동해 남서해역에서의 살오징어 유생 출현 특성을 파악하기 위해 2015년 8, 9, 11월 여수 근해부터 평해 연안까지 총 35개 정점에서 IKMT 네트(망목 : 500μm)를 사용하였으며, 초기 생활단계의 주요 해양환경 인자인 수온은 CTD(SBE9plus)로 관측하였다. 유생의 월별 외투장 자료의 통계처리를 위하여 SPSS software(ver. 12.0)를 이용하였다. 채집된 살오징어 유생의 개체수는 총 228개체로 외투장 범위는 1.4-21.9㎜였다. 유생밀도 범위는 8월에 0.2-5.2inds./1,000m3, 9월에 0.1-3.2inds./1,000m3, 11월에 0.3-7.9inds./1,000m3로 나타났다. 전반적으로 유생은 연안측 정점보다 조사해역의 동남부인 부산 근해에서 더 높은 밀도를 보였다. 8, 9, 11월의 유생출현률은 각각 64.3%, 62.9%, 68.6%였다. 평균외투장 범위는 5.24-5.68㎜였으며, 월별 평균외투장은 유의한 차이를 나타내지 않았다(p>0.05). 또한 외투장 분포에서 4-5㎜ 구간의 유생이 최다 출현빈도를 보였다. 유생이 채집된 정점에서 유생의 생존이 가능한 수온대가 8월에는 대부분의 정점에서 표층부터 약 20m 부근까지 유생이 서식하기에 부적합한 수온대가 존재하였던 반면, 9월과 11월에는 표층부터 유생이 서식하기 적합한 수온대가 형성되었다. 또한 얕은 수심의 연안쪽 정점에서는 표층에서 저층까지 적수온대가 형성되었으며, 100m 이상의 깊은 수심의 외양 쪽 정점에서는 표층부터 수온약층의 상층부까지 유생의 생존가능한 수온대가 형성되었다.
서해에서 살오징어(Todarodes pacificus) 유생 분포를 파악하기 위해 2013년 - 2015년 춘계(4월)와 추계(11월) 자원조사선 탐구 20호로 18정점에 대해 CTD 관측 및 지름 60 cm, 망목 333 μm의 봉고네트를 이용한 경사 채집을 실시하였다. 조사기간 동안 채집된 유생은 총 4개체로 2014년과 2015년 추계에 각 2개체였으며, 유생의 외투장은 1.5 - 8.3 mm이었다. 조사기간 동안 춘계와 2013년 추계에는 유생이 출현하지 않았다. 유생밀도는 2014년 추계에 0.1 inds./1,000 m3과 0.2 inds./1,000 m3, 2015년 추계에 0.1 inds./1,000 m3과 0.2 inds./1,000 m3로 나타났다. 유생이 채집된 정점에서 배아발달 및 유생의 생존이 가능한 수온대(15 - 24 )는 수심 56 m보다 얕은 곳에 위치하였다.
A small dam is of hydraulic structures, which is always exposed to risk by flood, and it’s very important to ensure structural safety. A probabilistic analysis, quantifying variable as a risk factor to ensure safety of small dam, identifying its coefficient of variation, which has become increasingly important. In this study, the risk of seepage failure of foundation within a small dam was estimated based on flood scenarios by rainfall quantile. The final compound risk was evaluated combining probabilities, related to seepage failure and flood level. The seepage failure probability was estimated by performing seepage analysis depending on the water level difference between upstream and downstream in small dam. The probable flood level was estimated by considering hydraulic uncertainty associated with channel geometry, and movable gate operation during the flooding season, applied a probable flood considering hydrologic uncertainty evaluated by Bayesian approach. The safety evaluation of small dam with probabilistic-based compound risk expect to use the index for hydraulic structure design in the future.
매오징어 Watasenia scintillans 유생분포양상을 알아보기 위해 2015년 8, 9, 11월 R/V 탐구 21호로 동해 남서부연안 28개 정점 에 대해 CTD관측 및 IKMT(망목: 500 μm)를 사용하여 저층(최대 수심 100 m)에서 표층까지 경사채집을 실시한 결과, 채집된 매오징어 유생의 개체수는 총 238개체로 외투장(ML) 범위는 0.6 ~ 18.5 였다. 조사기간 중 8월이 9월과 11월보다 유생의 출현정점 수, 출현개체 수, 유생분포밀도에서 현저히 높았다. 특히 8월에 냉수괴가 분포하는 포항 ~평해까지의 동해연안에서 가장 높은 밀도를 보였다. 유생이 채집된 정점의 연직수온분포에서 매오징어의 부화수온(6 ~ 16 )은 주로 40 ~ 180 m의 수심에 위치하였다.
