Browsing by Issue Date, starting with "1998-02"

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QTS: A QOS-guaranteed transport system for broad-band multimedia communications
(1998-02-01)
Yuang, MC
;
Liu, JC
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a quality of-service (QOS)guaranteed transport system (QTS), which offers various QOS's at the transport layer for broad-band multimedia communications, The QTS, composed of a bandwidth allocator and a transport protocol module, supports three classes of applications requiring different bit rates, delay sensitivity, and loss sensitivity, The bandwidth allocator intelligently manages the allocation of transport-layer bandwidth at the expense of imposing inevitable blocking of delay-sensitive application connections, The transport protocol module of the QTS performs rate-based flow control for delay-sensitive applications based on transfer rates predetermined by the bandwidth allocator, In addition, the module accomplishes error control only for loss-sensitive applications, As a result, as will be shown, by providing guaranteed rates and reducing the error control overhead, the QTS offers satisfactory bounded delays and jitters for delay-sensitive applications, while incurring minimal throughput degradation for loss-sensitive applications, Finally, we demonstrate the superiority of the QTS over transmission control protocol (TCP) via simulation results in terms of maximum and mean system delays and delay jitter.
Highly oriented (Zr0.7Sn0.3)TiO4 thin films grown by rf magnetron sputtering
(1998-02-01)
Wu, FJ
;
Tseng, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Thin films of (Zr0.7Sn0.3)TiO4 on Si(100) were prepared by rf magnetron sputtering in the present study. Films of a highly preferred [020] orientation, as demonstrated by X-ray diffraction and transmission electron microscopic examinations, were grown successfully on a Si substrate with in situ postannealing at 700 degrees C. The chemical composition of the films, measured by secondary ion mass spectroscopy, exhibited a uniform concentration distribution for all species. A study by X-ray photoelectron spectroscopy further revealed some firm evidence of a molecular orbital that affected the chemical structure. The dielectric constants of 400-nm-thick (Zr0.7Sn0.3)TiO4 films in the present study were >18 for the films with a preferred orientation and similar to 11 for polycrystalline films.
上聯:自古帝王多流氓下聯:從來英雄皆無賴橫批:為人民服務
(1998-02-01)
管管
QTS: A QOS-guaranteed transport system for broad-band multimedia communications
(1998-02-01)
Yuang, MC
;
Liu, JC
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a quality of-service (QOS)guaranteed transport system (QTS), which offers various QOS's at the transport layer for broad-band multimedia communications, The QTS, composed of a bandwidth allocator and a transport protocol module, supports three classes of applications requiring different bit rates, delay sensitivity, and loss sensitivity, The bandwidth allocator intelligently manages the allocation of transport-layer bandwidth at the expense of imposing inevitable blocking of delay-sensitive application connections, The transport protocol module of the QTS performs rate-based flow control for delay-sensitive applications based on transfer rates predetermined by the bandwidth allocator, In addition, the module accomplishes error control only for loss-sensitive applications, As a result, as will be shown, by providing guaranteed rates and reducing the error control overhead, the QTS offers satisfactory bounded delays and jitters for delay-sensitive applications, while incurring minimal throughput degradation for loss-sensitive applications, Finally, we demonstrate the superiority of the QTS over transmission control protocol (TCP) via simulation results in terms of maximum and mean system delays and delay jitter.
【臨床頻道】齒顎矯正治療時機
(國立陽明大學牙醫校友會, 1998-02)
馮懷珍
Real-time scanning tunneling microscopy observation of Si(100)-(2x1)->(2xn)-> c(4x4) structural phase transitions
(1998-02-01)
Lin, DS
;
Wu, PH
;
物理研究所
;
Institute of Physics
We report on the discovery of Si(100)-(2 x 1)-->(2 x n)-->c(4 x 4) structural phase transitions. Annealing the Si(100)-(2 x 1) surface between 590 and 700 degrees C for some hours causes dimer vacancies to increase and nucleate into chains, ultimately forming the (2 x n) structure. After further annealing. c(4 x 4) areas appear grow. and finally cover the entire surface. Experimental results raise the possibility not only that c(4 x 4) is a stable low-temperature structure of Si(100), but that (2 x 1) is a high-temperature phase stabilized at room temperature owing to its kinetic limitations. (C) 1998 Elsevier Science B.V.
專訪管管先生
(1998-02-01)
管管
Synthesis of carbon-chain tethered bistetraoxa-cage compounds
(1998-02-01)
Chern, JH
;
Wu, HJ
;
Wang, SL
;
Liao, FL
;
應用化學系
Carbon-chain tethered bistetraoxa-cage compounds 7a-c and 8a-c were synthesized from 2-methyl-furan in a four-step sequence. They were obtained from ozonolysis of the syn bisadducts 5a-c and the anti bisadducts 6a-c in dichloromethane at -78 degrees C followed by reduction with dimethyl sulfide. The structure of the anti bisadduct 6a was proven by X-ray crystallographical analysis.
【逍遙遊】蘭陽-新桃花之旅
(國立陽明大學牙醫校友會, 1998-02)
董醒任
High precision, low cost mask for deep x-ray lithography
(1998-02-01)
Shew, BY
;
Cheng, Y
;
Shih, WP
;
Lu, M
;
Lee, WH
The precision of transferred patterns are highly dependent on the quality of the mask in deep x-ray lithography. Many parameters, such as the critical energy of the synchrotron light, beamline optics and even the microstructure to be exposed should be considered in mask design. In this paper, the design rules and the boundary conditions for deep x-ray mask are discussed in general. The method of making a precision, multilayer mask using UV lithography technique is also described.
