• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 15
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 25
  • 7
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 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.
1

Designing a Procurement Management Model to Reduce Project Delays in a Hydraulic and Automation Systems Company

Vereau, Melanie, Rojas, Jose, Aderhold, Daniel, Raymundo, Carlos, Dominguez, Francisco 01 January 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This study focuses on the factors that cause project delays in an industrial hydraulic company. More specifically, the article also addresses the development of on-demand engineered products and the impact of the procurement process on delays. As part of the investigation, the authors assessed the historical data of the projects completed in 2017 before determining the critical path for each project in an attempt to identify which project stages may be improved. After further assessing the resulting data, the planning and procurement procedures were deemed as requiring improvement. Next, the article proposes a training plan and new procedures based on the Project Management Body of Knowledge guidelines for Engineer-to-Order projects. In conclusion, the results showed that delays were effectively reduced after implementing these new procedures in both Project Management stages.
2

Innovative GTO Thyristor Based Switches Through Unity Gain Turn-Off

Li, Yuxin 10 November 2000 (has links)
The Gate Turn-Off (GTO) Thyristor has the best voltage blocking and current conducting capabilities among all known high power semiconductor devices. To improve its dynamic performances to meet the increased demand in high-performance high-power applications, a special driving technique, namely unity gain turn-off, is studied. Several innovative approaches, which realize this driving requirement, are proposed, analyzed and experimentally demonstrated in this dissertation. The Emitter Turn-Off Thyristor (ETO) is a new family of high power semiconductor devices that is suitable for megawatt power electronics application. ETOs with voltage and current ratings of 4.0~6.0 kV and 1.0~4.0 kA, have been developed and demonstrated. These power levels are the highest in silicon power devices and are comparable to those of the GTO. Compared to the conventional GTO, the ETO has a much shorter storage time, voltage controlled turn-off capability, and a much larger reverse biased safe operation area (RBSOA). These combined advantages make the ETO based power system simpler in terms of dv/dt snubber, di/dt snubber and over current protection, resulting in significant savings at the system level. Experimental and numerical simulation results that demonstrate the advantages of the ETO are presented. A new family of snubberless turn-off GTO, the Resonant Gate Commutated Thyristor (RGCT) is proposed and investigated. By using a transient high commutation voltage, the RGCT can achieve unity turn-off gain and snubberless turn-off capability even with a relatively high gate loop stray inductance. Therefore conventional GTOs with flexible gate lead can be used to achieve the state-of-the-art performance similar to that of the Integrated Gate Commutated Turn-Off thyristor (IGCT). Detailed current commutation analysis and experimental results are presented. A novel equivalent circuit model for the GTO under the unity gain turn-off is proposed. This model is composed of a step current source, which represents the open-base PNP turn-off behavior, in series with a diode that represents the GTO's gate-cathode junction. This equivalent circuit can be used to analyze the turn-off transient behavior of a system employing this GTO. A new mechanism that dominates the failure of the GTO under the unity gain turn-off condition is identified and analyzed. Innovative hybrid GTO-based devices all have significant gate lead stray inductance. During the turn-off transition, this stray inductor will interact with the turn-off voltage source, the junction capacitance of the GTO's gate-cathode, causing effective current injection into the GTO's emitter junction when the voltage on the device is already high. Design guidelines and solutions for different types of GTO-based hybrid devices are provided. / Ph. D.
3

A critical evaluation of exchange traded option 'Delta' as a risk management tool for self-managed superannuation funds

