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1.
《Agricultural Systems》2003,76(2):457-482
Agricultural policy makers were helped to construct and use a decision support system (DSS) to identify problems and assess potential solutions for a river basin in Sri Lanka. Through building the DSS themselves, policy makers should reach better decisions. The main aim of the study was to test whether this could be done using a tool called a Bayesian network (BN) which is accessible to non-specialists and able to provide a generic, flexible framework for the construction of DSS. Results from a workshop indicated that the approach showed promise, providing a common framework for discussion and allowing policy makers to structure complex systems from a multi-disciplinary perspective. The need for a multi-disciplinary perspective was clearly demonstrated. The study also suggested improvements to the ways in which BNs can be used in practice. Further workshops with farmers highlighted the importance of involving them in the planning process and suggested more effective ways of doing this while using BNs. 相似文献
2.
Thomas C. Ponsioen Huib Hengsdijk Joost Wolf Martin K. van Ittersum Reimund P. Rötter Tran Thuc Son Alice G. Laborte 《Agricultural Systems》2006
Agricultural research in East and Southeast Asia is increasingly challenged by the search for land-use options that best match multiple development objectives of rural societies (e.g., increased income, food security, and reduced environmental pollution). In order to support the identification of sustainable land-use options and to support decision making with respect to land use, a tool was developed for quantifying inputs and outputs of cropping systems at the field level. TechnoGIN, the tool described in this paper, integrates systems analytical and expert knowledge and different types of agronomic data enabling the assessment of inputs and outputs of a broad range of cropping systems and the evaluation of their resource use efficiencies. By using methods of spatial aggregation in combination with linear programming, results can also be used to explore trade-offs in resource-use efficiencies at higher levels such as the farm household, municipality and province. New features in TechnoGIN compared with similar tools include the annual rotation of up to three crops, the distinction between aerobic and anaerobic growing conditions of crops, and the procedure for estimating crop nutrient uptake. TechnoGIN is illustrated with results from the Tam Duong district in North Vietnam. The design of TechnoGIN enables easy access to its data, parameters and assumptions, and rapid generation and evaluation of input–output relationships of cropping systems in order to add new information and to improve data. TechnoGIN raises awareness about the assumptions incorporated and thus supports data collection and setting of the research agenda with respect to agro-ecological processes for which knowledge is incomplete, and is relevant for showing trade-offs between production, economic and environmental impacts of different land-use systems. 相似文献
3.
This paper designed and developed a multi-objective programming (MOP) model to illustrate the dynamic relationship among technologies, productive activities, constraints and farmers’ objectives in the peri-urban vegetable production system and use the model as an economic tool in analysing probable consequences of a given action or innovation on the farm. The best compromise solution was generated using four analytical steps, as follows: single-objective optimization (to determine the ideal and anti-ideal values of the objective functions); constrained optimization (to generate the set of Pareto non-dominated solutions); cluster analysis (to trim down efficient set into smaller homogeneous groups); and compromise programming (to determine where the best compromise solution lies). 相似文献
4.
为了系统地分析沿海经济发达地区土地利用问题,提出适宜于该区域全面协调发展的土地利用策略。采用案例分析法,以宁波市大嵩新城为例,通过分析沿海发达地区城市发展定位,新一轮规划实施背景下新城建设发展过程中所面临的用地制约和用地问题,有针对性地从开源节流两方面提出适宜于大嵩新城发展的可行用地策略。经测算,大嵩新城通过改旧挖潜,可以增加建设用地650 hm2,通过上山下海可增加建设用地860 hm2,能有效缓解当前的用地矛盾。研究结果表明,坚持内涵挖潜以及结合自身地缘优势调整好用地空间布局的土地利用策略,既可以为地方政府制定新一轮规划管控措施提供一定参考,同时也可以为保障区域城市建设发展用地提供可行的建议。 相似文献
5.
