• The Journal of Fisheries Business Administration
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• v.34 no.1
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• pp.157-183
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• 2003

유류오염 사고를 사전에 예방할 수 있는 정책 수단으로는 여러 가지가 있지만 주요한 것으로는 인센티브제의 활용을 들 수 있다. 유류오염 사고를 예방하고 관리하기 위한 인센티브는 유출 사고로 인해 발생한 해양자원의 피해에 대해 가해자에게 배상책임(liability for losses due to spills)을 부과함으로써 제공될 수 있다. 유류오염 사고로 인한 피해액을 실제 화폐단위로 계량화하는 작업은 배상책임 부과제도를 정책수단으로 활용하기 위해 해결해야 할 가장 어려운 과제이다. 따라서, 최근 미국과 캐나다를 중심으로 발전하고 있는 자연자원 피해에 대한 가치 평가법(Natural Resource Damage Assessment : NRDA)은 배상책임 부과제도를 정책적으로 보완할 수 있는 이론적 도구로 간주되고 있다. NRDA는 잠재적인 가해자들에게 그들이 자연환경을 보존해야 하는 사회적 의무를 이행하지 못하고 이를 훼손하게 될 때 이로 인해 발생하는 모든 사회적 비용을 직접 부담해야 한다는 명확한 재무적 인센티브(financial incentive)를 부여함으로써 가해자 보상 원칙 (polluter pays principle)을 실현 할 수 있게 한다. 본 연구는, 유류오염 사고로 인한 환경자원 피해의 경제적 가치를 추정하는 가장 중요한 이론적 모형으로 활용되고 있는 가상상황평가법(CVM)에 대한 기초 개념과 이론적 체계, 그리고 이를 실제 피해액 추정에 성공적으로 적용시키기 위해 해결해야 할 문제점 등을 다루었다. 이를 위해, 본 연구에서는 1988년 캐나다 북서부 연안에서 발생한 Nestucca 유류오염 사고를 사례연구의 대상으로 선정하고, 사고 당시 캐나다 연방정부와 British Columbia 주정부를 대신하여 해양오염에 의한 환경피해의 경제적 가치를 추정한 미국의 컨설팅 회사인 RCG/Hagler, Baily Inc.의 가상상황평가법(CVM) 적용 사례를 분석 검토하였다. Nestucca 사례연구에서는 이들 연구자들이 실제로 활용한 설문지 설계, 설문방법 및 표본설계 등을 분석하였으며, 또한 CVM이 본질적으로 갖고 있는 방법론적 문제점들을 연구자들이 어떻게 해결하려고 했는가를 고찰하였다. 그리고, WTP 추정을 위해 RCG 연구자들이 사용한 사전규제접근법(ex ante regulatory approach)으로 인해 야기될 수 있는 환경자원 피해액 추정 방법의 한계점도 함께 검토하였다. 캐나다 연방정부와 British Columbia 주정부는 Nestucca 유류오염 사고로 인한 자연 자원 피해에 대한 손해배상으로 $4.3 Million의 보상금을 지급 받게 된다. 캐나다 정부는 이 보상금으로 Nestucca Oil Spill Trust Fund를 설립하여 피해를 입은 자연자원의 원상회복(restoration)을 위한 다양한 연구 프로젝트에 자금을 지원하고 있다. Nestucca 유류오염 사고를 계기로 캐나다 정부와 학계는 해양자원의 피해에 대한 경제적 가치평가와 자원의 원상회복에 대한 체계적인 접근 방안을 처음으로 마련 시행하게 되었다는 점에서, Nestucca 유류오염 사고에 대한 사례연구는 캐나다의 해양환경 보존 정책을 연구하는 출발점으로 평가될 수 있을 것이다. 이에 비해, 우리나라에서 대표적인 유류오염사고로 알려져 있는 시프린스호 사고와 관련된 손해배상금은 주로 연안어민들의 어업피해 배상으로 이루어져 있으며, 간접피해에 대한 배상액 48억 5천만원도 대부분 치어방류, 여수대학교 종묘배양장건립 등 피해지역 연안어업 발전을 위한 사업에 투자되었다.

• Steel and Composite Structures
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• v.39 no.2
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• pp.201-213
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• 2021

Currently, there is a lack of research in the design approach to avoid column wall failure in the concrete filled double skin steel tubular (CFDST) column-beam connections. In this paper, a finite element model has been developed and verified by available experimental data to analyze the failure mechanism of CFDST column-beam connections. Various finite element models with different column hollow ratios (χ) were established. The simulation result revealed that with increasing χ the failure mode gradually changed from yielding of end plate, to local failure of the column wall. Detailed parametric analyses were performed to study the failure mechanism of column wall for the CFDST column-beam connection, in which the strength of sandwiched concrete and steel tube and thickness of steel tube were incorporated. An analytical model was proposed to predict the moment resistance of the assembled connection considering the failure of column wall. The simulation results indicate that the proposed analytical model can provided a conservative prediction of the moment resistance. Finally, an upper bound value of χ was recommend to avoid column wall failure for CFDST column-beam connections.

• Geomechanics and Engineering
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• v.21 no.5
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• pp.423-432
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• 2020

Hydraulic conductivity is one of the engineering properties of soil. This study focusses on the influence of cement content on the hydraulic conductivity of cemented sand, which is investigated based on the results from numerical analysis and laboratory testing. For numerical analysis the cemented samples were scanned using X-ray Computed Tomography (CT) while laboratory testing was carried out using a triaxial setup. Numerical analysis enables us to simulate flow through the sample and provides insight to the microstructure. It quantifies the pore volume, proportion of interconnected voids and pore size distribution in both cemented and uncemented samples, which could be computed only through empirical equations in case of laboratory testing. With reduction in global voids, the interconnecting voids within the samples also reduce with cement content. Gamma cumulative distribution function is used to predict the percentage of voids lesser than a given pore volume. Finally, the results obtained from both numerical analysis and laboratory testing are compared.

