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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.
201

考慮韋伯分配下兩個相依製程之管制 / Process Control for Two Dependent Subprocess under Weibull Shock Model

陳延宗, Chen, Yen-Tsung Unknown Date (has links)
Today, most products are produced by several dependent subprocesses. This paper considers the economic-statistical process control for two dependent subprocesses with two assignable causes following Weibull shock distributions. We construct the individual X control chart to monitor the in-coming quality produced by previous process, and use the cause-selecting control chart to monitor the specific quality produced by current process. By using the charts, we can effectively and economically distinguish which subprocess is out of control. The renewal theorem approach is extended to construct the cost model for our proposed control charts, and the successive quadratic programming algorithm and a finite difference gradient method in the Fortran IMSL subroutine (dnconf) is used to determine the optimal design parameters of the proposed control charts. Finally, we give an example to show how to construct and apply the proposed control charts. Furthermore, the sensitivity analysis illustrates the effects of cost and process parameters on the optimal design parameters and the minimal expected cost per unit time for the proposed control charts.
202

量測誤差對X-S2管制圖設計參數之影響

郭又升, Kuo, Yu-Sheng Unknown Date (has links)
隨著經濟不斷的發展,企業間的競爭也愈趨激烈,因此在以利潤最大、付出成本最小的前提下,一些可能造成成本增加的因素就不能不重視。在量測產品的特性所使用的量測機器,可能因為量測設備的不精確造成誤差,進而影響測量產品品質特性的實際值。是以量測儀器測量產品特性時的誤差對於管制圖的設計參數的影響及使用管制圖監控製程的能力是我們所關切的課題。 本文探討量測誤差對 — 管制圖的效應。運用George Tagaras非對稱管制圖的概念,及同時考慮Taguchi的損失函數和測量誤差下,以更新理論方法建立 — 管制圖,並推導出目標函數,再透過最佳化的技巧以決定 — 管制圖的最佳經濟設計參數值。另外討論管制圖在統計層面的表現,並與經濟設計的結果作比較。 在資料分析方面,本研究考慮32組製程和成本參數組合,透過最佳化技巧找出 — 經濟及經濟統計管制圖之最小單位時間平均成本及最佳設計參數組合。再利用敏感度分析,觀察量測誤差對設計參數的影響,另外得知重要的製程和成本參數為何。這些可作為製程工程師決策參考之用。
203

選控圖的推導 / The Development of Cause-Selecting Control Chart

呂淑君, Leu, Shwu Jiun Unknown Date (has links)
在子製程相關下所產生的品質特性資料使Shewhart管制圖無法對各別的製程狀態加以解釋,而選控圖可診斷前後製程的責任歸屬。本文提出有n個子製程時,建立選控圖的方法及在製程上之應用,以追蹤製程變異之發生,明確地劃分出子製程的責任歸屬。文中並以模擬資料和實際例證說明,在相關品質特性的資料中,選控圖的建立及診斷效果。在實務上,若產品是由許多相關的子製程共同製造而成時,對於受到前製程影響的品質特性,即可用選控圖進行管制,以獲得正確的製程狀態訊息,並進一步採取正確的管制行動。
204

損失函數在■管制圖設計上的應用 / The application of loss function in ■ control chart design

施乃萍, Shin, Nai Ping Unknown Date (has links)
最近三十年來,最佳經濟設計管制圖已被考慮用來維持製程的穩定.由於在 實務上■管制圖被廣泛使用,是以大多數管制圖經濟模型的發展,都以單一 非機遇因素下的■管制圖為研究對象,但在實務上製程常會受二個或二個 以上非機遇因素的干擾.是以本研究利用更新理論方法建立二個非機遇因 素成本模式.又為使成本模式包含顧客的聲音以顯示品質的重要,本研究提 出以產品出廠後對社會的損失替代傳統上的成本考量.當推導出能反應顧 客滿意度的二個非機遇因素製程成本模式後,藉著最佳化技巧可決定■管 制圖的最佳設計參數值,並由例子的分析說明模式參數對最佳設計參數值 的影響 .另外,■經濟管制圖與Shewhart■管制圖間的成本比較顯現前者 能有顯著改善.最後,在考慮損失函數下■管制圖的建立與應用將被舉例說 明.
205

