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        검색결과 132

        82.
        1986.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The author tried to clarify the distribution of the total length and body weight of the file h, Navodos modcstus, caught by trawl net during July, 1984 in the southern sea korea. Among the catches of five times fishing operation, 1540 individuals were randomly sampled for the measurement. The results are summarized as follows; " The distribution of total length showed bimodal type, wbich was able to analyzed into two normal distributions N(17.46, 1. 022) and N(22.09, 1. 772). And smaller group was much than older one. The age of the sample estimated from the total length distribution of. smaller group was 1. 5 to 2, and the larger group 2. 5 to 4. The relationship between the total length and the body weight can be presented as following equation: W=0.01726 L2.8507 ' or W= 0.01109 L3.0 or W= 0.01109 L3.0
        3,000원
        83.
        1984.12 구독 인증기관 무료, 개인회원 유료
        여름철에 분무(噴霧) 수경재배(水耕栽培)를 통(通)해 옥수수의 청초(靑草) 사료(飼料) 생산(生産)에 관(關)한 실험(實驗)을 하기 위하여 1985년(年) 6월(月) 28일(日)부터 7월(月) 17일(日) 까지 경북대학교내(慶北大學校內) 비닐하우스에서 실시(實施)한 본(本) 실험(實驗)의 결과(結果)를 요약(要約)하면 다음과 같다. 1) 24시간(時間) 침종(浸種)후 48시간(時間) 전처리(前處理)한 다음 치상한 것이 생육(生育)에 좋다고 사료(思料)된다. 2) 육묘(育苗) 상자당(箱子當) 450 g 치상한 것이 생초(生草) 1kg 생육(生育)에 드는 종자(種子)값이 가장 적게 들었다. 3) Hyponex 1,000배, Yogen 300배로 영양제(營養劑)를 매일(每日) 산포(散布)하는 것이 생체중(生體重)이 가장 무거웠고, 2일(日)에 1회(回) 산포시(散布時)는 Yogen 300배로, 3일(日)에 1회(回) 산포시(散布時)는 Hyponex 500배로 산포(散布)하는 것이 좋다고 사료(思料)된다. 그러나 생초(生草) 1 kg 생육(生育)에 드는 최소(最少)의 종자(種子)값만 73만원 정도(程度)의 비용(費用)이 들므로 여름철엔 청초(靑草) 사료(飼料) 구입(購入)이 용이(容易)한 계절(季節)인 관계(關係)로 여름철에 별(別)로 효과적(效果的)인 방법(方法)이 못된다고 사료(思料)된다.
        4,000원
        84.
        2022.06 KCI 등재 서비스 종료(열람 제한)
        This research investigated the effect of the eruption of Japan Sakurajima volcano on the concentration of ultrafine particle when the north Pacific high pressure exists in the Busan in summer. As a result of analyzing the forward trajectory using the HYSPLIT model, the air parcel from Sakurajima volcano passed through the sea in front of Busan at 1500 LST on July 17, 24 hours after the volcanic eruption. As a result of analyzing the PM10 and PM2.5 concentrations in the Busan for two days from July 16 to 17, 2018, the Sakurajima eruption in Japan, it can be seen that there was a high increase in PM10 and PM2.5 concentrations compared to the previous day. As a result of analyzing the backward trajectory, the air mass that reached Busan at 1300 LST on July 17, 2018 has moved near the Sakurajima volcano at 1,500 m, 2,000 m, and 3,000 m. The concentration of SO4 2- in PM2.5, the concentration of all three stations in Busan showed a sharp increase from 1000 LST on July 17th. Looking at the NH4 + concentration in PM2.5, it shows a very similar variation trend to SO4 2-, and the correlation coefficient between the two components is 0.96 for Jangrimdong and Yeonsandong, and 0.85 for Busan New Port. Looking at the NO3 - concentration in PM2.5, the same high concentrations as SO4 2- and NH4 + were not observed in the afternoon of July 17th.
        85.
        2021.10 KCI 등재 서비스 종료(열람 제한)
        The relationship between night cooling rate and meteorological elements was investigated over the past five years (2016-2020), using weather data from the new (Daegu(143)) and old (Shinam(860)) Daegu Regional Meteorological Agency located in the suburban and urban regions, respectively. There was a correlation between the total daily amount of solar radiation (Stot) and the night cooling rate in the both regions. However, a higher correlation was observed at the new Daegu Regional Meteorological Agency station (Daegu(143)). In particular, data from the new Daegu Regional Meteorological Administration's observatory, which experiences a low thermal storage effect caused by artificial structures, showed a higher correlation between nighttime cooling and weather factors. The reason for this is that the lesser the heat storage effect caused by the artificial structures, the better the effect of surface radiation cooling on temperature reduction. These findings confirm that the correlation between night cooling and weather factors can be used to assess the impact of artificial structures in cities.
