36 research outputs found

    Energy-Efficient Software

    Get PDF
    The energy consumption of ICT is growing at an unprecedented pace. The main drivers for this growth are the widespread diffusion of mobile devices and the proliferation of datacenters, the most power-hungry IT facilities. In addition, it is predicted that the demand for ICT technologies and services will increase in the coming years. Finding solutions to decrease ICT energy footprint is and will be a top priority for researchers and professionals in the field. As a matter of fact, hardware technology has substantially improved throughout the years: modern ICT devices are definitely more energy efficient than their predecessors, in terms of performance per watt. However, as recent studies show, these improvements are not effectively reducing the growth rate of ICT energy consumption. This suggests that these devices are not used in an energy-efficient way. Hence, we have to look at software. Modern software applications are not designed and implemented with energy efficiency in mind. As hardware became more and more powerful (and cheaper), software developers were not concerned anymore with optimizing resource usage. Rather, they focused on providing additional features, adding layers of abstraction and complexity to their products. This ultimately resulted in bloated, slow software applications that waste hardware resources -- and consequently, energy. In this dissertation, the relationship between software behavior and hardware energy consumption is explored in detail. For this purpose, the abstraction levels of software are traversed upwards, from source code to architectural components. Empirical research methods and evidence-based software engineering approaches serve as a basis. First of all, this dissertation shows the relevance of software over energy consumption. Secondly, it gives examples of best practices and tactics that can be adopted to improve software energy efficiency, or design energy-efficient software from scratch. Finally, this knowledge is synthesized in a conceptual framework that gives the reader an overview of possible strategies for software energy efficiency, along with examples and suggestions for future research

    Experimental Evaluation of Growing and Pruning Hyper Basis Function Neural Networks Trained with Extended Information Filter

    Get PDF
    In this paper we test Extended Information Filter (EIF) for sequential training of Hyper Basis Function Neural Networks with growing and pruning ability (HBF-GP). The HBF neuron allows different scaling of input dimensions to provide better generalization property when dealing with complex nonlinear problems in engineering practice. The main intuition behind HBF is in generalization of Gaussian type of neuron that applies Mahalanobis-like distance as a distance metrics between input training sample and prototype vector. We exploit concept of neuron’s significance and allow growing and pruning of HBF neurons during sequential learning process. From engineer’s perspective, EIF is attractive for training of neural networks because it allows a designer to have scarce initial knowledge of the system/problem. Extensive experimental study shows that HBF neural network trained with EIF achieves same prediction error and compactness of network topology when compared to EKF, but without the need to know initial state uncertainty, which is its main advantage over EKF

    Bioinspired metaheuristic algorithms for global optimization

    Get PDF
    This paper presents concise comparison study of newly developed bioinspired algorithms for global optimization problems. Three different metaheuristic techniques, namely Accelerated Particle Swarm Optimization (APSO), Firefly Algorithm (FA), and Grey Wolf Optimizer (GWO) are investigated and implemented in Matlab environment. These methods are compared on four unimodal and multimodal nonlinear functions in order to find global optimum values. Computational results indicate that GWO outperforms other intelligent techniques, and that all aforementioned algorithms can be successfully used for optimization of continuous functions

    Addressing Energy Efficiency in System Design: A Journey FromArchitecture to Operation

