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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.
1

試題預覽對國中生英語聽力表現之影嚮:個案研究 / The Effects of Test Question Preview on Junior High School Students' English Listening Comprehension: a Case Study

陳淑菁, Chen,Shu-ching Unknown Date (has links)
本研究主要探討四方面。第一、探討試題預覽是否有助於聽力成績表現。第二、進一步探究試題預覽的效益是否因聽力程度不同而有所差異。第三、了解學生以試題預覽方式參加聽力測驗的實際經驗與看法。第四、研究試題預覽是否是一個可行的評量聽力的測驗方式。 參加本實驗的受試者為來自竹山國中120位三年級的學生。首先,他們被分為能力相當的兩組,每一組再被細分為高、中、低三個能力組別,接著研究者分別對兩組受試者施以聽力測驗,不同之處在於實驗組提供試題預覽。最後,實驗組的受試者須填寫一份關於他們對此測驗方式 (試題預覽方式) 的經驗及觀感。 本研究之主要發現如下: 1. 受試者在聽力測驗中顯著受益於試題預覽。 2. 高、中程度的受試者比低程度的受試者從試題預覽中獲得較多的助益。 3. 由問卷統計結果得知大部分受試者對於試題預覽表達正面的態度。 4. 試題預覽促進聽者預測聽力內容及使用由上而下的聽力理解方式是一個可行的評量聽力的測驗方式。 最後, 本研究建議老師們在實施聽力測驗時應以試題預覽的方式進行。再者, 老師們可以以試題預覽做為訓練聽力時的教學活動。另外, 老師們必須考慮學生聽力程度的不同並為低程度者設計額外的聽力訓練活動以便提升其聽力理解能力。 / The present study chiefly focuses on four issues. The first issue concerns whether test question preview method can make test takers get better scores on listening comprehension tests or not. The second issue examines whether the effectiveness of test question preview varies with the students’ proficiency levels or not. The third issue aims to probe test takers’ practical experience of taking the listening comprehension test with question preview test method. The fourth issue explores if question preview method is practical in measuring the students’ listening comprehension. The participants of this study were 120 third-year students at Chu-shan Junior High School. Firstly, they were divided into two homogeneous groups, each group were further subdivided into three subgroups- high, medium and low proficiency. Then the researcher administered the experimental test to both the experimental group and the control group; the only difference in the treatment was that question preview was used to the experimental group. At last, the experimental group was asked to fill in a questionnaire designed to investigate the experience of taking the listening test with test question preview method. The major findings of the study are as follows: (1)The junior high EFL students benefited significantly from the test question preview. (2)Listeners of high and medium proficiency level gained much assistance from the question preview than those of low proficiency level. (3)Questionnaire responses confirmed the positive effects of the test question preview. (4)The test question preview promoted information prediction and top-down information processing of test takers; therefore, it is a practical method for assessing learners’ listening comprehension. Therefore, it is suggested that teachers incorporate question preview method in the tests of listening comprehension. In addition, it is necessary for teachers to use question previewing as a teaching activity when training students’ listening skills. Finally, teachers should pay more attention to the differences in students’ listening ability and design some other additional activities for low proficiency listeners to promote their ability of understanding the previewed questions and improve efficiency of listening.
2

Efeito de métodos químicos de indução de copa no desenvolvimento da seringueira (Hevea brasiliensis Muell. Arg. cv. RRIM 600) / Effect of chemical methods of branch induction on growth of rubber tree (Hevea brasiliensis Muell. Arg. cv. RRIM 600)

