The problem of defining changes in demographic old age in Poland in a spatial context

The author analyzes the demographic characteristics of the elderly population in Poland. The focus is on the spatial distribution of the elderly around the country.     

平面三次微分系统研究综述

本文首先阐明了研究E3的重要意义,然后指出E3的一般性质。奇点的分类与判定极限环线与奇异闭轨的存在性与唯一性,相对位置与代数曲线解．     

产品全过程的环保成本意识及评价

本文将“环保成本”概念引入产品评价(即在包括产品开发、生产、消费、回收处置的全过程中将环保治理费纳入产品成本),并从企业、国家、消费者利益的角度论述“环保成本法”在中国实施的必要性和可行性,提出产品评价的环保成本因子及其评价模式,进一步探讨解决费用分摊问题的可行途径。     

师专热学教学改革的几点体会

介绍了在热学教学改革中引入“热学中的创造性思维”．为前沿课题“开窗口”．为后续课程“留接口”的思考与实践。     

Lactation and fertility in Rural Bangladesh

Summary Analysis of data from various phases of a study of post-partum amenorrhoea in Bangladesh illustrated good aggregate consistency of response on menstrual status, but less individual consistency on duration of post-partum amenorrhoea. Using life table techniques, the median duration of amenorrhoea was calculated as 19.9 months for women with births between February and September 1974. There were substantial seasonal variations in duration, with the median decreasing from 21.5 months for women with February births to 16.9 months for those with September births. By contrast, the median duration of post-partum amenorrhoea varies by only two months for women in the lowest and highest quartiles of weight and weight for height. The seasonal pattern was similar for all weight groups.     

Demographic transformation in Poland

The author presents a general review of the demographic transition in Poland from 1750 to the present day. Official data are used to describe the fluctuations in birth and death rates over this period.     

A gold key to initiate a new situation in family planning work]

Because of the popularization of a responsible agricultural production system, the livilihood of peasants has been improving greatly, while the demands and needs of the general public are also increasing at the same time. Still under the influence of the traditional belief of carrying on one's family line and emphasis on having male children, married people prefer to have more childre, and the birth rate is now rising again. In order to solve this new problem, we need to teach the peasants national policies on population, land utilization, and food supply. In order to initiate a new situation in family planning work, we need to control this "gold key" of ideological education and propaganda. The emphasis should be placed on ideological education for cadres at all levels as well as the general public in order that they may understand the Party's strategy. Education on the national strategy should be combined with material interests of the peasants, and reward and punishment in production should also be linked up with that of family planning. Social measures are needed to reduce economic burdens of the peasants, offer better treatment for single-child households, and provide adequate care for old and retired people. Family planning projects should be consolidated and improved. Scientific management, facilities and techniques for birth control, compensation for working personnel in family planning, and other practical problems deserve immediate attention and solution.     

Determination of recovery effort for a probabilistic recovery system under various inventory control policies

In this study we investigate the desired level of recovery under various inventory control policies when the success of recovery is probabilistic. All the used and returned items go into a recovery process that is modelled as a single stage operation. The recovery effort is represented by the expected time spent for it. The effect of increasing recovery effort on the success probability together with unit cost of the operation is included by assuming general forms of dependencies. Alternative to recovered items, demand is satisfied by brand-new items. Four inventory control policies that differ in timing of and information used in purchasing decision are proposed. The objective is to find the recovery level together with inventory control parameter that minimize the long-run average total cost. A numerical study covering a wide range of system parameters is carried out. Finally computational results are presented with their managerial implications.