Enticott, Steven John, n/a January 2006 (has links)
This research discusses the use of Delta in regulating the investment behaviour of the Trustees of Self-Managed Superannuation Funds (SMSFs) who use Exchange Traded Options (ETOs) in their investment strategies. An ETO represents a contract between two parties, giving the taker (the buyer) the right, but not the obligation, to buy or sell a parcel of shares at a predetermined price, on or before a predetermined date, to or from the writer (the seller). It is acceptable for SMSF Trustees to use ETO investments as part of their overall investment strategy, providing that leverage or mere speculation are not the reasons behind that investment. It is important to note that neither the Regulator, the Australian Taxation Office (ATO), nor its predecessor, the Australian Prudential Regulatory Authority (APRA), actually state what constitutes 'speculation', or what the allowable uses for derivatives are. There are no practical guidelines. This is a key issue for this research, which aims, as practically as possible, to fill these crucial gaps. A Trustee must abide by their superannuation fund's overriding covenants and investment strategy, and inform its members, through Risk Management Statements, of the trust's derivative strategy. While ETOs can be used to manage risk, they also carry a level of risk themselves. Delta measures an ETO's value movement in correlation with a movement in the option's underlying share price. An ETO carrying a low Delta generally means a cheaper price (premium) per contract than an option carrying a higher Delta. The lower the Delta, however, the lower the chance there is of a positive result for the buyer. This research shows that an ETO Delta of less than 0.2 gives results in favour of buyers in only 11 out of 100 occurrences. This figure rises to 42 out of 100 when Delta is greater than 0.8. From the sampled data, there is an overall financial loss to the buyer of -1.91%, with the financial return results being mixed at all levels of Delta. The overall return results have been compiled without preference to market direction, and clearly highlight the natural premium bias (which the buyer pays) to the seller. What this data does is reenforce the need for Trustees to have a solid view of market directions, or a set strategy in place, as buyers of ETOs. The conclusions drawn from the findings show that the chance of loss (when buying), or gain (when selling) ETOs with a Delta of; - less than 0.20 is 89%; - less than 0.40 is 74%; - less than 0.60 is 66%; - less than 0.80 is 57%; - greater than 0.80 is 58%; For example, a Trustee buying an ETO with a Delta of less than 0.20, faces an 89% chance of loss; a Trustee selling an ETO with a Delta of less than 0.20, faces an 89% chance of gain. The findings on overall financial returns (profit or loss) offer additional support to this critical review of Delta as a risk measurement tool. Whist it is impossible to know the motives or actual positions of portfolio managers of SMSF at any time, the aim of the thesis is to provide a measurement tool that can be used to assist the trustee at any given time by measuring the option risk element alone. When interpreting the findings, the reader must remember that ETO strategies are numerous, and a high-risk profile for one strategy may represent a low risk for another. Further to this, an ETO strategy's risk profile may change with the overlaying of another ETO. For example, where a Call option is bought, the risk involved in that purchase is represented by the premium paid. However, another Call option can then be sold against that position, with a later (or earlier) date to expiry, and with a higher strike price. This 'overlay' reduces the initial risk, but impacts on the maximum gain. It is vital that Trustees have a solid understanding of the basics of ETO strategies before considering using Delta as a measure of risk. The research proposes some guidelines Trustees can use when assessing an ETO strategy against their derivative/investment risk profile. For example, a Trustee buying an ETO with a Delta of less than 0.20, faces an 89% chance of loss; a Trustee selling an ETO with a Delta of less than 0.20, faces an 89% chance of gain. The findings on overall financial returns (profit or loss) offer additional support to this critical review of Delta as a risk measurement tool. Whist it is impossible to know the motives or actual positions of portfolio managers of SMSF at any time, the aim of the thesis is to provide a measurement tool that can be used to assist the trustee at any given time by measuring the option risk element alone. When interpreting the findings, the reader must remember that ETO strategies are numerous, and a high-risk profile for one strategy may represent a low risk for another. Further to this, an ETO strategy's risk profile may change with the overlaying of another ETO. For example, where a Call option is bought, the risk involved in that purchase is represented by the premium paid. However, another Call option can then be sold against that position, with a later (or earlier) date to expiry, and with a higher strike price. This 'overlay' reduces the initial risk, but impacts on the maximum gain. It is vital that Trustees have a solid understanding of the basics of ETO strategies before considering using Delta as a measure of risk. The research proposes some guidelines Trustees can use when assessing an ETO strategy against their derivative/investment risk profile. (table inserted) The findings from 2400 data samples show strong trends in support of the underlying premise (see Figure: Positive Results Versus Delta (ETO Buyers) below). Given these findings, the research concludes that Delta can be used as a measure of risk by SMSF Trustees. Delta may not be suitable, however, for measuring multiple layers of combined ETO positions, a type of derivative strategy not suited to or usual in the context of measuring risk within a SMSF. (table inserted) There is a major difference between simple and simplistic solutions offering practical answers in an environment of increasing complexity. Often, simple solutions offer far more value to the less experienced, when compared to complex ones, especially given the growing number of SMSFs, and the increasing lack of expertise in the areas of superannuation and risk management that this growth implies.
4

A novel approach to computer-aided configuration design based on constraint satisfaction paradigm

