Regional Planning of Wastewater Reuse for Irrigation and River Rehabilitation

Subject to a few agri‐environmental restrictions, municipal wastewater can be utilised for agricultural irrigation and river rehabilitation. This paper develops a single‐year Planning Model for a region in Israel which consists of a city and three potential wastewater consumers. The model incorporates, in one endogenous system, the economic, physical and biological relationships in the water–soil–plant–environment system and its objective is to maximise the regional social welfare. The model determines the optimal crop mix and the optimal allocation of the limited water and land resources among all potential users. Then, different allocation approaches from the concept of transferable utility games are applied to determine a reasonable and fair allocation of the additional net benefits which will be acceptable to all the players. The results support the collaboration among the economic entities and indicate economic and environmental advantages which can serve the decision‐makers.     

Land use optimization in watershed scale

Managing a watershed for satisfying the inhabitant's demand is a difficult task if one has to maintain a reasonable balance between usually conflicting environmental flows and demands. The solution to these complex issues requires the use of mathematical techniques to take into account conflicting objectives. Many optimization models exist for general management systems but there is a knowledge gap in linking practical problems with the optimum use of all land resources under conflicting demands in a watershed. In the present study, an optimization problem has been formulated for the Brimvand watershed, Iran, comprising ca. 9572 ha to find out the most suitable land allocation to different land uses, viz. orchard, irrigated farming, dry farming and rangeland targeting soil erosion minimization and benefit maximization.     

Non‐Parametric Modelling of CO2 Emission Quota

Dutch glasshouse firms are facing the introduction of a system of tradable CO₂ emission quotas. This paper employs a non‐parametric method for modelling tradable CO₂ emissions of Dutch glasshouse firms. The method is capable of generating shifts in CO₂ emissions across the sample of firms. Moreover, changes in volumes of outputs produced and inputs used are computed. Results show that firms using a conventional heating technology will be net purchasers of CO₂ emissions, whereas firms using more advanced heating technologies will sell part of their emission quota.     

Investment planning under uncertainty and flexibility: the case of a purchasable sales contract*

Investment decisions are not only characterised by irreversibility and uncertainty but also by flexibility with regard to the timing of the investment. This paper describes how stochastic simulation can be successfully integrated into a backward recursive programming approach in the context of flexible investment planning. We apply this hybrid approach to a marketing question from primary production which can be viewed as an investment problem: should grain farmers purchase sales contracts which guarantee fixed product prices over the next 10 years? The model results support the conclusion from dynamic investment theory that it is essential to take simultaneously account of uncertainty and flexibility.     

Incorporating risk in a positive mathematical programming framework: a dual approach

In this study we develop a new methodological proposal to incorporate risk into a farm‐level positive mathematical programming (PMP) model. We estimate simultaneously the farm nonlinear cost function and a farmer‐specific coefficient of absolute risk aversion as well as the resource shadow prices. The model is applied to a sample of representative arable crop farms from the Emilia‐Romagna region in Italy. The estimation results confirm the calibration ability of the model and reveal the values of the individual risk aversion coefficients. We use the model to simulate different scenarios of crop price volatility, in order to explore the potential risk management role of an agri‐environmental scheme.     

Tradable water saving certificates to improve urban water use efficiency: an ex‐ante evaluation in a French case study

This paper proposes a system of tradable Water Saving Certificates to improve the efficiency of water allocation between Drinking Water Utilities at river basin level. A market institutional set‐up, inspired from recent policy developments in the energy sector, is proposed. An original analytical price‐endogenous model is developed to simulate trade intensity, equilibrium price and efficiency gains in this urban water market. The economic model is implemented in a French case study using mathematical programming. It is used for conducting an ex‐ante evaluation of trade possibilities and efficiency gains, considering different spatial restrictions aimed at controlling environmental externalities. Our modelling exercise provides evidence of the benefits of the proposed Water Saving Certificate scheme.     

The Essential Role of Sense of Community in a Youth Sport Program

This multiphased study identifies the salient benefits that parents seek for their families from a youth sport program. Phase 1, a preseason focus group study of parents of swimmers in three clubs (N = 15), indicated parents seek a sense of community for their children and themselves, and sense of community is linked to their desire for children to learn sport and life skills. Phase 2, a postseason survey of parents in the same three clubs (N = 129), tested the relationships among coaching quality, friendships, organizational communication, sport and life skills, sense of community, parents' satisfaction, and their repeat purchase intention. Using path analysis, sense of community was identified as the key driver of satisfaction and repeat purchase intention, with swimming improvement also having a significant effect on satisfaction. These findings highlight the central role sense of community plays for participants and their families in youth sport contexts.     

新围海涂土地利用结构优化模型及其应用

为了进一步探讨数学规划模型在新围海涂土地利用结构优化中的应用,在模型分析与实例应用相结合的基础上,选择浙江沿海新围海涂作为典型研究区,根据当地滩涂开发利用总体规划要求,结合实际开发需要,应用数学规划方法构建土地利用结构优化决策模型,对规划范围内新围海涂的土地利用结构进行优化配置。研究结论:应用数学模型对研究区内土地利用结构优化配置是可行的。但是今后需要进一步研究空间优化配置方法,实现定性、定量和定位三者的统一。     

美国GE公司CEO继任规划的启示

继任规划在企业追求长期战略和持久业绩的过程中起着关键作用。而CEO继任规划则是企业最重大的战略决策。美国GE公司由于建立了一套行之有效的CEO继任规划程序,从而保证企业能够培养合适的CEO候选人。公司CEO继任规划包括内部接班继任、内部竞争继任、突然政变继任和广泛选择继任等4种方式。每一种继任方式都有其优势和劣势。不存在适用于所有公司的继任方式。不同的公司如何选择适合的继任方式取决于公司本身的条件。目前,我国企业正在进入经营者大换班高峰期,可以借鉴美国GE公司CEO继任规划的成功经验,进一步完善继任机制。     

关于高职C语言教学改革的探索

根据高职院校C语言课程教学的现状,结合作者教学实践经历,从教材选择、学习兴趣培养、教学方法与手段和考核方式培养等方面,提出了改进高职院校C语言教学的建议。