- 标题
- 摘要
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- 实验方案
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The Monte Carlo Ray-Trace Method in Radiation Heat Transfer and Applied Optics || The MCRT Method for Participating Media
摘要： The MCRT Method for Participating Media So far we have only considered energy interactions between rays and surfaces. Two possible outcomes – absorption and reflection – have been identified, and corresponding models have been formulated and used to describe radiation heat transfer among surfaces. When a ray incident to a surface is neither absorbed nor reflected, it is said to be transmitted. Thermal radiation passing through lenses, filters, and the earth’s atmosphere are familiar examples of transmission. This chapter deals with emission, absorption, refraction, and scattering of thermal radiation within a medium through which it is propagating. Such media are said to be “participating.”
关键词： Emission,Thermal Radiation,Refraction,Radiation Heat Transfer,Transmission,Absorption,Reflection,MCRT Method,Scattering,Participating Media
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Kota Kinabalu, Malaysia (2018.10.7-2018.10.10)] 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Enhancement of Wireless Power Transmission Based on Side-Positioned Metamaterials
摘要： Inserting a metamaterial slab between the source and receiver coils of the wireless power transfer (WPT) system is a conventional way to improve the transmission performance. However, the free energy transfer space benefited from WPT system is impeded by the inserted metamaterial slab. This paper explores effects of side-positioned metamaterial slabs on wireless power transmission efficiency. Simulations of the WPT system indicate that the side-positioned meta material slab can achieve the same improvements as the center-positioned one in terms of the wireless power transmission, which was verified by experiments. the experiments show that more side-positioned metamaterial energy the significantly. Therefore the side-positioned metamaterial slabs are more efficient and flexible for enhancement of practical WPT systems.
关键词： side- transmission,wireless power transfer,center-positioned,metamaterials,wireless power postitoned
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Frequency-Selective Rasorber with a Transparent Window Between Absorption Bands
摘要： In this paper, a novel frequency-selective rasorber (FSR) which has a transmission band between two absorption bands is proposed. The FSR is composed of curved metal sheets with lumped resistors printed on a dielectric substrate and a frequency selective surface (FSS) used as the ground plane of the absorber. An equivalent circuit model of the structure is given for analyzing its operation mechanism. A good stability of the transmission and two-band absorption under the incident angle o30 for TE and TM polarizations has been obtained.
关键词： equivalent circuit model,transmission band,frequency-selective rasorber,absorption bands,FSR
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Miniaturized Quasi-Elliptic BPF with High Selectivity Based on Combining CPWs and CSRR in a Single Dual-Mode SIW Cavity
摘要： A fifth-order bandpass filter with quasi-elliptic response based on combining two coplanar waveguides (CPWs) and a complementary open loop resonator (CSRR) in a single dual-mode substrate integrated waveguide (SIW) cavity is proposed. The presented filter has advantages of compact size and high selectivity because the CPWs and CSRR are etched on the top metal surface of dual-mode SIW cavity and multiple transmission zeros (TZs) are produced. The TZs are realized by the multipath energy flow and electric and magnetic mixed coupling in the proposed structure. A prototype filter with center frequency of 5.8 GHz is designed, fabricated and measured. The measured results agree with the simulated ones.
关键词： quasi-elliptic response,coplanar waveguides,bandpass filter,substrate integrated waveguide,transmission zeros,complementary open loop resonator
更新于2025-09-04 15:30:14
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[IEEE 2018 2nd IEEE Advanced Information Management,Communicates, Electronic and Automation Control Conference (IMCEC) - Xi'an (2018.5.25-2018.5.27)] 2018 2nd IEEE Advanced Information Management,Communicates,Electronic and Automation Control Conference (IMCEC) - Ice Detection of Transmission Line Based on Image Fusion
摘要： In order to maintain the safe and stable operation of the power system, early detection and early warning of the icing on transmission lines and avoiding the occurrence of ice-coating accidents, a method based on digital image processing is proposed to determine the icing status of transmission lines. In the process of icing detection of transmission lines, the quality of images of icing transmission lines from the natural environment is poor due to objective factors, and the present detection methods are difficult to accurately extract the boundaries from the low-quality icing images of transmission lines. In response to this problem, a method based on image fusion technology is proposed to determine the icing condition of transmission line. The transmission line is image pre-processing, wavelet transform detected through detection, morphological processing, line extraction and weighted fusion, after that, the ice thickness of transmission line is calculated by pixel comparison. The model was simulated in MATLAB and compared with the results of other existing edge detection methods, showing that the edge details obtained by this method are clearer and the ice thickness measurement is more accurate.
