Estimation of CARA Preferences and Positive Mathematical Programming

The purpose of this paper is to combine the estimation of output price risk and positive mathematical programming (PMP). It reconciles the risk programming presented by Freund with a consistent estimate of the constant absolute risk aversion (CARA) coefficient. It extends the PMP approach to calibration of realized production outputs and observed input prices. The results of this specification include 1) uniqueness of the calibrating solution, 2) elimination of the tautological calibration constraints typical of the original PMP procedure, 3) equivalence between a phase I calibrating solution and a solution obtained by combining phase I and phase II of the traditional PMP procedure. In this extended PMP framework, the cost function specification involves output quantities and input prices—contrary to the myopic cost function of the traditional PMP approach. This extension allows for a phase III calibrating model that replaces the usual linear technology with relations corresponding to Shephard lemma (in the primal constraints) and the marginal cost function (in the dual constraints). An empirical example with a sample of farms producing four crops illustrates the novel procedure.

Tool Positioning Algorithm Based on Smooth Tool Paths for 5-axis Machining of Sculptured Surfaces

The current research of the 5-axis tool positioning algorithm mainly focuses on searching the local optimal tool position without gouging and interference at a cutter contact（CC） point,while not considering the smoothness and continuity of a whole tool path.When the surface curvature varies significantly,a local abrupt change of tool paths will happen.The abrupt change has a great influence on surface machining quality.In order to keep generated tool paths smooth and continuous,a five-axis tool positioning algorithm based on smooth tool paths is presented.Firstly,the inclination angle,the tilt angle and offset distance of the tool at a CC point are used as design variables,and the machining strip width is used as an objective function,an optimization model of a local tool positioning algorithm is thus established.Then,a vector equation of tool path is derived by using the above optimization model.By analyzing the equation,the main factors affecting the tool path quality are obtained.Finally,a new tool position optimization model is established,and the detailed process of tool position optimization is also given.An experiment is conducted to machine an aircraft turbine blade by using the proposed algorithm on a 5-axis blade grinding machine,and the machined blade surface is measured with a coordinate measuring machine（CMM）.Experimental and measured results show that the proposed algorithm can ensure tool paths are smooth and continuous,improve the tool path quality,avoid the local abrupt change of tool paths,and enhance machining quality and machining efficiency of sculptured surfaces.

ASYMPTOTIC SURROGATE CONSTRAINT METHOD AND ITS CONVERGENCE FOR A CLASS OF SEMI-INFINITE PROGRAMMING

A class of constrained semi\|infinite minimax problem is transformed into a simple constrained problem, by means of discretization decomposition and maximum entropy method, making use of surrogate constraint. The paper deals with the convergence of this asymptotic approach method.

Construction of clinical research nurse training program based on position competence

BACKGROUND As one of the most important members in clinical trials,the number of clinical research nurses(CRN)can't keep up with the growth of experimental projects,so it is urgent to build clinical research training and strengthen the background knowledge of nurses.AIM To construct CRN training program based on position competence,accelerate the construction of CRN talent pool,and provide scientific guidance significance for CRN training.METHODS Based on the position competence model,combined with literature research and qualitative interview results,the first draft was prepared of the CRN training program.Two rounds of correspondence with 16 experts were conducted using the Delphi method to determine the training program.RESULTS The effective recovery rate of the expert correspondence questionnaire was 100%and the authority coefficients of the 2 rounds of experts were 0.826 and 0.895.Finally,4 first-level indicators and determine 15 s-level indicators of training objectives.The training program included 4 first-level indicators,training requirements,content,methods,assessment and evaluation,15 s-level indicators,and 74 third-level indicators.CONCLUSION The CRN training program based on position competence is scientific and extendable,providing a basis for participation in CRN training.

Study on the Grey Polynomial Geometric Programming

In the model of geometric programming, values of parameters cannot be gotten owing to data fluctuation and incompletion. But reasonable bounds of these parameters can be attained. This is to say, parameters of this model can be regarded as interval grey numbers. When the model contains grey numbers, it is hard for common programming method to solve them. By combining the common programming model with the grey system theory, and using some analysis strategies, a model of grey polynomial geometric programming, a model of θ positioned geometric programming and their quasi-optimum solution or optimum solution are put forward. At the same time, we also developed an algorithm for the problem. This approach brings a new way for the application research of geometric programming. An example at the end of this paper shows the rationality and feasibility of the algorithm.

Higher-Order Duality for Minimax Fractional Type Programming Involving Symmetric Matrices

Convexity and generalized convexity play important roles in optimization theory. With the development of programming problem, there has been a growing interest in the higher-order dual problem and a lot of related generalized convexities are given. In this paper, we give the convexity of (F, α ,p ,d ,b , φ )β vector-pseudo- quasi-Type I and formulate a higher-order duality for minimax fractional type programming involving symmetric matrices, and give the weak, strong and strict converse duality theorems under the condition of higher-order (F, α ,p ,d ,b , φ )β vector-pseudoquasi-Type I.

