Browsing by Issue Date, starting with "2001-06-23"

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具高能隙偏移層結構之薄膜場效電晶體元件
(2001-06-23)
張俊彥
一種具高能隙偏移層結構之薄膜場效電晶體元件，係在基底上的源極/汲極和閘極底下閘極絕緣層之間,垂直疊放複數個不同能隙之半導體層,該複數個半導體層包含高-低-高-低能隙,低-高-低能隙,高-低-高能隙或低-高能隙結構的半導體層,其中低能隙半導體層鄰接閘極絕緣層,作為載子的通道層，在元件導通時能傳導載子，而鄰接通道層的高能隙偏移層,能在該元件關閉狀態下，阻擋傳導載子發生能帶到能帶的穿透傳輸，降低閘極感應之汲極漏電流,另外,鄰接高能隙偏移層的低能隙半導體層，形成半導體與金屬層之間的歐姆接觸區,當做源極/汲極的接觸層,而鄰接閘極的高能隙介面層，則是用來捕捉可能存在於通道層與閘極絕緣層之間的介面缺陷,使元件特性便不會受閘極絕緣層20的介面特性直接影響，並讓該元件在導通狀態下能維持相當大的導通電流，同時在關閉狀態下,能大幅降低元件之關閉電流,提高其開/關電流比，適合應用到液晶顯示器上,可以大幅提升其畫面品質。
Lower bounds for wide-sense nonblocking Clos network
(2001-06-28)
Tsai, KH
;
Wang, DW
;
Hwang, F
;
應用數學系
;
Department of Applied Mathematics
The 3-stage Clos network is generally considered the most basic multistage interconnecting network (MIN). The nonblocking property of such network has been extensively studied in the past. However, there are only a few lower bound results regarding wide-sense nonblocking. We show that in the classical circuit switching environment, to guarantee wide-sense nonblocking for large r, 2n - 1 center switches are necessary, where I is the number of input switches and n is the number of inlets of each input switch. For the multirate environment, we show that for large r, any 3-stage Clos network needs atleast 3n - 2 center switches to guarantee wide-sense nonblocking. Our proof works even for the two-rate environment. (C) 2001 Elsevier Science B.V. All rights reserved.
Synthesis of novel acetal thia-cage compounds
(2001-06-29)
Wu, CY
;
Lin, HC
;
Wang, ZY
;
Wu, HJ
;
應用化學系
The synthesis of novel acetal this-cage compounds has been accomplished by the direct substitution for the oxygen atom by the sulfur atom in the reaction of the acetal groups of era-cages with Lawesson reagent (LR). Reaction of the tetraoxa-cage compound 2 with LR in dichloromethane at 25 degreesC sequentially gave the monothia-, dithia-, trithia-, and tetrathia-cage compounds 3, 6, 7, and 9. The reaction mechanism for the conversion from era-cages into thia-cages was proposed. The diacetal trioxa-cages 18-20 and 24-26 were also transformed into the thia-cages 21-23 and 27-29, respectively. Reaction of the trioxa-cages 34 and 35 with LR under the same reaction conditions gave the thia-cages 36 and 37 with the carbonyl group intact. Treatment of the pentaoxa[5]-peristylane 40 with LR in chloroform under supersonic shaking at refluxing temperature gave the monothia[5]peristylane 41 and the dithia-[5] peristylane 42. Attempts to synthesize the thia[5]-peristylanes from the tetraoxa-cage 51 and the transformation from the parent (unsubstituted) pentaoxa[5]peristylane 46 to the thia-cages have been made. Reaction of the pentaoxa[5]-peristylane 40 with P2S5 in refluxing toluene gave 41, 42, and a rearrangement product 47. The synthesis of new heterocyclic cage compounds 59 and 60, which contain oxygen, nitrogen, and sulfur atoms in the same molecule, was also accomplished.
Frequency control in a low voltage, wide tuning VCO design at 2.4 GHz
(2001-07-01)
Kao, YH
;
Chien, CC
;
傳播研究所
;
Institute of Communication Studies
A low voltage and wide tuning rang voltage controlled oscillator (VCO)( at 2.4 GHz is developed for ISM applications. A design procedure wit the parasitics of packaged devices considered is offered A VCO with a 200 MHz tuning range for les than 2 V using a packaged varactor is demonstrated.
