36 resultados para networks text analysis text network graph Gephi network measures shuffed text Zipf Heap Python

em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland


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Cyber security is one of the main topics that are discussed around the world today. The threat is real, and it is unlikely to diminish. People, business, governments, and even armed forces are networked in a way or another. Thus, the cyber threat is also facing military networking. On the other hand, the concept of Network Centric Warfare sets high requirements for military tactical data communications and security. A challenging networking environment and cyber threats force us to consider new approaches to build security on the military communication systems. The purpose of this thesis is to develop a cyber security architecture for military networks, and to evaluate the designed architecture. The architecture is described as a technical functionality. As a new approach, the thesis introduces Cognitive Networks (CN) which are a theoretical concept to build more intelligent, dynamic and even secure communication networks. The cognitive networks are capable of observe the networking environment, make decisions for optimal performance and adapt its system parameter according to the decisions. As a result, the thesis presents a five-layer cyber security architecture that consists of security elements controlled by a cognitive process. The proposed architecture includes the infrastructure, services and application layers that are managed and controlled by the cognitive and management layers. The architecture defines the tasks of the security elements at a functional level without introducing any new protocols or algorithms. For evaluating two separated method were used. The first method is based on the SABSA framework that uses a layered approach to analyze overall security of an organization. The second method was a scenario based method in which a risk severity level is calculated. The evaluation results show that the proposed architecture fulfills the security requirements at least at a high level. However, the evaluation of the proposed architecture proved to be very challenging. Thus, the evaluation results must be considered very critically. The thesis proves the cognitive networks are a promising approach, and they provide lots of benefits when designing a cyber security architecture for the tactical military networks. However, many implementation problems exist, and several details must be considered and studied during the future work.

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Cross-sector collaboration and partnerships have become an emerging and desired strategy in addressing huge social and environmental challenges. Despite its popularity, cross-sector collaboration management has proven to be very challenging. Even though cross-sector collaboration and partnership management have been widely studied and discussed in recent years, their effectiveness as well as their ability to create value with respect to the problems they address has remained very challenging. There is little or no evidence of their ability to create value. Regarding all these challenges, this study aims to explore how to manage cross-sector collaborations and partnerships to be able to improve their effectiveness and to create more value for all partners involved in collaboration as well as for customers. The thesis is divided into two parts. The first part comprises an overview of relevant literature (including strategic management, value networks and value creation theories), followed by presenting the results of the whole thesis and the contribution made by the study. The second part consists of six research publications, including both quantitative and qualitative studies. The chosen research strategy is triangulation, as the study includes four types of triangulation: (1) theoretical triangulation, (2) methodological triangulation, (3) data triangulation and (4) researcher triangulation. Two publications represent conceptual development, which are based on secondary data research. One publication is a quantitative study, carried out through a survey. The other three publications represent qualitative studies, based on case studies, where data was collected through interviews and workshops, with participation of managers from all three sectors: public, private and the third (nonprofit). The study consolidates the field of “strategic management of value networks,” which is proposed to be applied in the context of cross-sector collaboration and partnerships, with the aim of increasing their effectiveness and the process of value creation. Furthermore, the study proposes a first definition for the strategic management of value networks. The study also proposes and develops two strategy tools that are recommended to be used for the strategic management of value networks in cross-sector collaboration and partnerships. Taking a step forward, the study implements the strategy tools in practice, aiming to show and to demonstrate how new value can be created by using the developed strategy tools for the strategic management of value networks. This study makes four main contributions. (1) First, it brings a theoretical contribution by providing new insights and consolidating the field of strategic management of value networks, also proposing a first definition for the strategic management of value networks. (2) Second, the study makes a methodical contribution by proposing and developing two strategy tools for value networks of cross-sector collaboration: (a) value network mapping, a method that allows us to assess the current and the potential value network and (b) the Value Network Scorecard, a method of performance measurement and performance prediction in cross-sector collaboration. (3) Third, the study has managerial implications, offering new solutions and empirical evidence on how to increase the effectiveness of cross-sector collaboration and also allow managers to understand how new value can be created in cross-sector partnerships and how to get the full potential of collaboration. (4) And fourth, the study also has practical implications, allowing managers to understand how to use in practice the strategy tools developed in this study, providing discussions on the limitations regarding the proposed tools as well as general limitations involved in the study.

