40 resultados para software-defined storage
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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ICT contributed to about 0.83 GtCO2 emissions where the 37% comes from the telecoms infrastructures. At the same time, the increasing cost of energy has been hindering the industry in providing more affordable services for the users. One of the sources of these problems is said to be the rigidity of the current network infrastructures which limits innovations in the network. SDN (Software Defined Network) has emerged as one of the prominent solutions with its idea of abstraction, visibility, and programmability in the network. Nevertheless, there are still significant efforts needed to actually utilize it to create a more energy and environmentally friendly network. In this paper, we suggested and developed a platform for developing ecology-related SDN applications. The main approach we take in realizing this goal is by maximizing the abstractions provided by OpenFlow and to expose RESTful interfaces to modules which enable energy saving in the network. While OpenFlow is made to be the standard for SDN protocol, there are still some mechanisms not defined in its specification such as settings related to Quality of Service (QoS). To solve this, we created REST interfaces for setting of QoS in the switches which can maximize network utilization. We also created a module for minimizing the required network resources in delivering packets across the network. This is achieved by utilizing redundant links when it is needed, but disabling them when the load in the network decreases. The usage of multi paths in a network is also evaluated for its benefit in terms of transfer rate improvement and energy savings. Hopefully, the developed framework can be beneficial for developers in creating applications for supporting environmentally friendly network infrastructures.
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Työssä tutkitaan tiedonsiirtoa eri modulaatioilla, bittinopeuksilla ja amplitudin voimakkuuksilla ja tuloksia tarkastellaan Bit Error Ration avulla. Signaaleja siirrettiiin myös koodattuna ja vertailtiin koodauksen etuja ja haittoja verrattuna koodaamattomaan tietoon. Datavirta kulkee AXMK-kaapelissa, joko tasasähkön mukana, tai maadoituskaapelissa. Tuloksissa havaittiin, että suurempi bittinopeus ei kasvattanut häviöiden määrää. Koodauksen käyttö toisaalta vähenti bittivirheiden määrää.
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As computer networks grow larger and more complex there is a need for a new, simpler kind of approach to configuring them. Software Defined Networking (SDN) takes the control plane away from individual nodes and centralizes the network control by utilizing a flow based traffic management. In this thesis the suitability of SDN in a small ISP (Internet Service Provider) network is considered for an alternative to the current traditional core network and access network OSSs (Operations Support System), mainly to simplify the network management but also to see what else would SDN offer for such an environment. Combining information learned from a theoretical study on the matter to a more practical experiment of SDN network simulation using Mininet simulation software and OpenDayLight SDN controller software does this. Although the simulation shows that SDN is able to provide the functionality needed for the network, the immaturity of the technology suggests that for a small ISP network there is no need to utilize SDN just yet. For when SDN becomes more commonplace a brief transition plan is introduced.
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Software projects have proved to be troublesome to be implemented and as the size of software keeps increasing it is more and more important to follow-up the projects. The proportion of succeeded software projects is still quite low in spite of the research and the development of the project control methodologies. The success and failure factors of projects are known, as well as the project risks but nevertheless the projects still have problems with keeping the schedule and the budget and achieving the defined functionality and adequate quality. The purpose of this thesis was to find out what deviations are there in projects at the moment, what causes them, and what is measured in projects. Also project deviation was defined in the viewpoint of literature and field experts. The analysis was made using a qualitative research approach. It was found out that there are still deviations in software projects with schedule, budget, quality, requirements, documenting, effort, and resources. In addition also changes in requirements were identified. It was also found out that for example schedule deviations can be affected by reducing the size of a task and adding measurements.
