Browsing by Issue Date, starting with "2012-08"

Now showing 1 - 20 of 35853

"Dielectrophoretic placement of quasi-zero-, one-, and two-dimensional nanomaterials into nanogap for electrical characterizations"
(2012-08-01)
Lin, Yen-Fu
;
Chiu, Shao-Chien
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Wang, Sheng-Tsung
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Fu, Sheng-Kai
;
Chen, Chien-Hsiang
"DEP is one of promising techniques for positioning nanomaterials into the desirable location for nanoelectronic applications. In contrast, the lithography technique is commonly used to make ultra-thin conducting wires and narrow gaps but, due to the limit of patterning resolution, it is not feasible to make electrical contacts on ultra-small nanomaterials for a bottom-up device fabrication. Thus, integrating the lithography and dielectrophoresis, a real bottom-up fabrication can be achieved. In this work, the device with the nanogap in between two nanofinger-electrodes is made using electron-beam lithography from top down and the ultra-small nanomaterials, such as colloidal PbSe quantum dots, polyaniline nanofibers, and reduced-graphene-oxide flakes, are placed in the nanogap by DEP from bottom up. The threshold electric field for the DEP placement of PbSe nanocrystals was roughly estimated to be about 8.3 x 104 V/cm under our experimental configuration. After the DEP process, several procedures for reducing contact resistances are attempted and measurements of intrinsic electron transport in versatile nanomaterials are performed. It is experimentally confirmed that electron transport in both PbSe nanocrystal arrays and polyaniline nanofibers agrees well with Prof. Ping Sheng's model of granular metallic conduction. In addition, electron transport in reduced-graphene-oxide flakes follows Mott's 2D variable-range-hopping model. This study illustrates an integration of the electron-beam lithography and the DEP techniques for a precise manipulation of nanomaterials into electronic circuits for characterization of intrinsic properties."
A Cost-Effective Strategy for Road-Side Unit Placement in Vehicular Networks
(2012-08-01)
Wu, Tsung-Jung
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Liao, Wanjiun
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Chang, Chung-Ju
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電機工程學系
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Department of Electrical and Computer Engineering
In this paper, we study the Roadside Unit (RSU) placement problem in vehicular networks. We focus on the highway-like scenario in which there may be multiple lanes with exits or intersections along the road. In our model, each vehicle can access RSUs in two ways: 1) direct delivery, which occurs when the vehicle is in the transmission range of the RSUs, and 2) multi-hop relaying, which takes place when the vehicle is out of RSU transmission range. We account for both access patterns in our placement strategy and formulate this placement problem via an integer linear programming model such that the aggregate throughput in the network can be maximized. We also take into account the impact of wireless interference, vehicle population distribution, and vehicle speeds in the formulation. The performance of the proposed placement strategy is evaluated via ns-2 simulations together with VanetMobisim to generate vehicle mobility patterns. The results show that our strategy leads to the best performance as compared with the uniformly distributed placement and the hot spot placement. More importantly, our solution needs the least number of RSUs to achieve the maximal aggregate throughput in the network, indicating that our scheme is indeed a cost effective yet highly efficient placement strategy for vehicular networks.
Simulations of subsonic vortex-shedding flow past a 2D vertical plate in the near-continuum regime by the parallelized DSMC code
(2012-08-01)
Tseng, K. C.
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Kuo, T. C.
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Lin, S. C.
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Su, C. C.
;
Wu, J. S.
A general-purpose Parallel Direct Simulation Monte Carlo Code, named PDSC, is used to simulate near-continuum subsonic flow past a 2D vertical plate for studying the vortex-shedding phenomena. An unsteady time-averaging sampling method and a post-processing procedure called DREAM (DSMC Rapid Ensemble Averaging Method) have also been implemented, reducing the overall computational expense and improving the sampling quality of time-dependent flow problems in the rarefied flow regime. Parametric studies, including the temporal variable time step (TVTS) factor, the number of particles per cell, the domain size, and the Reynolds number, have been conducted, obtaining the Strouhal number and various aerodynamic coefficients of the flow. Results are compared to experimental data in the continuum regime available in the literature, demonstrating the capacity of PDSC and DREAM to simulate near-continuum vortex-shedding problems within acceptable computational time. (C) 2012 Elsevier B.V. All rights reserved.
Optimal two-layer directive microphone array with application in near-field acoustical holography
(2012-08-01)
Bai, Mingsian R.
