• 한국환경과학회지
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• 제16권2호
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• pp.171-178
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• 2007

It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and tile water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period($1961{\sim}2005$) in Daegu and Chupungnung. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Daegu is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon. But, it is different compared with Japanese huge cities such as Tokyo, Osaka and Nagoya, indicating a standstill in relative humidity change after 1980s.

• Journal of Advanced Marine Engineering and Technology
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• 제37권3호
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• pp.260-265
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• 2013

Impressed current cathodic protection (ICCP) system is one of the most promising corrosion protection methods. The Effect of ICCP system can be changed at diverse conditions. Particularly, temperature and relative humidity plays a crucial role in CP (Cathodic Protection) effect. Thus, in this study, the influence of temperature and relative humidity on concrete specimens was investigated. Specimens were concrete slab type with a base of $400mm{\times}400mm$ and height of 70mm. To enhance the effect of CP system, seawater was used as an electrolyte. Used anode for ICCP system was mixed metal oxide (MMO) titanium. Test factors were natural potential, CP potential, CP current, and 4-hour depolarization potential. From this study, it could be confirm that CP potential and current were highly influenced by temperature and relative humidity.

• 무역학회지
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• 제46권2호
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• pp.337-354
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• 2021

Several previous studies have not been able to derive consistent research results on the impact of the level of corruption in local countries on foreign direct investment. Therefore, in order to suggest that this study should consider the relative level of corruption rather than the level of absolute corruption, 1) first, examine the moderating effect of the absolute level of corruption on the determinants of foreign direct investment, and 2) examine the moderating effect of the relative corruption on the determinants of foreign direct investment. This study collected 9-year data from 2012 to 2020 based on the Corruption Perceptions Index (CPI) published by Transparency International. A total of 549 observations (country-year) from 82 countries were sampled and a generalized estimation equation (GEE) analysis was performed. As a result of empirical analysis, it was found that the moderating effect of absolute corruption did not appear, whereas the moderating effect of relative corruption reversed the negative (-) relationship between cultural distance and foreign direct investment into a positive (+) relationship. Based on these empirical results, this study suggest that Korean companies need to consider the relative level of corruption with Korea instead of the absolute level of corruption of the investee when conducting foreign direct investment.

• 대한수학회논문집
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• 제33권2호
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• pp.485-494
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• 2018

In this paper some newly developed results based on the growth properties of relative order (relative lower order), relative type (relative lower type) and relative weak type of entire and meromorphic functions on the basis of integer translation applied upon them are investigated.

• 응용통계연구
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• 제34권5호
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• pp.697-710
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• 2021

상대오차를 이용한 예측법은 상대오차(혹은 퍼센트오차)가 중요시되는 분야, 특히 계량경제학이나 소프트웨어 엔지니어링, 또는 정부기관 공식통계 부분에서 기존 예측방법 외에 선호되는 예측방법이다. 그 동안 상대오차를 이용한 예측법은 선형 혹은 비선형 회귀분석 뿐 아니라, 커널회귀를 이용한 비모수 회귀모형, 그리고 정상시계열분석에 이르기까지 그 범위가 확장되어 왔다. 그러나, 지금까지의 분석은 고정효과(fixed effect)만을 고려한 것이어서 임의효과(random effect)에 관한 상대오차 예측법에 대한 확장이 필요하였다. 본 논문의 목적은 상대오차예측법을 일반화선형혼합모형(GLMM)에 속한 감마회귀(gamma regression), 로그정규회귀(lognormal regression), 그리고 역가우스회귀(inverse gaussian regression)의 패널자료(panel data)에 적용시키는데 있다. 이를 위해 실제 자동차 보험회사의 손해액 자료를 사용하였고, 최량예측량과 최량상대오차예측량을 각각 적용-비교해 보았다.

• 대한토목학회논문집
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• 제7권3호
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• pp.175-181
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• 1987

개단 강관말뚝의 선단지지력은 폐색 효과에 의하여 발생되는데 이 폐색 효과는 말뚝의 직경에 대한 관입깊이의 비 즉, 상대 관입깊이와 밀접한 관계가 있는 것으로 알려져 있다. 이에 본 연구에서는 폐색 효과를 종합적으로 평가하기 위하여 지반의 상대밀도와 모형말뚝의 상대 관입 깊이를 달리하여 재하시험을 수행하였으며 개단 말뚝의 유효직경을 축소시킬 목적으로 십자 모양의 칸막이 판을 선단에 부착한 모형말뚝에 대한 시험도 병행하였다. 그 결과로서 개단 말뚝은 말뚝의 극한 지지력을 기준으로 폐색효과를 평가할 때 말뚝 타설 지반이 단단할수록 작은 상대관입깊이에서 큰 폐색효과를 얻을 수 있으나 100%의 폐색효과는 지반의 상대밀도에 상관없이 대략 상대관입깊이 25 정도에서 발휘된다는 사실을 알았다. 그리고 칸막이 판의 설치로 인한 폐색효과의 증대는 기대하기 어려운 것으로 판단된다.

