• Title/Summary/Keyword: roadblock

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Vehicle Collision Simulation for Roadblocks in Nuclear Power Plants Using LS-DYNA (LS-DYNA를 이용한 원자력발전소의 로드블록에 대한 차량 충돌 시뮬레이션)

  • SeungGyu Lee;Dongwook Kim;Phill-Seung Lee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.2
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    • pp.113-120
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    • 2023
  • This paper introduces a simulation method for the collision between roadblocks and vehicles using LS-DYNA. The need to evaluate the performance of anti-ram barriers to prepare for vehicle impact has increased since vehicle impact threats have been included as a design criterion for nuclear power plants. Anti-ram barriers are typically certified for their performance through collision experiments. However, because Koreas has no performance testing facilities for anti-ram barriers, their performance can only be verified through simulations. LS-DYNA is a specialized program for collision simulation. Various organizations, including NCAC, distributes numerical models that have been validated for their accuracy with collision tests. In this study, we constructed a finite element model of the most critical vehicle barrier module and simulated collision between roadblocks and vehicles. The calculated results were verified by applying the validation criteria for vehicle safety facility collision simulations of NCHRP 179.

The Comparison of Noise-induced Hearing Loss Evaluation Criteria for Management (소음성난청 관리를 위한 판정기준간의 비교)

  • 남궁원자;원정일
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.123-134
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    • 1998
  • The study was performed to investigate the differences among various evaluation criteria for noise-induced hearing loss(NIHL). The subjects were 100 workers who had received detailed audiometric examinations after the periodic annual examination for hearing loss. The evaluation criteria included were as follows: The criterion I was NIHL of 50dB or greater at 4,000Hz in either ear which is one of the legal requirements for determining occupational hearing loss in Korea. The criterion II was NIHL of 40dB or greater by 4-divided classification(a+b+c+d/4 at 500Hz(a), 1,000Hz(b), 2,000Hz(c), 4,000Hz(d)) which is also one of the legal requirements for determining occupational hearing loss in Korea. The criterion III was NIHL of 31dB of greater by 6-divided classification(a+2b+2c+d/6) which is the workers' compensation standard. The criterion IV was NIHL of 40dB or greater by 6-divided classification(a+2b+2c+d/6), the criterion used to prohibite workers to be employed in the noisy workplace. The criterion V was NIHL of 40dB or greater by 3-divided classification(a+b+c/3) which is the guideline of the Japanes Labour Department. The results were as follows; 1. The percentage of workers with NIHL by the criterion I was the highest(96%) and covered all workers with NIHL diagnosed by other criteria. Therefore, this criterion was the most sensitive one for early detection of NIHL among various evaluation criteria. 2. The percentage of workers with NIHL by the criterion II was 29% of the subjects, but all of them could be diagnosed as having NIHL by the criterion I and 33.1% of the NIHL by the criterion III could not be covered by the criterion II. Thus, this criterion was not considered suitable as an initial step for determining occupational hearing loss. 3. The percentage of workers with NIHL by the criterion III was 45% of the subjects. This percentage was 46.9% of the NIHL by the criterion I and was estimated to cover 3.6% of all noise exposed workers. 4. The percentage of workers with NIHL by the criterion IV was 28% of the subjects, but 37.8% of the NIHL by the criterion III and 70.8% of the NIHL by the criterion I were not covered by the criterion. Therefore, these workers could have been employed in the noisy workplaces. 5. Employed relocation which was one of the post management methods was an option in the criterion I in Korea and in the criterion V in Japan. The number of NIHL by the criterion I was 6.7times greater than that by the criterion V. Thus, although employee relocation was not used exclusively, many more workers with NIHL could have been relocated. In conclusion, this study revealed that the criteria being used for managing occupational hearing loss showed a lack uniformity among them. In addition, since these criteria are all relied on the total threshold shifts caused by the noise exposure at the time of hearing test with no consideration given to the past noise exposure history nor age, it can be said that they are not an effective tool for occupational hearing loss management. Since legal requirements are usually followed after being diagnosed as having NIHL, it is recommended that a uniform diagnostic criterion should be used to minimize confusion. Pre-employment hearing tests should also be utilized so as to managing occupational hearing loss after employment rather than being used as a legal roadblock of prohibiting workers with mild hearing loss from being employed. Thus, what is needed is an establishment of a rational criterion for occupational hearing loss management rather than for legal requirements.

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Current Status and Activation Plan of Hospice Palliative Care in Korea - Based on Hospice Palliative Care Facilities Survey (국내 호스피스.완화의료 현황 및 활성화 방안 - 호스피스.완화의료 기관 조사를 바탕으로)

  • Kyung, Min-Ho;Jang, Yu-Mi;Han, Kyung-Hee;Yun, Young-Ho
    • Journal of Hospice and Palliative Care
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    • v.13 no.3
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    • pp.143-152
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    • 2010
  • Purpose: This study aimed to evaluate the current status of hospice palliative care facilities in Korea. Based on the result, we attempted to suggest activation plans of hospice palliative in Korea. Methods: To conduct a survey, we obtained a list of hospice palliative care facilities from related agencies and academic societies. A survey was conducted from February, 2009 to March, 2009. The survey was consisted of general characteristics of organizations, manpower, facilities & equipments, and so on. In addition, we used data from Statistics Korea to estimate the number of beds required and the bed occupancy rate. Results: Total number of facilities responded to the questionnaire were 53. Forty-two facilities were general hospitals and 6 facilities were clinics among the total 53 facilities, and 18.8% of facilities were located in Seoul, Incheon and Gyeonggido. Overall bed occupancy rate was rather low as 21.9%, and there were 4 provinces where bed occupancy rates were 0%. Deaths in hospice palliative care facilities during 2008 were 6.3% of total deaths from cancers. As for the questions about the financial status of facilities, 86% of facilities were answered financial insufficiency. Also more than half of the facilities gave financial insufficiency as the reason for shortage of human resource supplies and inability to achieve the standard for authorization by the government. Facilities answered in order to activate the hospice palliative care, governmental support is needed, mostly in financial support (71.2%), donation tax deduction (43.1%), and setting up a public utility foundation (23.5%). Conclusion: This study showed low rates of hospice palliative care use and bed occupancy in Korea. Regional variance in bed occupancy rate was significantly high. As a roadblock for these problems, most of the facilities cited financial insufficiency. Therefore, there must be some action plans to boost financial support to activate hospice palliative care in Korea. Finally, efforts to improve these circumstances including lack of understanding about hospice and palliative care, are needed as well.