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Diplomityössä määritellään sähkönjakeluverkon suunnitteluperusteet. Suunnitteluperusteet antavat ohjeet verkostosuunnittelijoille siitä, miten sähköverkko suunnitellaan sähköteknisesti oikein, taloudelliset näkökohdat huomioiden. Työn alussa määritellään kaikkiin suunnittelutehtäviin vaikuttavat sähkötekniset ja taloudelliset laskentaparametrit. Oikeiden parametrien käyttäminen on ehdottoman tärkeää totuudenmukaisten lopputulosten saavuttamiseksi. Eniten lopputuloksiin vaikuttaville laskentaparametreille suoritetaan työn loppuosassa herkkyysanalyysi, jotta tulevaisuuden mahdollisesti erilaiset olosuhteet voitaisiin huomioida. Varsinaisissa suunnitteluun liittyvissä osioissa käsitellään keski- ja pienjänniteverkkojen suunnittelunlisäksi jakelumuuntajan mitoittaminen, sekä määritellään rajat erilaisille verkoston rakenteille. Erityisesti elinkaarikustannusajattelua painotetaan suunnittelutehtävissä ottamalla huomioon komponenttien koko pitoaikana syntyvät kustannukset.

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Langattomien lähiverkkotekniikoiden yleistyessä langattomien verkkojen ja palveluiden kysyntä on kasvanut nopeasti. Varsinkin vuonna 1997 julkistettu IEEE:n 802.11b-standardi on mahdollistanut langattomien verkkotekniikoiden nopean kehityksen. Tässä työssä esitetään suunnitelma kahden verkon välisen rajapinnan rakenteesta ja to-teutuksesta. Rajapintaa kutsutaan yhdysliikennepisteeksi. Sen pääasiallisena tehtävänä on toimia solmupisteenä kaikelle verkkojen väliselle tietoliikenteelle ja hallinnoida niin sisäverkkoa käyttäjineen kuin ulkoverkon puolelle kytkettyjä operaattoreita. Yhdyslii-kennepisteen tehtävänä on tunnistaa sisäverkon käyttäjät, auktorisoida heidät yhteis-työssä operaattorien kanssa, huolehtia sisäverkon käyttäjien verkko-osoitteista ja toimia verkkoliikenteen välittäjänä. Yhdysliikennepiste kykenee reitittämään käyttäjän oikealle operaattorille ja huolehtii siitä, että käyttäjällä on pääsy palveluihin, joiden käyttämiseen tällä on valtuutus. Työssä määritellään yhdysliikennepisteen rajapinnat sekä siihen liitettäviä operaattoreita että sisäverkkoon tarjottavia peruspalveluita varten. Lisäksi määritellään yhdysliikenne-pisteen sisäiset rajapinnat. Yhdysliikennepiste ei rajoita käytettyä verkkotekniikkaa, mutta tässä työssä keskitytään IEEE 802.11b -standardin mukaisiin WLAN-verkkoihin. Yhden tai useamman operaattorin verkkoja on olemassa sekä langallisessa että langat-tomissa ympäristöissä. Näissä verkoissa jokainen Internet-operaattori huolehtii kuiten-kin vain omista asiakkaistaan. Sisäverkko on suljettu, siihen pääsevät liittymään vain operaattorin omat asiakkaat. Työn tuloksena syntynyt yhdysliikennepiste on ratkaisu, jonka avulla voidaan rakentaa monioperaattorialueverkko, joka on avoin kaikille sen käyttäjille.

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Tämän pro gradu-tutkimuksen tavoitteena oli tutkia strategista verkoston kehittämistä rakennusalalla maalausaliurakoitsijayrityksen näkökulmasta. Tavoitteena oli vastata miten aliurakoitsijayritys voisi strategisesti kehittää verkostojaan ja muodostaa kokonaiskäsitys rakennusalan nykyisestä kilpailuympäristöstä ja hahmottaa rakennusalan verkostoympäristöä. Tämän kvalitatiivisen tutkimuksen teoriaosa käsittelee strategisen verkostoitumisen motiiveita, kuvaa erilaisia strategisia verkostotyyppejä sekä nostaa esiin verkostoitumisen haasteita. Tutkimuksen empiirinen osa muodostui haastattelemalla Lahden ja lähialueiden rakennusliikkeiden keskijohtoa. Tutkimusmetodina käytettiin teemahaastattelua. Tutkimustulokset osoittavat, että aliurakointia pääasiassa tekevän rakennusalan pk-yrityksen on mahdollista kehittää yhteistyösuhteitaan ja verkostojaan strategisesti. Strateginen vertikaalinen yhteistyö on helpommin mahdollista erikoistumalla. Lisäksi joustavuus, sitoutuminen ja luottamus ovat olennaisia arvoa lisääviä ominaisuuksia alalla.

