• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.175-179
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• 2007

수중 천이 신호를 탐지하기 위한 기존의 기법은 에너지 변화와 스펙트럼 변이를 이용한 것으로 백색잡음 환경에서 탐지가 잘 되지만 유색잡은 환경에서는 탐지가 잘 되지 않는다. 본 논문에서는 백색잡은 환경과 유색잡음 환경에서 수중 천이 신호의 탐지성능을 높이기 위해 Double-Density 이산 웨이블렛 변환과 CFAR Power-Law기법을 이용한다.

• 대한가정학회지
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• 제41권12호
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• pp.147-168
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• 2003

The researcher worked with 1001 middle and high school students so as to inquire into family-related variables affecting adolescents' school life maladjustment, relying on average, standard deviation and hierarchical regression. The following are the major findings. 1) The research shows that to look into school life maladjustment on the basis of analysis models including family environment variables and family relationship variables in addition to family background variables offers more explanatory power. 2) Of all the variables, parent relationship variables turned out to have the greatest influences on maladjustment to teacher relationship and teaming activity areas among the subordinate areas of school life maladjustment. 3) Of all the variables, family's physical variables have the greatest influence on maladjustment to regulation-keeping relationship and opposite sex relationship among the subordinate areas of school life maladjustment. 4) Of all the variables, sibling relationship variables have the greatest influence on maladjustment to friendship among the subordinate areas of school life maladjustment. 5) Parent relationship variables have the greatest influence on total school life maladjustment followed by family physical environment, structural environment, the number of family members, cultural environment and residential variables in the right order.

• 대한건축학회논문집:구조계
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• 제34권2호
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• pp.83-90
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• 2018

This study was conducted to investigate the living environment of semi-basement housing units in multi-household houses. It analyzed measurements of temperature and humidity obtained from the housing units. For this study, temperature and humidity sensors were installed in 10 semi-basement housing units to measure interior temperature and humidity for 13 months. A survey was conducted to get information about the occurrence of dew condensation and mildew and to investigate residents' satisfaction level with the residential environment. According to the result, all the housing units under study had dew condensation and mildew. The average summer temperature of the 10 housing units was $27.84^{\circ}C$, and average humidity was 64.91%RH, while the average winter temperature was $20.6^{\circ}C$, and the average humidity was 40.12%RH. Depending on the condition of each housing unit, deviation was big. Residents' average level of satisfaction with the living condition was 2.03 which shows a low satisfaction (on a scale of 1-5 with 5 being completely satisfied.).

• 설비공학논문집
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• 제27권11호
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• pp.596-602
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• 2015

In this study, experiments using bioelectronic signals and questionnaire surveys were carried out in learning conditions when temperatures changed from low- and high-uncomfortable to comfortable. As a result, the stress factor Photoplethysmography (PPG) decreased, while the Root Mean Square of Standard Deviation (RMSSD) of PPG increased when the indoor temperature was changed from low- or high-uncomfortable to comfortable. Additionally, the absolute power of the ${\alpha}$-wave in the brain increased. According to the analysis of the association between the questionnaire and bioelectronic signals, the standard deviation of the stress factor as measured by pulse was closely related to the result of the thermal sensation questionnaire. In addition, it was found that the concentration on studying improved under comfortable temperatures when compared to uncomfortable temperatures.

• 한국도로학회논문집
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• 제11권2호
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• pp.159-166
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• 2009

고속도로에서 교통사고에 중요한 두 영향요소는 운전자요소와 도로환경요소로 구분되어 진다. 그동안 여러 연구에서 도로환경요소중 설계요소로 알려진 곡선반경, 종단경사, 편경사, 관찰속도와 교통사고와 관련성을 연구하였고 그 밀접한 관련성을 제시하고자 하였다. 본 논문에서는 이들 관련요소 크기가 교통사고와 관련성이 깊다는 사실에 대하여 상관관계분석을 통하여 확인하고자 하였다. 이에 더하여 이들 설계관련요소의 표준편차를 설계일관성으로 정의하고 교통사고의 증감과 비교하여 봄으로써 표준편차로 특징 지워지는 설계요소와 설계속도의 일관성이 교통사고 발생과 상관성이 깊다는 사실을 도출하였다. 본 논문의 결과는 선형설계과정에서 설계일관성의 수치화된 활용을 더 활성화시킬 것으로 기대된다.

