Browsing by Issue Date, starting with "2007-05-31"

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Device and method for integrating sound effect processing and active noise control
(2007-05-31)
Bai, Mingsian R.
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Ou, Kuen-Ying
;
Lin, Jain-Liang
A device and a method for integrating 3D sound effect processing and active noise control are proposed. A digital signal processor incorporates an artificial reverberator and a 3D spatial audio processor into an audio module. The audio signal is presented via an earphone. Next, a microphone embedded in the vicinity of the loudspeaker inside the headset is used to sense an external noise while playing, and feed it back to an active noise controller, which generates an anti-noise to eliminate the external noise. Therefore, the signal to noise ratio can be increased and the 3D sound field effect can be significantly enhanced. In addition, a head-related transfer function is more efficiently implemented on the basis of an interaural transfer function in the spatial audio processing to reduce the filter order lower and hence the computation loading.
Method and apparatus for telephone routing between PTN and PSTN
(2007-05-31)
Chang, Ming-Feng
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Lin, Yi-Bing
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Liang, Ching-Feng
Disclosed is a method and apparatus applicable to an interface between PSTN and PTN for telephone routing. The interface includes a branch switch, a key system, a network branch switch, and media gateway, etc. The telephone routing method and apparatus of the present invention creates, maintains, and utilizes a call-back routing table to enable a specified PSTN user to call the callback external leased line to reach a specified PTN user in a one-stage dialing manner. The process of one-stage dialing includes PTN call origination to PSTN, PSTN call origination to PTN, and callback tag insertion in the call-back routing table. The call-back routing table consists of a plurality of call-back tags. Each call-back tag consists of at least a data triple, i.e. PTN user identifier, PSTN called party telephone number, and callback leased line identifier.
Vertical-channel organic thin-film transistors with meshed electrode and low leakage current
(2007-06-01)
Zan, Hsiao-Wen
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Yen, Kuo-Hsi
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光電工程學系
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顯示科技研究所
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Department of Photonics
In this study, we have successfully fabricated vertical-channel organic thin-film transistors with a channel length smaller than 100nm. It is found that Fowler-Nordheim tunneling is the dominant mechanism determining the ultra short-channel device behavior. To improve the gate control capability, a meshed source electrode pad had been used. This significantly lowers the gate and drain driving voltages (<10V), improves the saturation characteristics and reduces the leakage current. The improvement may be due to the fringing field around the source electrode, which suppresses the tunneling effect.
Chaos in a modified van der Pol system and in its fractional order systenis
(2007-06-01)
Ge, Zheng-Ming
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Zhang, An-Ray
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機械工程學系
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Department of Mechanical Engineering
Chaos in a modified van der Pot system and in its fractional order systems is studied in this paper. It is found that chaos exists both in the system and in the fractional order systems with order from 1.8 down to 0.8 much less than the number of states of the system, two. By phase portraits, Poincare maps and bifurcation diagrams, the chaotic behaviors of fractional order modified van der Pot systems are presented. (c) 2005 Elsevier Ltd. All rights reserved.
Universal share for the sharing of multiple images
(2007-06-01)
Fang, Wen-Pinn
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Lin, Ja-Chen
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資訊工程學系
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Department of Computer Science
To share numerous grey-valued images (or numerous color-valued images), this study presents a system with a universal share. A company organizer can use this universal share to attend the recovery meeting of any shared image. No storage space is wasted; i.e. for each shared image, the total storage space occupied by all generated shares (including the universal share) is identical to the image size.
Magneto-electrodynamical modeling and design of a microspeaker used for mobile phones with considerations of diaphragm corrugation and air closures
(2007-06-01)
Chao, Paul C. -P.
