• The Korean Journal of Ecology
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• 제23권4호
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• pp.293-298
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• 2000

To study the effect of global warming on the growth of plants and plant populations throughout their life cycle under a field-like condition, we constructed a Temperature Gradient Chamber (TGC) in Tsukuba, Japan. The chamber had slender shape : 30 m long. 3 m wide, and 2.5 m high. That satisfactory performance was confirmed by a test throughout all seasons in 1998: the projected global warming condition in the near future was simulated. That is, independent of a great daily or seasonal change in ambient meteorological conditions, air temperatures at the air outlet were warmed 5$^{\circ}C$ higher than those at the ambient (the annual mean was 14.3$^{\circ}C$) with precision of ${\pm}$0.2$^{\circ}C$ (the annual means were 19.2$^{\circ}C$) with a rising rate of approximately 1$^{\circ}C$ every 5 m. This chamber will enable us to study the effects of global warming on growth of plants and plant populations because their abilities to control air temperature are excellent. TGC is expected that it would be utilized for studying the effect of global warming on plant growth under natural weather conditions.

• 한국응용곤충학회지
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• 제39권3호
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• pp.141-147
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• 2000

봄재배 국화에서 아메리카잎굴파리 성충은 5월 상순부터 황색 끈끈이트랩에 유인되기 시작하여 7월중순까지는 발생량이 많고 7월하순부터 수확기까지는 비교적 밀도가 낮았고 가장 발생량이 많은 시기는 6월중순~하순이었다. 유충의 밀도는 5월하순부터 서서히 증가하기 시작하여 7월상순에 가장 높았고 이후부터는 급격히 감소하여 절화를 생산하는 시기에는 밀도가 가장 낮았다. 가을재배에서는 봄재배에 비하여 셩충의 유인수는 비교적 낮은 수준이었으나 9월하순 10월중순에 유인량이 비교적 많았고 유충의 밀도변화도 수확기까지 성충과 비슷한 경향이었다. 정식후 국화 생장에 따른 피해엽율의 변화는 봄재배에서 4주째부터 피해엽이 나타나지 시작하였으며 5주째까지는 피해엽율이 비교적 낮았으나 6주째부터는 70% 이상으로 급격히 증가하여 수확기까지 계속되었다. 국화 품종에 따른 아케리카잎굴파리에 의한 피해엽율은 대국에서는 수방력이 초기에 피해가 약간 낮게 나타났지만 후기에는 조사된 모든 품종에서 45% 수준으로 높았고, 소국에서는 사티니스가 21.3%로 리건, 카산드라 등의 50% 수준보다 낮았다. 본 시험에서 검정된 국화품종은 모두 국화의 생장과 함께 피해엽이 증가하였다.

• 한국토양동물학회지
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• 제9권1_2호
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• pp.16-23
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• 2004

본 연구는 서부 호주의 Durokkopin 자연 보호 구역에 서식하고 있는 흰개미의 개미집과 서식밀도를 조사하기 위해 수행되었다. 조사결과 Woodland에서의 흰개미 집의 분포와 서식밀도가 Shrubland보다 월등히 높았으며, 일부 흰개미집의 경우 조사기간인 14개월 동안 크기가 감소한 것으로 조사되었으나, 일반적으로 조사기간 중 흰개미 집의 크기 변화는 거의 없었으며, 계급별 구성비율 또한 거의 변화가 없는 것으로 조사되었다. 그러나, 흰개미 개체수는 개미집이 작을수록 증가율이 높은 것으로 조사되었다. 본 연구결과를 토대로 종합해 보면, 두 조사지역 중 Wooldland가 Shurubland보다 공시 흰개미인 Drepanotermes tomminensis (Hill)에 보다 나은 서식처를 제공하는 것으로 사료된다.

