• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 10
  • 10
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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 AN ANTENNA/PEDESTAL FOR TRACKING LEO AND MEO IMAGING SATELLITES

Turner, W. C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper takes one through the processes followed by a designer when responding to a specification for an earth terminal. The orbital parameters of Low-Earth Orbiting and Medium-Earth Orbiting (LEO and MEO) satellites that affect autotracking and pointing of an antenna are presented. The do’s and don’ts of specifying (or over specifying) the antenna feed and pedestal size are discussed. The axis velocity and acceleration rates required of a Y over X and El over AZ type pedestal are developed as a function of satellite altitude, radio frequency of operation, and ground antenna terminal diameter. Decision criteria are presented leading to requiring a tilt mechanism or a third axis to cover direct and near overhead passes using an El over Az pedestal. Finally, the expressions transforming Y over X configuration position angles to azimuth and elevation axis position angles are presented.
2

Automatisk trimning av externa axlar / Automatic tuning of external axis

Eliasson, Per-Emil January 2004 (has links)
<p>This master theses deals with different methods for automatic tuning of the existing controller for external axis. </p><p>Three methods for automatic tuning have been investigated. Two of these are based on the manuell method used today. The third method is based on optimal placement of the dominant poles. Different sensitivity functions are important for this method. </p><p>At the end of the thesis, a proposal of a complete tool for automatic tuning is given.</p>
3

Automatisk trimning av externa axlar / Automatic tuning of external axis

Eliasson, Per-Emil January 2004 (has links)
This master theses deals with different methods for automatic tuning of the existing controller for external axis. Three methods for automatic tuning have been investigated. Two of these are based on the manuell method used today. The third method is based on optimal placement of the dominant poles. Different sensitivity functions are important for this method. At the end of the thesis, a proposal of a complete tool for automatic tuning is given.
4

Characterization of Asphalt Mixture Cracking Resistance Based on Mix Design Parameters

Quasem, Tanvir 05 May 2022 (has links)
No description available.
5

Dynamic Characterization of Aseismic Bearings for Girder Bridges: Bi-directional Seismic Performance Assessment and Design Parameter Exploration / 耐震機能を有する桁橋用支承の動的特性分析:2方向地震動に対する性能評価および適正設計値の探索

HE, XINHAO 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22757号 / 工博第4756号 / 新制||工||1744(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 五十嵐 晃, 教授 高橋 良和, 准教授 古川 愛子 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
6

Robust Design With Binary Response Using Mahalanobis Taguci System

Yenidunya, Baris 01 August 2009 (has links) (PDF)
In industrial quality improvement and design studies, an important aim is to improve the product or process quality by determining factor levels that would result in satisfactory quality results. In these studies, quality characteristics that are qualitative are often encountered. Although there are many effective methods proposed for parameter optimization (robust design) with continuous responses, the methods available for qualitative responses are limited. In this study, a parameter optimization method for solving binary response robust design problems is proposed. The proposed method uses Mahalanobis Taguchi System to form a classification model that provides a distance function to separate the two response classes. Then, it finds the product/process variable settings that minimize the distance from the desired response class using quadratic programming. The proposed method is applied on two cases previously studied using Logistic Regression. The classification models are formed and the parameter optimization is conducted using the formed MTS models. The results are compared with those of the Logistic Regression. Conclusions and suggestions for future work are given.
7

少量連串下最適設計參數值之決定 / The Decision of the Best Fitted Design Parameters on Small Runs

嚴珮文, Yen, Pay Wen Unknown Date (has links)
管制圖之經濟模型首由Duncan(1956)提出,自此之後陸續有學者致力研究經濟管制圖,包括X-bar管制圖、S管制圖等。但R管制圖之經濟設計目前尚無人提出。而在實務上,部份產業可能由於產品過於昂貴,或者產品的製造時間所需甚長,而使得品檢時所抽取的樣本數無法達到25個,這時若採用傳統的管制圖來分析製程,將無法顯示製程真正的狀態。因此本研究首先探討少量連串下X-bar和R管制圖之製作原理,並計算及整理出較完整的少量連串下X-bar和R的管制係數表。接著假設非機遇因素只影響製程運用Banerjee和Rahim(1987)的更新理論方法,建立少量連串情形下的R經濟管制圖。再利用最佳化方法,即可求得最適設計參數值。於是,少量連串情形下的R經濟管制圖得以建立。最後,我們將舉一個例子來說明如何獲得最適設計參數值、決定關鍵參數,以及少量連串情形下R經濟管制圖之建立與應用。
8

BOM removal by biofiltration- Developing a quantitative basis for comparison

Shen,Dinghua (David) 14 June 2010 (has links)
Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.
9

BOM removal by biofiltration- Developing a quantitative basis for comparison

Shen,Dinghua (David) 14 June 2010 (has links)
Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.
10

Inverzní analýza spolehlivosti předpjatého mostu / Inverse reliability analysis of prestressed bridge

Lipowczan, Martin January 2018 (has links)
The proposed diploma thesis deals with the application of methodology and tools of inverse analysis for design of selected structural parameters using a fully probabilistic analysis to determine the level of its reliability. The method based on artificial neural networks is used to approximate the inverse function. The inverse analysis was carried out in two ways that differs in the method of obtaining reliability indicators. The structure analyzed in this work was an existing bridge. The year of construction is estimated approximately between the years 1955 to 1960. The bridge is located close to the Uherský Ostroh. It is a one-piece concrete slab made of MPD3 and MPD4 girders post-tensioned by tendons. Based on the 2006 and 2007 diagnostic surveys, laboratory tests, normative regulations and recommendations and, last but not least, sensitivity analyses, an inverse design of selected design parameters was performed for required limit states. Various load levels, different alternatives of design parameters and different neural network structures were studied.

Page generated in 0.0546 seconds