    Get PDF
    Digital-transformation initiatives have led to major efficiencies and cost savings but at the cost of consuming nearly 10 percent of the world’s electricity. Energy consumption research has increased datacentre, network, and hardware efficiency, but a neglected aspect of energy research has been the energy consumption of the software applications that underpin digital transformation. To date, software architects have lacked the knowledge, guidance, and tools to allow them to understand the energy properties of their systems. The research reported in this thesis begins to address this situation by developing practical knowledge, techniques, and tools to allow software architects to play their part in controlling the energy consumption of our modern digital world. The work commences with an investigation into formal architectural description languages, through a literature review and a case study, resulting in two research contributions, namely a comprehensive systematic survey of architecture description languages from 1991 to 2015, and a case study of practical ADL use at scale in industry. The second part of the research investigates how to assist architects in prioritising energy efficiency through a study of how experienced architects focus their attention for maximum effectiveness, which leads to the development of a model to guide architecture practitioners, which is validated and refined through a large survey of practising software architects. The research contribution is a refined and validated model for architectural effort prioritisation. The third aspect of the research examines the energy-related guidance available to architects and having found little generally applicable advice, analyses a significant industrial case study to understand how leading-edge practitioners addressed energy efficiency, contributing a set of three energy-related architectural principles, which can be used to guide architects in improving application energy efficiency. Finally, we consider the practical problem of understanding the runtime energy properties of a system, and designed a novel approach to estimate the energy consumption of execution scenarios via application execution tracing and a cost-based energy model. We created a proof of concept implementation of the approach and validated its consistency and correctness through practical testing. The contribution of this work was twofold, namely the design of a practical system for allocating energy to application execution scenarios, and a tested, open-source, proof-of-concept implementation of the system. Hence, the result of this work is six distinct contributions to knowledge in the area of ADLs (the survey and practical case study), architectural practice (the prioritisation model and the architectural principles for energy efficiency) and application energy efficiency (the design of the energy allocation system and the proof-of-concept implementation), which collectively can help architects to treat energy efficiency as a first class architectural concern in their work

    Coordination in Service Value Networks - A Mechanism Design Approach

    Get PDF
    The fundamental paradigm shift from traditional value chains to agile service value networks (SVN) implies new economic and organizational challenges. This work provides an auction-based coordination mechanism that enables the allocation and pricing of service compositions in SVNs. The mechanism is multidimensional incentive compatible and implements an ex-post service level enforcement. Further extensions of the mechanism are evaluated following analytical and numerical research methods