Bernardes, Marcos Silveira 26 March 1990 (has links)
Objetivando-se estudar o efeito de métodos químicos de indução de copa no desenvolvimento da seringueira, realizou-se experimento em condições de campo, em Casa Branca-SP, aplicando-se reguladores vegetais de crescimento em plantas enxertadas do cultivar RRIM 600 com 20 meses de idade, com 1,70 a 3,00 m de altura e último lançamento foliar maduro. O experimento foi delineado em Blocos ao Acaso com quatro repetições, utilizando-se como tratamentos, a aplicação de hidrazida maléica a 500, 750 e 1. 000 ppm, chlormequat a 1.000, 1.500 e 2.000 ppm, daminozide a 2.000, 3.000 e 4.000 ppm e a testemunha. Durante a realização do experimento efetuaram-se avaliações das seguintes variáveis: perímetro do tronco, espessura de casca, altura da árvore, altura do tronco, comprimento da copa, diâmetro da copa, número e porcentual de árvores ramificadas, número de ramos, concentração de ramos, ângulo de inserção dos ramos, índice de área foliar, coeficiente de absorção de radiação e danos por vento. Estudos de correlação foram feitos para analisar a influência das características da copa sobre o desenvolvimento das árvores. Nas condições em que foi conduzido o experimento, os resultados obtidos permitiam concluir que a indução de copa por métodos químicos pode incrementar o crescimento do perímetro do tronco, reduzindo o período de imaturidade da seringueira e que a injúria ou morte da gema apical aumentam a susceptibilidade das copas a danos por vento. O melhor tratamento foi com daminozide a 2.000 ppm, que apresentou ganho de 25% no perímetro relativo do tronco em relação à testemunha. Os tratamentos com daminozide apresentaram ganhos em perímetro do tronco sem comprometer a resistência das copas a danos por vento. Os tratamentos com chlormequat e hidraliza maléica não apresentaram ganhos em perímetro do tronco sendo que o último comprometeu a resistência das copas a danos por vento. O perímetro do tronco está positivamente correlacionado com a altura da árvore, o comprimento da copa, o diâmetro médio da copa e a espessura de casca; e negativamente relacionado com a altura do tronco. / This study describes the influences of chemical methods of branch induction on growth of Hevea brasiliensis. The experiment was situated in Casa Branca-SP, Brazil, where growth regulators were sprayed on buddings of cultivar RRIM 600, 20 months after planting. The experiment was delineated in randon blocks with 4 repetitions with the following treatments: maleic hydrazide at 500, 750 and 1,000 ppm; chlormequat at 1,000, 1,500 and 2,000 ppm; daminozide at. 2,000, 3,000 and 4,000 ppm, and control. Tree girth, bark thickness, tree and crown height, crown length, crown width, branch number and concentration, branch slope, leaf area index, canopy light absorption and wind damage measurements were carried out at regular intervals, during experiment period. Correlation studies were made to explain the relationships between canopy characters and tree growth. Under the prevailing experimental conditions we may derive the following conclusions: branch induction by chemical methods may increase the tree girth, reducing immature period of rubber; injury to the terminal apex increases susceptibility to wind damage; the best treatment was daminozide at 2,000 ppm presenting 25% gain on tree girth compared to control; daminozide treatments enhanced tree girth without changing the wind damage susceptibility; chlormequat and maleic hydrazide treatments did not increase tree girth, and the latest reduced the crowns wind damage resistance; tree girth is positive correlated with tree height, crown length, crown width and bark thickness, and negative correlated with crotch height.
3

Efeito de métodos químicos de indução de copa no desenvolvimento da seringueira (Hevea brasiliensis Muell. Arg. cv. RRIM 600) / Effect of chemical methods of branch induction on growth of rubber tree (Hevea brasiliensis Muell. Arg. cv. RRIM 600)

