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Prevalence of Metabolic Obese Normal Weight and Related Risk Factors in South China
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作者 Xuehua LUO Zien LIANG +7 位作者 Yan LI Qingbin WU Zhiqiang PAN Yuqing LIANG Lingyu LI Juanjuan MAI Huijun XIE Li HAN 《Medicinal Plant》 CAS 2021年第2期74-78,共5页
[Objectives]Metabolic obese normal weight(MONW)is becoming one of the pubic problems which are threatening human health.Whereas,MONW was facing a great challenge for limited attention,especially for the female in Chin... [Objectives]Metabolic obese normal weight(MONW)is becoming one of the pubic problems which are threatening human health.Whereas,MONW was facing a great challenge for limited attention,especially for the female in China.The aim of this research was to estimate the prevalence of MONW and its related risk components in South China.[Methods]A community-based cross-sectional study was performed on 3349 residents aged 18-93 years in The First Affiliated Hospital of Jinan University,Guangzhou,China,in 2019.Data was collected by physical examination data which included physical measurements and laboratory examinations.[Results]In all subjects,55%were females(M/F=1509/1840).The prevalence of MONW was 16.09%(0.04%for male,16.05%for female,P<0.001).The prevalence increased significantly with increasing age in both genders(P<0.001).The binary logistic regression analysis shows that among the risk factors with MONW,age,BMI,gender,systolic pressure,hypertension[Male:ORs=2.56,95%CI(1.23,5.32);Female:ORs=2.88,95%CI(1.76,4.71)]and hypertriglyceridemia[Male:ORs=3.23,95%CI(1.67,6.19);Female:ORs=2.57,95%CI(1.64,4.03)]were found to be statistically significant.The level of ALT in MONW group was(27.88±15.85)in male and(24.33±15.75)in female,which were significantly higher than those in the non-MetS group.[Conclusions]The prevalence of MONW was pretty high.We considered MONW be significantly associated with the increase of ALT.Female gender,advanced age,and elevated ALT were independent risk factors for MONW.It was high time that the government should raise the public attention toward metabolic function in normal weight population.Effective prevention and treatment strategies for MONW and its risk factors should be developed targeting different ages and genders. 展开更多
关键词 Metabolic Obese normal weight PREVALENCE Related risk factor
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Therapeutic Effect of Lifestyle Intervention Combined with Drug Therapy on Patients with Normal Weight Polycystic Ovary Syndrome
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作者 ZHANG Yan XU Qiongkai +1 位作者 HUANG Shaozhen ZHOU Huanlian 《外文科技期刊数据库(文摘版)医药卫生》 2021年第7期042-043,共4页
Objective: to investigate the clinical efficacy and lifestyle of clomiphene citrate in the treatment of normal weight polycystic ovary syndrome. Methods: from June 2017 to June 2018, 76 patients with normal weight pol... Objective: to investigate the clinical efficacy and lifestyle of clomiphene citrate in the treatment of normal weight polycystic ovary syndrome. Methods: from June 2017 to June 2018, 76 patients with normal weight polycystic ovary syndrome diagnosed and treated in our hospital were investigated and analyzed. All patients were randomly divided into experimental group and control group. The control group was given clomiphene citrate to induce ovulation, and the experimental group was given lifestyle intervention therapy on the basis of the control group. The therapeutic effects of the two groups were compared. Results: the experimental group was significantly higher than the control group, and the difference was statistically significant (P < 0.05) after statistical calculation of the treatment effect of the patient. The indexes of luteinizing hormone experimental group, endometrial thickness, ovarian volume and the like of the patient were all thicker than those of the control group. The comparison results of the two data groups showed that there was a difference (P < 0.05). Conclusion: lifestyle intervention combined with drug-induced ovulation in patients with normal weight polycystic ovary syndrome can increase the endometrial thickness of patients, which is of great significance for clinical promotion and application. 展开更多
关键词 polycystic ovary syndrome with normal weight clomiphene citrate inducing ovulation lifestyle inte
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Process Capability Analysis of Delivering Neonatal Care with Normal Weight (Case Study of Neonatal Weight Data at a Maternity Clinic in Banjarmasin)
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作者 Dewi Anggraini 《Journal of Life Sciences》 2011年第12期996-1002,共7页
Statistical Quality Control (SQC) is used to analyze and monitor quality characteristic measurements of normal neonatal weight in a maternity clinic in Banjarmasin in this paper. The objective of this study is to as... Statistical Quality Control (SQC) is used to analyze and monitor quality characteristic measurements of normal neonatal weight in a maternity clinic in Banjarmasin in this paper. The objective of this study is to assist medical practitioners in observing pregnant women to deliver their babies with normal weight. It is also assumed that pregnant women who delivered their babies in the clinic have been monitored during their nine-month pregnancy. Thus, they can manage their own pregnancy to deliver normal weight babies. The use of Statistical Process Control (SPC) tools, such as frequency histogram, probability plot, and the implementation of Shewhart, R, and S control charts as primary techniques, are presented to display the monitoring aspects of the process. In addition, Process Capability Analysis (PCA) is performed to ensure that the process outcomes are capable of meeting certain requirements or specifications. The Process Capability Ratio (PCR) for the process is also presented. This analysis is an essential part of an overall quality improvement program. 展开更多
关键词 Process capability analysis Shewhart control chart R-chart normal neonatal weight.
