Browsing by Issue Date, starting with "2004-10-15"

Now showing 1 - 20 of 69362

Influence of the aspect ratio of bioactive nanofillers on rheological behavior of PMMA-based orthopedic materials
(2004-10-15)
Liu, TY
;
Chen, SY
;
Liu, DM
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this investigation, calcium-deficient hydroxyapatite (CDHA) nanocrystals with needle-like geometry were synthesized and incorporated with Poly(methyl methacrylate), PMMA, to form CDHA-PMMA nanocomposites. Rheological behaviors of the PMMA-CDHA melting suspensions were systematically investigated in terms of solid loading and aspect ratio of the CDHA nanoparticles. The maximum solid loadings of nano-CDHA particles with aspect ratios of 7.2, 10.4, and 17 were determined to be 28, 31, and 57%, respectively. An increase in solid concentrations causes pronounced shear-thinning behavior. This result suggests that a strong interaction, including Van der Waals attraction and mechanical interlocking, between the nano-CDHA particles makes the nanocomposite mixture more non-Newtonian. Furthermore, it was found that packing efficiency and yield strength in the suspension were strongly influenced by the aspect ratio, especially above the critical value of 8.8. The obtained critical aspect ratio and solid content provide not only appropriate design in the PMMA-CDHA polymeric suspension for fabrication process but also optimal conditions for the fabrication of orthopedic devices via injection molding or extrusion. (C) 2004 Wiley Periodicals, Inc.
Effects of compressive epitaxial strain on the magnetotransport properties of single-phase electron-doped La0.7Ce0.3MnO3 films
(2004-10-15)
Chang, WJ
;
Hsieh, CC
;
Juang, JY
;
Wu, KH
;
Uen, TM
Single-phase electron-doped manganite thin films with nominal composition of La0.7Ce0.3MnO3 (LCeMO) have been prepared on SrTiO3 (100) substrates by pulsed laser deposition. The conditions for obtaining purely single-phase LCeMO films lie within a very narrow window of substrate temperature (T(s)similar to720 degreesC) and laser energy density (E(D)similar to2 J/cm(2)) during deposition. In situ postdeposition annealing, mainly to relax the possible epitaxial in-plane tensile strain between the film and the substrate, leads to an increasing c-axis lattice constant accompanied by the formation of secondary CeO2 phase and higher metal-insulator transition temperature. This is indicative of a strong coupling between the electron and lattice degree of freedom. (C) 2004 American Institute of Physics.
RoVegas: a router-based congestion avoidance mechanism for TCP Vegas
(2004-10-15)
Chan, YC
;
Chan, CT
;
Chen, YC
;
資訊工程學系
;
Department of Computer Science
Transmission control protocol (TCP) Vegas detects network congestion in the early stage and successfully prevents periodic packet loss that usually occurs in TCP Reno. It has been demonstrated that TCP Vegas outperforms TCP Reno in many aspects. However, TCP Vegas suffers several problems that inhere in its congestion avoidance mechanism, these include issues of rerouting, persistent congestion, fairness, and network asymmetry. In this paper, we propose a router-based congestion avoidance mechanism (RoVegas) for TCP Vegas. By performing the proposed scheme in routers along the round-trip path, RoVegas can solve the problems of rerouting and persistent congestion, enhance the fairness among the competitive connections, and improve the throughput when congestion occurs on the backward path. Through the results of both analysis and simulation, we demonstrate the elfectiveness of RoVegas. (C) 2004 Elsevier B.V. All rights reserved.
Microwave properties of a Y0.7Ca0.3Ba2Cu3O7-delta inicrostrip ring resonator with various hole concentrations
(2004-10-15)
Lai, LS
;
Juang, JY
;
Wu, KH
;
Uen, TM
;
Lin, JY
Superconducting ring resonator with a Y0.7Ca0.3Ba2Cu3O7-delta ground plane was fabricated by using Y0.7Ca0.3Ba2Cu3O7-delta thin film deposited on both sides of a LaAlO3 (LAO) substrate. The resonator exhibits a high quality factor Q > 10(4) at T < 30 K, and from empirical relation,T-c/T-c,T-max = 1 - 82.6(p - 0.16)(2), we obtained the hole concentration p. By controlling the oxygen contents of the ring resonator, the hole concentration p was controlled from 0.218 to 0.088, determined by the empirical relation, in the same film. The temperature dependence of the resonance frequency, f(T), was then systematically studied. By using Chang's inductive formula and taking a functional form (lambda(5K)/lambda (T))(2) = 1 - (T/T-c)(2) at T < 0.6T(c), the London penetration depths lambda(5K) for various oxygen contents at 5K were obtained, respectively. Finally, it allows us to test the Uemura relation 1 /lambda(2)(5K) proportional to T-c from the over- to the underdoped regime in the same sample. (C) 2004 Elsevier B.V. All rights reserved.
