• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.1
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• pp.26-36
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• 2023

공군 조종사들이 비행 중에 겪는 지속적이고 강도 높은 소음은 조종사의 생리적(physiological) 및 심리적(psychological) 상태에 부정적인 영향을 미칠 수 있다. 이는 조종사의 비행 능력(performance)에 부정적인 영향을 주게 되며 임무 완수 및 비행 안전을 저해시키는 치명적인 결과로 이어질 수 있다. 대한민국 공군은 조종사들의 청력 보호를 위해 수동 소음 감쇠(Passive Noise Cancellation, PNC) 및 능동 소음 감쇠(Active Noise Cancellation, ANC) 기술이 적용된 헤드셋 및 헬멧을 사용 중이다. 그러나, 소음 저감 기술이 조종사의 청력 보호, 비행 능력, 및 비행 안전에 미치는 효용성에 대한 공군 조종사의 인식은 아직 연구된 바가 없다. 따라서 본 연구는 소음과 관련된 이론적 배경을 고찰하였고, 이후 설문조사를 통해 공군 조종사들(n=154)의 조종석 내 소음 및 소음 감쇠 기술에 대한 인식을 분석하였다. 분석 결과, 능동 소음 감쇠(ANC) 기술이 적용된 헤드셋 및 헬멧의 사용은 소음이 조종사의 생리적 상태에 미치는 영향에는 유의미한 효과가 없지만(p=0.402), 심리적 상태에 미치는 영향은 유의미하게 감소시키는 것으로 나타났다(p<0.001). 따라서, 능동 소음 감쇠(ANC) 기술이 적용된 비행 헤드셋 및 헬멧 사용의 필요성을 강조하였고, 이를 통해 조종사의 비행 능력(performance) 저하 방지 및 비행 안전 증진에 기여하고자 한다.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.104-110
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• 2009

It is well known that the saponin of Korean red ginseng (KRG) has an anti-oxidant effect and could suppress the accumulation of lipid peroxidation. The aim of the present study was to observe the inhibitory effect of KRG on mice with noise-induced hearing loss, and to determine its optimal dose. BALB/c mice with a normal hearing level and normal Preyer's reflexes were used in the study. The mice in the permanent-threshold-shift (PTS) group were exposed to noise (120-dB SPL, white noise band) in a noise booth for 3 h a day, for three consecutive days. The mice in the experimental group were given heat-processed red-ginseng extract (50 mg/kg, 100 mg/kg, and 200 mg/kg), and those in the control group were given normal saline alone during their noise exposure. The mice in the temporary-threshold-shift (TTS) group were exposed to noise (120 dBSPL, white noise band) in a noise booth for 3 h. The mice in the experimental group were given heat-processed red-ginseng extract (50 mg/kg, 100 mg/kg, and 200 mg/kg), and those in the control group were given normal saline alone before their noise exposure. The hearing levels of the mice were measured through auditory brainstem response (ABR) immediately and I, 3, 5, 7, and 14 days after their noise exposure. Cochleae were removed from the mice 14 days after their noise exposure. lmmunochemical and immunofluorescent staining were performed to observe the expression of 8-oxoG in cochlea. In the PTS group, the hearing function of the mice in all the groups was not recovered after their noise exposure. In the TTS group, however, the hearing function of the mice in all the groups was recovered within 14 days. Reduced hearing impairment and early recovery were observed in the mice that were given 200 mg/kg KRG, and early recovery was observed in the mice that were given 100 mg/kg KRG The immunopositive staining of 8-oxoG was detected in the stria vascularis in the control group but was diminished in the mice that were given 200 mg/kg KRG The ingestion of more than 100 mg/kg KRG demonstrated a protection and recovery effect on the noiseinduced-TTS group. Since KRG has been reported to be a safe compound even up to hundreds of mg/kg, a higher concentration of it may effectively protect and recover TTS.

• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.736-746
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• 2010

Purpose: This study was done to identify the distribution and related factors for stage of change for wearing hearing protection devices (HPDs) by workers in environments with high noise. Predictors of Use of Hearing Protection Model and Trans-theoretical Model were tested. Methods: The participants were 755 workers from 20 noisy work places in Busan and Gyeongnam. Data were collected from January to April 2008 using self-administered questionnaires, and analyzed using multiple logistic regression. Results: There were significant differences in social mode (OR=1.35, 95% CI: 1.06-1.73) between precontemplation/contemplation and preparation stage, in males (OR=2.36, 95% CI: 1.24-4.51), workers with high school education or less (OR=1.39, 95% CI: 1.28-2.78), shift workers (OR=1.50, 95% CI: 1.02-2.21), workers who previously worked in noisy places (OR=1.39, 95% CI: 1.20-2.34), and workers who had previous hearing examinations (OR=1.89, 95% CI: 1.25-2.85), in the social model (OR=1.59, 95% CI: 1.42-1.78), and self-efficacy (OR=1.05, 95% CI: 1.02-1.08) between workers in preparation and action stages, in length of time working in noisy work places (OR=2.26, 95% CI: 1.17-4.39), social model (OR=1.66, 95% CI: 1.33-2.08), and perceived benefit (OR=0.95, 95% CI: 0.93-0.97) between action and maintenance stage. Conclusion: Social model was a common factor showing differences between two adjacent stages for wearing HPDs. The results provide data for developing programs to encourage workers to wear HPDs and application of these programs in work settings.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.3 no.1
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• pp.21-35
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• 1995

