• Journal of Ecology and Environment
• /
• 제36권4호
• /
• pp.347-370
• /
• 2013

A study on the presence of benthic dinoflagellates in the intertidal zone along the coasts of Jeju Island, Korea was conducted during 2011 and 2012. Identification and taxonomic observations were made of the benthic dinoflagellate samples using light and epifluorescence microscopy. Thirty-seven dinoflagellate taxa belong to five orders, nine families, 18 genera and 30 species, which are new records for Korean waters, were detected in this study. The detailed nomenclature, references, distribution, and illustrations are presented here. The commonly occurring genera were Amphidinium, Coolia, Ostreopsis, Prorocentrum, and Thecadinium. Among the recorded species, 26 were found only in sand sediment, seven in macroalgal samples, and four were found in both sand and macroalgal samples. Of the 37 species, nine were potentially toxic. These results suggest that diversified benthic dinoflagellates including several potentially toxic species occur in sand sediment and macroalgae in the intertidal zone along the coasts of Jeju Island. The morphological features of the identified species were more or less similar to observations made by previous studies in Korea and elsewhere. The presence of known toxic species may indicate a potential risk of toxicity in the marine ecosystem of Jeju Island. The present study can be helpful for further detailed taxonomic, toxicological, molecular phylogenetic studies and may help in the management and conservation of Jeju Island's marine ecosystem.

• 대한기계학회논문집A
• /
• 제26권3호
• /
• pp.544-552
• /
• 2002

Recommended seismic design guide for the flat bottom vortical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집A
• /
• pp.166-173
• /
• 2001

Recommended seismic design guide for the flat bottom vertical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.551-555
• /
• 1997

IJnder earthquake excitations, the hydrodynamic pressure exerted on the flat bottom vertical-cylindrical oil storage tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea. zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described. And seismic design program for the tanks is presented.

• Structural Engineering and Mechanics
• /
• 제59권1호
• /
• pp.123-132
• /
• 2016

Many military and commercial aging aircrafts flying beyond their design life may experience severe crack and corrosion damage, and thus lead to catastrophic failures. In this paper, were used in a finite element model to evaluate the effect of corrosion on the adhesive damage in bonded composite repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the corrosion, on the repair efficiency. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the adhesive damage localized on the level of corrosion and in the sides of patch, and the rectangular patch offers high safety it reduces considerably the risk of the adhesive failure.

• 기술혁신연구
• /
• 제22권2호
• /
• pp.185-220
• /
• 2014

본 연구의 목적은 신기술을 바탕으로 급속히 성장한 신재생에너지 분야 기업의 재정적 어려움을 계량적으로 파악하고 부도위험과 지속가능성을 예측하는 것이다. 태양광 및 풍력기업으로 대표되는 신재생에너지산업은 신생기업이 많은 분야이며, 또한 한국의 현실상 중소기업이 많은 영역이라 start-up기업, 중소기업의 연구란 관점에서도 의의가 있다. 기업의 부도가능성 측정에 관한 연구는 재무비율을 이용한 초기모형 구축을 통한 분석, 기업의 지배구조 분석을 통한 모형분석, 위험과 생존요인을 이용한 분석 등이 주를 이룬다. 본 연구의 분석방법으로 많은 국가에서 이용되고 있는 'Altman Z-score'를 채택하였다. 분석 표본은 한국의 태양광과 풍력분야 상장기업 121개 이며, KIS-VALUE Data를 중심으로 수집, 분석하였다. 분석 대상기간은 2006년부터 2011년이다. 알트만 스코어로 분석한 결과, 태양광과 풍력기업 중에서 '경계 태세(on-alert)'로 분류되어 부도위험에 크게 노출된 기업은 38%,'예의주시(watch)'가 필요한 기업은 38%로, 합하여 76%가 지속가능성에 의문을 받는 기업으로 측정되었다. 신생기업의 경우 순수한 중소기업이 대기업군에 속한 기업보다 지속가능성이 낮았다. 기업규모가 대체적으로 큰 풍력분야 기업과 규모가 작은 태양광분야 기업의 부도위험을 비교한 결과, 풍력기업군의 부도위험이 다소 높게 나타났으나 유의적이지는 않았다. 결과적으로 Altman Z-score의 유용성이 한국의 신재생에너지 산업군 분석에도 검증되었다고 할 수 있다. 본 연구는 신성장산업인 태양광, 풍력기업의 상당수가 부도위험에 직면하였다는 것을 실증적으로 보여준 점에 의의가 있다. 또한 신생 start-up 기업의 연구, 중소기업과 대기업군기업과의 비교연구를 진전시켰다는 점에 의미가 있다.

