Browsing by Issue Date, starting with "2006-06-01"

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Stable new bound soliton pairs in a 10 GHz hybrid frequency modulation mode-locked Er-fiber laser
(2006-06-01)
Hsiang, WW
;
Lin, CY
;
Lai, YC
;
光電工程學系
;
Department of Photonics
We report what is, to our knowledge, the first experimental observation of stable new bound soliton pairs at the 10 GHz repetition rate in a hybrid FM harmonic mode-locked Er-fiber laser (1177 soliton pairs simultaneously in the laser cavity). The two solitons in the soliton pair have the identical pulse shape and are with the antiphase (pi phase difference). Their time separation is about three times the FWHM soliton width and varies with the phase modulation strength. The corresponding mechanism for explaining the formation as well as the superior stability of these closely bound soliton pairs is also given. (c) 2006 Optical Society of America.
個人電腦之麥克風陣列系統
(2006-06-01)
胡竹生
;
鄭价呈
;
康創閔
;
劉維瀚
本發明係為一個人電腦之麥克風陣列系統，其利用通用串列匯流排資料擷取系統將類比聲音訊號放大並通過一帶通濾波器，最後將之轉換成數位聲音訊號，再利用語音訊號增強系統將擷取到之數位聲音訊號中聲音雜訊部分加以抑制並純化成一語音訊號，其整套系統具有低成本、便利性、擴充性及高彈性等優點，可在吵雜及回音存在的環境下消除非語音雜訊，且可根據語者方位、環境及器材的變動自行調整參數，以達到自動化高效能之語音純化效果。
Fabrication of a flexible and disposable microreactor using a dry film photoresist
(2006-06-01)
Tsai, Yuan-Chien
;
Yang, Shung-Jim
;
Lee, Hsun-Tsing
;
Jen, Hsiu-Ping
;
Hsieh, You-Zung
In this paper, we demonstrate that a low-cost flexible microreactor can be manufactured using a dry film photoresist in conjunction with photolithographic and hot roll lamination techniques. A microfluidic flow path and sample reservoir patterns were prefabricated in a dry film photoresist tape using traditional photolithographic methods. This tape was sandwiched between two plastic films - wells were prepouched on the cover film - that were bonded upon passage through a hot roll laminator. A simple Plexiglas reactor holder was designed and constructed to use in evaluating the flexible microchip reactor. We demonstrate a chemical synthesis of polyaniline that was performed with this polymeric microreactor using a hydrodynamic flow control system. The fabrication of this microreactor suggests that there is great potential for designing and prototyping disposable microscale reaction systems using dry film photoresist for a range of chemical and biochemical syntheses.
Agility evaluation using fuzzy logic
(2006-06-01)
Lin, CT
;
Chiu, H
;
Tseng, YH
;
管理科學系
;
Department of Management Science
"Change" seems to be one of enterprises' major characteristics in this new competitive era. Agile enterprise whereby an organization can change and adapt quickly to changing circumstances is increasingly viewed as a winning strategy. However, in embracing agile enterprise, there are important questions to be asked: what precisely is agility and how can it be measured? How can one assist in achieving and enhancing agility effectively? Answers to such questions are critical to the practitioners and to the theory of agile enterprise design. The foundation of agile enterprise lies in the integration of information system/technologies, people, business processes and facilities. Due to the ill-defined and vague indicators which exist within agility assessment, most measures are described Subjectively by linguistic terms which are characterized by ambiguity and multi-possibility, and the conventional assessment approaches cannot suitably nor effectively handle such measurement. However, fuzzy logic provides a useful tool for dealing with decisions in which the phenomena are imprecise and vague. Thus, the novelty in the paper is development of the absolute agility index, a unique and unprecedented attempt in agility measurement, using fuzzy logic to address the ambiguity in agility evaluation. Details of the approach and a framework of a fuzzy agility evaluation will be presented. An example is also used to illustrate the approach developed. (c) 2005 Elsevier B.V. All rights reserved.
