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Dissertations / Theses on the topic 'Bulk operations'
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Lee, Howoo. "A diffusion approximation for multi-server finite-capacity bulk queues /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265143146895.
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Donohue, Michael (Michael Tiahrt). "Application of queueing theory in bulk biotech manufacturing." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/66066.
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Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; in conjunction with the Leaders for Global Operations Program at MIT, June 2011."June 2011." Page 42 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 41).
One of the most challenging problems in Amgen's biological manufacturing facility is adhering to the daily schedule of production tasks. Delays in non-time critical tasks have been traced to temporary workload surges that exceed the production staff's capability to handle them. To quantify this effect, a method for creating an M/M/c queueing model that is specific for bulk biologic manufacturing processes was developed. The model was successfully validated by comparing the predicted results to the historical data for each of the five production shifts. A discussion of how to model different improvement programs is presented, and Amgen-specific data are presented. It was found that across-the-board task duration reductions will reduce the schedule deviation rate by up to 50%. Additionally, it is shown that implementing staff-cross training with other production areas will reduce the schedule deviation rate between 14% and 75%. Implementation aspects of these improvement initiatives in a regulated production environment are discussed.
by Michael Donohue.
S.M.
M.B.A.
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Duran, Pla Eduard. "Dimensionamiento y optimización de la operativa en las terminales de graneles sólidos = Dimensioning and optimization of operations for dry bulk terminals." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/395186.
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This thesis studies the factors that influence the optimization, and sizing, of dry bulk terminals, while looking for a model to reflect them.
At the same time it provides an overview of dry bulk shipping, and its marine operations, while identifying literature linked to the sector.
In the first part (Chapter 1 y 2) we study and analyze all the factors that tend to influence or affect the characteristics of a port terminal.
In the second part (Chapter 3 and 4) a series of international terminals are analyzed, called "Wold Champions" and a part of the largest bulk terminals in the spanish coast, as well.
After analyzing in detail the different types of terminals, it concludes by pointing out those decisive factors considered in the terminal design, such as ships dimensions, while considering that the sector volatility sometimes can force strategy changes due expected traffic modificationsEsta tesis estudia los factores que influyen en la optimización y dimensionamiento de las terminales de graneles sólidos, a la vez que busca un modelo para reflejarlos. A la vez pretende aportar una visión general del mundo del transporte marítimo de graneles sólidos, y su operativa, agrupando e identificado la bibliografía ligada al sector. En una primera parte (Capítulos 1 y 2) se estudian, y analizan, todos aquellos factores que influyen en las características de una terminal portuaria de graneles sólidos. En una segunda parte(Capítulos 3 y 4) se analizan una serie de terminales internacionales de graneles sólidos, las denominadas "campeones mundiales", y una gran parte de las mayores terminales ubicadas en el litoral español. Tras analizar detalladamente las diferentes tipologías de terminales se concluye señalando aquellos factores determinantes a la hora de proceder al diseño de la terminal, como son las dimensiones del buque, ala vez que se indica la volatilidad que sufre el sector y que en ocasiones puede obligar a cambios de estrategia por modificaciones sobre los tráficos previstos.
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Sikdar, Kieran Jonah. "Material Flow Optimization And Systems Analysis For Biosolids Management: A Study Of The City Of Columbus Municipal Operations." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1218074193.
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Kretschmann, Endel. "Uma abordagem ao Vehicle Routing Problem with pickup and delivery with time windows em navios : um caso de uma indústria química." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/184352.
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Os objetivos desta dissertação são comprovar empiricamente os benefícios da modelagem matemática como uma ferramenta de apoio ao processo decisório e apresentar uma forma de minimizar o custo do transporte marítimo de matérias-primas a granel, atendendo aos prazos e às demandas de quantidade de uma indústria química do ramo de fertilizantes em sua operação no Brasil. Isso será possível mediante o desenvolvimento de um modelo de programação linear inteira mista com as características do Vehicle Routing Problem with Pickup and Delivery with Time Windows (VRPPDTW) para representar as características do problema. O VRPPDTW é uma subclasse do clássico Vehicle Routing Problem que encontra grande aderência aos desafios industriais, ao poder encontrar soluções para o transporte de bens e pessoas. Para essa aplicação, diversas restrições de roteamento de navios heterogêneos, de agendamento das coletas e descargas das matérias-primas, de oferta e demanda por diferentes tipos de insumos e de capacidade de cargas de portos e navios foram elaboradas e implementadas para caracterizar situações às quais o processo de planejamento de entregas está atualmente submetido. Diferentes instâncias com dados cedidos pela companhia foram processadas e resolvidas em tempos aceitáveis, a partir da utilização do solver IBM ILOG CPLEX© 12.1.0. Resultados econômicos mais eficazes dos que aqueles atualmente percebidos pela empresa foram encontrados.This thesis purposes are to prove empirically the mathematical modeling benefits as a support tool to the decision-making process and to present a way to minimize bulk raw materials maritime transport costs, attending to deadlines and quantity demand of a chemical fertilizer industry in its operations in Brazil. This will be possible through the development of a mixed linear and integer programming model with the characteristics of the Vehicle Routing Problem with Pickup and Delivery with Time Windows (VRPPDTW) to represent the problem characteristics. The VRPPDTW is a subclass of the classic Vehicle Routing Problem that finds great adhesion to industrial challenges, to be able to find solutions for the transport of goods and people. For this application, several constraints for heterogeneous ship routing, scheduling for raw material charges and discharges, supply and demand for different types of products and ports’ and ships’ cargo capacity were elaborated and implemented to characterize situations to which the delivery planning process is currently submitted. Different instances with data provided by the company were processed and solved in acceptable times, using the IBM ILOG CPLEX © 12.1.0 solver. Economic results more effective than those currently perceived by the company were found.
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Víšek, Jakub. "Hromadná orchestrácia v multirepo CI/CD prostrediach." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-445562.
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Multirepo model přístupu ke správě a verzování zdrojového kódu, jež zahrnuje použití mnoha oddělených repozitářů verzovacích systémů, je poslední dobou často zmiňován v odborné literatuře. Jednou z jeho nevýhod je množství zdlouhavých, nezajímavých a repetitivních úkonů, které je nutno provádět při hromadných operacích tvořících transakce napříč těmito repozitáři. Multirepo repozitáře navíc umožňují využití široké škály technologií, což jen umocňuje riziko lidské chyby, ke které při ručně prováděných hromadných operacích může dojít. V rámci této práce je navrženo, implementováno a otestováno řešení pro automatizaci operací prováděných napříč množstvím repozitářů uspořádaných v multirepo modelu, což s nimi uživatelům zlepšuje zkušenost.
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Psarros, George Ad. "Operational risk management of bulk carriers." Thesis, University of Strathclyde, 2008. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21970.
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The proposed study had been performed behind the premise of proposing a methodology for estimating the current operational risk of bulk carriers. Hence, a high level risk assessment has been conducted for evaluating the safety performance of dry bulk cargo transportation. This included the preparatory step for setting the problem's boundary limits, hazard identification for the prioritization of causes and effects, risk analysis for the quantification of risks and risk evaluation for assessing the significance and the acceptability of the estimated risk. The relevant aspects that are taken into account consist of the vessel's function (carriage of payload), operational phase (ocean transit), external (weather conditions, routeing) and internal (cargoes) influences, accident category (foundering) and the risk associated with crew (fatalities) and property (loss of vessel and cargo). Apparently, many factors were competing for attracting attention, and therefore, the Pareto principle was applied for narrowing the analysis where corrosion was identified as a main situation of causing harm. The attached uncertainty in the aforementioned operational domain is dealt with the Bayesian Networks technology and concurrently the construed prioritization to corrosion is verified by the developed risk model. The estimated risk was found As Low As Reasonably Practicable and the potential of improvement is considered by addressing preventive (design) and mitigating (operational) measures. Furthermore, their effectiveness as action implementing risk management decision is illustrated by employing Life Cycle Cost Analysis, a decision making technique for exploiting different investment opportunities.
