PRODUCTION-ORIENTED INFORMATION SYSTEMS FOR AGRICULTURAL SUBSECTORS: PRINCIPLES AND TECHNIQUES

The existence of problems which are peculiar to agricultural subsectors explains the presence of organisations associated with individual commodities or commodity groups. Modern developments in information systems can contribute to meeting organisations' information requirements, but it is necessary to design systems consistent with both the principles and techniques of economic analysis and the general methodology. Following the definition of a subsector, a review of the principles for information systems and the relevant economic concepts shows the formal equivalence of many basic ideas. Despite reservations which have been expressed about the current potential for quantitative techniques, an input/output approach could have an important role as a flexible component of subsector information systems.     

北京市农业资源管理信息系统建设的问题及对策研究

[目的]为积极开展分区域农业资源管理信息系统建设,探索信息化管理区划资源的有效途径,更好地实现北京市各类农业资源的获取、处理、传播和合理利用。[方法]文章结合多年的实践工作,通过对北京市农业资源管理信息系统建设内容和功能的描述,指出北京建设农业资源管理信息系统面临的问题并提出对策建议。[结果]问题主要是:对农业资源信息数据重视程度不够,对农业资源信息数据投入不足,农业资源信息分散且缺乏有效的开发整合机制,在技术层面存在系统对接和需求方面的问题,人才队伍建设亟待加强,法规制度建设滞后。[结论]提出了农业资源管理信息系统建设措施,加强政府在农业资源管理信息系统建设中的主导作用,加大资金投入力度及对资金投入的监管和引导,整合各方资源,充实农业资源数据的完整,与互联网平台和云数据平台进行对接同时深化服务功能,满足目标人群需求,加快建设高水平人才队伍,制定和完善相应的制度规范和法规政策。     

AGRICULTURAL POLICIES IN THE USSR: PROBLEMS,TRENDS AND PROSPECTS

The paper, after presenting a brief profile of USSR agriculture, elaborates on the main goals of USSR agricultural policies as well as on the main instruments used for implementing these policies. It tries to point out the achievements and constraints of these policies which are underlying Mr Gorbachev's efforts towards a reform of the USSR food economy. The main elements of this reform, so far as they have already become visible at this stage, are discussed and the inherent risks are indicated. The paper finishes with a brief speculative look at the possible effects of the reform measures on the world food economy, if they were implemented consistently and successfully.     

FoxPro与渔政信息管理

ＦｏｘＰｒｏ是目前最流行的微机平台关系型数据库产品。本文简单介绍了ＦｏｘＰｒｏ在渔政信息管理中的应用     

OPTIMAL FERTILIZER CARRYOVER AND CROP RECYCLING POLICIES FOR A TROPICAL GRAIN CROP

The consequences of carryover for the optimal application of fertilizer are considered using dynamic programming. The conclusions are relevant for the further problem of deciding how many grain crops to harvest from grain sorghum plants grown in a tropical environment. Dynamic programming is also used for solving this problem for the Ord River Valley, and takes account of the interrelations between season and crop cycle number. Data were obtained from investigations conducted in the area.     

MALLEE WHEAT FARMERS' DEMAND FOR CROP AND RAINFALL INSURANCE

Producers' demand for a crop insurance program with indemnities based on their actual yields and a rainfall insurance program with indemnities based on area rainfall is analysed. Actuarial costs of these hypothetical programs are estimated. Tobit procedures are used to analyse factors influencing the amount which farmers would be willing to pay for the alternative insurance programs. Factors related to the absolute size of risk and capacity to bear risk, as well as personal characteristics and risk attitudes of producers, have effects on the demand for insurance as hypothesised. Problems of adverse selection are associated with the area yield-based program, while both crop and rainfall insurance programs may involve some moral hazard. Producer participation in either program would be limited.     

农作物种植适宜性评估系统的设计与实现

该文介绍了利用GIS平台的叠加分析和统计分析等功能所建立的农作物种植适宜性评估系统的设计思路、特点和功能,系统通过分析气候资源、土壤资源和地形条件对农作物种植适宜性的影响,建立评价和区划指标,提高了农作物引种栽培气候适宜性评估和农业气候区划的自动化水平。     

关于企业债权管理的问题和防范措施

文章列出了企业债权管理方面常见的六个问题,针对这些问题提出了七项防范措施.     

FARM FINANCIAL MANAGEMENT: EMERGING PROBLEMS*

It is unlikely that the changes giving rise to the need for more attention to the agricultural finance areas will slow down in the foreseeable future. Financial parameters will be the major determinants of the entrepreneurial independence of family size and large food and natural fiber producers. The financial problems already confronting farming are numerous and complex, and the task ahead for the agricultural economists is great since time cannot be neutral in its effect if progress is to be achieved.     

