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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.
61

Analysis of 2D Optical Waveguide Structures Using Frequency-Domain Finite-Different Method

Lin, Zheng-Wei 13 July 2004 (has links)
Abstract This thesis applies the method of finite-difference frequency -domain to solve the field when light propagating through the optical waveguide. Comparing with other method, method of finite-difference time-domain which required to be calculated with larger matrices and without any ideal approximate rapid solution, our method only needs to solve the joint equations. Method of finite-difference frequency -domain will be more efficient than method of finite- difference time-domain in optical waveguide simulation. However, all that we need to confer with are how to sample the effective indices for set grind points and the deal for the boundary conditions in partial differential equations, including electric wall, magnetic wall, absorption boundary and other boundary conditions, etc. Next, we confer with the difference deal between TE and TM waves respectively. Final, we confer with high-order finite-difference and the method for calculating extremely large area or extremely high precision in order to use the method of finite-difference frequency-domain to find the incident, reflective, and scattering fields by the fastest and the exactest procedures.
62

A Study on Vocabulary Frequency and VOcabulary Teaching in Junior and Senior High Schools

Liao, Chi-feng 23 July 2006 (has links)
Ever since the Ministry of Education handed down the policy ¡§One guiding principle, different versions,¡¨ criticizing voices had emerged from everywhere. Parents, teachers, and students all had something to say. What has gone wrong with the education reformation previously claiming to take our children to a better place? Thanks to my current part-time job, I soon learned that there seemed to be existing a noticeable gap between the vocabulary taught in junior high school and senior high schools. Also, vocabulary teaching methods adopted in different school levels might as well take place as pivotal element and lower students¡¦ learning efficiency. There are presently eighteen senior high schools, public or private, in the Kaohsiung city and three versions(¤T¥Á, »·ªF, ÀsÄË) of English text books are used in these schools. The situation, however, in junior high schools is a bit more complex because six different versions(±d°a, «n¤@, ®Ô¤å, ¿«ªL, ¦ó¹Å¤¯, ¦XÁn) are randomly selected from semester to semester simply based on the opinions of teachers in charge of different grades. Knowing how the teaching materials are selected, I decided to conduct a research by choosing three most frequently used versions of English textbooks from both junior high and senior high schools and to, based on Dr. Gao(°ª·Ó©ú)¡¦s word-frequency-checking program, figure out that into which levels the vocabulary taught at two levels falls. The study is, furthermore, attached with two sets of interviews aiming at junior and senior high school teachers and a questionnaire directing to students of both levels with the purpose of a better understanding of the authentic EVT situations in the academic environment. Contrary to the common perception, that there is a vocabulary gap between the two high school levels, the figures surprisingly show us that the junior and senior high English textbooks are very much consecutive on vocabulary. This result reveals one fact that even the vocabulary is consecutively compiled, all of the efforts will still be in futility if the time given to students to absorb new knowledge isn¡¦t enough. As for the interview section, almost all of the interviewees agreed that the conception to emphasize ¡§word frequency¡¨ is rather critical in vocabulary learning. Nonetheless, other factors such as time limit and personal background also get involved to influence the expected goal. The researcher, by means of the gained data, tried to set forth the outcome and come up with a solution hoping to provide the English learners a sounder set of learning tools and the relevant authorities an alternative of selecting textbooks while promising our people a ¡§consecutive¡¨ academic curriculum.
63

Dual-Frequency Microstrip Arrays with a Dual-frequency Feed Network

Huang, Chien-Chin 15 June 2000 (has links)
No
64

Fisheries Biology of Sergestid shrimp, Sergia lucens, in the Southwestern Coast of Taiwan

Huang, Chen-Yi 15 July 2000 (has links)
This study investigated the basic biology as well as vital statistics of the Sakura shrimp, Sergia lucens in the southwestern coast of Taiwan. The research includes length-weight relationship, spawning season, sex ratio and Von Bertalanffy equation. All sample had found partly grown eggs. The greatest spawn in January and July. It is possible that one population in the fishing area. Analysis of Covariance(ANCOVA) on the relationship between length and weight shows that male and female has the similar growth rate; but male shrimp appeared to be heavier than female for about 0.0217 g. There are more female than male in fishing area, and the ratio increase toward large size group. The growth rate of Sergia lucens is allometric. Result from morphometric study as well as fluctuation in GSI shows that the Sergested shrimp of the southwestern Taiwan can be classified as belonging to one single population but with the possible existence of two spawning subgroups. Analysis on length frequency distribution computer package, FiSAT, showed that total mortality and natural mortality was equal to 7.86 and 5.02, respectively.
65

Chemical information based elastic network model a novel way to identification of vibration frequencies in proteins /

Raj, Sharad K., January 2009 (has links)
Thesis (M.S.M.E.)--University of Massachusetts Amherst, 2009. / Open access. Includes bibliographical references (p. 91-95).
66

Radio frequency identification (RFID) at SMG Manufacturing, Inc.

