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虾夷扇贝动态能量收支模型参数的测定 被引量:11
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作者 张继红 吴文广 +3 位作者 徐东 任黎华 牛亚丽 赵学伟 《水产学报》 CAS CSCD 北大核心 2016年第5期703-710,共8页
本研究以虾夷扇贝为实验生物,介绍了动态能量收支(dynamic energy budget,DEB)模型5个关键基本参数的测定及计算方法,分析了方法的利弊及注意事项,为贝类DEB模型参数的准确获取提供参考方法。采用壳长与软体部湿重回归法计算虾夷扇贝的... 本研究以虾夷扇贝为实验生物,介绍了动态能量收支(dynamic energy budget,DEB)模型5个关键基本参数的测定及计算方法,分析了方法的利弊及注意事项,为贝类DEB模型参数的准确获取提供参考方法。采用壳长与软体部湿重回归法计算虾夷扇贝的形状系数δm;采用静水法测定不同温度条件下虾夷扇贝的呼吸耗氧率,计算阿伦纽斯温度TA参数;采用饥饿法测定、计算单位时间单位体积维持生命所需的能量[]、形成单位体积结构物质所需的能量[EG]和单位体积最大储存能量[EM]3个参数。室内饥饿实验持续60 d,直至呼吸耗氧率及软体部干重基本保持恒定。结果显示,壳长(SL)与软体部湿重(WW)的回归关系式为WW=0.0118SL3.4511(R2=0.9365),根据公式V=(δm L)3,对软体部湿重的立方根和壳长进行线性回归,所得的斜率即为形状系数δm值(δm=0.32);获得不同规格的虾夷扇贝耗氧率与水温(热力学温度,K)倒数的线性回归关系,线性回归方程斜率的绝对值为阿伦纽斯温度TA,平均为(4160±767)K。饥饿实验结束时,软体部干重和呼吸耗氧率分别降低了56%和81%。虾夷扇贝的耗氧率稳定在0.17 mg/(ind·h),经计算获得[]=25.9 J/(cm^3·d);饥饿持续30天之后,虾夷扇贝软体部干重基本维持在(0.25±0.01)g,经计算获得[EG]=3160 J/cm^3,[EM]=2030 J/cm^3。动态DEB理论是基于能量代谢的物理、化学特性而建立的,体现了生物能量代谢的普遍性规律,能够反映摄食获取能量在不同发育生长阶段的能量分配情况。但是,DEB模型参数的测定及计算比较复杂。基本参数的准确获取将影响其他参数以及模型的准确性。本研究为虾夷扇贝DEB模型的构建奠定基础。 展开更多
关键词 虾夷扇贝 动态能量收支 模型参数评估
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基于多参数评估模型的电线电缆质量检测研究
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作者 盛景南 《中国质量监管》 2023年第5期84-85,共2页
文章研究了一种基于多参数评估模型的电线电缆质量检测方法。该方法通过采集多个参数数据,建立评估模型,对电线电缆进行质量评估和缺陷检测。研究表明,该方法能够有效地检测电线电缆中的缺陷,提高了检测准确率。
关键词 电线电缆 质量检测 参数评估模型
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苹果中乙撑硫脲膳食摄入风险的非参数概率评估 被引量:12
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作者 叶孟亮 聂继云 +2 位作者 徐国锋 闫震 郑丽静 《农业工程学报》 EI CAS CSCD 北大核心 2016年第1期286-297,共12页
为明确国产苹果中乙撑硫脲残留水平及量化中国居民乙撑硫脲膳食摄入风险。基于渤海湾(辽宁、山东、河北)和西北黄土高原(陕西、山西、河南)两大苹果优势主产区采集的282份苹果样品,运用专业风险评估软件@Risk,尝试构建非参数概率评... 为明确国产苹果中乙撑硫脲残留水平及量化中国居民乙撑硫脲膳食摄入风险。基于渤海湾(辽宁、山东、河北)和西北黄土高原(陕西、山西、河南)两大苹果优势主产区采集的282份苹果样品,运用专业风险评估软件@Risk,尝试构建非参数概率评估模型,对中国居民乙撑硫脲膳食摄入风险进行概率评估。结果表明:参试的282份苹果样品,乙撑硫脲检出率为80.9%,残留量均值为6.1μg/kg,最高残留量为74.1μg/kg,绝大多数苹果样品(占90.4%)乙撑硫脲残留量〈10.0μg/kg。282份苹果样品中乙撑硫脲残留量的离散程度较大(变异系数达134.6%),不同省份变异系数排序,陕西(150.7%)〉辽宁(146.8%)〉河北(91.2%)〉山东(88.1%)〉河南(54.9%)〉山西(51.8%)。不同年龄组人群膳食摄入风险存在明显差异,幼儿(2~6岁)和儿童(7~13岁)乙撑硫脲膳食摄入风险均明显高于青少年(14~17岁)和成年(18~59岁),为重点监控对象。总体而言,不同年龄组人群乙撑硫脲膳食摄入风险均很低,其中慢性膳食摄入风险介于0.35%~13.12%,急性膳食摄入风险介于0.22%~3.94%,均远低于100%;不同省份和不同主产区苹果乙撑硫脲膳食摄入风险虽存在明显差异,但均远低于100%,不同省份和不同主产区苹果乙撑硫脲膳食摄入风险也是可以接受的。基于最大残留限量估计值(estimate maximum residue limit,e MRL),建议中国苹果中乙撑硫脲最大残留限量值设为0.2 mg/kg。本研究可为苹果质量安全监管和今后系统开展果品质量安全风险评估提供有益借鉴和参考。 展开更多
关键词 模型 风险评估 农药 苹果 乙撑硫脲 膳食摄入 参数概率评估模型
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苹果中4种常用农药残留及其膳食暴露评估 被引量:48
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作者 叶孟亮 聂继云 +2 位作者 徐国锋 闫震 郑丽静 《中国农业科学》 CAS CSCD 北大核心 2016年第7期1289-1302,共14页
【目的】对国产苹果中多菌灵、甲基硫菌灵、吡虫啉和灭幼脲4种常用农药残留及其膳食暴露进行评估,明确并量化中国居民食用苹果途径的上述4种常用农药膳食摄入风险水平,为苹果安全生产、消费及质量安全监管提供依据。【方法】基于渤海湾... 【目的】对国产苹果中多菌灵、甲基硫菌灵、吡虫啉和灭幼脲4种常用农药残留及其膳食暴露进行评估,明确并量化中国居民食用苹果途径的上述4种常用农药膳食摄入风险水平,为苹果安全生产、消费及质量安全监管提供依据。【方法】基于渤海湾(辽宁、山东、河北)和西北黄土高原(陕西、山西、河南)两大苹果优势主产区采集的282份苹果样品,运用专业风险评估软件@Risk,尝试构建非参数概率评估模型,对中国居民食用苹果途径的农药膳食摄入(暴露)风险进行概率评估。首先对282份苹果样品中上述4种农药残留检测值进行分布拟合,拟合度运用Chi-Squared、Anderson-Darling、Kolmogorov-Smirnov 3种统计方法进行检验,综合考虑3种评估拟合结果,确定最佳拟合分布。STMR、HR取最佳分布拟合值,%ADI和%ARf D分别表示慢性膳食摄入风险和急性膳食摄入风险。