Effects of Professional Development on Using Differentiated Instruction with Gifted and Talented Students in the Library Media Center

Hayes, Kristi Lynn 01 December 2011 (has links)
Library media specialists (LMSs) have a unique position within a school, which is the opportunity to reach out to every student, especially to gifted and talented students who can benefit from having more advocates within their learning communities. Collaborating with other education professionals is beneficial to all students and many library media specialists already make this a normal part of their job responsibilities. The LMSs who are participants of Project CATALYST (Collaboration among Teachers and Librarians Yields Successful Teaching) are required to collaborate with classroom teachers in order to provide more enriching opportunities for students when they come to the library media center. So, the purpose of this project was to introduce gifted and talented terminology and strategies that focus on differentiated instruction for gifted and talented students to LMSs participating in Project CATALYST grant through the Ohio Valley Educational Cooperative (OVEC). This will meet two specific needs: providing the LMSs opportunities to collaborate with classroom teachers while becoming another resource for gifted and talented students that can enhance their learning beyond the classroom. The LMSs who participate in Project CATALYST were introduced to specific gifted and talented terminology and strategies that focus on differentiated instruction for gifted and talented students through a three-hour professional development. The participants completed an online pre-survey that identified the specific needs of the group and the professional development was designed with these needs in mind. After participating in the professional development, the participants were asked to complete an online post-survey to determine if the professional development was effective in changing the awareness and instructional practices of the participants when working with gifted and talented students. The pre- and post-surveys were analyzed to validate the effectiveness of the project and found that there was positive response by library media specialists to professional development on using differentiated instruction with gifted and talented students in the library media center. The small changes in instructional practices by 70 percent of the participants validate the effectiveness of the project in enlightening educators in the needs of gifted and talented students and the need to collaborate with other educators to provide enriching and challenging learning activities for these unique students.
206

Mätning av utrustningseffektivitet : En fallstudie utförd på Gnutti Powertrain AB / Measurement of equipment efficiency : A case study performed at Gnutti Powertrain AB

Malmberg, André, Tibratt, Marcus January 2012 (has links)
Syftet med studien är att få en förståelse för hur utrustningseffektiviteten kan mätas i ett producerande företag. Vår studie utförs på ett företag i Alvesta som heter Gnutti Powertrain AB som bland annat tillverkar precisionskomponenter till motorer. Genom att vi skapar en analysmodell utifrån studerade teorier beskrivs ett systematiskt tillvägagångssätt som slutligen ska leda till att syftet uppnås. Utifrån analysmodellen studeras och beskrivs först Gnutti Powertrain AB´s nuvarande tillvägagångssätt för att sedan jämföras och analyseras gentemot de studerade teorierna. Med hjälp av analysmodellen struktureras också vår studie på företaget och vårt utförande och resultat utifrån detta kommer sedan att presenteras. Analysmodellen nämner att en processkartläggning först ska göras. I processkartläggningen väljs först en specifik process ut, vilken i vårt fall blev produktionsprocessen för en rulle av stål. Därefter lokaliserar, dokumenterar och beskriver vi alla de aktiviteter som bygger upp processen. Enligt nästa steg i analysmodellen görs en värdeflödeskarta som behandlar alla de aktiviteter som tillför värde till produkten och nämner data som är viktig att samla in för att kunna göra beräkningar och utvärderingar. Denna data samlades in och presenterades i värdeflödeskartan. Värdeflödeskartan kan också underlätta identifieringen av de mest kritiska aktiviteterna. I vår studie var de kritiska aktiviteterna redan utvalda på förhand som fyra olika maskiner i flödet då de vid senare tillfälle eventuellt ska byggas samman till en linje. Som sista steg i analysmodellen görs beräkningar på utrustningseffektiviteten med hjälp av TAK. En del av datan från värdeflödeskartan kunde användas för att göra TAKberäkningarna. Resten av den data som krävdes vid beräkningarna samlades in genom intervjuer och möten med personal eller genom egna mätningar i produktionen. TAK-värdet varierar på de fyra maskinerna och även fyra olika beräkningar görs på varje maskin där olika data från störningar används. De olika värdena varierar mellan cirka 61% till 91%. Utifrån beräkningarna görs jämförelser om hur olika störningar påverkar TAK-värdet där även varje störning beskrivs. Vid utförandet och beräkningarna uppkom flera olika tankar och funderingar på nuläget hos Gnutti Powertrain AB. Något som tydligt framkom var att de rapporteringar som varje operatör gör i affärssystemet inte alltid är korrekta. Då TAK III beräkningarna helt bygger på rapporterna medför detta att både vårt och Gnutti Powertrain AB´s TAK-värden kan bli felaktiga. Resultatet och diskussionen kring resultatet ledde till att vi kunde dra vissa slutsatser för att kunna komma med rekommendationer till företaget. Det konstateras att Gnutti Powertrain AB bör använda nuvarande mätmetod för TAK men fokusera på att förbättra deras rapporteringar i affärssystemet.
207

