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Laparoscopic liver resection for hepatocellular carcinoma complicated with significant portal hypertension:A propensity score-matched survival analysis 被引量:1
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作者 Zhang-You Guo Yuan Hong +2 位作者 Bing Tu Yao Cheng Xiao-Mei Wang 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2023年第4期358-365,共8页
Background: Significant portal hypertension(SPH) is a relative contraindication for patients with resectable hepatocellular carcinoma(HCC). However, increasing evidence indicates that liver resection is feasible for H... Background: Significant portal hypertension(SPH) is a relative contraindication for patients with resectable hepatocellular carcinoma(HCC). However, increasing evidence indicates that liver resection is feasible for HCC patients with SPH. Methods: HCC patients with cirrhosis who underwent laparoscopic liver resection(LLR) in two centers from January 2013 to April 2018 were included. Surgical and survival outcomes were analyzed to explore potential prognostic factors. Propensity score matching(PSM) analysis was performed to minimize bias. Results: A total of 165 patients were divided into two groups based on the presence(SPH, n = 76) or absence(non-SPH, n = 89) of SPH. Patients in the SPH group had longer operative time, more blood loss, and more advanced TNM stage than patients in the non-SPH group( P < 0.05). However, there were no significant differences in the postoperative 90-day mortality rate( n = 0), overall postoperative complications(47.4% vs. 41.6%, P = 0.455), Clavien-Dindo classification( P = 0.347), conversion to open surgery(9.2% vs. 6.7%, P = 0.557), or length of hospitalization(16 vs. 15 days, P = 0.203) between the SPH and non-SPH groups before PSM. Similar results were obtained after PSM. The 1-, 3-, and 5-year overall survival(OS) and recurrence-free survival rates in the SPH group were not significantly different from those in the non-SPH group both before and after PSM(log-rank P > 0.05). After PSM, alpha-fetoprotein(AFP) ≥ 400 μg/L [hazard ratio(HR) = 4.71, 95% confidence interval(CI): 2.69-8.25], ascites(HR = 2.18, 95% CI: 1.30-3.66), American Society of Anesthesiologists(ASA) classification(Ⅲ vs. Ⅱ)(HR = 2.13, 95% CI: 1.11-4.07) and tumor diameter > 5 cm(HR = 3.91, 95% CI: 2.02-7.56) independently predicted worse OS. Conclusions: LLR for patients with HCC complicated with SPH appears feasible at the price of increasing operative time and blood loss. AFP, ascites, ASA classification and tumor diameter may predict the prognosis of HCC complicated with SPH after LLR. 展开更多
关键词 Hepatocellular carcinoma significant portal hypertension Laparoscopic liver resection Propensity score matching analysis
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Significant wave height forecasts integrating ensemble empirical mode decomposition with sequence-to-sequence model
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作者 Lina Wang Yu Cao +2 位作者 Xilin Deng Huitao Liu Changming Dong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期54-66,共13页
As wave height is an important parameter in marine climate measurement,its accurate prediction is crucial in ocean engineering.It also plays an important role in marine disaster early warning and ship design,etc.Howev... As wave height is an important parameter in marine climate measurement,its accurate prediction is crucial in ocean engineering.It also plays an important role in marine disaster early warning and ship design,etc.However,challenges in the large demand for computing resources and the improvement of accuracy are currently encountered.To resolve the above mentioned problems,sequence-to-sequence deep learning model(Seq-to-Seq)is applied to intelligently explore the internal law between the continuous wave height data output by the model,so as to realize fast and accurate predictions on wave height data.Simultaneously,ensemble empirical mode decomposition(EEMD)is adopted to reduce the non-stationarity of wave height data and solve the problem of modal aliasing caused by empirical mode decomposition(EMD),and then improves the prediction accuracy.A significant wave height forecast method integrating EEMD with the Seq-to-Seq model(EEMD-Seq-to-Seq)is proposed in this paper,and the prediction models under different time spans are established.Compared with the long short-term memory model,the novel method demonstrates increased continuity for long-term prediction and reduces prediction errors.The experiments of wave height prediction on four buoys show that the EEMD-Seq-to-Seq algorithm effectively improves the prediction accuracy in short-term(3-h,6-h,12-h and 24-h forecast horizon)and long-term(48-h and 72-h forecast horizon)predictions. 展开更多