The prospect that decision support systems (DSS) can help farmers adjust their management to suit seasonal conditions by putting scientific knowledge and rational risk management algorithms at farmers’ fingertips continues to challenge the science and extension community. A number of reviews of agricultural DSS have called for a re-appraisal of the field and for the need to reflect on past mistakes and to learn from social and management theory. The objective of this paper was to investigate whether there is an emerging consensus, among stakeholders in DSS for Australian agriculture, about the lessons learned from past experience with DSS tools. This investigation was conducted in three parts. The first part was a distillation of suggestions for best practice from the relevant literature. The second part was a reflection on what the champions of five current DSS development and delivery efforts in Australia learned from their recent efforts. The third part tested the level of support for the combined findings from the first and second approaches by surveying 23 stakeholders in the research, development, delivery and funding of DSS.The key propositions relating to best practice that were supported by the survey, listed according to the strength of support, were: 1. It is essential to have a plan for delivery of the DSS beyond the initial funding period. 2. DSS need to be embedded in a support network consisting of farmers, consultants and researchers. 3. DSS development requires the commitment of a critical mass of appropriately skilled people. 4. A DSS should aim to educate farmers’ intuition rather than replace it with optimised recommendations. 5. A DSS should enable users to experiment with options that satisfy their needs rather than attempt to present ‘optimised’ solutions. 6. DSS tools stand on the quality and authority of their underlying science and require ongoing improvement, testing and validation. 7. DSS development should not commence unless it is backed by marketing information and a plan for delivery of the DSS beyond the initial funding period.While the DSS stakeholders supported the proposition that it is essential to have a plan for delivery of a DSS beyond the funding period, the majority resisted the notion of DSS development being market-driven and especially commercial delivery of DSS. We argue that since public funding of the delivery of DSS for farmers’ management of climate risk is highly unlikely, reaping the benefits of lessons learned from past efforts will require that DSS stakeholders change their perception of the commercial delivery model or find an alternative way to fund the delivery of DSS beyond the R&D phase. 相似文献
6.
《Agricultural Systems》1999,59(3):311-325
Sustainability is a human-centred concept that comprises multiple aspects and objectives of different interest groups. Sustainable development is not readily measurable, except as a compromise between different parts of society, of which some may try to represent future generations of mankind. To determine a sustainable development path in the relationship between agriculture and its natural environment, a profound knowledge of this complex system and its behaviour under different socio-economic conditions is necessary. We present a modelling system which consists of a set of hierarchically linked modules. These modules describe production activities in a way that allows an economic and ecological analysis of these techniques. The heart of the modelling system is a multiple goal linear programming model, which is generated by data base modules. Simulation of single farm models as well as regional models based on simultaneously optimised farm types is possible. The modelling system appears to be a highly flexible tool with respect to the number and type of farms, sites and production techniques. Environmental objectives can easily be included and different levels of goal achievement can be simulated. It is well suited for single farm analysis as well as for regional models, for static as well as dynamic approaches. It allows rapid adoption of the model and rapid calculation of scenarios. Therefore, it is suited for use in interactive environments with users which are interested in repeated runs with little changes in the goal function, prices, subsidies or technical coefficients. The results can be used for policy decisions as well as the strategic planning of individual farmers. Applications of the modelling system will be presented in following papers. In this paper the kind of information the model can generate and the circumstances of their usage are shown. © 相似文献
7.
车间排产对提高车间的效率至关重要,智能排产可以极大提高加工的自动化和智能化水平。但传统生产过程中大多采用固定的工时数据进行产线作业时间估算,而拖拉机混流装配以工人作业为主,工人作业时间不固定甚至存在较大差异。为满足智能排产要求,提出通过数字孪生车间对生产计划进行仿真评价以增强与实际车间的交互与反馈。搭建与现场拖拉机装配线一致的数字孪生三维模型场景及人机交互界面,根据MES系统中的过点信息实现装配线模型实时驱动,建立了一个拓展性强、可灵活复用的数字孪生系统。分析了生产计划评价指标,提出通过生产计划管理系统与孪生装配线的交互反馈,实现对基于数字孪生装配线的生产计划仿真运行及评价。通过数字孪生装配线采集到的实际工时仿真运行生产计划,可以得到优化后的生产计划。将低产、正常和高产月份各5d内的实际生产计划与本系统生成的计划进行对比,结果表明本系统仿真评价后得到的生产计划更优越。 相似文献
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9.
