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4189 Uppsatser om Coupled cluster methods - Sida 1 av 280

Tidsberoende kvantkemiska beräkningar av optisk absorption hos polymerer och molekyler med litet bandgap

The vertical electronic excitation energies for the narrow-bandgap polymers LBPF, EP37 and EP62 have been calculated using Density Functional Theory (DFT). Also the vertical excitation energies for the acceptor unit of LBPF have been calculated using the Hartree-Fock (HF), DFT and Coupled Cluster (CC) methods. The calculations cover the visible and infrared wave length region and two strong transitions are obtained, one corresponding to the pi to pi* transition and one corresponding to the pi to Acceptor transition. The excitation energies obtained from DFT are below the corresponding experimental results and attempts have therefore been made to perform bench-marking calculations using a hierarchy of CC methods..

Utvärdering av klusteranalytiska metoder i kombination med bibliografisk koppling: en bibliometrisk kartläggning av aktuella forskningsteman inom informationsvetenskap

The purpose of this thesis is to evaluate the combination of bibliographic coupling and three hierarchical cluster analytic techniques: average, complete and single linkage. Bibliographic coupling is applied as a measure of similarity between recently published articles and the cluster techniques are used for the partition of a set of articles into subsets of articles with similar research focus. The field of information science is applied as the test arena and the selection of data, i.e., the article population to be partitioned, is based on a number of central journals. Methods of evaluation include both quantitative approaches as well as a qualitative one. For comparing the resulting partitions, adjusted Rand index is utilized and for the establishment of cluster coherence and isolation, measures of average normalized coupling strength is applied.

Forskningsfronten inom informationsvetenskap ? en bibliometrisk analys

The aim of this study is to analyze and describe the research front within information science. To reach this purpose we ask the following research question: Which research themes can be identified within the subject field of information science by using bibliographic coupling in combination with cluster analysis.The data for our study consists of articles from the journals Journal of the American Society for Information Science and Technology and Journal of Documentation throughout the years 2004-2006. The bibliographic information from the articles was analyzed with the combined methods of bibliographic coupling and cluster analysis. This gave fifteen clusters within which we identified research themes. When analyzing these results we found four main fields of research within the research front of information science: Information retrieval, bibliometrics, knowledge organization and information science as research discipline.

Body Coupled Communication: Ändring av prototypkort

Kommunikation genom att använda människokroppen som  överföringsmedium, med kapacitiv koppling mellan hud och sensor, har varit ett pågående forskningsområde för PAN (Personal Area Network) sedan Thomas Guthrie Zimmerman introducerade tekniken 1995. Anledningen till detta är att undersöka fördelar och användningsområden för en kommunikationsmetod som ej sänder ut RF-signaler och därmed minska risken för obehörig avlyssning.Denna rapport beskriver ett examensarbete som undersöker möjligheten till eliminering av USB- till UART-konverterare på Microchip BodyCom genom mjukvaru-USB-stack och kombinera denna med Body Coupled Communication funktionalitet i en gemensam mikrokontroller. Vidare studeras om programkoden i Body Coupled Communication sändare kan modifieras för att utöka funktionaliteten.Det var givet i förutsättningarna att mikrokontroller från Microchip skulle användas, vidare var lågt pris respektive låg strömförbrukning viktigt, särskilt för sändaren. Metoden för att uppnå detta har varit användning av Microchip BodyCom development kit tillsammans med Microchip USB low pin count development kit och Microchip USB firmwareframework.Resultatet blev att USB- till UART-omvandlare kunde integreras med Microchip BodyCom genom att använda mjukvaru-USB-stack och en modifierad programkod för BodyCom i en gemensam mikrokontroller.Endast fantasin sätter gränsen för vad Body Coupled Communication kan användas till. Det skulle t.ex.

Företagskluster och närhet i Katutura, Namibia : En studie kring småföretag, närhet och klusterfördelar

In Economic Geography, there has been a strong interest of how different forms of proximity impacts businesses. In addition, there is also a strong interest in business agglomeration, as a result businesses cluster together through physical proximity, networks and knowledge. In the development sector, there is a strong interest on how to best support the creations and growth of small enterprises.This essay emphasises on the business cluster formations in Katutura, a suburb to Windhoek the capital city of Namibia. It oversees the impacts of different types of cluster formations and their effects on the businesses. In addition, this essay will identify the main clusters in Katutura and state what makes them unique from each other and what is a common cluster feature.

Internetbokhandelns rekommendationssystem : en undersökning av Amazon.coms Similar Items.

The aim of this thesis is to examine one part of Amazon.coms recommender systems: Similar Items. The purpose is also to show the difficulties with subject access, i. e. to find a similar book to the one you just read; problems with traditional systems versus the usefulness with recommender systems like Amazon.coms Similar Items. Similar Items presents a set, a cluster of related items to a given item based on customers co-purchase.