Optimization Model on Quadratic Programming Problem with Fuzzy

In this paper, the authors propose a computational procedure by using fuzzy approach to fred the optimal solution of quadratic programming problems. The authors divide the calculation of the optimal solution into two stages. In the first stage the authors determine the unconstrained minimization and check its feasibility. The second stage, the authors explore the feasible region from initial point to another point until the authors get the optimal point by using Lagrange multiplier. A numerical example is included to support as illustration of the paper.

Jerk-limited feedrate scheduling and optimization for five-axis machining using new piecewise linear programming approach

In this paper, a new computation method and an optimization algorithm are presented for feedrate scheduling of five-axis machining in compliance with both machine drive limits and process limits. Five-axis machine tool with its ability of controlling tool orientation to follow the sculptured surface contour has been widely used in modern manufacturing industry. Feedrate scheduling serving as a kernel of CNC control system plays a critical role to ensure the required machining accuracy and reliability for five-axis machining. Due to the nonlinear coupling effects of all involved drive axes and the saturation limit of servo motors, the feedrate scheduling for multi-axis machining has long been recognized and remains as a critical challenge for achieving five-axis machine tools’ full capacity and advantage. To solve the nonlinearity nature of the five-axis feedrate scheduling problems, a relaxation mathematical process is presented for relaxing both the drive motors’ physical limitations and the kinematic constraints of five-axis tool motions. Based on the primary optimization variable of feedrate, the presented method analytically linearizes the machining-related constraints, in terms of the machines’ axis velocities, axis accelerations and axis jerks. The nonlinear multi-constrained feedrate scheduling problem is transformed into a manageable linear programming problem. An optimization algorithm is presented to find the optimal feedrate scheduling solution for the five-axis machining problems. Both computer implementation and laboratorial experiment testing by actual machine cutting were conducted and presented in this paper. The experiment results demonstrate that the proposed method can effectively generate efficient feedrate scheduling for five-axis machining with constraints of the machine tool physical constraints and limits. Compared with other existing numerical methods, the proposed method is able to find an accurate analytical solution for the nonlinear constrained five-axis feedrate scheduling problems without compromising the efficiency of the machining processes.

Kinematic Geometry for the Saddle Line Fitting of Planar Discrete Positions

The position synthesis of planar linkages is to locate the center point of the moving joint on a rigid link, whose trajectory is a circle or a straight line. Utilizing the min-max optimization scheme, the fitting curve needs to minimize the maximum fitting error to acquire the dimension of a planar binary P-R link. Based on the saddle point programming, the fitting straight line is determined to the planar discrete point-path traced by the point of the rigid body in planar motion. The property and evolution of the defined saddle line error can be revealed from three given separate points. A quartic algebraic equation relating the fitting error and the coordinates is derived, which agrees with the classical theory. The effect of the fourth point is discussed in three cases through the constraint equations. The multi-position saddle line error is obtained by combination and comparison from the saddle point programming. Several examples are presented to illustrate the solution process for the saddle line error of the moving plane. The saddle line error surface and the contour map presented to show the variations of the fitting error in the fixed frame. The discrete kinematic geometry is then set up to disclose the relations of the separate positions of the rigid body, the location of the tracing point on the moving body, and the position and orientation of the saddle line to the point-path. This paper presents a new analytic geometry method for saddle line fitting and provides a theoretical foundation for position synthesis.

Stabilizing model predictive control scheme for piecewise affine systems with maximal positively invariant terminal set

An efficient algorithm is proposed for computing the solution to the constrained finite time optimal control （CFTOC） problem for discrete-time piecewise affine （PWA） systems with a quadratic performance index. The maximal positively invariant terminal set, which is feasible and invariant with respect to a feedback control law, is computed as terminal target set and an associated Lyapunov function is chosen as terminal cost. The combination of these two components guarantees constraint satisfaction and closed-loop stability for all time. The proposed algorithm combines a dynamic programming strategy with a multi-parametric quadratic programming solver and basic polyhedral manipulation. A numerical example shows that a larger stabilizable set of states can be obtained by the proposed algorithm than precious work.

