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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.
521

Adaptive control for Mars atmospheric flight

Restrepo, Carolina Isabel 15 May 2009 (has links)
The new vision for space exploration will focus on sending humans to the moon and eventually to Mars. This endeavor presents new challenges that are critically different from the past experience with robotic missions to Mars. For example, the strict landing accuracy requirements for a manned space vehicle make it necessary to fly a controlled entry trajectory rather than a more robust ballistic entry trajectory used for some robotic missions. The large variations in Mars atmospheric properties make a controlled entry and a safe precision landing for manned missions a difficult engineering problem. Model reference adaptive control is a candidate solution for the Mars entry control problem. This type of controller has an adaptation mechanism that reduces tracking errors in the presence of uncertain parameters such as atmospheric density or vehicle properties. This thesis develops two different adaptive control systems for the Mars ellipsled, a vehicle which is much larger than those that carried robotic payloads to Mars in the past. A sample mission will have multiple ellipsleds arriving at Mars carrying an assortment of payloads. It is of critical importance that the vehicles land in close proximity to each other to best assure that the crew has manageable access to their payloads. The scope of this research encompasses the atmospheric flight of the ellipsled, starting at the entry interface point through the final parachute deployment. Tracking performance of an adaptive controller for prescribed entry trajectories in the pres¬ence of atmospheric and vehicle model uncertainties is shown here. Both adaptive controllers studied in this thesis demonstrate successful adaptation to uncertainties in the Martian atmosphere as well as errors in the vehicle properties. Based on these results, adaptive control is a potential option for controlling Mars entry vehicles.
522

A Study on the Related Factors of Life Adjument among Elementary Students

Chang, Chiou-wen 01 July 2007 (has links)
The main goals of the present study were to examine the related factors of life adjument among elementary students. The study investigated the elementary students of the 6th grade during the 2006 school year within the Kaohsiung County, including 1041 students. ¡§Perceptual Parenting Style Scale of Elementary Students¡¨, ¡§Percep- tual Marital Relationship Scale of Elementary Students¡¨, ¡§Inventory of Parents Attach- ment¡¨, ¡§Interpersonal Relationship Scale of Elementary Students¡¨, ¡§Self-efficacy Scale of Elementary Students¡¨, ¡§Emotional Intelligence Scale of Elementary Students¡¨, and ¡§Life Adjument Scale of Elementary Students¡¨ were used. The results were ana- lyzed with descriptive statistics, T-test, one-way ANOVA, two-way ANOVA, Cano- nical Correlation, Stepwise Regression Procedure, and Structural Equation Modeling. The conclusion and findings were listed as follows: (1) The current situation of perceptual parenting style, perceptual marital relationship, parents attachment, family atmosphere, interpersonal relationship, self-efficacy, emotional intelligence, and life adjument of elementary students were great. (2) In the interpersonal relationship, self-efficacy, emotional intelligence, and life adjument of elementary students, girls were greater than boys. (3) In the perceptual parenting style, parents attachment, family atmosphere, and self- efficacy of elementary students, students with high socioeconomic status were better than low socioeconomic status. (4) There was a significant difference on the perceptual parenting style, perceptual marital relationship, parents attachment, family atmosphere, interpersonal rela tionship, self-efficacy, emotional intelligence, and life adjument among elemen- tary students of different parenting style. (5) In the perceptual parenting style, perceptual marital relationship, parents attachment, family atmosphere, interpersonal relationship, self-efficacy, emotional intelligence, and life adjument of elementary students, students with high level attachment were superior to low level attachment. (6) There was a interaction relationship in the self-efficacy, emotional intelligence, and life adjument of elementary students for two factors of sex and perceptual paren- ting style. (7) Canonical relationships were found among the family atmosphere, interpersonal relationship, self-efficacy, and emotional intelligence of elementary students. (8) Canonical relationships were found among the family atmosphere, interpersonal relationship, self-efficacy, emotional intelligence, and life adjument of elementary students. (9) The family atmosphere, interpersonal relationship, and self-efficacy of elementary students had an obvious predictability to the emotional intelligence. (10) The family atmosphere, interpersonal relationship, self-efficacy, and emotional intelligence of elementary students had an obvious predictability to the life adjument. (11) Subjects didn¡¦t fit with the model based on the relationships that the perceptual parenting style, perceptual marital relationship, parents attachment, interpersonal relationship, and self-efficacy of elementary students affected emotional intelligence and life adjument, and then emotional intelligence affected life adjustment. Based on the above findings, constructive suggestions were provided for the parents, teachers, and school authorities. Further research was also suggested.
523

The Research on Recognition of Ethics Atmosphere, and the Influences of Organizational Promises on Organizational Civil Behaviors-Based on the examples of Hsinying Operation office and Chiali Operation Office of Chunghwa Telecom.

