Browsing by Issue Date, starting with "1998-03-19"

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Gain flattening of erbium-doped fibre amplifier using fibre Bragg gratings
(1998-03-19)
Dung, JC
;
Chi, S
;
Wen, SF
;
光電工程學系
;
Department of Photonics
A new technique, using fibre-Bragg gratings with different centre frequencies to reflect the different channel signals at different positions, is proposed for flattening the gain spectrum of an erbium-doped fibre amplifier. A designed gain excursion of <0.1dB can be achieved for 16 channel multiplexed signals with 0.1mW input power in the 1532-1562nm wavelength region.
Secure broadcasting in large networks
(1998-03-25)
Sun, HM
;
Shieh, SP
;
資訊工程學系
;
Department of Computer Science
It is common that users or hosts in a large network are partitioned and organized as a hierarchical tree where children of the same parent form a group. Secure broadcasting intends to provide a secure communication channel from a sending principal to a group of legal receiving principals. Only legal receiving principals can decrypt the message, and illegal receiving principals cannot acquire any information from the broadcasted message. In this paper, we propose a secure broadcasting protocol in which only one packet is transmitted for every broadcast, and the size of the broadcasted packet is small. (C) 1998 Elsevier Science B.V.
Bandwidth assignment paradigms for broadband integrated voice/data networks
(1998-03-25)
Yuang, MC
;
Huang, YR
;
資訊工程學系
;
Department of Computer Science
Broadband Integrated Services Digital Networks (BISDNS)/Asynchronous Transfer Mode (ATM) are expected to support diverse applications demanding different bandwidth and Quality of Services (QoSs). Particularly for integrated voice and data networks, voice traffic results in call losses and data traffic suffers from longer delays should networks have insufficient bandwidth. The main goal of the paper is to analytically determine optimal bandwidth allocated to voice and data by means of a queueing model with heterogeneous arrivals and multiple designated channels. The accuracy of analytical results is confirmed by simulation results. On the basis of the analysis, the paper proposes a bandwidth assignment paradigm for the assignment of network bandwidth to voice and data in an effort to guarantee minimal data delay and voice call blocking probability. The run time complexity of the bandwidth assignment computation and paradigm construction is shown to be polynomial bounded. Consequently, the resulting bandwidth assignment assures QoSs in terms of data delay and voice call blocking probability under various network loads. (C) 1998 Elsevier Science B.V.
Dielectric tunability of barium strontium titanate/silicone-rubber composite
(1998-03-30)
Liou, JW
;
Chiou, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The dielectric tunability, which is defined as the percentage change of the permittivity under DC biasing, is over 30% for polycrystalline barium strontium titanate (BST) under a field of 5000 V cm(-1) at around the Curie peak. Various volume fractions (18%, 40%, 52%, and 64%) of BST powder are mixed with silicons rubber to obtain a multi-phase dielectric composite. The effective permittivity of the composite follows the Maxwell-Garnett relation with a shape parameter of about 14 for volume fractions below 52%. The dielectric tunabilities at 5000 V cm(-1) for the samples made with 52% and 64% powder are about 0.7% and 7.4%, respectively. The results are compared to the dielectric tunabilities obtained on the basis of series, parallel, and logarithmic models. It is suggested that the dielectric tunability is enhanced when a sample with a more continuous BST powder phase is obtained. An increase of the permittivity with a small DC field applied to the composite is attributed to the effect of polarization of the interface between the BST and silicone-rubber phases.
【海天遊蹤】托雷多行腳
(國立陽明大學牙醫校友會, 1998-04)
葉光儀
交大登山社的點滴
(交大青年社, 1998-04)
山坳
在交大登山社已經三年半了，很高興藉著交青社徵稿的時候，表達自己參與登山社活動的一些感想。
女之秋
(交大青年社, 1998-04)
粟本亞美
深閨怨，千堆愁，有誰知，有誰憐。等待，一復如是的等待，愛與恨已經變得不重要了。
傍晚欲雨的水細紗
(交大青年社, 1998-04)
若農
風來天陰水波湧湧圈圈來去織成了湖的水細紗擾弄的是你底心還是湖底心
編輯小語
(交大青年社, 1998-04)
九孔
;
聖賢
;
家榮
;
建亨
;
怡竹
當初之所以會加入交青社，只是因為社長是自己的好朋友，而交青社又正在緊急徵兵，所以我就帶著一顆懵懂未知的心成為交青社的正式社員，剛開始的時候，交青社的確是沒什麼事要做，只要固定的每個禮拜去開會就好了，但是厲害的才在後頭呢！
Magnetoresistance behavior of Ni layer under Cu film
(1998-04-01)
Wu, CY
;
Yao, YD
;
Lin, JJ
;
物理研究所
;
Institute of Physics
The weak-localization effect is very sensitive to the presence of magnetic moments. We use it to study the formation of localized moments in thin Ni layers under a 100 Cu film. The Ni thickness varies between 0 and 4 Angstrom. We measured the magnetoresistance (MR) of these samples at temperatures ranging from 0.4 to 21 K. The magnetic field with the strength of up to 1 T, was applied normal to the film surface. We find that MR is more positive In samples with Ni underlayer than in Cu film. Comparing our results with the prediction of weak localization theory, the magnetic moment is detected only in Ni underlayers thicker than 2 Angstrom.