        86.
        2021.06 KCI 등재 서비스 종료(열람 제한)
        This research investigated the characteristics of fine particle concentration and ionic elements of PM2.5 during sea breeze occurrences during summertime in Busan. The PM10 and PM2.5 concentrations of summertime sea breeze occurrence days in Busan were 46.5 ㎍/㎥ and 34.9 ㎍/㎥, respectively. The PM10 and PM2.5 concentrations of summertime non-sea breeze occurrence days in Busan were 25.3 ㎍/㎥ and 14.3 ㎍/㎥, respectively. The PM2.5/PM10 ratios of sea breeze occurrence days and non-sea breeze occurrence days were 0.74 and 0.55, respectively. The SO4 2-, NH4 +, and NO3 - concentrations in PM2.5 of sea breeze occurrence days were 9.20 ㎍/㎥, 4.26 ㎍/㎥, and 3.18 ㎍/㎥ respectively. The sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) of sea breeze occurrence days were 0.33 and 0.05, respectively. These results indicated that understanding the fine particle concentration and ionic elements of PM2.5 during sea breeze summertime conditions can provide insights useful for establishing a control strategy of urban air quality.
        87.
        2021.03 KCI 등재 서비스 종료(열람 제한)
        This paper has presented not only the spatial coverage change of climate extreme events in summer and winter seasons during the period of 2000-2017, but also their future projections in 2021-2100, South Korea through analysis of a Combined Climate Extreme Index (CCEI). The CCEI quantifies the spatial coverage of climate extreme events based on a set of five indicators. MK (Modified Korean)-PRISM (Parameter-elevation Regression on Independent Slopes Model)v1.2 (1×1km) and RCP scenario data (1×1km) were applied to CCEI. Results indicated that in average, 21.7% of the areas in the summer and 23.6% in the winter experienced climate extremes from 2000 to 2017 regardless of types of climate extreme events in South Korea. The summer of 2003 and 2009 was relatively cool and humid, while the summer of 2014 and 2015 was cool and dry and the summer of 2016 was warm and dry. The extreme events with much above normal maximum and minimum temperature during the study period were detected but not much below normal maximum and minimum temperature after 2015. For RCP2.6 and RCP8.5 scenarios, there were statistically significant trends with spatial coverage expansion of climate extreme events in the future. It might be concluded that climate extreme events in the summer and winter seasons were affected simultaneously by two or more indicators than a single indicator in South Korea.
        88.
        2021.03 KCI 등재 서비스 종료(열람 제한)
        We examined the ocean forcing, associated with the different trends in precipitation between North and South Korea, using GPCC V2018 precipitation and OISST V2 sea surface temperature (SST) for the recent thirty years of 1982-2011. As a result of linear regression, the precipitation trends in the monsoon (June and July) and post-monsoon (August and September) seasons were different between North and South Korea, respectively, with increased and decreased trends, during the both monsoon seasons. During the monsoon season, the results of detrended correlation and composite analysis showed the opposite relationships of precipitation with SSTs in the equatorial Pacific and Arctic Oceans between North and South Korea. It was identified that large-scale atmospheric circulation linked to ENSO can differently affect the Korean Peninsula. On the other hand, during the post-monsoon season, the correlation and composite patterns across the oceans in the Northern Hemisphere were generally similar for the two Koreas. It was suggested that near the ocean of the Korean Peninsula and the land surface forcings might affect the precipitation variability during the post-monsoon season, especially in North Korea.
        89.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        In this study, the impact of cumulus parameterization usage in Weather Research and Forecasting (WRF) model on reproducing summer precipitation in South Korea is evaluated. Two sensitivity experiments are set up with using cumulus parameterization (ON experiment) and without using cumulus parameterization, which is called Convection Permitting Model (OFF experiment). For the both ON and OFF experiments, the horizontal grid resolution is 2.5km, and initial and lateral boundary conditions are derived from ERA5 reanalysis data. Overall, both of the two experiments can capture the spatial distribution of 2014 summer mean and extreme precipitation but show dry biases in the southern region of Korean Peninsula. Occurrence percentage analyses for different precipitation intensity reveal that OFF experiments show better performance than ON experiment for extreme precipitation. In the case of heavy rainfall over Gyeongnam region for 25 August 2014, OFF experiment shows similar characteristic of rainfall to the observations, although it simulates earlier precipitation peak. On the other hand, ON experiment underestimates the amount of precipitation. Also, vertical distribution of equivalent potential temperature and strong southerly wind which play an important role in developing heavy rainfall on 25 August 2014 are better simulated in OFF experiment.