Tsai, Pai-Chang 25 July 2001 (has links)
Abstract Ever since the telecommunication is opened and liberalized, it to be privately owned is inevitable, however if the government promotes the policy of privately owning by the people, what concerns the employees of the public enterprises most will be the loss of guarantee of work rights, and they will fear that their labor conditions and welfares be influenced, and thus adapt the behaviors of being uncooperative and resistant, and simultaneously tend to move away from the centripetal force of the company. This research is proceeded by means of questionnaires on the basis of the relative factors and its relations of the recognition on ethics atmosphere, organizational promises and organizational civil behaviors of the employees of Chunghwa Telecom, since the Hsinying Operation Office and Chiali Operation Office of Chunghwa Telecom were merged on June 1, 2000. The research targets were those three of the one staying in the Hsinying Operation Office, the one being transferred from Chiali to Hsinying Operation Office, and the one staying in the Chiali Service Center. Study was made on the influences of relative factors between the ethics atmosphere, organizational promises and organizational civil behaviors after the organization is merged. A total of 260 questionnaires were distributed, after 193 copies were returned and turned to be effective and been analyzed with supportive evidences, the data was processed with analysis of validity, t examination, analysis of coefficient of variation on sole factors, Pierson¡¦s relative analysis and rotating analysis. Studies were made on the differences and its relative influences of individual variations and categories of employees to the ethics atmosphere, organizational promises and organizational civil behaviors after the organizations of Chinese Telecom were merged. After the results of the research are synthesized, it is found that: (1)There is a remarkable diversity among different categories of employees on ethics atmosphere, organizational promises and organizational civil behaviors. (2)Among different categories of employees, the performance on organizational civil behavior of the employee being transferred from Chiali to Hsinyin outranks the other two on ethics atmosphere and organizational promises. (3)Males care more about the ethics atmosphere than females, yet there is no remarkable diversity on organizational promises and organizational civil behaviors between two sexes. (4)After the amalgamation, of these three categories of employees, the employee of Hsinying Operation Office agreed least with the care toward the ethics atmosphere, therefore, the humane care of the organization should be reinforced to raise the satisfaction degree on ethics atmosphere and the identification degree on organizational promises of the organization, in order to promote the raise on organizational civil behaviors of the companies. (5)Other than that sex and seniority having remarkable negative influences on being persistence to one¡¦s duty in individual variation, whereas marriage has remarkable positive influences on being persistence to one¡¦s duty, categories of employees has remarkable negative influences on human relations to others, whereas there is no remarkable influence on the three structures of organizational civil behaviors for the rest individual variations. (6)They all have remarkable positive influences on the trend of regulations of ethics atmosphere towards the three structures of organizational civil behaviors, there are remarkable positive influences on individual profit towards human relations to others. For organizational promises, emotional promises has remarkable influences on organizational profits and human relations to others, whereas they all have remarkable positive influences for continuous promises to being persistence to one¡¦s duty and moral promises to being persistence to one¡¦s duty and human relations to others. According to the results of the above research, the following suggestions are made: create new business aggressively to guarantee the work rights of the employees, and promote the will to accept the revolution of being privately owned by the people of the employees; enhance the cultivation of the personnel to decrease the resistance on the revolution of being privately owned by the people of the employees; institute anew each system appropriately; reinforce the functions of communication and coordination among the units, delegate the authorities of positions specifically to raise the operational efficiency of the organization: improve the ethics atmosphere and organizational promises to raise the centripetal force and will to work of the employees. Key words: Ethics Atmosphere, Organizational Promises, Organizational Civil Behavior, Chunghwa Telecom.
524

