The interaction of shock waves in cylindrical structures

An experimental investigation into the validity and use of the hydraulic jump analogy for studying the interaction of shock waves in air with cylindrical structures.     

Personal Attachment to the Union in Small Bargaining Units

Union member attachment research has generally examined large unions organizing large employers. The present study presents a conceptual model and related data concerning various aspects of the union attachment expressed by individuals in small bargaining units. The results show differences among individuals in commitment based on their union experiences and demographic characteristics. Résumé Les études traitant de la loyatué qu'éprouvent les membres envers leur syndicats examinent généralement des syndicats importants au sein d'entreprises de taille. La présente étude offre un modèle conceptuel et les données relatives aux divers aspects de la loyauté exprimée par des individus appartenant à de petites unités de négociations. Les résultats démontrent les différences de loyauté chez les membres selon leur experience syndicale et les caractéristiques démographiques.     

A contribution to the assessment of scenic quality of landscapes based on preferences expressed by the public

The purpose of this paper is to validate a model for predicting the public's preference for a landscape using simple statistical techniques. The model assigns numerical values to 42 landscape variables grouped into physical, aesthetic and psychological attributes. The landscape value is obtained using an additive value function. The results of the model on certain landscapes are compared with the preference expressed by the public in a survey of 183 people.The homogeneity of the survey responses was checked in each photograph. It was determined that means and standard deviations of the scores represent the true preference.A strong positive association was observed between preference and certain landscape attributes such as expression, soil use or colour. A marked negative association was detected with respect to landscape alterations.A linear regression was carried out to analyse the predictive capacity of the model. The independent variable was the global score assigned by the model to each photograph and the dependant variable was the mean of the scores assigned by the survey respondents. The high level of correlation obtained indicates that the model is a good predictor of the public's preferences in relation to the set of photographs shown in the survey.To complete the analysis of the model as a preference predictor, a multiple linear regression was carried out between the mean score obtained in the survey and the model elements. Attributes and variables that have the greatest influence on pubic preference were detected.     

Modeling international trade flows and market shares for agricultural commodities: a modified Armington procedure for rice

The Armington procedure (AP) has become increasingly popular in agricultural trade analyses. However, some arguments have arisen concerning the relevance of using the procedure for such analyses. This study examines the assumptions commonly made when using the Armington procedure and suggests modifications for agricultural trade analyses. Results from models utilizing rice-trade data suggest that the assumptions of the single constant elasticity, in particular, may not be appropriate for analyzing agricultural trade. These results also suggest that, with proper modifications, the AP can be applied to agricultural trade. Further, results of a modified Armington procedure indicate that trade in rice exports is highly competitive and that changes in market shares of individual exporters are not independent of changes in budget expenditure allocated to imports.     

Projecting Canadian Grain Shipments

The magnitude of future grain exports will profoundly affect many segments of the Canadian economy besides agriculture. Changes in structure of the existing grain transportation system, for example, may be required because of substantial increases in grain movement from country elevators to terminal positions. Grain trade projections are reviewed and the implications discussed. Results indicate that Canadian grain exports may increase from the past five-year average of 534 million bushels to a 1980 level of 811 million bushels and with the possibility of a billion bushel export level being achieved. All segments of the economy affected by the Canadian grain industry must be prepared to adjust their future operations to efficiently accommodate the increased level of grain exports .     

The Effectiveness of the U.K. Travel Allowance

This paper discusses a method for analyzing the pricing and production behaviour of a mature oligopoly, characterized by stable market shares and well established patterns of price leadership. The oligopoly utilized as an example is the US primary producers of copper. The paper develops three pricing/production strategies which are felt to be most relevant to the US primary producers. While one of these strategies (collusive monopolistic pricing) is more desirable to the oligopoly, the ability of the oligopoly to impose any of the strategies depends upon market conditions and government stockpile intervention. A generalized logit probability model is developed and estimated to indicate the effects of market conditions and government action upon the ability of the oligopoly to impose its desired pricing/production strategies.