Marcos Silveira Bernardes 26 March 1990 (has links)
Objetivando-se estudar o efeito de métodos químicos de indução de copa no desenvolvimento da seringueira, realizou-se experimento em condições de campo, em Casa Branca-SP, aplicando-se reguladores vegetais de crescimento em plantas enxertadas do cultivar RRIM 600 com 20 meses de idade, com 1,70 a 3,00 m de altura e último lançamento foliar maduro. O experimento foi delineado em Blocos ao Acaso com quatro repetições, utilizando-se como tratamentos, a aplicação de hidrazida maléica a 500, 750 e 1. 000 ppm, chlormequat a 1.000, 1.500 e 2.000 ppm, daminozide a 2.000, 3.000 e 4.000 ppm e a testemunha. Durante a realização do experimento efetuaram-se avaliações das seguintes variáveis: perímetro do tronco, espessura de casca, altura da árvore, altura do tronco, comprimento da copa, diâmetro da copa, número e porcentual de árvores ramificadas, número de ramos, concentração de ramos, ângulo de inserção dos ramos, índice de área foliar, coeficiente de absorção de radiação e danos por vento. Estudos de correlação foram feitos para analisar a influência das características da copa sobre o desenvolvimento das árvores. Nas condições em que foi conduzido o experimento, os resultados obtidos permitiam concluir que a indução de copa por métodos químicos pode incrementar o crescimento do perímetro do tronco, reduzindo o período de imaturidade da seringueira e que a injúria ou morte da gema apical aumentam a susceptibilidade das copas a danos por vento. O melhor tratamento foi com daminozide a 2.000 ppm, que apresentou ganho de 25% no perímetro relativo do tronco em relação à testemunha. Os tratamentos com daminozide apresentaram ganhos em perímetro do tronco sem comprometer a resistência das copas a danos por vento. Os tratamentos com chlormequat e hidraliza maléica não apresentaram ganhos em perímetro do tronco sendo que o último comprometeu a resistência das copas a danos por vento. O perímetro do tronco está positivamente correlacionado com a altura da árvore, o comprimento da copa, o diâmetro médio da copa e a espessura de casca; e negativamente relacionado com a altura do tronco. / This study describes the influences of chemical methods of branch induction on growth of Hevea brasiliensis. The experiment was situated in Casa Branca-SP, Brazil, where growth regulators were sprayed on buddings of cultivar RRIM 600, 20 months after planting. The experiment was delineated in randon blocks with 4 repetitions with the following treatments: maleic hydrazide at 500, 750 and 1,000 ppm; chlormequat at 1,000, 1,500 and 2,000 ppm; daminozide at. 2,000, 3,000 and 4,000 ppm, and control. Tree girth, bark thickness, tree and crown height, crown length, crown width, branch number and concentration, branch slope, leaf area index, canopy light absorption and wind damage measurements were carried out at regular intervals, during experiment period. Correlation studies were made to explain the relationships between canopy characters and tree growth. Under the prevailing experimental conditions we may derive the following conclusions: branch induction by chemical methods may increase the tree girth, reducing immature period of rubber; injury to the terminal apex increases susceptibility to wind damage; the best treatment was daminozide at 2,000 ppm presenting 25% gain on tree girth compared to control; daminozide treatments enhanced tree girth without changing the wind damage susceptibility; chlormequat and maleic hydrazide treatments did not increase tree girth, and the latest reduced the crowns wind damage resistance; tree girth is positive correlated with tree height, crown length, crown width and bark thickness, and negative correlated with crotch height.
4

Korrigering för slumpfel och metodeffekter i sambandsanalys av enkätdata med SQP 2.0 / Correction for method effects and random error in correlation analysis of survey data using SQP 2.0

