Browsing by Issue Date, starting with "2008-01-24"

Now showing 1 - 20 of 56325

Influence of molecular dipoles on the photoluminescence and electroluminescence of dipolar spirobifluorenes
(2008-01-24)
Chiang, Chih-Long
;
Tseng, Shih-Min
;
Chen, Chin-Ti
;
Hsu, Chao-Ping
;
Shu, Ching-Fong
This Full Paper investigates a series of strongly fluorescent donor-acceptor-substituted spirobifluorene compounds, red 2-diphenylamino-7-(2,2-dicyanovinyl)-9,9'-spirobifluorene (DCV), green 2-diphenylamino-9,9'-spirobifluorene7-carxoxaldehyde (CHO), and blue 2-diphenylamino-7-(2,2-diphenylvinyl)-9,9'-spirobifluorene (DPV), together with their spiro-linked "dimeric" analogs, 2DCV, 2,2'-bis(diphenylamino)-9,9'-spirobifluorene-7,7'-dicarboxaldehyde (2CHO), and 2,2'-bis(diphenylamino)-7,7'bis(2,2-diphenylvinyl)-9,9'-spirobifluorene (2DPV), respectively. The emission optical density and, hence, the intensity of photoluminescence (PL) or electroluminescence (EL) of the "dimeric" analogs is presumed to increase, which is beneficial for organic light-emitting diode (OLED) applications. The physical properties, including the dipole moments obtained from quantum chemistry calculations, emission solvatochromism, fluorescence quantum yield (Of) as well as the EL of these six spirobifluorene compounds have been examined in detail. We found that Of as well as OLED performance (EL efficiency and intensity) of the strongly dipolar DCV decrease significantly in the "dimeric" analog 2DCV, but less so in the moderately dipolar CHO and 2CHO, and only slightly in the weakly dipolar DPV and 2DPV. This is parallel to the intramolecular dipole moment, which is large for 2DCV, medium for 2CHO, and very small for 2DPV. Here, we show for the first time systematically that the luminescence intensity is closely correlated with the local electric field induced by the molecular dipole. A strong electric field may facilitate radiationless decay channels with a charge-transfer nature, leading to a high quenching rate. Consistent with this conclusion, which is derived from the red DCV/2DCV and green CHO/2CHO, our new blue fluorophore DPV with an essentially zero dipole moment has successfully achieved one of the best electrofluorescent blue OLEDs. At the same time, by doping the highly dipolar DCV into an isolated environment with the low-polarity Alq(3) as the host matrix, we obtained a very high performance of saturated yellow OLEDs as well, This is possibly due to the reduction of emission-quenching dipoles from the neighboring molecules. Our results have provided an important insight in designing luminescent materials, as follows: molecular dipole moments should be kept at a low magnitude to avoid quenching induced by a strong local electric field in the chromophore.
Electrical transport studies of individual IrO2 nanorods and their nanorod contacts
(2008-01-30)
Lin, Y. H.
;
Sun, Y. C.
;
Jian, W. B.
;
Chang, H. M.
;
Huang, Y. S.
We have studied the electrical transport properties of individual single-crystalline IrO2 nanorods prepared by the metal-organic chemical vapour deposition method. With the help of the standard electron-beam lithographic technique, individual nanorods are contacted by Cr/Au submicron electrodes from above. Utilizing two-probe, three-probe and four-probe measurement configurations, not only the intrinsic electrical transport properties of the individual nanorods but also the electronic contact resistances, Rc(T), have been determined from 300 K down to liquid-helium temperatures. Our measured resistivity behaviour of the nanorods is in close agreement with the current theoretical understanding of this rutile material. On the other hand, we found that the temperature behaviour of the electronic contact resistance obeys the law log R-C alpha T-1/2 over an extremely wide temperature range, from approximately 100 K down to liquid-helium temperatures. This latter conduction process is ascribed to the hopping of electrons through nanoscale Cr granules and/or an amorphous coating incidentally formed at the interface between the submicron Cr/Au electrode and the nanorod.
