一种地区分销系统的利润优化模型及其算法

研究由一个地区分销中心和多个不同的零售商组成的地区分销系统,假设顾客需求是随机的价格弹性需求.在基于价格折扣的联合决策供应链契约下,由地区分销中心提供一个价格折扣,以系统各成员追求利润最大化为目标,建立了地区分销系统的利润优化模型,并给出了一种基于遗传算法的求解策略.最后,通过算例说明该模型的有效性.     

今冬明春国内木材市场预测

种种迹象表明,今冬明春整个木材市场将呈现资源相对宽松,市场交易平淡,价格做升微降的态势。 1. 资源相对宽松。在保护生态环境的强烈呼声下,美俄等产材大国,限制森林采伐。我国木材产量也只保持1993年的水平,并减少了原木进口。资源总量并不宽松。但是,由于受国家宏观调控的制约,一部分需求沉淀了,因而广大销区普遍出现了交易清淡、销售不畅、库存滞     

木材经营企业销售管理信息系统

本文分析了木材经营企业销售信息系统,该信息系统由数据输入处理模块,销售、价格、库存模块,信息输出模块等组成,具有提供和查寻木材销售量、材种销售量与销售价格预测、库存量预测等功能.     

主动开拓市场 促进产品销售

为促进产品销售、搞活流通、盘活资金,乌尔旗汉林业局努力在启动市场上下功夫,花大力气,拓宽销售渠道,使林产品的销售向广度和深度发展,增强了企业的经济活力. 面对库存加大、市场销售不畅局面,这个局利     

今年我区木材经营的困难与机遇

三月下旬全区木材市场调查会议情况表明,今年一季度我区及全国木材市场形势清淡,价格平稳,三月底、四月初整个木材销售形势仍处在市场低谷。从全国形势看,沿海地区几次需求反弹无力,市面行情再度平稳,内地各大区则需求低下,市场形势似起又落。在我区,桂林地区三月份未见明显的市场回升势头,与去年同期相比,杉元、松元、松板等需求情况均差于去年。河池地区,由于去年下半年销售形势不好,一季度库存较多,各种木材价格与去年底基本一     

基于供应链的企业库存成因及优化控制研究

基于企业全面库存管理思想,对库存成本、库存控制、库存系统优化等管理经验与前人研究成果进行分析,借鉴先进企业的库存管理理念和方法,以大型制造企业为核心研究对象,在集供应商、制造商、经销商为一体的供应链作为研究框架的基础上,运用供应链系统理论作为研究方法,分析了库存管理现状、影响因素及产生原因,从优化生产管理、整合企业内部供应链和跨企业供应链的角度提出库存控制的相应对策,以实现全面的库存优化,从而提高企业的经营效益。     

美国阔叶材市场

1.木材供应 与前几个月相比,2002年12月的阔叶材产量较低.秋季是木材采伐的旺季,12月(尤其在圣诞节前),术材采伐量明显减少.随着冬季潮湿、雨雪季节的来临,木材采伐受阻,更加剧了原木供应紧张矛盾.目前,许多制材厂难以维持足够的原木库存,将来也难以保障库存.这样,原木短缺致使原木和新鲜锯材(生材)价格上扬.原木涨价使得销售原木有利可图,因而不是将原木锯解成锯材出售.与此相似,新鲜锯材与窑干锯材间的价格差越来越小,锯材干燥厂为了获利的锯材销售所承受的困难日益加大,有的干燥厂只好临时关闭干燥炉.     

10月份日本南洋材市场

东南亚原木价格短暂急剧下降后,开始呈现出上升的趋势。然而,较上月相比,10月的价格没有化变。11月4日,在每月举行的日本南洋锯材会议上,一位贸易公司负责人说“国内胶合板厂有足够的原木库存,他们只需要现货采购,以弥补他们所需的数量”。目前的情况下,受需求放缓的影响,价格增长会减慢。     

欧洲热带阔叶材市场动态

ITTO热带木材市场报告称，近来由于库存量较高，荷兰和德国对娑罗双木（meranti）锯材和小方材的需求不急，生意集中到密度和耐久性较高的木材上。尽管远东的产量下降，由于需求较低，满足供应仍无问题。在英国很流行的细木工材——娑罗双木（meranti tembaga）2007下半年价格下跌，目前趋于稳定。虽然非洲楝（sapele）仍然是在英国受喜爱的细木工材，但马来西亚的娑罗双木在价格上更具竞争力。     

需求不确定情况下的供应链价格补贴契约研究

研究市场需求随机且受零售价格影响环境下单个供应商和单个零售商所组成的两级供应链，针对供应商和零售商的3种不同市场地位的情况，分析了价格补贴契约如何使供应链达到协调。结果表明：在3种情况下价格补贴契约都能使供应链协调。最后通过计算案例，得到了供应商利润和零售商利润随契约参数变化的情况。     

Determination of optimal rotation period under stochastic wood and carbon prices

The valuation of forest stands is traditionally based on a profit calculus involving revenue from wood sales and associated costs. Currently, the role of carbon management in forests is actively discussed. In a stochastic setting we extend the analysis of the optimal rotation period by considering uncertain revenue streams from carbon trading. We develop a real options model given uncertainties in future wood and CO₂ price behaviour. A detailed sensitivity analysis of the numerical results for both cases – with and without carbon sequestration – is provided. We find that optimal rotation periods vary considerably with (i) the type of price process, (ii) the way how carbon income is defined, and (iii) the selection of discount rates.     

