• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.911-916
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• 2012

It is important to identify dynamic characteristics of nuclear fuel components. Since the fuel always exposed to turbulent flow, the dynamic contact between grids and rods is one of the fuel failure modes. The dynamic behavior of grids in nuclear fuels is quite complex, since two pairs of spring support are placed in the limited space. The strap in a cell has single spring and double dimples and this paper focuses on investigation of the grid strap(Test Fuel Strap, TFS) vibration in one cell. To identify the grid strap vibration, modal analysis of the strap is performed using Finite Element Method (FEM). Modal testing on a $5{\times}5$ grid structure without rods is performed. The modal testing results are compared to analytic results. In addition, random test considering rod effect is performed about a $5{\times}5$ grid with rods under real contact condition in the air. Finally, the strap vibration of a $5{\times}5$ fuel bundle in INvestigation of Flow INduced vIbraTion(INFINIT) facility is measured in real fluid velocity condition without heating. It is shown that modal frequencies from the test are almost equal to those peak frequencies in the INFINIT test.

• 한국콘텐츠학회논문지
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• 제21권8호
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• pp.294-304
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• 2021

의료기관은 환자의 만족도 충족과 타 의료기관과의 경쟁력 향상을 위해 신축보다는 기존 병원 건물을 리모델링하게 된다. 의료기관 리모델링은 의료의 질과 환자 안전의 수준 향상을 위해 강화된 법과 제도로 인하여 점차 증가하고 있다. 다만 선행연구들은 의료기관 리모델링에 대해 건축적 요소 등 제한된 범위에서만 논의가 이루어졌다. 이에 본 연구는 의료기관 리모델링의 법적 제문제를 다각적으로 검토함으로써 향후 리모델링을 계획하는 의료기관에게 기본적인 자료를 제공하고자 한다. 의료기관 리모델링은 공사 여건의 제한으로 공사 기간이 길어지고, 환자에게 소음·분진 등의 피해를 발생시킨다. 따라서 사전에 환자의 피해를 예방하고 적정한 의료기관의 리모델링을 지원하는 방안이 필요하다. 이에 의료기관 리모델링 활성화 및 지원에 관한 법률 마련이 필요하다. 그리고 의료기관은 공사기준 자율 준수 체크리스트, 사전 방지조치 및 사후 개선조치, 병원 내 감염과 방사선 노출에 대한 대책을 마련해야 한다.

• 한국산업보건학회지
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• 제23권3호
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• pp.261-265
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• 2013

The purpose of this study was to evaluate noise level exposures at different locations such as the left and right ears of the shooter, control room, waiting soldier location and drill ground. For this study, we visited two military rifle ranges and took measurements with a sound level meter (3M Quest SoundPro TM) at five different locations with values of Peak (dB(A)) and Max (dB(A)). The highest peak value of impulse noise level averaged 150.4 dB(A), ranging from 149.6 to 150.5 dB(A) at both the left and right ear sides. This result was significantly different between both left and right ear side locations and at other locations such as the control room, waiting soldier location, and drill ground (P < 0.001). Frequency of impulse noise exposure level showed that the left ear of shooter had the highest frequency (20 times) at over 150 dB(A). This study confirmed that there is a need for proper controls to reduce the amount of impulse noise exposure at military rifle ranges.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2009년도 정기 학술대회
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• pp.226-229
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• 2009

굴삭기는 다양한 산업 분야에서 폭넓게 이용되고 있는 대표적인 장비임에도 불구하고 작업 환경은 매우 열악하여 굴삭 조종자는 각종 소음이나 진동, 분진에의 노출뿐만 아니라 산업재해의 위험성 또한 높다. 이러한 문제점들을 타개하기 위하여 현재 국내에서는 2006년부터 지능형굴삭시스템(Intelligent Excavating System)에 의한 자동화된 굴삭기의 개발을 위하여 연구를 진행 중에 있다. 자동화 굴삭시스템 구축에 있어서 센싱(sensing)을 통해 획득된 지형 및 주변 환경정보를 활용하여 숙련공의 휴리스틱스(heuristics)를 바탕으로 설계된 모듈을 통해 최적의 굴삭 작업 계획을 세우고, GUI (Graphic User Interface)를 제공하여 실시간 작업진행 상태 파악 및 모니터링(monitoring) 내용을 굴삭기 조종자와 공사 감독관에게 제공하는 Task Planning System의 개발은 생산성, 안전성, 작업의 품질 및 장비의 성능에도 지대한 영향을 미치며 자동화된 굴삭시스템을 개발함에 있어서 필수적으로 요구되어지는 핵심기술이다. 본 논문에서는 자동화 굴삭시스템을 위한 자동화 계획생성 시스템인 Task Planning System의 현재까지 진행된 연구 내용과 모니터링 및 작업에 대한 최소간섭을 위한 Task Planning System Interface를 소개한다.

• 한국산업보건학회지
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• 제20권2호
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• pp.94-101
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• 2010

This study was performed to examine the asymmetry of hearing loss among the noise exposed male workers. Findings of otoscopic examination, pure tone audiometry and tympanometry were evaluated for 179 male workers working in the noise exposed workplace. And also selfadministered structured questionnaires were used for each worker's work-related and general characteristics including personal health behaviors. There were significant differences of hearing threshold between right and left ears at 1,000 Hz and 3,000 Hz(p<0.05). And also significant differences of hearing threshold were noted in the age group over 50 at 3,000 Hz, the high risk drinking group either at 3,000 Hz and 4,000 Hz, the work duration group 10-19 years at 3,000 Hz, the noise exposure group under 90 dB(A) at 3,000 Hz, the noise exposure group over 90 dB(A) at 1,000 Hz, the non-wearing protective device group at 4,000 Hz, and the wearing protective device group at 3,000 Hz(p<0.05). Further study is needed to explore the extent and the related factors of the asymmetry of hearing loss in the general population and occupationally noise exposed group.

