Browsing by Issue Date, starting with "2019-03-14"

Now showing 1 - 20 of 8012

METHOD FOR MANUFACTURING WIDE-BANDGAP OXIDE EPITAXIAL FILM
(2019-03-14)
RAY-HUA HORNG
;
YEN-CHU LI
;
CHUN-YI TUNG
;
SI-HAN TSAI
;
LI-CHUNG CHENG
The present invention provides a method for manufacturing a wide-bandgap oxide epitaxial film. An epitaxial film with superior physical properties, such as high saturated drift velocity of electrons, small dielectric constant, high thermal stability, and excellent high-temperature resistance, is formed on a substrate. In addition, because the oxide epitaxial film is grown by metal-organic chemical vapor deposition (MOCVD), the yield is improved significantly and defects in the epitaxy is reduced.
Femtosecond electronic relaxation and real-time vibrational dynamics in 2 '-hydroxychalcone
(2019-03-14)
Yamakita, Yoshihiro
;
Yokoyama, Nanae
;
Xue, Bing
;
Shiokawa, Naoyuki
;
Harabuchi, Yu
Femtosecond ultrafast electronic relaxation and vibrational dynamics in 2'-hydroxychalcone after deep ultraviolet (DUV) excitation were observed by two types of pump-probe spectroscopy experiments, i. e., DUV-pump pulse and visible-broadband-probe pulse (DUV/Vis) experiments and DUV-pump and DUV-probe (DUV/DUV) pulse experiments. Time-dependent density functional theory (TDDFT) calculations were performed to elucidate relaxation dynamics from the third singlet electronic excited state S-3. The DUV/Vis experiments and TDDFT calculations have disclosed the ultrafast dynamics of internal conversion from the initial S-3 state (tau(1) approximate to 35 fs) to the S-1 state via a rapid process through the S-3/S-2 conical intersection and proton transfer [OH: tau(2)(H) approximate to 93 and OD: tau(2)(D) approximate to 164 fs] before deactivation through the S-1/S-0 conical intersection (tau(3) approximate to 690 fs). Thanks to the ultrashort pump and probe pulses, real-time observation of vibrational modes coupled to the electronic excitation was realized providing both amplitudes and phases. Spectrogram analyses were performed based on the real-time spectra obtained by the DUV/Vis experiments, in which instantaneous vibrational frequencies reflecting molecular structural change after the impulsive excitation were visualized. The vibrational frequency of central C=C bond stretch decreases from similar to 1600 cm(-1) to similar to 1560 cm(-1) in about 200-500 fs and recovers in similar to 550 fs. Normal mode analyses along the decay path support the observed variation of the C=C stretching frequency. The temporal weakening of the central C=C bond is connected with the angle of the two aromatic rings which flip back to the initial conformation.
Effect of Etching Depth on Threshold Characteristics of GaSb-Based Middle Infrared Photonic-Crystal Surface-Emitting Lasers
(2019-03-14)
Li, Zong-Lin
;
Lin, Shen-Chieh
;
Lin, Gray
;
Cheng, Hui-Wen
;
Sun, Kien-Wen
We study the effect of etching depth on the threshold characteristics of GaSb-based middle infrared (Mid-IR) photonic-crystal surface-emitting lasers (PCSELs) with different lattice periods. The below-threshold emission spectra are measured to identify the bandgap as well as band-edge modes. Moreover, the bandgap separation widens with increasing etching depth as a result of enhanced diffraction feedback coupling. However, the coupling is nearly independent of lattice period. The relationship between threshold gain and Bragg detuning is also experimentally determined for PCSELs and is similar to that calculated theoretically for one-dimensional distributed feedback lasers.