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Cleaver, James Arnold Stafford. "Velocity distributions in conical hoppers." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387131.
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Ripollés, Sanchis Teresa. "Interfacial and Bulk Operation of Polymeric Solar Cells by Optoelectronics and Structural Techniques." Doctoral thesis, Universitat Jaume I, 2014. http://hdl.handle.net/10803/277095.
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This Ph.D. Thesis focuses on the investigation of organic photovoltaic (OPV) technology, especially in aspects of experimental device processing, and optoelectronic and electrical characterization on OPV devices to be readily marketable. More specifically, the topics addressed are the following: origin of recombination current,open-circuit voltage and crystallinity, transport driving force, contact selectivity and interface states, alternative hole transporting layers and oxygen and degradation routes.
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Fusari, Flavio. "Continuous wave and modelocked femtosecond novel bulk glass lasers operating around 2000 nm." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/1694.
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This thesis reports on the development of glass-based femtosecond laser sources around 2 µm wavelength. In order to be able to produce 2 µm radiation the dopants used were trivalent Thulium (Tm³⁺) and trivalent Holmium (Ho³⁺) that could be optically pumped with Ti:Sapphire radiation at 0.8 µm and semiconductor disk lasers (SDL) at 1.2 µm. The samples were produced at Leeds University and polished in-house in bulk form and deployed in free space laser cavities. Tellurite compounds doped with Tm³⁺ produced stable continuous wave 1.94 µm radiation when pumped at 800 nm with a maximum efficiency of 28.4% with respect to the absorbed power and maximum output power around 120 mW when pumped using a Ti:Sapphire operating around 0.8 µm. The radiation was broadly tunable across 130 nm. Tm³⁺-Ho³⁺ doubly doped tellurite samples lased around 2.02 µm with maximum efficiency of 25.9% and with P[subscript(OUT)]=75 mW and a smooth tunability of 125 nm. The fluorogermanate glass doped with Tm³⁺ gave an absorbed to output power efficiency of 50%. The maximum continuous wave output powers obtained were around 190 mW and limited by the available pump power at 0.8 µm. These results together with a very low threshold of 60 mW of incident power were comparable to the crystalline counterparts to this gain medium. The Tm3+ tellurite and the Tm³⁺-Ho³⁺ tellurite compounds were also pumped by an SDL operating at 1215 nm to obtain an indication of the viability of such a pump scheme. The results were a maximum internal slope efficiency of 22.4% with a highest output power of 60 mW. The comparison demonstrated that 1.2 µm pumping was competitive with using 0.8 µm wavelength. The use of semiconductor saturable absorbing mirror (SESAM) technology was used for the modelocking of these lasers. The SESAM was produced in Canada and implanted with As⁺ ions in order to reduce the relaxation time. Trains of transform-limited laser pulses at 222 MHz as short as 410 fs centred at 1.99 µm were produced for the first time with a bulk Tm³⁺:Fluorogermanate glass. The maximum average output power obtained was of 84 mW. The same SESAM deployed on the Tm³⁺-Ho³⁺ Tellurite compounds gave trains of transform-limited pulses as short as 630 fs at 2.01 µm with a repetition rate of 143 MHz and a maximum averaged output power of 43 mW. The regime of propagation obtained was soliton-like and the modelocking was self-starting. The results obtained with bulk glass were very promising and open interesting research pathways within the realm of amorphous bulk gain media.
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Harris, Cory Angelo. "Operation of buck regulator with ultra-low input voltage." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91825.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-102).
Based on the LTC3621 and LTC3624, the designed buck regulator proposed in this thesis aims to lower the allowed input voltage and increase efficiency compared to the original part without making significant changes to quiescent current and part performance. This thesis will discuss additions and modifications made to the original afformentioned parts in order to achieve said goal. This thesis will provide an in depth analysis through simulations of the results of the changes made and a comparison of performance between the original and the redisigned part.
by Cory Angelo Harris.
M. Eng.
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Petrie, Alexander Craig. "Ultra-Low-Supply-Voltage Analog-to-Digital Converters." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/9122.
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This thesis presents techniques to implement analog-to-digital converters (ADCs) under an ultra-low-supply-voltage of 0.2 V to reduce the power consumption. The thesis proposes a dynamic bulk biasing circuit to adjust the PMOS bulk voltage to balance the NMOS and PMOS drain currents to guarantee functionality in the presence of process, voltage, and temperature variations. The dynamic bulk bias circuit is analyzed rigorously to show its functionality. This thesis also describes a new comparator suitable for a 0.2-V supply using ac-coupling, stacked input pairs, and voltage-boosted load capacitor. A 10-bit 5-kS/s successive-approximation-register (SAR) ADC in a 180-nm CMOS process with a supply voltage of 0.2 V demonstrates these ideas. The ADC exhibits a differential nonlinearity (DNL) and integral nonlinearity (INL) within +0.42/-0.45 and +0.62/-0.67 LSB, respectively. The measured SFDR and SNDR at 5 kS/s with a Nyquist-frequency input are 65.9 dB and 52.1 dB, respectively. The entire ADC and dynamic bulk biasing circuitry consume 22 nW including leakage power to yield a figure-of-meirt (FoM) of 8.8 fJ/conv.-step. Measurements of multiple chips show the proposed dynamic bulk biasing fully recovers the ADC performance when the supply voltage is varied. The nW power consumption makes the design well suited for wireless sensor node and energy harvester applications.
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Sohlström, Klas. "Operation Black Buck : En teorikonsumerande fallstudie om strategiskt bombflyg under Falklandskriget." Thesis, Försvarshögskolan, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-10145.
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The Falklands War is well studied but there are currently no theoretically based analyzes specifically aimed at explaining Operation Black Buck, a long-range bombing of Argentine targets on the Falklands with strategic bombers, despite its controversial and unique nature. By illustrating the case on the basis of a theory-consuming approach, this study examines the purpose of the operation in an effort to understand why the British Air Force justified the missions despite the great challenges. The theoretical framework for this study is seen through the eyes of the most prominent theorists in modern air power debate; John Warden and Robert Pape. The important aspect in this study is not the authors disagreements but rather that their theories can be seen as complementary to each other in understanding this case. The study shows that the purpose of Operation Black Buck was aimed at denying the Argentines the opportunity to use the airport at Stanley for military purposes. In addition, there was a deterrent value that indirectly gave a strategic effect by deploying strategic bombers to demonstrate will, determination and hint at the ability to strike the Argentine mainland. The driving force behind the operation was the British effort in trying to achieve air superiority which was a critical objective during the war.
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Ramachandran, Bhaskar. "Dynamic operation of sensorless dead-time optimization in digitally controlled synchronous buck converters." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447688.
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Nousek, Petr. "Porovnávací studie nízkonapěťových operačních zesilovačů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218696.
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This work deals with methods used in design of low voltage operational amplifiers. It describes some of the most commonly used methods. Properties of these methods are verified by computer simulation of operational transconductance amplifiers that are utilizing them.
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Perrot, Fabrice. "The effects of multi-current impulses on the low current bulk distribution in varistor materials, under continuous AC operation." Thesis, University of Brighton, 1995. https://research.brighton.ac.uk/en/studentTheses/0c2ff4b0-630d-41b1-8241-658d582ac6d5.