【结果】参试的282份苹果样品,255份(占90.4%)苹果样品中检出了农药残留。在检出的4种常用农药中,多菌灵的检出率最高,达到81.9%;其次为甲基硫菌灵和吡虫啉,分别为52.1%和39.0%;灭幼脲的检出率最低,仅为31.2%。绝大多数苹果样品中农药残留量处于较低水平,最大检出浓度为0.9251 mg·kg^(-1)(多菌灵),但仍远低于最大残留限量值3.0 mg·kg^(-1)。样品中4种常用农药残留量均值依次为多菌灵(0.1042 mg·kg^(-1))>灭幼脲(0.0182 mg·kg^(-1))>甲基硫菌灵(0.0082 mg·kg^(-1))>吡虫啉(0.0050 mg·kg^(-1))。样品中4种常用农药残留量离散程度有异,变异系数分别达到232.8%(甲基硫菌灵)、214.8%(吡虫啉)、174.1%(灭幼脲)和136.4%(多菌灵)。282份苹果样品农药残留量分布规律较明显,随着农药残留浓度的升高,样品所占的比例均呈逐渐降低的趋势。27份(占9.6%)苹果样品中未检出上述4种常用农药,198份(占70.2%)苹果样品中检出2种及以上农药残留,19份(占6.7%)苹果样品甚至检出4种农药残留。不同年龄组人群食用苹果途径的上述4种常用农药慢性膳食摄入风险(%ADI)分别为0.2120%—35.1100%(多菌灵)、0.0051%—0.8240%(吡虫啉)、0.0049%—0.1710%(甲基硫菌灵)和0.0004%—0.0152%(灭幼脲);急性膳食摄入风险(%ARf D)分别为0.1940%—16.0500%(多菌灵)和0.0122%—0.9400%(吡虫啉)。幼儿(2—6岁)和儿童(7—13岁)2个年龄组人群由于体重较轻,而苹果摄入量相对较高,膳食摄入风险明显高于其他年龄组人群,为重点监控对象。不同年龄组人群之间,随着年龄的增加,农药膳食摄入风险整体呈逐渐下降趋势;同一年龄组人群,选取的百分位点值越高,农药膳食摄入风险越大。【结论】中国苹果中多菌灵、甲基硫菌灵、吡虫啉和灭幼脲这4种常用农药检出率较高,但所有样品农药残留量均低于最大残留限量。中国居民食用苹果途径的上述4种常用农药慢性和急性膳食摄入风险均很低,幼儿和儿童2个年龄组人群膳食摄入风险明显高于其他年龄组人群,需重点关注。 展开更多
关键词 苹果 农药残留 膳食暴露 参数概率评估模型 风险评估
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能力评估系数的发展
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作者 姜月娇 《哈尔滨师范大学自然科学学报》 CAS 2015年第6期32-35,共4页
介绍能力评估理论的发展过程及各系统的原理.研究表明对能力进行分类即判断一个给定系统处理能力的大小是非常重要的.只基于反应时间的、并与标准并行处理进行比较的能力评估理论已经非常成熟.随着研究的深入,人们逐渐把焦点转移到如何... 介绍能力评估理论的发展过程及各系统的原理.研究表明对能力进行分类即判断一个给定系统处理能力的大小是非常重要的.只基于反应时间的、并与标准并行处理进行比较的能力评估理论已经非常成熟.随着研究的深入,人们逐渐把焦点转移到如何将准确率也融入到能力评估理论中.对此,认知神经科学领域中的研究者们也提出了一套比较完善的科学理论. 展开更多
关键词 工作量能力系数 LBA模型 能力评估函数参数模型 准确率 函数
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The gas discharge visualization(GDV)order parameter model based on the principle of mastering both permanence and change
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作者 XIN Yu ZHANG Lei +3 位作者 ZHAO Qiancheng SHE Yurong SHE Zhensu SONG Shuna 《Digital Chinese Medicine》 CAS CSCD 2024年第3期231-240,共10页
Objective To investigate the human body’s complex system,and classify and characterize the human body’s health states with“a comprehensive integrated method from qualitative to quantitative”.Methods This paper int... Objective To investigate the human body’s complex system,and classify and characterize the human body’s health states with“a comprehensive integrated method from qualitative to quantitative”.Methods This paper introduces the concept of“order parameters”and proposes a method for establishing an order parameter model of gas discharge visualization(GDV)based on the principle of“mastering both permanence and change(MBPC)”.The method involved the fol-lowing three steps.First,average luminous intensity(I)and average area(S)of the GDV im-ages were calculated to construct the phase space,and the score of the health questionnaire was calculated as the health deviation index(H).Second,the k-means++clustering method was employed to identify subclasses with the same health characteristics based on the data samples,and to statistically determine the symptom-specific frequencies of the subclasses.Third,the distance(d)between each sample and the“ideal health state”,which determined in the phase space of each subclass,was calculated as an order parameter describing the health imbalance,and a linear mapping