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RAIN-128算法的中间相遇攻击 被引量:1
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作者 杜小妮 郑亚楠 +1 位作者 梁丽芳 李锴彬 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第1期327-334,共8页
RAIN是一族SPN结构的轻量级分组密码算法,该算法具有软硬件实现效率高、安_全性强等特点。中间相遇攻击被广泛应用于分组密码算法的安全性分析中。该文通过分析RAIN-128的结构特性和截断差分特征,利用差分枚举技术分别构造了4轮和6轮中... RAIN是一族SPN结构的轻量级分组密码算法,该算法具有软硬件实现效率高、安_全性强等特点。中间相遇攻击被广泛应用于分组密码算法的安全性分析中。该文通过分析RAIN-128的结构特性和截断差分特征,利用差分枚举技术分别构造了4轮和6轮中间相遇区分器,给出了8轮及10轮的中间相遇攻击。当攻击轮数为8轮时,预计算阶段的时间复杂度为2^(68)次8轮RAIN-128加密,存储复杂度为2^(75)bit,在线攻击阶段的时间复杂度为2^(109)次8轮加密,数据复杂度是2^(72)个选择明文;当攻击轮数为10轮时,预计算阶段的时间复杂度为2^(214)次10轮加密,存储复杂度为2^(219)bit,在线攻击阶段的时间复杂度为2^(109)次10轮加密,数据复杂度是2^(72)个选择明文,分析结果显示,RAIN-128可以抵抗中间相遇攻击,并具有较高的安全冗余。 展开更多
关键词 分组密码 rain-128 中间相遇攻击 差分枚举技术
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Unrolling a rain-guided detail recovery network for single-image deraining
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作者 Kailong LIN Shaowei ZHANG +1 位作者 Yu LUO Jie LING 《Virtual Reality & Intelligent Hardware》 2023年第1期11-23,共13页
Background Owing to the rapid development of deep networks, single-image deraining tasks have progressed significantly. Various architectures have been designed to recursively or directly remove rain, and most rain st... Background Owing to the rapid development of deep networks, single-image deraining tasks have progressed significantly. Various architectures have been designed to recursively or directly remove rain, and most rain streaks can be removed using existing deraining methods. However, many of them cause detail loss, resulting in visual artifacts. Method To resolve this issue, we propose a novel unrolling rain-guided detail recovery network(URDRN) for single-image deraining based on the observation that the most degraded areas of a background image tend to be the most rain-corrupted regions. Furthermore, to address the problem that most existing deep-learningbased methods trivialize the observation model and simply learn end-to-end mapping, the proposed URDRN unrolls a single-image deraining task into two subproblems: rain extraction and detail recovery. Result Specifically, first, a context aggregation attention network is introduced to effectively extract rain streaks;thereafter, a rain attention map is generated as an indicator to guide the detail recovery process. For the detail recovery sub-network, with the guidance of the rain attention map, a simple encoder–decoder model is sufficient to recover the lost details.Experiments on several well-known benchmark datasets show that the proposed approach can achieve performance similar to those of other state-of-the-art methods. 展开更多
关键词 Image deraining rain attention Detail recovery Unrolling network Context aggregation attention
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Plant life form determines spatiotemporal variability and climate response of plant seed rain in subtropical forests
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作者 Yuyang Xie Zehao Shen +2 位作者 Xuejing Wang Liu Yang Jie Zhang 《Forest Ecosystems》 SCIE CSCD 2024年第2期193-201,共9页
Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients.In this study,we collected seeds from four sites in the Dalaoling Nature Reserve... Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients.In this study,we collected seeds from four sites in the Dalaoling Nature Reserve,Hubei Province,China,between 2011 and 2014,measured seed output and seed mass as seed rain traits,and compared their interannual and elevational variation.Then,we ran phylogenetic generalized mixed linear models(PGLMMs) to explore the effects of temperature and precipitation as well as interspecific differences on seed rain,and fitted the best regression models for seed rain vs.weather of canopy and understory species.The results showed no correlation between values of seed output and seed mass.However,the variation of the two traits showed significantly positive correlation.Seed output of canopy species generally decreased with increasing elevation,and showed significant interannual difference;however,seed output of understory species and seed mass for both canopy and understory species did not show consistency tends along elevational or in interannual variation.Seed output was significantly affected by temperature and precipitation,while seed mass mainly varied due to interspecific differences.Weather explained more the variation of the seed output of canopy species than that of understory species,with R^(2) values of 43.0%and 29.9%,respectively.These results suggested that canopy plants contributed more to the reproductive dynamics of the whole communities,and the canopy's buffer effect on the underground weakened the response of understory plants to weather variation in terms of their reproductive strategy. 展开更多
关键词 Seed rain Seed output Seed mass ELEVATION Interannual variation Lifeform