A case study in packing shed design illustrates the basic nature of planning to cope with change in horticulture to meet the demands of changing markets or to take advantage of new developments in production methods or post-harvest practices.The planning process consists of two parts; first, making the decision to change and, secondly, implementing this change. The decision to change is made in an environment made up of people, the technology and facilities they have available and economic incentives and risks. Within this environment the decisiondashmaking process follows an orderly procedure, beginning with the recognition of need, then listing objectives, developing and evaluating schemes.Implementing a new scheme is basically a problem in facilities design, involving flow-charting the processes, formulating plans for material flow and equipment layout, followed by construction from building and site plans. Progress through facilities design requires systematic decisiondashmaking at all stages and is characterised by feedback loops.Together, the development and evaluation of schemes and the orderly approach to facilities design constitute a design method for planning for change in horticulture. 相似文献
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《Agricultural Water Management》2001,51(3):187-201
This paper describes a decision support system (DSS) that was developed to improve planning and management for the large irrigation schemes in the Alentejo region of Portugal. The system was designed to help in the analysis and evaluation of the crops and crop systems that can potentially be cultivated, together with identification of limitations affecting crop selection and crop yields. It integrates socio-economic and biophysical data at the field level to analyse the performance of an irrigation scheme in terms of the adoption of irrigation by farmers and farmers’ incomes. The final output is given in the form of specific actions and policies for the irrigated areas. The DSS was designed initially to be used in the Alqueva project, a large irrigation scheme that is under construction in Alentejo. Nevertheless, the final framework is generic in nature, being suitable for planning and policy evaluation in other large irrigation schemes. 相似文献
12.
文章从西部的区域发展条件出发,初步探讨了西部大开发的国土资源规划问题,认为搞好西部地区国土规划是搞好西部大开发的重中之重,强调西部大开发应审慎行事,搞好试点规划和重点规划以及国土整治规划。 相似文献
13.
《Agricultural Systems》2002,74(1):179-220
All correct reasoning is a grand system of tautologies, but only God can make direct use of that fact. The rest of us must painstakingly and fallibly tease out the consequences of our assumptions. (Herbert Simon in ‘The Sciences of the Artificial’, p.15)Decision support systems (DSS), like other information systems (IS) before them, were designed to serve functions deemed by ‘management scientists’ to be potentially useful to managers. But the unwelcome fact is that the use of agricultural DSSs by managers of farms has been low. This paper probes possible reasons for this through interpretation of agricultural DSS case histories and several strands of relevant social theory. From nine cases of DSS development effort and 14 products interpreted comparatively, a number of generalisations are made that serve as reference points in the following search for explanation in theory.First, the nature of management practice of family farms is explored and differences between the internal structure governing personal action and the scientific approach to practice are contrasted. Next, the interaction between the nature of the particular action/practice and the nature of the DSS is explored. A DSS designed to provide integrated, optimal recommendations for management typifies the DSS as a proxy for a manager's decision process. Examples of elaborate expert systems that simply were not used dramatically illustrate the resistance of family farmers to have their decision processes by-passed. On the other hand, the DSS designed to serve as a tool in a modified decision process is shown to have experienced higher use, by deriving and exploiting ‘deep,’ abstract information about the system, by introducing a powerful ‘logic,’ or a combination of both.A number of the referenced case stories demonstrate the resurgence of the decision support mode whereby the simulator is