Fluorescence enhancement induced by quadratic electric-field effects on singlet exciton dynamics in poly(3-hexylthiophene) dispersed in poly(methyl methacrylate)
(2019-03-14)
Iimori, Toshifumi
;
Awasthi, Kamlesh
;
Chiou, Chin-Shiun
;
Diau, Eric Wei-Guang
;
Ohta, Nobuhiro
The dynamics of the exciton generated by photoexcitation of a regioregular poly(3-hexylthiophene) (P3HT) polymer dispersed in a poly(methyl methacrylate) (PMMA) matrix was examined using electro-photoluminescence (E-PL) spectroscopy, where electric field effects on the photoluminescence (PL) spectra were measured. The quadratic electric-field effect was investigated using the modulation technique, with field-induced changes in the PL intensity monitored at the second harmonic of the modulation frequency of the applied electric field. Absorption and PL spectra indicated the formation of both ordered crystalline aggregates and amorphous regions of P3HT polymer chains. Although previous studies of electric field effects on -conjugated polymers have generally shown that the PL intensity is decreased by electric fields, we report that the PL intensity of P3HT and PL lifetime increased with the quadratic electric-field effect. The magnitude of the change in PL intensity was quantitatively explained in terms of the field-induced decrease in the nonradiative decay rate constants of the exciton. We proposed that a delayed PL, originating from charge carrier recombination, was enhanced in the presence of electric fields. The rate constant of the downhill relaxation process of the exciton, which originated from the relaxation in distributed energy levels due to an inherent energetic disorder in P3HT aggregates, was implied to decrease in the presence of electric fields. The radiative decay rate constant and PL quantum yield of P3HT dissolved in solution, which were evaluated from the molar extinction coefficient and the PL lifetime, were compared with those of P3HT dispersed in a PMMA matrix.
Fourier transform microwave spectroscopy of Criegee intermediates: The conformational behaviour of butyraldehyde oxide
(2019-03-14)
Cabezas, Carlos
;
Guillemin, Jean-Claude
;
Endo, Yasuki
;
應用化學系
;
Department of Applied Chemistry
Four conformers of the n-propyl-substituted Criegee intermediate, CH3CH2CH2CHOO, also named n-butyraldehyde oxide, have been observed by Fourier transform microwave spectroscopy. The transient species was produced using a pulsed electric discharge of a gas mixture of 1,1-diiodobutane/O-2 diluted in Ar or Ne. The observation of only syn species is in contrast to the results of other previous studies of alkyl-substituted Criegee intermediates, in particular, those for the structural isomers, isobutyraldehyde oxide ((CH3)(2)CHCHOO), and methyl-ethyl-ketone oxide (C2H5C(CH3)OO), for which syn and anti species have been observed coexisting in the gas phase.
SOLAR-BLIND DETECTING DEVICE WITH WIDE-BANDGAP OXIDE
(2019-03-14)
RAY-HUA HORNG
;
YEN-CHU LI
;
CHUN-YI TUNG
;
SI-HAN TSAI
;
LI-CHUNG CHENG
The present invention provides a solar-blind detecting device with a wide-bandgap oxide, which comprises an oxide epitaxial sensing layer disposed on a substrate for improving the property as well as substantially increasing the photocurrent in the oxide epitaxial sensing layer under the stimulation of ultraviolet light. Particularly, the sensing performance for the deep ultraviolet region (200˜280 nanometers) is enhanced significantly.
Tailoring Magnetoelectric Coupling in BiFeO3/La0.7Sr0.3MnO3 Heterostructure through the Interface Engineering
(2019-03-15)
Yi, Di
;
Yu, Pu
;
Chen, Yi-Chun
;
Lee, Hsin-Hua
;
He, Qing
Electric field control of magnetism ultimately opens up the possibility of reducing energy consumption of memory and logic devices. Electric control of magnetization and exchange bias are demonstrated in all-oxide heterostructures of BiFeO3 (BFO) and La0.7Sr0.3MnO3 (LSMO). However, the role of the polar heterointerface on magnetoelectric (ME) coupling is not fully explored. Here, the ME coupling in BFO/LSMO heterostructures with two types of interfaces, achieved by exploiting the interface engineering at the atomic scale, is investigated. It is shown that both magnetization and exchange bias are reversibly controlled by switching the ferroelectric polarization of BFO. Intriguingly, distinctly different modulation behaviors that depend on the interfacial atomic sequence are observed. These results provide new insights into the underlying physics of ME coupling in the model system. This study highlights that designing interface at the atomic scale is of general importance for functional spintronic devices.
