Optimistic Adaptation of Decentralised Role-based Software Systems

The complexity of computer networks has been rising over the last decades. Increasing interconnectivity between multiple devices, growing complexity of performed tasks and a strong collaboration between nodes are drivers for this phenomenon. An example is represented by Internet-of-Things devices, whose relevance has been rising in recent years. The increasing number of devices requiring updates and supervision makes maintenance more difficult. Human interaction, in this case, is costly and requires a lot of time. To overcome this, self-adaptive software systems (SAS) can be used. SAS are a subset of autonomous systems which can monitor themselves and their environment to adapt to changes without human interaction. In the literature, different approaches for engineering SAS were proposed, including techniques for executing adaptations on multiple devices based on generated plans for reacting to changes. Among those solutions, also decentralised approaches can be found. To the best of our knowledge, no approach for engineering a SAS exists which tolerates errors during the execution of adaptation in a decentralised setting. While some approaches for role-based execution reset the application in case of a single failure during the adaptation process, others do not make assumptions about errors or do not consider an erroneous environment. In a real-world environment, errors will likely occur during run-time, and the adaptation process could be disturbed. This work aims to perform adaptations in a decentralised way on role-based systems with a relaxed consistency constraint, i.e., errors during the adaptation phase are tolerated. This increases the availability of nodes since no rollbacks are required in case of a failure. Moreover, a subset of applications, such as drone swarms, would benefit from an approach with a relaxed consistency model since parts of the system that adapted successfully can already operate in an adapted configuration instead of waiting for other peers to apply the changes in a later iteration. Moreover, if we eliminate the need for an atomic adaptation execution, asynchronous execution of adaptation would be possible. In that case, we can supervise the adaptation process for a long time and ensure that every peer takes the planned actions as soon as the internal task execution allows it. To allow for a relaxed consistent way of adaptation execution, we develop a decentralised adaptation execution protocol, which supports the notion of eventual consistency. As soon as devices reconnect after network congestion or restore their internal state after local failures, our protocol can coordinate the recovery process among multiple devices to attempt recovery of a globally consistent state after errors occur. By superseding the need for a central instance, every peer who received information about failing peers can start the recovery process. The developed approach can restore a consistent global configuration if almost all peers fail. Moreover, the approach supports asynchronous adaptations, i.e., the peers can execute planned adaptations as soon as they are ready, which increases overall availability in case of delayed adaptation of single nodes. The developed protocol is evaluated with the help of a proof-of-concept implementation. The approach was run in five different experiments with thousands of iterations to show the applicability and reliability of this novel approach. The time for execution of the protocol and the number of exchanged messages has been measured to compare the protocol for different error cases and system sizes, as well as to show the scalability of the approach. The developed solution has been compared to a blocking approach to show the feasibility compared to an atomic approach. The applicability in a real-world scenario has been described in an empirical study using an example of a fire-extinguishing drone swarm. The results show that an optimistic approach to adaptation is suitable and specific scenarios can benefit from the improved availability since no rollbacks are required. Systems can continue their work regardless of the failures of participating nodes in large-scale systems.:Abstract VI 1. Introduction 1 1.1. Motivational Use-Case 2 1.2. Problem Definition 3 1.3. Objectives 4 1.4. Research Questions 5 1.5. Contributions 5 1.6. Outline 6 2. Foundation 7 2.1. Role Concept 7 2.2. Self-Adaptive Software Systems 13 2.3. Terminology for Role-Based Self-Adaptation 15 2.4. Consistency Preservation and Consistency Models 17 2.5. Summary 20 3. Related Work 21 3.1. Role-Based Approaches 22 3.2. Actor Model of Computation and Akka 23 3.3. Adaptation Execution in Self-Adaptive Software Systems 24 3.4. Change Consistency in Distributed Systems 33 3.5. Comparison of the Evaluated Approaches 40 4. The Decentralised Consistency Compensation Protocol 43 4.1. System and Error Model 43 4.2. Requirements to the Concept 44 4.3. The Usage of Roles in Adaptations 45 4.4. Protocol Overview 47 4.5. Protocol Description 51 4.6. Protocol Corner- and Error Cases 64 4.7. Summary 66 5. Prototypical Implementation 67 5.1. Technology Overview 67 5.2. Reused Artifacts 68 5.3. Implementation Details 70 5.4. Setup of the Prototypical Implementation 76 5.5. Summary 77 6. Evaluation 79 6.1. Evaluation Methodology 79 6.2. Evaluation Setup 80 6.3. Experiment Overview 81 6.4. Default Case: Successful Adaptation 84 6.5. Compensation on Disconnection of Peers 85 6.6. Recovery from Failed Adaptation 88 6.7. Impact of Early Activation of Adaptations 91 6.8. Comparison with a Blocking Approach 92 6.9. Empirical Study: Fire Extinguishing Drones 95 6.10. Summary 97 7. Conclusion and Future Work 99 7.1. Recap of the Research Questions 99 7.2. Discussion 101 7.3. Future Work 101 A. Protocol Buffer Definition 103 Acronyms 108 Bibliography 10