Photoluminescence studies of GaN films of different buffer layer and doping concentration
(1998-02-01)
Shen, CC
;
Shu, CK
;
Lin, HC
;
Ou, J
;
Chen, WK
Photoluminescence (PL) measurements of GaN films with various buffer thicknesses and Si-doping concentrations have been carried out. PL response of one specific sample was studied for temperature dependence. The results showed that the band gap energy reduction is linearly proportional to the temperature increase with a slope of similar to-4 x 10(-4) eV.K-1 and that the activation energies for donor-bound and acceptor-bound exciton transitions are 15 and 18 meV, respectively. In Si-doped GaN films, the PL data indicated that the reduced gap depends on the third power of carrier concentration as n(1/3). We also obtained a concentration coefficient of 2.34 x 10(-4) eV.cm and a band gap energy of 3.426 eV in the undoped GaN film.
專訪管管先生
(1998-02-01)
管管
Construction use of abandoned soils
(1998-02-01)
Shan, HY
;
Meegoda, JN
;
土木工程學系
;
Department of Civil Engineering
Taiwan is a county under rapid development. Excavation in thousands of construction sites generated a huge amount of soils. In many cases, the soils are disposed randomly such that they are termed abandoned soils. A comprehensive study was conducted to investigate for reuse options of these soils: sub-grade construction, cement block production, structural concrete production, and asphalt concrete production. Five soils, representing predominant soil types in Taiwan were selected in this study. The compaction test results demonstrated that all five soils were suitable for subgrade construction. The compression tests for cement mortar showed that all soils produced mixes with strengths higher then 3.45 MPa and may be used to make cement blocks. The compressive strength test results of soil concrete samples showed that all soils except for the mix having 100% of soil No. 5 produced strengths higher than 17.25 MPa. The wet/dry durability test showed that the pozzolanic action of the soil concrete samples continued beyond 28 days and there seemed to be no detrimental effects. A comprehensive mix design was performed for each soil type and also developed a control mixture to test the use of abandoned soils in hot mix asphalt concrete. The study demonstrated that with proper design even clayey soils can be used to produce construction materials. (C) 1998 Elsevier Science B.V.
【告示板】中區校友會近況
(國立陽明大學牙醫校友會, 1998-02)
編輯室
Phonon-plasmon interaction in GaN films studied by Raman scattering
(1998-02-01)
Shen, CC
;
Shu, CK
;
Lin, HC
;
Chen, WK
;
Chen, WH
GaN films of different buffer thicknesses (from 0 to 600 Angstrom) were grown on (0001) sapphire using MOCVD. The epitaxial films show autodoping with carrier concentration ranging from 8 x 10(16) to 5 x 10(17) cm(-3) as determined by Hall measurements. The Raman scattering reveals that the A(1)(LO) mode shifts from 733 to 740 cm(-1) as a result of the phonon-plasmon interaction.
Grain boundary precipitation reactions in a wrought Fe-8Al-5Ni-2C alloy prepared by the conventional ingot process
(1998-02-01)
Hwang, CN
;
Liu, TF
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Block-decoupling linear multivariable systems: Necessary and sufficient conditions
(1998-02-01)
Lin, CA
;
Wu, CM
;
電控工程研究所
;
Institute of Electrical and Control Engineering
We study block decoupling of linear multivariable systems under unity-feedback configuration. We consider plants which have unstable pole-zero coincidences and give necessary and sufficient conditions for the existence of the block decoupling controllers. The conditions are particularly simple for plants with only simple unstable pole-zero coincidences. An illustrative example is given. (C) 1998 Elsevier Science Ltd. All rights reserved.
專訪管管先生
(1998-02-01)
管管
Impurity-limited mobility of semiconducting thin wires in n-type gallium arsenide
(1998-02-01)
Wu, CC
;
Lin, CJ
;
應用數學系
;
電子工程學系及電子研究所
;
Department of Applied Mathematics
The impurity-limited mobility of semiconducting thin wins for the nonparabolic band structure of electrons in n-type gallium arsenide has been investigated by scattering from ionized impurities or from the uniform distribution of remote impurities. Results are shown that the impurity-limited mobility due to scattering from background impurities increases monotonically and slowly with increasing temperature, while the impurity-limited mobility due to scattering from remote impurities increases rapidly with temperature. It is also shown that the mobility for both types of impurities decreases with increasing wire radius. However, for scattering from remote impurities, the mobility appears slowly decreasing with the wire radius at higher temperatures. (C) 1998 American Institute of Physics. [S0021-8979(98)07903-1].
Recursive minimum energy algorithm for image interpolation
(1998-02-01)
Liu, PC
;
Chang, WT
;
Shen, WZ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An interpolation method based on the criterion to maximize the smoothness is proposed. In contrast to the conventional approach, where the interpolated signal is made smooth by low-pass filtering, in the proposed method, the smoothness is obtained by minimizing a global energy function. With the minimum energy formulation for interpolation, a recursive method is used to derive the solution and named as the recursive minimum energy algorithm. Because the smoothness is improved by increasing the calculation iteration but not by increasing the tap length, the controllability of this system is increased. Experiments show that the smoothness and the frequency performance obtained by the proposed algorithm are better than those of the conventional method. Also, the corresponding architecture design for the image interpolation is presented and shown to be suit for VLSI implemented.