    Engenharia de sistemas baseada em modelos: um sistema para o tráfego & ambiente

    Get PDF
    Doutoramento em Gestão IndustrialThe contemporary world is crowded of large, interdisciplinary, complex systems made of other systems, personnel, hardware, software, information, processes, and facilities. The Systems Engineering (SE) field proposes an integrated holistic approach to tackle these socio-technical systems that is crucial to take proper account of their multifaceted nature and numerous interrelationships, providing the means to enable their successful realization. Model-Based Systems Engineering (MBSE) is an emerging paradigm in the SE field and can be described as the formalized application of modelling principles, methods, languages, and tools to the entire lifecycle of those systems, enhancing communications and knowledge capture, shared understanding, improved design precision and integrity, better development traceability, and reduced development risks. This thesis is devoted to the application of the novel MBSE paradigm to the Urban Traffic & Environment domain. The proposed system, the GUILTE (Guiding Urban Intelligent Traffic & Environment), deals with a present-day real challenging problem “at the agenda” of world leaders, national governors, local authorities, research agencies, academia, and general public. The main purposes of the system are to provide an integrated development framework for the municipalities, and to support the (short-time and real-time) operations of the urban traffic through Intelligent Transportation Systems, highlighting two fundamental aspects: the evaluation of the related environmental impacts (in particular, the air pollution and the noise), and the dissemination of information to the citizens, endorsing their involvement and participation. These objectives are related with the high-level complex challenge of developing sustainable urban transportation networks. The development process of the GUILTE system is supported by a new methodology, the LITHE (Agile Systems Modelling Engineering), which aims to lightening the complexity and burdensome of the existing methodologies by emphasizing agile principles such as continuous communication, feedback, stakeholders involvement, short iterations and rapid response. These principles are accomplished through a universal and intuitive SE process, the SIMILAR process model (which was redefined at the light of the modern international standards), a lean MBSE method, and a coherent System Model developed through the benchmark graphical modeling languages SysML and OPDs/OPL. The main contributions of the work are, in their essence, models and can be settled as: a revised process model for the SE field, an agile methodology for MBSE development environments, a graphical tool to support the proposed methodology, and a System Model for the GUILTE system. The comprehensive literature reviews provided for the main scientific field of this research (SE/MBSE) and for the application domain (Traffic & Environment) can also be seen as a relevant contribution.O mundo contemporâneo é caracterizado por sistemas de grande dimensão e de natureza marcadamente complexa, sócio-técnica e interdisciplinar. A Engenharia de Sistemas (ES) propõe uma abordagem holística e integrada para desenvolver tais sistemas, tendo em consideração a sua natureza multifacetada e as numerosas inter-relações que advêm de uma quantidade significativa de diferentes pontos de vista, competências, responsabilidades e interesses. A Engenharia de Sistemas Baseada em Modelos (ESBM) é um paradigma emergente na área da ES e pode ser descrito como a aplicação formal de princípios, métodos, linguagens e ferramentas de modelação ao ciclo de vida dos sistemas descritos. Espera-se que, na próxima década, a ESBM desempenhe um papel fundamental na prática da moderna Engenharia de Sistemas. Esta tese é dedicada à aplicação da ESBM a um desafio real que constitui uma preocupação do mundo actual, estando “na agenda” dos líderes mundiais, governantes nacionais, autoridades locais, agências de investigação, universidades e público em geral. O domínio de aplicação, o Tráfego & Ambiente, caracteriza-se por uma considerável complexidade e interdisciplinaridade, sendo representativo das áreas de interesse para a ES. Propõe-se um sistema (GUILTE) que visa dotar os municípios de um quadro de desenvolvimento integrado para adopção de Sistemas de Transporte Inteligentes e apoiar as suas operações de tráfego urbano, destacando dois aspectos fundamentais: a avaliação dos impactos ambientais associados (em especial, a poluição atmosférica e o ruído) e a divulgação de informação aos cidadãos, motivando o seu envolvimento e participação. Estes objectivos relacionam-se com o desafio mais abrangente de desenvolver redes de transporte urbano sustentáveis. O processo de desenvolvimento do sistema apoia-se numa nova metodologia (LITHE), mais ágil, que enfatiza os princípios de comunicação contínua, feedback, participação e envolvimento dos stakeholders, iterações curtas e resposta rápida. Estes princípios são concretizados através de um processo de ES universal e intuitivo (redefinido à luz dos padrões internacionais), de um método simples e de linguagens gráficas de modelação de referência (SysML e OPDs/OPL). As principais contribuições deste trabalho são, na sua essência, modelos: um modelo revisto para o processo da ES, uma metodologia ágil para ambientes de desenvolvimento baseados em modelos, uma ferramenta gráfica para suportar a metodologia proposta e o modelo de um sistema para as operações de tráfego & ambiente num contexto urbano. Contribui-se ainda com uma cuidada revisão bibliográfica para a principal área de investigação (ES/ESBM) e para o domínio de aplicação (Tráfego & Ambiente)

    Combining SOA and BPM Technologies for Cross-System Process Automation

    Get PDF
    This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation

    The model of interoperable electronic business of payments systems founded on ontologies

