Browsing by Author "Lin, CY"

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A low complexity group-wise PIC based mixed-mode MIMO-OFDM system
(2004)
Deng, JH
;
Lin, CY
;
Lee, TS
;
電信工程研究所
;
Institute of Communications Engineering
A mixed-mode MIMO-OFDM system with the reduced complexity group-wise parallel interference cancellation (G-PIC) algorithm is proposed. At the transmitter, the data stream is first demultiplexed into two groups of substreams, one with capacity constraint via the spatial multiplexing (SM) mode and the other with link quality constraint via the space-time block coding (STBC) mode. At the receiver, a reduced complexity GPIC is proposed to separate the transmitted streams from different antennas and is based on the following procedures: First, a group-wise MMSE detector and ordering strategy are designed for each group to provide reliable initial decisions for recursive PIC. Second, a recursive group-wise detector, which consists of a conventional PIC, subspace projector and reduced size NIL searcher, is developed. Simulation results show that the proposed reduced complexity G-PIC provides almost identical performance compared to the conventional BLAST and relatively lower computational load.
A method to extract spots from the image of the ELISA (Enzyme-Linked Immunosorbent Assay) Spot Assay
(2001)
Lin, CY
;
Ching, YT
;
Wu-Hsieh, BA
;
資訊工程學系
;
Department of Computer Science
ELISA (Enzyme-Linked Immunosorbent Assay) Spot Assay is a method widely used by immunologists to enumerate cytokine-producing cells within a specific cell population. The result of ELISA is presented in an image containing numerous color spots. We present a method to extract and to count the number of spots. The proposed method is based on color analysis. Since CIE L(*)u(*)v(*) space have linear perceptibility of color differences, we convert the RGB space to L(*)u(*)v(*) space. The system is trained to obtain the standard color of the spots and get the color difference image in L(*)u(*)v(*) space. According to the feature of the spots we design a special matched filters to filter out the noise and enhance the spots. Finally a binary image is obtained. In the binary images, pixels in the spots have gray scale 255 and the others are 0. Our design makes it easy to analyze the perimeter and size of the spots in addition to counting them in the binary image.
A multi-channel MAC protocol with power control for multi-hop mobile ad hoc networks
(2001)
Tseng, YC
;
Wu, SL
;
Lin, CY
;
Sheu, JP
;
資訊工程學系
In a mobile ad-hoc networks (MANET), one essential issue is Medium Access Control (MAC), which addresses how to utilize the radio spectrum efficiently and to resolve potential contention and collision among mobile hosts on rising the medium. Existing works have dedicated to using multiple channels [4, 6, 9. 10, 12, 18. 20] and power control [7, 13. 21] to improve the performance of MANET: III this paper.,ve investigate the possibility of bringing the concepts of power control a,ld multi-channel medium access together in the MAC design problem in a MANET: Existing protocols only address one of these issues independent): The proposed protocol is characterized by the following features: (i) it follows an "on-demand" style to assign, channels to mobile hosts. (ii) the number of channels required is independent of the network topology and degree, (iii) it flexibly adapts to host mobility: (iv) no form of clock synchronization is required, and(v) power control is used to exploit frequency reuse. Power control may also extend battery life and reduce signal interference. both of,which are important in wireless communication Through simulations, we demonstrate the advantage of our new protocol.
A multi-channel MAC protocol with power control for multi-hop mobile ad hoc networks
(2002)
Wu, SL
;
Tseng, YC
;
Lin, CY
;
Sheu, JP
;
資訊工程學系
In a mobile ad hoc network (MANET), one essential issue is Medium Access Control (MAC), which addresses how to utilize the radio spectrum efficiently and to resolve potential contention and collision among mobile hosts on using the medium. Existing works have been dedicated to using multiple channels and power control to improve the performance of MANET. In this paper, we investigate the possibility of bringing the concepts of power control and multi-channel medium access together in the MAC design problem in a MANET. Existing protocols only address one of these issues independently. The proposed protocol is characterized by the following features: (i) it follows an 'on-demand' style to assign channels to mobile hosts, (ii) the number of channels required is independent of the network topology and degree, (iii) it flexibly adapts to host mobility, (iv) no form of clock synchronization is required and (v) power control is used to exploit frequency reuse. Power control may also extend battery life and reduce signal interference, both of which are important in wireless communication. Through simulations, we demonstrate the advantage of our new protocol.
