Browsing by Issue Date, starting with "2015-06"

Now showing 1 - 20 of 21657

A geometry based efficient decoder for underdetermined MIMO systems
(2015-06-01)
Huang, Chung-Jung
;
Lee, Chang-Shen
;
Chung, Wei-Ho
;
Lee, Ta-Sung
;
電機資訊學士班
In this paper, a geometry based decoder with low decoding complexity and exact maximum-likelihood (ML) performance is proposed for underdetermined multiple-input multiple-output (MIMO) systems. In the proposed decoder, an underdetermined MIMO system can be divided into a multiple-input single-output (MISO) sub-system and a regular MIMO sub-system in which numbers of transmit and receive antennas are equal. An efficient slab search algorithm (ESSA) is adopted to efficiently obtain valid candidate points in the MISO sub-system. By adopting ESSA in the MISO sub-system and sphere decoding algorithm (SDA) in the MIMO sub-system, ML solution of underdetermined MIMO system can be obtained with low computational complexity. To further reduce the computational complexity, a near-ML SDA is proposed to more efficiently find the candidate points in the MIMO sub-system. In addition, an optimal preprocessing technique is proposed from the geometrical perspective and the comprehensive analysis on the complexity reduction is also provided. Simulation results indicate that the proposed approach significantly reduces the complexity as compared to existing ML decoders, particularly for systems with large number of antennas and/or high-order constellations. (C) 2015 Elsevier Inc. All rights reserved.
Latch-Up Protection Design With Corresponding Complementary Current to Suppress the Effect of External Current Triggers
(2015-06-01)
Tsai, Hui-Wen
;
Ker, Ming-Dou
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The robustness against latch-up in the integrated circuits can be improved by supporting complementary current at the pad under the latch-up current test (I-test). By inserting additional junctions to form parasitic bipolar sensors, the external trigger can be monitored, and the ESD protection devices can be applied to provide such current and decrease the related perturbation to the internal circuits. The proposed design and the previous work with a single guard ring have been fabricated in the same 0.5-mu m 5-V process. The experimental results confirm the enhanced latch-up tolerance of this work and the practicability in the SOC era.
智慧創作專用權之性質與使用倫理──給原創條例的幾點建議
(交通大學科技法律研究所, 2015-06)
林孟玲
;
Meng-Ling Lin
原住民族智慧創作保護條例的制定，對於保護原住民族的傳統智慧創作、文化成果之表達有顯著的貢獻。原創條例雖然立法意旨甚佳，是專門為保護原住民族傳統智慧創作所量身定作之立法，也注意到了原住民族智慧創作有別於著作權之概念，而做出調整。但是條例所用的權利保護概念，卻仍沿用著作權之規定，是美中不足之處。例如：「智慧創作專用權」的內涵仍沿用著作權的權利概念「智慧創作財產權」與「智慧創作人格權」；如果對於智慧創作專用權造成侵害，智慧創作專用權人的救濟管道與著作權受侵害的救濟方式並無二致，包括：排除侵害請求權、請求防止侵害請求權、損害賠償請求權、請求銷毀侵害智慧創作之物。此外，原創條例並未提及使用原住民族之傳統智慧創作時，不能違反原住民族傳統價值等觀念，有如進行關於原住民族的學術研究時，有特別應遵守的研究倫理。本文從智慧創作專用權性質之討論出發，繼而探討智慧創作財產權與智慧創作人格權之內涵。舉例說明基於部落習慣法而來的，智慧創作之使用所應注意之使用倫理後，最後亦根據部落習慣法，闡述現行智慧創作專用權之權利救濟管道妥適性。本文之建議期使原創條例能真正落實其立法目的：保護原住民族傳統智慧創作以及促進原住民族文化發展。
Improvement of Resistive Switching Characteristic in Silicon Oxide-Based RRAM Through Hydride-Oxidation on Indium Tin Oxide Electrode by Supercritical CO2 Fluid
(2015-06-01)
Chang, Kuan-Chang
;
Tsai, Tsung-Ming
;
Chang, Ting-Chang
;
Zhang, Rui
;
Chen, Kai-Huang
Supercritical carbon dioxide (SCCO2) fluid technology was applied to indium-tin-oxide (ITO) electrode to improve the resistive switching characteristic of silicon oxide RRAM through hydride oxidation for the first time. We found device power consumption can be effectively reduced so that side effects can be also restricted under device operation. By applying SCCO2 fluid, more oxygen ions will be introduced into the ITO electrode and thus the participation of net oxygen ions in the RRAM redox reaction will increase. Fourier transform spectroscopy and X-ray photoelectron spectroscopy were used to confirm hydride oxidation on ITO electrode. Combined with the current fitting results, we proposed a reaction model to explain the improvement of resistive switching in RRAM by SCCO2 fluids.
