• Journal of the Korean earth science society
• /
• v.39 no.6
• /
• pp.555-567
• /
• 2018

In order to identify the characteristics of sea surface temperature (SST) differences between microwave SST from GCOM-W1/AMSR2 and in-situ measurements in the western coast of Korea, a total of 6,457 collocated matchup data were produced using the in-situ temperature measurements from marine buoy stations (Deokjeokdo, Chilbaldo, and Oeyeondo) from July 2012 to December 2017. The accuracy of satellite microwave SSTs was presented by comparing the ocean buoy data of Deokjeokdo, Chilbaldo, and Oeyeondo stations with the AMSR2 SST data more than five years. The SST differences between the microwave SST and the in-situ temperature measurements showed some dependence on environmental factors, such as wind speed and water temperature. The AMSR2 SSTs were tended to be higher than the in-situ temperature measurements during the daytime when the wind speed was low ($<6ms^{-1}$). On the other hand, they showed positive deviation increasingly as the wind speed increased for nighttime. In addition, increasing tendency of SST differences was related to decreasing sensitivity of microwave sensors at low temperatures and data contamination by land. A monthly analysis of the SST difference showed that unlike the previous trend, which was known to be the largest in winter when strong winds were blowing, the SST difference was largest in summer in Deokjeokdo and Chilbaldo buoy stations. This seemed to be induced by differential tidal mixing at the collocated matchup points. This study presented problems and limitations of the use of microwave SSTs with high contribution to the SST composites in the western coastal region off the Korean peninsula.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.2
• /
• pp.109-118
• /
• 1985

This experiment was carried out to evaluate the water quality in the lower part of the Nagdong river in Korea. Three hundred and sixty water samples were collected from the 15 stations from December 1981 to November 1982 by tide(see Fig.1). Water temperature, pH, chloride ion, salinity, total coliform, fecal coliform, viable cell count and the composition of coliform were observed to evaluate the water quality. The variations of water temperature was ranged from $2.0^{\circ}C\;to\;29.5^{\circ}C$ and as mean value from $15.8^{\circ}C\;to\;18.9^{\circ}C$. The range of pH was 6.00-8.88 and 7.20-7.96 as mean value. The concentration of chloride ion from St. 1 to 5 was higher as 17.51-771 mg/l in flood tide than 13.12-264.58 mg/l in ebb tide. Specially, water quality at St.1 (Samrangjin) which located about 46 km far from Hadan was also influenced by tide. Salinities of water in flood tide were a litte higher ($11.05{\sim}31.08\%0$) than those of in ebb tide ($7.80{\sim}29.28\%0$). Total coliform MPN's ranged from 3.6/100 m/l to 460,000/100ml. The geometric mean value of the upper area (included St. $1{\sim}3$) was $259{\sim}538/100ml$, that of the middle area (included St. $4{\sim}6$) was $1,097{\sim}39,544/100ml$ for it leveled heavy contamination. Specially, in the ebb tide St. 10 was influenced by St. 6 and 7. In the upper area, the geometric mean value of fecal coliform MPN's was $109{\sim}199/100ml$ but in the area in cluded St. 5, 6 and 7 were heavily contaminated by domestic sewage, waste water from the factories area and bird's excrement. Composition of coliform was $17\%$ Escherichia coli group, $33\%$ Citrobacter freundii group, $28\%$ Enterobacter aerogenes group and $21\%$ others. Plate count of samples was varied from <30 to $3.9{\times}10^4/ml$ during the study period.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.2018-2022
• /
• 2009

