Browsing by Issue Date, starting with "2008-01-16"

Now showing 1 - 20 of 56338

A variables sampling plan based on C-pmk for product acceptance determination
(2008-01-16)
Wu, Chien-Wei
;
Pearn, W. L.
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability indices are useful management tools, particularly in the manufacturing industry, which provide common quantitative measures on manufacturing capability and production quality. Most supplier certification manuals include a discussion of process capability analysis and describe the recommended procedure for computing a process capability index. Acceptance sampling plans have been one of the most practical tools used in classical quality control applications. It provides both vendors and buyers to reserve their own rights by compromising on a rule to judge a batch of products. Both sides may set their own safeguard line to protect their benefits. Two kinds of risks are balanced using a well-designed sampling plan. In this paper, we introduce a new variables sampling plan based on process capability index C-pmk to deal with product sentencing (acceptance determination). The proposed new sampling plan is developed based on the exact sampling distribution hence the decisions made are more accurate and reliable. For practical purpose, tables for the required sample sizes and the corresponding critical acceptance values for various producer's risk, the consumer's risk and the capability requirements acceptance quality level (AQL), and the lot tolerance percent defective (LTPD) are provided. A case study is also presented to illustrate how the proposed procedure can be constructed and applied to the real applications. (C) 2006 Elsevier B.V. All rights reserved.
Surface modified gold nanowires for mammalian cell transfection
(2008-01-16)
Kuo, Chiung-Wen
;
Lai, Jun-Jung
;
Wei, Kung Hwa
;
Chen, Peilin
;
材料科學與工程學系
Aminothiol modified gold nanowires have been used as vectors for the delivery of plasmid DNA into two different types of mammalian cells: 3T3 and HeLa. It was measured that positively charged gold nanowires with a diameter of 200 nm and a length around 5 mu m were capable of carrying 1 pg of plasmid DNA per nanowire into cells. Compared with other transfection reagents, the gold nanowires exhibited the highest transfection efficiency while almost no cytotoxicity was observed. In addition, it has been shown that individual nanowires can be visualized with sub-micrometer resolution, which may allow the use of functionalized multi-segment nanowires as local probes for the investigation of the microenvironment inside cells.
以結合半準位信號及多階層錯誤編碼的光碟防盜拷方法
(2008-01-16)
高銘盛
;
廖晨吟
;
葉人瑋
一種以結合半準位信號及多階層錯誤編碼的光碟防盜拷方法,本發明之方法是先於光碟設有加密鍵,再以設於光碟導入區之半準位信號及多階層錯誤編碼保護該加密鍵,使該加密鍵被正確解復之機率曲線產生明顯截止現象,達到防制盜拷之功效,而截止現象是依一定範圍之反射率而判斷。本發明係為一種低成本及防制各種方式盜拷之方法,並解決習用0位元與1位元被輕易複製的問題,且適用於一般播放器,不需複雜的配備及精密的檢測電路。
基板排序派工之方法
(2008-01-16)
巫木誠
;
陳德珊
本發明係揭露一種基板排序派工之方法,此方法包含提供卡匣配對關係、基板配對關係及排序機,並設置有輸入埠及輸出埠,且依據卡匣配對關係經演算法產生派工序列,將複數個第一卡匣依派工序列配送至輸入埠,且第一卡匣中的複數個第一基板,藉由排序機之機械手臂依基板配對關係移動與特定第二卡匣配對者至輸出埠,產出與第二卡匣內複數個第二基板完全配對的複數個第三卡匣,並將已配對的第二、第三卡匣送入壓合機進行壓合,藉此派工序列縮短第三卡匣產出時程,提昇壓合機之產能利用率。
Soluble phenanthrenyl imidazole for photo-electrical conversion of solar cell
(2008-01-17)
Wei, Kung-Hwa
;
Chang, Yao-Te
A novel material of phenanthrenyl imidazole is applied to a solar cell. A phenanthrenyl-imidazole moiety is introduced to reduce a power band of a polymer, so that a photocurrent and an optoelectrical transformation efficiency are improved. Thus, a polymer having the novel material is very suitable to be used in a solar cell to acquire a high optoelectrical transformation efficiency.
GaInP/GaAs HBT wideband transformer Gilbert downconverter with low voltage supply
(2008-01-17)
Tseng, S. -C.
;
Meng, C. C.
;
Wu, C. -K.
;
電信工程研究所
;
Institute of Communications Engineering
A low-voltage wideband downconverter along with an integrated transformer RF balun using the 2 mu m GaInP/GaAs HBT technology is demonstrated. This transformer is a symmetric type and plays a role as a single-to-differential balun. Without the parasitic between the transformer and the substrate, the transformer can work at higher frequencies. This transformer downconverter operates from 1.5 to 14 GHz with around 20 dB conversion gain and 1.8 GHz IF 3 dB bandwidth. The frequency range of the mixing operation is wide and covers the digital video broadcasting via satellite (DVB-S) bands. This mixer is therefore useful for DVB-S applications.
