• 미생물학회지
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• 제24권2호
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• pp.184-193
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• 1986

Interrelation between environmental influences on soil microorganisms and it's effect on disease development in ginseng (Panax ginseng C.A. Meyer) field were studied to obtain a preventive measures against the root rot of ginseng caused by soil-borne pathogens in soil in three major Korean ginseng producing areas such as Kumsan, Goesan and Poonggi. Populations of actinomycetes were relatively high in fall season from September to November. Their numbers were highly populated in healthy plot in field than replanted disease field of ginseng, whereas ratio of Trichoderma spp to actinomycetes increased in healthy plot of field indicating the higher numbers of Trichoderma spp pressented in healthy plot field. The numbers of propagules of Trichoderma spp generally increased in early summer through early fall season. Their numbers were also highly populated in the healthy plot of fields. The contents of organic matter and phosphate in healthy plot of field were somewhat high, and phophate/organic matter ratio and Mg content were high in diseased replanted field. All of the soil samples showed a weak acidic pH from 4.5 to 4.7. Soilmoisture content was increased during winter season and it did not show any significant changes curing the growing period, showing 24.6% in healthy plot in field and 19.5% in deseased plot in field respectively. Soil temperature was highest in July and August and lowest in January and February.

• 아시안잔디학회지
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• 제25권2호
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• pp.195-201
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• 2011

해조추출물과 2종의 키토산 제형을 뗏장잔디 생산농장에서 가을철에 creeping bentrgass (Agrostis palustris Huds) Penn-A1 품종과 Kentucky bluegrass (Poa pratensis L.) 혼용품종(Midnight 33%, Moonlight 33%, Prosperity 33%)에 살포하였다. 잔디 질에 미치는 잔디 잎색, 엽록소함량 및 NDVI을 조사하였다. 키토산과 해조추출물 처리는 엽록소 함량과 잔디생장에서 유의성 있게 증가하였다. Kentucky bluegrass 종의 혼용품종과 creeping bentrgass 종의 Penn-A1 품종의 잔디에 엽록소 함량과 잔디생장이 키토산 제형 과 해조추출물의 엽면시비에 의해 유의성 있게 증가하였다. 잔디의 잎색은 유의성이 없었다. 이들 결과는 키토산 제형과 해조추출물이 가을철 골프장에 잔디관리에 도움이 될 것으로 생각한다.

• 한국물환경학회지
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• 제27권3호
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• pp.306-313
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• 2011

In this paper, runoff characteristics of South-Han river watershed in terms of refractory organic matters were investigated. The concentrations of DOC, POC, R-DOC, R-POC in runoff and flow rates were determined by monitoring 27 times in dry season and 4 times in rainy season. The concentrations of the dissolved refractory organic matter, R-DOC was the lowest in fall and similar in the other dry seasons. The particulate refractory organic matter, R-POC showed less fluctuation than R-DOC. In summer, mass loading was the highest than other dry seasons. The concentrations of R-DOC, R-POC were showed to be affected by runoff volume. The mass loading grows higher as runoff volume gets higher.

• 한국조경학회지
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• 제30권4호
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• pp.19-27
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• 2002

When we research a landscape or make a Landscape Impact Assessment, we use the image of a specific season like summer or fall. Since there are four distinct seasons, each with a different landscape, researchers need to understand viewers′visual preferences for individual seasonal landscapes. The purpose of this study is to investigate viewers′visual preferences according to seasonal change and the respondent′s age, gender and profession. In this research, the independent variable is season: suing, summer, fall, winter and snowy winter. Three landscape types used in the experiment: forest, street and agriculture. Each landscape type has two sites for reliability. The assessment media for this research are pictures featuring landscapes taken in each of the four seasons. The study used the "paired comparison" method for taking the score of visual preference. The results of this study are as follows: 1. The summer landscape has the highest visual preference score. However, spring and fall landscapes should also be considered for visual landscape evaluation. 2. The visual preference of winter landscape covered with snow is very high, but since snow is temporal and irregular, it is difficult to consider this factor for visual landscape evaluation. 3. The visual preference score of winter is the lowest of four seasons. The attractive factors of spring are flowers, summer is greenery and fall is autumnal tints. But these are not present in winter. 4. The result of visual preferences according to age groups, gender and profession have no serious differences. 5. Visual preference to scenery of 4 seasons by age group was not different from general preference and thus was concluded to have no connection with age. 6. As a result from the research of visual preference to scenery of 4 seasons by sex, women were shown to like snow-scene more than men. This study presents an indication of general preferences of seasonal landscapes. It is expected that more advanced study will proceed after this one.