Effect of atomic geometry on shot noise in aluminum quantum point contacts
(2006-06-01)
Yao, J.
;
Chen, Y. -C.
;
Di Ventra, M.
;
Yang, Z. Q.
;
電子物理學系
We investigate the role of atomic geometry on shot-noise properties of aluminum atomic contacts using first-principles calculations. We study both the effect of atomic separation in the wire as well as the geometry of the contacts. We find that shot noise, as opposed to conductance, is very sensitive to atomic details. In particular, the Fano factor for the asymmetric contact structures is more than double that of the symmetric ones due to increased backscattering, and is within the experimental range. These results indicate that shot noise may be used as a tool to infer the atomic geometries of quantum point contacts.
Identifying a design management package to support concurrent design in building wafer fabrication facilities
(2006-06-01)
Dzeng, RJ
;
土木工程學系
;
Department of Civil Engineering
Concurrent design is commonly used in building a semiconductor wafer fabrication facilities to shorten projects. Current practice in managing a design schedule involves preset milestones that represent percentages of completion. Such a simple control scheme does not provide sufficient information to support concurrent design. This study presents an analytical model that applies a cluster identification algorithm to separate the work of designing a multisystem project into management packages that support concurrent design. Tasks within a package have strong informational dependency relationships on each other, and are not suited for concurrent design. Tasks of different packages have weak dependency relationships on each other, and are suited for concurrent design. Tendering design work based on these packages may reduce the number of design interfaces between participating design firms. Possible application of the model includes the management of design schedule, design contract tendering, and design information flow.
Dual-bandpass filters with serial configuration using LTCC technology
(2006-06-01)
Lin, KC
;
Chang, CF
;
Wu, MC
;
Chung, SJ
;
電信工程研究所
A dual-bandpass filter that utilizes a serial configuration of the inductive coupled-line (ICL) filter and the capacitive coupled-line (CCL) filter is investigated in this study. Numerical analysis is presented for the difference between the ICL and CCL filters. The dual-bandpass filter has a similar behavior to the individual single-band filter around the corresponding passband. An extra transmission zero can be generated between the two pass-bands of the dual-bandpass filter in that the ICL and CCL filters exhibit an out-of-phase response. Four architectures of dual-bandpass filters are proposed for the 2.4/5-GHz systems. Two of them are demonstrated by the low-temperature co-fired ceramic multilayer technology. Measurements results agree quite well with the simulation ones.
Repairing of etching-induced damage of high-k Ba0.5Sr0.5TiO3 thin films by oxygen surface plasma treatment
(2006-06-01)
Tsai, Kou-Chiang
;
Wu, Wen-Fa
;
Chao, Chuen-Guang
;
Lee, Jain-Tsai
;
Hsu, Jwo-Lun
Ba0.5Sr0.5TiO3 (BST) thin films were patterned for fabricating BST capacitors in a helicon-wave plasma system. The optimization conditions were an Ar (80%)/Cl-2 (20%) gas mixture with a helicon-wave plasma power and a substrate bias rf power of 1500 and 90 W, respectively. From results of X-ray photoelectron spectroscopy, physical ion bombardment is more effective than chemical reaction for removing Sr, while Ti can be removed by the formation of volatile TiClx. Ba was primarily removed by chemically assisted physical etching (such as that using BaClx) Some etching residues consisting of Ba and Sr were found after the BST films were etched and increased leakage current density. Oxygen surface plasma treatment can effectively repair surface damage caused by etching, and it reduced the leakage current density of the BST capacitor from 4.0 x 10(-7) to 3.0 x 10(-8) A/cm(2) at 1 MV/cm and increased the breakdown field to similar to 2 MV/cm at 1.0 x 10(-6) A/cm(2).
Doped poly(methyl methacrylate) photopolymers for holographic data storage
(2006-06-01)
Lin, Shiuan Huei
;
Lin, June-Hua
;
Chen, Po-Lin
;
Shiao, Yi -Nan
;
Hsu, Ken Y.