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Wang, Chunkai
;
Juan, Shen-Wei
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機械工程學系
;
Department of Mechanical Engineering
Conventional near-field acoustical holography (NAH) is generally based on the free-field assumption, which can cause errors when interfering sources are present in practical environments. To cope with this problem, previous research suggested a combined pressure-velocity approach for NAH that provides certain advantages to rejection of interferences. This paper revisits this idea in a broader context of optimal array design and examines the feasibility of using unidirectional microphones in each channel of the array such that the robustness of inverse reconstruction is enhanced against interfering sources. As indicated in the simulation, the numerical noise in finite difference estimation of particle velocity can nullify the advantage of the well-conditioned velocity-based reconstruction. In the proposed approach, the characteristics of each array channel consisting of two microphones are tailored by taking into account not only the directivity, but also the robustness against self-noise. An objective function based on directivity index and white noise gain is exploited in a linear quadratic optimization of a two-element end-fire array. The proposed optimal array is validated in conjunction with the equivalent source model (ESM) -based NAH through numerical simulations, with an interfering source positioned behind the array. The results have shown the directive optimal array has yielded improved quality of images in comparison with conventional approaches in the presence of an interfering source and sensor noise. (C) 2012 Acoustical Society of America. [http://dx.doi.org/10.1121/1.4734238]
Generating tri-chaos attractors with three positive Lyapunov exponents in new four order system via linear coupling
(2012-08-01)
Li, Shih-Yu
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Huang, Sheng-Chieh
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Yang, Cheng-Hsiung
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Ge, Zheng-Ming
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機械工程學系
This paper presents a new hyperchaotic system with three positive Lyapunov exponents (called Tri-Chaos). Via linear coupling, Mathieu, and van der Pol systems are coupled with each other and then become a new four order system-Mathieu-van der Pol autonomous system. As we know, two positive Lyapunov exponents confirm hyperchaotic nature of its dynamics and it means that the system can present more complicated behavior than ordinary chaos. We further generate three positive Lyapunov exponents in a new coupled nonlinear system and anticipate the advanced application in secure communication. Not only a new chaotic system with three Lyapunov exponents is proposed, but also its implementation of an electronic circuit is put into practice in this article. The phase portrait, electronic circuit, power spectrum, Lyapunov exponents, and 2-D and 3-D parameter diagram of tri-chaos with three positive Lyapunov exponents of the new system will be shown in this paper.
交大資訊人
(2012-08)
College of Computer Science
;
資訊學院
[院長的話] P.1 [產學合作] P.2 交大「鑽石計畫」資通實驗室推展產學合作 [國際學術交流] P.3 資訊學院盛邀國際知名學者蒞校交流拓廣國際視野 [人物專訪] P.5 曾煜棋院長-大膽假設、勇於發想，化腐朽為神奇陳志成所長-培養獨立研究精神堅持不懈克服萬難 [資訊系友] P.7 台電董座黃重球：把握學習機會豐富生命內涵資工人永遠的家-「資訊系友會」 [獲獎捷報] P.9 [學生獲獎] P.10 魏綾音、張郡庭同學榮獲 Google 安妮塔博格紀念獎學金 [活動花絮] P.11 100 學年度資公小畢典：帶著資工精神飛往錦繡前程 [院系消息] P.13 資訊學院課程大翻新 101 學年度正式實施發行人 / 曾煜棋院長；顧問 / 莊榮宏副院長
New water-soluble highly selective fluorescent chemosensor for Fe (III) ions and its application to living cell imaging
(2012-08-01)
Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
A new rhodamine-based chemosensor exhibits excellent selectivity for Fe3+ ions over a wide range of tested metal ions Ag+, Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ in an aqueous solution. The binding of Fe3+ to chemosensor 1 produces an absorption band at 564 nm and an emission band at 588 nm because Fe3+-binding induces ring-opening of the spirolactam in 1. The binding ratio of the 1-Fe3+ complexes was determined to be 1:1 according to a Job plot. The association constant (K-a) of Fe3+ binding in chemosensor 1 was 6.9 x 10(3) M-1. The maximum fluorescence enhancement caused by Fe3+ binding in chemosensor 1 occurred at a pH range of 6-7.5. The fluorescence microscopy experiments in this study demonstrated that chemosensor 1 can be used as a fluorescent probe for detecting Fe3+- in living cells. (C) 2012 Elsevier B.V. All rights reserved.
