Browsing by Issue Date, starting with "2009-04-06"

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Photonic crystal heteroslab-edge microcavity with high quality factor surface mode for index sensing
(2009-04-06)
Lu, Tsan-Wen
;
Hsiao, Yi-Hua
;
Ho, Wei-De
;
Lee, Po-Tsung
;
光電工程學系
In this report, we propose a photonic crystal heteroslab-edge microcavity design for optical index sensing, where the high quality (Q) surface mode is confined by mode-gap effect. By optimizing the barrier region of the microcavity, high Q factor of 6.6x10(5) is obtained in simulations. Lasing actions with high Q factor and low threshold of 6400 and 0.55 mW are obtained from the real devices. High index sensing response and small detectable index variation of 625 nm per refractive index unit and 3.6x10(-6) are obtained in simulations.
A polarizer-free three step switch using distinct dye-doped liquid crystal gels
(2009-04-06)
Lin, Yi-Hsin
;
Yang, Chih-Ming
;
光電工程學系
;
Department of Photonics
A polarizer-free three step switch using distinct dye-doped liquid crystal (LC) gels is demonstrated in reflective mode. By controlling the spatial distribution of the density of polymer networks, the distinct dye-doped LC gels can produce multiple states: bright, dark, and information states without patterning indium-tin oxide. The multiple states are generated by adapting different polymer network density in different display regions. The dark state is due to the combination of scattering and absorption. It can be further extended for a four step switch. The potential applications are decorative displays, electrically tunable iris, and electrically tunable low pass or high pass filter.
SiGe nanorings by ultrahigh vacuum chemical vapor deposition
(2009-04-06)
Lee, C. -H.
;
Shen, Y. -Y.
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Liu, C. W.
;
Lee, S. W.
;
Lin, B. -H.
Formation of SiGe nanorings from Si capped Si(0.1)Ge(0.9) quantum dots (QDs) grown at 500 degrees C by ultrahigh vacuum chemical vapor deposition was investigated. SiGe nanorings have average diameter, width, and depth of 185, 30, and 9 nm, respectively. Based on both Raman and x-ray diffraction results, the formation of SiGe nanorings can be attributed to Ge outdiffusion from central SiGe QDs during in situ annealing. Moreover, the depth of SiGe nanorings can be controlled by Si cap thickness. The Si cap is essential for nanorings formation.
High output power density from GaN-based two-dimensional nanorod light-emitting diode arrays
(2009-04-06)
Lee, Ya-Ju
;
Lin, Shawn-Yu
;
Chiu, Ching-Hua
;
Lu, Tien-Chang
;
Kuo, Hao-Chung
Here we propose and realize a scheme for making a direct contact to a two-dimensional nanorod light-emitting diode (LED) array using the oblique-angle deposition approach. And, more importantly, we demonstrate highly efficient electrical carrier injection into the nanorods. As a result, we show that at a 20 mA dc current injection, the light output power density of our nanorod LED array is 3700 mW cm(-2). More general, this contact scheme will pave the ways for making direct contacts to other kinds of nanoscale optoelectronic devices.
Nonadaptive algorithms for threshold group testing
(2009-04-06)
Chen, Hong-Bin
;
Fu, Hung-Lin
;
應用數學系
;
Department of Applied Mathematics
Threshold group testing first proposed by Damaschke is a generalization of classic group testing. Specifically, a group test is positive (negative) if it contains at least u (at most 1) positives, and if the number of positives is between I and u, the test outcome is arbitrary. Although sequential group testing algorithms have been proposed, it is unknown whether an efficient nonadaptive algorithm exists. In this paper, we give an affirmative answer to this problem by providing efficient nonadaptive algorithms for the threshold model. The key observation is that disjunct matrices, a standard tool for group testing designs, also work in this threshold model. This paper improves and extends previous results in three ways: 1. The algorithms we propose work in one stage, which saves time for testing. 2. The test complexity is lower than previous results, at least for the number of elements which need to be tested is sufficiently large. 3. A limited number of erroneous test outcomes are allowed. (C) 2008 Elsevier B.V. All rights reserved.
On the spanning fan-connectivity of graphs
(2009-04-06)
Lin, Cheng-Kuan
;
Tan, Jimmy J. M.