Ljung, Björn January 2013 (has links)
Sambandsanalys av surveydata kompliceras av förekomsten av slumpfel och metodeffekter i de avgivna svaren. Dessa felkällor kan leda till betydande över- eller underskattning av sambanden mellan undersökta variabler, och riskerar att leda till felaktiga slutsatser. En sedan länge känd metod för att estimera och kontrollera för slumpfel och metodeffekter i enkätdata är den så kallade Multitrait Multimethod-metoden (MTMM). Nackdelen med MTMM-metoden är att den kräver att varje fråga som ska analyseras ställs minst tre gånger i samma enkät, vilket gör att ansatsen i praktiken oftast inte är möjlig att tillämpa. Sedan 2012 finns dock ett verktyg, SQP 2.0, som gör det möjligt att skatta slumpfel och metodeffekter i enkätdata utan att genomföra MTMM-experiment. Den här uppsatsen utvärderar prediktionerna från SQP 2.0 på en enkät om arbetslivsrelaterade frågor besvarad av svenska och brittiska respondenter. Programvarans prediktioner jämförs med resultat från MTMM-experiment, och effekten på sambandsanalysen av att tillämpa SQP-programvarans prediktioner av slumpfel och metodeffekter studeras. Slutsatserna från studien är att SQP 2.0 ger predicerade värden för slumpfel och metod-effekter som ligger nära de MTMM-estimerade i de flesta fall, men att betydande avvikelser också förekommer. Vidare konstateras att korrigering för slumpfel och metodeffekter har en betydande effekt på absolutvärdet av korrelationerna mellan variabler under de studerande förhållandena: korrelationerna i det studerade fallet ökar kraftigt efter justering. Korrelationernas relativa storlek förändras i mindre utsträckning, men för en enkät med mer varierade frågetyper kan också dessa påverkas kraftigt. / Correlation analysis of survey data is complicated by the presence of random errors and method effects in the answers given. These factors can lead to significant over- or underestimation of the correlations between variables. A well-established method for estimating and controlling for random error and method effects in survey data is the Multitrait-Multimethod (MTMM) approach. The disadvantage of this method is that it requires that each survey item to be analysed is asked multiple times in the same survey, making the approach hard to use in many practical situations. Since 2012 there is a tool available, SQP 2.0, to predict random errors and method effects in survey data without performing MTMM experiments. This paper evaluates the use of predictions from the SQP 2.0 software on the correlation analysis of a survey of work related matters answered by Swedish and British respondents. The software's predictions are compared with results from MTMM experiments, and the effect on the correlations of applying the SQP software's predictions of random errors and method effects are studied. The conclusion of the study is that SQP 2.0 gives predicted values for random error and method effects that are close to the MTMM-estimates in most cases, but that considerable deviations also occur. It is further concluded that controlling for random error and method effects has a significant effect on the absolute values of the correlations between variables in the studied cases: the correlations in the study increase substantially after adjustment. The relative sizes of the correlations between variables change to a lesser extent, but a questionnaire with more varied question types may have lead to different results in this respect.
5

