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11.
数学建模活动对培养人才的作用   总被引:25,自引:0,他引:25  
文章论述建模活动对培养人才的作用 ,对专科院校高等数学教学改革具有启发性 .  相似文献   
12.
Aparna Gupta 《Physica A》2011,390(20):3524-3540
This paper presents and calibrates an individual’s stochastic health evolution model. In this health evolution model, the uncertainty of health incidents is described by a stochastic process with a finite number of possible outcomes. We construct a comprehensive health status index (HSI) to describe an individual’s health status, as well as a health risk factor system (RFS) to classify individuals into different risk groups. Based on the maximum likelihood estimation (MLE) method and the method of nonlinear least squares fitting, model calibration is formulated in terms of two mixed-integer nonlinear optimization problems. Using the National Health Interview Survey (NHIS) data, the model is calibrated for specific risk groups. Longitudinal data from the Health and Retirement Study (HRS) is used to validate the calibrated model, which displays good validation properties. The end goal of this paper is to provide a model and methodology, whose output can serve as a crucial component of decision support for strategic planning of health related financing and risk management.  相似文献   
13.
In this paper, we study inverse optimization for linearly constrained convex separable programming problems that have wide applications in industrial and managerial areas. For a given feasible point of a convex separable program, the inverse optimization is to determine whether the feasible point can be made optimal by adjusting the parameter values in the problem, and when the answer is positive, find the parameter values that have the smallest adjustments. A sufficient and necessary condition is given for a feasible point to be able to become optimal by adjusting parameter values. Inverse optimization formulations are presented with 1 and 2 norms. These inverse optimization problems are either linear programming when 1 norm is used in the formulation, or convex quadratic separable programming when 2 norm is used.  相似文献   
14.
The correctness of an in-place permutation algorithm is proved. The algorithm exchanges elements belonging to a permutation cycle. A suitable assertion is constructed from which the correctness can be deduced after completion of the algorithm.An in-place rectangular matrix transposition algorithm is given as an example.  相似文献   
15.
“知行统一” 的观念在教育界已深入人心,但是要做到切实履行却非易事。经过为期九年的精心打造,上海交通大学开设的创新型实践课程“结构模型设计与制作” 初步实现了“学与行” 的有机融合,教学效果显著,深受学生欢迎。本文是对该课程的总结与反思,希望对我国相关工科教学改革起到有益的借鉴作用。  相似文献   
16.
Professional vocalists encounter demands requiring voluntary control of phonation, while utilizing a considerable range of frequency and intensity. These quantifiable acoustic events can be measured and represented in a phonetogram. Previous research has compared the phonetograms of trained and untrained voices and found significant differences between these groups. This study was designed to assess the effects of vocal training for singers over a period of nine months. Phonetogram contour changes were examined, with the primary focus on expansion of frequency range and/or intensity control. Twenty-one first-year, master's level, vocal music students, who were engaged in an intensive vocal performance curriculum, participated in this study. Following nine months of vocal training, significant differences were revealed in the subjects' mean frequency range and minimum vocal intensity across frequency levels. There was no significant difference for the mean maximum vocal intensity across frequency levels following vocal training.  相似文献   
17.
A method is reviewed for conversion of a microphone signal into calibrated Sound Pressure Level (SPL) units. The method follows American National Standards Institute (ANSI) standard for S1.4 SPL meters and requires an accurate SPL meter and an accurate calibration sound source for conversion. Accuracy and validation data from test signals and human phonation are provided. The results indicate that under typical speech conditions, an absolute accuracy of plus or minus 1.6 dB (type I SPL meter) can be obtained with a miniature head-mounted microphone.  相似文献   
18.
This paper addresses a class of problems called mixed-integer bilinear programming problems. These problems are identical to the well known bilinear programming problems with the exception that one set of variables is restricted to be binary valued, and they arise in various production, location—allocation, and distribution application contexts. We first identify some special cases of this problem which are relatively more readily solvable, even though their continuous relaxations are still nonconvex. For the more general case, we employ a linearization technique and design a composite Lagrangian relaxation-implicit enumeration-cutting plane algorithm. Extensive computational experience is provided to test the efficacy of various algorithmic strategies and the effects of problem data on the computational effort of the proposed algorithm.  相似文献   
19.
As computing resources continue to improve, global solutions for larger size quadrically constrained optimization problems become more achievable. In this paper, we focus on larger size problems and get accurate bounds for optimal values of such problems with the successive use of SDP relaxations on a parallel computing system called Ninf (Network-based Information Library for high performance computing).  相似文献   
20.
研究选择了以2,4-二硝基苯肼衍生化三元梯度洗脱的高效液相色谱测定大气中11种醛酮类化合物的最佳色谱分离条件,醛酮类化合物的检出限0.45到2.04ng,各化合物保留时间和相对标准偏差s,≤0.38%在所测定的含量范围内具有很好的线性关系,每种化合物的相关系数均大于0.999;研究了涂敷2,4-二硝基苯肼硅胶吸附采样夹的制作方法,并应用于大气环境中醛酮类化合物的分析。方法简单、快速,11种醛酮类化  相似文献   
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