• 대한수의학회지
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• 제36권1호
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• pp.131-142
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• 1996

The effect of relative humidity in swine house on swin pleuropneumonia was examined in piglets experimentally infected with Actinobacillus pleuropneumoniae serotype 5. A total of 20 piglet were grown under 30~40%, 41~50%, 51~64% and 65~80% relative humidity chambers after intratracheal inoculation of A pleuropneumoniae. Characteristic fibrinous pleuropneumonia was observed in the pigs grown at the low relative humidity groups. The detailed results were as follows : 1. Growth performance and environment conditions were lower than high relative humidity groups. 2. Characteristic histopathological findings were fibrinous pleuritis and pneumonia accompanied congestion, hemorrhage, thrombosis and edematous change. 3. Antigenic distribution of inoculated bacterium was found mainly in alveolar macrophages or accumulated foci of macrophages adjacent to necrotic area. 4. Characteristic electron microscopic findings were proliferation of type II pneumocyte with increased lamella bodies and activated alveolar macrophages with pseudopods and widening of interstitium.

• International Journal of Ocean System Engineering
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• 제4권1호
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• pp.1-18
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• 2014

Heave plates have been widely used to enhance viscous damping and thus reduces the heave response of Spar platforms. Single heave plate attached to the keel of the Spar has been reported in literature (Tao and Cai 2004). The effect of double heave plates on hydrodynamic response in random waves has been investigated in this study. The influence of relative spacing $L_d/D_d$ ($D_d$-the diameter of the heave plate) on the hydrodynamic response in random waves has been simulated in wave basin experiments and numerical model. The experimental investigation has been carried out using 1:100 scale model of Spar with double heave plates in random waves for different relative spacing and varying wave period. The influence of relative spacing between the heave plates on the motion responses of Spar are evaluated and presented. Numerical investigation has been carried out to investigate effect of relative spacing on hydrodynamic characteristics such as heave added mass and hydrodynamic responses. The measured results were compared with those obtained from numerical simulation and found to be in good agreement. Experimental and numerical simulation shows that the damping coefficient and added mass does not increase for relative spacing of 0.4 and the effect greater than relative spacing on significant heave response is insignificant.

• 대한안전경영과학회지
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• 제25권1호
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• pp.51-58
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• 2023

Determination of explosion reference pressure is important in designing and testing flameproof enclosures (Ex d). Although relative humidity affects to explosion pressure, its effect is not well investigated for the gas group IIB, IIA, and I. This study tested explosion pressure for Ethylene (8 vol.%), Propane (4.6 vol.%), and Methane (9.8 vol.%), which are the representative gas of the gas group IIB, IIA, and I, at ambient temperature and atmospheric pressure (1 atm) under different relative humidity (0% ~ 80%). Ethylene- and Propane-air mixed gases generally tended to decrease as the relative humidity increased; however, explosion pressure was largely dropped at 20% of relative humidity compared to 0% and 10% of relative humidity. On the other hand, Methane-air mixture gas showed similar pressures at 0% and 10% of relative humidity; but no explosion occurred at more than 20%. The results of this study can be used in setting a testing protocol of explosion reference pressure for designing and testing a flameproof enclosure.

• 한국환경과학회지
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• 제13권6호
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• pp.591-597
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• 2004

In this study, sixty chemicals including 47 pesticides were screened for estrogenic activity using E-screen assay. MCF-7 cell, used in E-screen assay, is known to be proliferated by addition of estrogenic chemicals. Eight of the measured pesticides showed estrogenic activity at the concentration range of 100-10,000nM. Their relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 20-65% and 0.01-1.0%, respectively, when compared with 1.0nM of $\beta-Estradiol-17-acetate(E_{2}).$ DDVP and diazinone showed most strong estrogenic potency(RPP; 1.0%) and effect(RPE; 65%) of the eight pesticides. These results are in agreement with estrogenic activity of bisphenol A is known as a positive endocrine disrupter. Also, in this study, paraquat, DDVP, 4-chloro-3-methylphenol, 2,4,6-trichlorophenol and diazinon of the measured pesticides are estimated to estrogenic chemical.