Patient-Reported Factors Facilitating Participation in Prevention of Mother to Child Transmission of HIV Programs in Kara, Togo, West Africa

Background: Despite efforts to expand prevention of mother-to-child transmission (PMTCT) of HIV in resource-limited settings, only 53% of women in sub-Saharan Africa receive adequate PMTCT services. Understanding factors that enable successful program completion are crucial to improving adherence rates to PMTCT programs in these settings. Using a positive deviance approach, we explored patient and provider’s perspectives on factors enabling women to successfully access and adhere to PMTCT services to identify areas of program improvement and further reduce HIV transmission. Methods: Semi-structured interviews were conducted with 11 health care workers (HCWs) at two health centers in Kara, Togo and 34 women who had successfully completed the PMTCT program at those facilities. Women were identified using purposive sampling and content theme analysis was used to analyze the data. Results: Knowledge and belief in the potential to give birth to an HIV-negative child, supported by facilitating factors on the individual and community levels, was the cornerstone to women’s PMTCT program success. Effective program education and peer-to-peer interactions fostered the participants’ knowledge and belief in PMTCT, with the resulting internal motivation driving continued participation and adherence. The welcoming environment, availability of peer support groups and financial assistance from the health facility, further facilitated success, with women using this facility-based community to seek advice and support from HCWs and peers. Financial, physical, and emotional support from relatives was also important in ensuring unhindered access. Finally, the faith-based communities’ acceptance and support for HIV-positive women further encouraged participants to adhere to the program. Conclusion: Understanding and believing in the ability to have an HIV-negative baby was the most important facilitator for PMTCT program adherence. This led to internal motivation that was continually reinforced through facility and community supportive environments focused on addressing barriers. Efforts to improve PMTCT success should focus on all of these factors through a patient-centered approach.

AIGC背景下高校计算机编程公共课的教育变革

伴随人工智能生成内容(AIGC,AI-Generated Content)的蓬勃发展,计算机编程教育迎来了巨大的变化与挑战。作为高等院校计算机编程公共课的教育工作者,要紧随技术迭代创新变化,充分重视,冷静应对,积极探索并思考在AIGC影响下如何转变教师的角色与定位,如何设定符合智能时代人才培养需求的教学目标和教学内容,并结合AIGC大胆尝试调整教学模式,探索出具有本校特色、结合学生实际发展需要的计算机编程公共课。

数字时代传播学专业的定位与趋势——基于11个国家一流传播学专业培养方案的分析

从人才培养的角度看,传播学人才培养目标、任务、要求及相关专业内容、课程设置等都体现出鲜明的时代性。面向新一轮的科技革命、产业变革和媒介化社会现实,如何应对数字传播时代带来的一系列挑战,是传播学人才培养必须直面并给予回应的重要课题。本文以11个国家一流传播学专业的培养方案为样本,通过分析其人才培养目标、师资结构、课程体系、实践教学、国际交流等,总结中国传播学专业定位的特征,并进一步探讨数字传播技术发展背景下传播学人才培养与专业建设的新趋势,以期为传播学学科发展提供参考。

职业本科辅导员职业能力培养存在的问题与对策探索

在职业本科教育中,辅导员的职业能力在很大程度上影响院校的管理和育人质量。文章结合职业本科教育在新时代经济社会发展中的定位,简述提升职业能力对辅导员的重要作用,分析辅导员职业能力培养面临的角色认知模糊、内驱动力不足、培训机会有限、支持体系欠缺等问题,并从精准全面定位角色、强化内驱发展意识、开展进阶能力培训、提升综合职业能力等维度提出应对措施,以期为促进辅导员全面发展、提升管理水平、强化育人成效提供借鉴。

程序性死亡受体配体1在肛管鳞状细胞癌患者中的表达水平及其对生存预后影响的初步探索

目的探讨肛管鳞状细胞癌(anal squamous cell carcinoma,ASCC)患者中程序性死亡受体配体1(programmed death-ligand 1,PD-L1)的表达水平及其对患者预后的影响,以期为免疫治疗在ASCC患者中的临床应用提供依据。方法本研究为一项回顾性研究,收集了2016年5月至2024年1月在中山大学附属第一医院确诊并接受根治性放化疗的Ⅱ~Ⅲ期ASCC患者(n=20)的临床病理资料。利用免疫组织化学方法检测患者(n=14)肿瘤样本中PD-L1的表达水平,采用综合阳性评分(combined positive score,CPS)评价PD-L1染色强度。PD-L1阳性判读标准为CPS≥1,根据所有患者CPS值的中位数将患者分为PD-L1高表达组(CPS≥20,n=7)和低表达组(CPS<20,n=7),并采用Log-rank生存分析比较PD-L1高表达组和低表达组患者的生存预后。结果20例患者的中位随访时间为33.4个月。所有患者的3年总生存率、无进展生存率、无局部复发生存率和无远处转移生存率分别为83.9%、78.6%、92.9%和85.7%。14例患者的肿瘤样本PD-L1免疫组织化学检测均为阳性(CPS≥1)。生存分析结果显示,PD-L1高表达组和PD-L1低表达组患者的3年总生存率分别为80.0%和100%(P=0.371),3年无进展生存率分别为60.0%和100%(P=0.134),3年无局部复发生存率分别为100%和100%(P=1.000),3年无远处转移生存率分别为60.0%和100%(P=0.134)。结论ASCC患者中PD-L1表达阳性率高,PD-L1高表达和低表达患者生存预后无显著差异。

