On the design of aspect-oriented composition models for software evolution

Aspect-oriented programming is an emerging approach in software development,\ud which provides new possibilities for separation of concerns. Aspectoriented\ud languages offer abstractions for the implementation of concerns\ud whose modularization cannot be achieved by using traditional programming\ud languages. Such concerns are generally termed as crosscutting concerns. It is\ud generally agreed that separating the right concerns from each other enhances\ud software quality factors such as reusability and adaptability. The separated\ud concerns in software must be composed together so that software behaves\ud according to its requirements in a coherent way. We refer to language mechanisms\ud that separate and compose concerns as 'composition mechanisms'. This\ud thesis evaluates the software composition mechanisms of current aspectoriented\ud languages from the perspective of software quality factors such as\ud evolvability, comprehensibility, predictability and adaptability. Based on this\ud study, the thesis proposes novel extensions to current aspect-oriented\ud languages so that programs written in these languages exhibit better quality.\ud A considerable number of aspect-oriented languages has been introduced for\ud modularizing crosscutting concerns. Naturally, these languages share a number\ud of common concepts and have distinctive features as well. For this reason, we\ud propose a reference model that aims to capture the common and distinctive\ud concepts of aspect-oriented languages. This reference model provides a basis\ud to understand the important characteristics of the state-of-the-art AOP\ud languages and helps us to compare the AOP languages with each other.\ud Furthermore, it exposes the issues that have to be considered when a new\ud aspect-oriented language needs to be developed.\ud In this thesis, we analyse the four main aspect-oriented concepts of the reference\ud model, namely join point, pointcut, advice and aspect, and identify problems\ud related to their use in various AOP languages. Based on this analysis, we\ud propose extensions of the existing concepts and/or design new ones to address\ud the identified problems.\ud In current aspect-oriented languages, pointcuts select join points of a program\ud based on lexical information such as explicit names of program elements.\ud However, this reduces the adaptability of software, since it involves too much\ud information that is hard-coded, and often implementation-specific. We claim\ud that this problem can be reduced by referring to program elements through their\ud semantic properties. A semantic property describes for example the behavior\ud of a program element or its intended meaning. We formulate requirements for\ud the proper application of semantic properties in aspect-oriented programming.\ud We discuss how to use semantic properties for the superimposition of aspects,\ud and how to apply superimposition to bind semantic properties to program\ud elements. To achieve this, we propose language constructs that support semantic\ud composition: the ability to compose aspects with the elements of the base\ud program that satisfy certain semantic properties.\ud The current advice-pointcut binding constructs of AOP languages maintain\ud explicit dependencies to advices and aspects. This results in weaving specifications\ud that are less evolvable and need more maintenance during the development\ud of a system. We show that this issue can be addressed by providing associative\ud access to advices and aspects instead of using explicit dependencies in\ud the weaving specification. To this aim, we propose to use a designating (query)\ud language in advice-pointcut bindings that allows for referring aspect/advices\ud through their (syntactic and semantic) properties. We also present how semantic\ud properties can be applied to provide reusable (adaptable) aspect abstractions.\ud Aspect-oriented languages provide means to superimpose aspectual behavior –\ud in terms of advices - on a given set of join points. It is possible that not just a\ud single, but several advices need to execute at the same join point. Such "shared"\ud join points may give rise to issues such as determining the exact execution\ud order and the other possible dependencies among the aspects. We present a\ud detailed analysis of the problem, and identify a set of requirements upon mechanisms\ud for composing aspects at shared join points. To address the identified\ud issues, we propose a general and declarative model for defining constraints\ud upon the possible compositions of aspects at a shared join point. By using an\ud extended notion of join points, we show how concrete aspect-oriented\ud programming languages can adopt the proposed model.\ud The thesis also presents how the proposed extensions and new constructs are\ud adopted by the aspect-oriented language Compose*. To evaluate the proposed\ud constructs, we provide qualitative analyses with respect to various software\ud engineering properties, such as evolvability, modularity, predictability and\ud adaptability

Declarative Aspect Composition

Aspect-oriented languages provide means to attach certain program units (e.g. advice, filters) to a given set of join points. It is possible that not just a single , but several units need to execute at the same join point. Aspects that specify the insertion of these units are said to "share" the same join point. Such shared join points may give rise to several issues, such as determining the exact execution order and the dependencies among the aspects. In this position paper, we outline a declarative approach that addresses this problem. We evaluate it with respect to several software engineering properties, in particular comprehensibility, predictability and evolvability

Mechanical and thermal induced phase transformations in superduplex stainless steel

The aim of this work is to study the microstructural changes in SAF 2507 type superduplex stainless steel due to heat treatments and mechanical fatigue process. Specimens were heat treated in the 400-1360 °C temperature range for 1 and 5 hours respectively. An other series of specimens were periodically loaded by using a fatigue testing machine. The microstuctural changes were investigated by using a complex micromagnetic measuring system which includes a Barkhausen noise measuring and a magnetic harmonic analysing system. The RMS value of the Barkhausen noise, the distortion factor (k), and magnetic coercivity values were measured. The microstuctural changes were investigated by metallography using scanning electron microscope