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Tämä diplomityö kuvaa viestintä sovelluksen ytimen kehitystyön Symbian-alustalle. Koko sovelluksen vaatimuksena oli vastaamattomiin puheluihin vastaaminen ennalta määritellyillä tekstiviesteillä käyttäjän määrittelemien sääntöjen mukaisesti. Ei-toiminnallisia vaatimuksia olivat resurssien käytön vähentäminen ja uudelleenkäytön mahdollistaminen. Täten tämän työn tavoitteena oli kehittää ydin, joka kapseloi sovelluksen sellaisen toiminnallisuuden, joka on käyttöliittymästä riippumatonta ja uudelleenkäytettävää. Kehitystyössä ohjasi Unified Process, joka on iteroiva, käyttötapauksien ohjaama ja arkkitehtuurikeskeinen ohjelmistoprosessi. Se kannusti käyttämään myös muita teollisuudenalan vakiintuneita menetelmiä, kuten suunnittelumalleja ja visuaalista mallintamista käyttäen Unified Modelling Languagea. Suunnittelumalleja käytettiin kehitystyön aikana ja ohjelmisto mallinnettiin visuaalisesti suunnittelun edistämiseksi ja selkiyttämiseksi. Alustan palveluita käytettiin hyväksi kehitysajan ja resurssien käytön minimoimiseksi. Ytimen päätehtäviksi määrättiin viestien lähettäminen sekä sääntöjen talletus ja tarkistaminen. Sovelluksen eri alueet, eli sovelluspalvelin ja käyttöliittymää, pystyivät käyttämään ydintä ja sillä ei ollut riippuvuuksia käyttöliittymätasolle. Täten resurssien käyttö väheni ja uudelleenkäytettävyys lisääntyi. Viestien lähettäminen toteutettiin Symbian-alustan menetelmin. Sääntöjen tallettamiseen tehtiin tallennuskehys, joka eristää sääntöjen sisäisen ja ulkoisen muodon. Tässä tapauksessa ulkoiseksi tallennustavaksi valittiin relaatiotietokanta. Sääntöjen tarkastaminen toteutettiin tavanomaisella olioiden yhteistoiminnalla. Päätavoite saavutettiin. tämä ja muut hyviksi arvioidut lopputulokset, kuten uudelleenkäytettävyys ja vähentynyt resurssien käyttö, arveltiin juontuvan suunnittelumallien ja Unified Processin käytöstä. Kyseiset menetelmät osoittivat mukautuvansa pieniinkin projekteihin. Menetelmien todettiin myös tukevan ja kannustavan kehitystyön aikaista oppimista, mikä oli välttämätöntä tässä tapauksessa.
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Tässä työssä tutkitaan ohjelmistoarkkitehtuurisuunnitteluominaisuuksien vaikutusta erään client-server –arkkitehtuuriin perustuvan mobiilipalvelusovelluksen suunnittelu- ja toteutusaikaan. Kyseinen tutkimus perustuu reaalielämän projektiin, jonka kvalitatiivinen analyysi paljasti arkkitehtuurikompponenttien välisten kytkentöjen merkittävästi vaikuttavan projektin työmäärään. Työn päätavoite oli kvantitatiivisesti tutkia yllä mainitun havainnon oikeellisuus. Tavoitteen saavuttamiseksi suunniteltiin ohjelmistoarkkitehtuurisuunnittelun mittaristo kuvaamaan kyseisen järjestelmän alijärjestelmien arkkitehtuuria ja luotiin kaksi suunniteltua mittaristoa käyttävää, työmäärää (komponentin suunnittelu-, toteutus- ja testausaikojen summa) arvioivaa mallia, joista toinen on lineaarinen ja toinen epälineaarinen. Näiden mallien kertoimet sovitettiin optimoimalla niiden arvot epälineaarista gloobaalioptimointimenetelmää, differentiaalievoluutioalgoritmia, käyttäen, niin että mallien antamat arvot vastasivat parhaiten mitattua työmäärää sekä kaikilla ominaisuuksilla eli attribuuteilla että vain osalla niistä (yksi jätettiin vuorotellen pois). Kun arkkitehtuurikompenttien väliset kytkennät jätettiin malleista pois, mitattujen ja arvoitujen työmäärien välinen ero (ilmaistuna virheenä) kasvoi eräässä tapauksessa 367 % entisestä tarkoittaen sitä, että näin muodostettu malli vastasi toteutusaikoja huonosti annetulla ainestolla. Tämä oli suurin havaitu virhe kaikkien poisjätettyjen ominaisuuksien kesken. Saadun tuloksen perusteella päätettiin, että kyseisen järjestelmän toteutusajat ovat vahvasti riippuvaisia kytkentöjen määrästä, ja näin ollen kytkentöjen määrä oli mitä todennäköisemmin kaikista tärkein työmäärään vaikuttava tekijä tutkitun järjestelmän arkkitehtuurisuunnittelussa.
