Browsing by Issue Date, starting with "2013-08-30"

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Poly(ethylene glycol) modified activated carbon for high performance proton exchange membrane fuel cells
(2013-08-30)
Tsai, Li-Duan
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Chien, Hung-Chung
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Wang, Cheng-Hong
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Lai, Chien-Ming
;
Lin, Jiunn-Nan
A high water retention membrane is developed by co-assembling poly(ethylene glycol) (PEG) grafted activated carbon (AC-PEG) with Nafion. The AC-PEG is prepared via a sol gel process. The use of PEG as a transporting medium in AC-PEG shows a largely improved water retention ability, a higher proton conductivity and a reduced swelling ratio, making it well suited for proton exchange membrane fuel cells (PEMFCs). Further, the composite membranes show improved mechanical properties at high temperature, thus ensuring the structural stability of membranes during the fuel cell operation. Compositional optimized AC-PEG/Nafion composite membrane (15 wt% compared to Nafion) demonstrates a better performance than the commercially available counterpart, Nafion 212, in fuel cell measurements. To identify the key factor of the improved performance, current interrupt technique is used to quantitatively verify the changes of resistance under different relative humidity environment. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Modeling contaminant transport in a two-aquifer system with an intervening aquitard
(2013-08-30)
Liu, Chih-Tien
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Yeh, Hund-Der
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Yeh, Li-Ming
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環境工程研究所
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應用數學系
This study deals with the issue of one-dimensional solute transport in a two-aquifer system, where an aquitard lies between two aquifers. Different from previous studies on analysis of the contaminant transport affected by the presence of an aquitard, we developed a mathematical transport model in an aquifer-aquitard-aquifer system with considering transport of solutes in the aquitard governed by both advection and diffusion. The Laplace-domain solution of the model for concentration distributions is obtained by the Laplace transform technique and its corresponding time-domain results are computed numerically by using Laplace numerical inversion. An explicit finite difference model is also developed to simulate two-dimensional contaminant transport process in the system. The simulated depth-averaged concentrations in the lower and upper aquifers slightly differ from those predicted by the present solution. The results show that the movement of contaminant in the upper aquifer is slowed down considerably due to the advective transport in aquitard. When neglecting the aquitard advection (a zero Pedet number), the concentration level in the lower aquifer will be underestimated, especially at late times. In addition, the contaminant concentration in the lower aquifer increases significantly with aquitard's Peclet number. (C) 2013 Elsevier B.V. All rights reserved.
Enhanced particle destabilization and aggregation by flash-mixing coagulation for drinking water treatment
(2013-08-30)
Lin, Jr-Lin
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Pan, Jill R.
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Huang, Chihpin
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環境工程研究所
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生物科技學系
In water treatment plants (WTPs), the operation of rapid mixing in coagulation units dominates particle destabilization and the formation of flocs. The goal of this study was to investigate the effect of enhanced rapid-mixing intensity (velocity gradient [G]) on the performance of coagulation for natural turbid water treatment. Two surface-water samples of low and high turbidity were coagulated by using polyaluminum chloride (PACl), with G values ranging from 200 to 800 s(-1),and the destabilization of particles and dissolved organic matter (DOM) was determined, followed by measurement of filterability of the supernatant. Furthermore, the effect of high rapid mixing on the coagulation efficiency was studied by using a pilot-scale, in-line instantaneous flash mixer (IFM) which could generate much higher G than a conventional mechanical mixing of WTP. The results of Jar test showed that the enhanced reduction in turbidity was accompanied by the improved filterability of the supernatant, which was due to the formation of larger flocs with strong structure in response to higher rapid-mixing intensity, especially for low-turbidity water. It was found that the fractal dimension (D-f) of coagulated flocs is inversely proportional to the recovery factor of broken flocs. The in-line IFM with intensive mixing (G > 5000 s(-1)) substantially improved the removal of particles and DOM, as a result of the formation of large flocs. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
Growth of lattice-matched InAlN/GaN on Si (111) substrate for ultraviolet photodiode application
(2013-09-01)
Binh Tinh Tran
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Chang, Edward Yi
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材料科學與工程學系
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Department of Materials Science and Engineering
In this paper, we report on the growth of high quality In (x) Al1-x N/GaN hetero-structures on Si substrate by metal organic chemical vapor deposition with various indium compositions (x = 10.2, 16.2 and 17.6%). The lattice-matched In0.176Al0.838N/GaN structure shows a smooth surface with good crystalline quality. In addition, the ultraviolet photodiode device shows excellent device characteristics with a low leakage current of 0.12 A mu A, and a high spectral response. It has good quantum efficiency of 94 mA/W and 44% at 265 nm which is comparable to that of the InAlN photodiode grown on sapphire substrate.
