• 대한전자공학회논문지TC
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• 제49권1호
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• pp.19-25
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• 2012

RFID 시스템에서의 성능은 단일 무선 채널을 공유하는 통신으로 인하여 태그 충돌 중재과정이 중요하다. 기본적인 프로토콜인 BT(Binary Tree) 알고리즘 및 재인식과정에서의 성능향상을 위한 ABS(Adaptive Binary Splitting)는 이상적인 환경에서의 태그응답을 전제하고 있다. 무선통신에서는 실질적으로 캡처 효과 (Capture Effect)가 존재하게 되는데, BT 및 ABS 프로토콜은 태그를 인식하지 못하는 치명적인 상황이 발생할 수 있다. 본 논문에서 제시하는 FTB(Feedback TagID with Binary splitting) 알고리즘은 ABS 프로토콜의 캡처 효과에 의한 문제점을 해결하고 성능 개선을 기대할 수 있다.

• 한국산업보건학회지
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• 제9권2호
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• pp.90-99
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• 1999

Fume extracting welding gun is one of the promising options for reducing the welder's fume exposure. The performance of the gun was assessed on the basis of capture efficiency. Capture efficiencies were measured in a test chamber recommended by American Welding Society. The overall capture efficiency was turned out to be above 95%. But it did not include the effect of crossdraft existing in the real work environment because all experiments were conducted in a closed chamber. It thus needs more work in the future. In addition, the future directions for improving the pres ent commercial techniques of the gun were discussed.

• KEPCO Journal on Electric Power and Energy
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• 제4권1호
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• pp.33-38
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• 2018

This study applied upgrades to the processes of a 10 MW wet amine $CO_2$ capture pilot plant and conducted performance evaluation. The 10 MW $CO_2$ Capture Pilot Plant is a facility that applies 1/50 of the combustion flue gas produced from a 500 MW coal-fired power plant, and is capable of capturing up to 200 tons of $CO_2$. This study aimed to quantitatively measure efficiency improvements of post-combustion $CO_2$ capture facilities resulting from process upgrades to propose reliable data for the first time in Korea. The key components of the process upgrades involve absorber intercooling, lean/rich amine exchanger efficiency improvements, reboiler steam TVR (Thermal Vapor Recompression), and lean amine MVR (Mechanical Vapor Recompression). The components were sequentially applied to test the energy reduction effect of each component. In addition, the performance evaluation was conducted with the absorber $CO_2$ removal efficiency maintained at the performance evaluation standard value proposed by the IEA-GHG ($CO_2$ removal rate: 90%). The absorbent used in the study was the highly efficient KoSol-5 that was developed by KEPCO (Korea Electric Power Corporation). From the performance evaluation results, it was found that the steam consumption (regeneration energy) for the regeneration of the absorbent decreased by $0.38GJ/tonCO_2$ after applying the process upgrades: from $2.93GJ/ton\;CO_2$ to $2.55GJ/tonCO_2$. This study confirmed the excellent performance of the post-combustion wet $CO_2$ capture process developed by KEPCO Research Institute (KEPRI) within KEPCO, and the process upgrades validated in this study are expected to substantially reduce $CO_2$ capture costs when applied in demonstration $CO_2$ capture plants.

• 한국콘텐츠학회논문지
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• 제13권2호
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• pp.8-18
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• 2013

본 논문은 Html5 모바일 웹상에서 학습 동영상을 수강하면서 재학습이 필요한 영역을 타임라인의 비디오 프레임 형태로 재생 시간과 함께 캡쳐하여 저장한다. Html5의 Video 태그를 활용하여 최대 9개까지 캡쳐 프레임의 목록을 표시할 수 있고 프레임 이미지를 선택하면 저장한 재생 시간 위치부터 실행하는 방식으로 구현한다. 캡쳐 프레임 실행은 전체 학습에 비해 재학습 프레임만 부분적인 학습이며 집중 학습의 효과로 학습자 맞춤형 스토리텔링을 구현할 수 있다. 무작위 순서에 따라 구간 반복 학습 할 수 있으므로 학습자 수준별 맞춤 반복 학습에 따른 학업 성취도에 긍정적인 효과를 줄 수 있다.

