939 resultados para integrated lot sizing and scheduling models


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Straw on sowing line modifies seed germination environment regarding temperature and water content. Given these considerations, the aim of this study was to evaluate different mechanisms for coverage mobilization on the sowing line and their effect on germination environment of maize seeds, mainly in relation to the dynamics of straw in the seedbed, water content and soil temperature. Treatments consisted on the combination of two mechanisms at front of furrow opener, composed of cutting disc and row cleaners, with three mechanisms behind the seed furrower for returning the soil, consisting of three covering mechanisms, commercial and prototype models. It was found that straw presence on the surface of sowing line contributed to germination of maize seeds, maintenance of temperature and soil water content. The cutting disc treatment, associated with prototype, introduced percentages of water content near the ones in bottom layer, and this soil water content was 29.7% with 93.75% of straw coverage and deeper seeding depth, granting better conditions for seed germination. However, the straw coverage removal on soil by the row cleaners and its low sowing depth caused water loss in the lines resulting in great reduction of the emergence speed index in maize seedlings.

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In development of human medicines, it is important to predict early and accurately enough the disease and patient population to be treated as well as the effective and safe dose range of the studied medicine. This is pursued by using preclinical research models, clinical pharmacology and early clinical studies with small sample sizes. When successful, this enables effective development of medicines and reduces unnecessary exposure of healthy subjects and patients to ineffectice or harmfull doses of experimental compounds. Toremifene is a selective estrogen receptor modulator (SERM) used for treatment of breast cancer. Its development was initiated in 1980s when selection of treatment indications and doses were based on research in cell and animal models and on noncomparative clinical studies including small number of patients. Since the early development phase, the treatment indication, the patient population and the dose range were confirmed in large comparative clinical studies in patients. Based on the currently available large and long term clinical study data the aim of this study was to investigate how the early phase studies were able to predict the treatment indication, patient population and the dose range of the SERM. As a conclusion and based on the estrogen receptor mediated mechanism of action early studies were able to predict the treatment indication, target patient population and a dose range to be studied in confirmatory clinical studies. However, comparative clinical studies are needed to optimize dose selection of the SERM in treatment of breast cancer.

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This study investigates futures market efficiency and optimal hedge ratio estimation. First, cointegration between spot and futures prices is studied using Johansen method, with two different model specifications. If prices are found cointegrated, restrictions on cointegrating vector and adjustment coefficients are imposed, to account for unbiasedness, weak exogeneity and prediction hypothesis. Second, optimal hedge ratios are estimated using static OLS, and time-varying DVEC and CCC models. In-sample and out-of-sample results for one, two and five period ahead are reported. The futures used in thesis are RTS index, EUR/RUB exchange rate and Brent oil, traded in Futures and options on RTS.(FORTS) For in-sample period, data points were acquired from start of trading of each futures contract, RTS index from August 2005, EUR/RUB exchange rate March 2009 and Brent oil October 2008, lasting till end of May 2011. Out-of-sample period covers start of June 2011, till end of December 2011. Our results indicate that all three asset pairs, spot and futures, are cointegrated. We found RTS index futures to be unbiased predictor of spot price, mixed evidence for exchange rate, and for Brent oil futures unbiasedness was not supported. Weak exogeneity results for all pairs indicated spot price to lead in price discovery process. Prediction hypothesis, unbiasedness and weak exogeneity of futures, was rejected for all asset pairs. Variance reduction results varied between assets, in-sample in range of 40-85 percent and out-of sample in range of 40-96 percent. Differences between models were found small, except for Brent oil in which OLS clearly dominated. Out-of-sample results indicated exceptionally high variance reduction for RTS index, approximately 95 percent.