Investigation of GaN LED with Be-implanted Mg-doped GaN layer
(2004-10-15)
Huang, HW
;
Kao, CC
;
Chu, JT
;
Kuo, HC
;
Wang, SC
We report the electrical and optical characteristics of GaN light emitting diode (LED) with beryllium (Be) implanted Mg-doped GaN layer. The p-type layer of Be-implanted GaN LED showed a higher hole carrier concentration of 2.3 x 10(18)CM(-3) and low specific contact resistance value of 2.0 x 10(-4) Omegacm(2) than as-grown p-GaN LED samples without Be-implantation. The Be-implanted GaN LEDs with InGaN/GaN MQW show slightly lower light output (about 10%) than the as-grown GaN LEDs, caused by the high RTA temperature annealing process. (C) 2004 Elsevier B.V. All rights reserved.
Accelerating network security services with fast packet classification
(2004-10-15)
Shieh, S
;
Lee, FY
;
Lin, YW
;
資訊工程學系
;
Department of Computer Science
To protect a network, secure network systems such as intrusion detection system (IDS) and firewall are often installed to control or monitor network traffic. These systems often incur substantial delay for analyzing network packets. The delay can be reduced with fast packet classification, which can effectively classify network traffic, and consequently accelerate the analysis of network packets. In the last few years, many researchers devoted to providing fast packet classification methods for multidimensional classifier. However, these methods either suffer from poor performance and huge storage requirement, or are lack of dimension scalability. In this paper, we propose a packet classification method based on tuple space search, and use the multidimensional binary search tree (Kd-tree) to improve search performance. The proposed scheme requires only O(d log W) search time and controlled storage requirement, where d is the number of dimensions, and W is the utmost bit length for specifying prefixes in a classification rule. It features fast packet classification, and supports dynamic update which is a basic requirement of many secure network services, such as IDS and firewall. (C) 2004 Elsevier B.V. All rights reserved.
Electromigration failure mechanisms for SnAg3.5 solder bumps on Ti/Cr-Cu/Cu and Ni(P)/Au metallization pads
(2004-10-15)
Shao, TL
;
Chen, YH
;
Chiu, SH
;
Chen, C
;
材料科學與工程學系
The electromigration behavior of SnAg3.5 solder bumps is investigated under the current densities of 1x10(4) A/cm(2) and 5x10(3) A/cm(2) at 150degreesC. Different failure modes were observed for the two stressing conditions. When stressed at 1x10(4) A/cm(2), damage occurred in both the anode/chip side and the cathode/chip side. However, failure happened only in the cathode/chip side under the stressing of 5x10(3)A/cm(2). A three-dimensional simulation of the current-density distribution was performed to provide a better understanding of the current-crowding behavior in the solder bump. The current-crowding effect was found to account for the failure in the cathode/chip side. In addition, both the temperature increase and the thermal gradients were measured during the two stressing conditions. The measured temperature increase due to Joule heating was as high as 54.5degreesC, and the thermal gradient reached 365degreesC/cm when stressed by 1x10(4)A/cm(2). This induced thermal gradient may cause atoms to migrate from the chip side to the substrate side, contributing to the failure in the anode/chip side. Moreover, the formation of intermetallic compounds in the anode/chip side may also be responsible for the failure in the anode/chip side. (C) 2004 American Institute of Physics.
The super laceability of the hypercubes
(2004-10-16)
Chang, CH
;
Lin, CK
;
Huang, HM
;
Hsu, LH
;
資訊工程學系
A k-container C(u, v) of a graph G is a set of k disjoint paths joining u to v. A k-container C(u, v) is a k*-container if every vertex of G is incident with a path in C(u, v). A bipartite graph G is k*-laceable if there exists a k*-container between any two vertices u, v from different partite set of G. A bipartite graph G with connectivity k is super laceable if it is i*-laceable for all i less than or equal to k. A bipartite graph G with connectivity k is f-edge fault-tolerant super laceable if G - F is i*-laceable for any 1 less than or equal to i less than or equal to k - f and for any edge subset F with F = f < k - 1. In this paper, we prove that the hypercube graph Q(r) is super laceable. Moreover, Qr is f-edge fault-tolerant super laceable for any f less than or equal to r - 2. (C) 2004 Elsevier B.V. All rights reserved.