Berkovich nanoindentation and deformation mechanisms in GaN thin films
(2008-01-30)
Tsai, Chien-Huang
;
Jian, Sheng-Rui
;
Juang, Jenh-Yih
;
電子物理學系
;
Department of Electrophysics
The deformation mechanisms of GaN thin films obtained by metal-organic chemical vapor deposition (MOCVD) method were studied using nanoindentation with a Berkovich diamond indenter, micro-Raman spectroscopy and the cross-sectional transmission electron microscopy (XTEM) techniques. Due to the sharpness of the tip of Berkovich indenter, the nanoindentation-induced deformation behaviors can be investigated at relatively lower load and, hence, may cover wider range of deformation-related phenomena over the same loading range. The load-displacement curves show the multiple "pop-ins" during nanoindentation loading. No evidence of nanoindentation-induced phase transformation and cracking patterns were found up to the maximum load of 300 mN, as revealed from the micro-Raman spectra and the scanning electron microscopy (SEM) observations within the mechanically deformed regions. In addition, XTEM observation performed near the cross-section of the indented area revealed that the primary deformation mechanism in GaN thin film is via propagation of dislocations on both basal and pyramidal planes. The continuous stiffness measurement (CSM) technique was used to determine the hardness and Young's modulus of GaN thin films. In addition, analysis of the load-displacement data reveals that the values of hardness and Young's modulus of GaN thin films are 19 +/- 1 and 286 +/- 25 GPa, respectively. (C) 2007 Elsevier B.V. All rights reserved.
Electrical transport studies of individual IrO(2) nanorods and their nanorod contacts
(2008-01-30)
Lin, Y. H.
;
Sun, Y. C.
;
Jian, W. B.
;
Chang, H. M.
;
Huang, Y. S.
We have studied the electrical transport properties of individual single-crystalline IrO(2) nanorods prepared by the metal-organic chemical vapour deposition method. With the help of the standard electron-beam lithographic technique, individual nanorods are contacted by Cr/Au submicron electrodes from above. Utilizing two-probe, three-probe and four-probe measurement configurations, not only the intrinsic electrical transport properties of the individual nanorods but also the electronic contact resistances, Rc(T), have been determined from 300 K down to liquid-helium temperatures. Our measured resistivity behaviour of the nanorods is in close agreement with the current theoretical understanding of this rutile material. On the other hand, we found that the temperature behaviour of the electronic contact resistance obeys the law log R(C) alpha T(-1/2) over an extremely wide temperature range, from approximately 100 K down to liquid-helium temperatures. This latter conduction process is ascribed to the hopping of electrons through nanoscale Cr granules and/or an amorphous coating incidentally formed at the interface between the submicron Cr/Au electrode and the nanorod.
Electrochemical fabrication and magnetic properties of highly ordered silver-nickel core-shell nanowires
(2008-01-31)
Lin, Shih-Chin
;
Chen, San-Yuan
;
Chen, Yun-Tien
;
Cheng, Syh-Yuh
;
交大名義發表
Ordered silver-nickel core-shell nanowire arrays were successfully fabricated by electrodeposition. The ordered silver nanowire arrays embedded in a porous alumina template were first fabricated from an aqueous solution of Ag(NO3)(2) and Ac(NH3). After removing out the template, the obtained silver nanowire arrays were subsequently electrodeposited with nickel at 1.6-2.6 V and 60 degrees C using the electrolyte composed of NiSO4, NiCl2 and H3BO3. Transmission electron microscopy observation revealed that a similar to 15 nm thick nickel film was coated on the surface of the silver nanowires with about 200 nm in diameter. It was found that the silver nanowires with nickel coating showed enhanced magnetic properties in comparison to that of pure silver nanowires. The magnetic force microscope image of silver-nickel core-shell nanowires showed magnetic domain state. In addition, the hysteresis loops of the silver-nickel nanowire arrays showed a coercive field of 180 Oe, almost independent of the applied magnetic field. However, it was observed that a larger magnetic domain was found in parallel direction than that in perpendicular direction. (c) 2007 Elsevier B.V. All rights reserved.
