Browsing by Issue Date, starting with "2018-01-16"

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電阻抗斷層攝影術影像之後處理系統與後處理方法
(2018-01-16)
蔡德明
一種電阻抗斷層攝影術影像之後處理系統包含處理裝置與後處理裝置，後處理裝置耦接處理裝置。處理裝置用以根據量測數據並透過解算方法產生第一電阻抗斷層攝影術影像。量測數據是利用電阻抗斷層攝影儀器測量。後處理裝置用以接收第一電阻抗斷層攝影術影像，以及透過類神經網路演算法對第一電阻抗斷層攝影術影像進行後處理以產生第二電阻抗斷層攝影術影像。
Remarkably High Hole Mobility Metal-Oxide Thin-Film Transistors
(2018-01-17)
Shih, Cheng Wei
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Chin, Albert
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Lu, Chun Fu
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Su, Wei Fang
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電子工程學系及電子研究所
High performance p-type thin-film transistor (p-TFT) was realized by a simple process of reactive sputtering from a tin (Sn) target under oxygen ambient, where remarkably high field-effect mobility (mu(FE)) of 7.6 cm(2)/Vs, 140 mV/dec subthreshold slope, and 3 x 10(4) on-current/off-current were measured. In sharp contrast, the SnO formed by direct sputtering from a SnO target showed much degraded mu(FE), because of the limited low process temperature of SnO and sputtering damage. From the first principle quantum-mechanical calculation, the high hole mu(FE) of SnO p-TFT is due to its considerably unique merit of the small effective mass and single hole band without the heavy hole band. The high performance p-TFTs are the enabling technology for future ultra-low-power complementary-logic circuits on display and three-dimensional brain-mimicking integrated circuits.
AlGaInP Red LEDs with Hollow Hemispherical Polystyrene Arrays
(2018-01-17)
Cheng, Wen-Ching
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Huang, Shih-Yung
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Chen, Yi-Jiun
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Wang, Chia-Sheng
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Lin, Hoang Yan
A hollow hemispherical polystyrene (HHPS) was fabricated to reduce total internal reflection in AlGaInP-based LEDs. At an injection current of 350 mA, the external quantum efficiencies of LED-I, LED-II, LED-III, and LED-IV are 20.92%, 24.65%, 27.28%, and 33.77% and the wall-plug efficiencies are 17.11%, 20%, 22.5%, and 27.33%, respectively. The enhanced performance is attributed to the light output power enhancement through the surface roughness, microlens-liked PS hemisphere, and scatter-liked HHPS array. In this paper, the rigorous coupled wave analysis (RCWA) numerical method was also conducted to demonstrate the HHPS array effectively enlarge the effective light cone.
PredCRP: predicting and analysing the regulatory roles of CRP from its binding sites in Escherichia coli
(2018-01-17)
Tsai, Ming-Ju
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Wang, Jyun-Rong
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Yang, Chi-Dung
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Kao, Kuo-Ching
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Huang, Wen-Lin
Cyclic AMP receptor protein (CRP), a global regulator in Escherichia coli, regulates more than 180 genes via two roles: activation and repression. Few methods are available for predicting the regulatory roles from the binding sites of transcription factors. This work proposes an accurate method PredCRP to derive an optimised model (named PredCRP-model) and a set of four interpretable rules (named PredCRP-ruleset) for predicting and analysing the regulatory roles of CRP from sequences of CRP-binding sites. A dataset consisting of 169 CRP-binding sites with regulatory roles strongly supported by evidence was compiled. The PredCRP-model, using 12 informative features of CRP-binding sites, and cooperating with a support vector machine achieved a training and test accuracy of 0.98 and 0.93, respectively. PredCRP-ruleset has two activation rules and two repression rules derived using the 12 features and the decision tree method C4.5. This work further screened and identified 23 previously unobserved regulatory interactions in Escherichia coli. Using quantitative PCR for validation, PredCRP-model and PredCRP-ruleset achieved a test accuracy of 0.96 (=22/23) and 0.91 (=21/23), respectively. The proposed method is suitable for designing predictors for regulatory roles of all global regulators in Escherichia coli. PredCRP can be accessed at https://github.com/NctuICLab/PredCRP.