Illuminance formation and color difference of mixed-color light emitting diodes in a rectangular light pipe: an analytical approach
(2008-01-20)
Cheng, Chu-Ming
;
Chern, Jyh-Long
;
光電工程學系
;
Department of Photonics
We developed an analytical method of illuminance formation for mixed-color LEDs in a rectangular light pipe in order to derive American National Standards Institute (ANSI) light uniformity, ANSI color uniformity, and color difference of light output using photometry, nonimaging, and colorimetry. The analytical results indicate that the distributions of illuminance and color difference vary with different geometric structures of light pipes and the location of the light sources. It was found that both the ANSI light and the ANSI color uniformity on the exit plane of the light pipe are reduced exponentially with the increase in length of the light pipe. It is evident that a length scale L/A greater than unity assures that the mixed-color LED sources on the entrance plane are uniformly illuminated with acceptable uniform brightness and color on the exit plane of the rectangular light pipe, where L is the length of the light pipe, and A is a constant, which is a geometric parameter for the scale unit of the light pipe's input face. Furthermore, the ANSI light uniformity can be minimized, and the ANSI color uniformity can be maximized under the condition of multilight-source locations P = Q = +/- A/4, where P and Q are the coordinates along the long axis and the short axis, respectively, with one being the entrance plane of the light pipe. We can conclude that the optimum form factor of the light pipe is a square shaped cross section, with the length scale L/A being equal to unity and with multilight sources located individually on positions of A/4 in order to achieve very uniform illuminations with the highest light efficiency and compact package for the optical system with mixed-color LEDs, where L is the length of the light pipe. (C) 2008 Optical Society of America.
Carrier-mediated exchange coupling and fermi surface topology
(2008-01-20)
Huang, Wen-Min
;
Lai, Hsin-Hua
;
Chang, Cheng-Hung
;
Lin, Hsiu-Hau
;
物理研究所
We investigate the carrier-mediated exchange coupling between two ferromagnets, sandwiching an intermediate thin layer with Rashba interaction. The effective exchange coupling is obtained by integrating out the itinerant carriers. It turns out that the magnetic trends depend sensitively upon the topology of the Fermi surface. As the topology changes from "wedding cake" to "donut", the mediated exchange goes from the oscillatory Ruderman-Kittel-Kasuya-Yosida to the non-collinear spiral interactions accordingly. It is rather surprising that the Fermi surface topology determines which type of magnetic interaction becomes dominant. Finally, we also discuss potential applications for carrier-mediated exchange coupling across the junction.
The cutoff phenomenon for ergodic Markov processes
(2008-01-20)
Chen, Guan-Yu
;
Saloff-Coste, Laurent
;
應用數學系
;
Department of Applied Mathematics
We consider the cutoff phenomenon in the context of families of ergodic Markov transition functions. This includes classical examples such as families of ergodic finite Markov chains and Brownian motion on families of compact Riemannian manifolds. We give criteria for the existence of a cutoff when convergence is measured in L(p)-norm, 1 < p < infinity. This allows us to prove the existence of a cutoff in cases where the cutoff time is not explicitly known. In the reversible case, for 1 < p <= infinity, we show that a necessary and sufficient condition for the existence of a max-L(p) cutoff is that the product of the spectral gap by the max-L(p) mixing time tends to infinity. This type of condition was suggested by Yuval Peres. Illustrative examples are discussed.
Side-wall effects on the bifurcation of the flow through a sudden expansion
(2008-01-20)
Tsui, Yeng-Yung
;
Wang, Hong-Wen
;
機械工程學系
;
Department of Mechanical Engineering
Three-dimensional computations have been performed to study the flow through a symmetric sudden expansion with an expansion ratio of 3 at low Reynolds numbers. The aspect ratio of the flow channel is allowed to vary within a wide range to examine its influence on the flow which bifurcates from a symmetric state to an asymmetric state. The results reveal that the critical Reynolds number of the symmetry-breaking bifurcation increases while the aspect ratio is reduced. The flow behaviour near the side walls is illustrated by using limiting streamlines. The origin of the Singular points identifiable on the side wall can be traced back to the recirculating flows and the relevant reattachment/separation points in the core of the channel. It is seen that the determination of the exact critical Reynolds number is not trivial because it depends on how to define asymmetric flow. Computations have also been conducted to show that a slight asymmetry in the channel geometry causes a smooth transition from symmetric to non-symmetric states. Copyright (C) 2007 John Wiley & Sons, Ltd.
Optically modulated internal strain in InGaN quantum dots grown on SiNx nano masks
(2008-01-21)
Chang, H. J.
;
Chen, T. T.
;
Huang, L. L.
;
Chen, Y. F.
;
Tsai, J. Y.
Optically modulated internal strain has been observed in InGaN quantum dots (QDs) deposited on SiNx nano masks. The modulated internal strain can induce a number of intriguing effects, including the change of refractive index and the redshift of InGaN A(1)(LO) phonon. The underlying mechanism can be well accounted for in terms of the variation of internal strain through the converse piezoelectric effect arising from the screening of the internal electric field due to spatial separation of photoexcited electrons and holes. Our results point out a convenient way for the fine tuning of physical properties in nitride-based semiconductor nanostructures, which is very important for high quality optoelectronic devices. (c) 2006 Optical Society of America.
交大e-News第018期
(2008-01-21)
Secretariat
;
國立交通大學秘書室
主动式可调变电流的薄膜晶体管电路结构
(2008-01-23)
林彦仲
;
黄建智
;
杨佳峰
;
王俊雄
;
谢汉萍
本发明涉及一主动式可调变电流的薄膜晶体管电路结构，特别是应用在主动式发光组件与其显示阵列面板的画素电路。本发明结构包括电流源、数据线、扫描线、直流电压信号线、多个储存电容、多个开关晶体管与一驱动晶体管。其中多个储存电容形成串联结构，其功能为薄膜晶体管电路结构由开启期间转为关闭期间时，其中一储存电容因负回授效应而使得该多个储存电容间的节点的电位下降，进而使得流经发光组件的电流下降，以实现电流调变功能。多个开关晶体管功能为开关功能，以作为控制该电流源的电流方向。
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.