Probing a nonuniform two-dimensional electron gas with random telegraph signals
(2008-02-01)
Chen, Ming-Jer
;
Lee, Chien-Chih
;
Lu, Ming-Pei
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We observe a sequence of two-level random telegraph signals (RTSs) in the drain/source current of a 1.7 nm gate oxide silicon metal-oxide-semiconductor field-effect transistor. The RTS magnitude is transformed into the apparent Debye length around a negatively charged oxide trap. We achieve excellent reproduction of the Debye data (40 down to 5 nm). This leads to the quantified area spanned by the dominant conductive percolation paths in the underlying two-dimensional electron gas (2DEG). We find that most of the 2DEG in inversion is recovered in a largest threshold voltage sample (similar to 0.35 V), while for the lowest threshold (similar to 0.15 V), a certain conductive filament is likely to occur. The gate direct tunneling current further corroborates the percolation picture. (c) 2008 American Institute of Physics.
BaMgAl10O17 : Eu blue phosphors with MgO coating and microwave irradiation
(2008-02-01)
Kuo, Kuan-Ting
;
Lee, Shu-Ping
;
Chen, San-Yuan
;
Cheng, Bing-Ming
;
Lu, Hsiao-Chi
Europium-activated barium magnesium aluminate (BaMgAl10O17:Eu (BAM)) phosphor particles were modified by surface coating with MgO using a polyol method. The photoluminescence (PL) properties of the MgO-coated BAM phosphors showed slightly improved blue-emission intensity compared to the unmodified ones, and reached a stronger peak intensity with 5.25% MgO coating, under vacuum ultraviolet (VUV) 147 nm excitation. Upon microwave irradiation on the MgO-coated BAM phosphors, the PL properties of the MgO-coated phosphors exhibited a much enhanced relative PL ratio, and a maximum relative PL ratio can be achieved when as high as 10.5% MgO was deposited on the phosphor surface. However, for mechanically ground phosphor powder, it was found that although the intensity of the MgO-coated BAM turned stronger with increasing MgO concentration under microwave irradiation, the purity of the resulting luminescence was slightly disrupted by the presence of a new peak near 470 nm, corresponding to BaMg3Al14O25 compound. (C) 2007 Elsevier Ltd. All rights reserved.
石牌再添社區活動平台－陽明人參與北投扶輪社活動側寫
