• 한국대기환경학회지
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• 제16권4호
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• pp.399-408
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• 2000

This study evaluated the SO2 adsorption characteristics using a continous moving bed system. Natural manganese oxide (NMO) reaction condition such as L/D the starting time of the NMO feed, feed rate, and flow rate of simulated flue gas, and NMO size were tested. The results showed that optimum L/D was 1.0 in this moving bed system. The higher the feeding rate was the higher the SO2 removal efficiency was and the higher the flow rate of simulated flue gas was the shorter the time to reach the euqilibirum concentration was. The final SO2 con-centration when it reaches the equilibrium concentration was not affected by the starting time of the NMO feed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.580-582
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• 2001

In moving coil LOA, the variation of mover position and the consequent changes of coil flux path affect the coil inductance because of unbalanced magnetic circuit. Furthermore, the armature field shifts and distorts the airgap flux density distribution due to the magnet alone by a certain amount, which cause the unbalanced reciprocating force. In this paper, we propose the reduction method of armature reaction and coil inductance. The proposed LOA has the shorted ring the saturated core, the double coil, and Halbach array.

• 한국소음진동공학회논문집
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• 제21권9호
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• pp.858-867
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• 2011

As applying an active control technique to a pneumatic vibration isolation system, the settling time for the payload excitation could be remarkably reduced as well as the improvement of isolation performance for the ground vibration. Some previous researches were dealt with the settling time through the simulation or experiment but, the discussion on the simulation or experimental results including moving parts, such as a XY-stage, on the isolation table rarely exists. As considering the moving part, the dynamic model could be time varying system and in such a case the force imposed on pneumatic vibration isolation table could be described by inertial forces of moving parts according to Newton's 3rd law, the action and reaction law. In this paper, the simulation procedure of the 3-DOF active pneumatic vibration isolation system including moving parts by TDC(time delay control) technique is proposed and the effectiveness through simulation results are also shown.

• 설비공학논문집
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• 제11권5호
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• pp.605-614
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• 1999

Orbiting scroll mass center is different from the basic circle's for the normal involute profile. As for the orbiting scroll balanced conditions, the dynamic modeling are set up. The influences on sealing, reaction forces between the moving elements and forces from the moving elements to the compressor frame are analyzed in this paper. The simulation and experiment results are presented.

• 감성과학
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• 제20권1호
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• pp.115-132
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• 2017

본 연구는 운전자 연령대와 뇌손상 여부에 따라 다양한 반응시간 과제에서의 반응시간과 반응정확성에서 어떠한 차별성이 있는지 살펴볼 목적으로 수행되었다. 이를 위해 30-50대의 중년운전자, 65세 고령운전자, 그리고 65세 이상의 뇌졸중 고령운전자들을 대상으로 단순반응, 2-선택반응, 자극 이심률을 달리한 4-선택반응, 탐색반응 및 동적자극 탐지 과제에 대한 수행을 비교하였다. 본 연구의 결과를 정리하면 다음과 같다. 첫째, 전반적으로 중년, 고령 및 뇌졸중 고령운전자 순으로 느린 반응시간을 보였으나 자극 이심률이 작은 조건($5^{\circ}$)에 비해 큰 조건($10^{\circ}$)에서 뇌졸중 고령운전자의 반응시간이 다른 집단에 비해 더 두드러지게 지연되었다. 둘째, 전체 반응시간에서 단순 반응시간을 감산한 반응시간을 분석한 결과, 2-선택반응 과제와 동적자극 탐지과제에서의 집단간 반응시간 차이는 유의하지 않았는데, 이것은 이러한 과제들에서의 반응시간 차이가 단순 반응시간에 의해 주로 결정된다는 것을 시사한다. 셋째, 일시적 기억을 요구하는 탐색과제에서는 두 고령운전자 집단이 중년운전자 집단에 비해 유의하게 느리고 부정확한 수행을 보였다. 넷째, 집단간 반응정확성에서의 차이는 선택 대안이 많은 과제와 기억을 요구하는 과제에서 두드러졌다. 이러한 결과는 기억 요구를 수반하는 탐색과제는 중년과 고령운전자 사이의 수행을, 반면 자극 이심률 조건은 뇌졸중 여부에 따른 고령운전자 집단에서의 수행 차이를 민감하게 반영할 수 있음을 시사한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.185-191
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• 2002

In this study a 3-dimensional analytical model is developed, which can analyses dynamic responses of curved bridges subject to moving vehicles. A 5-axle semi-trailer is modeled to simulate the actual tire forces that are redistributed by vehicle rolling effect due to the centrifugal force. The 1-span curved bridge with two steel box girders is modeled using the frame elements. The dynamic response characteristics of curved box girder bridges are examined and compared for two different support conditions. One is the case that two shoes are arranged at the outer sides of box girders with larger space between the two shoes and the other is that two shoes at the center of each box girder. In the curved bridges, the dynamic effect of moving vehicles influences the reaction force much more than other responses, such as displacement or stress, especially the upward reaction of inner-radius shoes. It is more advantageous for the reaction considering dynamic effect when shoes are arranged further at the outer sides of box girders than when shoes at the center of each box. The shoes for curved bridges with two-box girder system should be arranged to have larger distance.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.833-841
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• 2021