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Atherosclerosis is a life-long vascular inflammatory disease and the leading cause of death in Finland and in other western societies. The development of atherosclerotic plaques is progressive and they form when lipids begin to accumulate in the vessel wall. This accumulation triggers the migration of inflammatory cells that is a hallmark of vascular inflammation. Often, this plaque will become unstable and form vulnerable plaque which may rupture causing thrombosis and in the worst case, causing myocardial infarction or stroke. Identification of these vulnerable plaques before they rupture could save lives. At present, in the clinic, there exists no appropriated, non-invasive method for their identification. The aim of this thesis was to evaluate novel positron emission tomography (PET) probes for the detection of vulnerable atherosclerotic plaques and to characterize, two mouse models of atherosclerosis. These studies were performed by using ex vivo and in vivo imaging modalities. The vulnerability of atherosclerotic plaques was evaluated as expression of active inflammatory cells, namely macrophages. Age and the duration of high-fat diet had a drastic impact on the development of atherosclerotic plaques in mice. In imaging of atherosclerosis, 6-month-old mice, kept on high-fat diet for 4 months, showed matured, metabolically active, atherosclerotic plaques. [18F]FDG and 68Ga were accumulated in the areas representative of vulnerable plaques. However, the slow clearance of 68Ga limits its use for the plaque imaging. The novel synthesized [68Ga]DOTA-RGD and [18F]EF5 tracers demonstrated efficient uptake in plaques as compared to the healthy vessel wall, but the pharmacokinetic properties of these tracers were not optimal in used models. In conclusion, these studies resulted in the identification of new strategies for the assessment of plaque stability and mouse models of atherosclerosis which could be used for plaque imaging. In the used probe panel, [18F]FDG was the best tracer for plaque imaging. However, further studies are warranted to clarify the applicability of [18F]EF5 and [68Ga]DOTA-RGD for imaging of atherosclerosis with other experimental models.

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Millions of enterprises move their applications to a cloud every year. According to Forrester Research “the global cloud computing market will grow from a $40.7 billion in 2011 to $241 billion in 2020”. Due to increased interests and demand broad range of providers and solutions have appeared in the market. It is vital to be able to predict possible problems correctly and to classify and mitigate risks associated with the migration process. The study will show the main criteria that should be taken into consideration while making decision of moving enterprise applications to the cloud and choosing appropriate vendor. The main goal of the research is to identify main problems during the migration to a cloud and propose a solution for their prevention and mitigation of consequences in case of occurrence. The research provides an overview of existing cloud solutions and deployment models for enterprise applications. It identifies decision drivers of an applications migration to a cloud and potential risks and benefits associated with this. Finally, the best practices for the successful enterprise-to-cloud migration based on the case studies analysis are formulated.

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This research focused on operation of a manpower pool within a service business unit in Company X and aimed to identify how the operation should be improved in order to get most out of it concerning the future prospects of the service business unit. This was done by analyzing the current state of the manpower pool related operations in means of project business, project management and business models. The objective was to deepen the understanding and to highlight possible areas of improvement. The research was conducted as a qualitative single-case study utilizing also an action research method; the research approach was a combination of conceptual, action-oriented and constructive approaches. The primary data was collected with executing a comprehensive literature review and semi-structured theme interviews. The main results described how the manpower pool operates as part of the service business unit in project business by participating in different types of delivery projects; process flows for the project types were mapped. Project management was analyzed especially from the resource management point of view, and an Excel-based skills analysis model was constructed for this purpose. Utilization of operational business models was also studied to define strategic direction for development activities. The results were benchmarked against two competitors in order to specify lessons to be learnt from their use of operational business models.

