Browsing by Issue Date, starting with "2010-10-15"

Now showing 1 - 20 of 45051

Optical power equalization for upstream traffic with injection-locked Fabry-Perot lasers in TDM-PON
(2010-10-15)
Huang, Ting-Tsan
;
Sheu, Lih-Gen
;
Chi, Sien
;
光電工程學系
;
Department of Photonics
An optical power equalization of upstream traffic in time-division-multiplexed passive optical network (TDM-PON) based on injection-locked Fabry-Perot lasers has been experimentally investigated. The upstream transmitters with stable spectrum are achieved by using an external injection light source in the optical line terminal (OLT). The different upstream powers can be equalized by injection locking a Fabry-Perot laser diode (FP-LD) biased below threshold current in OLT. The dynamic upstream power range from -8.5 to -19.5 db m is reduced to a 1.6 dB maximal power variation, when the uplink signal is directly modulated at 1.25 Gb/s. (C) 2010 Elsevier B.V. All rights reserved.
Preparation and characterization of high-durability zwitterionic crosslinked proton exchange membranes
(2010-10-15)
Ye, Yun-Sheng
;
Chen, Wen-Yi
;
Huang, Yao-Jheng
;
Cheng, Ming-Yao
;
Yen, Ying-Chieh
The present present paper describes the development of a novel proton exchange membrane comprising a poly (styrene sulfonic acid-co-4-vinylpyridine) copolymer that was crosslinked with a haloalkyl crosslinker through the formation of ionic bonding linkages The nucleophilic substitution of these crosslinked membranes as well as a model reaction between pyridine and 1-bromobutane was confirmed by nuclear magnetic resonance (NMR) Tough and flexible membranes of a high mechanical strength were prepared. They demonstrated very elevated thermal, hydrolytic and oxidative stabilities as compared to other sulfonated polymers. The crosslinked membrane composed of zwitterionic molecules with a crosslinking fraction of 90.3, denoted SP-1, exhibited a proton conductivity of ca 7 1 x 10(-2) S cm(-1) at 30 degrees C under 90% relative humidity; a value comparable to that of Nafion 117 Moreover, the crosslinked SP-1 membrane possessed the highest selectivity for methanol fuel cells (3 38 x 10(5) S cm(-3) s), approximately five times that of Nafion 117. thus implying its potential for practical use in high-energy-density devices (C) 2010 Elsevier B.V All rights reserved.
ALM: An adaptive location management scheme for approximate location queries in wireless sensor networks
(2010-10-15)
Yeh, Lo-Yao
;
Huang, Chen-Che
;
Wu, Cheng-En
;
Huang, Jiun-Long
;
資訊工程學系
Location management is an important issue for object tracking applications of wireless sensor networks. Since locations obtained by most positioning techniques are inherently imprecise, users may send approximate location queries with precision constraints to trade for energy consumption of sensor nodes. Therefore, we propose an Adaptive Location Management scheme called ALM to process approximate location queries. ALM employs a two-tier storage architecture (i.e., centric storage node and local storage node) to facilitate approximate query resolving and to reduce the energy consumption of sensor nodes. We propose a storage node relocation and replication mechanism, which can create, remove replicas of storage nodes and adjust the positions of storage nodes according to the location queries and updates. As such, the number of forwarding location update and query messages is reduced by the proposed storage node relocation and replication mechanism, thereby conserving more energy. The experimental results show that compared with EASE (Xu et al. (2008) [18]), ALM is able to reduce the number of transmission messages and the energy consumption of sensor network, and prolong the network lifetime. (C) 2010 Elsevier B.V. All rights reserved.
Growth and optical properties of high-density InN nanodots
(2010-10-15)
Ke, W. C.
;
Lee, S. J.
;
Kao, C. Y.
;
Chen, W. K.
;
Chou, W. C.