Under the Surface of Sex Trafficking: Socio-Economic and Cultural Perpetrators of Gender-Based Violence in India

In this work, I will focus on the act of sex trafficking as it exists in the country of India. Specifically, I will focus on sex trafficking as a gendered representation of three distinct dimensions of India’s existing conditions: 1) gender inequality, 2) historic and current cultural scripts, and 3) socio-economic conditions. I contend that these three dimensions are at the heart of sex trafficking and serve as forms of violence against women. Furthermore, in adding to the literature, this paper proposes a victim-focused/human rights focused approach, which will assist India in successfully combating trafficking within its own borders and lend new levels of analysis in understanding systemic responses to this global circumstance so central to the context of globalization. In supporting these claims, this thesis analyzes a combination of qualitative and quantitative data sets, primarily categorized as secondary sources, which have been compiled throughout several years on the topic of sex trafficking. Furthermore, in supporting a victim-focused/human rights focused approach, information gathered from interviews with two employees of the South African organization Activists Networking Against the Exploitation of Children (ANEX), as well as South African service provider guidelines to assisting victims of trafficking, will be detailed and analyzed

MODELLING OF SUGAR TRANSFER DURING OSMOTIC DEHYDRATION OF CARROTS

Mass transfer was quantitatively investigated during osmotic dehydration of carrot slices and layers. The distribution of water and sugar was determined in longitudinal and radial directions of root samples. Using the solution of Fick´s I. and II. laws the effective diffusion coefficients of sugar depending on geometric parameters in radial layers and longitudinal slices were estimated according to cylindrical and rectangular coordinate systems. The observed dependency of Dr,s and Dl,s was found to be in line with the absence of alteration in longitudinal and the existing difference in radial directions of the tissue structure in carrot root

Effect of cultivation systems on maize productivity and production profitability

In the past decades maize was produced on the largest scale in Hungary. The extreme weather conditions and the rising energy prices of the last years forced the farmers to produce with the least input and with the highest yield stability possible. Our research was carried out on the land of Vásárhelyi Róna Kft. where a 9-hectare area was partitioned for three equal parcels. The three parcels were cultivated with different basic cultivating methods: ploughing, loosening and strip tillage. Nine-nine different maize hybrids were sowed in each cultivated parcels. In the course of the research we examined the moisture content of the soil, the morphologic features of the hybrids and average yield by hectares. We calculated the total cost, theoretical incomings and earnings by growing maize per hectare. According to our one-year research we came to the result that the most productive method was tilling proceeding even though it had the highest cost. On the other hand we found that the hybrids reacted differently to the various cultivation procedures. Realizing the results we suggest farmers should take notice of rational tilling and the importance of choosing hybrids

Effect of cultivation systems on maize productivity and production profitability

In the past decades maize was produced on the largest scale in Hungary. The extreme weather conditions and the rising energy prices of the last years forced the farmers to produce with the least input and with the highest yield stability possible. Our research was carried out on the land of Vásárhelyi Róna Kft. where a 9-hectare area was partitioned for three equal parcels. The three parcels were cultivated with different basic cultivating methods: ploughing, loosening and strip tillage. Nine-nine different maize hybrids were sowed in each cultivated parcels. In the course of the research we examined the moisture content of the soil, the morphologic features of the hybrids and average yield by hectares. We calculated the total cost, theoretical incomings and earnings by growing maize per hectare. According to our one-year research we came to the result that the most productive method was tilling proceeding even though it had the highest cost. On the other hand we found that the hybrids reacted differently to the various cultivation procedures. Realizing the results we suggest farmers should take notice of rational tilling and the importance of choosing hybrids

