Browsing by Author "Chan, CH"

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A thermal-aware power management Soft-IP for platform-based SoC designs
(2004)
Chan, CH
;
Chang, YC
;
Ho, HC
;
Chiueh, H
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電信工程研究所
A novel thermal-aware power management (TAPM) Software Intellectual Property (Soft-IP) for modem platform-based SoC designs is presented. This research proposes the system-level architecture of thermal-aware power management, which includes a power management bus (PMB), TAPM Soft-IP and interface circuitry for proposed PMB. Each component of proposed design is encapsulated into a Soft-IP. With above design, system architects are able to incorporate on-chip power-controls and sensors to achieve nominal power dissipation and ensure the targeting system working within specification. The design yields intricate control and optimal management with little system overhead and minimum hardware requirements, as well as provides the flexibility to support different management schemes. The proposed system and its components are designed, implemented and verified by a prototype chip, which was fabricated in a TSMC 0.25 mu m 1P5M standard CMOS technology through National Chip Implementation Center (CIC), Taiwan.
Behavior and surface energies of polybenzoxazines formed by polymerization with argon, oxygen, and hydrogen plasmas
(2004-11-15)
Chen, JK
;
Lin, IK
;
Ko, FH
;
Huang, CF
;
Chen, KS
Polybenzoxazine (PBZZ) thin films can be fabricated by the plasma-polymerization technique with, as the energy source, plasmas of argon oxygen or hydrogen atoms and ions. When benzoxazine (BZZ) films are polymerized through the use of high-energy argon atoms, electronegative oxygen atoms, or excited hydrogen atoms, the PBZZ films that form possess different properties aid morphologies in their surfaces. High-energy argon atoms provide a thermodynamic factor to initiate the ring-opening polymerization of BZZ and result in the polymer surface having a grid-like structure. The ring-opening polymerization of the BZZ film that is initiated by cationic species such as oxygen atoms in plasma, is propagated around nodule structures to form the PBZZ. The excited hydrogen atom plasma initiates both polymerization and decomposition reactions simultaneously in the BZZ film and Results in the formation of a porous structure on the PBZZ surface. We evaluated the surface energies of the PBZZ films polymerized by the action of these three plasmas by measuring the contact angles of diiodomethane and water droplets. The surface roughness of the films range from 0.5 to 26 nm, depending on the type of carrier gas and the plasma-polymerization time. By estimating changes in thickness, we found that tie PBZZ film synthesized by the oxygen plasma-polymerization process undergoes the slowest rate of etching in CF(4) plasma. (C) 2004 Wiley Periodicals, Inc.
Computation of the protein structure entropy and its applications to protein folding processes
(2003-06-01)
Chan, CH
;
Lyu, PC
;
Hwang, JK
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生物科技學系
;
生物資訊及系統生物研究所
We have developed a general method to compute the structure, entropies of protein sequences. Structure entropy gives a quantitative measure of structure, conservation. This relationship is similar to that between sequence entropy and sequence conservation. Experimental studies in protein folding have suggested that residues relevant to protein folding, or the so-called "hot spot" residues, are usually structurally conserved, though not necessarily conserved in sequences. Hence, the ability to compute structure entropy can help identify important residues related to protein folding. In this work, we have applied our approach to several model proteins frequently used in protein folding experiments. Our results suggest a close relationship between the structure entropies of residues and their rates of amide proton exchange, and we are able to identity regions of residues that are important in protein folding.
In situ characterization of CuCMP slurry and defect reduction using IR thermal camera
(2004-09-01)
Chan, CH
;
Chen, JK
;
Chang, FC
;
應用化學系
;
Department of Applied Chemistry
In order to choose appropriate property of Cu chemical-mechanical polishing (CMP) slurry, we used IR thermal camera to distinguish this slurry that belonged to Preston or non-Preston. The adoption of the IR thermal camera is to choose suitable non-Preston Cu CMP slurry in situ and find out optimal changing timing of step endpoint. Additionally supplementing robust CMP machine, appropriate Cu film quality and pre-treatment, we could obtain a total defect number is less than 10(1) order and achieve excellent Cu CMP performance. Such Cu CMP technology resulting in Cu damascene process work and make sure 0.13 mum and beyond 100 nm Cu process to be reliable and practical. (C) 2004 Published by Elsevier B.V.
Relationship between local structural entropy and protein thermostability
(2004-12-01)
Chan, CH
;
Liang, HK
;
Hsiao, NW
;
Ko, MT
;
Lyu, PC
We developed a technique to compute structural entropy directly from protein sequences. We explored the possibility of using structural entropy to identify residues involved in thermal stabilization of various protein families. Examples include methanococcal adenylate kinase, Ribonuclease HI and holocytochrome c(551). Our results show that the positions of the largest structural entropy differences between wild type and mutant usually coincide with the residues relevant to thermostability. We also observed a good linear relationship between the average structural entropy and the melting temperatures for adenylate kinase and its chimeric constructs. To validate this linear relationship, we compiled a large dataset comprised of 1153 sequences and found that most protein families still display similar linear relationships. Our results suggest that the multitude of interactions involved in thermal stabilization may be generalized into the tendency of proteins to maintain local structural conservation. The linear relationship between structural entropy and protein thermostability should be useful in the study of protein thermal stabilization. (C) 2004 Wiley-Liss, Inc.
The study of adhesive forces between the type 3 fimbriae of Klebsiella pneumoniae and collagen-coated surfaces by using laser tweezers
(2004)
Chan, CH
;
Fan, CC
;
Huang, YJ
;
Peng, HL
;
Hsu, L
Adherence to host cells by a bacterial pathogen is a critical step for establishment of infection. It will contribute greatly to the understanding of bacterial pathogenesis by studying the biological force between a single pair of pathogen and host cell. In our experiment, we use a calibrated optical tweezers system to detach a single Klebsiella pneumoniae, the pathogen, from collagen, the host. By gradually increasing the laser power of the optical tweezers until the Klebsiella pneumoniae is detached from the collagen, we obtain the magnitude of the adhesive force between them. This happens when the adhesive force is barely equal to the trapping force provided by the optical tweezers at that specific laser power. This study is important because Klebsiella pneumoniae is an opportunistic pathogen which causes suppurative lesions, urinary and respiratory tract infections. It has been proved that type 3 fimbrial adhesin (mrkD) is strongly associated with the adherence of Klebsiella pneumoniae. Besides, four polymorphic mrkD alleles: namely, mrkDv1, v2, v3, and v4, are typed by using RFLP. In order to investigate the relationship between the structure and the function for each of these variants, DNA fragments encoding the major fimbrial proteins mrkA, mrkB, mrkC are expressed together with any of the four mrkD adhesins in E. coli JM 109. Our study shows that the E. coli strain carrying the mrkDv3 fimbriae has the strongest binding activity. This suggests that mrkDv3 is a key factor that enhances the adherence of Klebsiella Pneumoniae to human body.