The tsunami hazard analysis is performed for testing the application of probabilistic tsunami hazard analysis to nuclear power plant sites in the Korean Peninsula. Tsunami hazard analysis is based on the seismic hazard analysis. Probabilistic method is adopted for considering the uncertainties caused by insufficient information of tsunamigenic fault sources. Logic tree approach is used. Uljin nuclear power plant (NPP) site is selected for this study. The tsunamigenic fault sources in the western part of Japan (East Sea) are used for this study because those are well known fault sources in the East Sea and had several records of tsunami hazards. We have performed numerical simulations of tsunami propagation for those fault sources in the previous study. Therefore we use the wave parameters obtained from the previous study. We follow the method of probabilistic tsunami hazard analysis (PTHA) suggested by the atomic energy society of Japan (AESJ). Annual exceedance probabilities for wave height level are calculated for the site by using the information about the recurrence interval, the magnitude range, the wave parameters, the truncation of lognormal distribution of wave height, and the deviation based on the difference between simulation and record. Effects of each parameters on tsunami hazard are tested by the sensitivity analysis, which shows that the recurrence interval and the deviation dominantly affects the annual exceedance probability and the wave heigh level, respectively.
Probabilistic tsunami hazard analysis (PTHA) is based on the approach of probabilistic seismic hazard analysis (PSHA) which is performed using various seismotectonic models and ground-motion prediction equations. The major difference between PTHA and PSHA is that PTHA requires the wave parameters of tsunami. The wave parameters can be estimated from tsunami propagation analysis. Therefore, a tsunami simulation analysis was conducted for the purpose of evaluating the wave parameters required for the PTHA of Uljin nuclear power plant (NPP) site. The tsunamigenic fault sources in the western part of Japan were chosen for the analysis. The wave heights for 80 rupture scenarios were numerically simulated. The synthetic tsunami waveforms were obtained around the Uljin NPP site. The results show that the wave heights are closely related with the location of the fault sources and the associated potential earthquake magnitudes. These wave parameters can be used as input data for the future PTHA study of the Uljin NPP site.
남산의 소나무림, 신갈나무림 그리고 아까시나무림에서 2008년 1월부터 2009년 12월까지의 월별 낙엽생산량과 토양의 유기탄소량을 조사하였다. 소나무림은 2008년과 2009년 모두 10월에 낙엽생산량이 가장 많았으며, 2008년 1월과 2009년 12월에 낙엽생산량이 가장 적었다. 신갈나무림은 2008년과 2009년 모두 11월에 낙엽생산량이 가장 많았으며, 2월에 낙엽생산량이 가장 적었다. 아까시나무림은 2008년 11월과 2009년 10월에 낙엽생산량이 가장 많았으며, 2008년 1월과 2009년 12월에 낙엽생산량이 가장 적었다. 이것은 한반도 중부에서 상록성의 소나무림이 낙엽성의 참나무숲 보다 더 일찍 낙엽이 진다는 것을 의미한다. 소나무림과 신갈나무림, 아까시나무림의 2년 평균의 낙엽생산량은 7.07, 6.36, 5.02 ton ha-1로 소나무가 가장 많았다. 소나무림과 신갈나무림, 아까시나무림의 2년 평균의 토양유기탄소량은 76.2, 68.6, 72.5 ton C ha-1로 소나무림에서 가장 많았다. 이처럼 소나무숲에서 높게 나타난 것은 남산에서 신갈나무나 아까시나무를 벌목하여 임목밀도가 줄었기 때문이다.
The uniform hazard spectra for seven major cities in Korea, Seoul, Daejeon, Daegu, Busan, Gwangju, Ulsan, and Inchon are suggested. Probabilistic seismic hazard analyses were performed using the attenuation equations derived from seismology research in Korea since 2000 and the seismotectonic models selected by expert assessment. For the estimation of the uniform hazard spectra, the seismic hazard curves for several frequencies and PGAs were calculated by using the spectral attenuation equations. The seismic hazards (annual exceedance probability) calculated for the 7 metropolises ranged from about 1.4305×0-4/yr to 1.7523×10-4/yr and averaged out at about 1.5902×10-4/yr with a log standard deviation of about 0.085 at 0.2 g. The uniform hazard spectra with recurrence intervals of 500, 1000, and 2500 years estimated by using the calculated mean seismic hazard on the frequencies presented peak values at 10.0 Hz, and the log standard deviations of the difference between metropolises ranged from about 0.013 to 0.209. In view of the insignificant difference between the estimated uniform hazard spectra obtained for the considered metropolises, the mean uniform hazard spectrum was estimated. This mean uniform hazard spectrum is expected to be used as input seismic response spectrum for rock sites in Korea.
