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| 1 | ROC曲线在临床医学诊断实验中的应用显示文摘随着先进医学技术的迅猛发展,各种新诊断试验层出不穷,但并不是每一种新诊断试验肯定比旧试验好。如果医学工作者,特别是临床医生,能够掌握一些评价与解释诊断试验的有关知识,及时取舍或灵活运用新的诊断试验,可以更好地为患者服务。为了进一步推广receiver operating characteristic(ROC)曲线分析方法的应用,本文首先介绍诊断实验的相关慨念,ROC曲线分析的定义、原理及分类,ROC曲线曲线下面积(AUC)及其最佳工作点的确定,然后用SPSS软件具体说明其应用。 | 王敬瀚 | 2008 | 中华高血压杂志2008，16，2： | 81 |
| 2 | A Survey on Terahertz Communications显示文摘With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications. | Zhi Chen Xinying Ma Bo Zhang Yaxin Zhang Zhongqian Niu Ningyuan Kuang Wenjie Chen Lingxiang Li Shaoqian Li | 2019 | China Communications2019，16，2： | 43 |
| 3 | S-wave crustal and upper mantle's velocity structure in the eastern Tibetan Plateau——Deep environment of lower crustal flow显示文摘A teleseismic profile consisting of 26 stations was deployed along 30°N latitude in the eastern Tibetan Plateau. By use of the inversion of P-wave receiver function, the S-wave velocity structures at depth from surface to 80 km beneath the profile have been determined. The inversion results reveal that there is significant lateral variation of the crustal structure between the tectonic blocks on the profile. From Linzhi north of the eastern Himalayan Syntaxis, the crust is gradually thickened in NE direction; the crustal thickness reaches to the maximum value (~72 km) at the Bangong-Nujiang suture, and then decreased to 65 km in the Qiangtang block, to 57―64 km in the Bayan Har block, and to 40―45 km in the Sichuan Basin. The eastern segment of the teleseismic profile (to the east of Batang) coincides geographically with the Zhubalong-Zizhong deep seismic sounding profile carried out in 2000, and the S-wave velocity structure determined from receiver functions is consistent with the P-wave velocity structure obtained by deep seismic sounding in respect of the depths of Moho and major crustal interfaces. In the Qiangtang and the Bayan Har blocks, the lower velocity layer is widespread in the lower crust (at depth of 30―60 km) along the profile, while there is a normal velocity distribution in lower crust in the Sichuan Basin. On an average, the crustal velocity ratio (Poisson ratio) in tectonic blocks on the profile is 1.73 (σ = 0.247) in the Lhasa block, 1.78 (σ = 0.269) in the Banggong-Nujiang suture, 1.80 (σ = 0.275) in the Qiangtang block, 1.86 (σ = 0.294) in the Bayan Har blocks, and 1.77 (σ = 0.265) in the Yangtze block, respectively. The Qiangtang and the Bayan Har blocks are characterized by lower S-wave velocity anomaly in lower crust, complicated Moho transition, and higher crustal Poisson ratio, indicating that there is a hot and weak medium in lower crust. These are considered as the deep environment of lower crustal flow in the eastern Tibetan Plateau. Flowage of the ductile material in lower crust may be attributable to the variation of the gravitational potential energy in upper crust from higher on the plateau to lower off plateau. | Paul SILVER | 2008 | Science China Earth Sciences2008，51，2： | 24 |
| 4 | Deep tectonic setting of the 2008 Wenchuan M_s8.0 earthquake in southwestern China―Joint analysis of teleseismic P-wave receiver functions and Bouguer gravity anomalies显示文摘Teleseismic P-wave receiver functions at 20 broadband seismic stations in the Longmenshan fault zone (LMFZ) and its vicinity were extracted, and the crustal thickness and the P- and S-wave velocity ratio were calculated by use of the H-k stacking algorithm. With the results as constraints, the S-wave ve-locity structures beneath each station were determined by the inversion of receiver functions. The crustal structure of the Rear-range zone is similar to that of the Songpan-Garze Block, whereas the velocity structure of the Fore-range zone resembles that of Sichuan Basin, implying that the Central Principal Fault of LMFZ is the boundary between the eastern Tibetan Plateau and the Yangtze Block. Lower velocity zone exists in lower crust of the Songpan-Garze Block and the central-southern seg-ment of the Rear-range zone, which facilitates the detachment of the material in upper and middle crust. Joint analysis of the receiver functions and the Bouguer gravity anomalies supports the thesis on the detachment-thrust mode of the