Kartläggning av biblioteks- och informationsvetenskap i Skandinavien - En bibliometrisk undersökning

This paper aims to map and contrast the research front and theresearch base of Library and Information Science (LIS) inScandinavia during 1980-1989 and 2003-2013 from articlespublished in Web of Science.The research questions are:1. How is the research base and research front in LIS inScandinavia between 1980-1989 and 2003-2012 structured?2. What differences can be observed between the two time periods1980-1989 and 2003-2012 with regards to the research base?3.

En analys av forskningsfronten inom medicinsk etik

The purpose of this Masters thesis is to analyze the research front within medical ethics. We wish to identify which research themes that are included in the subject field of medical ethics. The research themes can be identified by a couple of bibliometrical methods and techniques. In our case, it is bibliographic coupling combined with a cluster analysis. The analysis is accomplished by the extracted references from articles in the two journals Bioethics and Journal of medical ethics.

A targeted evaluation of OpenEye?s methods for virtual ligand screens and docking

The process of drug discovery is very slow and expensive. There is a need for reliable in silico methods; however the performance of these methods differs.This work presents a targeted study on how the drug discovery methods used in OpenEye?s tools ROCS, EON and FRED perform on targets with small ligands. It was examined if 12 compounds (markers) somewhat similar to AMP could be detected by ROCS in a random data set comprised of 1000 compounds. It was also examined if EON could find any electrostatic similarities between the queries and the markers.

Biblioteks- och informationsvetenskap ? en positionsbestämning. Svenska avhandlingar och uppsatser i en interpretativ innehållsanalys

The purpose of this study is to gauge the current state of Swedish library and information science research. LIS is generally defined as a cross- or multidisciplinary subject, according to some coupled with heterogenity or dichotomy within the subject. In light of Jack Meadows?s description of the scientific community growth and scientific communication, the following two research questions are formulated as basis for the study: 1. What are the current themes, what range of theories and methods are used in our research material? 2.

Challenges and Opportunities in Swedish Apiculture

Bees are of importance for the global food security. In Europe 84% and in the World 35% of all the agricultural crops are dependent of animal pollination (Winfree et al., 2011:1). In agricultural production there is a huge lack of pollinators (Azien & Harden, 2009). A problem that is widely spread. In Sweden the problem becomes clear when looking at the statistics of the number of bee colonies during the last 20 years, where it has been a decline with 63 % (Statistiska Centralbyrån & Jordbruksverket, 2011).

Virtualiserad testmiljo? : Utva?rdering av virtualiseringsprogramvaror

Virtualization has increasingly been adopted in the last decade and the usages of virtualized environments are going to be an important part of how computers are used in the nearby future. There are a lot of advantages with virtualization and different methods have been developed to make it as efficient as possible.Forsmarks Kraftgrupp were interested in the possibility of taking advantage of virtualization in their testing environment.In this report, hypervisors of type 1 and type 2 and containers have been evaluated to determine which method and what program is preferable on a server cluster of four HP ProLiant DL380 Generation 4. Because of the hardware specifications of the DL380, focus has been on virtualization programs that do not require hardware assisted virtualization.The results show that it is possible to use some of the type 2 hypervisors on the HP ProLiant DL380 Generation 4. The suggested virtualization programs are VMware Workstation or Oracle VirtualBox. .

Phosphorus in agricultural soils around the Baltic Sea : comparisons of different laboratory methods as indices for phosphorus leaching to waters

Eutrophication of the Baltic Sea is a serious problem. A major contributing factor is diffuse losses of phosphorus (P) from agricultural land in surrounding countries. In order to estimate P losses, environmental monitoring of small agriculture-dominated catchments is being carried out in most of these countries. Evaluation of the risk of P leaching to waters is usually based on chemical tests originally developed to quantify the amount of soil P available for plant production. The tests are performed in different ways in the different countries and a number of different extraction agents are in use.

Luftprovtagning samt analys av mono- och diisocyanater

When exposed to them, isocyanates can induce serious injuries in the respiratory tract and irritation on the skin and in the eyes. They are therefore interesting from the point of view of occupational health. The purpose of this thesis was to collect isocyanates in air with impinger-filter samplers and solvent free samplers. Furthermore the isocyanates were to be analyzed with liquid chromatography-mass spectrometry. The solvent free sampler consists of a polypropylene tube and filter holder fitted with glass fiber filters impregnated with derivatization reagent, coupled with a pump.

Bestämning av osäkerheten hos skattningar av tyngdaccelerationen

In this master's thesis the problem of determining the uncertainty for an estimator of an unknown parameter is considered. The case we study is the estimation of gravity using a reversible pendulum. This involves the estimation of the point where two regression lines intersect. The estimated gravity is a function the coordinates of this point. One way to determine the uncertainty of this estimator is to use bootstrap methods.

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