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Determination of Carboplatin Dose by Area Under the Curve in Combination Chemotherapy for Senile Non-small Cell Lung Cancer 被引量:1
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作者 殷铁军 刘菁菁 +1 位作者 胡长耀 刘梦涛 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2007年第6期710-712,共3页
To preliminarily determine the appropriate dosage of carboplatin (CBP) at AUC of 5 mg-M1^-1·min^-1 in the combination chemotherapy for Chinese senile patients with non-small cell lung cancer (NSCLC). Thirty-f... To preliminarily determine the appropriate dosage of carboplatin (CBP) at AUC of 5 mg-M1^-1·min^-1 in the combination chemotherapy for Chinese senile patients with non-small cell lung cancer (NSCLC). Thirty-five Chinese senile patients with NSCLC in advanced stage (Ⅲ/Ⅳ) were given 96 cycles of combination chemotherapy. Chemotherapy schedules included Taxol+CBP, Gemzar+CBP and NVB+CBE The dose of CBP was at 5 mg.mL^-1·min^-1 of area under the concentration-time curve (AUC). Side effects and quality of life were observed before and after the chemotherapy. Myelosuppression was severe and commonly observed. Grade 3/4 of granulocytopenia was found in 47.9% (46/96) of the patients and grade 3/4 of thrombocytopenia was noted in 28.1% (27/96) of the subjects. However, other side effects were slight. The mean score of quality of life (QOL), according to the criteria of QOL for Chinese cancer patients had reduced 6.8. At 5 mg.mL^-1·min^-1 by AUC, the hematological toxicity of CBP was severe and it had some negative effects on the QOL. The administration of CBP at 5 mg.mL^-1·min^-1 by AUC may be too high for Chinese senile patients with non-small cell lung cancer. 展开更多
关键词 senile patients non-small cell lung cancer carboplatin area under the concentration-time curve quality of life
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Area under the curve of methotrexate and creatinine clearance are outcome - determining factors in primary CNS lymphomas 被引量:9
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作者 FerreriAJ GuerraE +14 位作者 RegazziM PasiniF AmbrosettiA PivnikA GubkinA CalderoniA SpinaM BrandesA FerrareseF RognoneA GoviS Dell’OroS LocatelliM VillaE ReniM 《中国神经肿瘤杂志》 2004年第1期12-12,共1页
Although high-dose methotrexate(HD-MTX)is the most effective drug against primary CNS lymphomas(PCNSL),outcome-de-termining variables related to its administration schedule have not been defined.The impact on toxicity... Although high-dose methotrexate(HD-MTX)is the most effective drug against primary CNS lymphomas(PCNSL),outcome-de-termining variables related to its administration schedule have not been defined.The impact on toxicity and outcome of the area under thecurve(AUC(MTX)),dose intensity(DI(MTX))and infusion rate(IR(MTX))of MTX and plsamatic creatinine clearance(CL(crea))was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-basedcombinations.Anticon-vulsants were administered in 31 pts(69%).Age>60 years,anticonvulsant therapy,slow IR(MTX)(</=800 mgm(-2)h(-1)),and reduced DI(MTX)(</=1000 mgm(-2)wk(-1))were significantly correlated with low AUC(MTX)values.Seven pa- 展开更多
