中国科学院机构知识库网格系统: 检索

Fishery catch is affected by geographic expansion, fishing down food webs and climate change in Aotearoa, New Zealand 期刊论文 OAI收割
PEERJ, 2023, 卷号: 11, 页码: 27
作者: Lavin, Charles Patrick; Pauly, Daniel; Dimarchopoulou, Donna; Liang, Cui; Costello, Mark John

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收藏 | 浏览/下载：10/0 | 提交时间：2023/11/30

New Zealand Fisheries Ocean warming Mean trophic level Mean temperature of the catch Fishing down marine food webs Fishing-in-Balance index

Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT 期刊论文 OAI收割
Astrophysics and Space Science, 2020, 卷号: 365, 页码: 158
作者: HXMT

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收藏 | 浏览/下载：51/0 | 提交时间：2022/02/08

Insight-HXMT Geant4 simulation Background observation Astrophysics - Instrumentation and Methods for Astrophysics Abstract: Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, in-orbit backgrounds of these three telescopes had been estimated through Geant4 simulation, in order to investigate the instrument performance and the achievement of scientific goals. In this work, these simulated backgrounds are compared with in-orbit observations. Good agreements are shown for all three telescopes. For HE, (1) the deviation of the simulated background rate after two years of operation in space is 5 % from the observation (2) the total background spectrum and the relative abundance of the 67 keV line show long-term increases both in simulations and observations. For ME, (1) the deviation of simulated background rate is within 15 % from the observation, and (2) there are no obvious long-term increase features in the background spectra of simulations and observations. For LE, the background level given by simulations is also consistent with observations. The consistencies of these comparisons validate that the Insight-HXMT mass model, i.e., space environment components and models adopted, physics processes selected, and detector constructions built, is reasonable. However, the line features at 7.5 and 8.0 keV, which are obvious in the observed spectra of LE, are not evident in simulations. This might result from uncertainties in the LE constructions.

A sub-pixel extraction method for the center of the circular structure from spot array calibration target (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者: Liu Y.; Zhang T.; Yang H.; Gao X.; Liu Y.

收藏 | 浏览/下载：75/0 | 提交时间：2013/03/25

The imaging measurement system must be calibrated before application. In calibration procedure sub-pixel center extraction is the crucial step for the final accuracy. In this paper a new sub-pixel extraction method is proposed. Edge detection at pixel level is obtained using LOG operator then sub-pixel edge detection is realized using the Facet model. Finally the least squares ellipse fitting is operated on the sub-pixel edge to determine the sub-pixel center. Experiment on a series of simulated images indicates that this algorithm is able to realize the center location accuracy of 0.01-0.02 pixel and meets the requirement of sub-pixel level. (2012) Trans Tech Publications Switzerland.

Systemic model for software cost analyzing and optimizing (EI CONFERENCE) 会议论文 OAI收割
2011 IEEE 3rd International Conference on Communication Software and Networks, ICCSN 2011, May 27, 2011 - May 29, 2011, Xi'an, China
作者: Zhanglei; Zhanglei

收藏 | 浏览/下载：60/0 | 提交时间：2013/03/25

Constructing low cost software is the main method to save energy source in computer science. Traditional research about software cost is only in one level. They are partial in some degree. To settle the problem a systemic model for software cost analyzing and optimizing is proposed in this paper. In this systemic model software cost analyzing and optimizing are from low level to high level. It can provide all-sided analyzing and optimizing in instruction source code level and structure level. Some suggestions and methods are given in each level to enrich the model. The systemic model expresses a new point of view in software cost. 2011 IEEE.

Timing generator of scientific grade CCD camera and its implementation based on FPGA technology (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
作者: Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

The Timing Generator's functions of Scientific Grade CCD Camera is briefly presented: it generates various kinds of impulse sequence for the TDI-CCD video processor and imaging data output acting as the synchronous coordinator for time in the CCD imaging unit. The IL-E2TDI-CCD sensor produced by DALSA Co.Ltd. use in the Scientific Grade CCD Camera. Driving schedules of IL-E2 TDI-CCD sensor has been examined in detail the timing generator has been designed for Scientific Grade CCD Camera. FPGA is chosen as the hardware design platform schedule generator is described with VHDL. The designed generator has been successfully fulfilled function simulation with EDA software and fitted into XC2VP20-FF1152 (a kind of FPGA products made by XILINX). The experiments indicate that the new method improves the integrated level of the system. The Scientific Grade CCD camera system's high reliability stability and low power supply are achieved. At the same time the period of design and experiment is sharply shorted. 2010 Copyright SPIE - The International Society for Optical Engineering.

