• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.515-524
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• 2016

The purpose of this study was to identify how safety awareness and self-efficacy affect the safety practice with elementary school students. The participants were 369 elementary school students(4~6th grade) in Changwon city. Data were collected using self-report questionnaires and analyzed with the SPSSWIN 22.0 program. Analysis methods were t-test, one way ANOVA, Scheffe test, Pearsons correlation coefficient and multiple linear regression. As a results, safety awareness was an average 2.97 point which was moderate levels and self-efficacy was on over intermediate level of an average 3.73 point. Safety practice was an 3.00 point. Safety practice had statistically significant difference according to grade, number of family, mother's education, character and school life attitude. Safety awareness(r=.41, p<.001) and self-efficacy(r=.39, p<.001) was significant correlation with safety practice. Fire safety(${\beta}=.22$, t=3.56) and self-efficacy(${\beta}=.27$, t=5.32) were significantly influenced safety practice and explaining 24.0% of the variance. From the results of this study, I proposed the education programs to increase safety practice in elementary school students that emphasizes self-efficacy and safety awareness.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.125-131
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• 2013

When fire occurs in complex or building, toxic gas is important factor for evacuation because it cause death of evacuees. The effect of toxic gas which effects human motion is calculated using Purser's Fractional Effective Dose(FED). The FDS_EVAC is used for evacuation. However, FED of FDS_EVAC has some problem of application because it dose not considers evacuees's gender and age groups but using single subject. In this study, numerical analysis using modified FED which considers gender and age group of evacuees was performed. We investigate the effect of improved FED on the evacuation. We applied evacuation analysis to exhibition centre where the evacuees was set one thousand five hundred people. The FED is increasing with children 2%, male 17%, female 4%, adult 13% and elderly people 22%. Fatality is increasing due to increased FED.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.218-226
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• 2016

In the original design of K2 tank the Vertical Sensor Unit(VSU) was mounted to measure the attitude of the main gun to enhance the hit probability. In this research, as a part of efforts to reduce the cost of K2, it was theoretically simulated and evaluated to use the data from Inertial Navigation System(INS) for the calculation of the gun attitude instead of the direct measurement using VSU. It was found that the negative effect of INS approach is negligible and the elimination of VSU is technically possible and beneficial to the system.

• Explosives and Blasting
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• v.13 no.1
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• pp.20-31
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• 1995

Many methods and techniques to reduce ground vibrations are well known. Some of them are to adopt electric milisecond detonators with a sequential blasting machine or an initiating system with an adequate number of delay intervals. The types of electric detonators munufactured in Korea include instantaneous, decisecond and milisecond delays byt numbers of delay intervals are only limite from No.1 to No.20 respectively. It is not sufficient to control accurately milisecond time with these detonators in tunnel excavation. Sequential fire time refers to adding an external time delay to a detonators norminal firing time to obtain sequential initiation and it is determined by sequential timer setting. To reduce the vibration level, sequential blasting machine with decisecond detonatore was adopted. A total of 134 blasting was recorded at various sites. Blast-to-structure distances ranged from 20.3 to 42.0 meter, where charge weight varied from 0.25 to 0.75 kg per delay. The results can be summarized as follow : 1. The effects of sequential blasting machine on the vibration level are discussed. The vibration level by S.B.M. are decreased approximately 14.38~18.05 to compare to level of conventional blasting and cycle time per round can be saved. 2. The empirical equations of particle velocity were obtained in S,B.M. and conventional blastin. $V=K(D/W^{1/3})-n$. where the values for n and k are estimated to be 1.665 to 1.710 and 93.59 to 137 respectively. 3. The growth of cracks due to vibrations are found but the level fall to within allowable value.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.193-202
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• 2005

Marine risk assessment considers events such as collision/grounding, sinking/capsize, fire/explosion and flooding, developing relationships between their causes and effects. In addition, risk assessment of previously sunken ships are also necessary since they continuously have possibility for further oil spill or can cause other marine accidents. The objective of this paper is to develop the risk assessment systems for sunken ships to prevent oil spill and further marine causalities in order to preserve safe and clean oceans around Korea peninsula. The risk assessment systems for sunken ships comprise of database management sub-system for sunken ships, qualitative risk assessment sub-system, quantitative risk assessment sub-system, and cost-benefit analysis subsystem.

