• Journal of Korea Water Resources Association
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• v.51 no.10
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• pp.875-886
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• 2018

This study evaluated drought severity by bivariate frequency analysis using drought magnitude and precipitation deficit. A drought event was defined by Standardized Precipitation Index (SPI) and the precipitation deficit was estimated using reference precipitation corresponding to the SPI -1. In previous studies, drought magnitude and duration were used for bivariate frequency analysis. However, since these two variables have a largely linear relationship, extensibility of drought information is not great compared to the univariate frequency analysis for each variable. In the case of drought in 2015, return periods of 'drought magnitude-precipitation deficit' in the Seoul, Yangpyeong, and Chungju indicated severe drought over 300 years. However, the result of 'drought magnitude-duration' showed a significant difference by evaluating the return period of about 10, 50, and 50 years. Although a drought including the rainy season was seriously lacking in precipitation, drought magnitude did not adequately represent the severity of the absolute lack of precipitation. This showed that there is a limit to expressing the actual severity of drought. The results of frequency analysis for 'drought magnitude-precipitation deficit' include the absolute deficit of precipitation information, so which could consider being a useful indicator to cope with drought.

• Journal of Korea Water Resources Association
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• v.45 no.10
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• pp.983-995
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• 2012

In this study, it was intended to analyze the spatio-temporal distribution of historical drought events occurred in Korea by way of drought frequency analysis using SPI (Standardized Precipitation Index), and Drought spell was executed to estimate drought frequency as per drought severity and regions. Also, SDF (severity-duration-frequency) curves were prepared per each weather stations to estimate spatial distribution characteristics for the severe drought areas of Korea, and Potential Drought Hazard Map was prepared based on the derived SDF curves. Drought frequency analysis per drought stage revealed that severe drought as well as extreme drought frequency were prominently high at Geum River, Nakdong River, and Seomjin River basin as can be seen from SDF curves, and drought severity was found as severer per each drought return period in the data located at Geum River, Nakdong River, and Seomjin River basins as compared with that of Seoul weather station at Han River basin. In the Potential Drought Hazard Map, it showed that Geum River, Seomjin River, and Yeongsan River basins were drought vulnerable areas as compared to upper streams of Nakdong River basin and Han River basin, and showed similar result in drought frequency per drought stage. Drought was occurred frequently during spring seasons with tendency of frequent short drought spell as indicated in Potential Drought Hazard Map of different season.

• Journal of Ecology and Environment
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• v.41 no.5
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• pp.132-141
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• 2017

The importance of forests continues to increase throughout the world, and one of the reasons is that a forest is a major place to emit terpenes, which have been reported to be beneficial to human health. In South Korea, forests occupy about 64% of the total land area and consist mainly of pine and oak trees. Since only a limited number of forests have been analyzed to date, a comprehensive understanding of terpenes emitted from regional forests remains in its infancy in Korea. Here, to gain insights into terpenes from regional forests located in South Korea, we review the characteristics of Korean forests and recent studies on major terpenes emitted from regional forests as well as from native trees dominant in South Korea. We also discuss meteorological factors that affect the terpene emissions in Korean forests. In conclusion, 18 types of terpenes were detected in Korean forests and their compositions in different forests are largely dependent on the dominant plant species in the forest. Moreover, terpene emissions in Korean forests are affected by various environmental factors, including temperature, amount and duration of daylight, season, and age of trees. To improve the understanding of the characteristics of terpene distribution, more studies are required on the terpene production of Korean forests in various regions.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.1
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• pp.26-30
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• 2015