A near-optimal low-complexity transceiver for CP-free multi-antenna OFDM systems
(2006-01-01)
Lin, CY
;
Wu, JY
;
Lee, TS
;
資訊工程學系
;
電信工程研究所
Conventional orthogonal frequency division multiplexing (OFDM) system utilizes cyclic prefix (CP) to remove the channel-induced inter-symbol interference (ISI) at the cost of lower spectral efficiency. In this paper, a generalized sidelobe canceller (GSC) based equalizer for ISI suppression is proposed for uplink multi-antenna OFDM systems without CP. Based on the block representation of the CP-free OFDM system, there is a natural formulation of the ISI suppression problem under the GSC framework. By further exploiting the signal and ISI signature matrix structures, a computationally efficient partially adaptive (PA) implementation of the GSC-based equalizer is proposed for complexity reduction. The proposed scheme can be extended for the design of a pre-equalizer, which pre-suppresses the ISI and realizes CP-free downlink transmission to ease the computational burden of the mobile unit (MU). Simulation results show that the proposed GSC-based solutions yield equalization performances almost identical to that obtained by the conventional CP-based OFDM systems and are highly resistant to the increase in channel delay spread.
A novel thin-film transistor with self-aligned field induced drain
(2001-01-01)
Lin, HC
;
Yu, CM
;
Lin, CY
;
Yeh, KL
;
Huang, TY
In this letter, a novel thin-film transistor with a self-aligned field-induced-drain (SAFID) structure is reported for the first time. The new SAFID TFT features a self-aligned sidewall spacer located on top of the drain offset region to set its effective length, and a bottom gate (or field plate) situated under the drain offset region to electrically induce the field-induced-drain (FID). So, unlike the conventional off-set-gated TFTs with their effective FID length set by two separate photolithographic masking layers, the new SAFID is totally immune to photomasking misalignment errors, while enjoying the low off-state leakage as well as high turn-on characteristics inherent in the FID structure. Polycrystalline silicon TFTs with the new SAFID structure have been successfully fabricated with significant improvement in the on/off current ratio.
A platform-based MPEG-4 Advanced Video Coding (AVC) decoder with block level pipelining
(2003)
Wang, SH
;
Peng, WH
;
He, YW
;
Lin, GY
;
Lin, CY
We present a baseline MPEG-4 AVC (Advanced Video Coding) decoder based on an optimized platform-based design methodology. With this methodology, we jointly optimize the software and hardware design of the decoder. Overall decoding throughput is increased by synchronizing the software and the dedicated co-processors. The synchronization is achieved at macroblock-level pipelining. In addition, we optimize the decoder software by enhancing the frame buffer management, boundary padding, and content aware inverse transform. To speed up motion compensation and inverse transform, which are the most computationally intensive modules, two dedicated acceleration modules are realized. For comparison, the proposed prototype decoder and MPEG-4 AVC reference decoder are evaluated on an ARM platform, which is one of most popular portable devices. Our experiments show that the throughput of the MPEG-4 reference decoder can be improved by 6 to 7 times. On an ARM966 board, the optimized software without hardware acceleration can achieve a decoding rate up to 5 frames per second (fps) for QCIF video sequences. With the dedicated accelerators, the overall throughput is increased by about 30% to reach 6.6 fps on the average and is up to 10.3 fps for slow motion video sequences.
A probabilistic signal-strength-based evaluation methodology for sensor network deployment
(2005)
Kuo, SP
;
Tseng, YC
;
Wu, FJ
;
Lin, CY
;
資訊工程學系
The deployment of senor networks have attracted a lot of attention recently. In essence this issue is concerned with how well a sensing field is monitored by sensors to achieve a particular coverage. In this paper, we propose a signal-strength-based approach to evaluate how well a sensing field is covered/monitored. We first formulate object tracking by a single sensor as a Gaussian-error model. Then we establish an error model on location estimation given that the location of an object is known. This leads to a model to evaluate a sensor network with given locations of sensors. We then apply the result to several applications, such as adding more sensor nodes for error reduction and scheduling power modes (awake or sleep) of sensors, and demonstrate our simulation results.
A robust image hiding method using wavelet technique
(2006-01-01)
Lin, CY
;
Ching, YT
;
資訊工程學系
;
Department of Computer Science
A robust wavelet-based image hiding methods, that hide still images, E, inside a covered image, C, to establish a composite image, P, are presented. We can hide up to three full-size embedded images inside a cover image while maintaining the quality of the composite image. The embedded images retain easily recognizable when extracted. The embedded images can be extracted fairly completely even when lossy compression or cropping is applied to the composite image. The proposed method does not require the original cover image to extract the embedded image.
