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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

INTEGRATION OF UNIGRAPHICS AND COST ADVANTAGE FOR AIRCRAFT ENGINE PARTS CONFIGURATION

Chintamaneni, Prashantkumar January 2000 (has links)
No description available.
122

Reynolds stress measurements in a turbine tip leakage vortex

Heckel, Scott P. 10 October 2009 (has links)
An experimental study of the structure of turbulence in a tip leakage vortex was conducted in a large scale, linear turbine cascade. The study was performed in a cross sectional plane 0.96 of the axial chord length downstream of the blade leading edge. The cascade consisted of five blades with an aspect ratio of one and an axial chord of 235.2 mm. The tip clearance gap was nominally 2.1% of the blade span. A specially designed rotatable x-wire hot wire probe with high spatial resolution was used to measure both the mean velocity distribution and all six components of the Reynolds stress tensor. An automated probe positioning and digital signal processing system was developed to facilitate quick, accurate measurements at a large number of data points. A geared stepper-motor drive mechanism was used to rotate the endflow hot-wire probe about its axis. Performance of the probe and the data analysis routines was verified by measurements in a fully developed pipe flow. The contribution of turbulence to the over a1l 1osses was investigated by studying both the general level of turbulence and the work done on the fluid by the turbulence stresses. This allowed the study of the physical mechanisms of loss production; spanwise mixing processes were found to be major contributors. The high level of turbulence in the tip leakage vortex was found to amount to about 36% of the total pressure loss generated by the plane near the blade trailing edge. / Master of Science
123

An Urban Detail

Ralat-Sotomayor, Hector J. 31 December 2003 (has links)
What defines the architectural character of a space? What defines the architectural character of a Detail? What defines the relationship between space and details as Architecture? These questions lead the study of space as a Whole through the investigation of its parts - shape, material, assembly and its surroundings. The investigation examined how the detail influences the space it assembles, how space conforms the structure embracing it and how a structure affects its surroundings. Observing how the Whole evolved through the process was an additional task of the study. The design intended to create among every element a vocabulary apprehensible throughout the entirety of the project. The manipulation of each material, detail and edifice to share this vocabulary developed cohesion among them. This relationship allowed the inhabitant to have a complete perception of the element and Whole's character. / Master of Architecture
124

Making Moves: Exploring Adaptability in Makerspaces

Rapavi, Paulina E. 02 June 2021 (has links)
Adaptability is defined as having the capacity to be modified for a new use or purpose; the quality of being able to adjust to new conditions. Adaptability in a space can have many venues and effects depending on the intent of its flexibility. This thesis will explore several methods of adaptability in design in context with a Makerspace, a community space which functions to provide the facilities and work environment for a variety of creators to use. In a building typology, a Makerspace with a large variety of users, the ability for the spaces to be informed by and reactive to each individual user is imperative to its objective. The approach to exploring adaptable design solutions is in analyzing the potential makers occupying the space, what their specific needs are and how can architectural designs become flexible in a way that allows the Makers to craft their own work environments. The primary objectives of this thesis are to: 1. Explore some of the various definitions of adaptability and how those meanings can be incorporated into design solutions 2. Identify spaces in the project that can be adapted for their specific purpose 3. Determine the methods of adaptability suited to the building typology and its users 4. Discuss adaptable design in terms of fixed and kinetic characteristics 5. Design spaces that are responsive to the site, the project's purpose and the unique needs of each user. The site of the project is located on the 500 block of South Broadway Street, Baltimore MD in the upper Fells Point district. Site dimensions are roughly 55' by 200' of infill space between surrounding retail and residential properties. This site was chosen to accommodate a Makerspace as it is central to Baltimore city's three major arts districts (Bromo, Highlandtown, and Station North Arts Districts) and could be considered a hub where local makers convene and establish a work space for a period of time that has the specific equipment and environment they require. / Master of Architecture / Adaptability is defined as having the capacity to be modified for a new use or purpose; the quality of being able to adjust to new conditions. This thesis explores ways in which architectural design can be adaptable. To have the quality of being able to adjust to new conditions, in this case the people that will use the space and the purpose of the spaces. Baltimore city is home to a large variety of local artists and creators working on their craft. The three major arts districts in the city, Bromo, Highlandtown, and Station North cultivate a community of people that create and consume artistic and innovative projects. In order to most successfully create, an artist should have access to a work environment that is not a hindrance but an asset to their process. The arts community of Baltimore could greatly benefit from a place that offers suitable work environments to a community which does not typically have a designated place. This thesis uses the building type: Makerspace which is a facility used as a tool for creators or "makers" to enter with an idea and facilitate a project. A makerspace can provide access to communal equipment that would otherwise be expensive for the individual maker to own, private and/or public work spaces to use for the maker's individual needs and a sense of community. The Makerspace was chosen as the vessel for exploration into adaptable design because of the nature of the building's purpose. The people that will inhabit and use the spaces will have a variety of specific needs in a work space. I wanted to explore how the designs of spaces could become flexible to accommodate those specific needs. The primary objectives of this thesis are to: 1. Explore some of the various definitions of adaptability and how those meanings can be incorporated into design solutions 2. Identify spaces in the project that can be adapted for their specific purpose 3. Determine the methods of adaptability suited to the building typology and its users 4. Discuss adaptable design in terms of fixed and kinetic characteristics 5. Design spaces that are responsive to the site, the project's purpose and the unique needs of each user.
125