Analysis of GeOI FinFET 6T SRAM Cells With Variation-Tolerant WLUD Read-Assist and TVC Write-Assist
(2015-06-01)
Hu, Vita Pi-Ho
;
Fan, Ming-Long
;
Su, Pin
;
Chuang, Ching-Te
;
電子工程學系及電子研究所
This paper analyzes the impacts of read-assist and write-assist circuits on GeOI FinFET 6T SRAM cells considering intrinsic random variations, process corner, and temperature variation. The word-line under-drive (WLUD) read-assist is more efficient to improve the read static noise margin and read V-MIN of fast-N slow-P corner GeOI FinFET SRAM cells compared with the Silicon-On-Insulator (SOI) counterparts. GeOI FinFET SRAM cells with WLUD show less cell read access-time degradation compared with the SOI counterparts at both 25 degrees C and 125 degrees C. With transient voltage collapse (TVC) write-assist, the write-ability and variation tolerance of GeOI and SOI FinFET SRAM cells are improved. The temperature dependence of data retention time is different between the GeOI and SOI FinFET SRAM cells. The maximum TVC write-assist pulsewidth constrained by the data retention failure is smaller in GeOI FinFET SRAMs at 25 degrees C and becomes comparable at 125 degrees C compared with the SOI FinFET SRAMs.
The Relationship Among Academic Self-concept, Learning Strategies, and Academic Achievement: A Case Study of National Vocational College Students in Taiwan via SEM
(2015-06-01)
Chen, Bryan H.
;
Chiu, Wan-Ching
;
Wang, Chih-Chuan
;
交大名義發表
;
National Chiao Tung University
This study focuses on the effect of academic self-concept on the use of learning strategies conducive to academic achievement. Data from 407 national vocational college students in Taiwan were analyzed by structural equation modeling through the LISREL 8.80 version. The results of this study can be summarized as follows: (a) academic self-concept has a significant positive effect on deep, surface and strategic approaches, as well as academic achievement, (b) of all the learning strategies, strategic approach has a significant positive effect, and surface approach has a significant negative effect on academic achievement, and (c) strategic approach mediated a positive relationship between academic self-concept and academic achievement. Overall, these findings suggest that higher level educators may offer positive encouragement to increase students' learning motivation, efficiency, and self-concept and assist in the development of recognition concerning self-learning and meta-cognitive skills. These findings may help students to select the best learning approaches and improve their academic performance. Implications for the design of educational models and curricula in vocational college education are also discussed.
