발전소 주변해역 식물플랑크톤의 군집 특성

강연식,Kang, Yeon-Shik 한국조류학회(藻類) 2008 ALGAE Vol.23 No.1

This study analyzes characteristics of phytoplankton communities around Wolseong nuclear power plant by selecting 16 stations from July 2006 to June 2007 and understands the influences on standing crops and chlorophyll a of phytoplankton by passing through the cooling water system. The total species number is 283, among which diatoms is 208 occupying 73.5% of total taxa. The mean of total standing crops is 469,380-3,704,114 cells L-1. It is the highest in April 2007 because blooming of Chaetoceros socialis occurs during this period. The mean standing crops of microplankton and nanoplankton are average 129,666-3,392,640 cells L-1 and 240,943-650,505 cells L-1 respectively, which occupy 54.01% and 46.54% of total standing crops. The mean concentrations of total chlorophyll a is 0.64-5.39 μg L-1. The mean concentrations of chlorophyll a of microplankton, nanoplankton and picoplankton are 1.33 μg L-1, 0.21 μg L-1 and 0.49 μg L-1 respectively. Dominant species around Wolseong neclear power plant during this study are Chaetoceros debilis, Chaetoceros socialis, Leptocylindrus danicus, Pseudo-nitzschia fraudulenta, P. subfraudulenta and Thalassiosira decipiens. Fluctuation rates of standing crops and chlorophyll a concentrations of phytoplankton passing through the cooling water system are 22.80% and 50.48% respectively. Decrease of standing crops and chlorophyll a concentrations of phytoplankton means that community structure of phytoplnakton may change at the discharge areas.

POSCO Lightweight Solutions for Electric Vehicle

강연식 한국자동차공학회 2018 한국자동차공학회 Workshop Vol.2018 No.5

고강도 자동차부품 냉간성형 기술

강연식,김태효 대한금속재료학회(구 대한금속학회) 2021 재료마당 Vol.34 No.3

분할된 ALE 방법에 의한 평금형 열간압출의 3차원 유한요소해석

강연식,양동열,Kang, Yeon-Sick,Yang, Dong-Yol 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.11

In the analysis of metal forming process, ALE(Arbitrary Lagrangian Eulerian) finite element methods have been increasingly used for the capability to control mesh independently from material flow. The methods can be divided into two groups i.e., coupled and split formulations. In the present work, the split ALE formulation is used for computational efficiency. A split ALE finite element method developed for rigid-viscoplastic materials and applied to the analysis of hot square die extrusion. Since thermal state greatly affects the product quality, an ALE scheme for temperature analysis is also presented. As computational examples, profile shapes as square and cross-like sections are chosen.

서해 중동부 연안수역과 경기만에서 일차 생사력과 동화계수에 관한 연구

강연식,최중기 한국해양학회 1992 韓國海洋學會誌 Vol.27 No.3

서해 중동부 연안수역과 경기만에서 식물플랑크톤에 의한 일차 생산력과 동화계수 에 영향을 주는 요소들을 규명하고자 1989년 3월부터 1990년 10월까지 chl-a 농도, 광 조건, 수온, 염분도 및 투명도 등을 현장에서 조사하였다. 식물플랑크톤에 의한 chl-a 농도는 서해 중등부 연안수역에서 0.78~4.79 ug/l이었으며, 경기만에서는 0.91~4.3 ug/l의 변화폭을 보였다. 서해 중등부 연안수역에서 일일 평균 일일 생산력과 년 평균 생산력은 각각 37.23~1104.44(평균 361.54) mgC/m$^2$/d,131.96 mgC/m$^2$/yr이었으며 경 기만에서는 37.01~1028.46(평균236.89)mgC/m$^2$/d,86.46mgC/m$^2$/yr 으로 서해 중동부 연안수역이 경기만보다 다소 높게 측정되었다. 동화계수는 살펴보면 서해 중동부 연안 수역에서는 1.13~11.03mgC/mg chl-a/hr 이었으며, 경기만에서는 1.47~24.28mgC/mg chl-a/hr으로 조사되어 경기만이 다소 높게 측정되었다. 연구대상 해역에서는 다른 해 역에 비해 조사된 측정치들이 다소 높게 나타났다. P-I curve에서의 a(light utilization efficiency)는 서해 중동부 연안 수역에서 0.01~0.62[mgC/mg chl-a/hr] 이었으며, 경기만에서는 0.03~0.93[mgC/mg chl-a/hr]/[uE/m$^2$/sec]으로 조사되어 경 기만에 출현하는 식물플랑크톤이 좀더 빚을 효율적으로 이용하는 것으로 나타났다. 빛 에 대한 식물플랑크톤의 생리적인 적응상태를 지시하는 I/SUB k/값은 서해 중동부 연 안수역에서 평균120.37uE/m$^2$/sec 이었으며, 경기만에서는 48.35uE/m$^2$/sec으로 측정 되어, 경기만에서 출현하는 식물플랑크톤이 서해 중동부 연안수역에서 출현하는 식물 플랑크톤보다 상대적으로 낮은 광에 적응되어 있었다.