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Diplomityön tavoitteena oli kehittää kolmannen sukupolven fyysistä protokollakerrosta matkapuhelimen ohjelmistoarkkitehtuurille. Kolmannen sukupolven matkapuhelinjärjestelmät ovat aikaisempia järjestelmiä monimutkaisempia. Ohjelmiston koon ja monimutkaisuuden sekä aikataulujen kiireellisyyden vuoksi on tullut tarve ottaa käyttöön formaaleja menetelmiä ohjelmiston kehitystyöhön. Formaalit kuvauskielet mahdollistavat tarkan, yksiselitteisen ja simuloitavissa olevan järjestelmäkuvauksen muodostamisen. Fyysinen protokollakerros tarjoaa tiedon siirtoa ylemmille protokollakerroksille. Tämän tiedonsiirron hallinta vaatii protokollakerrosten välistä viestinvälitystä. Formaaleja kuvauskieliä käyttämällä voidaan viestinvälityksen toteutusta automatisoida ja siinä tarvittavaa logiikkaa havainnollistaa. Työssä suunniteltiin, toteutettiin ja testattiin ylempien protokollakerrosten kanssa kommunikoivaa osaa fyysisestä protokollakerroksesta. Tuloksena saatiin solunvalintatoiminnallisuuden vaatiman kommunikoinnin ja tilakoneen toteutus ohjelmistoarkkitehtuurissa. Ohjelmistonkehityksen alkuvaiheiden havaittiin olevan fyysisen kerroksen suorituskyvyn kannalta merkittävässä asemassa, koska tällöin viestinvälityksen optimointi on helpointa. Formaalit kuvauskielet eivät ole sellaisenaan täysin soveltuvia tarkoin määritellyn ohjelmistoarkkitehtuurin osien kehitykseen.
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Currently there is a vogue for Agile Software Development methods and many software development organizations have already implemented or they are planning to implement agile methods. Objective of this thesis is to define how agile software development methods are implemented in a small organization. Agile methods covered in this thesis are Scrum and XP. From both methods the key practices are analysed and compared to waterfall method. This thesis also defines implementation strategy and actions how agile methods are implemented in a small organization. In practice organization must prepare well and all needed meters are defined before the implementation starts. In this work three different sample projects are introduced where agile methods were implemented. Experiences from these projects were encouraging although sample set of projects were too small to get trustworthy results.
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The aim of this master´s thesis is to study which processes increase the auxiliary power consumption in carbon capture and storage processes and if it is possible to reduce the auxiliary power consumption with variable speed drives. Also the cost of carbon capture and storage is studied. Data about auxiliary power consumption in carbon capture is gathered from various studies and estimates made by various research centres. Based on these studies a view is presented how the power auxiliary power consumption is divided between different processes in carbon capture processes. In a literary study, the operation of three basic carbon capture systems is described. Also different methods to transport carbon dioxide and carbon dioxide storage options are described in this section. At the end of the thesis processes that consume most of the auxiliary power are defined and possibilities to reduce the auxiliary power consumption are evaluated. Cost of carbon capture, transport and storage are also evaluated at this point and in the case that the carbon capture and storage systems are fully deployed. According to the results, it can be estimated what are the processes are where variable speed drives can be used and what kind of cost and power consumption reduction could be achieved. Results also show how large a project carbon capture and storage is if it is fully deployed.