The characteristics of hole trapping in HfO2/SiO2 gate dielectrics with TiN gate electrode
(2004-10-18)
Lu, WT
;
Lin, PC
;
Huang, TY
;
Chien, CH
;
Yang, MJ
The characteristics of charge trapping during constant voltage stress in an n-type metal-oxide-semiconductor capacitor with HfO2/SiO2 gate stack and TiN gate electrode were studied. We found that the dominant charge trapping mechanism in the high-k gate stack is hole trapping rather than electron trapping. This behavior can be well described by the distributed capture cross-section model. In particular, the flatband voltage shift (DeltaV(fb)) is mainly caused by the trap filling instead of the trap creation [Zafar , J. Appl. Phys. 93, 9298 (2003)]. The dominant hole trapping can be ascribed to a higher probability for hole tunneling from the substrate, compared to electron tunneling from the gate, due to a shorter tunneling path over the barrier for holes due to the work function of the TiN gate electrode. (C) 2004 American Institute of Physics.
走訪泰雅族的聖山－大霸尖山
(國立陽明大學, 2004-10-18)
林純芳
相傳，大壩尖山是泰雅族的發祥地之一，在大壩尖山上的兩個石孔，分別出生了一男一女，這對男女便是泰雅族人的祖先。對於這孕育生命的聖地，我自然是多了一份崇敬與好奇.....
驀然間回眸，便與美麗邂逅
(國立陽明大學, 2004-10-18)
TM Wang
;
Tricia
;
陽明電子報編輯小組
醫學館旁小徑2004 / 7 / 26、照片
校園步道
(國立陽明大學, 2004-10-18)
崇平
;
陽明電子報編輯小組
夏天的腳步近了.. 艷陽高照的午後.. 校園的步道，綠葉成蔭.. 涼風徐徐...帶來枕木的氣息.. 按下快門，抓住春天的尾巴.....
陽明電子報「天涯行旅」徵文及照片
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
就要Fun暑假了，驛動的心哪，也開始活蹦亂跳起來了吧？陽明電子報規劃新的專欄「天涯行旅」，請所有的陽明師生一起來投稿：無論國內、外的任何景點；文章長短、內容及形式不拘；若無文字僅附照片亦可，但須附圖片說明.....
生物資訊研究所專題演講公告
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
http://binfo.ym.edu.tw/edu/seminars/102004.htm 講題：Tango with friendly bioinformatics resources: A combination of data mining and experimental approaches in cancer research 主講：Dr.Vivian C.-J. Lee (EMBL-European Bioinformatics Institute, Cambridge, UK) 時間：93年10月20日（星期三）中午12:30 地點：傳醫大樓乙棟4樓401教室 http://binfo.ym.edu.tw/edu/seminars/102204.htm 講題：Functional Genomics and Proteomics for Cancer Analysis 主講：Dr.Jorg Dietrich Hoheisel (Functional Genome Analysis at the DKFZ) 時間：93年10月22日（星期五）中午12:30 地點：活動中心第一會議室
校園美景等你發現
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
春天來了！在粉嫩的花卉和新葉綠芽的交相映照下，校園真是美不勝收！可不可以邀請你公開校園中某個私密角落、自己獨享的美景.....
陽明歷史照片巡禮
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
發黃的照片是否可以讓你陷入時間的隧道中？在這時光隧道中是否勾起你想念的人物、想念的事情？在這初春的時節，電子報於本期起將分次把得來不易的百來張珍貴校園照片逐一向大家介紹，希望隨著這些圖像的重現，再次將大夥的情感凝聚起來！
國科會九十年度永續發展研究徵求計畫重點說明
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
行政院國家科學委員會九十四年度永續發展研究開始徵求計畫構想書，詳情請至永續會 http://www.nsc.gov.tw/csdr/ 網站查詢，構想書無需備文，請依說明規定於九十三年十一月五日十七時前，以電子郵件傳至該會賴開顏小姐hnlai@nsc.gov.tw
臺北市"病人安全"Logo及創意標語徵選
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
活動內容：一、主辦單位：臺北市政府衛生局二、協辦單位：財團法人基督復臨安息日會臺安醫院三、題材：以表現出「臺北市病人安全週Logo及創意標語」，參考內容 1.避免藥物錯誤 2.落實院內感染控制 3.杜絕手術部位錯誤、病人錯誤及手術程序錯誤 4.避免病人辨識錯誤 5.預防病人跌倒
停水通知
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
茲因93 年10月15、16、17、18、19日實施全校水池水塔清洗作業，清洗期間影響供水之範圍及時間如后，請預作準備，不便之處，祈請諒察。
熱帶醫學研究所專題演講公告
(國立陽明大學, 2004-10-18)
陽明電子報編輯小組
講題： cDNA biochips for global gene expression analysis 主講者：黃正仲教授時間： 10 月20 日下午1:30 地點：研究大樓四樓458室經辦：熱帶醫學研究所