Modelling and Optimization of Energy Efficient Assembly Line Balancing Using Modified Moth Flame Optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time.  Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Multi-Objective Optimisation of CNC Milling Process for Al 6061 using Modified NSGA-II

Computer numerical controlled (CNC) growth has revolutionised the manufacturing sectors by changing the way people work. In milling process, it has contributed to the higher productivity and better quality of the products. Although a lot of researches have been done on how to improve the process, the process improvement does not stop there because of evolving materials, methods and technologies. This paper presents a multi-objective optimisation of CNC milling process in order to achieve desired surface roughness and minimise machining time for Al 6061. A full factorial experiment has been conducted to model surface roughness by controlling three variables; spindle speed, feed rate and depth of cut. Multi-objective optimisation has been performed using modified Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) with two levels crossover. The optimisation result concluded that the modified NSGA-II was able to converge to Pareto-optimal, but having difficulties to spread solutions in wider range

Gross and histological evaluation of fresh chicken carcass: comparison between slaughtered and cervical dislocated methods

The study was conducted to evaluate the gross and histological appearances of fresh chicken carcasses between slaughtered and cervical dislocated methods. In this study, 5 adult broiler chickens with homogenous weight were slaughtered and another 5 chickens were cervically dislocated. The chickens were left at room temperature for 30 min prior to gross examination and sampling for histological examination. The gross appearance of muscle and internal organs was evaluated and compared. The internal organs were fixed with 10% formalin for 72 h before went through the process of dehydration, clearing, impregnation, embedding process into paraffin wax and process of sectioning and staining with Haematoxylin and Eosin. The sections were examined under light microscope. Results in this study revealed that the gross examination of the carcass killed by slaughtering method had showed pallor appearance as compared to the chickens killed by cervical dislocation method which appeared reddish in almost all of the organs. Histologically, there was no significant different in terms of distribution or composition of erythrocytes in the visceral organs except in lungs, kidney and liver where the chickens killed by slaughtering method contains less erythrocytes as compared to the chicken killed by cervical dislocation

Analysis of measurement and calculation of MSD complaint of chassis assembly workers using OWAS, RULA and REBA method

Car assembly is a combination of all components that form one completed vehicle unit. The work process is manually done and repeatedly, which contributes to a risk of musculoskeletal disorders (MSD). Chassis assembly is a job with a high level of complexity and associated with MSD risk for its employees. This study consists of 30 assembly activities divided into six groups based on posture and working methods used during the work process. Group A consists of 7 assemblies, Group B consists of 8 assemblies, Group C consists of 5 assemblies, Group D consists of 2 assemblies, Group E consists of 5 assemblies, and Group F consists of 3 assemblies. This study aims to compare the measurement and calculation of the risk level of MSD workers by using the RULA, REBA, and OWAS methods. The results of the measurements and computations acquired using these three approaches yielded the same risk category: 83.33 % medium risk/dangerous in working groups A, C, D, E, and F, and 16.67 % very high risk/highly hazardous in working group B. These six groups, particularly group B, requires immediate attention to reduce worker complaints of MSD

Ergonomics study in Quick Response Manufacturing (QRM) automotive workstation environment to overcome employee complaints

The assembly line is an important process in producing a complete car unit before the product is checked and delivered to the consumer. Assembly workers during working hours are affected by work position, workload, placement of components and aids during the process and equipment used in assisting heavy work processes. Work positions with non-ergonomic workloads impact the disability and musculoskeletal complaints (MSD) of workers. The purpose of this study is to identify the ergonomic risks of assembly workers. Analytical methods using the Nordic Body Map (NBM) and QRM principles were used in this study. The results of the analysis of the level of complaints of workers’ MSD during the work were obtained for the categories of not sick (NS) 27.94%, slightly sick (SS) 36.76%, sick (S) 29.69% and very sick (VS) 5.6%. The most dominant complaints about S and VS complaints were shoulders, arms, back, waist, buttocks, wrists and hands. MSD complaints that employees feel are in the middle category with an average score of 64 points which means immediate remedial action is needed. Using the time-focused QRM principle, improvements in work procedures and designing ergonomic tools are needed to minimize MSD complaints that impact working hours faster, and there is no overtim

