• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.446-449
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• 2001

본 논문에서는 태풍의 진로와 세기를 ES_BLRNN을 이용해 예측하였다. 기존의 방법인 수치모델이나. CLIPER모델을 사용함에 있어서, 통계적 방법인 CLIPER모델은 예측성능면에서 수치모델보다 그 성능이 떨어지고, 반면에 수치모델의 성능은 CLIPER 모델에 비해 우수하나 슈퍼컴퓨터(Cray-2S, FUSITSU)를 이용하여야만 예보가 가능한 제약점을 가지고 있다. 또한 수치모델을 슈퍼컴퓨터로 계산할 경우 약 30분 정도가 소요되는 점을 감안할 때, ES_BLRNN은 이들의 단점을 보안할 수 있는 하나의 방편이라 생각된다. 게다가 ES_BLRNN의 경우 개인용 컴퓨터로도 충분히 사용 가능할 만큼 비용이 저렴하고, 681개의 태풍을 학습할 때 결리는 시간은 약 5분 정도이며, 146개의 태풍을 예측하는데 걸리는 시간은 약 3초 정도(Pentium MMX 200 Processor, RAM 64m, OS: RedHat LINUX 5.2. language ; ANSI-C)로써, 슈퍼컴퓨터나 CLIPER모델에 비해 훨씬 빠르게 결과를 볼 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.275-275
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• 2012

본 연구에서는 Pacific-Japan (PJ) 대기패턴과 북서태평양 지역의 열대성 태풍 활동에 대한 관계를 분석하였다. 특히 한반도에 영향을 미치는 태풍을 중심으로 낙동강 유역의 태풍에 의해 유발된 여름철(June-September) 강수의 지역적 특성 변화를 진단하였다. 분석 결과, 양(+)의 PJ 기간에 발생하는 대기순환패턴의 변화는 태풍의 활동에 보다 유리한 작용을 하는 것으로 나타났다. 한반도에 영향을 미치는 태풍에 대한 진로 분석 결과, 양(+) PJ 기간동안 태풍이 주로 남서쪽으로 향하는 경향이 있으며, 음(-)의 PJ 기간에는 북동쪽으로 향하는 경향이 있는 것으로 나타났다. 태풍 진로의 변향점(recurve)은 양(+)의 PJ 기간에는 보다 북서쪽에 위치하며 음(-)의 PJ 기간에는 보다 북동쪽에 치우쳐 있음이 분석되었다. 따라서, 음(-)의 PJ기간 보다 양(+)의 PJ 기간에 태풍의 활동이 활발하며, 낙동강유역에서 태풍에 의해 유발된 강수가 통계적으로 유의한 증가패턴이 뚜렷하게 발생하고 있는 것으로 확인되었다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.325-332
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• 2008

To characterize the initiation, propagation and termination of Cochlodinium polykrikoides blooms in the southeast coastal waters of Korea, 2007, we have analyzed the data set of phytoplankton composition, physical and chemical water properties, and meterological data. The development of C. polykrikoides bloom in 2007 can be summarized in three steps. The first stage from middle of July to end of August was characterized by an unusually persistent and strong southerly wind. C. polykrikoides blooms established already by the strong wind in the middle of south coastal waters were advected intermittently into the study area. Accordingly, highly variable cell densities of C. polykrikoides were observed. At the second stage a favorable growing conditions for C. polykrikoides was developed, which was directed by changes in wind direction from south to northeast and thus enhanced transportation of offshore waters into inshore (August 8 to 30). C. polykrikoides bloom occurred through typical mechanism and showed high cell density. The last stage was represented by disappearance of C. polykrikoides. Typoon 'Nari' carrying heavy rain brought an unfavorable habitat to C. polykrikoides. Low saline condition formed in coastal water due to typoon effects continuously drove the dominant species to diatoms and flagellates which were prevailing over C. polykrikoides in this circumstances(from the middle of September). These stepwise processes could be the causative mechanism of the extraordinarily persistent C. polykrikoides bloom observed in southeast coastal water of Korea, 2007.

• Ocean Science Journal
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• v.43 no.2
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• pp.81-90
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• 2008

A study of estuarine flows during a neap tide was performed using 13-hour roving acoustic Doppler current profiles (ADCP) and conductivity-temperature-depth (CTD) profiles in the Altamaha River estuary, Georgia, U.S.A. The least-squared harmonic analysis method was used to fit the tidal ($M_2$) component and separate the flow into two components: the tidal and residual ($M_2$-removed) flows. We applied this method to depth-averaged data. Results show that the $M_2$ component demonstrates over 95% of the variability of observation data. As the flow was dominated by the $M_2$ tidal component in a narrow channel, the tidal ellipse distribution was essentially a back-and-forth motion. The amplitude of $M_2$ velocity component increased slightly from the river mouth (0.45 m/sec) to land (0.6 m/sec) and the phase showed fairly constant values in the center of the channel and rapidly decreasing values near the northern and southern shoaling areas. The residual flow and transport calculated from depth-averaged flow shows temporal variability over the tidal time scale. Strong landward flows appeared during slack waters which may be attributed to increased baroclinic forcing when turbulent mixing decreases.

