69 resultados para service discovery


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In recent years, XML has been accepted as the format of messages for several applications. Prominent examples include SOAP for Web services, XMPP for instant messaging, and RSS and Atom for content syndication. This XML usage is understandable, as the format itself is a well-accepted standard for structured data, and it has excellent support for many popular programming languages, so inventing an application-specific format no longer seems worth the effort. Simultaneously with this XML's rise to prominence there has been an upsurge in the number and capabilities of various mobile devices. These devices are connected through various wireless technologies to larger networks, and a goal of current research is to integrate them seamlessly into these networks. These two developments seem to be at odds with each other. XML as a fully text-based format takes up more processing power and network bandwidth than binary formats would, whereas the battery-powered nature of mobile devices dictates that energy, both in processing and transmitting, be utilized efficiently. This thesis presents the work we have performed to reconcile these two worlds. We present a message transfer service that we have developed to address what we have identified as the three key issues: XML processing at the application level, a more efficient XML serialization format, and the protocol used to transfer messages. Our presentation includes both a high-level architectural view of the whole message transfer service, as well as detailed descriptions of the three new components. These components consist of an API, and an associated data model, for XML processing designed for messaging applications, a binary serialization format for the data model of the API, and a message transfer protocol providing two-way messaging capability with support for client mobility. We also present relevant performance measurements for the service and its components. As a result of this work, we do not consider XML to be inherently incompatible with mobile devices. As the fixed networking world moves toward XML for interoperable data representation, so should the wireless world also do to provide a better-integrated networking infrastructure. However, the problems that XML adoption has touch all of the higher layers of application programming, so instead of concentrating simply on the serialization format we conclude that improvements need to be made in an integrated fashion in all of these layers.

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This thesis is grounded on four articles. Article I generally examines the factors affecting dental service utilization. Article II studies the factors associated with sector-specific utilization among young adults entitled to age-based subsidized dental care. Article III explores the determinants of dental ill-health as measured by the occurrence of caries and the relationship between dental ill-health and dental care use. Article IV measures and explains income-related inequality in utilization. Data employed were from the 1996 Finnish Health Care Survey (I, II, IV) and the 1997 follow-up study included in the longitudinal study of the Northern Finland 1966 Birth Cohort (III). Utilization is considered as a multi-stage decision-making process and measured as the number of visits to the dentist. Modified count data models and concentration and horizontal equity indices were applied. Dentist s recall appeared very efficient at stimulating individuals to seek care. Dental pain, recall, and the low number of missing teeth positively affected utilization. Public subvention for dental care did not seem to statistically increase utilization. Among young adults, a perception of insufficient public service availability and recall were positively associated with the choice of a private dentist, whereas income and dentist density were positively associated with the number of visits to private dentists. Among cohort females, factors increasing caries were body mass index and intake of alcohol, sugar, and soft drinks and those reducing caries were birth weight and adolescent school achievement. Among cohort males, caries was positively related to the metropolitan residence and negatively related to healthy diet and education. Smoking increased caries, whereas regular teeth brushing, regular dental attendance and dental care use decreased caries. We found equity in young adults utilization but pro-rich inequity in the total number of visits to all dentists and in the probability of visiting a dentist for the whole sample. We observed inequity in the total number of visits to the dentist and in the probability of visiting a dentist, being pro-poor for public care but pro-rich for private care. The findings suggest that to enhance equal access to and use of dental care across population and income groups, attention should focus on supply factors and incentives to encourage people to contact dentists more often. Lowering co-payments and service fees and improving public availability would likely increase service use in both sectors. To attain favorable oral health, appropriate policies aimed at improving dental health education and reducing the detrimental effects of common risk factors on dental health should be strengthened. Providing equal access with respect to need for all people ought to take account of the segmentation of the service system, with its two parallel delivery systems and different supplier incentives to patients and dentists.