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Composition Cesàro Operator on the Normal Weight Zygmund Space in High Dimensions 被引量:1
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作者 Si XU Xuejun ZHANG Shenlian LI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2021年第1期69-84,共16页
Let n>1 and B be the unit ball in n dimensions complex space C^(n).Suppose thatφis a holomorphic self-map of B andψ∈H(B)withψ(0)=0.A kind of integral operator,composition Cesàro operator,is defined by T_(... Let n>1 and B be the unit ball in n dimensions complex space C^(n).Suppose thatφis a holomorphic self-map of B andψ∈H(B)withψ(0)=0.A kind of integral operator,composition Cesàro operator,is defined by T_(φ)ψ(f)(z)=∫^(1)0f[φ(tz)]Rψ(tz)dt/t,f∈(B)z∈B.In this paper,the authors characterize the conditions that the composition Cesàro operator T_φ,ψis bounded or compact on the normal weight Zygmund space Z_μ(B).At the same time,the sufficient and necessary conditions for all cases are given. 展开更多
关键词 normal weight Zygmund space Composition Cesàro operator Boundedness and compactness
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Composition operators on the normal weight Dirichlet type space in the unit disc
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作者 Xuejun ZHANG Min ZHOU Hongxin CHEN 《Frontiers of Mathematics in China》 SCIE CSCD 2022年第4期545-552,共8页
Let p>0 andνbe a normal function on[0,1).In this paper,several equivalent characterizations are given for which composition operators are bounded or compact on the normal weight Dirichlet type space D_(ν)^(p)(D)i... Let p>0 andνbe a normal function on[0,1).In this paper,several equivalent characterizations are given for which composition operators are bounded or compact on the normal weight Dirichlet type space D_(ν)^(p)(D)in the unit disc. 展开更多
关键词 Composition operator normal weight Dirichlet type space BOUNDEDNESS COMPACTNESS unit disc
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Dombi-Normalized Weighted Bonferroni Mean Operators with Novel Multiple-Valued Complex Neutrosophic Uncertain Linguistic Sets and Their Application in Decision Making 被引量:1
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作者 Tahir Mahmood Zeeshan Ali +1 位作者 Dulyawit Prangchumpol Thammarat Panityakul 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第3期1587-1623,共37页
Although fuzzy set concepts have evolved,neutrosophic sets are attractingmore attention due to the greater power of the structure of neutrosophic sets.The ability to account for components that are true,false or neith... Although fuzzy set concepts have evolved,neutrosophic sets are attractingmore attention due to the greater power of the structure of neutrosophic sets.The ability to account for components that are true,false or neither true nor false is useful in the resolution of real-life problems.However,simultaneous variations render neutrosophic sets unsuitable in specific circumstances.To enable the management of these sorts of issues,we combine the principle of multi-valued neutrosophic uncertain