Study of Reliable Control Via an Integral-Type Sliding Mode Control Scheme
(2012-08-01)
Liang, Yew-Wen
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Ting, Li-Wei
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Lin, Li-Gang
;
電機工程學系
;
Department of Electrical and Computer Engineering
This paper studies the active reliable control issues for a class of second-order nonlinear uncertain systems using an integral-type sliding mode control (ISMC) strategy. The proposed ISMC reliable scheme is shown to be able to tolerate some of the actuators' faults whenever the fault detection and diagnosis information is available. The presented scheme also maintains the main advantages of the ISMC designs, including robustness, rapid response, and ease of implementation. When the uncertainties and the output of the faulty actuators are matched regarding the nominal healthy subsystem, the state trajectories of the nominal healthy subsystem and the uncertain faulty system are identical. As a result, the engineers may adopt an optimal strategy for the nominal system, creating a desired trajectory for that of the uncertain faulty system to follow. Simulation results demonstrate the benefits of the proposed scheme.
An Intelligent Knowledge-Based and Customizable Home Care System Framework with Ubiquitous Patient Monitoring and Alerting Techniques
(2012-08-01)
Chen, Yen-Lin
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Chiang, Hsin-Han
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Yu, Chao-Wei
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Chiang, Chuan-Yen
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Liu, Chuan-Ming
This study develops and integrates an efficient knowledge-based system and a component-based framework to design an intelligent and flexible home health care system. The proposed knowledge-based system integrates an efficient rule-based reasoning model and flexible knowledge rules for determining efficiently and rapidly the necessary physiological and medication treatment procedures based on software modules, video camera sensors, communication devices, and physiological sensor information. This knowledge-based system offers high flexibility for improving and extending the system further to meet the monitoring demands of new patient and caregiver health care by updating the knowledge rules in the inference mechanism. All of the proposed functional components in this study are reusable, configurable, and extensible for system developers. Based on the experimental results, the proposed intelligent homecare system demonstrates that it can accomplish the extensible, customizable, and configurable demands of the ubiquitous healthcare systems to meet the different demands of patients and caregivers under various rehabilitation and nursing conditions.
Probability Models for the Splitting Discovery Algorithm in Wireless Networks
(2012-08)
Gau, Rung-Hung
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電機工程學系
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Department of Electrical and Computer Engineering
In this letter, we propose probability models and derive novel analytical results for the splitting discovery algorithm, which could be applied to medium access control and leader selection in wireless networks. When the splitting discovery algorithm is applied to wireless medium access control, we derive the expected value and the probability distribution function for the number of steps it takes to discover the node with the largest instantaneous channel gain. In addition, we derive the corresponding network throughput. We show that our equation-based numerical results are consistent with event-based simulation results.
Recognizing tactic patterns in broadcast basketball video using player trajectory
(2012-08-01)
Chen, Hua-Tsung
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Chou, Chien-Li
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Fu, Tsung-Sheng
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Lee, Suh-Yin
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Lin, Bao-Shuh P.
"The explosive growth of the sports fandom inspires much research on manifold sports video analyses and applications. The audience, sports fans, and even professionals require more than traditional highlight extraction or semantic summarization. Computer-assisted sports tactic analysis is inevitably in urging demand. Recognizing tactic patterns in broadcast basketball video is a challenging task due to its complicated scenes, varied camera motion, frequently occlusions between players, etc. In basketball games, the action screen means that an offensive player perform a blocking move via standing beside or behind a defender for freeing a teammate to shoot, to receive a pass, or to drive in for scoring. In this paper, we propose a screen-strategy recognition system capable of detecting and classifying screen patterns in basketball video. The proposed system automatically detects the court lines for camera calibration, tracks players, and discriminates the offensive/defensive team. Player trajectories are calibrated to the real-world court model for screen pattern recognition. Our experiments on broadcast basketball videos show promising results. Furthermore, the extracted player trajectories and the recognized screen patterns visualized on a court model indeed assist the coach/players or the fans in comprehending the tactics executed in basketball games informatively and efficiently. (C) 2012 Elsevier Inc. All rights reserved."
Dynamic multiple criteria decision making in changeable spaces: from habitual domains to innovation dynamics
(2012-08-01)
Yu, Po-Lung
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Chen, Yen-Chu
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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
"Human behaviors involve dynamic, evolving, interactive and adaptive processes. Important decision makings usually are dynamic, involving multiple criteria in changeable spaces. This article introduces the behavior mechanism that integrates the findings of neural science, psychology, system science, optimization theory and multiple criteria decision making. It shows how our brain and mind operate and describes our behaviors and decision making as dynamic processes of multiple criteria decision making in changeable spaces. Unless extraordinary events occur or special effort exerted, the dynamic processes will be stabilized in certain domains, known as Habitual Domains. Habitual Domains, which play a vital role in upgrading the quality of our decision making and lives, will be explored. In addition, as important consequential derivatives, concepts of Competence Set Analysis and Innovation Dynamics will also be discussed. Note that these concepts involve transitions between dynamic and static states."