Vilém Flusser und die analog/digital-Differenz innerhalb der Fotografie

Anhand der Fototheorie des Medienphilosophen Vilém Flussers wird in dieser Arbeit die Differenz analoger und digitaler Fotografie untersucht. Ausgehend von der Fragestellung, ob das Verhältnis analoger und digitaler Fotografie ein Kontinuum (in der das eine Medium sein vorangegangenes ablöst) oder eine Opposition (in der beide Formen eigenständige Medien des Wissens sind) darstellt, dient Flussers Theorie als Leitfaden, um die Bedeutung der A/D-Unterscheidung zu erfassen. Über Heideggers Phänomenologie, die frühe Kybernetik und einer medientheoretischen Betrachtung anhand des Bauhaustheoretikers Laszlo Moholy-Nagy und Marshall McLuhan wird die Fotophilosophie Flussers kritisch beleuchtet und abschließend die These vertreten, analoge und digitale Fotografie als eigenständige epistemische Medien zu begreifen

Identyfikacja warunków koniecznych sukcesu serwicyzacji przedsiębiorstw produkcyjnych

The purpose of this paper is to employ a necessary condition analysis (NCA) approach to investigate the level of necessity of two conditions, separate organization for services and interfirm collaboration for service business performance depending on the type of adopted service orientation (services in support of the product (SSP) and services in support of the client’s actions business orientation (SSC). Servitization is now becoming an important factor favorable to manufacturers competitiveness. The adoption of service orientation and adequate service strategies includes building up an ability to deliver services and also, according to contingency theory, it requires changes in structure of organization. Unfortunately, it is not clear whether manufacturers should create a separate organization for services or if they should pursue an integration of the service organization into its corresponding product base strategic business unit. Empirical evidence and theoretical contributions can be found to support both sides of the argument. Moreover, some of the findings are inconsistent and even contrary to each other. Using a survey data set collected from a sample of 186 Polish manufacturers, this study explored the levels of necessity of the components by NCA. The research revealed that neither in case of SSP BO nor SSC BO separation of organization for services is not necessary condition to achieve both low and high level of service business performance. Also, the results show that different levels of service business performance require different threshold levels of inter-collaboration. This condition is more necessary when firms are SSC oriented.Celem opracowania jest zbadanie poziomu konieczności wystąpienia dwóch warunków, tj. wydzielenia usługowej jednostki organizacyjnej oraz współpracy międzyfunkcyjnej, do osiągnięcia rożnych poziomów przychodów ze sprzedaży usług przedsiębiorstw produkcyjnych w zależności od rodzaju przyjętej orientacji oferty produktowej na usługi (tj. usługi wspierające produkt – SSP i usługi wspierające działania klienta – SSC). Serwicyzacja staje się obecnie ważnym czynnikiem sprzyjającym konkurencyjności producentów. Zjawisko to, rozumiane jako przyjęcie strategii biznesowej zorientowanej na usługi, zgodnie z teorią dopasowania organizacyjnego wymaga m.in. zmian w strukturze organizacyjnej. Producenci mogą wydzielić autonomiczną jednostkę usługową lub dążyć do integracji organizacji usługowej z produktową. W wynikach badań empirycznych oraz w teorii można znaleźć argumenty przemawiające za jedną lub drugą opcją. Niestety, obecnie osiągnięte wyniki wykazują sprzeczność. Na podstawie przeprowadzonych badań ankietowych na próbie 186 producentów warunki konieczne zostały zbadane z wykorzystaniem jednej z nieparametrycznych metod, tj. Necessary Condition Analysis (NCA). Badanie wykazało, że zarówno w przypadku oferty usługowej typu SSP, jak i SSC wydzielenie organizacji usług nie jest warunkiem koniecznym do osiągnięcia zarówno niskiego, jak i wysokiego poziomu przychodów z usług. Tymczasem już współpraca międzyfunkcyjna warunkuje osiąganie rożnych poziomów przychodów z usług. Warunek ten silniej ogranicza osiągane przychody z usług w przypadku dostarczania przez producenta oferty kategorii SSC