(國立陽明大學, 2008-02-01)
吳小瑄
2008年1月13日北投扶輪社於本校生活文化廣場舉辦「『樹之饗宴－音樂嘉年華會』社區服務日」活動，主題為「感性、熱情、健康、希望」，目的在與社區組織及北投居民友善互動，推廣植樹環保之重要概念，並傳達北投扶輪社對於服務社會的熱情與理念。當日上午8點30分開始，北投扶輪社先率眾整理社區環境，於致遠三路及東華街入口之公園舉行櫻花捐贈及揭碑儀式，隨後便將活動重心移至本校生活文化廣場，展開熱鬧的抽獎與表演節目。本次活動中，除了舉辦公益活動已行之有年的北投扶輪社，與熱心在地事務的協辦伙伴，如東華里、立農里、永明里等里辦公事及社區發展協會等單位之外，最引陽明人注意的，莫過於陽明社團的精彩表演。經招募後共計5個社團參與表演並擔任助理主持工作，包含有愛杏管弦樂團、國標社、熱舞社、手語社與吉他社。熱舞社同學在會場的賣力演出生活文化廣場位於校門東側，是陽明人上下山必經之地，亦是石牌人親山步道的必跨門檻，對內為校內熱門之學生活動場地，面外則剛好是石牌人生活圈，地理位置不但特殊而且重要，早已成為地標之一。正因地點合適，活動可說未演先轟動，在北投扶輪社強力宣傳下，當日現場人潮不絕，中央廣場中跳蚤市場的叫賣聲更引來川流不息的人潮。本次活動中，露天舞台首先上場的是充滿動感節奏的熱舞社，連續兩首Hip Hop熱舞再加上社團老骨頭相挺演出之故事型勁曲「有壞人，殺光他們」，熱舞張力立即驅走臘月寒意，將現場氣氛炒熱起來。後有吉他社以「愛神」、「童年」與「夜來香」將現場拉入時光隧道，接下來國標社的恰恰及slow tango的炫麗舞姿則讓台下大爆口哨與掌聲，音樂與歡樂吸引越來越多的觀眾，各方讚嘆聲則讓到場為社團加油的姜學務長露出欣慰與感動的笑容。台上認真表演的陽明同學而後，有手語社「三個心願」青春俏皮並融合舞台劇風格呈現，與第二首「飛龍在天」的誇張逗趣表演及現場小教學，讓全場捧腹大笑，並有社區發展協會志工來洽詢學習手語的相關資訊。最後壓軸的愛杏管弦樂團，以場前解說來帶領聆聽管弦樂之美，熱鬧豐富的慶典樂曲為表演劃下句點，只留下陣陣餘音繞樑的驚豔印象給現場觀眾。姜學務長於會場之剪影社團走出校園，與社區友善互動，是教育部大專社團評鑑重點，課輔組十分鼓勵社團參與，並期望藉由吸引在地居民認識陽明社團，與在地公益團體長期交流，建立友好互動默契，與社區共同經營石牌特色文化。而生活文化廣場則是成為串連各方團體的交流平台，在這平台中，社團找到表演舞台與觀眾；在這平台中，北投扶輪社找到了同樣致力於深耕地方文化的好伙伴；在這平台中，我們發現，陽明學生不是璞玉，已成充滿自信的鑽石閃閃發亮。生活文化廣場，就在學生社團與社區互動中，漸漸萌發出自己的生命力，也逐漸讓外界瞭解陽明社團得天獨厚，擁有一隅令人稱羨的驚豔角落。生活廣場上民眾欣賞繪畫比賽的作品多元化的使用不但可活絡該場地，且讓社團人能藉由各項活動培養團隊合作力，並能與校外團體互動，增廣見聞，堪稱體驗學習之範例，十分期待以此路徑培育出新生醫領導人才。最近，有國內科技大廠規劃軍艦岩健康健行，從親山步道開始，瞭解陽明花徑蝶路之美，並向課輔組申請借用生活文化廣場，作為摸彩活動場地，並徵召社團人擔任校園小天使，引導校外人士探索校園。只要是公益健康的活動，課輔組樂見其成。校內單位若需與社區互動或舉辦各項活動，歡迎多加使用本場地。歡迎光臨陽明生活文化廣場！圖/文課輔組吳小瑄
5.7 GHz Gilbert I/Q downconverter integrated with a passive LO quadrature generator and an RF Marchand balun
(2008-02-01)
Syu, Jin-Siang
;
Meng, Chinchun
;
Yen, Ying-Chieh
;
電信工程研究所
;
Institute of Communications Engineering
A 5.7 GHz I/Q downconversion mixer is demonstrated in this letter using 0.35 mu m SiGe BiCMOS technology. A quarter-wavelength coupled line and two center-tapped transformers are utilized to generate differential quadrature LO signals. A miniaturized Marchand balun is placed before the common-base-configured RF input stage of each I/Q Gilbert mixer to generate balanced RF signals. All the reactive passive elements are placed directly on the standard silicon substrate. The 5.7 GHz I/Q downconverter achieves 7 dB conversion gain, -26 dBm IP1dB, and -18 dBm IIP3 at the power consumption of 3.875 mW and 2.5 V supply voltage.
