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1مؤتمر
المؤلفون: Hsiao A.-Y., Yang C.-F., Wang T.-S., Lin I., Liao W.-J.
مصطلحات موضوعية: 5G Wireless Communications, Base Station Deployment, Field Coverage, Millimeter Wave Propagation, Ray Tracing
الوصف: This paper presents ray tracing simulations for wave propagation at millimeter-wave frequencies to be applied in future 5G wireless communications. Since attenuation and blockage of millimeter-wave propagation in urban are much more severe than those at microwave frequencies, the line-ofsight rays and non-line-of-sight reflected rays should be dominant propagation mechanisms. Field distributions will be more constrained and therefore new approaches to improve the coverages of the 5G wireless communications will be needed. The ray tracing method can be applied to evaluate those approaches for improving field coverages in the deployment of the 5G base stations. Copyright 2017 IEEE.
وصف الملف: 117 bytes; text/html
العلاقة: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Volume 2017-January , Page: 1901 - 1902; http://ir.lib.ntust.edu.tw/handle/987654321/74870Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/74870/1/index.htmlTest
الإتاحة: https://doi.org/10.1109/APUSNCURSINRSM.2017.8072993Test
http://ir.lib.ntust.edu.tw/handle/987654321/74870Test
http://ir.lib.ntust.edu.tw/bitstream/987654321/74870/1/index.htmlTest -
2مؤتمر
المؤلفون: Wang C.-C., Huang J.-F.
المساهمون: 國立臺灣科技大學電子工程系
مصطلحات موضوعية: Antenna accessories, Antennas, Code division multiple access, Electromagnetic compatibility, Microwave antennas, Microwaves, Plastic molds, Technical presentations, Telecommunication, Wave propagation, CDMA 2000, Cellular CDMA, Cellular systems, Dense urban environments, Field strengths, International symposium, Lee models, Measurement results, Path loss (PL), Path loss prediction, Propagation paths, Wave propagation characteristics, Wireless (WiFi) communication, Crack propagation
الوصف: This paper presents the significant measurement results on wave propagation characteristics at an 870 MHz (CDMA2000 band) cellular system in Taipei city, dense urban environments. Furthermore, observed field strength values are converted into path loss and are compared with different path loss prediction methods Hata and COST 231 Walfisch-Ikegami. It's apparent the measured propagation path loss in Taipei city is higher at 0-5dB (dependent on distances) than the two models. Our study also indicates that expression used in Lee model in some previous papers needs to be corrected. 穢 2007 IEEE.
العلاقة: 2007 IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications, MAPE 2007,pp.790-793, Hangzhou; http://ir.lib.ntust.edu.tw/handle/987654321/27549Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/27549/-1/index.htmlTest
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3مؤتمر
المؤلفون: Liao A.-H., Shen C.-C., Li P.-C.
المساهمون: 國立臺灣科技大學電機工程系
مصطلحات موضوعية: Background noise, Contrast agent, Contrast imaging, Contrast-to-tissue ratio, Empirical mode decomposition, Ensemble empirical mode decomposition, Finite number, Fundamental bands, Hilbert Huang transforms, Image contrasts, Intrinsic modes, Micro-bubble, Nonlinear imaging, Pulse-inversion, Pulse-inversion technique, Second harmonics, Tissue signals, Ultrasound contrast imaging, Acoustic signal processing, Acoustic waves, Data flow analysis, Image processing, Ultrasonic applications, Ultrasonics, Underwater acoustics, Acoustic wave propagation
الوصف: Ultrasound nonlinear contrast imaging often has limited contrast because acoustic wave propagation in tissue is also nonlinear. In this study, a new ultrasound contrast imaging method which combines pulse-inversion technique with empirical mode decomposition (EMD) and the ensemble empirical mode decomposition (EEMD) in Hilbert-Huang transform (HHT) is explored to enhance the contrast between bubbles and surrounding tissues. The EMD is a method associated with HHT that allows decomposition of the data into a finite number of intrinsic modes (IMF). EEMD method further utilizes the ensemble of IMF with added white noise to better differentiate the nonlinear microbubble signal from the nonlinear tissue signal. This hypothesis was tested on pulse-inversion (PI) nonlinear imaging. Our results showed that the contrast-to-tissue ratio (CTR) in the fundamental band and the second harmonic band was improved by 10.2 and 4.3 dB after EEMD. However, echoes from contrast agent areas after decomposition may vary from the original data. By extracting microbubble component and suppressing background noise, it is demonstrated both numerically and experimentally that the EEMD can noticeably improve image contrast. 穢2009 IEEE.