High density InN/GaN nanodots were grown by pulsed mode (PM) metal-organic chemical vapor deposition (MOCVD). InN nanodots density of up to similar to 5 x 10(10) cm(-2) at a growth temperature of 550 degrees C was achieved. The high diffusion activation energy of 2.65 eV due to high NH(3) flow rate generated more reactive nitrogen adatoms on the growth surface, and is believed to be the main reason for the growth of high density InN nanodots. In addition, an anomalous temperature dependence of the PL peak energy was observed for high density InN nanodots. The high carrier concentration, due to high In vacancy (V(ln)) in the InN nanodots, thermally agitated to the conduction band. As the measurement temperature increased, the increase of Fermi energy resulted in blue-shifted PL peak energy. From the Arrhenius plot of integrated PL intensity, the thermal activation energy for the PM grown InN nanodots was estimated to be E(a)similar to 51 meV, indicating strong localization of carriers in the high density InN nanodots. (C) 2010 Elsevier B.V. All rights reserved.
Long-Cavity Fabry-Perot Laser Amplifier Transmitter With Enhanced Injection-Locking Bandwidth for WDM-PON Application
(2010-10-15)
Lin, Gong-Ru
;
Liao, Yu-Sheng
;
Chi, Yu-Chieh
;
Kuo, Hao-Chung
;
Lin, Gong-Cheng
We simulate the injection-locking performance of a 1% antireflection coated Fabry-Perot laser amplifier (AR-FPLA) and demonstrate the 2.5-Gbit/s DWDM-PON application with the directly modulated AR-FPLA based ONU transmitter under side-mode injection-locking condition. The effect of the AR-FPLA front-facet reflectivity on the injection locking range detuning and the Q-factor are interpreted from theoretical simulations and are experimentally characterized. A 25-channel locking capacity is reported for such a side-mode injection-locked AR-FPLA with corresponding wavelength locking range of 30 nm, the minimal requested power of -7 dBm and gain extinction ratio of < 7 dB by reducing its front-facet reflectivity to 1%. At bit rate of 2.5 Gbit/s, the BER of 10(-12) is achievable for the nearest 17 channels of AR-FPLA at receiving power of -21 dBm, and all of the 25 injection-locked channels with SMSR of > 35 dB can guarantee the BER of < 10(-9) with their worst receiving sensitivity degrading to -19 dBm.
Nanoscratch study of Zn(1-x)Mn(x)O heteroepitaxial layers
(2010-10-15)
Chang, Yu-Ming
;
Chang, Zue-Chin
;
Lian, Derming
;
Yang, Chu-Shou
;
Yau, Wei-Hung
We investigated the nanotribological properties of Zn(1-x)Mn(x)O epilayers (0 <= x <= 0.16) grown by molecular beam epitaxy (MBE) on sapphire substrates. The surface roughness and friction coefficient (mu) were analyzed by means of atomic force microscopy (AFM) and hysitron triboscope nanoindenter techniques. The nanoscratch system gave the mu value of the films ranging from 0.17 to 0.07 and the penetration depth value ranging 294-200nm when the Mn content was increased from x = 0 to 0.16. The results strongly indicate that the scratch wear depth under constant load shows that higher Mn content leads to Zn(1-x)Mn(x)O epilayers with higher shear resistance, which enhances the Mn-O bond. These findings reveal that the role of Mn content on the growth of Zn(1-x)Mn(x)O epilayers can be identified by their nanotribological behavior. (C) 2010 Elsevier B.V. All rights reserved.
Nanoscratch study of Zn1-xMnxO heteroepitaxial layers
(2010-10-15)
Chang, Yu-Ming
;
Chang, Zue-Chin
;
Lian, Derming
;
Yang, Chu-Shou
;
Yau, Wei-Hung
We investigated the nanotribological properties of Zn1-xMnxO epilayers (0 <= x <= 0.16) grown by molecular beam epitaxy (MBE) on sapphire substrates. The surface roughness and friction coefficient (mu) were analyzed by means of atomic force microscopy (AFM) and hysitron triboscope nanoindenter techniques. The nanoscratch system gave the mu value of the films ranging from 0.17 to 0.07 and the penetration depth value ranging 294-200nm when the Mn content was increased from x = 0 to 0.16. The results strongly indicate that the scratch wear depth under constant load shows that higher Mn content leads to Zn1-xMnxO epilayers with higher shear resistance, which enhances the Mn-O bond. These findings reveal that the role of Mn content on the growth of Zn1-xMnxO epilayers can be identified by their nanotribological behavior. (C) 2010 Elsevier B.V. All rights reserved.