Performance modeling and analysis of TCP and UDP flows over software defined networks
(2019-03-15)
Lai, Yuan-Cheng
;
Ali, Ahsan
;
Hossain, Md Shohrab
;
Lin, Ying-Dar
;
資訊工程學系
Software Defined Networking (SDN) decouples the control plane from the data plane, thereby facilitating network virtualization, dynamic programmability and flexibility in network management. Previous studies on SDN modeling focus only on packet-level arrivals. However, if flow-level arrivals are not also considered, the model cannot properly reflect the true probability of packets being sent to the controller. Accordingly, the present study proposes two analytical models for predicting the performance of TCP and UDP flows over SDN, respectively, given the assumption of both flow-level arrivals and packet-level arrivals. In constructing the models, the switch and controller are considered jointly and four-dimensional states are used to evaluate the steady-state probabilities of the states. Analytical formulae are derived for the average packet delay and packet loss probability of the TCP and UDP flows. Simulation results very well match with the analytical ones, thereby validating our analytical models. The results show that TCP significantly outperforms UDP over SDN architectures. In particular, TCP reduces the packet delay by 12 similar to 50% and the packet loss probability by 25 similar to 100%.
Risk of cholangiocarcinoma in patients undergoing therapeutic endoscopic retrograde cholangiopancre-atography or cholecystectomy: A population based study
(2019-03-15)
Wang, Chi-Chih
;
Tsai, Ming-Chang
;
Sung, Wen-Wei
;
Yang, Tzu-Wei
;
Chen, Hsuan-Yi
BACKGROUND Cholangiocarcinoma is a highly lethal disease that had been underestimated in the past two decades. Many risk factors are well documented for in cholangiocarcinoma, but the impacts of advanced biliary interventions, like endoscopic sphincterotomy (ES), endoscopic papillary balloon dilatation (EPBD), and cholecystectomy, are inconsistent in the previous literature. AIM To clarify the risks of cholangiocarcinoma after ES/EPBD, cholecystectomy or no intervention for cholelithiasis using the National Health Insurance Research Database (NHIRD). METHODS From data of NHIRD 2004-2011 in Taiwan, we selected 7938 cholelithiasis cases as well as 23814 control group cases (matched by sex and age in a 1:3 ratio). We compared the previous risk factors of cholangiocarcinoma and cholangiocarcinoma rate in the cholelithiasis and control groups. The incidences of total and subsequent cholangiocarcinoma were calculated in ES/EPBD patients, cholecystectomy patients, cholelithiasis patients without intervention, and groups from the normal population. RESULTS In total, 537 cases underwent ES/EPBD, 1743 cases underwent cholecystectomy, and 5658 cholelithiasis cases had no intervention. Eleven (2.05%), 37 (0.65%), and 7 (0.40%) subsequent cholangiocarcinoma cases were diagnosed in the ES/EPBD, no intervention, and cholecystectomy groups, respectively, and the odds ratio for subsequent cholangiocarcinoma was 3.13 in the ES/EPBD group and 0.61 in the cholecystectomy group when compared with the no intervention group. CONCLUSION In conclusion, symptomatic cholelithiasis patients who undergo cholecystectomy can reduce the incidence of subsequent cholangiocarcinoma, while cholelithiasis patients who undergo ES/EPBD are at a great risk of subsequent cholangiocarcinoma according to our findings.