Deriving the Vehicle Speeds from a Mobile Telecommunications Network
(2013-09-01)
Liou, Ren-Huang
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Lin, Yi-Bing
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Chang, Yu-Long
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Hung, Hui-Nien
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Peng, Nan-Fu
Vehicle speeds are often measured by intelligent transportation systems (ITSs) by utilizing sensors or software solutions. Our previous work proposed the Lin-Chang-Huangfu (LCH) scheme to compute the cell residence times by the standard counter values in mobile telecommunications switches. In this paper, we use mathematical and statistical developments to investigate the accuracy of the LCH scheme by deriving the bias of the cell residence times computed in this scheme. Then, we extend the LCH scheme with some filtering and compensation techniques for vehicle speed estimation and validate our approach with vehicle detector (VD) measurements at National Highway 3, Longtan Township, Taoyuan County, Taiwan. Our study indicates that the LCH scheme is an effective approach to vehicle speed estimation.
「溫度」
(深河出版有限公司, 2013-09-01)
晨野
Critical point defect detection for small-pixel thin-film transistor array applied to medical display
(2013-09-01)
Wang, Yao-Chin
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Lin, Bor-Shyh
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光電系統研究所
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影像與生醫光電研究所
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生醫電子轉譯研究中心
羅時成教授專訪
(國立陽明大學, 2013-09)
方諾妮
Predictors of survival and neurologic outcomes in children with traumatic out-of-hospital cardiac arrest during the early postresuscitative period
(2013-09-01)
Lin, Yan-Ren
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Wu, Han-Ping
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Chen, Wen-Liang
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Wu, Kuan-Han
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Teng, Tsung-Han
BACKGROUND: The outcome of children with traumatic out-of-hospital cardiac arrest (OHCA) is poor, and the information regarding survival in the postresuscitative period is limited. The aim of this study was to determine the clinical features during the early postresuscitative period that may predict survival or neurologic outcomes in children with traumatic OHCA. METHODS: Information on 362 children (<19 years) who presented to the emergency departments of three medical centers and experienced traumatic OHCA during the study period (January 2003 to December 2010) were retrospectively included. The postresuscitative clinical features during the early postresuscitative period, defined as the first hour after achieving sustained return of spontaneous circulation, which correlated with survival and neurologic outcomes were analyzed. RESULTS: Among 152 children (42%) who achieved sustained return of spontaneous circulation, 34 (9.4%) survived to discharge, and 11 (3%) had good neurologic outcomes (Pediatric Cerebral Performance Category Scale, 1 or 2). Early postresuscitative clinical features, which reflected initial cardiac output and end-organ perfusion, can predict the chance of survival. Such features included the following: high or normal blood pressure, normal heart rate, sinus rhythm, urine output of more than 1 mL/kg per hour, and noncyanotic skin color (all p < 0.05). Initial Glasgow Coma Scale (GCS) score of greater than 7 predicted a good neurologic outcome in survivors (p = 0.008). CONCLUSION: Predictors of survival were high or normal blood pressure, normal heart rate, sinus rhythm, urine output of more than 1 mL/kg per hour, and noncyanotic skin color. Most importantly, initial GCS score of greater than 7 predicted a good neurologic outcome in survivors. (Copyright (C) 2013 by Lippincott Williams & Wilkins)