Gay, Steven M. January 2004 (has links) (PDF)
Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2004. / Includes bibliographical references.
67

Feeding behaviour of lions (phanthera leo ) on a small reserve

Lehmann, MB, Funston, PJ, Owen, CR, Slotow, R 12 November 2007 (has links)
The prey selection and predatory behaviour of a single pride of lions (Panthera leo) was studied in the 8500 ha Karongwe Game Reserve from 1999–2005. The study focused on the difference between prey selection in the first three years when a two-male coalition was present with a similar period thereafter when one of the males was removed and subadult males dispersed from the pride. A total of 662 kills were recorded, with blue wildebeest (Connochaetes taurinus), warthog (Phacochoerus africanus), waterbuck (Kobus ellipsiprymnus), zebra (Equus burchelli) and impala (Aepyceros melampus) being the most preferred species. Although there was preference for these species, and adult prey were favoured, there was no significant selection for prey size, age or gender. There was a significant difference in the number of kills made when the two-male coalition was present as opposed to the single pride male. The solitary pride male spent significantly more time with the females and shared most of their kills, and during this period dispersing subadult males killed a substantial amount of prey when separated from the pride. Knowledge on predator feeding behaviour is important for managers to assess impact on prey populations in small reserves in order to manage them correctly, thereby preventing depletion of such populations.
68

Free vibration of rotating hollow spheres containing acoustic media

Shatov, MY, Joubert, SV, Coetzee, CE, Fedotoc, IA 16 April 2008 (has links)
Abstract When avibratingstructureisrotatedwithrespecttoinertialspace,thevibratingpatternrotatesatarateproportionalto the inertialrateofrotation.Bryanfirstobservedthiseffectin1890.Theeffect,calledBryan’seffectinthesequel,has numerous navigationalapplicationsandcouldbeusefulinunderstandingthedynamicsofpulsatingstarsandearthquake series inastrophysicsandseismology.Bryan’sfactor(thecoefficientofproportionalitybetweentheinertialandvibrating pattern rotationrates)dependsonthegeometryofthestructureandthevibrationmodenumber.The‘‘gyroscopiceffects’’ of ahollowisotropicsolidspherefilledwithaninviscidacousticmediumareconsideredhere,butthetheoryisreadily adapted toahollowisotropicsolidcylinderfilledwithaninviscidacousticmedium.Alineartheoryisdevelopedassuming, among othermildconditions,thattherotationrateisconstantandmuchsmallerthanthelowesteigenfrequencyofthe vibrating system.Thuscentrifugalforcesareconsideredtobenegligible.Beforecalculatingsolutionsforthedisplacement of aparticleintheisotropic,spherical,distributedbody,Bryan’sfactorisinterpretedusingacomplexfunction.Hereitis demonstrated thatneitherBryan’seffectnorBryan’sfactorisinfluencedbyincludinglight,isotropic,viscousdampingin the mathematicalmodel.Hencedampingisneglectedinthesequel.Twoscenariosarethenidentified.Firstly,wemay assume thattheacousticmediumiscompletelyinvolvedintherotation(thespheroidalmode).Secondly,wemayassume that theacousticmediumremainsstaticwithrespecttotheinertialreferenceframe(thetorsionalmode).Weinvestigatethe spheroidal modeusinganumericalexperimentthatcomparestherotationalangularrateofasphere(filledwithaninviscid acoustic medium)withthoseofitsvibratingpatternsatbothhighandlowvibrationfrequency.
69

Theoretical studies of radio-frequency sheath

Xiang, Nong, 1964- 03 August 2011 (has links)
Not available / text
70

THE EFFECT OF UNIFORMLY SPACED ELASTIC SUPPORTS ON THE MODAL PATTERNS ANDNATURAL FREQUENCIES OF A UNIFORM CIRCULAR RING

McKinley, Joseph William, 1937- January 1970 (has links)
No description available.

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