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Vuonna 2013 uudistunut sähkömarkkinalaki toi sähköverkkoyhtiöille velvoitteen parantaa sähkönjakeluverkkojensa toimintavarmuutta suurhäiriötilanteissa. Toimenpiteet tämän velvoitteen täyttämiseksi näkyvät merkittävinä verkostoinvestointeina. Diplomityössä tarkastellaan uudistuneen sähkömarkkinalain tuomia vaikutuksia Imatran Seudun Sähkön jakeluverkkoa koskeviin verkostoinvestointeihin. Päätavoitteena on selvittää, millaisia toimenpiteitä uuden sähköntoimitusvarmuustason vaatimusten täyttämiseksi tarvitaan ja mitkä ovat optimaaliset ratkaisut näiden toimenpiteiden toteuttamiseksi. Uudella sähköntoimitusvarmuustasolla on vaikutusta jakeluverkon rakennemuutoksiin tulevien 15 vuoden aikana, mutta näiden rakennemuutosten vaikutukset kantavat useiden kymmenien vuosien päähän.

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Well managed information promotes competitive advantage and economic value for the company. The challenge is to use information effectively in complex networks. Decision making in network is complicated due to many independent sources of information. The aim of the present study was to identify and map the internal information flows and used information resourced by functions and roles, to make proposals to the case organization to improve the information management and to improve the situational awareness and process flows. In the present study, an inductive approach was applied, with the aim to find out gaps and bottlenecks of information flow of an aircraft maintenance organization and its network. The empirical part was conducted with observing the processes and with questionnaires. Theoretical part of this study consists on reviewing relevant literature on maintenance management in aviation and information management in aviation. Together with empirical evidence and the literature used in the study the gaps were found and suggestions for improvements were done. The outcome of this study contributes the organization in its bigger goal to improve the productivity. The information management of the network is one actor in the field and will pave the way to smoother operation and situational awareness. The lack of rules and requirements for information management and spreading is a challenge in information management. The excessive data overburden may cause problem in the actors’ situation-awareness due to non-availability of the right information.

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Tämän tutkimuksen tavoitteena oli selvittää kuinka yrittäjän verkostot muodostuvat ja minkälainen niiden rakenne on. Tavoitteena oli myös saada tietoa yrittäjän sosiaalisten verkostojen merkityksestä yrittäjälle. Tutkimus toteutettiin laadullisena tutkimuksena. Tutkimusaineisto kerättiin strukturoidulla haastattelulla ja tutkimusaineiston rinnalla käytettiin yrittäjien havainnollistamia piirroksia sekä tieteellisiä julkaisuja ja kirjallisuutta. Haastateltavina oli sekä nais- että miesyrittäjiä eri paikkakunnilta Etelä-Suomen alueelta. Tutkimustulosten mukaan yrittäjien verkostoissa voidaan havaita eri tasoja, jotka rakentuvat eri tavoilla ja ovat yrittäjälle merkitykseltään erilaisia. Verkoston eri tasoille sijoittuu yrittäjälle tärkeitä ihmisiä sen mukaan mitä hyötyä ja arvoa heillä yrittäjälle on. Tulokset osoittavat, että verkostojen rakentamiseen vaikuttavat sekä liiketoiminnan laatu, motiivit sekä yrittäjän persoona. Tulokset ovat linjassa tämän tutkimuksen perustana olevien teorioiden kanssa. Viitteitä löytyy myös siitä, että yrittäjän sukupuolella on myös merkitystä siihen, millaiseksi sosiaaliset verkostot rakentuvat sekä henkilökohtaisessa elämässä että liike-elämän puolella. Sosiaalisista verkostoista saatavat hyödyt ovat moninaisia. Lisätutkimuksia tulisi tehdä tehokkaiden työkalujen kehittämiseksi henkilöstön ja yrittäjän omien resurssien tunnistamiseksi. Tätä kautta myös yrittäjyyskasvatusta ja yrittäjäneuvontaa voitaisiin tehostaa.