고리, 월성, 울진과 영광 연안해역에서 식물플랑크톤 군집의 생태학적 특성 Ⅲ. 우점종 분포와 환경요인들

강연식,최중기,엄희문,Gang, Yeon Sik,Choe, Jung Gi,Eom, Hui Mun 한국조류학회(藻類) 2003 ALGAE Vol.18 No.1

In order to investigate the distribution of dominant phytoplankton species in the coastal waters of Gori, Wolseong, Uljin and Younggwang, the standing crops of dominant species were studied during 1992-1996 and the relationships between standing crops and environmental variables were analyzed.The standing crops of diatom Skeletonema costatum, Thalassiosira decipiens, Chaetoceros debilis, Pseudo-nitzchia seriata, Paralia sulcata and dinoflgaellate Prorocentrum triestinum were on average from 16,373 to 118,549 cellso$l^{-1}$, from 11,180 to 210,313 cellso$l^{-1}$, from 23,341 to 55,889 cellso$l^{-1}$, from 6,784 to 15,766 cellso$l^{-1}$, from 342 to 41,596 cellso$l^{-1}$ and from 4,828 to 22,397 cellso$l^{-1}$ in the four study areas, respectively. The standing crops of Skeletonema costatum, Thalassiosira decipiens and Paralia sulcata were higher in Younggwang, while Chaetoceros debilis, Pseudo-nitzschia seriata and Prorocentrum triestinum were higher in Wolseong than other areas. The standing crops of silicoflgaellate Distephanus speculum were from 157 to 4,239 cellso$l^{-1}$ in the four study areas, showing an tendency increasing in Uljin. The abundance rates of Skeletonema costatum, Thalassiosira decipiens and Chaetoceros debilis were from 7.04 to 15.74%, from 6.95 to 33.69% and from 5.17 to 13.88% in the four study areas, respectivelyThe results of correlation coefficient between standing crops of dominant species and environmental variables show that phosphates were related with the distribution of dominant species in Gori, Uljin and Younggwang, while nitrogen compounds affected the distribution of dominant species in Wolseong. In addition, salinity and temperature affected the distribution of dominant species in Wolseong and Younggwang, respectively.

MSC ADAMS를 이용한 SUAV 착륙장치의 낙하해석을 위한 연구

강연식,한재도,안오성,신정우,이영신,공정표 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

월성원전 주변해역 식물플랑크톤 군집의 장기적인 분포 특성(1987-2010)

강연식,임주환,전인성 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.6

Brackish Lakes in Shinpo District, North Korea. I. Zooplankton

강연식,김세화,Kang, Yeon-Shik,Kim, Say-Wa 한국하천호수학회 2003 생태와 환경 Vol.36 No.2

북한 신포지구에 위치하는 3개 호수는(호만포호, 현금호, 대인호)동물플랑크톤 출현 결과와 염분도로 (현금호는 2002년 5월과 10월에 2.8ppt와 0.8ppt, 대인호는 1.5ppt와 0.5ppt) 보아 기수호임이 밝혀졌다. 3개 호수에서 출현한 34종류의 동물플랑크톤 중 요각류와 윤충류가 각각 15종과 7종 동정되었으며 34종류 중 담수종은 24종, 기수종과 해산종은 각각 6종과 4종이었다. 기수성 요각류인 Pseudodiaptomus와 Sinocalanus tenellus는 3개 호수에 모두 분포하고 있었으며 3개 호수 모두에서 기수종과 해산종의 출현양이 동물플랑크톤 출현양의 90%이상을 차지하고 있었다. 5월에 현금호에서 S. tenellus가 입방미터당 59,000개체로 대량 출현하여 이때 기수종과 해산종의 출현양은 전체 동물플랑크톤 출현양의 99%를 넘었다. 연구 지역의 기수호를 보호하기 위한 기초자료를 제공하기 위해서는 장기 조사가 필요한 것으로 나타났다. Three lakes (lake Homanpo, Hyunkum and Daein) were revealed to be brackish by the results of zooplankton fauna and salinities (2.8 ppt and 0.8 at lake Hyunkum in May and October 2002, and 1.5 and 0.5 at the Daein) in Shinpo district, North Korea. Among 34 taxa of zooplankton occurred, copepods and rotifers showed the prosperity in species number with 15 species and 7 species, respectively. Twenty four taxa of freshwater animals, six brackish ones and four marine ones were found, Brackish copepods, Pseudodiaptomus inopinus and Sinocalanus tenellus, were found in all lakes. More than 90% of zooplankton abundances consisted of brackish and marine species in three lakes. The outburst of S. tenellus was observed (59,000 indiv./$m^3$) at lake Hyunkum in May, when the proportion of brackish and marine zooplankton exceeded 99% of total zooplankton abundance. Long-term monitoring appears to be needed to provide basic data to protect brackish lakes in the study area.

Adaptive Nonlinear Model Predictive Path-Following Control for a Fixed-wing Unmanned Aerial Vehicle

강연식,양광진,Salah Sukkarieh 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.1

This paper presents an adaptive Nonlinear Model Predictive Control (NMPC) for the path-following control of a fixed-wing unmanned aerial vehicle (UAV). The objective is to minimize the mean and maximum errors between the reference path and the UAV. Navigating in a cluttered environment requires accurate tracking. However, linear controllers cannot provide good tracking performance due to nonlinearities that arise in the system dynamics and physical limitations such as actuator saturation and state constraints. NMPC provides an alternative since it can combine multiple objectives and constraints, which minimize the objective function. However, it is difficult to decide appropriate control horizon since the path-following performance depends on the profile of the path. Therefore, a fixed-horizon NMPC cannot guarantee accurate tracking performance. An adaptive NMPC that varies the control horizon according to the path curvature profile for tight tracking is proposed in this paper. Simulation results show that the proposed adaptive NMPC controller can follow the path more accu-rately than a conventional, fixed-horizon NMPC.