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Cloud computing enables on-demand network access to shared resources (e.g., computation, networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort. Cloud computing refers to both the applications delivered as services over the Internet and the hardware and system software in the data centers. Software as a service (SaaS) is part of cloud computing. It is one of the cloud service models. SaaS is software deployed as a hosted service and accessed over the Internet. In SaaS, the consumer uses the provider‘s applications running in the cloud. SaaS separates the possession and ownership of software from its use. The applications can be accessed from any device through a thin client interface. A typical SaaS application is used with a web browser based on monthly pricing. In this thesis, the characteristics of cloud computing and SaaS are presented. Also, a few implementation platforms for SaaS are discussed. Then, four different SaaS implementation cases and one transformation case are deliberated. The pros and cons of SaaS are studied. This is done based on literature references and analysis of the SaaS implementations and the transformation case. The analysis is done both from the customer‘s and service provider‘s point of view. In addition, the pros and cons of on-premises software are listed. The purpose of this thesis is to find when SaaS should be utilized and when it is better to choose a traditional on-premises software. The qualities of SaaS bring many benefits both for the customer as well as the provider. A customer should utilize SaaS when it provides cost savings, ease, and scalability over on-premises software. SaaS is reasonable when the customer does not need tailoring, but he only needs a simple, general-purpose service, and the application supports customer‘s core business. A provider should utilize SaaS when it offers cost savings, scalability, faster development, and wider customer base over on-premises software. It is wise to choose SaaS when the application is cheap, aimed at mass market, needs frequent updating, needs high performance computing, needs storing large amounts of data, or there is some other direct value from the cloud infrastructure.
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Formal software development processes and well-defined development methodologies are nowadays seen as the definite way to produce high-quality software within time-limits and budgets. The variety of such high-level methodologies is huge ranging from rigorous process frameworks like CMMI and RUP to more lightweight agile methodologies. The need for managing this variety and the fact that practically every software development organization has its own unique set of development processes and methods have created a profession of software process engineers. Different kinds of informal and formal software process modeling languages are essential tools for process engineers. These are used to define processes in a way which allows easy management of processes, for example process dissemination, process tailoring and process enactment. The process modeling languages are usually used as a tool for process engineering where the main focus is on the processes themselves. This dissertation has a different emphasis. The dissertation analyses modern software development process modeling from the software developers’ point of view. The goal of the dissertation is to investigate whether the software process modeling and the software process models aid software developers in their day-to-day work and what are the main mechanisms for this. The focus of the work is on the Software Process Engineering Metamodel (SPEM) framework which is currently one of the most influential process modeling notations in software engineering. The research theme is elaborated through six scientific articles which represent the dissertation research done with process modeling during an approximately five year period. The research follows the classical engineering research discipline where the current situation is analyzed, a potentially better solution is developed and finally its implications are analyzed. The research applies a variety of different research techniques ranging from literature surveys to qualitative studies done amongst software practitioners. The key finding of the dissertation is that software process modeling notations and techniques are usually developed in process engineering terms. As a consequence the connection between the process models and actual development work is loose. In addition, the modeling standards like SPEM are partially incomplete when it comes to pragmatic process modeling needs, like light-weight modeling and combining pre-defined process components. This leads to a situation, where the full potential of process modeling techniques for aiding the daily development activities can not be achieved. Despite these difficulties the dissertation shows that it is possible to use modeling standards like SPEM to aid software developers in their work. The dissertation presents a light-weight modeling technique, which software development teams can use to quickly analyze their work practices in a more objective manner. The dissertation also shows how process modeling can be used to more easily compare different software development situations and to analyze their differences in a systematic way. Models also help to share this knowledge with others. A qualitative study done amongst Finnish software practitioners verifies the conclusions of other studies in the dissertation. Although processes and development methodologies are seen as an essential part of software development, the process modeling techniques are rarely used during the daily development work. However, the potential of these techniques intrigues the practitioners. As a conclusion the dissertation shows that process modeling techniques, most commonly used as tools for process engineers, can also be used as tools for organizing the daily software development work. This work presents theoretical solutions for bringing the process modeling closer to the ground-level software development activities. These theories are proven feasible by presenting several case studies where the modeling techniques are used e.g. to find differences in the work methods of the members of a software team and to share the process knowledge to a wider audience.
