994 resultados para 7038-214
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COD discharges out of processes have increased in line with elevating brightness demands for mechanical pulp and papers. The share of lignin-like substances in COD discharges is on average 75%. In this thesis, a plant dynamic model was created and validated as a means to predict COD loading and discharges out of a mill. The assays were carried out in one paper mill integrate producing mechanical printing papers. The objective in the modeling of plant dynamics was to predict day averages of COD load and discharges out of mills. This means that online data, like 1) the level of large storage towers of pulp and white water 2) pulp dosages, 3) production rates and 4) internal white water flows and discharges were used to create transients into the balances of solids and white water, referred to as “plant dynamics”. A conversion coefficient was verified between TOC and COD. The conversion coefficient was used for predicting the flows from TOC to COD to the waste water treatment plant. The COD load was modeled with similar uncertainty as in reference TOC sampling. The water balance of waste water treatment was validated by the reference concentration of COD. The difference of COD predictions against references was within the same deviation of TOC-predictions. The modeled yield losses and retention values of TOC in pulping and bleaching processes and the modeled fixing of colloidal TOC to solids between the pulping plant and the aeration basin in the waste water treatment plant were similar to references presented in literature. The valid water balances of the waste water treatment plant and the reduction model of lignin-like substances produced a valid prediction of COD discharges out of the mill. A 30% increase in the release of lignin-like substances in the form of production problems was observed in pulping and bleaching processes. The same increase was observed in COD discharges out of waste water treatment. In the prediction of annual COD discharge, it was noticed that the reduction of lignin has a wide deviation from year to year and from one mill to another. This made it difficult to compare the parameters of COD discharges validated in plant dynamic simulation with another mill producing mechanical printing papers. However, a trend of moving from unbleached towards high-brightness TMP in COD discharges was valid.
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This thesis studies the properties and usability of operators called t-norms, t-conorms, uninorms, as well as many valued implications and equivalences. Into these operators, weights and a generalized mean are embedded for aggregation, and they are used for comparison tasks and for this reason they are referred to as comparison measures. The thesis illustrates how these operators can be weighted with a differential evolution and aggregated with a generalized mean, and the kinds of measures of comparison that can be achieved from this procedure. New operators suitable for comparison measures are suggested. These operators are combination measures based on the use of t-norms and t-conorms, the generalized 3_-uninorm and pseudo equivalence measures based on S-type implications. The empirical part of this thesis demonstrates how these new comparison measures work in the field of classification, for example, in the classification of medical data. The second application area is from the field of sports medicine and it represents an expert system for defining an athlete's aerobic and anaerobic thresholds. The core of this thesis offers definitions for comparison measures and illustrates that there is no actual difference in the results achieved in comparison tasks, by the use of comparison measures based on distance, versus comparison measures based on many valued logical structures. The approach has been highly practical in this thesis and all usage of the measures has been validated mainly by practical testing. In general, many different types of operators suitable for comparison tasks have been presented in fuzzy logic literature and there has been little or no experimental work with these operators.
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The purpose of the work was to realize a high-speed digital data transfer system for RPC muon chambers in the CMS experiment on CERN’s new LHC accelerator. This large scale system took many years and many stages of prototyping to develop, and required the participation of tens of people. The system interfaces to Frontend Boards (FEB) at the 200,000-channel detector and to the trigger and readout electronics in the control room of the experiment. The distance between these two is about 80 metres and the speed required for the optic links was pushing the limits of available technology when the project was started. Here, as in many other aspects of the design, it was assumed that the features of readily available commercial components would develop in the course of the design work, just as they did. By choosing a high speed it was possible to multiplex the data from some the chambers into the same fibres to reduce the number of links needed. Further reduction was achieved by employing zero suppression and data compression, and a total of only 660 optical links were needed. Another requirement, which conflicted somewhat with choosing the components a late as possible was that the design needed to be radiation tolerant to an ionizing dose of 100 Gy and to a have a moderate tolerance to Single Event Effects (SEEs). This required some radiation test campaigns, and eventually led to ASICs being chosen for some of the critical parts. The system was made to be as reconfigurable as possible. The reconfiguration needs to be done from a distance as the electronics is not accessible except for some short and rare service breaks once the accelerator starts running. Therefore reconfigurable logic is extensively used, and the firmware development for the FPGAs constituted a sizable part of the work. Some special techniques needed to be used there too, to achieve the required radiation tolerance. The system has been demonstrated to work in several laboratory and beam tests, and now we are waiting to see it in action when the LHC will start running in the autumn 2008.
