Mohammad Reza Marjani - Academia.edu (original) (raw)
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Papers by Mohammad Reza Marjani
The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symp... more The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symptoms among poultry slaughtering workers in Iran. The study consisted of two phases. In the first phase, musculoskeletal disorders in three poultry slaughtering industries in Kerman city were surveyed by standardized Nordic questionnaire among 190 workers. The result of this phase has revealed high rate musculoskeletal problems in workers due to poor working conditions. It was found that the majority of workers had experienced some kind of symptoms and pain from the musculoskeletal system felt at some time in the last 12 months. Based on the findings, some of the ergonomic guidelines were presented. The result of the second phase shows that female workers had a higher pain than male workers in the shoulder body regions. This study indicated that, poultry slaughtering could be generally considered as a high risk occupation for developing musculoskeletal symptoms.
Management Science Letters, 2015
Independent Journal of Management & Production, Mar 1, 2017
International Journal of Operational Research, 2021
Journal of Industrial Engineering Research in Production Systems, Feb 20, 2015
Iranian journal of health, safety and environment, 2018
Due to the variety of treatment processes, the decision to choose the best treatment process is d... more Due to the variety of treatment processes, the decision to choose the best treatment process is difficult. This paper describes a fuzzy grey relational analysis (GRA) method for selection of the optimal wastewater treatment process. The rating of all alternatives and the weight of each criterion is described by linguistic variables, which can be expressed in triangular fuzzy numbers. Then, a vertex method is used to calculate the distance between two triangular fuzzy numbers. According to the concept of the GRA, a fuzzy relative relational degree is defined to determine the ranking order of all alternatives by calculating the degree of fuzzy grey relational coefficient to both the fuzzy positive ideal solution (FPIS) and fuzzy negative ideal solution (FNIS) simultaneously. Furthermore, a case study is carried out and solved by both methods (i.e., GRA and fuzzy GRA) to show the feasibility and effectiveness of the proposed method. In the case study, five anaerobic wastewater treatmen...
The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symp... more The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symptoms among poultry slaughtering workers in Iran. The study consisted of two phases. In the first phase, musculoskeletal disorders in three poultry slaughtering industries in Kerman city were surveyed by standardized Nordic questionnaire among 190 workers. The result of this phase has revealed high rate musculoskeletal problems in workers due to poor working conditions. It was found that the majority of workers had experienced some kind of symptoms and pain from the musculoskeletal system felt at some time in the last 12 months. Based on the findings, some of the ergonomic guidelines were presented. The result of the second phase shows that female workers had a higher pain than male workers in the shoulder body regions. This study indicated that, poultry slaughtering could be generally considered as a high risk occupation for developing musculoskeletal symptoms.
Crossdocking is a relatively new logistics strategy which can reduce Inventory holding, order pic... more Crossdocking is a relatively new logistics strategy which can reduce Inventory holding, order picking and transportation costs while speed up the physical flow in the supply chain. The vehicle routing decisions also play an important role in the efficiency of the distribution system. This article addresses the integration problem of crossdocking into the heterogeneous fleet vehicle routing problem to introduce heterogeneous fleet vehicle routing problem with crossdocking. In the considered problem, a set of heterogeneous vehicles transport products from suppliers to customers via a crossdock. The problem was formulated as an integer programming model to determine the best vehicle routes and the optimal number of different types of vehicles minimizing the total operational and transportation cost. Since the considered problem is NPhard, a heuristic algorithm based on a variable neighborhood search is suggested. Numerical experiments show that the proposed algorithm can find high qual...
Independent Journal of Management & Production, 2017
Applied Mathematical Modelling, 2016
Abstract The bullwhip effect is an undeniable phenomenon in supply chains that has a negative eff... more Abstract The bullwhip effect is an undeniable phenomenon in supply chains that has a negative effect on their performance and efficiency. There are a variety of causes for the appearance of the bullwhip effect, one most important of which is the existence of uncertain demand. Due to the variety of causes as well as in order to recognize relevant factors, it is important to be able to quantify the bullwhip effect in a supply-chain environment. In this study, we aim to quantify the bullwhip effect in a 3-stage supply chain with multiple retailers. First, we quantify the bullwhip effect, order rate variance ratio (OVR) and inventory variance ratio (IV) in a pipeline supply chain, for which we develop a relation to calculate the bullwhip effect. Then we extend it to a supply chain with multiple retailers. We analyze the impact of service levels on the bullwhip effect for both defined supply chain situations. This analysis, which highlights the importance of the impact of service levels on the bullwhip effect, can be considered the main contribution of this paper. In addition, we survey the influence of the correlation coefficient on the bullwhip effect.