第二十五篇：秤中藥的天平
(國立陽明大學, 2008-02-01)
高怡宣
;
陳金山
秤中藥的天平一邊比較重，另一邊比較輕，為什麼可以保持平衡呢，我們以身邊的小物品來實驗看看。力矩。衣架、線、湯匙、鉗子。 1. 將衣架剪斷，用最長的那段做支架，並用奇異筆標示等距的長度。 2. 將一根繩子綁在支架的中央，用手提著繩子的另一端，做為支點。然後在支點的左右兩側，在不同的位置，放置不同數目的湯匙，試著使支架保持平衡，不會傾斜。力矩（torque）是影響物體轉動的物理量，力矩的計算公式是「與支點的距離」乘以「重量」。當力矩的總和為零時，這個系統會維持轉動的平衡的狀態。在日常生活的應用包括﹕秤中藥的天平、國中化學課所使用的天平、以及小朋友玩的翹翹板。現在的菜市場都在使用電子秤，可以同時顯示重量及金額。在古時候（good old days），菜市場的攤販使用各式各樣的天平來稱重量，然後用心算的方式，來計算金額。那時候，因為怕被多收錢，所以客人的心算能力也很強。醫放系所高怡宣 / 陳金山老師秤中藥的天平（感謝台北市北投區尊賢街245號的鴻春參藥行提供樣品拍照）國中理化課所使用的天平（感謝台北市中正區太原路52號的尚樁五金行提供樣品拍照）在臺北市的國小及公園堙A翹翹板已經很少見了。（這張照片是在臺北縣永和市的四號公園拍照的）
A 40-MHz double differential-pair CMOS OTA with-60-dB IM3
(2008-02-01)
Lo, Tien-Yu
;
Hung, Chung-Chih
;
電信工程研究所
;
Institute of Communications Engineering
A configuration of a linearized operational transconductance amplifier (OTA) for low-voltage and high-frequency applications is proposed. By using double pseudodifferential pairs and the source-degeneration structure under nano-scale CMOS technology, the norlinearity caused by short channel effect from a small feature size can be minimized. A robust common-mode control system is designed for input and output common-mode stability and thus reduces distortion caused by common-mode voltage variation. Mining ability can be achieved by using MOS transistors in the linear region. The linearity of the OTA is about -60-dB third-order inter-modulation (IM3) distortion for up to 0.9 V-pp at 40 MHz. This OTA was fabricated by the TSMC 180-nm deep n-well CMOS process. It occupies a small area of 15.1 X 10(-3) mm(2) and the power consumption is 9.5 mW under a 1.5-V supply voltage.
本期摘要
(國立陽明大學, 2008-02-01)
陽明電子報編輯小組
一年復始，萬象更新。在本期電子報中，新的一年陽明也有許多的好消息與大家分享。首先，是陽明大家庭期待已久的陽明附設醫院的蘭陽院區興建案終於在一月20日經建會審核通過，未來將可為蘭陽地區的居民健康把關，也可望提供更完善重症醫療、生醫科技、教學研究實習的實際觀察研究場域。另一方面，於細胞生物學研究上傅毓秀教授臍帶幹細胞研究上也傳出世界首例登上《公共科學圖書館》（PLoS One）期刊的好消息，為糖尿病治療提供不同於以往的思考模式。陽明電子報在豬年的最後一期也換上了新衣迎接鼠年的到來。希望新版面的新氣象能夠讓讀者閱讀起來更舒適與方便，對陽明大學也能夠進一步的認識。有多久沒出來戶外走走了呢？本期課輔部落格為您報導北投扶輪社與陽明各社團於陽明生活文化廣場的活動紀實，在欣賞活動紀錄之餘，不忘到山腳下的陽明生活文化廣場走走活絡活絡筋骨。在嚴寒的冬日裡，走走路暖暖身是不錯的選擇。走走路總是會餓的，在副刊的過年特輯也為您準備了熱呼呼的台北好吃年糕哪裡吃的介紹，祝所有讀者在來年都能事事如意，年年高！陽明電子報編輯小組敬啟
Synthesis and physical characteristics of AlOx-coated ZnO nanorod arrays grown in aqueous solution at low temperatures
(2008-02-01)
Hsiao, Chi-Sheng
;
Chen, San-Yuan
;
Cheng, Syh-Yuh
;
材料科學與工程學系
;
Department of Materials Science and Engineering
AlOx-ZnO core-shell nanorods arrays have been successfully synthesized by soaking the ZnO nanorods in the sol-gel solution of Al(NO3)(3) and NH4OH at room temperature. It was found that both crystal growth and morphology of the AlOx-ZnO core-shell nanorods are strongly influenced by the solution pH value. SEM image shows that the AlOx-ZnO core-shell nanorods can be perpendicularly grown on the ZnOf/Si substrate under the solution only with a pH value of 6-7. High-resolution TEM observation demonstrates that the structure of the AlOx layer is amorphous and the ZnO nanorod core remains single crystal. After annealed at 400 degrees C in N-2 atmosphere, a strong photoluminescence peak corresponding to blue emission (similar to 450 nm) was detected from the AlOx-ZnO core-shell nanorods that may result from the induced defects due to interaction between AlOx shell and ZnO nanorods. (C) 2007 Elsevier Ltd. All rights reserved.