Vector quantization based on genetic simulated annealing
(2001-07-01)
Huang, HC
;
Pan, JS
;
Lu, ZM
;
Sun, SH
;
Hang, HM
Genetic algorithm (GA) has been successfully applied to codebook design for vector quantization (VQ). However, most conventional GA-based codebook design methods need long runtime because candidate solutions must be fine tuned by LBG. In this paper, a partition-based GA is applied to codebook design, which is referred to as genetic vector quantization (GVQ). In addition, simulated annealing (SA) algorithm is also used in GVQ to get more promising results and the corresponding method is referred to as GSAVQ. Both GVQ and GSAVQ use the linear scaling technique during the calculation of objective functions and use special crossover and mutation operations in order to obtain better codebooks in much shorter CPU time. Experimental results show that both of them save more than 71-87% CPU time compared to LEG. For different codebook sizes, GVQ outperforms LEG by 1.1-2.1 dB in PSNR, and GSAVQ outperforms LBG by 1.2-2.2 dB in PSNR. In addition, GVQ and GSAVQ need a little longer CPU time than, the maximum decent (MD) algorithm, but they outperform MD by 0.2-0.5 dB in PSNR. (C) 2001 Elsevier Science B.V. All rights reserved.
Energy-effectiveness of nonthermal plasma reactors for toluene vapor destruction
(2001-07-01)
Lin, CH
;
Bai, HL
;
環境工程研究所
;
Institute of Environmental Engineering
The energy-effectiveness of packed-bed and nonpacked-bed plasma reactors for the destruction of toluene vapors is evaluated on the basis of the power consumption of the reactor system. The operation and design parameters being evaluated include the applied voltage, inlet gas flow rate, and toluene concentration. The optimal operational conditions for the target destruction of toluene vapors, with minimum power consumption, are determined. The results showed that a packed-bed plasma reactor has a higher toluene destruction efficiency and a lower power consumption than a nonpacked-bed plasma reactor. The toluene destruction efficiency is increased as both the inlet gas flow rate and the toluene gas concentration are decreased. For a plasma reactor 2 cm in diameter and packed with 5-mm glass pellets, > 90% of toluene destruction can be reached at an applied voltage of 8.7 kV, inlet toluene concentrations <1,000 ppm, and gas flow rates of < 680 cm(3)/min. The corresponding energy-effectiveness is about 15 g toluene/kW (.) h.
A review and discussion of epistemological commitments, metacognition, and critical thinking with suggestions on their enhancement in internet-assisted chemistry classrooms
(2001-07-01)
Tsai, CC
;
師資培育中心
;
Center of Teacher Education
Heuristic algorithm for optimal design of the two-level wireless ATM network
(2001-07-01)
Din, DR
;
Tseng, SS
;
資訊工程學系
;
Department of Computer Science
In this paper, we investigate the optimal assignment problem of cells in PCS (Personal Communication Service) to switches in a wireless ATM network. Given cells and switches on an ATM network (whose locations are fixed and known), the problem is grouping cells into clusters and assigning these clusters to the switches in an optimum manner. This problem is modeled as a complex integer programming problem and finding an optimal solution of this problem is NP-complete. A three-phase heuristic algorithm MCMLCF (Maximum cell and minimum local communication first) consisting of Cell Pre-Partitioning Phase, Cell Exchanging Phase, and Cell Migrating Phase, is proposed. First, in the Cell Pre-Partitioning Phase, a three-step procedure (Clustering Step, Packing Step, and Assigning Step) is proposed to group cells into clusters. Second, Cell Exchanging Phase, is proposed to greatly improve the result by repeatedly exchanging two cells in different switches. Finally, Cell Migrating Phase is proposed to reduce cost by repeatedly migrating all cells in a used switch to an empty switch. Experimental results indicate that the proposed algorithm runs efficiently. Comparing the results of the algorithm to a naive heuristic called NSF, we have shown that the computation time is reduced by 30.1%. Experimental results show that Cell Exchanging and Cell Migrating phases can reduce the total cost by 34.1% on average. By comparing the results of the proposed algorithm to the genetic algorithm, the heuristic method came close to optimum - on average within 5%.