linguistic sets and complex fuzzy sets to develop the principle of multivalued complex neutrosophic uncertain linguistic sets.Multi-valued complex neutrosophic uncertain linguistic sets can contain grades of truth,abstinence,and falsity,and uncertain linguistic terms,which are expressed as complex numbers whose real and imaginary parts are limited to the unit interval.Some important Dombi laws are elaborated along with Bonferroni mean operators,which offer a flexible general structure with modifiable factors.Bonferroni means aggregation operators perform a significant role in conveying the magnitude level of options and characteristics.To determine relationships among any number of attributes,we develop multi-valued complex neutrosophic uncertain linguistic Dombi-normalized weighted Bonferroni mean operators and discuss their important properties with some special cases.By using these laws,we can deploy themulti-attribute decisionmaking(MADM)technique using the novel principle of multi-valued complex neutrosophic uncertain linguistic sets.To determine the power and flexibility of the elaborated approach,we resolve some numerical examples based on the proposed operator.Finally,the work is validated with the help of comparative analysis,a discussion of its advantages,and geometric expressions of the elaborated theories. 展开更多
关键词 Multi-valued complex neutrosophic uncertain linguistic sets Dombi normalized weighted Bonferroni mean operators multi-attribute decision-making methods
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Spectrum of Normal Weighted Composition Operators on the Fock Space Over C^N 被引量:4
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作者 Li Xia FENG Lian Kuo ZHAO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2019年第9期1563-1572,共10页
By using commutative C*-algebra techniques, spectrum and essential spectrum of normal weighted composition operators on the Fock space over CN are completely characterized. As an application, spectrum of self-adjoint ... By using commutative C*-algebra techniques, spectrum and essential spectrum of normal weighted composition operators on the Fock space over CN are completely characterized. As an application, spectrum of self-adjoint weighted composition operators on the Fock space are obtained also. 展开更多
关键词 FOCK space weigh TED composition OPERATOR normal SPECTRUM
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A Class of Normal Weighted Composition Operators on the Fock Space of C^n 被引量:3
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作者 Lian Kuo ZHAO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2015年第11期1789-1797,共9页
This paper characterizes a class of normal weighted composition operators and their spectrum on the Fock space of Cn.
关键词 Fock space weighted composition operator normal SPECTRUM
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Metabolically obese normal-weight children
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作者 Fernando Guerrero-Romero Martha Rodríguez-Moran 《World Journal of Clinical Pediatrics》 2012年第4期37-39,共3页
