• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.6
• /
• pp.77-87
• /
• 2009

Potential risks of communicable disease outbreaks have significantly increased in the era of global society. However, contingency planning of local governments for communicable diseases is not prepared to the proper level in various governmental sectors of many countries. Human being has been remarkable advances in medical science and public health. However, Severe Acute Respiratory Syndrome (SARS) still remains as a very dangerous transmissible disease that has great potential to create catastrophic consequences of casualties. The SARS outbreak between November 2002 and July 2003 resulted in 8,096 known infected cases and 774 deaths with a mortality rate of 9.6% worldwide (WHO, 2004). It is regarded as one of the human health disasters. Since about sixty-six percent of total SARS cases in the world were reported in People's Republic of China, Korean tour industry was significantly affected as a neighboring country. The objective of this research is to investigate major factors of Korea entry data sets, and to analyze economic impacts of Korean tour business interruption due to the period of SARS outbreak with tourist cases of four countries: Japan, U.S.A., China, and Taiwan. Results from this research show the seasonal and long-term trends of entry data sets of four countries, and direct and indirect impacts of SARS to Korean tour industry.

• Journal of the Korean earth science society
• /
• v.21 no.5
• /
• pp.623-634
• /
• 2000

This study was conducted to analyze the patterns associated with the short-term variability of CO$_2$ concentrations over 24-h scale within and across the Korean Peninsula. In the course of our study, we compared the data sets obtained from Moo-Ahn (MAN) station located in the far western coastal area of Korea with those determined from major background observatory stations around the world from the periods of Aug. 1995 to Dec. 1997. The mean CO$_2$ concentration of the MAN area for the whole study periods, when computed using the daily mean values, was found out to be 374.5${\pm}$6.6 ppm (N=884); seasonal mean values were found out to be 378${\pm}$5.2 (spring: N=181), 372${\pm}$10.2 (summer: N =210), 372${\pm}$7.2 (fall: N=243), and 376${\pm}$5.4 ppm (winter: N=206). When the data from MAN was compared with those of major background stations, the effects of both daily and seasonal components appear to vary distinctively across different stations. Those effects are expected to reflect the mixed effects of various factors which include: seasonal pollution patterns, weather conditions, vegetation, and so forth. Based upon this comparative analysis, we suspect that the MAN area is under the strong influence of anthropogenic source processes relative to all the other stations under consideration. If that is not the case, the existence of enhanced CO$_2$ level may be rather ubiquitous phenomena in Korea. More detailed inspection of CO$_2$ behavior from various respects is strongly desired in the future.

• Journal of Korea Water Resources Association
• /
• v.42 no.5
• /
• pp.385-396
• /
• 2009

The spatial distribution of precipitation trends according to urbanization, geographical and topographical conditions have been studied. In this study, precipitation data from 1973 to 2006 were analyzed for 56 climatological stations including the Seoul metropolis in South Korea. In addition to annual average daily precipitation, monthly average daily precipitation in April, July, October and January were analyzed, considering seasonal effect. The geographical and topographical characteristics of these sites were examined using GIS analysis. Land use status of the study area was also examined to estimate the extent of urbanization. The study results indicate that annual average precipitation increased, and monthly average precipitation in April and October decreased, while those in January and July increased. Considering urbanization effect, annual average precipitation and monthly average precipitation in July increased; however, monthly average precipitation in January, April and October decreased. Furthermore, compared with urbanization rate and proximity to coast, average elevation of study area appeared to be the most close correlation with annual and monthly averages of precipitation trends.

• Journal of Advanced Navigation Technology
• /
• v.26 no.5
• /
• pp.249-260
• /
• 2022

Student pilots receiving flight education are inexperienced in piloting and situation judgment skills and are greatly affected by various factors such as psychological, physical, and environmental factors. In particular, one of the most influential factors in the flight education of student pilots is the weather conditions. Unlike large aircraft used in the air transportation business, small aircraft used for flight education have a great impact on education, such as flight restrictions depending on weather conditions, psychological pressure in severe weather, and deterioration of student skills. Therefore, in this study, the meteorological characteristics of meteorological factors that have a great influence on small aircraft were analyzed. As a result of the analysis, an efficient and safe training operation method was suggested to a professional pilot aviation training organization through the adjustment of the training period for the season, the increase in aircraft operation rate, and a safe solo flight plan considering the weather.

