• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.11-14
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• 2007

Noise level and Airflow amount of a kitchen hood are affected by the conditions of airflow path. Thus this study is expected to be used as a basic reference in designing airflow path of apartment housing throughout analysing changes in noise level and airflow amount from the various conditions of airflow path. Noise level generated by the kitchen hood is estimated in a kitchen and a living room of two constructed apartment houses, and an experiment is conducted in an half anechoic chamber to analyze noise level and airflow amount by the different length, diameter and number of windings of a round shaped soft duct which is connected to the kitchen hood. The measured results in apartment houses show that the noise level in both apartments exceeds the NC standard greatly in living spaces. In apartment A, a regular apartment house, the noise level was $NC-65{\sim}75$, $NC-45{\sim}60$ and NC-70, NC-45 in the kitchen and living room with an operation of kitchen hood in 1 and 3 stages. In apartment B, an apartment complex, the noise level was NC-55 and NC-60 in the kitchen and living room with an operation of kitchen hood in 3 stages. In particular, there was an increase of noise level at 125Hz-band resulted from an amplification of sound, which requires adequate measures in noise reduction. The results measured in Half anechoic chamber show 99% of airflow amount increase with the modification of a duct' s diameter from ${\Phi}$ 100mm to ${\Phi}$ 125mm, 37% of airflow amount increase with the modification of a duct' s diameter from ${\Phi}$ 125mm to ${\Phi}$ 150mm, and 173% of airflow amount increase with the modification of a duct' s diameter from ${\Phi}$ l00mm to ${\Phi}$ 150mm. The noise level was lower than the level measured in apartment housing about 20 in NC-value and 11.4 in dB(A)-value, which was interpreted as the effect of the load by the pressure condition at the rear end of the duct. Also, an amplification of sound in 125Hz-band influenced NC-value considerably, therefore effective measure is needed.

• 생물정신의학
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• 제21권4호
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• pp.168-174
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• 2014

Objectives Sensory gating dysfunctions in patients with schizophrenia and bipolar disorder have been investigated through two similar methods ; P50 suppression and prepulse inhibition paradigms. However, recent studies have demonstrated that the two measures are not correlated but rather constitute as distinct neural processes. Recent studies adopting spectral frequency analysis suggest that P50 suppression reflects the interaction between gamma and other frequency bands. The aim of the present study is to investigate which frequency component shows more significant interaction with gamma band. Methods A total of 108 mood disorder patients and 36 normal subjects were included in the study. The P50 responses to conditioning and test stimuli with an intra-pair interval of 500 msec were measured in the study population. According to P50 ratio (amplitude to the test stimulus/amplitude to the conditioning stimulus), the subjects with P50 ratio less than 0.2 were defined as suppressed group (SG) ; non-suppressed group (NSG) consisted of P50 ratio more than 0.8. Thirty-five and 25 subjects were included in SG and NSG, respectively. Point-to-point correlation coefficients (PPCCs) of both groups were calculated between two time-windows : the first window (S1) was defined as the time-window of one hundred millisecond after the conditioning auditory stimulus and the second window (S2) was defined as the time-window of 100 msec after the test auditory stimulus. Spectral frequency analysis was performed to investigate which frequency band results in the difference of PPCC between SG and NSG. Results Significant reduction of PPCC between S1 and S2 was observed in the SG (Pearson's r = 0.24), compared to PPCC of the NSG (r = 0.58, p < 0.05). In spectral frequency analysis, gamma band showed "phase-reset" and similar responses after the two auditory stimuli in suppressed and non-suppressed group. However in the case of alpha band, comparison showed significantly low PPCC in SG (r = -0.14) compared to NSG (r = 0.36, p < 0.05). This may be reflecting "phase-out" of alpha band against gamma band at approximately 50 msecs after the test stimulus in the SG. Conclusions Our study suggests that normal P50 suppression is caused by phase-out of alpha band against gamma band after the second auditory stimulus. Thus it is demonstrated that normal sensory gating process is constituted with attenuated alpha power, superimposed on consistent gamma response. Implications of preserved gamma and decreased alpha band in sensory gating function are discussed.

