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oe1(光电查) - 科学论文

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出版时间
  • 2019
研究主题
  • Distributed optical fiber sensing
  • Optical frequency domain reflection
  • Polynomial regression algorithm
  • Nonlinear tuning compensation
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Hebei University of Technology
333 条数据
?? 中文（中国） ▾

  • Thermal performance analysis of a novel linear cavity receiver for parabolic trough solar collectors

    摘要： The trough solar thermal power generation system is one of the most mature solar thermal power generation systems. A novel major arc-shaped linear cavity receiver with a lunate channel based on the black cavity effect principle for parabolic trough solar collectors is proposed in this work. The effects of the inclination angle, collecting temperature, surface emissivity and aperture width on the heat loss are thoroughly analyzed with a two-dimensional numerical model coupling natural convection with surface radiation. In addition, the thermal performance of the proposed linear cavity receiver is compared with that of the Solel’s UVAC series evacuated collector tube. The results show that: (1) The natural convection heat loss is significantly affected by the inclination angle, while the radiation heat loss is mainly affected by the surface emissivity and the collecting temperature. (2) The aperture width of the receiver has a great impact on the thermal performance. The larger the aperture width is, the greater the heat losses. However, the aperture width can also affect the optical performance and the manufacturing cost. The reasonable aperture width for this kind of linear cavity receiver is about 50–70 mm with consideration of all these factors. (3) The proposed linear cavity receiver demonstrates comparative or even better thermal performance as traditional evacuated collector tubes, especially in high temperature range. In general, the proposed linear cavity receiver has the comparative shape and size as the traditional evacuated collector tubes. More importantly, it has the advantages of raising the collecting temperature and reducing the production and maintenance costs. Therefore, it can be used to replace the evacuated collector tube which has poor performance due to long-term operation.

    关键词： Cavity receiver,Parabolic trough solar collector,Surface radiation,Natural convection,Thermal performance,Linear receiver

    更新于2025-09-23 15:23:52

  • Suggestion for Comprehensive Quality Assurance of Medical Linear Accelerator in Korea

    摘要： ????????? ???? ???????? ????? ?? ????(Task Group: TG) 40 ???? 1994? ??? ??? ?????????, ????????, ? ????????? ?? ??? ?????? ??? ?????? ?? ????? ???? ?? 2010?? AAPM TG-142? ?????. ??? ?? ????? ?? ????? ?? ????? ???? ?? ????????? ?????????? ?2015-005? "????? ???????? ?? ????"? ?????. ???????????? ? ?????? ????????? ?? ???? ?? ? ??, ????? ??? ??, ???? ??/??/???? ? ???? ?? ? ???? ?? ?? ??? ??? ???????? ???? ????? ????? ???? ??. ?? ?? ??????? 3?? ?????????, ?????????, ???????? ?? ?? ????????(Non-IMRT, IMRT, SRS/SBRT)? ???????? ?? ???? ??, ?? ? ????? ????, ??? ???? ?? ?? ???? ??? ??? ?? ????? ????? ??. ??? ???? ?????? ???? ????? ??? ? ?? ???? ?? ??? ?? ???? ?? ? ?????? ?? ?? ????? ??, ?? ? ????? ???? ????? ???? ?? ????. ???? ? ????? ?????? ??? ? ???? ???? ?? ???????? ?? ? TG-142? ??? ?? ??? ??? ?????? ?? ?????? ?? ?? ?? ?????. ??? ?????? ?? ???? ??? ?? ??? ??????? ?? ???? ?? ???? ??? ? ??? ????.

    关键词： TG-142,Linear accelerator,NSSC Notification,Quality assurance

    更新于2025-09-23 15:23:52

  • [IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - High-Accuracy Phase-Compensating System Design Using Successively Linearized Constraints

    摘要： This paper develops a new iterative algorithm for the design of an all-pass phase-compensating filter (AP-PCF). This design algorithm employs the linear programming method through successively linearizing the nonlinear constraints as linear ones, and the AP-PCF is designed using the minimax criterion. The resulting AP-PCF is useful in the compensation of phase distortions of a variety of nonlinear-phase digital systems including digital communication channels. The basic idea of this design algorithm is to successively convert the nonlinear design constraints into linear ones and thus the design problem becomes a linear optimization problem. Based on such a problem conversion, the obtained linear optimization problem can be easily solved. A computer simulation example is given for showing the accuracy enhancement.

    关键词： non-linear phase channel,phase-compensating filter,all-pass digital system,Digital communications

    更新于2025-09-23 15:23:52

  • [IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Series Expansions for Matrix Inverses

    摘要： Various convergent matrix series formulae for the inverse of positive definite matrices are derived starting from series expansions of a simple matrix exponential function. The structure of these series assures a stable numerical computation since successive terms of the series are obtained through a multiplication with a matrix whose condition becomes better and better as the computation progresses.

    关键词： solution of linear systems,matrix inverse

    更新于2025-09-23 15:23:52

  • The joint weight enumerator of an LCD code and its dual

    摘要： A binary linear code is called LCD if it intersects its dual trivially. We show that the coefficients of the joint weight enumerator of such a code with its dual satisfy linear constraints, leading to a new linear programming bound on the size of an LCD code of given length and minimum distance. In addition, we show that this polynomial is, in general, an invariant of a matrix group of dimension 4 and order 12. Also, we sketch a Gleason formula for this weight enumerator.