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The first part of this work gives a broad introduction on the origins of ZnO bismuthbased v aristor materials. The electrical properties of ZnO varistors follow, giving a detailed and up to date review of all the models published with an attempt to explain their complex conduction mechanisms. Stresses found in HV networks are also reviewed in detail, their knowledge being necessary to link the de gradation and fail ure mechanisms of ZnO varistors which are explained at depth. The manufacture of ZnO varistors on a laboratory scale is also presented: disc type as well as thick-film type varistors were manufactured and tested during this inv estigation. The parameters influencing the microstructure and electrical characteristics of varistors during sintering were reviewed. Testing sequences used by manufacturers as well as surge arrester testing standards were also assessed to derive tests for the laboratory produced samples.
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Silva, Tiago Lopes da. "Cost efficiency in the Portuguese water sector: the case of multimunicipal systems operating at the bulk level." Master's thesis, NSBE - UNL, 2013. http://hdl.handle.net/10362/11602.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsThe purpose of this paper is to study the cost efficiency of multimunicipal systems operating at the bulk level in the Portuguese water sector. We will use Pooled OLS, Fixed Effects and Stochastic Frontier Analysis (SFA) to study the role of structural variables such as water losses, network density, water sources, quality measures, rainfall and topography in explaining the cost differences among those systems. Moreover, using SFA we determine operators’ efficiency scores. We found that inefficiency of operators remained constant over time. The main source of the distance to the cost frontier is a high degree of inefficiency and not exogenous random shocks.
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Erasmus, Gert Botha. "Stochastic models of steady state and dynamic operation of systems of congestion." Thesis, Pretoria : [s.n.], 2006. http://hdl.handle.net/2263/28814.
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(i) The thesis sets out to address the problematic phenomenon of Systems of Congestion via Basic Queueing Theory. The theory, and its application in practice, appears to be a field of study which is the common domain of “theorists” and “practitioners”. (ii) This professional dichotomy has come about due to diverging interests in that one group is mainly interested in the purity of mathematical modelling, and the other group is motivated to use modelling, which conveniently employs applications oriented solutions. (iii) The schism between the groups has been accentuated by the “practitioners” who in addition to having an interest in steady state system behaviour make use of methods of modelling of the transient operation of complex Systems of Congestion. (iv) At the outset the thesis demonstrates how closed form solutions are obtained for steady state and transient state operation of a selection of Systems of Congestion. The attendant mathematical derivations are elegant and intricate. (v) Having revealed the limited utility of closed-form solutions the thesis proceeds to investigate the feasibility of using dynamical systems theory to study the transient behaviour of complex Systems of Congestion. (vi) The creation of Chaos Theory in recent decades suggests that it may be employed as a useful tool in analysing Systems of Congestion. Iterative Chaos Theory methods of orbit generation for complete Systems of Congestion are therefore examined. The use of such orbit generation methods is found to be satisfactory for simple Systems of Congestion. More than a perfunctory knowledge of chaos mapping is however required. The simplicity of modelling is emphasized. (vii) Based on the results of benchmarking the creation of dynamic system orbits against an existing simulation method, the research advances to modelling of the transient operation of complex systems. Once again the iterative method of orbit generation displays the ease of modelling while simultaneously unfolding system dynamics graphically. (viii) One may hopefully contend that a tool of eminent utility has been developed to aid practitioners in studying and optimizing Systems of Congestion.Thesis (PhD (Industrial Engineering))--University of Pretoria, 2006.
Industrial and Systems Engineering
Unrestricted
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Parria, Gavin. "Pressure Analysis during Bull Heading Operations in a Deep-Water Environment Using a Fluid Modeling Simulator and Sensitivity Analysis." Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10243995.
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A bull heading operation is a static non-circulating well control method used to regain integrity of the wellbore. This method is used when there is no drill/tubing string in the wellbore to circulate the kick out of the wellbore. A bull-heading operation requires the use of hydraulic force to overcome the static shut-in pressures of the reservoirs and provide a differential pressure. This differential pressure is required to overcome wellbore and formation friction forces and drive the kill fluid, at a desired flow rate, down the wellbore.
In tight conventional reservoirs it is very difficult to accurately simulate the requirements needed to conduct a Bullhead operation. Is it critical to properly estimate the maximum anticipated surface pressure expected during any well control operation. If not done accurately, the equipment used during this operation can surpass its limitations, leading to compromising the integrity of the equipment. The key component to estimate is the differential pressure required to force the oil back into the reservoir at a required kill fluid velocity. A specific kill fluid velocity is required to hydraulically kill the well by preventing the reservoir fluids from u tubing with the heavier kill fluid. Bullhead simulations don’t focus on injection pressure modeling, which is believed the reason why the required differential pressure is being underestimated in deep-water applications. The goals of this project is to create a reservoir model, analyze the three-dimensional fluid flow that will occur during a bull heading operation, and conduct a sensitivity analysis on the parameters that affect the injection pressure. This will allow us to accurately estimate the injection pressure required to force the oil back into the reservoir and also determine what impact certain reservoir properties have on injection pressure.
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BOTELHO, LEONARDO GONDINHO. "A METHOD FOR THE OPERATIONAL DISTRIBUTION PLANNING: APPLICATION FOR CASES WITH SUPPLY OF LIQUID BULKS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4694@1.
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Esta dissertação apresenta o estudo de um método para o
planejamento operacional da distribuição de granéis
líquidos, que visa à otimização dos recursos corporativos e
a redução de custos operacionais. Iniciando pelo conceito
da gestão do conhecimento, procura-se extrair as melhores
práticas da empresa através da experiência dos seus
profissionais. Todas as informações obtidas são
estruturadas e organizadas em um sistema de apoio a
decisão (SAD), a fim de montar uma base de conhecimento
para suportar e assistir os processos de negócio
relacionados à distribuição: previsão de demanda,
programação de abastecimentos e roteirização de veículos.
Baseado em pesquisas bibliográficas fundamentadas em
disciplinas relacionadas à análise dos processos supra
descritos e, principalmente, no conhecimento adquirido na
própria empresa, são sugeridas soluções heurísticas para
os problemas de planejamento da distribuição. Com o
objetivo de validar a utilização deste método, é
apresentado um estudo de caso realizado em uma empresa
distribuidora de GLP (Gás Liquefeito de Petróleo),
comparando os resultados obtidos antes e depois da sua
aplicação. Os indicadores de desempenho adotados pela
mesma apresentam os benefícios e valores agregados,
ratificando a eficiência do referido método.This dissertation presents the study of a method for the operational distribution planning of liquid bulks, that aims the optimization of the corporate resources and the operational cost reduction. Starting by the concept of the knowledge management, it pursuits to extract the company`s best practices through the experience of its professionals. All the information obtained are structured and organized in a support decision system (SAD), in order to build a knowledge base to support and to assist the business processes related with the distribution: demand forecast, supply programming and vehicle routing. Based on bibliography researches well-founded in disciplines related with the analysis of the processes described above and, specially, from the knowledge gained in the company, heuristics solutions are proposed for the distribution planning problems. With the purpose of validating this method utilization, it is presented a study case in a LPG distribution company (liquid petroleum gas), comparing the results achieved before and after its application. The key performance indicators adopted present benefits and add values, ratifying the efficiency of the method above mentioned.
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Rahim, Nasrudin Abd. "Closed-loop control of a current-mode AC/DC buck converter in 4 quadrant P-Q operation." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/1342.
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Rovná, Tereza. "Měření kvality osvětlení na operačních sálech." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242187.
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This thesis is focused on measuring the quality of lighting in operating rooms. Operating lights are very demanding in terms of quality requirements for each parameter, so it is important to specify exactly these parameters and check them regurarly. To measure the quality of the light source, was used a special kit from Maquet. Measurement procedure was not as accurate as it was for operating lighting need, therefore, this work includes a proposal to improve the measurement of quality lighting in operating theaters. In cooperation with University Hospital Brno Bohunice University Hospital Motol and the company Maquet measured nine operating lights, each light were compared in terms of parameters such as maximum light intensity, light distribution in the surgical field. In each category were selected several lighting, which reached the best results. The various parameters were compared with values declared by the manufacturer.