The nonlinear dynamics of the sea breeze

Walter, Kevin Robert 15 November 2004 (has links)
The response of the land and sea breeze circulation to two highly simplified dynamical models is presented. The first dynamical model is the explicit specification of an oscillating interior heat source analogous to that from Rotunno (1983). Emphasis is placed on the variation of the response with heating amplitude and latitude. In addition, a weakly nonlinear analysis focuses on the dynamic forcing of nonlinear features such as a semi-diurnal gravity wave, fronts, and asymmetry in the magnitude of onshore and offshore flow. One surprising result is the identification of a cycle-mean surface divergence pattern at both 0? and 45?. At 45?, this divergence pattern is accompanied by a cycle mean shore-parallel response due to the Earth's rotation. The second dynamical model is the explicit specification of an oscillating surface heat flux. Again, comparison is made between simulations at different heating amplitudes, and between simulations at different latitudes. To address changes in the solution due to the heating method itself, comparison is made between solutions from the surface heating method and solutions from the interior heating method. Finally, solutions across the planetary continuum are explored for critical latitude dependence in high-amplitude simulations.
525

Physicochemical Characteristic Analysis of Atmosphere Suspended Particles in the Heavy Industry Peripheral Area

Chou, Yu-kuang 09 September 2009 (has links)
Kaohsiung city for the south Taiwan industry strategic place, the Siaogang area is a heavy industry stands in great numbers the area, the rendering plant, the steel plant, petrifies the factory, the incineration plant, the shipyard, the airport and so on, moreover also has transport means and so on the container truck, carriage vehicle, airplane, The air quality fraction defective occupies crown of the whole city. Kaohsiung important empty unclean control key of suspended particulate pollution, This research is for the purpose of discussing Physicochemical characteristic analysis of air suspended particles in the heavy industry peripheral area, understood in the heavy industry peripheral area air the suspended particles pollutant originates. Physicochemical characteristic analysis discussion atmosphere pollutants to influence Siaogang area. This research in May 2009 period picks each time continual sampling 24 hours to carry on each week twice sampling respectively, the East, West, South and North central area average in the Siaogang area 5 points, altogether gathers 20 samples. Another gathers motorcycle/automobile/diesel car/boiler/voltaic arc boiler/fritting furnace/road dusts different of samples, altogether 14 samples. This research uses air sampling instrument (GAST) carries on the sampling to air of the Siaogang area. Using the scanning type electron microscope (Scanning electron microscope, SEM) and instruments and so on XRD (X-ray Diffractometer, XRD) carry on the metallic element and the physicochemical characteristic analysis. The time can of because of the Siaogang area atmosphere in the suspended particulate matter origin type and the contribution quantity, relevance of in order to help control of air suspended particles in the heavy industry peripheral area pollutant and the source of pollution. This research the main of purpose this study by under construction in the air in the surrounding areas of heavy industry in the pollutants of sampling technology, and discussion of pollutants by the scene size distribution and inorganic salts, and so particulate surface characteristics and analysis for the structure and composition. This research also use a variety of discussion on the valuable instrument analysis to peripheral areas of heavy industry in the pollutants in air of surface and microstructure characteristics, the result of the above analysis, may further in-depth understanding of the heavy industries in peripheral areas of pollutants characteristics, also took granular than in the air pollutants and other kinds of granular pollutant emission sources and physicochemical characteristics of the apparent, discussion of heavy industry in peripheral areas of major sources of granular pollutants for source decrement measures. Future expected completion of roads, schools, residential, farmland, rivers the downwind side of the land of bare ground, farming, construction site River dust, straw, dead wood, rubber, PVC plastic, PE/PP plastics non-heavy industry surrounding area of micro photo, composition and organizational analysis, and than the judgment against a database of all particulate sources.
526

Ocean-atmosphere interaction in the seasonal to decadal variations of tropical Atlantic climate

Okumura, Yuko. January 2005 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 135-148).
527

Pectic methyl and non-methyl esters and the environmental implications of methanol emissions from plants

Finlay, Christine Jane. January 2007 (has links)
Thesis (Ph.D.) -- University of Glasgow, 2007. / PhD thesis submitted to Environmental, Agricultural and Analytical Chemistry, Department of Chemistry, University of Glasgow. Includes bibliographical references. Print version also available.
528

Using virtual environments to visualize atmospheric data : can it improve a meteorologist's potential to analyze the information?

Ziegeler, Sean Bernard. January 2002 (has links)
Thesis (M.S.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.
529

Classification of air pollution regimes in the Missouri region

Weber, Eric E. Lupo, Anthony R. January 2009 (has links)
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Anthony R. Lupo. Includes bibliographical references.
530

Extrapolations of the flux of dimethylsulfide, carbon monoxide, carbonyl sulfide, and carbon disulfide from the oceans /

Kettle, A. James. January 2000 (has links)
Thesis (Ph. D.)--York University, 2000. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 370-416). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ59143

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