• Structural Engineering and Mechanics
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• 제82권4호
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• pp.417-434
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• 2022

In this work, a review of mechanical metamaterials and seismic protection systems that use them is carried out, focusing on passive protection systems. During the last years, a wide variety of classical systems of seismic protection have demonstrated to be an effective and practical way of reducing the seismic vulnerability of buildings, maintaining their health and structural integrity. However, with the emergence of metamaterials, which allow obtaining uncommon mechanical properties, new procedures and devices with high performance have been developed, reducing the seismic risk through novel approaches such as: seismic shields and the redirection of seismic waves; the use of stop band gaps and the construction of buried mass resonators; the design of pentamodal base isolators. These ideas are impacting traditional areas of structural engineering such as the design and building of highly efficient base isolation systems. In this work, recent advances in new seismic protection technologies and researches that integrate mechanical metamaterials are presented. A complete bibliometric analysis was carried out to identify and classify relevant authors and works related with passive seismic protection system based on mechanical metamaterial (pSPSmMMs). Finally, possible future scenarios for study and development of seismic isolators based on mechanical metamaterials are shown, identifying the relevant topics that have not yet been explored, as well as those with the greatest potential for future application.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.395-400
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• 2005

The ship hull part is always exposed to severe corrosive environments. Therefore, it should be protected in appropriate ways to reduce corrosion problems. So there are two effective methods in order to protect the corrosion of ship hull. One is the paint coating as a barrier between steel and electrolyte (seawater) and the other is the cathodic protection(CP) supplying protection current. In the conventional design process of the cathodic protection system the required current densities of protected materials have been used. However, the anode position of field or laboratory experiment for obtaining the required current density for CP is significantly different from anode position for real structures. Therefore, the recent CP design must consider the optimum anode position for potential distribution equally over the ship hull. The CP design companies in the advanced countries can obtain the potential distribution results on the cathodic materials by using the computer analysis module. This study would show how to approach the potential analysis in the field of corrosion engineering. The computer program can predict the under protection area on the structure when the boundary condition and analysis procedure are reasonable. In this analysis the polarization curve is converted to the boundary condition in material data.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.19-26
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• 1997

Firesafety design engineerings have been mainly derived from complicated rearrangement of descriptive specifications in codes or regulations through a great number of lessons from fire disasters. In this paper, the author refers to some recent developments in the field of building fire protection. At first, the author expresses his viewpoints concerning performance-based design codes, which have been popular throughout the world as a symbol of freedom from restricted usage of building materials and components prescrived in regulation or bylaws, in spite of some conflicts between objects-oriented design method and industrial mass production. Secondly, the author introduces several innovative fire protection methods adopted for large or void spaces in building complex. Finally, the author forcasts a next development of firesafety science and technology, aimed at securing personal safety in hyperscale urban areas.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.299-304
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• 2003

The design of an occupant protection equipment has been considered as the important process in developing a new car since the crash performance plays an important role on the market. The cost is increased when an unexpected real test is carried out in the proto-design stage. Thus, the exact prediction of a crash performance can reduce the number of full-car test. In this research, the robust design of an airbag system considering the frontal crash is suggested to predict the more reliable responses. On the contrary, most existing researches do not consider the uncertainties. The uncertainties treated in this research are the tolerances of the vent hole, the time to fire and the length of a strap in airbag and the tolerance of the load limiter load in seat belt. The Taguchi method is utilized to determine the robust optimum of each parameter

• 한국의류산업학회지
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• 제23권6호
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• pp.781-789
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• 2021