「我感受到…父親的亡魂」：艾騰．伊格言電影中的創傷與翻譯
(國立陽明交通大學出版社, 2013-09-01)
蕭瑞莆
人類在上一個世紀完成許多壯舉也同樣地留下一些對生靈包括人類自己都無法磨滅的傷害，例如種族大屠殺。亞美尼亞裔加拿大導演艾騰．伊格言的《A級控訴》（2002）作為首部有關發生於1915年至1923年的亞美尼亞種族大屠殺電影，至今仍引發爭議。爭議焦點多在電影作為再現歷史的媒介是否為達美學效果而犧牲了歷史真實。這個疑問其實是個古老問題，口述、文字及影像如何可能代表、詮釋、或翻譯所指物或事件。同時，在大屠殺受難者一代接著一代逐漸凋零的現在，更重要的是《A級控訴》如何處理否認種族大屠殺的後續效應，並自種族大屠殺後世代的位置（加拿大多元文化主義語境的亞美尼亞離散族裔，以及其他族群）反省歷史文化遺產的意義。伊格言與伊恩．貝福在《字幕：論電影中的外異性》指出，「每一部電影都是外國電影，外異於某處某一位觀眾，且並非僅就語言而言」。我們不禁好奇，之於伊格言什麼是翻譯？為何需要翻譯？以及參與翻譯活動如何使主體與客體對象發生轉變？本論文整理主張保持外國語陌生／外異性的翻譯觀，如班雅明、里克爾、與安竹．班哲民的語言哲學，以及他整理拉普郎虛對佛洛依德無意識的討論，亦即「無意識作為（被）翻譯」的場域，嘗試描繪伊格言的翻譯觀。進而援引賀栩的「後－記憶」以及「家人觀看／觀看家人」的觀視位置，閱讀短片《Arshile的畫像》（1995）以及《A級控訴》的重要片段。我要指出，伊格言透過拉非與希莉亞的對話場景側面提出他的翻譯觀，並回應美學相對於歷史真實的爭議。發生於黑暗房間的事件是觀影活動的寓言，歷史事件如何向我們顯現，端看是否能夠打開所謂自保的身分認同的疆界。
Dynamic origin-destination demand flow estimation under congested traffic conditions
(2013-09-01)
Lu, Chung-Cheng
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Zhou, Xuesong
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Zhang, Kuilin
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
This paper presents a single-level nonlinear optimization model to estimate dynamic origin destination (OD) demand. The model is a path flow-based optimization model, which incorporates heterogeneous sources of traffic measurements and does not require explicit dynamic link-path incidences. The objective is to minimize (i) the deviation between observed and estimated traffic states and (ii) the deviation between aggregated path flows and target OD flows, subject to the dynamic user equilibrium (DUE) constraint represented by a gap-function-based reformulation. A Lagrangian relaxation-based algorithm which dualizes the difficult DUE constraint to the objective function is proposed to solve the model. This algorithm integrates a gradient-projection-based path flow adjustment method within a column generation-based framework. Additionally, a dynamic network loading (DNL) model, based on Newell's simplified kinematic wave theory, is employed in the DUE assignment process to realistically capture congestion phenomena and shock wave propagation. This research also derives analytical gradient formulas for the changes in link flow and density due to the unit change of time-dependent path inflow in a general network under congestion conditions. Numerical experiments conducted on three different networks illustrate the effectiveness and shed some light on the properties of the proposed OD demand estimation method. (C) 2013 Elsevier Ltd. All rights reserved.
Real options game over the business cycle
(2013-09-01)
Huang, Hsing-Hua
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Chuang, Wei-Liang
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
This paper studies the impact of business cycles on firms' strategic investment decisions by developing and solving a continuous time regime-dependent real options game in an asymmetric duopoly. The value functions, roles and optimal investment timing decisions of the two firms in the expansion and recession states are jointly determined. We show that the preemptive investment equilibrium, where the leader invests earlier than its own first-best investment timing, is pro-cyclical. Moreover, the simultaneous investment equilibrium, where the firms simultaneously invest late and enjoy waiting flexibility as a tacit collusion, is counter-cyclical. In addition, we specifically demonstrate that the values of the leader and follower in the expansion state are smaller than those in the recession state when the preemptive equilibrium prevails in the expansion state and the simultaneous equilibrium prevails in the recession state. (C) 2013 Elsevier B.V. All rights reserved.