关键词 PCNSL area under the curve of methotrexate and creatinine clearance are outcome determining factors in primary CNS lymphomas AUC MTX CNS
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Predicting potential invasion risks of Leucaena leucocephala(Lam.)de Wit in the arid area of Saudi Arabia
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作者 Haq S MARIFATUL Darwish MOHAMMED +3 位作者 Waheed MUHAMMAD Kumar MANOJ Siddiqui H MANZER Bussmann W RAINER 《Journal of Arid Land》 SCIE CSCD 2024年第7期983-999,共17页
The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum e... The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum entropy(MaxEnt)modeling to forecast the likelihood of Leucaena leucocephala(Lam.)de Wit invasion in Saudi Arabia under present and future climate change scenarios.Utilizing the MaxEnt modeling,we integrated climatic and soil data to predict habitat suitability for the invasive species.We conducted a detailed analysis of the distribution patterns of the species,using climate variables and ecological factors.We focused on the important influence of temperature seasonality,temperature annual range,and precipitation seasonality.The distribution modeling used robust measures of area under the curve(AUC)and receiver-operator characteristic(ROC)curves,to map the invasion extent,which has a high level of accuracy in identifying appropriate habitats.The complex interaction that influenced the invasion of L.leucocephala was highlighted by the environmental parameters using Jackknife test.Presently,the actual geographic area where L.leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range,suggesting that it had the capacity to expand further.The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve.Precipitation and temperature were the primary factors influencing the potential distribution of L.leucocephala.Currently,an estimated area of 216,342 km^(2)in Saudi Arabia was at a high probability of invasion by L.leucocephala.We investigated the potential for increased invasion hazards in the future due to climate change scenarios(Shared Socioeconomic Pathways(SSPs)245 and 585).The analysis of key climatic variables,including temperature seasonality and annual range,along with soil properties such as clay composition and nitrogen content,unveiled their substantial influence on the distribution dynamic of L.leucocephala.Our findings indicated a significant expansion of high risk zones.High-risk zones for L.leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios,particularly evident in southern Makkah,Al Bahah,Madina,and Asir areas.The results,backed by thorough spatial studies,emphasize the need to reduce the possible ecological impacts of climate change on the spread of L.leucocephala.Moreover,the study provides valuable strategic insights for the management of invasion,highlighting the intricate relationship between climate change,habitat appropriateness,and the risks associated with invasive species.Proactive techniques are suggested to avoid and manage the spread of L.leucocephala,considering its high potential for future spread.This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge.It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions. 展开更多