Non-obese children with elevated serum insulin levels and metabolic disorders such as,hyperglycemia,hypertension,and/or hypertriglyceridemia are a subset of children in high risk of developing cardiovascular disease l... Non-obese children with elevated serum insulin levels and metabolic disorders such as,hyperglycemia,hypertension,and/or hypertriglyceridemia are a subset of children in high risk of developing cardiovascular disease later in life.Since usually the health policies for the prevention of the obesity associated disorders in children are based on the screening focused on the obese,frequently the metabolically obese normalweight(MONW) children are not identified in primary care setting.Given that characterization of the MONW children is an important public health issue,and that a large amount of resources might be unnecessarily used in the screening of metabolic risk of nonobese children; we review data regarding criteria for the early recognition of this subset of children in high risk of developing cardiovascular disease.Results of our review suggests that the presence of family history of type 2 diabetes and/or hypertension,the elevated percentage of body fat,and the high birth-weight should be taken into account as criteria of high cardiovascular risk,irrespective of obesity. 展开更多
关键词 Children normal-weight CARDIOVASCULAR risk factors Screening OBESITY
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结合图论Normalized Cut方法的彩色图像分割研究 被引量:1
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作者 任爱红 白婷婷 《甘肃科学学报》 2012年第3期147-150,共4页
归一化彩色图像分割中高斯核函数的参数选择直接影响到分割效果.为了寻找无参数的权值计算方法,提出将彩色图像中的像素点视为RGB空间的三维向量,使用向量的方向和幅值差异来衡量像素点的相似性,再使用Normalized Cut方法进行分割.实验... 归一化彩色图像分割中高斯核函数的参数选择直接影响到分割效果.为了寻找无参数的权值计算方法,提出将彩色图像中的像素点视为RGB空间的三维向量,使用向量的方向和幅值差异来衡量像素点的相似性,再使用Normalized Cut方法进行分割.实验结果表明,该方法能有效区分不同的颜色信息,计算复杂度不大,兼顾了算法的运算时间及分割效果,对不同的彩色图像均能得到准确的分割结果. 展开更多
关键词 图论 权值函数 归一割 彩色图像分割
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Diabetes in adolescents without obesity in India:An underrecognized phenotype
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作者 Rashi Agrawal Akhila Bhandarkar Nitin Kapoor 《World Journal of Clinical Pediatrics》 2025年第4期537-541,共5页
Adolescent type 2 diabetes mellitus(T2DM)is on the rise in India and is commonly attributed to co-existence of overweight and obesity in adolescents.In this line,a study by Maheshwari et al titled‘Prevalence of obesi... Adolescent type 2 diabetes mellitus(T2DM)is on the rise in India and is commonly attributed to co-existence of overweight and obesity in adolescents.In this line,a study by Maheshwari et al titled‘Prevalence of obesity,determinants,and its association with hyperglycaemia among community dwelling older adolescents in India’concluded that overweight,obesity,socioeconomic factors and higher education status were responsible for hyperglycemia in adolescents aged 15-19 years in India.We highlight that there is a significant prevalence of T2DM even in normal body mass index(BMI)and below normal BMI subjects,as mentioned in their study.There is a high prevalence of normal weight obesity in Indian adolescents which often gets missed due to a large population with normal BMI in the country.In this letter,we analyze the importance of measurement of central adiposity beyond routine BMI measurements. 展开更多