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Chiu, Chi-Wei
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Hsu-Pang, Yuan
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電控工程研究所
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Institute of Electrical and Control Engineering
Recent design trends for modern mobile phones are evolving to be miniaturized and versatile sounds in quality. To these ends, a microspeaker with a corrugated diaphragm is employed to broaden the sound frequency range. Due to the fact that diaphragm corrugation and air closures were not considered in any past studies, this study presents comprehensive modeling with the consideration of diaphragm corrugations and air closures. It starts with the modeling on the subsystems of the voice coil motor (VCM) in the speaker. The magnetic field of the VCM is modeled by one set of finite elements, while the corrugated diaphragm is modeled by another set of finite elements. In addition, the air closures above or below the diaphragm are modeled by the third group of finite elements based on basic acoustics. Simulations are conducted with and without air closures. It is found that: 1) the speaker with 45 degrees corrugation exhibits overall higher (better) sound pressure levels (SPLs), while 2) the 75 degrees corrugation leads to unsatisfied, low SPLs below 1 kHz and two undesired antiresonances at higher frequencies. The theoretical findings are successfully validated by experiments.
AlGaInAs quantum-well as a saturable absorber in a diode-pumped passively Q-switched solid-state laser
(2007-06-01)
Huang, S. C.
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Liu, S. C.
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Li, A.
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Su, K. W.
;
Chen, Y. F.
We demonstrate what is believed to be the first use of AlGaInAs quantum wells (QWs) as a saturable absorber in the Q switching of a high-power diode-pumped Nd-doped 1.06 mu m laser. The barrier layers are designed to locate the QW groups in the region of the nodes of the lasing standing wave to avoid damage. With an incident pump power of 13.5 W, an average output power of 3.5 W with a Q-switched pulse width of 0.9 ns at a pulse repetition rate of 110 kHz was obtained. (c) 2007 Optical Society of America.
Robust environmental change detection using PTZ camera via spatial-temporal probabilistic modeling
(2007-06-01)
Hu, Jwu-Sheng
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Su, Tzung-Min
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper proposes a novel procedure for detecting environmental changes by using a pan-tilt-zoom (PTZ) camera. Conventional approaches based on pixel space and stationary cameras need time-consuming image registration to yield pixel statistics. This work proposes an alternative approach to describe each scene with a Gaussian mixture model (GMM) via a spatial-temporal statistical method. Although details of the environment covered by the camera are lost; this model is efficient and robust in recognizing scene and detecting scene changes in the environment. Moreover, the threshold selection for separating different environmental changes is convenient by using the proposed framework. The effectiveness of the proposed method is demonstrated experimentally in an office environment.
Preparation of UV-curable intercalated/exfoliated epoxide/acrylateclays nanocomposite resins
(2007-06-01)
Wang, Yu-Young
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Hsieh, Tsung-Eong
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材料科學與工程學系
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Department of Materials Science and Engineering
Preparation of UV-curable intercalated/exfoliated epoxide/acrylateclays nanocomposite resins with the addition of specific monomers and solvent via the consideration of solubility parameter and chemical reactivity was carried out in this work. Due to the good compatibility with surfactant in acrylateclays and the cationic oligorner in resin matrix, the two additive monomers dispersed uniformly in resin matrix with the swollen acrylateclays before UV curing. As revealed by conversion ratio and DTG analyses, chemical bonds between the two additive monomers, the cationic oligomers and surfactant in acrylateclays were formed during UV irradiation. This, in turn, generated a hybrid acrylate-based/epoxy network and effectively enlarged the lamellae spacing of inorganic clays in nanocomposite resins prepared in this work. The XRD and TEM characterizations revealed that the intercalated clay domains containing exfoliated lamellae about 1 nm in thickness uniformly disperse in polymeric matrix. The nanocomposite resin containing 5 wt.% inorganic filler possessed the physical properties as follows: Td-5% = 213 degrees C, CTE = 80.5 ppm/degrees C, moisture absorption = 6.12%, average optical transmittance = 83.17%, and adhesion strength on glass substrate = 43.8 kgf/cm(2). The analyses above indicated that the formation of polymeric interpenetrating networks and nanometer-scale exfoliation of clay lamellae not only improve the thermal properties and resistance to moisture permeation, but also retain highly optical transmittance and satisfactory adhesion strength of nanocomposite resins prepared in this work. A better device lifetime property was hence achieved when the nanocomposite resins were applied to the packaging of OLEDs.
