Browsing by Author "Lee, JH"

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A new method for texture analysis using morphological gradient texture histograms
(1996-05-01)
Lee, JH
;
Hsueh, YC
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
A new method using Morphological Gradients, which measures the degree of roughness of image surface, is proposed for texture analysis. In this method, the local texture feature for a given pixel is characterized by its corresponding morphological gradient, and the global texture aspect of an image, denoted the Morphological Gradient Texture Histogram (MGTH), is used as a distinguishing feature for texture analysis and classification. To evaluate the performance of the proposed method, supervised texture classification and rotated texture classification are applied. Experimental results reveal high accuracy classification rates and show that the proposed method is a good tool for texture analysis.
A new method for texture analysis using morphological gradient texture histograms
(1996-05-01)
Lee, JH
;
Hsueh, YC
;
資訊工程學系
;
Department of Computer Science
A new method using Morphological Gradients, which measures the degree of roughness of image surface, is proposed for texture analysis. In this method, the local texture feature for a given pixel is characterized by its corresponding morphological gradient, and the global texture aspect of an image, denoted the Morphological Gradient Texture Histogram (MGTH), is used as a distinguishing feature for texture analysis and classification. To evaluate the performance of the proposed method, supervised texture classification and rotated texture classification are applied. Experimental results reveal high accuracy classification rates and show that the proposed method is a good tool for texture analysis.
Chemical solution deposition of Zn1-xZrxO thin films as active channel layers of thin-film transistors
(2006)
Lee, JH
;
Lin, P
;
Ho, JC
;
Lee, CC
;
材料科學與工程學系
Sol-gel derived Zn1- xZrxO films and thin-film transistors (TFTs) were investigated in this study, where x ranges from 0.00 to 0.10. The effects of the Zr additive on the crystallinity, grain size, and surface morphology of Zn1- xZrxO films are discussed. Zn1- xZrxO-TFTs exhibited much lower off-state current (I-OFF) and higher on/off ratio than pure ZnO-TFT. The behavior of I-OFF related to the carrier concentration (n) of Zn1-xZrxO films and the correlation between n and the grain size are interpreted. The optimized I-OFF and on/off ratio of Zn1- xZrxO-TFT were 3.24 x 10(-13) A/mu m and 8.89 x 10(6) where x = 0.03, respectively. (c) 2006 The Electrochemical Society.
Design of power control mechanisms with PCM realization for the uplink of a DS-CDMA cellular mobile radio system
(1996-08-01)
Chang, CJ
;
Lee, JH
;
Ren, FC
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電信工程研究所
;
電信研究中心
Power control (PC) is an important issue in a direct sequence-code division multiple access (DS-CDMA) cellular mobile radio system. Higher link performance and greater system capacity cannot be achieved unless an appropriate PC mechanism is employed. In previous research, a delta-modulation (DM) realization of strength-based and SIR-based PC mechanisms for uplink communication has been studied by simulation. In order to obtain higher PC trackability, in this paper we study a pulse-code-modulation (PCM) realization of the above two PC mechanisms for the uplink of a DS-CDMA cellular mobile radio system. The simulation results presented here indicate that PC mechanisms with PCM realization for the uplink can achieve a lower outage probability and thus higher link performance than PC mechanisms with DM realization. We also obtain optimal design parameters such as the stepsize and the control mode for the two PCM PC mechanisms. In addition, we compare the two PCM PC mechanisms in terms of their outage probability and stability and find that the strength-based mechanism has a higher outage probability but greater stability than the SIR-based mechanism.
Design of power control mechanisms with PCM realization for the uplink of a DS-CDMA cellular mobile radio system
(1996-08-01)
Chang, CJ
;
Lee, JH
;
Ren, FC
;
電信工程研究所
;
電信研究中心
Power control (PC) is an important issue in a direct sequence-code division multiple access (DS-CDMA) cellular mobile radio system. Higher link performance and greater system capacity cannot be achieved unless an appropriate PC mechanism is employed. In previous research, a delta-modulation (DM) realization of strength-based and SIR-based PC mechanisms for uplink communication has been studied by simulation. In order to obtain higher PC trackability, in this paper we study a pulse-code-modulation (PCM) realization of the above two PC mechanisms for the uplink of a DS-CDMA cellular mobile radio system. The simulation results presented here indicate that PC mechanisms with PCM realization for the uplink can achieve a lower outage probability and thus higher link performance than PC mechanisms with DM realization. We also obtain optimal design parameters such as the stepsize and the control mode for the two PCM PC mechanisms. In addition, we compare the two PCM PC mechanisms in terms of their outage probability and stability and find that the strength-based mechanism has a higher outage probability but greater stability than the SIR-based mechanism.