International Journal of Operational Research, 2021
The International Journal of Advanced Manufacturing Technology, 2011
Crossdocking is a distribution strategy in which distribution centers operate as transfer points ... more Crossdocking is a distribution strategy in which distribution centers operate as transfer points to harmonize the continuous physical flow through supply chain with the least storage. The coordination of this system in a network of crossdocks with multitype and time-restricted pickups and deliveries requires a complex planning. This paper addresses the distribution planning problem of crossdocking network, considering transshipment possibility
The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symp... more The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symptoms among poultry slaughtering workers in Iran. The study consisted of two phases. In the first phase, musculoskeletal disorders in three poultry slaughtering industries in Kerman city were surveyed by standardized Nordic questionnaire among 190 workers. The result of this phase has revealed high rate musculoskeletal problems in workers due to poor working conditions. It was found that the majority of workers had experienced some kind of symptoms and pain from the musculoskeletal system felt at some time in the last 12 months. Based on the findings, some of the ergonomic guidelines were presented. The result of the second phase shows that female workers had a higher pain than male workers in the shoulder body regions. This study indicated that, poultry slaughtering could be generally considered as a high risk occupation for developing musculoskeletal symptoms.
Management Science Letters, 2015
Independent Journal of Management & Production, Mar 1, 2017
International Journal of Operational Research, 2021
Journal of Industrial Engineering Research in Production Systems, Feb 20, 2015
Iranian journal of health, safety and environment, 2018
Due to the variety of treatment processes, the decision to choose the best treatment process is d... more Due to the variety of treatment processes, the decision to choose the best treatment process is difficult. This paper describes a fuzzy grey relational analysis (GRA) method for selection of the optimal wastewater treatment process. The rating of all alternatives and the weight of each criterion is described by linguistic variables, which can be expressed in triangular fuzzy numbers. Then, a vertex method is used to calculate the distance between two triangular fuzzy numbers. According to the concept of the GRA, a fuzzy relative relational degree is defined to determine the ranking order of all alternatives by calculating the degree of fuzzy grey relational coefficient to both the fuzzy positive ideal solution (FPIS) and fuzzy negative ideal solution (FNIS) simultaneously. Furthermore, a case study is carried out and solved by both methods (i.e., GRA and fuzzy GRA) to show the feasibility and effectiveness of the proposed method. In the case study, five anaerobic wastewater treatmen...
The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symp... more The goal of this study was to investigate risk factors for the prevalence of musculoskeletal symptoms among poultry slaughtering workers in Iran. The study consisted of two phases. In the first phase, musculoskeletal disorders in three poultry slaughtering industries in Kerman city were surveyed by standardized Nordic questionnaire among 190 workers. The result of this phase has revealed high rate musculoskeletal problems in workers due to poor working conditions. It was found that the majority of workers had experienced some kind of symptoms and pain from the musculoskeletal system felt at some time in the last 12 months. Based on the findings, some of the ergonomic guidelines were presented. The result of the second phase shows that female workers had a higher pain than male workers in the shoulder body regions. This study indicated that, poultry slaughtering could be generally considered as a high risk occupation for developing musculoskeletal symptoms.
Crossdocking is a relatively new logistics strategy which can reduce Inventory holding, order pic... more Crossdocking is a relatively new logistics strategy which can reduce Inventory holding, order picking and transportation costs while speed up the physical flow in the supply chain. The vehicle routing decisions also play an important role in the efficiency of the distribution system. This article addresses the integration problem of crossdocking into the heterogeneous fleet vehicle routing problem to introduce heterogeneous fleet vehicle routing problem with crossdocking. In the considered problem, a set of heterogeneous vehicles transport products from suppliers to customers via a crossdock. The problem was formulated as an integer programming model to determine the best vehicle routes and the optimal number of different types of vehicles minimizing the total operational and transportation cost. Since the considered problem is NPhard, a heuristic algorithm based on a variable neighborhood search is suggested. Numerical experiments show that the proposed algorithm can find high qual...
Independent Journal of Management & Production, 2017
Applied Mathematical Modelling, 2016
Abstract The bullwhip effect is an undeniable phenomenon in supply chains that has a negative eff... more Abstract The bullwhip effect is an undeniable phenomenon in supply chains that has a negative effect on their performance and efficiency. There are a variety of causes for the appearance of the bullwhip effect, one most important of which is the existence of uncertain demand. Due to the variety of causes as well as in order to recognize relevant factors, it is important to be able to quantify the bullwhip effect in a supply-chain environment. In this study, we aim to quantify the bullwhip effect in a 3-stage supply chain with multiple retailers. First, we quantify the bullwhip effect, order rate variance ratio (OVR) and inventory variance ratio (IV) in a pipeline supply chain, for which we develop a relation to calculate the bullwhip effect. Then we extend it to a supply chain with multiple retailers. We analyze the impact of service levels on the bullwhip effect for both defined supply chain situations. This analysis, which highlights the importance of the impact of service levels on the bullwhip effect, can be considered the main contribution of this paper. In addition, we survey the influence of the correlation coefficient on the bullwhip effect.
International Journal of Operational Research, 2021
The International Journal of Advanced Manufacturing Technology, 2011
Crossdocking is a distribution strategy in which distribution centers operate as transfer points ... more Crossdocking is a distribution strategy in which distribution centers operate as transfer points to harmonize the continuous physical flow through supply chain with the least storage. The coordination of this system in a network of crossdocks with multitype and time-restricted pickups and deliveries requires a complex planning. This paper addresses the distribution planning problem of crossdocking network, considering transshipment possibility