In this paper, we report our investigations on thick holographic recording material of the phenanthrenequinone doped poly(methyl methacrylate) (PQ:PMMA) photopolymer. The design strategy and fabrication technique for making thick polymer samples with negligible shrinkage and good optical quality are presented. The physical mechanism for holographic recording in PQ:PMMA material is described, and methods for improving are proposed. Based on these methods, photopolymer samples with different compositions are fabricated and experimentally characterized. The results show that by modifying compositions, the material sensitivity and dynamic range for volume holographic recording have been improved.
HfAlON n-MOSFETs incorporating low-work function gate using ytterbium silicide
(2006-06-01)
Wu, CH
;
Hung, BF
;
Chin, A
;
Wang, SJ
;
Yen, FY
The authors have fabricated low-temperature fully silicided YbSi2-x-gated n-MOSFETs that used an HfAION gate dielectric with a 1.7-nm EOT. After a 600 degrees C rapid thermal annealing, these devices displayed an effective work function of 4.1 eV and a peak electron mobility of 180 cm(2)/V(.)s. They have additional merit of a process compatible with current very large scale integration fabrication lines.
Direct observation of structure effect on ferromagnetism in Zn1-xCoxO nanowires
(2006-06-01)
Jian, WB
;
Wu, ZY
;
Huang, RT
;
Chen, FR
;
Kai, JJ
Diameter-controllable single-crystalline ZnO nanowires (NWs), with the [0001] growth direction in the plane, have been fabricated by using thermal evaporation method. The as-grown NWs with diameters of similar to 40 nm were implanted with various amounts of Co ions. These Zn1-xCoxO (x <= 0.11) NWs possessed a high density of bombardment-induced orientation variations and stacking faults, and exhibited paramagnetic behavior. After thermal annealing, the structural defects largely disappeared and noticeable hysteresis in the magnetization loops were observed, indicating the presence of apparent ferromagnetic ordering in the NWs. This result provides important insight into the role played by defects in relation to the occurrence of ferromagnetism in diluted magnetic semiconductor NWs.
A new class of wideband multisection 180 degrees hybrid rings using vertically installed planar couplers
(2006-06-01)
Chi, CH
;
Chang, CY
;
電信工程研究所
;
Institute of Communications Engineering
A new class of wideband multisection 180 degrees hybrid rings using the vertically installed planar (VIP) coupler is proposed. On the basis of the reconfigured ideal single-section 180 degrees hybrid ring (i.e., the 180 degrees hybrid ring with an ideal phase inverter), the multisection 180 degrees hybrid rings can be realized by properly cascading of single-section 180 degrees hybrid rings. Compared with the conventional hybrid ring, the two-section hybrid rings exhibit wide bandwidth, size reduction, and easily achievable high power-division ratios. Design equations based on the equal-ripple functions are derived. Design curves for the equal and unequal power-division ratio are also described. In addition, a cascade of single-section cascadable hybrid rings with a unit element at each I/O port can be used for bandwidth enhancement. Good agreement is obtained between the experimental and simulated results.
Protecting mobile-agent data collection against blocking attacks
(2006-06-01)
Shao, Min-Hua
;
Zhou, Hanying
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Full-scale adoption of mobile agent technology in untrustworthy network environment, such as Internet, has been delayed due to several security complexities. The protection of mobile agents against the attacks of malicious hosts is considered a very challenging security problem. It has inspired lot of research interest, but very few measures exist to counter blocking attack where a host with malicious intentions refuses to transmit a mobile agent to the next host. It becomes an important requirement for the agent owner to rescue the data collected by the agent under custody and redeem a loss. In this paper, we present two schemes that rescue the offering results from a malicious host's blocking attack, and make a comparison of their performance from several aspects. Our approach has two new features that previous protocols lack. It allows the proper handling of time-sensitive offers and supports the gradual decision-making execution. (C) 2005 Elsevier B.V. All rights reserved.