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Krbal, Michal. "Účinnost přeměny elektrické energie na světlo u současných světelných zdrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218541.
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The goal of this diploma’s thesis is to inform about present development of light sources, new technologies and about achieved parameters of these light sources. The thesis is mainly directed to describe efficiency of transformation electric energy to light at single types of light sources. There are described the concrete technical parameters of sources quoted by manufacturers and the contructional solution of single types of light sources. There is created a graphic comparation of electrotechnical and light parameters of the light sources.
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Huang, Yu-Yao, and 黃鈺堯. "Analyses of Key Influence Factors of Timecharter Operations in the Dry Bulk Shipping Sector by the Application of Fuzzy Delphi and DEMATEL." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/52176533957620581203.
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碩士國立臺灣海洋大學
航運管理學系
98
Due to the bulk shipping market is uncertain and risky, making chartering decision is one of the most difficult challenges of operation management. Generally, the charter period of timecharter is longer than voyagecharter, and the risk of breaching the contract which the shipowners face is higher than voyagecharer. Since 1 July 2009 the Baltic dry index (BDI) components only calculated by trip timecharter hire. The shipping market is under considerable risks, how to make the chartering decisions the most efficiency to make the profit of shipping companies maximum. Therefore, according to the results of literature reviews and in-depth interviews, this research concludes timecharter operations key influencial factors of bulk shipping, to discuss these factors by questionnaire. In order to understand the key influencial factors of timecharter operations, this research applied the method of Fuzzy Delphi Method to analyze the importance of key influencial factors of timecharter operations, and meanwhile, clarify the causal relationship among each influential factor by utilizing the decision making and trial evaluation laboratory (DEMATEL). 1. Using Fuzzy Delphi analysis the importance of key factors, concerning the integral evaluation criteria, “Reputation” is valued the most, followed by “Speed and consumption”, “Crisis handling”, “Trading limits” and “Forecast of market price”. 2. Using DEMATEL analysis the relevance of key factors, concerning the integral criteria, “Chartering period” exerts the greatest effect on the overall influential degree, followed in descending order by “Payment condition” and “Reputation”. More specifically, the main influential factor is “Scale of operation”, and following are “Trading limits” and “Cargo exclusion and sub-let”. Additionally, the most crucial influenced factor is “Payment condition”, and the second and third among those being affected are “Delivery and redelivery” and “Reputation”. The results of this study can contribute to dry bulk corporations in making timechartering decisions.
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Lu, Pie-Ya, and 魯沛亞. "Discussion on Bulk Carriers loading and unloading operations and freight safety for the owner’s and Master’s responsibilities and obligations as per charter party requirements." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6b93pg.
Full textAbstract:
碩士國立高雄海洋科技大學
航運技術研究所
106
According to Review of Maritime Transport(RMT), world seaborne trade in UNCTAD reached 10,287 (Million of tons) in 2016. Within them, bulk cargo (five major bulks plus dry cargo in minor bulks) has accounted for 5,511 (Million of tons). It is 53.57% of total seaborne trade load. From the perspective of ton-miles, bulk cargo accounted for 31,336 / 55,057 billion ton-miles in 2016. In 2017, these numbers would increase to 32,008 and 56,299 respectively. The main purpose of this thesis is to establish standard operating procedures (S.O.P) and safety management guidelines for cargo handling in bulk cargo ships. The following theories, rules and regulations, case studies and literature review, expert visits, telephone interviews, observation methods, and practical experience methods, will be used as a method of study; .1. Cargo loading theory of bulk carrier hull strength, stability, shear stress, and bending momentum 2.. Interviews with major bulk carrier companies by way of professional visits and in fact the ship understands the method of 3D load Master cload 6.1 1 in anticipation of Pre- loading plans and loading Seq.procedures. 3. Reviews of IMSBC-Code and SOLAS requirements, especially guidelines for the loading/unloading and safety of transportation of soybeans, bauxite ore and coal. 4. Studies of bulk carriers fail and successful cases 5. review literatures within which are thesis papers regarding Charter Party and academic reports of loading and unloading, port-based and cargo-borne safety, then,apply observation and practical experience on literature review conclusion to complete the requirements of the lease. This thesis is based on the above theories case studies and practical experiences from author who has worked as bulk carrier Captain for more than 20 years. The goal is to establish standard operating procedures (SOP) for bulk cargo loading and guidelines for safety management of cargo on board. The other goal is to provide guides for ship companies and masters to jointly implement the regulations for the satisfactory fulfillment of the responsibilities and obligations owed to the charter in the C/P. Ultimate purpose is to avoid damages of ship and cargo on board (total loss or serious damage) during navigation.
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Ceze, Luis H. "Bulk operation and data coloring for multiprocessor programmability /." 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3290193.
Full textAbstract:
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7423. Adviser: Josep Torrellas. Includes bibliographical references (leaves 133-139) Available on microfilm from Pro Quest Information and Learning.
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Lin, Terq-Der, and 林正德. "A study of cargo safety operation of cape size bulk carrier." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/72210523968977185121.
Full textAbstract:
碩士國立臺灣海洋大學
商船學系
103
Transportation is the cradle of human civilization. Vessels are an important means of sea transport, and freight contracts are the main operating businesses for shipping companies. In early times, the tonnage of vessel was small; nowadays, thanks to the advance of technology, tonnage is getting greater and greater, with four hundred thousands of tonnage for bulk carriers. The building of loading decks and ports is getting larger in size and commodity loading faster in speed. The requirements for security examination of loading metacentric height, shearing force and bending moment on cargo transportation are hence very strict. This study focused on the operation of loading of bulk carriers, how to complete the transport task successfully and the protection of marine environments to prevent marine pollution and ensure the safety of the vessels, cargo and human life. The enlargement of bulk carriers has become the current trend in sea freight transportation. For this reason, this study investigated and analyzed the need of cargo stowage variations by calculating the cargo load based on the data from onboard local loading calculator No. 158 on a cape size bulk carrier in one trip charter voyage and checking cargo weights using Excel program and the loading manual for comparison. From the calculations of cargo load distributed to each hold in the carrier in four different cargo loading scenarios A,B,C and D, the following key conclusions were made. Same cargo calculations by position (in scenarios A, B, C, and D): (1) Draft 17.02 even keel; (2) Sea condition: Ocean; (3) Displacement 184,381T; (4) Measured specific gravity of sea water 1.025; (5) Propeller immersion ratio 151.7%. Different cargo calculations by position: (1) In scenario A, homogeneous hold loading condition, the cargo was distributed in 9 holds, resulting in -35.01% and -28.04% each of the maximum values for shear force and bending moment, and the transverse metacentric height corrected for free surface effect at 9.37m and The cargo loaded in 9 holds was within the permissible GoM and weight limit. (2) In scenario B, alternate hold loading condition, the cargo was distributed in holds 1, 3, 5, 7 and 9 resulting in -97.34% and 72.92% each of the maximum values for shear force and bending moment and the transverse metacentric height corrected for free surface effect at 6.90m. The cargo loads in holds 1, 3, 5, 7 and 9 were closer to the permissible weight limit and caused more stress on the steel plates, posing a higher risk to old ships. (3) In scenario C, block hold loading condition，the cargo was distributed in holds 1, 3, III 4, 5, 6, 7 and 9 resulting in 90.9% and 54% each of the maximum values for shear force and bending moment, and the transverse metacentric height corrected for free surface effect within the permissible limit, 8.28m. The cargo loads in holds 1, 4, and 6 were closer to the permissible weight limit and caused more stress on the steel plates, posing a higher risk to old ships. (4) In scenario D, block hold loading condition, the cargo was distributed in holds 1, 3, 4, 6, 7 and 9, resulting in 109.08% and 104.48% each of the maximum values for shear force and bending moment, which exceeded 100% of the maximum values for both and would cause the ship to be damaged and break in this spot, while the transverse metacentric height corrected for free surface effect was within the permissible limit, at 7.72m. The load in hold 1 exceeded the permissible weight limit, whereas the cargo weight in hold 5, which was not loaded with cargo, did not meet the safety minimum requirement of 6,263 - 36,097 MT. This means more stress on the steel plates and the subsequent occurrence of damage and breakage in this spot. This study verified computer features of cargo loading. By swiftly providing accurate safety data for cargo loading, one can reduce unnecessary waste of time on complicated manual calculations. Time saved is money earned. It is crucial for cargo safety check and requirement and the development and training of personnel in the future.