EstiNet OpenFlow Network Simulator and Emulator
(2013-09-01)
Wang, Shie-Yuan
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Chou, Chih-Liang
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Yang, Chun-Ming
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資訊工程學系
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Department of Computer Science
In this article, we introduce the EstiNet OpenFlow network simulator and emulator, and present its support for testing the functions and evaluating the performances of software-defined networks' OpenFlow controller's application programs. EstiNet uses an unique kernel re-entering simulation methodology to enable unmodified real applications to run on nodes in its simulated network. As a result, without any modification, real NOX/POX or Floodlight OpenFlow controllers can readily run on a host in an EstiNet simulated network to control thousands of simulated OpenFlow switches. EstiNet has the characteristics of a simulator and an emulator at the same time. It combines the advantages of the simulation and emulation approaches without their respective shortcomings. EstiNet uses real OpenFlow controller programs, real network application programs, and the real TCP/IP protocol stack in the Linux kernel to generate correct, accurate, and repeatable SDN application performance results. In this article, we compare EstiNet with ns-3 and Mininet regarding their capabilities, performance, and scalability.
A new hybrid fabrication process for a high sensitivity MEMS microphone
(2013-09-01)
Chao, Paul C. -P.
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Tsai, Chun-Yin
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Chiu, Chi-Wei
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Tsai, Che-Hung
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Tu, Tse-Yi
A novel multi-layer stacking capacitive type microphone is designed in this study based on theoretical analysis and numerical simulations, while fabricated via two standard stable silicon-based MEMS processes-PolyMUMPs and SOIMUMPs. The adoption of two standardized processes helps greatly to increase yield rate. The sensitivity of the microphone is first determined by an analytical model based on an equivalent circuit, which is followed by finite element (FEM) analyses on the capacitance value, static pull-in voltage and dynamic characteristics. Based on the developed analytical model, varied dimensions of the microphone are optimized and then the performance is validated by analytical simulations. In the next step, micro-fabrication of the microphone is accomplished using two standard processes, PolyMUMPs and SOIMUMPs provided by MEMSCAP. Experiments are conducted to acquire the information of pull-in voltage for safe operation and frequency response in sensitivity for performance evaluation. In the static case, experimental results show a good agreement with the analytical results with 90 Mpa residual stress assumed. As for dynamic validation, the frequency response is measured in an anechoic room adopting the exciting frequency as the audible range from 100-10 kHz. The measured sensitivity is as around 0.78 and 1.7 mV/Pa from 100 to 10 kHz, under the biases of 2 and 4.5 V, respectively. Within the audible frequency range, the proposed device maintains the loss as less as 2.7 dB (ref. to V/Pa), under 3 dB-the commonly acceptable drop within audible frequency range.
Reconfigurable Multi-Resolution Performance Profiling in Android Applications
(2013-09-01)
Lin, Ying-Dar
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Chang, Kuei-Chung
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Lai, Yuan-Cheng
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Lai, Yu-Sheng
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資訊工程學系
The computing of applications in embedded devices suffers tight constraints on computation and energy resources. Thus, it is important that applications running on these resource-constrained devices are aware of the energy constraint and are able to execute efficiently. The existing execution time and energy profiling tools could help developers to identify the bottlenecks of applications. However, the profiling tools need large space to store detailed profiling data at runtime, which is a hard demand upon embedded devices. In this article, a reconfigurable multi-resolution profiling (RMP) approach is proposed to handle this issue on embedded devices. It first instruments all profiling points into source code of the target application and framework. Developers can narrow down the causes of bottleneck by adjusting the profiling scope using the configuration tool step by step without recompiling the profiled targets. RMP has been implemented as an open source tool on Android systems. Experiment results show that the required log space using RMP for a web browser application is 25 times smaller than that of Android debug class, and the profiling error rate of execution time is proven 24 times lower than that of debug class. Besides, the CPU and memory overheads of RMP are only 5% and 6.53% for the browsing scenario, respectively.
