Browsing by Issue Date, starting with "2007-06-18"

Now showing 1 - 20 of 59543

50/50 beam splitter using a one-dimensional metal photonic crystal with parabolalike dispersion
(2007-06-18)
Shen, Linfang
;
Yang, Tzong-Jer
;
Chau, Yuan-Fong
;
電子物理學系
;
Department of Electrophysics
The spatial dispersion properties of a one-dimensional metal photonic crystal have been analyzed and five types of dispersion curves have been shown at a normalized frequency less than 1. It is demonstrated that by exploiting a parabolalike dispersion behavior, a metal photonic crystal slab can be used to realize an exactly 50/50 beam splitter. (c) 2007 American Institute of Physics.
Effects of laser sources on the reverse-bias leakages of laser lift-off GaN-based light-emitting diodes
(2007-06-18)
Wu, Yewchung Sermon
;
Cheng, Ji-Hao
;
Peng, Wei Chih
;
Ouyang, Hao
;
材料科學與工程學系
The KrF pulsed excimer laser (248nm) and the frequency-tripled neodymium doped yttrium aluminum garnet laser (355nm) have been used to separate GaN thin films from sapphire substrates and transfer to bond other substrate. However, these processes would increase the dislocation density, resulting in an increase of the leakage current. In this study, the effects of these two laser sources on the reverse-bias leakages of InGaN-GaN light-emitting diodes were studied. (c) 2007 American Institute of Physics.
交大e-News第004期
(2007-06-20)
Secretariat
;
國立交通大學秘書室
9.5 GHz GaInP/GaAs HBT divide-by-two frequency divider using super-dynamic D-type flip-flop technique
(2007-06-21)
Wei, H.-J.
;
Meng, C.
;
Chang, Y. W.
;
Huang, G.-W
;
電信工程研究所
A frequency divider with super-dynamic D-type flip-flop is demonstrated in 2 mu m GaInP/GaAs HBT (f(T) = 40 GHz) technology. By biasing the HBT devices around the peak transit-time frequency (f(T)), the operating frequency of a D-FT with ECNFP (emitter-coupled negative feedback pairs) can be improved. At a supply voltage of 5 V a divide-by-two function of 9.5 GHz is achieved.
用於車輛之影音記錄器
(2007-06-21)
吳炳飛
;
陳昭榮
;
彭信元
本發明係一種用於車輛之影音記錄器，係設有車輛緊急狀況判斷能力，並啟動車輛的行駛過程影音記錄，並且將資料加密保存。若是該車輛肇事或是有交通意外之責任歸屬問題，則可藉由本記錄器所保存之資料作為判斷依據。
多層有機分子光電元件之製造方法
(2007-06-21)
孟心飛
;
洪勝富
;
許千樹
;
林世昌
;
廖華賢
提供一種在製造過程中不會產生層間互溶現象之高安定性多層有機分子光電元件、以及可利用較簡便的溶液製程製造多層有機分子光電元件之方法。
Large-time solutions for groundwater flow problems using the relationship of small p versus large t
(2007-06-21)
Yeh, Hund-Der
;
Wang, Chih-Tse
;
環境工程研究所
;
Institute of Environmental Engineering
An approximate solution is useful if the corresponding analytical solution is complicated and difficult to accurately evaluate. In the past, the relationship of small p versus large t was commonly applied to the Laplace domain solution and could successfully obtain a large-time solution in the groundwater area. The large-time solution usually has a simpler form than the analytical solution and is much easier for estimating the transient behavior of the groundwater flow system. However, Chen and Stone (1993) pointed out that the use of this relationship might fail to yield the correct solution in calculating the wellbore flux for the constant head test problem. Later, Mathias and Zimmerman (2003) indicated that a poor result was obtained by Gerke and van Genuchten (1993) when using the relationship of small p versus large t to derive the water transfer coefficient for the dual-porosity media problem. This note is to show the detailed mathematical derivations involved in the issues that Chen and Stone (1993) and Gerke and van Genuchten (1993) addressed and to ensure that the relationship of small p versus large t is correct to obtain a large-time solution for transient groundwater flow problems.
