Browsing by Issue Date, starting with "2011-02-01"

Now showing 1 - 20 of 42303

2-Step self-assembly method to fabricate broadband omnidirectional antireflection coating in large scale
(2011-02-01)
Yeung, K. M.
;
Luk, W. C.
;
Tam, K. C.
;
Kwong, C. Y.
;
Tsai, M. A.
We have developed a simple and reproducible 2-step self-assembly method for the fabrication of broadband, omnidirectional antireflection coating on glass substrate with 4 in. size. The glass surface has been modified to be positively charged, then the negatively charged nano silica is self-assembled to the glass substrate by electrostatic attraction. The nanostructure on the glass substrate reduces the reflection significantly, which results in enhanced transmittance. Transmittance as high as 97.7% at 499 nm has been obtained for a double-side coated glass substrate. Obvious reduction in weighted reflectance is still observed up to 60 degrees incident angle. (C) 2010 Elsevier B.V. All rights reserved.
Investigation of the Atmospheric Helium Dielectric Barrier Discharge Driven by a Realistic Distorted-Sinusoidal Voltage Power Source
(2011-02-01)
Hung, C. -T.
;
Chiu, Y. -M.
;
Hwang, F. -N.
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Chiang, M. -H.
;
Wu, J. -S.
The non-equilibrium atmospheric-pressure parallel-plate helium dielectric barrier discharge (DBD) driven by a realistic 20 kHz distorted-sinusoidal voltage waveform has been investigated by means of simulations and experiments. A self-consistent one-dimensional fluid modeling code considering the non-local electron energy balance was applied to simulate the helium DBD. The effect of selecting plasma chemistry was investigated by comparing simulations with experiments. The results show that the simulations, which include more excited helium, metastable helium and electron-ion-related reaction channels, can faithfully reproduce the measured discharged temporal current quantitatively. Based on the simulated discharge properties, we have found that there is complicated mode transition of discharges from the long Townsend-like to the "dark current"-like, then to the short primary Townsend-like and the short secondary Townsend-like for the helium DBD that is driven by a realistic distorted-sinusoidal voltage power source. Discharge properties in different periods of discharge are discussed in detail in the paper.
All-optical controllable trapping and transport of subwavelength particles on a tapered photonic crystal waveguide
(2011-02-01)
Lin, Pin-Tso
;
Lee, Po-Tsung
;
光電工程學系
;
Department of Photonics
We propose that a tapered photonic crystal waveguide design can unify optical trapping and transport functionalities to advance the controllability of optical manipulation. Subwavelength particles can be trapped by a resonance-enhanced field and transported to a specified position along the waveguide on demand by varying the input wavelength. A simulated transport ability as high as 148 (transport distance/wavelength variation) is obtained by the waveguide with 0.1 degrees tilted angle. Stable trapping of a 50 nm polystyrene particle can be achieved with input power of 7 mW. We anticipate that this design would be beneficial for future life science research and optomechanical applications. (C) 2011 Optical Society of America
Hybrid-Patent Classification Based on Patent-Network Analysis
(2011-02-01)
Liu, Duen-Ren
;
Shih, Meng-Jung
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Effective patent management is essential for organizations to maintain their competitive advantage. The classification of patents is a critical part of patent management and industrial analysis. This study proposes a hybrid-patent-classification approach that combines a novel patent-network-based classification method with three conventional classification methods to analyze query patents and predict their classes. The novel patent network contains various types of nodes that represent different features extracted from patent documents. The nodes are connected based on the relationship metrics derived from the patent metadata. The proposed classification method predicts a query patent's class by analyzing all reachable nodes in the patent network and calculating their relevance to the query patent. It then classifies the query patent with a modified k-nearest neighbor classifier. To further improve the approach, we combine it with content-based, citation-based, and metadata-based classification methods to develop a hybrid- classification approach. We evaluate the performance of the hybrid approach on a test dataset of patent documents obtained from the U.S. Patent and Trademark Office, and compare its performance with that of the three conventional methods. The results demonstrate that the proposed patent-network-based approach yields more accurate class predictions than the patent network-based approach.
Development of an improved spatial reconstruction technique for the HLL method and its applications
(2011-02-01)
Smith, Matthew R.
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Lin, K. -M.
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Hung, C. -T.
;
Chen, Y. -S.
;
Wu, J. -S.