关键词： image fusion,wavelet transform,line extraction,detection of icing on transmission line,morphology,edge detection
更新于2025-09-04 15:30:14
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Asymmetric light transmission effect based on an evolutionary optimized semi-Dirac cone dispersion photonic structure
摘要： In this paper, we present the numerical and experimental demonstration of asymmetric light transmission by a compact photonic crystal (PC) structure, which sustains semi-Dirac cone dispersion. The semi-Dirac point is obtained by exploiting plane-wave expansion method in a rectangular unit cell of a cylindrical dielectric rod, forming a PC structure. The preselected part of the corresponding PC structure is optimized via differential evolution to maximize the transmission efficiency in one direction, and to minimize in the opposite direction. In this regard, finite-difference time-domain method is integrated with the optimization algorithm to numerically design a compact PC structure with asymmetric light transmission effect. The detailed numerical investigation of the optimized PC structure is represented, and the experiments in the microwave regime are performed to verify the numerical results. The experimentally measured transmission efficiency reaches 78% for one direction, whereas in the opposite direction it reduces to 11%. The physical mechanism of asymmetric light transmission is related to differences of the projection of the wave incident from both directions into the eigenmodes of the photonic structure.
关键词： asymmetric light transmission,semi-Dirac cone dispersion,photonic crystal,differential evolution,finite-difference time-domain method
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland, New Zealand (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Wideband Metamaterial Antenna Design
摘要： This paper presents the design of composite right/left handed (CRLH TL) wideband metamaterial antenna. The bandwidth enhancement was achieved by replacing horizontal ohm’s shape slot with series horizontal slot. A comprehensive parametric analysis using Computer Simulation Technology CST software is carried out by varying the position of the slot Ln to determine the effectiveness of the concept and find the right position of the slot for obtaining the wideband. From the simulation work, it was found that the impedance bandwidth covered from 2.2 GHz to 4.6 GHz which is equivalent to 75% fractional bandwidth. The antenna has a compact size of 30 by 16.80 mm2. It has three different resonating bands at 2.6 GHz, 3.4 GHz and 4.5 GHz within the range with realised peak gain of 2.39 dBi, 2.41 dBi, and 3.22 dBi respectively and average efficiency of 95%.
关键词： wideband,metamaterial,composite right hand left hand transmission line,computer simulation technology (CST),bandwidth
更新于2025-09-04 15:30:14
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[IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Performance of Time-Reversal for Indoor Communications
摘要： In this paper, we study the performance of time-reversal technique for wireless data transmission in indoor environment. The principle of operation of this technique is to use the time-reversed channel impulse response of the propagating medium in order to modulate the data to be sent. This technique allows reducing the effect of multi-paths and the delay spread of the received signal at the position of the receiver. The coherence bandwidth of the channel is increased. Therefore, for a targeted bit error rate, the data rate which can be sent over the channel will be increased theoretically when the time-reversal technique is used. Measurements results carried out in an indoor environment are presented and analyzed. These results are promoting and show the possibility to create independent channels with multiple users.
关键词： indoor measurement,time-reversal,spatial and temporal focusing,MISO,wireless data transmission
更新于2025-09-04 15:30:14
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Optical characterization of high and low resistive silicon samples suitable for reconfigurable antenna design
摘要： Highly resistive (HR) silicon (Si) can behave as a switch when illuminated by optical source of suitable wavelength. Different reconfigurable passive structures, such as filters, waveguides, and antennas, can be constructed using such silicon switches. This letter presents experimental characterization of high and low resistive (HR & LR) silicon for switching application. In the experiment, HR Si is modeled on a switched transmission line by halogen lamp and a laser source. The experiment of utilizing halogen lamp for Si switch characterization is cost-effective and can assist engineers in designing reconfigurable antennas. In future, this experiment could be utilized in designing novel reconfigurable antennas.
关键词： reconfigurable antenna,low resistive (LR) silicon,meandered transmission line,high resistive (HR) silicon,optical excitation,halogen lamp
更新于2025-09-04 15:30:14
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Complexity considerations: efficient image transmission over mobile communications channels
摘要： In this paper the computational complexity of the image transmission over mobile communications channel is investigated. The computational complexity due to the amount of transmitted data and the utilized data protection schemes is analyzed over wireless channel with the different image transmission scenarios. The proposed secured and efficient protection technique is presented in this research work with lower computational complexity. The presented technique is based on chaotic-Baker encryption which is utilized as an interleaver to randomize the data packet in the proposed secured interleaved channel coding technique. The proposed technique is evaluated utilizing convolutional codes with different constraint lengths and single error correction block code. Different images with the size variation are utilized for evaluating the proposed image transmission scenarios. Numerical analysis of the different scenarios is presented. The secret key generation of chaotic-Baker encryption is discussed; it can be generated automatically or manually. Several computer simulation experiments are carried out to evaluate the proposed techniques performance. Different objective measures error based metrics are used such as the Bit Error Rate (BER), Peak Signal to Noise Ratio (PSNR) and Number of Lost packet percentage (NLP%) to measure the error performance of the proposed technique and quality of the received images. Simulation results reveal a good performance and the superiority of the proposed technique with lower computational complexity of the proposed image transmission scenarios.
关键词： Chaotic-Baker interleaver,Mobility,Wireless communications,Secured interleaved channel coding technique,Image transmission,Data computational complexity
更新于2025-09-04 15:30:14