积极心理学视角下学生团体心理辅导方案设计与实施

近年来,我国大学生群体心理健康问题不容乐观,得到了社会的普遍关注。为了促进大学生保持健康成长,团体心理辅导模式应运而生,具有实施方便、见效快的特点。基于积极心理学的理论基础,阐述了将其融入到学生团体心理辅导工作的必要性和可行性,最后提出了具体辅导方案设计举措与实施保障路径,旨在为高校心理健康教育工作高质量发展提供切实有效的参考支持。

基于激光定位技术的机器人非接触无编程示教方法与实现

针对现有机器人示教系统操作复杂、示教编程难度高及需操纵机器人等问题,提出一种基于激光定位技术的机器人非接触无编程示教方法。以示教笔代替机器人末端工具绘制示教轨迹,通过激光定位技术获取示教笔的示教路径和动作,并通过机器人逆运动学求解及轨迹规划得到各个关节的控制轨迹,实现机器人的快速非接触无编程示教。最后通过搭建桁架式六轴机器人硬件和软件系统,实现了基于激光定位技术的机器人非接触无编程示教,验证了提出的示教方法的可行性。所提示教方法简化了示教过程,降低了操纵机器人带来的安全风险,且无需操作人员具备编程能力,使机器人示教工作具有良好的适应性,具有广阔的应用空间。

Optimized parameters of downhole all-metal PDM based on genetic algorithm

Currently,deep drilling operates under extreme conditions of high temperature and high pressure,demanding more from subterranean power motors.The all-metal positive displacement motor,known for its robust performance,is a critical choice for such drilling.The dimensions of the PDM are crucial for its performance output.To enhance this,optimization of the motor's profile using a genetic algorithm has been undertaken.The design process begins with the computation of the initial stator and rotor curves based on the equations for a screw cycloid.These curves are then refined using the least squares method for a precise fit.Following this,the PDM's mathematical model is optimized,and motor friction is assessed.The genetic algorithm process involves encoding variations and managing crossovers to optimize objective functions,including the isometric radius coefficient,eccentricity distance parameter,overflow area,and maximum slip speed.This optimization yields the ideal profile parameters that enhance the motor's output.Comparative analyses of the initial and optimized output characteristics were conducted,focusing on the effects of the isometric radius coefficient and overflow area on the motor's performance.Results indicate that the optimized motor's overflow area increased by 6.9%,while its rotational speed reduced by 6.58%.The torque,as tested by Infocus,saw substantial improvements of38.8%.This optimization provides a theoretical foundation for improving the output characteristics of allmetal PDMs and supports the ongoing development and research of PDM technology.

胃癌合并腹膜转移的一线免疫治疗分析

目的探究免疫治疗对胃癌合并腹膜转移(gastric cancer peritoneal metastasis,GCPM)患者的疗效。方法回顾性收集2019—2023年北京大学肿瘤医院既往未接受全身治疗的同时性GCPM患者191例的临床资料,按照治疗方法分为接受免疫治疗组(n=87)和未接受免疫治疗组(n=104),并根据两组患者的基线特征对不同亚组进行分析,同时按程序性死亡受体配体1(programmed death-ligand 1,PD-L1)联合阳性分数(combined positive score,CPS)评分、抗人表皮生长因子受体2(human epidermal growth factor receptor-2,HER-2)和CLDN18.2表达情况对免疫治疗组进行亚组分析。比较两组患者的临床疗效和不同亚组间患者的中位无进展生存(median progression-free survival,mPFS)时间和中位总生存(median overall survival,mOS)时间。结果接受免疫治疗组患者mOS时间较未接受免疫治疗组有延长趋势(20.7个月∶17.2个月,P=0.05)。接受免疫治疗组患者和未接受免疫治疗组患者的mPFS时间无明显差异(5.9个月∶6.0个月,P=0.40)。进一步分析生物标志物表达和免疫治疗获益的关系,结果显示,在GCPM患者中,HER-2阳性患者接受免疫联合化疗的OS时间优于单纯化疗,而CLDN18.2和PD-L1的表达情况均未能预测联合免疫治疗的获益情况。结论联合免疫治疗相比单纯化疗可以一定程度延长GCPM患者的OS时间,但仍需对适合免疫治疗的人群进行筛选和优化治疗方案。免疫治疗亚组分析揭示了不同分子分型和临床特征GCPM人群在接受免疫治疗后的获益情况,可协助筛选适合免疫治疗的人群。