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In this doctoral thesis, a power conversion unit for a 10 kWsolid oxide fuel cell is modeled, and a suitable control system is designed. The need for research was identified based on an observation that there was no information available about the characteristics of the solid oxide fuel cell from the perspective of power electronics and the control system, and suitable control methods had not previously been studied in the literature. In addition, because of the digital implementation of the control system, the inherent characteristics of the digital system had to be taken into account in the characteristics of the solid oxide fuel cell (SOFC). The characteristics of the solid oxide fuel cell as well the methods for the modeling and control of the DC/DC converter and the grid converter are studied by a literature survey. Based on the survey, the characteristics of the SOFC as an electrical power source are identified, and a solution to the interfacing of the SOFC in distributed generation is proposed. A mathematical model of the power conversion unit is provided, and the control design for the DC/DC converter and the grid converter is made based on the proposed interfacing solution. The limit cycling phenomenon is identified as a source of low-frequency current ripple, which is found to be insignificant when connected to a grid-tied converter. A method to mitigate a second harmonic originating from the grid interface is proposed, and practical considerations of the operation with the solid oxide fuel cell plant are presented. At the theoretical level, the thesis discusses and summarizes the methods to successfully derive a model for a DC/DC converter, a grid converter, and a power conversion unit. The results of this doctoral thesis can also be used in other applications, and the models and methods can be adopted to similar applications such as photovoltaic systems. When comparing the results with the objectives of the doctoral thesis, we may conclude that the objectives set for the work are met. In this doctoral thesis, theoretical and practical guidelines are presented for the successful control design to connect a SOFC-based distributed generation plant to the utility grid.

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Työn tavoitteena oli mallintaa maastotyökoneen ajomoottorin hybridisointiin soveltuvan napavaihteiston dynamiikka. Työ tehtiin osana Saimaan ammattikorkeakoulun tutkimusprojektia, jonka tarkoituksena oli ajomoottorin ja integroidun napavaihteiston kaupallistaminen maastotyökoneisiin. Maastotyökoneena simulointimallissa käytettiin tyypillistä maataloustraktoria, johon kytkettiin vielä peräkärry. Traktorin renkaiden napaan oli kytketty ajomoottorina toimiva sähkömoottori, jonka sisään simuloitu napavaihteisto oli integroitu. Napavaihteiston dynamiikan mallintamiseen käytettiin monikappaledynamiikan simulointiohjelmistoa (Adams). Ohjelmalle määritettiin napavaihteiston komponenttien parametrit, joista voitiin simuloida vaihteiston dynaaminen käyttäytyminen. Simuloidusta mallista saatiin kytkimiin kohdistuvat voimat kytkentätilanteessa sekä sähkömoottorin väännön suunnanvaihtotilanteessa eri akselin pituuksilla, eri kytkinten nopeuseroilla, eri traktorin painoilla ja eri kuormilla ajettaessa. Mallissa simuloitiin myös sähkömoottorin käyttäytyminen vaihteenvaihtotilanteessa eri pyörimisnopeuden säätimen kertoimilla. Työssä huomattiin, että akselin mitoituksella voitiin vaikuttaa vaihteistossa ilmeneviin voimiin kytkimen kytkentähetkellä. Myös kytkimen hammastuksessa olevalla hammasvälyksellä voitiin vaikuttaa kytkimiin kohdistuviin voimiin suunnanvaihtotilanteissa. Vaihteistoon kohdistuvista voimista voidaan jatkossa suunnitella kytkimen ja akselin profiili, jotta vaihteisto kestää siihen kohdistuvat voimat.