The integral form of the conventional HLL fluxes are presented by taking integrals around the control volume centred on each cell interface. These integrals are demonstrated to reduce to the conventional HLL flux through simplification by assuming spatially constant conserved properties. The integral flux expressions are then modified by permitting the analytical inclusion of spatially linearly varying conserved quantities. The newly obtained fluxes (which are named HLLG fluxes for clarification, where G stands for gradient inclusion) demonstrate that conventional reconstructions at cell interfaces are invalid and can produce unstable results when applied to conventional HLL schemes. The HLLG method is then applied to the solution of the Euler Equations and Shallow Water Equations for various common benchmark problems and finally applied to a 1D fluid modeling for an argon RF discharge at low pressure. Results show that the correct inclusion of flow gradients is shown to demonstrate superior transient behavior when compared to the existing HLL solver and conventional spatial reconstruction without significantly increasing computational expense. (C) 2010 Elsevier Inc. All rights reserved.
靜態隨機存取記憶體裝置
(2011-02-01)
楊仕琪
;
楊皓義
;
莊景德
;
黃威
本發明係揭露一種靜態隨機存取記憶體裝置，包含複數個記憶體組、複數個寫入控制電路、複數個電源開關組及一位址解碼器，每一寫入控制電路對應連接於每一記憶體組，當位址解碼器接收一寫入資料而產生一控制訊號，並據此開啟其中一電源開關組，使對應之寫入控制電路將一寫入位元資料寫入於對應之記憶體組內，寫入完成後隨之關閉，以減少靜態隨機存取記憶體裝置中的電晶體開啟時間，讓電晶體可進入回復的狀態，因此，可有效減緩晶片（IC）中的靜態隨機存取記憶體受正/負溫度偏壓不穩定性的影響，進而提高存取速度、穩定度及降低功率消耗等優點。
奈米級之藥物傳送裝置、製備方法及用途
(2011-02-01)
陳三元
;
胡尚秀
;
劉典謨
;
郭冠廷
在此揭示活體內監控及釋放藥物的奈米裝置與方法。所揭示的奈米裝置特徵在於具有一裝載有藥物的奈米球，可透過磁性刺激而將其中的藥物釋出。也可將此奈米裝置當作一種顯影劑，於活體內造影並監控所釋出藥物或是單獨注入活體標的位置處之藥物的濃度與分佈情形。
Enhanced Stimulated Emission from Optically Pumped Gallium Nitride Nanopillars
(2011-02-01)
Lo, Ming-Hua
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Cheng, Yuh-Jen
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Kuo, Hao-Chung
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Wang, Shing-Chung
;
光電工程學系
We report the observation of an enhanced stimulated emission from optically pumped GaN nanopillars. The nanopillars were fabricated from an epitaxial wafer by patterned etching followed by crystalline regrowth. When the sample was optically excited, a strong stimulated emission peak emerged from a broad spontaneous emission background. The emission was attributed to electron-hole plasma gain at high carrier density. The emission slope efficiency was greatly enhanced by 20 times compared with a GaN substrate under the same pumping configuration. We remark that the enhancement is due to better gain and photon interaction from the multiple scattering of photons among nanopillars. (C) 2011 The Japan Society of Applied Physics
IMS EMERGENCY SERVICES: A PRELIMINARY STUDY
(2011-02-01)
Lin, Yi-Bing
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Tsai, Meng-Hsun
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Tu, Yuan-Kuang
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資訊學院
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College of Computer Science
Emergency call and walkie-talkie are two services utilized in emergency situations. During Typhoon Morakot in 2009, we experienced the deficiency of emergency call service that cannot continuously track callers in real time and walkie-talkie communications where a speaker may not be granted the permission to talk. These issues can be resolved by the emergency call and push-to-talk over cellular services in IP Multimedia Subsystem. This article conducts a preliminary study on how these two services can be effectively exercised in IMS.
SU-8 serial MEMS switch for flexible RF applications
(2011-02-01)
Chao, Tzu-Yuan
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Hsu, M. C.
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Lin, C-D
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Cheng, Y. T.
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電子工程學系及電子研究所
This paper presents a novel SU-8 micromachining process for MEMS series switch fabrication. The switch is designed with a clamped-clamped SU-8 (5 mu m)/Cu (2 mu m)/SU-8 (3 mu m) beam structure driven by electrostatic force, which is fabricated on a silicon substrate with a resistivity of similar to 5 Omega cm. Experimental results show that the switch can exhibit better than -4.48 dB insertion loss and -28.2 dB isolation up to 12 GHz. Such a large insertion loss is mainly caused by substrate loss which can be further reduced down to -0.75 dB as long as the substrate resistivity is increased up to 100 Omega cm.