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Scrum is an agile project management approach that has been widely practiced in the software development projects. It has proven to increase quality, productivity, customer satisfaction, transparency and team morale among other benefits from its implementation. The concept of scrum is based on the concepts of incremental innovation strategies, lean manufacturing, kaizen, iterative development and so on and is usually contrasted with the linear development models such as the waterfall method in the software industry. The traditional approaches to project management such as the waterfall method imply intensive upfront planning and approval of the entire project. These sort of approaches work well in the well-defined stable environments where all the specifications of the project are known in the beginning. However, in the uncertain environments when a project requires continuous development and incorporation of new requirements, they do not tend to work well. The scrum framework was inspiraed by Nonaka’s article about new product developement and was later adopted by software development practitioners. This research explores conditions for and benefits of the application of scrum framework beyond software development projects. There are currently a few case studies on the scrum implementation in non-software projects, but there is a noticeable trend of it in the scrum practitioners’ community. The research is based on the real-life context multiple case study analysis of three different non-software projects. The results of the research showed that in order to succeed within scrum projects need to satisfy certain conditions – necessary and sufficient. Among them the key factors are uncertainty of the project environment, not well defined outcomes, commitment of the scrum teams and management support. The top advantages of scrum implementation identified in the present research include improved transparency, accountability, team morale, communications, cooperation and collaboration. Further researches are advised to be carried out in order to validate these findings on a larger sample and to focus on more specific areas of scrum project management implementation.
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Software quality has become an important research subject, not only in the Information and Communication Technology spheres, but also in other industries at large where software is applied. Software quality is not a happenstance; it is defined, planned and created into the software product throughout the Software Development Life Cycle. The research objective of this study is to investigate the roles of human and organizational factors that influence software quality construction. The study employs the Straussian grounded theory. The empirical data has been collected from 13 software companies, and the data includes 40 interviews. The results of the study suggest that tools, infrastructure and other resources have a positive impact on software quality, but human factors involved in the software development processes will determine the quality of the products developed. On the other hand, methods of development were found to bring little effect on software quality. The research suggests that software quality is an information-intensive process whereby organizational structures, mode of operation, and information flow within the company variably affect software quality. The results also suggest that software development managers influence the productivity of developers and the quality of the software products. Several challenges of software testing that affect software quality are also brought to light. The findings of this research are expected to benefit the academic community and software practitioners by providing an insight into the issues pertaining to software quality construction undertakings.
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After a productivity decrease of established national export industries in Finland such as mobile and paper industries, innovative, smaller companies with the intentions to internationalize right from the start have been proliferating. For software companies early internationalization is an especially good opportunity, as Internet usage becomes increasingly homogeneous across borders and software products often do not need a physical distribution channel. Globalization also makes Finnish companies turn to unfamiliar export markets like Latin America, a very untraditional market for Finns. Relationships consisting of Finnish and Latin American business partners have therefore not been widely studied, especially from a new-age software company’s perspective. To study these partnerships, relationship marketing theory was taken into the core of the study, as its practice focuses mainly on establishing and maintaining relationships with stakeholders at a profit, so that the objectives of all parties are met, which is done by a mutual exchange and fulfillment of promises. The most important dimensions of relationship marketing were identified as trust, commitment and attraction, which were then focused on, as the study aims to understand the implications Latin American business culture has for the understanding, and hence, effective application of relationship marketing in the Latin American market. The question to be answered consecutively was how should the dimensions of trust, commitment and attraction be understood in business relationships in Latin America? The study was conducted by first joining insights given by Latin American business culture literature with overall theories on the three dimensions. Through pattern matching, these insights were compared to empirical evidence collected from business professionals of the Latin American market and from the experiences of Finnish software businesses that had recently expanded into the market. What was found was that previous literature on Latin American business culture had already named many implications for the relationship marketing dimensions that were relevant also for small Finnish software firms on the market. However, key findings also presented important new drivers for the three constructs. Local presence in the area where the Latin American partner is located was found to drive or enhance trust, commitment and attraction. High-frequency follow up procedures were in turn found to drive commitment and attraction. Both local presence and follow up were defined according to the respective evidence in the study. Also, in the context of Finnish software firms in relationships with Latin American partners, the national origins or the foreignness of the Finnish party was seen to enhance trust and attraction in the relationship