POST PROCESSING SYSTEM AND POST PROCESSING METHOD FOR ELECTRICAL IMPEDANCE TOMOGRAPHY IMAGES
(2018-01-18)
Charles Tak-Ming CHOI
A post processing system for electrical impedance tomography (EIT) images includes a processing device and a post processing device, and the post processing device is coupled to the processing device. The processing device is configured to generate a first EIT image through a solving method based on the measuring data. The measuring data is measured by an electrical impedance tomography instrument. The post processing device is configured to receive the first EIT image and post-process the first EIT image through a neural network algorithm to generate a second EIT image. The neural network algorithm is a feed forward neural network, a recurrent neural network, a convolutional neural network or a deep neural network, and an accuracy of the second electrical impedance tomography image is higher than an accuracy of the first electrical impedance tomography image.
郭若瑩　以環保理念推動「森活芳式」
(國立交通大學傳播與科技學系, 2018-01-19)
黃俊軒
郭若瑩，森活芳式有限公司的創辦人，2013年與在美國一起念大學的同學巫芷菁成立了森活芳式有限公司，以成立目的環保方式是為了在推廣台灣推廣、精油和以銷售精油來推動環保，是目前在台灣少數唯一以不破壞生態環境為前提下來之下生產精油的公司。
Simulating Open Quantum Systems with Hamiltonian Ensembles and the Nonclassicality of the Dynamics
(2018-01-19)
Chen, Hong-Bin
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Gneiting, Clemens
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Lo, Ping-Yuan
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Chen, Yueh-Nan
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Nori, Franco
The incoherent dynamical properties of open quantum systems are generically attributed to an ongoing correlation between the system and its environment. Here, we propose a novel way to assess the nature of these system-environment correlations by examining the system dynamics alone. Our approach is based on the possibility or impossibility to simulate open-system dynamics with Hamiltonian ensembles. As we show, such (im) possibility to simulate is closely linked to the system-environment correlations. We thus define the nonclassicality of open-system dynamics in terms of the nonexistence of a Hamiltonian-ensemble simulation. This classifies any nonunital open-system dynamics as nonclassical. We give examples for open-system dynamics that are unital and classical, as well as unital and nonclassical.
獅潭義民廟　當地信仰、活動中心
(國立交通大學傳播與科技學系, 2018-01-19)
殷顗霖
墾首黃南球於清光緒2年（西元1876年）率眾至獅潭開發，期間遭到原住民多次侵擾，故赴新竹新埔鎮恭請義民爺分靈於現址奉祀，義民廟因此成為獅潭鄉民的信仰中心。
Biclustering of transcriptome sequencing data reveals human tissue-specific circular RNAs
(2018-01-19)
Liu, Yu-Chen
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Chiu, Yu-Jung
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Li, Jian-Rong
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Sun, Chuan-Hu
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Liu, Chun-Chi
Background: Emerging evidence has been experimentally confirmed the tissue-specific expression of circRNAs (circRNAs). Global identification of human tissue-specific circRNAs is crucial for the functionality study, which facilitates the discovery of circRNAs for potential diagnostic biomarkers. Results: In this study, circRNA back-splicing junctions were identified from 465 publicly available transcriptome sequencing samples. The number of reads aligned to these identified junctions was normalized with the read length and sequence depth for each sample. We generated 66 models representing enriched circRNAs among human tissue transcriptome through biclustering algorithm. The result provides thousands of newly identified human tissue-specific circRNAs. Conclusions: This result suggests that expression of circRNAs is not prompted by random splicing error but serving molecular functional roles. We also identified circRNAs enriched within circulating system, which, along with identified tissue-specific circRNAs, can serve as potential diagnostic biomarkers.