Li, Jingxin 28 February 2005
The trend in todays manufacturing industry is changing from mass production to mass customization. The companies which win the markets are those which can deliver highly customized products at the fastest rate and allow for life-cycle participation of customers regardless of where they are and when they participate. One of the strategies for implementing the mass customization paradigm is to implement the product development according to the assemble-to-order (ATO) pattern. Under the ATO pattern, the design of a product becomes the determination of a configuration which contains a set of pre-developed components configuration design for short. The configuration design problem can be well treated as a constraint satisfaction problem (CSP). The mature methods are available for CSP, but there are several limitations with CSP for configuration design. This thesis proposes a novel approach to configuration design. This approach is based on a CSP but adds a wrapper (product data model, PDM for short) over the CSP model. Consequently, both the customer and the other life cycle development programs only communicate with the PDM, and a more intelligent and user-friendly computer system for configuration design can then be implemented. Both the conceptual design and implementation of such a wrapper are discussed in this thesis. A computer prototype system for elevator design is developed for demonstrating the effectiveness of this approach.
5

A novel approach to computer-aided configuration design based on constraint satisfaction paradigm

Li, Jingxin 28 February 2005 (has links)
The trend in todays manufacturing industry is changing from mass production to mass customization. The companies which win the markets are those which can deliver highly customized products at the fastest rate and allow for life-cycle participation of customers regardless of where they are and when they participate. One of the strategies for implementing the mass customization paradigm is to implement the product development according to the assemble-to-order (ATO) pattern. Under the ATO pattern, the design of a product becomes the determination of a configuration which contains a set of pre-developed components configuration design for short. The configuration design problem can be well treated as a constraint satisfaction problem (CSP). The mature methods are available for CSP, but there are several limitations with CSP for configuration design. This thesis proposes a novel approach to configuration design. This approach is based on a CSP but adds a wrapper (product data model, PDM for short) over the CSP model. Consequently, both the customer and the other life cycle development programs only communicate with the PDM, and a more intelligent and user-friendly computer system for configuration design can then be implemented. Both the conceptual design and implementation of such a wrapper are discussed in this thesis. A computer prototype system for elevator design is developed for demonstrating the effectiveness of this approach.
6

Rediseño del proceso de ingeniería de detalle en una empresa de ingeniería de mecánica industrial

Chiong Rayo, Rodrigo January 2014 (has links)
Ingeniero Civil Industrial / La mejora de procesos es una de las estrategias más utilizadas por las empresas para mejorar su posición competitiva. De sus disciplinas, el rediseño de procesos (BPR, por Business Process Redesign) es una de las más usadas y ha permitido a muchas empresas mejorar la eficiencia y eficacia de sus procesos de forma considerable, dejando de lado las pretensiones de cambios radicales que la literatura de BPR proponía inicialmente. Enercom S.A. es una empresa chilena especializada en el diseño y fabricación de equipos industriales en procesos térmicos, de secado y combustión. Estos son altamente complejos y diseñados a medida según las especificaciones del cliente, clasificando a la empresa como de diseño a la medida (ETO, por Engineered to Order). La gerencia de la empresa desea realizar una revisión de sus procesos, en particular del proceso de ingeniería de detalle que detectan como fuente de numerosos errores. El objetivo del proyecto se centrará en la reducción del número de Productos No Conformes (PNC) originados en el proceso de ingeniería de detalle, basándose en la metodología de Cameron y Braiden [2004]. Una evaluación de la organización permite comprender el funcionamiento y las características particulares del proceso de venta, diseño y fabricación de equipos, que concentra el 90% de sus ingresos anuales. Se detecta en esta etapa que el proceso de ingeniería de detalle concentra el 38,7% de los Productos No Conformes detectados, validando la decisión de rediseñar este proceso particular. El consecuente levantamiento del proceso de ingeniería de detalle, junto con un análisis de causa-efecto y de causa raíz de los PNC detectados, deja en evidencia que la falta de especificación de requerimientos y criterios de diseño y el alto nivel de incertidumbre del proceso son responsables de casi el 80% de las no conformidades detectadas. Durante el rediseño del proceso se pone especial énfasis en mitigar las principales causas de no conformidad detectadas, seleccionando de la literatura las mejores prácticas que reduzcan los costos y mejoren la calidad del proceso. También se rediseñan los sistemas que soportan el proceso: la estructura organizacional y los sistemas de información de la empresa. Finalmente, se incluye una propuesta de plan de implementación como un primer acercamiento hacia la implementación de este rediseño en la empresa. Este trabajo muestra que el proyecto tiene beneficios económicos importantes y que el costo de implementación es relativamente bajo, por lo que se recomienda continuar con las siguientes etapas del proyecto propuestas en la metodología. Se determina que BPR es aplicable a empresas del sector ETO y que permite obtener beneficios importantes, siempre que se limite a procesos unitarios y dentro una misma unidad de negocios.
7