关键词 significant wave height wave forecasting ensemble empirical mode decomposition(EEMD) Seq-to-Seq long short-term memory
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Detection of Clinically Significant Warm Reactive Anti-A1 in a Post Red Blood Cells Transfusion Patient with Acute Lymphoblastic Leukemia
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作者 Ahmed Alharbi Alenazi Abdullah Mahal +14 位作者 Al Saqri Faisal Wasel Haya Alotaibi Abdulmohsen Hassan Jalal Shareefi Ahmed Almutairi Saleh Alharbi Abrar Almutairi Eiman Alzabaidi Waleed Almutariy Hiyam Alotaibi Rayyan Alfraidi Rawan Alahmadi Omar Alghamdi Abdullah Alotaibi Sarah 《Case Reports in Clinical Medicine》 2023年第6期180-188,共9页
The purpose of this article is to report that some anti-A1 that react at 37°C are IgG antibodies and are clinically significant, as they can cause the destruction of a proportion of A1 cells in vivo following the... The purpose of this article is to report that some anti-A1 that react at 37°C are IgG antibodies and are clinically significant, as they can cause the destruction of a proportion of A1 cells in vivo following the transfusion of red blood cells. Therefore, when a serum of an individual contains anti-A1, further testing of the plasma against group A1, A2, and O by referencing red blood cells and individual cells against anti-A1 lectin (Dolichos biflorus lectin) must be performed. Confirming the specificity of anti-A1 by referencing red blood cells is also important in selecting the appropriate blood for transfusion. ABO antibodies are naturally occurring and activate the complement cascade, making them more likely to cause severe transfusion reactions compared to antibodies to other RBC antigens. 展开更多
关键词 Anti-A1 Clinical significant Direct Antiglobulin Testing Anti-A1 Lectine Compatibility
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Detection rate of clinically insignificant prostate cancer ncreases with repeat prostate biopsies
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作者 Bumsoo Park Seong-Soo Jeon +4 位作者 Sung-Ho Ju Byong-Chang Jeong Seong-II Seo Hyun-Moo Lee Han-Yong Choi 《Asian Journal of Andrology》 SCIE CAS CSCD 2013年第2期236-240,I0007,共6页
To analyze if clinically insignificant prostate cancer (CIPC) is more frequently detected with repeat prostate biopsies, we retrospectively analyzed the records of 2146 men diagnosed with prostate cancer after one o... To analyze if clinically insignificant prostate cancer (CIPC) is more frequently detected with repeat prostate biopsies, we retrospectively analyzed the records of 2146 men diagnosed with prostate cancer after one or more prostate biopsies. The patients were divided into five groups according to the number of prostate biopsies obtained, e.g, group I had one biopsy, group 2 had two biopsies and group 3 had three biopsies. Of the 2146 patients diagnosed with prostate cancer, 1956 (91,1%), 142 (6.6%), 38 (1.8%), 9 (0.4%) and 1 (0.1%) men were in groups 1, 2, 3, 4 and 5, respectively. Groups 4 and 5 were excluded because of the small sample sizes. The remaining three groups (groups 1, 2 and 3) were statistically analyzed. There were no differences in age or prostate-specific antigen level among the three groups. CIPC was detected in 201 (10.3%), 28 (19.7%) and 9 (23.7%) patients in groups 1, 2 and 3, respectively (P〈O.O01). A multivariate analysis showed that the number of biopsies was an independent predictor to detect ClPC (0R=2.688 for group 2; 0R=4.723 for group 3). In conclusion, patients undergoing multiple prostate biopsies are more likely to be diagnosed with CIPC than those who only undergo one biopsy. However, the risk still exists that the patient could have clinically significant prostate cancer. Therefore, when counseling patients with regard to serial repeat biopsies, the possibility of prostate cancer overdiagnosis and overtreatment must be balanced with the continued risk of clinically significant disease. 展开更多
关键词 clinically insignificant prostate cancer (CIPC) clinically significant prostate cancer (CSPC) BIOPSY early detection ofcancer prostatic neoplasms