Goal programming approach for sustainable forest management （case study in Iranian Caspian forests）

We used a goal programming technique to determine the optimal harvest volume for the Iranian Caspian forest. We collected data including volume, growth, wood price at forest roadside, and variable harvesting costs. The allometric method was used to quantify seques- trated carbon. Regression analysis was used to derive growth models. Expected mean price was estimated using wood price and variable harvesting costs. Questionnaire was used to determine the constraints and the equation coefficients of the goal programming model. The optimal volume was determined using the goal programming method according to multipurpose forest management. LINGO software was used for analysis. Results indicated that the optimum volumes of species were 250.25 m3.ha-1 for beech, 59 m3.ha-1 for hornbeam, 73 m3.ha-1 for oak, 41 m3.ha-1 for alder, and 32 m3.ha-1 for other species. The total optimum volume is 455.25 m3.ha-1.     

Impact of stochastic price and growth processes on optimal rotation age

This paper analyses timber harvesting in the Finnish economic and wood production environment. Empirical evidence including stumpage prices, silvicultural costs, etc., since 1949 covers all non-industrial private forestry. Stumpage price and volume growth processes are proxied by GBMs. Optimal harvesting age solutions and numerical results recognising price drift, price and growth volatility, volume growth, value growth and stand establishment costs, as well as thinning benefits, are provided for Scots pine. Moreover, comparative static and sensitivity solutions, including numerical results, show the impact of the discount rate, price drift, and price and growth volatilities on optimal harvesting age. Price volatility prolonged harvesting age by some 5–9 years, and growth volatility by about 1–2, but negative price drift for discount rates from 5 to 2% fell by roughly 6–10 years. Ignoring the future thinning benefits prolonged the harvesting age only by 1–2 years, but ignoring future stand establishment costs reduced it by 2–4 years. Including the price drift and volatility violated the 70 year age limit in the Forest Act for discount rates exceeding 3.5%. The recommended harvesting age of 80 years could be established only by ignoring the price drift. In all, this study produces solutions and programs that can be incorporated into a forest management planning software product widely used in Finland (Hynynen et al. in For Ecol Manage 207(1–2):5–18, 2005).

适应价格的用材林主伐决策模型的研究

本文研究了木材价格的变化为一自相关随机过程时用材林采伐的随机决策分析问题,分析了用材林经营决策中的不确定性因素及其对经营决策的影响,建立了一个针对主伐的木材市场价格随机变动的适应价格的主伐决策模型,利用动态规划求得在一个给定决策期内的主伐最优经营策略,对应这个策略有一个最大的期望效益。并进一步分析了在价格波动情况下和不同贷款利率下的最优策略。     

华山松木蠹象防治指标研究

在曲靖市海寨林场遭华山松木蠹象危害的华山松林分内设样地并作解析木观测，结果表明，华山松木蠹象危害指数与华山松材积损失率间有明显的相关关系，其相关关系可用一元回归方程表示为Y=-0.398654+0.055908X(X为华山松木蠹象危害指数，Y为华山松材积损失率)在此基础上，考虑不同的立木生长量、木材价格、防治费用和防治效果，进一步推算出华山松木蠹象防治指标的动态模型为X     

中小型空调生产企业需求预测方法的研究

空调是季节性比较强的产品，淡旺季需求与产能的不均衡会导致空调企业成本的增加。本文在分析空调产品需求特点及市场发展趋势的基础上，对国内中小型空调生产企业的需求预测进行研究，结合企业自身状况选择适用的需求预测方法建立完整的需求预测体系，并就其在实践中的运用给出具体说明。     

Paper or plastic? The United States’ demand for paper and paperboard in packaging

Analysis of consumer demand for packaging suggests that: plastic packaging is a luxury good, while paper packaging is a normal good, paper packaging demand increases with the price of plastic packaging, and that demand for paper packaging is most sensitive to its own price, and to the income of consumers. In a complementary analysis of input demand in the converting paper industry it was found that the demand for each paper grade is price inelastic, capital and other materials are substitutes for paper, while labor is a complement, technical change rapidly decreases the use of unbleached kraft packaging and industrial converting, and increases the use of other grades. The demand for each paper grade, derived from the consumer demand and the factor demand functions, showed that, from 1983 to 1991, the demand for paper in packaging was influenced mainly by consumer income, and by the price of paper packaging, and less so by the price of paper itself, or by the price of plastic packaging.     

Land Allocation with the Introduction of Teak: A Case Study of Smallholder Farms in Southern Togo

Subsistence landholders in southern Togo are interested in planting teak on their land for income generation. The purpose of this study was to determine how smallholder farmers could allocate land among maize, cassava, and teak plantings in order to optimize financial returns. A linear programming model was developed to calculate the optimal land allocation for maize, cassava, and teak. The model was solved for five farmer types using 15- and 30-yr teak rotations, with timber priced at alternative market and government market prices, and with discount (real interest) rates of 8, 11, and 15%. The analyses indicate that growing teak is profitable for most smallholders if grown on a 15-yr rotation and sold on the alternative market. For Land Rich-Labor Poor farmers, teak is profitable under all regimes.     

基于TSF-Stanford模型的广东省家用电脑废弃量估算研究

根据近年来广东省家用电脑的销售量,采用时间序列预测法预测了2012～2020年的销售量,运用斯坦福估算模型估算了2012～2022年的废弃量。结果表明:逐年稳步上升的家用电脑销售量,随着时间的推移将建立一个巨大的潜在丢弃池,累计到2022年废弃量将达到4154.19万台。对广东省开展废旧家用电脑回收工作提出了建议。