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張珮宜. "An Analysis of the Operational Competitiveness for Bulk Shipping Companies." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/96525605749482332450.
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Mapoma, Unathi. "The effect of operational effectiveness on global competitiveness of the Richards Bay Dry Bulk Terminal." Thesis, 2011. http://hdl.handle.net/10500/4459.
Full textAbstract:
This study is an exposition of research into the effect of operational efficiency to global competitiveness, with the Richards Bay Dry Bulk Terminal (DBT) being the case study. The Richards Bay DBT is the main dry bulk terminal in the South African ports, operated by Transnet Ports Terminals (TPT), which is a division of the state-owned Transnet Ltd. Because of the strategic position of the DBT as the main dry bulk terminal of the country and also that it is a state owned entity, its competitiveness or otherwise is a reflection of South Africa the country as a trade destination. The research seeks to investigate the problem of the declining volumes handled by the DBT, which is traced to the possible operational inefficiencies and is likely to impede competitiveness of the DBT. While this study will not propose the ultimate solutions to the DBT’s problems, it will identify the root causes and symptoms of the problems, which will ultimately guide what needs to be tested as a better solution. Based on this, it is argued that this topic should generate a lot of interest to the stakeholders both locally and internationally.
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Lu, Chung-Hsing, and 呂忠信. "An Analysis of Operational Revenues and Costs between ROC and FOC Bulk Carriers." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/56609994187592652421.
Full textAbstract:
碩士國立臺灣海洋大學
航運管理學系
98
According to the statistics of UNCTAD (2006-2010), the tonnages of national fleets decrease gradually in these years, especially in bulk shipping sectors. For increasing the number of national fleet, Taiwan Government has recently executed some shipping policies, such as the deregulation of sailing directly between the Taiwan strait and hiring foreign crew members. This study uses quantified analysis to explore the discrepancies in operational revenues and costs between ROC and FOC bulk carriers under time charter contracts. Meanwhile, it also takes Taiwan Government’s shipping policies into consideration in order to realize the effect of nation fleets’ flagging-back or flagging-in. The findings of this study are as follows: 1.In respect of operational revenues, though Taiwan Government not only allows ROC bulk carries to sail directly between the Taiwan strait, but also permit them to load cargoes in third place for discharging in Taiwan or China ports like those FOC bulk carries; it is hard to get more charter hire paid by charterers. The operational revenues of ROC bulk carriers are still lower than FOC bulk carriers. 2.In respect of operational costs, after quantified analysis of influence factors, it finds that the operational costs of ROC supramax bulk carriers are USD 1.1 million more than FOC supramax bulk carriers approximately and the operational costs of ROC panamax bulk carriers are USD 1.4 million more than FOC panamax bulk carriers approximately. 3.Through the analysis of operational revenues and costs, it shows that Taiwan Government’s shipping policies have no attraction for Taiwan bulk shipping companies to change their FOC bulk carriers to ROC bulk carriers. The shipping authorities of Government should reduce more restrictions about vessel registrations. It is expected that the findings of this study can serve as a good reference for Taiwan bulk shipping companies and the shipping authorities of Government in reviewing relevant shipping policies.
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Jiang, Xiaowei. "Architecture support for Operating System survivability and efficient bulk memory copying and initialization." 2010. http://www.lib.ncsu.edu/theses/available/etd-12162009-142713/unrestricted/etd.pdf.
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Hsieh, Hua-Yu, and 謝華育. "The Analysis of Shipping Markets and Operating Models in the Bulk Shipping Sectors." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/87099072966001577068.
Full textAbstract:
碩士國立臺灣海洋大學
航運管理學系
104
Bulk shipping market is alomost competitive. Due to the drop of demand, the freight and hire are taking a downturn now. This study is based on the carrier’s position, focuses on three aspects in bulk shipping status, operation model and the empirical analysis of bulk coal transport business, etc. In order to analyze the current supply of ship tonnages, the demand of cargoes and the market freights statement in the bulk shipping market, we use the latest data from United Nations Conference on Trade and Development (UNCTAD), Institute of Shipping Economics and Logistics (ISL), and Clarkson Research Services. While focusing on bulk shipping markets, these operation models are divided into Voyage Charter (V/C), Time Charter (T/C) and Bareboat Charter (B/C) to discuss, in order to understand the advantages and disadvantages in different operation model of markets. We conduct empirical analysis by case study, and Data Envelopment Analysis (DEA) is the methodology of this study based on Without Explicit Outputs (WEO) model to integration of the various input variables. We discuss how the current market enhancing its coal transportation and operating performance by input variables from real case and real company, which from eight ports in Indonesia and Australia. In this study, result as follow: 1. The bulk shipping market situation analysis found that the current cargo volume growth is still slower than ship tonnages, which shows that ship tonnage supply are overflow. Due to the overall shipping markets are still in doldrums, shipping companies are in the hard time. In recent years, it’s volatility in freight market, especially to large vessels such as Capesize and Panamax are more serious. Therefore, in order to maintain their competitiveness under the hardship, Ship owners have to master cargo demand, shipping supply and freight market in recent days. 2. Bulk shipping business model analysis of different operating models have different risks, costs and responsibilities to ship owners and charterers, but they have their own advantages and disadvantages. According to the volatility of freights, shipping companies could respond to the market by operation model in different periods. Shipping industry are highly correlated with risk management. When there are owners’ market, the market freights are high, it’s better to be Voyage Charter (V/C) to enhance the profits. When there are charterers’ market, the market freights are low, so it’s better to be Time Charter (T/C) to avoid the cost which ships unable to lease in bad times.The length of the lease in time charter will also affect ship owner’s benefits, if the freight rise in redelivery point, the ship owner will have an advantage in negotiations. In order to increase revenue, ship owner could bargain Trip Time Charter, or Time Charter in a short term to increase the diversity of the contact. In the other hand, when tariffs goes down, it’s hard to negotiate for the ship owner, so bargaining a longer-term Period Time Charter is a good way to transfer the operating costs charterer. 3. In the case analysis, we found that Indonesian ports are more efficient than Australian port, especially the port D in Indonesia. In order to enhance the performance of loading, bulk shipping company A could select Indonesian Ports A, B and D to load more often. And for a better quality of coal source, Australian port A is selectable. If there are bulk cargos need to be loading from Australia, crews could do some maintenance and ship repairing during the voyage due to its long way, which also reduce the unit cost of bunker.
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Chen, Tsang-Yung, and 陳蒼詠. "A High-Efficiency Synchronous Buck Converter with Burst-Mode Operation." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/26029223237857526685.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
100
This thesis implements a high-efficiency synchronous buck converter with pulse width modulation (PWM) or Burst mode. The buck converter operates with PWM at heavy load and with Burst mode at light load. The dominant power loss of dc-dc converters at light load is switching loss. Therefore, the converter efficiency can be improved by reducing the switching frequency and adding zero current detector circuit. The specifications of the buck converter are the input voltage of 5 V, output voltage of 3.3 V, and the converter switching frequency of 1 MHz at the PWM mode or 700 kHz at the Burst mode. The buck converter operates at the PWM Mode when the load current is higher than 200 mA, or the converter operates at the Burst mode. The presented converter with these two operation modes achieves optimal efficiency at a wide range of the load current. The maximum efficiency with the Burst mode is 88.4% at load current of 70 mA. At the PWM mode, the maximum efficiency is 94.8% at loading current of 400 mA.