Tropical Tasar culture is forest and agro-based activity that covers agricultural and industrial activity. Tasar silk is produced by the silkworm, Antheraea mylitta which is polyphagous in nature. A large number of pests are reported to attack both the host plant as well as silkworm. As the rearing is conducted outdoor silkworms are exposed to attack of various pests during their life cycle. Eocanthecona furcellata (Hemiptera: Pentatomidae) is the major predator of tasar silkworm during young age rearing. Both nymphs and adults of the stink bug suck the heamolymph of silkworm leading to death. The present work was undertaken to study the life cycle of E. furcellata on larvae of vapourer tussock moth which is a major pest of tasar host plants. The incubation period, nymphal duration and total developmental period from egg to adult was $8.0{\pm}0.45d$, $16.0{\pm}3.24$ and $22.0{\pm}4.20d$, respectively. Pre-oviposition, oviposition and longevity of male and female stink bug was $3.20{\pm}0.38$, $17.60{\pm}1.86$, $42.40{\pm}1.94$, $37.00{\pm}3.18d$, respectively. Analysis of the data revealed no significant difference in life cycle of the predator when provided silkworm and vapourer tussock moth larvae as hosts. Which clearly indicates that E. furcellata can multiply on vapourer tussock moth larvae during non rearing periods. Adoption of recommended pest control measures for defoliators of tasar host plants during non-rearing periods will help in reducing the incidence of host plant pests and also in reducing the incidence of stink bug during rearing season. During the study it was also observed that larvae semilooper, boll headed caterpillar and nymphs of leaf hopper serve as alternate/secondary hosts to E. furcellata during non rearing seasons.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.679-688
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• 2008

Air-heating vaporizer usually is used to regasify LNG at satellite areas because of the small demand of natural gas there. The common type of air heating vaporizer which exists in the market is the longitudinally finned type with 8 fins, 55 mm fin length and 2mm fin thickness. To contribute in developing an efficient air-heating vaporizer, experiment on finned type air-heating vaporizer using 8 fins, 50mm(fin length) with 2 mm(fin thickness) which exist in the market and 4 fins, 75 mm(fin length) with 2 mm(fin thickness), which is proposed, were conducted. Then, both types of vaporizers are compared. The experiments were conducted in one hour by varying the ambient condition and the length of the vaporizer. The ambient air was controlled so that it has the same temperature, humidity and air velocity with air condition in every season available and the length was varied 4000 mm, 6000 mm and 8000 mm for each type of vaporizer. Additional experiment with longer duration, i.e. In this experiment, the main aspects in analyzing the characteristics of the air heating vaporizer the inlet-outlet enthalpy difference and the outlet temperature of the working fluid. $LN_2$ is used to substitute LNG because of safety reason. The results show that the characteristics of the finned type 4fin75le vaporizer are comparable to finned type 8fin50le vaporizer.

• Atmosphere
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• v.21 no.1
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• pp.109-121
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• 2011

This study revisits the definition of Changma, which is the major rainy season in Korea and corresponds to a regional component of the East Asian summer monsoon system. In spite of several decades of researches on Changma, questions still remain on many aspects of Changma that include its proper definition, determination of its onset and retreat, and relevant large-scale dynamical and thermodynamical features. Therefore, this study clarifies the definition of Changma (which is a starting point for the study of interannual and interdecadal variability) using a basic concept of air mass and front by calculating equivalent potential temperature (${\theta}_e$) that considers air temperature and humidity simultaneously. A negative peak in the meridional gradient of this quantity signifies the approximate location of Changma front. This front has previously been recognized as the boundary between the tropical North Pacific air mass and cold Okhotsk sea air mass. However, this study identifies three more important air masses affecting Changma: the tropical monsoon air mass related to the intertropical convergence zone over Southeast Asia and South China Sea, the tropical continental air mass over North China, and intermittently polar continental air mass. The variations of these five air masses lead to complicated evolution of Changma and modulate intensity, onset and withdrawal dates, and duration of Changma on the interannual time scale. Importantly, use of ${\theta}_e$, 500-hPa geopotential height and 200 hPa zonal wind fields for determining Changma onset and withdrawal dates results in a significant increase (up to~57%) in the hindcast skill compared to a previous study.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.31 no.1
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• pp.81-90
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• 2018

Objectives : This study was performed to investigate the characteristic of Seborrheic Dermatitis(SD) patients who visited Korean medicine clinics. Methods : The study was carried out with 140 SD outpatients who visited fourteen Gowoongyul Korean traditional medical clinics from January to December 2016 and was completed by reviewing patients' survey. Results : 1. Among 140 patients, there were 61 male patients(43.6%), 79 female patients(56.4%). The average age of the patients was $32.6{\pm}10.9years$ old, with many in their 20s and 30s in the distribution. 2. The average duration of disease was $4.2{\pm}4.11years$. 3. 80% of the patients had experience of treatment, 58.6% only took Western medicine, 17.1% had experience of both Western and Korean medicine treatment, and 4.3% received only Korean medicine treatment. 4. Analysis of seasonal effects of SD showed that 48.6% of the respondents reported that skin disease always appeared regardless of the season, with 33.6% in winter, with 29.3% in summer and 25.7% in seasonal change. 5. The rate of family history of seborrheic dermatitis was low(6.4%), and 75.7% of the patients answered that they had no family history of skin disease. 6. The major lesion of SD appeared on face(87.9%) and scalp(36.4%). 7. 70.7% answered they do some kind of self-managements. 70.0% used moisturizers. Bathing therapy was performed in 17.1%, and 55% were taking the health supplement food, and 35.7% restricted the avoidance diet such as instant and fatty foods. Conclusions : This study demonstrated the various clinical characteristics of Korean patients with seborrheic dermatitis.