was established between the d and the H.Further,the health implications of GDV signals were explored by analyzing subclass symptom profiles.We also compare the mean square error(MSE)with classification methods based on age,gen-der,and body mass index(BMI)indices to verify that the phase space possesses the ability to portray the health status of the human body.Results This study preliminarily tested the reliability of the order parameter model on data samples provided by 20 participants.Based on the discovered linear law,the current model can use d calculated by measuring the GDV signal to predict H(R^(2)>0.77).Combined with the symptom profiles of the subclasses,we explain the classification basis of the phase space based on the pattern identification.Compared with common classification methods based on age,gender,BMI,etc.,the MSE of phase space-based classification was reduced by an order of magnitude.Conclusion In this study,the GDV order parameter model based on MBPC can identify sub-classes and characterize individual health levels,and explore the TCM health meanings of the GDV signals by using subjective-objective methods,which holds significance for establishing mathematical models from TCM diagnosis principles to interpret human body signals. 展开更多
关键词 Gas discharge visualization(GDV) Traditional Chinese medicine(TCM) Order parameters Math-physical model Individualized health assessment
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目标跟踪的非线性回归方法 被引量:2
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作者 王正明 周海银 邵长林 《弹道学报》 CSCD 北大核心 2000年第1期24-30,48,共8页
讨论目标跟踪数据融合的常用非线性回归模型 ,研究参数估计的初值获取方法 ,求估计值的迭代算法 ,估计值的校准方法 ,估计值方差矩阵的估算方法 .使用本文方法处理目标跟踪数据速度快、精度高 。
关键词 数据融合 非线性模型 参数估计 校准 评估
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Discussion of skill improvement in marine ecosystem dynamic models based on parameter optimization and skill assessment 被引量:1
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作者 沈程程 石洪华 +2 位作者 刘永志 李芬 丁德文 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期683-696,共14页
Marine ecosystem dynamic models(MEDMs) are important tools for the simulation and prediction of marine ecosystems. This article summarizes the methods and strategies used for the improvement and assessment of MEDM ski... Marine ecosystem dynamic models(MEDMs) are important tools for the simulation and prediction of marine ecosystems. This article summarizes the methods and strategies used for the improvement and assessment of MEDM skill, and it attempts to establish a technical framework to inspire further ideas concerning MEDM skill improvement. The skill of MEDMs can be improved by parameter optimization(PO), which is an important step in model calibration. An effi cient approach to solve the problem of PO constrained by MEDMs is the global treatment of both sensitivity analysis and PO. Model validation is an essential step following PO, which validates the effi ciency of model calibration by analyzing and estimating the goodness-of-fi t of the optimized model. Additionally, by focusing on the degree of impact of various factors on model skill, model uncertainty analysis can supply model users with a