Sort optimization algorithm of median filtering based on FPGA (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Machine Vision and Human-Machine Interface, MVHI 2010, April 24, 2010 - April 25, 2010, Kaifeng, China
作者: Li S.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The traditional sorting algorithm of median filtering is optimized according to the hardware structure features of FPGA. FPGA is used to acquire the data parallelly for comparing the data of the same column in the median filtering window. Comparing results shared by adjacent filter window are saved temporarily to match the new round of median filtering by using FPGA internal resources. This method can reduce the comparing times from current 21 down to 13 and improve the algorithm efficiency nearly 40%.The experimental results prove that the optimized algorithm can filter a 1K1K gray-level image in about 20ms which ensure the proposed algorithm can be applied in the real-time image median filtering system. 2010 IEEE.

A new research of sub-pixel level accuracy of TDICCD remote sensing image registration (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: He B.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

In the field of remote sensing imaging TDICCD remote sensing images have a lot of their own characteristics such as high-resolution large amount of information less overlapping parts of pixels additional image blurring etc. Therefore there exist many difficulties especially in terms of high-accuracy registration of pairs of images. For that this paper presents two new pixel interpolation method for sub-pixel level registering images that allows for scaling translation and rotation. The proposed technique which is based on the maximization of the correlation coefficient function combines an efficient pixel-moving interpolation scheme with surface fitting which greatly reduces the overall computational cost. The accuracy of the algorithm is evaluated by calculating correlation coefficient of couples of points belonging to images transformed with preset factors and also comparing it to other sorts of methods. The experiment results show that the accuracy of registration reaches 0.01 pixels. 2010 IEEE.

Autocollimation form dual-frequency laser diffraction grating interferometer design and analysis (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Wang C.-G.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

Propose a new measurement system of autocollimation form laser grating heterodyne interferometer. Take grating diffraction and polarization optics as theoretical foundation second furthermore combined with electronics knowledge to analyze the system. First make use of autocollimation diffraction of grating measurement information obtained by dual-frequency laser belongs to ac signal the interferometer measurement system take grating pitch as measuring datum the structure is simple possess great gain and high signal-noise ratio therefore stable completely overcome the disadvantages of DC level drift caused by light intensity variation of single-frequency laser system can achieve nanometer resolution. 2010 IEEE. reduce the impact of environmental factors easy to install and debug measurement error is small

The registration of aerial infrared and visible images (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Educational and Information Technology, ICEIT 2010, September 17, 2010 - September 19, 2010, Chongqing, China
作者: Liu J.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

In order to solve the registration problem of different source image existed on aerial image fusion algorithms based on Particle Swarm Optimization (PSO) are applied as search strategy in this paper and Alignment Metric (AM) is used as judgment. This study has realized the different source image registration of infrared and visible light with high speed high accuracy and high reliability. Basically with little restriction of gray level properties a new alignment measure is applied which can efficiently measure the image registration extent and tolerate noise well. Even more the intelligent optimization algorithm - Particle Swarm Optimization (PSO) is combined to improve the registration precision and rate of infrared and visible light. Experimental results indicate that the study attains the registration accuracy of pixel level and every registration time is cut down over 40 percent compared to traditional method. The match algorithm based on AM solves the registration problem that greater differences between different source images are existed on gray and characteristic. At the same time the adoption of combining the intelligent optimization algorithms significantly improves the searching efficiency and convergence speed of the algorithms and the registration result has higher accuracy and stability which builds up solid foundation for different source image fusion. The method in this paper has a magnificent effect and is easy for application and very suitable for engineering use. 2010 IEEE.

An intelligent method for early design and decision of space payload (EI CONFERENCE) 会议论文 OAI收割
2010 1st IEEE International Conference on Progress in Informatics and Computing, PIC 2010, December 10, 2010 - December 12, 2010, Shanghai, China
作者: Han C.-S.; Wen M.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

This paper is concerned with the design and decision method of space payload in the early design phase. The objective is to develop a generalized intelligent framework to assist designers in designing space payload. A multi-level method is introduced which is based on the combination of case-based reasoning (CBR) multicriteria rough sets theory (MRST) and kernel-based self-organizing maps (KSOM). The first is CBR module which aims to help designers to obtain some similar cases of the new situation. The second is MRST module which can extract the decision rules of configuration seletion. The third is KSOM module which can reduce the variable range and design space of the space payload. The results demonstrate the effectiveness of the proposed design method. 2010 IEEE.