국내 고등교육기관의 외국인 유학생 수는 지난 15년간 1만여 명에서 14만여 명으로 꾸준히 증가하는 추세에 있다. 본국을 떠나 새로운 환경을 접하는 외국인 유학생은 상위교육기관으로 전환을 동시에 경험하기 때문에 대학적응에 많은 어려움을 겪는다. 이때 교우관계는 외국인 유학생의 적응을 돕는 기제로 이해된다. 그러나 민족적 울타리(ethnic enclave)이론에 기반을 둔 관점은 교우관계의 구성이 모국인 친구집단에 편중될 때 특정한 영역의 대학 적응에 관한 어려움이 강화될 수 있다는 추측을 가능하게 한다. 모국 출신 중심적 교우관계가 다양한 친구집단으로부터 각기 다른 방식으로 대학적응에 관한 도움을 받을 기회를 제한할 수 있기 때문이다. 이러한 가능성을 검증할 목적으로 이 연구는 서울 소재의 한 대학에 재학 중인 중국인 유학생 195명의 자료를 활용하여 모국 출신 중심의 교우관계와 학업성취 및 정서적 적응 사이의 관계를 분석하였다. 분석결과, 교우관계에서 모국인 친구가 높은 비율을 차지하는 중국인 유학생의 경우 학업성취가 낮은 경향이 확인되었다. 또한, 정서적으로 어려움을 겪을 가능성도 높은 것으로 나타났다. 이러한 결과는 대학기관이 외국인 유학생의 대학적응을 위해 그들의 교우관계를 다변화할 방안을 모색해야 한다는 점을 시사한다.
Recently, the frequency of natural disasters in Korea is increasing due to the influence of global climate change, and the importance of quick and accurate monitoring and corresponding response is frequently and strongly stressed in terms of disaster management. In this regard, this study describes a development of realtime safety evaluation system (RSEE) which enables to carryout real-time measurement and safety evaluation of some important SOC water infrastructures (dams, weirs, cut slopes, retaining walls, levees and bridges) installed along the nation registered large scale rivers.
The Integrated Water Infrastructures Safety Management Platform(WINS+) provides safety information of water infrastructures such as dams, weirs, bridges, cut slopes, retaining walls and levees designated as the first class infrastructures to be maintained according to the nations’s safety law. The WINS+ is incorporated with a computerized Standard Operating Procedure (SOP) system that provides crisis warning level (green/blue/yellow/orange/red) to central and individual disaster response managers of waterside structures. Thus it is expected that by using the WINS+ we may strengthen disaster responsiveness and reduce the time for recovery and response at emergency.
The river levees along the state owned rivers or local rivers are a major infrastructure of the nation, and it is necessary to be able to quickly and accurately evaluate the safety of each structure in case of a disaster such as flood or earthquake, so as to enable preemptive disaster response. In this study, a “real-time safety assessment method of river levees” was developed to understand the safety of river levee in real time and cope with disaster situations preemptively and effectively, and its applicability was examined. The real-time safety evaluation method of the river embankment developed in this study is based on two systems; ① real-time monitoring system by instruments and ② safety evaluation DB system of river embankment based on fragility curves using numerical analysis results. In order to validate its applicability, the safety of Munsan levee located in the upstream area of Kangjeong-Goryeong Weir was evaluated by applying the proposed method.
A series of disaster response drill was conducted using a robust and integrated safety management platform (WINS+) which can provide multi-functions of safety evaluation in realtime, disaster information provision and recovery actions for major water infrastructures, which are designated as nation’s first class infrastructures, under natural disasters such as floods or earthquakes. It is believed that the experience of disaster response drills using the new integrated safety management system (WINS+) enhances our capability of preparedness and response against disasters, and that the validity of WINS+ can be clearly confirmed.
Background: A critical features of Alzheimer’s disease (AD) is cognitive dysfunction, which partly arises from decreased in acetylcholine levels. AD afftected brains are characterized by extensive oxidative stress, which is thought to be primarily induced by the amyloid beta (Aβ) peptide. In a previous study, Cinnamomum loureiroi tincture inhibited acetylcholinesterase (AchE) activity. That study identified AChE inhibitor in the C. loureiroi extract. Furthermore, the C. loureiroi extract enhanced memory in a trimethyltin (TMT)-induced model of cognitive dysfunction, as assessed via two behavioral tests. Rosa laevigata extract protected against oxidative stress-induced cytotoxicity. Administrating R. laevigata extracts to mice significantly reversed Aβ-induced learning and memory impairment, as shown in behavioral tests. Methods and Results: We conducted behavioral to examine the synergistic effects of C. loureiroi and R. laevigata extracts in inhibiting AChE and counteracting TMT-induced learning and memory losses. We also performed biochemical assays. The biochemical results showed a relationship between increased oxidative stress and cholinergic neurons damage in TMT-treated mice. Conclusions: A diet containing C. loureiroi and R. laevigata extracts ameliorated learning and memory impairments in the Y-maze and passive avoidance tests, and exerted synergistic inhibitory effect against AChE and lipid peroxidation.