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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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Electrical properties of multiple high-dose Si implantation in p-GaN
(1999-07-15)
Lai, WC
;
Yokoyama, M
;
Tsai, CC
;
Chang, CS
;
Guo, JD
This work performs Si ion implantation the electrical conductive type of the p-GaN film from p-type to n-type. Multiple implantation method is also used to form a uniform Si implanted region in the p-type GaN epitaxial layer. Implant energies for the multiple implantation are 40, 100, and 200 KeV. The implant dose is 5 x 10(15) cm(-2) for each implant energy. After implantation, the samples are annealed in a N-2 ambient for different annealing temperatures and annealing times. The activation efficiency reaches as high as 20% when annealing the sample at 1000 degrees C. The carrier activation energy is about 720 meV. The low activation energy indicates that the hopping process mechanism is the dominant mechanism for the activation of the Si implantation in p-GaN. Moreover, the rectifying I-V characteristic of the p-n GaN diode is also examined.
Electrical properties of the Si implantation in Mg doped p-GaN
(1999-11-01)
Lai, WC
;
Yokoyama, M
;
Tsai, CC
;
Chang, CS
;
Guo, JD
This work performs Si ion implantation to activate and convert the electrical conduction of p-GaN films from p-type to n-type. Multiple implantation method is used to form a uniform Si implanted region in the p-type GaN epitaxial layer. Implantation energies for the multiple implantation are 10, 100, and 200 keV. The implantation dose is 5 x 10(15) cm(2) for each implantation energy. After implantation, the samples were annealed in an N-2 ambient for different annealing temperatures and annealing times. The activation efficiency reaches as high as 20% when annealing the sample at 1000 degrees C,. The carrier activation energy is about 720 meV. The low activation energy indicates that the hopping process mechanism is the dominant mechanism for the activation of the Si implant in p-GaN. In addition, the rectifying I-V characteristic of the p-n GaN diode is also examined.
Developing an Internet Attitude Scale for high school students
(2001-08-01)
Tsai, CC
;
Lin, SSJ
;
Tsai, MJ
;
師資培育中心
;
Center of Teacher Education
Although educators over the past decade have developed various scales measuring students' computer attitudes, few of them have constructed scales specifically for attitudes towards the Internet. The purpose of this study was to develop an Internet attitude scale for high school students. Through both revising a previous scale proposed by Selwyn (1997) [Selwyn, N. (1997), Students' attitudes toward computers: validation of a computer attitude scale for 16-19 education. Computers & Education, 28(1), 35-41] and writing new items, this study developed an Internet Attitude Scale of 18 items, with the following four subscales: perceived usefulness, affection? perceived control, and behavior. This study also explored gender differences on the scale, and the relationship between Internet experience and students' responses on the scale. Research data gathered from 753 Taiwan high school students revealed that students of different gender and various Internet experiences did not show statistical differences on the perceptions toward the potential usefulness of the Internet subscale. However, male students tended to express more positive feeling, lower anxiety, and higher confidence toward using the Internet than female students. Students having more Internet experience tended to show similar positive attitudes than those of less experience. (C) 2001 Elsevier Science Ltd. All rights reserved.
Long-term photocapacitance decay behavior in undoped GaN
(2001-10-01)
Chung, HM
;
Pan, YC
;
Chuang, WC
;
Chen, NC
;
Tsai, CC
We have measured the dynamic response of the photocapacitance of a Schottky diode made of an undoped GaN epilayer grown by metalorganic vapor phase epitaxy. The measurements were performed after the suspension of a white light for a specified "waiting" time, t. The results indicate that the capacitance exhibits a logarithmic function of t from which a time constant of approximately 34.5 s and a cross-sectional area of less than 2.89 x 10(-27) cm(2) were retrieved. These are interpreted as the characteristic time and the cross-sectional area of electron capture by the traps associated with dislocations formed in the epifilm, respectively.
Development of cognitive structures and information processing strategies of elementary school students learning about biological reproduction
(2001-12-01)
Tsai, CC
;
Huang, CM
;
師資培育中心
;
Center of Teacher Education
The purpose of this study was to explore 28 Taiwanese fifth graders' development of knowledge on biological reproduction. The students received three weeks of instruction about biological reproduction and were interviewed to determine their cognitive structures. The interviews were conducted three times, at weekly intervals throughout the instruction, and an additional interview was conducted two months after the instruction. The interview data were analysed through a flow map method to show cognitive structure, and the students' information processing strategies, derived from an analysis of the flow map data, were also explored. The results suggest that there are three stages of cognitive structure development. In the first stage, categorised as 'knowledge development', both the extent of knowledge and the richness of networking of ideas increase. In the second stage, categorised as 'knowledge extension', only the amount of knowledge continues to increase. In the final stage, called 'knowledge refinement', the amount of knowledge recalled decreases, while the richness in networking of ideas remains stable. At the same time, the use of higher-order information processing modes (e.g., narrative containing statements inferring and explaining) increases dramatically. This implies that the rich connections between concepts and the use of higher-order information processing strategies may facilitate maturation of connected knowledge in memory.