為獅潭默默付出的建設者—廖松鎮
(國立交通大學傳播與科技學系, 2018-01-19)
殷顗霖
今年八十歲的廖松鎮，曾任新店村簡易自來水管理小組的理事長、推動獅潭義民廟改建、擔任仙山靈洞宮的主任委員，一生為獅潭建設。
Pressure effect on impurity local vibrational mode and phase transitions in n-type iron-doped indium phosphide
(2018-01-19)
Lin, Chih-Ming
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Hsu, I-Jui
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Lin, Sin-Cheng
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Chuang, Yu-Chun
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Chen, Wei-Ting
The evolution of iron local vibrational mode (Fe LVM) and phase transitions in n-type iron-doped indium phosphide (InP:Fe) were investigated at ambient temperature. In-situ angle-dispersive X-ray diffraction measurements revealed that InP: Fe starts to transform from zinc-blende (ZB) to rock-salt (RS) structure around 8.2(2) GPa and completes around 16.0(2) GPa. The Raman shift of both transverse and longitudinal optical modes increases monotonically with increasing pressure, while their intensities become indiscernible at 11.6(2) GPa, suggesting that the pressure-induced phase transition is accompanied by significant metallization. In contrast, originally absent at ambient pressure, the Raman shift of Fe LVM appears at similar to 420 cm(-1) near 1.2 GPa and exhibits a dome shape behavior with increasing pressure, reaching a maximum value of similar to 440 cm-1 around 5 GPa, with an apparent kink occurring around the ZB-RS transition pressure of similar to 8.5(2) GPa. The Fe K-edge X-ray absorption near edge structure (XANES) confirmed the tetrahedral site occupation of Fe3+ with a crystal field splitting parameter Delta(t)=38k . mole(-1). Our calculations indicate that the energy parameters governing the phase transition are Delta(t)=0.49 and Delta(o) =1.10 kJ . mole(-1),respectively, both are much smaller than Delta(t) = 38 kJ . mole(-1) at ambient.
Laser co-ablation of bismuth antimony telluride and diamond-like carbon nanocomposites for enhanced thermoelectric performance
(2018-01-21)
Chen, Tsung-Han
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Chen, Po-Hung
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Chen, Chun-Hua
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材料科學與工程學系
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Department of Materials Science and Engineering
A novel design of thermoelectric hetero-nanocomposite films comprising well-aligned oriented (Bi,Sb)(2)Te-3 (BST) nanocrystals and randomly dispersed diamond-like carbon (DLC) clusters has been realized for the first time using dual-beam pulsed laser co-deposition on SiO2 insulated Si substrates. The simultaneously deposited DLC additives were found not only to successfully prevent the thermally induced rapid growth of BST for having consistent nanostructures across the whole BST: DLC film, but also to effectively reduce the thermal transport as qualitatively evidenced by micro-Raman characterizations. The significantly enhanced Seebeck coefficients up to 550 mV K-1 and the corresponding power factor of similar to 46 mu W cm(-1) K-2 revealed comparable to or higher than previously reported values for BST or BSTbased nanocomposites, which evidently originated from the presence of multiple BST:DLC heterointerfaces as clarified in the Pisarenko plot.
Real-time CRP detection from whole blood using micropost-embedded microfluidic chip incorporated with label-free biosensor
(2018-01-21)
Tsai, Meng-Zhe
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Hsiung, Chan-Te
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Chen, Yang
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Huang, Cheng-Sheng
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Hsu, Hsin-Yun
We demonstrate the detection of C-creative protein (CRP) from whole blood samples without sample pretreatment by using a lab-on-a-chip system consisting of a microfluidic chip and a label-free biosensor. The microfluidic chip includes an array of microposts for filtering blood cells and allows only plasma to flow through and reach the guided-mode resonance (GMR) biosensor for real-time monitoring. The developed GMR sensor can achieve a bulk sensitivity of 186 nm RIU-1, which supports a limit of detection of 3.2 ng mL(-1) for recombinant CRP spiked in human serum. The results are comparable with those obtained using enzyme-linked immunosorbent assay. In addition, we demonstrate the efficacy of filtration of blood cells using microposts and simultaneous measurement of CRP concentration using a GMR sensor by using whole blood and plasma samples.