The role of TLE4 as a tumor suppressor in acute myeloid leukemia and regulator of hematopoietic and bone development

Shin, Thomas H. 06 February 2017 (has links)
The presence of AML1-ETO (RUNX1-CBF2T1), a fusion oncoprotein resulting from a t(8;21) chromosomal translocation, is a necessary but insufficient event in the development of a subset of acute myeloid leukemias (AML). Although AML1-ETO is able to block differentiation and immortalize hematopoietic stem cells, other contributory events are required for cell proliferation and leukemogenesis, suggesting that specific tumor suppressor genes may counteract the leukemic potential of AML1-ETO. In studying del(9q), one of the most common concomitant chromosomal abnormalities with t(8;21), we identified the loss of TLE4 as a key cooperating event in the development of AML1-ETO AML, leading to increased cell proliferation, blocked apoptosis and differentiation, as well as cytarabine resistance in leukemic cells. This suggested TLE4 functions as a tumor suppressor gene in AML.We found these effects are mediated by the loss of TLE4 regulation of a COX-Wnt inflammatory axis. These effects were consequently reversible by Wnt signaling and cyclooxygenase inhibition, pointing towards anti-inflammatory agents as potentially new therapeutic and adjuvant strategies for AML. While studies in Drosophila implicate TLE/Groucho as a key mediator of various signaling pathways, including receptor tyrosine kinase/Ras/MAPK, Notch, Myc, and Wnt pathways, there is surprisingly little known about the role of TLE in mammalian development. Using a Tle4 knockout (T4KO) mouse, we identified previously unknown roles for Tle4 in regulating vertebrate mammalian hematopoietic and bone development. T4KO mice manifest leukocytopenia and defective hematopoietic stem cell populations. Using serial transplantation and stromal co-culture, we find that these hematopoietic deficiencies arise due to both intrinsic dysfunction of hematopoietic stem cells as well as defective extrinsic regulation of hematopoiesis by the stem cell niche. Additionally, T4KO mice are severely runted and exhibit markedly decreased bone mineralization concomitant with defective osteoblast function and decreased mineral apposition rates. Many of the pathways regulated by TLE are aberrant in cancer, which has led to increasing studies connecting TLE with various malignancies, including synovial cell sarcoma and glioblastoma. Our findings have great implications for current understanding of TLE function in not only cancer, but also bone and hematopoietic development.
8

The role of THPO/MPL signaling in AML1-ETO self-renewal

Griesinger, Andrea January 2011 (has links)
No description available.
9

Modeling and Analysis of Acute Leukemia using Human Hematopoietic Stem and Progenitor Cells

Lin, Shan January 2016 (has links)
No description available.
10

Improving organizational agility and resilience within Engineer-to-order strategy

Trkawi, Murad January 2022 (has links)
Companies must be flexible and adaptable to compete in today's market. Those with such skills can better meet changing customer needs. Customization can add value by meeting customers' specific needs. Engineer-to-order (ETO) is used as a strategy to meet customer needs. High-mix, low-volume products are promoted. This creates uncertainty about the demand that the organization needs to deal with in a fast and efficient way, which results in applying agile as an approach to dealing with uncertainty. In addition, the organization needs to be more resilient to the vulnerability to which the market exposes the organization. However, at the same time, the organization needs the ability to make sense of the state of its environment, detect new threats, adopt new technologies and organizational attributes, and contribute to its resilience. However, it is unclear how to simultaneously develop an agile-based manufacturing strategy and a more resilient organization. Evidently, research is limited regarding the management of both the ability to move quickly and easily (Agile) and the organization's capacity to rapidly adapt to and respond to all types of risks (Resilience) within complex ETO organizations. In light of this, the purpose of this study is to investigate how agile and resilient practices can be implemented in ETO organizations to facilitate the production of complex or specialized products, as well as the capacity to absorb stress, recover essential functionality, and thrive under altered conditions. This study has primarily adopted a qualitative methodology, which uses both a case study approach and a literature review. The case study is based on interviews, a document study, and questionaries. The result from this study presents critical areas to improve from the point of view of agile and resilient practices so that the organization can have better performance and productivity. Improving areas such as communication, management style, the development of a model and knowledge management, the desired organizational structure, and the customer's role is essential in order to increase the organization's efficiency and decrease its uncertainty and risks.

Page generated in 0.0778 seconds