Computer Science Journal (AGH University of Science and Technology, Krakow)
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Portable Userspace Virtual Filesystem Switch
Get PDFMultiple different filesystems — including disk-based, network, distributed, abstract — arean integral part of every operating system. They are usually written as kernel modules and abstracted to the user via a virtual filesystem switch. In this paper we analyse the feasibility of reimplementing the virtual filesystem switch as a userspace daemon and applicability of this approach in real-life usage. Such reimplementation will require a way to virtualise processes behaviour related to filesystem operations. The problem is non-trivial, as we assume limited capabilities of the VFS switch implemented in userspace. We present a layered architecture comprising of a monitoring process, the VFS abstraction and real filesystem implementations. All working in userspace. Then, we evaluate this solution in four areas: portability, feasibility, usability and performance. Our results demonstrate possible gains in using the userspace-based approach with monolithic kernels, but also underline problems that are encountered in this approach
From Quantity To Quality: Massive Molecular Dynamics Simulation of Nanostructures under Plastic Deformation in Desktop and Service Grid Distributed Computing Infrastructure
Get PDFThe distributed computing infrastructure (DCI) on the basis of BOINC andEDGeS-bridge technologies for high-performance distributed computing is usedfor porting the sequential molecular dynamics (MD) application to its paral-lel version for DCI with Desktop Grids (DGs) and Service Grids (SGs). Theactual metrics of the working DG-SG DCI were measured, and the normal dis-tribution of host performances, and signs of log-normal distributions of othercharacteristics (CPUs, RAM, and HDD per host) were found. The practicalfeasibility and high efficiency of the MD simulations on the basis of DG-SG DCIwere demonstrated during the experiment with the massive MD simulations forthe large quantity of aluminum nanocrystals ( ∼ 102–103). Statistical analysis(Kolmogorov-Smirnov test, moment analysis, and bootstrapping analysis) ofthe defect density distribution over the ensemble of nanocrystals had shownthat change of plastic deformation mode is followed by the qualitative changeof defect density distribution type over ensemble of nanocrystals. Some limita-tions (fluctuating performance, unpredictable availability of resources, etc.) ofthe typical DG-SG DCI were outlined, and some advantages (high efficiency,high speedup, and low cost) were demonstrated. Deploying on DG DCI al-lows to get new scientific quality from the simulated quantity of numerousconfigurations by harnessing sufficient computational power to undertake MDsimulations in a wider range of physical parameters (configurations) in a muchshorter timeframe
JELLY VIEWS : EXTENDING RELATIONAL DATABASE SYSTEMS TOWARD DEDUCTIVE DATABASE SYSTEMS
Get PDFThis paper regards the Jelly View technology, which provides a new, practical methodology for knowledge decomposition, storage, and retrieval within Relational Database Management Systems (RDBMS). Intensional Knowledge clauses (rules) are decomposed and stored in the RDBMS founding reusable components. The results of the rule-based processing are visible as regular views, accessible through SQL. From the end-user point of view the processing capability becomes unlimited (arbitrarily complex queries can be constructed using Intensional Knowledge), while the most external queries are expressed with standard SQL. The RDBMS functionality becomes extended toward that of the Deductive Database
hp-HGS strategy for inverse AC/DC resistivity logging measurement simulations
Get PDFIn this paper we present resistivity logging measurement simulation with the usage of two types of borehole logging devices: operating with zero frequency (direct current, DC) and those operating with higher frequencies (alternate current, AC). We perform simulations of 3D resistivity measurements in deviated wells, with the sharp angle between the borehole and formation layers. We introduce hierarchical adaptive genetic strategy interfaced with adaptive finite element method. We apply the strategy for the solution of the inverse problem, where we identify the resistivities of the formation layers based on a given measurement. We test the strategy on both direct and accurate currect cases.
