• 한국응용곤충학회지
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• 제53권3호
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• pp.287-293
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• 2014

팥나방 (Matsumuraeses phaseoli) (나비목: 잎말이나방과)은 한국에서 팥 (Vigna angularis)과 녹두 (Vigna radiata)의 꽃과 꼬투리를 가해하는 주요 해충의 하나인데, 수원지방에서 이 곤충의 발육 특성과 월동태를 추정할 목적으로 야외 ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL) 조건에서 인공사육을 통해 발육과정이 관찰되었다. 갓 부화한 유충 집단들은 약 14일 간격으로 인공사료를 이용하여 1년 이상 야외에서 사육되었는데, 봄에서 고온인 여름철로 감에 따라 발육기간이 짧아지고, 가을철로 감에 따라 다시 길어지는 경향이었다. 유충 혹은 번데기 발육에서 여름철 하면 현상은 발견되지 않았다. 2008년 10월 8일 사육이 시작된 집단은 번데기 상태로 월동하였는데, 6%의 생존율을 보이며 이듬해 4월말 우화하였다. 10월 23일에 사육이 시작된 집단은 노숙유충태로 월동하였는데, 이듬해 4월말 용화하여, 5월 초중순에 2%의 최종 생존율을 보이며 우화하였다. 한편 실내에서 사육되어 5령까지 발육된 유충들을 11월과 2월 사이에 야외로 옮겨 사육하였을 때, 생존하는 개체들은 발견하지 못하였다. 항온조건 ($25^{\circ}C$, 15L:9D)에서 갓 산란된 알을 11월과 12월 중에 야외로 옮겨 유지하였을 때, 월동하여 부화하는 알은 발견되지 않았다. 또 항온조건에서 갓 우화한 성충들을 11월과 12월 중 야외로 옮겨 사육하였을 때, 모두 사망하였다. 이 결과로 팥나방은 한국의 수원지방에서 10월 중 부화한 유충들이 유충과 번데기로 월동할 수 있는 것으로 추정되었다.

• 한국해양학회지:바다
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• 제3권1호
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• pp.45-52
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• 1998

1996년 하계동안 한국 서해 대안반도 연근해에서 부유퇴적물의 총함량과 분포경향 및 부유물질의 입도특성을 측정하였고, 수온과 염분의 수괴특성치와 비교하여 부유퇴적물의 운반양상을 해석하였다. 연구해역의 하계 수괴 특성은 수온과 염분이 수직적으로 균질한 연안수괴와 수온약층이 뚜렷한 외양수괴로 구분되는 바, 연안수와 외양수는 강한 조석전선의 영향으로 활발하게 혼합되지 않았다. 그런데 경기만으로부터 유래된 저염의 연안수는 조석전선의 외양역에서 밀도약층대를 따라 중층 저염수를 형성하였고, 남쪽방향으로 이동하는 것으로 분석되었다. 부유물 총함량(TSM)은 경기만 입구의 연안수역에서 5 mg/l 이상으로 높았으며, 외양수역에서 대체로 2 mg/l 이하로 낮게 측정되었다. 외양수역에서는 수괴 홍탁도가 상층과 하층에 비하여 높게 나타나는 중층 혼탁수가 형성되었으며, 경기만 연안해역에서 유래한 부유물질은 위에서 설명된 수괴이동을 따라 남쪽방향으로 이동되는 것으로 규명된다. 부유물질의 입자크기는 전체적으로 2~9 ${\mu}m$의 평균입자 범위이며, 평균입자가 7 ${\mu}m$ 이상인 조립질 부유물은 경기만 연안수역의 혼탁수와 외양역 중층 저염수의 혼탁수에서 우세하다. 따라서 수괴분포와 연관된 부유물질의 입자특성은 부유물질의 이동과 거동방향의 해석에 긍정적인 자료로 여겨진다.

