Browsing by Issue Date, starting with "2006-06-19"

Now showing 1 - 20 of 63144

Efficient white-light-emitting diodes based on poly(N-vinylcarbazole) doped with blue fluorescent and orange phosphorescent materials
(2006-06-19)
Shih, Ping-I
;
Shu, Ching-Fong
;
Tung, Yung-Liang
;
Chi, Yun
;
應用化學系
We have fabricated polymer white-light-emitting devices possessing a single emitting layer containing a hole-transporting host polymer, poly(N-vinylcarbazole), and an electron-transporting auxiliary, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, doped with a blue-light-emitting amino-substituted distyrylarylene fluorescent dye and an orange-light-emitting osmium phosphor. The doubly doped device exhibited an intense white emission having Commission Internationale de l'Eclairage coordinates of (0.33, 0.34), a high external quantum efficiency of 6.12% (13.2 cd/A), and a maximum brightness of 11 306 cd/m(2). The color coordinates remained unchanged over a range of operating voltages, even at luminance as high as 1x10(4) cd/m(2). (c) 2006 American Institute of Physics.
Packet classification using diagonal-based tuple space search
(2006-06-20)
Lee, FY
;
Shieh, S
;
資訊工程學系
;
Department of Computer Science
Multidimensional packet classification has attracted considerable research interests in the past few years due to the increasing demand on policy based packet forwarding and security services. These network services typically involve determining the action to take on packets according to a set of rules. As the number of rules increases, time for determining the best matched rule for an incoming IP packet will increase and subsequently incur long processing delay. To address this issue, in this paper we propose a two-dimensional packet classification algorithm which focuses on reducing time for classification while keeping reasonable memory requirement in practice. Our approach extends the tuple space framework and then allows performing binary search on the tuple space. To our knowledge, the proposed scheme is the first binary search scheme on two-dimensional tuples. With the proposed scheme, given a filter set with n two-dimensional filters, it requires only O(log(w)) hash operations to determine the best matched filter, where w is the maximum prefix length of filters. The proposed scheme achieves fast packet classification, and according to our experimental results, it does not require huge memory space. This makes it useful for network applications that require high speed packet classification. (c) 2005 Elsevier B.V. All rights reserved.
Background comparator offset calibration technique for flash analog-to-digital converters
(2006-06-20)
Huang
;
Chun-Cheng
;
Wu
;
Jieh-Tsorng
A background-calibrated comparator and a background-calibrated flash analog-to-digital converter are disclosed for using in mixed-signal integrated circuit design in particular on the high-speed analog-to-digital converter circuit. Without affecting the operation of the comparator, the disclosure is directed at reducing the unpredictable input offset voltage originated from the variation of process parameters and environmental factors. The background-calibrated comparator includes a random chopping comparator, a calibration processor, and a random sequence generator. The background-calibrated flash analog-to-digital converter (ADC) includes a background-calibrated comparator array together with a reference voltage generator, a thermometer code edge detector, and a set of digital encoders.
Biofunctional ZnO nanorod arrays grown on flexible substrates
(2006-06-20)
Liu, TY
;
Liao, HC
;
Lin, CC
;
Hu, SH
;
Chen, SY
A square pattern of thioctic acid self-assembled ZnO nanorod arrays was grown on a large 4-in. thermoplastic polyurethane (TPU) flexible substrate via an in situ soluthermal process at low temperature (348 K). With the addition of dimercaptosuccinic acid (DMSA), the surface chemistry forms a disordered ZnO phase, and the morphology of the ZnO- DMSA nanorods changes with various DMSA addition times. As evidenced by the Zn-2p3/2, C-1s, O-1s, S-2p, and N-1 s scans of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), DMSA and proteins were conjugated on the single crystalline ZnO nanorods. The photoluminescence (PL) spectra indicated that the optical properties of ZnO nanorod arrays were changed while the DMSA was inserted, and proteins were conjugated. Furthermore, a control test found that the ZnO nanorods show a significant improvement in sensitive characterization over the ZnO film. As another proteins (e. g., human serum albumin, HSA) were bound onto the ZnO- bovine serum albumin (BSA) nanorod arrays, an enhanced ultraviolet emission intensity was detected. On the basis of these results, one might be expected to conjugate specific biomolecules on the biofunctional ZnO nanorod arrays to detect the complementary biomolecules by PL detecting.