A magyar börtönügy arcképcsarnoka

A Szegedi Fegyház és Börtön 130 éves évfordulója alkalmából az intézet méltó keretek között emlékezett meg hazánk börtönügyének – talán egy kissé elfeledett – jeles képviselőjéről. A szegedi Csillagbörtön első igazgatójának börtönügyi szakirodalmi tevékenységét összefoglaló tanulmány, mely tartalmazza Törökfalvi Török Kálmán életének fontosabb mozzanatait, kapcsolatát a magyar börtönügy jeles képviselőjével, Tauffer Emillel

Kvantitatív genetikai vizsgálatok a Pannon fehér nyúlpopulációban = Quantitative Genetic Studies on the Pannon White rabbit population

A kutatómunka során kialakítottam a Pannon fehér nyúlállományban jelentős tulajdonságokat értékelő matematikai modelleket. Ezek segítségével becsültem a tulajdonságok genetikai paramétereit, illetve a szelekciós haladást. Elemeztem az állomány genetikai szerkezetét, illetve a beltenyésztési leromlást. Az eredmények alapján megállapítható, hogy a vizsgált értékmérők öröklődhetősége alapján a tulajdonságok alkalmasak a szelekcióra. A szelekciós haladás nagysága viszonylag csekély. Az állományra a zárt szerkezet jellemző, emiatt a teljes állomány beltenyésztett, azonban a beltenyésztési leromlás csekély. A projekt keretében kidolgozott modellek, illetve az alkalmazott eljárások beépültek a Pannon fehér nyúlállomány tenyésztési programjába. A szelekció a BLUP tenyészértékek alapján történik. | During the accomplishment of the project mathematical models were developed for the traits having importance in the Pannon white rabbit population. Using these models genetic parameters and selection response were estimated. Population structure and inbreeding depression were evaluated. Based on the results it can be concluded that according to the estimated heritabilities the analyzed traits are suitable for improvement by selection. Selection response was relatively low. The population structure is closed thus the whole population is inbred. Nevertheless inbreeding depression is negligible. The mathematical models and the used methodology are built into the breeding program of the Pannon white rabbit population. The selection is based ont he BLUP breeding values

Polimerek és kompozitok frontális szintézise = Frontal Synthesis of Polymers and Composites

Elvégeztük az akrilamid - trietilánglikol-dimetakrilát (TGDMA) kopolimerizációs front termokémiai vizsgálatát, konkrétan az SHS-eljárásnál (Self Heating High Temperature Synthesis) közölt modell rendszerünkre történő alkalmazhatóságának tekintetében. Az elektromos energia tárolására alkalmas új eljárást és berendezést fejlesztettünk ki. Polimer szerkezetet alakítottunk ki, amely vezeti az elektromos áramot. Benne olyan szerves molekulákat helyeztünk el, amelyek alkalmasak az elektromos töltés felvételére, tárolására és leadására. Szabályozható elektrokémiai tulajdonságú anyagok előállítását valósítottuk meg: grafitot és különböző adalékanyagokat egyaránt tartalmazó kompozitokat állítottunk elő frontális polimerizációval. Anyagaink nagy csereáramsűrűséggel rendelkeznek, így hatékony elektródanyagként alkalmazhatóak galvánelemekben, elektrokémiai cellákban, A különböző minőségű, és mennyiségű adalékanyagok befolyásolják a vezetést. A vezetési mechanizmus felderítése érdekében a grafit - poliakrilát határfelületet XPS, ESCA módszerrel tanulmányoztuk. Új, ultrahangos iniciálás lehetőségét vizsgáltuk frontpolimerizációs reakciókban. Akrilamid - TGDMA alapú, kémiai módszerekkel történő felületmódosításra alkalmas kompozitokat állítottunk elő fronpolimerizációval. Módosítás után felületükön karboxil-, illetve hidroxil csoportokat tartalmaznak. Ezek az anyagok jól használhatók szintéziselektródok készítésénél. | The thermochemistry of the acrylamide - trienthylene-glycol-dimetacrylate front have been studied to test the applicability of SHS-model (Self Heating High Temperature Synthesis). A new method and device have been developed for the storage of electric energy: polymer structure have been developed adding organic components to make it able to take, store, and discharge electric energy. Materials with tunable electric and electrochemical properties were invented. Based upon their good properties, these materials are effective for batteries, synthesis electrodes, etc. Additives have a significant effect on the tunable features as conductivity, current density during electrolysis, etc. XPS and ESCA studies were performed to understand the conducting mechanism. Numeric simulations on molecular structure also have been done. Surface modification of electrode materials (carboxylation and hydroxylation) were performed and studied to make wider possibilities to alternate electrochemical properties for electrosynthesis. New ultrasonic initiation method have been developed and studied to eliminate chemical initiators

Székelyföld gazdasági fejlettségének pozicionálása A külföldi mőködő tőke és a pénzügyi szektor hatása a regionális fejlődésre

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DYNAMIC LOCAL FIELD CORRECTION IN THE CALCULATION OF ELECTRONIC STOPPING POWER'

Energy loss of slow charged particles in a degenerate electron gas is calculated on the basis of the dielectric theory. The influence of dynamic local field correction is examined. A straightforward extension of this theory to problems that exceed the validity of the first Born approximation is discussed