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Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China
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作者 Xiuping YAO Ruoying LI +1 位作者 Xiaohong BAO Qiaohua LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期73-83,共11页
An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(... An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR. 展开更多
关键词 extreme torrential rain rotational kinetic energy kinetic energy generation and transport barotropic process
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Spatiotemporal characteristics of seed rain and soil seed bank of artificial Caragana korshinskii Kom. forest in the Tengger Desert, China
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作者 SHEN Jianxiang WANG Xin +9 位作者 WANG Lei WANG Jiahui QU Wenjie ZHANG Xue CHANG Xuanxuan YANG Xinguo CHEN Lin QIN Weichun ZHANG Bo NIU Jinshuai 《Journal of Arid Land》 SCIE CSCD 2024年第4期550-566,共17页
Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants durin... Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles. 展开更多
关键词 ecological restoration soil seed bank seed rain artificial forest vegetation desertification Caragana korshinskii Tengger Desert
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Mesoscale and Microphysical Characteristics of a Double Rain Belt Event in South China on May 10–13,2022
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作者 郭照华 谌芸 +1 位作者 肖天贵 曾智琳 《Journal of Tropical Meteorology》 SCIE 2024年第1期61-75,共15页
A second rain belt sometimes occurs ahead of a frontal rain belt in the warm sector over coastal South China,leading to heavy precipitation.We examined the differences in the mesoscale characteristics and microphysics... A second rain belt sometimes occurs ahead of a frontal rain belt in the warm sector over coastal South China,leading to heavy precipitation.We examined the differences in the mesoscale characteristics and microphysics of the frontal and warm sector rain belts that occurred in South China on May 10–13,2022.The southern rain belt occurred in an environment with favorable mesoscale conditions but weak large-scale forcing.In contrast,the northern rain belt was related to low-level horizontal shear and the surface-level front.The interaction between the enhanced southeasterly winds and the rainfall-induced cold pool promoted the persistent growth of convection along the southern rain belt.The convective cell propagated east over the coastal area,where there was a large temperature gradient.The bow-shaped echo in this region may be closely related to the rear-inflow jet.By contrast,the initial convection of the northern rain belt was triggered along the front and the region of low-level horizontal shear,with mesoscale interactions between the enhanced warm-moist southeasterly airflow and the cold dome associated with the earlier rain.The terrain blocked the movement of the cold pool,resulting in the stagnation of the frontal convective cell at an early stage.Subsequently,a meso-γ-scale vortex formed during the rapid movement of the convective cell,corresponding to an enhancement of precipitation.The representative raindrop spectra for the southern rain belt were characterized by a greater number and higher density of raindrops than the northern rain belt,even though both resulted in comparable hourly rainfalls.These results help us better understand the characteristics of double rain belts over South China. 展开更多
关键词 double rain belts in South China mesoscale rainstorm cyclonic shear line cold pool bow-shaped echo microphysical characteristics
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Effect Evaluation of CBL Combined with Rain Classroom Teaching Method in Medical Statistics
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作者 Man Luo Xiaofang Zhang Wei Liu 《Open Journal of Applied Sciences》 2024年第5期1204-1213,共10页
Objective: To explore the application effect of CBL combined with rain classroom teaching method in medical statistics courses. Methods: The undergraduate students of medical imaging technology in 2019 and 2020 in a u... Objective: To explore the application effect of CBL combined with rain classroom teaching method in medical statistics courses. Methods: The undergraduate students of medical imaging technology in 2019 and 2020 in a university were selected as the research objects. A cluster sampling method was used to select 79 undergraduate students from 2019 in the control group and 75 undergraduate students from 2020 in the experimental group. Traditional teaching method and CBL combined with rain classroom teaching method was used in the control group and experimental group respectively. The final examination scores of the two groups were compared. In experimental group, the correlation between the average score in the rain classroom and the final examination score was tested, and the teaching effect was evaluated. Results: The average score of final examination in experimental group and control group was 79.13 ± 10.32 points and 71.54 ± 14.752 points, respectively, which had a statistically significant difference (Z = 2.586, P = 0.012);the final examination scores of the students in the experimental group were positively correlated with the average scores of the rain classroom (r = 0.372, P = 0.001), and the proportion of satisfaction in the experimental group was 94.7%. Conclusion: The CBL combined with rain classroom teaching method can improve the teaching effectiveness of medical statistics courses. 展开更多