Temperature-Dependent Transfer Characteristics of Low Turn-On Voltage InGaZnO Metal-Oxide Devices With Thin Titanium Oxide Capping Layers
(2015-06)
Hsu, Hsiao-Hsuan
;
Cheng, Chun-Hu
;
Chiou, Ping
;
Chiu, Yu-Chien
;
Yen, Shiang-Shiou
This paper reports an InGaZnO thin-film transistor involving a wide bandgap gate dielectric of ZrO2 and IGZO/TiOx channel stack. According to our experimental results, the IGZO TFT with a thin TiOx channel capping layer shows good device integrity of a low threshold voltage of 0.37 V, a small sub-threshold swing of 77 mV/decade, and a high mobility of 33 cm(2)/V.s under a low drive voltage of < 2 V. We also demonstrate that the significantly improved electrical property is mainly contributed by the enhanced channel electric field after TiOx capping, associated with maximizing charge accumulated capability. The favorable high-temperature transfer characteristics are also obtained in IGZO/TiOx TFT, indicating a weak Fermi-level pinning in IGZO/TiOx channel structure. With the operating temperature increasing further, the thermal activated effect shall dominate IGZO channel property beyond percolation conduction.
Photocatalytic reduction of NO2 and CO2 using molybdenum-doped titania nanotubes
(2015-06-01)
Nhat Huy Nguyen
;
Wu, Hung-Yu
;
Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
The preparation of molybdenum-doped hydrothermal titania nanotubes (Mo-doped TNTs) and its special photocatalytic reduction activity on NO2 and CO2 gases are reported for the first time. The TNTs photocatalysts were synthesized by hydrothermal method while Mo metal species was doped at different process steps corresponding to three fabrication methods: hydrothermal, precipitation, and impregnation. The materials were then characterized by BET, SEM, TEM, ICP, TPD, XPS, UV-Vis adsorption, and XRD analyses. The results indicated that Mo doping was successful by precipitation and impregnation, but not by the conventional hydrothermal method. It also revealed that the doping of Mo did not considerably affect the morphology, microstructure, and crystalline structure. However, it moderately changed the electronic band structure as well as surface acidity and basicity of the TNTs materials. The NO2 photocatalytic reaction results showed that the doping of Mo sharply declined the oxidation ability of TNTs while surprisingly enhanced its reduction ability. The CO2 reduction results further confirmed this special reduction ability of Mo-doped TNTs, which produced much higher yields of methane and carbon monoxide. The photocatalytic reaction results of both NO2 and CO2 showed that Mo-doped TNTs prepared by the precipitation method provided the highest reduction ability, which may be due to its chemical oxidation states of Mo4+ and Mo5+. (C) 2015 Elsevier B.V. All rights reserved.
Interactive Visual Analysis for Vehicle Detector Data
(2015-06-01)
Chen, Yi-Cheng
;
Wang, Yu-Shuen
;
Lin, Wen-Chieh
;
Huang, Wei-Xiang
;
Lin, I-Chen
Visualization of vehicle detection (VD) data is essential because the data play an important role in traffic control and policy development. Most previous works focus on visualizing trajectories obtained from global positioning system (GPS), which are detailed but less representative. In contrast, VD data report the traffic statistic at each sensing site during a time span, including speed, flow, and occupancy of each lane, which contain comprehensive traffic information for analysis. In this work, we visualize three-year VD data of freeways in Taiwan. The visualization depicts the traffic situation at a site over time using a color-coded chart that extends from left to right over time. The charts are vertically stacked and horizontally aligned according to VD\'s located mileage and data time, respectively, to provide global insight. Our system allows semantic zoom, which changes the chart appearance in a continuous manner, to enable macro- and micro- scopic visualizations. Analysts can explore events that span an area with different sizes and that persist a time span with various lengths. To ensure the feasibility of our visualization, before the system design, we conducted a study with experts who work in the national freeway bureau and the institute of transportation of Taiwan. We also showed our results to the experts after the prototype system was built. The feedback shows that our VD data visualization is helpful to traffic control and policy development.
A 12-Step Sensorless Drive for Brushless DC Motors Based on Back-EMF Differences
(2015-06-01)
Wang, Samuel
;
Lee, An-Chen
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a new 12-step sensorless drive for brushless dc motor based on back-electromotive force (back-EMF) differences, which are estimated from the disturbance observer (DOB) structure. Availability of rotor position information with a resolution of 30 degrees and commutation without phase shift are the advantages of using the back-EMF differences. Unlike the conventional methods that obtain part of the back-EMF signal from the manipulation of three phase voltages, the proposed DOB structure can access the entire back-EMF profile. By designing a proper low-pass filter in the DOB structure, the back-EMF difference can be well detected with lower sensor noise. Compensation of delay commutation introduced by the filter is also discussed. Experiment results showed that the proposed sensorless drive is capable of running the motor in lower speed, and performs better under different speed and load torque as compared with the conventional method.