The Immersed Boundary Method for Two-Dimensional Foam with Topological Changes
(2012-08-01)
Kim, Yongsam
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Seol, Yunchang
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Lai, Ming-Chih
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Peskin, Charles S.
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數學建模與科學計算所(含中心)
We extend the immersed boundary (IB) method to simulate the dynamics of a 2D dry foam by including the topological changes of the bubble network. In the article [Y. Kim, M.-C. Lai, and C. S. Peskin, J. Comput. Phys. 229: 5194-5207, 2010], we implemented an IB method for the foam problem in the two-dimensional case, and tested it by verifying the von Neumann relation which governs the coarsening of a two-dimensional dry foam. However, the method implemented in that article had an important limitation; we did not allow for the resolution of quadruple or higher order junctions into triple junctions. A total shrinkage of a bubble with more than four edges generates a quadruple or higher order junction. In reality, a higher order junction is unstable and resolves itself into triple junctions. We here extend the methodology previously introduced by allowing topological changes, and we illustrate the significance of such topological changes by comparing the behaviors of foams in which topological changes are allowed to those in which they are not.
An investigation of natural convection of three dimensional horizontal parallel plates from a steady to an unsteady situation by a CUDA computation platform
(2012-08-01)
Fu, Wu-Shung
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Wang, Wei-Hsiang
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Huang, Shang-Hao
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機械工程學系
;
Department of Mechanical Engineering
"The heat transfer of natural convection in three dimensional horizontal parallel plates with a heated bottom surface is investigated numerically. For enlarging the application domain, the compressibility of the fluid is taken into consideration instead of the Boussinesq assumption. Numerical methods of the Roe scheme, preconditioning and dual time stepping are adopted for solving governing equations of a low speed compressible flow. A non-reflection condition is used at both apertures in order to decrease computational grids and a CUDA computational platform is developed to economize massive computing time. Variations of thermal and flow fields are examined in detail. The results show that accompanied with elongating the length of the heated bottom surface, both thermal and flow fields are changed from a steady to an unsteady situation. (C) 2012 Elsevier Ltd. All rights reserved."
A CLOUD MODEL AND CONCEPT PROTOTYPE FOR COGNITIVE RADIO NETWORKS
(2012-08-01)
Wu, Sau-Hsuan
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Chao, Hsi-Lu
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Ko, Chun-Hsien
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Mo, Shang-Ru
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Jiang, Chung-Ting
The FCC's approval for the first commercial operation in TV white space gives new momentum to the development of cognitive radio in TVWS. On the other hand, the rapid growth of Cloud computing makes it possible and more economical to build a CR metropolitan area network with commodity hardware. In view of the opportunity and challenges brought about by these two technologies, we propose a CR cloud networking model that is able to support CR access in TVWS. Making use of the flexible and vast computing capacity of the cloud, a database and a cooperative spectrum sensing algorithm that estimates the radio power map of licensed users are realized on a CR cloud implemented with Microsoft's Windows Azure Cloud platform. The CRC can support CSS, dynamic spectrum access and mobility management. A medium access control protocol is also developed for this CRCN model to collect sensing reports and provide access to the TVWS and CRC services. Through this CRCN prototype, important network parameters such as the mean squared errors in CSS, the CR channel vacating delay, and the cloud-based handover time are measured for the design and deployment of the CRCN concept.
Bi-criteria minimization for the permutation flowshop scheduling problem with machine-based learning effects
(2012-08-01)
Chung, Yu-Hsiang
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Tong, Lee-Ing
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工業工程與管理學系
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Department of Industrial Engineering and Management
In traditional scheduling problems, the processing time for the given job is assumed to be a constant regardless of whether the job is scheduled earlier or later. However, the phenomenon named "learning effect" has extensively been studied recently, in which job processing times decline as workers gain more experience. This paper discusses a bi-criteria scheduling problem in an m-machine permutation flowshop environment with varied learning effects on different machines. The objective of this paper is to minimize the weighted sum of the total completion time and the makespan. A dominance criterion and a lower bound are proposed to accelerate the branch-and-bound algorithm for deriving the optimal solution. In addition, the near-optimal solutions are derived by adapting two well-known heuristic algorithms. The computational experiments reveal that the proposed branch-and-bound algorithm can effectively deal with problems with up to 16 jobs, and the proposed heuristic algorithms can yield accurate near-optimal solutions. (C) 2012 Elsevier Ltd. All rights reserved.