• 산업경영시스템학회지
• /
• 제38권3호
• /
• pp.64-77
• /
• 2015

An effective method for produce munitions effectiveness data is to calculate weapon effectiveness indices in the US military's Joint Munitions Effectiveness Manuals (JMEM) and take advantage of the damage evaluation model (GFSM) and weapon Effectiveness Evaluation Model (Matrix Evaluator). However, a study about the Range Safety that can be applied in the live firing exercises is very insufficient in the case of ROK military. The Range Safety program is an element of the US Army Safety Program, and is the program responsible for developing policies and guidance to ensure the safe operation of live-fire ranges. The methodology of Weapon Danger Zone (WDZ) program is based on a combination of weapon modeling/simulation data and actual impact data. Also, each WDZ incorporates a probability distribution function which provides the information necessary to perform a quantitative risk assessment to evaluate the relative risk of an identified profile. A study of method to establish for K-Range Safety data is to develop manuals (pamphlet) will be a standard to ensure the effective and safe fire training at the ROK military education and training and environmental conditions. For example, WDZs are generated with the WDZ tool as part of the RMTK (Range Managers Tool Kit) package. The WDZ tool is a Geographic Information System-based application that is available to operational planners and range safety manager of Army and Marine Corps in both desktop and web-based versions. K-Range Safety Program based on US data is reflected in the Korean terrain by operating environments and training doctrine etc, and the range safety data are made. Thus, verification process on modified variables data is required. K-Range Safety rather than being produced by a single program, is an package safety activities and measures through weapon danger zone tool, SRP (The Sustainable Range Program), manuals, doctrine, terrain, climate, military defence M&S, weapon system development/operational test evaluation and analysis to continuously improving range safety zone. Distribution of this K-range safety pamphlet is available to Army users in electronic media only and is intended for the standing army and army reserve. Also publication and distribution to authorized users for marine corps commands are indicated in the table of allowances for publications. Therefore, this study proposes an efficient K-Range Safety Manual producing to calculate the danger zones that can be applied to the ROK military's live fire training by introducing of US Army weapons danger zone program and Range Safety Manual

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
• /
• pp.191-198
• /
• 1994

The nonlinear dynamic behaviors of guardrail established on the local or high way have been investigated using BARRIER Ⅶ program with respect to four design variables such as section type of beams and posts, impact angle, impact velocity and vehicle weight. Computer simulation programs are sophisticated analytical models for analyzing dynamic vehicle/barrier interactions and provide a relatively inexpensive alternative to full scale crash testing. This study has been focused on the structural adequacy, occupant risk, and vehicle trajectory. For this purpose, the maximum deflection and impact force have been calculated to design the clear zone and to analyze effect of impact attenuation. Also, the acceleration of vehicle and exit angle after collision have been computed to estimate the occupant risk. From this study, it is suggested that we should strengthen the design criteria of guradrail to prevent from disastrous traffic accidents.

• Nuclear Engineering and Technology
• /
• 제35권6호
• /
• pp.547-555
• /
• 2003

Fire hazard and risk analysis at Nuclear Power Plants is implemented on the basis of the normal operational configuration. This steady configuration, however, can be changed due to the temporary displacement of equipment, electric cable and irregular movement of workers through the fire compartments when the on-line maintenance is processed during the power operation mode or the scheduled outage mode for the refueling. With the consequence of this configuration change, the fire analysis condition and the evaluation result will be different from those that were analyzed based on the steady configuration. In this context, at this paper, the general items for the reassessment are categorized when the configuration has changed. The contemporary zone models for the detail fire analysis are also illustrated for their application for each classified condition.

• 한국공작기계학회논문집
• /
• 제14권5호
• /
• pp.1-6
• /
• 2005

Machining is a one of the broadly used manufacturing process to produce the parts, products and various molds and dies. The environmental impact due to aerosol generation via atomization process is a major concern associated with environmental consciousness. This paper presents the experimental results to analyze the characteristics of cutting fluid aerosol generation in grinding process. Experimental results show that the generated fine aerosol which particle size less than 10micron appears near worker's breath zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This quantitative analysis can be provided the basic knowledge f3r further research for environmentally conscious machining technology developments.