• 대한안전경영과학회지
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• 제17권2호
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• pp.107-115
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• 2015

The study targeted Japanese employees who have visited hospital for spinal disorder. The study analyzed work environment and pain relief methods of work-related back pain patients, and the relationship between back pain and other body parts. The purpose of this study was to provide draw up measures for patients with back pain and to provide basic data for the sustainable prevention program. The study result of back pain, in other words, employees suffering from lumbago, had disparity between occupations; the highest number of patients were made up of 16-years or above long-serving employees, and below 5-years of short-serving employees. There were more patients complaining of chronic lumbago than acute lumbago, and patients recognized poor posture as the primary cause of lumbago. Furthermore, 99.5% of spinal disorder patients complain back pain, 23.2% use only alternative therapy, and 15.2% visit clinic and hospital with alternative therapy. Patients showed pain reduction and high satisfaction after using alternative therapy. The study targeted Japanese employees where complement therapy is more generalized than that of Korea, and thus there should be multilateral management programs provided in Korea as well.

• 한국습지학회지
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• 제21권4호
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• pp.354-364
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• 2019

스리랑카는 지리적으로 섬으로 형성된 국가로 기후변화에 민감한 나라이다. Kurunegala시는 2009년부터 2019년까지 약 11년 동안 도심지 내 연평균 기온이 0.69±0.37℃로 꾸준하게 증가하였으며, 강우패턴도 변화하고 있다. 그러나 도시 개발 계획시 기후변화 및 기후재난에 대한 규정이 미흡하여 인적 및 물적 피해가 우려되고 있다. 따라서 본 연구는 스리랑카 Kurunegala시의 인문학적 및 자연적 특성을 조사분석하고 기후변화 적응에 대한 방안을 수립하기 위하여 수행되었다. Kurunegala시의 기후변화 적응방안은 기후변화에 대한 정성적 위험 평가를 수행하여 개발하였다. 정성적 위험평가 결과 Kurunegala시의 주요 문제점은 음용수, 수자원 및 건강 관련 인프라로 분석되었다. 물부족 및 도시 내 온도를 완화하기 위한 방안으로는 기존 사회인프라에 비점오염저감, 도시 열섬현상 저감 및 건전한 물순환 체계 구축 등 다양한 효과를 유도하는 저영향개발기술(Low Impact Development, LID)의 적용이 효과적인 것으로 나타났다. 본 자료는 Kurunegala시와 같이 기후변화에 따른 물문제를 안고 있는 도시의 물문제 해결에 활용될 수 있다.

• 한국환경보건학회지
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• 제36권5호
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• pp.391-401
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• 2010

A reduction in risk of occupational exposure to chemical hazards within the workplace has been the focus of attention both through industry initiatives and legislation. The aims of this study were to develop an exposure matrix by industry and process, and to apply this matrix to control the risk of occupational exposure to Dichloromethane (DCM). The exposure matrix is a tool to convert information on industry and process into information on occupational risk. The exposure matrix comprised industries and processes involving DCM, based on an exposure database provided by KOSHA (the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. The risk assessment of the exposure matrix was performed using Hallmark risk assessment tool. The results of the risk assessment were indicated by a Danger Value (DV) calculated from the combination of hazard rating (HR), duration of use rating (DUR), and risk probability rating (RPR) of exposure to the chemical, and were divided into four control bands which were related to control measures. The applicability of the risk assessment of the exposure matrix was evaluated by a field study, and survey of the employees of the exposure matrix groups. Among 45 industries examined, this study found that greater attention should be paid to two industries: the manufacture of other optical instruments and photographic equipment, and the manufacture of printing ink, and to one process among 47 examined, the packing process in the manufacture of printing ink, because these were regarded as carrying the highest risk. This tool of a risk assessment for the exposure matrix can be applied as a general exposure information system for hazard control, risk quantification, setting the occupational exposure limit, and hazard surveillance. The exposure matrix includes workforce data, and it provides information on the numbers of exposed workers in Korea by agent, occupation, and level of exposure and risk.