The effect of the morphology of nanocrystalline CeO2 on ethanol reforming
(2007-06-25)
Hsiao, Wei-In
;
Lin, Ya-Shiuan
;
Chen, Yu-Chie
;
Lee, Chi-Shen
;
應用化學系
CeO2 nanocrystals of cubic and rod shape have been synthesized under hydrothermal conditions on controlling the pH, temperature and duration of reaction. High-resolution transmission electron microscopy indicates that exposed crystal planes are {110} and {100} for rods but {100} for cubes. These nanocrystals have been used in the preparation of a Rh/CeO2 catalyst on an Al2O3 support to test the catalytic activity for ethanol reforming. These catalysts as prepared show good H-2 selectivity compared to catalysts with irregular CeO2 nanoparticles. The {100}/{110}-dominant surface structures play a crucial role in enhancing ethanol reforming; this reaction is important for fuel-cell applications. (c) 2007 Elsevier B.V. All rights reserved.
Surface waves and volume waves in a photonic crystal slab
(2007-06-25)
Hwang, Raybeam
;
電信工程研究所
;
Institute of Communications Engineering
The volume and surface waves supported by a 2D PC slab with termination condition are systematically studied using the rigorous mode-matching method incorporating the Floquet's solutions. It is interesting to observe that the surface waves are caused by the perturbation of the PC-slab modes from the imposed termination condition, enabling the transition from volume wave to surface wave. The perturbed dispersion curves and electric field strength distribution over the structure are drawn together with the unperturbed ones (without termination condition) to identify the type of bound waves. (C) 2007 Optical Society of America
The roles of hydrophobic group on the surface of ultra low dielectric constant porous silica film during thermal treatment
(2007-06-25)
Luo, Jen-Tsung
;
Wu, Wen-Fa
;
Wen, Hua-Chiang
;
Wan, Ben-Zu
;
Chang, Yu-Ming
Porous silica films with ultra low-k (below 2) and low leakage current densities (10(-8) A/cm(2) or lower at an electric field of 1.8 MV/cm) were prepared by the surfactant-template method. Hexamethyldisilazane (HMDS), a surface modification agent, was utilized to yield hydrophobic groups on the surface of porous silica film to prevent the absorption of moisture. It effectively retained the low permittivity properties of the films. Thermal treatment at high temperature (> 350 degrees C) destroyed surface hydrophobic groups and generated hydrophilic groups (Si-OH), which replaced the surface Si(CH3)(3) groups, and resulted in the absorption of moisture. However, Si-OH not only resulted in the absorption of moisture but also initiated the formation of trimethylsilyl groups on the surface by HMDS. When the damaged film is repaired by HMDS again, the k value falls to its initial value (which may be below 1.6). A denser hydrophobic low-k film is formed and the electrical properties are improved. (C) 2007 Elsevier B.V. All rights reserved.
Observation of the negative differential capacitance in Schottky diodes with InAs quantum dots near room temperature
(2007-06-25)
Lin, S. D.
;
Ilchenko, V. V.
;
Marin, V. V.
;
Shkil, N. V.
;
Buyanin, A. A.
The negative differential capacitance (NDC) of Schottky diodes with the layers of InAs quantum dots (QDs) has been clearly observed near room temperature. A simple model involving two zero-dimensional quantum states is proposed to explain the NDC behavior. The simulation results show that the NDC is caused by the fast charging-discharging process in the second states of QDs.
Reconfigurable switched-capacitor input circuit with digital-stimulus acceptability for analog tests
(2007-06-26)
Hong
;
Hao-Chiao
A reconfigurable switched-capacitor input circuit with digital-stimulus acceptability for analog tests disclosed in the present invention provides the digital input interfaces, which are comprised of capacitors, analog switches and digital circuits, for the usage of testing the mixed-signal circuits. The present invention provides a low-priced testing platform to accomplish the testing of circuits and to solve the problems of high-cost mixed mode tester and of utmost restrictions against the surrounding condition. Therefore, the present invention improves the testability, reduces the test cost, shorten the processes of designation and efficiently seize on the time-to-market.
