Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.
As a result of the increasingly serious air pollution worldwide, there are many social costs in the country. In general, there are legal measures to improve air quality such as investment projects, input of public funds, attraction of private capital, and regulation of air pollution prevention. In this study, we propose future legislative policies through the following analysis on the status of various researches in domestic and foreign countries for the improvement of air quality and related legal system. The domestic indoor air quality is getting better through ongoing management. From a legal perspective, The air quality law, such as indoor air quality law and environmental law, has been continuously revised to improve indoor air quality. However, contrary to the air quality law, indoor air quality management is carried out by various related departments under current law. Due to the different management facilities and management standards of each ministry, the effectiveness of relevant laws is deteriorated in organically managing multi-use facilities. This may lead to confusion and may be an impediment to the effective achievement of the institution's objectives. The pollutants of interior space are one of the main causes not only building materials, but also office equipment such as computers. however, The pollutants to be managed under the current legislation are mainly limited to building materials. In addition, the criteria set for each pollutant have a problem that it depends on the after-regulation standard that is made after the pollutant is released from the pollutant source. There is a need for systematic analysis and research to prevent adverse effects that may occur due to pollution sources through the prevention system. It is time to change the direction of regulation-oriented policies and to make policy changes that can improve air quality through systems such as emission trading system..
The purpose of this study was to provide a practical guide to the proper way of lifting a patient using various types of stretcher that rescue crews use by analyzing the load on the lumbar region. The experiment was conducted with working male and female rescue crews. Having mixed groups of gender complete tasks such as lifting, moving, and unloading a patient using four different types of stretcher, we recorded variations of the lumbar bending angle and calculated the load on the lumbar region using 3D SSPP. The data showed, in terms of the lumbar bending angle, it was greater when only females were involved in the work, and there were very significant differences in the angle depending on the types of stretcher used and body sizes of each subject. In the analysis of the load on the lumbar based on the bending angle, NIOSH was over the recommended limit in certain groups. Utilizing the analysis, it is recommended, in the medium and long term, to improve equipments for rescue personnel and to guide them to the proper way of working.
The purpose of this study was to provide a practical guide to the use of various stretchers that rescue workers use by analyzing muscle fatigue degree associated with lifting a patient. The experiment was conducted with working male and female rescue crews. Having mixed groups of gender complete tasks such as lifting, moving, and unloading a patient using four different types of stretcher, we recorded each muscle fatigue degree in the shoulder and lower back regions of each subject. The data showed, in terms of muscle activity, differences within each group of genders and its combinations were significant in certain muscle groups depending on the types of stretcher used and body sizes of each subject, and, when it comes to Elerctor Spenae, the female subjects used more muscular strength than the males did. In regards to the muscle fatigue degree, there was no significant difference found within each group of the genders, body sizes, and their combinations. However, in the case of applying different models of stretcher, there were significantly differences in the fatigue degree.
The International Space Station (ISS) orbits the Earth within the inner radiation belt, where high-energy protons are produced by collisions of cosmic rays to the upper atmosphere. About 6 astronauts stay in the ISS for a long period, and it should be important to monitor and assess the radiation environment in the ISS. The tissue equivalent proportional counter (TEPC) is an instrument to measure the impact of radiation on the human tissue. KASI is developing a TEPC as a candidate payload of the ISS. Before the detailed design of the TEPC, we performed simulations to test whether our conceptual design of the TEPC will work propertly in the ISS and to predict its performance. The simulations estimated that the TEPC will measure the dose equivalent of about 1:1 mSv during a day in the ISS, which is consistent with previous measurements.
A research project was conducted to study work-related musculoskeletal disorders (MSDs) at a die-casting plant in Korea. The project was consisted of 4 main parts; education on the topics of MSDs for all workers, symptom survey, medical check-up, investigation of MSD risk factors. The result of symptom survey showed that 89.5% of the respondents complained pains on at least one part of the body. After cross-sectional analysis of various information and risk factors based upon NIOSH criteria, 83.3% of respondents were considered as active health surveillance level 1, and 16% of the respondents were considered as active health surveillance level 2 those are at high risk of having MSDs based upon a criteria developed by Institute of Labor Science at University of Incheon. Also the result of medical examination by a industrial medicine MD showed that 41workers(44.1%) out of 93 workers examined were considered as MSD patient group at moderate level, and 10 workers(10.8%) were considered as MSD patient group at relatively high level that require certain level of medical treatment and ergonomics interventions for their workplace. The analysis of the work environment using various ergonomic investigation techniques revealed that repeated awakard postures(50%) and highly repatitive task(37.5%) were two most contributing risk factors for the on-set of MSD at this work site followed by handling of heavy object(8.3%), and vibration(4.2%).
Usually, we have many difficulties in funding because of the prejudice that the bridge inspection facilities are not a critical part in bridges. Also, high initial cost resulted in the decrease trend in installing the bridge inspection facilities.
But, in this research, we reached to the conclusion that installing fixed bridge inspection facilities are most economical and more effective in required time, input man-power and equipments than any other means to approach bridges by analysis considering LCC(Life Cycle Cost).