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Hwang, Kun-Ho, and 黃坤和. "The Operation Risk Analysis of Liquid Bulk Tanker on Chemical Shipping Docks in Kaohsiung Port." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/09734496063547059989.
Full textAbstract:
碩士國立高雄海洋科技大學
航運管理研究所
94
The chemical industries including the related products and raw materials are prosperously developing and the quantities of various liquid bulk chemicals are gradually increasing in Taiwan, the port of Kaohsiung owns the largest volume for those liquid bulk cargos handling. Some potential risks could occur frequently on loading and discharging port during the operation process for those liquid cargos, which may cause extreme horrible fatalities due to careless operation in port district. Consequently, it is obviously to comprehend the influential risk variables about the variables of potential safety operation, further analysis and evaluation with regard to the safety operation for different docks in Kaohsiung is the purpose of this research. This paper starts with an overall analysis for the process of liquid bulk cargo handling based on the relating international Marine Transportation Convention and Code, Reference and the experience of operational practice, and finds the various risk variables of influencing the safety factors of operation. Secondly, the evaluation of influential variables is investigated by conducting a questionnaire survey on Captains and Chief Officers. Finally, methodologies of the Factor Analysis are used to classify and simplify the risk variables, and then Gray Relative Analysis and Fuzzy Similarity Measure Analysis are used to find out the risk valuation in different docks. The result shows that four important factors of safety operation on liquid bulk handling are the followings: the First Factor is the vessel operation in handling, the Second Factor is the vessel related constructions and equipments, the Third Factor is the personnel and interface relating with ship and shore, and the Fourth Factor is the environment on operating docks. Furthermore, Kaohsiung port for liquid bulk cargo handling could be divided into three districts named Chung Dao, Chien Jen and Chung Yu. The Second Factor must be requested on the highest level of taking notice of safety operation for ship owners when all liquid bulk vessels berth at Chung Dao district, other Factors are requested on the highest level notices in Chien Jen district. Additionally, as to geographic site, both of Chung Dao and Chien Jen are occupied the vast hinterland, it’s difficult to control the land-hauling vehicles frequently getting in/out of port that would easily cause the potential risks occurrence. Finally, this article could provide the specific suggestions for Kaohsiung Harbor Bureau and liquid bulk terminal proprietors in safety operation from the results.
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Chien, Su-Ching Chang, and 張簡素卿. "The Study of Operational Performance in Taiwanese Listed Container and Bulk Cargo Shipping Companies." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/6qh7v5.
Full textAbstract:
碩士國立高雄科技大學
財富與稅務管理系
107
This study sourced data from 2010 to 2017, and collected financial indicators and non-financial indicators of ten Taiwanese listed container and bulk cargo shipping companies, to investigate the factor related to operational performance. This research used cash and short-term solvency, enterprise growth capability, corporate governance capability to develop hypothesis. This research used linear multiple regression model to analyze the relationship between those financial indicators and ROA (Return on assets), ROE (Return on equity) respectively. The results show that cash flow ratio, current ratio, net growth rate, total number of directors, and chairman serving as general manager at the same time have significant influences on corporate operational performance.
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Chung, Cheng-Chi, and 鍾政棋. "An Analysis of Vessel Registration and Operational Performance of Bulk Shipping Firms in Taiwan." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/84612732066147686366.
Full textAbstract:
博士國立交通大學
交通運輸研究所
92
In the past few years, operation of bulk shipping has faced the severest challenge within the shipping related industries. The management of bulk shipping is different from liner shipping. The main context of this study is to examine the issues of vessel registration and operational performance of bulk-shipping firms in Taiwan. In order to analyze the operational characteristics of bulk shipping in depth, this study begins with exploring the operation patterns of bulk carriers and patterns of charter chains based on the analysis of regulation and case study. This study finds that the patterns of bulk charter should also include vessel sublet, vessel subcharter and cargo subcharter besides the three basic operations: voyage charter, time charter and demise charter of bulk carrier chartering. In other words, bulk carriers ought to focus on vessel and cargo, and apply chartering strategies of sublet and subcharter strategies alternately, in addition to traditional chartering patterns, to effectively improve its competitiveness. For patterns of vessel registration, this study adopts Analytic Hierarchy Process (AHP) and ANOVA method to analyze degree of influence of related factors on vessel registration choice of Taiwan bulk shipping firms. The result indicates that reducing operational cost is the most important factor among all factors that influence registration decision making, followed by adapting to market environments and improving operational conditions. In terms of evaluation criteria, the key factor is trading area restriction. Other important factors are crew cost, crew supply, openness of domestic market, finance plan and tax burden. Regarding with operational performance, this study adopts Data Envelopment Analysis (DEA) and Statistical Analysis methods to evaluate operational performance of five local public bulk-shipping firms. The results of this study show that the vessel shipping revenue ratio of ROC is far bellow FOC. However, if we consider vessel deadweight tonnage against shipping revenue, the ratio difference becomes very limited between ROC and FOC vessels. Based on the results of Window Analysis, charter hire and freight revenue are relatively stable for bulk shipping firms who are mainly long-term T/C or COA, because their operation lowers the direct impact of market freight variations. It also reveals that it is necessary for bulk-shipping firms to consider the scale efficiency for more efficient operation. The above findings provide a good reference for bulk-shipping firms in adopting proper operational strategy. Moreover, the flagging out ratio of national vessels in Taiwan has been increased year by year, in which bulk carriers have the highest ratio. Trading area restriction and crew cost are considered as the key influence factors to the bulk carrier’s vessel registration decisions. If it is desired to avoid flagging out of national vessels, it is suggested that proper measures must be taken to alleviate these key factors by government.
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LIU, JEN-HAO, and 劉人豪. "Impact Factors Analysis of the Risk for Bulk Terminal Shipside Operation-A Case Study in Kaohsiung." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/36173885070064536341.
Full textAbstract:
碩士國立高雄海洋科技大學
航運管理研究所
105
This paper studies and analyzes the risk factors of shipyard wharf，Firstly, four risk facets and 15 risk factors were developed through literature review, terminal operation regulations, expert interview and first questionnaire survey, and the risk factors of shipyard operations were analyzed. Secondly, a second expert‘s questionnaire survey were conducted to assess the risk factors of the shipments of the bulk cargo wharf, and the weights were evaluated by AHP. Finally, the relevant risk strategy was put forward, The shipping company, the shipping company, the port company, the loading and unloading company, provide the relevant measures to avoid the risk of the ship's side of the operation. The results of this study show that the weight of the risk of the ship's bulk operation is analyzed by AHP: it is the most important factor for the "people", and the risk factors are " The most important part of the operation of the staff concerned is that the work of the staff concerned is not only the need for time to arrange education and pre-school education. It is also necessary to strictly follow the requirements of the standard operating procedures. , But also to remind the staff of the unit at any time to pay attention to the safety of the work process.
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Van, Jaarsveld Stephan. "A control system for the efficient operation of bulk air coolers on a mine / Stephan van Jaarsveld." Thesis, 2015. http://hdl.handle.net/10394/15700.
Full textAbstract:
Eskom provides 98% of South Africa’s ever increasing electricity demand. The mining sector
is a vital contributor to the economy, but also consumes vast amounts of electricity. This
sector is responsible for almost 15% of the country’s electricity usage.
Mines heavily depend on the supply of cold water and air. Refrigeration systems are therefore
constantly operational and can account for 25% of a mine’s electricity costs. The need
therefore exists to investigate possible energy savings initiatives.
