• 대한토목학회논문집
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• 제31권6B호
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• pp.499-505
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• 2011

저수지내에서의 탁수층의 혼합거동은 연중 온도변화에 영향을 받으며, 특히 여름철에 발생하는 한 개 내지 두 개의 수온약층과 이에 따라 밀도가 다른 연직층 분포에 의해 변화한다. 이와 같은 밀도성층은 연직방향의 혼합을 제한하고 저수지내에서 다양한 수리학적인 거동을 야기한다. 따라서 저수지내에서는 특정 수질 문제를 해결하기 위해 선택취수를 수행할 수 있다. 본 연구에서는 이와 같은 선택취수의 효울을 해석하기 위하여 성층흐름의 수리학적 특성에 관한 실험연구를 수행하였다. two-tank 기법을 이용한 성층수조에서 밀도경사와 유량을 변수로 한 각 조건별 취수구 주변의 수리학적 특성을 입자영상유속계(PIV)를 이용하여 측정하였다. 측정된 유속장을 이용하여 Richardson 수에 따른 선택취수의 효율에 대한 상관관계를 제시하였다.

• 한국환경과학회지
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• 제3권3호
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• pp.185-195
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• 1994

Masan bay is one of the polluted enclosed bays, which has red tides problem and the formation of oxygen deficient water in the bottom layer. Most important factors that cause eutrophication and red tide is nutrient materials containing nitrogen and phosphorus which stem from terrestrial sources and nutrients released from sediment. Therefore, to improve of water quality, reduction of these nutrient loads should be indispensible. At this study, the three-dimensional numerical hydrodynamic and eutrophication model, which were developed by Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the phytoplankton production and also to evaluate the effect of water quality improvement plans on phytoplankton production. In field sorvey, the range of concentrations of chlorophyll-a at surface area was found to be 29.17 - 212.5mg/m3, which were exceeding eutrophication criteria. The constant currents defined by integrating the simulated tidal currents over 1 tidal cycle showed the counterclockwise eddies in the southern part of Budo. The general directions of constant currents were found to be southward at surface and northward at bottom over all the bay. The eutrophication model was calibrated with the data surveyed in the field area in June, 1993. The calculated results are in fairly good agreement with values within relative error of 30%. The pollutant load from the sources such as the input from terrestrial release from the sediment was reduced by the rate of 50, 70, 90, 98% to effect of phytoplankton production. Phytoplankton production was reduced to of the 90% reduction of the input loads from terrestrial sources and 8% in 90% reduction of the load from sediment.

• The Korean Journal of Ecology
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• 제27권3호
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• pp.173-177
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• 2004

갈조류 지충이의 표면에 부착하는 착생해조류의 종수, 풍부도, 부착위치 및 기능형을 조사하기 위하여 남해안 9개 무인도와 서해안의 격포 해안에서 2001년 여름에 지충이를 채취하였다. 지충이에 착생하는 해조류는 총 25종이 동정되었는데, 분류군 별로는 녹조류 6종(24%), 갈조류 2종(8%), 홍조류 17종(68%) 이었고 남해군의 장고섬, 노루섬, 소목과도에서 생육하는 지충이에 가장 많은 9종이 착생하였다. 착생 해조류 중에서 애기가시덤불, 구멍갈파래, 가위갯쇠털의 순으로 출현 빈도가 높았으며 애기가시덤불은 모든 해안에서 발견되었다. 또한 애기가시덤불, 두갈래사슬풀, 애기서실은 지충이 엽체의 하부에, 붉은실류는 상부에 부착하여 생육하였다. 기능형으로는 막상형 8%, 사상형 52%, 성긴분지형 32%, 유절석회조형 8%가 존재하였으며 각상형과 혁질형 해조류는 없었다. 위다년생인 지충이의 착생해조류는 봄과 여름에 관찰되는 바위두룩과 같은 종이나 사상형의 일년생 해조류가 주로 나타났으며, 유성생식을 하는 이들은 포자생성 및 방출을 숙주 해조류인 지충이의 엽체가 탈락되는 늦가을 이전에 일어난다.