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This dissertation analyses the growing pool of copyrighted works, which are offered to the public using Creative Commons licensing. The study consist of analysis of the novel licensing system, the licensors, and the changes of the "all rights reserved" —paradigm of copyright law. Copyright law reserves all rights to the creator until seventy years have passed since her demise. Many claim that this endangers communal interests. Quite often the creators are willing to release some rights. This, however, is very difficult to do and needs help of specialized lawyers. The study finds that the innovative Creative Commons licensing scheme is well suited for low value - high volume licensing. It helps to reduce transaction costs on several le¬vels. However, CC licensing is not a "silver bullet". Privacy, moral rights, the problems of license interpretation and license compatibility with other open licenses and collecting societies remain unsolved. The study consists of seven chapters. The first chapter introduces the research topic and research questions. The second and third chapters inspect the Creative Commons licensing scheme's technical, economic and legal aspects. The fourth and fifth chapters examine the incentives of the licensors who use open licenses and describe certain open business models. The sixth chapter studies the role of collecting societies and whether two institutions, Creative Commons and collecting societies can coexist. The final chapter summarizes the findings. The dissertation contributes to the existing literature in several ways. There is a wide range of prior research on open source licensing. However, there is an urgent need for an extensive study of the Creative Commons licensing and its actual and potential impact on the creative ecosystem.
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Value chain collaboration has been a prevailing topic for research, and there is a constantly growing interest in developing collaborative models for improved efficiency in logistics. One area of collaboration is demand information management, which enables improved visibility and decrease of inventories in the value chain. Outsourcing of non-core competencies has changed the nature of collaboration from intra-enterprise to cross-enterprise activity, and this together with increasing competition in the globalizing markets have created a need for methods and tools for collaborative work. The retailer part in the value chain of consumer packaged goods (CPG) has been studied relatively widely, proven models have been defined, and there exist several best practice collaboration cases. The information and communications technology has developed rapidly, offering efficient solutions and applications to exchange information between value chain partners. However, the majority of CPG industry still works with traditional business models and practices. This concerns especially companies operating in the upstream of the CPG value chain. Demand information for consumer packaged goods originates at retailers' counters, based on consumers' buying decisions. As this information does not get transferred along the value chain towards the upstream parties, each player needs to optimize their part, causing safety margins for inventories and speculation in purchasing decisions. The safety margins increase with each player, resulting in a phenomenon known as the bullwhip effect. The further the company is from the original demand information source, the more distorted the information is. This thesis concentrates on the upstream parts of the value chain of consumer packaged goods, and more precisely the packaging value chain. Packaging is becoming a part of the product with informative and interactive features, and therefore is not just a cost item needed to protect the product. The upstream part of the CPG value chain is distinctive, as the product changes after each involved party, and therefore the original demand information from the retailers cannot be utilized as such – even if it were transferred seamlessly. The objective of this thesis is to examine the main drivers for collaboration, and barriers causing the moderate adaptation level of collaborative models. Another objective is to define a collaborative demand information management model and test it in a pilot business situation in order to see if the barriers can be eliminated. The empirical part of this thesis contains three parts, all related to the research objective, but involving different target groups, viewpoints and research approaches. The study shows evidence that the main barriers for collaboration are very similar to the barriers in the lower part of the same value chain; lack of trust, lack of business case and lack of senior management commitment. Eliminating one of them – the lack of business case – is not enough to eliminate the two other barriers, as the operational model in this thesis shows. The uncertainty of the future, fear of losing an independent position in purchasing decision making and lack of commitment remain strong enough barriers to prevent the implementation of the proposed collaborative business model. The study proposes a new way of defining the value chain processes: it divides the contracting and planning process into two processes, one managing the commercial parts and the other managing the quantity and specification related issues. This model can reduce the resistance to collaboration, as the commercial part of the contracting process would remain the same as in the traditional model. The quantity/specification-related issues would be managed by the parties with the best capabilities and resources, as well as access to the original demand information. The parties in between would be involved in the planning process as well, as their impact for the next party upstream is significant. The study also highlights the future challenges for companies operating in the CPG value chain. The markets are becoming global, with toughening competition. Also, the technology development will most likely continue with a speed exceeding the adaptation capabilities of the industry. Value chains are also becoming increasingly dynamic, which means shorter and more agile business relationships, and at the same time the predictability of consumer demand is getting more difficult due to shorter product life cycles and trends. These changes will certainly have an effect on companies' operational models, but it is very difficult to estimate when and how the proven methods will gain wide enough adaptation to become standards.
