PROCESSING AND QUALITY EVALUATION OF WHOLE CANNED 'DWARF' GOLDEN APPLES (SPONDIAS CYTHEREA)

‘Dwarf’ golden apples (Spondias cytherea) were canned in sucrose syrup of either 30 d?Brix (L) or 40 d?Brix (H). Processing was either by hot filling (HF) of syrup at 92C in filled cans or by steam‐exhausting (SE) of the filled cans at 85C for 12–14 min, followed by processing at 100C for 20 min (W₂₀) or 30 min (W₃₀). Sensory evaluation of commercial sterile products, SE‐LW₃₀ and SE‐LW₃₀ indicated there were no differences (P < 0.05) in appearance, color, taste, aroma and texture. Overall scores indicated that fruits in syrup were liked definitely to like slightly. Panelists indicated that they might or definitely will purchase the products. Fruits in 40 d?Brix syrup were firmer than in 30 d?Brix syrup. By week 8 of storage at 28–30C, pH was stable between 3.6–3.7, and ‘cut‐out’d?Brix of syrup for LW₃₀ and HW₃₀ products was 24.0 – 24.5 and 28.5, respectively.     

CONCURRENT ENGINEERING DESIGN FOR ENVIRONMENT

This paper attempts to give a brief overview of the concept of design for environment (DfE) as part of the concurrent engineering philosophy. DfE includes designing for recyclability, reuseability, durability, and maintainability. DfE also promotes the reduction of energy consumption and product emissions as a means of environmental consciousness. As part of this research into DfE, five Hunter Valley–based Australian businesses were used as case studies in an attempt to discover what role DfE plays in local Australian industry.     

Shelf life considerations in a family production context

In this paper we consider a piece of manufacturing equipment dedicated to the production of a family of items. With known level demand rates for the individual items the policy used is to cycle through production of all of the items every T units of time. The paper addresses the choice among two adjustment options when the cost-minimizing T value leads to potential spoilage of an item because of shelf life considerations. The less obvious option of slowing the production rate of the concerned item is shown to be more cost effective than simply reducing the T value.     

A comparison between two photographic methods for the determination of relative bidirectional reflectance

Two simple photographic methods have recently been proposed for the measurement of relative bidirectional reflectance (Lillesand and Kiefer 1979, Curran 1980). These two methods were used to calculate the relative bidirectional reflectance of ten contrasting surfaces. The photographic relative bidirectional reflectance so recorded, was then compared with the radiometric bidirectional reflectance for each surface. Two conclusions were drawn: first, that relative bidirectional reflectance can be measured using these simple photographic techniques, and second, that there was no significant difference between the Lillesand and Kiefer and Curran methods for photographically deriving relative bidirectional reflectance.     

Analysis of material and capacity requirements with Q-GERT

The purpose of this paper is to report on research conducted to develop a simulation model which incorporates the basic MRP logic into the modelled production process. The objective of the modelling effort is to provide information necessary for planning and controlling of the material and capacity requirements of a production process that includes stochastic processes. The modelling and analysis procedure exploits the fact that the structure of the production process can be logically modelled as a network flow process. The technique employed to facilitate the network modelling is Q-GERT (Graphical Evaluation and Review Technique) modelling and simulation language. A case application is presented to demonstrate a prototype model, followed by a report of the simulation results. The model is designed to provide answers and insights to the following questions: (1) how long must each production centre operate to yield the specified quantities of finished products, (2) what is the expected lead time required to complete the production of finished products, (3) what are the utilization rates for various processing stations, and/or percentage idle times due to lack of preprocess inventories, and (4) where do bottlenecks occur in the production process, as evidenced by large queues of materials or subassemblies prior to the machine centres.     

External environment of an autonomous manufacturing agent: dynamics and representation

A formal representation of an agent's external environment is proposed, that can be used in information flow analysis. An autoregressive process of second order is applied as the mathematical tool. The dependency X(t) = f[X[0), X(1)] is derived and the characteristic features of the dynamics of the external environment are discussed. The proposed formal representation increases the set of tools for modelling and simulation of autonomous functioning manufacturing agents. It allows for the agent rigorous information input definition and assists systems analysts in the evaluation of an information structure using different attributes of the external environment.     

Feedback controller design for plants with modes and disturbances above the sampling frequency

The digital feedback controller design technique of Eitelberg (1988) could not treal closed-loop performance accurately if the continuous-time plan. had significant models and signals above the sampling frequency. Here, the above simple techinque's applicability is extended by implementing the controller with additional analogue low-pass filters, cancelled by digital ‘high-pass’ terms at or below the sampling frequency.     

Production and inventory policies for an integrated manufacturing firm

The coordination of production and inventory decisions for raw materials, intermediate products and finished goods is important. We compare some decision rules for a ‘firm that uses a single raw material to manufacture n different parts which are then assembled into the final product. Demand for the final product is probabilistic and there are costs of holding inventory and of ordering, manufacture and assembly. These characteristics are an idealization of the problem faced by a manufacturer of scaffolds in which the major processes are the manufacture of different sheet metal parts and their assembly.

We develop production rules that use system-wide information. We use simulation to evaluate the performance of these rules and compare system behaviour to that under production rules that are derived separately for each item and use only local information about that item's status.