• Korean System Dynamics Review
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• v.6 no.1
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• pp.99-123
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• 2005

Although the generation market is competitive, the power market is easily exercised the market power by one generator due to its special futures such as a limited supplier, large investment cost, transmission constraints and loss. Specially, as Korea Electric industry restructuring is similar US competitive wholesale electricity market structure which discovered the several evidences of market power abuse, when restructuring is completed the possibility that market power will be exercised is big. Market power interferes with market competitions and efficiency of system. The goal of this study is to investigate the market price effects of the potential market power and the proposed market power mitigation strategy in Korean market using the forecasting wholesale electricity market model. This modeling is developed based on the system dynamics approach. it can analyze the dynamic behaviors of wholesale prices in Korean market. And then it is expanded to include the effect of market condition changed by 'strategic behavior' and 'real time pricing.' This model can generate the overall insights regarding the dynamic impact of output withholding by old gas fire power plant bon as a marginal plant in Korean market at the macro level. Also it will give the energy planner the opportunity to create different scenarios for the future for deregulated wholesales market in Korea.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.124-130
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• 2004

The structure of the nonpremixed methane-air counterflow flames in microgravity was investigated by axisymmetric simulation with Fire Dynamics Simulator (FDS) to evaluate the numerical method and to see the effects of strain rate and fuel concentration on the diffusion flame structure in microgravity. Results of FDS for the methane mole fractions, $X_m$=20, 50, and 80% in the fuel stream, and the global strain rates $a_g$=20, 50, and $90s^{-1}$ for each methane mole fraction were compared with those of OPPDIF, an one-dimensional flamelet code. There was good agreement in the temperature and axial velocity profiles between the axisymmetric and one-dimensional computations. It was shown that FDS is applicable to the counterflow flames in a wide range of strain rate and fuel concentration by predicting accurately the flame thickness, flame positions and stagnation points.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.322-325
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• 2011

본 연구는 넓은잎 딱총나무 잎으로부터 유도된 캘러스의 형태학적 특성과 효능에 관한 것이다. 딱총나무에서 유도된 캘러스 내의 세포들을 촬영한 표면주사현미경 사진에서 분열능이 높은 세포의 특성을 보여주었다. 유도된 넓은잎 딱총나무 캘러스를 생물반응기 내에서 배양시켜 얻은 딱총나무 식물세포배양 추출물은 DPPH 제거 및 $PPAR{\alpha}$ 활성 실험결과에서 자유라디컬 제거능 및 항염증 효능이 높게 나타났다. 이러한 딱총나무 캘러스 세포 배양 추출물은 화장품의 항노화 신소재로서 응용될 수 있다.

• Korean Journal of Remote Sensing
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• v.25 no.1
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• pp.85-94
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• 2009

This paper presents the capability to use QuickBird imagery for effects of forest disturbance in Okgye burned area. Particular attention of this paper deals with the NBR-derived mapping burn severity on QuickBird imagery to locate reliable rehabilitation(namely, secondary succession) over postfire surface. Comparisons of the mapping forest disturbance derived from QuickBird NBR data and the mapping burn severity derived from Landsat ${\Delta}NBR$ data show substantial agreement (KHAT value =0.7886). The method calculated from the correlation between QuickBird wetness and Landsat ETM+ band7 may have application to forest harvest disturbance.

• Steel and Composite Structures
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• v.33 no.1
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• pp.143-162
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• 2019

A number of desirable characteristics concerning excellent durability, aesthetics, recyclability, high ductility and fire resistance have made stainless steel a preferred option in engineering practice. However, the relatively high initial cost has greatly restricted the application of stainless steel as a major structural material in general construction. This drawback can be partially overcome by introducing composite stainless steel-concrete structures, which provides a cost-efficient and sustainable solution for future stainless steel construction. This paper presents a preliminary numerical study on stainless steel-concrete composite beam-to-column joints with bolted flush endplates. In order to ensure a consistent corrosion resistance within the whole structural system, all structural steel components were designed with austenitic stainless steel, including beams, columns, endplates, bolts, reinforcing bars and shear connectors. A finite element model was developed using ABAQUS software for composite beam-to-column joints under monotonic and symmetric hogging moments, while validation was performed based on independent test results. A parametric study was subsequently conducted to investigate the effects of several critical factors on the behaviour of composite stainless steel joints. Finally, comparisons were made between the numerical results and the predictions by current design codes regarding the plastic moment capacity and the rotational stiffness of the joints. It was concluded that the present codes of practice generally overestimate the rotational stiffness and underestimate the plastic moment resistance of stainless steel-concrete composite joints.