Seismic isolation of rigid cylindrical tanks using friction pendulum bearings
(2001-07-01)
Wang, YP
;
Teng, MC
;
Chung, KW
;
土木工程學系
;
Department of Civil Engineering
Storage tanks are vulnerable to earthquakes, as numerous major earthquakes have demonstrated. The trend of recent revisions to make seismic design criteria for large-scale industrial storage tanks increasingly stringent has made development of cost-effective earthquake-resistant design and retrofit techniques for industrial tanks imperative. This study assesses the feasibility of seismic base isolation for making liquid-filled storage tanks earthquake resistant. The sliding-type friction pendulum seismic (FPS) bearings are considered rather than the elastomeric bearings because the dynamic characteristics of an FPS-isolated tank remain unchanged regardless of the storage level. This work has devised a hybrid structural-hydrodynamic model and solution algorithm, which would permit simple, accurate and efficient assessment of the seismic response of rigid cylindrical storage tanks in the context of seismic isolation. Extensive numerical simulations confirm the effectiveness of seismic base isolation of rigid cylindrical tanks using FPS bearings. Copyright (C) 2001 John Wiley & Sons, Ltd.
4-cycle group-divisible designs with two associate classes
(2001-07-01)
Fu, HL
;
Rodger, CA
;
應用數學系
;
Department of Applied Mathematics
In this paper we investigate a partitioning problem, setting the existence problem for all group-divisible designs with first and second associates in which the blocks are 4-cycles.
Comparison of the recording dynamics of phenanthrenequinone-doped poly(methyl methacrplate) materials
(2001-07-01)
Mumbru, J
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Solomatine, I
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Psaltis, D
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Lin, SH
;
Hsu, KY
A comparative analysis of phenanthrenequinone-doped poly(methyl methacrylate) materials fabricated at California Institute of Technology and National Chiao Tung University is performed in order to understand the differences exhibited in their recording and baking dynamics. (C) 2001 Published by Elsevier Science B.V.
Laminar forced convection in a channel with a moving block
(2001-07-01)
Fu, WS
;
Ke, WW
;
Wang, KN
;
機械工程學系
;
Department of Mechanical Engineering
Heat transfer rate in a channel with an insulated moving block on a heated surface was studied numerically. For enhancing the heat transfer rate of the heated surface, the block moves back and forth on the heated surface. Then the thermal boundary layer attached to the heated surface is destroyed by the moving block and a new thermal boundary layer reforms immediately as the block passes through. Consequently, a remarkable heat transfer enhancement of the heated surface is attained. This subject belongs to a kind of moving boundary problems, and the modified Arbitrary Lagrangian Eulerian method is suitable for solving this subject. The results show that the maximum increment of heat transfer rate is about 98% in the study. (C) 2001 Elsevier Science Ltd. All rights reserved.
Stack gate PZT/Al2O3 one transistor ferroelectric memory
(2001-07-01)
Chin, A
;
Yang, MY
;
Sun, CL
;
Chen, SY
;
材料科學與工程學系
We have developed single transistor ferroelectric memory using stack gate PZT/Al2O3 structure. For the same similar to 40 Angstrom dielectric thickness, the PZT/Al2O3/Si gate dielectric has much better C-V characteristics and larger threshold voltage shift than those of PZT/SiO2/Si. Besides, the ferroelectric MOSFET also shows a large output current difference between programmed on state and erased off state, The <100 ns erase time is much faster than that of Flash memory where the switching time is limited by erase time.
Low cogging torque and high efficient 3-phase spindle motors by reshaping magnetic circuit profiles
(2001-07-01)
Chiu, KC
;
Huang, DR
;
Shieh, HPD
;
光電工程學系
;
Department of Photonics
The dynamic characteristics of a 3-phase spindle motor with 12-poles and 9-slots can be improved by reshaping the magnetic circuit profiles. The stator cores were designed with different ratios of x/y where x is the gap angle between 2-slots and y is the expanded angle of a slot. Experiment and finite element analyses (FEA) results show that x/y ratio of 1/2.5 is an optimal design in achieving dynamic performance for DVD drives applications.
Why recognition in a statistics-based face recognition system should be based on the pure face portion: a probabilistic decision-based proof
(2001-07-01)
Chen, LF
;
Liao, HYM
;
Lin, JC
;
Han, CC
;
資訊工程學系
It is evident that the process of face recognition, by definition, should be based on the content of a face. The problem is: what is a "face"? Recently, a state-of-the-art statistics-based face recognition system, the PCA plus LDA approach, has been proposed (Swets and Weng, IEEE Trans. pattern. Anal. Mach. Intell. 18 (8) (1996) 831-836). However, thr authors used "face" images that included hail, shoulders, face and background. Our intuition tells us that only a recognition process based on a "pure" Face portion can be called face recognition. The mixture of irrelevant data may result in an incorrect set of decision boundaries. In this paper, we propose a statistics-based technique to quantitatively prove our assertion. For the purpose of evaluating how the different portions of a Face image will influence the recognition results, a hypothesis testing model is proposed. We then implement the above mentioned face recognition system and use the proposed hypothesis testing model to evaluate the system. Experimental results show that the influence of the "real"-face portion is much less than that of the nonface portion. This outcome confirms quantitatively that recognition in a statistics-based face recognition system should be based solely on the "pure" face portion. (C) 2001 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.
