Browsing by Issue Date, starting with "2007-06-25"

Now showing 1 - 20 of 59536

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.
;
Trappey, A. J. C.
;
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.
Dual-metal-gate-integration complementary metal oxide semiconductor process scheme using Ru positive-channel metal oxide semiconductor and TaC negative-channel metal oxide semiconductor gate electrodes
(2007-07-01)
Chang, Wen-Tung
;
Hsieh, Tsung-Eong
;
Lee, Chung-Ju
;
材料科學與工程學系
;
Department of Materials Science and Engineering
This article presents the development of a wet removal process on the integration of complementary metal oxide semiconductor (CMOS) dual metals with Ru for positive-channel metal oxide semiconductor and TaC for negative-channel metal oxide semiconductor on high-k HfO2 gate dielectric. The integration scheme focused on the wet etching capability for the first metal and the selectivity control on the high-k dielectrics under the metal gate. Using the developed chemical, ceric ammonium nitrate and nitric acid mixture used for Ru metal removal and HfO2 treated with Ar/O-2 plasma by selective diluted hydrofluoric wet etching, a CMOS dual-metal-gate structure was achieved with satisfactory device fabrication. (c) 2007 American Vacuum Society.
Self-healing ring-based time-sharing passive optical networks
(2007-07-01)
Yeh, Chien-Hung
;
Chi, Sien
;
光電工程學系
;
Department of Photonics
A new ring-based time-shared passive optical network (PON), with a self-healing function to prevent the occurrence of fiber-fault, has been proposed and investigated experimentally. By using the new optical line termination and single fiber path architecture, the proposed self-healing ring topology PON can be revived promptly under single fiber failure. The system performances of the proposed access network are also measured and discussed.
Increased expression of extracellular matrix proteins in rapid atrial pacing-induced atrial fibrillation
(2007-07-01)
Lin, Chih-Sheng
;
Lai, Ling-Ping
;
Lin, Jiunn-Lee
;
Sun, Yu-Ling
;
Hsu, Chih-Wei
BACKGROUND: Atria[ fibrillation (AF) is characterized by structural remodeling of the extracellular matrix (ECM) in cardiac atrium. OBJECTIVE: The purpose of this study was to gain further insight into atrial ECM remodeling at the molecular Level and to test whether altered expression of ECM proteins was associated with the disease. METHODS: Sustained AF was induced in nine adult pigs after 3-4 weeks of continuous rapid atrial pacing at a rate of 600 bpm. Histologic studies and immunohistochemical stain were performed to identify the potential pathologic substrate underlying abnormalities in atrial tissues with sustained AF. RESULTS: In the pathologic findings, the fraction of myocardial ECM (ECM%) was measured, with a significantly greater ECM% found in the AF group compared with the sham operated group (n = 6; i.e., pigs with normal sinus rhythm [SR]). A set of 9,182 genes was screened with cDNA microarray analysis. In AF animals, expression of 121 genes increased and 24 genes decreased by >= 1.75-fold compared with SR animals. Significant up-regulation of fibronectin-1 (4.9-fold), fibrillin-1 (3.1-fold), and fibromodulin (1.9-fold) in the fibrillating atria was confirmed by quantitative real-time reverse transcriptase-polymerase chain reaction. Western blot analysis revealed significantly increased atrial fibronectin-1, fibrillin-1, and fibromodulin in the AF group compared with the SR group (1.5-, 2.7-, and 2.1-fold, respectively). Immunohistochemical staining of AF tissue displayed increased accumulation of fibronectin-1 and fibrillin-1 in the atrial interstitial space. CONCLUSION: Increased expression of ECM proteins in fibrillating atria supports the hypothesis that ECM metabolism contributes to the development of AF.
階梯損失函數在評估環境風險上之應用研究
(2007-07-01)
潘浙楠
;
周慧玲
;
Jeh-Nan Pan
;
Hui-Ling Chou
;
Institute of Business and Management
近年來，由於工業高度的發展及資源過度的利用，以致造成環境污染與自然生態破壞，明顯降低了民眾的生活品質。有鑑於環境污染問題對生態及人類生活所造成的影響及危害，世界各國均著手訂定相關罰則。我國行政院環境保護署制定空氣污染防制法，即針對排放空氣污染物之固定污染源及移動污染源之多寡，採累進方式徵收空氣污染防制費以落實污染者付費之原則。本研究在第一階段擬依據此環保法規，建立適用於環保/空氣污染資料之階梯損失函數(step loss function)；第二階段則比較INLF(inverted normal loss function)、田口單邊二次損失函數及修正型損失函數MINLF(modified inverted normal loss function)與階梯損失函數的差異，並進行階梯損失函數與製程能力指標的關係式之推導，以期能藉由望小特性製程能力指標反應製程潛在風險及損失；最後我們以高雄縣某人造樹脂公司提供之氮氧化物(Nox)連續自動監測紀錄資料為例進行統計分析，除了以階梯損失函數估算其所造成之損失外，並對異常違規損失部分提供初步的估計。
Synthesis of In2O3 nanocrystal chains and annealing effect on their optical properties
(2007-07-01)
Ko, T. S.