Verformungen und Spannungen von Kegelradverzahnungen effizient berechnet

Schaefer, Steffen 06 September 2018 (has links)
Diese Arbeit beschäftigt sich mit speziellen Methoden zur näherungsweisen Berechnung der Zahnverformungen sowie -spannungen im Kontext der Zahnkontaktsimulation von Kegelrad- und Hypoidverzahnungen. Die näherungsweise Berechnung ermöglicht kurze Simulationszeiten und ist damit die Voraussetzung für eine effiziente Verzahnungsoptimierung. Die Anwendung neuer Fertigungsverfahren ermöglicht es, dabei geometrische Ausprägungen des Zahnprofils, Zahnfußes und der Flankentopologie zu realisieren, die mit den speziellen Methoden der näherungsweisen Berechnung bisher nicht oder nur unzureichend genau abgebildet werden können. In der vorliegenden Arbeit werden deshalb Näherungsmethoden entwickelt, mit denen z.B. auch Zahnprofile mit großer Asymmetrie, elliptischen Zahnfußkurven und logarithmischen Flankentopologiemodifikationen zuverlässig berechnet werden können.:1 Einleitung 2 Stand der Technik 2.1 Zahnkontaktsimulation 2.2 Die Verzahnungsgeometrie als Basis der Zahnkontaktsimulation 2.3 Methoden für die Zahnkontaktsimulation 2.3.1 Komplexe Methoden für die Verformungs- und Spannungsberechnung 2.3.2 Näherungsmethoden für die Verformungs- und Spannungsberechnung 2.4 Verzahnungen mit Sondermerkmalen 3 Zahnkontaktsimulation auf Basis der Einflusszahlenmethode 3.1 Herangehensweise bei der Betrachtung 3.2 Zerlegung der Verformungen und Spannungen in lineare und nicht lineare Anteile 3.3 Annahmen für die Formulierung des Zahnkontaktproblems 3.4 Bestimmung der potenziellen Zahnkontakte 3.5 Einflusszahlenmethode 3.6 Lösung des reibungsfreien Zahnkontaktproblems 3.7 Radkörpereinfluss 3.8 Wechselwirkung zwischen den Zähnen 4 Näherungsweise Biegeverformungsberechnung 4.1 Vereinfachung der Verzahnungsgeometrie 4.2 Berechnungsmethode 4.3 Allgemeine Verformungsabklingfunktion 4.3.1 Allgemeine Verformungsabklingfunktion für den unendlich langen Zahn 4.3.2 Allgemeine Abklingfunktion für den endlich langen Zahn 4.3.3 Berechnung der Zahnverformung unter Einzelast mittels FEM 4.3.4 Einfluss der Kraftangriffshöhe und der Profilform 4.3.5 Fehlerverhalten der allgemeinen Verformungsabklingfunktion 4.3.6 Einfluss der veränderlichen Normalschnittgeometrie 4.4 Bezugswert der Biegeverformung 4.4.1 Näherungslösung 4.4.2 Wahl einer Methode zur Verbesserung der Bezugswertberechnung 4.4.3 Auswahl des BEM-Verfahrens 4.4.4 Verfahrensbeschreibung für das BEM-Programm-Modul 4.4.5 Auswertung der BEM-Verformungen an der Stelle einer Streckenlast 4.4.6 Überprüfung des BEM-Programm-Moduls und Genauigkeitsbewertung 4.4.7 Effiziente Berechnung des BEM-Bezugswerts 4.5 Korrekturen für den Ersatzzahn 4.5.1 Stirnseitenunstetigkeit 4.5.2 Krümmungseigenschaften des Zahnes 4.6 Zahnberandungseinfluss 4.7 Berechnung der verbesserten Biegeverformungseinflusszahlen 5 Näherungsweise Berechnung der Kontaktverformung und -spannung 5.1 Vereinfachung der Kontaktgeometrie 5.2 Berechnung der Kontaktverformungseinflusszahl und der Kontaktspannung mit der ZZM 5.3 Komplexe Einflüsse auf die Kontaktverformung und -spannung 5.3.1 Wechselwirkungseinfluss 5.3.2 Zahnberandungseinflüsse 5.4 Erweiterung der ZZM zur Berücksichtigung von Kopfkanten 5.5 Verbesserte Berechnung der Kontaktverformungseinflusszahl und der Pressung 6 Näherungsweise Berechnung der Zahnfußspannung 6.1 Berechnungsmethode 6.2 Allgemeine Spannungsabklingfunktion 6.2.1 Allgemeine Spannungsabklingfunktion für den unendlich und endlich langen Zahn 6.2.2 Einfluss der Kraftangriffshöhe und der Profilform 6.2.3 Fehlerverhalten der allgemeinen Spannungsabklingfunktion 6.3 Bezugswert der Zahnfußspannung 6.4 Korrektur für den Ersatzzahn 6.4.1 Einfluss des Schrägungswinkels auf die Zahnbreitenlage des Zahnfußspannungsmaximums 6.4.2 Stirnseitenunstetigkeit 6.4.3 Einfluss der Zahnwindung auf die Zahnfußspannung 6.4.4 Einfluss der Flankenlinienkrümmung auf die Zahnfußspannung 6.5 Berechnung der Zahnfußspannung nach der verbesserten Methode 7 Verifikation und Validierung der verbesserten Berechnungsmethoden 7.1 Herangehensweise bei der Verifikation und Validierung 7.2 Verifikation 7.2.1 Allgemeine Vorbetrachtungen zur Genauigkeit 7.2.2 Sensibilitätsstudie 7.3 Validierung 7.3.1 Vorgehensweise bei der Validierung 7.3.2 Ausgewählte Messungen von Paul 7.3.3 Tragbildvergleich an Praxisverzahnungen 7.4 Konvergenzverhalten bei der Zahnkontaktsimulation mit BECAL-BEM 8 Zusammenfassung und Ausblick

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