Cooperative Radio Source Positioning and Power Map Reconstruction: A Sparse Bayesian Learning Approach
(2015-06-01)
Huang, Din-Hwa
;
Wu, Sau-Hsuan
;
Wu, Wen-Rong
;
Wang, Peng-Hua
;
電機資訊學士班
It is known that in addition to spectrum sparsity, spatial sparsity can also be used to further enhance spectral utilization in cognitive radio systems. To achieve that, secondary users (SUs) must know the locations and signal strength distributions (SSDs) of primary users\' base stations (PUBSs). Recently, a group sparse total least squares method was developed to cooperatively sense the PUBSs\' signal strength and estimate their locations. It approximates PUBSs\' power decay with a path loss model (PLM), assumes PUBSs\' locations on some grid points, and then accomplishes the estimation tasks. However, the parameters of the PLM have to be known in advance, and the accuracy of the location estimation is bounded by the resolution of the grid points, which limit its practical applications. In this paper, we propose a sparse Bayesian learning method to solve the problems. We use a Laplacian function to model the power decay of a PUBS and then derive learning rules to estimate corresponding parameters. The distinct features of the proposed method are that most parameters are adaptively estimated, and little prior information is needed. To further enhance the performance, we incorporate source number detection methods in the proposed algorithm such that the number of the PUBSs can be precisely detected, facilitating the estimation of PUBSs\' locations and SSDs. Moreover, the proposed algorithm is modified into a recursive mode to adapt to SUs\' mobility and time-variant observations. Simulations show that the proposed algorithm has good performance, even when the spatial measurement rate is low.
發光二極體的封裝結構及其封裝方法
(2015-06-01)
王興宗
;
郭浩中
;
陳信助
;
陳國儒
1.一種具有螢光粉體層的發光二極體的封裝結構，應用於一固態照明裝置中，該封裝結構至少包含：一發光晶片，其中該發光晶片為一藍光晶片；一封裝體，用以將該發光晶片封裝於其中，且該封裝體具有一出光面，其中該封裝體包含一架體與封膠，該發光晶片係設置於該架體內，該封膠填滿該架體以封裝該發光晶片，其中該基板之材質為聚乙烯對苯二甲酸酯，該封膠之材質包含矽膠；複數個襯墊，設置於該出光面的週邊；一基板；以及一螢光粉體層覆蓋於該基板之一表面上以形成一光電轉換板材，其中該螢光粉體層包含複數個螢光粉體、矽樹脂黏著劑與含烴基之溶劑，該複數個螢光粉體的材質為SrO2-MgO-SiO2-Eu2 O3，該螢光粉體層的一厚度係100μm，以及一濃度係50wt%；其中該光電轉換板材設置於該複數個襯墊上，使該螢光粉體層以一間距面對該封裝體之該出光面。
Voluntary disclosure, excess executive compensation, and firm value
(2015-06-01)
Chung, Huimin
;
Judge, William Q.
;
Li, Yi-Hua
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This study refines\' and extends Anglo-American research exploring excess executive compensation and its effects on firm value using data from Taiwan, a country in which the board members and executives of a firm often have friendly relations with one another. We find that excess executive compensation is negatively related to firm value but that voluntary disclosure practices moderate this relationship. Specifically, our results indicate that excess executive compensation has a positive effect on firm value when firms disclose comprehensive information voluntarily and that this effect is more pronounced in group-affiliated firms. Moreover, firms that provide comprehensive voluntary disclosure appear to alleviate agency problems more efficiently when their controlling shareholders have higher private benefit incentives or when these firms have higher quality corporate governance. (C) 2015 Elsevier B.V. All rights reserved.