Non-d-wave superconducting induced by current in d-wave superconductors with mass anisotropy
(1998-04-01)
Dai, MC
;
Yang, TJ
;
電子物理學系
;
Department of Electrophysics
Underlain by the Ginzburg-Landau theory of a d-wave superconductor with mass anisotropy lambda = m(x)/m(y), we derived the non-zero subsidiary order parameter induced by an external current. The amplitude of induced s-component depends on the amplitude and direction of the current. The extreme values appear in some specific conditions. Unlike the isotropic case, we find that the current density is not parallel to the wave vector except for lambda = 1.
[廣告]
(交大青年社, 1998-04)
[交大青年社]
勝華科技股份有限公司；萬士達亞太有限公司
【海天遊蹤】生活外一章
(國立陽明大學牙醫校友會, 1998-04)
黃逸峰
交大文學獎新詩組
(交大青年社, 1998-04)
[交大青年社]
[得獎名單]
Tighter error bounds and weighted error metrics for hierarchical radiosity
(1998-04-01)
Chang, CC
;
Shih, ZC
;
資訊工程學系
;
Department of Computer Science
In this paper we first derive a tighter error bound on form factors as a subdivision criterion for the hierarchical radiosity algorithm. Such an error bound can reduce more unnecessary links and improve the performance of the hierarchical radiosity algorithm to meet a user-specified error tolerance. We then propose a weighted error metric in form factor computation such that more effort is automatically applied to shadow boundaries. Evaluating form factors along shadow boundaries with a higher degree of precision should enhance the quality of human perception. Using the proposed tighter error bound on the weighted error metric, we not only improve the performance but also increase the accuracy of the hierarchical radiosity algorithm. (C) 1998 John Whey & Sons, Ltd.
交大文學獎散文組
(交大青年社, 1998-04)
[交大青年社]
[得獎名單]
焚信五百封
(交大青年社, 1998-04)
李欣岳
終於熬過這世紀末的聖嬰年，走過了諸事不順的詭異。這該是一個普天同慶的新年。從九六年的狂牛症，去年初的口蹄疫，再來是目前正熱的禽流感。牛、豬、雞，一種種的飛禽走獸被人們殺光，那再來呢？也許諾亞方舟不遠矣！舊約聖經的記載，自諾亞方舟後，才有了後世人們一路百轉千迴的走來，直到現在的一日千里，真是讓人慶祝的諾亞方舟。
清大輻生所事件省思
(交大青年社, 1998-04)
交大諮商中心
清大輻生所事件，震驚了整個社會。除了清大本身外，地緣關係最近的交大，算是受到最大的衝擊。或許有的同學因為這次的事件觸動個人的內心深處，久久無法從低潮的情緒中恢復，也或許有的同學因此而對自己的感情或友情產生懷疑與害怕，也可能有部分的同學對我們周遭的生活環境產生極度的不安全與恐慌感，諮商中心的老師們希望藉著這一篇文章談談我們的看法，也提供同學們有關兩性與人際交往的建議。
Effect of MgO addition on the electrical transport properties of highly Sb-doped BaTiO3 ceramics
(1998-04-01)
Chiou, BS
;
Wang, IH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
BaTiO3 ceramics doped with Sb donors and Mg acceptors have been fabricated. The lattice constant ratio c/a and the Curie point T-c decrease with increasing Sb concentration. The minimum room temperature resistivity rho(min) of the codoped BaTiO3 occurs at a composition of 0.9 mole% Sb2O3-1 mole % MgO as compared to the literature reported rho(min) at 0.3 mole % antimony for the Sb2O3-doped BaTiO3. The Mg2+ ion acts as an acceptor in the BaTiO3 ceramics, which compensates the donor contribution from Sb3+ and shifts the doped-BaTiO3 semiconducting region to higher antimony content. The calculated donor concentration confirms the compensation effect of Mg acceptors over Sb donors. The temperature dependence of both barrier height and dielectric constant of specimens is discussed. (C) 1998 Chapman & Hall.
窗
(交大青年社, 1998-04)
朱健林
直的橫的顫動的格子截斷傾洩底流光於是在我眼底都是不完整