        90.
        2020.07 KCI 등재 서비스 종료(열람 제한)
        This research investigated the meteorologically relevant characteristics of high PM2.5 episodes in Busan. The number of days when daily mean PM10 concentration exceeded 100 ㎍/m3 and the PM2.5 concentration exceeded 50 ㎍/m3 over the last four years in Busan were 24 and 58, respectively. Haze occurrence frequency was 37.6% in winter, 27.4% in spring, 18.6% in fall, and 16.4% in summer. Asian dust occurrence frequency was 81.8% in spring, 9.1% in fall and winter, and 0% in summer. During summer in Busan, high PM2.5 episode occurred under the following meteorological conditions. 1) Daytime sea breeze. 2) Mist and haze present throuout the day. 3) Anti-cyclone located around the Korean peninsula. 4) Stable layer formed in the lower atmosphere. 5) Air parcel reached Busan by local transport rather than by long-range transport. These results indicate that understanding the meteorological relevance of high PM2.5 episodes could provide insight for establishing a strategy to control urban air quality.
        91.
        2020.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the spatio-temporal patterns of summertime thermal environments in the two subtropical cities (Jeju and Seogwipo) of Jeju Island, Korea are examined. Long-term average data from Jeju and Seogwipo show that higher human sensible temperature (HST) than air temperature (T) due to the high humidity effects associated with warm sea surface temperature around Jeju Island is most distinct during mid-summer period (late July-early August). Comparatively, their trend analyses reveal that summertime intra-seasonal changes with more increasing HST than T are most obviously observed in late summer (late September-early October) and regionally in Seogwipo. According to the hourly temperature-humidity data measured at approximately 30 HOBO temperature-humidity sensors deployed in the two subtropical cities during 2019 summer, the greater HST than T during mid-summer period maximizes up to 6.2°C and 7.0°C across the urban areas of Jeju and Seogwipo, respectively in early afternoon, leading to consecutive inter-daily heat wave events. The examination of their spatial patterns demonstrates that bioclimatic heat waves in these two subtropical cities are affected primarily by the urban heat island phenomenon. However, it should not be overlooked that local moisture advection from the warm ocean adjacent to the subtropical cities can modify the stronger heat wave pattern toward urban cores. It is also notable that according to comparisons of local HST and T distributions between impervious urban cores and neighboring urban parks, not only the size of green space but also other ecological properties including species of vegetation may be crucial factors to the mitigation of hot thermal environments in subtropical cities during summers.
        92.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        Climate change affects the occurrence of heat waves in Korea. Heat wave gives significant impacts not only to human health, but also adversely affects on traffic accidents both directly and indirectly. This study analyzed heat wave impacts on traffic accidents in summer time (JJA) from 2012 to 2017 timely. To consider some occupations work in earlier or later than regular working hour, 04~20h is set for this study. Generalized additive model is used to analyze the relation between the temperature and traffic accidents. The results showed that the traffic accidents in high temperature increases in 04~08h, 08~12h, and especially 18~20h. The percent difference for relative risk of traffic accidents is 2.34% (95% confidence interval: 1.140, 3.269) when the temperature increase by 1°C in 18~20h. The results of this study suggest some requirements for measures to prevent traffic accidents in the morning and evening hours with increasing temperatures.
        93.
        2019.07 KCI 등재 서비스 종료(열람 제한)
        This study investigated the relationship between heat-related illnesses obtained from healthcare big data and daily maximum temperature observed in seven metropolitan cities in summer during 2013~2015. We found a statistically significant positive correlation (r = 0.4~0.6) between daily maximum temperature and number of the heat-related patients from Pearson's correlation analyses. A time lag effect was not observed. Relative Risk (RR) analysis using the Generalized Additive Model (GAM) showed that the RR of heat-related illness increased with increasing threshold temperature (maximum RR = 1.21). A comparison of the RRs of the seven cities, showed that the values were significantly different by geographical location of the city and had different variations for different threshold temperatures. The RRs for elderly people were clearly higher than those for the all-age group. Especially, a maximum value of 1.83 was calculated at the threshold temperature of 35℃ in Seoul. In addition, relatively higher RRs were found for inland cities (Seoul, Gwangju, Daegu, and Daejeon), which had a high frequency of heat waves. These results demonstrate the significant risk of heat-related illness associated with increasing daily maximum temperature and the difference in adaptation ability to heat wave for each city, which could help improve the heat wave advisory and warning system.