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In the beginning of the 1990s the legislation regarding the municipalities and the system of central government transfers were reformed in Finland. This resulted in a move from detailed governmental control to increased municipal autonomy. The purpose of this decentralization was to enable the municipalities to better adapt their administration and service supply to local needs. The aim of this study was to explore the effects of the increased municipal autonomy on the organization of services for people with intellectual disabilities. Did the increased autonomy cause the municipalities to alter their service supply and production and did the services become more adapted to local needs? The data consists of statistical information on service use and production, and also of background data such as demographics, economics and political elections on 452 municipalities in Finland from the years 1994 and 2000. The methods used are cluster analysis, discriminant analysis and factor analysis. The municipalities could be grouped in two categories: those which offered mainly one kind of residential services and others which had more varied mixes of services. The use of institutional care had decreased and municipalities which used institutional care as their primary form of service were mostly very small municipalities in 2000. The situation had changed from 1994, when institutional care was the primary service for municipalities of all sizes. Also the service production had become more differentiated and the municipalities had started using more varied ways of production. More municipalities had started producing their own services and private production had increased as well. Furthermore, the increase in local autonomy had opened up possibilities for local politics to influence both the service selection and methods of production. The most significant motive for changes in the service structure was high unemployment and an increasing share of elderly people in the population, particularly in sparsely populated areas. Municipalities with a low level of resources had made more changes in their service organization while those with more resources had been able to carry on as before. Key words: service structure, service for people with intellectual disabilities, municipalities, contingency theory, New Public Management

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The ultimate goal of this study has been to construct metabolically engineered microbial strains capable of fermenting glucose into pentitols D-arabitol and, especially, xylitol. The path that was chosen to achieve this goal required discovery, isolation and sequencing of at least two pentitol phosphate dehydrogenases of different specificity, followed by cloning and expression of their genes and characterization of recombinant arabitol and xylitol phosphate dehydrogenases. An enzyme of a previously unknown specificity, D-arabitol phosphate dehydrogenase (APDH), was discovered in Enterococcus avium. The enzyme was purified to homogenity from E. avium strain ATCC 33665. SDS/PAGE revealed that the enzyme has a molecular mass of 41 ± 2 kDa, whereas a molecular mass of 160 ± 5 kDa was observed under non-denaturing conditions implying that the APDH may exist as a tetramer with identical subunits. Purified APDH was found to have narrow substrate specificity, converting only D-arabitol 1-phosphate and D-arabitol 5-phosphate into D-xylulose 5-phosphate and D-ribulose 5-phosphate, respectively, in the oxidative reaction. Both NAD+ and NADP+ were accepted as co-factors. Based on the partial protein sequences, the gene encoding APDH was cloned. Homology comparisons place APDH within the medium chain dehydrogenase family. Unlike most members of this family, APDH requires Mn2+ but no Zn2+ for enzymatic activity. The DNA sequence surrounding the gene suggests that it belongs to an operon that also contains several components of phosphotransferase system (PTS). The apparent role of the enzyme is to participate in arabitol catabolism via the arabitol phosphate route similar to the ribitol and xylitol catabolic routes described previously. Xylitol phosphate dehydrogenase (XPDH) was isolated from Lactobacillus rhamnosus strain ATCC 15820. The enzyme was partially sequenced. Amino acid sequences were used to isolate the gene encoding the enzyme. The homology comparisons of the deduced amino acid sequence of L. rhamnosus XPDH revealed several similar enzymes in genomes of various species of Gram-positive bacteria. Two enzymes of Clostridium difficile and an enzyme of Bacillus halodurans were cloned and their substrate specificities together with the substrate specificity of L. rhamnosus XPDH were compared. It was found that one of the XPDH enzymes of C. difficile and the XPDH of L. rhamnosus had the highest selectivity towards D-xylulose 5-phosphate. A known transketolase-deficient and D-ribose-producing mutant of Bacillus subtilis (ATCC 31094) was further modified by disrupting its rpi (D-ribose phosphate isomerase) gene to create D-ribulose- and D-xylulose-producing strain. Expression of APDH of E. avium and XPDH of L. rhamnosus and C. difficile in D-ribulose- and D-xylulose-producing strain of B. subtilis resulted in strains capable of converting D-glucose into D-arabitol and xylitol, respectively. The D-arabitol yield on D-glucose was 38 % (w/w). Xylitol production was accompanied by co-production of ribitol limiting xylitol yield to 23 %.