العلاقة: 2009 IEEE International Ultrasonics Symposium, IUS 2009, Rome; http://ir.lib.ntust.edu.tw/handle/987654321/26749Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/26749/-1/index.htmlTest
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4دورية أكاديمية
المؤلفون: Wang, T.-S., Yang, C.-F.
المساهمون: 國立臺灣科技大學電機工程系
مصطلحات موضوعية: Mobile communications, Ray tracing, Tunnel, Uniform theory of diffraction (UTD), Wave propagation
الوصف: This paper presents a ray-tube tracing method to simulate waves propagating in curved road tunnels from base stations for mobile communications. Ray tubes are traced by including multiple reflections in the curved tunnels and diffractions from wedges of t
العلاقة: IEEE Transactions on Antennas and Propagation, Vol.54, Issue.9, pp.2577-2584; http://ir.lib.ntust.edu.tw/handle/987654321/29762Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/29762/-1/index.htmlTest
الإتاحة: https://doi.org/10.1109/TAP.2006.880674Test
http://ir.lib.ntust.edu.tw/handle/987654321/29762Test
http://ir.lib.ntust.edu.tw/bitstream/987654321/29762/-1/index.htmlTest -
5تقرير
المؤلفون: 楊成發
مصطلحات موضوعية: 物件互聯網, 天線, 電波傳播, RFID靜態驗測技術, Internet of Things (IOT), RFID, antenna, wave propagation, RFID static test
الوصف: 執行機構：國立台灣科技大學電機工程系 ; 計畫編號：NSC99-2221-E011-051 ; 研究期間：9908~ 10007 ; 研究經費(仟元)：660 ; 本子計畫乃針對物件互聯網之天線設計與電波傳播分析等關鍵技術進行研發，來與其他子計畫共同合作研發物件互聯網之RFID關鍵技術及系統，其中主要的應用頻段涵蓋超高頻及微波頻段。計畫期程為三年來完成下列研究工作：（1）擬針對特定辨識功能來設計出相對應之標籤天線，其中包含：微型化全向性標籤天線、微型化內建式標籤天線、可貼附於金屬之標籤天線、以及兼具近場/遠場辨識標籤天線等。（2）為提高系統辨識率，將研製多款具備不同功能之讀取器天線，例如：高增益寬頻陣列天線、可變四極化天線、近場讀取天線、可變場型天線、以及波束掃瞄陣列天線等。此外，亦將研製相關射頻電路，例如：功率分波器、射頻切換器、相位延遲傳輸線段、方向耦合器、巴特爾矩陣等，其中將使用人工傳輸線及左右手傳輸線來設計部分的電路元件。（3）針對RFID系統效能之優劣，本計畫擬發展RFID靜態驗測技術與天線干擾檢測技術，其中包含：最大讀取距離測試、貼附位置選擇、以及干擾測試等。（4）為改善RFID系統之辨識率，將以低階讀取器協定來編輯調整讀取器參數至最佳化，期提升硬體之工作效能。（5）本計畫擬發展射線追蹤與時域有限差分電波混合模擬程式來計算電波傳播特性，並與場強分佈量測結果比較驗證之，來評估物件互聯網之場強分佈特性及讀取範圍，期能改善與優化之。 This sub-project is to investigate the antenna design and wave propagation properties for Internet of Things (IOT) to cooperate with other sub-projects for developing RFID key technologies and system, where applications in UHF and microwave bands are focused. This three-year sub-project is to accomplish the following works: (1) Tag antenna designs for certain RFID applications, including: miniature omni-directional tag antenna, miniature embedded tag antenna, metal mounting tag antenna, and near and far field tag antenna. (2) To enhance the performance on tag reading, several reader antennas will be designed, such as antennas for broadband, high gain, reconfigurable pattern, reconfigurable polarization, beam switching and near-field identification. Also, some RF circuits, including power divider, RF switch, directional coupler, phase delay transmission line and Bulter Matrix will be designed by using artificial transmission lines and right/left handed transmission lines. (3) For evaluate the performance of the RFID system, the technologies of the RFID static test and antenna interference test will be developed, which may be applied to obtain maximum readable range, determine the proper locations of the tags, measure antenna interferences, etc. (4) To improve the readability of the RFID system, the parameters of the reader will be tuned by using the low-level reader protocol (LLRP). (5) To ...
