• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.162-170
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• 2009

This paper deals with a closed-loop remanufacturing system with one manufacturer and one remanufacturer. The manufacturer sells new products bearing the 'Extended Producer Responsibility (EPR).' It is assumed that the manufacturer's collection rate of used products depends only on the buy-back cost, while that of the remanufacturer depends on the minimum allowed quality level of used products in addition to the buy-back cost. Through the development of mathematical models with the objective function of maximizing profit, we study an efficient operation policy of each party. The decision variables are the unit selling price of new products and remanufactured products, the unit buy-back cost of the used products of the manufacturer and remanufacturer, and the minimum allowed quality level. The validity of the model is examined through numerical examples and sensitivity analysis.

• Culinary science and hospitality research
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• v.12 no.1 s.28
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• pp.188-202
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• 2006

With large corporations entering into the foodservice market, competitions among those foodservice providers became intense, leading to differentiated quality services in terms of portioning out the meal, its portion and waiting time, not to mention food quality. The purpose of providing foodservice is to satisfy its customers, to secure optimum level of profits, and attain continuous quality improvement. To have such purpose attained, all other factors affecting the foodservice should be allowed to play a role. The intensity of the work performed by the employees should be maintained at a steady level and systematically controlled. 'Service First’ principles upholding that customer satisfaction comes from good service should be applied at all times; customer satisfaction comes from the satisfaction of the employees. Customer satisfaction through good service will contribute to an increase in revenue which we get by subtracting operating expenses from the total sales, as it will lead to concluding a long-term supply contract or renewing the existing contract. To keep the operating expenses to the minimum level, it is important to effectively perform the cost control. Since personnel expenses occupy a large portion of the operating expenses, it is imperative to effectively control the labor costs. For this reason, this study will present an effective program for disposition of men with a large organization being centered around, where the number of people served at the mess hall varies greatly depending on a day of the week and a mealtime of the day.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.61-66
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• 2017

The appropriate level of irrigation for turfgrasses is vital to the performance of the turfgrass as well as conservation of water. Linear gradient irrigation system (LGIS) facilitates long-term study of turf performance under continuous irrigation gradients at extreme ends of the irrigation scale. The objectives of this study were to: a) determine the minimum irrigation requirements and relative drought resistance in three warm season turfgrasses; and b) evaluate the medium to long-term effects of irrigation levels on turf persistence, weed invasion, and susceptibility to diseases. Results suggest that grasses differed in drought resistance and persistence under variable irrigation regimes. Irrigation (Ep) required for consistent acceptable turf quality for respective grasses was Cynodon dactylon x C. transvaalensis (61%), Zoysia matrella L. Merr (73%), and Stenotaphrum secundatum 'Palmetto' (86%). Brown patch infection was most prevalent in Stenotaphrum secundatum 'Palmetto' at 12 and 125% Ep irrigation. Cynodon dactylon x C. transvaalensis and Zoysia matrella L. Merr were better able to adapt to the various irrigation regimes, and this ability allowed these species to resist drought, and maintain turf coverage which in turn, kept weeds and the occurrence of diseases at bay. Ranking these grasses for their drought tolerance abilities showed that Cynodon dactylon x C. transvaalensis had the most outstanding resistance against drought, followed by Zoysia matrella L. Merr, and lastly, Stenotaphrum secundatum 'Palmetto'. Despite having the highest irrigation requirement, Stenotaphrum secundatum 'Palmetto' was still not able to maintain persistence at high irrigation regimes. Likewise, this grass also lost turf coverage at low irrigation levels.