关键词 area under the curve invasive species invasion risks climate change MaxEnt model
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Derivations of Vector Area and Volume Elements in Curved Coordinate Systems for Flux Vector Fields Helping Eye Disease
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作者 Haya Ruchvarger 《Journal of Applied Mathematics and Physics》 2022年第10期2906-2922,共17页
Our aim in this paper is to interest retinal eye specialists in preventing dry macula degeneration by a special flurry vector field through open or closed curved surfaces. The flux of vector fields through surfaces is... Our aim in this paper is to interest retinal eye specialists in preventing dry macula degeneration by a special flurry vector field through open or closed curved surfaces. The flux of vector fields through surfaces is based on vector element area and volume element. Therefore, we explain a few geometrical derivations of area and volume elements in curved orthogonal coordinate systems. We hope that by derivation of a spatial vector field flurry against drusen through open or closed surfaces due to the Gauss theorem might select drusen under eye retina cells without destroying the cells and prevent macula degeneration. A changed flurry of a magnetic or electric vector field through a closed line causes an electric or magnetic vector field on the surface closed by the line. We also hope that derivation by Stokes’ and Greens’ theorems, with the help of iron, might help eye cells to get in life. 展开更多
关键词 Vector area Element Volume Element curved Coordinates Vector Flux Macula Degeneration
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SOME REMARKS ABOUT THE AREA-PRESERVING CONVEX CURVE FLOW IN THE PLANE
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作者 PiLing 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第4期417-428,共12页
Using Picard's theorem and the Leray-Schauder fixed point theorem to reinvestigate the area-preserving convex curve flow in the plane which is considered as a coupled system and thus different from the setting han... Using Picard's theorem and the Leray-Schauder fixed point theorem to reinvestigate the area-preserving convex curve flow in the plane which is considered as a coupled system and thus different from the setting handled by Gage. 展开更多
关键词 Picard's theorem Leray-Schauder fixed point theorem maximum principle area-preserving convex curve flow.
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COMPUTING AREAS BOUNDED BYRATIONAL BEZIER CURVES 被引量:4
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作者 Guojin Wang Thomas W. Sederberg 《Computer Aided Drafting,Design and Manufacturing》 1994年第2期18-27,共2页