关键词 rain Classroom CBL Medical Statistics
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On Adaptation Measures to Solve Tel-Aviv’s Environmental Problems with “Sunny Rain”
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作者 Michael Noppe 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第1期23-26,共4页
Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s ... Adaptation measures were proposed using“Sunny Rain”to solve Tel Aviv’s environmental problems to cool the air in the city and save humanity from climate catastrophe and fight air pollution;the Yarkon,“Tel Aviv’s main river”will no longer be a dirty ditch;the fog from Ben-Gurion Airport was cleaned;neighborhoods,parks,around Tel Aviv were greened and all green spaces were irrigated with“Sunny Rain”. 展开更多
关键词 “Sunny rain adaptation measures environmental problems the Yarkon.
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THE IMPACT OF DIFFERENT PHYSICAL PROCESSES AND THEIR PARAMETERIZATIONS ON FORECAST OF A HEAVY RAINFALL IN SOUTH CHINA IN ANNUALLY FIRST RAINING SEASON 被引量:6
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作者 张旭斌 万齐林 +2 位作者 薛纪善 丁伟钰 李昊睿 《Journal of Tropical Meteorology》 SCIE 2015年第2期194-210,共17页
An ensemble prediction system based on the GRAPES model, using multi-physics, is used to discuss the influence of different physical processes in numerical models on forecast of heavy rainfall in South China in the an... An ensemble prediction system based on the GRAPES model, using multi-physics, is used to discuss the influence of different physical processes in numerical models on forecast of heavy rainfall in South China in the annually first raining season(AFRS). Pattern, magnitude and area of precipitation, evolution of synoptic situation, as well as apparent heat source and apparent moisture sink between different ensemble members are comparatively analyzed. The choice of parameterization scheme for land-surface processes gives rise to the largest influence on the precipitation prediction. The influences of cumulus-convection and cloud-microphysics processes are mainly focused on heavy rainfall;the use of cumulus-convection parameterization tends to produce large-area and light rainfall. Change in parameterization schemes for land-surface and cumulus-convection processes both will cause prominent change in forecast of both dynamic and thermodynamic variables, while change in cloud-microphysics processes show primary impact on dynamic variables. Comparing simplified Arakawa-Schubert and Kain-Fritsch with Betts-Miller-Janjic schemes, SLAB with NOAH schemes, as well as both WRF single moment 6-class and NCEP 3-class with simplified explicit schemes of phase-mixed cloud and precipitation shows that the former predicts stronger low-level jets and high humidity concentration, more convective rainfall and local heavy rainfall, and have better performance in precipitation forecast. Appropriate parameterization schemes can reasonably describe the physical process related to heavy rainfall in South China in the AFRS, such as low-level convergence, latent heat release, vertical transport of heat and water vapor, thereby depicting the multi-scale interactions of low-level jet and meso-scale convective systems in heavy rainfall suitably, and improving the prediction of heavy rainfall in South China in the AFRS as a result. 展开更多
关键词 numerical weather prediction heavy rainfall in South China in annually first raining season GRAPES model multi-physics parameterization ensemble prediction
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STUDY ON THE RELATIONSHIP BETWEEN BRIGHTNESS TEMPERATURE FROM GMS-5 INFRARED CLOUD IMAGERY AND SURFACE RAIN RATES DURING THE RAINING SEASONS OF FUJIAN PROVINCE 被引量:2
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作者 林长城 张长安 +3 位作者 林忠敏 林祥明 谢怡芳 郑淑贞 《Journal of Tropical Meteorology》 SCIE 2003年第1期74-79,共6页
The GMS-5 infrared cloud imagery for two yearly first raining seasons in 1998 and 1999 are used to study the relationship between brightness temperature and surface rain rates. The result shows that it is likely to ha... The GMS-5 infrared cloud imagery for two yearly first raining seasons in 1998 and 1999 are used to study the relationship between brightness temperature and surface rain rates. The result shows that it is likely to have large probability of heavy precipitation with the decrease of brightness temperature and the gradual increase of rainfall intensity; for areas of low temperature, the brightness temperature is better determined for atmosphere above rain gauge stations with multiple points sampling than with single point one; for the yearly first raining season, the threshold brightness temperature is set at 4.6℃ for indication of heavy precipitation in the Fujian area. 展开更多