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This thesis describes current and past n-in-one methods and presents three early experimental studies using mass spectrometry and the triple quadrupole instrument on the application of n-in-one in drug discovery. N-in-one strategy pools and mix samples in drug discovery prior to measurement or analysis. This allows the most promising compounds to be rapidly identified and then analysed. Nowadays properties of drugs are characterised earlier and in parallel with pharmacological efficacy. Studies presented here use in vitro methods as caco-2 cells and immobilized artificial membrane chromatography for drug absorption and lipophilicity measurements. The high sensitivity and selectivity of liquid chromatography mass spectrometry are especially important for new analytical methods using n-in-one. In the first study, the fragmentation patterns of ten nitrophenoxy benzoate compounds, serial homology, were characterised and the presence of the compounds was determined in a combinatorial library. The influence of one or two nitro substituents and the alkyl chain length of methyl to pentyl on collision-induced fragmentation was studied, and interesting structurefragmentation relationships were detected. Two nitro group compounds increased fragmentation compared to one nitro group, whereas less fragmentation was noted in molecules with a longer alkyl chain. The most abundant product ions were nitrophenoxy ions, which were also tested in the precursor ion screening of the combinatorial library. In the second study, the immobilized artificial membrane chromatographic method was transferred from ultraviolet detection to mass spectrometric analysis and a new method was developed. Mass spectra were scanned and the chromatographic retention of compounds was analysed using extract ion chromatograms. When changing detectors and buffers and including n-in-one in the method, the results showed good correlation. Finally, the results demonstrated that mass spectrometric detection with gradient elution can provide a rapid and convenient n-in-one method for ranking the lipophilic properties of several structurally diverse compounds simultaneously. In the final study, a new method was developed for caco-2 samples. Compounds were separated by liquid chromatography and quantified by selected reaction monitoring using mass spectrometry. This method was used for caco-2 samples, where absorption of ten chemically and physiologically different compounds was screened using both single and nin- one approaches. These three studies used mass spectrometry for compound identification, method transfer and quantitation in the area of mixture analysis. Different mass spectrometric scanning modes for the triple quadrupole instrument were used in each method. Early drug discovery with n-in-one is area where mass spectrometric analysis, its possibilities and proper use, is especially important.

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When authors of scholarly articles decide where to submit their manuscripts for peer review and eventual publication, they often base their choice of journals on very incomplete information abouthow well the journals serve the authors’ purposes of informing about their research and advancing their academic careers. The purpose of this study was to develop and test a new method for benchmarking scientific journals, providing more information to prospective authors. The method estimates a number of journal parameters, including readership, scientific prestige, time from submission to publication, acceptance rate and service provided by the journal during the review and publication process. Data directly obtainable from the web, data that can be calculated from such data, data obtained from publishers and editors, and data obtained using surveys with authors are used in the method, which has been tested on three different sets of journals, each from a different discipline. We found a number of problems with the different data acquisition methods, which limit the extent to which the method can be used. Publishers and editors are reluctant to disclose important information they have at hand (i.e. journal circulation, web downloads, acceptance rate). The calculation of some important parameters (for instance average time from submission to publication, regional spread of authorship) can be done but requires quite a lot of work. It can be difficult to get reasonable response rates to surveys with authors. All in all we believe that the method we propose, taking a “service to authors” perspective as a basis for benchmarking scientific journals, is useful and can provide information that is valuable to prospective authors in selected scientific disciplines.