• Animal cells and systems
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• 제15권3호
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• pp.243-249
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• 2011

The genetic diversity and population history of the Asian shore crab, Hemigrapsus sanguineus, were investigated with a nucleotide sequence analysis of 536 base pairs (bp) of the mitochondrial cytochrome c oxidase subunit I gene (COI) in 111 samples collected from four populations in Korea and one in Japan. In total, 28 haplotypes were defined by 27 variable nucleotide sites in the COI region examined. The observed haplotypes had a shallow haplotype genealogy and no geographical associations. Most of the populations had high haplotype diversity (0.656-0.788) and low nucleotide diversity (0.00165-0.00244), and significant negative values for Fu's $F_S$, suggesting rapid and recent population growth from an ancestral population and sudden population expansion. The pairwise fixation indices ($F_{ST}$) estimated with the exact test and the migration rates indicate that substantial gene flow occurs among these populations as a result of sea currents, except between the Yellow Sea coast of Korea (BUA) and the Pacific Ocean coast of Japan (JPA). These two populations (BUA and JPA) showed significant genetic differentiation and low migration rate.

• Journal of Plant Biology
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• 제30권4호
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• pp.299-309
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• 1987

The seasonal pattern and the annual magnitude of the internal (or biochemical) and plant-soil cycles of phophorus in adjacent three different herb plant populations-Helianthus tuberosus L., Artemisia princeps Pampan and Phalaris anundinacea L.-in an old field of the basin in the Mt. Geumoh were investigated. A lot of the phosphorus demand for the three populations was supplied by the withdrawal from below-ground organ in early growing period, by the absorption from soil in mid-growing period and by the withdrawal from stem in later growing period. But in the A. princeps and P. arundianacea populations, a great deal of phosphorus seemed to be absorbed prior to the first withdrawal. The annual amount of the phosphorus flowing throughthe internal cycle was about 59% of the total hosphorus flow on theorgan level in the H. tuberosus population, 41% in the A. princeps population and 32% in the P. arundinacea population, indicating that the tuber plant had the most developed internal cycle system. The annual amount of phosphorus which took part in the plant-soil cycle in the stand of the three populations was in the range of 4.49-5.65 gPm-2, corresponding to only 3-8% of the extractable phosphorus contained in the soil of 0-20 cm depth. The fact that the H. tuberosus population is higher in the extent fo internal cycle but smaller in the magnitude of plant-soil cycle and lower in the turnover rate of phsophorus than the other two populations suggests that the growth of H. tuberosus population may be less dependent on soil phosphorus availability than those of the other two populations.

• 생태와환경
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• 제53권3호
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• pp.295-303
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• 2020

We investigated the growth response and population regeneration of four halophyte species: Suaeda japonica, Salicornia europaea, Suaeda maritima and Suaeda glauca, when climate change proceeds caused by increased CO₂ concentration and temperature. The plants collected from habitat in 2018 were transplanted into Wagner pots, and cultivated for two years in greenhouse divided into a control (ambient condition) and a treatment (elevated CO₂+elevated temperature). The shoot length of halophytes was measured in July of each year, and the population regeneration rate was measured in October 2019. The shoot lengths of S. japonica and S. glauca had no difference between control and treatment for two years. Those of S. europaea were longer in control than treatment for two years. Those of S. maritima had no difference between control and treatment in 2018 but were longer in control than treatment in 2019. In control, the shoot lengths of S. japonica, S. europaea and S. glauca had no difference between years while those of S. maritima were longer in 2018 than in 2019. In treatment, those of S. japonica, S. europaea and S. maritima were shorter in 2019 than 2018 but S. glauca had no difference between years. The regeneration rates of S. japonica, S. europaea and S. glauca were lower treatment than control, and there was no difference in the regeneration rate of S. maritima. In conclusion, if climate change progresses caused by the increase of CO₂ concentration and temperature, the shoot lengths of S. japonica, S. europaea and S. maritima will be shortened, and the regeneration rate of population will be increased only in the S. maritima.

• 한국환경과학회지
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• 제8권4호
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• pp.443-449
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• 1999

This paper describe the working of algal culture system under batch and continuous feeding effluents in biological treatment process. The main objective of this study was the determination of fundamental opeating parameters such as dilution rates, light intensity, biomass concentration, nutrients contents, which engender an effective nutrient and organic waste removal process. The results of this research indicate that the algae system will remove effectively nutrient and organic waste. In batch cultures, 91.8% dissolved orthophosphate and 83.3% ammonia nitrogen were removed from the sewage in ten days. In continuous flow systems, a detention time of 2.5 days was found adequate to remove 91% T-P, 87% T-N and 95% $NH_3-N$. At 22-28$^{\circ}C$, 60 rpm, with an intensity of 3500 Lux, the specific growth rate, k was 0.59/day in batch experiments. The optimal growth temperature and nutrients rate (N/P) were respectively $25^{\circ}C$ and 3~5. With an abundant supply of untrients, it was possible to sustain substantial population densities in the temperature range of 22~28$^{\circ}C$.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.200-204
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• 1986