Tvarosloví a slovní druhy v českých gramatikách francouzštiny / Flexional morphology and Parts of speech classification in Czech grammars of French

PEROUTKOVÁ, Jitka January 2010 (has links)
This work is divided into three major parts. The first one deals with parts of speech themselves {--} with what they are, with the criteria for sorting them and finally it presents the history of linguistic theories, related to the parts of speech. The second one presents the progress and results of bibliographic searches, during which we were looking for czech grammar books, dealing with French. The third part presents the actual analysis of manuals, that were found, focusing on the classification of the parts of speech.
126

Vývoj SLM procesních parametrů pro tenkostěnné díly z niklové superslitiny / Development of SLM process parameters for thin-walled nickel superalloy components

Kafka, Richard January 2021 (has links)
The diploma thesis deals with the development of process parameters of SLM technology for the material IN718. The main goal is an experimental development of a set of parameters for the production of thin-walled parts with regard to material density, surface roughness and tightness. The essence of the development of parameters is an experimental explanation of the influence of laser power and scanning speed on the morphology of single tracks, which are used for the production of a thin wall. Together with walls of larger widths and volume samples, it is possible to create an intersection of parameters by which is possible to create components formed by a combination of thin-walled and volume geometry. The performed research created a material set, where the parameters of thin walls are used for the area of contours of bulk samples. We managed to produce a wall with an average width of 0.15 mm and roughness of 6 m, which meets the requirement for the tightness. The meander scanning pattern achieved a relative material density of 99.92%, which is more than with the supplier's parameters. Based on the acquired knowledge, it was possible to apply a set of parameters to components combining both geometries.
127