交大e-News第248期-交通大學與國家中山科學研究院打造產業一條龍團隊發展國防科技與通訊技術
(2018-01-22)
國立交通大學秘書室
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Secretariat
Uplink performance enhancement for LTE licensed-assisted access to unlicensed spectrum
(2018-01-22)
Tsai, Cheng-Jie
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Lee, Tsern-Huei
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電機工程學系
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Department of Electrical and Computer Engineering
Licensed-assisted access (LAA) is a new operation mode of carrier aggregation for the Long Term Evolution Advanced systems to transmit data on both licensed and unlicensed spectrum. To deal with the issue of co-existence with WiFi systems, LAA is required to perform listen-before-talk, which can significantly impact its resource utilization. In this paper, the concept called multi-subframe scheduling (MSS) which can enhance the performance of uplink LAA data transmission is presented. MSS allows a user equipment to have multiple channel sensing opportunities and/or to transmit data continuously for multiple subframes. Both scheduling-based and random access schemes are evaluated and compared. The optimum configuration of MSS which maximizes resource utilization of LAA is also provided. Numerical results show that MSS improves resource utilization on the unlicensed spectrum significantly.
Monolithic integration of GaN-based light-emitting diodes and metal-oxide-semiconductor field-effect transistors: reply
(2018-01-22)
Lee, Ya-Ju
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Yang, Zu-Po
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Chen, Pin-Guang
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Hsieh, Yung-An
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Yao, Yung-Chi
We present some comments to the paper "Monolithic integration of GaN-based light-emitting diodes and metal-oxide-semiconductor field-effect transistors: comment" [Opt. Express 22, A1589 (2014)]. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Revealing the Atomic Defects of WS2 Governing Its Distinct Optical Emissions
(2018-01-24)
Lin, Yung-Chang
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Li, Shisheng
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Komsa, Hannu-Pekka
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Chang, Li-Jen
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Krasheninnikov, Arkady V.
Defects and their spatial distribution are crucial factors in controlling the electronic and optical properties of semiconductors. By using scanning transmission electron microscopy and electron energy loss spectroscopy, the type of impurities/defects in WS2 subdomains with different optical properties is successfully assigned. A higher population of Cr impurities is found in the W-terminated edge domain, while the S-terminated domain contains more Fe impurities, in accordance with the luminescence characteristics of chemical-vapor-grown WS2 of a hexagonal shape. In agreement with the first-principles calculations, the domains with Cr substitutional dopants exhibit strong trion emission. Fe atoms tend to gather into trimer configuration and introduce deep acceptor levels which compensate the n-type doping and suppress trion emission. It is also discovered that the domain with higher luminescence but smaller defect concentration tends to get oxidized more rapidly and degrade the 2D structure with many triangular holes. Excitons tend to accumulate at the edges of the oxidized triangular holes and results in enhanced PL emission. The findings indicate that choosing stable elements as dopant and controlling the number of specific edge structures within a crystal domain of 2D transitional metal dichalcogenides can be a new route to improve the optical properties of these materials.
