Browsing by Issue Date, starting with "2011-05-23"

Now showing 1 - 20 of 41306

Investigation of efficiency droop for InGaN-based UV light-emitting diodes with InAlGaN barrier
(2011-05-23)
Tu, Po-Min
;
Chang, Chun-Yen
;
Huang, Shih-Cheng
;
Chiu, Ching-Hsueh
;
Chang, Jet-Rung
The efficiency droop in InGaN-based UV light emitting device (LED) with AlGaN and InAlGaN barrier is investigated. Electroluminescence results indicate that the light performance of quaternary LEDs can be enhanced by 25% and 55% at 350 mA and 1000 mA, respectively. Furthermore, simulations show that quaternary LEDs exhibit 62% higher radiative recombination rate and low efficiency degradation of 13% at a high injection current. We attribute this improvement to increasing of carrier concentration and uniform redistribution of carriers. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3591967]
Single-molecule refrigerators: Substitution and gate effects
(2011-05-23)
Liu, Yu-Shen
;
Chen, Yu-Chang
;
電子物理學系
;
Department of Electrophysics
Using a first-principles approach, we investigate the quantum cooling effects in single-molecule junctions. In comparison with the unsubstituted butanethiol single-molecule junction as a refrigerator, the amino-substituted butanethiol single-molecule junction shows significant enhancement in the coefficient of performance (COP). The enhancement is attributed to the appearance of new states in the neighborhood of chemical potentials due to amino substitution. The COP of butanethiol refrigerator can be improved further by the gate voltages. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3593379]
Generation of optical vortex array with transformation of standing-wave Laguerre-Gaussian mode
(2011-05-23)
Lin, Y. C.
;
Lu, T. H.
;
Huang, K. F.
;
Chen, Y. F.
;
電子物理學系
We develop a novel method of creating optical vortex array by the conversion of a standing-wave Laguerre-Gaussian (LG) mode. Theoretically, by employing the transformational relation, the standing-wave LG mode is verified to be transformed from a pair of crisscrossed Hermite-Gaussian (HG) modes, embedded with optical vortex array, consists of a TEM(n,m) mode and a TEM(m,n) mode. Due to close correspondence between the transformational relation and the mode conversion of astigmatic lenses, we successfully generate the optical vortex array by transforming a standing-wave LG mode into the crisscrossed HG modes via a pi/2 cylindrical lens mode converter. The investigation may provide useful insight in the study of the vortex light beam and its further applications. (C) 2011 Optical Society of America
Fabrication of an asymmetric Bragg coupler-based polymeric filter with a single-grating waveguide
(2011-05-23)
Chuang, Wei-Ching
;
Huang, Yu-Tai
;
Lin, Hui-Chi
;
Lee, An-Chen
;
機械工程學系
In this work, a first report on fabricating an asymmetric Bragg coupler-based filter on polymeric waveguides without input-waveguide grating was revealed. The fabrication process we developed was using holographic interference techniques, capillary effect, soft lithography, and micro molding process. The transmission dip of about. -9.2 dB and the 3 dB transmission bandwidth of about 0.125 nm were obtained from a filter. (C) 2011 Optical Society of America
Phase noise suppression of optical OFDM signals in 60-GHz RoF transmission system
(2011-05-23)
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Chao, Ming-I
;
光電系統研究所
;
Institute of Photonic System
The dispersion-induced phase noise (PN) in an OFDM RoF system at 60 GHz leads to not only subcarrier phase rotation (PRT) but also intercarrier interference (ICI) to severely degrade the transmission performance, when a commercial cost-effective DFB laser with the linewidth of several MHz is adopted. To mitigate both PRT and ICI, a post PN suppression algorithm is proposed, and it does not require any bandwidth-consuming pilot tone. For a 25.78-Gbps 16-QAM OFDM RoF signal using the laser with 1.8-MHz linewidth, employing the algorithm can extend the maximum transmission distance which corresponds to 3-dBm power penalty at the BER of 2 x 10 (3) from 75 km to more than 115 km, i.e. 50% increment of transmission distance. (C) 2011 Optical Society of America
Analysis of the carrier-suppressed single-sideband modulators used to mitigate Rayleigh backscattering in carrier-distributed PON
(2011-05-23)
Chow, C. W.
;
Wang, C. H.
;
Yeh, C. H.
;
Chi, S.