关键词 normal weight obesity Adolescents Body mass index Metabolic syndrome Body composition Visceral fat Cardiometabolic risk
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Dietary antioxidant index and cardiometabolic risks in normal-weight individuals:Evidence from the National Health and Nutrition Examination Survey
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作者 Ting Xue Xiuying He +5 位作者 Yiyang Xu Ji Fang Min Lin Lihua Cai Tian Zheng Li Li 《Asia Pacific Journal of Clinical Nutrition》 2025年第6期941-951,共11页
Background and Objectives:Caloric restriction is the most popular dietary intervention for preventing metabolicdisorders.However,its benefits are limited in normal-weight individuals.This study aimed to examine the as... Background and Objectives:Caloric restriction is the most popular dietary intervention for preventing metabolicdisorders.However,its benefits are limited in normal-weight individuals.This study aimed to examine the associationbetween composite dietary antioxidant index(CDAI)and metabolically unhealthy normal weight(MUNW),as well as the relationship between CDAI and cardiometabolic mortality among normal-weight individuals,in order to provide personalized dietary recommendations.Methods and Study Design:This study consistedof two parts:(1)a cross-sectional analysis exploring the association between CADI and MUNW;and(2)aprospective cohort analysis assessing CDAI in relation to cardiometabolic mortality.Adult participants with normalweight from the National Health and Nutrition Examination Survey(2007-2018)were enrolled and classifiedinto quartile groups based on CDAI for the analyses.Results:Among 4,590 participants included in this study,472(7.82%)were diagnosed with MUNW.After full adjustment,the odds ratios(95%confidence intervals)forMUNW across the increasing CDAI levels were 0.80(0.50-1.29),0.85(0.51-1.41),and 0.48(0.26-0.87),respectively(p for trend=0.026).This inverse association appeared to be attenuated among participants aged 20~59years old(p for interaction=0.035).During 32,113 person-years of follow-up,82 cardiometabolic deaths occurred.After full adjustment,the hazard ratios(95%confidence intervals)for cardiometabolic mortality acrossthe increasing CDAI levels were 0.78(0.35-1.73),0.51(0.20-1.27),and 0.40(0.19-0.87),respectively(p for trend=0.014).Conclusions:CDAI was inversely associated with MUNW and cardiometabolic mortality in a normalweightpopulation in the United States.These findings warrant confirmation through interventional studies. 展开更多
关键词 ANTIOXIDANT metabolically unhealthy normal weight NUTRITION the National Health and Nutrition Examination Survey cardiometabolic mortality
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城市公共安全韧性评价及提升策略研究——以内蒙古包头市为例
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作者 杨雪 孙秋月 《安全》 2025年第3期19-26,共8页
