생태계제어 구조물의 파랑제어 효과에 관한 연구

김현주(Hyeon-Ju Kim),류청로(Cheong-Ro Ryu),손원식(Won-Sig Son) 한국해양공학회 1996 韓國海洋工學會誌 Vol.10 No.4

Multipurpose development of the coast and ocean can be considered as multifunction construction combining the functions of coastal protection, waterfront amenity and creation or rehabilitation of habitats. Multifunction development of coastal and ocean spaces can be accomplished by applying the ecosystem control structure of artificial habitats which will cultivate fishing ground with ecological harmony to the coastal protection system. To evaluate the applicability of ecosystem control structures as a fundamental coastal protection structure, wave control function of the structure is studied by numerical and physical analyses.<br/> Dimensional analysis and hydraulic experiment point out the importance of width and crest depth of ecosystem control structure, construction water depth and wave steepness. Wave control efficiency is estimated by the attenuation coefficient (KH) according to wave steepness (Ho/Lo), relative constructed water depth (hi/Ho), relative berm width (B/Lo) and relative crest depth (hB/Ho) of ecosystem control structure. Empirical formulas are suggested based on the results of model test by applying the multiple regression method, and compared with previous works on other coastal structures. A hybrid model based on this experimental results and numerical wave shoaling-dissipation-breaking model appears to be valid for the analysis of wave transformation around ecosystem control structure in the coastal waters.

생태계 제어구조물의 월파제어 특성

김현주(Hyeon-Ju Kim),류청로(Cheong-Ro Ryu) 한국해양공학회 1997 韓國海洋工學會誌 Vol.11 No.2

Coastal disaster induced by waves and countermeasures were investigated in the viewpoint of reduction of overtopping rate and harmony with environment in fishing port. The reduction method of wave overtopping rate using ecosystem control structures was proposed and studied on the efficiency by hydraulic and numerical experiments. The estimation models on wave overtopping rate was proposed after comparing previous models with dimensional analysis and experimental results. Control function of wave overtopping by use of ecosystem control structures was simulated and discussed with combining wave shoaling-dissipation-breaking deformation model around ecosysetm control structures and newly proposed calculation model for wave overtopping rate. Feasibility of ecosystem control structures could be confirmed for reduction of wave overtopping and fisheries-based multipurpose development of coastal zone.

생태계 제어 시설물의 설계 및 배치 최적화 ( 1 ) 연승식 양식시설의 계류력 특성 및 동요저감에 관한 연구

류청로,김현주 ( Cheong Ro Ryu,Hyeon Ju Kim ) 한국수산과학회 1995 한국수산과학회지 Vol.28 No.1

To develop the optimal design method for the longline type scallop culturing facilities in the open sea, numerical calculations and hydraulic model experiments are carried out for the stability and function optimization. Using the results for the motion and tension of the facilities, stable design concepts and effects of motion control system by vertical anchor and resistance discs are discussed. The results of this study that can be applied to the design are as follows: 1) Total external forces by design wave(H_(⅓)=6.7m, T_(⅓)=12sec) at the coastal waters of Jumunjin for unit facility (one main line) are estimated to 5-20 tons, and required anchor weights are 10-40 tons in the case of 2-point mooring system. Though the present facilities are stable to steady currents, but is unstable to the extreme wave condition of return period of 10 years. 2) The dimensions and depth of array systems must be designed considering the ecological environments as well as the physical characteristics including the mooring and holding forces that are proportional to the length and relative depth of main line to wave length, and the number of buoys and nets. 3) Oscillation of the facility is influenced by water particle motion and the weight of hanging net, and is excited at both edge, especially at the lee side. To reduce the motion of the nets, the vertical anchoring system and the resistence disc method are recommended by the experimental results. 4) The damage of rope near the anchor by abrasion should be prevented using the ring-type connection parts or anchor chains.

생태계 제어 시설물의 설계 및 배치 최적화 ( 2 ) - 흐름장에서의 인공어초의 침하 및 매몰 특성 -

류청로(Cheong Ro Ryu),김현주(Hyeon Ju Kim),이한수(Han Su Lee),신동일(Dong Il Shin) 한국수산과학회 1997 한국수산과학회지 Vol.30 No.1

Sediment transport around artificial habitat which is induced by the change of flow due to installation of the structure plays a role not only as a defect function of subsidence and burial but also bottom-environment control function. This study examined the characteristics of local scouring and deposition with sediment sizes, current velocities and installation direction of artificial habitat in flow field. Resultant subsidence and burial processes are investigated and discussed with Reynolds number. Together with sediment number and dimensionless time elapse, prediction formulas are established by combining these relationships. Bottom control function as cultivating effects is discussed with installation direction, and applicability of countermeasures is compared and stone pavement method is recommended.