    Get PDF
    Predmet ove disertacije je razvoj i primena modela interoperabilnog elektronskog poslovanja platnih sistema zasnovanog na ontologijama i Resource-Event-Agent - REA (ISO/IEC 15944-4:2007) ontološkoj objektnoj strukturi sistema. Istraživanje je bazirano na globalnim poslovnim standardima finansijske industrije - referentnim modelima za razmenu informacija. Saznanja iz implementacije sistema za kliring čekova i sistema za direktno zaduženje u Udruženju banaka Srbije koji su realizovani korišćenjem obrazaca za poslovnu integraciju (EIP - Enterprise Integration Patterns) i standardizovanih sistema poruka primenjena su u istraživanju. Istraživanje je prilagođeno i za implementaciju interoperabilnih platnih sistema u Srbiji. Različiti platni sistemi u procesu elektronskog poslovanja su u interakciji sa različitim poslovnim sistemima učesnika. Poslovni sistemi učesnika podržavaju veliki broj korisnika i poslovnih procesa sa specifičnim zahtevima. Osnovni problem je heterogenost između poslovnih procesa, podataka i korišćenih IT tehnologija. Iz tog razloga vreme, finansijska sredstva i informatički resursi se troše na prevođenje podataka iz jednog sistema u drugi. Razmena finansijskih transakcija elektronskim putem postala je prevladavajuća. Time nastaje potreba za razvojem modela interoperabilnog elektronskog poslovanja platnog sistema za razmenu finansijskih transakcija i njihovu obradu. Standardizacija u domenu modeliranja platnih sistema, koja će biti razmatrana, treba da doprinese i većoj efikasnosti ostalih sistema elektronskog poslovanja i interoperabilnosti elektronskog poslovanja učesnika. U svakoj državi platni sistem se sastoji od skupa platnih instrumenata, bankarskih procedura i sistema za prenos sredstava između finansijskih institucija u cilju obezbeđivanja cirkulacije novca. Centralna banka neposredno definiše, reguliše i usmerava tokove novca i ispunjava svoju osnovnu funkciju regulatora finansijskih tokova putem kontrole platnih sistema. Najvažniji je Real Time Gross Settlement System - RTGS, sa kojim su hijerarhijski povezani sistemi banaka i drugih finansijskih institucija, pravnih i fizičkih lica. Među njima su klirinške kuće, agenti, procesorske kuće i zakonom definisane institucije koje se bave izvršenjem, procesiranjem,akvizicijom ili distribucijom informacija o finansijskim transakcijama, ali i drugi sistemi elektronskog poslovanja. Platni sistemi, na način opisan u ovom radu, objedinjuju elemente koji figurišu u svakom sistemu baziranom na porukama, tehnološke elemente nadređenih institucija koji su implicirani standardnim formatom poruka, ambijentalne uslove zadate mestom na kome se platni sistem ostvaruje (mesto u finansijskoj vertikali, vrsti procesiranja za koje je opredeljen, geopolitičkoj topologiji i drugim mogućim elementima), potrebnoj komunikacionoj interakciji, neophodnim informacionim tehnologijama za realizaciju pojedinačnih i opštih zadataka...The subject of this dissertation is development and application of the model of interoperable e-Business of payment systems based on ontologies and Resource-Event-Agent - REA (ISO/IEC 15944-4:2007) ontological object system structure. Referential models in the information exchange upon global business standards of financial industry are basis for this investigation. It will apply the experience and knowledge from the implementation of the Check Clearing and Direct Debit systems within the Association of Serbian Banks, created by the use of Enterprise Integration Patterns (EIP) and the standardized systems of messages. The investigation will be adjusted to the implementation of interoperable payment systems in Serbia. Various payment systems in the process of electronic transaction interact with various participants′ business systems. Participants’ business systems support a great number of users and business processes with specific requirements. In this, the basic problem is dissimilarity between business processes, data and IT technologies. From that reason, time, financial, and informatics resources are wasted on the data transfer from one to another system. Today, the exchange of financial transactions electronically became predominant. This calls for the development of models of interoperable e-Business of payment systems for the exchange of financial transactions and their processing. The standardization in the domain of payment system modeling, considered in this study should contribute to greater efficiency of other electronic business systems and to interoperability of participants’ electronic businesses. In every country payment system comprises a number of payment instruments, banking procedures, and the systems for the fund transfer between financial institutions. That alowws the circulation of money in the country. The Central Bank directly defines, regulates and directs the money flow, and fulfills the function of the regulator of financial flows through the control of the payment systems. The most important is Real Time Gross Settlement System - RTGS, which for the mentioned reasons, is mainly under the supervision of Central Bank. Banks′ systems and the systems of other financial institutions are connecting by RTGS System. Among them there are institutions like clearing houses, payment agents, processing houses, and other. They are defined by law, deals with implementation, processing, information acquisition, or distribution regarding financial transactions, as well as other systems of electronic business. Payment systems, on the wyu described in this work, unify the elements, existent in every system based on messages, technological elements of supervising institutions, implicated by the standard message format, ambient conditions imposed by the place with the implemented payment system (in financial vertical, with kind of processing for which it is committed, geo-political typology, and other possible elements), required communicational interaction, information technologies necessary for realization of general and specific tasks..
    corecore