Minska skrotning av provartiklar / Reduce scrapping of test items

Jansson, Andreas, Sundström, Jenny January 2018 (has links)
Målet med detta projekt var att minska skrotning av provartiklar på Scania genom att ta fram ett förslag på flöde för vidare distribuering. Även att ta fram villkor för vilka artiklar som är aktuella för vidareförsäljning, kvantifiera mängden artiklar som kan säljas vidare och utvärdera ekonomin. Detta med hänsyn till att endast undersöka avdelningen RT (Truck Chassis Development) på Scania. Projektet startade på initiativ av Scania CV AB då de såg potential för vidareförsäljning i artiklar som i dagsläget skrotades efter en provmontering. Projektet utfördes i fyra olika steg under 10 veckor och arbetet planerades med hjälp av ett GANT‐schema. I nulägesbeskrivningen utfördes ett antal möten och besök på olika inblandade avdelningar på Scania. På så sätt skaffades en överblicksbild över hur problemet såg ut, hur processen runt om kring var uppbyggt och hur information för att lösa problemet skulle tas fram. En undersökning av hur flödet ser ut innan skrotning utfördes och presenteras i form av tre faser kallade beställnings‐, provnings‐ och skrotningsfasen. Genomförande, resultat och analys består av rubriker hämtade från planeringsstadiet i PDCA‐hjulet. Dessa är identifiering av problemet, analys av problemet och presentation av ett lösningsförslag. Även en utvärdering av ekonomin presenteras där ekonomiska beräkningar på det möjliga försäljningsvärdet från ASB (begagnat försäljning) som skrotades under 2017, antagna implementeringskostnader och förväntade intäkter vid försäljning hos ASB utfördes. Dessa utifrån egna antaganden och CW2:s (reservdelslager) försäljningsstatistik år 2017. Resultatet presenteras i form av lösningsförslaget som är ett visuellt flöde mellan MPAP (Prototype Assembly) i By 220 och ASB i Hovsjö. Villkor för vilka artiklar som är aktuella för vidareförsäljning har tagits fram i form av komplettering av Scanias befintliga skortoningsbedömning. Kvantifieringen av mängden serieartiklar blev 1 113 stycken och utgjordes av 310 stycken unika serienummer. Utifrån utvärderingen av ekonomin blev resultatet att flödet skulle kunna ge en besparing på ca 1 Mkr under år 2017. En slutsats av projektet är att en implementering av lösningsförslaget skulle bidra till besparingar och även minska på skrotningen av provartiklar. / The aim of this project was to reduce scrapping of test items at Scania by proposing a flow for further distribution. Also, present terms for which items are relevant for further distribution, quantification of the amount of items that may be sold and evaluate the economy. This with consideration of only evaluate the RT (Truck Chassis Development) department at Scania. This project started on the initiative of Scania CV AB because they saw potential for a further distribution of items which currently are scrapped after a test assembly. The project was carried out in four different steps during 10 weeks and the work was planned with a GANT‐schedule. In the description of the current situation a number of interviews was conducted on different departments at Scania. Through the interviews an understanding of the problem, how the process looks like and how information to solve the problem was gathered. An evaluation of how the flow before scrapping was carried out and is presented by three phases called ordering, testing and scrapping phase. The implementation, result and analysis chapter contains headlines gathered from the planning phase in the PDCA‐wheel. These headlines are identification of the problem, analysing the problem and a presentation of a solution. An evaluation of the economy is also presented showing the possible financial calculations of the total scrapped sales value in 2017 from ASB (second‐hand market), assumed implementation costs and the expected income from sales at ASB. This based on own assumptions and CW2’s (spare parts storage) sales statistics in 2017. The results are presented by the suggested solution which is presented as a visual flow between MPAP (Prototype Assembly) in By 220 and ASB in Hovsjö. The terms of which items are relevant for further distribution has been established by adding terms to the scrapping evaluation at Scania. The quantification of the amount of items was 1 113 pieces and the detected amount of different serial numbers was 310. Based on the evaluation of the economy the result was calculated to a saved amount of about 1 MSEK in year 2017. The conclusion of the project is that an implementation of the suggested solution would contribute savings and reduce the scrapping of test items.
128

Multiobjective Coordination Models For Maintenance And Service Parts Inventory Planning And Control