LMFZ. A double-detachment pattern is suggested to the tectonic setting in the Songpan-Garze Block. The upper detachment occurs at the depth of 10-15 km, and represents a high-temperature ductile shear zone. There is a lower detachment at the depth of about 30 km, below which the lower crust flow exists in the eastern Tibetan Plateau. Interpretation of the Bouguer gravity anomalies indicates that the Sichuan Basin is of higher density in upper and middle crust in compari-son with that of the Songpan-Garze Block. The LMFZ with higher density is the result from the thrusting of the Songpan-Garze Block over the Sichuan Basin. In the lower crust, higher P velocity and higher density in the Sichuan Basin are related to more rigid material, while lower S velocity and lower density in the Songpan-Garze Block are related to the softened and weakened material. The higher density block beneath the Sichuan Basin obstructs the eastward flow of lower crustal material from the Tibetan Plateau, which is driven by the compression of northward movement of Indian Plate. The eastward movement of upper and middle crustal material is also obstructed by the rigid Yangtze Block, resulting in the stress concentrated and accumulated along the LMFZ. When the stress releases sharply, the Wenchuan Ms8.0 earthquake occurs. | LOU Hai1, WANG ChunYong1, L ZhiYong2, YAO ZhiXiang1, DAI ShiGui2 & YOU HuiChuan1 1 Institute of Geophysics, China Earthquake Administration, Beijing 100081, China 2 Earthquake Administration of Sichuan Province, Chengdu 610041, China | 2009 | Science China Earth Sciences2009，52，2： | 21 |
| 5 | Shear wave velocity structure of the crust and upper mantle underneath the Tianshan orogenic belt显示文摘From April, 2003 to September, 2004, a passive broadband seismic array consisting of 60 stations was deployed over the Tianshan orogenic belt by State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration. Among them, 51 stations make up an about 500-km-long profile across the Tianshan Mountains from Kuytun to Kuqa. The receiver function profile and S-wave velocity structure of the crust and upper mantle down to 100 km deep are obtained by using the re-ceiver function method (Liu et al. 1996, 2000). The main results can be summarized as follows: (1) A clear mountain root does not exist beneath the Tianshan Mountains, and the crust-mantle boundaries underneath the stations mostly have transitional structures. This implies that the material differentia-tion between the crust and mantle is not yet accomplished and the orogenic process is still going on. (2) The crust beneath the Tianshan Mountains has laterally blocked structures in direction perpendicular to the mountain strike, and the crust-mantle boundary has a clear dislocation structure. Both of them correspond to each other. (3) The offsets of the Moho discontinuity are highly correlated to the tectonic borders on the surface and that corresponding to the frontal southern Tianshan fault reaches to 14 km. This manifests that large vertical divergent movement took place between different blocks. This sup-ports the discontinuous model of the Tianshan orogeny, and the Tarim block subduction is restricted only to the southern side of the South Tianshan. (4) Inside the upper and middle crust of the Tianshan Mountains exist several low-velocity bodies correlated with high seismicity located on the moun-tain-basin jointures on both sides of the mountain and between different blocks, and the low-velocity bodies on the mountain-basin jointures are inclined obviously to the mountain. This implies that the low-velocity bodies may be correlated closely to the thrust and subduction of the basins on both sides of the mountain, the splicing of adjacent blocks and the fast uplift of the Tianshan Mountains. | LI Yu LIU QiYuan CHEN JiuHui LI ShunCheng GUO Biao LAI YuanGen | 2007 | Science China Earth Sciences2007，50，3： | 16 |