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An exchange traded fund (ETF) is a financial instrument that tracks some predetermined index. Since their initial establishment in 1993, ETFs have grown in importance in the field of passive investing. The main reason for the growth of the ETF industry is that ETFs combine benefits of stock investing and mutual fund investing. Although ETFs resemble mutual funds in many ways, also many differences occur. In addition, ETFs not only differ from mutual funds but also differ among each other. ETFs can be divided into two categories, i.e. market capitalisation ETFs and fundamental (or strategic) ETFs, and further into subcategories depending on their fundament basis. ETFs are a useful tool for diversification especially for a long-term investor. Although the economic importance of ETFs has risen drastically during the past 25 years, the differences and risk-return characteristics of fundamental ETFs have yet been rather unstudied area. In effect, no previous research on market capitalisation and fundamental ETFs was found during the research process. For its part, this thesis seeks to fill this research gap. The studied data consist of 50 market capitalisation ETFs and 50 fundamental ETFs. The fundaments, on which the indices that the fundamental ETFs track, were not limited nor segregated into subsections. The two types of ETFs were studied at an aggregate level as two different research groups. The dataset ranges from June 2006 to December 2014 with 103 monthly observations. The data was gathered using Bloomberg Terminal. The analysis was conducted as an econometric performance analysis. In addition to other econometric measures, the methods that were used in the performance analysis included modified Value-at-Risk, modified Sharpe ratio and Treynor ratio. The results supported the hypothesis that passive market capitalisation ETFs outperform active fundamental ETFs in terms of risk-adjusted returns, though the difference is rather small. Nevertheless, when taking into account the higher overall trading costs of the fundamental ETFs, the underperformance gap widens. According to the research results, market capitalisation ETFs are a recommendable diversification instrument for a long-term investor. In addition to better risk-adjusted returns, passive ETFs are more transparent and the bases of their underlying indices are simpler than those of fundamental ETFs. ETFs are still a young financial innovation and hence data is scarcely available. On future research, it would be valuable to research the differences in risk-adjusted returns also between the subsections of fundamental ETFs.

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Työn tavoitteena oli kehittää yritykselle selkeä ja toimiva hankintatoiminnan suorituskykymittaristo, jonka avulla tietojärjestelmien tuottama tietosaadaan hyötykäyttöön. Tavoitteena oli myös selvittää yrityksen hankintatoiminnan nykytila. Selvitys auttoi sopivien mittareiden valinnassa. Teoriaosassa käsiteltiin suorituskyvyn mittaamista hankintatoiminnassa, mittariston suunnittelua ja käyttöönoton vaiheita sekä erilaisia malliratkaisuja hankintatoiminnan suorituskyvyn mittaamiselle. Empiirisessä osassa perehdyttiin yrityksen hankintatoiminnan nykytilaan sekä rakennettiin teorian, nykytila-analyysin ja hankintahenkilökunnan näkemysten pohjalta suorituskykymittaristo yrityksen osto-osastolle. Hankintatoiminnan nykytilanteen arvioinnissa korostuivat parhaillaan tapahtuvat suuret muutokset. Suorituskykymittaristo laadittiin siten, että se kattaa tärkeimmät osa-alueet myymäläketjun hankintatoiminnassa. Työn tuloksena kehitetty mittaristo koostuu toimittaja-, valikoima-, materiaalivirta- sekä varastomittareista.

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The objective of the thesis was to create a performance measurement system for the logistics process of a company. In addition, one goal was to make suggestions for improvements based on description and analysis of the process and current measures. The logistics process was described in detail, and the objectives for it were derived from the company strategy and goals. Suggestions for performance measurement system and process improvement were made based on current state analysis. As a result of the thesis, three new performance measures were decided to take into use. In addition, several improvements were suggested to the ERP system to make process smoother. Some of the improvements have already been added to the system and the rest will be added in the near future.

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Maritime safety is an issue that has gained a lot of attention in the Baltic Sea area due to the dense maritime traffic and transportation of oil in the area. Lots of effort has been paid to enhance maritime safety in the area. The risk exists that excessive legislation and other requirements mean more costs for limited benefit. In order to utilize both public and private resources efficiently, awareness is required of what kind of costs maritime safety policy instruments cause and whether the costs are in relation to benefits. The aim of this report is to present an overview of the cost-effectiveness of maritime safety policy instruments focusing on the cost aspect: what kind of costs maritime safety policy causes, to whom, what affects the cost-effectiveness and how cost-effectiveness is studied. The study is based on a literature review and on the interviews of Finnish maritime experts. The results of this study imply that cost-effectiveness is a complicated issue to evaluate. There are no uniform practices for which costs and benefits should be included in the evaluation and how they should be valued. One of the challenges is how to measure costs and benefits during the course of a longer time period. Often a lack of data erodes the reliability of evaluation. In the prevention of maritime accidents, costs typically include investments in ship structures or equipment, as well as maintenance and labor costs. Also large investments may be justifiable if they respectively provide significant improvements to maritime safety. Measures are cost-effective only if they are implemented properly. Costeffectiveness is decreased if a measure causes overlapping or repetitious work. Costeffectiveness is also decreased if the technology isn’t user-friendly or if it is soon replaced with a new technology or another new appliance. In future studies on the cost-effectiveness of maritime safety policy, it is important to acknowledge the dependency between different policy instruments and the uncertainty of the factors affecting cost-effectiveness. The costs of a single measure are rarely relatively significant and the effect of each measure on safety tends to be positive. The challenge is to rank the measures and to find the most effective combination of different policy instruments. The greatest potential offered for the analysis of cost-effectiveness of individual measures is their implementation in clearly defined risk situations, in which different measures are truly alternative to each other. Overall, maritime safety measures do not seem to be considered burdening for the shipping industry in Finland at the moment. Generally actors in the Finnish shipping industry seem to find maintaining a high safety level important and act accordingly.