An approach is presented for computing integral values, such as areas and volumes of revo-lution . of regions bounded by rational plane B zier curves. The method approximates rational curveswith polynomial curves, an... An approach is presented for computing integral values, such as areas and volumes of revo-lution . of regions bounded by rational plane B zier curves. The method approximates rational curveswith polynomial curves, and then computes the integral values on those polynomial curves. Errorbounds are provided. For high precision, this new algorithm performs much more quickly than con-ventional numerical methods. 展开更多
关键词 B zier curves area : volume of revolution polynomial approximation: error bounds
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Secure Authentication of WLAN Based on Elliptic Curve Cryptosystem 被引量:1
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作者 张龙军 韩玮 陈克非 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第5期645-650,共6页
The security of wireless local area network (WI.AN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to t... The security of wireless local area network (WI.AN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEES02.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WI.AN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet. 展开更多
关键词 SECURITY wireless local area network (WLAN) elliptic curve cryptosystem
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基于EKC&Lorenz Curve的山东省生态用地时空演变及保护区划研究 被引量:20
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作者 安国强 《中国土地科学》 CSSCI CSCD 北大核心 2018年第9期89-96,共8页
研究目的:剖析近20年山东省生态用地时空演变特点,划分不同保护区域,为编制国土资源空间规划、保护生态用地提供参考。研究方法:采用环境库兹涅兹曲线(EKC),判断全省生态用地的发展趋势;根据洛伦兹曲线(Lorenz Curve)和基尼系数(Gini)方... 研究目的:剖析近20年山东省生态用地时空演变特点,划分不同保护区域,为编制国土资源空间规划、保护生态用地提供参考。研究方法:采用环境库兹涅兹曲线(EKC),判断全省生态用地的发展趋势;根据洛伦兹曲线(Lorenz Curve)和基尼系数(Gini)方法,描述全省生态用地的分布及其演变特征;利用地理信息系统(GIS),遥感(RS)等方法获取数据并输出计算结果。研究结果:1996年以来全省生态用地总面积减少了46.8×10~4 hm^2,减少态势具有明显的"平稳—加速—减缓"的阶段性特征;全省生态用地分布基尼系数由1996年的0.523降低为2016年的0.480,生态用地区域分布趋于均衡。研究结论:(1)随着生态文明建设和美丽中国战略的深入实施,将来有可能出现生态用地由减少到增加的拐点;(2)本文把全省划分为三类不同的保护区域,并根据不同保护区的特点提出了差别化的土地利用方向和生态保护政策。 展开更多
关键词 土地生态 生态用地保护区 环境库兹涅兹曲线 洛伦兹曲线 基尼系数 标准化分布指数
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Optimal Weights in Nonparametric Analysis of Clustered ROC Curve Data
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作者 Yougui Wu 《Journal of Applied Mathematics and Physics》 2015年第7期828-834,共7页
In diagnostic trials, clustered data are obtained when several subunits of the same patient are observed. Within-cluster correlations need to be taken into account when analyzing such clustered data. A nonparametric m... In diagnostic trials, clustered data are obtained when several subunits of the same patient are observed. Within-cluster correlations need to be taken into account when analyzing such clustered data. A nonparametric method has been proposed by Obuchowski (1997) to estimate the Receiver Operating Characteristic curve area (AUC) for such clustered data. However, Obuchowski’s estimator gives equal weight to all pairwise rankings within and between cluster. In this paper, we modify Obuchowski’s estimate by allowing weights for the pairwise rankings vary across clusters. We consider the optimal weights for estimating one AUC as well as two AUCs’ difference. Our results in this paper show that the optimal weights depends on not only the within-patient correlation but also the proportion of patients that have both unaffected and affected units. More importantly, we show that the loss of efficiency using equal weight instead of our optimal weights can be severe when there is a large within-cluster correlation and the proportion of patients that have both unaffected and affected units is small. 展开更多