본 연구에서는 낙동강 하구둑의 주요 기능 중에서 용수공급에 지장을 초래하는 염수침입 및 염해피해 방지 효과에 대하여 재평가 하고자 한다. 평가범위는 수치모형을 이용하여 낙동강 하구둑 건설 이전의 지형상황을 재현하고, 하구둑이 없는 조건 하에서 상류유입유량을 변화시키며 외해를 통한 염분 침입 가능범위를 수치모의 함으로서 하구둑의 효과를 간접적으로 평가하였다. 연구에 사용된 수치모형인 EFDC 모형 입력자료로 낙동강 하류부 및 외해 수역에 대한 3차원 지형도를 작성하였고. 평면 직교곡선격자망을 이용하여 대상 지역을 분할하였다. 초기조건으로 전 수역을 담수(염도 0.0psu)로 가정한 상태에서 하류단 경계에 실측 조위 및 해수조건(염도 33psu)을 적용하고 상류단에는 $50m^3/sec$를 적용하여 약 20일간 수행된 결과를 사용하였다. 상류유입유량을 $10^{\sim}250m^3/sec$의 범위로 변화시키고, 하류단 경계조건으로 조위를 적용하여 수치모의를 수행한 결과 염수침입현상에 제일 큰 영향을 미치는 요소는 상류로부터 유입하는 유량인 것으로 나타났다. 그 이외에 담수와 해수의 밀도 차이에 인한 밀도류형성 및 조석에 의한 염수의 밀어올림현상이 하류에서 상류로 염수가 침입하는데 다소의 영향이 있었다. 유입유량이 $250m^3/sec$에서 $10m^3/sec$로 감소할 경우 염분농도 1psu의 도달범위는 11km에서 50km정도로 증가하였다.

• Korean Journal of Environmental Biology
• /
• v.19 no.2
• /
• pp.137-145
• /
• 2001

Although tidal current affects the distribution of zooplankton significantly, its impacts were usually ignored when the studios on the zooplankton abundance were conducted even in the Yellow Sea where tidal current was very strong. Furthermore, information on the tidal impacts was very limited in the Yellow Sea. In this study, the tidal current effects on the abundances of copepod genera Acartia, Calanopia, Calanus, Centropages, Corycaeus, Labidocera, Paracalanus, Tortanus in a fixed sampling station near the Sonanjido (Island) were studied. The abundance of copepods collected by the same sampling method nab highest when the tidal current was fastest at 2 or 3 hours after the high or low tide.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.500-505
• /
• 2004

인천지역은 지형이 낮은 관계로 배수가 원활하지 못한 지역이 있고 또한 서해안 특유의 높은 조석간만의 차이로 인하여 만조시에는 배수가 어려워 침수가 발생하는 지역이 많다. 이에 대하여 매립된 인천교 주변 하수관거의 통수능을 수치해석을 통하여 분석하고 배수 체계 및 인천교 주변의 내수 배제에 대한 문제점을 파악하여 침수 개선방안을 제시하므로써 인천교 주변 매립지의 침수피해를 경감시키고자 하였다. 통수능 분석을 위한 수치해석 프로그램으로 SWMM모형이 선정되었으며 보다 정확한 해석을 위하여 대상 유역을 수십 개의 소유역으로 구분하여 소유역의 유출을 계산한 후에 관로 내 흐름에 대하여 해석을 실시하였다. 소유역에서의 보다 정확한 유출량 산정을 위하여 평균유출계수(C값)를 사용치 않고 소유역마다 산출된 별도의 유출계수를 이용하였다. 유출량 산정을 위한 강우강도는 기존의 인천대공식과 최근의 강우량을 감안한 해석결과를 비교하여 기존의 인천대 공식 사용이 가능함을 판단하고 이를 사용하여 20년, 30년 빈도의 확률강우강도를 산정하였다. 설계빈도에 대하여 유역 내 침수 피해를 경감시키는 4개의 대안을 선정하여 각각의 대안에 대한 해석을 실시하여 침수피해 개선효과를 비교하여 최적의 대안을 판단하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.5 s.305
• /
• pp.79-84
• /
• 2005

In this paper, we developed an omni-directional surveillance and motion detection method. The fish-eye lens provides a wide field of view image. Using this image, the equi-distance model for the fish-eye lens is applied to get the perspective and panorama images. Generally, we must consider the trade-off between resolution and field of view of an image from a camera. To enhance the resolution of the result images, some kind of interpolation methods are applied. Also the moving edge method is used to detect moving objects for the object tracking.