| 6 | Crustal thicknesses and Poisson's ratios beneath the Chuxiong-Simao Basin in the Southeast Margin of the Tibetan Plateau显示文摘In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is time-corrected.Results show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and northeast.The apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan Plateau.Relatively thin crustal thickness in the zone between Chuxiong City and the Red River Fault indicates possible uplift of mantle in this area.The positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust thickening.Comparison of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers. | ZiQi Zhang Yuan Gao | 2019 | Earth and Planetary Physics2019，3，1： | 15 |
| 7 | The Qitai radio telescope显示文摘This study presents a general outline of the Qitai radio telescope(QTT)project.Qitai,the site of the telescope,is a county of Xinjiang Uygur Autonomous Region of China,located in the east Tianshan Mountains at an elevation of about 1800 m.The QTT is a fully steerable,Gregorian-type telescope with a standard parabolic main reflector of 110 m diameter.The QTT has adopted an umbrella support,homology-symmetric lightweight design.The main reflector is active so that the deformation caused by gravity can be corrected.The structural design aims to ultimately allow high-sensitivity observations from 150 MHz up to115 GHz.To satisfy the requirements for early scientific goals,the QTTwill be equipped with ultra-wideband receivers and large field-of-view multi-beam receivers.A multi-function signal-processing system based on RFSo C and GPU processor chips will be developed.These will enable the QTT to operate in pulsar,spectral line,continuum and Very Long Baseline Interferometer(VLBI)observing modes.Electromagnetic compatibility(EMC)and radio frequency interference(RFI)control techniques are adopted throughout the system design.The QTT will form a world-class observational platform for the detection of lowfrequency(nano Hertz)gravitational waves through pulsar timing array(PTA)techniques,pulsar surveys,the discovery of binary black-hole systems,and exploring dark matter and the origin of life in the universe.The QTT will also play an important role in improving the Chinese and international VLBI networks,allowing high-sensitivity and high-resolution observations of the nuclei of distant galaxies and gravitational lensing systems.Deep astrometric observations will also contribute to improving the accuracy of the celestial reference frame.Potentially,the QTT will be able to support future space activities such as planetary exploration in the solar system and to contribute to the search for extraterrestrial intelligence. | Na Wang Qian Xu Jun Ma Zhiyong Liu Qi Liu Hailong Zhang Xin Pei Maozheng Chen Richard N.Manchester Kejia Lee Xingwu Zheng Hans J.Kärcher Wulin Zhao Hongwei Li Dongwei Li Martin Süss Matthias Reichert Zhongyi Zhu Congsi Wang Mingshuai Li Rui Li Ning Li Guljaina Kazezkhan Wenming Yan Gang Wu Lang Cui Ming Zhang Haitao Li | 2023 | Science China(Physics,Mechanics & Astronomy)2023，66，8： | 14 |
| 8 | Reduced hemoglobin and increased C-reactive protein are associated with upper gastrointestinal bleeding显示文摘AIM: To investigate the early upper gastrointestinal endoscopy(endoscopy) significantly reduces mortality resulting from upper gastrointestinal(GI) bleeding. METHODS: Upper GI bleeding was defined as 1a, 1b, 2a, and 2b according to the Forrest classification. The hemoglobin(Hb), and C-reactive protein(CRP) were examined at around the day of endoscopy and 3 mo prior to endoscopy. The rate of change was calculated as follows:(the result of blood examination on the day of endoscopy- the results of blood examination 3 mo prior to endoscopy)/(results of blood examination 3 mo prior to endoscopy). Receiver operating characteristic curves were created to determine threshold values. RESULTS: Seventy-nine men and 77 women were enrolled. There were 17 patients with upper GI bleeding: 12 with a gastric ulcer, 3 with a duodenal ulcer, 1 with an acute gastric mucosal lesion, and 1 with gastric cancer. The area under the curve(AUC), threshold, sensitivity, and specificity of Hb around the day of endoscopy were 0.902, 11.7 g/dL, 94.1%, and 77.1%, respectively, while those of CRP were 0.722, 0.5 mg/dL, 70.5%, and 73%, respectively. The AUC, threshold, sensitivity, and specificity of the rate of change of Hb were 0.851,-21.3%, 76.4%, and 82.6%, respectively, while those of CRP were 0.901, 100%, 100%, and 82.5%, respectively. CONCLUSION: Predictors for upper GI bleeding were Hb < 11.7 g/dL, reduction rate in the Hb > 21.3% and an increase in the CRP > 100%, 3 mo before endoscopy. | Minoru Tomizawa Fuminobu Shinozaki Rumiko Hasegawa Akira Togawa Yoshinori Shirai Noboru Ichiki Yasufumi Motoyoshi Takao Sugiyama Shigenori Yamamoto Makoto Sueishi | 2014 | World Journal of Gastroenterology2014，20，5： | 13 |