quantitative assessment of model confi dence. Research on MEDMs is ongoing; however, improvement in model skill still lacks global treatments and its assessment is not integrated. Thus, the predictive performance of MEDMs is not strong and model uncertainties lack quantitative descriptions, limiting their application. Therefore, a large number of case studies concerning model skill should be performed to promote the development of a scientifi c and normative technical framework for the improvement of MEDM skill. 展开更多
关键词 marine ecosystem dynamic models global optimization CALIBRATION model skill VALIDATION UNCERTAINTY
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The Credibility Estimators under MLINEX Loss Function
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作者 ZHANG Qiang CUI Qian-qian CHEN Ping 《Chinese Quarterly Journal of Mathematics》 2018年第1期43-50,共8页
In this paper, MLINEX loss function was considered to solve the problem of high premium in credibility models. The Bayes premium and credibility premium were obtained under MLINEX loss function by using a symmetric qu... In this paper, MLINEX loss function was considered to solve the problem of high premium in credibility models. The Bayes premium and credibility premium were obtained under MLINEX loss function by using a symmetric quadratic loss function. A credibility model with multiple contracts was established and the corresponding credibility estimator was derived under MLINEX loss function. For this model the estimations of the structure parameters and a numerical example were also given. 展开更多
关键词 MLINEX loss function Bayes premium Credibility estimator Multiple contracts
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Passenger Flow Status Evaluation in Subway Station Based on Probabilistic Neural Network
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作者 SUN Jianhui HU Hua LIU Zhigang 《International English Education Research》 2018年第3期34-37,共4页
This paper select the escalator with large flow in the station as the object, analysing the correlation of the AFC data of the in and out gates and the passenger flow parameters by passenger flow density and the passi... This paper select the escalator with large flow in the station as the object, analysing the correlation of the AFC data of the in and out gates and the passenger flow parameters by passenger flow density and the passing time acquired and calculated in the waiting area of the prediction escalator to select the gates related to the predicted the escalator. NARX neural network is used to predict the model of the passenger flow parameters of the escalator waiting area based on the related gates' AFC data, then a probabilistic neural network model was established by using the AFC data and predicted passenger flow parameters as input and the passenger flow status in the escalator waiting area of subway station as output.The result shows the predicting model can predict the passenger flow status of the escalator waiting area better by the AFC data in the subway station. Research result can provide decision basis for the operation management of the subway station. 展开更多