• 한국환경과학회지
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• 제7권6호
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• pp.833-843
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• 1998

It is noted that the red tides and the oxygen-deficient water mass are extensively developed in Masan Bay during summer. The nutrients mass balance was calculated in Masan Bay, using the three-dimensional numerical hydrodynamic model and the material cycle model. The material cycle model was calibrated with the data obtained on the field of the study area in June 1993. The nutrients mass balance calculated by the combination of the residual currents and material cycle model results showed nutrients of surface and middle levels to be transported from the inner part to the outer part of Masan Bay, and nutrients of bottom level to be transported from outer part to inner part of Masan Bay. The uptake rate of DIN in the box A1(surface level of inner part) was found to be 337. 5mg/$m^3$ㆍday, the largest value in all 9 boxes and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1, and the regeneration rate of DIN was found to be 78.2mg/$m^3$ㆍday in the box A3(bottom level of inner part), and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1. The regenerations of DIN and DIP in the water column of the entire Bay were found to be 7.66ton/day and 760kg/day, respectively. And the releases of DIN and DIP from the sediments of the entire Bay were found to be 2.86ton/day and 634kg/day, respectively. The regeneration rate was 2.5 times as high as the release rate in DIN, and 1.2 times in DIP. The results of mass balance calculation showed not only the nutrients released from the sediments but the nutrients regenerated in water column to be important in the control and management of water quality in Masan Bay.

• 대기
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• 제27권4호
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• pp.455-466
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• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.

• Nutritional Sciences
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• 제8권2호
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• pp.111-117
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• 2005

It has been more than three decades since the first assay assessing circulating 25 (OH)D in human subjects was performed That publication as well as several that followed it defined 'normal' nutritional vitamin D status in human populations. Recently, the wisdom by which 'normal' circulating 25 (OH)D levels in human subjects were assigned in the past has come under question. It appears that sampling human subjects, who appear to be free from disease, and assessing 'normal' circulating 25 (OH)D levels by plotting a Gaussian distribution is grossly inaccurate. There are many reasons why this method is inaccurate, including race, lifestyle habits, sunscreen usage, age, latitude, and inappropriately low dietary recommendations for vitamin D. For instance, a 400 IU/day. AI for vitamin D is insignificant when one considers that a 10-15 minute whole body exposure to peak summer sun will generate and release up to 20,000 IU vitamin $D_3$ into the circulation. Recent studies, which orally administered up to 10,000 IU/day vitamin $D_3$ to human subjects for several months, have successfully elevated circulating 25 (OH)D levels to those observed in individuals from sun-rich environments. Further, we are now able to accurately assess sufficient circulating 25 (OH)D levels utilizing specific biomarkers instead of guessing what an adequate level is. These biomarkers include intact parathyroid hormone (PTH), calcium absorption, bone mineral density (BMD), insulin resistance and pancreatic beta cell function. Using the data from these biomarkers, vitamin D deficiency should be defined as circulating levels of 25 (OH)D$\leq$30 ng/mL. In certain cases, such as pregnancy and lactation, significantly higher circulating 25 (OH)D levels would almost certainly be beneficial to both the mother and recipient fetus/infant.

• 한국영양학회:학술대회논문집
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• 한국영양학회 2004년도 추계학술대회
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• pp.22-33
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• 2004

It has been more than three decades since the first assay assessing circulating 25(OH)D in human subjects was performed. That publication as well as several that followed it defined 'normal' nutritional vitamin D status in human populations. Recently, the wisdom by which 'normal' circulating 25(OH)D levels in human subjects were assigned in the past has come under question. It appears that sampling human subjects, who appear to be free from disease, and assessing 'normal' circulating 25(OH)D levels by plotting a Gaussian distribution is grossly inaccurate. There are many reasons why this method is inaccurate, including race, lifestyle habits, sunscreen usage, age, latitude, and inappropriately low dietary recommendations for vitamin D. For instance, a 400IU/day. AI for vitamin D is insignificant when one considers that a 10-15 minute whole body exposure to peak summer sun will generate and release up to 20,000 IU vitamin $D_3$ into the circulation. Recent studies, which orally administered up to 10,000 IU/day vitamin $D_3$ to human subjects for several months, have successfully elevated circulating 25(OH)D levels to those observed in individuals from sun-rich environments. Further, we are now able to accurately assess sufficient circulating 25(OH)D levels utilizing specific biomarkers instead of guessing what an adequate level is. These biomarkers include intact parathyroid hormone (PTH), calcium absorption, bone mineral density (BMD), insulin resistance and pancreatic beta cell function. Using the data from these biomarkers, vitamin D deficiency should be defined as circulating levels of $25(OH)D{\leq}30ng/mL$. In certain cases, such as pregnancy and lactation, significantly higher circulating 25(OH)D levels would almost certainly be beneficial to both the mother and recipient fetus/infant.