Improved design and data interpretation of a multi-purpose borehole testing device for soft rock
(2006-06-01)
Pan, YW
;
Liao, JJ
;
Huang, AB
;
Chang, JC
;
Liao, HJ
The authors previously developed a multi-purpose borehole testing device (BTD). The purpose of the BTD was designed for obtaining mechanical properties including anisotropic elastic modulus and interface shear strength properties for soft rock that may be easily disturbed during sampling. Since the creation of the previous BTD, a few minor problems were experienced during in situ testing operation. In the present work, improvements both in equipment design and data interpretation were made. Improved design of BTD successfully reduced the chance for pressure meter test (PMT) membrane breakage, allowed larger expansion of borehole jack test (BJT), improved the waterproof of the bottom compartment and made easy for the whole equipment setup. The refined design has improved the in situ performance of BTD. New approach of data interpretation was also proposed. A series of BTD tests, including BJTs, borehole plate loading tests and borehole shear tests were carried out to demonstrate the capability of the refined borehole test device. (c) 2005 Elsevier Ltd. All rights reserved.
On the performance of multicarrier DS-CDMA with imperfect power control and variable spreading factors
(2006-06-01)
Wang, LC
;
Chang, CW
;
電信工程研究所
;
Institute of Communications Engineering
Multicarrier direct-sequence code-division multiple access (MC-DS-CDMA) becomes an attractive technique for the future fourth-generation (4G) wireless system because it can flexibly adapt transmission rates by changing both time and frequency spreading factors and possesses many physical-layer advantages in dispersive fading channels. However, power control errors (PCE) and the complete multiple access interference,(MAI) from all the intersubcarriers may significantly degrade the performance of the MC-DS-CDMA system. In this paper, we propose an analytical method to evaluate the joint effects of the PCE and the complete MAI on the multirate MC-DS-CDMA system. From analysis and simulation, we obtain some important insights into the performance issues of the MC-DS-CDMA system. First, the effect of PCE can exacerbate the impact of the complete MAI on the MC-DS-CDMA system, or vice versa. For BER = 10(-3) in a considered case, the joint effect of the complete MAI and PCE further degrades the performance by 2.1 dB compared with the sum of the degradation from the complete MAI and the PCE individually. Second, increasing frequency- or time-domain spreading gain can improve the performance of the MC-DS-CDMA system, but the system also becomes more sensitive to power control errors. Third, a larger PCE can possibly make the frequency-domain diversity diminish faster than the gain obtained from the time-domain spreading although an MC-DS-CDMA system with a larger frequency-domain spreading gain (M) is usually better than that with a larger time-domain spreading gain (G(o)). In our example, for the standard deviation of PCE (a,) equal to 0 dB, the BERs with (M, G(o)) = (4,16) and (16,4) are 9.3 X 10(-4) and 3.7 X 10(-5), respectively, while for sigma(e) = 4 dB, the BER performances of the two cases are all in the order of 10(-3).
Crosstalk-insensitive via-programming ROMs using content-aware design framework
(2006-06-01)
Chang, MF
;
Chiou, LY
;
Wen, KA
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Various code patterns of a via-programming read only memory (ROM) cause significant fluctuations in coupling noise between, bitlines (BLs). This crosstalk between BLs leads to read failure in high-speed via-programmable ROMs and limits the coverage of applicable code patterns. This work presents a content-aware design framework (CADF) for via-programming ROMs to overcome the crosstalk induced read failure. The CADF ROMs employ a content-aware structure and correspondent code-structure programming algorithm to reduce the amount of coupling noise source while maintaining nonminimal BL load for crosstalk reduction. A 256-Kb conventional ROM and a 256-Kb CADF ROM were fabricated using a 0.25-mu m logic CMOS process. The measured results ascertain that the read induced read failure is suppressed significantly by CADF. The CADF ROM also reduced 86.2% and 94.5% in power consumption and standby current compared to the conventional ROM, respectively.
