j. razmi

Spatial displacement of the population is not only a physical phenomenon, but also of view point of social, cultural, economic issues, the disconnection of their natural and emotional ties with the previous environment creates problems in adapting to the new environment and quality of life. In this regard, the current research was conducted with the aim of investigating the impact of resettlement on the quality of life through economic, social, cultural, environmental and physical indicators in the displaced villages of Khuzestan province. And in that, the settlement of 14 villages of Khuzestan province that were displaced due to natural disasters such as floods were considered. The questions raised for this purpose included: How many percent of the variance of the quality of life do the different realms of life explain? Which of the economic, social, environmental and physical indicators has the least and most positive and negative impact on the quality of life of displaced villages?

The current research is an analytical and applied research. According to the nature and purpose of the research project, information was collected by documentary method and the questionnaire was completed through questions made by the researcher. According to the information received from the Housing Foundation, the statistical population under study includes all displaced villages of Khuzestan province, which consists of the heads of households of 14 displaced villages, totaling 1816 heads of households. For this purpose, a total of 14 villages in the province were identified due to the reason of their displacement. Sampling from the statistical population was done by stratified random sampling and using proportional assignment method. First, the total number of statistical samples was estimated using Cochran's adjusted formula, then according to the population of each village, the number of samples proportional to the population of that village was determined, which included 112 household heads in total. The collected information was analyzed using regression analysis and factor analysis techniques through SPSS software to determine the true picture of the villagers' quality of life and their level of satisfaction with the displacement phenomenon.

To measure the level of satisfaction of displaced households in Khuzestan province, four domains: environment, economic factors, social and cultural factors, and physical factors were studied. The results showed that the environmental factor with the highest factor load explained about 32.65% of the variance of the quality of life of the displaced villages. The economic factor by being placed in the second rank of satisfaction determined about 15.536% of the variance of the quality of life, and the social and cultural factors also showed the third level of satisfaction among displaced villagers by expressing 10.883% of the variance for a specific reason. Finally, the physical factor has the lowest level of satisfaction of the relocated households with 8.529% of the variance of the quality of life.

The highest level of satisfaction in the displaced villages of Khuzestan province is related to the environmental field and the lowest level is related to the physical field. The factor analysis of the studied areas determined the level of satisfaction of the villagers on different aspects of the quality of life at an average level. In addition, comparing the results with the research background showed that in other countries, especially third world countries and developing countries, resettlement was often forced and had negative consequences in terms of social separation, employment problems and lack of access. However, resettlement in Khuzestan province is voluntary and has shown 67.6% satisfaction to achieve the studied indicators.

The bullwhip effect is one of the most important problems in the supply chain management. It can cause large inefficiency in supply chain. Although there are many researches about bullwhip effect, few studies have investigated this phenomenon caused by product price fluctuation. In this paper we consider a two-period supply chain consisting of one supplier, one wholesaler and one retailer. The wholesale price may increase greatly in the beginning of second period. If this happens, a large number of end customers will go to purchase the product from retailer. For managing the end customers’ demands in the second period, we consider two ordering strategies available to the retailer including optimal order quantity strategy and hedging strategy with call option. For each strategy, we calculate the bullwhip effect ratio for two periods and compare the results. We found that the lower exercise price in hedging strategy compared with the wholesale price in the optimal order quantity strategy must not contribute to extra product purchase. The research provides new insights into how hedging strategy can reduce bullwhip effect.

The development of supply chain distribution systems from single- to multi-channel networks for delivering items to end customers has effected many changes in the retail sector. Following the adoption of multi-channel distribution strategies and rapid development of relevant technologies, the Omni-channel approach can yield significant benefits and facilitate trade with customers. This paper aims to optimize a multi-product, multi-level Omni-channel distribution network and shipping flows of products within the network under uncertain conditions. A multi-objective mathematical model is developed that minimizes the costs of supply chain while maximizing customer satisfaction over different scenarios. In order to solve the proposed model, a combined algorithm is developed based on Benders Decomposition (BD) and Lagrangian Relaxation (LR). The presented model and solution approach is implemented in a case study of a distribution system, a large e-commerce startup and online store. Five different scenarios with various service levels are investigated and the numerical results are discussed compared to previous findings. The efficiency of the proposed combined BD-LR solution algorithm is also demonstrated. The results obtained from the case study show that higher service levels are correlated with higher levels of customer satisfaction and lower cost of the system.

In the present economic context, the operating theater is considered as a critical activity in health care management. This paper describes a model for operating room (OR) planning under constraint of a unique equipment. At first level we schedule elective surgeries under the uncertainty of using a unique equipment. At the second level we consider emergency surgeries, and at the third level a coefficient factor for surgeons is introduced in using this unique equipment. The planning problem consists in scheduling a unique equipment and assigning elective cases to different periods over a planning horizon to minimize the sum of elective patient related costs and overtime costs of ORs. The most important factor that we have focused on this paper is equipment resource constraint. A new mathematical programming model is first proposed and at the second and third level, a new stochastic mathematical programming model is proposed. Then sample average approximation is presented to approximate the problem with sample size N and then Lingo is used as an exact approach. Because of NP-hardness, exact method does not work for large size problems, so a Metaheuristic approach (differential evolution) is proposed for large size problems. Numerical results show that important gains (approximately 3.5 % in overall cost) can be realized by this stochastic OR planning model.