A software-hardware co-implementation of MPEG-4 Advanced Video Coding (AVC) decoder with block level pipelining
(2005-08-01)
Wang, SH
;
Peng, WH
;
He, YW
;
Lin, GY
;
Lin, CY
We present a baseline MPEG-4 Advanced Video Coding (AVC) decoder based on the methodology of joint optimization of software and hardware. The software is first optimized with algorithm improvements for frame buffer management, boundary padding, content-aware inverse transform and context-based entropy decoding. The overall decoding throughput is further enhanced by pipelining the software and the dedicated hardware at macroblock level. The decoder is partitioned into the software and hardware modules according to the target frame rate and complexity profiles. The hardware acceleration modules include motion compensation, inverse transform and loop filtering. By comparing the optimized decoder with the committee reference decoder of Joint Video Team (JVT), the experimental results show improvement on the decoding throughput by 7 to 8 times. On an ARM966 board, the optimized software without hardware acceleration can achieve a decoding rate up to 5.9 frames per second (fps) for QCIF video source. The overall throughput is improved by another 27% to 7.4 fps on the average and up to 11.5 fps for slow motion video sequences. Finally, we provide a theoretical analysis of the ideal performance of the proposed decoder.
A two-phase fuzzy mining and learning algorithm for adaptive learning environment
(2001)
Tsai, CJ
;
Tseng, SS
;
Lin, CY
;
資訊工程學系
;
Department of Computer Science
As computer-assisted instruction environment becomes more popular over the world, the analysis of historical learning records of students becomes more important. In this work, we propose a Two-Phase Fuzzy Mining and Learning Algorithm, integrating data mining algorithm, fuzzy set theory, and look ahead mechanism, to find the embedded information, which can be provided to teachers for further analyzing, refining or reorganizing the teaching materials and tests, from historical learning records.
An efficient interference cancellation scheme for CP-Free MIMO-OFDM systems
(2005)
Lin, CY
;
Lee, TS
;
電信工程研究所
;
Institute of Communications Engineering
Conventional orthogonal frequency division multiplexing (OFDM) systems use cyclic prefix (CP) to protect signal from the multipath channel induced distortions. However, the presence of CP could greatly decrease the effective data rate. In this paper, an interference cancellation scheme based on the generalized sidelobe canceller (GSC) principle is proposed for interference suppression of CP-free multiple-input multiple-output (MIMO) OFDM systems. An associated reduced complexity implementation based on the partially adaptive (PA) scheme is also proposed by exploiting the structural information of the signal and interference signature matrices. As well, we study sampling error in the proposed system. Under the block transmission model, a simple sampling error estimation method is proposed. Whenever sampling error is known, the proposed GSC equalizer can he directly applied based on the timing offsetted system model. Simulation results show that the performance of the proposed solution is almost identical to that obtained by the conventional CP-based MIMO-OFDM system under either the synchronous or asynchronous scenario.
Analysis of instability in a critical dimension bar due to focus and exposure
(2005-08-01)
Kuo, YK
;
Chao, CG
;
Lin, CY
;
材料科學與工程學系
;
Department of Materials Science and Engineering
in the photolithography processing of semiconductor, the line width becomes smaller and smaller. Therefore, the requirements of process window are stricter than before. Among them, the control of focus and exposure dose is one of the most important factors that may affect the line width. Bad control of focus and exposure may not only affect line width. but also cause the increment of rejects of products. The research mainly explored the effects of focus and exposure dose on line widths of different photo resists. The research obtained related coefficients of exposure dose line width and focus line width by coating photo resist of different components on the surface of the silica wafer. The results of research found that focus may not only change line width but also had a positive-negative symmetric relationship with line width. It also found that there was linear relationship between exposure dose and line width. (c) 2004 Elsevier Ltd. All rights reserved.
Analysis of instability line width and white wall created by the photolithography process
(2004-11-01)
Kuo, YK
;
Chao, CG
;
Lin, CY
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In the photolithography processing of semiconductor, line width is smaller and smaller. Therefore, the requirements of process window are stricter than before. In the small line width, the formation of serious white wall will affect line width and cause rejects in following process. The study conducted research on the control of best focus in which particularly explored the relationship between exposure dose and line width and the phenomenon of white wall generated by focus. The research obtained related coefficients of exposure dose-line width and exposure dose-white wall by coating photo resist of different components with the same thickness on the surface of fused silica wafer. The results of research found that exposure dose might not only change line width but also had important effects on white wall. Among others, the most important factor for exposure dose is the component of sensitivity of photo resist. (C) 2004 Elsevier Ltd. All rights reserved.
Comparing lanes in the pulsed-field gel electrophoresis (PFGE) images
(2001)
Cheng, WZ
;
Yen, KS
;
Lin, CY
;
Ching, YT
;
Yang, YL
Pulsed-field Gel Electrophoresis (PFGE) is an important tool in genomic analysis. The result of PFGE is presented in an image. Each image contains several lanes. And each lane consists of bands. Two lanes are identical if the relative positions of bands are the same. We present a method that uses computer to extract the lanes and compare the lanes in the electrophoresis images. The presented method consists of two major steps. The first step is image processing and lane extraction. The second step is to convert a lane into chain code representation. The lane comparison is carried out through calculating the longest common subsequence between lanes. We define the distance between lanes in term of the LCS and the lengths of two lanes. Two lanes have smaller distance tend to have similar pattern. This method eliminates those very different patterns to help biologists reduce the lanes that need to be compared.