To enhance the design and comfort of waist-protection corsets, this study analyzed the product characteristics of five types of posture-correction corsets that are available commercially. Additionally, subjective evaluation of the corsets was conducted on women aged 20 to 60 years, in terms of design, material preference, fit, comfort, degree of correction, freedom of movement, tightness, and convenience of front fastening. Following product analysis, the five corset types were divided into: two soft, one semi-hard, and two hard types in terms of the degree of elongation. As a result of pattern analysis, the soft type was designed to improve fit by reflecting the body curvature, whereas the semi-hard and hard types were relatively flat. Through the wearing sensation assessment, the hard type manufactured by company S was the best in terms of design, material, fit, comfort, correction degree, and freedom of movement. The soft type was average in design, material, and fit while relatively poor in the correction degree and tightness. The results indicated that soft materials, flexible bones with appropriate tension, patterns designed to snugly fit the body with large curvature at the top and bottom for better inflection, and adjustable support belts that can be double-fixed are crucial elements in improving the corset design to boost the comfort of wearing. These study results are helpful in the development of waist-protection corsets with excellent wearing comfort and design appreciated by customers.

• 전기학회논문지
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• 제67권12호
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• pp.1619-1625
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• 2018

Portable electronic devices secondary batteries can cause fire and explosion due to micro-current change in addition to the situation of short-circuit inrush current, safety can not be secured with a general operation limited current fuse. Therefore, in secondary battery, it is necessary for the protector to satisfy both the limit current type operation in the open-short-circuit inrush current and the current detection operation characteristic in the micro current change situation and for this operation, a fuse for the current detection type secondary battery protection circuit can be applied. The purpose of this study is to design a protection device that operates stably in the hazardous situation of small capacity secondary battery for portable electronic devices through the design of low melting fuse elements alloy of sensing type fuse and secures stability in abnormal current state. As a result of the experiment, I-T and V-T operation characteristics are satisfied in a the design of the alloy of the current sensing type self-contained low melting point fuse and the resistance of the heating resistor. It is confirmed that it can prevent accidents of short circuit over-current and micro current change of secondary battery.

• 한국가스학회지
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• 제8권2호
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• pp.54-60
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• 2004

본 논문은 완전 밀폐방식의 LNG 저장탱크에서 코너 프로텍션과 2차 바닥판에 걸리는 최대 von Mises 응력과 최대 변위량을 유한요소법으로 해석하였다. LNG 저장탱크의 시운전 과정에서 질소가스로 탱크에 채워져 있는 공기를 퍼징하기 위해 코너 프로텍션에 공급할 수 있는 최대 가스압력은 1,500pa이다. 코너 프로텍션과 2차 바닥판에 공급된 가스압력 1,500pa에 의한 구조물 자체의 안전성은 대단히 높다. 그러나, 내부탱크와 같은 $9\%$ 니켈강재로 제작된 코너 프로텍션과 2차 바닥판에 8,475Pa의 높은 가스압력을 공급하면 2차 바닥판에는 833MPa의 최대 von Mises 응력이 걸리고, 1.9m의 대변형이 2차 바닥판의 중심부에서 발생하여 크게 뒤틀리며, 소성변형 또는 파괴가 일어날 수도 있다는 해석결과를 제시하고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.256-258
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• 1998

This paper presents a control system design for the UPFC of FACTS devices by optimal control scheme to enhance small-signal stability in the Power system. The feature of this UPFC controller is coordinated with generator exciter controller(AVR, PSS) to improve the total Power system stability and performance.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.471-472
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• 2005

• 한국화재소방학회논문지
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• 제23권2호
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• pp.6-12
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• 2009

최근 세계적으로 대규모 지진들이 발생하고 있다. 이러한 지진의 피해는 진동에 의한 피해보다 지진으로 소방시설이 기능을 상실하여 전기 및 가스설비의 파손으로 발생하는 화재를 진압하지 못한 2차적 피해가 더 크다. 따라서 현재 우리나라의 지진 발생 추이를 확인할 필요가 있다. 본 연구에서는 미국과 일본의 소방시설의 지진피해 사례 및 내진설계기준을 분석 하였으며, 우리나라와 유사한 미국의 기준과 비교한 결과 소방시설 내진설계기준의 적용범위가 우리나라의 건축 구조물의 특성에 매우 비효율적인 것으로 나타났다. 이에 따라 국내 현실을 감안하여 적용범위를 설정하도록 제안하였다.