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State-of-the-art predictions of atmospheric states rely on large-scale numerical models of chaotic systems. This dissertation studies numerical methods for state and parameter estimation in such systems. The motivation comes from weather and climate models and a methodological perspective is adopted. The dissertation comprises three sections: state estimation, parameter estimation and chemical data assimilation with real atmospheric satellite data. In the state estimation part of this dissertation, a new filtering technique based on a combination of ensemble and variational Kalman filtering approaches, is presented, experimented and discussed. This new filter is developed for large-scale Kalman filtering applications. In the parameter estimation part, three different techniques for parameter estimation in chaotic systems are considered. The methods are studied using the parameterized Lorenz 95 system, which is a benchmark model for data assimilation. In addition, a dilemma related to the uniqueness of weather and climate model closure parameters is discussed. In the data-oriented part of this dissertation, data from the Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite instrument are considered and an alternative algorithm to retrieve atmospheric parameters from the measurements is presented. The validation study presents first global comparisons between two unique satellite-borne datasets of vertical profiles of nitrogen trioxide (NO3), retrieved using GOMOS and Stratospheric Aerosol and Gas Experiment III (SAGE III) satellite instruments. The GOMOS NO3 observations are also considered in a chemical state estimation study in order to retrieve stratospheric temperature profiles. The main result of this dissertation is the consideration of likelihood calculations via Kalman filtering outputs. The concept has previously been used together with stochastic differential equations and in time series analysis. In this work, the concept is applied to chaotic dynamical systems and used together with Markov chain Monte Carlo (MCMC) methods for statistical analysis. In particular, this methodology is advocated for use in numerical weather prediction (NWP) and climate model applications. In addition, the concept is shown to be useful in estimating the filter-specific parameters related, e.g., to model error covariance matrix parameters.

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The significance of services as business and human activities has increased dramatically throughout the world in the last three decades. Becoming a more and more competitive and efficient service provider while still being able to provide unique value opportunities for customers requires new knowledge and ideas. Part of this knowledge is created and utilized in daily activities in every service organization, but not all of it, and therefore an emerging phenomenon in the service context is information awareness. Terms like big data and Internet of things are not only modern buzz-words but they are also describing urgent requirements for a new type of competences and solutions. When the amount of information increases and the systems processing information become more efficient and intelligent, it is the human understanding and objectives that may get separated from the automated processes and technological innovations. This is an important challenge and the core driver for this dissertation: What kind of information is created, possessed and utilized in the service context, and even more importantly, what information exists but is not acknowledged or used? In this dissertation the focus is on the relationship between service design and service operations. Reframing this relationship refers to viewing the service system from the architectural perspective. The selected perspective allows analysing the relationship between design activities and operational activities as an information system while maintaining the tight connection to existing service research contributions and approaches. This type of an innovative approach is supported by research methodology that relies on design science theory. The methodological process supports the construction of a new design artifact based on existing theoretical knowledge, creation of new innovations and testing the design artifact components in real service contexts. The relationship between design and operations is analysed in the health care and social care service systems. The existing contributions in service research tend to abstract services and service systems as value creation, working or interactive systems. This dissertation adds an important information processing system perspective to the research. The main contribution focuses on the following argument: Only part of the service information system is automated and computerized, whereas a significant part of information processing is embedded in human activities, communication and ad-hoc reactions. The results indicate that the relationship between service design and service operations is more complex and dynamic than the existing scientific and managerial models tend to view it. Both activities create, utilize, mix and share information, making service information management a necessary but relatively unknown managerial task. On the architectural level, service system -specific elements seem to disappear, but access to more general information elements and processes can be found. While this dissertation focuses on conceptual-level design artifact construction, the results provide also very practical implications for service providers. Personal, visual and hidden activities of service, and more importantly all changes that take place in any service system have also an information dimension. Making this information dimension visual and prioritizing the processed information based on service dimensions is likely to provide new opportunities to increase activities and provide a new type of service potential for customers.

