The purpose of this study is to reduce the probability of occurrence of electric fires as a preemptive preventive measure, and to strengthen the capability of preventing electric fires by strengthening the cooperative function between electric fire-related departments and establishing a cooperative system. In this study, the general aspects of electric fires were identified by reviewing the literature such as ignition mechanisms of electric fires. And the major electrical fires that occurred in the last 10 years were classified into ignition factors (short circuit, overload/overcurrent, and earth leakage/ground fault) and ignition sources (wiring/wiring appliances, electrical equipment/household appliances). And the 4M technique was used to analyze the potential causes of ignition at the fire site and to suggest preventive measures. In the case In this study, out of 48 electrical fires in the past 10 years, 16 short-circuit fires, 3 overload/ overcurrent fires, 3 short-circuit and earth fault fires, 16 fires in wiring/wiring appliances, and 10 fires in electrical equipment/home appliances classified as cases. And prevention measures were presented in terms of human, machine, media, and management by using the 4M technique. For the preemptive prevention of electric fires, strengthening the compulsory electrical safety inspection and making it mandatory to report when new or expanding electric facilities, charging a fee for electric safety inspection for detached houses and granting benefits subject to inspection completion, improvement of the electric safety voluntary inspection table and safety indications; It was suggested as a policy to organize and operate electrical safety inspection personnel in a two-person team (mixed), establish a close work cooperation system with related organizations, and strengthen electrical safety education and publicity.
This study is prepared on the ground of consulting business in an objective of an improvement of productivity that was proceeded on industrious-purpose reel manufacturer, S corp. the purpose of this study is to achieve an improvement of productivity of the production line of industrious-purpose reel via 4M analysis and separate team activities. The method for study was proceeded with 4M analysis via video recording, one of the steps of separate team activities. Separate team activity is newly established concept, indicating what is modified and expanded partial process among previously existing 6-Sigma methodologies so that measures of various variables in the manufacturing production line are applied. The first procedure is a 4M analysis via video recording. firstly, consultant records videos for relevant process, conducting 4M analysis based on collected data to derive wasting factors in each process. Secondly, it is a procedure to derive and select proper measures, meaning that measures for removing wasting factors based on derived results are elicited, selecting a measure with high probability of application via negotiation between consultants and separate teams. The last procedure is an application of selected measures to real production line, reflecting an environment of production field to derive an effect of increasing practical productivity rather than a qualitative effect as a measure with trust and flexibility.
This research modified the checklist used in the universities in USA, England and Korea considering the current situation of Korea, and conducted case studies upon each section of appointed chemical laboratories based on 4M criteria, which stands for Machine, Media, Man and Management. The purpose of the studies is to assess how dangerous the laboratories are and to contribute to prevention of accidentsin the laboratories as well as reducing loss of lives and property. The result of this research found out the harmful and hazardous factors based on the 4M-type checklist and predicted the dangerousness as it multiplies possible frequency by intensity. Protective equipment, safety facilities in laboratories, emergency exit and compressed gas cylinder are found to be more dangerous, so the result shows that it is desirable to improve ventilation, safety facilities and circumstances of the laboratory through the investment.
Glass melting process is influenced by both control and observation factors, where control factors include quantity and mixing ratio of raw material, the amount of fuel and air in-take. Further observation factors include temperature and pressure at eac
이 연구의 목적은 진동대를 사용한 지진모의 기술의 현상황을 살펴보고 그의 신뢰성을 검토하는 것이다. 1자유도 및 3자유도 알루미늄 전단구조 모델이 사용되었으며, 4m{\times}4m 6자유도 진동대가 1940 El centro 지진 가속도 기록(NS요소)를 재현하기 위해 수평 1방향으로 흔들어졌다. 진동대의 실제 가속도 이력과 목표 가속도 이력을 비교할 때, 전반적인 이력은 매우 흡사했으나 실제 진동의 저 주파수 영역은 목표치보다 후리에 변환 강도에서 낮은 값을 대체로 나타내고 있었다. 자유진동 및 백색파 실험은 고유주파수에 대해서는 거의 일치하는 값을 나타내고 있으나 감쇠계수에 대해서는 자유진동실험의 경우 1.4%, 백색파실험의 경우 14.8%를 나타내어 큰 차이를 보여주고 있다. 층 전단력 대 층간변위의 이력곡선으로부터 전제적으로 선형탄성거동을 나타내고 있으나 이 이력곡선의 모습이 층 강성을 한축으로 하는 타원형을 나타내어 점성감쇠의 영향을 암시하고 있다.
Net primary productivity (NPP) is considered as an important indicator for forest ecosystem since the role of the forest is highlighted as a key sector for mitigating climate change. The objective of this research is to estimate changes on the net primary productivity of forest in South Korea under the different climate change scenarios. The G4M (Global Forest Model) was used to estimate current NPP and future NPP trends in different climate scenarios. As input data, we used detailed (1 km × 1 km) downscaled monthly precipitation and average temperature from Korea Meteorological Administration (KMA) for four RCP (Representative Concentration Pathway) scenarios (2.6/4.5/6.0/8.5). We used MODerate resolution Imaging Spectroradiometer (MODIS) NPP data for the model validation. Current NPP derived from G4M showed similar patterns with MODIS NPP data. Total NPP of forest increased in most of RCP scenarios except RCP 8.5 scenario because the average temperature increased by 5°C. In addition, the standard deviation of annual precipitation was the highest in RCP8.5 scenario. Precipitation change in wider range could cause water stress on vegetation that affects decrease of forest productivity. We calculated future NPP change in different climate change scenarios to estimate carbon sequestration in forest ecosystem. If there was no biome changes in the future NPP will be decreased up to 90%. On the other hand, if proper biome change will be conducted, future NPP will be increased 50% according to scenarios.