• Water for future
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• v.26 no.4
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• pp.35-46
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• 1993

The variations of water surface elevation due to bridge are studied using one_dimensional dynamic wave equation. The preissmann scheme is used to solve the dynamic wave equation and the bridges was treated as internal boundary conditions. Main causes of bridge backwater are the proportion of the contracted area due to bridge, roughness coefficient and discharge coefficient. The effect of discharge coefficient in weir flow condition is comparatively small. This model is verified by applying to the Suyoung River. which suffered a severe damage by typoon Gladys. The rise of water level through bridge is 1.53-1.08m in the reach of 4.25-6.20km from the downstream of river. The simulation results of the model have good agreements with the observed data.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.606-613
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• 2004

One of the major forces that causes landslide is the amount of underground water resulted from rainfall and shear strength. As a result of close study on the landslide area affected by typoon Rusa it is observed that many landslides took place at the interface of rock and soil. Based on this observation that shear strength at the interface played a great role in landslide of the hilly area, two shear strengths were measured on different places, one at the interface between rocks and soil and the other just on soil. The two values thus derived were compared and used to review the safety factor for the hilly areas already collapsed. Back analysis was also used to calculate the ground water table according to the different rock types at the time when degradation happened.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.172-178
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• 2003

As a typoon gets into harbour, a moored ships shows erratic motions and even mooring line failures is occurred. Such troubles may be caused by harbour resonance phenomena, result in large motion amplitudes at law frequency, which is closed to the natural frequency of the moored ship. The nonlinear motions of a moored ship beside quay are simulated under external forces due to wave, current including mooring forces in time domain. The forces due to waves are obtained from source and dipole distribution method in the frequency domain. The current forces are calculated by using slow motion maneuvering equation in the horizontal plane. The wind forces are calculated from emperical formula of ABS and the mooring forces of ropes and fenders are modeled as linear spring.

• Journal of The Geomorphological Association of Korea
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• v.18 no.3
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• pp.83-92
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• 2011

The properties and changes of geomorphic relief and coastal deposits were analyzed at Goreabul sand beach in Yeongdeok-gun, the largest that in east coast of Kyungsangbuk-do Province. As the result of grain size analysis, in almost season except summer, the sands mainly deposited in Goraebul sand beach because longshore current drift northward contrary to Gangwon-do east coast, and summer longshore current is weak or change direction to south ward. Sand beach mostly came form erosion owing to typoon and storm and was deposit more coarse sand in the summer, and was produced deposition actively in the fall and winter. Front side of sand dune came from deposition on sand every season by sea breeze, especially in the winter.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.429-434
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• 2005

The dynamics of phytoplankton community after the formatiom of turbidity was assessed at Dam barrage of Lake Imha from May 2003 to July 2004. The maximum turbidity of 1221 NTU during September and October 2003 was well correlated with heavy precipitation caused by Typoon Maemi. A total of 102 phytoplankton taxa was identified and the most abundant phytoplankton group was Bacillariophyceae with 63 taxa, followed by Chlorophyceae with 23 taxa, Cyanophyceae with 9 taxa, 3 taxa each of Synurophyceae and Cryptophyceae and Euglenophyceae with 1 taxon. The total standing crops ranged between 270 indls. $mL^{-1}$ and 4,515 indls. $mL^{-1}$ during the investigation Periods. The three species, Cryptomonas ovata, Cyclotella sp. and Microcystis aeruginosa predominated in sequence after the decrease of turbidity.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.473-476
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• 2006

천해역의 파랑발달에 대한 태풍경로의 영향력을 분석 하였다. 우리나라 남동해안에 주로 피해를 초래할 것으로 판단되는 태풍의 경로를 '남해안 상륙 후 내륙 통과'와 '대한해협통과'로 분류하고 각 경로에 따른 태풍규모와 파랑발달을 1956년 부터 2004년까지의 기상자료를 바탕으로 검토하였다. 태풍 경로의 영향력 분석은 천해역 파랑발달의 주요외력이 지형조건에 의해 결정되므로(즉, 폐쇄해역은 태풍의 바람장이 주요외력이며, 개방해역은 심해 전달파랑과 바람장의 영향을 동시에 받는다), 개방해역과 폐쇄해역의 경우로 나누어 수치모형실험을 통해 수행하였다. 실험조건은 태풍 "매미"의 강도와 특성 값을 기준으로 하였으며, 대상해역은 부산신항 인근해역과 원전항 인근해역을 개방형과 폐쇄형 해역으로 대별하여 실험을 수행하였다. 자료의 분석결과 최근 이상기후현상으로 태풍의 강도가 커지고 있음을 뒷받침 하는 근거는 찾아보기 힘들었으며, 2000년대 이후로 남해안에 상륙하는 경로'1'이 대한해협을 통과하는 경로(경로'2')보다 그 내습빈도가 커지고 있음을 볼 수 있었다. 태풍의 경로와 풍향이 같은 방향인 경로'1'일 때 에너지가 집중되어 태풍중심기압과 풍속과 파고의 증가가 함께 일어난다. 그러나 태풍의 경로와 풍속의 방향이 일치하지 않는 경로'2'의 경우는 에너지가 분산되므로 태풍중심기압과 풍속은 함께 증가하나 파랑에너지는 함께 발달하지 않는 것으로 보였다. 내습한 태풍의 강도를 경로별로 비교한 결과, 경로'1'이 경로'2'보다 큰 강도를 가지고 연악역에 영향을 미치는 것으로 판단되었다.