关键词 Subway station Escalator waiting area AFC data Probabilistic neural network Passenger flow status
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收益法评估公路收费权的难点探讨
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作者 胡欣欣 郝国瑞 《交通财会》 2013年第4期35-39,共5页
转让公路收费权首先要对公路收费权的价值进行科学合理的评估,收益法是评估公路收费权的首选方法,本文从收益法评估公路收费权模型的选择入手,基于选取的模型将收益法评估的难点聚焦于模型中参数的测算,进而对参数测算进行了深入的探讨... 转让公路收费权首先要对公路收费权的价值进行科学合理的评估,收益法是评估公路收费权的首选方法,本文从收益法评估公路收费权模型的选择入手,基于选取的模型将收益法评估的难点聚焦于模型中参数的测算,进而对参数测算进行了深入的探讨并提出测算时的注意事项,以期日后评估人员在使用收益法评估公路收费权时能有所借鉴以及有助于评估工作的进行能够更加科学合理。 展开更多
关键词 公路收费权收益法评估模型参数测算
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An additive-multiplicative rates model for multivariate recurrent events with event categories missing at random 被引量:2
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作者 YE Peng SUN LiuQuan +1 位作者 ZHAO XingQiu XU Wei 《Science China Mathematics》 SCIE CSCD 2015年第6期1163-1178,共16页
Multivariate recurrent event data arises when study subjects may experience more than one type of recurrent events. In some situations, however, although event times are always observed, event categories may be partia... Multivariate recurrent event data arises when study subjects may experience more than one type of recurrent events. In some situations, however, although event times are always observed, event categories may be partially missing. In this paper, an additive-multiplicative rates model is proposed for the analysis of multivariate recurrent event data when event categories are missing at random. A weighted estimating equations approach is developed for parameter estimation, and the resulting estimators are shown to be consistent and asymptotically normal. In addition, a model-checking technique is presented to assess the adequacy of the model. Simulation studies are conducted to evaluate the finite sample behavior of the proposed estimators, and an application to a platelet transfusion reaction study is provided. 展开更多
关键词 additive-multiplicative rates model missing data multivariate recurrent events semiparametricmodel weighted estimating equation
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Sequential Estimate for Generalized Linear Models with Uncertain Number of Effective Variables 被引量:1
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作者 LU Haibo WANG Zhanfeng WU Yaohua 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第2期424-438,共15页
For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of parameter.This method can determine a minimum sample size under which effective variables... For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of parameter.This method can determine a minimum sample size under which effective variables contributing to the model are identified and estimates of regression parameters achieve the required accuracy.The authors prove that the proposed sequential procedure is asymptotically optimal.Numerical simulation studies show that the proposed method can save a large number of samples compared to the traditional sequential approach. 展开更多
关键词 Confidence set generalized linear regression sequential sampling stopping rule
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