• Korean Journal of Environment and Ecology
• /
• v.34 no.1
• /
• pp.55-62
• /
• 2020

To estimate headwater stream temperature with seasonal variations, we analyzed precipitation, runoff and air temperature in experimental forest of Kangwon National University, Gangwon-do (2017~2018 years). The daily mean value of headwater stream temperature for spring was 6.9~17.7℃ and correlated with air temperature, that for summer and fall were 12.2~26.3℃ and 3.6~19.3℃, correlated with air temperature and runoff. Based on seasonal variations, we applied for stepwise multiple linear regression analyses to estimate headwater stream temperature with seasonal variations. The equations were headwater stream temperature(WT)_spring=(0.553×Air temperature)+(0.086×Runoff)+4.145 (R²=0.505; p<0.01), WT_summer=(0.756×Air temperature)+(-0.072×Runoff)+2.670 (R²=0.510; p<0.01), and WT_fall=(0.738×Air temperature)+(0.028×Precipitation)+2.660 (R²=0.844; p<0.01). The coefficient of determination (R²) was greater than when it was estimated by air temperature in all seasons and progressively increased from spring to winter. Therefore, we indicated difference on estimated magnitude of stepwise multiple linear regression, due to effects on headwater stream temperature of different environmental factors with seasonal variations. Furthermore, temporal factors with spatial characteristics (e.g., river versus headwater stream) could be recommended for estimating headwater stream temperature.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.7 no.2
• /
• pp.51-59
• /
• 2002

The seasonal variation in species composition and abundance distribution of zooplankton was studied in the Seomjin river estuary along the salinity gradients. In this estuary, marine taxa predominated in all seasons and very limited number of freshwater species appeared. The total abundances showed a seasonal fluctuation. The highest total abundance appeared in spring with over 3,000 individuals/m$^3$. In summer, the high abundance was sustained although it decreased a little. The abundance was minimal in fall with about 500 individuals/m$^3$. When the study area was divided into three salinity regimes, oligohaline (salinity less than 5 psu), mesohaline (5${\sim}$18 psu), and polyhaline zone (over 18 psu), the zone of high abundance as well as the composition of zooplankton community in each salinity regime changed seasonally. In fall, marine copepods predominated in oligohaline zone while marine species other than crustaceans dominated in polyhaline zone. However, in winter copepods predominated in all area. In spring and summer, holozoic dinoflagellate Noctiluca scintillans dominated in higher salinity regimes. We listed major copepod species of each salinity regime for each season with the ranges of water temperatures (T) and salinities (S) of their occurrence. T, S's of maximum abundances of those major copepod species were also reported. The observed very wide tolerance ranges of major copepod species for salinity suggested that the concept of 'indicator species' should be used in quantitative context rather than qualitative.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.647-658
• /
• 2018

The aim of this study is to investigate the seasonal changes of phytoplankton communities based on the environmental changes in a dense oyster farming area (Hansan-Geoje Island) from June to December 2016. The water temperature varied from $14^{\circ}C$ to $28.8^{\circ}C$ and its salinity ranged from 29.4 to 34.2 psu. Nitrate+nitrite was kept at c.a. $3.0{\mu}M$ on the surface layer from June to July, below the concentration limit in August and early September, and then gradually increased from late September. Ammonia was high on July 20 and August 10, and its seasonal characteristics were not clear. Phosphate ranged from 0.01 to $0.7{\mu}M$ on the surface layer, and its seasonal changes were similar to those of nitrate+nitrite. Mean silicate concentrations were $10.7{\mu}M$ on the surface and $15.7{\mu}M$ in the bottom layer, and it was not acted as a limiting factor for the growth of phytoplankton. Among the phytoplankton community, Bacillariophyceae, Dinophyceae and Cryptophyceae was 61.2%, 22.5%, and 13.6%, respectively. In late June, dinoflagellate Prorocentrum donghaiense was dominant in the outer waters(St. T1), later on, Cryptomonas spp. and Chaetoceros spp. were dominant, respectively. From late September to October, diatoms Pseudo-nitzschia spp. and Chaetoceros spp. were stimulated under non-stratified condition after the typhoon. In December, A. sanguinea was found to be $1.7{\times}10^5cells\;L^{-1}$. Seasonally, relative high phytoplankton biomass may be favorable to maintain high production of filter feeder oyster in the dense oyster farming areas of Hansan and Geoje Island.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.2
• /
• pp.150-158
• /
• 1993