Developing science activities through a networked peer assessment system
(2002-01-01)
Tsai, CC
;
Lin, SSJ
;
Yuan, SM
;
教育研究所
;
師資培育中心
This paper described the use of a networked peer assessment system to facilitate the development of inquiry-oriented activities for secondary science education. Twenty-four preservice teachers in Taiwan participated in this study and experienced a three-round peer assessment for developing science activities. The findings suggested that teachers tended to develop more creative, theoretically relevant, and practical science activities as a result of the networked peer assessment. However, the peers' evaluations were not highly consistent with experts' (e.g., university professors) grades. This study also revealed that students who offered detailed and constructive comments on reviewing and criticizing other peers' work might help them improve their own work, especially in the beginning stage of revising their original work. (C) 2002 Elsevier Science Ltd. All rights reserved.
Low-etch-pit-density GaN substrates by regrowth on free-standing GaN films
(2002-05-20)
Tsai, CC
;
Chang, CS
;
Chen, TY
;
光電工程學系
;
Department of Photonics
In this study, GaN substrates with low-density etch pits were obtained by regrowth on free-standing GaN films (two steps) by hydride vapor-phase epitaxy (HVPE). The etch-pit density was lower than 4x10(4) cm(-2) by atomic-force microscopy. The density is significantly lower than that of the HVPE-grown (one-step) GaN films (HVPE GaN), using sapphire as a substrate. The optical and electrical properties of the two-step HVPE-grown GaN substrates are superior to those of HVPE GaN. Temperature-dependent photoluminescence measurements reveal that thermal quenching behavior of the 2.9 eV band is possibly attributed to a shallow acceptor level at about 118+/-5 meV above the valence band. (C) 2002 American Institute of Physics.
Exploring students' cognitive structures in learning science: a review of relevant methods
(2002-09-01)
Tsai, CC
;
Huang, CM
;
教育研究所
;
Institute of Education
Understanding how people think and how people organise knowledge are always major concerns for educational researchers. Hence, educators have developed various ways of representing learners' 'cognitive structures'. This article provides a review of the use of five methods of representing cognitive structures-free word association, controlled word association, tree construction, concept map and flow map. Through comparing the types of analyses that are generated from these cognitive structure representation methods, this paper discusses the applications, as well as the limitations, among these methods.
Novel low-temperature polycrystalline-silicon power devices with very-low on-resistance using excimer laser-crystallization
(2004)
Cheng, HC
;
Chang, FL
;
Lin, MJ
;
Tsai, CC
;
Liaw, CW
Low-temperature poly-Si lateral double-diffused metal oxide semiconductor (LTPS LDMOS) with high voltage and very low on-resistance has been achieved using excimer laser crystallization at 400 degreesC substrate heating for the first time. The ON/OFF current ratios were 2.96 x 10(5) and 6.72 x 10(6) while operating at V-ds = 0.1 and 10 V, respectively. The maximum current limit was up to 10 mA and maximum power limit could be enhanced over 1 W at V-ds = 90 V and V-gs = 20 V. The R-on,R-sp with dimensions of W/L-ch = 600 mum/12 mum could be significantly decreased 6.67 x 10(2) times in magnitude as compared with conventional offset drain thin-film-transistors. (C) 2004 The Electrochemical Society.
Optimal design of metal seated ball valve mechanism
(2004-02-01)
Tsai, CC
;
Chang, CY
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
A seat is a device mounted in a valve. When a ball valve is in the closed position, the seat seals the ball valve. The seat is usually made from plastic or rubber, so it can be damaged by high pressure or high temperature environments. The objective of this study is to design a new metal seat mechanism for the ball valve. To design a new metal seat, there are four steps to the engineering design process: planning and clarifying the task; conceptual design; embodiment design; detailed design. Some useful tools from the Quality Function Deployment (QFD) technique and the Theory of Inventive Problem Solving (TRIZ) method are used in this design process. The design optimization is completed by the ANSYS package. The novel design of the metal-seated ball valve provides low torque, low wear and long life.

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