关键词 雨季 GMS-5 云层温度 雨量强度 福建 降雨 相互关系
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ANALYSES OF INTRASEASONAL OSCILLATION CHARACTERISTICS OF FLOOD-CAUSING RAINSTORMS IN XIJIANG RIVER VALLEY DURING THE ANNUALLY FIRST RAINING SEASON IN THE PAST YEARS 被引量:1
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作者 罗秋红 纪忠萍 +2 位作者 吴乃庚 蔡洁云 孙汉明 《Journal of Tropical Meteorology》 SCIE 2011年第2期136-146,共11页
Based on the daily precipitation data of nine stations representing the Xijiang River valley and the National Center for Environmental Prediction/National Center for Atmospheric Research (USA) reanalysis data, this st... Based on the daily precipitation data of nine stations representing the Xijiang River valley and the National Center for Environmental Prediction/National Center for Atmospheric Research (USA) reanalysis data, this study uses the wavelet analysis and band-pass filter methods to investigate the atmospheric intraseasonal oscillation characteristics of flood-causing rainstorms in the valley during the annually first raining seasons in 1968, 1994, 1998, 2002 and 2005. Results show that the daily precipitation in the valley exhibits significant quasi-biweekly (10 to 20 days) oscillations. The flood-causing rainstorms in the valley were mainly associated with the confluence of low-frequency warm and humid airflow in the lower latitudes and cold and dry airflow in the higher latitudes. The low-frequency vortexes were propagating or in control when this type of rainstorms took place over the valley, being favorable for the convergence of moisture at lower levels and thus vital to the formation of the rainstorms. 展开更多
关键词 暴风雨 intraseasonal 摆动 过滤器 Xijiang 河山谷 每年第一雨季
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ON THE RELATIONSHIP BETWEEN PRECIPITATION ANOMALIES IN THE FIRST RAINING SEASON (APRIL-JUNE) IN SOUTHERN CHINA AND SST OVER OFFSHORE WATERS IN CHINA 被引量:1
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作者 邓立平 王谦谦 《Journal of Tropical Meteorology》 SCIE 2002年第1期75-84,共10页
Precipitation anomalies in the first raining season of southern China were analyzed,with the suggestion that there are obvious interannual variation of peak values.In the raining season,the general tendency of precipi... Precipitation anomalies in the first raining season of southern China were analyzed,with the suggestion that there are obvious interannual variation of peak values.In the raining season,the general tendency of precipitation is not obvious and the anomalous oscillation is multi-scale.Corresponding to years of more or less precipitation in the raining season,there are sharply opposite distribution across the nation in the simultaneous periods.In addition,by studying the distribution of correlation between anomalous precipitation in southern China in the first raining season and SSTA over offshore waters of China in the preceding period (June ~August of the previous year),a sensitive zone of waters has been found that has steady effect on the precipitation of southern China in the season.Discussions are also made of the sensitive period,its simultaneous SSTA and subsequent anomalous circulation field in relation to precipitation anomalies and simultaneous circulation field in the first raining season of southern China.In the last part of the work,relationship between the SSTA in the sensitive zone and global SSTA is analyzed.A possible mechanism by which SSTA in offshore Chinese waters affects the precipitation anomalies in the first raining season of southern China is put forward. 展开更多
关键词 雨季 海水 海洋表面温度 中国 SSTA 降水 五月 六月
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PRELIMINARY DISCUSSIONS OF BASIC CLIMATIC CHARACTERISTICS OF PRECIPITATION DURING RAINING SEASONS IN REGIONS SOUTH OF CHANGJIANG RIVER AND ITS RELATIONSHIP WITH SST ANOMALIES 被引量:1
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作者 陈绍东 王谦谦 钱永甫 《Journal of Tropical Meteorology》 SCIE 2003年第2期191-200,共10页
Basic climatic characteristics are analyzed concerning the precipitation anomalies in raining seasons over regions south of the Changjiang River (the Yangtze). It finds that the regions are the earliest in eastern Chi... Basic climatic characteristics are analyzed concerning the precipitation anomalies in raining seasons over regions south of the Changjiang River (the Yangtze). It finds that the regions are the earliest in eastern China where raining seasons begin and end. Precipitation there tends to decrease over the past 50 years. Waters bounded by 9(S -1(S, 121(E - 129(E are the key zones of SST anomalies that affect the precipitation in these regions over May ~ July in preceding years. Long-term air-sea interactions make it possible for preceding SST anomalies to affect the general circulation that come afterwards, causing precipitation anomalies in the raining seasons in regions south of the Changjiang River in subsequent years. 展开更多