| 9 | Dislocation structure of the crust-mantle boundary and low-velocity body within the crust beneath the Dabie Shan collision orogen显示文摘From April of 2001 to March of 2002, a passive seismic array experiment was car- ried out in the Dabie Shan and its adjacent region. In this experiment, totally 34 broadband seismic stations were deployed along a profile across the Dabie Shan orogen and North-China platform. This profile is about 500 km long from Cuilin (34°40′N, 114°49′E), Henan Province, to Dajipu (30°20′N, 115°03′E), Hubei Province. The space between stations is about 3?8 km in the Dabie Shan orogenic belt and about 15?20 km in other area. The receiver function profile and S-wave velocity structure of the crust and upper mantle down to 100 km depth along the profile are investigated in terms of the receiver function techniques (Liu et al., 1996, 2000). Our results show that the crust beneath the Dabie Shan orogen has an obviously asymmetric blocked structure in the direction perpendicular to the mountain strike. The maximal crustal thickness reaches to 42 km. The crust-mantle boundary has a dislocation structure correlated to the crustal blocks and the largest offset reaches to 8 km. In the kernel of the orogen exists a low-velocity body inside the crust, which is separated into two parts corresponding to the South Dabie and North Dabie on the surface, respectively. Probably a vertical divergent movement between both took place in history. The crust below this low-velocity area has a positive gradient velocity structure with the depth, and the upper mantle down to the depth of 70 km has the lower S-wave velocity than its both sides. Beneath the Dabie Shan, however, a high-velocity anomaly exists in the upper mantle below 70 km. | LIU Qiyuan1, Rainer Kind2, CHEN Jiuhui1, YUAN Xiaohui2, LI Shuncheng1, GUO Biao1, Kurt Wylegalla2 & LAI Yuangen1 1. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China 2. GeoForschungZentrum Potsdam, Telegrafenburg A17, Potsdam, D-14473, Germany | 2005 | Science China Earth Sciences2005，48，7： | 12 |
| 10 | Non-Orthogonal Multiple Access(NOMA) for Future Downlink Radio Access of 5G显示文摘Multiple access(MA) technology is of most importance for 5G. Non-orthogonal multiple access(NOMA) utilizing power domain and advanced receiver has been considered as a promising candidate MA technology recently. In this paper, the NOMA concept is presented toward future enhancements of spectrum efficiency in lower frequency bands for downlink of 5G system. Key component technologies of NOMA are presented and discussed including multiuser transmission power allocation, scheduling algorithm, receiver design and combination of NOMA with multi-antenna technology. The performance gains of NOMA are evaluated by system-level simulations with very practical assumptions. Under multiple configurations and setups, the achievable system-level gains of NOMA are shown promising even when practical considerations were taken into account. | LI Anxin LAN Yang CHEN Xiaohang JIANG Huiling | 2015 | China Communications2015，12，S1： | 12 |
| 11 | Impact of one satellite outage on ARAIM depleted constellation configurations显示文摘Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted constellations is a practical problem that needs to be faced and researched further. It is a shortcut that improves the availability in position domain whose key idea is to replace the conventional least squares process with a non-least-squares estimator to lower the integrity risk in exchange for a slight increase in nominal position error. The contributions given in this paper include two parts: First, the impacts of one satellite outage on different constellations are analyzed and compared. The conclusion is that GPS is more sensitive and vulnerable to one satellite outage. Second, a constellation weighted ARAIM(CW-ARAIM)position estimator