Investigating the value of information sharing in multi-echelon supply chains
(2007-06-01)
Chen, Mu-Chen
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Yang, Taho
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Yen, Chi-Tsung
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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
Under the structure of multiple business entities, supply chain management (SCM) offers the external and internal integration of business processes in enterprises. The most important objective of SCM is to enhance the supply chain performance such as reinforcing the service level and increasing profit as well as reducing order cycle time and inventory. In recent years, due to the advancement of information technology, enterprises can manage the product flow and the information flow via economical and efficient mechanisms. The well-organized information sharing can enhance the supply chain performance and allow enterprises to refine their strategies of supply chain in order to maximize their profits. The previous studies pointed out the positive effect of information sharing on the efficiency of supply chain. However, relatively little literature focuses on the performance analysis for multi-echelon supply chain with various information sharing scenarios. By using the simulation technique, this paper models different scenarios of information sharing, and further analyzes the impacts of information quality on multi-echelon supply chain performance. In addition, this paper employs Data Envelopment Analysis (DEA) to integrate multiple performance measures to ensure the information sharing scenarios with enhanced performance.
A hybrid fuzzy-optimization approach to customer grouping-based logistics distribution operations
(2007-06-01)
Sheu, Jiuh-Biing
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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 an integrated fuzzy-optimization customer grouping based logistics distribution methodology for quickly responding to a variety of customer demands. The proposed methodology involves three main mechanisms: (1) pre-route customer classification using fuzzy clustering techniques, (2) determination of customer group-based delivery service priority and (3) en-route goods delivery using multi-objective optimization programming methods. In the process of pre-route customer classification, the proposed method groups customers' orders primarily based on the multiple attributes of customer demands, rather than by static geographic attributes, which are mainly considered in classical vehicle routing algorithms. Numerical studies including a real-world application are conducted to illustrate the applicability of the proposed method and its potential advantages over existing operational strategies. Using the proposed method, it is shown that the overall performance of a logistics distribution system can be improved by more than 20%, according to the numerical results from the case studied. (c) 2006 Elsevier Inc. All rights reserved.
An efficient code generation algorithm for non-orthogonal DSP architecture
(2007-06-01)
Lee, Yi-Hsuan
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Chen, Cheng
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資訊工程學系
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Department of Computer Science
To meet strict speed and power requirements for embedded applications, many high-end digital Signal Processors (DSPs) commonly employ non-orthogonal architectures that are typically characterized by irregular data paths, heterogeneous registers, and multiple memory banks. Obviously to harvest the benefits provided by this non-orthogonal architecture sufficient compiler support is necessary and important. However, the complexity of such architectures presents a great challenge to compiler design and the usual compilation techniques for general-purpose CPUs do not adapt well to the irregularity of DSP. The entire code generation process must include the following phases: intermediate representation, code compaction, instruction scheduling, memory bank assignment (or variable partition), and register/accumulator assignment. Much related research only considers some phases, which is inadequate. In this paper, we present an effective code generation algorithm named Rotation Scheduling with Spill Codes Predicting (RSSP) to maximally exploit the benefits of non-orthogonal architectures. It contains six parts that cover almost the entire phases of the code generation process. As well as introducing the detailed principles and algorithms of the proposed RSSP, we use an analytic model to evaluate its preliminary performance. Evaluation results clearly demonstrate the effectiveness of the proposed method. Furthermore, we also present some preliminary ideas to generalize RSSP, which can make it more practicable and suit various DSPs with similar architectural features.
A note on parallel-machine scheduling with deteriorating jobs
(2007-06-01)
Jeng, A. A. K.
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Lin, B. M. T.