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The validation of HY-2 altimeter measurements of a significant wave height based on buoy data 被引量:7
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作者 WANG Jichao ZHANG Jie YANG Jungang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第11期87-90,共4页
HY-2 has been launched by China on August 16, 2011 which assembles multi-microwave remote sensing payloads in a body and has the ability of monitoring ocean dynamic environments. The HY-2 satellite data need to be cal... HY-2 has been launched by China on August 16, 2011 which assembles multi-microwave remote sensing payloads in a body and has the ability of monitoring ocean dynamic environments. The HY-2 satellite data need to be calibrated and validated before being put into use. Based on the in-situ buoys from the Nation- al Data Buoy Center (NDBC), Ku-band significant wave heights (SWH, hs) of HY-2 altimeter are validated. Eleven months of HY-2 altimeter Level 2 products data are chose from October 1, 2011 to August 29, 2012. Using NDBC 60 buoys yield 902 collocations for HY-2 by adopting collocation criteria of 30 min for tempo- ral window and 50 km for a spatial window. An overall RMS difference of the SWH between HY-2 and buoy data is 0.297 m. A correlation coefficient between these is 0.964. An ordinary least squares (OLS) regression is performed with the buoy data as an independent variable and the altimeter data as a dependent vari- able. The regression equation of hs is hs (HY-2)=0.891 × hs (NDBC)+0.022. In addition, 2016 collocations are matched with temporal window of 30 rain at the crossing points of HY-2 and Jason-2 orbits. RMS difference of Ku-band SWH between the two data sets is 0.452 m. 展开更多
关键词 ALTIMETER BUOY significant wave height VALIDATION regression analysis
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The validation of the significant wave height product of HY-2altimeter–primary results 被引量:7
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作者 CHEN Chuntao ZHU Jianhua +5 位作者 LIN Mingsen ZHAO Yili HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第11期82-86,共5页
The HY-2 satellite was successfully launched on 16 August 2011. The HY-2 significant wave height (SWH) is validated by the data from the South China Sea (SCS) field experiment, National Data Buoy Center (NDBC/ bu... The HY-2 satellite was successfully launched on 16 August 2011. The HY-2 significant wave height (SWH) is validated by the data from the South China Sea (SCS) field experiment, National Data Buoy Center (NDBC/ buoys and Jason-1/2 altimeters, and is corrected using a linear regression with in-situ measurements. Com- pared with NDBC SWH, the HY-2 SWH show a RMS of 0.36 m, which is similar to Jason- 1 and Jason-2 SWH with the RMS of 0.35 m and 0.37 m respectively; the RMS of corrected HY-2 SWH is 0.27 m, similar to 0.27 m and 0.23 m of corrected Jason-1 and Jason-2 SWH. Therefore the accuracy of HY-2 SWH products is close to that of Jason-1/2 SWH, and the linear regression function derived can improve the accuracy of HY-2 SWH products. 展开更多
关键词 ALTIMETER significant wave height VALIDATION linear regression CORRECTION root mean square
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Recent Significant Tornadoes in China 被引量:19
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作者 Ming XUE Kun ZHAO +2 位作者 Mingjung WANG Zhaohui LI Yongguang ZHENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第11期1209-1217,共9页
1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100(Fan and... 1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100(Fan and Yu,2015),even though both countries are located in a similar latitudinal zone of the Northern Hemisphere. 展开更多
关键词 LST Recent significant Tornadoes in China
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Validation of Chinese HY-2 satellite radar altimeter significant wave height 被引量:10
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作者 YE Xiaomin LIN Mingsen XU Ying 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第5期60-67,共8页
Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency (Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational signif... Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency (Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational significant wave height (SWH) for more than three years (October 1, 2011 to present).We validated along-track Ku-band SWH data of HY-2 satellite against National Data Buoy Center (NDBC) in-situ measurements over a time period of three years from October 1, 2011 to September 30, 2014, the root mean square error (RMSE) and mean bias of HY-2 SWH is 0.38 m and (-0.13±0.35) m, respectively. We also did cross validation against Jason-2 altimeter SWH data, the RMSE and the mean bias is 0.36m and (-0.22±0.28) m, respectively. In order to compare the statistical results between HY-2 and Jason-2 satellite SWH data, we validated the Jason-2 satellite radar altimeter along-track Ku-band SWH data against NDBC measurements using the same method. The results demonstrate the validation method in this study is scientific and the RMSE and mean bias of Jason-2 SWH data is 0.26 m and (0.00±0.26) m, respectively. We also validated both HY-2 and Jason-2 SWH data every month, the mean bias of Jason-2 SWH data almost equaled to zero all the time, while the mean bias of HY-2 SWH data was no less than -0.31m before April 2013 and dropped to zero after that time. These results indicate that the statistical results for HY-2 altimeter SWH are reliable and HY-2 altimeter along-track SWH data were steady and of high quality in the last three years. The results also indicate that HY-2 SWH data have greatly been improved and have the same accuracy with Jason-2 SWH data after April, 2013. SWH data provided by HY-2 satellite radar altimeter are useful and acceptable for ocean operational applications. 展开更多
关键词 significant wave height VALIDATION Chinese HY-2 satellite radar altimeter
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Long-Term Characterization of Sea Conditions in the East China Sea Using Significant Wave Height and Wind Speed 被引量:5
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作者 ZHENG Kaiwen OSINOWO Adekunle Ayodotun +1 位作者 SUN Jian HU Wei 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第4期733-743,共11页
In this study, the statistical characterization of sea conditions in the East China Sea(ECS) is investigated by analyzing a significant wave height and wind speed data at a 6-hour interval for 30 years(1980–2009), wh... In this study, the statistical characterization of sea conditions in the East China Sea(ECS) is investigated by analyzing a significant wave height and wind speed data at a 6-hour interval for 30 years(1980–2009), which was simulated and computed using the WAVEWATCH Ⅲ(WW3) model. The monthly variations of these parameters showed that the significant wave height and wind speed have minimum values of 0.73 m and 5.15 ms^(-1) and 1.73 m and 8.24 ms^(-1) in the month of May and December, respectively. The annual, seasonal, and monthly mean sea state characterizations showed that the slight sea generally prevailed in the ECS and had nearly the highest occurrence in all seasons and months. Additionally, the moderate sea prevailed in the winter months of December and January, while the smooth(wavelets) sea prevailed in May. Furthermore, the spatial variation of sea states showed that the calm and smooth sea had the largest occurrences in the northern ECS. The slight sea occurred mostly(above 30%) in parts of the ECS and the surrounding locations, while higher occurrences of the rough and very rough seas were distributed in waters between the southwest ECS and the northeast South China Sea(SCS). The occurrences of the phenomenal sea conditions are insignificant and are distributed in the northwest Pacific and its upper region, which includes the Southern Kyushu-Palau Ridge and Ryukyu Trench. 展开更多
关键词 significant wave HEIGHT WIND speed SEA state OCCURRENCE
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Estimating significant wave height from SAR imagery based on an SVM regression model 被引量:9
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作者 GAO Dong LIU Yongxin +2 位作者 MENG Junmin JIA Yongjun FAN Chenqing 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第3期103-110,共8页