Refrigeration systems are typically used to lower the temperature of water and air. Bulk Air
Coolers (BACs) are used to produce cold air. The aim of this study is to investigate possible
electricity cost savings in a mine refrigeration system. This can be achieved by enabling
equipment to dynamically adapt to changes in their environment. Electricity usage reduction
has the greatest financial impact if it occurs during Eskom peak periods. Time-dependent
schedules of operation are therefore used to achieve this objective.
Due to the lack of such a controller in the mining industry, the focus of this study is a
BAC control system. A BAC controller would be able to follow guidelines that could lead to
electricity cost savings. It was therefore developed and incorporated in the Real-time Energy
Management System (REMS). The BAC controller combines various inputs and constraints
to determine the output. An electricity usage reduction during the Eskom evening peak
period was consequently achieved.
The BAC controller was implemented on three sites. Electrical energy usage during the
evening peak period was reduced via the load shifting method. This aids Eskom in their
effort to reduce the peak period demand. Air temperature and dam levels were closely
monitored during the peak period. If any preset condition was violated, the load shifting
was abandoned for that day.
It was shown that a total power reduction of 7 MW is possible between the three sites. The
electricity savings occurred in the evening peak period. A calculation was made to determine
the possible annual savings by using the achieved daily cost savings. The winter months were
not included in the calculation. An annual cost saving of R1 166 694.41 is therefore possible
without having to reduce output quantities.MIng(Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
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Wei, Yuang-Hung, and 魏源宏. "A Dual –Mode Operation Synchronous CMOS Switching Buck Regulator with Temperature Sensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/33766003498224950459.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
99
In recent years, the smart touch mobile phones, Global Positioning System（GPS）satellite navigation unit, driving recorder, high definition（HD）digital camera, Light-Emitting Diode（LED）lighting, and related electronic products have emerged. It makes the system end of product development companies extensively use microprocessors, digital signal processing（DSP）, and multi-module systems to increase product functionality and meet product demand. Hence, it increases demand for the power of their respective function module. The control of system and system design also increase the difficulty. In this thesis, we use the mechanism of pulse width modulation （PWM）and pulse frequency modulation（PFM）to control and manage our power regulator which can effectively control the current flow to the output at the right time. When working in heavy load periods, it can sense the temperature of the regulator. When the regulator is operating at temperature T1 to temperature T2, heat is the result of power lost. At this point, the system will reduce the switching frequency of power transistors to reduce switching power consumption and remain at a reasonable frequency to control the problem that low frequency causes higher ripple voltage on the output. In the mean time, the regulator also shuts down the idle circuits to ensure the unnecessary power loss. In addition, to protect the chip at boot time from too large current and being burnt down, the soft start circuit is designed to limit start up current. When the temperature is higher than T1, the soft start circuit is turn off to prevent the output voltage from disturbances. When the temperature is greater than T2, send a signal to start the cooling fan system. In this thesis, the operation voltage of regulator is from 3V to 5V and the output voltage is 1.8V, and the maximum efficiency is 97.3%. The chip is designed with TSMC 0.35um 2P4M polycide CMOS process.
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Fang, hsin-hsiung, and 方信雄. "The relationships between key success factors and operational performance of National-flag Bulk Shipping Corporation in Taiwan." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/62134688491762190107.
Full textAbstract:
碩士國立臺灣海洋大學
航運管理學系
92
This study examines the relationships between the key success factors and performance of the national (ROC-Flag) bulk shipping in Taiwan. This paper focuses on three main discussions as follows: (1) exploring the difference between importance of operational key variable and actual performance; (2) identifying national bulk shipping firms into two categories – high performance and low performance – and examining the difference between these two categories; (3) evaluating the relationship between the key success factors and performance between these two categories. From questionnaire, using factor analysis, cluster analysis, discriminate analysis and T-testing, this research made the conclusions as below: (1) the difference between the importance of operational key variable and actual performance of national bulk-flag corporation is evident and more efforts are needs to control the thirty operational key variable. (2) Based on the evaluation of operational performance, the national bulk-flag corporation can be classified into two categories – high performance and low performance. There is significant distinction found in their performance but national bulk-flag corporation well manage the key success factors no matter it is high performance or low performance.
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Chen-Chin, Pan, and 潘生進. "Raw-Petrochemical Materials in Bulk Chemical Carrier for Cargo Transfer Operation of Hazards Simulation Analysis – Example of Kaohsiung Harbor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/76490909735394568371.
Full textAbstract:
碩士國立高雄海洋科技大學
海事資訊科技研究所
101
Vessel carriers is one of the traditional industries, the petrochemical industry affect our life deeply every day, Oil and chemical product transportation are easy caused pollution and disaster to occur by their physical properties , but current time more country economic and personal needs and dependent more in petrochemical industry. Kaohsiung harbor is Taiwan's main import and export of petrochemical raw materials in bulk, the bulk liquid chemical has danger to human and environment are different from oil pollution and human hazard by their physical properties. For these reason, it is necessary to understand whole procedure about liquid chemical cargo operation in Kaohsiung harbor by visually observed with IMO rule, this study has find one more “chemical pipe wharf (W-99)” of Kaohsiung port by chapter 17 of IBC Code in IMO rule. And keep looking deep for more chemical peril information to analysis by ALOHA consequences software of gas leaking、GHS and NFPA-704、HMIS、WISER of various chemical parameters and understructure by frame of “Mediterranean Regional Marine Pollution Emergency Response Centre for the Marine Chemical Transport Integrated Decision Support Information System”﹙REMPEC- MIDSIS-TROCS﹚.And hopes to become a useful reference information and set for the future of the built at the “Port of Kaohsiung Intercontinental Container Centered with petrochemical storage and transportation center II”. Keyword: Petrochemical Industry, IMO, Kaohsiung Harbor, Bulk Chemical Carrier, Hazard Analysis
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高偉倫. "An Evaluation of Operational Performance of Bulk Shipping Corporations by Using the DEA with Two-stage Production Process." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59311543666951672713.
Full textAbstract:
碩士國立臺灣海洋大學
航運管理學系
100
The sharp fluctuation in bulk shipping markets and freight rates highlights the difficulty in operating bulk shipping corporations. In the highly competitive global environment, the relatively small-scale of bulk shipping market in Taiwan makes the business operations much more difficult than other bulk shipping markets. Therefore, how to enhance shipping competitiveness by improving the operational performance is an important issue for bulk shipping corporations. However, seldom researches focused on this issue in the past. The evaluation of operational performance on shipping industry mostly focused on the container shipping corporations only, or put both bulk shipping and container shipping corporations together. Besides, the evaluation of shipping industry mainly used the DEA approach with one stage analysis, which failed to explore the real efficiency of different stages. Lastly, past researches used cross-sectional analysis, and less explortion of the changes of vertical-sectional efficiencies. Therefore, this research evaluates the operational performance of eight listed bulk-shipping corporations in Taiwan over the period of 2005-2010 by using the DEA approach with two-stage production process, to analyze the advantages and disadvantages of bulk shipping corporations in different stages and periods. As a result, for bulk shipping corporations, diversification strategies may have a positive impact on operational performance, especially when facing the market’s downturn of shipping industry. When it comes to the market efficiency of shipping companies, some were found to exhibit market efficiency, which represented that the company's stock price has been fully reflected on the market. The others were market inefficient, which represented that the revenues have not been reflected on the company's stock price. In order to improve market efficiency, shipping companies should promote the stability of revenues to reduce the uncertainty in bulk shipping market. This research also used Malmquist production index to analyze the operating performance in different periods. It shows that the growth of bulk shipping companies have been slowed down after the financial tsunami in the third quarter of 2008. Therefore, operational efficiency and market efficiency still have some room for improvement. The results may provide a good reference on operational decision making for bulk shipping corporations.
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Yi, Ming-Chin, and 易明進. "Analysis and implement of Buck converter stable operating in ceramic output capacitor." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53530426649115832510.