关键词 DIAGNOSTIC Test Optimal WEIGHT ASYMPTOTIC RELATIVE Efficiency Receiver Operating Characteristic curve area under a ROC curve
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FPGA Implementation of Elliptic-Curve Diffie Hellman Protocol
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作者 Sikandar Zulqarnain Khan Sajjad Shaukat Jamal +1 位作者 Asher Sajid Muhammad Rashid 《Computers, Materials & Continua》 SCIE EI 2022年第10期1879-1894,共16页
This paper presents an efficient crypto processor architecture for key agreement using ECDH(Elliptic-curve Diffie Hellman)protocol over GF2163.The composition of our key-agreement architecture is expressed in consist... This paper presents an efficient crypto processor architecture for key agreement using ECDH(Elliptic-curve Diffie Hellman)protocol over GF2163.The composition of our key-agreement architecture is expressed in consisting of the following:(i)Elliptic-curve Point Multiplication architecture for public key generation(DESIGN-I)and(ii)integration of DESIGN-I with two additional routing multiplexers and a controller for shared key generation(DESIGN-II).The arithmetic operators used in DESIGN-I and DESIGNII contain an adder,squarer,a multiplier and inversion.A simple shift and add multiplication method is employed to retain lower hardware resources.Moreover,an essential inversion operation is operated using the Itoh-Tsujii algorithm with similar hardware resources of used squarer and multiplier units.The proposed architecture is implemented in a Verilog HDL.The implementation results are given on a Xilinx Virtex-7 FPGA(field-programmable gate array)device.For DESIGN-I and DESIGN-II over GF2163,(i)the utilized Slices are 3983 and 4037,(ii)the time to compute one public key and a shared secret is 553.7μs and 1170.7μs and(iii)the consumed power is 29μW and 57μW.Consequently,the achieved area optimized and power reduced results show that the proposed ECDH architecture is a suitable alternative(to generate a shared secret)for the applications that require low hardware resources and power consumption. 展开更多
关键词 Elliptic curve cryptography point multiplication key-agreement diffie hellman area optimized architecture FPGA
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布鲁氏菌病患者外周血白细胞及血小板参数的变化及临床意义 被引量:1
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作者 乔坤艳 刘韦娜 +2 位作者 郑晓雅 苏瑞 杨悦杰 《天津医药》 CAS 2024年第4期391-396,共6页