A new method for estimating significant wave height(SWH) from advanced synthetic aperture radar(ASAR) wave mode data based on a support vector machine(SVM) regression model is presented. The model is established... A new method for estimating significant wave height(SWH) from advanced synthetic aperture radar(ASAR) wave mode data based on a support vector machine(SVM) regression model is presented. The model is established based on a nonlinear relationship between σ0, the variance of the normalized SAR image, SAR image spectrum spectral decomposition parameters and ocean wave SWH. The feature parameters of the SAR images are the input parameters of the SVM regression model, and the SWH provided by the European Centre for Medium-range Weather Forecasts(ECMWF) is the output parameter. On the basis of ASAR matching data set, a particle swarm optimization(PSO) algorithm is used to optimize the input kernel parameters of the SVM regression model and to establish the SVM model. The SWH estimation results yielded by this model are compared with the ECMWF reanalysis data and the buoy data. The RMSE values of the SWH are 0.34 and 0.48 m, and the correlation coefficient is 0.94 and 0.81, respectively. The results show that the SVM regression model is an effective method for estimating the SWH from the SAR data. The advantage of this model is that SAR data may serve as an independent data source for retrieving the SWH, which can avoid the complicated solution process associated with wave spectra. 展开更多
关键词 advanced synthetic aperture radar wave mode support vector machine significant wave height
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Risk factors for clinically significant macular edema in a multi-ethnics population with type 2 diabetes 被引量:7
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作者 Ong Ming Jew Mohammadreza Peyman Subrayan Visvaraja 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第4期499-504,共6页
·AIM:To determine the risk factors of clinically significant macular edema (CSME) in patients with non-proliferative diabetic retinopathy (NPDR) in a multi-ethnics Malaysian population. ·METHODS:We performed... ·AIM:To determine the risk factors of clinically significant macular edema (CSME) in patients with non-proliferative diabetic retinopathy (NPDR) in a multi-ethnics Malaysian population. ·METHODS:We performed a case control study in which 150 patients with bilateral NPDR and CSME in either eye were compared to 150 patients with bilateral NPDR and no CSME in both eyes. CSME and NPDR were graded according to Early Treatment of Diabetic Retinopathy Study criteria. Student’s t-test, odds ratio and multiple logistic regression analysis were performed to analyze the duration of diabetes, body mass index (BMI), blood pressure(BP), total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TG), fasting blood glucose (FBG), HbA1c, full blood count, serum creatinine and proteinuria between the two groups. ·RESULTS:Both groups were matched in terms of age, gender and ethnicity. Duration of diabetes, total serum cholesterol, serum LDL, FBG, HbA1c and serum creatinine were significantly higher in the CSME group (P <0.05). The hemoglobin, packed cell volume were significantly lower in the CSME group (P <0.05). There was no significant difference for serum HDL, TG, BMI, systolic and diastolic BP. Multiple logistic regression analysis showed that total serum cholesterol and HbA1c had significantly high odds of developing CSME. ·CONCLUSION:HbA1c and total cholesterol are the two most important risk factors associated with CSME in patients with NPDR. 展开更多
关键词 risk factors clinically significant macular edema DIABETES
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The seasonal variations in the significant wave height and sea surface wind speed of the China's seas 被引量:5
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作者 ZHENG Chongwei PAN Jing +3 位作者 TAN Yanke GAO Zhansheng RUI Zhenfeng CHEN Chaohui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第9期58-64,共7页
Long-term variations in a sea surface wind speed (WS) and a significant wave height (SWH) are associated with the global climate change, the prevention and mitigation of natural disasters, and an ocean resource ex... Long-term variations in a sea surface wind speed (WS) and a significant wave height (SWH) are associated with the global climate change, the prevention and mitigation of natural disasters, and an ocean resource exploitation, and other activities. The seasonal characteristics of the long-term trends in China's seas WS and SWH are determined based on 24 a (1988-2011) cross-calibrated, multi-platform (CCMP) wind data and 24 a hindcast wave data obtained with the WAVEWATCH-III (WW3) wave model forced by CCMP wind data. The results show the following. (1) For the past 24 a, the China's WS and SWH exhibit a significant increasing trend as a whole, of 3.38 cm/(s.a) in the WS, 1.3 cm/a in the SWH. (2) As