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Service researchers and practitioners have repeatedly claimed that customer service experiences are essential to all businesses. Therefore comprehension of how service experience is characterised in research is an essential element for its further development through research. The importance of greater in-depth understanding of the phenomenon of service experience has been acknowledged by several researchers, such as Carú and Cova and Vargo and Lusch. Furthermore, Service-Dominant (S-D) logic has integrated service experience to value by emphasising in its foundational premises that value is phenomenologically (experientially) determined. The present study analyses how the concept of service experience has been characterised in previous research. As such, it puts forward three ways to characterise it in relation to that research: 1) phenomenological service experience relates to the value discussion in S-D logic and interpretative consumer research, 2) process-based service experience relates to understanding service as a process, and 3) outcome-based service experience relates to understanding service experience as one element in models linking a number of variables or attributes to various outcomes. Focusing on the phenomenological service experience, the theoretical purpose of the study is to characterise service experience based on the phenomenological approach. In order to do so, an additional methodological purpose was formulated: to find a suitable methodology for analysing service experience based on the phenomenological approach. The study relates phenomenology to a philosophical Husserlian and social constructionist tradition studying phenomena as they appear in our experience in a social context. The study introduces Event-Based Narrative Inquiry Technique (EBNIT), which combines critical events with narratives and metaphors. EBNIT enabled the analysis of lived and imaginary service experiences as expressed in individual narratives. The study presents findings of eight case studies within service innovation of Web 2.0, mobile service, location aware service and public service in the municipal sector. Customers’ and service managers’ stories about their lived private and working lifeworld were the foundation for their ideal service experiences. In general, the thesis finds that service experiences are (1) subjective, (2) context-specific, (3) cumulative, (4) partially socially constructed, (5) both lived and imaginary, (6) temporally multiple-dimensional, and (7) iteratively related to perceived value. In addition to customer service experience, the thesis brings empirical evidence of managerial service experience of front-line managers experiencing the service they manage and develop in their working lifeworld. The study contributes to S-D logic, service innovation and service marketing and management in general by characterising service experience based on the phenomenological approach and integrating it to the value discussion. Additionally, the study offers a methodological approach for further exploration of service experiences. The study discusses managerial implications in conjunction with the case studies and discusses them in relation to service innovation.

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Market microstructure is “the study of the trading mechanisms used for financial securities” (Hasbrouck (2007)). It seeks to understand the sources of value and reasons for trade, in a setting with different types of traders, and different private and public information sets. The actual mechanisms of trade are a continually changing object of study. These include continuous markets, auctions, limit order books, dealer markets, or combinations of these operating as a hybrid market. Microstructure also has to allow for the possibility of multiple prices. At any given time an investor may be faced with a multitude of different prices, depending on whether he or she is buying or selling, the quantity he or she wishes to trade, and the required speed for the trade. The price may also depend on the relationship that the trader has with potential counterparties. In this research, I touch upon all of the above issues. I do this by studying three specific areas, all of which have both practical and policy implications. First, I study the role of information in trading and pricing securities in markets with a heterogeneous population of traders, some of whom are informed and some not, and who trade for different private or public reasons. Second, I study the price discovery of stocks in a setting where they are simultaneously traded in more than one market. Third, I make a contribution to the ongoing discussion about market design, i.e. the question of which trading systems and ways of organizing trading are most efficient. A common characteristic throughout my thesis is the use of high frequency datasets, i.e. tick data. These datasets include all trades and quotes in a given security, rather than just the daily closing prices, as in traditional asset pricing literature. This thesis consists of four separate essays. In the first essay I study price discovery for European companies cross-listed in the United States. I also study explanatory variables for differences in price discovery. In my second essay I contribute to earlier research on two issues of broad interest in market microstructure: market transparency and informed trading. I examine the effects of a change to an anonymous market at the OMX Helsinki Stock Exchange. I broaden my focus slightly in the third essay, to include releases of macroeconomic data in the United States. I analyze the effect of these releases on European cross-listed stocks. The fourth and last essay examines the uses of standard methodologies of price discovery analysis in a novel way. Specifically, I study price discovery within one market, between local and foreign traders.