Measurement of protein in lens by Raman spectroscopy
(2015-06-01)
Ueda, Toshihiko
;
Nakanishi-Ueda, Takako
;
Ando, Masahiro
;
Mizuno, Aritake
;
Uda, Shigekazu
Fluorescence microscopy colocalization of lipid-nucleic acid nanoparticles with wildtype and mutant Rab5-GFP: A platform for investigating early endosomal events
(2015-06-01)
Majzoub, Ramsey N.
;
Chan, Chia-Ling
;
Ewert, Kai K.
;
Silva, Bruno F. B.
;
Liang, Keng S.
Endosomal entrapment is known to be a major bottleneck to successful cytoplasmic delivery of nucleic acids (NAs) using cationic liposome-NA nanopartides (NPs). Quantitative measurements of distributions of NPs within early endosomes (EEs) have proven difficult due to the sub-resolution size and short lifetime of wildtype EEs. In this study we used Rab5-GFP, a member of the large family of GTPases which cycles between the plasma membrane and early endosomes, to fluorescently label early endosomes. Using fluorescence microscopy and quantitative image analysis of cells expressing Rab5-GFP, we found that at early time points (t < 1 h), only a fraction (approximate to 35%) of RGD-tagged NPs (which target cell surface integrins) colocalize with wildtype EEs, independent of the NP\'s membrane charge density. In comparison, a GTP-hydrolysis deficient mutant, Rab5-Q79L, which extends the size and lifetime of EEs yielding giant early endosomes (GEEs), enabled us to resolve and localize individual NPs found within the GEE lumen. Remarkably, nearly all intracellular NPs are found to be trapped within GEEs implying little or no escape at early time points. The observed small degree of colocalization of NPs and wildtype Rab5 is consistent with recycling of Rab5-GDP to the plasma membrane and not indicative of NP escape from EEs.Taken together, our results show that endosomal escape of PEGylated nanoparticles occurs downstream of EEs i.e., from late endosomes/lysosomes. Our studies also suggest that Rab5-Q79L could be used in a robust imaging assay which allows for direct visualization of NP interactions with the luminal membrane of early endosomes. (C) 2015 Elsevier B.V. All rights reserved.
Examining the diagnostic criteria for Internet addiction: Expert validation
(2015-06-01)
Hsu, Wen-Yu
;
Lin, Sunny S. J.
;
Chang, Shan-Mel
;
Tseng, Yin-Hsing
;
Chiu, Nan-Ying
Background/Purpose: Internet addiction is the coming problem around the world. The diagnostic criteria for Internet addiction among adolescents (DC-IA-A) has become a widely used measure for assessing the presence of Internet addiction in Taiwan. This study examined the diagnosis criteria for Internet addiction in adolescents by expert evaluation. Methods: Twenty psychiatrists rated the adequacy of each criterion in DC-IA-A. The content validity and homogeneity reliability proposed by Aiken were calculated. Results: The coefficients content validity and homogeneity reliability showed twenty psychiatrists agreed on each of DC-IA-A as relevant to the diagnosis of Internet addiction, though several criteria need improvements. Two criteria "excessive time spent on Internet activities and leaving the Internet" and "excessive effort spent on activities necessary to obtain access to the Internet" should be omitted, and the criteria of "tolerance" should be modified. Conclusion: The diagnostic criteria for Internet addiction among adolescents should be revised to meet the real condition of this population. Copyright (C) 2014, Elsevier Taiwan LLC & Formosan Medical Association. All rights reserved.