Development of a discrete event simulation tool for assembly line simulation

Discrete event simulation (DES) is a powerful tool for better decision-making. Its application can be found in almost every sector ranging from industrial to services. However, the cost of commercial DES tools sometimes makes them unaffordable for small and medium enterprises. On the other hand, the open-source DES requires good programming knowledge for model customization. This paper presents the development of the DES tool specifically for production and assembly line simulation. The developed tool known as Discrete Event Simulation for Assembly Line (DESIMAL) is flexible enough to support different types of the assembly line. Testing and validation have been conducted using an industrial case study. The result indicated that the developed DESIMAL has similar output with a small error margin (1.08% – 3.60%) compared with commercial DES software. In comparison with real problem output, DESIMAL obtained the result with an error of less than 5%. Therefore, the developed DESIMAL has been validated as an acceptable tool for assembly line simulation. The main contribution of this work is an establishment of DES tool for assembly line simulation

Parameters of effects in decision making of automotive assembly line using the Analytical Hierarchy Process method

The automotive industry contributes high income to most of the countries. The assembly line is an essential part of the automotive industry because it combines all the components into a complete body unit. Assembly lines often experience delays in meeting production targets, requiring overtime to complete. Musculoskeletal Disorder (MSD) complaints among assembly workers predominantly lie in trimming, chassis, and finishing processes. Improvements are needed to reduce complaints according to the priority process. This study aims to prioritize the process on the assembly line with the parameters of work position, workload, work layout and equipment. This study implements the Analytical Hierarchy Process (AHP) method to achieve the objectives of the decision-making process. Preliminary weighting priorities for chassis, finishing and trimming are 0.6153, 0.2313 and 0.1533; respectively highest weight is in the chassis process and will be a priority for this study in optimizing solutions

An overview of the fundamental approaches that yield several image denoising techniques

Digital image is considered as a powerful tool to carry and transmit information between people. Thus, it attracts the attention of large number of researchers, among them those interested in preserving the image features from any factors that may reduce the image quality. One of these factors is the noise which affects the visual aspect of the image and makes others image processing more difficult. Thus far, solving this noise problem remains a challenge for the researchers in this field. A lot of image denoising techniques have been introduced in order to remove the noise by taking care of the image features; in other words, getting the best similarity to the original image from the noisy one. However, the findings are still inconclusive. Beside the enormous amount of researches and studies which adopt several mathematical concepts (statistics, probabilities, modeling, PDEs, wavelet, fuzzy logic, etc.), there is also the scarcity of review papers which carry an important role in the development and progress of research. Thus, this review paper intorduce an overview of the different fundamental approaches that yield the several image-denoising techniques, presented with a new classification. Furthermore, the paper presents the different evaluation tools needed on the comparison between these techniques in order to facilitate the processing of this noise problem, among a great diversity of techniques and concepts

Modelling and optimization of energy efficient assemblyline balancing using modified moth flame optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time. Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Progression approach for image denoising

Removing noise from the image by retaining the details and features of this treated image remains a standing challenge for the researchers in this field. Therefore, this study is carried out to propose and implement a new denoising technique for removing impulse noise from the digital image, using a new way. This technique permits the narrowing of the gap between the original and the restored images, visually and quantitatively by adopting the mathematical concept ''arithmetic progression''. Through this paper, this concept is integrated into the image denoising, due to its ability in modelling the variation of pixels’ intensity in the image. The principle of the proposed denoising technique relies on the precision, where it keeps the uncorrupted pixels by using effective noise detection and converts the corrupted pixels by replacing them with other closest pixels from the original image at lower cost and with more simplicity