深度学习方法在作物遥感分类中的应用和挑战

[目的]准确估算作物的面积和分布对粮食安全至关重要。与传统的机器学习方法相比,深度学习具有多种优势,如端到端训练、可迁移性。为有效利用高时空数据进行作物识别提供了新的机遇。已有多种模型被应用于作物分类任务中,针对不同的分类任务,如何有效地选择模型,并对其进行训练和使用已成为关键问题。[方法]文章回顾了利用深度学习模型对作物分类的主要研究。N维卷积神经网络(N-D CNN)(N=1、2、3)和递归神经网络(RNN)已被有效用于作物分类任务。长短期记忆RNN(LSTM RNN)和门控循环单元RNN(GRU RNN)是RNN的变体,解决了随着时间序列增加RNN出现的梯度消失或爆炸问题。此外,还有研究使用CNN和RNN(我们称为RCNN)的混合模型对作物进行分类。该文首先阐述了使用深度学习方法进行作物制图的背景和意义,并介绍了CNN和RNN模型结构。然后回顾了一些典型的研究,包括模型的结构、遥感数据源、数据处理方法和分类精度。最后,总结了使用深度学习方法进行作物分类的挑战以及现有解决方案的局限性。[结果](1)1-D CNN可用于提取时间特征,或时间+光谱特征,分类效果良好;2-D CNN已被广泛应用于单时相数据的空间特征提取,分类精度依赖于数据源;3-D CNN应用较少,但具有很大的潜力,尤其是时间+空间维度的特征提取;(2)相同条件下(架构、数据源、研究区域、类别),LSTM RNN和GRU RNN分类效果通常高于普通RNN,而前两者的效果差距不大,但GRU RNN训练时间较短;(3)CNN+RNN混合模型(RCNN)用RNN比3-D CNN更适合提取时间特征。这主要是由于RNN建立了对序列数据的长期依赖,而3-D CNN卷积核是局部计算的。[结论]通过分析,认为深度学习技术是作物遥感分类的有效工具。此外,与其他模型相比,RCNN,3-D CNN和GUR RNN具有更大的潜力。     

新疆大叶白麻资源及其开发利用前景

大叶白麻俗称罗布麻,是一种抗逆性强,经济价值高的多年生野生纤维植物,广泛分布于新疆塔里木河冲积平原,被誉为“野生纤维之王”,“罗布麻”入药历史逾千年。文章阐述了大叶白麻分布区域及环境特点、塔里木河地区资源数量、利用现状和开发前景。     

RESOURCE DEGRADATION ON AGRICULTURAL LAND: INFORMATION PROBLEMS,MARKET FAILURES AND GOVERNMENT INTERVENTION*

Information problems impede private contracting for the supply of many natural resource services. They are also likely to prevent the government identifying and achieving optimum levels of natural resource degradation on agricultural land. In particular, the distributional impacts of government intervention create incentives for strategic distortions of information by interested parties. Resource conservation measures which impose costs on beneficiaries, and which provide positive incentives for farmers to monitor resource degradation, may be superior because they reduce information problems.     

TREATMENT OF RISK IN A CROP PROTECTION INFORMATION SYSTEM

The importance of risk in a farm-level management information system designed to help farmers make spraying decisions relating to leaf rust of barley is examined. Using utility functions which were elicited for a small number of cereal growers, and probability distributions of yield losses generated using the information system, it was found that strategy assessment using the criterion of maximisation of expected monetary value or the criterion of maximisation of expected utility could be expected to lead to identical recommendations in most years, for a wide range of risk attitudes.     

基于MapObjects的北京市农产品标准化生产基地信息管理系统设计与实现

无公害农产品、绿色食品和有机农产品是农产品消费安全的有效保障。随着"三品"生产基地的不断增加,迫切需要对认证信息进行高效、可视化管理。该文以北京市生产基地为管理对象,设计了数据库结构及认定基地和认证产品一体化编码规范,以.NET为开发平台,集成MapObjects,开发了北京市农产品标准化生产基地信息管理系统,实现了基本信息可视化管理、基地信息查询统计、空间数据与属性数据的交互查询、产地认定、辅助规划等功能,为相关认证和规划部门提供管理和决策信息。     

新形势下高标准农田建设管理政策存在的问题及建议

目的 高标准农田建设是“藏粮于地,藏粮于技”的重要措施,在粮食安全问题重要性凸显的背景下,加强高标准农田建设意义非凡。通过分析机构改革后农田建设管理政策在实施过程中存在的问题及相应措施,将为政策完善提供方向和依据。方法 文章选取4个粮食主产省的8个粮食大县进行调研,组织省、市、县各级农田建设管理部门人员、新型经营主体等,采用半结构性方式进行访谈,研究分析农田建设政策落实及项目实施中存在的问题。结果 农田建设在提高粮食产能、促进农业机械化、增加农民收入、新增耕地指标和改善农田生态环境方面发挥了成效,但机构改革后的农田政策执行中还存在机制不全、体制不顺的问题,在组织协调、资金管理、项目内容管理和制度标准方面都有体现。问题根源主要来自政府部门及相关主体存在的“路径依赖”“重管理、轻服务”“一刀切”等倾向。结论 需从体制机制上完善农田建设管理政策,让高标准农田项目建设更高效,为保障粮食安全发挥更大作用。     

MONTE CARLO SIMULATION OF MANAGEMENT SYSTEMS

Monte Carlo simulation is not a substitute for proper theoretical model construction, nor is it a substitute for proper experimental design and statistical analysis. Rather Monte Carlo simulation is a method of performing experiments on functionally expressed models. As such, careful attention should be given to primary model construction, experimental design and statistical analysis. Although simulation procedures in general allow testing of various policies, decisions and rules relating to an operating system, Monte Carlo simulation facilitates a more vaned type of experimentation. This results from the random generation of finite observations for otherwise undefined functional relations. Monte Carlo is also well adapted to situations requiring an approximation of the stochastic influences often found in real world operating and decision systems. This is especially relevant when theoretical analysis is unable to relate certain phenomena. Monte Carlo techniques Frovide a means of experimentation from which statements of statistical inference may be made. Such inferences will facilitate logical consistency of analytical models. Monte Carlo techniques provide a means of performing experiments from whch statements of statistical inference may be made.     

新农村建设规划中的问题与建议

新农村建设规划对新农村建设至关重要。该文从分析新农村建设规划存在的6个问题入手,阐述了新农村建设规划目的、总体思路和规划基本原则,提出了新农村建设规划要分类指导、稳步推进,立足现状、统筹规划等五项编制建议。