Particle size distribution in a Continuous Mixed Suspension Mixed Crystal Removal (CMSMPR) crystallizer has been analyzed using the Population Balance (PB) model. This method presents difficulties when the growth rate of crystal depends on the crystal size. Recent studies indicate that in many cases the growth rate is dependent on size when the crystal sizes are small. In this study, a Residence Time Distribution(RTD) model was proposed to take the size dependence into account together with an appropriate numerical scheme. When compared with the approximate results based on PB model, RTD model results showed improvements also a nucleation effect which is normally unimportant for steady state analysis. Start-up data for NaCl-Water-Ethanol system was compared with computed values.

• 한국수산과학회지
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• 제14권4호
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• pp.253-259
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• 1981

어획대상 자원에 있어서 감소계수를 z, 완전가입 년령을 a, 최고년령을 b라 할 때 체장조성과 성장곡선식을 이용해서 감소계수 z를 구하는 수학적 모형을 설정하여 고등어와 전갱이의 생잔율을 추도한 결과를 요약하면 다음과 같다. 1. 평균년령을 $U_t$라 하면 a, b, z 및 $U_t$의 관계식은 $$U_t=\frac{a-b ex p[-z(b-a)]}{1-ex p[-z(b-a)]}+\frac{1}{z}$$이다. 2. 성장곡선식을 사용하여 체장조성표의 각 체장계급에 해당하는 년령을 추정하고 전계급에 걸친 평균년령을 계산하였다. 3. $U_t$값을 a, b, z 및 $U_t$와의 관계식에 대입하여 감소계수 z값을 구하고 생잔율 exp(-z) 값을 구하였다. 4. 한국 연안 (제1해구)산 고등어와 전갱이의 감소계수, 생잔율 및 생잔율의 $95\%$ 신뢰구간을 계산한 결과는 고등어가 0.87909, 0.41516, 0.35966-0.47264 전갱이가 2.22327, 0.10825, 0.06897-0.14974이었다.

• 한국인구학회:학술대회논문집
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• 한국인구학회 2006년도 후기학술대회 및 정기총회
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• pp.113-128
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• 2006

본 연구는 지난 30년간(1975년${\sim}$2004년) 한국의 경제성장과정에서 교육부문별(초등 ${\cdot}$ 중등 ${\cdot}$ 고등교육) 역할을 추정하는 데 주목적이 있다. 본 연구방법은 첫째, 신고전학파 Solow의 외생적 경제성장이론을 접목한 Cobb-Douglas 모형을 확장하여 1인당 경제성장 추정을 위한 내생성장모형을 제시하였다. 둘째, 자료 한계를 극복하기 위하여 동 아시아 7개국 자료를 바탕으로 시계열 및 횡단면 자료를 블록으로 구축하여 앞의 내생성장모형을 이용하여 pooling방법으로 1인당 경제성장에 물적자본, 단순노동력, 인적자본, 지적자본(R&D), 초기년도의 기술수준 등의 기여분을 추정하였다. 이러한 각 생산요소의 직접적인 추정결과로부터 각 요소간(고등교육, 중등교육, 지적자본) 상호작용으로 인한 간접적인 기여분을 재 추정하여 보정된 결과를 제시하였다. 1975년${\sim}$2004년간 한국의 경제성장 과정에서 인적자본요소 중 중등교육의 역할이 가장 큰 87.0%, 물적자본이 39.6%, 초등교육이 6.6%, R&D자본이 24.1%를 보였으며 중등교육과 R&D자본에 간접적으로 기여한 대학교육이 -53.9%, 지식 ${\cdot}$ 정보기반사회의 의미가 감소한 단순노동력은 -1.4%, 기술추격을 가능케 하는 1975년도 초기기술수준이 -3.0%의 추정결과를 보여주고 있다.