Formal Aspects of Grid Brokering

Coordination in distributed environments, like Grids, involves selecting the most appropriate services, resources or compositions to carry out the planned activities. Such functionalities appear at various levels of the infrastructure and in various means forming a blurry domain, where it is hard to see how the participating components are related and what their relevant properties are. In this paper we focus on a subset of these problems: resource brokering in Grid middleware. This paper aims at establishing a semantical model for brokering and related activities by defining brokering agents at three levels of the Grid middleware for resource, host and broker selection. The main contribution of this paper is the definition and decomposition of different brokering components in Grids by providing a formal model using Abstract State Machines

Bruchia flexuosa (Schwägr.) Müll. Hal.: egy igazi különlegesség a magyar mohaflórában = Bruchia flexuosa (Schwägr.) Müll. Hal. a true peculiarity in the Hungarian bryoflora

Abstract – The fifth European occurrence of the moss species Bruchia flexuosa possessing a holarctic distribution range with a North American centre was encountered in Hungary. Outside of the North American continent only two Asian (both from Japan) and four European occurrences from four different countries (Italy, Austria, Slovenia, Croatia) have hitherto been reported. Apart from the recent Japan findings and the Croatian record observed in 1987, all other European records date back to the 19th century. Our paper reports the circumstances of the Hungarian occurrence along with a short descriptions and photographic illustrations of both the species and its habitat. Keywords: Bruchiaceae, bryoflora of Hungary, Europe, rare mosses | Összefoglalás – A Bruchia flexuosa egy holarktikus faj észak-amerikai elterjedési centrummal. Az amerikai kontinensen kívül ez idáig csak Japánból jelezték kettő, valamint Európából négy előfordulását (Olaszország, Ausztria, Szlovénia, Horvátország). A recens japán előfordulások mellett az európai adatok – az 1987-ben talált horvátot leszámítva – mind a 19. századból származnak. Az újonnan felfedezett Barcs környéki populáció a faj ötödik észlelése Európában és a hetedik az északamerikai térségen kívül. Kulcsszavak: Bruchiaceae, Európa, florisztika, Magyarország mohaflórája, ritka mohá

INVESTIGATION OF THE GLUED INSULATED RAIL JOINTS APPLIED TO CWR TRACKS

This article summarizes the research results related to our own conducted extensive laboratory tests of polymer composite and steel fishplated glued insulated rail joints (GIRJs), namely axial tensile tests as well as vertical static and dynamic tests. The investigation dealt with the examination of GIRJs assembled with steel and special glass-fiber reinforced plastic (polymer composite) fishplates, both of them for CWR railway tracks (i.e. so-called gapless tracks or, in other words, railway tracks with continuously welded rails). The exact rail joint types were MTH-P and MTH-AP, consistently. The MTH P types have been commonly applied for many years in the CWR tracks in Europe, mainly in Hungary. The MTH-AP rail joints consist of fishplates that are produced by the APATECH factory (Russia). They are made of a fiberglass-amplified polymer composite material at high pressure and controlled temperature. This solution can eliminate electrical fishplate lock and early fatigue failures just as it can ensure adequate electrical insulation. The advantage of such rail joints can be that they are probably able to ensure the substitution of the glued insulated rail joints with relatively expensive steel fishplates currently applied by railway companies, e.g. Hungarian State Railways (MÁV). The aim of the mentioned research summarized in this paper is to formulate recommendations on technical applicability and on the technological instructions that are useful in everyday railway operation practice on the basis of the measurements and tests carried out on rail joints in laboratory

Investigation of glued insulated rail joints with special fiber-glass reinforced synthetic fishplates using in continuously welded tracks

In this paper the authors partially summarize the results of a research on glued insulated rail joints with fiber-glass reinforced plastic fishplates (brand: Apatech) related to own executed laboratory tests. The goal of the research is to investigate the application of this new type of glued insulated rail joint where the fishplates are manufactured at high pressure, regulated temperature, glass-fiber reinforced polymer composite plastic material. The usage of this kind of glued insulated rail joints is able to eliminate the electric fishplate circuit and early fatigue deflection and it can ensure the isolation of rails’ ends from each other by aspect of electric conductivity

Strategies for Increased Energy Awareness in Cloud Federations

This chapter first identifies three scenarios that current energy aware cloud solutions cannot handle as isolated IaaS, but their federative efforts offer opportunities to be explored. These scenarios are centered around: (i) multi-datacenter cloud operator, (ii) commercial cloud federations, (iii) academic cloud federations. Based on these scenarios, we identify energy-aware scheduling policies to be applied in the management solutions of cloud federations. Among others, these policies should consider the behavior of independent administrative domains, the frequently contradicting goals of the participating clouds and federation wide energy consumption

Csigasorral függesztett gerenda szabadrezgése modálanalízissel

Egy csigasorral függesztett gerenda szabadrezgését vizsgáljuk. A gerendát Bernoulli-Euler rúdként modellezzük, és bemutatjuk a szerkezet sajátrezgésalakjait és sajátkörfrekvenciáit feszített és feszítetlen függesztőkábel esetén a folytonos rúd differenciálegyenletének megoldásával. A kábel feszített, vagy feszítetlen voltától függ ̋oen beszélünk aktív és passzív függesztésr ̋ol. Az aktív és passzív függesztés rezgésalakjai egymásnak megfeleltethet ̋oek, az állapotváltozások során a modális koordináták transzformációja id ̋ofüggetlen módon végezhető. Numerikus módszert mutatunk a rezgés számítására, az aktív és passzív állapotok közötti váltás kezelésére. Különböző kezdőállapotokat használva szimuláljuk a tartó szabadrezgését. Megmutatjuk, hogy még az aktív és passzív függesztések közötti váltás okozta erős nemlinearitás mellett is képes a szerkezet periodikus szabadrezgést végezni