• 한국환경과학회지
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• 제18권8호
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• pp.857-865
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• 2009

The physical properties of an atmospheric boundary layer in Wolryong, a west coastal region of Jeju, South Korea, in terms of the atmospheric stability and roughness length, is important and relevant to both engineers and scientists. The study is aiming to understand the atmospheric stability around this region and its effect on the roughness length. We calculate the Monin-Obukhov length(L) against 3 typical regions of the atmospheric condition - unstable regime (-5$-0.2{\leq}H/L{\leq}0.2$) and stable regime (0.2

• 한국전자파학회지:전자파기술
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• 제4권2호
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• pp.4-10
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• 1993

이동통신에서, 전파경로는 이동국의 위치변동때문에 시간 및 공간에 따라 변한다. 전파경로 손실은 주 파수와 거리뿐만 아니라 안테나 높이, 지형구조와 인위적 환경에 따라 탄라지브로 이동 전파신호의 전파 경로손실을 예측하기는 매우 어렵다. 본 고에서는 대전 및 서울 지역에서 전계강도를 측정하여 단구간 중앙치,500m 거리별 평균치 및 표준 편차를 산출하여 분석하였다. 분석 결과, 경로손실 특성이 예측모텔과 유사하였으며, 특히 단구간 중앙치 는 기지국 안테나 높이, 지형구조와 인위적 환경에 의존하며, 표준편차는 2-1OdBuV사이에 있음을 알 수 있다.

• 센서학회지
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• 제25권4호
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• pp.291-296
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• 2016

The ideal chemical sensor must show the similar result under the same condition for accurate measurement of gases regardless of time. However, the actual responses of chemical sensors have been shown the lacks of repeatability and reproducibility because of the drift which has been caused by aging and pollution of the sensor and the environment change such as temperature and humidity. If the problems are not properly taken into considerations, the stability and reliability of the system using chemical sensors would be decreased. In this paper, we analyzed the sensor's drift and applied the three different compensation methods(DWT( Discrete Wavelets Transform), Baseline Manipulation, Internal Normalization) for reducing the effects of the drift in order to improve the stability and the reliability of short term of the chemical sensors. And in order to compare the results of the methods, the standard deviation was used as a criterion. The sensor drift was analyzed by a trend line graph. We applied the three methods to the successive data measured for three days and compared the results. As a result of comparison, the standard deviation of DWT showed lowest value. (Before compensation: 7.1219, DWT: 1.3644, Baseline Manipulation: 2.5209, Internal Normalization: 3.1425).

• KIEAE Journal
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• 제9권4호
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• pp.23-28
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• 2009

Standard sound source currently used in heavy-weight floor impact sounds that cause many social problems has excessive low-frequency energy within a range from 63 Hz to 125 Hz, and is difficult to evaluate and measure. To solve these problems, studies are widely performed using a new impact source, the impact ball. In this study, the sound fields in a receiving room were compared and analyzed according to the current impact source, the bang machine, and the impact ball. And deviation of sound pressure level according to the impact source positions were compared. In case of impact ball, the sound pressure level was lower at 63 Hz and below and higher at 125 Hz and above. The same trend was observed at the low-frequency range on the horizontal and vertical planes, regardless of the type of the impact source, which showed the influence of the room mode. There was a problem with the variations in the sound pressure level according to the size or shape of the receiving room. And it also shows that change of source positions may effect the single number rating scheme.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.936-939
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• 2015

현재, 영상처리는 다양한 분야에서 활용되고 있으며, 영상을 전송, 처리, 저장하는 과정에서 발생하는 잡음을 제거하기 위해, 영상복원에 관한 많은 연구가 진행되고 있다. 영상에 첨가되는 잡음은 발생원인과 형태에 따라 다양한 종류가 있으며, AWGN(additive white Gaussian noise)이 대표적이다. 본 논문에서는 영상에 첨가된 AWGN을 완화하기 위해, 표준편차에 따라 필터의 가중치를 다르게 적용하는 알고리즘을 제안하였다. 그리고 객관적 판단을 위해 기존의 방법들과 비교하였으며, 판단의 기준으로 PSNR(peak signal to noise ratio)을 사용하였다.