In a little more than a decade regional planning has emerged as a vital component of the development planning process in Saudi Arabia. From its limi ted beginnings in physical planning its scope has rapidly widened and the latest plans attempt comprehensive regional planning within the context of a multi-level development planning effort. This experience has been rich and varied, and various innovatory approaches and techniques have been introduced. This study was conducted with a view to evaluating Saudi experience and placing it in an international perspective. With these aims in mind, a comprehensive planning model has been developed and a number of key questions posed, the answers to which reflect the acceptability and practicality of the planning system. The model is based upon a review of international experience of countries with different political, social and cultural settings, and at different stages of development. The model consists of four main components: planning activities, plan making bodies, decision making bodies and implementing bodies with a feedback from the public and private sectors. The model was tested against the planning experience of three countries with widely differing political, social and economic settings: Canada with its laissez-faire economy, the United Kingdom with its mixed economy, and Poland with its command economy. It was concluded that the model is sufficiently robust to act as a framework wi thin which to describe and analyse the Saudi experience. The context for regional planning in Saudi Arabia was analysed. The study included the political and administrative systems, the economy,the settlement structure, the sectoral planning process, the spatial planning process, and the past experience in regional planning. Then, the current regional planning experience which includes the National Settlement Strategy and the Regional Comprehensive Planning Project were discussed and analysed, taking the five comprehensive regional development plans (Hail, Qassim, Baha, Tabuk and Makkah) as case studies. This "current" experience was evaluated against the comprehensive planning model and the key questions for an acceptable planning system. It has been found that the Saudi planning system is fairly well developed at the national and local scales. However, at the regional scale, although there is political commitment there is little in the way of administrative arrangements for plan making and implementation. A set of proposals for improving the planning system has been presented for future action.

Airline schedule punctuality is a complex problem and one of the major concerns of the airline top management. Flight schedule disturbances may occur as delays and/or cancellations. There are many internal and external reasons for delays. These delays may propagate in the aircraft cycles and cause a large schedule disturbance. This may influences passenger satisfaction and airline resources. The objective of this research is to formulate a systematic approach for schedule punctuality which supports management decision making. The punctuality management system is structured to combine all schedule punctuality components, input and output variables. Five models are incorporated in this system. The first model is the disturbance model which generates random delays based on an estimated Lognormal delay distribution function. The delay analysis is carried out from a one year sample of delay statistics in which general, original , reactionary and other delay types are classified. The second model is the recovery model which incorporates the disturbance model with management strategies to determine delay propagation. A PC based simulation model (SKDMOD) is developed as a prototype which integrates disturbance and recovery models using SIMSCRIPT 11.5. 18 management strategies are simulated covering ground times (30, 40 and 50 minutes), maximum delay times to assign spare aircraft (1, 2, 3, 4, 5, and 6 hours) and spare aircraft using part of the domestic network of Saudi Arabia. The third model is the passengers' attitude model which determines the delay impact functions and the maximum passenger revenue loss based on 262 responses from a passenger interview survey. The fourth model is the revenue model which estimates the passengers' revenue loss. The fifth model is the cost model which estimates the extra cost resulting from implementation of the management strategies. All strategies are evaluated to determine the optimum based on profit and profit margin. OPTIM is the optimization program developed to find the optimum strategy(ies). This approach provides a guidelines for the management of punctuality. It integrates all the tools developed in a decision support system framework.

No description available.

No description available.

No description available.

No description available.

No description available.

. The present study has two parts. In the first (Chapters 2 an 3) Fisher's theory of sex ratio is extended and in the second (described in Chapters 4, 5 and 6) the methods of quantitative genetics were applied to a laboratory population of Drosophila melanogaster to evaluate the amount of genetic variance in sex ratio. In Chapter 2 the relationship between birth control, sex preference and sex ratio was considered. It has been suggested that in some human populations the desire for male or female offspring coupled with the knowledge of methods of birth control can influence the distribution of family sizes. The consequences of this situation have been analysed using the evolutionarily stable strategy concept. . In Chapter 3, using precise genetic models, I have studied the evolution of the sex ratio in a population in which interactions between siblings exist but these interactions are not symmetrical with respect to the sexes. Some interesting differences between cooperative and aggressive models have emerged. The second part of the thesis is composed of three experiments. Experiment I was designed for investigation of the variability in the sex ratio character and identification. of the sources of heterogeneity apart from that due to binomial sampling. The results showed a close agreement with the expectations from random segregation and indicated that genetic or environmental factors affecting sex ratio were virtually absent. It has been reported that environmental factors can "distort the sex ratio in several species. One such factor is the age of parents. Experiment II was performed to study this suggestion in Drosophila melanogaster in the hope of obtaining some information about the mechanisms involved in this distortion. The data indicated that this phenomenon, at least in D, rosophila melanogaster is non-existent. In Experiment III artificial selection for sex ratio was performed. Nine generations of selection were unable to increase the sex ratio of the population. Selection was very effective in increasing the number of females, but the presence of sex-linked lethals was shown to be responsible. It was concluded that all of the empirical evidence supports a Mendelian interpretation and gives no support" to any theory invoking" adaptive sex ratio.

In this thesis, a case study approach has been used to investigate the planning and implementation of urban development at local level in the periphery of Barcelona, Spain. From a review of existing literature on the case study research methods in the social sciences, certain guidelines for the research design emerged. A conceptual framework was first assembled, from which research hypotheses were derived, to act as a loose analytical framework within which case study findings could be considered. The conceptual framework incorporates a review of the planning, legislative and developmental backgrounds; and the nine postulated hypotheses concern three interrelated aspects of planning and implementation: planning and control mechanisms, agency roles and activities, and the decision-making process itself. The actual case study method focuses on the compilation, structuring and analysis of three case study 'data-bases', comprising on-file documentation, plans, photographs etc obtained from local planning authorities and development agencies. First-hand accounts from agency personnel were also taken into account in the interpretation of data. The thesis makes a contribution to knowledge in the subject area in two ways. First, the research findings break new ground as regards existing literature on the development process in Spain. The case studies, both individually and collectively, provide new inSights into how and why the planning system failed in its statutorily attributed planning and control functions at local level; and conceptualization and analysis of decision-making in the case studies provide new perspectives on the Spanish planning process. Second, the development and application of a case study research method to investigate the functioning, at local level, of one of Europe's lesser developed planning systems, provides scope for the subsequent adaptation and use of this method for the monitoring and exchange of urban management experience in different planning environments and the conduct of international comparative research.

No description available.