a whole, the increasing trend of the China's seas WS and SWH is strongest in March-April-May (MAM) and December-January-February (DJF), followed by June-July-August (JJA), and smallest in September-October-November (SON). (3) The areal extent of significant increases in the WS was largest in MAM, while the area decreased in JJA and DJF; the smallest area was apparent in SON. In contrast to the WS, almost all of China's seas exhibited a significant increase in SWH in MAM and DJF; the range was slightly smaller in JJA and SON. The WS and SWH in the Bohai Sea, the Yellow Sea, East China Sea, the Tsushima Strait, the Taiwan Strait, the northern South China Sea, the Beibu Gull and the Gulf of Thailand exhibited a significant increase in all seasons. (4) The variations in China's seas SWH and WS depended on the season. The areas with a strong increase usually appeared in DJF. 展开更多
关键词 sea surface wind speed significant wave height long-term variation seasonal difference
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A newly developed ocean significant wave height retrieval method from Envisat ASAR wave mode imagery 被引量:2
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作者 Chenqing Fan Xiaochen Wang +1 位作者 Xudong Zhang Dong Gao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第9期120-127,共8页
The main objective of this paper is to propose a newly developed ocean Significant Wave Height (SWH) retrieval method from Envisat Advanced Synthetic Aperture Radar (ASAR) imagery. A series of wave mode imagery from J... The main objective of this paper is to propose a newly developed ocean Significant Wave Height (SWH) retrieval method from Envisat Advanced Synthetic Aperture Radar (ASAR) imagery. A series of wave mode imagery from January, April and May of 2011 are collocated with ERA-Interim reanalysis SWH data. Based on the matched datasets, a simplified empirical relationship between 22 types of SAR imagery parameters and SWH products is developed with the Genetic Algorithms Partial Least-Squares (GA-PLS) model. Two major features of the backscattering coefficient σ0 and the frequency parameter S10 are chosen as the optimal training feature subset of SWH retrieval by using cross validation. In addition, we also present a comparison of the retrieval results of the simplified empirical relationship with the collocated ERA-Interim data. The results show that the assessment index of the correlation coefficient, the bias, the root-mean-square error of cross validation (RMSECV) and the scattering index (SI) are 0.78, 0.07 m, 0.76 m and 0.5, respectively. In addition, the comparison of the retrieved SWH data between our simplifying model and the Jason-2 radar altimeter data is proposed in our study. Moreover, we also make a comparison of the retrieval of SWH data between our developed model and the well- known CWAVE_ENV model. The results show that satisfying retrieval results are acquired in the low-moderate sea state, but major bias appears in the high sea state, especially for SWH>5 m. 展开更多
关键词 significant wave height ENVISAT ASAR GA-PLS optimal feature SUBSET
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Comparative analysis of significant wave height between a new Southern Ocean buoy and satellite altimeter 被引量:3
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作者 Jianjun Kang Runyu Mao +1 位作者 Yiting Chang Hongli Fu 《Atmospheric and Oceanic Science Letters》 CSCD 2021年第5期49-55,共7页
In-situ observation is restricted by the strong wind and waves in the Southern Ocean.A Westerlies EnvironmentalMonitoring Buoy(WEMB)was firstly deployed in the Southern Ocean during China’s 35th Antarctic Expedition,... In-situ observation is restricted by the strong wind and waves in the Southern Ocean.A Westerlies EnvironmentalMonitoring Buoy(WEMB)was firstly deployed in the Southern Ocean during China’s 35th Antarctic Expedition,facilitating further understanding of the oceanic environmental characteristics of this region.With the develop-ment of technology and the improvement of data processing methods,the accuracy of satellite altimeter productsis constantly improved,thus making it possible to inspect and evaluate the in-situ observation data.Based on theL3 products of multiple satellite altimeters,this paper analyzes and corrects the significant wave height(SWH)data of WEMB by means of data matching,error statistics,and linear least-squares fitting.Through this study,the authors obtained the following results.The effect of gravitational acceleration changes with latitude on SWHaccuracy is fairly small.Due to the low response of WEMB to high-frequency waves,there is a systematic devia-tion.A feasible correction method is therefore proposed to improve the SWH accuracy of WEMB.The temporalvariation of the corrected SWH is highly consistent with that of the 10 m wind during the observation period,and its average value reaches 3.8 m. 展开更多