Nano Approach Investigation of the Conduction Mechanism in Polyaniline Nanofibers
(2011-02-01)
Lin, Yen-Fu
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Chen, Chien-Hsiang
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Xie, Wen-Jia
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Yang, Sheng-Hsiung
;
Hsu, Chain-Shu
A nanotechnological approach is applied to measurements of the electric field dependence of resistance under a high electric field while in low voltage. With this technique, the conduction mechanism on a mesoscopic scale is explored in a single, nonagglomerated nanofiber. Polyaniline nanofibers are prepared by vigorous mixing of aniline and oxidation agent ammonium persulfate in acid solution. They exhibit a uniform nanoscale morphology rather than agglomeration as that produced via conventional chemical oxidation. The as-synthesized polyaniline nanofibers are doped (dedoped) with a HCl acid (NH(3) base), and their temperature behaviors of resistances follow an exponential function with an exponent of T(-1/2). To measure the conduction mechanism in a single nanofiber, the dieiectrophoresis technique is implemented to position nanofibers on top of two electrodes with a nanogap of 100-600 nm, patterned by electron-beam lithography. After the devices are irradiated by electron beam to reduce contact resistances, their temperature behaviors and electric field dependences are unveiled. The experimental results agree well with the theoretical model of charging energy limited tunneling. Other theoretical models such as Efros-Shklovskii and Mott's one-dimensional hopping conduction are excluded after comparisons and arguments. Through fitting, the size of the conductive grain, separation distance between two grains, and charging energy per grain in a single polyaniline nanofiber are estimated to be about 4.9 nm, 2.8 nm, and 78 meV, respectively. The nanotechnological approach, where the nanogap and the dielectrophoresis technique are used for single nanofiber device fabrication, Is applied for determination of mesoscopic charge transport in a polyaniline conducting polymer.
Large field-induced strains in a lead-free piezoelectric material
(2011-02-01)
Zhang, J. X.
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Xiang, B.
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He, Q.
;
Seidel, J.
;
Zeches, R. J.
Piezoelectric materials exhibit a mechanical response to electrical inputs, as well as an electrical response to mechanical inputs, which makes them useful in sensors and actuators(1). Lead-based piezoelectrics demonstrate a large mechanical response, but they also pose a health risk(2). The ferroelectric BiFeO(3) is an attractive alternative because it is lead-free, and because strain can stabilize BiFeO(3) phases with a structure that resembles a morphotropic phase boundary(3). Here we report a reversible electric-field-induced strain of over 5% in BiFeO(3) films, together with a characterization of the origins of this effect. In situ transmission electron microscopy coupled with nanoscale electrical and mechanical probing shows that large strains result from moving the boundaries between tetragonal- and rhombohedral-like phases, which changes the phase stability of the mixture. These results demonstrate the potential of BiFeO(3) as a substitute for lead-based materials in future piezoelectric applications.
Analysis for diving regulator applying local heating mechanism of vapor chamber in insert molding process
(2011-02-01)
Wang, Jung-Chang
;
Li, Ai-Tsung
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Tsai, Yu-Pin
;
Hsu, Ray-Quen
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機械工程學系
This paper aims to use the local heating mechanism, along with the excellent thermal performance of vapor chamber, to analyze and enhance the strength of products formed after insert molding process. In the insert molding process, the metal insert is firstly placed into the mold, and then formed into an embedded plastic product named diving regulator by injection molding. These results indicate that, the product formed by the local heating mechanism of vapor chamber can reduce the weld line efficiency and achieve high strength, which passed the standard of 15.82 N-m torque test, with a yield rate up to 100%. (C) 2010 Elsevier Ltd. All rights reserved.
NEW HEURISTICS FOR SOLVING THE ECONOMIC LOT SCHEDULING PROBLEM WITH REWORKS
(2011-02-01)
Chang, Yu-Jen
;
Yao, Ming-Jong
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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
In this study, we are interested in the economic lot scheduling problem (ELSP) that considers manufacturing of the serviceable products and remanufacturing of the rework products. In this paper, we formulate a mathematical model for the ELSP with reworks using the common cycle approach in which only one manufacturing lot and only one rework lot for each product exist during a common cycle. In order to solve this problem, we propose two heuristics that not only search for the optimal cycle time and an optimal production sequence, but also utilize a simple scheduling heuristic to schedule the starting time of all the manufacturing and rework lots so as to minimize the average total costs. The first heuristic is a simple heuristic that employs a 2-opt search to obtain a close-to-optimal production sequence. The second heuristic, which is a refined version of the simple heuristic, employs a bisection search to look for an optimal cycle time. In our numerical experiments, we compare the effectiveness of both heuristics using randomly generated instances.
Scheduling with Centralized and Decentralized Batching Policies in Concurrent Open Shops
(2011-02-01)
Lin, B. M. T.
;
Cheng, T. C. E.