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The study examines international cooperation in product development in software development organisations. The software industry is known for its global nature and knowledge-intensity, which makes it an interesting setting to examine international cooperation in. Software development processes are increasingly distributed worldwide, but for small or even medium-sized enterprises, typical for the software industry, such distribution of operations is often possible only in association with crossing the company’s boundaries. The strategic decision-making of companies is likely to be affected by the characteristics of the industry, and this includes decisions about cooperation or sourcing. The objective of this thesis is to provide a holistic view on factors affecting decisions about offshore sourcing in software development. Offshore sourcing refers to a cooperative mode of offshoring, where a firm does not establish its own presence in a foreign country, but utilises a local supplier. The study examines product development activities that are distributed across organisational and geographical boundaries. The objective can be divided into two subtopics: general reasons for international cooperation in product development and particular reasons for cooperation between Finnish and Russian companies. The focus is on the strategic rationale at the company level, in particular in small and medium-sized enterprises. The theoretical discourse of the study builds upon the literature on international cooperation and networking, with particular focus on cooperation with foreign suppliers and within product development activities. The resource-based view is also discussed, as heterogeneity and interdependency of the resources possessed by different firms are seen as factors motivating international cooperation. Strategically, sourcing can be used to access resources possessed by an industrial network, to enhance the product development of a firm, or to optimise its cost structure. In order to investigate the issues raised by the theoretical review, two empirical studies on international cooperation in software product development have been conducted. The emphasis of the empirical part of the study is on cooperation between Finnish and Russian companies. The data has been gathered through four case studies on Finnish software development organisations and four case studies on Russian offshore suppliers. Based on the material from the case studies, a framework clarifying and grouping the factors that influence offshore sourcing decisions has been built. The findings indicate that decisions regarding offshore sourcing in software development are far more complex than generally assumed. The framework provides a holistic view on factors affecting decisions about offshore sourcing in software development, capturing the multidimensionality of motives for entering offshore cooperation. Four groups of factors emerged from the data: A) strategy-related aspects, B) aspects related to resources and capabilities, C) organisation-related aspects, and D) aspects related to the entrepreneur or management. By developing a holistic framework of decision factors, the research offers in-depth theoreticalunderstanding of offshore sourcing rationale in product development. From the managerial point of view, the proposed framework sums up the issues that a firm should pay attention to when contemplating product development cooperation with foreign suppliers. Understanding different components of sourcing decisions can lead to improved preconditions for strategising and engaging in offshore cooperation. A thorough decisionmaking process should consider all the possible benefits and risks of product development cooperation carefully.
