• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.64-70
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• 2023

Maritime transport is dominant in the overall volume of all international transportation. Existence and overcoming of problems, which cause pressure on shipping safety, remain actual and fully concern both maritime and inland transport. Increasing speed and cargo capacity of the ships along with the reduction of crew members lead to the automation of a growing number of work processes, which indicates the need to actively introduce appropriate measures in the security system of sea-going ships and commercial ports and to develop modern approaches to minimize negative events and incidents in the process of ship operation. Advantages in use of modern methods of monitoring the safety of ship operations, management of possible events and incidents, including investigation of accidents, first, aimed at prevention of negative occurrences and ways of prevention on this basis. Considering statistics on incidents increase, this work presents analysis of general ship accident rate, study of major accidental events growth annually, and investigation of causes of incidents, which most frequently occur in port waters and at open sea. A survey of current approaches to ensuring the safety of shipping by implementing effective tools, such as event and incident management, has been conducted.

• 한국초등과학교육학회지:초등과학교육
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• 제30권1호
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• pp.61-70
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• 2011

In this study, we examined the types and the characteristics of elementary school teachers' strategies for coping with critical incidents in science classes. Teachers' epistemological beliefs about science were then investigated on the bases of the types of their coping strategies. The teachers (N=107) in 23 elementary schools were asked to respond to an open-ended question about the critical incidents they had experienced in science classes and how to cope with them. Seven types of coping strategies were identified as follows: avoiding, reinterpretation, adjusting, prevaricating, justifying, exploring, and explaining. Among them, adjusting and justifying were the major strategies. In order to classify teachers' epistemological beliefs about science, their coping strategies were grouped into four categories such as transferring facts, constructing facts, transferring meanings, and constructing meanings. The results indicated that most teachers still possessed traditional epistemological beliefs about science. The potential of critical incidents as a probe for revealing teachers' epistemological beliefs about science is discussed.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.186-189
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• 2010

Reflection(R($\omega$)), transmission(T($\omega$)) and loss(L($\omega$)) characteristics of multi-layer metamaterials are investigated experimentally in free space with the incident EM waves perpendicular to the substrate plane. The sample is made of split-ring resonators(SRRs) and wires which are the typical model of metamaterials. The R($\omega$) and T($\omega$) of multi-layer metamaterials have been calculated from the measured S-parameters. In this paper, we got the impedance-matched result according to the curves of R($\omega$), meanwhile the T($\omega$) decreased with increasing number of layers. At last, we attained the result that the L($\omega$) gets to nearly 98% around 8 GHz, with R($\omega$)=T($\omega$)=0. The design presented in this paper achieves experimented loss near unity.

• 한국해양환경ㆍ에너지학회지
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• 제11권1호
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• pp.35-41
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• 2008

월파형 파력발전장치는 월류된 파랑으로 인하여 발생한 수두차를 이용하여 터빈을 구동하는 일종의 파랑에너지 변환장치로써 파랑에너지를 전기 에너지로 변환하는 장치이다. 본 연구에서는 먼저 상용 CFD코드 인 Fluent를 사용하여 수치조파수조를 구현하고, Reynolds-Averaged Navier-Stokes 방정식과 VOF 모델을 이용하여 2차원 수치 선형 규칙파를 생성한 후 이를 계산 결과와 비교 검증을 수행하였다. 다음으로 월류 성능의 최적 설계점과 파력발전 장치의 월류 충전량을 고찰하기 위하여 여러 가지 파랑조건과 형상변수들에 대하여 계산을 수행 하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.263-267
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• 2011

본 연구는 에틸렌-공기 혼합물로 채워져 있는 굽은 관에서의 충격파와 화염의 상호 작용, 화염 가속, 연소폭발천이 현상을 수치적으로 살펴보았다. 여기서 사용되는 모델은 지배방정식으로 Navier-Stokes 방정식과 경계조건 처리 방법으로 ghost fluid 기법을 사용하였다. 굽은 관에서 여러 충격파 강도를 이용한 모델링을 통하여 화염과 강한 충격파의 충돌에 의한 열점 생성과 화염 전파의 가속 현상을 확인하였으며 추가적으로 평균 화학적 열 발생률이 대략 20 MJ/($g{\cdot}s$)이 되는 지점에서 최초 폭굉이 발생한다는 것을 확인하였다. 즉, 우리는 복잡한 형상에 의한 효과를 포함하는 수치적 계산 결과를 기반으로 관에서의 강한 충격파, 충격파와 화염의 상호 작용, 열점, 연소폭발천이 현상 등의 발생을 확인하였다.

