In this paper, we raised the performance of heuristic algorithm to assign job to workers in parallel line inspection process without sequence. In previous research, we developed the heuristic algorithm. But the heuristic algorithm can't find optimal solution perfectly. In order to solve this problem, we proposed new method to make initial solution called FN(First Next) method and combined the new FN method and old FE method using previous heuristic algorithm. Experiments of assigning job are performed to evaluate performance of this FE+FN heuristic algorithm. The result shows that the FE+FN heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are optimal solutions, this heuristic algorithm can find the optimal solution perfectly.

In this paper, the author devised new decision recommendation ordering method of items attributed by age to improve accuracy of recommender system. In conventional recommendation system, recommendation order is decided by high order of preference prediction. However, in this paper, recommendation accuracy is improved by decision recommendation order method that reflect age attribute of target customer and neighborhood in preference prediction. By applying decision recommendation order method to recommender system, recommendation accuracy is improved more than conventional ordering method of recommendation.

In this study, we developed a heuristic algorithm to get better efficiency of clustering than conventional algorithms. Conventional clustering algorithm had lower efficiency of clustering as there were no solid method for selecting initial center of cluster and as they had difficulty in search solution for clustering. EMC(Expanded Moving Center) heuristic algorithm was suggested to clear the problem of low efficiency in clustering. We developed algorithm to select initial center of cluster and search solution systematically in clustering. Experiments of clustering are performed to evaluate performance of EMC heuristic algorithm. Squared-error of EMC heuristic algorithm showed better performance for real case study and improved greatly with increase of cluster number than the other ones.

In this paper, we developed a heuristic algorithm to assign job to workers in parallel line inspection process without sequence. Objective of assigning job in inspection process is only to assign job to workers evenly. But this objective needs much time and effort since there are many cases in assigning job and cases increase geometrically if the number of job and worker increases. In order to solve this problem, we proposed heuristic algorithm to assign job to workers evenly. Experiments of assigning job are performed to evaluate performance of this heuristic algorithm. The result shows that heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are more than two optimal solutions, this heuristic algorithm can find the optimal solution with 98% accuracy.

We adapted association rules of data mining in order to investigate the relation among the factors of musculoskeletal disorders and proposed the method of preventing the musculoskeletal disorders associated with multiple logistic regression in previous study. This multiple logistic regression was difficult to establish the method of preventing musculoskeletal disorders in case factors can't be managed by worker himself, i.e., age, gender, marital status. In order to solve this problem, we devised association rules of factors of musculoskeletal disorders and proposed the interactive method of preventing the musculoskeletal disorders, by applying association rules with the result of multiple logistic regression in previous study. The result of correlation analysis showed that prevention method of one part also prevents musculoskeletal disorders of other parts of body.

The authors used association rules and patterns in sequential of data mining in order to raise the efficiency of engineering changes. The association rule can reduce the number of engineering changes since it can estimate the parts to be changed. The patterns in sequential can perform engineering changes effectively by estimating the parts to be changed from sequence estimation. According to this result, unnecessary engineering changes are eliminated and the number of engineering changes decrease. This method can be used for improving design quality and productivity in company managing engineering changes and related information.

The authors devised and presented the method of development for project management system. The function and item for project management system are also presented in this article. This is the case of developing a practical system for project management in electronic company. The electronic company can utilize this method as a guideline of development. This can bring great economical effect to electronic company by saving the costs and time for development. The electronic company can apply this method easily. Moreover, waste of costs can be prevented by installing system just with necessary function and items.

Objectives: The aim of this study is to determine prevalence and related factors of musculoskeletal symptoms in electronics assembly line workers. Method: A questionnaire survey was performed on 350 workers in In-chon city. The questionnaire consisted of questions on the general characteristics, work duration, working hours, hobby activity hours, housekeeping activity hours and standardized descriptions of NOISH on musculoskeletal symptoms. Result: Complaint rates of musculoskeletal symptoms by anatomical site were as follows: shoulder, 67% : neck, 40.4% : waist, 28.7% : wrist and hand, 27.1% : foot and leg, 14.4% : arm and elbow, 11.2%. Significantly higher prevalence of shoulder musculoskeletal symptom was found women than men, married than unmarried, less than 1hours housekeeping activity than over 1hours housekeeping activity. Multiple logistic regression analysis identified gender, marital status and housekeeping activity as the main affecting factors for shoulder musculoskeletal symptoms. Conclusions: The most prevalence of musculoskeletal symptoms was shoulder site. It was higher in married women and over 1hours housekeeping activity in a day. It is recommended that married women should be reduce housekeeping activity time.

The production using U-shaped line is studied. This research presents the relationship among machining time, cycle time and production rate in a U-shaped line. The U-shaped line produces shafts by automated machines. In this paper when any production rate is given the U-shaped line always satisfies the production rate. An algorithm is developed for the determination of cycle time, the number of machines and workers of the U-shaped line in order to minimize the total machine capacity and the number of workers for any given production rate. The U-shaped line was successfully designed by applying the proposed algorithm.

The contamination problem is getting worse now a day because of the industrial activities. Recently it has been announced that there's environmental hormone in river and lake which produces clean water, also there's too many of algae reproduces under the water and some virus in the drinking water. The quality of water is very important. pure and clean water is not only a precondition for human being to live but a basic factor to improve the quality of life. so a water purification system must be developed. This study is about the surface washing treatment technique. We tried to use a rotary nozzle to get a tush degree of efficiency, for it was not enough with present way of washing. The nozzle is run by water pressure. The results of the experiment are as follows. We got a clean and equal surface after washing. After washing, the water's maximum consistency was 330NTU and it shows that this way is better than before one with 215NTU. Clean level of the filter was 6˚and it's 2.8 times higher than 17˚with the old way. We can see the results that the new way of washing is more effective than old way based on this study.

This research aims at the improvement of the manufacturing productivity of . kitchen furniture industry. W company deals with the orders of 2 types - the one is the batch order for mass production, and the other is the order of a customized single set. But, because the company has a single manufacturing system appropriate to mass production despite of the above 2 types-orders, the problems of increasing work-in-process, throughput time and material handling time were resulted in, and the overall productivity was generally low. We proposed a new material handling method to substitute the traditional one, the rearrangement of facility layout, and the introduction of a proper outsourcing method. This research results in about 80% increase in production quantity in the same period.