Synthesis and VUV photoluminescence characterization of (Y,Gd)(V,P)O-4 : Eu3+ as a potential red-emitting PDP phosphor
(2007-06-26)
Wu, Chia-Chin
;
Chen, Kuei-Bo
;
Lee, Chi-Sen
;
Chen, Teng-Ming
;
Cheng, Bing-Ming
YVO4:Eu3+-based phosphors in three series with compositions (Y1-xEux)(V1-zPz)O-4, (Y0.95-yGdyEu0.05)(V0.4P0.6)O-4 and (Y0.95-yEu0.05Gdy)(V1-zPz)O-4 were synthesized and investigated as potential red-emitting phosphors for a plasma display panel (PDP). The optimal substitution proportions of P for V and Gd for Y were determined to be 60 and 20 mol %, respectively, for (Y0.95-yGdy)(V1-zPz)O-4 doped with 5 mol % Eu3+. The vacuum ultraviolet PL and PLE spectra and chromaticity characteristics for the synthesized phosphors were measured and compared against those of a commercial red-emitting phosphor. Pumping the (Y,Gd)(P,V)O-4:Eu3+ phosphors at a wavelength of 172 nm is more efficient than that at 147 nm. For VUV excitation at 147 nm, the CIE chromaticity coordinates for our red-emitting (Y1-yGdy)(V0.4P0.6)O-4:Eu3+ are (0.6614,0.3286), as compared to (0.6443, 0.3613) for (Y,Gd)BO3:Eu3+ from Kasei Optonix Ltd. We suggest that the composition-optimized (Y0.75Gd0.20Eu0.05)(V0.4P0.6)O-4 can serve as an alternative phosphor to replace a widely used red-emitting commercial phosphor such as (Y,Gd)BO3: Eu3+ or Y2O3: Eu3+.
Arranging numbers on circles to reach maximum total variations
(2007-06-28)
Liao, Ying-Jie
;
Shieh, Min-Zheng
;
Tsai, Shi-Chun
;
資訊工程學系
;
Department of Computer Science
The dartboard problem is to arrange n numbers on a circle to obtain maximum risk, which is the sum of the q-th power of the absolute differences of adjacent numbers, for q >= 1. Curtis showed that the dartboard problem admits a greedy algorithm. We generalize the dartboard problem by considering more circles and the goal is to arrange kn number on k circles to obtain the maximum risk. In this paper, we characterize an optimal arrangement for k = 2 and show that the generalized dartboard problem also admits a greedy algorithm.
Embedded network-controlled omni-directional motion system with optical flow based navigation
(2007-06-28)
Wu, Li-Wei
;
Cheng, Jung-Hung
;
Chang, Yung-Jung
;
Hu, Jwu-Sheng
The present invention discloses an embedded network-controlled omni-directional motion system with optical flow based navigation, wherein multiple motion units and at least one embedded network control system are installed to the body, and at least one optical flow sensor is installed on the ground-facing surface of the body. The movement of the body is driven by the motion units, and the motion unit has an omni-directional wheel and a motor device. The optical flow sensors detect the state of motion and create optical-flow detection data. The embedded network control system exchanges motion control instructions and optical-flow detection data with an external information-processing unit via a communication network. Further, the motion system of the present invention may also connect with peripheral control devices to increase the control convenience of the system. As the system of the present invention adopts an optical flow based navigation technology, the system of the present invention can be free from the influence of wheel sliding, environmental variation, and accumulated errors and can achieve accurate navigation.
Greedy anti-void routing protocol for wireless sensor networks
(2007-07-01)
Liu, Wen-Jiunn
;
Feng, Kai-Ten
;
電信工程研究所
;
Institute of Communications Engineering
The unreachability problem (i.e. the so-called void problem) which exists in the greedy routing algorithms has been studied for the wireless sensor networks. However, most of the current research work can not fully resolve the problem (i.e. to ensure the delivery of packets) within their formulation. In this letter, the Greedy Anti-void Routing (GAR) protocol is proposed, which solves the void problem by exploiting the boundary finding technique for the Unit Disk Graph (UDG). The proposed Rolling-ball UDG boundary Traversal (RUT) is employed to completely guarantee the delivery of packets from the source to the destination node. The proofs of correctness for the proposed GAR protocol are also given at the end of this letter.
介面系統、方法及裝置
(2007-07-01)
陳登吉
;
彭士榮
;
蔣加洛
本發明係揭露一種介面系統、方法及裝置,適用於一電子裝置,其包含一載入模組、一指令資料庫、一巨集模組、一物件模組、一指令輸入模組及一處理模組。載入模組用以載入一辨識裝置及一應用軟體;指令資料庫,包含複數個動作指令,任一動作指令皆對應應用軟體之一操作動作;巨集模組用以設定複數個巨集指令,以執行應用軟體之一組操作動作,其中任一巨集指令皆對應一組動作指令;物件模組用以將應用軟體之相對位置設定為操作動作控制之操作物件;指令輸入模組連結辨識裝置,用以輸入辨識裝置辨識一動作訊號所產生之一輸入指令;處理模組根據輸入指令,從指令資料庫中取得相對應之動作指令,並於載入之應用軟體中執行動作指令相對應之操作動作。
Fabrication of microcavity light-emitting diodes using highly reflective AlN-GaN and Ta2O5-SiO2 distributed Bragg mirrors
(2007-07-01)
Huang, G. S.
