Numer czasopisma
Computer Science
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ISSN: 1508-2806
e-ISSN:
Data wydania
2017
Rocznik
Vol. 18
Numer
No. 1
Prawa dostępu
Dostęp: otwarty dostęp
Uwagi:
Prawa: CC BY 4.0 
Uznanie autorstwa 4.0 Międzynarodowe (CC BY 4.0)
Strony
Opis
Rocznik czasopisma (rel.)
Rocznik czasopisma
Computer Science
Vol. 18 (2017)
Artykuły numeru (rel.)
Artykuł
Dostęp ograniczony
Analysis of series of measurements from job-centric monitoring by statistical functions
(2017) Hilbrich, Marcus; Frank, Markus
The rising number of executed programs (jobs) enabled by the growing amount of available resources from Clouds, Grids, and HPC (for example) has resulted in an enormous number of jobs. Nowadays, most of the executed jobs are mainly unobserved, so unusual behavior, non-optimal resource usage, and silent faults are not systematically searched and analyzed. Job-centric monitoring enables permanent job observation and, thus, enables the analysis of monitoring data. In this paper, we show how statistic functions can be used to analyze job-centric monitoring data and how the methods compare to more-complex analysis methods. Additionally, we present the usefulness of job-centric monitoring based on practical experiences.
Artykuł
Dostęp ograniczony
Predicting performance in a PaaS environment: a case study for a web application
(2017) Rząsa, Wojciech
This paper demonstrates how the combination of simulation and real-world experiments can be used to aid decisions concerning the performance of a distributed application. It presents a case study of performance analysis carried out for a commercial application implementing a web-based API server for mobile clients. The application was deployed on the Heroku cloud-based Platform as a Service (PaaS). The analysis described in this paper provided information required to choose the proper configuration of resources for the software. Simulation was used in the research to identify factors crucial to the performance of the application. This allowed for the preparation of basic experiments concentrating on these factors. Consequently, the basic parameters of resources crucial for the efficiency of the application could be benchmarked at insignificant cost and effort. This approach allows us to reliably aid decisions concerning resource configuration for an analyzed application. The simulation method used in this research is based on the formalism of Timed Colored Petri Nets, but the complexity of formal modeling is hidden from its users. Application developers are able to conveniently create a high-level model of their designs and perform simulations, while the reliability of the results is ensured by the formalism. The paper demonstrates the usefulness of the simulation method for analyzing real-world distributed systems.
Artykuł
Otwarty dostęp
The Airport Gate Assignment Problem – Multi-objective Optimization versus Evolutionary Multi-objective Optimization
(2017) Kaliszewski, Ignacy; Miroforidis, Janusz; Stańczak, Jarosław
In this paper, we approach the Airport Gate Assignment Problem by Multi-objective Optimization as well as Evolutionary Multi-objective Optimization. We solve a bi-criteria formulation of this problem by the commercial mixedinteger programming solver CPLEX and a dedicated Evolutionary Multi-objective Optimization algorithm. To deal with multiple objectives, we apply a methodology that we developed earlier to capture decision-maker preferences in multi-objective environments. We present the results of numerical tests for these two approaches.
Artykuł
Dostęp ograniczony
Building a synchrotron ontology: an analysis of a synchrotron control system in a collaborative environment
(2017) Szota-Pachowicz, Julia
This paper presents research on building a synchrotron ontology using analysis of a synchrotron control system and the aspects of collaborative ontology engineering. It includes a general description of the studied domain and the method used to develop a synchrotron domain ontology. The ontology is being created on the basis of a Solaris synchrotron control system in cooperation with the synchrotron facilities belonging to the Tango community. The first Polish synchrotron radiation facility Solaris is located at Jagiellonian University’s Third Campus in Krakow, Poland. Synchrotron is an unique source of electromagnetic radiation known as synchrotron radiation. This paper discusses the impact of the Solaris control system on the building of a synchrotron ontology. It also includes the main assumptions relating to the collaborative knowledge acquired for this domain. The synchrotron ontology will support the optimization of existing control systems and the development of a new synchrotron control system based on Tango controls or other technologies in a consistent manner. Using the same general assumptions and terms, this could be later used for integration and data sharing purposes. The synchrotron ontology can facilitate interoperation by the integration of information from different sources from one or many synchrotron control systems and integrate different parts of the controls systems that provide analogical or similar services. It can also be used to support the translation between different representations, especially regarding particular devices. Knowledge sharing and reuse is a big challenge in complex, distributed systems where the knowledge required is very specialized for different sets of functionalities or subsystems. Regarding synchrotron systems, many specialists must provide their support so the IT specialists are able to develop and maintain a control system. In this case, the synchrotron ontology can be a guideline for knowledge sharing and reuse.
Artykuł
Dostęp ograniczony
Numerical approaches to the heat transfer problem in modern electronic structures
(2017) Raszkowski, Tomasz; Samson, Agnieszka
The main aim of this paper is to present a detailed description of the research related to the modeling of heat conduction in modern electronic structures, including special consideration for numerical aspects of analyzed algorithms. The motivation to undertake the research as well as some of the most-important results of the experiments and simulations are also included. Moreover, a numerical approximation of the problem as well as the methodology used and a sample solution of the mentioned problem are presented. In the main part, the discretization techniques, Ordinary Differential Equation algorithms, and simulation results for Runge-Kutta’s and Gear’s algorithms are analyzed and discussed. Additionally, a new effective approach to the modeling of heat transfer in electronic nanostructures is demonstrated.
Artykuł
Dostęp ograniczony
Compression of image sequences in interactive medical teleconsultations
(2017) Malawski, Filip; Czekierda, Łukasz
Interactive medical teleconsultations are an important tool in modern medical practice. Their applications include remote diagnostics, conferences, workshops, and classes for students. In many cases, standard medium or low-end machines are employed, and the teleconsultation systems must be able to provide a high quality of user experience with very limited resources. Particularly problematic are large datasets consisting of image sequences that need to be accessed fluently. The main issue is insufficient internal memory, therefore, proper compression methods are crucial. However, a scenario where image sequences are kept in a compressed format in the internal memory and decompressed onthe-fly when displayed is difficult to implement due to performance issues. In this paper, we present methods for both lossy and lossless compression of medical image sequences that only require compatibility with the Pixel Shader 2.0 standard, which is present even on relatively old, low-end devices. Based on the evaluation of quality, size reduction, and performance, these methods have been proven to be suitable and beneficial for medical teleconsultation applications.