METHODS OF COGNITIVE ANALYSIS IN MEDICAL INFORMATION SYSTEMS OF DSS-TYPE
Get PDFThis paper demonstrates that AI methods, in particular linguistic mechanisms of semanticmeaning reasoning can be applied to the development of intelligent IT systems. They enablealso conducting an in-depth meaning analysis in the presented DDS information systems.This paper presents also IT mechanisms of object meaning description on selected examplesof spinal cord image analysis. The procedures for such semantic reasoning are based on themodel of cognitive resonance. They have been applied to the task of meaning interpretationof a selected type of central nervous system diagnostic images, as an intelligent analysismodule in IT systems. The application presented in this paper is of research character and itserves the preparation of efficient lesion detection methods applied to a dataset originatingfrom magnetic and resonance examinations of the spinal cord structures
THE EXTENSION OF TORQUE SCHEDULER ALLOWING THE USE OF PLANNING AND OPTIMIZATION IN GRIDS
Get PDFIn this work we present a major extension of the open source TORQUE Resource Manager system. We have replaced a naive scheduler provided in the TORQUE distribution with complex scheduling system that allows to plan job execution ahead and predict the behavior of the system. It is based on the application of job schedule, which represents the jobs’ execution plan. Such a functionality is very useful as the plan can be used by the users to see when and where their jobs will be executed. Moreover, created plans can be easily evaluated in order to identify possible inefficiencies. Then, repair actions can be taken immediately and the inefficiencies can be fixed, producing better schedules with respect to considered criteria
MOBILE SOCIAL NETWORKS FOR LIVE MEETINGS
Get PDFIn this article, we present an idea of combining social networking websites andmodern mobile devices abilities to transfer social networking activity to a higherlevel. Nowadays, these devices and websites are used to offer ability of remotecommunication (phone calls, message exchange etc.), which potentially can beused to notify people about meetings in the real world. Since the current socialnetwork models do not provide enough information for such notification (socialnetworking websites are examples of social networks) a new social network modelthat will be suitable for the above mentioned application is proposed and a newsocial platform that base on mobile devices is introduced. This platform cannotify users when their friends are nearby. The paper presents the model andthe simulation that verifies the approach
THE USE OF STANDARDS IN HELIO
Get PDFHELIO [8] is a project funded under the FP7 program for the discovery and analysis of data for heliophysics. During its development, standards and common frameworks were adopted in three main areas of the project: query services, processing services, and the security infrastructure. After a first, proprietary implementation of the security service, it was suggested moving it to a standard security framework to simplify the enforcement of security on the different sites. As the HELIO front end is built with Spring and the TAVERNA server (HELIO workflow engine) has a security framework compatible with Spring, it has been decided to move the CIS in Spring security [2]. HELIO has two different processing services: one is a generic processing service called HELIO Processing Services (HPS), the other is called Context Service (CTX) and it runs specific IDL procedures. The CTX implements the UWS [4] interface from the IVOA [5], a standard interface for job submission used in the helio and astro-physics community. In its final release, the HPS will expose an UWS compliant interface. Finally, some of the HELIO services perform queries, to simplify the implementation and usage of this services a single query interface (the HELIO Query Interface) has been designed for all these services. The use of these solutions for security, execution, and query allows for easier implementation of the original HELIO architecture and for a simpler deployment of the services
PRACTICAL EXPERIENCES WITH TORQUE META-SCHEDULING IN THE CZECH NATIONAL GRID
Get PDFThe Czech National Grid Infrastructure went through a complex transition inthe last year. The production environment has been switched from a commercialbatch system PBSPro, which was replaced by an open source alternative Torquebatch system.This paper concentrates on two aspects of this transition. First, we will presentour practical experience with Torque being used as a production ready batchsystem. Our modified version of Torque, with all the necessary PBSPro ex-clusive features re-implemented and further extended with new features likecloud-like behaviour, was deployed across the entire production environment,covering the entire Czech Republic for almost a full year.In the second part, we will present our work on meta-scheduling. This in-volves our work on distributed architecture and cloud-grid convergence. Thedistributed architecture was designed to overcome the limitations of a centralserver setup, which was originally used and presented stability and performanceissues. While this paper does not discuss the inclusion of cloud interfaces intogrids, it does present the dynamic infrastructure, which is a requirement forsharing the grid infrastructure between a batch system and a cloud gateway.We are also inviting everyone to try out our fork of the Torque batch system,which is now publicly available
INFORMATION EXTRACTION FROM CHEMICAL PATENTS
Get PDFThe development of new chemicals or pharmaceuticals is preceded by an indepth analysis of published patents in this field. This information retrieval is a costly and time inefficient step when done by a human reader, yet it is mandatory for potential success of an investment. The goal of the research project UIMA-HPC is to automate and hence speed-up the process of knowledge mining about patents. Multi-threaded analysis engines, developed according to UIMA (Unstructured Information Management Architecture) standards, process texts and images in thousands of documents in parallel. UNICORE (UNiform Interface to COmputing Resources) workflow control structures make it possible to dynamically allocate resources for every given task to gain best cpu-time/realtime ratios in an HPC environment