        94.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Agricultural or rural landscape provides various ecosystem services. However, the ecosystem services function is declining due to various environmental problems such as climate change, land use change, stream intensification, non-point pollution and garbage. The A1B scenario predicts that the mean air temperature of South Korea will rise 3.8℃ degrees celsius in 2100. Agricultural sector is very vulnerable to climate change, so it must be thoroughly predicted and managed. In Korea, the facility horticulture complex is 54,051ha in 2016 and is the 3rd largest in the world(MAFRA, 2014). Facilities of horticultural complexes are reported to cause problems such as groundwater decrease, vegetation and insects diversity reduction, landscapes damage and garbage increase, compared with the existing land use paddy fields. Heat island phenomenon associated with climate change is also accelerated by the high heat absorption of horticultural sites. Therefore, we analyzed the heat island phenomenon occurring in the facility of horticultural complex in Korea. As an improvement measurement, I examined how much air temperature is reduced by putting the channel and the open space. In the case of the Buyeo area, the Computational Fluid Dynamics (CFD) simulation was analyzed for the average summer temperature distribution in the current land use mode at 38.9℃. As an improvement measurement, CFD simulation after 10% of 6m water channel was found to have an effect of lowering the summer temperature of about 2.7℃ compared with the present average of 36.2℃. In addition, CFD simulations after analyzing 10% of the open space were analyzed at 34.7℃, which is 4.2℃ lower than the present. For the Jinju area, CFD simulations were analyzed for the average temperature of summer at 37.8℃ in the present land use pattern. As an improvement measure, CFD simulations after 10% of 6m water channel were found to have an effect of lowering the summer temperature of about 2.6℃ compared to the current average of 35.2℃. In addition, CFD simulations after analyzing 10% of the open space were analyzed at 33.9℃, which is 3.9℃ lower than the present. It can be said that the effect of summer temperature drop in open space and waterway has been proven. The results of this study are expected to be reflected in sustainable agriculture land use and used as basic data for government - level policy in land use planning for climate change.
        95.
        2018.03 KCI 등재 서비스 종료(열람 제한)
        The interannual variability of summer temperature during June-August (JJA) in South Korea was associated with geopotential height averaged in the East Sea (Korea-Japan Index, KJI) and in the subtropical western North Pacific (Western North Pacific Subtropical High Index, WNPSHI). The KJI was coupled with a decaying El Niño one month in advance, while the WNPSHI was influenced by Sea Surface Temperature (SST) anomaly in the western North Pacific and a developing El Niño one to three months ahead. Additionally, the JJA temperature over South Korea was affected by SST anomaly in the western North Pacific in May. Based on these teleconnections, a multivariate regression model using the SST surrogates for the KJI and WNPSHI and an univariate model using an area-averaged May SST were developed to reconstruct the JJA temperature over South Korea. Both of the empirical models reproduced the JJA and monthly temperatures reasonably well. However, when the simulated SSTs from global climate models were used, the multivariate model outperformed the univariate model. Further, for JJA temperature prediction, the multivariate model with 6-month lead SST outstripped one-month lead prediction of global climate models. Therefore, the empirical-dynamical approach can pave a promising way for summer temperature prediction in South Korea.
        96.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Persistent Extreme Temperature Events (PETEs) are defined in two steps; first, to define extreme temperature events, the 80th and 20th percentiles of daily maximum and minimum temperature were chosen. Then individual PETE was defined as an event which lasted three or longer consecutive extreme temperature days. In this study, we examined characteristics and changes of PETEs in Republic of Korea (ROK) using 14 weather stations with a relatively long-term period of data, 1954-2016. In ROK, PETEs lasted four-five days on average and occurred two-three times a year. PETEs lasted longer in summer than in winter and in maximum temperature than in minimum temperature. PETEs which lasted greater than seven days account for a greater proportion in summer than in winter. However, intensities of PETEs were greater in winter because of a larger temperature fluctuation. In both summer and winter, durations and intensities of persistent extreme high temperature events increased while those of persistent extreme low temperature events decreased. Changes of PETEs were closely related with both global warming and diverse large-scale climate variabilities such as AO, NAO and Nino 3.4.