• 융합정보논문지
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• 제10권11호
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• pp.9-15
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• 2020

향상된 프리앰블 탐지기술인 Message In Message (MIM) 기능을 적용한 무선 센서 노드들은 캡처 효과에 의한 동시전송 기회를 최대화하여 IEEE 802.15.4를 기반으로 동작하는 기존 센서들에 비해 시스템 성능을 크게 향상시킬 수 있다. 본 논문에서는 MIM 기능을 무선 센서 노드에 적용할 경우 얻을 수 있는 성능 이득을 분석하기 위해 MIM 캡처 확률 모델을 제안하였다. 그리고 MIM 캡처 효과에 따른 성능이득을 확인하기 위해 IEEE 802.15.4 및 MIM 동시전송 기능을 파이썬으로 구현하여 시뮬레이션을 수행하였다. 성능 평가를 통해 MIM 기법을 적용한 센서 노드는 IEEE 802.15.4 방식의 센서 노드에 비해 시스템 처리량은 34% 향상되었고 전송 지연은 31% 개선되어 전반적으로 MIM 캡처 확률 모델의 분석결과와 일치함을 확인할 수 있었다.

• 한국산업보건학회지
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• 제16권3호
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• pp.290-301
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• 2006

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank. Efficiency of push pull hood system is affected by various parameters, such as, cross draft, vessel shapes, tank surface area, liquid temperature. A previous work assisted by flow visualization technique qualitatively showed that a strong cross draft blown from the pull hood to push slot could destroy a stable wall-jet on the surface of tank, resulting in the abrupt escape of smoke from the surface. In this study, the tracer gas method was applied to determine the effect of cross-draft on the capture efficiency qualitatively. A new concept of capture efficiency was introduced, that is, linear efficiency. This can be determined by measuring the mass of tracer gas in the duct of pull hood while the linear tracer source is in between push slot and pull hood. By traversing the linear tracer source from the push slot to the pull hood, it can be found where the contaminant is escaped from the tank. Total capture efficiency can be determined by averaging the linear efficiencies. Under the condition of cross-draft velocities of 0, 0.4, 0.75, 1.05 and 1.47m/s, total capture efficiencies were measured as 97.6, 95.4, 94.6, 92.7 and 70.5% respectively. The abrupt reduction of efficiency with cross-draft velocity of 1.47m/s was due to the destruction of tank surface wall-jet by the counter-current cross-draft. The same phenomenon was observed in the previous flow visualization study. As an alternative to overcome this abrupt efficiency drop, the 20% increase of hood flow rates was tested, resulting in 20% efficiency increase.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.335-338
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• 2003

A finite element-based, integrated process model has been developed and applied to predict the detailed, three-dimensional aspects of the thermo-mechanical behavior occurring in the slab caster considering inclusion removal from molten steel by argon bubble flotation. Gas bubbles are simulated using the dispersion model calculating the volume fraction, and the bubble capture effect is included by a source term in the transport equation for particles. The process model is applied to the investigation of the effect of various process parameters on the inclusion removal in the molten steel.

• 천문학회보
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• 제38권1호
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• pp.77.2-77.2
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• 2013

xIn the present work, we explored the effect of the radiation on the effective impact parameter for capture in a fully general relativistic manner. To summarize our results, evidently due to the radiation drag (the Poynting-Robertson effect), critical impact parameter of point particle gets larger by the factor of two, thus, the effective cross section of the luminous relativistic star becomes 4 times larger than that of the star without radiation emission. In addition, the finite size effect of the star adds up to this growth of the effective cross section.

• 한국방사선학회논문지
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• 제3권3호
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• pp.23-25
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• 2009

Gd-157 material has very large neutron capture cross section in the thermal region. So it is very useful to shield material for thermal neutrons. Futhermore, in the neutron capture experiment and calculation, the neutron absorption and scattering are very important. Especially these effects are conspicuous in the resonance energy region and below the thermal energy region. In the case of very narrow resonance, the effect of scattering is to be more considerable factor. In the present study, we obtained energy dependent neutron absorption ratios of natural indium in energy region from 0.003 to 100 keV by MCNP-4B Code. The coefficients for neutron absorption was calculated for circular type and 1 mm thickness. In the lower energy region, neutron absorption is larger than higher region, because of large capture cross section (1/v). Furthermore it seems very different neutron absorption in the large resonance energy region. These results are very useful to decide the thickness of sample and shielding materials.

• ETRI Journal
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• 제18권3호
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• pp.127-145
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• 1996

A new analytic framework based on a linear algebra approach is proposed for examining the performance of a direct sequence spread spectrum (DS/SS) slotted ALOHA wireless communication network systems with delay capture. The discrete-time Markov chain model has been introduced to account for the effect of randomized time of arrival (TOA) at the central receiver and determine the evolution of the finite population network performance in a single-hop environment. The proposed linear algebra approach applied to the given Markov problem requires only computing the eigenvector ${\prod}$ of the state transition matrix and then normalizing it to have the sum of its entries equal to 1. MATLAB computation results show that systems employing discrete TOA randomization and delay capture significantly improves throughput-delay performance and the employed analysis approach is quite easily and staightforwardly applicable to the current analysis problem.