;
Chu, C. P.
;
Chen, J. R.
;
Chang, Y. A.
;
Lu, T. C.
The authors reported the synthesis of indium oxide nanocrystal chains on silicon substrates using gold nanoparticles as catalyst on native silicon dioxide. Scanning electron microscopy investigations showed that In2O3 nanocrystal chains were formed. The nanocrystal chains comprised many well shaped octahedron nanoparticles with their size ranging from 20 to 100 nm connected with each other to form a network. Both high resolution transmission, electron microscopy and diffraction pattern revealed that the In2O3 nanocrystal chains were single crystalline grown along the [111] direction. Photoluminescence study of In2O3 nanocrystal chains exhibited main photoemission at 544 nm due to the recombination between electrons in localized state induced by oxygen vacancies and holes in valence band. After the annealing treatment, the main photoluminescence peak not only slightly redshifted to 558 nm but also became narrower, which was attributed to the total localized state away from the conduction band caused by less defect distribution. (c) 2007 American Vacuum Society.
Activation of p38 mitogen-activated protein kinase by celecoxib oppositely regulates survivin and gamma-H2AX in human colorectal cancer cells
(2007-07-01)
Hslao, Po-Wen
;
Chang, Chia-Ching
;
Liu, Huel-Fang
;
Tsai, Chuan-Mei
;
Chiu, Ted H.
Cancer cells express survivin that facilitates tumorigenesis. Celecoxib has been shown to reduce human colorectal cancers. However, the role and regulation of survivin by celecoxib in colorectal carcinoma cells remain unclear. Treatment with 40-80 mu M celecoxib for 24 h induced cytotoxicity and proliferation inhibition via a concentration-dependent manner in RKO colorectal carcinoma cells. Celecoxib blocked the survivin protein expression and increased the phosphorylation of H2AX at serine- 193 (gamma-H2AX). The survivin gene knockdown by transfection with a survivin siRNA revealed that the loss of survivin correlated with the expression of gamma-H2AX. Meanwhile, celecoxib increased caspase-3 activation and apoptosis. Celecoxib activated the phosphorylation of p38 mitogen-activated protein (MAP) kinase. The phosphorylated proteins of p38 MAP kinase and gamma-H2AX were observed in the apoptotic cells. SB203580, a specific p38 MAP kinase inhibitor, protected the survivin protein expression and decreased the levels of gamma-H2AX and apoptosis in the celecoxib-exposed cells. The blockade of survivin expression increased the celecoxib-induced cytotoxicity; conversely, overexpression of survivin by transfection with a survivin -expressing vector raised the cancer cell proliferation and resisted the celecoxib-induced cell death. Our results provide for the first time that p38 MAP kinase participates in the down-regulation of survivin and subsequently induces the activation of gamma-H2AX for mediating apoptosis following treatment with celecoxib in human colorectal cancer cells. (c) 2007 Elsevier Inc. All rights reserved.
Characteristics of zirconium oxide gate ion-sensitive field-effect transistors
(2007-07-01)
Chang, Kow-Ming
;
Chao, Kuo-Yi
;
Chou, Ting-Wei
;
Chang, Chin-Tien
;
電子工程學系及電子研究所
In this study. the zirconium oxide (ZrO2) membrane has been successfully applied as a pH-sensitive layer for ion-sensitive field-effect transistors (ISFETs). It exhibited an excellent response range of 56.7-58.3 mV/pH from the fixed current measurement using HP4156A. The ZrO2 membrane prepared by direct current (DC) sputtering was used as a pH-sensitive film that showed good surface adsorption with oxide and silicon. The pH sensitivities slightly decreased in 1 M NaCl solution; however. the device showed a perfect linear response of 52.5 mV/pH. The linear pH sensitivity response was measured between pH 1 to 13 in a buffer solution that was provided by Riedel-deHan.