Heat transfer of porous medium with random porosity model in a laminar channel flow
(2001-07-01)
Fu, WS
;
Wang, KN
;
Ke, WW
;
機械工程學系
;
Department of Mechanical Engineering
In this paper, force convection heat transfer of a porous medium in a laminar channel flow is numerically investigated. The porous medium with random porosities is used to enhance heat transfer and the random porosities are derived by the Kinderman-Ramage procedure. The results show that when the mean porosity is larger than 0.5, the average Nusselt numbers are enhanced and better than the solid block case. Therefore, a porous medium with larger porosity and the proper bead diameter could provide more heat dissipation. For the random porosity distribution, the profiles of velocities are disordered and the channeling effect is not apparent near the plate region.
Dynamics of helical-wave emission in a fiber-coupled diode end-pumped solid-state laser
(2001-07-01)
Chen, YF
;
Lan, YP
;
電子物理學系
;
光電工程學系
;
Department of Electrophysics
We have generated TEM0,l* modes in an end-pumped microchip laser using a standard fiber-coupled diode. A rich set of dynamic behaviors, such as periodic and quasiperiodic self-modulation, chaotic pulsing and frequency locking was observed in the generated TEM0,l* modes. Experimental results confirm the theoretical predictions that the locking occurs as a subcritical bifurcation and that a region of coexisting locked and unlocked states exists.
Deployment of personalized e-catalogues: An agent-based framework integrated with XML metadata and user models
(2001-07-01)
Liu, DR
;
Lin, YJ
;
Chen, CM
;
Huang, YW
;
資訊管理與財務金融系註：原資管所+財金所
In e-commerce applications, supporting electronic catalogues (e-catalogues) to provide product-search services on the Internet is emerging as an important function of electronic brokers ( e-brokers). However, as the Internet expands, an increasing number of virtual stores are selling products on-line. The explosive growth of information is creating difficulties for customers searching for the product information they desire. In this work, an integrated framework is proposed to develop personalized e-catalogues. The proposed framework integrates XML-based metadata models, user models and agents. The XML-based metadata model can facilitate resource-discovery and format translation, and can flexibly model the definitions of diverse product attributes in heterogeneous data resources. The proposed user model can model a user's shopping interests to resources, categories and products. This work integrates the agent technology with the proposed metadata model and user model to develop a personalized e-catalogue system. The novel system effectively provides an integrated search for heterogeneous product information, as well as supporting personalized product search and browsing for each user based upon their profiles. (C) 2001 Academic Press.
Spin-orbit energy state splitting in semiconductor cylindrical and spherical quantum dots
(2001-07-01)
Voskoboynikov, O
;
Lee, CP
;
Tretyak, O
;
交大名義發表
;
National Chiao Tung University
We present a theoretical study of the spin-orbit interaction impact on electron energy states in small cylindrical and spherical quantum dots. The investigation is based on the effective one-electronic band Hamiltonian and the spin dependent boundary conditions. It has been demonstrated that the spin-orbit interaction can significantly modify the energy spectrum of InAs and InSb quantum dots. The splitting can provide a situation where only the lowest spin split energy states are bound in the dot. A reasonable agreement was found with data from more sophisticated theoretical models for the spherical quantum dots which is available in the literature.
High quality interpoly dielectrics deposited on the nitrided-polysilicon for nonvolatile memory devices
(2001-07-01)
Yang, WL
;
Chao, TS
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Cheng, CM
;
Pan, TM
;
Lei, TF
High quality interpoly dielectrics have been fabricated by using NH3 and N2O nitridation on polysilicon and deposition of tetra-ethyl-ortho-silitate (TEOS) oxide with N2O annealing. The surface roughness of polysilicon is improved and the value of weak bonds is reduced due to nitrogen incorporation at the interface, which improves the integrity of interpoly dielectrics, The improvements include a higher barrier height, breakdown strength, and charge-to-breakdown, and a lower leakage current and charge trapping rate than counterparts. It is found that this method can simutaneously improve both charge-to-breakdown (up to 20 C/cm(2)) and electric breakdown field (up to 17 MV/cm).