你畫清明上河圖呀
(2006-06-20)
管管
以腦電波控制的嵌入式網路機器人架構
(2006-06-21)
吳立偉
;
廖憲正
本發明係揭露一種以腦電波控制的嵌入式網路機器人架構，其係使用腦機界面（BCI）技術以及網路機器人(Internet Robot Agent）架構為基礎，並配合腦電波警覺程度偵測與指令轉譯技術，讓使用者可以藉由單純的意識活動來控制遠端機器人，進而與環境達到互動，如同根據使用者意識在遠端建立一可代表使用者之實體。此一系統架構能使重度殘障者擁有對環境的表達能力，亦可應用於多人連線之互動遊戲系統中。
無線區域網路支援服務品質之排程方法
(2006-06-21)
黃經堯
;
范裕隆
一種無線區域網路(WLAN)中站台之輪詢方法，包含下列步驟：取得相關於該等站台之服務品質(QoS)資訊；指定兩個計時器於需要該QoS保證之各該WLAN服務，一用於向上連結傳輸及另一用於向下連結傳輸；當該等計時器之具有最小值的計時器Tm之值低於一臨限值Tthr時，則起始一控制之存取週期(CAP)；與具有最小值計時器Tm之站台交換訊息(依據需要來輪詢，或向下連結與輪詢)；在傳送一輪詢之訊息之後，更新該具有最小值之計時器Tm；其中，若該Tm之值大於該臨限值Tthr時，退出該CAP並允許其它站台競爭資源。
Novel carbazole/fluorene hybrids: Host materials for blue phosphorescent OLEDs
(2006-06-22)
Shih, Ping-I
;
Chiang, Chih-Long
;
Dixit, Ajay Kumar
;
Chen, Ching-Kun
;
Yuan, Mao-Chuan
A series of carbazole/fluorene (CBZm-Fn) hybrids were effectively synthesized through Friedel-Crafts-type substitution of the carbazole rings. These compounds were thermally and morphologically stable host materials for OLED applications. Efficient blue phosphorescent OLEDs were obtained when employing CBZ1-F2 as the host and Firpic as the guest.
Bit error rate tester and pseudo random bit sequences generator thereof
(2006-06-22)
Chen, Wei-Zen
;
Huang, Guan-Sheng
A bit error rate tester and a pseudo random bit sequences (PRBS) generator thereof are provided. The bit error rate tester includes a transmitter PRBS generator, a master PRBS generator, a slave PRBS generator, a comparator, and a counting unit. The transmitter PRBS generator generates a parallel N-bit (N is an integer larger than 1) original PRBS, wherein an object to be tested receives the original PRBS and outputs a parallel N-bit code to be tested. The master and the slave PRBS generators generate a master and a slave parallel N-bit PRBS, respectively. The comparator receives, compares, and determines whether the code to be tested, the master and the slave PRBS are the same or not, and outputs a comparison result. The counting unit coupling to the comparator counts a number of bit errors based on the comparison result.
Device having an organic transistor integrated with an organic light-emitting diode's heterojunctions
(2006-06-22)
Meng, Hsin-Fei
;
Horng, Sheng-Fu
;
Hsu, Chien-Shu
;
Liu, Wen-Tsang
;
Yang, Yu-Zhong
A device having an organic transistor device integrated with an organic light-emitting diode's heterojunctions. This device at least comprises: a transparent substrate, an organic transistor and an organic light-emitting diode. The organic transistor at least includes an organic semiconductor layer, one of the organic semiconductor layers serves as the organic active layer of the organic light-emitting diode, and the organic active layer and the other organic semiconductor layers form heterojunctions. The present invention uses the organic semiconductor layer to simultaneously form the organic active layer of the organic transistor, so that the organic light-emitting diode and the organic transistor can be easily integrated together so as to solve the problem of the poor luminance efficiency of a conventional integrated organic transistor and organic light-emitting diode and the problem of its high manufacturing cost.
Flexible online association rule mining based on multidimensional pattern relations
(2006-06-22)
Wang, CY
;
Tseng, SS
;
Hong, TP
;
資訊工程學系
;
Department of Computer Science
Most incremental mining and online mining algorithms concentrate on finding association rules or patterns consistent with entire current sets of data. Users cannot easily obtain results from only interesting portion of data. This may prevent the usage of mining from online decision support for multidimensional data. To provide ad-hoc, query-driven, and online mining support, we first propose a relation called the multidimensional pattern relation to structurally and systematically store context and mining information for later analysis. Each tuple in the relation comes from an inserted dataset in the database. We then develop an online mining approach called three-phase online association rule mining (TOARM) based on this proposed multidimensional pattern relation to support online generation of association rules under multidimensional considerations. The TOARM approach consists of three phases during which final sets of patterns satisfying various mining requests are found. It first selects and integrates related mining information in the multidimensional pattern relation, and then if necessary, re-processes itemsets without sufficient information against the underlying datasets. Some implementation considerations for the algorithm are also stated in detail. Experiments on homogeneous and heterogeneous datasets were made and the results show the effectiveness of the proposed approach. (c) 2005 Elsevier Inc. All rights reserved.