为强化城市公共安全韧性提升其抗风险水平,立足于经济、社会、基础设施及生态环境4个维度,融合扰动力、适应力与恢复力核心特征,构建城市公共安全韧性评价指标体系;运用熵权法计算指标权重,结合正态云模型对城市公共安全韧性水平进行评... 为强化城市公共安全韧性提升其抗风险水平,立足于经济、社会、基础设施及生态环境4个维度,融合扰动力、适应力与恢复力核心特征,构建城市公共安全韧性评价指标体系;运用熵权法计算指标权重,结合正态云模型对城市公共安全韧性水平进行评价,并应用于内蒙古自治区包头市韧性评价中。结果表明:包头市公共安全综合韧性等级为较高韧性,在经济、基础设施与生态环境方面的韧性水平优于社会韧性。基于评价结果,提出以下提升策略:构建经济韧性架构、健全社会保障机制、夯实基础设施建设、强化生态环境考量。 展开更多
关键词 城市公共安全 韧性评价 熵权法 正态云模型
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基于改进YOLOv5s的被遮挡交通标志检测算法
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作者 蓝章礼 邢彩卓 张洪 《计算机工程》 北大核心 2025年第5期361-369,共9页
智能驾驶中道路交通标志的检测与识别极其重要,针对交通标志被遮挡时存在目标小、检测精度低的问题,提出一种基于改进YOLOv5s的被遮挡交通标志检测算法。通过自制中国遮挡交通标志数据集(COTSD),解决交通标志在被遮挡情况下数据集缺乏... 智能驾驶中道路交通标志的检测与识别极其重要,针对交通标志被遮挡时存在目标小、检测精度低的问题,提出一种基于改进YOLOv5s的被遮挡交通标志检测算法。通过自制中国遮挡交通标志数据集(COTSD),解决交通标志在被遮挡情况下数据集缺乏的问题,并根据细粒度物体检测需要模型提取丰富判别特征,提出一种基于MobileNetv2改进的主干网络。针对交通标志较小、被遮挡且分辨率较低,普通线性插值方式无法捕捉更高阶、更细节特征的问题,设计一种改进的动态权重上采样模块(DEUM),整合经过通道注意力加权之后的通道信息进行像素重排,生成高分辨率图像;针对综合交并比(CIoU)等损失函数对小目标位置变化敏感的问题,使用归一化高斯Wassertein距离(NWD)来优化边界框回归损失。实验结果表明,该算法在自制被遮挡COTSD上的准确率为93.60%,召回率为72.50%,F1值为81.71%,mAP@0.5为79%;在包含少量被遮挡交通标志的公开CCTSDB上的准确率为92.2%,召回率为78.8%,F1值为85%,mAP@0.5为88.5%。该算法有效提高了被遮挡后交通标志的检测精度。 展开更多
关键词 交通标志检测 遮挡条件 MobileNetv2模型 动态权重上采样模块 归一化高斯Wassertein距离
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华南体重正常人群相对脂肪质量指数升高与代谢疾病关联研究
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作者 陈婉兰 何佳林 +5 位作者 杨嘉璐 李思琪 张琪 赵婉滢 柳雁 夏敏 《华南预防医学》 2025年第10期1076-1080,1086,共6页
目的本研究旨在探讨体重正常者相对脂肪质量指数(RFM)与代谢性疾病的关系,及此类人群在华南地区分布情况。方法研究采用了华南区域自然人群慢性病前瞻性队列研究(SCC)2018—2020年采集的25~89岁参与者的基线数据。研究分析体重正常者RF... 目的本研究旨在探讨体重正常者相对脂肪质量指数(RFM)与代谢性疾病的关系,及此类人群在华南地区分布情况。方法研究采用了华南区域自然人群慢性病前瞻性队列研究(SCC)2018—2020年采集的25~89岁参与者的基线数据。研究分析体重正常者RFM在不同亚组人群的分布情况及其与糖尿病、高血压和血脂异常患病风险的关联。结果在体重正常人群中,女性高RFM比例显著高于男性(25.34%和18.03%),且差异随年龄增长而扩大。高RFM个体在低收入(23.86%)、低文化(32.69%)、少数民族(28.15%)、饮酒(22.99%)和不吸烟(23.68%)群体中的比例更高。体重正常人群中,高RFM的人群糖尿病(OR=1.58)、高血压(OR=1.67)和血脂异常(OR=1.68)的患病风险比低RFM者更高。结论RFM能有效识别正常体重但具有高代谢风险的人群,从而及早干预促进健康。 展开更多
关键词 相对脂肪质量指数 代谢性疾病 体重正常 糖尿病 高血压 血脂异常
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考虑能量转换装置可变效率的综合能源系统多目标优化调度 被引量:5
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作者 姜延卓 高冲 +4 位作者 刘艳云 张真理 叶荣江 李万彬 谢庆 《电力系统保护与控制》 北大核心 2025年第1期71-83,共13页
为了全面考虑综合能源系统的运行性能,提出一种计及能量转换装置可变效率的综合能源系统多目标优化运行方法。首先,对具有可变效率的能量转换设备运行特性曲线进行分段线性化处理。其次,建立以经济成本、碳排放量和综合能源利用效率为... 为了全面考虑综合能源系统的运行性能,提出一种计及能量转换装置可变效率的综合能源系统多目标优化运行方法。首先,对具有可变效率的能量转换设备运行特性曲线进行分段线性化处理。其次,建立以经济成本、碳排放量和综合能源利用效率为优化对象的多目标优化调度模型,并通过Charnes-Cooper变换解决综合能源利用效率目标的非凸非线性问题。最后,在求解该多目标模型时,运用规格化法平面约束法生成均匀分布的帕累托前沿,再采用改进熵权双基点法决策出折衷最优解。对修改的IEEE 33节点电网和8节点热网耦合的综合能源系统进行仿真分析。结果表明:优化后的模型和算法可以得到兼顾综合能源系统经济性、低碳性及高效性的优化运行方案,为决策者提供科学的决策参考。 展开更多
关键词 综合能源系统 多目标优化 可变效率 规格化法平面约束法 改进熵权双基点法
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低出生体重与足出生体重新生儿化脓性脑膜炎的临床分析
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作者 凌远连 卢燕彬 +2 位作者 刘小琳 周海燕 吴耀勋 《临床医学研究与实践》 2025年第10期42-45,共4页