Characteristics of multileaf holey light-emitting diodes for fiber-optic communications
(2008-02-01)
Yang, Hung-Pin D.
;
Yeh, Zao-En
;
Lai, Fang-I
;
Kuo, Hao-Chung
;
Chi, Jim Y.
An oxide-confined multileaf holey light-emitting diode (LED) in the 780 nm range is reported. The device is consisted of bottom distributed Bragg reflector (DBR), quantum wells QWs), and top DBR, with a multileaf holey structure within the p-ohmic contact ring for light extraction. The spontaneous emission from under the etched holes and internally reflected lights can be extracted and collimated out of the smaller etched leaf holes. High-resolution imaging studies indicate that the device emits with smaller beams mainly through the multileaf etched holes made it suitable for fiber-optic communications.
Electrical enhancement of polycrystalline silicon thin-film transistors using fluorinated silicate glass passivation layer
(2008-02-01)
Chang, Chia-Wen
;
Deng, Chih-Kang
;
Huang, Jiun-Jia
;
Wang, Tong-Yi
;
Lei, Tan-Fu
Polycrystalline silicon thin-film transistors (poly-Si TFTs) with a fluorinated silicate glass (FSG) passivation layer are proposed and demonstrated in this study. Experimental results reveal that the electrical characteristics can be improved by the incorporation of appropriate amounts of fluorine in the poly-Si film. The poly-Si TFTs with a FSG passivation layer show a high on-current, a low off-state gate-induced drain leakage (GIDL) current, a high field-effect mobility, and a suppressed kink effect, compared with the poly-Si TFTs with an undoped SiO(2) passivation layer. The presence of incorporated fluorine atoms from the FSG passivation layer in the poly-Si channel film can passivate the trap states at the grain boundaries. Furthermore, the incorporation of fluorine atoms can form stronger Si-F bonds near the source and drain sides to enhance the immunity against hot-carrier stress. In addition, the proposed poly-Si TFTs are easy to fabricate, have a low production cost, and are realized using a process compatible with modern TFT manufacturing technology.
Effects of high shear rate shearing on material structure and mechanical property of iPP/PC blends
(2008-02-01)
Lu, M. -C.
;
Chen, R. -H.
;
Chi, K. -H.
;
機械工程學系
;
Department of Mechanical Engineering
Polycarbonate (PC) and crystalline polymer, isotatic polypropylene (iPP), are extruded using a mechanical blending extruder and a reciprocated mechanism for shearing is designed to perform long term shearing at a high shear rate in the packing stage. The present work investigates the effects of high shear rate shearing on the orientation of the phase morphologies and mechanical properties. The experiment utilises the technologies of specimen preparation and observation to examine the change in phase morphology. Additionally, the mechanical properties of injection moulded specimens under different processing conditions are measured. Experimental results show that adding a little PC into the iPP matrix, less than around 20%, increases the tensile strength of specimens. The orientation of the phase is improved and most of the tensile strength of the blends is increased after shearing. The tensile strength of the shearing specimens with a PC content of,25% exceeds that of the normal specimens of pure iPP. A higher iPP content corresponds to a higher tensile strength after shearing. This investigation also considers the possibility of using iPP/PC blends in industrial applications, indicating that shearing is valuable in industrial applications when the PC content in iPP/PC blends is 25%.
Design and analysis of a fault-tolerant coplanar gyro-free inertial measurement unit
(2008-02-01)
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a novel design of a fault-tolerant, coplanar, and gyro-free inertial measurement unit (IMU) that consists of 13 single-axis linear accelerometers and can perform six degree-of-freedom (DOF) measurements for an object in motion. This design uses a combination of redundant accelerometers, an innovative real-time fault-identification technique, together with state-estimation techniques to facilitate robust six DOF measurements, even when some of its accelerometers produce faulty outputs. A design example indicates that the proposed fault-tolerant design and compensation algorithm can detect and correct the biased accelerometer outputs in real time. In this simulation example, the accelerometer measurement noise is assumed to be white and set at 0.1 m/s(2). The minimum detectable dc-offset value is 0.1 m/s(2), which is the same as the standard deviation of the accelerometer measurement noise. The compensated accelerometer outputs were used to construct an "observer-based" gyro-free IMU. The angular-velocity estimation accuracy is 4 x 10(3) rad/s, and the linear-acceleration accuracy is less than 0.24 m/s(2). The IMU output accuracy is not affected by the proposed fault-compensation algorithm.