Nowadays aviation noise significantly affects a number of people over the world. This paper is mainly focused on the effect of temporary and permanent hearing loss of cockpit crew, flight attendants, passengers, persons in communities exposed to aircraft overflight. Also this paper describes the human hearing mechanism and the processes of temporary and permanent hearing loss. The results of research are presented and the potential for hearing loss in aviation noise environments evaluated. The Occupational Safety and Health Administration (OSHA) hearing protection criteria are also addressed.

• The Journal of Korean Academy of Sensory Integration
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• v.7 no.1
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• pp.59-69
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• 2009

Objective : The purpose of the study is to examine the length of institutionalization and sensory modulation for preschooler without disabilities, and to investigate the relationship between the length of institutionalization and behavioral problem. Method : Mothers of preschoolers without disabilities between ages of 3 and 7 who attend D kindergarten was participated. Nursery school teacher of institutionalized children without disabilities between ages of 3 and 7 who attend child-welfare facilities was participated. We used Short Sensory Profile(SSP) and Children Behavior Check list. The results were analyzed with SPSS 11.0. Results : There was no significant difference between longer length of institutionalization and shorter length of institutionalization in sensory modulation and behavioral problem. Regarding the sensory modulation and behavior problem according to child-welfare facilities, means showed the statistically significant difference. Regarding sensory modulation of test items, movement sensitivity and low energy/weak showed the statistically significant difference in home-reared children than institutionalized children. Conclusions : The results of the study showed high correlation environmental effect in institutionalized children. Further research is needed to improve environmental for institutionalized children.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.103-106
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• 2013

During a military service, noise has unusual characteristics, and constitutes a serious hazard to hearing of military servicemen. The purpose of this study is to understand the use of hearing protection and to assess the safety effects of hearing protection by using a ear plug in military. A total of 208(the army : 101, an air force : 107) serviceman were studied utilizing a questionnaire to know how many serviceman use the hearing protection and a total of 202(the army : 110, an air force : 92) serviceman were also studied using a ear fit validation device to assess the safety effects of hearing protection by using a ear plug. The results showed that the army have low used of hearing protection than an air force because of the low frequency of the noise exposure in the army. Personal attenuation rate was increased with 8 dB after fitting education. Therefore, it is recommended that use of proper hearing protection and fitting education was more suitable for military servicemen who were being exposed of the noise in domestic military.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.57-63
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• 1984

To assess the hearing conservation by the hearing protection devices in the field, 1,237 healthy female weavers of 16 to 24 year old were surveyed from April 1982 to January 1983. By reviewing the charts, their working durations, hearing threshold shift levels and whether wearing the ear plugs or not were checked. The hearing threshold levels were measured at 4,000Hz by audiometry AA-30A, RION Japan. They were divided into two groups: an experimental group with ear plug and the control group without it. The threshold shift level above 40dB in controls was 44.6% in left and 40.9% in right ear and that in experimental group 8.0% in left and 6.6% in right ear. The distribution of threshold shift levels between control and experimental group was significantly different in both ears, but that between left and right ear not significantly different in both groups. The longer the working durations were, the more the proportion of high threshold shift levels was and the larger the differences in the proportion of above 40dB between both groups were.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.16-30
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• 1986

In order to prepare the fundamental data for the improvement of noisy working environments and the effective hearing conservation program on workers exposed to industrial noise, the authors surveyed the working processes and evaluated the noise levels on 56 manufacturing industries in Pusan area from April to July in 1985. The results were summarized as follows : 1. The noise level was the highest in shipbuilding and repairing(95.6 dBA), and followed by steel rolling(94.0 dBA), manufacture of motor vehicles(93.1 dBA), manufacture of fishing nets(92.9 dBA), manufacture of testiles(92.5 dBA), iron and steel foundries(89.3 dBA), manufacture of metal products(89.1 dBA), preserving and processing of marine foods(87.0 dBA), manufacture of rubber products(85.3 dBA), manufacture of plywood(84.9 dBA) and manufacture of paints(84.5 dBA). 2. Among fifty surveyed working processes, the noise level of twenty-one processes (42%) exceeded the threshold limit value for 8 hours per day. 3. As the allowable exposure times by governmental threshold limit values to industrial noise level(dBA), cocking of shipbuilding and repairing and plating(CGL) of steel rolling were the shortest(30 minutes), and followed by assembling(rivet) of manufacture of motor vehicles(1 hour) weaving of manufacture of textiles and shot, machine, pipe laying of shipbuilding and repairing(2 hours). 4. By the result of octave band analysis on noisy working processes in excess of 90 dBA, the sound level was the highest at 2,000 Hz or 4,000 Hz. 5. It was recognized that the measurement of overall sound pressure level was also effective as octave band analysis in evaluating the industrial noise.