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Third party logistics, and third party logistics providers and the services they offer have grown substantially in the last twenty years. Even though there has been extensive research on third party logistics providers, and regular industry reviews within the logistics industry, a closer research in the area of partner selection and network models in the third party logistics industry is missing. The perspective taken in this study was of expanding the network research into logistics service providers as the focal firm in the network. The purpose of the study is to analyze partnerships and networks in the third party logistics industry in order to define how networks are utilized in third party logistics markets, what have been the reasons for the partnerships, and whether there are benefits for the third party logistics provider that can be achieved through building networks and partnerships. The theoretical framework of this study was formed based on common theories in studying networks and partnerships in accordance with models of horizontal and vertical partnerships. The theories applied to the framework and context of this study included the strategic network view and the resource-based view. Applying these two network theories to the position and networks of third party logistics providers in an industrial supply chain, a theoretical model for analyzing the horizontal and vertical partnerships where the TPL provider is in focus was structured. The empirical analysis of TPL partnerships consisted of a qualitative document analysis of 33 partnership examples involving companies present in the Finnish TPL markets. For the research, existing documents providing secondary data on types of partnerships, reasons for the partnerships, and outcomes of the partnerships were searched from available online sources. Findings of the study revealed that third party logistics providers are evident in horizontal and vertical interactions varying in geographical coverage and the depth and nature of the relationship. Partnership decisions were found to be made on resource based reasons, as well as from strategic aspects. The discovered results of the partnerships in this study included cost reduction and effectiveness in the partnerships for improving existing services. In addition in partnerships created for innovative service extension, differentiation, and creation of additional value were discovered to have emerged as results of the cooperation. It can be concluded that benefits and competitive advantage can be created through building partnerships in order to expand service offering and seeking synergies.

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One of the main challenges in Software Engineering is to cope with the transition from an industry based on software as a product to software as a service. The field of Software Engineering should provide the necessary methods and tools to develop and deploy new cost-efficient and scalable digital services. In this thesis, we focus on deployment platforms to ensure cost-efficient scalability of multi-tier web applications and on-demand video transcoding service for different types of load conditions. Infrastructure as a Service (IaaS) clouds provide Virtual Machines (VMs) under the pay-per-use business model. Dynamically provisioning VMs on demand allows service providers to cope with fluctuations on the number of service users. However, VM provisioning must be done carefully, because over-provisioning results in an increased operational cost, while underprovisioning leads to a subpar service. Therefore, our main focus in this thesis is on cost-efficient VM provisioning for multi-tier web applications and on-demand video transcoding. Moreover, to prevent provisioned VMs from becoming overloaded, we augment VM provisioning with an admission control mechanism. Similarly, to ensure efficient use of provisioned VMs, web applications on the under-utilized VMs are consolidated periodically. Thus, the main problem that we address is cost-efficient VM provisioning augmented with server consolidation and admission control on the provisioned VMs. We seek solutions for two types of applications: multi-tier web applications that follow the request-response paradigm and on-demand video transcoding that is based on video streams with soft realtime constraints. Our first contribution is a cost-efficient VM provisioning approach for multi-tier web applications. The proposed approach comprises two subapproaches: a reactive VM provisioning approach called ARVUE and a hybrid reactive-proactive VM provisioning approach called Cost-efficient Resource Allocation for Multiple web applications with Proactive scaling. Our second contribution is a prediction-based VM provisioning approach for on-demand video transcoding in the cloud. Moreover, to prevent virtualized servers from becoming overloaded, the proposed VM provisioning approaches are augmented with admission control approaches. Therefore, our third contribution is a session-based admission control approach for multi-tier web applications called adaptive Admission Control for Virtualized Application Servers. Similarly, the fourth contribution in this thesis is a stream-based admission control and scheduling approach for on-demand video transcoding called Stream-Based Admission Control and Scheduling. Our fifth contribution is a computation and storage trade-o strategy for cost-efficient video transcoding in cloud computing. Finally, the sixth and the last contribution is a web application consolidation approach, which uses Ant Colony System to minimize the under-utilization of the virtualized application servers.