        97.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        In order to investigate the effect of air temperature reduction on an urban neighborhood park, air temperature data from five inside locations (forest, pine tree, lawn, brick and pergola) depending on surface types and three outside locations (Suwon, Maetan and Kwonsun) depending on urban forms were collected during the summer 2016 and compared. The forest location had the lowest mean air temperature amongst all locations sampled, though the mean difference between this and the other four locations in the park was relatively small (0.2-0.5℃). In the daytime, the greatest mean difference between the forest location and the two locations exposed to direct beam solar radiation (brick and lawn) was 0.5-0.8℃ (Max. 1.6-2.1℃). In the nighttime, the mean difference between the forest location and the other four locations in the park was small, though differences between the forest location and locations with grass cover (pine tree and lawn) reached a maximum of 0.9-1.7℃. Comparing air temperature between sunny and shaded locations, the shaded locations showed a maximum of 1.5℃ lower temperature in the daytime and 0.7℃ higher in the nighttime. Comparing the air temperature of the forest location with those of the residential (Kwonsun) and apartment (Maetan) locations, the mean air temperature difference was 0.8-1.0℃, higher than those measured between the forest location and the other park locations. The temperatures measured in the forest location were mean 0.9-1.3℃ (Max. 2.0-3.9℃) lower in the daytime than for the residential and apartment locations and mean 0.4-1.0℃ (Max. 1.3-3.1℃) lower in the nighttime. During the hottest period of each month, the difference was greater than the mean monthly differences, with temperatures in the residential and apartment locations mean 1.0-1.6℃ higher than those measured in the forest location. The effect of air temperature reduction on sampling locations within the park and a relatively high thermal environment on the urban sampling locations was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with a high sky view factor and surface types with high evapotranspiration potential (e.g. grass) showed the maximum air temperature reduction. In the urban areas outside the park, the low-rise building area, with a high sky view factor, showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, while in the nighttime the area with high-rise buildings, and hence a low sky view factor, showed high air temperature due to the effect of terrestrial (longwave) radiation emitted by surrounding high-rise building surfaces. The effect of air temperature reduction on the park with a high thermal environment in the city was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with high sky view factor and surface types (e.g., grass) with evapotranspiration effect showed maximum air temperature reduction. In the urban areas outside the park, the high sky view factor area (low-rise building area) showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, but in the nighttime the low sky view factor area (high-rise building area) showed high air temperature due to the effect of terrestrial (longwave) radiation emitted surrounding high-rise building surfaces.
        98.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        We studied the distribution of air temperature using the high density urban climate observation network data of Daegu. The observation system was established in February 2013. We used a total of 38 air temperature observation points (23 thermometers and 18 AWSs). From the distribution of monthly averaged air temperatures, air temperatures at the center of Daegu were higher than in the suburbs. The daily minimum air temperature was more than or equal to 25℃ and the daily maximum air temperature was more than or equal to 35℃ at the elementary school near the center of Daegu. Also, we compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas were faster than in urban areas. This is mainly due to the difference in surface heat capacity. These results indicate the influence of urbanization on the formation of the daily minimum temperature in Daegu.
        99.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to elucidate the chemical compositions of water-soluble inorganic ions in PM10 and PM2.5 aerosols collected during summer and winter in downtown Jejusi city. The ratios of NO3 - to the total mass of ionic species in PM10 and PM2.5 aerosols largely increase in winter compared to summer, while SO4 2- ratios in both aerosols appear to follow the opposite trend. Moreover, concentrations of Na+, Mg2+, Ca2+ and Cl- in PM10 and PM2.5-10 aerosols are higher in winter than in summer. The nitrate concentrations in PM10 and PM2.5 aerosols increase with an identical increase in excess ammonium during winter, however, nitrate formation during summer is not important owing to ammonium-poor conditions.
        100.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        The APHRODITE (Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation of water resources) data has been widely used for the evaluation of the numerical model due to its higher spatial and temporal resolutions. However, some studies have indicated that it significantly underestimates the extreme precipitation values for several regions such as South Asia compared with station-based observation. In this study, therefore, the 25 year (1981-2005) APHRODITE precipitation data over South Korea during June to September was improved using Automated Synoptic Observing System (ASOS) data from Korea Meteorological Administration (KMA). After the spatial resolution and temporal interval of the ASOS data were changed to be same as those in the APHRODITE data, the GEV (Generalized Extreme Value) distribution for each data was calculated. After then, the GEV distribution of the APHRODITE data was corrected through the quantile mapping method with ASOS data. The corrected APHRODITE data was similar to the annual mean precipitation of the ASOS data. In particular, the corrected annual mean precipitation over South Korea reasonably increased by ~10% and the extreme value of precipitation have significantly improved compared to those from the original APHRODITE data.
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