• 환경영향평가
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• 제8권1호
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• pp.93-105
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• 1999

Lately water quality of Daechong Reservoir has become more eutrophicated than ever before and there has been much concern over especially the eutrophication of the embayment near Daejon and Chongju Water Intake Tower every summer. The purpose of this study is to predict the impact of change in the pollutant loading, flowrate, nitrogen and phosphorus release from sediment, SOD(sediment oxygen demand) upon the water quality of Daechong Reservoir by WASP5/EUTR05 in order to suggest water quality management alternatives. The data of Sep. 1995 were used for the calibration of the model and those of Sep. 1997 was for verification. The result of the modeling can be summarized as follows. 1. The 50% increase(decrease) of pollutant loading has caused that of T-N concentration by 0.10-0.14 mg/l, T-P concentration by 0.003-0.005 mg/l, and CBOD concentration by 0.16-0.18 mg/l. But the ratio of DO change by the change of pollutant loading was relatively small. 2. The sensitivity test of NH4 flux to T-N and that of P04 flux to T-P shows that T-N and T-P concentration were changed more in the epilimnion segments (SEG4, SEG5, SEG6, SEG7) than the other segments. As SOD increases, DO was predicted to decrease more especially in the hypolimnion (SEG9-SEG14). 3. As flowrate increase, the concentration of T-N, T-P, and CBOD were predicted to decrease, but DO concentration increased especially in the hypolimnion segments(SEG11, SEG12, SEG13, and SEG14). As the flowrate changed from $119m^3/sec$ to $50m^3/sec$, the concentration of T-N and CBOD in the hypolimnion was predicted to decrease.

• 한국운동역학회지
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• 제15권4호
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• pp.143-151
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• 2005

This study was conducted to investigate the technical factors of Cuervo forward straight vaults with single twist, single and half twists, and double twists actually performed by three execellent male gymnasts participated in artistic gymnastics competition of 2003 summer Universiade in Daegu and the 85th National Sports Festival in Cheongju. To accomplish the research goals the Cuervo vaults of three gymnasts were filmed by using three digital camcorders set by 60 Hz, and data were collected through the DLT method of three dimensional cinematography. The kinematic and kinetic variables as each phasic time, CM displacement velocity, release angle inclination angle hip joint angle landing angle, average horse reaction force average moment arm average torque, whoe body's total remote local angular momentum were analyzed, so the following conclusions were reached. Generally to perform the better Cuervo vault, a gymnast should touch down on the board with the great horizontal velocity of the whole body through the fast run-up, and touch down on the horse by decreasing the horizontal displacement of the whole body during the preflight, so raise CM height gradually within a short horse contact time. He should increase the horse reaction force through checking the horizontal velocity of the whole body effectively and the inclination angular displacement of the handstand, if so he can have the large vertical velocity of the whole body. By using the acquired the velocity and the angular momentum of the whole body, he can vault himself higher and twist sufficiently, then he can get better if the body could be tilted by swinging both arms and perform the cat twist with a little flexions at hip joints. According to the above outcomes we can judge that the best athletes is LuBin, the better is YTY, and the next is JSM.

• 한국해양학회지:바다
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• 제7권4호
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• pp.2221-2221
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• 2002

한국 서해안의 곰소만에서 숙주-기생자 배양체 Prorocentrum minimum- Amoebophrya sp.를 분리하여 실험, 배양하는데 성공하였다. 본 연구는 이 숙주-기생체를 실험배양 하면서 광학 및 형광현미경 관찰을 토대로 규명된 적조생물 P minimum을 숙주로 하는 기생성 와편모류 Amoebophrya sp.의 생활사 단계를 보고한다. 이 기생성 와편모류에 의한 감염은 숙주 P minimum의 핵 내부에서 일어나고, 성장하여 결국은 세포질을 포함한 숙주 세포 공간의 대부분을 차지한다. 이 영양체의 세포 내의 성장이 완결되면 숙주의 각을 열고 세포 밖으로 나온다. 숙주 세포 밖의 자유유영 생활사 단계인 vermiform stage를 거쳐, 순간적으로 발산하여 수많은 dinospore를 형성하는 단계에 이른다. 우리나라 연안해역에서 춘·하계에 대규모 적조를 일으키는 원인 생물인 P. minimum과 이에 기생하는 본 Amoebophrya sp.의 숙주-기생배양체는 생물학적 적조제어기술 개발을 위한 중요한 생물재료의 하나이다.