Heat performances of a thermosyphon as affected by evaporator wettability and filling ratio
(2018-01-25)
Xu, Zhi
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Zhang, Yaning
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Li, Bingxi
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Wang, Chi-Chuan
;
Ma, Qin
A thermosyphon is considered an efficient heat dissipation device in engineering fields due to its low thermal resistance. The heat transfer mechanisms for thermosyphons at different evaporator wettability and filling ratios are not well detailed. A model considering evaporator wettability in terms of a contact angle is developed to detail the phase change process to explore the heat transfer mechanism for a thermosyphon in this study. The effects of evaporator wettability and filling ratio on the heat performances of a thermosyphon charged with water are investigated. It is observed that the simulated absolute temperatures with a contact angle are in better agreement with the experimental results with an average relative error of 0.15% than the simulation results without a contact angle (0.28%). The results show that a hydrophilic surface causes bubbles to easily depart the evaporator wall, thereby increasing the heat performance, whereas a hydrophobic surface causes bubbles to adhere to the evaporator wall, decreasing the heat performance. Further study shows that a low filling ratio of 12% will result in drying out, but a high filling ratio of 40% will prevent large bubbles from reaching the liquid surface, thereby decreasing the heat performance. The heat performance is best at filling ratios of 20-30% for an evaporator with a hydrophilic surface. (C) 2017 Elsevier Ltd. All rights reserved.
Anomalous Charge-Extraction Behavior for Graphene-Oxide (GO) and Reduced Graphene-Oxide (rGO) Films as Efficient p-Contact Layers for High-Performance Perovskite Solar Cells
(2018-01-25)
Jokar, Efat
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Huang, Zhong Yi
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Narra, Sudhakar
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Wang, Chi-Yung
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Kattoor, Vidya
Reduced graphene oxides (rGO) are synthesized via reduction of GO with reducing agents as a hole-extraction layer for high-performance inverted planar heterojunction perovskite solar cells. The best efficiencies of power conversion (PCE) of these rGO cells exceed 16%, much greater than those made of GO and poly(3,4-ethenedioxythiophene):poly(styrenesulfonate) films. A flexible rGO device shows PCE 13.8% and maintains 70% of its initial performance over 150 bending cycles. It is found that the hole-extraction period is much smaller for the GO/methylammonium lead-iodide perovskite (PSK) film than for the other rGO/PSK films, which contradicts their device performances. Photoluminescence and transient photoelectric decays are measured and control experiments are performed to prove that the reduction of the oxygen-containing groups in GO significantly decreases the ability of hole extraction from PSK to rGO and also retards the charge recombination at the rGO/PSK interface. When the hole injection from PSK to GO occurs rapidly, hole propagation from GO to the indium-doped tin oxide (ITO) substrate becomes a bottleneck to overcome, which leads to a rapid charge recombination that decreases the performance of the GO device relative to the rGO device.
Mechanism of a strange metal state near a heavy-fermion quantum critical point
(2018-01-26)
Chang, Yung-Yeh
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Paschen, Silke
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Chung, Chung-Hou
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電子物理學系
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電機學院
Unconventional metallic or strange metal (SM) behavior with non-Fermi liquid (NFL) properties, generic features of heavy-fermion systems near quantum phase transitions, are yet to be understood microscopically. A paradigmatic example is the magnetic field-tuned quantum critical heavy-fermion metal YbRh2Si2, revealing a possible SM state over a finite range of fields at low temperatures when substituted with Ge. Above a critical field, the SM state gives way to a heavy Fermi liquid with Kondo correlation. The NFL behavior, most notably a linear-in-temperature electrical resistivity and a logarithmic-in-temperature followed by a power-law singularity in the specific heat coefficient at low temperatures, still lacks a definite understanding. We propose the following mechanism as origin of the experimentally observed behavior: a quasi-2d fluctuating short-ranged resonating-valence-bond spin liquid competing with the Kondo correlation. Applying a field-theoretical renormalization group analysis on an effective field theory beyond a large-N approach to an antiferromagnetic Kondo-Heisenberg model, we identify the critical point and explain remarkably well the SM behavior. Our theory goes beyond the well-established framework of quantum phase transitions and serves as a basis to address open issues in quantum critical heavy-fermion systems.