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資訊工程學系
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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 Computer Science
We consider a parallel-machine scheduling problem of minimizing the total completion time. The processing time of a job is a linear function of its starting time and deterioration rate. This problem is known to be NP-hard, even for the case with two machines. In this note, we generalize an existing lower bound for the two-machine case to the general case with an arbitrary number of machines. Despite the generalization concerning machine number, our bound has one extra term that makes our bound tighter than the existing one.
The effects of prosodic boundaries on nasality in Taiwan Min
(2007-06-01)
Pan, Ho-hsien
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外國語文學系
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Department of Foreign Languages and Literatures
This study explores the effects of prosodic boundaries on nasality at intonational phrase, word, and syllable boundaries. The subjects were recorded saying phrases that contained a syllable-final nasal consonant followed by a syllable-initial stop. The timing, duration, and magnitude of the nasal airflows measured were used to determine the extent of nasality across boundaries. Nasal amplitudes were found to vary in a speaker-dependent manner among boundary types. However, the patterns of nasal contours and temporal aspects of the airflow parameters consistently varied with boundary type across all the speakers. In general, the duration of nasal airflow and nasal plateau were the longest at the intonational phrase boundary, followed by word boundary and then syllable boundary. In addition-to the hierarchical influence of boundary strength, there were unique phonetic markings associated with individual boundaries. In particular, two nasal rises interrupted by nasal inhalation occurred only across an intonation phrase boundary. Also, unexpectedly, a word boundary was marked by the longest postboundary vowel, whereas a syllable boundary was marked with the shortest nasal duration. The results here support the hierarchical effect of boundary on both domain-edge strengthening and cross-boundary coarticulation. (c) 2007 Acoustical Society of America.
Exploring design features for enhancing players' challenge in strategy games
(2007-06-01)
Hsu, Shang Hwa
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Wen, Ming-Hui
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Wu, Muh-Cherng
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工業工程與管理學系
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Department of Industrial Engineering and Management
This paper examines how to make a player feel more challenged in a strategic computer game. It is hypothesized that information availability and resource advantage affect play difficulty, which in turn affects the challenge experienced. The difficulty of play can be defined in terms of the mental workload that players experience and the physical effort that players exert. Forty-five male college and graduate students participated in a 3 x 3 ( information availability x resource advantage) between-subjects factorial design experiment. This experiment measured player mental workload, physical effort, and challenge. The results indicate that information availability affects player mental workload, and resource advantage affects levels of player physical effort, respectively. Moreover, the relationship between mental workload and challenge was found to be an inverted U-shaped curve; in other words, too much or too little mental workload may decrease player challenge. The relationship between physical effort and challenge exhibited similar characteristics.
Novel optomechanical alignment method using a numerical optimization methodology
(2007-06-01)
Lin, Tsung Y.
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Yu, M. T.
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Liu, W. T.
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機械工程學系
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Department of Mechanical Engineering
Alignment of optomechanical components is important when designing and manufacturing optical systems. This study used an optical fiber as a case study to develop an alignment method. The core diameter of a single-mode fiber is about 9 mu m, and any slight misalignment or deformation of the optical mechanism will cause significant optical losses in connections. Previous studies have shown that the currently used alignment methods are not efficient, and the precise position for the connection is not easy to locate. This study proposes a two-stage method to overcome these problems. In the first stage, the Nelder-Mead simplex method is used to move quickly to the optimum solution. In the second stage, a numerical optimization method is used to improve the accuracy. This study compares different numerical optimization method that can be used to find the ideal connection position. It can be concluded that the most stable method for the search direction is the steepest-descent method, because the light intensity distribution is similar to a Gaussian one, and the most efficient method for the step-size determination is polynomial interpolation. Therefore, the second stage uses the steepest-descent method with polynomial interpolation. (c) 2007 Society of Photo-Optical Instrumentation Engineers.
Robust mixture modeling using the skew t distribution
(2007-06-01)
Lin, Tsung I.
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Lee, Jack C.
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Hsieh, Wan J.