العلاقة: http://ir.lib.ntust.edu.tw/handle/987654321/21056Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/21056/1/NSC99-2221-E011-051.PDFTest
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6رسالة جامعية
المؤلفون: Parnika Gupta
مصطلحات موضوعية: Coupling Efficiency, III-V laser source, Photonic Chips, Wave Propagation, Ray Propagation
الوصف: 國立臺灣科技大學電子工程系 ; 學位：碩士 ; 指導教授：李三良 ; The integration of active and passive devices has been instrumental in achieving hybrid silicon laser as well as optical interconnects. In this thesis, the integration of active III-V laser and Silicon-On-Insulator Photonic Integrated Circuits through micro-mirror has been proposed. The micro-mirror is required to attain the phase matching with the grating coupler on the PIC surface. The light emitted by the III-V laser is input into the concave micro-mirror with alignment conditions such that the light reflected from the micro-mirror can be coupled into the grating coupler. The initial part of the thesis shows the simulation for coupling light using the FDTD wave propagation as well as Ray-tracing models. The FDTD modeling shows the highest coupling efficiency of 64% using an apodized grating coupler. The apodized grating thickness has been designed as 520 nm with an etch depth of 220 nm using the polysilicon overlay technique. The output waveguide thickness has been designed to be the standard 220 nm thickness for single-mode transmission. The Ray Tracing Model has been used to study the free space light propagation and reflection characteristics of the concave mirror. The laser source position has been designed to be 150 μm away from the concave mirror center and 167 μm away from the center of the concave mirror, near the edge of the 200 μm diameter mirror. The coupled power in this ray-tracing model has been computed to be 40.859% when the detector is at a distance of 100μm from the mirror edge. The thesis also presents the fabrication method of the semiconductor concave micro-mirror which includes the combination of V-groove fabrication and BCB coating followed by gold deposition on the top surface. The V-groove fabrication is achieved through the traditional anisotropic etching method followed by BCB spin coating in the V-grooves. Different BCB spin-coating parameters have been investigated for three different chips to determine the best mirror surface followed by gold ...
وصف الملف: 169 bytes; text/html
العلاقة: http://ir.lib.ntust.edu.tw/handle/987654321/77705Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/77705/1/index.htmlTest
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7تقرير
المؤلفون: 張大鵬
مصطلحات موضوعية: 修復材料, 超音波, 波傳, 活性粉混凝土, 自填充混凝土, 非破壞性檢測, 鋼筋混凝土, retrofitting material, ultrasonics, wave propagation, reactive powder concrete (RPC),self-compacting concrete (SCC), non-destructive testing, reinforced concrete (RC)