Systemy PRT jako szansa na radykalną poprawę transportu w mieście

Analyzing the effciency of contemporary public transport, one candetermine major or minor problems in almost every city. Cars are used only for a dozen or so minutes every day, and usually by no more than one person. The rest of the time, they require parking spaces, which occupy the difficult to save up city space. An alternative for them is group transport. But contemporary types of public transport, such as buses, streetcars, and the subway do not quite fulfill their functions. These difficulties force engineers to search for newer and more effective solutions, based on individual infrastructure. One of those solutions are the PRT systems. The aim of this paper is to present new types of public transport, such as PRT systems, and comparing their capabilities with other types of public transportation. The first chapters of this paper are dedicated to generally characterize the PRT systems, their features and history. The further part introduces the polish outlook on this specific type of transportation MISTER. The paper ends with an efficiency simulation of MISTER in Opole.Poddając analizie efektywność współczesnej komunikacji miejskiej, można określić w prawie każdym mieście większe lub mniejsze problemy. Pojazdy samochodowe użytkowane są tylko przez kilkanaście minut na dobę i zazwyczaj przez nie więcej niż jedną osobę. Przez resztę czasu wymagają miejsc parkingowych, które zajmują tak trudny do wygospodarowania teren w mieście. Alternatywą jest transport grupowy. Jednak współczesne rodzaje komunikacji miejskiej, jakimi są głównie autobusy, tramwaje i metro, nie do końca spełniają swoje funkcje. Trudności te wymuszają na inżynierach szukanie coraz nowszych i bardziej efektywnych rozwiązań, bazujących na indywidualnej infrastrukturze. Takim rozwiązaniem są systemy PRT. Niniejsza praca ma na celu zaprezentowanie nowego rodzaju komunikacji miejskiej, jakim są systemy PRT oraz porównanie ich możliwości z innymi rodzajami miejskiego transportu. Najpierw przedstawiono w niej ogólną charakterystykę systemów PRT, ich cechy i rozwój. W dalszej części omówiono polskie spojrzenie na ten specyficzny typ transportu, czyli projekt MISTER. Prace kończy symulacja efektywnościowa systemu MISTER dla miasta Opola

Epigenetikus reguláció a Drosophila melanogaster bithorax komplexében = Epigenetic regulation in the bithorax complex of Drosophila melanogaster

Fontosabb eredmények Kimutattuk, hogy a bithorax komplexben (Bx-C) a Polycomb Response Elementek (PRE-k), és a hozzájuk kapcsolódó Polycomb fehérjék nemcsak a cisz-regulátor régiók inaktív/zárt állapotának fenntartásában játszanak fontos szerepet, hanem az aktív/nyílt állapotú cisz-regulátorokban található enhanszerek hatásának modulálásában is. Ezt a hatás úgy fejti ki, hogy fizikailag a célgén promoteréhez kötődik. Ezzel összefüggésben kimutattuk egy, a bxd PRE-vel részben átfedő Targetáló Elem (TE) jelenlétét. A TE a PRE-hez hasonlóan moduláris szerkezetű. Igazoltuk, hogy ez az elem nemcsak a PRE promóterhez való kőtődésében játszik szerepet, hanem részt vesz a bxd régióban található enhanszereknek az Ubx promótere köré való szervezésében, azaz az „acticve chromatin hub” kialakításában. A TE ezt a funkcióját ektopikus környezetben, az iab-7 cisz regulátorban is megőrzi. A PRE-től határoló elemmel elválasztott bxd enhanszerek ektopikus aktivitást mutatnak, amely mind fenotípus analízissel, mind markergén expressziójának követésével kimutatható. Kinutattuk, hogy az ebi gén a Polycomb csoport génjei közé sorolandó, és a polyhomeotic génnel együtt az aktív állapotú cisz-regulátorokban fejti ki moduláló hatását. Kvantitatív RTPCR segítségével kimutattuk, hogy az Abd-B RNS mennyisége körülbelül duplájára nő polyhomeotic mutáns háttéren. | We showed that Polycomb Response Elements (PREs) and Polycomb proteins bound to them play an important role not only in maintaining inactive/closed conformation of cis-regulatory elements in the bithorax complex, but they are also involved in modulating the regulatory output of enhancers in the active/open domains. This latter effect is mediated by direct physical contact between the PRE and the promoter – enhancer complex. In connection with this we demonstrated the presence of a Targeting Element (TE) that partially overlaps with the bxd PRE. TE is, similarly to the PRE, modularly organized. We showed that this element is involved not only in targeting the PRE to the Ubx promoter, but also part of the machinery organizing the active chromatin hub around cognate promoter. We also demonstrated that the TE maintains its activity in ectopic context, in the iab-7 cis-regulatory region. Enhancers separated from the bxd PRE by a boundary region exhibit ectopic activity, as revealed by both phenotypic analysis and by monitoring the expression pattern of a marker gene. We identified the ebi gene as an unusual Polycomb group member, which, similarly to the polyhometic gene, participates in the modulation of enhancer output of active cis-regulatory regions. Using quantitative RTPCR we showed that the amount of the Abd-B RNA is doubled in polyhomeotic mutant background