in the hands of an expert intermediary as an alternative to easy-to-use software in the hands of a farmer. This is the mode of operational research/management science, which preceded the DSS.In comparison with hierarchical organizations, available options for overcoming the persistent ‘problem of implementation’ of the DSS in family farms are inherently weak. This focuses attention on the importance of the relationship between the DSS developer and the potential user. Drawing on a classic typology of possible configurations of ‘understanding’ between the scientist and the manager, four approaches to intervention are discussed. Three entail a degree of engagement that qualifies them as ‘participative.’ But one of these constitutes a departure from the DSS and broader IS traditions that places it in another paradigm. In this ‘mutual understanding’ relationship, intervention intent shifts from educating and persuading to recognition of and respect for other ways of viewing the world. This opens up the opportunities for co-creating information systems that utilise the comparative advantages of both practical and scientific knowledge. Intervention emphasis shifts from prescribing action to facilitating learning in actions.Although the DSS has fallen far short of expectations in its influence on farm management, the experience has been instructive in multiple ways to both farmers and professionals in agriculture. In many cases, farmers learned from the DSS and could then jettison it without loss. From disappointments scientists have sometimes learned what was needed to achieve a better outcome. From collated DSS experiences, important lessons for the future can be drawn.The paper concludes by conjecturing that the future of the DSS and related ISs, while more limited than once imagined, holds promise in four directions: a ‘small’ tool for aiding farmers' tactical decisions; a versatile simulator as a consultant's tool; a versatile simulator as the core of a facilitated ‘learning laboratory,’ and a formal framework that supports regulatory objectives in constraining and documenting farming practice. 相似文献
14.
基于改进A *算法的电动车能耗最优路径规划 总被引：1，自引：0，他引：1
提出一种基于改进A*算法的电动车能耗最优路径规划方法。根据车辆运行时的能耗,考虑能量损失与回收等因素,建立了运行能耗函数。设计了新的启发式能耗预估代价对A*算法进行改进,证明了所提出的启发式能耗预估代价满足可采纳性和一致性,确保改进的A*算法可获得能耗最优路径。针对电动车的里程焦虑问题,基于改进的A*算法,建立了根据车载电池的剩余电量、充电站位置、终点位置来寻找可达的能耗最小路径方法。仿真实验表明,提出的方法可以找到起点到终点的能耗最小路径,当车载电池能量不足时,可以找到经过充电站的可行最小能耗路径,减少里程焦虑,验证了所提方法的合理性和可行性。 相似文献
15.
Temporary water trading is an established and growing phenomenon in the Australian irrigation sector. However, decision support and planning tools that incorporate economic and biophysical factors associated with temporary water trading are lacking. In this paper the integration of an economic trading model with a hydrologic water allocation model is discussed. The integrated model is used to estimate the impacts of temporary water trading and physical water transfers. The model can incorporate economic and biophysical drivers of water trading. The economic model incorporates the key trade drivers of commodity prices, seasonal water allocations and irrigation deliveries. The hydrologic model is based on the Resource Allocation Model (REALM) framework, which facilitates hydrologic network simulation modelling. It incorporates water delivery system properties and operating rules for the main irrigation and urban centres in a study area.The proposed integration method has been applied to a case study area in northern Victoria, Australia. Simulations were conducted for wet and dry spells, a range of commodity prices and different irrigation distribution system configurations. Some example analyses of scenarios incorporating water trading were undertaken. From these analyses potential bottlenecks to trade that constrain the economic benefits from temporary water trading were identified. Furthermore, it was found that in certain areas of the system, trading can make impacts of long drought spells worse for water users, e.g. irrigators. Thus, the integrated model can be used to quantify short-term and long-term third party impacts arising from temporary water trading. These findings also highlight the need to link “paper trades” (estimated by economic models) to physical water transfers (estimated by biophysical models). 相似文献
16.