is proposed. The position solution is replaced by a constellation weighted average solution to eliminate the constellation difference. The new solution will move close to the constellation solutions with respect to the accuracy requirement. The simulation results under baseline GPS and Galileo dual-constellation show that the one GPS satellite outage will knock the availability from 91% to only 50%. The performance remains stable with one Galileo satellite outage. With the assistance of the CW-ARAIM method, the availability can increase from 50% to more than80% under depleted GPS configurations. Even without any satellite outage, the proposed method can effectively improve the availability from 91.29% to 98.75%. The test results under optimistic constellations further verify that a balanced constellation is more important than more satellites on orbit and the superiority of CW-ARAIM method is still effective. | Qian MENG Jianye LIU Qinghua ZENG Shaojun FENG Rui XU | 2019 | Chinese Journal of Aeronautics2019，32，4： | 11 |
| 12 | Crust and uppermost mantle structure of the Ailaoshan-Red River fault from receiver function analysis显示文摘S-wave velocity structure beneath the Ailaoshan-Red River fault was obtained from receiver functions by using teleseismic body wave records of broadband digital seismic stations. The average crustal thickness, Vp/Vs ratio and Poisson’s ratio were also estimated. The results indicate that the interface of crust and mantle beneath the Ailaoshan-Red River fault is not a sharp velocity discontinuity but a characteristic transition zone. The velocity increases relatively fast at the depth of Moho and then increases slowly in the uppermost mantle. The average crustal thickness across the fault is 36―37 km on the southwest side and 40―42 km on the northeast side, indicating that the fault cuts the crust. The relatively high Poisson’s ratio (0.26―0.28) of the crust implies a high content of mafic materials in the lower crust. Moreover, the lower crust with low velocity could be an ideal position for decoupling between the crust and upper mantle. | XU Mingjie1, WANG Liangshu1, LIU Jianhua2, ZHONG Kai1, LI Hua1, HU Dezhao1 & XU Zhen1 1. Department of Earth Sciences, Nanjing University, Nanjing 210093, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China | 2006 | Science China Earth Sciences2006，49，10： | 10 |
| 13 | Receiver function analysis for seismic structure of the crust and uppermost mantle in the Liupanshan area, China显示文摘A portable broadband seismic array was deployed from the northeast Tibetan Plateau to the southwest Ordos block, China. The seismic structure of the crust and uppermost mantle of the Liupanshan area is obtained using receiver function analysis of teleseismic body waves. The crustal thickness and Poisson's ratios are estimated by stacking the weighted amplitudes of receiver functions. Our results reveal complex seismic phases in the Liupanshan area, implying intense deformation at the boundary between the Tibetan Plateau and the Ordos block. The average crustal thickness is 51.5 km in the northeast Tibetan Plateau, 53.5 km in the Liupan Mountain and 50 km in the southwest Ordos block, resulting in a concave Moho beneath the Liupan Mountain. The Poisson's ratio of the Liupanshan area varies between 0.27-0.29, higher than the value of 0.25-0.26 to the east and west of the Liupan Mountain, suggesting partial melting in the lower crust. The variance in Poisson's ratio across the Liupan Mountain indicates notable changes in the crustal composition and mechanical properties, which may be formed by the northeastward flow of the Tibetan lower crust during the India-Eurasia collision. | TONG WeiWei WANG LiangShu MI Ning XU MingJie LI Hua YU DaYong LI Cheng LIU ShaoWen LIU Mian Eric SanDvol | 2007 | Science China Earth Sciences2007，50，z2： | 9 |