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統計學研究所
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資訊管理與財務金融系註：原資管所+財金所
A finite mixture model using the Student's t distribution has been recognized as a robust extension of normal mixtures. Recently, a mixture of skew normal distributions has been found to be effective in the treatment of heterogeneous data involving asymmetric behaviors across subclasses. In this article, we propose a robust mixture framework based on the skew t distribution to efficiently deal with heavy-tailedness, extra skewness and multimodality in a wide range of settings. Statistical mixture modeling based on normal, Student's t and skew normal distributions can be viewed as special cases of the skew t mixture model. We present analytically simple EM-type algorithms for iteratively computing maximum likelihood estimates. The proposed methodology is illustrated by analyzing a real data example.
Feature selection and combination criteria for improving accuracy in protein structure prediction
(2007-06-01)
Lin, Ken-Li
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Lin, Chun-Yuan
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Huang, Chuen-Der
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Chang, Hsiu-Ming
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Yang, Chiao-Yun
The classification of protein structures is essential for their function determination in bioinformatics. At present, a reasonably high rate of prediction accuracy has been achieved in classifying proteins into four classes in the SCOP database according to their primary amino acid sequences. However, for further classification into fine-grained folding categories, especially when the number of possible folding patterns as those defined in the SCOP database is large, it is still quite a challenge. In our previous work, we have proposed a two-level classification strategy called hierarchical learning architecture (HLA) using neural networks and two indirect coding features to differentiate proteins according to their classes and folding patterns, which achieved an accuracy rate of 65.5%. In this paper, we use a combinatorial fusion technique to facilitate feature selection and combination for improving predictive accuracy in protein structure classification. When applying various criteria in combinatorial fusion to the protein fold prediction approach using neural networks with HLA and the radial basis function network (RBFN), the resulting classification has an overall prediction accuracy rate of 87% for four classes and 69.6% for 27 folding categories. These rates are significantly higher than the accuracy rate of 56.5% previously obtained by Ding and Dubchak. Our results demonstrate that data fusion is a viable method for feature selection and combination in the prediction and classification of protein structure.
Theory and design of near-optimal MIMO OFDM transmission system for correlated multipath Rayleigh fading channels
(2007-06-01)
Hung, Kun-Chien
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Lin, David W.
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電子工程學系及電子研究所
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電信研究中心
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Department of Electronics Engineering and Institute of Electronics
We consider channel-coded multi-input multi-output (MIMO) orthogonal frequency-division multiplexing (OFDM) transmission and obtain a condition on its signal for it to attain the maximum diversity and coding gain. As this condition may not be realizable, we propose a suboptimal design that employs an orthogonal transform and a space-frequency interleayer between the channel coder and the multi-antenna OFDM transmitter. We propose a corresponding receiving method based on block turbo equalization. Attention is paid to some detailed design of the transmitter and the receiver to curtail the computational complexity and yet deliver good performance. Simulation results demonstrate that the proposed transmission technique can outperform the conventional coded MIMO OFDM and the MIMO block single-carrier transmission with cyclic prefixing.
Corrugated parallel-coupled line bandpass filters with multispurious suppression
(2007-06-01)
Kuo, J.-T.
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Wu, M.-H.
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電信工程研究所
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Institute of Communications Engineering
Corrugated coupled stages are devised to design bandpass filters with multispurious suppression. Through two-port analysis, the suppression is found critically dependent on equality of the even and odd mode phase velocities at even harmonics of design frequency f(o). Quarter-wave (lambda/4) corrugated stages are tuned to allocate inherent transmission zeros at both 2f(o), and 4f(o), and 6f(o) for some structures, so that the circuit is free of spurious at these frequencies. Coupled stages with proper coupling lengths are arranged to cancel unwanted peaks at 3f(o), 6f(o), and 7f(o), and tapped input/output scheme is employed to tackle those at 3f(o) and 5f(o). Measured data of designed filters show rejection levels better than 30 dB in upper stopband. Three circuits are fabricated and measured to demonstrate the idea.