;
光電工程學系
By using the carrier-suppressed single-sideband (CS-SSB) modulation, the Rayleigh backscattering (RB) experienced by the uplink signal can be effectively mitigated due to the reduction of the spectral overlap between the uplink signal and the distributed optical carrier. In this work, we first introduce the theoretical analysis of the CS-SSB generation using the dual-drive MZM (DD-MZM)-based and a dual-parallel MZM (DP-MZM)-based optical networking units (ONUs). Due to the different modulation mechanisms of the two CS-SSB modulations, the frequency components of the generated CS-SSB signals are also different. The transmission performance and the dispersion tolerance of the uplink signals generated by the two CS-SSB modulators are also analyzed and discussed. (C) 2011 Optical Society of America
Three-dimensional microprobe array
(2011-05-24)
Chiou Jin-Chern
;
Chang Chih-Wei
The present invention discloses a three-dimensional microprobe array assembly structure, wherein spacers are used in assembling edge-type microprobe arrays to form a three-dimensional structure, and the spacers reveal conductive pads of the edge-type microprobe arrays to benefit wire bonding. The present invention detects depths and angles and thus increases detection reliability. Besides, in the present invention, the related IC is integrated with the spacer to achieve circuit integration and reduce cost.
永恆之美：三島由紀夫《金閣寺》
(2011-05-25)
梁蘊嫻
;
開放教育推動中心
;
Open Education Office
課程首頁本課程是由交通大學新文藝復興閱讀計畫提供。 96 年 8 月當各大學紛紛摩拳擦掌準備迎接新生的同時，交通大學校長吳重雨則因為一則來自於七月份泰晤士報，有關於英國首相布朗公布其夏日讀書清單的新聞中，看到了他對知識的尊重。在這同時，吳重雨校長也思考著，要如何為學生準備追求知識的環境和激發他們對知識的尊重與喜愛。台積電張忠謀董事長曾陳述他 18 歲進入哈佛那一年，博覽文史哲理工經典群籍，至此奠定了他求知的基礎，並借海明威名言，將其改為「哈佛這一年為人生可帶走的盛宴。」吳重雨校長以張董事長的學習為借鏡，認為學生固然能藉由自我閱讀的方式學習到豐沛的知識，但透過名人、大師親臨現場地介紹經典書籍，更能加深學子們對於書籍的認識與興趣，這也是「新文藝復興閱讀計劃」 ( 以下簡稱 : 「經典名著選讀」 ) 活動展開籌劃的緣由。於是，吳重雨校長便積極敦請「交大通識教育委員會」，接手籌備本計劃的相關活動，而該中心也成為實際施行本計畫的策動、開課以及認證單位。至此，期許交大學子藉由閱讀、聽講來提昇人文素養、開拓視野的「新文藝復興閱讀計劃」，就此展開。
Substituent-induced delocalization effects on hydrogen-bonding interaction in poly(N-phenyl methacrylamide) derivatives
(2011-05-26)
Kuo, Shiao-Wei
;
Lin, Chien-Ting
;
Chen, Jem-Kun
;
Ko, Fu-Hsiang
;
Chang, Feng-Chih
Within small molecules, the hydrogen-bonding behaviors affected by delocalization have been studied thoroughly, but rare publication in macromolecules. Therefore, three poly(N-phenyl methacrylamide)s, poly(N-phenyl methacrylamide) (PNPAA), poly(N-4-methoxyphenyl methacrylamide) (PMPMA) and poly(N-4-bromophenyl methacrylamide) (PBPMA), with different inductive substitution at para position of benzene ring are prepared to investigate the substituent-induced delocalization effects on the hydrogen-bonding interaction behaviors. In this study, the variable-temperature FTIR spectrum is used as tool to study the self- and inter-association hydrogen-bonding interaction. FTIR analyses could provide evidences that there is relatively stronger inter-associative hydrogen bonding in poly(N-4-bromophenyl methacrylamide)/P4VP blends. High resolution (13)C CP/MAS solid-state NMR analyses indicate that the spin-lattice relaxation time (T) in all PBPMA blends are homogeneous on the scale at which spin-diffusion occurs within the time T(1)rho(H), also due to the enhancement by substituent inductive delocalization. (C) 2011 Elsevier Ltd. All rights reserved.
Effects on Oxidation Waves of Conjugated Polymers by Studying Photoluminescence Quenching and Electrogenerated Chemiluminescence
(2011-05-26)
Chen, Jiun-Tai
;
Chang, Ya-Lan
;
Fabian, Omar
;
Guo, Song
;
Lackowski, William M.
We study the electrochemical oxidation waves of conjugated polymers by examining photoluminescence (PL) quenching and electrogenerated chemiluminescence (ECL) of poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT). Different factors such as the anion concentration, the anion size, the electrochemical potential, and the coreactant concentration are investigated for their effects on the behavior of the oxidation waves. Our results show that the wave speeds of PL quenching or ECL can be increased by increasing the anion concentration, decreasing the anion size, or increasing the electrochemical potentials. In addition, the intensity of ECL can be controlled by the coreactant concentration. The transition from pinned to free ECL waves is also studied when an intermediate coreactant concentration is used. These results provide useful insights for understanding the electrochemical oxidation wave phenomenon.