| 14 | Application of isolation forest to extract multivariate anomalies from geochemical exploration data显示文摘Constructing a statistical model that best fits the background is a key step in geochemical anomaly identification. But the model is hard to be constructed in situations where the sample population has unknown and/or complex distribution. Isolation forest is an outlier detection approach that explicitly isolates anomaly samples rather than models the population distribution. It can extract multivariate anomalies from huge-sized high-dimensional data with unknown population distribution. For this reason,we tentatively applied the method to identify multivariate anomalies from the stream sediment survey data of the Lalingzaohuo district,an area with a complex geological setting,in Qinghai Province in China. The performance of the isolation forest algorithm in anomaly identification was compared with that of a continuous restricted Boltzmann machine. The results show that the isolation forest model performs superiorly to the continuous restricted Boltzmann machine in multivariate anomaly identification in terms of receiver operating characteristic curve,area under the curve,and data-processing efficiency. The anomalies identified by the isolation forest model occupy 19% of the study area and contain 82% of the known mineral deposits,whereas the anomalies identified by the continuous restricted Boltzmann machine occupy 35% of the study area and contain 88% of the known mineral deposits. It takes 4. 07 and 279. 36 seconds respectively handling the dataset using the two models. Therefore,isolation forest is a useful anomaly detection method that can quickly extract multivariate anomalies from geochemical exploration data. | WU Wei CHEN Yongliang | 2018 | Global Geology2018，21，1： | 9 |
| 15 | The upper mantle structure of the Tibetan Plateau and its implication for the continent-continent collision显示文摘The upper mantle structures of Himalayas-Tibet have been obtained from the mi-gration of receiver functions of the teleseismic events recorded by INDEPTH-III. The result of migration imaging shows a dipping interface subducting northward from the depth of 100 km to the 410-km discontinuity underneath southern Tibet. It indicates that the lithospheric mantle of the Indian continent had been detached from the crust and deeply subducted to the upper mantle of Eurasia during the Indo-Eurasian collision. This kind of continent-continent collision process is fundamentally different from the oceanic collision. | WU Qingju1, ZENG Rongsheng1 & ZHAO Wenjin2 1. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China 2. Institute of Geology, China Academy of Geological Sciences, Beijing 100037, China | 2005 | Science China Earth Sciences2005，48，8： | 7 |
| 16 | NYFR output pulse radar signal TOA analysis using extended Fourier transform and its TOA estimation显示文摘Nyquist folding receiver(NYFR) is a typical wideband analog-to-information architecture. Focusing on the noncooperative receiving, the pulse radar signal intercepted by the NYFR in time domain is analyzed. The NYFR outputs under different input conditions are investigated based on the extended Fourier transform(EFT) and the sampling theorem. Combining with the characteristic of the NYFR output in time domain, a new time of arrival(TOA) estimation method based on the energy envelope and the wavelet transform is proposed. The proposed estimation method can be adapted for the non-cooperative situation. It has no requirement for prior information to determine the threshold and is not necessary to transform the signal into baseband. Simulation results prove the correctness of the NYFR output expressions and show the efficacy of the proposed estimation method. | Zhaoyang Qiu Pei Wang Jun Zhu Bin Tang | 2017 | Journal of Systems Engineering and Electronics2017，28，2： | 6 |
| 17 | Artificial intelligence on diabetic retinopathy diagnosis: an automatic classification method based on grey level co-occurrence matrix and naive Bayesian model显示文摘AIM: To develop an automatic tool on screening diabetic retinopathy(DR) from diabetic patients.METHODS: We extracted textures from eye fundus images of each diabetes subject using grey level co-occurrence matrix method and trained a Bayesian model based on these textures. The receiver operating characteristic(ROC) curve was used to estimate the sensitivity and specificity of the Bayesian model.RESULTS: A total of 1000 eyes fundus images from diabetic patients in which 298 eyes were diagnosed as DR by two ophthalmologists. The Bayesian model was trained using