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THz Time-Domain Spectroscopy Studies of the Optical Constants of the Nematic Liquid Crystal 5CB
No full text[[abstract]]The optical constants of a nematic liquid crystal, 4'-n-pentyl-4-cyanobiphenyl (5CB), in the frequency range 0.3-1.4 THz were determined by terahertz (THz) time-domain spectroscopy. The real parts of the extraordinary refractive index n(e) and the ordinary refractive index n(o) of 5CB varied from 1.74 to 2.04 and from 1.59 to 1.83, respectively. Liquid-crystal 5CB exhibits a relatively small absorption loss in this frequency range. The birefringence of 5CB was found to be as large as 0.21. The experimental results indicate that liquid-crystal 5CB is potentially useful for device applications in the THz frequency range[[fileno]]2010144010097[[department]]物理
A wireless audio and burst communication link with directly modulated THz photoconductive antenna
No full text[[abstract]]We demonstrate transmission of audio and burst signals through a prototype THz analog communication link employing laser-gated low-temperature-grown GaAs dipole antenna as THz emitter and receiver. The transmission distance is about 100 cm. By using a direct voltage modulation format, we successfully demodulated a burst signal with a rising time of 41 mu s. The corresponding modulating bandwidth achieved was 23 kHz in this first experiment. Noise analysis reveals a 10% power fluctuation in the received signal with on-off extinction ratio of greater than 1000. The transmission of a six-channel analog and burst audio signal with least distortion is also demonstrated. We further demonstrate the fidelity of the transmission of a melody through the THz link with and without any amplification.[[fileno]]2010144010127[[department]]物理
Bandwidth enhancement phenomenon of a high-speed GaAs-AlGaAs based unitraveling carrier photodiode with an optimally designed absorption layer at an 830 nm wavelength
Get PDF[[abstract]]In this letter, the authors introduce a GaAs/AlGaAs based unitraveling carrier photodiode (UTC-PD) for a wavelength of around 830 nm. There is significant bias- and output-current-dependent bandwidth enhancement phenomena observed with this device. According to their microwave and optical-to-electrical measurement results, such distinct phenomena can occur under a much lower current density (0.3 mA/mu m(2) vs 0.05 mA/mu m(2)) than previously reported for InP-InGaAs UTC-PDs. This can be attributed to the self-induced field in the absorption region, made possible due to the optimized p-type doping profile.[[fileno]]2010144010135[[department]]物理
Electrically Controlled Liquid Crystal Phase Grating for Terahertz Waves
No full text[[abstract]]This work demonstrates the feasibility of electrically controlled liquid-crystal-based phase grating for manipulating the terahertz (THz) waves. This device can be utilized as a THz beam splitter and the beam splitting ratio of the zeroth- to the first-order diffractions can be tuned from 10 : 1 to 1: 1.[[fileno]]2010144010175[[department]]物理
Nonvolatile Memory with Switching Interfacial Polar Structures of Nano Si-in-Mesoporous Silica
Get PDF[[abstract]]We show an artificially engineered electret with Si nanocrystals embedded in mesoporous silica for nonvolatile memory. We attribute the polarization to from polar layers lying at the interfaces between one-side bonded Si nanocrystals and mesoporous silica matrix. Under external field, the Si nanocrystals could be displaced in the porechannels causing displaced charge distributions and therefore a field-controllable electric polarization. Nonvolatile memory is demonstrated with a metal-oxide-semiconductor field-effect transistor.[[fileno]]2010144010181[[department]]物理
A Study on Modified Historical Value-Based Approach for Test Case Prioritization during Software Development
No full text[[abstract]]Regression testing is a frequently executed maintenance process used to revalidate a modified software system. However, the test suite size of regression testing may grow significantly with new functionality over time. Thus it would take a lot of time to perform regression testing over and over again. To reduce the cost of regression testing, software testers may prioritize their test cases according to some measurements and run more important test cases within existing time constraints. However, most existing prioritization techniques regard regression testing as independent process. They didn’t take any advantage from past execution experience. Some important test cases would be executed repeatedly whereas some test cases would never be executed. To overcome this problem Kim and Porter proposed a history-based prioritization technique that can execute test cases based on the history execution profile. Unfortunately this approach only takes into account the history execution data without pertain some other important criteria in regression testing prioritization. In this thesis, we propose a method to improve the performance of the history-based prioritization technique for resource constraint environments. By investigating other important measurements and criteria, we incorporated the coverage information into the proposed method so that it will consider not only the history data but also the power of code-based prioritization techniques. Moreover, we analysis the relationship of the ratio of test case selected and executed with the fault detection ability of our proposed method to find out what is the appropriate test case selection ratio for regression testing.[[fileno]]2030240030085[[department]]資訊工程學
書海眺望：大獎賽與雙層漢堡：讀Teaching History 92 (1998) pp.6~15
No full text[[abstract]]大獎賽（Grand Prix）指一個國家最重要的賽車、賽馬等賽事，它與雙層漢堡又有什麼關係？它們之間沒有關係，兩者都是用來作為譬喻歷史教學中所設計的模式而已。這個教學設計的對象為七年級生，11歲或12歲，內容是英國史中的約翰王（King John），授課時間八個星期。[[fileno]]204_JA04_2006_n17_p14
影視史學與歷史學科能力──簡介「文華高中影視史學課程」
Get PDF[[abstract]]本文將簡介文華高中自～ 年於高一、高二、高三課程中所實施「歷史影片」教學內容與筆者在文華高中高一十三班結合「史料」、「歷史影片」的教學實驗。[[fileno]]204_JA04_2007_n18_p10
[[alternative]]From the Editor
No full text[[abstract]]學生應該是教學活動的主體，理想的教學應以學生為中心，這是當前從事教育者多半能朗朗上口的理念，也是老師們很想達成的目標。然而，如果我們對於學生學習上的初始條件不夠了解，不清楚他們坐在課堂上時，心中帶著哪些既有的觀念，存有哪些學習上待跳脫的概念障礙，則侈言進行學生本位的教學活動可以說基本上是空談。[[fileno]]204_JA04_2008_n19_p13
[[alternative]]How to Teach the Whole General History of Sui and Tang Dynasties in Only One 50-minuite Class: a Demonstration of History Teaching through Selected Materials and Questions
No full text[[abstract]]高雄中學的戴麗桑老師替我安排一個課時，指定講隋唐的歷史，就是給了我一個實驗的機會，十分寶貴。民國97年5月9日上午10時10分到11時，在高雄中學的這一堂課，就是一次課堂教學的實驗。[[fileno]]204_JA04_2009_n20_p