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This final project was made for the Broadband department of TeliaSonera. This project gives an overview on how internet service provider might build an access network so that they can offer triple-play services. It also gives information on what equipment is needed and what is required from the access, aggregation and edge networks. The project starts by describing the triple-play service. Then it moves on to optical fiber cables, the network technology and network architecture. At the end of the project there is an example of the process and construction of the access network. It will give an overview of the total process and problems that a network planner might face during the planning phase of the project. It will give some indication on how one area is built from the start to finish. The conclusion of the project presents some points that must be taken into consideration when building an access network. The building of an access network has to be divided to a time span of eight to ten years, where one year is one phase in the project. One phase is divided into three parts; Selecting the areas and targets, Planning the areas and targets, and Documentation. The example area gives indication on the planning of an area. It is almost impossible to connect all targets at the same time. This means that the service provider has to complete the construction in two or three parts. The area is considered to be complete when more than 80% of the real estates have fiber.

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There are several factors affecting network performance. Some of these can be controlled whereas the others are more fixed. These factors are studied in this thesis from the wide area network (WAN) perspective and the focus is on corporate networks. Another area of interest is the behavior of application protocols when used through WAN. The aim is to study the performance of commonly used application protocols in corporate networks. After identifying the performance problems in corporate WANs the thesis concentrates on methods for improving WAN performance. WAN acceleration is presented as a possible solution. The different acceleration methods are discussed in order to give the reader a theoretical view on how the accelerators can improve WAN performance. Guidelines on the installation of accelerators into a network are also discussed. After a general overview on accelerators is given, one accelerator vendor currently on market is selected for a further analysis. The work is also a case study where two accelerators are installed into a target company network for testing purposes. The tests are performed with three different application protocols that have been identified as critical applications for the target corporation. The aim of the tests is to serve as a proof of concept for WAN acceleration in the target network.

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Electricity distribution network operation (NO) models are challenged as they are expected to continue to undergo changes during the coming decades in the fairly developed and regulated Nordic electricity market. Network asset managers are to adapt to competitive technoeconomical business models regarding the operation of increasingly intelligent distribution networks. Factors driving the changes for new business models within network operation include: increased investments in distributed automation (DA), regulative frameworks for annual profit limits and quality through outage cost, increasing end-customer demands, climatic changes and increasing use of data system tools, such as Distribution Management System (DMS). The doctoral thesis addresses the questions a) whether there exist conditions and qualifications for competitive markets within electricity distribution network operation and b) if so, identification of limitations and required business mechanisms. This doctoral thesis aims to provide an analytical business framework, primarily for electric utilities, for evaluation and development purposes of dedicated network operation models to meet future market dynamics within network operation. In the thesis, the generic build-up of a business model has been addressed through the use of the strategicbusiness hierarchy levels of mission, vision and strategy for definition of the strategic direction of the business followed by the planning, management and process execution levels of enterprisestrategy execution. Research questions within electricity distribution network operation are addressed at the specified hierarchy levels. The results of the research represent interdisciplinary findings in the areas of electrical engineering and production economics. The main scientific contributions include further development of the extended transaction cost economics (TCE) for government decisions within electricity networks and validation of the usability of the methodology for the electricity distribution industry. Moreover, DMS benefit evaluations in the thesis based on the outage cost calculations propose theoretical maximum benefits of DMS applications equalling roughly 25% of the annual outage costs and 10% of the respective operative costs in the case electric utility. Hence, the annual measurable theoretical benefits from the use of DMS applications are considerable. The theoretical results in the thesis are generally validated by surveys and questionnaires.