目的探讨低出生体重(LBW)与足出生体重(NBW)新生儿化脓性脑膜炎的临床表现、实验室检查及治疗转归等方面的差异,以期为临床提供更有效的诊疗策略。方法选取2021年1月至2023年12月玉林市妇幼保健院儿科收治的147例化脓性脑膜炎患儿作为... 目的探讨低出生体重(LBW)与足出生体重(NBW)新生儿化脓性脑膜炎的临床表现、实验室检查及治疗转归等方面的差异,以期为临床提供更有效的诊疗策略。方法选取2021年1月至2023年12月玉林市妇幼保健院儿科收治的147例化脓性脑膜炎患儿作为研究对象,依据新生儿出生体重将其分为LBW组、NBW组。比较两组的一般资料、脑脊液和外周血指标、病原菌种类检测结果及治疗转归情况。结果147例化脓性脑膜炎患儿中,LBW组29例,NBW组118例。LBW组的胎龄、入院日龄小于NBW组,出生体重低于NBW组,住院天数长于NBW组(P<0.05)。LBW组的脑脊液中,葡萄糖水平低于NBW组,蛋白质水平和白细胞计数(WBC)高于NBW组(P<0.05);LBW组的外周血中,C反应蛋白(CRP)水平及WBC低于NBW组(P<0.05)。LBW组有2例脑脊液和7例外周血培养呈病原菌阳性,NBW组有14例脑脊液和19例外周血培养呈病原菌阳性。两组的治疗转归情况比较,差异无统计学意义(P>0.05)。结论LBW新生儿化脓性脑膜炎的临床表现以及脑脊液和外周血实验室检查结果更为复杂和严重。因此,在临床实践中,应给予LBW新生儿更密切的关注,通过早期识别、精准诊断、个体化治疗和多学科协作,降低化脓性脑膜炎的发病率和死亡率。 展开更多
关键词 低出生体重 足出生体重 化脓性脑膜炎
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基于法向量角约束配准的激光里程计
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作者 录一凡 高向川 +2 位作者 陈政康 许士鋆 宋文吉 《应用激光》 北大核心 2025年第11期206-215,共10页
为提高激光雷达帧间匹配精度与效率,解决激光里程计在室外大范围场景下运动轨迹漂移且实时性较差的问题,提出一种基于法向量角信息加权的点云配准算法。首先,采用正态分布变换(normal distributions transform,NDT)算法进行粗配准,提供... 为提高激光雷达帧间匹配精度与效率,解决激光里程计在室外大范围场景下运动轨迹漂移且实时性较差的问题,提出一种基于法向量角信息加权的点云配准算法。首先,采用正态分布变换(normal distributions transform,NDT)算法进行粗配准,提供良好的初始位姿;然后改进迭代最近点(iterative closest point,ICP)算法,通过点云的邻域特征计算匹配点对的法向量夹角来约束对应关系和精简匹配点对,并以此构建权重函数作为迭代误差函数的加权系数,加快迭代收敛速度并进一步减少不良对应关系对配准的影响,完成精配准。实验采用KITTI数据集的两个不同场景进行验证,与传统NDT-ICP的结合算法相比,所提算法分别使运动轨迹的全局平均误差降低了29%与21%,帧间配准效率分别提升了21%与11%,满足激光里程计有效性和实时性的要求。 展开更多
关键词 激光里程计 迭代最近点 法向量 权重系数 点云配准
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福建省沿海区域道路网络扩张对植被动态变化的影响机制
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作者 叶丽敏 黄锦樘 +2 位作者 邹泽耀 陈瑾 胡喜生 《环境科学》 北大核心 2025年第12期7865-7877,共13页
科学分析公路建设对植被动态变化的影响对指导道路网络布设和生态保护具有重要意义.以福建省沿海区域为例,基于2010年和2020年道路数据和归一化植被指数(NDVI),在不同尺度的研究单元上,运用核密度估算、网络分析、双变量空间自相关和地... 科学分析公路建设对植被动态变化的影响对指导道路网络布设和生态保护具有重要意义.以福建省沿海区域为例,基于2010年和2020年道路数据和归一化植被指数(NDVI),在不同尺度的研究单元上,运用核密度估算、网络分析、双变量空间自相关和地理加权回归模型(GWR)等方法,定量分析道路网络格局及其对植被时空变化的影响机制.结果表明,福建省沿海区域的道路核密度(KDE)呈现沿海高内陆低的分层结构,道路网络可达性(ACC)呈现以莆田市、福州市和泉州市为核心向外递减的“核心-边缘”空间分布格局;多尺度双变量空间自相关分析表明,道路网络指标与NDVI呈负相关,KDE与NDVI的Moran's I指数均值为-0.255,ACC与NDVI的Moran's I指数均值为-0.277,ACC与NDVI的相关性较KDE高,空间聚集性更强且受尺度影响较小;ΔKDE-ΔNDVI的Moran's I指数均值为-0.248,ΔACC-ΔNDVI的Moran's I指数均值为0.159,ΔKDE与ΔNDVI呈负相关,而ΔACC与ΔNDVI呈正相关,相关性随着尺度的增大而增大;道路指标与NDVI的相关性在1000 m×1000 m和县域尺度下较高;KDE与NDVI的回归系数在空间上具有较大的变化幅度,空间异质性明显,正回归系数主要集中在宁德市、福州市和漳州市滨海带,负相关性主要分布在研究区中部;ACC与NDVI的回归系数在空间上变化幅度较小,研究区大部分地区的ACC对植被覆盖起到抑制作用,空间聚集性较强且异质性显著.研究结果对促进福建省沿海地区道路网络建设与植被保护的协同具有启示意义. 展开更多
关键词 道路核密度(KDE) 可达性(ACC) 归一化植被指数(NDVI) 空间自相关 地理加权回归(GWR)
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基于正态云组合赋权-TOPSIS-灰色关联法的加工中心可靠性分配
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作者 杨戟 杨树清 +1 位作者 范颖 周德才 《机床与液压》 北大核心 2025年第10期30-39,共10页
在数控加工中心可靠性分配过程中,评价指标的权重对结果影响显著,传统方法采用线性加权法对评价指标的主、客观权重进行整合,但忽略了决策过程的随机性和不确定性,影响可靠性分配的准确性。针对此,提出一种基于正态云组合赋权-TOPSIS-... 在数控加工中心可靠性分配过程中,评价指标的权重对结果影响显著,传统方法采用线性加权法对评价指标的主、客观权重进行整合,但忽略了决策过程的随机性和不确定性,影响可靠性分配的准确性。针对此,提出一种基于正态云组合赋权-TOPSIS-灰色关联法的加工中心可靠性分配方法。利用正态云模型对AHP法、BWM法、熵权法和变异系数法得到的主、客观权重进行整合,得到评价指标的综合权重;然后,引入灰色关联分析法对TOPSIS分析方法进行改进,得到子系统的灰色关联相对贴近度,并计算得到各子系统准确的可靠性分配系数,实现了可靠性的准确分配;最后,利用所述方法对某型号数控加工中心进行可靠性分配,并与传统方法进行对比,证明了所述方法的有效性。 展开更多
关键词 加工中心 可靠性分配 正态云模型 组合赋权 灰色关联法
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