ALM: An adaptive location management scheme for approximate location queries in wireless sensor networks
(2010-10-15)
Yeh, Lo-Yao
;
Huang, Chen-Che
;
Wu, Cheng-En
;
Huang, Jiun-Long
;
資訊工程學系
Location management is an important issue for object tracking applications of wireless sensor networks. Since locations obtained by most positioning techniques are inherently imprecise, users may send approximate location queries with precision constraints to trade for energy consumption of sensor nodes. Therefore, we propose an Adaptive Location Management scheme called ALM to process approximate location queries. ALM employs a two-tier storage architecture (i.e., centric storage node and local storage node) to facilitate approximate query resolving and to reduce the energy consumption of sensor nodes. We propose a storage node relocation and replication mechanism, which can create, remove replicas of storage nodes and adjust the positions of storage nodes according to the location queries and updates. As such, the number of forwarding location update and query messages is reduced by the proposed storage node relocation and replication mechanism, thereby conserving more energy. The experimental results show that compared with EASE (Xu et al. (2008) [18]), ALM is able to reduce the number of transmission messages and the energy consumption of sensor network, and prolong the network lifetime. (C) 2010 Elsevier B.V. All rights reserved.
色散式增益導引光纖、色散式增益導引光纖放大器及色散式增益導引光纖雷射
(2010-10-16)
陳南光
;
賴暎杰
;
祁甡
本發明提供一種色散式增益導引光纖，其包含一纖芯，至少含有一光增益摻雜；以及複數個纖殼，包覆該纖芯，其中，因該纖芯與該等纖殼之折射率色散不相同而取得一基態模截止波長；並使得泵浦光利用全內反射機制之折射率導引模式在光纖中傳遞而信號光或雷射光則是依靠折射率反導引及增益導引方式傳遞。再者，基於前述所提及的色散式增益導引光纖，本發明另提出一種色散式增益導引光纖放大器及一種色散式增益導引雷射。
具安全防護裝置的隨身碟
(2010-10-16)
陳建廷
;
陳昱翰
;
廖倫德
;
趙昌博
一種具安全防護裝置的隨身碟，其利用控制器讀取密碼鎖之設定以准許或否准電腦經由連接埠將資料寫入隨身碟的記憶體，並利用連接控制鍵安全地控制隨身碟與電腦之間的斷連。隨身碟的控制器驗證密碼鎖之密碼與電腦使用者之密碼，以避免未經驗證的資料從電腦寫入隨身碟。另外，隨身碟利用控制器接收連結控制鍵的指令而安全地與電腦斷連，以避免不當地拔出隨身碟而毀損儲存於隨身碟的資料，或者輕易地連接。
多載波系統之通道估計方法
(2010-10-16)
洪崑健
;
林大衛
本發明係提供一種多載波系統之通道估計方法，係利用有限領航訊號取得導引子載波之通道響應，接著利用內插法運算解出資料子載波通道，藉此，更快速地估算出資料子載波的通道響應。本發明係用少數領航訊號進行通道估計，以更低運算量之方法精確地估算出各種通道延遲參數(如：初始延遲、平均延遲及均方根延遲擴散)，且本方法適用性廣，不需要配合特定功率延遲輪廓(power delay profile，PDP)，亦適用導引子載波配置不規則之通道。