• 대한수의학회지
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• 제32권2호
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• pp.275-280
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• 1992

To investigate the age at puberty and the seasonal breeding in Korean native goats, progesterone concentrations were measured in blood. Blood samples were collected from 8 goats at 10 day intervals from 2 months of age until the first estrus after birth, and then every 5 days for a further estrous cycle and the seasonal breeding. The mean age and weight at puberty were $195{\pm}57$ days($mean{\pm}S.D.$, range : 107~260 days) and $11.1{\pm}0.9kg$(range : 9.8~12.0kg), respectively. The mean age at first pregnancy after birth was $241{\pm}109$ days(range : 107~273 days). The estrus was observed 47.6% from October to December, and was highest in fall(38.1%) and lowest in spring and summer(14.3%). However, the estrus was observed every season. About 67% of total conception occurred form October to January. The parturition occurred 41.7% in spring, 25.0% in summer and winter, and 8.3% in fall, respectively. These results suggest that Korean native goats do not have a breeding season, but the reproductive activity is influenced by the season.

• Ocean and Polar Research
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• 제36권4호
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• pp.437-445
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• 2014

A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.

• 한국가축번식학회지
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• 제17권4호
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• pp.325-329
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• 1994

Seasonal and diurnal variation in serum testosterone was measured by radioimmunossary in 3 mature Korean native male goats. Blood was collected at 3-h intervals for 24h in each season. Mean levels of 4 seasons ranged from 0.82 to 2.06ng/ml and no difference was among seasons, although level in fall and winter was slightly higher. Diurnal level tended to increase at daytime in all season and when diurnal variation in level was compared to daily mean of each season, level of daytime greatly(P<0.05) increased in summer. However, variation between light and dark period in other seasons did not show significant difference. Daytime increase of testosterone was found 3 to 4 after dawn and level increased 1 to 2h ahead in summer and fall than that in others. These results in serum testosterone suggest that there was no great seasonal variation in endocrine function of goat testis.

• 한국농공학회논문집
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• 제59권2호
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• pp.91-99
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• 2017

The objective of this research was to investigate runoff characteristics of suspended solid (SS) and chemical oxygen demand (COD) from a paddy field watershed during storm events in the growing and non-growing seasons. Average of event mean concentration (EMC) of pollutants were 56.9 mg/L for SS and 23.9 mg/L for COD in the non-growing season and 50.3 mg/L for SS and 11.9 mg/L for COD in the growing season. The average EMC of SS in the study area was much lower than that in the uplands irrespective of cultivation, suggesting that paddy fields control soil erosion. This may be because flooding and wet soil in the growing season, and rice straw residue and stubble on the topsoil in the non-growing season reduce soil erosion. The changing tillage practice from fall tillage to spring tillage avoids soil erosion due to shortening of the tilled fallow period. However, the average EMC of COD in the non-growing season was about twice as much that in the growing season likely due to the runoff of organics like rice straw residues. The relationship between SS and COD loads and stormwater runoff volume was expressed by power function. The exponent for SS was higher than that for COD, suggesting that SS load increased with stormflow runoff more than COD load did. The mean SS and COD loads per storm during the non-growing season were much lower than those in the growing season, and therefore non-point source pollution in the growing season should be managed well.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.484-487
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• 2001

Runoff, sediments and nutrient losses were studied under different patterns of paddy field management: (1) fall and spring plowing (PL); (2) fall plowing for half of plot and spring plowing (SPL); (3) no-till for fall and spring plowing (NPL) during the non-cropping period in the southern Korea. Sediment losses from PL plot were 25% more than those from NPL plot. There was significant difference in nutrient losses via runoff water and sediment according to plowing practice (P < 0.01). Losses of total-N, ammonia-N, nitrate-N, total-P from NPL plot were larger than PL and SPL plots during study period. Sediment and total-P losses from SPL plot were close to those of PL plot.

• Ocean and Polar Research
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• 제25권4호
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• pp.483-491
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• 2003

Since the red grouper was declared overfished, the Gulf of Mexico Fishery Management Council must prepare a rebuilding plan considering the following alternative management policies: a Total Allowable Catch (TAC), 5-month season closure, 1800-pound trip limit, and a 50-fathom longline boundary. This study was aimed at evaluating the effects of proposed policies for rebuilding the red grouper stock in a 10-year period by developing a bioeconomic model. Under the assumption that the recreation sector was held to its share of TAC (24% of the total quota), the target stock biomass goal was attained in all policies. The NPV was the largest in the 5-month season closure policy if the output price did not fall. There were distributional effects on the different components of the fleets in the 1800-pound trip limit and the 50-fathom longline boundary policy.