;
Lu, T. C.
;
Kuo, H. C.
;
Wang, S. C.
;
Chen, Hou-Guang
We report the fabrication of microcavity light-emitting diodes (MCLEDs) with high reflectivity and crack-free AIN-GaN distributed Bragg reflector (DBR). The 5 lambda microcavity structure consists of an n-type GaN, ten pairs InGaN-GaN multiple quantum wells and p-type GaN sandwiched between the hybrid cavity mode of an AIN-GaN and a Ta2O5-SiO2 DBR. The AIN-GaN DBR has 29 periods with insertion of six AIN-GaN superlattice layers showing a crack-free surface morphology and a high peak reflectivity of 99.4% with a stopband of 21 nm. The output power of MCLED is about 11 mu W at an injection current of 7 mA. The electroluminescence has a polarization property with a degree of polarization of about 51 %.
Thea sinensis melanin prevents cisplatin-induced nephrotoxicity in mice
(2007-07-01)
Hung, Yao-Ching
;
Huang, G. Steven
;
Lin, Li-Wei
;
Hong, Meng-Yen
;
Se, Pei-San
The preventive effect of Thea sinensis melanin (TSM) against cisplatin-induced nephrotoxicity was studied on ICR mice. Animals were given 20 mg/kg i.p. of cisplatin, and TSM was injected i.p. in doses 10-40 mg/kg 2 h before intoxication. The protective effects were evidenced by a complete inhibition of the cisplatin-induced elevation of serum Blood Urea nitrogen (BUN), prevention of oxidative stress, and complete blockade of cisplatin-induced elevation of serum creatinine. TSM by itself, however, did not affect the renal functional parameters, including serum BUN and creatinine. Real-time RT-PCR was applied to quantify mRNA levels of cisplatin-treated mouse kidney compared to normal mouse kidney for selected marker genes. Cisplatin treatment increases mRNA levels 40-fold for glutathione-S-transferases (Gstp2), 15-fold for soluble epoxide hydrolase (Ephx1), 15-fold for lipocalin 2 (Lcn2), 9-fold for lysozyme (Lyz), 5-fold for UDP glycosyltransferase 2 (Utg2b), 30-fold for survival motor neuron (Smn1), 30-fold for guanidinoacetate methyltransferase (Gamt), 80-fold for urine retinol binding protein (Rbp4), 60-fold for aminopeptidase N (Apn), 60-fold for cytochrome P450 (Cyp2d18), and 100-fold for ornithine aminotransferase (Oat). Pre-administration of TSM restored normal expression of marker genes for cisplatin-treated mouse kidneys. TSM by itself, however, did not affect the transcription for marker genes. Results obtained demonstrate that TSM pre-administration can prevent the renal toxic effects of cisplatin. (c) 2007 Elsevier Ltd. All rights reserved.
Business and logistics hub integration to facilitate global supply chain linkage
(2007-07-01)
Trappey, C. V.
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Trappey, A. J. C.
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Lin, G. Y. P.
;
Liu, C. S.
;
Lee, W. T.
With the development and integration of the global supply chain, manufacturing industries are rapidly adjusting their modes of operation within and between enterprises. Existing manufacturing processes are being improved to meet the requirements of lean and agile manufacturing, and suppliers are given additional responsibilities to provide parts and services dynamically. An enterprise must strategically re-engineer its operations model to face the rapid changes of the global market place. This paper identifies prevailing challenges and highlights a future vision of the global logistics management framework for the automotive industry. An integrated business and logistics hub (IBLH) model integrating information flows (via the business hub) and material flows (via the logistics hub) is presented. This research uses the case of a Taiwan automobile parts and assembly manufacturer to analyse the processes of the IBLH. The goals of the case are to shorten supply chain processes, reduce inventory costs, and ensure information transparency during material flow and product distribution. Finally, this research provides suggestions to depict the case company's current limitations and deficiencies, and presents a future plan for e-logistics services.