关键词 气候特征分析 降雨季节 扬子江 降水
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Analysis of the effect of professional teaching staff construction in the training of low-level nurses in operating room 被引量:1
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作者 Chang-Xu Kan Yong-Chao He +2 位作者 Hong-Xu Ren Xiao-Yu Liu Liang-Chen Sun 《Nursing Communications》 2022年第1期52-56,共5页
Objective:To explore the application effect of constructing professional teaching staff in low-level training in operating room,so as to further optimize the teaching strength of operating room in our hospital and imp... Objective:To explore the application effect of constructing professional teaching staff in low-level training in operating room,so as to further optimize the teaching strength of operating room in our hospital and improve the training effect of junior nurses.Methods:Thirty-eight low-level nurses in the operating room of a third-class hospital in Yantai were selected for half a year's nurse training.With theoretical scores,overall nursing performance,nurses'self-awareness evaluation system and nurses'satisfaction with tutors as evaluation criteria,and based on the selection of high-quality teachers,various evaluation indexes before and after the training of low-level nurses in the operating room were compared and evaluated through the cultivation of practical teaching teachers'ability and the application of a series of teaching methods based on the change of c ompetence-based education(CBE)teaching mode,the application of guided learning interactive canadian education(BOPPPS)teaching model and p roblem-b ased l earning(PBL)teaching method.Results:After the training,the examination scores of low-level nurses were significantly improved(P<0.05),the teaching quality was highly recognized by low-level nurses,the quality of low-level nurses was improved,and patients'satisfaction with nurses was improved.Conclusion:It is of great significance to assist the construction of professional teachers in evidence-based medicine.Through the training of practical teaching teachers'ability and the application of a series of teaching methods based on the change of CBE teaching model,the application of BOPPPS teaching model and PBL teaching method,the training results of nurses have been significantly improved and improved,which is worthy of clinical reference and promotion. 展开更多
关键词 t raining of-level nurses c onstruction of teachers o perating room c ompetence-based education guided learning interactive canadian education p roblem-b ased l earning
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Towards Robust Rain Removal with Unet
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作者 Boxia Hu Yaqi Sun +2 位作者 Yufei Yang Ze Ouyang Feng Zhang 《Computers, Materials & Continua》 SCIE EI 2023年第4期879-890,共12页
Image deraining has become a hot topic in the field of computervision. It is the process of removing rain streaks from an image to reconstructa high-quality background. This study aims at improving the performance ofi... Image deraining has become a hot topic in the field of computervision. It is the process of removing rain streaks from an image to reconstructa high-quality background. This study aims at improving the performance ofimage rain streak removal and reducing the disruptive effects caused by rain.To better fit the rain removal task, an innovative image deraining method isproposed, where a kernel prediction network with Unet++ is designed andused to filter rainy images, and rainy-day images are used to estimate thepixel-level kernel for rain removal. To minimize the gap between synthetic andreal data and improve the performance in real rainy image handling, a lossfunction and an effective data optimization method are suggested. In contrastwith other methods, the loss function consists of Structural Similarity Indexloss, edge loss, and L1 loss, and it is adopted to improve performance. Theproposed algorithm can improve the Peak Signal-to-Noise ratio by 1.3% whencompared to conventional approaches. Experimental results indicate that theproposed method can achieve a better efficiency and preserve more imagestructure than several classical methods. 展开更多
关键词 rain removal edge optimization ROBUST Unet++
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Analysis, Variability and Rainfall Prediction in Sub-Saharan Africa: The Case of the Lake Guiers in Senegal
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作者 Abdou Arame Fall Saidou Ndao Aba Diop 《Open Journal of Ecology》 2023年第11期806-819,共14页