• Sleep Medicine and Psychophysiology
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• v.5 no.2
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• pp.170-176
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• 1998

Nowadays light therapy is accepted practice in the treatment for Seasonal Affective Disorder. The author reviewed the practical aspects of light therapy, latest treatment research on optimal parameters of light therapy and the mechanisms of action of light therapy. Therapeutic efficacy of light therapy using light visors & dawn simulators has been suggested but further studies are needed to clarify the efficacy. The treatment most strongly supported by research studies is light therapy using a light box to administer bright white light (2500 lux for 2 hours or 10000 lux for 30 minutes). Although some patients may be selective responders to morning light exposure, the optimal timing of light exposure still remains controversial. In practice, generally the duration of exposure can be increased or decreased as necessary and also the timing of exposure can be splitted (e.g. AM/PM usage) if optimal response is obtained. For most, a positive response of light therapy is usually noted within $4{\sim}5\;days$ and optimal response is obtained within 2 weeks. Generally the relapse of symptom occurs within days of discontinuation of light therapy, so to prevent relapse, light therapy should be continued throughout the winter season for typical seasonal affective disorder. Side effects of light therapy appear to be mild and well tolerated. Several theories for the mechanisms of action of light therapy at the basis of seasonal affective disorder had been suggested but remain still controversial. Further studies on the optimal parameters and the mechanisms of light therapy help us to better understand and treat not only seasonal affective disorders but also chronobiological disorders and nonseasonal affective disorders.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.2 s.57
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• pp.93-97
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• 2006

Staphylococcus aureus is found on the skin of $78{\sim}100%$ of children and adults with atopic dermatitis (AD) but only on the skin of $2{\sim}25%$ of healthy subjects. It is known that S. aureus and their endotoxins as superantigen have important roles in the exacerbation and prolongation of AD. This study was carried out for the detection of S. aureus in the skin of AD, age, sex, outbreak age of AD, treatment duration, aggravation season, and the relation of ooze and S. aureus. Most patients (84%) with AD show colonization of the skin with S. aureus and there is a correlation between the degree of colonization and the serous exudate. It seems likely that the inhibition of S. aureus is associated with improvement in the skin of AD patients.

• Journal of Korean Society of Health-System Pharmacists
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• v.35 no.4
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• pp.400-408
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• 2018

Background : Palivizumab is an intravenous monoclonal antibody which is used in the prevention of respiratory syncytial virus (RSV) infection. It is currently recommended for infants who are at high-risk for RSV infections due to preterm birth or other medical conditions such as congenital heart disease. Palivizumab is a humanized monoclonal antibody directed against an epitope in the antigenic site A of the protein F of RSV particles. Palivizumab is given once a month via intramuscular (IM) injection throughout the duration of the RSV season. Since palivizumab is known to have preventive effects against RSV infection for children with older siblings, the insurance coverage for palivizumab was expanded in October 2016. Methods : The electronic medical records of children under 2 years old who have older siblings who visited or were admitted to the Severance Hospital from October 2015 to May 2016 and from October 2016 to May 2017 were reviewed retrospectively. The data were then divided into two groups depending on the pilivizumab administration. Results : A total of 67 patients were enrolled in this study. The effectiveness in the reduction of hospitalization was statistically significant (p=0.009). Palivizumab decreased respiratory symptoms such as cough, rhinorrhea, and fever in patients with older siblings (p 0.05). Conclusions : In this study, palivizumab administration was effective in preventing RSV infection in infants with older siblings. Expanding palivizumab-prophylaxis administration to infants with older siblings may be effective in the prevention of upper respiratory infections.