• Earthquakes and Structures
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• v.13 no.3
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• pp.289-297
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• 2017

This paper presents seismic performance and reliability evaluation on steel-timber hybrid shear wall systems composed of steel moment resisting frames and infill light frame wood shear walls. Based on experimental observations, damage assessment was conducted to determine the appropriate damage-related performance objectives for the hybrid shear wall systems. Incremental time-history dynamic analyses were conducted to establish a database of seismic responses for the hybrid systems with various structural configurations. The associated reliability indices and failure probabilities were calculated by two reliability methods (i.e., fragility analysis and response surface method). Both methods yielded similar estimations of failure probabilities. This study indicated the greatly improved seismic performance of the steel-timber hybrid shear wall systems with stronger infill wood shear walls. From a probabilistic perspective, the presented results give some insights on quantifying the seismic performance of the hybrid system under different seismic hazard levels. The reliability-based approaches also serve as efficient tools to assess the performance-based seismic design methodology and calibration of relative code provisions for the proposed steel-timber hybrid shear wall systems.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.599-612
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• 2020

A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.

• Steel and Composite Structures
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• v.5 no.1
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• pp.17-34
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• 2005

This paper presents an experimental study and its findings of the behavior of circular and square stub columns filled with high strength concrete ($f_c^{\prime}$=49MPa) and polymer cement concrete (PCC) under concentric compressive load. Twenty-four specimens were tested to investigate the effects of variations in the tube shape (circular, square), wall thickness, and concrete type on the axial strength of stub columns. The characteristics of CFT stub columns filled with two types of concrete were investigated in order to collect the basic design data for using the PCC for the CFT columns. The experimental investigations included consideration of the effects of the concrete fill on the failure mode, ultimate strength, initial stiffness and deformation capacity. One of the key findings of this study was that circular section members filled with PCC retain their structural resistance without reduction far beyond the ultimate capacity. The results presented in this paper will provide experimental data to aid in the development of design procedures for the use of advanced concretes in CFT columns. Additionally, these results give structural designers invaluable insight into the realistic behavior of CFT columns.

• Mycobiology
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• v.29 no.4
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• pp.205-209
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• 2001

The Korean sawmills have recently recognized the importance of prevention of fungal discoloration due to increased losses in revenue. Before establishing integrated control strategies of fungal discoloration, more complete knowledge about causal organisms is needed. As a first step, we initiated a through survey of fungi colonizing commercially important softwood(Pinus dens flora, Pinus koraiensis, and Pinus radiata) logs and lumber in Korea. In this paper we report results obtained from Japanese red pine(Pinus densiflora) log study. In summer 2000, fungi were isolated from Japanese red pine logs in storage, and identified based on their cultural and morphological characteristics. A total of 595 fungi were isolated, representing 21 genera and 30 species. Mold fungi, mostly Trichoderma species, were the most frequently isolating fungi, representing more than half of all isolates. Dematiaceous fungi represented approximately one fifth of the isolates, and Rhinocladiella atorvirens was the most abundant in all samples. Opiostoma species represented 7% of all isolates from cores planted on malt extract agar(MEA) and the incidence of these species doubled with the addition of streptomycin and cycloheximide to MEA. The results indicate that Japanese red pine sapwood is susceptible to colonization by a variety of fungal species. As a result, control strategies that concentrate on one fungus may have limited success because of interference from competing flora.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.365-372
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• 2006

In this paper, the possibility of statistical modeling from the pulp and peroxide bleaching condition variables to predict optical properties of a bleached chemimechanical pulp used in a newsprint paper machine at Mazandaran Wood and Paper Industries Company (MWPI) was studied. Due to the variations in the opacity and the brightness of the bleached pulp at MWPI and to tackle this problem, it was decided to study the possibility of modeling the bleaching process. To achieve this purpose, Multi-variate Regression Analysis was used for model building and it was found that there is a relationship between independent variables and pulp brightness as well as pulp opacity, consequently, two models were constructed. Then, model validation was carried out using new data set in the bleaching plant at MWPI to test model predictive ability and its performance.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.199-208
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• 2007

Although many studies have focused on the biological and toxicological effects of phenol products, in particular, in reproductive tracts, the data about their effects in this estrogenic responsive tissue are much less clear. In addition, the in vitro and in vivo data concerning ED-adverse impacts in other endocrine organs, i.e. pituitary gland, are not understood well either. Thus, a further study is needed for providing a new insight into possible impacts of estrogenic EDs including phenol products in humans and wildlife. A combination of in vitro and in vivo system for examining EDs may bring better understanding into the regulatory mechanisms underlying EDs-induced events. In addition, this information may support for developing optimal screening methods of estrogenic EDs, in particular, phenol products.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.664-668
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• 2002

KR-31543,(2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran is a new neuroprotetive agent for ischemia-reperfusion damage. The in vitro and in vivo metabolism of KR-31543 in rats has been studied by LC-electrospray mass spectrometry. Rat liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of a metabolite M1. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC-MS/MS analysis with the synthesized authentic standard. Rat CYP3A1 and 3A2 are the major CYP isozymes involved in the formation of M1.