Full textAbstract:
碩士大同大學
電機工程學系(所)
97
Force weigh light and size small is the trend of power management Design concept. This thesis offers a concept which replaces large size Electrolytic capacitor by tiny size ceramic capacitor to reduce size of power management stage. These is a serious issue which power management control system can not operate stable for replacing electrolytic capacitor by ceramic capacitor. This thesis has issued the reasons for system not stable. It also researches basic theory of con-trol system and offers solution to improve stability of control system. This thesis also used simulation tool ( Mico-Sin) to create parameter which offered by basic control theory and used Analog Network Analyzer to measure real parameters. Compare simulation result, analysis result and value of theory to confirm this theory which issued by this thesis is correct.
44
Chen, Jyu-Hao, and 陳郡豪. "Design of Low Voltage and Low Current Micro- Operation Amplifier Using the Bulk-Driven Technique to Operate in Subthreshold Region." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/28597660499246545585.
Full textAbstract:
碩士國立聯合大學
電子工程學系碩士班
94
This thesis deeply investigate the characteristics of a MOSFET device using the bulk-driven technique to operate in subthreshold region for low current, low input voltage, high open loop gain, low power consumption, and low noise. It can used to design the low voltage amplifier to improve the limitation for the VGS voltage and the saturation voltage within the amplifier. The low voltage and current micro-operation amplifier is applied, and the source cross-coupled pair is used within the differential input, the static current of the amplifier is effectively reduced. The variation of amplifier for the supplied voltage to the temperature is improved by operated in the subthreshold region. Using HSPICE to simulate the characteristic of the micro-operation amplifier for the TSMC 0.18μm CMOS technology is verified. As the result shown that VDD= 0.6, power consumption< 10μW, open loop gain= 70dB. The used bulk-driven CMOS device in subthreshold is exactly deigned in the operation amplifier for low-voltage and low-power.
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Li, Yan-Cun, and 李彥村. "Boost and Buck-Boost Power-Factor-Corrected AC-to-DC Resonant Converters with ZVS Operation." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/ggv4e9.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
96
The research presents two novel high power factor ac-to-dc resonant converters with symmetrical topologies and zero-voltage-switching (ZVS) operation. The derived circuits are obtained from the integration of a dual-switch boost-type or buck-boost-type power factor corrector (PFC) into a half-bridge resonant converter. With symmetrical topology, the circuit is simple and the voltage and current stresses on the two active power switches are identical to each other. The PFC is operated at discontinuous conduction mode (DCM) to achieve unity power factor. The resonant energy tank of half-bridge resonant converter is designed to be inductive to retain ZVS operation. The design equations are derived based on fundamental approximation. Prototypes of the two proposed converters designed for 100 W and 50 W, respectively, were built and tested to verify the computer simulations and analytical predictions. Satisfactory results are obtained experimentally.
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Chen, Huai-Shun, and 陳懷舜. "Analysis and Modeling of SIDO Buck-Boost DC-DC Converter Operating in PCCM." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/41886093862679955857.
Full textAbstract:
碩士元智大學
電機工程學系
99
In this thesis, a single-inductor-double-output (SIDO) switching DC-DC converter in operating pseudo continuous conduction mode (PCCM) is studied. The system is thoroughly analyzed and the steady-state as well as the small signal models is established. Based on the models, an automatic design platform, SIDOLA, in MATLAB is built such that according to the provided system requirements, SIDOLA can generate all the required design parameters as well as the corresponding behavioral simulations including line/load/cross regulations, transient responses and stability analyses. Special efforts have been made for system stability analysis while there exist cross interferences between the two output nodes. Due to the cross interferences, the feedback system becomes complicated; therefore, sophisticated compensation schemes for system stability have been proposed and the results are examined by means of phase margin tests and Nyquist analyses. Following the design parameters calculated by SIDOLA, an HSPICE model of a design example was made in the TSMC 0.35um 2P4M CMOS process. According to the simulation results, the maximum peak-to peak output voltage ripple is less than 23mV and the output current ranges are between 40mA and 120mA. The DC-DC converter operates at a frequency in 0.3 MHz and a supply voltage ranging from 1.2 to 2.4V. The buck and boost output voltage holds 1.2V and 2.4V.
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Chang, Chia-Hua, and 張家鏵. "Study and Implementation of a High-Frequency Operation Interleaved Buck Power Factor Corrector with GaN FETs." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/71408853165577054989.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
101
The main purpose of this thesis is to study and implement an interleaved buck power factor corrector (PFC) with high-frequency operation. High-frequency operation can reduce the inductor size and the converter’s volume. The inductors for the interleaved topology are integrated into one inductor. Additionally, the traces on the PCB are treated as windings to further reduce the cost and volume. With the buck-type topology, the voltage rating for the output capacitor is lower. High switching frequency will result in higher switching loss. Therefore, GaN-based FETs are selected as the main switches to reduce the switching loss. In this thesis, simulations of controller and loss analysis are performed by PSIM and Simplis, respectively. Finally, a 300-W interleaved buck PFC prototype with an output of 80 V/3.75 A and a fixed switching frequency of 300 kHz was built to verify the operations of the circuit and theoretical analysis. The efficiency of the tested prototype reaches 95.21 % at full load. And the line current harmonic contents can also meet the IEC 61000-3-2 Class D regulations.
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Chen, Yukai, and 陳昱凱. "Design and Implementation of Maximum Power Point Tracker with Buck/Boost Operation Mode and Insulation Check." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/81765393283706369002.
Full textAbstract:
碩士國立中正大學
電機工程研究所
99
This study is to design a maximum power point tracker (MPPT) with Buck/Boost operation mode. The basic structure is formed with Buck and Boost converters. When input voltage is higher than output voltage, the MPPT operates in buck mode; otherwise, it operates in boost mode. When input voltage changes between high voltage and low voltage, the mechanism of changing reference input voltage is adopted to switch the operation mode. This tracker controller uses microcontroller TMS320LF2406A, and the control algorithm is based on the perturb and observe method. In addition, the PV input voltage is controlled for achieving maximum power point tracking. This study adds an insulation check function to detect the resistance between PV panel frame and ground. It can improve the safety of the MPPT. A 2.5 kW MPPT has been implemented, and the highest conversion efficiency can reach 99%.
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Yang, Sheng-Hong, and 楊勝宏. "Design and Implementation of an SIDO Buck-Boost DC-DC Converter Operating in PCCM." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/17935219311489810778.
Full textAbstract:
碩士元智大學
電機工程學系
99
The design and implementation of a Signal-Inductor-Double-Output(SIDO) switching buck-boost DC-DC converter is presented. The system operates in pseudo-continuous conduction mode(PCCM). By adaptively controlling the duty intervals for inductor charging, buck conversion, boost conversion, and freewheeling respectively, the system manages the dynamic inductor current level to achieve stable output voltages and high efficiency. The DC-DC converter was implemented in TSMC 0.35-μm 2P4M CMOS process with die size of 1.18×1.16 mm2. According to measurement results, the maximum peak-to peak output voltage ripple less than 90mV and current ranges between 50mA and 500mA. The DC-DC converter operates in frequency 350kHz and supply voltage ranges from 2 to 2.4V. The output voltage is 1.2V and 2.4V.
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Hsien-Liu, Hsiu, and 劉信賢. "Design of a Digital Controller for a Buck Converter Operating in Discontinuous Conduction Mode." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/12257276209524101667.
Full textAbstract:
碩士國立臺灣大學
電機工程學研究所
97
DC Power Converter with a digital compensator provides design flexibility and the possibilities of on-line adjustment of compensation. In this thesis , digital compensation designs for the converter working in both the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM) are described with emphasis on DCM operation. Experiments were also conducted using a DSP ，TMS320LF2812，to implement the compensator.