During the postulated severe accident of nuclear reactor, eutectic reaction leads to low-temperature melting of fuel cladding and early failure of core structure. In order to model eutectic melting with the moving particle semi-implicit (MPS) method, the eutectic reaction model is developed to simulate the eutectic reaction phenomenon. The coupling of mass diffusion and phase diagram is applied to calculate the eutectic reaction with the uniform temperature. A heat transfer formula is proposed based on the phase diagram to handle the heat release or absorption during the process of eutectic reaction, and it can combine with mass diffusion and phase diagram to describe the eutectic reaction with temperature variation. The heat transfer formula is verified by the one-dimensional melting simulations and the predicted interface position agrees well with the theoretical solution. In order to verify the eutectic reaction models, the eutectic reaction of uranium and iron in two semi-infinite domains is simulated, and the profile of solid thickness decrease over time follows the parabolic law. The modified MPS method is applied to calculate Transient Reactor Test Facility (TREAT) experiment, the penetration rate in the simulations are agreeable with the experiment results. In addition, a hypothetical case based on the TREAT experiment is also conducted to validate the eutectic reaction with temperature variation, the results present continuity with the simulations of TREAT experiment. Thus the improved method is proved to be capable of simulating the eutectic reaction in the severe accident.

• 한국초전도ㆍ저온공학회논문지
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• 제11권1호
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• pp.49-54
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• 2009

This paper presents the numerical simulation results on the moving type electrodynamic suspension (EDS) simulator and static type EDS simulator using high-Tc superconducting (HTS) levitation magnet. The levitation force of the EDS system is formed by the reaction between the moving magnet and the fixed ground conductor. The possible two ways to simulate the EDS system were simulated in this paper by using finite element method (FEM). The first way was the moving type simulator which consists of the fixed HTS magnet and the moving ground conductor. The second way was the static type simulator which consists of the fixed magnet, the fixed ground conductor and the ac current supply system. To verify the characteristics of high speed EDS system with the moving type simulator heavy, large and fast moving ground conductor is needed. The static type simulator can get the characteristics of the high speed EDS system by applying equivalent ac current to velocity, therefore it does not need large moving part. The static type EDS simulator, which can consist of an HTS magnet, the fixed ground conductor(s), an AC power supply and the measuring devices, also test the effect of the shape of the ground conductor easily. The plate type ground conductor made stronger levitation force than ring type ground conductor. Although the outer diameter 335 mm ring type ground conductor (Ring3) was larger than the outer diameter 235 mm ground conductor (Ring2), the levitation force by Ring2 was stronger than that by Ring3. From the calculation results on this paper, the consideration of the magnetic flux distribution according to the levitation height should be included in the process of the ground conductor design.

• 한국강구조학회 논문집
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• 제14권6호
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• pp.711-720
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• 2002

본 연구에서는 곡선교에서 주행차량에 의한 동적 응답을 보다 정밀하게 구현할 수 있는 3차원 해석 모형을 개발하였다. 원심력에 의한 차량의 롤링운동에 따른 차량의 쏠림현상을 구현하여 곡선교의 대표적인 응답특성인 편경사와 곡률반경에 따른 동적응답과 받침의 변화에 따른 동적 응답 특성을 규명하였으며, 2가지 지점조건에 대하여 주행차량에 의한 곡선교의 동적 특성을 비교 분석하였다. 또한 이와 함께 곡선교에서 어떤 파라미터가 하중 분배에 가장 효율적인가를 비교 분석하였다. 동적해석결과 받침이 외측에 배치된 경우가 중앙에 배치된 경우보다 더 유리하게 분석되었으며, 여러 가지 조건에 따라 하중분배 특성이 다르게 나타남을 알 수 있었다.

• 시큐리티연구
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• 제15호
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• pp.303-316
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• 2008

경호업무에 관한 중요한 것 중 하나는 위해상황발생시 경호원이 피경호인을 안전하게 보호하기 위한 최소한의 안전거리를 확보하는 것으로, 이는 도보대형과 군중과의 이격거리를 결정하는 것과 관계하여 근접경호의 가장 근간이 된다고 할 수 있다. 본 논문은 범인이 총기를 사용하여 위해를 시도하는 상황에서 경호원에게 요구되는 대응행위에 대한 이론의 기본이 되는 신체반응시간과 이동거리, 피경호인과 군중과의 안전거리에 관한 논리를 제시하여 보다 과학적인 대응방법을 실현할 수 있는 기초를 마련하고자 한다. 신체반응시간을 적용함에 있어, 기존에는 100m 주행시간을 기준으로 초당 이동거리로 산출하거나 또는 구간별 속도를 기준으로 산출하였으나 본문에서는 핸드볼경기의 골키퍼의 방어동작(시각적 인식)과 반응시간(선택적 반응)을 적용해 보았고 반응시간에 따른 이동거리를 산정하기 위해서는 왕복달리기의 기록을 적용하였다. 몇 가지 이론과 연구결과에서 훈련에 의해 선수들의 신체반응 시간을 단축시킬 수 있다는 것을 보여주고 있는데, 경호원도 훈련에 의해 신체반응시간을 단축시킬 수 있으며 이로 인한 대응효과를 개선할 수 있다. 중요한 것은 아주 짧은 반응시간 차이라도 안전확보에 큰 영향을 미치게 된다는 것이다. 피경호인과 경호원, 피경호인과 군중사이의 적절한 거리 선정은 자연방벽효과를 함께 적용하여 보다 효과적인 대응이 가능할 것이다.