依据天津第五设计院负责制作的天津拖拉机制造有限公司宝坻新工厂一期平面规划和工程设计纲领,设计和论证了新工厂的机加工车间、收割机装配车间、冲焊油联合车间、驾驶室车间和拖拉机装配车间等车间的工程能力,结果表明符合一期工程设计纲领的要求。 相似文献
17.
针对计算机辅助工艺规划中的切削用量决策问题,提出了一种基于Pareto遗传算法的切削用量优化算法。首先,以切削速度和进给量为优化变量,以切削效率和刀具耐用度为优化目标,通过对约束条件的分析,建立多目标优化模型。其次,改进选择算子,设置非劣解集以保存进化过程中用竞争法构造产生的Pareto最优解,从而保证算法的搜索方向;建立基于小生境技术的排挤机制以提高种群的多样性。然后,采用混合交叉算子和步长变异算子进行基因重组,经过若干次迭代,得到一个均匀分布于Pareto前沿的优化解集。最后,通过实例验证了该算法的可行性和有效性。 相似文献
18.
黄河流域典型灌区灌溉节水管理模型研究 总被引：2，自引：0，他引：2
以黄河流域上下游2个典型灌区为背景，针对灌区有其农业水管理现状，开发了灌溉节水策略分析决策支持系统（DSS）原型。DSS是一个规划工具，通过对不同策略下田间配水及供水系统的模拟分析及综合决策，寻求最优的策略集合，以达到节约灌溉用水量、提高农业用水效率及维持农业可持续发展的目的。该DSS系统主要用于黄河流域灌区提高农业水管理水平的策略分析，也可用于评估灌区续建配套及土地最佳利用方案等方面。 相似文献
19.
Optimal decision schemes for agricultural water quality management planning with imprecise objective 总被引：1，自引：0，他引：1
Agricultural activities are the main sources of water pollution to surface water and groundwater in rural areas. Extensive soil disturbance and application of fertilizer and manure in agriculture cause nonpoint source losses of soil and nutrients such as nitrogen and phosphorus. How to generate preferred decision schemes for agricultural activities that cause such nonpoint source water pollution is a critical issue for the decision makers. In this study, an inexact agricultural water quality management (IAWQM) model is developed and applied to a case study to generate optimal decision schemes for integrated water quality management within an agricultural system. The model is based on a hybrid fuzzy possibilistic robust programming approach, which improves upon the existing fuzzy possibilistic programming and fuzzy robust programming methods by allowing fuzzy information in the model's objective and constraints to be directly communicated into the optimization processes and resulting solutions. Optimal decision schemes for agricultural activities can be generated, including cropping area, manure/fertilizer applied, and livestock husbandry size, where implications of water quality/quantity restrictions for achieving regional economic development objectives are studied. The results of the case study indicate that useful information can be obtained through the proposed IAWQM model for providing feasible decision schemes, which reflect tradeoffs between economic and environmental considerations. The decision variables are useful for the decision makers to justify and/or adjust the decision schemes for agricultural activities through incorporation of their implicit knowledge on water quality management. 相似文献
20.
为缓解水资源供需紧张,指导区域用水管理,以社会、经济、生态综合发展为目标,供水量与需水量双向约束构建区域水资源优化配置模型.结合该模型特点,引入NSGA-Ⅲ算法对模型进行求解,以寻求Pareto前沿面与最优解集.同时,利用TOPSIS决策理论对众多Pareto可行解进行综合评价,选择权衡解作为最佳折衷方案.将该模型应用于南阳市鸭河口灌区进行验证,对灌区来水频率P=75%时下近期水平年与远期水平年进行水资源优化配置,并进行二次水资源供需平衡分析.结果表明,相对于基本方案,折衷方案在近期水平年余水量增长至11 497.60万m3,可节约水资源3 272.38万m3;远期水平年由缺水4 279.28万m3变为余水3 950.30万m3,可节约水资源8 229.58万m3,节水效果明显,符合鸭河口灌区整体规划与用水需求. 相似文献