A clock generator with cascaded dynamic frequency counting loops for wide multiplication range applications
(2006-06-01)
Chen, PL
;
Chung, CC
;
Yang, JN
;
Lee, CY
;
電子工程學系及電子研究所
This work presents a clock generator with cascaded dynamic frequency counting (DFC) loops for wide multiplication range applications. The DFC loop, which uses variable time period to estimate and tune the frequency of the digitally controlled oscillator (DCO), enhances the resolution of frequency detection. The conventional phase-frequency detector (PFD) and programmable divider are replaced with a digital arithmetic comparator and a DCO timing counter. The value in the DCO timing counter is separated into quotient and remainder vectors. A threshold region is set in the remainder vector to reduce the influence of jitter variation in frequency detection. The loop stability can be retained by cascading two DFC loops when the multiplication factor (N) is large. The proposed clock generator achieves a multiplication range from 4 to 13 888 with output peak-to-peak jitter less than 2.8% of clock period. A test chip for the proposed clock generator is fabricated in 0.18-mu m CMOS process with core area of 0.16 mm(2). Power consumption is 15 mW.@ 378 MHz with 1.8-V supply voltage.
Bounding the number of columns which appear only in positive pools
(2006-06-01)
Chen, H. B.
;
Hwang, F. K.
;
Li, C. M.
;
應用數學系
;
Department of Applied Mathematics
d-separable, (d) over bar -separable and d-disjunct matrices are the major tools in constructing pooling designs which has many applications to DNA experiments, for example, the clone library screening problem. While there exists a simple decoding for d-disjunct matrices, only brute-force methods are known for the other two. In this paper we identify structures in these two matrices which lead to significant improvements for decoding.
Ultrathin electron injection layer on indium-tin oxide bottom cathode for highly efficient inverted organic. light-emitting diodes
(2006-06-01)
Chu, TY
;
Chen, SY
;
Chen, JF
;
Chen, CH
;
電子物理學系
We have fabricated a highly efficient inverted bottom-emission organic light-emitting diode (IBOLED) based on an indium-tin oxide (ITO) bottom cathode deposited with an ultrathin 1 nm layer of Mg to promote electron injection. The threshold voltage of this IBOLED with a structure of ITO/Mg/Alq(3)/NPB/WO3/Al was 4.2V and an efficiencies of 4.66cd/A and 1.51 1m/W were achieved at an operational voltage of 8.9 V and a brightness of 940 cd/m(2). In comparison with an ITO/Alq(3) bottom cathode composition, a reduction in drive voltage from 13.8 to 7.8 V in voltage was obtained at 1 mA/cm(2). A charge-transfer dipole model is proposed to rationalize the enhanced electron injection.
The combined toxic effects of nonpolar narcotic chemicals to Pseudokirchneriella subcapitata
(2006-06-01)
Hsieh, SH
;
Tsai, KP
;
Chen, CY
;
環境工程研究所
;
Institute of Environmental Engineering
This paper presents the toxicity data of 10 nonpolar narcotic chemicals on Pseudokirchneriella subcapitata (green algae) assessed by a new algal toxicity testing technique conducted under air-tight environment. Based on DO production, median effective concentration (EC50) varies from 1.73mg/L (1-octanol) to8040 mg/L (2-propanol). The endpoint of algal growth rate reveals similar sensitivity as that from DO production. Compared to literature data, Pseudokirchneriella subcapitata and Nitrosomonas are apparently more sensitive to nonpolar narcotics than other organisms such as minnow, daphnia, and Tetrahymena pyriformis. Furthermore, good correlations between toxic effects observed from Pseudokirchneriella subcapitata and other aquatic organisms were found. Hence, algal toxicity test can be considered as a surrogate test for estimating the toxicity of nonpolar chemicals to fathead minnow, Microtox, activated sludge, Daphina magna, and Tetrohymena pyriformis. The combined effects of 13 binary mixtures of nonpolar chemicals were investigated using both additive-index method and isobologram analysis. overall speaking, the joint actions between these chemicals are strictly additive. Model analyses indicate that these compounds act on identical reaction sites or receptors, which verify that these chemicals are of the same toxicity mechanism (narcosis). (c) 2006 Elsevier Ltd. All rights reserved.