Martinez, Oscar 01 January 2008 (has links)
In many equipment-intensive organizations in the manufacturing, service and particularly the defense sectors, service parts inventories constitute a significant source of tactical and operational costs and consume a significant portion of capital investment. For instance, the Defense Logistics Agency manages about 4 million consumable service parts and provides about 93% of all consumable service parts used by the military services. These items required about US$1.9 billion over the fiscal years 1999-2002. During the same time, the US General Accountability Office discovered that, in the United States Navy, there were about 3.7 billion ship and submarine parts that were not needed. The Federal Aviation Administration says that 26 million aircraft parts are changed each year. In 2002, the holding cost of service parts for the aviation industry was estimated to be US$50 billion. The US Army Institute of Land Warfare reports that, at the beginning of the 2003 fiscal year, prior to Operation Iraqi Freedom the aviation service parts alone was in excess of US$1 billion. This situation makes the management of these items a very critical tactical and strategic issue that is worthy of further study. The key challenge is to maintain high equipment availability with low service cost (e.g., holding, warehousing, transportation, technicians, overhead, etc.). For instance, despite reporting US$10.5 billion in appropriations spent on purchasing service parts in 2000, the United States Air Force (USAF) continues to report shortages of service parts. The USAF estimates that, if the investment on service parts decreases to about US$5.3 billion, weapons systems availability would range from 73 to 100 percent. Thus, better management of service parts inventories should create opportunities for cost savings caused by the efficient management of these inventories. Unfortunately, service parts belong to a class of inventory that continually makes them difficult to manage. Moreover, it can be said that the general function of service parts inventories is to support maintenance actions; therefore, service parts inventory policies are highly related to the resident maintenance policies. However, the interrelationship between service parts inventory management and maintenance policies is often overlooked, both in practice and in the academic literature, when it comes to optimizing maintenance and service parts inventory policies. Hence, there exists a great divide between maintenance and service parts inventory theory and practice. This research investigation specifically considers the aspect of joint maintenance and service part inventory optimization. We decompose the joint maintenance and service part inventory optimization problem into the supplier s problem and the customer s problem. Long-run expected cost functions for each problem that include the most common maintenance cost parameters and service parts inventory cost parameters are presented. Computational experiments are conducted for a single-supplier two-echelon service parts supply chain configuration varying the number of customers in the network. Lateral transshipments (LTs) of service parts between customers are not allowed. For this configuration, we optimize the cost functions using a traditional, or decoupled, approach, where each supply chain entity optimizes its cost individually, and a joint approach, where the cost objectives of both the supplier and customers are optimized simultaneously. We show that the multiple objective optimization approach outperforms the traditional decoupled optimization approach by generating lower system-wide supply chain network costs. The model formulations are extended by relaxing the assumption of no LTs between customers in the supply chain network. Similar to those for the no LTs configuration, the results for the LTs configuration show that the multiobjective optimization outperforms the decoupled optimization in terms of system-wide cost. Hence, it is economically beneficial to jointly consider all parties within the supply network. Further, we compare the model configurations LTs versus no LTs, and we show that using LTs improves the overall savings of the system. It is observed that the improvement is mostly derived from reduced shortage costs since the equipment downtime is reduced due to the proximity of the supply. The models and results of this research have significant practical implications as they can be used to assist decision-makers to determine when and where to pre-position parts inventories to maximize equipment availability. Furthermore, these models can assist in the preparation of the terms of long-term service agreements and maintenance contracts between original equipment manufacturers and their customers (i.e., equipment owners and/or operators), including determining the equitable allocation of all system-wide cost savings under the agreement.
129

Improved Spare Part Forecasting for Low Quantity Parts with Low and Increasing Failure Rates

Lowas, Albert Frank, III 01 June 2015 (has links)
No description available.
130

Decision-making framework for inventory management of spare parts in capital-intensive industries