目的 研究布鲁氏菌病患者外周血白细胞及血小板参数的变化及其特点,探讨其临床应用价值。方法 纳入确诊布鲁氏菌病的患者90例,其中急性期59例,慢性期31例,另外选取同期40例健康人群为健康对照组。收集患者的临床症状等基本资料;采用全... 目的 研究布鲁氏菌病患者外周血白细胞及血小板参数的变化及其特点,探讨其临床应用价值。方法 纳入确诊布鲁氏菌病的患者90例,其中急性期59例,慢性期31例,另外选取同期40例健康人群为健康对照组。收集患者的临床症状等基本资料;采用全自动血液分析仪检测各组外周血白细胞计数、淋巴细胞计数、中性粒细胞计数、单核细胞计数、血小板计数、平均血小板体积(MPV)、血小板分布宽度(PDW);采用流式细胞仪检测外周血CD3^(+)T、CD4^(+)T及CD8^(+)T细胞计数,计算患者的中性粒细胞/淋巴细胞比值(NLR)及血小板/淋巴细胞比值(PLR),分析各细胞参数的变化特点并分析各参数对布鲁氏菌病的临床诊断价值。结果 慢性期组的关节痛和脊柱炎占比高于急性期组(P<0.05);与健康对照组相比,急性期组的白细胞计数、中性粒细胞计数、血小板计数及NLR均降低,慢性期组MPV和PDW降低,而CD3^(+)T细胞计数和单核细胞计数升高(P<0.05)。有关节炎症状的急性期布病患者白细胞计数、淋巴细胞计数、CD3^(+)T细胞计数和CD8^(+)T细胞计数低于无关节炎的急性期布病患者,而PLR则升高(P<0.05)。受试者工作特征(ROC)曲线分析结果显示中性粒细胞计数和NLR水平对于急性期布鲁氏菌病的ROC曲线下面积(AUC)分别为0.780和0.717,而CD3^(+)T细胞计数对于诊断慢性期布鲁氏菌病的AUC为0.748。在急性期患者中,CD3^(+)T、CD8^(+)T细胞计数及PLR水平对诊断关节炎的AUC分别为0.779、0.768、0.722。结论 急性期和慢性期布鲁氏菌病患者外周血白细胞和血小板参数均有不同程度的改变,对于布鲁氏菌病的诊断以及急性期布病患者关节炎的诊断有一定的临床应用价值。 展开更多
关键词 布鲁杆菌病 白细胞计数 血小板计数 关节炎 曲线下面积
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城市轨道交通轨面短波不平顺谱实测研究 被引量:1
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作者 房建 王宏轩 +3 位作者 郑稳稳 涂祥国 雷晓燕 练松良 《北京交通大学学报》 CAS CSCD 北大核心 2024年第1期96-105,共10页
针对城市轨道交通诱发的振动噪声问题,对轨面短波不平顺进行研究.首先,对上海市轨道交通线路轨面短波不平顺实测数据进行零均值化、剔除异常值、消除趋势项等预处理.其次,利用改进的协方差法计算得到轨面短波不平顺功率谱,分析轨道类型... 针对城市轨道交通诱发的振动噪声问题,对轨面短波不平顺进行研究.首先,对上海市轨道交通线路轨面短波不平顺实测数据进行零均值化、剔除异常值、消除趋势项等预处理.其次,利用改进的协方差法计算得到轨面短波不平顺功率谱,分析轨道类型、曲线半径及钢轨接头对轨面短波不平顺功率谱分布规律的影响.然后,基于非线性最小二乘法对轨面短波不平顺谱进行拟合.最后,提出我国城市轨道交通轨面短波不平顺统计谱表达式.研究结果表明:直线段接头区轨面短波不平顺功率谱密度曲线在整个分析波长范围内具有较多特征峰值;直线段接头区上、下行短波不平顺功率谱密度值随波长的分布特征和数值相差不大,说明上、下行的轨面不平顺状态基本相同;钢轨的磨耗程度与曲线半径呈负相关,内、外轨面不平顺功率谱密度的差异随曲线半径的增大而减小,曲线半径是影响轨面不平顺状态的主要因素之一;线路类型对轨面短波不平顺功率谱的影响不大,不同曲线半径、焊接接头影响明显,在对轨道进行维护和养护时需关注小曲线半径区段以及焊接接头区段的不平顺状态. 展开更多
关键词 城市轨道交通 轨面短波不平顺 功率谱密度 改进协方差法 焊接接头区 曲线半径
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比较浓度-时间曲线下面积与谷浓度指导万古霉素治疗重症患者的临床随机对照研究
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作者 王锐 何囡囡 +4 位作者 席振创 罗延年 高雪花 李美玲 曹雯 《中国急救医学》 CAS CSCD 2024年第11期996-1001,共6页
目的探讨浓度-时间曲线下面积和谷浓度指导万古霉素治疗重症患者的临床安全性和疗效差异。方法入选2021年1月至2023年12月收住兰州大学第二医院重症医学科因革兰阳性菌感染且经医师确认需使用万古霉素治疗的患者,经纳排标准筛选后,采用... 目的探讨浓度-时间曲线下面积和谷浓度指导万古霉素治疗重症患者的临床安全性和疗效差异。方法入选2021年1月至2023年12月收住兰州大学第二医院重症医学科因革兰阳性菌感染且经医师确认需使用万古霉素治疗的患者,经纳排标准筛选后,采用随机数字表法将入选患者分为两组进行前瞻性、随机、单盲对照研究,对照组以万古霉素谷浓度10~20 mg/L为目标靶值,观察组以万古霉素浓度-时间曲线下面积400~600 mg·h/L为目标靶值。经过监测,最终对照组77例、观察组79例符合目标靶值范围并进行相关统计学分析与比较。结果观察组万古霉素相关急性肾损伤(AKI)发生率明显低于对照组(P=0.002),两组临床疗效及总治疗时间差异无统计学意义。根据多因素Logistic回归分析显示,谷浓度(OR=1.021,95%CI 1.019~1.577,P=0.033)及急性生理学和慢性健康状况评价Ⅱ(APACHEⅡ)评分(OR=1.189,95%CI 1.055~1.339,P=0.004)是万古霉素相关AKI独立危险因素,采样总数量(OR=0.476,95%CI 0.247~0.917,P=0.000)是临床转归独立危险因素。对谷浓度与万古霉素相关AKI进行受试者工作特征(ROC)曲线分析,谷浓度预测万古霉素相关AKI临界值为15.65 mg/L,敏感度为0.786,特异度为0.697,ROC曲线下面积为0.727。结论基于浓度-时间曲线下面积为目标靶值的药物监测方法,可以减少万古霉素相关AKI发生,但临床疗效无差别。 展开更多
关键词 浓度-时间曲线下面积 谷浓度 万古霉素 肾毒性
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区域地质灾害易发性评价的证据权法原理与实践
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作者 冯振 陈亮 +3 位作者 王立朝 侯圣山 田怡帆 刘明学 《地质通报》 CAS CSCD 北大核心 2024年第7期1255-1265,共11页
在阐述证据权法概念与原理的基础上,以西北黄土高原滑坡、崩塌地质灾害高易发的兰州市区为评价区,详解基于证据权法的区域地质灾害易发性评价的技术流程,利用GIS工具,开展评价指标选取与相关性分析、证据因子权重与后验概率分析、评价... 在阐述证据权法概念与原理的基础上,以西北黄土高原滑坡、崩塌地质灾害高易发的兰州市区为评价区,详解基于证据权法的区域地质灾害易发性评价的技术流程,利用GIS工具,开展评价指标选取与相关性分析、证据因子权重与后验概率分析、评价模型检验、易发程度评价。分析结果显示,坡度、坡向、地层岩性、断层、绿化灌溉、土地利用类型等地质灾害影响因素之间呈无相关或弱相关性,符合相互独立的要求,组成的模型ROC曲线(接受者操作特征曲线)AUC值(曲线下面积)为0.85,具有较高的预测精度。理论与实践表明,与其他统计学方法相比,证据权法同时考虑了评价指标中存在地质灾害与不存在地质灾害2种情况,避免了当地质灾害不存在时权重偏大导致结果失真的问题。证据权法结果为地质灾害发生的绝对概率,可以作为不同区域、地区的地质灾害易发程度对比的依据。 展开更多
关键词 地质灾害 易发性评价 证据权 后验概率 ROC曲线 兰州
