Papers by Author: N. Ismail

Abstract: Integration of various types of handling equipment is one of the important methods to improve the efficiency of processes and productivity of a container terminal. Using ALVs, because of their ability in lifting a container from the ground by themselves, can reduce the delay of loading and unloading tasks in automatic container terminals.In this paper, a mixed-integer programming model, which considers the integration of ALVs, Quay Cranes and Yard Cranes, is developed. This model minimizes the makespan of the loading and unloading activities in an Automatic Container Terminal with limited buffer spaces.

Abstract: One significant decision in supply chain management is to determine the configuration of the supply chain network. However, studies that analyze different configurations are rare in the literature. This paper considers a supply chain network consisting of one supplier and a number of retailers. Two different configurations were proposed and were compared in terms of total cost for the network. In the first configuration, retailers directly order to the supplier and hold the inventory to meet the demand of customers. However, in the second configuration, a number of intermediate facilities were established to order products from the supplier and satisfy the demands of retailers. The inventory of retailers in the latter configuration is stored in the intermediate facilities. These two configurations were compared in terms of total cost. Numerical calculations indicate that the latter configuration was preferred in most cases.

Abstract: It has been a while since supply chain management (SCM) has shifted its focus from production efficiency to sustainability related issues. Implementing this strategic shift demands all supply chain members, all processes, and generally all of the elements to be involved in helping the chain move faster and further toward sustainability. This has necessitated the strong relationship between supply chain and the three sustainability pillars: environment, economy, and society. Having considered this essentiality, this paper, describes the supply chain, sustainable development and discusses their existing definitions in the literature. The relationship between supply chain and sustainability is then discussed and a framework for sustainable supply chain is proposed based on the previous suggested structures for supply chain and sustainable development.

Abstract: Many industrial problems need to be optimized several responses simultaneously. These problems are named multiple response optimization (MRO) and they can have different objectives such as Target, Minimization or Maximization. Committee machine (CM) as a set of some experts such as some artificial neural networks (ANNs) in combination with genetic algorithm (GA) is applied for modeling and optimization of MRO problems. In addition, optimization usually is done on Global Desirability (GD) function. Current article is a development for recent authors' work to determine economic run number for application of CM and GA in MRO problem solving. This study includes a committee machine with four different ANNs. The CM weights are determined with GA which its fitness function is minimizing the RMSE. Then, another GA specifies the final solution with object maximizing the global desirability. This algorithm was implemented on five case studies and the results represent the algorithm can get higher global desirability by repeating the runs and economic run number (ERN) depends on the MRO problem objective. ERN is ten for objective “Target”. This number for objectives which are mixture of minimization and maximization ERN is five. The repetition are continued until these ERN values have considerable increased in maximum GD with respect to average value of GD. More repetition from these ERN to forty five numbers cause a slight raise in maximum GD.

Abstract: Today organizations are required to deal with and manage a variety of challenges in their day-to-day activities. Examples of these challenges are issues related to quality of products/services, environment, employees’ safety and health, corporate social responsibilities, risks and many others. In response to these challenges, several Management Systems (MSs) and Management Systems Standards (MSSs) have been introduced in recent years to systematically guide an organization to cope with these challenges. The need to create Integrated Management System (IMS) is the result of increase in the number of these MSs and MSSs. There are also evidences in literature and practice that organizations have slowly started to tackle the IMS issue. The journal papers’ related to MSs Integration field, highlight that in theory any two MSs or even more are potentially capable of being integrated. In this study, it will be shown that the attitudes and approaches behind the two important function-specific MSSs developed by ISO Organization, i.e. Quality Management System (QMS) and Risk Management System (RMS) are largely similar and complementary. Hence, the integration of these two MSs seems justifiable. The main driver for such integration is to reduce the number of MSs in an organization and hence to decrease the number of resources employed. Also it will be demonstrated that the integration of these two MSs will result in more significant background, cultural context, techniques, procedures and synergy to an organization.

