Asia-Pacific Journal of Operational Research

Surface mining, often adopted for exploiting natural resources all over the world, is a major subject of debate as it causes major environmental impacts. It not only adversely alters the landscape but it also seriously hampers the traditional living conditions of numerous inhabitants, who may be displaced against their wishes without receiving necessary compensation. In this paper, goal programming is combined with the analytic hierarchy process to determine optimal decisions for the planned relocation of people where surface mining may take place in a densely populated environment, while addressing multiple conflicting objectives. The combined approach is illustrated with a numerical example highlighting its usage in other decision problems.

In this paper, we present a new trust region method for unconstrained nonlinear programming in which we blend adaptive trust region algorithm by non-monotone strategy to propose a new non-monotone trust region algorithm with automatically adjusted radius. Both non-monotone strategy and adaptive technique can help us introduce a new algorithm that reduces the number of iterations and function evaluations. The new algorithm preserves the global convergence and has local superlinear and quadratic convergence under suitable conditions. Numerical experiments exhibit that the new trust region algorithm is very efficient and robust for unconstrained optimization problems.

Home delivery service is one of the most important cost drivers in e-commerce industry. We consider the three-dimensional container packing problem under home delivery service, where each rectangular item with its specific destination is loaded orthogonally onto a rectangular container so that the utilization rate of the container space is maximized. In our framework, we assume the routing of a consignment to be given, which turns out that there is an order of unloading items with respect to the consignment. If we load items without considering the order of unloading items, we may unload and reload other unconcerned items drastically while unloading the required item. Therefore, in this paper, the unloading costs for a consignment are precisely defined according to the invisible and untouchable rule, and a subvolume scheme based algorithm is proposed. Our experimental results suggest our approach to be promising.

We address the problem of scheduling proportionally deteriorating jobs in two-machine open shop in which one of the machines is non-bottleneck. The objective is to minimize the makespan. We show that the decision version of the problem is -complete in the ordinary sense, and present for it a fully polynomial-time approximation scheme.

This study develops a modified two-stage DEA model based on the model of Chen and Zhu (2004) to evaluate China's agricultural efficiency and repaired efficiency (for stricken cultivated land) in a single DEA implementation. The government expenditures and the difference of various cultivated land types are identified as the external influence factors for agricultural efficiency in former works. Those are internalized into the empirical model.

The results indicate that the repaired and agricultural efficiencies are positively correlated on a significant level, which implies an efficient utilization of governmental service expenditures that in turn drives high performance in agricultural efficiency. The external effects analysis finds that increasing the degree of education for agricultural employees improves the agricultural efficiency and that developing a mechanized irrigation system is beneficial in enhancing repaired efficiency for fallow land. Information on repaired cultivated land utilization, which was extracted from analysis on optimal ratios and includes the quantity of excess and deficit for each region, is also provided.

Average options are path-dependent and have payoffs which depend on the average price over a fixed period leading up to the maturity date. This option is of interest and important for thinly-traded assets since price manipulation is prohibited, and both the investor and issuer may enjoy a certain degree of protection from the caprice of the market. However, to deal with unexpected situations incurred the usual simple average options may not be sufficient. Therefore, in this paper, we consider to propose a more general weight instead of the simple average, for which it may be possible to control the weight in the light of the unexpected circumstances. Further, we derive approximate solutions for the weighted sums of asset prices, and in order for these formulae to be applicable some adjustment must be taken into account along with Monte Carlo simulations. Finally, some comparisons for these results are made.

We consider a two-level supply chain for a perishable product with stock dependent demand, and study the supply chain coordination issues with quantity discount contract under both symmetric and asymmetric information. We design an optimal quantity discount contract for the vendor, and show that the quantity discount contract can coordinate the supply chain under symmetric information. However, the vendor is not able to realize supply chain coordination with only quantity discount contract if the buyer's holding cost is private information since the buyer may keep this information private for bargaining a higher price discount. Nevertheless, quantity discount contract is still beneficial to the vendor as compared to the case without quantity discount. Numerical experiments are conducted to demonstrate the theoretical results.