In order to investigate the content and seasonal variation of the extractive components including taste compounds, free amino acids, nucleotides and related compounds, quanternary ammonium bases, and guanidino compounds of ascidian collected from the south coast of Korea were determined bimonthy from April to October in 1990. The extractive nitrogen was composed of $60{\sim}62\%$ as free amino acids, $12{\sim}16\%$ as betaines, $5{\sim}9\%$ as nucleotides, and others as trimethylamine oxide(TMAO) and total creatinine. The muscle of ascidian was rich in such free amino acids as taurine, proline, glutamic acid, glycine and glycinebetaine. Most of nitrogenous compounds in the extractives showed a marked seasonal variation with a maximum in summer or autumn. AMP content was relatively high among nucleotides. Succinic acid, malic acid, lactic acid and pyroglutaric acid were the major organic acids in ascidian. The results of omission test suggested that the taste of ascidian is attributed to mainly free amino acid, betaines, nucleotides and nonvolatile organic acid in order.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.294-295
• /
• 2011

전력수급계획은 소비자의 전력 사용량을 예측하고 적정한 공급능력을 확보하는 것이 목적인데, 수요예측 정확도를 향상시키고 전력설비를 적기에 준공시킬수록 적정공급능력 확보가 용이하다. 그러나 최근 전력수요는 계절적, 시간대별로 경향이 과거와는 상이하게 나타나고 있는데 이로 인해 발전기를 예방 정비할 수 있는 기간이 짧아지고 있다. 한편 향후 몇 년간은 준공되는 발전기가 적어 중/단기 수급계획이 더욱 어려울 전망이다. 따라서 최근 수요추세를 고려하여 수요예측 정확도를 향상시키고 현재보다 탄력적인 부하감축제도 시행이 요구된다.

• The Korea Swine Journal
• /
• v.18 no.6 s.202
• /
• pp.166-171
• /
• 1996

여름철이 되면 평균 기온이 27도씨이상 되는 무더운 날씨가 계속되고 장마로 인하여 습도가 높아지면 불괘지수가 높아져서 관리자들도 모든 일이 짜증스럽고 주위가 산만해지기 쉬운 계절이다. 또한 여름철에는 양돈장에 파리와 모기 등의 해충이 많이 발생하고 유해 가스가 많이 생기며 사료가 쉽게 변질되는 등으로 돼지의 사육에 직접 간접으로 불리하게 미치는 영향이 커서 발육이나 번식 능력을 떨어뜨리게 된다. 특히 돼지는 선천적으로 다른 가축에 비하여 땀샘이 퇴화되고 피하지방이 두껍고 체지방축적이 많은 관계로 더위에 매우 약하므로 무더움 여름철에는 신진대사와 호르몬 분비 조절기능이 비정상적인 경우가 많아 사료섭취량 감소, 발육 지연 및 번식 성적에 관련되는 발정, 배란, 수태율, 산자수 등이 감소하게 된다. 따라서 무더운 날씨가 계속되는 여름철에는 다른 계절보다 돼지의 사육에 적합한 온도, 습도, 환기 등에 많은 관심을 기울여서 쾌적한 사육 환경을 조성하여 생산성을 높일 수 있도록 하고 그 중에서도 여름철에 돼지의 수태율을 향상시킬 수 있는 관리 대책을 강구해야겠다.