الوصف: 執行機構：國立臺灣科技大學營建工程系 ; 計畫編號：NSC96-2221-E011-112-MY3 ; 研究期間：9808~ 9907 ; 研究經費(仟元)：752 ; 鋼筋混凝土構造物具有相當可靠的耐久性及強度，但在地震作用下，部份鋼筋混凝土構造物的構件會承受不同程度的震損破壞，常見構件震損破壞包括：柱端混凝土的軸力脆性破壞、短柱效應的剪力破壞、樓版柱冠四週或梁端的剪穿破壞、軸力與側移交互作用的挫屈或斷裂破壞等，可用適當方式加以修復，工程常用的修補/補強屬於外部植入式的修補法，有水泥基系、樹脂基系、鋼板、纖維等外部植入式的修補材料，除須有強度與耐久性外，也須與既有鋼筋混凝土構件間有良好界面相容性，方能使修補構件獲得原設計服務性能及日後耐震性。本研究案之補修/補強材料為無收縮水泥砂漿、活性粉混凝土與自填充混凝土，以超音波技術為主導，輔以微觀結構影像，探討：(1)修補料材強度發展過程；(2)界面層微觀粘合性質；(3) 修補材料及界面之強度發展、波傳變化與微觀機制間之關係；(4)發展強度及波傳預測模型，及數值模擬分析，作為評估適宜性的依據；(5)實驗室原型修補樑柱構件之修補料材強度效能發展驗證；(6)結合數值模擬與原型修補樑柱構件實驗驗證，作為全尺寸構件之模擬。並以傳統水泥砂漿材料為對照，進行材料補強效果比較，以期研發有助於鋼筋混凝土構件耐震功能之材料，及適宜的震損構件修復材料。 Reinforced concrete (RC) structures have rather reliable durability and strength. However, under seismic action, partial structural members of RC structures may subject to some earthquake damage to various extents. The most commonly observed earthquake damages of members include the brittle failure of concrete due to axial load near the ends of column, shear failure due to the effects of short column, punching shear failure of floor around crown of column and ends of girders/beams, buckling or fracture failure due to the interaction of axial load and lateral displacement, etc. For those existing earthquake-damaged RC members that can be properly retrofitted to restore their original functions, the retrofitting method adopted by the domestic construction society belongs to outer imbedding retrofit method. The used retrofit materials including Portland-cement-based, resin-based, steel plate, fiber polymer, etc., need to have not only an adequate strength and durability, but also a good compatibility on the interface such that the retrofitted structural members can restore their service function of original design and earthquake resistance later. In this project, Portland-cement-based retrofitting materials, including reactive powder concrete (RPC), self-compacting concrete (SCC), and shrinkage-free mortar are investigated by using ultrasonic techniques with microstructure images as an assistant technique. Several topics will be ...
العلاقة: http://ir.lib.ntust.edu.tw/handle/987654321/15037Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/15037/1/962221E011112MY3Test（第3年）.PDF
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8تقرير
المؤلفون: 楊成發
مصطلحات موضوعية: 行動通信, 電波傳播, Mobile communication, Wave propagation
الوصف: 執行機構：國立臺灣科技大學電機工程系 ; 計畫編號：NSC90-2213-E011-032 ; 研究期間：9008 ~ 9107 ; 研究經費(仟元)：481
وصف الملف: application/pdf; 611448 bytes
العلاقة: http://ir.lib.ntust.edu.tw/handle/987654321/4882Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/4882/1/NSC90-2213-E011-032.pdfTest
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9تقرير
المؤلفون: 楊成發
مصطلحات موضوعية: 無線通信, 都會區, 電波傳播, 射線追蹤法, 物理光學近似法, 繞射, 實地量測, Wireless communication, Urban area, Wave propagation, Ray tracing method, Physical optics approximation, Diffraction；Field measurement
الوصف: 執行機構：台灣科技大學電機工程系 ; 計畫編號：NSC87-2213-E011-060 ; 研究期間：8608 ~ 8707 ; 研究經費(仟元)：691
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العلاقة: http://ir.lib.ntust.edu.tw/handle/987654321/5301Test; http://ir.lib.ntust.edu.tw/bitstream/987654321/5301/1/NSC87-2213-E011-060.pdfTest
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10تقرير
المؤلفون: 楊成發
مصطلحات موضوعية: 無線通訊, 波傳播, 光線跟蹤, 穿透, Wireless communication, Wave propagation, Ray tracing, Penetration
الوصف: 執行機構：國立台灣工業技術學院電機工程技 ; 計畫編號：NSC85-2213-E011-018 ; 研究期間：8408 ~ 8507 ; 研究經費(仟元)：302 ; 本研究發展了電波傳播模擬程式,來分析同一建築物內的無線電波傳播特性,同時使用向量網路分析儀測量了建築物體的反射與穿透特性,以獲得電波傳播模擬所需的結構參數。在量測建築物體的結構參數上,乃使用自由空間法中的穿透量測和反射量測,以獲得磚牆及鋼筋混凝土牆的等效介電常數,其中牆壁是以均勻厚度及介電材質的平板結構來模擬。另一方面,電波傳播模擬程式是依據射線追蹤法來發展,此一模擬程式配合量測所得牆壁之介電常數,可以模擬電波在建築結構物中的多次反射及穿透特性,來評估室內無線通信電波的傳播情形。