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The Internet has transformed the scope, boundaries and dynamics of social and economic interactions. It is argued to have broadened the notion of the community from physical, colocated groups towards collectives that are able to transcend time and space, i.e. virtual communities. Even if virtual communities have been on the academic agenda for a couple of decades, there is still surprisingly little research on knowledge sharing within them. In addition, prior research has largely neglected the complex dynamics between Internet-based communication channels and the surrounding communities in which they are embedded. This thesis aims at building a better understanding of knowledge sharing supported by conversational technologies in intra-organisational virtual communities and external virtual communities supporting relationships with customers. The focus is thus on knowledge sharing in types of virtual communities that seem to be of relevance to business organisations. The study consists of two parts. The first part introduces the research topic and discusses the overall results. The second part comprises seven research publications. Qualitative research methods are used throughout the study. The results of the study indicate that investigation of the processes of knowledge sharing in virtual communities requires a socio-technical perspective, combining the individual, social and technological levels, and understanding the interplay between them. It is claimed that collective knowledge in virtual communities creates the enabling structure for knowledge sharing, and forms the invisible structure of the community on the basis of which it operates. It consists of a shared context, social capital and a unique community culture. The Internet does not inevitably erode social interaction: it seems that supporting social relationships by means of communication technology is a matter of quantity rather than quality. In order to provide access to external knowledge and expertise, firms need to open themselves up to an array of Internet-based conversations, and to consider the relevance of virtual communities to their businesses.
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This dissertation is based on four articles dealing with modeling of ozonation. The literature part of this considers some models for hydrodynamics in bubble column simulation. A literature review of methods for obtaining mass transfer coefficients is presented. The methods presented to obtain mass transfer are general models and can be applied to any gas-liquid system. Ozonation reaction models and methods for obtaining stoichiometric coefficients and reaction rate coefficients for ozonation reactions are discussed in the final section of the literature part. In the first article, ozone gas-liquid mass transfer into water in a bubble column was investigated for different pH values. A more general method for estimation of mass transfer and Henry’s coefficient was developed from the Beltrán method. The ozone volumetric mass transfer coefficient and the Henry’s coefficient were determined simultaneously by parameter estimation using a nonlinear optimization method. A minor dependence of the Henry’s law constant on pH was detected at the pH range 4 - 9. In the second article, a new method using the axial dispersion model for estimation of ozone self-decomposition kinetics in a semi-batch bubble column reactor was developed. The reaction rate coefficients for literature equations of ozone decomposition and the gas phase dispersion coefficient were estimated and compared with the literature data. The reaction order in the pH range 7-10 with respect to ozone 1.12 and 0.51 the hydroxyl ion were obtained, which is in good agreement with literature. The model parameters were determined by parameter estimation using a nonlinear optimization method. Sensitivity analysis was conducted using object function method to obtain information about the reliability and identifiability of the estimated parameters. In the third article, the reaction rate coefficients and the stoichiometric coefficients in the reaction of ozone with the model component p-nitrophenol were estimated at low pH of water using nonlinear optimization. A novel method for estimation of multireaction model parameters in ozonation was developed. In this method the concentration of unknown intermediate compounds is presented as a residual COD (chemical oxygen demand) calculated from the measured COD and the theoretical COD for the known species. The decomposition rate of p-nitrophenol on the pathway producing hydroquinone was found to be about two times faster than the p-nitrophenol decomposition rate on the pathway producing 4- nitrocatechol. In the fourth article, the reaction kinetics of p-nitrophenol ozonation was studied in a bubble column at pH 2. Using the new reaction kinetic model presented in the previous article, the reaction kinetic parameters, rate coefficients, and stoichiometric coefficients as well as the mass transfer coefficient were estimated with nonlinear estimation. The decomposition rate of pnitrophenol was found to be equal both on the pathway producing hydroquinone and on the path way producing 4-nitrocathecol. Comparison of the rate coefficients with the case at initial pH 5 indicates that the p-nitrophenol degradation producing 4- nitrocathecol is more selective towards molecular ozone than the reaction producing hydroquinone. The identifiability and reliability of the estimated parameters were analyzed with the Marcov chain Monte Carlo (MCMC) method. @All rights reserved. No part of the publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the author.
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1884/10/11 (Numéro 214).
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1903/09/09 (Numéro 7038).
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Destinataire de l'envoi : Marie-Antoinette (reine de France ; 1755-1793)