• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.398-404
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• 1985

This study was conducted to define the seasonal differences in the morphological characteristics, the photosynthetic abilities and the dark respirations of the 4-year old ginseng leaves. Chlorophyll-a content in the ginseng leaf was significantly decreased at September than at June but content of chlorophyll-b was not showed seasonal difference. At June, the amounts of chlorophyll a and b in the ginseng leaves grown in the back row were rather abundant than those grown in the front row, but no significant differencies were detected between rows at September. The estimated optimum light intensity for the photosynthesis of ginseng leaves was higher at June than at September and higher in the front row than the back row but was significantly decreased by air temperature above 25$^{\circ}C$. The light compensation point was elevated in higher temperature and at September than June. The amount of photosynthesis was significantly increased in the ginseng plant grown in the front row than the back row at June but the reverse was significant at September. The highest photosynthesis was observed in temperature range of 20 - 25$^{\circ}C$ at June and range of 15 -20$^{\circ}C$ at September. The optimum temperature range of photosynthesis was 21$^{\circ}C$ to 25$^{\circ}C$ at June and 14$^{\circ}C$ to 21$^{\circ}C$ at September, and that was higher in the back row than the front row. High temperature significantly stimulated the dark respiration of ginseng leaves and the respiratory quotients(Q$\_$10/) of the ginseng leaves showed a significant seasonal variation.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.719-726
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• 2016

The effect of high and low temperatures on seedling quality while raising of paprika (Capsicum annuum L.) seedlings, and their early development after planting was investigated. The control raising seedling temperature (RST) was $23^{\circ}C$; high temperature, $31^{\circ}C$; and low temperature, $15^{\circ}C$ throughout the raising seedling period. At $15^{\circ}C$ and $30^{\circ}C$, plant height, stem diameter, fresh weight, dry weight, number of leaves, and seedling leaf area were significantly lower than those at $23^{\circ}C$. At 4 weeks after planting, seedling's growth characteristics showed a similar pattern. Compared to $23^{\circ}C$, seedlings raised at $15^{\circ}C$ and $30^{\circ}C$ had an increased dry weight and leaf area per unit time after planting than during the seedling raising period. At 4 weeks after planting, crop growth rate and leaf area index were unaffected by RST, and relative growth rate and net assimilation rate at RSTs of $15^{\circ}C$ and $31^{\circ}C$ were higher than those those at RST of $23^{\circ}C$. At an RST of $15^{\circ}C$, growth speed and net assimilation rates were higher after planting than before planting, according to increased photosynthetic rate. Thus, high and low temperatures during the seedling raising period significantly reduced seedling growth and plant growth after planting. After planting, seedlings raised at $15^{\circ}C$ recovered more quickly than did those raised at $31^{\circ}C$.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.103-109
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• 2007

To investigate the effects of artificial vegetation island (AVI) on fish distribution, we compared fish fauna from artificial vegetation island (AVI) area, which installed in 2000, natural vegetation area (NVA) and vegetation-free area (VFA) at Kyungan Stream area of Lake Paldang from Jul. to Nov., 2005. Results showed that 11 families 23 genera 24 fish species were distributed in the AVI and NVA. Squalidus japonicus coreanus, a small-size fish which generally lives at the downstream, dominated absolutely in the individual numbers. However, only 6 families 11 genera 12 species of fishes caught at the VFA, and dominant fishes were Hemibarbus labeo and Erythroculter erythropterus, a medium to large-size migratory fishes which live in mid-depth of water column. The dominance index was high at the AVI (0.778) and NVA (0.868), whereas the diversity index and evenness index were high at the VFA. Fish distribution at AVI was similar to that of the NVA in numbers of species, indicating that the AVI could playa role as spawning and inhabitation zone to a variety of fishes. We believe that AVI may be used for a restoration of the damaged and disturbed littoral ecosystem.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.43-47
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• 2013

This study was conducted to develop the most effective method in promoting onion set in cultivars 'Josaengsseondebol' and 'Daeji' for all year-round production. This was done by extending the day length for 41 days. For both cultivars, the period to reach the maximum number of leaves developed was shortened as the exposure to day length increased. Between the two cultivars, 'Josaengsseondebol' reaches its maximum leaf formation for a shorter duration compared with 'Daeji'. In effect to bulb size, cultivar 'Josaengsseondebol' having a night break of 1, 2, and 16 hours light condition had better bulb enlargement compared with the non-treated bulbs. In the case of cultivar 'Daeji', only bulbs exposed to a night break of 2 and 16 hours light condition had better bulb enlargement. The percentage of marketable set yield in cultivar 'Josaengsseondebol' having a night break of 1 hr, 2 hrs, 16 hrs light condition, and control or untreated bulbs were 84%, 92%, 90%, and 6% respectively. In the case of cultivar 'Daeji', treated with a night break of 1 hr, 2 hrs, 16 hrs light condition, and untreated bulbs had a percentage marketable set yield of 7%, 55%, 64%, and 0% respectively. Based on these results, it is therefore concluded that night break treatment is considered to be effective method in promoting off-season onion set cultivation in cultivar 'Josaengsseondebol'.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.210-221
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• 2000