해수의 광학적 성질과 해양기초생산 - 동열대 대서양 oligotrophic zone을 중심으로 -

윤홍주 ( Hong Joo Yoon ),류청로 ( Cheong Ro Ryu ),김기태 ( Ki Tae Kim ),김현주 ( Hyeon Ju Kim ) 한국수산학회 1995 한국수산과학회지 Vol.28 No.2

Using the optical data from the EUMELI 3 and 4 missions, the optical properties are discussed in relation to primary production in the oligotrophic zone of the Eastern Atlantic Ocean. The depth of euphotic layer (Z(eu)), the total accumulated concentration of pigment (C(TOT)) and the concentration of pigment (C) are 88m, 12.4mgm(-2) and 0.14mgm(-3), respectively for the EUMELI 3 mission, and 101.7m, 10.0mgm(-2) and 0.10mgm(-3), respectively for the EUMELI 4 mission. The concentration of pigment is higher in autumn (EUMELI 3) than in spring (EUMELI 4). This indicates that the concentration of photosynthetic pigment has a close correlation with vertical attenuation coefficient (K(λ)) that changes seasonally in the euphotic layer. While the spectral distributions of downward irradiance (Ed) for the wave length of 470nm increase with depth, those of upward irradiance (Eu) for the wave length range between 410nm and 490nm are constant, because the study area is covered with the blue and clear oceanic deep waters. The vertical attenuation coefficients of downward irradiance (Kd) and upward irradiance (Ku) have low values between 0.02 and 0.06m(-1) due to the low absorption and scattering by the photosynthetic pigment of phytoplankton. Therefore this zone has the characteristics of the case I waters with low concentrations of photosynthetic pigment, and can be c1assifed into IB.

수치실험조건에 따른 해양파랑특성의 통계적 안정한계

김현주,류청로 한국수산학회 1987 한국수산과학회지 Vol.20 No.5

Stochastic stability criterias for ocean wave analysis and simulation are studied using the data simulated by the linear superposition method. To clarify the criterias, the effects of the simulation parameters on the variance of stochastic properties of ocean waves are investigated, and the stable conditions of the parameters are estimated through the comparative study on the stochastic properties of simulated waves and well-known ocean waves. The simulation parameters considered are high frequency cut-off, data length, and number and phase angle of component waves. Statistical characteristics analysed are wave height, period and steepness, and the formation of groups of higher waves, resonance periods, steeper higher waves and extreme run-length of the run.

해양파랑의 통계적 변동성 해석

김현주,류청로,김종욱 한국수산학회 1989 한국수산과학회지 Vol.22 No.1

Using computer simulated irregular waves, variations of ocean wave statistics according to sea state are analyzed, and the reasonable conditions that transform the energy spectrum to individual wave statistics are discussed. Ocean wave statistics varying with sea state are found to respond linearly to the spectral peakedness parameter Q_p and spectrum moments m_n(n=0, 1, 2, …, ∝). It is clarified that the 2nd-order spectrum moment is a reasonable parameter which represents the wave statistics including wave periods, and that the spectrum analysis should be carried out under the conditions of minimum data length of 10 times of peak period Tp with time lag of 7Tp to satisfy the stable condition of wave statistics.

착저식 인공어초에 작용하는 파력특성에 관한 연구

김현주,류청로 한국수산학회 1994 한국수산과학회지 Vol.27 No.5

The methods to determine the hydrodynamic coefficients for the fixed type artificial reefs which were constructed to control ecological system in coastal waters are compared and discussed by model test results. To calculate the wave forces, least square method show good agreement with the experimental results and more stability than maximum force component method or Fourier decomposition method. This modified least square method of weighting the square of measured force turned out to be the most feasible method for maximum force. Using the feasible method, hydrodynamic characteristics for artificial reefs on uniform slopes offshore and breaking zone were studied. They were properly related to Keulegan-Carpenter's number and found larger than previous results. Wave force coefficients for artificial reefs around breaking zone were distributed from 1.5 to 2.5, and the mean value was 2.0. Drag force components were more in evidence than inertia force in maximum force which is important parameter to evaluate stability for high-permeability structures. A formula for the calculation of the maximum force for artificial reefs design is proposed, using structural dimension, water particle velocity and Keulegan-Carpenter's number.

한국 연안의 극치 파랑환경과 Freak Wave의 특성에 관한 연구

류청로,윤홍주,박종화,김현주 한국환경과학회 1993 한국환경과학회지 Vol.2 No.3

Extreme environments and freak wave characteristics in the coastal waters of Korean Peninsula are analyzed using the observed wave data. Freak wave has been intensely emphasized as an important environmental force parameter in several recent research works. However, the mechanism and occurrence probability of freak wave are not clarified. The aims of this study are: to summarize the distribution of extreme environment for wind waves, and to find occurrence probability of freak wave in the coastal waters of Korean Peninsula. These extreme sea conditions are discussed by applying extreme value analysis method, and the statistic characteristics are summarized which can be used to the design and analysis of coastal structures. The mechanism and the occurrence probability of freak wave are also discussed in detail using wave parameters in considered with wave deformation in the coastal waters.