The aim of this article is to predict the rainfall evolution of a sub-Saharan area in which one of the most important freshwater resources is located: Lake Guiers. Characterized by short seasonal rains of three months... The aim of this article is to predict the rainfall evolution of a sub-Saharan area in which one of the most important freshwater resources is located: Lake Guiers. Characterized by short seasonal rains of three months, it experienced a long period of drought in the 1970s. We begin by analyzing the temporal distribution of the rainfall including the variability of the data, with a view to predicting a possible return. For this reason, we present here univariate modeling results of rainfall series collected on three stations in the area. The challenge lies in the adequacy of the parameters for the monthly rainfall series, which generates more or less significant forecast errors on the learning bases because of the missing data. This later motivated their conversion to moving average series. On the other hand, the normality of the latter seems to be rejected by the D’Agostino test. Student’s and Mann-Whitney’s tests confirmed the homogeneity. The autocorlograms show the presence of autoregressive terms in the data. Dickey-Fuller and Mann-Kendall tests reveal both trend and seasonality. The stationarity tests of Dickey-Fuller, Phillips-Perron and KPSS have shown that they are non-stationary. As a result, we did an ARIMA modeling method using the Box-Jenkins [1] method with the R software, which involves estimating model parameters, tests of significance, analysis of residualss, selection according to information criteria and forecasts. The results obtained during the learning-test phase showed a quasi-similarity of the base-tests in all the series except for that of Louga. 展开更多
关键词 Time Series rain TREND Stationarity RESIDUALS Model FORECAST
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Predecessor Rain Events in the Yangtze River Delta Region Associated with South China Sea and Northwest Pacific Ocean(SCS-WNPO)Tropical Cyclones
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作者 Huiyan XU Xiaofan LI +1 位作者 Jinfang YIN Dengrong ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第6期1021-1042,共22页
Predecessor rain events(PREs) in the Yangtze River Delta(YRD) region associated with the South China Sea and Northwest Pacific Ocean(SCS-WNPO) tropical cyclones(TCs) are investigated during the period from 2010 to 201... Predecessor rain events(PREs) in the Yangtze River Delta(YRD) region associated with the South China Sea and Northwest Pacific Ocean(SCS-WNPO) tropical cyclones(TCs) are investigated during the period from 2010 to 2019.Results indicate that approximately 10% of TCs making landfall in China produce PREs over the YRD region;however,they are seldom forecasted. PREs often occur over the YRD region when TCs begin to be active in the SCS-WNPO with westward paths, whilst the cold air is still existing or beginning to be present. PREs are more likely to peak in June and September. The distances between the PRE centers and the parent TC range from 900 to 1700 km. The median value of rain amounts and the median lifetime of PREs is approximately 200 mm and 24 h, respectively. Composite results suggest that PREs form in the equatorward jet-entrance region of the upper-level westerly jet(WJ), where a 925-hPa equivalent potential temperature ridge is located east of a 500-hPa trough. Deep moisture is transported from the TC vicinity to the remote PREs region. The ascent of this deep moist air in front of the 500-hPa trough and frontogenesis beneath the equatorward entrance region of the WJ is advantageous for the occurrence of PREs in the YRD region. The upper-level WJ may be affected by the subtropical high and westerly trough in the Northwest Pacific Ocean, and the occurrence of PREs may favor the maintenance of the upper-level WJ. The upper-level outflow of TCs in the SCS plays a secondary role. 展开更多
关键词 tropical cyclone heavy rain westerly trough upper-level jet stream
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Rainfall Monitoring Using a Microwave Links Network:A Long-Term Experiment in East China
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作者 Xichuan LIU Kun ZHAO +2 位作者 Mingzhong ZOU Kang PU Kun SONG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第9期1567-1583,共17页