• 한국항해학회지
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• 제17권1호
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• pp.37-48
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• 1993

When the vessel is running at the very low Froude numbers, the free-surface is difficult to be disturbed, wave-making is negligible, and the double -model velocity potential gives a very good approximation for calculating the velocity distribution just outside the boundary layer. If the speed of incident flow is gradually increased, the most perceptible change is the rise of the flow surface at stem. With further increase in speed, the nature of the flow at the bow changes completely, The flow ahead of the bow becomes more distrubed, the rise at the stem to stagnation height disappear, and the first wave crest, of less than the stagnation height, appears a small distance downstream from the stem. The present study is concerned with a small region of this flow, mainly in the bow region. The present investigation is primarily an experimental study of the flow in the bow region of s ship model, and it is undertaken in order to investigated systematically, the effect of bow geometry on this flow. The long-range objective is to use these results to guide the development of a mathematical model for predicting the flow about a ship's bow.

• 한국세라믹학회지
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• 제43권1호
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• pp.62-67
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• 2006

Time-of-flight impact-collision ion scattering spectroscopy (TOF-ICISS) using 2 keV $He^+$ ion was applied to study the geometrical structure of the $BaTiO_3$ thin film which was grown on the MgO(100) surface. Hetero-epitaxial $BaTiO_3$ layers were formed on the MgO(100) surface by thermal evaporation of titanium followed first by oxidation at $400^{\circ}C$, subsequently by barium evaporation, and finally by annealing at $800^{\circ}C$. The atomic structure of $BaTiO_3$ layers was investigated by the scattering intensity variation of $He^+$ ions on TOF-ICISS and by the patterns of reflection high energy electron diffraction. The scattered ion intensity was measured along the <001> and <011> azimuth varying the incident angle. Our investigation revealed that perovskite structured $BaTiO_3$ layers were grown with a larger lattice parameter than that of the bulk phase on the MgO(100) surface.

• 한국군사과학기술학회지
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• 제1권1호
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• pp.114-127
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• 1998

A user friendly computer code(EMCOMST; Electro-Magnetic response for COMposite STructures) was developed which provides with computations of the response characteristics such as reflectance and transmittance to the incident wave angles, frequencies, composite thicknesses, ply orientations, and types of backplate as the linearly polarized transverse electro-magnetic wave is emitted to the advanced composite structures. In this investigation were reviewed the electromagnetic characteristics of the continuous orthotropic fiber-reinforced organic matrix composites with or without ferrite fillers, which are actively applied to low-weight and high-strength aircraft structures. Also were calculated the response of the three layered compound structures which have appropriately stacked above-mentioned materials as transmitting layer, absorbing layer, reflection layer, respectively under the specific thickness constraints for mechanical strength design requirements. For the composite structures presented in this study, minimum reflectance value less than -5㏈ can be obtained in the frequency range of 4 to 12 ㎓. In addition, analysis of structures attached isotropic radar absorbing materials(RAM) is facilitated by putting the material properties in the material input card entries adequately.

• 한국중재학회지:중재연구
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• 제24권2호
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• pp.81-107
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• 2014

ADR has recently been expanded, making it possible to solve traffic accident disputes, which is a matter of urgency for parties to avoid. This point serves as an important procedural element. Such disputes are an area that requires a quick resolution. To try to solve any dispute that occurs in the complex environment of modern times one-by-one through litigation does not make sense. It gives an undue burden on the judicial body and the investigation agency. Like litigation, today's arbitration system, should have effective conflict resolution. The arbitration of automobile traffic accident disputes can be seen as roughly adjusted through the insurance company, the Dispute Coordinating Committee, and the Crime Victims Protection Act. It consists of experts mainly, and the resolution of automobile traffic accident disputes can be resolved through the Sajonsa and workers insurance company. However, adjustments to failure incident mostly need attention. Most of a company's compensation insurance indemnity needs to be processed in practice. In addition, a vicious cycle of litigation and delay period is repeated if a lawyer is appointed. There are unreasonable adjustment systems in the midst of these. Avoiding traffic accidents allows parties to resolve disputes better. Arbitration of disputes in automobile traffic accidents handled by arbitration institutions is desirable. It is determined that the handling of a case by a village attorney is efficient.

• 한국항해항만학회지
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• 제30권2호
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• pp.131-136
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• 2006

Researches on a superstructure built on a floating structure in the shape of pontoon type have begun in recent years. A superstructure responds by wave load and it is important to evaluate its habitability. The purpose of this study is evaluation and investigation of habitability of a superstructure due to wave for 10 year return period. In this study, response analyses of the superstructure built on middle-sized floating structure due to the waves of three cases were carried out by 3-D integration analysis, which means analyzing the calculation model integrated a superstructure with a floating structure, and its habitability was evaluated by the evaluation diagrams. As the result, the habitability differed by each wave condition The use of a superstructure is restricted according to the disposition of a floating structure for incident wave angle.