An original solution method ("Snippy") is developed for the rectangular stock cutting problem, and compared with the commercially available package "OREC" by applying both methods to industrial order books. Arguments are presented to show that the solutions found by Snippy are optimal for all except one of the order books. Snippy incorporates two innovations. The first is a new method for generating guillotinable cutting patterns, the Trickle Method. This is an incremental dynamic programming technique which is especially suited for interaction with the Simplex Method via column generation. The second development involves a class of non-guillotinable patterns that can be constructed using essentially guillotine techniques. In particular, a relatively minor modification to the Trickle Method allows the generation of good non-guillotinable patterns.

Whole document restricted, see Access Instructions file below for details of how to access the print copy. / An analysis of the industrial productivity of New Zealand heavy engineering companies is presented, and methods for improving the overall productivity of the heavy engineering industry and similar industries with job-shop type production are developed. The industry's productivity problems had been obvious for years. However, due to the lack of data and inadequacy of existing productivity improvement approaches, it had never been possible to quantify the extent of these problems, to analyse their causes and to develop methodologies for long-term improvement. The present investigation consists of two major aspects. The scientific element is concerned with the development of a methodology for productivity improvement appropriate to the situation of heavy engineering in New Zealand. This is supported by practice-oriented work in the industry, consisting of data acquisition activities in general, and of pilot studies in selected companies in order to assemble, analyse and evaluate specific data on productivity problems, and to apply and test the results thereof. The development of a methodology for productivity improvement is based on an extensive survey of literature on productivity measurement and improvement methods. The results of this survey, which was performed in parallel with the collection of industrial data, indicate that existing methods are not adequate to satisfy the requirements of productivity improvement in the local heavy engineering industry. On this basis, in-depth pilot studies in ten heavy engineering companies were performed. The objectives and methodology of these pilot studies are described in detail, as their results have a sizeable impact on the overall methodology chosen for this research. One of the most important conclusions drawn from the pilot studies is that productivity problems in the New Zealand heavy engineering industry cannot be solved by concentrating solely on workshop fabrication and technological factors. Generally these problems have complex cause-and-effect structures, and a multitude of non-technological factors from outside the workshop are involved. In order to account for these interrelated factors, a systems engineering approach was used, which offers a suitable basis for a productivity improvement methodology applicable to the situation as identified in the pilot studies. A main step in the system engineering approach is the development of a systems model which is used for structuring the complex inter-relationships found in practice. On the basis of this systems model of heavy engineering productivity a Productivity Assurance Programme is developed. This programme combines elements of quality assurance methods and the 'productivity cycle' principle of continuing improvement. The main elements of the Productivity Assurance Programme are matrices developed for the evaluation of the requirements of productive heavy engineering operation, and for the analysis of the productivity levels of the company where they are applied. The combination of these aspects provides a decision base on which organisational improvements can be founded. Due to its modular structure and the flexibility in defining specific productivity requirements, the applicability of the Productivity Assurance Programme is not limited to New Zealand heavy engineering companies, but also covers other job shop type industries with similar productivity problems. I case study illustrates the application of the Productivity Assurance Programme in practice.

This work presents a 50-industry input-output model of Northland's economy and demonstrates how input-output analysis could be used to enhance regional planning in New Zealand. As it is the first regional input-output model in this country to incorporate significant survey and secondary data the survey procedure and model construction are outlined. The input-output table is used to discuss important regional transactions and the purchase and sales patterns of industries. The model analyses industries' contributions to export receipts and import payments and calculates the impact of changes in export receipts on regional income and imports. A comprehensive multiplier analysis of Northland's economy covers output, income, employment and imports and confidence limits for the multipliers are developed using the Monte Carlo technique to simulate survey errors. The model explores the economic implications of forestry expansion in Northland and discusses the areas available for afforestation, planting rates, tree management, wood supply and wood processing options in the region. The modifications made to the model and data requirements for simulating forestry expansion are outlined and employment and income impacts given for three types of processing complexes and for forestry expansion as a whole. Finally an economic evaluation is made of the impacts of processing-plant construction and supporting services.

A mechatronic chewing robot of 6-DOF mechanism which consists mainly of the skull, six crank actuators, end effector and motion control system has been designed and is required to simulate human chewing behaviours while the chewed food properties are evaluated. The robotic mechanism is proposed and its kinematic parameters are defined according to the biomechanical findings and measurements of the human masticatory system. This thesis is concerned with the design and implementation of trajectory tracking control for robotic jaw actuators via Galil motion controller. The aim of this project is to simulate the dynamics behaviour and force-motion control of the robot, and to quantitatively assess food texture changes during chewing. A control system based Galil motion control card has been formed to achieve the motion of simulated human mastication. Some real human mastication motion have been tracked and used as targeted trajectories for the robot to reproduce. Several experiments have been executed to measure the jaw movements and chewing forces. To reduce the vibration of the actuators and protect sensitive linkage part of the robot, the traditional PID control and some advanced control theories were implemented to achieve most effective efforts. A mathematical model was also designed at the first stage when a test actuator powered by brushless motor was formed; however, it is finally proven not well controlled in either mechanical and control ways. Major features of the built robot including the motion control system are presented and tested. Experimental results including free chewing, soft-food and hard-food chewing are given where the foods are simulated by foam and hard objects. Also the joint actuations and driving torques required are compared for the chewing of different foods. In conclusion, tracking motion control has been attempted on the physical robot and a solution to the trajectory control has been developed.