关键词 Mooring buoy Southern ocean Satellite altimeter significant wave height
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Validation of significant wave height retrieval from co-polarization Chinese Gaofen-3 SAR imagery using an improved algorithm 被引量:3
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作者 SHENG Yexin SHAO Weizeng +5 位作者 ZHU Shuai SUN Jian YUAN Xinzhe LI Shuiqing SHI Jian ZUO Juncheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第6期1-10,共10页
Chinese Gaofen-3(GF-3) is the first civilian satellite to carry C-band(5.3 GHz) synthetic aperture radar(SAR).During the period of August 2016 to December 2017, 1 523 GF-3 SAR images acquired in quad-polarizatio... Chinese Gaofen-3(GF-3) is the first civilian satellite to carry C-band(5.3 GHz) synthetic aperture radar(SAR).During the period of August 2016 to December 2017, 1 523 GF-3 SAR images acquired in quad-polarization(vertical-vertical(VV), horizontal-horizontal(HH), vertical-horizontal(VH), and horizontal-vertical(HV)) mode were recorded, mostly around China's seas. In our previous study, the root mean square error(RMSE) of significant wave height(SWH) was found to be around 0.58 m when compared with retrieval results from a few GF-3 SAR images in co-polarization(VV and HH) with moored measurements by using an empirical algorithm CSARWAVE. We collected a number of sub-scenes from these 1 523 images in the co-polarization channel,which were collocated with wind and SWH data from the European Centre for Medium-Range Weather Forecasts(ECMWF) reanalysis field at a 0.125° grid. Through the collected dataset, an improved empirical wave retrieval algorithm for GF-3 SAR in co-polarization was tuned, herein denoted as CSARWAVE2. An additional 92 GF-3 SAR images were implemented in order to validate CSARWAVE2 against SWH from altimeter Jason-2, showing an about 0.52 m RMSE of SWH for co-polarization GF-3 SAR. Therefore, we conclude that the proposed empirical algorithm has a good performance for wave retrieval from GF-3 SAR images in co-polarization. 展开更多
关键词 Gaofen-3 synthetic aperture radar significant wave height
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China's Shale Gas Geological Investigation and Prospecting Have Made Significant Progress 被引量:4
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作者 HAO Ziguo FEI Hongcai +1 位作者 HAO Qingqing LIU Lian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第2期727-728,共2页
Since 2015, the China Geological Survey has implemented a major program of "Geology Survey of Land Energy Mineral Resources". Till now, a total of billions of RMB have been invested and seven engineering projects ha... Since 2015, the China Geological Survey has implemented a major program of "Geology Survey of Land Energy Mineral Resources". Till now, a total of billions of RMB have been invested and seven engineering projects have been established, all of which has greatly enhanced the geological survey and exploration of China's continental shale gas in an attempt to overcome the oil and gas shortage. 展开更多
关键词 In China’s Shale Gas Geological Investigation and Prospecting Have Made significant Progress
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Study on Technologies for Information Monitoring and Quick Response of Agricultural Focuses and Significant Events 被引量:2
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作者 ZHAO Rui-xue KOU Yuan-tao XIAN Guo-jian MAO Guang-wei 《Agricultural Sciences in China》 CAS CSCD 2010年第5期764-770,共7页
This article analyzed the importance of information monitoring and quick response on agricultural focuses and significant events, proposed the workflow and technical framework for information monitoring and quick resp... This article analyzed the importance of information monitoring and quick response on agricultural focuses and significant events, proposed the workflow and technical framework for information monitoring and quick response based on modern information technologies, and explained key technologies during implementation and the functional structure for prototype system of the technical support platform. 展开更多