Bidirectional free space optical communication (FSO) in WDM access network with 1000-m supportable free space link
(2019-03-15)
Yeh, Chien-Hung
;
Guo, Bo-Shen
;
Chang, Yao-Jen
;
Chow, Chi-Wai
;
Gu, Chong-Sin
In this demonstration, we propose and investigate experimentally a bidirectional wavelength-division-multiplexed (WDM) free space optical communication (FSO) system integrated with fiber access network for wireless traffics. Here, there are four 10 Gbit/s on-off keying (OOK) WDM-FSO signals would propagate through a 25 km single-mode fiber (SMF) transmission and a 6 m free space transmission length for the bidirectional downstream and upstream FSO traffics. Moreover, an accurately simulation of detected powers of FSO wavelength under different free space transmission lengths can be estimated based on the proposed WDM-FSO system architecture. Therefore, according to the experimental and simulated results, the bidirectional WDM-FSO transmission can achieve 1000 m free space transmission length based on the obtained power sensitivity of each FSO signal.
Efficient high-power dual-wavelength lime-green Nd:YVO4 lasers
(2019-03-15)
Chen, Y. F.
;
Liu, Y. C.
;
Pan, Y. Y.
;
Gu, D. Y.
;
Cheng, H. P.
An efficient high-power dual-wavelength lime-green Nd:YVO4 self-Raman laser is inventively developed by using two different lithium triborate (LBO) crystals. The first and second LBO crystals are employed to generate the 559 nm lime and 532 nm green lasers, respectively. The temperature of the first LBO crystal is fixed at the optimal phase matching, whereas the temperature of the second LBO crystal is tuned to flexibly control the relative strengths between the 532 and 559 nm waves. When the temperature of the second LBO crystal is set for the maximal total output power, the 532 and 559 nm output powers, respectively, are 7.1 and 2.9 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 31.6%. When the temperature is controlled for the balanced output, the 532 and 559 nm powers, respectively, are 4.3 and 4.2 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 26.9%. (C) 2019 Optical Society of America
我國保險業暨保險輔助人間防制洗錢暨打擊資恐監理之研究
(交通大學科技法律學院（原名稱：交通大學科技法律研究所）, 2019-03-15)
黃天牧
;
邵之雋
;
Tien-Mu Huang
;
Jy-Juinn Shaw
本文簡介保險業與保險輔助人之洗錢與資恐監理規範與實際作業，並綜述國內外犯罪人士利用保險商品進行洗錢與資恐常見不法態樣，以及英美國家對保險業與保險輔助人間防範洗錢與資恐相關法令規範。本文發現在如何建置符合我國保險業與保險輔助人間防制洗錢與資恐有效監理法規與作業方面，可從兩個面向著手：保險輔助人與保險公司建構合作通路管理機制之作法，以及增進保險輔助人與保險公司確認及驗證客戶身分之作法。此外，為避免業務員偏重業績，而忽略相關協力義務，本文建議將業務員之執行防制洗錢及打擊資恐之狀況納入酬金制度之一環，以實際得受領之佣金，來管控業務員之作業。
現行證券交易法對臺灣存託憑證（TDR）之規範依據
(交通大學科技法律學院（原名稱：交通大學科技法律研究所）, 2019-03-15)
王志誠
;
Chih-Cheng Wang
在2012年1月4日增訂證券交易法第165條之2規定之前，證券主管機關雖認為臺灣存託憑證（TDR）係屬「外國之其他具有投資性質之有價證券」，但司法實務上亦有判決認為，存託機構在我國內所發行之臺灣存託憑證，雖是「表彰存放於保管機構之外國發行人有價證券」，仍與該外國發行人在外國發行之「外國有價證券」本身有別，導致證券主管機關是否曾依證券交易法第6條第一項規定之授權，將臺灣存託憑證核定公告為證券交易法上之有價證券，產生重大爭議。至於我國於2012年1月4日增訂證券交易法第165條之2規定後，因已對於來我國第二上市或第二上櫃之有價證券，明定其有價證券在中華民國募集、發行及買賣之管理、監督，準用證券交易法第6條規定，臺灣存託憑證成為我國證券交易法上之有價證券，應無疑義，但司法實務上竟有判決認為證券交易法第165條之2之規範對象與臺灣存託憑證無關。本文期能釐清實務爭議之所在，並從解釋論之觀點提出管蠡之見，以杜爭議。