醫學院約翰霍普金斯大學附設醫院交換學生心得
(國立陽明大學, 2013-09)
郭宇如
Vacant Parking Space Detection Based on Plane-based Bayesian Hierarchical Framework
(2013-09-01)
Huang, Ching-Chun
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Tai, Yu-Shu
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Wang, Sheng-Jyh
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, we propose a vacant parking space detection system that operates day and night. In the daytime, the major challenges of the system include dramatic lighting variations, shadow effect, inter-object occlusion, and perspective distortion. In the nighttime, the major challenges include insufficient illumination and complicated lighting conditions. To overcome these problems, we propose a plane-based method which adopts a structural 3-D parking lot model consisting of plentiful planar surfaces. The plane-based 3-D scene model plays a key part in handling inter-object occlusion and perspective distortion. On the other hand, to alleviate the interference of unpredictable lighting changes and shadows, we propose a plane-based classification process. Moreover, by introducing a Bayesian hierarchical framework to integrate the 3-D model with the plane-based classification process, we systematically infer the parking status. Last, to overcome the insufficient illumination in the nighttime, we also introduce a preprocessing step to enhance image quality. The experimental results show that the proposed framework can achieve robust detection of vacant parking spaces in both daytime and nighttime.
後統一、公民社會與文明現代
(深河出版有限公司, 2013-09-01)
甯應斌
Dynamic Traffic Control with Fairness and Throughput Optimization Using Vehicular Communications
(2013-09-01)
Chen, Lien-Wu
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Sharma, Pranay
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Tseng, Yu-Chee
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資訊工程學系
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Department of Computer Science
Traffic congestion in modern cities seriously affects our living quality and environments. Inefficient traffic management leads to fuel wastage in volume of billion gallons per year. In this paper, we propose a dynamic traffic control framework using vehicular communications and fine-grained information, such as turning intentions and lane positions of vehicles, to maximize traffic flows and provide fairness among traffic flows. With vehicular communications, the traffic controller at an intersection can collect all fine-grained information before vehicles pass the intersection. Our proposed signal scheduling algorithm considers the flows at all lanes, allocates more durations of green signs to those flows with higher passing rates, and also gives turns to those with lower passing rates for fairness provision. Simulation results show that the proposed framework outperforms existing works by significantly increasing the number of vehicles passing an intersection while keeping average waiting time low for vehicles on non-arterial roads. In addition, we discuss our implementation of an Zigbee-based prototype and experiences.
The use of the grey-Taguchi method for the optimization of a silicon nanowires array synthesized using electroless Ag-assisted etching
(2013-09-01)
Chiou, Ai-Huei
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Wu, Wen-Fa
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Chen, Ding-Yeng
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Hsu, Chun-Yao
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機械工程學系
A simple and convenient method for the production of silicon nanowires (SiNWs) that are single crystalline, well aligned and which have large area is direct synthesis onto p-type (100) silicon (Si) wafers, using electroless Ag-assisted etching, in which Ag is both the oxidant and the catalyst. This study proposes a method for the optimization of the etching process parameters for SiNW arrays with multiple performance characteristics, using grey-Taguchi analysis. The effect of the etching process parameters (etching time, solution (AgNO3/HF) temperature, silver nitrate (AgNO3) concentration and hydrogen fluoride (HF) concentration) on the length, diameter, structure, and morphology of the SiNW arrays were studied. In the confirmation runs, grey relational analysis shows that the length of the SiNW arrays is increased from 15.80 to 23.07 mu m, and the diameter is decreased from 76.77 to 66.65 nm. Further, the linear relationship for the SiNW arrays can be adjusted by increasing the etching time (from 15 to 45 min) and the solution temperature (from 25 to 75 degrees C). The axial orientation of the SiNWs is determined to be along the [001] direction, which is the same as that of the initial Si wafer. The large area SiNW arrays have potential applications in interconnect, bio-technology and optoelectronic devices.