• 한국수산과학회지
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• 제51권3호
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• pp.338-343
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• 2018

Recently, commercial catches of the common squid Todarodes pacificus have dramatically decreased in Korean and Japanese waters. The relationship between common squid catches and environmental factors was investigated using squid catches, climate indices and observed seawater temperatures in Korean waters. Common squid consist of three spawning stocks: autumn, winter, and summer. The autumn stock is the largest in Korea, and its main fishing season appears to have shifted from September in the 1980s to October in the 1990s. We observed negative correlations between the spring Southern Oscillation Index and Korean catches and between the winter Pacific Decadal Oscillation and Japanese catches. Despite global warming, no conspicuous increases in October seawater temperatures have been observed at 10 and 50 m in Korean waters since the mid-1900s. Instead, the 50 m water layer of the East Sea appears to be gradually cooling. Moreover, temperatures at 50 m in the East Sea and the South Sea were significantly negatively correlated with squid catches in Korea and Japan, respectively. Our preliminary analysis indicates a link between climate change, seawater temperature, and squid catches in Korean waters, which helps to inform the direction of subsequent research to identify the cause of rapid decreases in this squid resource.

• 한국초지조사료학회지
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• 제7권1호
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• pp.8-17
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• 1987

Four foreign pasture cultivars such as Lotus corniculatus cv. Maitland, Trifolium pratense cv. Deben, Lolium perenne cv. $S_{23}$ and .Dactylis glomerata cv. $S_{26}$ were tested with "Kwisan" series, a common upland soil in Southern part of Korea. The cultivars in single or mixture were grown in pot with two levels of light intensity, i.e. a full sun light condition and 50% interception. Dry matter yield of top and root and their seasonal changes, the number of tillers or branches per plant and finally competative effects of mixtures were evaluated by estimating the expected yield, relative yield totals and compensation index. The results are summarized as follows: 1. Maitland showed a significant decrease in dry matter yield in shade condition, but the number of branches of Maitland was higher than those of Deben. 2. Maitland showed higher dry matter yield than Deben during the mid-summer period, while $S_{23}$, showed higher dry matter yield than $S_{26}$ during early season. 3. Mixtures of $S_{23}$ and Maitland, and $S_{26}$ and Deben gave better response to grasses by increasing the number of tillers in shade condition. 4. Combinations of Lotus corniculatus cv. Maitland and Dactylis glomerata cv. $S_{26}$ and Trifolium pratense cv. Deben and Dactylis glomerata cv. $S_{26}$ gave higher relative yield totals and higher compensation index, which envisages that the pasture establishment rates can be enhanced when those mixtures were sown by the oversowing method in the upland soil where phosphate level is very low and infertile in general.n general.

• 한국식물병리학회지
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• 제14권5호
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• pp.433-439
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• 1998

The studies on the ecology of virus disease on Chinese cabbage (Brassica campestris subsp. pekinensis) cultivated in alpine area of Kangwon province during summer season to analyse its influence on damage and develope a prediction model were performed from 1993 to 1997. Virus disease on Chinese cabbage occurring in the alpine area showed various symptom types and among there, necrotic spots and dwarf were mainly detected. The disease was increased from early August and continued mid September in every year. The occurrence of virus disease was the highest in 1994 with 20.5%, and the number of aphid vectors were also the highest during the same period. The number of aphids in the alpine areas showed twice peaks every year. For the analysis of damage by virus infection, the infection and injured ratio of all treatments were more than 90% and 80%, respectively. The most important factor for the occurrence of virus disease on Chinese cabbage was temperature. Factors influencing the development of the viral disease in the alpine area were maximum temperature and number of aphid vectors.

• 한국지형학회지
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• 제28권4호
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• pp.1-13
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• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

• 식물병연구
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• 제29권4호
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• pp.425-432
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• 2023

키위산업은 키위나무가 급속하게 시들면서 1-2년 사이에 말라죽는 키위 쇠락증상의 출현으로 위협을 받고 있다. 쇠락증상의 주요 증상은 뿌리 피층 붕괴, 잎 괴사, 낙엽, 열매 표피 주름 및 잔가지 시들음이다. 키위 쇠락증상은 장마 후 한여름에 골드키위(Actinidia chinensis var. chinensis)와 그린키위(A. chinensis var. deliciosa)에서 모두 발생하였다. 키위 쇠락증상은 침수나 통기 불량으로 인해 수분이 많은 점질토양에서 심하게 발생하는 것으로 나타났다. 이 증상과 직접적인 관련이 있는 병원균은 없었다. 키위 쇠락증상은 침수와 같은 수분 스트레스에 강한 바운티대목(Bounty 71)을 사용하여 효율적으로 예방할 수 있을 것으로 전망된다.