Formation of porous carbon materials with in situ generated NaF nanotemplate
(2006-06-22)
Huang, Chih-Hao
;
Chang, Yu-Hsu
;
Wang, Hsiao-Wan
;
Cheng, Soofin
;
Lee, Chi-Young
Porous carbon materials with pore sizes from 3 to 200 nm were synthesized by reacting hexafluorobenzene with Na liquid at 623 K. NaF crystals, a byproduct formed in the reaction, acted as nanotemplate to assist the pore formation. By employing hexafluorobenzene to react with Na incorporated within the channels ( diameter 200 nm) of anodized aluminum oxide ( AAO) membranes at 323- 623 K, the carbon material can be fabricated into aligned porous nanotube arrays ( ca. 250 nm in diameter, ca. 20 nm in wall thickness, ca. 0.06 mm in length, and ca. 3-90 nm in pore diameter). These materials were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray energy dispersive spectroscopy, electron diffraction, thermal gravimetric analysis, and nitrogen physical adsorption experiments.
Self-alignment manufacturing method of the microlens and the aperture using in optical devices
(2006-06-22)
Chiu, Yi
;
Hsu, Wen Syang
;
Chang, Yu-Ru
The present invention discloses a self-alignment manufacturing method of a microlens and an aperture using in an optical device. The method manufactures the aperture and the circular opening in the opaque film on a transparent substrate, and utilizes the self-alignment backside exposure technology to precisely integrate the aperture and the microlens made by macromolecule material without any combination step. The claimed method is simpler than conventional technology and can precisely align and integrate the microlens and the aperture with a continuous batch manufacture. Since the aperture and the circular opening are concentric circles and formed in same step, the microlens and the aperture can be precisely aligned with the backside exposure. The claimed invention can effectively improve the optical resolution and efficiency of the optical access and measurement devices.
A novel design of high-speed divide-by-3/4 counter for a dual-modulus prescaler
(2006-06-25)
Shih, Yi-Shing
;
Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A novel design for a high-speed divide-by-3/4 counter is presented. The proposed design reduces not only the critical path delay but also the feedback path delay, hence it can increase the operating speed. With this divide-by-3/4 counter, a divide-by-127/128 dual-modulus prescaler (DMP), implemented in 0.18 mu m CMOS technology, shows a maximum operating frequency of 7.0 GHz with 2.4mW power consumption at 1.8V supply voltage, which has 25% speed improvement and still consumes less power as well compared to the recently-reported one.
Study on the interface thermal stability of metal-oxide-semiconductor structures by inelastic electron tunneling spectroscopy
(2006-06-26)
Huang, CF
;
Tsui, BY
;
Tzeng, PJ
;
Lee, LS
;
Tsai, MJ
The bias polarity-dependent inelastic electron tunneling spectroscopy is employed to detect the thermal stability of the Ta-Pt/SiO2/Si and Ta-Pt/HfO2/Si structures. This work provides a direct evidence that the Fermi-level pinning of metal gates is counted for the generation of extrinsic states due to interface interaction. A Ta2O5 layer forms at the Ta-Pt/SiO2 interface during thermal annealing whereas only an intermittent Ta-O bond is observed at the Ta-Pt/HfO2 interface. Although the heat of formation of HfO2 is lower than that of SiO2, Si presumably diffuses into HfO2 layer and replaces Hf atoms during the high-temperature annealing. (c) 2006 American Institute of Physics.
Band gap engineering and spatial confinement of optical phonon in ZnO quantum dots
(2006-06-26)
Lin, KF
;
Cheng, HM
;
Hsu, HC
;
Hsieh, WF
;
光電工程學系
Both band gap engineering and spatial confinement of optical phonon were observed depending upon the size of ZnO quantum dots at room temperature. Size-dependent blueshifts of photoluminescence and absorption spectra reveal the quantum confinement effect. The measured Raman spectral shift and asymmetry for the E-2(high) mode caused by localization of optical phonons agree well with that calculated by using the modified spatial correlation model. (c) 2006 American Institute of Physics.