SIPv6 analyzer: an analysis tool for 3GPP IMS services
(2008-02-01)
Chen, Whai-En
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Sung, Yueh-Hsin
;
Lin, Yi-Bing
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資訊工程學系
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Department of Computer Science
The 3rd Generation Partnership Project (3GPP) defines IP Multimedia Core Network Subsystem (IMS) to support IP-based multimedia services. IMS utilizes protocols such as IP version 6 (IPv6), Session Initiation Protocol (SIP), and Real-time Transport Protocol (RTP) to deliver the multimedia content. This paper proposes an analysis tool referred to as SIPv6 Analyzer to investigate the IMS-related protocols during IMS service deployment. The SIPv6 Analyzer not only dissects the protocol headers but also provides user-friendly functions such as message flow generation and audio/video replay for IPv6, SIP, and RTP. We describe the design of the SIPv6 Analyzer and use examples to illustrate how it works. Copyright (C) 2006 John Wiley & Sons, Ltd.
Triangle-free distance-regular graphs
(2008-02-01)
Pan, Yeh-jong
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Lu, Min-hsin
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Weng, Chih-wen
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應用數學系
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Department of Applied Mathematics
Let Gamma denote a distance-regular graph with diameter d >= 3. By a parallelogram of length 3, we mean a 4-tuple xyzw consisting of vertices of Gamma such that partial derivative(x,y)=partial derivative(z,w)=1, partial derivative(x,z)=3, and partial derivative(x,w)=partial derivative(y,w)=partial derivative(y,z)=2, where partial derivative denotes the path-length distance function. Assume that Gamma has intersection numbers a(1)=0 and a(2)not equal 0. We prove that the following (i) and (ii) are equivalent. (i) Gamma is Q-polynomial and contains no parallelograms of length 3; (ii) Gamma has classical parameters (d,b,alpha,beta) with b <-1. Furthermore, suppose that (i) and (ii) hold. We show that each of b(b+1)(2)(b+2)/c (2), (b-2)(b-1)b(b+1)/(2+2b-c (2)) is an integer and that c (2)<= b(b+1). This upper bound for c (2) is optimal, since the Hermitian forms graph Her(2)(d) is a triangle-free distance-regular graph that satisfies c (2)=b(b+1).
陽明大學附設醫院蘭陽院區興建案通過
(國立陽明大學, 2008-02-01)
秘書室
宜蘭的醫療品質不足，導致許多宜蘭人須千里迢迢北上至台北地區就診，東部醫療資源原本就不及西部。以東部為例，花蓮有屬於醫學中心等級的慈濟醫院，宜蘭地區卻沒有。經建會於一月20日通過教育部陳報的「陽明大學附設醫院蘭陽院區興建案」，總經費約為六十三億元，政府將於宜蘭市後火車站之「生物醫學產業特定專用區」內，興建本校附設醫院蘭陽院區。第一期工程預估於二○一三年完成，將可大幅提升宜蘭地區醫療品質。校方表示，希望聯合當地的醫療院所及社區，共同建立一個醫療服務與健康支持網絡，使宜蘭民眾能就近獲得方便而優質的醫療服務。「蘭陽院區」的發展主軸，將以重症醫療、心血管醫學、腫瘤醫學、神經醫學、胸腔醫學、老人醫學、社區醫學為主。蘭陽院區第一期工程計畫將包括：可容納四百張急性病床的醫療大樓、教學研究大樓、動力中心及地下停車場，而這也是宜蘭地區第一個大型醫學中心，預估在二○一三年完工啟用。可望提供重症醫療、生醫科技、教學研究實習等使用，第二期工程則包括醫護宿舍，預估二○一六年完工。除了蘭陽院區的興建案之外，從今年元月一日起，原有的署立宜蘭醫院，直接改制為陽明大學附設醫院之「新民院區」，提供蘭陽地區鄉親醫療照護服務。未來本校多元臨床教學資源，將可提供學生更豐富之訓練需求，培育更符合社會期待之未來醫生。秘書室編輯報導