危險！經國大橋如虎口
(2011-05-29)
王升含
;
Department of Communication and Technology
;
傳播與科技學系
經國大橋是連接新竹與竹北的重要通路，也是許多人每天必經的路段。此路段交通壅塞、線道過於複雜等問題，仍有待新竹縣市政府合力解決。
什麼是藝術？
(2011-05-29)
林書羽
;
Department of Communication and Technology
;
傳播與科技學系
「台灣民眾美感素養發展與藝術教育改進之研究」報告中提到，政府耗費大量財力於藝術相關設施建構和活動推展，但是民眾的參與度並不高，顯示藝術教養未能普及與深入人民生活。由此可見，藝術教育不單單只是美術館的責任，政府必須從教育制度上，建立完善的藝術教育，才能補足民眾「美感」的缺乏。
同志教育　行不行
(2011-05-29)
陳蕾
;
Department of Communication and Technology
;
傳播與科技學系
教育部宣布自民國一百年九月開始將把同性戀教育納入國中、小的性別教育當中。而聽聞教育部此政策的發布，引起了部分老師以及家長的反對，並在網路上貼文聯署，以「不是反同性戀團體」的聲明為基礎，反對在正值青春期的學習階段，納入同志議題，以免混淆孩子對性別的認知。
不識字　煙波釣叟
(2011-05-29)
沈祐平
;
Department of Communication and Technology
;
傳播與科技學系
釣客在水源區岸邊釣魚。忽然馬達聲大作，管理局人員乘著高耗油的氣艇前來，道：「你在這裡釣魚會污染水源，不要給遊客看見，去馬路看不見的地方釣。」
多元視角勾勒魅力台北
(2011-05-29)
蔡妙鈴
;
Department of Communication and Technology
;
傳播與科技學系
讓生活也成為一種美學，是近年來越來越流行的生活方式，而生活在台灣的首善之都台北，要如何成為一門學問呢? 實踐大學建築設計系希望透過一系列的演講，喚起生活在台北的人對於這座城市的迷戀！
螢幕裡的城市　電影城市之美
(2011-05-29)
鄭家宜
;
Department of Communication and Technology
;
傳播與科技學系
從電影中看到城市之美，讓心在城市間漫遊，讓自己愛上這整座城市。
拒絕老化傳統歌仔新創意
(2011-05-29)
李庭蕙
;
Department of Communication and Technology
;
傳播與科技學系
「我身騎白馬，走三關～」聽這首耳熟能詳的曲調，立刻能聯想到傳統戲曲─歌仔戲，可見音樂在歌仔戲中扮演相當重要的角色。不過，歌仔戲曲調並非一層不變，透過不斷的嘗試與變化，從傳統與創新激盪出的新思維，企圖吸引更多觀眾群。
媒說之言整形應不應該
(2011-05-29)
徐志玲
;
Department of Communication and Technology
;
傳播與科技學系
媒體給了人們太多關於美的訊息，讓人們相信人是可以借由後天的動作來變得更美，像是整形，但是有誰知道這又何嘗不是一種商業炒弄的行為呢?
糧食危機向誰報告？
(2011-05-29)
張宇翔
;
Department of Communication and Technology
;
傳播與科技學系
國立清華大學的退休教授彭明輝，將豐富的統計資料與國外農業經驗相整合，寫成了《糧食危機關鍵報告：台灣觀察》一書，對台灣農業未來的發展提出一個具整體性的見解。有別於坊間談論農業的書籍，在主題上多著眼於作物栽植的技巧、園藝的布置、設計，以及文學性的農村文化記錄，《糧食危機關鍵報告：台灣觀察》將台灣的農業問題放到全球糧食危機的脈絡底下進行探討，宏觀的針對台灣偏低的糧食自給率與扼殺農業的政策提出批評。
Suming舒米恩　唱所欲言
(2011-05-29)
陳文玲
;
Department of Communication and Technology
;
傳播與科技學系
圖騰樂團主唱Suming以阿美族語創作個人專輯，憑藉著《Suming舒米恩首張個人創作專輯》，入圍第二十二屆金曲獎最佳原住民專輯獎、最佳原住民語歌手獎、最佳專輯製作人獎。從他的歌詞、旋律創作中看到原鄉的樸實風貌，也看到音樂的本質——唱出自我。