Size dependence of photoluminescence and resonant Raman scattering from ZnO quantum dots
(2006-06-26)
Cheng, HM
;
Lin, KF
;
Hsu, HC
;
Hsieh, WF
;
光電工程學系
ZnO quantum dots (QDs) of controlled sizes have been fabricated by a simple sol-gel method. The blueshift of room-temperature photoluminescence measurement from free exciton transition are observed decreasing with the QD size that is ascribed to the quantum confinement effect. From the resonant Raman scattering, the coupling strength between electron and longitudinal optical phonon, deduced from the ratio of the second- to the first-order Raman scattering intensity, diminishes with reducing the ZnO QD diameter. The size dependence of electron-phonon coupling is principally a result of the Frohlich interaction.
Guided three-dimensional molecular self-assembly on silicon substrates
(2006-06-26)
Chang, CC
;
Sun, KW
;
Kan, LS
;
Kuan, CH
;
生物科技學系
We demonstrate three-dimensional (3D) self-assemble growth of the metallothionein (Mn,Cd-MT-2) molecules on patterned semiconductor substrates. The MT molecules deposited on the patterned substrates were found to grow into 3D rod or ring-type nanostructures, depending on the shape of patterned nanostructures on the substrates. Dense arrays of 3D molecular nanorods or rings with an area density close to 10(10) cm(-2) were demonstrated with a pore size of 20 nm and a pitch size of 100 nm. Those engineered molecular nanostructures provide an excellent opportunity for biological applications, sensing sources of nanodevices, biochemical reactions on surfaces, and even single molecule studies. (c) 2006 American Institute of Physics.
Synthesis and characterization of poly(fluorene)-based copolymers containing various 1,3,4-oxadiazole dendritic pendants
(2006-06-27)
Wu, Chung-Wen
;
Tsai, Chien-Min
;
Lin, Hong-Cheu
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A series of poly( fluorene)s (PFs) containing different generations of poly( benzyl ether) dendritic wedges with oxadiazole (OXD) peripheral functional groups, including copolymers bearing carbazole (CAZ) pendent groups, were synthesized. The dendritic side-chain polymers possessed excellent solubility in common solvents and good thermal stability with decomposition temperatures of 5% weight loss at more than 370 degrees C. Photophysical studies reveal that the photoluminescent ( PL) properties of the dendronized polymers were greatly affected by the size of the dendritic side chains. The G1- and G2-substituted PF derivatives greatly suppress the aggregation PF backbones and thus to induce pure blue PL emission ( with shorter wavelengths than PF). Excitation of the peripheral functional groups leads to substantial energy transfer from the dendrons to the poly( fluorene) backbones. In addition, the excitation of PF bearing G2 dendrons (G2-OXD) at 303 nm creates stronger fluorescence than that at 390 nm, indicating that the intensity of the sensitized emission ( by OXD absorption at 303 nm) is even stronger than that of a direct poly( fluorene) emission ( by PF backbone absorption at 390 nm). Double-layer light-emitting diode ( LED) devices with the configuration of ITO/PEDOT/polymer/LiF/Al were fabricated and reported. The device with PF bearing G0 dendrons and CAZ pendants (G0-OXDCAZ) as an emitter shows a turn-on voltage of 4.5 V and a bright luminescence of 2446 cd/m(2) at 12 V with a power efficiency of 0.24 cd/A at 100 mA/cm(2).
Infrared absorption of CH3SO2 detected with time-resolved Fourier-transform spectroscopy
(2006-06-28)
Chu, LK
;
Lee, YP
;
應用化學系
;
應用化學系分子科學碩博班
;
Department of Applied Chemistry
A step-scan Fourier-transform spectrometer coupled with a 6.4 m multipass absorption cell was employed to detect time-resolved infrared absorption spectra of the reaction intermediate CH3SO2 radical, produced upon irradiation of a flowing gaseous mixture of CH3I and SO2 in CO2 at 248 nm. Two transient bands with origins at 1280 and 1076 cm(-1) were observed and are assigned to the SO2-antisymmetric and SO2-symmetric stretching modes of CH3SO2, respectively. Calculations with density-functional theory (B3LYP/aug-cc-pVTZ and B3P86/aug-cc-pVTZ) predicted the geometry, vibrational, and rotational parameters of CH3SO2 and CH3OSO. Based on predicted rotational parameters, the simulated absorption band of the SO2-antisymmetric stretching mode that is dominated by the b-type rotational structure agrees satisfactorily with experimental results. In addition, a band near 1159 cm(-1) observed at a later period is tentatively attributed to CH3SO2I. The reaction kinetics of CH3+SO2 -> CH3SO2 and CH3SO2+I -> CH3SO2I based on the rise and decay of absorption bands of CH3SO2 and CH3SO2I agree satisfactorily with previous reports. (c) 2006 American Institute of Physics.