Taking into account the rescheduling problem during the scheduling phase

The scheduling problem in production management has been studied for a considerable time, and several types of software are used. A problem arises in updating the production planning, or ‘rescheduling’, when an unexpected event occurs in the shop control. Solving this problem is difficult because the implications of such events are usually impossible to forecast. To prevent this problem, we propose to manipulate a set of equivalent schedules during the short time schedule. Then, if an unexpected event prevents realization of a given schedule, it will be possible to find an equivalent one, without full rescheduling. The primary requirement is to find a formal representation of a set of schedules. This has already been explored using CPM graphs with nodes associated to a set of tasks. We propose in this paper to use an extension of such graphs, PQR trees, that represent both precedence and group constraints. We first reiterate the notion of PQR trees. We present methods to take into account date constraints in such a structure, and we give a model for the general job-shop problem.     

THE ECONOMICS OF TENANT RIGHTS IN NINETEENTH CENTURY IRISH AGRICULTURE

The Land Act of 1870, which introduced "tenant rights" to most of Ireland, was the prototype of the modern land reform. This paper develops an alternative to the conventional view that the Land Act was instituted to redistribute wealth. It is suggested that tenant rights became economically valuable as a result of massive emigration from Ireland in the nineteenth century. Data on land rents and landlord investment are consistent with this "efficiency" hypothesis, and tend to refute the "redistribution" hypothesis.     

IMPROVING JOB SHOP PERFORMANCE THROUGH PROCESS QUEUE MANAGEMENT UNDER TRANSFER BATCHING

This research investigated the value of protecting the continuity of release batchs in a transfer batching environment, by modifying the SPT rule. A simulation model of a job shop was used to test the modified SPT rule. The performance measures evaluated were mean flow time, flow time variance, and mean lateness. Conditions under which the SPT modification improved results were as follows: large number of transfer batches, small setup time to process time ratio, and large variation in process times from station to station. The results suggest that shop loading is not a significant factor affecting performance of the modified SPT rule.     

Does Time of Voting Affect Exit Poll Results?

This study analyzes time of voting effects on the results ofexit poll data collected in a Cleveland municipal tax referendum.The data reveal significant differences both in the times differentgroups vote and in the reported levels of support for the taxlevy by time of day. The temporal variation in the reportedlevels of support for the tax levy are then shown to be directlyrelated to the times when different support groups cast theirballots. Collectively, these findings suggest the need for day-longinterviewing in the design of exit polls.     

The labour process and workplace injuries in the Canadian meat packing industry

Il est nécessaire, pour s'assurer de la productivité, de maintenir un niveau satisfaisant de la santé de travail, et même les ressources, dévouées à la sécurité industrielle, peuvent réduire les bénéfices., Cette contradiction est évidente dans l'abattage et la transformation de viande au Canada qui est caractérisée dans les années récentes par un décroissement d'emploi et de salaire, mais il se passe aussi un accroissement du rendement et des blessures du travail. La relation entre l'organisation du travail et les blessures industrielles est examinée dans une étude de deux abattoires, Usine A et Usine B. Chez Usine A, l'augmentation de l'organisation du travail correpond aux blessures industrielles tandis que Usine B était beaucoup plus équilibré. Une solution du problème de la santé du travail chez Usine A est difficile à obtenir à cause des intérêts contradictoires entre les ouvriers et l'administration. The problem of occupational health is rooted in the fact that a satisfactory level of occupational health is necessary to maintain productivity in an industrial society and yet resources devoted to workplace health and safety can detract from profitability. This contradictory situation is evident in the Canadian meat packing industry which in recent years has experienced declining relative wage and employment levels and an intensified labour process along with a concomitant increase in workplace injuries. The relationship between the labour process and occupational injuries is explored in case studies of two packinghouses, Plant A and Plant B. In Plant A an intensified labour process went hand in hand with a rising rate of workplace injuries, whereas in Plant R the organization of work and the rate of workplace injuries showed a more stable pattern. A soIution to the occupational health problem at Plant A has so far proved elusive due to the contradictory interests of labour and management.     