Iterative Inter-Cell Interference Cancellation Receiver for LDPC-Coded MIMO Systems
(2019-03-15)
Sun, Wei-Cheng
;
Chen, Yan-Tong
;
Yang, Chia-Hsiang
;
Ueng, Yeong-Luh
;
電子工程學系及電子研究所
In an ultra-dense cellular system, users at the cell-edge are susceptible to inter-cell interference (ICI) because of the overlap of the spectrum. To combat ICI, this paper investigates two iterative ICI cancellation approaches for low-density parity-check-coded multiple-input multiple-output systems. One approach includes separate signal and interference detectors; the other one employs a joint detector for both the desired signal and interference. The joint-detector approach achieves a comparable error-rate performance with only half the computational complexity when compared to the separate-detector counterpart. An iterative ICI cancellation receiver using the joint detector is proposed and implemented. Its hardware efficiency is significantly enhanced by leveraging an efficient coordinate rotation digital computer based processing array, an adaptive input-range scaling scheme, and an area-efficient log-likelihood ratio calculator. The iterative ICI cancellation receiver is flexible enough to support multiple modulations of up to 256-QAM. The maximum gross throughput is 1.24 Gb/s for a 4x4 256-QAM configuration in a 40-nm CMOS technology. The proposed iterative receiver outperforms the current state-of-the-art works in both the throughput-to-area ratio and the normalized energy metrics, despite the added ICI capability.
職業工會適用我國罷工投票規範之研究──德國法制之啟示
(交通大學科技法律學院（原名稱：交通大學科技法律研究所）, 2019-03-15)
邱羽凡
;
Yu-Fan Chiu
我國職業工會自2011年新勞動三法實施後，逐步朝向自主化與多元化的發展，並發展出不同於以往勞健保職業工會模式的工運路線，亦有進行罷工之事例出現，此均讓職業工會適用罷工規範的相關問題開始受到矚目。勞資爭議處理法第54條第一項規定：「工會非經會員以直接、無記名投票且經全體過半數同意，不得宣告罷工及設置糾察線。」此一規範限制工會於宣告罷工前，應先經過罷工投票且取得全體工會會員過半數同意。由於職業工會具有「跨廠場、跨企業」以及「結合相關職業技能之勞工」二大特點，職業工會應如何在罷工投票中適用「全體過半數」之規範，迭生爭論。本文分析德國法上相關討論，釐清罷工投票程序的目的在於實現工會民主，故「全體會員過半數」應以爭議範圍中的工會會員為全體會員的範圍，而違反罷工投票規範應屬工會違反對於會員的義務，不應導出罷工違法以及讓雇主取得對於工會或勞工請求損害賠償之權利。現行勞資爭議處理法第54條第一項將罷工投票規範置於勞資爭議處理法的爭議行為章之中，實有導引讓人誤解罷工投票之組織（工會）內部效力要件為外部效力之問題，故立法上應將罷工投票事項回歸為工會依章程自主所保障的權限，以落實工會內部的直接民主，而不宜再將規範工會與其會員間的事項與勞資爭議處理法中的罷工合法要件併列，造成不當限制工會與勞工之罷工權的結果。
非律師者之法律業務參與──論英國2007年法律服務業法
(交通大學科技法律學院（原名稱：交通大學科技法律研究所）, 2019-03-15)
陳鋕雄
;
Chih-Hsiung Chen
英國於2007年通過著名的法律服務業法，可謂大幅改寫既有法律服務提供之遊戲規則，對歐美國家造成深遠影響。該法在高度管制及放任市場運作這兩種模式中找到平衡點，於規範目的中明示了保護消費者、促進競爭及建立一個具有獨立、健全、多元及有效法律服務市場之決心。該法在監管方面最為特別之處，在於創設由非法律人組成的法律服務委員會，由其作為法律服務之最終監督機構，而日常活動之監管，則交由專業人員自行組成的認證監管機構負責。該法亦創設法律申訴辦公室，以行政調解來統一處理消費者對於法律服務之申訴。雖然英國此一新法帶給消費者更大的選擇自由，對整體法律服務市場帶來極大的利益，然而，有些潛在的法律倫理問題需要注意。本文擬就英國之法律服務業法及實施成效加以分析，並探討此法於運作上所可能產生之倫理議題，最後則會為我國提出政策建議，以期引起更多有志者的討論。
Strange superconductivity near an antiferromagnetic heavy-fermion quantum critical point
(2019-03-15)
Chang, Y. Y.