無線網路環境中之繞送方法及繞送路徑之修復方法
(2010-10-16)
賴俊羽
;
黃貴笠
;
王瑞堂
;
曾建超
;
吳昭男
本發明提供一種無線網路環境中非對稱式的繞送方法及繞送路徑之修復方法。在無線網路環境中包括至少一管理單元、至少一閘道器及複數行動節點，管理單元與閘道器相連。當一新行動節點加入網路時，即傳送訊息至管理單元以取得識別碼，網路中每個節點都記錄相對於管理單元之深度，使得整個網路由內而外的形成以管理單元為中心之坡度（Gradient）。當行動節點有資料欲傳送給管理單元時，可向鄰近節點表格（neighbor table）中深度（depth）較低的任何一個行動節點傳送封包，亦即往距離管理單元較近的行動節點繞送封包。當網路後端有資料欲透過管理單元傳送給行動節點時，管理單元採用來源繞送（source routing）的方式將封包繞送給行動節點。當有一行動節點損壞需修復繞送路徑時，行動節點傳送一控制訊息給管理單元以更新管理單元到行動節點之下行繞送路徑，並選擇一個鄰近節點做為父節點，再以父節點到管理單元之路徑做為行動節點到管理單元之路徑。
同軸體積全像光儲存系統及其資訊儲存結構
(2010-10-16)
孫慶成
;
余業緯
;
謝舒菁
同軸體積全像光儲存系統儲存資料時，全像資料的資訊強度以”+”字形分布於儲存媒質上，因此同一儲存軌跡或二儲存軌跡的相鄰二儲存頁可能發生串音的現象。資訊強度分布方向與儲存媒質的儲存軌跡存在一定旋轉角度，即可加速資訊強度的遞減速度，以有效降串音的現象；且可縮短二全像資訊的讀取中心間的距離，而可提高儲存媒質之儲存密度。
一種成長ＩＩＩ－Ｖ族氮化物薄膜之方法及其結構
(2010-10-16)
李威儀
;
黃信雄
;
陳奎銘
;
葉彥顯
一種成長III-V族氮化物薄膜之方法及其結構，其係利用氫化物蒸氣相磊晶方法來進行。此方法至少包含在介於900℃至950℃間之第一成長溫度，且以每分鐘0.5℃至10℃之一升溫速度，緩慢地於基板上磊晶成長一升溫氮化物層，直至溫度升溫至介於1000℃至1050℃間之第二成長溫度。本發明之升溫氮化物層，其晶格品質會隨著膜層高度而緩慢變化，因而能消除藍寶石基板與氮化鎵層之間因晶格不匹配而造成的應力。
廢不廢死你說呢?
(2010-10-17)
張瑜庭
;
Department of Communication and Technology
;
傳播與科技學系
「殺人影展3 亞洲與世界的對話」台北場於十月十日，國際廢除死刑日正式落幕。但是台灣推動廢除死刑運動者，還不能離開舞台，因為他們的工作還沒做完……
侯硐。貓與老礦城的華爾滋
(2010-10-17)
陳俐吟
;
Department of Communication and Technology
;
傳播與科技學系
侯硐，一個在舊時代以產煤聞名的村落，當礦工的背影走入歷史、礦車被火車取而代之，貓，成為了這個小村莊最吸引人的風景。或坐或趴，或優雅或俏皮，牠們的一舉一動都抓住遊客的目光，在這裡，貓有一百種姿態，這裡，是侯硐。
台灣的小歐洲雪霸
(2010-10-17)
張芳瑜
;
Department of Communication and Technology
;
傳播與科技學系
想要到有著如詩般風景的地方去旅遊，非得要到國外去尋覓嗎？在台灣的雪霸公園一帶，便是以它綺麗的風景以及所栽種的溫帶水果為名。隨著季節的變化，都有著不盡相同的風情，在初秋，滿山即將可採收的蘋果水梨更讓人不禁想大快朵頤一番。
莎拉的鑰匙開啟歷史真相
(2010-10-17)
徐子晴
;
Department of Communication and Technology
;
傳播與科技學系
一場來不及的告別，一個永遠不能觸及的家族秘密，由二次大戰間德國人屠殺猶太人的事件，串起了這一連串的故事。不能忽視的悲痛，最後如何在未來重生？
新伊索寓言
(2010-10-17)
歐人瑋
;
Department of Communication and Technology
;
傳播與科技學系
在某個村子的邊緣，有一個很大的雞捨。裡面的雞從雞蛋孵化出來之後，就過著不用擔心食物也不用擔心危險的安逸生活。在村子外面的森林裡，有一群野雞，為了尋找食物，他們鍛鍊出了結實的雙腳；為了躲避天敵的攻擊，他們有了敏銳的觀察力。這是一隻雞的故事，也不只是一隻雞的故事。
探訪死後四十種生活
(2010-10-17)
沈祐平
;
Department of Communication and Technology
;
傳播與科技學系
與其說談論的是死後世界，其實更像某種烏托邦小說，只是談的並非生活，而是試圖尋找人生哲學上，那也許根本不存在的理想鄉。