;
Hsu, D. Frank
;
Hsu, Lih-Hsing
;
資訊工程學系
Let G be a graph. The connectivity of G, kappa(G), is the maximum integer k such that there exists a k-container between any two different vertices. A k-container of G between u and v, C(k)(u, v), is a set of k-internally-disjoint paths between u and v. A spanning container is a container that spans V(G). A graph G is k*-connected if there exists a spanning k-container between any two different vertices. The spanning connectivity of G, kappa*(G), is the maximum integer k such that G is w*-connected for 1 <= w <= k if G is 1*-connected. Let x be a vertex in G and let U = {y(1), y(2,) . . . , y(d)} be a subset of V(G) where x is not in U. A spanning k - (x, U)-fan, F(k)(x, U), is a set of internally-disjoint paths {P(1), P(2,) . . . , P(k)} such that P(i) is a path connecting x to y(i) for 1 <= i <= k and U(i=1)(k) V(P(i)) = V(G). A graph G is k*-fan-connected (or k(f)*-connected) if there exists a spanning Fk(x, U)-fan for every choice of x and U with vertical bar U vertical bar = k and x is not an element of U. The spanning fan-connectivity of a graph G, kappa(f)*(G), is defined as the largest integer k such that G is w(f)*-connected for 1 <= w <= k if G is 1(f)*-connected. In this paper, some relationship between kappa(G), kappa*(C), and kappa(f)*(G) are discussed. Moreover, some sufficient conditions for a graph to be k(f)*-connected are presented. Furthermore, we introduce the concept of a spanning pipeline-connectivity and discuss some sufficient conditions for a graph to be k*-pipeline-connected. Published by Elsevier B.V.
交大e-News第045期
(2009-04-06)
Secretariat
;
國立交通大學秘書室
Scheduling method for supporting quality of service (QoS) in wireless local area network (WLAN)
(2009-04-07)
Huang
;
Ching Yao
;
Fan
;
Yu Long
A method for polling of stations in a Wireless Local Area Network (WLAN), including the steps of: obtaining Quality of Service (QoS) information related to the stations; assigning two timers to each WLAN service requiring QoS guarantee, one for uplink transmission and the other for downlink transmission; starting a Controlled Access Period (CAP) when a minimum timer Tm is below the threshold Tthr; polling the station with the minimum timer; updating the minimum timer after a polling message is sent; quitting CAP and permitting the resource contention if the minimum timer Tm is larger than the threshold Tthr.
サスペンデッドナノワイヤチャネルを有するトランジスタ構造とその製造方法
(2009-04-09)
林鴻志
;
蘇俊榮
;
徐行徽
;
李冠樟
【課題】サスペンデッドナノワイヤチャネルを有するトランジスタ構造とその製造方法を提供する。【解決手段】サスペンデッドナノワイヤチャネルを有するトランジスタ構造とその製造方法は、基板と、基板上に位置するサイドゲートと、基板とサイドゲート上を被覆する誘電層と、サイドゲートの側辺に位置し、誘電層との間に気隙を有するサスペンデッドナノワイヤチャネルと、誘電層上に設置され、サスペンデッドナノワイヤチャネルの両端に分設されるソース電極とドレイン電極と、からなる。サイドゲートの静電力のサスペンデッドナノワイヤチャネルに対する吸着と分離により、等価サイドゲートの誘電層厚さを快速に変化させ、素子がスイッチ状態上で快速に切り換わる、或いは、チャネルの初期電圧を変化させる。【選択図】図１
Multirate synthesis of reverberators using subband filtering
(2009-04-10)
Bai, Mingsian R.
;
Ou, Kwuen-Yieng
;
Zeung, Pingshun
;
機械工程學系
;
Department of Mechanical Engineering
As an important element in three-dimensional audio reproduction, reverberators serve to enhance the sense of spaciousness by synthesizing the sound reflections and reverberations pertaining to a particular listening environment. However, direct implementation of room responses generally proves impractical due to the extreme complexity of system dynamics. To overcome the difficulties encountered in long convolutions, an efficient multirate signal processing technique is proposed in this paper on the basis of subband filtering scheme. In this method, the frequency dependent property of reverberation time is incorporated into the design procedure. Further simplification follows from the synthesized infinite impulse response (IIR) implementation for each subband. Specifically, the regular IIR filter, the cascaded comb filters and nested allpass filters, and the cascaded comb filter and an FIR filter are developed to implement the subband filters. Genetic algorithms (GA) are employed to optimize the parameters of reverberators. Subjective listening tests are carried out to assess the performance of the proposed techniques. The results demonstrate that the implemented multirate reverberators are capable of delivering natural sensation of room reverberations, as compared to direct measurement. (C) 2008 Elsevier Ltd. All rights reserved.