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1. Fish oils are rich in the long-chain n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids. Linseed oil and green plant tissues are rich in the precursor fatty acid, a-linolenic acid (18:3n-3). Most vegetable oils are rich in the n-6 PUFA linoleic acid (18:2n-6), the precursor of arachidonic acid (20:4n-6). 2. Arachidonic acid-derived eicosanoids such as prostaglandin E2 are pro-inflammatory and regulate the functions of cells of the immune system. Consumption of fish oils leads to replacement of arachidonic acid in cell membranes by eicosapentaenoic acid. This changes the amount and alters the balance of eicosanoids produced. 3. Consumption of fish oils diminishes lymphocyte proliferation, T-cell-mediated cytotoxicity, natural killer cell activity, macrophage-mediated cytotoxicity, monocyte and neutrophil chemotaxis, major histocompatibility class II expression and antigen presentation, production of pro-inflammatory cytokines (interleukins 1 and 6, tumour necrosis factor) and adhesion molecule expression. 4. Feeding laboratory animals fish oil reduces acute and chronic inflammatory responses, improves survival to endotoxin and in models of autoimmunity and prolongs the survival of grafted organs. 5. Feeding fish oil reduces cell-mediated immune responses. 6. Fish oil supplementation may be clinically useful in acute and chronic inflammatory conditions and following transplantation. 7. n-3 PUFAs may exert their effects by modulating signal transduction and/or gene expression within inflammatory and immune cells.

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This thesis studies how the case company could digitalize its supply chain and what kind of advantages this would create in the light of supply chain efficiency. The case company manufactures several pulp products that are used for paper, fabrics and packaging products by customers worldwide. The paper and pulp industry has been paying more and more attention to increasing supply chain efficiency with new operating and service models made possible by today’s information technology. The main focus of this study is on the supply chain between the case company and its key customers and the goal is to find ways to make the operations between them as efficient as possible. The study relays heavily on collaboration techniques and digitalization technologies. In addition to a theoretical framework, the study includes several empirical studies that offer real-life examples of how these theories and technologies are applied in operating environments similar to the case company. A plan with strategic and operational levels is created according to the findings of the previous sections to support the case company’s future operations. The plan is based on an RFID-supported collaboration model that aims to advance information sharing between the supply chain partners. The time for an RFID-investment is sought to be very optimal and the benefits of such system to be noteworthy, but challenging to measure in monetary terms.

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Cardiopulmonary reflexes are activated via changes in cardiac filling pressure (volume-sensitive reflex) and chemical stimulation (chemosensitive reflex). The sensitivity of the cardiopulmonary reflexes to these stimuli is impaired in the spontaneously hypertensive rat (SHR) and other models of hypertension and is thought to be associated with cardiac hypertrophy. The present study investigated whether the sensitivity of the cardiopulmonary reflexes in SHR is restored when cardiac hypertrophy and hypertension are reduced by enalapril treatment. Untreated SHR and WKY rats were fed a normal diet. Another groups of rats were treated with enalapril (10 mg kg-1 day-1, mixed in the diet; SHRE or WKYE) for one month. After treatment, the volume-sensitive reflex was evaluated in each group by determining the decrease in magnitude of the efferent renal sympathetic nerve activity (RSNA) produced by acute isotonic saline volume expansion. Chemoreflex sensitivity was evaluated by examining the bradycardia response elicited by phenyldiguanide administration. Cardiac hypertrophy was determined from the left ventricular/body weight (LV/BW) ratio. Volume expansion produced an attenuated renal sympathoinhibitory response in SHR as compared to WKY rats. As compared to the levels observed in normotensive WKY rats, however, enalapril treatment restored the volume expansion-induced decrease in RSNA in SHRE. SHR with established hypertension had a higher LV/BW ratio (45%) as compared to normotensive WKY rats. With enalapril treatment, the LV/BW ratio was reduced to 19% in SHRE. Finally, the reflex-induced bradycardia response produced by phenyldiguanide was significantly attenuated in SHR compared to WKY rats. Unlike the effects on the volume reflex, the sensitivity of the cardiac chemosensitive reflex to phenyldiguanide was not restored by enalapril treatment in SHRE. Taken together, these results indicate that the impairment of the volume-sensitive, but not the chemosensitive, reflex can be restored by treatment of SHR with enalapril. It is possible that by augmenting the gain of the volume-sensitive reflex control of RSNA, enalapril contributed to the reversal of cardiac hypertrophy and normalization of arterial blood pressure in SHR.