• 한국전자파학회논문지
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• 제19권2호
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• pp.174-180
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• 2008

전원을 on/off하는 스위칭 방식을 이용한 펄스 증폭기는 입력 신호를 변조하는 방식에 비해 효율 및 잡음 특성이 우수하며, 입력단에 별도의 펄스 변조기가 필요 없어 회로가 간단하다. 현재 스위칭 방식의 펄스 증폭기는 스위칭 회로의 특성 상 rise 시간에 비해 fall 시간이 길어지는 단점이 있다. 본 논문에서는 fall 시간을 개선한 스위칭 회로를 제안하였다. 펄스 증폭기에 제안한 스위칭 회로를 적용하여 측정한 결과, 펄스 출력이 27 dBm에서 rise/fall 시간이 각각 5.7 ns, 21.9 ns인 결과를 얻었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.399-401
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• 1988

This paper describes the experiment and design of Rogowski - wound coil used to measure a pulsed current with pulsewidth on the order of 100nsec in the kiloampere range. Radius of coil is 2.75cm, total number of turns are 26 and cross -sectional area is 1 cm. The coil have 3ns rise time, 0.2nsec transit time and sensitivity is 4v/kA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.238-240
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• 2007

This paper present adaptation method of rail potential test to verify DC railway system's performance and safety. For protection of person and utility caused by rail potential rise, international standard to limit rail potential rise is made and rail potential is tested at the time of plan and construction of DC railway system in foreign country. So, we need rail potential test at the opening time and prepare a continuous monitoring technique of rail potential and a limitation method of rail potential rise. For these, we describe cause of rail potential rise, international standard about rail potential, protection principle, an example of calculation and measurement, and adaptation method for performance test.

• 한국공간구조학회논문집
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• 제19권2호
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• pp.51-61
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• 2019

The objective of this study is to analysis the seismic response of 200m spanned honeycomb lattice domes under horizontal and up-down ground motion of El Centro earthquake. For the analysis of seismic response of the honeycomb lattice domes by rise/span ratio, the time history analysis is used for the estimation of the dynamic response. The low rise lattice dome is less deformed and less stressed than the high rise lattice dome for the earthquake ground motion. The 3-dimensional earthquake response is not significantly different the dynamic response of one directional ground motion. The earthquake response of domes with LRB isolation system is significantly reduced for the asymmetric vertical deformation and the horizontal and vertical accelerations.

• 국제초고층학회논문집
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• 제7권4호
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• pp.409-415
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• 2018

Recently, many countries around the world began to show interest in safety against terrorism, fire, and natural disasters. This study aimed to propose a quantitative measurement system for emergency evacuation and safety for various kinds of terrorism and fire within high-rise multi-purpose facilities, which can measure the pedestrians' ordinary walking patterns in the concourse with the highest pedestrian volume out of all the spaces within multi-story buildings, predict pedestrians' evacuation walking lines when a sudden disaster breaks out, and analyze the gait coefficient, occupant density, and evacuation behavior time.

• 한국정밀공학회지
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• 제26권8호
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• pp.112-118
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• 2009

A pressure rise is generated while air bearing stages are moving in high vacuum environment. This study analyzed this pressure rise phenomenon theoretically and verified it experimentally using two different kinds of stages - linear and rotary air bearing stages. Results indicate that the pressure rise was caused by additional leakage resulting from stage velocity, along with adsorption and outgassing of gas molecules from the guide rail surface. Though tilting of the stage due to acceleration and deceleration reached several micrometers, it had a negligible effect on pressure rise because the tilting time was very short. Therefore, a rotary air bearing stage showed much less pressure rise than a linear stage because the rotary stage theoretically has nothing to do with the above causes. Additional leakage caused by stage velocity was inevitable if the stage had movements, but pressure rise caused by adsorption and outgassing could be suppressed by improving the surface quality to reduce real surface area, and by coating the guide rail surface with titanium nitride (TiN) which has less adhesion probability of gas molecules. The results also indicate that the pressure rise increased when the air bearing stage operated under high vacuum conditions.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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• pp.267-274
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• 1996

Differential shortening of vertical members in high-rise buildings affect other structural members that have to be considered such as horizontal members and exterior cladding. of many elements which affect the total amount of shortening, different loading history mainly comes from the different construction time. Shortening of 66 story concrete columns were investigated and compared according to the different construction time, little difference was found between the total shortening of interior and that of exterior column.

• 전기학회논문지P
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• 제56권2호
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• pp.104-108
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• 2007

This paper deals with an approach to the reduction of potential rise according to the buried depth of structure. In order to analyze the surface potential rise of structure, an electrolytic tank which simulates the semi-infinite earth has been used. The potential rise has been measured and analyzed for types of structure using an electrolytic tank experimental apparatus in real time. The structure models were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. When a test current flowed through structure models, potential gradient was the highest value in case of the outline frame type(structure model A). The distributions of surface potential rise are dependent on the resistivity and absorption percentage in concrete attached to structure model.

• 국제초고층학회논문집
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• 제10권1호
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• pp.45-54
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• 2021

The adaptive reuse of 20th-century high-rise architecture poses important questions about the prevalence of authorized discourses in the heritage conservation field. Based on a two-year teaching experience at Tongji University about the adaptive reuse of the Metropolo Hotel (Palmer and Turner, 1934), an iconic historic high-rise building in the Shanghai Bund area, this paper will show the extent to which disciplinary and urban authorized heritage discourses are present in the development of design and representation strategies in adaptive reuse. Using discourse analysis as a method, this paper will make the argument that disciplinary discourses have a limited effect in the practice of adaptive reuse, which is perceived as a fundamentally creative activity. At the same time, the paper reveals how urban discourses have a much more lasting effect, confirming the intimate links between adaptive reuse and the wider phenomena of beautification and gentrification of high-rise listed areas.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1396_1397
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• 2009

Recently, there has been considerable interest in electromagnetic pulse (EMP) source for no lethal directed energy weaponry applications. The compactness of the Marx generator, coupled with its ability to be powered by battery technology, makes it a viable handled impulse source. The marx generator has 2 stages. Each stage was constructed one charging capacitor, two electrodes and one charging resistor. A inductance structure is used in order to improve the switching performances fo the whole generator. The experiments of rise time in pure gas and mixtures of gases were described. The experimental results show that the rise time characteristics of the marx generator can be controlled through varying insulation gas.