Abstract: Polishing is a secondary process in machining. The application of polishing process is crucial to obtained final appearance of a product. This study addresses parameter analysis on flat and dry polishing to determine the most influence parameter which effect surface roughness. For this purpose, Design of Experiment (DOE) is used as a methodology in the analysis. The polishing process is conducted on Comau robotic cell and the combination of grit size, polishing time and polishing force are subjected on the material by using pneumatic polishing tool. Two-level factorial experiment design is conducted and result is interpreted by using statistical software. From the result it is shown that grit size and polishing time give the main effect on surface roughness. However for 2-way interaction effect, polishing time and polishing force contribute significantly on surface roughness. This suggested that for flat and dry polishing, consideration on these parameters is an essential aspect in order to achieve a good surface finished.

Abstract: In this study, a multi-objective optimization method for an unrelated parallel machine scheduling problem was addressed. The model, simultaneously takes into account the minimization of makespan and machine utilization cost. Then, because of the complexity of the problem, a heuristic algorithm will be developed to solve the mathematical model. To show the validity of the model, and also solution approach, a case will be randomly generated, and solved by the heuristic algorithm and also Lingo optimization software. The results show the validity of the model and also solution approach.

Abstract: The shortage of material and environmental legislations have encouraged car manufacturers to recycle used material in end of life vehicles (ELVs), reverse logistics are essential to the concerns of the automotive supply chain. In this research, a profit model multi-echelon reverse logistics network including collection center, shredder center and recycling center is developed to recycle automotive parts. The work was continued by illustrating empirical application in wiring harness manufacturer that would like to recycle wire harnesses and extract copper. With regards to the complexity of the reverse logistics network, traditional method cannot be implemented for solving them. Thus, an evolutionary algorithm based genetic algorithm (GA) is applied as a solution methodology to solve mixed integer linear programming model and find the optimum solution. The results emphasize the efficiency of the modeling and solving method so that in the case study the company gained more than 27 thousand dollars through the establishment of reverse logistics for recycling copper.

Abstract: Due to the fact that material is being removed from the bulk material, all machining operations have some impact on the resulting surface integrity of the machined components. This paper presents an investigation on surface microhardness on machining of TiC reinforced aluminium LM6 alloy composite using uncoated carbide tool under dry cutting condition. The experiments that were carried out consisted of different cutting parameters based on combination of cutting speed, feed and depth of cut as the parameters of cutting process. The microhardness of machined surface at a range of cutting speed, feed and depth of cut were measured. The results show that the microhardness was generally found to be higher near the machined surface layer than the hardness of the matrix in the bulk material during machining for all cutting condition. Microhardness increases beyond the bulk hardness of material occurred 50 μm below machined surface, and then microhardness starts to decrease and reaches the bulk hardness. The microhardness values increases with increased the feed and depth of cut. The highest microhardness recorded was 68 HV_0.5 when machining at a lower cutting speed of 100 m min^-1, feed of 0.2 mm rev^-1 and depth of cut of 1.0 mm.

Abstract: Submerged arc welding (SAW) is a well-known method to weld seam in manufacturing of large diameters steel pipes in oil and gas industry. The main subject of SAW design is selection of the optimum combination of input variables for achieving the desired output variables of weld. Input variables include voltage, amperage and speed of welding and output variables include residual stresses due to welding. On the other hand, main target in multi response optimization (MRO) problem is to find input variables values to achieve to desired output variables. Current study is a combination and modification of some works of authors in MRO and SAW subjects. This study utilizes an experiment design according to Taguchi arrays. Also a committee machine (CM) modeling the problem by CM using two approaches. The first CM consists eight experts with traditional approach in computation and second CM includes elite experts. Genetic algorithm was applied to find CM weights and desired responses. Results show that proposed approach in CM has a smaller root mean squire error (RMSE) than traditional approach. The validation of CM model is done by comparison of results with simulation of SAW process and residual stresses in a finite element environment. Finally, the results show few differences between the real case responses and the proposed algorithm responses.