Design and implementation of a hybrid sub-band acoustic echo canceller (AEC)
(2009-04-10)
Bai, Mingsian R.
;
Yang, Cheng-Ken
;
Hur, Ker-Nan
;
機械工程學系
;
Department of Mechanical Engineering
An efficient method is presented for implementing an acoustic echo canceller (AEC) that makes use of hybrid sub-band approach. The hybrid system is comprised of a fixed processor and an adaptive filter in each sub-band. The AEC aims at reducing the echo resulting from the acoustic feedback in loudspeaker-endosure-microphone (LEM) systems such as teleconferencing and hands-free systems. In order to cancel the acoustical echo efficiently, various processing architectures including fixed filters, hybrid processors, and sub-band structure are investigated. A double-talk detector is incorporated into the proposed AEC to prevent the adaptive filter from diverging in double-talk situations. A de-correlation filter is also used alongside sub-band processing in order to enhance the performance and efficiency of AEC. All algorithms are implemented and verified on the platform of a fixed-point digital signal processor (DSP). The AECs are evaluated in terms of cancellation performance and computation complexity. In addition, listening tests are conducted to assess the subjective performance of the AECs. From the results, the proposed hybrid sub-band AEC was found to be the most effective among all methods in terms of echo reduction and timbral quality. (C) 2008 Elsevier Ltd. All rights reserved.
串聯式車牌辨識系統
(2009-04-11)
王舜正
;
李錫堅
本發明提供一種串聯式車牌辦識系統,其係藉由車牌字元區域偵測模組接收一影像,並搜尋出影像中每一個近似車牌範圍,接著找出每一個近似車牌範圍中所有具有連續相同像素之序列,並將這些序列經過塗抹、濾除與連接區塊擷取處理後,取得每一個近似車牌範圍的車牌字元區域影像,而在驗證後輸出已確認之車牌字元區域影像,再來將已確認之車牌字元區域影像送入車牌字元切割與辨識模組中,以取得所有獨立字元影像,並在獨立字元影像經過字元驗證辨識後,獲得所有車牌字元資訊。因此,本發明具有高準確率、快速即時運算及具有學習能力之優點。
龍文化－－世界篇
(2009-04-12)
何宛芯
;
Department of Communication and Technology
;
傳播與科技學系
龍傳文化－－總論
「孤女」文化形塑台灣老電影
(2009-04-12)
張雅晴
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Department of Communication and Technology
;
傳播與科技學系
台灣電影中的女性(我已將分類從影評改為文化現象!)
《我曾侍候過英國國王》
(2009-04-12)
蔡尚翰
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Department of Communication and Technology
;
傳播與科技學系
我曾侍候過英國國王
幕後　一聲演繹台前光鮮
(2009-04-12)
洪效凡
;
Department of Communication and Technology
;
傳播與科技學系
日本的動漫業蓬勃發展，延伸出許多有趣的產業，擁有無限的商機與市場。相較於台灣，動漫產業被視為次文化，雖擁有一定的人氣，卻無法提高其素質，只能不斷地追求日本的步伐，渴望某天台灣動漫也可成為世界焦點。
出走
(2009-04-12)
黃惠琳
;
Department of Communication and Technology
;
傳播與科技學系
無
芭薩提的顏色　革命狂想詩
(2009-04-12)
陳怡秀
;
Department of Communication and Technology
;
傳播與科技學系
還是寶萊塢
發展的腳步歷史永恆的記憶
(2009-04-12)
郭大齊
;
Department of Communication and Technology
;
傳播與科技學系
農村
超速緋聞集八卦焦點於一身
(2009-04-12)
鄭秀芳
;
Department of Communication and Technology
;
傳播與科技學系
0