Etching of rf magnetron-sputtered indium tin oxide films
(1996-06-01)
Chiou, BS
;
Lee, JH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this study, the etching of indium tin oxide (ITO) films with various acidic solutions are studied and the activation energies for etching calculated. On the basis of the etching data, a diluent hydrochloric acid is selected for further investigation. The surface morphology of the HCl-etched films are examined. Pinholes resulted from enhanced etching of the grain boundaries are found. Films with larger grains exhibit coarser etched surfaces. The opto-electrical properties of the films are studied and the figure of merits for these films evaluated.
Secure bootstrapping and routing in an IPv6-based ad hoc network
(2003)
Tseng, YC
;
Jiang, JR
;
Lee, JH
;
資訊工程學系
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Department of Computer Science
The mobile ad hoc network (MANET), which is characterized by an infrastructureless architecture and multi-hop communication, has attracted a lot of attention recently. In the evolution of IP networks to version 6, adopting the same protocol would guarantee the success and portability of MANETs. In this paper we propose a secure bootstrapping and routing protocol for MANETs. Mobile hosts can autoconfigure and even change their IP addresses based on the concept of CGA (cryptographically generated address), but they can not hide their identities easily. The protocol is modified from DSR (dynamic source routing) to support secure routing. The neighbor discovery and domain name registration in IPv6 are incorporated and enhanced with security functions. The protocol is characterized by the following features: (i) it is designed based on IPv6, (ii) relying on a DNS server it allows bootstrapping a MANET with little pre-configuration overhead, so network formation is light-weight, and (iii) it is able to resist a variety of security attacks.
Sol-gel-derived Zn((1-x))Mg(x)O thin films used as active channel layer of thin-film transistors
(2005-07-01)
Lee, JH
;
Lin, P
;
Lee, CC
;
Ho, JC
;
Wang, YW
Sol-gel derived n-type Zn((1-x))Mg(x)O (x = 0-0.45) thin films and thin-film transistors (TFTs) with active channel layers made of the films were investigated. The films were prepared at 500 degrees C. The effects of Mg doping on the crystallinity, optical transparency, grain size, and charge-carrier concentration (n) of the films were examined. The Fermi level of the films, as derived from the temperature dependence of n, was similar to 0.12eV below the conduction band. The donor concentration and donor level (E(d)) were derived by a curve fitting method based on the electrical neutrality condition. Ed was found to be similar to 0.3 eV below the conduction band. The composition dependence of the TFT output characteristics was interpreted and correlated to the width of the depletion region adjacent to the grain boundaries. When the grains were almost depleted at x = 0.2, the TFT showed an enhancement mode and an on/off ratio of 10(6).
Sol-gel-derived Zn(1-x)MgxO thin films used as active channel layer of thin-film transistors
(2005-07-01)
Lee, JH
;
Lin, P
;
Lee, CC
;
Ho, JC
;
Wang, YW
Sol-gel derived n-type Zn(1-x)MgxO (x = 0-0.45) thin films and thin-film transistors (TFTs) with active channel layers made of the films were investigated. The films were prepared at 500 degrees C. The effects of Mg doping on the crystallinity, optical transparency, grain size, and charge-carrier concentration (n) of the films were examined. The Fermi level of the films, as derived from the temperature dependence of n, was similar to 0.12eV below the conduction band. The donor concentration and donor level (E-d) were derived by a curve fitting method based on the electrical neutrality condition. Ed was found to be similar to 0.3 eV below the conduction band. The composition dependence of the TFT output characteristics was interpreted and correlated to the width of the depletion region adjacent to the grain boundaries. When the grains were almost depleted at x = 0.2, the TFT showed an enhancement mode and an on/off ratio of 10(6).
Texture classification using fuzzy uncertainty texture spectrum
(1998-08-01)
Lee, YG
;
Lee, JH
;
Hsueh, YC
;
資訊工程學系
;
Department of Computer Science
A new method using fuzzy uncertainty, which measures the uncertainty of the uniform surface in an image, is proposed for texture analysis. A grey-scale image can be transformed into a fuzzy image by the uncertainty definition. The distribution of the membership in a measured fuzzy image, denoted by the fuzzy uncertainty texture spectrum (FUTS), is used as the texture feature for texture analysis. To evaluate the performance of the proposed method, supervised texture classification and rotated texture classification are applied. Experimental results reveal high-accuracy classification rates and show that the proposed method is a good tool for texture analysis. (C) 1998 Elsevier Science B.V. All rights reserved.