policy to users, computers, sites, domains, and organizational units Use Group Policy to configure the user and computer environment, including software distribution and upgrade, certificate enrollment, security settings, folder redirection, and many other available policy settings Use Resultant Set of Policy (RSoP) and other tools to manage and troubleshoot Group PolicyWRITTEN BY A LEADING 70-294 EXAM EXPERT!Don Poulton, MCSA, MCSE, A+, Network+, Security+, has been involved in consulting with small training providers as a technical writer, during which time he wrote training and exam prep materials for Windows NT 4.0, Windows 2000, and Windows XP. More recently, he has written or co-authored several certification volumes on Security+, Windows XP, and Windows Server 2003, published by Que Publishing.See Inside Back Cover for Exclusive Access to 70-294Practice Questions! Helps you identify your strengths and weaknesses, so you can assess your readiness to take the actual 70-294 exam Provides detailed explanations of correct and incorrect answers Features a variety of study modes, so you can work your way through the questions in the manner that best suits your study preferences Covers each 70-294 exam objectiveU.S. $59.99CAN. $74.99U.K. £42.99www.examcram.comISBN: 0-7897-3651-9
Similarities and differences of gene expression in yeast stress conditions
Authors: Oleg Rokhlenko, Ydo Wexler, Zohar Yakhini
Venue: Bioinformatics (2007)

Motivation and Methods: All living organisms and the survival of all cells critically depend on their ability to sense and quickly adapt to changes in the environment and to other stress conditions. We study stress response mechanisms in Saccharomyces cerevisiae by identifying genes that, according to very stringent criteria, have persistent co-expression under a variety of stress conditions. This is enabled through a fast clique search method applied to the intersection of several co-expression graphs calculated over the data of Gasch et al. This method exploits the topological characteristics of these graphs. Results: We observe cliques in the intersection graphs that are much larger than expected under a null model of changing gene identities for different stress conditions but maintaining the co-expression topology within each one. Persistent cliques are analyzed to identify enriched function as well as enriched regulation by a small number of TFs. These TFs, therefore, characterize a universal and persistent reaction to stress response. We further demonstrate that the vertices (genes) of many cliques in the intersection graphs are co-localized in the yeast genome, to a degree far beyond the random expectation. Co-localization can hypothetically contribute to a quick co-ordinated response. We propose the use of persistent cliques in further study of properties of co-regulation. Supplementary information: http://www.cs.technion.ac.il/~olegro/stress.html Contact: olegro@cs.technion.ac.il
SQLite (Developer's Library)
Authors: Chris Newman
Venue:  (2004)

SQLite is a small, fast, embeddable database. What makes it popular is the combination of the database engine and interface into a single library as well as the ability to store all the data in a single file. Its functionality lies between MySQL and PostgreSQL, however it is faster than both databases.In SQLite, author Chris Newman provides a thorough, practical guide to using, administering and programming this up-and-coming database. If you want to learn about SQLite or about its use in conjunction with PHP this is the book for you.