    关键词： LCD code,Linear programming bounds,Linear binary code

    更新于2025-09-23 15:22:29

  • [IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Supporting Low-Latency Applications through Hybrid Cost-Optimised Cloudlet Placement

    摘要： Low-latency applications such as augmented reality, cognitive assistance, and context-aware computation are better supported by augmenting cloud networks with cloudlet enabled edge computing solution. This overcomes the high-transmission latency arising from the edge devices in the access segment to cloud servers located in the core. In this talk, we will review our recently proposed hybrid cost-optimization framework for optimal cloudlet placement over existing passive optical access networks, subject to capacity and latency constraints. In our work, we formulate a mixed-integer non-linear program to identify ideal locations (either at the central office (CO), remote node (RN), or in the field) for cloudlet placement over three deployment areas of differing population densities. Our results point to the fact that the installation of more RN and CO-located cloudlets will yield an improved cost optimal solution than the installation of field cloudlets alone, and that the percentage of the incremental energy budget arising from the installation of cloudlets are low.

    关键词： non-linear mixed-integer programming,passive optical access network,cloud computing,low-latency,Tactile Internet,cloudlets,cost-optimization

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - A widely linear MMSE RFID receiver with multi-antenna for physical layer collision recovery

    摘要： In this paper, a novel widely linear minimum-mean-square-error (MMSE) anti-collision receiver for passive ultra high frequency (UHF) multi-antenna radio-frequency identification (RFID) systems is proposed. By establishing that real-world tag signals are essentially noncircular in the complex filed, the proposed widely linear estimator is proven to have better performance in recovering data from collision when compared with its linear counterpart. Simulations on tags in conflicting response is conducted, justifying the performance advantages of the proposed receiver over the conventional linear one.

    关键词： radio-frequency identification (RFID),widely linear MMSE,signal recovery,anti-collision,multi-antenna

    更新于2025-09-23 15:22:29

  • A novel discriminant multiscale representation for ear recognition

    摘要： This paper proposes a novel representation for ear recognition. It introduces a new alternative of binarised statistical image features based on multiscale framework. The proposed representation allows capturing the image content at multiple resolutions. The recognition accuracy can be enhanced by the following steps. First, for a given ear image, a set of multiscale response images are derived from the bank of binarised statistical image features (B-BSIF) filter. Second, the obtained response images are summarised by concatenating their histograms, which are obtained at each scale. Finally, a discriminative ear image representation is build by projecting the above mentioned histograms into a linear discriminant analysis subspace. The proposed representation is applied on three public databases: IIT Delhi-1, IIT Delhi-2 and USTB. The obtained recognition accuracy confirms its performance than the recent existing methods.

    关键词： multi-resolution analysis,ear recognition,B-BSIF,WLDA,K-NN,whitened linear discriminant analysis

    更新于2025-09-23 15:22:29

  • UHD 3D medical system of small‐ and medium‐sized monitor

    摘要： With the development of ultra-high definition (UHD) display technology and stereoscopic 3D display technology, 3D ultra-high monitor will help surgeons obtain the spatial hierarchy of internal tissues, identify tissue surfaces and blood vessels clearly, locate the focus precisely and reduce surgery time. Compared with normal 2D medical monitors, 3D medical monitors will lose more brightness because of the 3D application, so it is necessary to design a high-brightness backlight system to guarantee the display stability and the accuracy of the diagnosis. This paper presents a novel processing system for 4K UHD 3D medical monitor with the architecture combined with universal SOC (system on a chip) and specialized FPGA (field programmable gate array). A hardware system is designed with high efficiency and reliable brightness stability control for small- and medium-sized monitors. Furthermore, we analyze the two dimming modes of linear dimming and PWM dimming for a better application in medical monitor.

    关键词： medical monitor,PWM dimming,3D,linear dimming,brightness stability

    更新于2025-09-23 15:22:29

  • [IEEE 2018 2nd International Conference on Telematics and Future Generation Networks (TAFGEN) - Malaysia (2018.7.24-2018.7.26)] 2018 2nd International Conference on Telematics and Future Generation Networks (TAFGEN) - Modelling of Different Types of SOA Characteristics

    摘要： An investigation of gain, optical power, and amplified spontaneous emission (ASE) noise characteristics of different types of semiconductor optical amplifier (SOA) operating in the conventional (C-) band is carried out. The types of SOAs include linear, nonlinear and in-line SOA that are customized configuration through OptiSystem software. These SOAs are further simulated in MATLAB using a numerical steady-state model to determine and evaluate their performance. The results showed that the linear SOA has the most ideal and distinct characteristics, as compared to the nonlinear and in-line SOAs rendering it more suitable as gain medium in the multiwavelength fiber laser (MWFL) application.

    关键词： modelling,linear and nonlinear types,semiconductor optical amplifier,multiwavelength fiber laser

    更新于2025-09-23 15:22:29