Quartz-Blazed Grating Applied on Autostereoscopic Display
(2012-08-01)
Chen, Chien-Yue
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Deng, Qing-Long
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Lin, Bor-Shyh
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Hung, Wen-Cheng
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光電系統研究所
By applying reactive ion etching (RIE) to a blazed grating on quartz substrates, the grating can be utilized as a splitter in autostereoscopic displays. Furthermore, a solution for the pattern alignment on transparent substrates is also proposed. By measuring the diffraction efficiency and crosstalk between the left and right fields of view (FOV), the capability of the element to deliver stereoscopic images is demonstrated.
Using analytic network process and turbo particle swarm optimization algorithm for non-balanced supply chain planning considering supplier relationship management
(2012-08-01)
Che, Z. H.
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Chiang, Tzu-An
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Che, Zhen-Guo
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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
"Supply chain planning has been regarded as a key strategic decision-making activity for the enterprises under the current business circumstances. From the point of supply chain planning, the important issues are to find suitable and quality partners and to decide upon an appropriate production-distribution plan. In this study, hence, we address to develop a decision methodology for supply chain planning in multi-echelon non-balanced supply chain system, taking into account such four criteria as cost, quality, delivery and supplier relationship management and considering quantity discount and capacity constraints. The proposed methodology is based on the analytic network process and turbo particle swarm optimization (TPSO), to evaluate partners and to determine an optimal supply chain network pattern and production-distribution mode. Finally, to demonstrate the performance of the proposed TPSO algorithm, comparative numerical experiments are performed by TPSO, particle swarm optimization (PSO) and genetic algorithm (GA). Empirical analysis results demonstrate that TPSO can outperform PSO and GA in non-balanced supply chain planning problems."
A New Prosody-Assisted Mandarin ASR System
(2012-08-01)
Chen, Sin-Horng
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Yang, Jyh-Her
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Chiang, Chen-Yu
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Liu, Ming-Chieh
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Wang, Yih-Ru
This paper presents a new prosody-assisted automatic speech recognition (ASR) system for Mandarin speech. It differs from the conventional approach of using simple prosodic cues on employing a sophisticated prosody modeling approach based on a four-layer prosody-hierarchy structure to automatically generate 12 prosodic models from a large unlabeled speech database by the joint prosody labeling and modeling (PLM) algorithm proposed previously. By incorporating these 12 prosodic models into a two-stage ASR system to rescore the word lattice generated in the first stage by the conventional hidden Markov model (HMM) recognizer, we can obtain a better recognized word string. Besides, some other information can also be decoded, including part of speech (POS), punctuation mark (PM), and two types of prosodic tags which can be used to construct the prosody-hierarchy structure of the testing speech. Experimental results on the TCC300 database, which consists of long paragraphic utterances, showed that the proposed system significantly outperformed the baseline scheme using an HMM recognizer with a factored language model which models word, POS, and PM. Performances of 20.7%, 14.4%, and 9.6% in word, character, and base-syllable error rates were obtained. They corresponded to 3.7%, 3.7%, and 2.4% absolute (or 15.2%, 20.4%, and 20% relative) error reductions. By an error analysis, we found that many word segmentation errors and tone recognition errors were corrected.
Mesogenic Schiff Base with Bromo End Group: Synthesis and Thermotropic Properties
(2012-08-01)
Ha, Sie-Tiong
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Lee, Teck-Leong
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Lin, Hong-Cheu
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Ito, Masato M.
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Abe, Kazuma
A new homologous series of Schiff base esters comprising a terminal bromo substituent was studied. The bromo substituent contributes to the molecular polarizability, thus, affecting intermolecular interactions, hence, resulting in smectic polymorphism. The mesomorphic properties were studied using differential scanning calorimeter and polarizing optical microscope attached to a Linkam hotstage. Whilst the lower members, n-ethanoyloxy and n-butanoyloxy derivatives were non-mesogens, n-hexanoyloxy member exhibited monotropic (less stable) smectic A and smectic B phases. Further lengthening of the alkanoyloxy chain from C8 to C12 (medium members), led to formation of enantiotropic (more stable) smectic A and smectic B mesophases based on the observation of both phases during heating and cooling cycles. The high members of the series, C14, C16 and C18 exhibited enantiotropic smectic A phase and monotropic smectic B phase. The homologous members were compared with structurally related series to establish their chemical structure-mesomorphic behaviour relationships.