• 한국해양학회지
• /
• v.7 no.1
• /
• pp.15-18
• /
• 1972

The observations of hourly change of salinity and temperature were made in the Korea Strait from August 1968 to July 1969. The largest hourly change of salinity and temperature was shown in August and the smallest in April. The range of hourly change of temperature (5.67-15.75$^{\circ}C$ on the depth of 125m) and salinity (32.1-34.3 on 20m layer) were significantly wide in August. These changes are correlated with the movement of water masses vertically and horizontally caused by changing direction and force of the current.

• Journal of the Korean earth science society
• /
• v.23 no.3
• /
• pp.270-279
• /
• 2002

The concentrations of major greenhouse pollutants which include $CO_2$ and $CH_4$ were determined from the outlet of 42 ventpipes in Nan-Ji-Do area of Seoul during September/October of 2000. Using these data, the concentration distribution of major greenhouse gases was checked and compared. The mean concentrations of $CO_2$ and $CH_4$, computed using the data sets collected from 42 ventpipes, were 27.8 and 50.9%, respectively. Because the concentration levels were different not only between plain and slope areas of each sector but also between chemicals, evaluation of the data sets was made after dividing them separately into four data groups. The results of our analysis clearly indicate that their distribution is rather homogeneous than those of minor constituents of landfill ventilated gases (e.g., Hg).

• Journal of Gifted/Talented Education
• /
• v.16 no.2
• /
• pp.143-166
• /
• 2006

On the basis of exploration for the effect of grade skipping and early graduation on socio-emotional adjustments of early college entrants, this study sought to present educational and counseling implications for the promotion of efficiency in practicing grade skipping and early graduation. Fifty-two students were asked to report their IQs and GPAs and to respond the Self-Esteem Inventory(Coopersmith, 1967, 1981, 1984) and the Attitude toward Schooling Scale(Lee & Lee, 2000). The data collected were analyzed by MANOVA and MANCOVA. On the contrary to concern for socio-emotional development of early entrants, the result indicated that there was not any statistically evidence to show the differences in socio-emotional adjustments between early entrants and the counterparts in the K University. However, there were significant group differences in attitude toward schooling(e,g,. the opportunities and informations for grads skipping and early graduation).

• Journal of Chest Surgery
• /
• v.42 no.3
• /
• pp.355-360
• /
• 2009

Background: Benign teratoma is mostly asymptomatic, but this tumor rarely ruptures into the adjacent structure such as the pleural space, pericardium, lung parenchyma or tracheobronchial tree. Thus, it is important to differentiate ruptured teratoma from unruptured teratoma. This study evaluated the difference between ruptured and unruptured benign teratoma. Material and Method: Twenty-four cases of surgically resected benign teratomas were reviewed retrospectively. The clinical symptoms, chest CT findings and operative findings of the ruptured teratoma were compared with those of the unruptured teratoma. Especially, the tumor size, wall thickness, location of the mass, internal septation, homogeneity, calcification and ancillary findings were evaluated on CT. Result: Of the 24 patients, 7 patients were diagnosed with ruptured teratoma. Severe symptoms were more commonly found for ruptured teratoma than for unruptured teratoma. The ruptured teratoma had a tendency to display calcification and such ancillary findings as collapse or consolidation of the lung parenchyma. For the ruptured teratoma, the resection was performed by sternotomy or thoracotomy, and more lung resection was included. Conclusion: Calcification within the mass and changes in the lung parenchyma on the preoperative CT findings can be diagnostic signs of a ruptured teratoma. The demonstration of ruptured teratoma is important not only for making the early diagnosis, but also for the surgical planning.