Du Toit, Deirdre 12 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Effective management of spare parts inventory is essential to companies because it influences inventory costs and asset utilization. The vast and diverse portfolio of spare parts, intermittent demand patterns and contradicting objectives between departments are examples of some of the factors that complicate Spare Parts Management (SPM). Managers of spare parts are faced with trade-off decisions between risk and cost on a daily basis. These decisions include, amongst many, determining appropriate stock levels and order frequencies. Despite the importance of SPM, decisions are however often made intuitively in practice with little factual support, and the decision-making process is commonly constrained within departmental silos. Even though there is a large body of academic knowledge on this topic, practical applications of spare parts inventory solutions lag behind theoretical studies. The majority of studies in literature focus on single components of SPM, such as demand forecasting and parts classification, whereas fewer studies consider the decision-making process itself. This study proposes a decision-making framework for spare parts inventory management. The framework is based on a wide-ranging literature review that focuses on capturing the essence of Spare Parts Management (SPM), but also acknowledges the interconnectedness of the problem. Therefore, core inventory management principles, as well as closely related topics such as Supply Chain Management (SCM) and Physical Asset Management (PAM), are studied in the context of spare parts. The broad scope of the literature study leads to a holistic approach to the problem and prevents sub-optimization. The proposed framework condenses principles from various fields of study (SCM, PAM, Classification and Inventory Management) into a stepwise methodology presented as a decision-making framework. The objective of the framework is to provide managers with a structured process, based on factual information, to enable better decision-making in the field. Furthermore, the framework aims to capture the fundamentals of SPM in a simplistic manner to ease the adoption of the framework in practice. A case study is conducted in the South African mining industry to validate the framework. The case study demonstrates that the framework is practical, provides structured guidance, and assists managers to make trade-off decisions in managing spare parts inventory. / AFRIKAANSE OPSOMMING: Effektiewe voorraadbestuur van onderdele is belangrik vir maatskappye omdat dit voorraadkoste en die benutting van bates beïnvloed. Die bestuur van onderdele is ’n komplekse probleem. Ondermeer is die portefeulje van onderdele items breed en divers, die vraagpatrone sporadies en word die voorraadvlakke geaffekteer deur kontrasterende doelwitte tussen verskillende departemente. Bestuurders van onderdele word daagliks gekonfronteer met besluite rakende risiko’s en kostes, soos om toepaslike voorraadvlakke te bepaal en om te besluit wanneer om bestellings te plaas. Hierdie besluite word dikwels intuïtief geneem met min feitelike ondersteuning en insette in die besluitnemingsproses word gereeld beperk tot sekere departemente. Ten spyte van die geweldige akademiese belang in die onderwerp, is daar min suksesvolle praktiese toepassings. Die meerderheid van studies in die literatuur fokus op spesifieke elemente van onderdele bestuur, soos vooruitskatting en klassifisering van parte, terwyl minder op die besluitnemingsproses konsentreer. Hierdie studie stel ’n besluitnemingsraamwerk vir die bestuur van onderdele voorraad voor. Die raamwerk is gegrond op ’n deeglike literatuurstudie wat die essensie van onderdele bestuur ondersoek, maar ook die interverbondenheid van die probleem in ag neem. Voorraadbestuurbeginsels en verwante onderwerpe soos Voorsieningskettingbestuur en Fisiese Batebestuur word dus bespreek. Die breë omvang van die literatuurstudie lei tot ’n holistiese benadering wat sub-optimering van die probleem voorkom. Die voorgestelde raamwerk som beginsels uit verskillende relevante studievelde op in ’n stapsgewyse metode wat voorgestel word as ’n besluitnemingsraamwerk. Die doel van die raamwerk is om bestuurders te voorsien met ’n gestruktureerde proses, gebaseer op feitelike inligting, om besluitneming in die veld te verbeter. Verder poog die raamwerk om die fundamentele konsepte in voorraadbestuur vas te vang in ’n eenvoudige manier sodat die raamwerk maklik geïmplementeer kan word in die praktyk. Die voorgestelde raamwerk is gevalideer deur middel van ’n gevallestudie in die Suid-Afrikaanse mynbedryf. Die gevallestudie toon dat die voorgestelde raamwerk prakties is, die besluitnemingsproses op ’n gestruktureerde wyse lei, en bestuurders help om beter, ingeligte besluite te neem.

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