;
Hsu, F.
;
Kirchner, S.
;
Mou, C. Y.
;
Lee, T. K.
The heavy fermion systems CeMIn5 with M = Co, Rh, Ir, the "115" family, provide a prototypical example of strange superconductivity with unconventional d-wave pairing and strange metal normal state, emerged near an antiferromagnetic quantum critical point. The microscopic origin of strange superconductivity and its link to antiferromagnetic quantum criticality of the strange metal state are still long-standing open issues. We propose a microscopic mechanism for strange superconductors, based on the coexistence and competition between the Kondo correlation and the quasi-2d short-ranged antiferromagnetic resonating-valence-bond spin-liquid near the antiferromagnetic quantum critical point via a large-N Kondo-Heisenberg model and renormalization group analysis beyond the mean-field level. The interplay of these two effects provides a qualitative understanding on how superconductivity emerges from the strange metal state and the observed superconducting phase diagrams for CeMIn5.
以微溝槽結構來控制霜成核的位置之用途與其方法
(2019-03-16)
呂明璋
;
羅景文
本發明實施例提供一種用以控制霜成核的微溝槽結構，其包括基板。基板具有非粗糙的表面，其中表面具有沿著第一方向延伸的一個或多個微溝槽。所述用以控制霜成核的微溝槽結構具有良好的抗冰與去冰效果。
光學應力感測元件、系統及方法
(2019-03-16)
盧贊文
;
吳家政
;
李柏璁
本發明提供一種光學應力感測元件，乃將至少兩個光學應力感測單元包覆於一包覆體內而可受應力作用來產生形變，其中，每個光學應力感測單元是由多個奈米柱體沿著單一排列方向所構成，這些光學應力感測單元於平面上是以相對於一座標軸夾不同角度來排列，且其兩兩相鄰的夾角為銳角。當光學應力感測元件在平面上受到一未知應力，可透過各光學應力感測單元之光學共振波長變化與資料庫比對後，而感知應力之方向、種類與大小。此外，本發明還提出一種基於該光學應力感測元件之感測系統及感測方法。
可防止採樣誤差的高效率靜電微粒液相採樣器
(2019-03-16)
蔡春進
;
徐兆廷
本發明揭示一種高效率靜電微粒液相採樣器，該採樣器採用乾式收集、濕式萃取的採樣方式以避免採樣誤差。乾式收集分為兩階收集微粒，第一階以碳纖維束進行電暈放電，讓氣膠微粒帶電，第二階利用高電壓圓桿-接地圓柱間的電場，使帶電微粒以靜電力收著於接地的圓柱壁面；濕式萃取時，利用間歇性開啟與關閉的電磁閥，將去離子水以脈衝方式注入採樣器沖洗圓柱壁面上收集的氣膠成為液體樣本，並進行後續氣膠液體樣本的手動或自動的化學分析。