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目标区域引导的RRT^(*)机械臂路径规划算法
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作者 孟月波 张子炜 +2 位作者 吴磊 刘光辉 徐胜军 《计算机科学与探索》 CSCD 北大核心 2024年第9期2407-2421,共15页
针对传统RRT^(*)算法在机械臂路径规划的过程中存在规划效率低、路径质量不佳、机械臂位姿不当等问题,提出一种目标区域引导的RRT^(*)机械臂路径规划算法(TA-RRT^(*))。在传统RRT^(*)算法基础上,引入目标偏向策略并使用球形子集约束采样... 针对传统RRT^(*)算法在机械臂路径规划的过程中存在规划效率低、路径质量不佳、机械臂位姿不当等问题,提出一种目标区域引导的RRT^(*)机械臂路径规划算法(TA-RRT^(*))。在传统RRT^(*)算法基础上,引入目标偏向策略并使用球形子集约束采样,缩小采样范围并使新节点朝向目标点扩展,增强目标导向性;对新节点采用直连策略,让算法可以更快地收敛从而提升路径生成速度。对初始规划路径去除冗余点并使用三次B样条曲线转换成平滑路径,优化了路径质量。对机械臂进行位姿约束,通过机械臂逆运动学判断机械臂连杆位姿可达性,并利用包络盒模型判断机械臂是否与障碍物碰撞。实验结果表明,在二维以及三维场景下,TA-RRT^(*)算法在采样次数、规划时间、路径长度以及平滑度等方面的性能均优于RRT^(*)算法,验证了该方法的正确性及可行性。机械臂仿真实验以及在真实环境下的测试结果显示,加入位姿约束后机械臂运行规划好的轨迹时,机械臂各个关节在运行规划路径的过程中并未与障碍物发生碰撞且具有良好的稳定性。 展开更多
关键词 RRT^(*)算法 机械臂路径规划 目标区域引导 三次B样条曲线
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动态增强磁共振成像定量参数联合表观扩散系数值对外周带前列腺癌的诊断价值研究
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作者 刘婷婷 王晓辉 +3 位作者 王洪兴 潘锋 李昊 胡海峰 《临床误诊误治》 CAS 2024年第13期71-76,共6页
目的探究动态增强磁共振成像(DCE-MRI)定量参数联合表观扩散系数(ADC)值诊断外周带早期前列腺癌的价值。方法选取2019年2月至2021年12月经穿刺病理学检查确诊为外周带早期前列腺癌31例和前列腺炎27例为研究对象。患者均进行DCE-MRI定量... 目的探究动态增强磁共振成像(DCE-MRI)定量参数联合表观扩散系数(ADC)值诊断外周带早期前列腺癌的价值。方法选取2019年2月至2021年12月经穿刺病理学检查确诊为外周带早期前列腺癌31例和前列腺炎27例为研究对象。患者均进行DCE-MRI定量参数检查,以病理学检查结果为金标准,分析不同患者的DCE-MRI特征。并采用受试者工作特征曲线下面积(AUC)分析基于DCE-MRI定量参数与扩散加权成像(DWI)序列对外周带早期前列腺癌与前列腺炎的诊断价值。结果31例前列腺癌患者中,T2加权成像(T2WI)以外周带结节状低信号为主,占58.06%;DWI以结节状、弥漫性高信号,ADC值下降为主,占51.61%;DCE-MRI可见病灶早期强化,以延迟后病灶造影剂退出,强化曲线呈流出型为主,占64.52%。27例前列腺炎患者中,T2WI以外周带单侧或双侧弥漫性不均匀低信号为主,占51.85%;DWI可见外周带单侧或双侧不规则高信号,ADC值降低为主,占59.26%;DCE-MRI可见病灶早期强化,以延迟后造影剂退出不明显,强化曲线呈流入型为主,占81.48%。外周带早期前列腺癌患者ADC值低于前列腺炎,速率常数(Kep)值、转移常数(K^(trans))高于前列腺炎(P<0.05)。DCE-MRI定量参数联合ADC值诊断外周带早期前列腺癌的AUC为0.862(95%CI:0.659,0.865)、敏感度为87.10%,特异度为81.48%,准确度为84.48%,阳性预测值为84.38%,阴性预测值为84.62%。结论DCE-MRI定量参数联合ADC值对外周带早期前列腺癌的诊断效能良好,能显著提高临床检出率,为疾病的诊断与治疗提供依据。 展开更多
关键词 前列腺肿瘤 前列腺炎 动态增强磁共振成像 扩散加权成像 病理学 诊断 受试者工作特征曲线 曲线下面积
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骨科术后患者万古霉素AUC_(0~24h)影响因素分析及预测模型研究
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作者 杨浩 熊雄 +1 位作者 刘长江 金小越 《中国药师》 CAS 2024年第1期66-75,共10页
目的探讨万古霉素在骨科术后患者中的24 h曲线下面积(AUC_(0~24h))的影响因素,并预测分析AUC_(0~24h)较好的药代动力学模型。方法纳入新疆医科大学第六附属医院2018年1月至2022年12月进行骨科手术并使用万古霉素的患者,收集患者的基本... 目的探讨万古霉素在骨科术后患者中的24 h曲线下面积(AUC_(0~24h))的影响因素,并预测分析AUC_(0~24h)较好的药代动力学模型。方法纳入新疆医科大学第六附属医院2018年1月至2022年12月进行骨科手术并使用万古霉素的患者,收集患者的基本信息、用药情况、血常规和血生化指标,分析影响骨科术后患者万古霉素AUC_(0~24h)的因素。采用一级药代动力学公式、个体化给药辅助决策系统(JPKD)和万古霉素日剂量消除率公式计算AUC_(0~24h)。结果最终纳入91例患者,结果发现胱抑素C(OR=189.168,P=0.005)和单次剂量(OR=19.160,P<0.001)是骨科术后患者万古霉素AUC_(0~24h)的独立保护因素,视黄醇结合蛋白是万古霉素AUC_(0~24h)的独立危险因素(OR=0.910,P<0.05)。通过对骨科术后患者万古霉素AUC_(0~24h)模型预测分析,JPKD软件和万古霉素日剂量消除率公式的绝对权重偏差均低于30%,JPKD软件和万古霉素日剂量消除率公式的AUC_(0~24h)与一级药代动力学公式的AUC_(0~24h)组内相关系数分别为0.781和0.524。结论胱抑素C是影响骨科术后患者万古霉素AUC_(0~24h)的重要因素,JPKD软件较万古霉素日剂量消除率公式方法更适用于预测骨科术后万古霉素AUC_(0~24h)。 展开更多
关键词 骨科术后 万古霉素 24 h曲线下面积 预测模型
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肾小管及肾小球标志物在2型糖尿病患者不同肾损伤阶段诊断价值的研究
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作者 张琳 谢荣荣 +5 位作者 杨芳远 李眉 罗莎 万晓华 田玮 杨金奎 《首都医科大学学报》 CAS 北大核心 2024年第3期429-437,共9页