Computer method for ELISA spot assay analysis
(2005-08-01)
Lin, CY
;
Ching, YT
;
Wu-Hsieh, BA
;
資訊工程學系
;
Department of Computer Science
The ELISA (enzyme-linked immunosorbent assay) spot assay is a method widely used by immunologists to enumerate cytokine-producing cells within a specific cell population. The ELISA results are presented in an image containing numerous colored spots. We present a method to identify the spots in the image and report on important statistics regarding them. The proposed method employs color analysis in the CIE Luv color space and matched filter technique. The system is trained to obtain a standard color for the spots and calculate the color differences between the spots and background in the Luv space. Matched filters are then used to remove noise and enhance the spots in the color difference map. Intensity thresholding is applied to obtain a binary image in which the pixels in the spots have a grayscale of 1 while the grayscale of the other pixels is 0. A software system is implemented, based on this method, to help immunologists analyze the results obtained from the. ELISA. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
Computer-aided manufacturing of spiral bevel and hypoid gears by applying optimization techniques
(2001-07-04)
Lin, CY
;
Tsay, CB
;
Fong, ZH
;
機械工程學系
;
Department of Mechanical Engineering
A mathematical model of an ideal spiral bevel and hypoid gear-tooth surfaces based on the GIeason hypoid gear generator mechanism is proposed. Using the proposed mathematical model, the tooth surface sensitivity matrix to the variations in machine-tool settings is investigated. Surface deviations of a real cut pinion and gear with respect to the theoretical tooth surfaces are also investigated. An optimization procedure for finding corrective machine-tool settings is then proposed to minimize surface deviations of real cut pinion and gear-tooth surfaces. The results reveal that surface deviations of real cut gear-tooth surfaces with respect to the ideal ones can be reduced to only a few microns. Therefore, the proposed method for obtaining corrective machine-tool settings can improve the conventional development process and can also be applied to different manufacturing machines and methods for spiral bevel and hypoid gear generation. An example is presented to demonstrate the application of the proposed optimization model. (C) 2001 Elsevier Science B.V. All rights reserved.
Computer-aided manufacturing of spiral bevel and hypoid gears with minimum surface-deviation
(1998-08-01)
Lin, CY
;
Tsay, CB
;
Fong, ZH
;
機械工程學系
;
Department of Mechanical Engineering
The linear regression method to minimize the deviations of a real cut gear-tooth-surface is investigated in this paper. Based on the Gleason hypoid gear generator, a mathematical model of the tooth surface is proposed. Applying the proposed mathematical model, the sensitivities of tooth surface due to the variations of machine-tool setting are also investigated. The corrective machine-tool settings, calculated by using the sensitivity matrix and the linear regression method, are used to minimize the tooth-surface deviations. The minimization problem was solved by using the singular value decomposition (SVD) method. The result of this paper can improve the conventional development process and be also applied to different manufacturing machines and methods. Two examples are presented to demonstrate the proposed methodology. (C) 1998 Elsevier Science Ltd. All rights reserved.
Direct generation of 10GHz 816fs pulse train from an asynchronous modelocked Er-fiber laser
(2005)
Lin, CY
;
Hsiang, WW
;
Tien, MF
;
Lai, Y
;
光電工程學系
By employing the technique of asynchronous modelocking (ASM), we have Successfully demonstrated the direct generation of stable 10GHz 816fs Pulse trains with Super-Mode-Suppression-Ratio > 70dB from a hybrid modelocked Er-fiber laser. (c) 2005 Optical Society of America.
Direct generation of a 10 GHz 816 fs pulse train from an erbium-fiber soliton laser with asynchronous phase modulation
(2005-09-15)
Hsiang, WW
;
Lin, CY
;
Tien, MF
;
Lai, YC
;
光電工程學系
By employing the technique of asynchronous mode locking, we have successfully demonstrated direct generation of stable 10 GHz 816 fs pulse trains with a supermode-suppression ratio > 70 dB from a hybrid mode-locked Er-fiber laser. When the modulation frequency deviates from the cavity harmonic frequency by 15-40 kHz, stable femtosecond soliton pulses are formed. Our results demonstrate that asynchronous mode locking can act as an effective mechanism for achieving a shorter pulse width and for stabilizing high-repetition-rate pulse trains in soliton fiber lasers. (c) 2005 Optical Society of America.