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資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This article considers batch scheduling with centralized and decentralized decisions. The context of our study is concurrent open shop scheduling where the jobs are to be processed on a set of independent dedicated machines, which process designated operations of the jobs in batches. The hatching policy across the machines can be centralized or decentralized. We study such scheduling problems with the objectives of minimizing the maximum lateness, weighted number of tardy jobs, and total weighted completion time, when the job sequence is determined in advance. We present polynomial time dynamic programming algorithms for some cases of these problems and pseudo-polynomial time algorithms for some problems that are NP-hard in the ordinary sense. (C) 2010 Wiley Periodicals, Inc. Naval Research Logistics 58: 17-27, 2011
管網滲漏偵測方法與裝置
(2011-02-01)
黃彥禎
;
葉弘德
本發明提出一種管網滲漏偵測方法，其包括步驟：建構一管網，該管網中具有至少一滲漏點與一流場；計算該流場的一穩態解；對該流場施加一擾動；以及基於該穩態解而計算該流場的一暫態解以獲得與該至少一滲漏相關的滲漏資訊。
Interview with Editor-in-Chief of IEEE Transactions on Fuzzy Systems
(2011-02-01)
Lin, Chin-Teng
;
交大名義發表
;
National Chiao Tung University
Sliding Observer for Friction Compensation in a Linear-Motor-Driven Motion System
(2011-02-01)
Horng, Rong-Hwang
;
Lee, An-Chen
;
機械工程學系
;
Department of Mechanical Engineering
In this work, a sliding-mode observer is developed for estimating unavoidable frictions and undesired disturbance in motion systems. The estimated parameters are then feedback for compensation to achieve precise control. With proper observability analysis performed by using Lie derivative method, the design of observer is based on the underlying nonlinear system with LuGre friction Model. While maintaining the stability of the observer, we choose the observer gains to make the system a dissipative one. As a conclusion in the last section, the proposed method is applied to a linear-motor-driven motion system. The experimental results show that the tracking and positioning performance with the proposed friction compensation method are smaller than those of the disturbance observer (DOB) compensation or without friction compensation.
Pharmaceutical Poisoning Exposure and Outcome Analysis in Children Admitted to the Pediatric Emergency Department
(2011-02-01)
Lin, Yan-Ren
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Liu, Tzu-Hsuan
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Liu, Tzu-An
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Chang, Yu-Jun
;
Chou, Chu-Chung
Background: Pharmaceuticals involved in childhood poisoning vary, and treatment of poison exposure can be a challenge for primary physicians when children are unconscious or histories are lacking. Knowledge of the clinical manifestations and prognosis of poisoning will help primary physicians perform appropriate clinical assessments. In this study, we aim to report on patient characteristics, outcomes, and clinical features of pediatric poisoning in the emergency department. Methods: We retrospectively evaluated the medical records of 87 children younger than 18 years of age and presented to the emergency department with pharmaceutical poisoning (2001-2008). The detailed categories of pharmaceutical were reported, and their associations with patient outcomes were analyzed. Furthermore, children were divided into two groups, based on the reasons for poison exposure (accidental or intentional poisoning). Clinical features and outcomes between accidental or intentional poisoning were analyzed, and the cut-off age for high risk of intentional poisoning was also calculated. Results: Age groups of adolescents (48.3%) and preschool age (32.2%) children were the major representation. Neurologic system agents (48.3%) and analgesics (18.4%) were the most common causes of poisoning. Among the two major agents above, anxiolytic/hypnotic drugs (lorazepam) and acetaminophen were the most frequent causes. Of all children, 70.1% had duration of major symptoms for <= 1 day, and intentional poisoning caused significantly longer duration of hospital stay than accidental poisoning did (p = 0.008). Moreover, female gender (p < 0.001), older age (p < 0.001), and analgesics (p = 0.008) were more predominantly associated with intentional poisoning in children, and the cut-off age for high risk of intentional poisoning was over 10.5 years. Conclusion: Neurologic system agents and analgesics were responsible for the majority of cases. Intentional poisoning caused longer hospital length of stay than accidental poisoning, and the factors associated with intentional poisoning were older age, female, and neurologic system agents. Copyright (C) 2011, Taiwan Pediatric Association. Published by Elsevier Taiwan LLC. All rights reserved.
Exploring Topological Defects in Epitaxial BiFeO(3) Thin Films
(2011-02-01)
Vasudevan, Rama K.
;
Chen, Yi-Chun
;
Tai, Hsiang-Hua
;
Balke, Nina
;
Wu, Pingping
Using a combination of piezoresponse force microscopy (PFM) and phase-field modeling, we demonstrate ubiquitous formation of center-type and possible ferroelectric closure domain arrangements during polarization switching near the ferroelastic domain walls in (100) oriented rhombohedral BiFeO(3). The formation of these topological defects is determined from the vertical and lateral PFM data and confirmed from the reversible changes in surface topography. These observations provide insight into the mechanisms of tip-induced ferroelastic domain control and suggest that formation of topological defect states under the action of local defect- and tip-induced fields is much more common than previously believed.