The population habitat and density of Korean scallops, Chlamys farreri, were investigated to estimate population ecological characteristics from samples randomly collected around Wando from November, 1998 to October, 1999. Age and growth of the Korean scallops were determined from their ring radii. Maturation and spawning were studied using data of ovary maturity stage, gonadosomatic index, and fecundity. Seawater temperature and specific gravity ranged from 7.6 to $25.9^{\circ}C$ and from 1.0188 to 1.0260, respectively. Also dissolved oxygen and pH ranged from 6.48 to 9.50 ppm and from 8.17 to 8.80. Rocky and gravel bottom had a maximum habitat density of $$28.83 inds/100m^2$$ , which accounted for 82.4 % of the overall habitat area. The relationship between shell length (SL, mm) and shell height (SH, mm) of the Korean scallops was fitted : SH=1.021 SL+2.211 $(R^2=0.989)$. The shell length-total weight (TW, g) relationship was $TW=0.0003; SL^{2.837};(R^2=0.980)$. Then von Bertalanffy growth parameters were estimated from a nonlinear regression method, and the values were as follows : $SH_{\infty}=117.4 mm$K=0.61/year,; and; t_0=-0.017 year., The 50 % maturity at age was 0.21 year with the shell height of 18.3 mm, and spawning occurred twice a year, that is, June/July and October. The relationship between fecundity (Fc) and shell length was$Fc=697.03 SL^{2.683}(R^2=0.984)$, and the fecundity-gonad weight (GW, g) relationship was Fc=10,076,090 GW+15,608,781 $(R^2=0.990)$.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.41-47
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• 2009

Post-tensioned concrete pavement(PTCP) was developed to built long-span concrete pavement(120 m span) and to maintain long-term service life(over 40 years) of concrete pavement. In the present study, research for high-durable concrete was conducted to utilize the advantage of PTCP construction method efficiently. First of all, 20% of fly ash(by binder weight) was replaced to control alkali silica reaction. Second, silica fume was applied to improve the water-permeability and early-age strength. Results of tests for mechanical properties, water-permeability resistance, and surface-scaling resistance of ternary blended cement concrete showed that the early-age strength was improved significantly with addition of silica fume. The water-permeability resistance was improved from "Low" to "Very Low"(ASTM C 1202). However, surface-scaling resistance was decreased with an increase of silica fume, therefore, content of silica fume should be kept in less than 5%(by binder weight) to assure field application considering durability. The results of air-void analysis showed that durability factors were improved since spacing factors were estimated as 250$\pm$15 micron in adjusted mixtures.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.543-547
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• 2005

해수소통을 전제한 경우 새만금호 내측의 염분변화가 만경강의 평수량 및 홍수량 유입에 따라 혼합확산되는 것을 평가하고 배수갑문 방류시 담수가 외해에 미치는 영향범위를 평가하기 위한 수치모형실험이 실시되었다. 이때 새만금호 내부의 관리수위는 DL=-1.5m, DL=-0.5m, DL=-0.0m, DL=+0.5m가 고려되었다. 외해역의 평가는 새만금을 포함한 전체해역에 대해 외해경계에서 4개의 주요분조($M_2,S_2,K_1,O_1$)의 진폭과 위상각을 대입하고 2차원 ADCIRC 및 3차원 TIDE3D 모형을 적용하였다. 내부는 여기에 3개 연직층을 고려한 3차원 ICM 모델이 추가 적용되었다. 내부의 혼합확산 평가 결과는 시간이 지남에 따라 외해에서 유입되는 염수가 상대적으로 저염인 담수호 내부로 유입 확산되는 것이 평면적으로나 연직방향으로 변화되는 것을 매우 뚜렷하게 나타남을 알 수 있고, 최소 1개월 이상 경과되어야 만경호측에 외해수가 혼합되는 것으로 분석된다. 수문을 개방하지 않은 상태에서 새만금 방조제 외해의 최강창낙조시 조류속도는 0.5-0.6m/s 정도에 해당되는 것으로 분석되었다. 신시갑문을 개방하는 경우 관리수위가 DL=-1.5m와 DL=+0.5m로 변함에 따라 갑문 전면 10Km-l3Km에 이르는 해역까지 수문개방에 따라 0.5m/s의 유속이 형성된다. 가력갑문을 개방하는 경우는 신시갑문의 개방에 따른 영향보다는 작지만 갑문 전면 14Km까지 0.5m/s의 강한 유동이 관리수위별로 나타나고 있다. 이러한 결과는 담수 방류로 인한 영향이 주기적으로 낙조시에 발생되어 새만금 방조제 전면의 해수순환과 유동에 적지 않은 영향을 미칠 개연성을 제시하는 것으로 해석된다.$\cdot$유출에 의한 수질변화양상을 단계적으로 구분하여 수질변화에 중요한 영향을 미치는 인자에 대한 이론적인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심