• 한국수산과학회지
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• 제40권6호
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• pp.394-410
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• 2007

Anchovy spawn from the end of May to mid-October, when the water temperature is $14.8-27.2\;^{\circ}C$ and the salinity is 26.0-33.6 psu. The main spawning season is between July to August, when the water temperature is $21.7-27.2\;^{\circ}C$ and the salinity is between 26.0-32.2 psu. The main spawning grounds of anchovy are coastal areas shallower than 50 m around the islands located in the Jeju Strait. Anchovy larvae are distributed near the fronts between Chuja-do, Jangsu-do, Yeoseo-do, and the open sea rather than in the spawning grounds. Anchovy eggs and larvae density increased in accordance with the high level of $Chlorophyll-{\alpha}$ during the summer season (July-August). In terms of the suspended sediment (SS) levels along the northern coast of the Jeju Strait, high densities of anchovy eggs (12.0-18.0 mg/L) were observed, mainly in the area affected by the coastal waters of the southern sea with high SS levels, while larvae (10.0-19.0 mg/L) tended to be distributed over a wide area with high SS levels, including the open sea. In terms of the dissolved oxygen (DO) content, eggs (5.4-6.8 mg/L) were observed in coastal areas with a high DO content, while larvae (4.2-6.4 mg/L) were distributed widely in areas with a relatively low DO content, from the southern coast to the open sea.

• 한국임상수의학회지
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• 제33권6호
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• pp.351-355
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• 2016

This study was conducted to investigate reasons for culling of Chungcheong dairy herds and to investigate the relationships between cow parity, interval from calving to culling, or season and culling reasons. Lactation data from 826 cows on 9 dairy farms from 2013 to 2015, including reasons for culling, dates of birth, last calving, and culling, were analyzed. The overall culling rate was 29.8% (246/826), with mammary problems (23.2%) being the most prevalent reason for culling, followed by infertility (14.2%) and downer cow syndrome (11.0%). The culling rate varied among farms (18.8-43.1%, p < 0.05), but was greater in parity $4{\leq}(40.7%)$ than parities 1, 2, or 3 (17.9-23.6%), whereas the rate was less frequent during mid lactation (21.1%) than in early (36.2%) or late (42.7%) lactation. Moreover, the culling rate was greater during summer (35.8%) than other seasons (20.3-23.2%). Mammary problems, downer cow syndrome, and metabolic disorders were the more common reasons for culling during early lactation, whereas infertility was predominant during late lactation. Our data show that the culling rate in Chungcheong dairy herds was associated with cow parity, interval from calving to culling, and season, with the main reasons for the removal of cows from dairy herds being mammary problems, infertility, and downer cow syndrome.

• 한국지형학회지
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• 제28권3호
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• pp.37-49
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• 2021

Analysis and prediction of storm surges are very important because the global warming has raised sea levels and increased the frequency of massive typhoons, accelerating damage of coastal flooding. However, the data for storm surge prediction is lacking due to the short history of observation in South Korea. The purpose of this study is to investigate the spatial and temporal characteristics of the previous surges and tsunamis based on the historical documents published during the Joseon Dynasty. In addition, we tried to evaluate the damage and spatial extent of such disasters, using the expressions about surge records including heights and number of administrative divisions. As a result, a total of 175 records of surges and tsunamis were compiled from 1392 to 1910: 145 events were extracted through the analysis of the ancient documents, and 30 events were from the previous research. Most of the strorm surges occurred along the west coast during summer season. More than half of the total surges were concentrated for 120 years from the mid 1600s to the mid 1700s, which was estimated to be highly relevant to the climate conditions in East Asia during the Little Ice Age. Hazardous areas by storm and tidal surges were also extracted, including Asan, Ganghwa, and Siheung during the Joseon Dyanisity period.