A STUDY ON IMPLEMENTATION AND IMPROVIZATION OF SUPPLY CHAIN- A CASE STUDY ON ELGI EQUIPMENTS PVT LTD, INDIA

MARIA JOSEPH, ALFRED January 2012 (has links)
See thesis
208

Heavy-tail statistical monitoring charts of the active managers' performance

Chen, Chun-Cheng 03 August 2006 (has links)
Many performance measurement algorithms can only evaluate measure active managers' performance after a period of operating time. However, most investors are interested in monitoring the active managers' performances at any time, especially, when the performance is going down. So that the investors can adjust the targets and contents of their portfolios to reduce their risks. Yashchin,Thomas and David (1997) proposed to use a statistical quality control (SQC) procedure to monitor active managers' performances. In particular, they established the IR (Information Ratio) control charts under normality assumption to monitor the dynamic performances of active managers. However, the distributions of IR statistic usually possess fat tail property. Since the underlying distribution of IR is an important hypothesis in building up the control chart, we consider the heavy tail distributions, such as mixture normal and generalized error distribution to fit the IR data. Based on the fitted distribution, the IR control charts are rebuilt. By simulations and empirical studies, the remedial control charts are found to detect the shifts of active managers' performances more sensitively.
209

A Two-sided Cusum For First-order Integer-valued Autoregressive Processes Of Poisson Counts

Yontay, Petek 01 July 2011 (has links) (PDF)
Count data are often encountered in manufacturing and service industries due to ease of data collection. These counts can be useful in process monitoring to detect shifts of a process from an in-control state to various out-of-control states. It is usually assumed that the observations are independent and identically distributed. However, in practice, observations may be autocorrelated and this may adversely affect the performance of the control charts developed under the assumption of independence. In this thesis, the cumulative sum (CUSUM) control chart for monitoring autocorrelated processes of counts is investigated. To describe the autocorrelation structure of counts, a Poisson integer-valued autoregressive moving average model of order 1, Poisson INAR(1), is employed. Changes in the process mean in both positive and negative directions are taken into account while designing the CUSUM chart. A trivariate Markov Chain approach is utilized for evaluating the performance of the chart.
210

Kompatibilitätsanalyse dynamischen Verhaltens von integrierten Automobil-Steuergeräten

Glockner, Matthias, Hardt, Wolfram, Fuchs, Maximilian, Macht, Michael 08 June 2007 (has links) (PDF)
In Premium-Fahrzeugen werden derzeit ca. 60-70 Steuergeräte (SG) verbaut. Steuergeräte sind „eingebettete Systeme“ und stellen die zentralen Rechen- und Steuereinheiten für die elektrischen und elektronischen Systeme im Fahrzeug dar. Mit Hilfe der Steuergeräte, die über Bus-Systeme (z.B. CAN-Bus) miteinander vernetzt sind, können komplexe Funktionen realisiert werden. Das Motor- Steuergerät ist eines der bekanntesten. Der steigende Innovationsgrad im Elektrik- / Elektronik- Umfeld zwingt die Autohersteller, in immer kürzeren Zeitabständen, neue Steuergeräte mit höherer Rechenleistung und neuen Funktionen zu entwickeln. Aufgrund der steigenden Anzahl von Steuergeräten, spielt deren Rückwärtskompatibilität eine immer wichtigere Rolle.

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