• Water for future
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• v.9 no.2
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• pp.87-100
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• 1976

These studies are aimed at the analysis of systematic variation pattern of water resources in Korean river catchments and the development of their simulation models from the stochastic analysis of monthly and annual hydrologic data as main elements of water resources, i.e. rainfall and streamflow. In the analysis, monthly & annual rainfall records in Soul, Taegu, Pusan and Kwangju and streamflow records at the main gauging stations in Han, Nakdong and Geum river were used. Firstly, the systematic variation pattern of annual streamflow was found by the exponential function relationship between their standard deviations and mean values of log-annual runoff. Secondly, stochastic characteristics of annual rainfall & streamflow series were studied by the correlogram Monte Carlo method and a single season model of 1st-order Markov type were applied and compared in the simulation of annual hydrologic series. In the simulation, single season model of Markov type showed better results than LN-model and the simulated data were fit well with historical data. But it was noticed that LN-model gave quite better results in the simulation of annual rainfall. Thirdly, stochastic characteristics of monthly rainfall & streamflow series were also studied by the correlogram and spectrum analysis, and then the Model-C, which was developed and applied for the synthesis of monthly perennial streamflow by lst author and is a Markov type model with transformed skewed random number, was used in the simulation of monthly hydrologic series. In the simulation, it was proved that Model-C was fit well for extended area in Korea and also applicable for menthly rainfall as well as monthly streamflow.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.627-633
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• 1997

Gonad structure, germ cell development and reproductive cycle of the smallmouth scorpionfish, Scorpaena miostoma were investigated based on histological method. Samples were collected monthly in the vicinity of Suyoung Bay, Pusan, Korea from November 1995 to October 1996. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consists of numerous testicular cysts which contain numerous germ cells in same developmental stage. The ovary consists of several ovarian lamellae originated from ovarian outer membrane. Oogonia originated from the inner surface of the ovarian lamella protrude to the ovarian cavity in oocyte stage, and they are suspended by the egg stalk. Biological minimum size of female and male were 12.5cm in total length. Gonadosomatic index (GSI) of female (3.81) and male (0.23) were the highest in October. Reproductive cycle was classified into the following successive stages: in female, growing stage $(May\~August)$, maturation stage $(September\~October)$, ripe and spawning stage $(November\~December)$, recovery and resting stage $(January\~April)$, and in male, growing stage $(June\~August)$, maturation stage $(September\~October)$, ripe and spent stage $(November\~January)$ and recovery and resting stage $(February\~May)$.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.160-166
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• 1996

Objective of this study was to investigate the effects of all current speed on the microclimates above and inside the plug stand under artificial light. Maximum air temperature appeared near the top of the plug stand. Difference in air temperature inside the plug stand increased with the decreasing air current speed. Difference in relative humidity(DRH) to the relative humidity at the Inlet of the main air flow conditioner Inside and above the plug stand decreased with the increasing air current speed. Relative humidity inside the plug stand was 10-15% higher than that above the plug stand. DRH inside a stand of plug at air current speed of 0.3m s$^{-1}$ was about two times as many as that at air current speed of 0.9 m s$^{-1}$ . DRH inside the plug stand was 2.8-6.5% higher at LAI of 2.6 than that at LAI of 0.5. Gradient for the vapour pressure deficit was distinctly appeared at the low air current speed. Direction of vapour pressure flux is from the medium surface upwards. Difference in vapour pressure(DVPD) to the vapour pressure deficit at the inlet of the main air flow conditioner inside and above the plug stand decreased with the increasing height above the medium surface. DVPD inside the plug stand was 0.3-0.4㎪ higher at air current speed of 0.9m s$^{-1}$ than that at air current speed of 0.3m s$^{-1}$ . Results for the effects of air current speed on the relative humidity and vapour pressure deficit indicated that the microclimates above and inside the plug stand at the rear region in plug trays were slightly unfavorable compared to those at middle region.