four extracted textures including contrast, entropy, angular second moment and correlation using a training dataset. The Bayesian model achieved a sensitivity of 0.949 and a specificity of 0.928 in the validation dataset. The area under the ROC curve was 0.938, and the 10-fold cross validation method showed that the average accuracy rate is 93.5%.CONCLUSION: Textures extracted by grey level cooccurrence can be useful information for DR diagnosis, and a trained Bayesian model based on these textures can be an effective tool for DR screening among diabetic patients. | Kai Cao Jie Xu Wei-Qi Zhao | 2019 | International Journal of Ophthalmology(English edition)2019，12，7： | 6 |
| 18 | A new method of ionospheric-free hybrid differential positioning based on a double-antenna CAPS receiver显示文摘Chinese Area Positioning System (CAPS) is a transmitted satellite navigation system moved by the Chinese Academy of Sciences. Three basic modes of navigation and positioning with CAPS are given, and then a comparative analysis is made in this paper. In terms of the principle that the ionospheric delay is at an inverse ratio to the frequency square, a new ionospheric-free positioning method based on a double-antenna CAPS receiver is put forward. Then the hybrid differential observations and the solving equations and algorithms for one epoch and multi epochs are deduced according to the basic principle of the method. The method may remove the global errors in signal emission, propagation, transmission and receiving (e.g., ionospheric delay, hardware delay, and clock error). So it is very convenient for the single-epoch solution and multi-epoch navigation and positioning, and may efficiently improve the precision of real time CAPS navigation. Furthermore, the method can be used not only for the geometric orbit determination of CAPS GEO and IGSO satellites and the navigation and positioning, but also for the estimation of the tropospheric zenith delay, which is useful for the study of water vapor changes in the atmosphere. Polynomials are used in this method to express the tropospheric zenith delay and CAPS satellite orbits within the limited time interval, which reduces the num- ber of unknown parameters and thus speeds the computation. | GUO JinYun1,2, HAN YanBen1 & CHANG XiaoTao3 1 National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2 College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266510, China 3 Chinese Academy of Surveying and Mapping, Beijing 100039, China | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，3： | 5 |
| 19 | Numerical investigation of thermal performance of heat loss of parabolic trough receiver显示文摘Based on the analysis of computation methods and heat transfer processes of the parabolic trough receiver running in steady state, a two-dimensional empirical model was developed to investigate the thermal performance of heat loss of parabolic trough receivers under steady state equilibrium. A numerical simulation was conducted for the parabolic trough receiver involved in a literature. Comparisons between numerical and experimental results show that the empirical model is accurate enough and can be used to investigate the thermal performance of heat loss of parabolic trough receivers. The thermal performance of heat loss of UVAC3 and the new-generation UVAC2008 was investigated respectively. The simulation results show that selective coatings and annular pressure influence the thermal performance of heat loss of parabolic trough receivers greatly, wind velocity influences the thermal performance of thermal loss of parabolic trough receivers only a little in contrast with the emittance of selective coatings and air pressure in annular space. And the thermal performance of thermal loss of the new-generation parabolic trough receiver has been improved in a large amount. | Modibo Kane TRAORE | 2010 | Science China(Technological Sciences)2010，53，2： | 5 |
| 20 | 诊断能力评价的统计学方法——ROC分析显示文摘ROC是Receiver Operating Characteristic的缩写,目前ROC分析已经被广泛应用于临床诊断研究中,特别是在针对定量资料的诊断能力评价中,发挥了重要的作用。在诊断能力分析中,通常从经过“金标准”诊断方法确诊的患者和非患者人群中各抽取一个样本,并对受试者完成试验诊断方法的诊断检查,通过与金标准诊断结果的比较,计算灵敏度、 | 李雪迎 | 2011 | 中国介入心脏病学杂志2011，19，3： | 5 |
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