目的探讨肾小管及肾小球相关标志物在2型糖尿病(type 2 diabetes mellitus,T2DM)患者不同肾损伤阶段的诊断价值。方法选取于2018年4月1日至2019年10月31日入住首都医科大学附属北京同仁医院内分泌科的T2DM患者272例,完善临床生化指标及... 目的探讨肾小管及肾小球相关标志物在2型糖尿病(type 2 diabetes mellitus,T2DM)患者不同肾损伤阶段的诊断价值。方法选取于2018年4月1日至2019年10月31日入住首都医科大学附属北京同仁医院内分泌科的T2DM患者272例,完善临床生化指标及尿蛋白四项:尿微量白蛋白/肌酐(urinary albumin to creatinine ratio,ACR)、α1-微球蛋白/肌酐(urinary α1-microglobulin to creatinine ratio,UA1CR)、免疫球蛋白G/肌酐(urinary immunoglobulin G to creatinine ratio,UIGG)、转铁蛋白/肌酐(urinary transferrin to creatinine ratio,UTRF);进行眼底照相、核医学99mTc-EC检测肾有效血浆流量(effective renal plasma flow,ERPF)和99mTc-DTPA检测肾小球滤过率(glomerular filtration rate,GFR)。根据ACR和眼底检查结果分为4组:正常蛋白尿无糖尿病视网膜病变(diabetic retinopathy,DR)132例,即对照组(ACR≤30 mg/g);正常蛋白尿合并DR 32例,为糖尿病肾病(diabetic kidney disease,DKD)前期组;微量蛋白尿组78例(30<ACR≤300 mg/g)和大量蛋白尿组30例(ACR>300 mg/g)。比较四组间尿蛋白四项和ERPF、GFR的水平,通过受试者工作特征(receiver operating characteristic,ROC)曲线评价上述各指标在不同肾损伤阶段的诊断价值。结果尿蛋白四项和ERPF、GFR的水平在不同组间差异有统计学意义(P<0.05)。在尿蛋白正常组中,DR组中肾小管功能标志物UA1CR较对照组明显升高(P<0.01);肾小球功能标志物ACR、UTRF和GFR在两组间差异无统计学意义(P>0.05),DR组UIGG较对照组升高(P<0.01)。在微量蛋白尿组和大量蛋白尿组,尿蛋白四项随肾损伤程度增加而增加,而ERPF和GFR随肾损伤程度增加而降低。ROC曲线分析显示,在尿蛋白排出正常的T2DM患者中合并DR组中肾小管功能标志物UA1CR和ERPF的曲线下面积(area under the curve,AUC)分别为68.2%(P<0.01)和60.5%(P<0.05),而肾小球功能标志物ACR和GFR的AUC均小于60%,差异无统计学意义(P>0.05)。尿蛋白四项及GFR在微量和大量蛋白尿组的AUC均大于60%(P<0.05),ERPF在大量蛋白尿组AUC为67.2%(P<0.05)。结论T2DM极早期微血管改变即ACR正常仅有DR时,肾小管标志物UA1CR先于肾小球标志物ACR和GFR发生变化。肾损伤早期,肾小管标志物诊断效能优于肾小球;肾损伤后期,肾小球标志物诊断效能优于肾小管。提示DKD肾小管功能的改变可能早于肾小球。 展开更多
关键词 糖尿病肾病 肾小管标志物 Α1-微球蛋白 肾有效血浆流量 ROC曲线下面积
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基于光纤传感器的视频图像几何失真校正方法
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作者 张西广 张龙飞 樊银亭 《激光杂志》 CAS 北大核心 2024年第3期150-155,共6页
视频图像在传播过程中会出现信息畸变,致使图像几何失真,为此提出基于光纤传感器的视频图像几何失真校正方法。分析视频图像像素节点在光敏区域分布情况,提取亚像素视差信息,通过面阵CCD图像传感器获取畸变视频图像;利用畸变曲线近似模... 视频图像在传播过程中会出现信息畸变,致使图像几何失真,为此提出基于光纤传感器的视频图像几何失真校正方法。分析视频图像像素节点在光敏区域分布情况,提取亚像素视差信息,通过面阵CCD图像传感器获取畸变视频图像;利用畸变曲线近似模型计算出视频图像畸变率,确定畸变图像坐标,并结合双线性灰度插值算法推导校正参数,实现视频图像的几何失真校正。实验结果表明,所提方法能够有效校正不同种类的视频图像几何畸变,校正后的图像与原图像相似度高超过0.97,图像边缘模糊程度降低,提高了图像的视觉观测效果。 展开更多
关键词 传输面阵CCD多模图像传感模型 几何矩阵 畸变率曲线 畸变率 插值法
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基于斑马算法优化支持向量回归机模型预测页岩地层压力
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作者 赵军 李勇 +2 位作者 文晓峰 徐文远 焦世祥 《岩性油气藏》 CAS CSCD 北大核心 2024年第6期12-22,共11页
针对陇东地区三叠系延长组7段(长7段)页岩孔隙结构复杂、非均质性强、地层压力预测精度较低等问题,提出了一种基于斑马算法优化支持向量回归机(ZOA-SVR)模型预测地层压力的方法,并在实际钻井中进行了应用,将预测结果与基于机器算法的模... 针对陇东地区三叠系延长组7段(长7段)页岩孔隙结构复杂、非均质性强、地层压力预测精度较低等问题,提出了一种基于斑马算法优化支持向量回归机(ZOA-SVR)模型预测地层压力的方法,并在实际钻井中进行了应用,将预测结果与基于机器算法的模型和常规地层压力预测方法结果进行了对比。研究结果表明:①ZOA-SVR模型以实测地层压力数据为目标变量,优选与陇东地区长7段页岩地层压力数据关联度达到0.70以上的深度、声波时差、密度、补偿中子、自然伽马、深侧向电阻率、泥质含量等7个参数作为输入特征参数,设置训练样本数为40,交叉验证折数为5,初始化斑马种群数量为10,最大迭代次数为70,对惩罚因子和核参数进行优化并建模,参数优化后拟合优度指标R2达到0.942,模型预测的地层压力数据在训练集和测试集上的绝对误差均低于1 MPa,预测测试集地层压力数据与实测压力数据的平均相对误差为2.42%。②ZOA-SVR模型在研究区长7段地层压力预测中优势明显,比基于粒子群优化算法、灰狼算法和蚁群算法的模型具有更好的参数调节及优化能力,R2分别提高了0.209,0.327,0.142;比等效深度法、Eaton法、有效应力法预测的地层压力精度更高,相对误差分别降低了32.53%,15.31%,5.91%。③ZOA-SVR模型在实际钻井中的应用结果显示,研究区长7段地层压力在垂向上分布较稳定,泥页岩段的地层压力高于砂岩段,地层压力系数主要为0.80~0.90,整体上属于异常低压环境,与实际地层情况相符。 展开更多
关键词 页岩 地层压力 斑马优化算法 支持向量回归机 机器学习 测井曲线 长7段 三叠系 陇东地区
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