关键词 agricultural focus significant event information monitoring quick response technical platform
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Calculation of Significant Wave Height Using the Linear Mean Square Estimation Method 被引量:2
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作者 GAO Yangyang YU Dingyong +1 位作者 LI Cuilin XU Delun 《Journal of Ocean University of China》 SCIE CAS 2010年第4期327-332,共6页
Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave he... Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave height in this paper.Twenty-eight-year time series of wave data collected from three ocean buoys near San Francisco along the California coast are analyzed.It is proved theoretically that the computation error will be reduced by using as many measured data as possible for the calculation of significant wave height.Measured significant wave height at one buoy location is compared with the calculated value based on the data from two other adjacent buoys.The results indicate that the linear mean square estimation method can be well applied to the calculation and prediction of significant wave height in coastal regions. 展开更多
关键词 significant wave height linear mean square estimation method orthogonality principle
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Significant Mercury Isotope Anomalies in Hydrothermal Altered Coals from the Huaibei Coalfield,China 被引量:2
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作者 ZHENG Liugen SUN Ruoyu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第6期2263-2264,共2页
Igneous intrusion into coal-bearing strata can cause an abrupt increase of temperature-pressure and trigger hydrothermal circulation at the igneous rock-coal contact zone. The conductive heat of intruded lnagma and co... Igneous intrusion into coal-bearing strata can cause an abrupt increase of temperature-pressure and trigger hydrothermal circulation at the igneous rock-coal contact zone. The conductive heat of intruded lnagma and convective migration of secondary hydrothermal fluids have been observed to significantly alter the concentrations and modes of occurrence of mercury (Hg) in thermally-intruded coals. 展开更多
关键词 Hg rock significant Mercury Isotope Anomalies in Hydrothermal Altered Coals from the Huaibei Coalfield China
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Significant wave height estimation using azimuth cutoff of C-band RADARSAT-2 single-polarization SAR images 被引量:6
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作者 REN Lin YANG Jingsong +1 位作者 ZHENG Gang WANG Juan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第12期93-101,共9页
This paper proposes two simple models, look-up table(LUT) model and empirical model, to directly retrieve significant wave height(Hs) using synthetic aperture radar(SAR) azimuth cutoff(λc). Both models aim at... This paper proposes two simple models, look-up table(LUT) model and empirical model, to directly retrieve significant wave height(Hs) using synthetic aperture radar(SAR) azimuth cutoff(λc). Both models aim at C-band VV, HH, VH, and HV single-polarization SAR images. The LUT model relates Hs to λc, while the empirical model relates Hs to both λc and SAR range-to-velocity(β). The LUT model coefficients are derived by simulation under different sea states and observation conditions, which depend on incidence angle(θ), wave direction(dw), and βbut are independent of polarization. The empirical model coefficients are obtained by fitting the collocated data,which only depend on polarization. To fit empirical model coefficients and validate the two models, C-band RADARSAT-2 fine quad-polarization(VV+HH+VH+HV) single-look complex(SLC) SAR images and collocated buoy data are collected. Retrieved Hs, using Yang model and the two models proposed in this paper from four kinds of polarization SAR data, are compared with buoy Hs. Results show that both LUT and empirical models have the capacity of retrieving Hs from C-band RADARSAT-2 co-polarization SAR data, while Yang model is not suitable for these kinds of SAR data. Moreover, the empirical model is also valid for cross-polarization SAR data showing clear ocean wave stripes. 展开更多
关键词 SAR single-polarization significant wave height azimuth cutoff
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