THE OPINION-POLICY NEXUS IN GERMANY

This article analyzes the previously unresearched relationshipbetween mass public opinion and public policy in contemporaryWest Germany. By studying approximately 150 cases over the lastdecade, the nature of German democracy is revealed in relationto the overall consistency between majority preferences andgovernment action. The opinion-policy nexus is explored in regardto the impact of issue saliency, landslide majorities, differentcategories of issues (e.g., redistributive, foreign policy),and the partisan composition of the government (i.e., SocialD emocratic vs. Christian Democratic). In addition, there isa cross-national comparison of results for West Germany withthe author's previous research on opinion and policy in theUnited States, Britain, and France. The findings indicate that(like other nations studied) public opinion and public policyin Germany are inconsistent in a majority of instances and that(unlike Britain or France) the partisan composition of the governmentdoes not matter vis-à-vis the degree of policy-opinioncongruence.     

Intensive Hog Farming in Manitoba: Transnational Treadmills and Local Conflicts*

L'exploitation intensive des porcheries a connu un essor rapide dans L'Ouest canadien. La croissance de L'agriculture industrielle porcine manitobaine est analysée comme une étude de cas d'un «tapis roulant de production transnational». La production et les exportation ont augmenté de façon considérable alors que L'industrie est devenue plus concentrée; mais des coûts environnementaux, entre autres des préoccupations quant aux odeurs et à la qualité de L'eau, sont devenus plus visibles. Les gouvernements provinciaux ont encouragé, par des politiques néolibérales, L'expansion de cette Industrie et ont hésitéà imposer des exigences réglementaires. Le processus d'approbation des porcheries a été en grande partie ramené au niveau des municipalités rurales. Il reste que cela s'est traduit en une controverse politique acharnée dans plusieurs collectivités locales, ce qui a forcé le gouvernement du Manitoba àétudier une réglementation plus rigoureuse dans ce secteur d'activité. Intensive hog operations have grown at a rapid rate in Western Canada. The growth of factory hog farming in Manitoba is analysed as a case study of a “transnational treadmill of production.” Output and exports have increased dramatically and the industry has become more concentrated, but negative environmental externalities, notably odour and water‐quality concerns, have become more visible.Provincial governments have promoted the expansion of this industry through neo‐liberal policies and have been reluctant to impose regulatory restrictions. The hog barn approval process has been largely downloaded to the rural municipal level. However, this has resulted in fierce political controversy in many local communities, which has forced the Manitoba government to consider more active regulation of hog factory farms.     

Disabling School? Professionalisation of special education and student welfare in the Finnish compulsory school

This article examines the birth and growth of the Finnish student welfare system and special education. The study takes a socio-historical approach and its theoretical point of departure lies in the concepts of the welfare state and professionalisation. The student welfare system and special education have grown enormously, especially after the Second World War. Now this growth has reached its peak because of the economic recession. The critical connection between professionalism and the modern welfare state lies in the fact that the prerogative of experts to identify, define and manage various human deficiencies and problem is, to a great extent, manoeuvred and legitimated by the state. Although the form and scope of the student welfare and special education have changed, one thing has remained the same; measures are still directed against the individual student.     

FEAR OF NUCLEAR WAR AND INTERCOUNTRY DIFFERENCES IN THE RATE OF SAVING

This paper demonstrates that, across nineteen OECD countries for 1981-84, a survey-based measure of the perceived likelihood of nuclear war is negatively correlated with the rate of net private saving, holding other determinants of saving constant. The estimates indicate that a 10 percent increase in the fraction of the population that believes a world war is likely is associated with a decline of 4.1 percentage points in the net private saving rate. This finding is consistent with other evidence based on U.S. aggregate time series and cross-individual data suggesting that fear of nuclear war decreases savings.