A Similarity-Based Learning Algorithm Using Distance Transformation
(2015-06-01)
Hu, Yuh-Jyh
;
Yu, Min-Che
;
Wang, Hsiang-An
;
Ting, Zih-Yun
;
交大工研院聯合研發中心
Numerous theories and algorithms have been developed to solve vectorial data learning problems by searching for the hypothesis that best fits the observed training sample. However, many real-world applications involve samples that are not described as feature vectors, but as (dis) similarity data. Converting vectorial data into (dis) similarity data is more easily performed than converting (dis) similarity data into vectorial data. This study proposes a stochastic iterative distance transformation model for similarity-based learning. The proposed model can be used to identify a clear class boundary in data by modifying the (dis) similarities between examples. The experimental results indicate that the performance of the proposed method is comparable with those of various vector-based and proximity-based learning algorithms.
Pressure-Induced Phase Transitions in InAs Studied by Angular-Dispersive X-ray Diffraction and Raman Spectroscopy
(2015-06-01)
Lin, Chih-Ming
;
Lin, Kung-Liang
;
Chern, Yu-Ker
;
Lin, Yu-Kun
;
Chuang, Yu-Chun
Pressure-induced phase transitions in indium arsenide (In As) at ambient temperature were investigated by using angular-dispersive X-ray diffraction (ADXRD) and Raman scattering under high pressure up to around 9.8(1) and 9.9(2) GPa, respectively, with a 4:1 (in volume ratio) methanol-ethanol mixture as the pressure transmitting medium (PTM). In situ ADXRD measurements revealed that In As starts to transform from zinc blende (ZB) structure to rock-salt (RS) phase at 6.7(1) GPa, consistent with most previously reported studies. The phase transition proceeds steadily over a wide range of pressures and reaches completion at the highest applied pressure of 9.8 GPa with significant metallization, as suggested by the disappearance of Raman modes. In contrast to previous studies, our data did not show evidence of structural transition to Cnncm phase, presumably due to the different PTMs used and/or insufficient pressure applied. The order of appearance of the major diffraction peaks of RS phase In As with increasing pressure and intensity are explained by the binding energy density of the corresponding plane families. The zero-pressure isothermal bulk moduli (B-0) and its first-pressure derivatives (B-0\') for the ZB In As are 64(4) GPa and 3.8(2), respectively. The intensity of both the LO and TO phonon modes of ZB phase In As exhibits an abrupt decrease at 7.7(1) GPa, where equal weight fractions of ZB and RS phases are identified, suggesting the metallic nature of the RS phase.
Fabrication of pure aluminum nanowires by using injection molding process in ambient air
(2015-06-01)
Chen, Shih-Hsun
;
Wang, Chiu-Yen
;
Chen, Yung-Chang
;
Hun, Chien-Wan
;
Chen, Shih-Fan
A simple method to prepare aluminum nanowires was achieved by using the injection molding process in the air. The Al nanowires were made with the average diameter of 60 nm and length of several micrometers. The difference between mold dimension and nanowires was caused by removing the outer oxide shell of Al nanowires. XRD, EDS and SAED results showed that the Al crystalline nanowires were fabricated exactly. The proposed concept successfully established a simple and low-cost method to have high-temperature and soft nano-materials under the non-vacuum surroundings. (C) 2015 Elsevier B.V. All rights reserved.
Influence of Surface State on Biochemical Sensing Using SiGe Nanowire
(2015-06-01)
Lai, Chiung-Hui
;
Chang, Kow-Ming
;
Chen, Yi-Ming
;
Chen, Chu-Feng
;
Kuo, Po-Shen
Nanowires are extensively used to fabricate highly sensitive electrical sensors for detection of biological and chemical species. The hole mobility can be promoted by the increasing Ge fraction in SiGe, achieved by the oxidation-induced Ge condensation. However, oxidation increases the number of surface states, which brings the nonnegligible contribution in mobility degradation. In this work, 3-aminopropyltrimethoxysilane (APTMS) was used as a biochemical reagent to modify the surface of SiGe nanowires, then bonding to bio-linker, bis (3-sulfo-N-hydroxysuccinimide ester) sodium salt (BS3). Various methods have been proposed for increasing sensitivity of boron-doped SiGe nanowires, such as capping layer, surface treatment, and annealing temperature.