• 한국환경보건학회지
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• 제34권2호
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• pp.153-160
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• 2008

Personal noise exposure was assessed in railroad operators working in 40 operation units including the Gyeongbu line, Honam line, and Janghang line between 2004 and 2006. 8-hour TWA were assessed based on the MOL (Ministry of Labor) guideline on noise evaluation, and 17% of these measurements exceeded 85 dBA while 70% were over 80 dBA. When the ACGIH TLV is adopted, 40% of measurements were over TLV (85 dBA). The noise exposure risk of railroad operators was higher for diesel locomotive operation and longer operational distances; in addition, the risk was higher for passenger car operation compared to freight car driving. Given that in Korea, over the past 30 years diesel locomotives have provided most of the railway's motive power and that hearing protective equipment is not likely to be used by workers during operation, railroad operators are at a high risk of noise-induced hearing loss. The result of audiometric test among 568 railroad operators showed that 32.6% of those tested had a hearing threshold shift of more than 40 dB. In conclusion, this study calls for more fundamental measures including noise control countermeasures within the operation areas, development of equipment that generates less noise and adopting limitation on the operation distance for a work shift.

• 한국환경보건학회지
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• 제39권4호
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• pp.354-359
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• 2013

Objectives: The purpose of this study was to investigate exposure levels to K2 rifle noise at a military rifle range among soldiers in training, the left and right ears of shooters, and control managers in the day and night times. Methods: For this study, we visited military rifle ranges and measured the noise of a K2 rifle with a sound level meter (3M Quest SoundPro$^{TM}$) at four different locations with values of Peak (dB(A)) and Max (dB(A)). Results: The highest peak value of impulse noise level averaged 150.4 dB(A), ranging from 149.7 to 150.5 dB(A) at the left-ear side. Impulse noise levels in the daytime were also recorded as higher than during the night. This result was significantly different between daytime and nighttime locations, such as soldier training, right ear of shooter, and control manager (P < 0.001). Conclusion: This study confirmed that there is a need for proper management of impulse noise at military rifle ranges.

• 한국산업보건학회지
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• 제24권1호
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• pp.74-78
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• 2014

Objectives: Purpose of this study was to evaluate the noise level exposures at the different cannonball type and locations in the tank gun drill ranges. Methods: We visited the tank gun drill ranges and measured with a sound level meter(3M Quest SoundPro$^{TM}$) with the value of Peak(dB(A)). Results: The highest peak value of impulse noise level averaged 166.3 dB(A) at the site of loading solider. The highest peak value of impulse noise level by size of cannonball averaged 165.9 dB(A) at the 120 mm size cannonball of the tank. This result was significantly different from the other size of cannonballs such as 7.62 mm, 90 mm, and 105 mm(p < 0.001). Among the four types of soldier site on the tank, average noise levels of loading soldier, 156.6 dB(A), were higher than the other three types of soldier site (p > 0.05). Conclusions: This study confirmed that there were needed for a proper control to reduce the amount of impulse noise exposure at the tank gun drill ranges.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 추계학술대회 논문집
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• pp.211-215
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• 1999

It is well known that a long-term exposure to a loud noise environment affects performance, since it distracts attention, and also is able to evoke stress accompanied by negative emotional states. The purpose of this study was to analyze dynamics of subjective and physiological variables during long-lasting (30 min) exposure to intensive white noise (85 dB[A]). Physiological signals on 23 college students were recorded by BIOPAC, Grass Neurodata systems and AcqKnowledge 3.5 software. Autonomic variables, namely skin conductance level (SCL), non-specific SCR number (N-SCR), inter-beat intervals in ECG (RR intervals), heart rate variability index (HF/LF ratio of HRV), respiration rate (RESP), and skin temperature (SKT) were analyzed on 5 min epoch basis. Psychological assessment (subjective rating of stress level) was also repeated on every 5 min basis. Regression and correlation analyses were employed to trace the time course of the dynamics of the subjective and autonomic physiological variables and their relationship. Results showed that intense noise evokes subjective stress with associated autonomic nervous system responses. However, it was shown that physiological variables endure specific changes in the process of exposure to loud white noise. Discussed are probable psychophysiological mechanisms mediating reactivity to long-term auditory stimulation of high intensity.

• 한국산업보건학회지
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• 제28권4호
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• pp.416-424
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• 2018

Objective: The objective of this study was to estimate the numbers of employees occupationally exposed to noise according to their industry and size. Methods: A Delphi panel consisting of 15 occupational health experts estimated the exposure prevalence of noise in workplace. Data on Industrial Accident Compensation Insurance provided from Occupational Safety and Health Research Institute were combined to produce the exposure population. Results: In Korea, 16.0% of employees, 2,539,890 out of 15,838,926, was estimated to exposed to noise occupationally. The rate was 32.7% and 10.3% in manufacturing sector and non-manufacturing sector, respectively. The highest rate, 52.5%, was found in manufacturing industries of wood and of products of wood and cork(except furniture) and of other transport equipment. Sorted by their size of business, the rate was higher as the number of employee was larger in manufacturing sector. Conclusions: Compared to the same rate estimated in the US, 17.2%, the result of this study seems to be in a resonable range.