The first long-term rainfall monitoring experiment using the commercial microwave links(CMLs)network in East China is introduced.The network,located in Jiangyin,Jiangsu Province,consists of 49 links with frequencies r... The first long-term rainfall monitoring experiment using the commercial microwave links(CMLs)network in East China is introduced.The network,located in Jiangyin,Jiangsu Province,consists of 49 links with frequencies ranging from 15 GHz to 26 GHz and lengths from 1.14 km to 4.78 km.An OTT PARSIVEL disdrometer is deployed to refine the local rain-induced attenuation relationship,and the CML observations are compared simultaneously with five rain gauges.The inversion parameters of the CML are optimized by minimizing the error of the accumulated rainfall of historical rainfall events.The inversion results show that the daily accumulated rainfall retrieved by the CMLs agrees well with the rain gauge measurements.As an opportunistic approach to monitor near-surface rainfall with high spatiotemporal representativeness and accuracy,the CML network can be used to monitor and forecast urban flood disasters,especially in regions where the widepread deployment of conventional meteorological instruments is impractical. 展开更多
关键词 rainfall monitoring microwave links rain rate inversion path-average rainfall accumulation rainfall field
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Analysis of Rainstorm Process in South China from September 7 to 8, 2022
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作者 Yiwei Wang 《Journal of Geoscience and Environment Protection》 2023年第8期161-167,共7页
Based on the NCEP data of the United States, a rainstorm process in South China during September 7 to 8, 2022 was studied. Synoptic method is a qualitative and empirical forecasting method. The results show that: In e... Based on the NCEP data of the United States, a rainstorm process in South China during September 7 to 8, 2022 was studied. Synoptic method is a qualitative and empirical forecasting method. The results show that: In early September 2022, the cold air behind the trough line from northeast China to North China can directly drive southward and invade South China from the east road. Typhoon Hinnamnor is located in the saddle field between the mainland subtropical high and the offshore subtropical high. It moves northward on the west side of the coastal subtropical high, affecting the Taiwan Island and the coastal areas of East China. During September 7-8, the wave trough of the 925 hPa Easterly wave was located near 110°E. Easterly jet existed in the southeast of South China. The center of the easterly jet was located to the east of Hainan Island, which could transport abundant water vapor from the sea surface to the sky over South China. The precipitable water in the whole layer of the atmosphere decreased from the southern coastal areas to the north, reaching more than 50 mm in southern China, of which most of the South China Sea, Hainan Island and parts of the western part of Guangdong Province exceeded 60 mm, providing sufficient water vapor supply. The circulation field with convergence at low level and divergence at high level is conducive to vertical uplift to form precipitation. 展开更多
关键词 South China Heavy rain Easterly Wave Subtropical High
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THE RELATIONSHIP BETWEEN SOUTH CHINA SEA SOUTHWEST MONSOON ANOMALIES AND IMPORTANT WEATHER IN GUANGDONG PROVINCE DURING THE RAINING SEASONS
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作者 谢炯光 纪忠萍 +1 位作者 谷德军 梁建茵 《Journal of Tropical Meteorology》 SCIE 2008年第2期113-116,共4页
The activity of South China Sea southwest monsoon (SCSSM) has direct impacts on the anomalies of important weather in Guangdong province during the raining seasons. So it is necessary to explore thoroughly the activit... The activity of South China Sea southwest monsoon (SCSSM) has direct impacts on the anomalies of important weather in Guangdong province during the raining seasons. So it is necessary to explore thoroughly the activity pattern of SCSSM and its relationship with important weather anomalies in the province. In this paper, the methods of composite analysis and correlation statistics are used to study the relationship between the onset date and intensity of SCSSM and the important weather, such as precipitation trends in Guangdong province during the annually first and second raining seasons, the timing of the annually first and last typhoon and the number of typhoons landing in Guangdong province. The results show that the rainfall is less than normal during the first raining season, but more than normal during the second one and there are more tropical cyclones landing in Guangdong province in the years of early SCSSM onset. The rainfall is more than normal during the second raining season and there are more tropical cyclones landing in Guangdong province in the years of strong SCSSM. The relationship between the SST of April - June, July - September and previous winter (December - February) and 500 hPa geopotential height and the onset date and intensity of SCSSM is analyzed. Some mechanisms between the onset dates and intensity of SCSSM and the important weather anomalies in Guangdong province are preliminarily explored. The results can be used for reference in short-term climate forecast. 展开更多
关键词 季候风 湍流 结构
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