• 대한전자공학회논문지TE
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• 제42권2호
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• pp.23-28
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• 2005

본 논문에서는 밀리미터파 대역의 주파수를 실시간으로 이루어지는 차량간 통신시스템에 적용하기 위해 전파경로 분석과 전파경로손실 예측 모델을 제안하였다. 다중경로에 의한 반사파의 영향을 분석하기 위해 차량정체가 많은 대도시 지역 편도 2차선의 도로에서 차량과 차량 사이에 통신이 이루어지는 경우를 가정하였다. 제안모델의 시뮬레이션 결과, 전파직선경로 100[m]를 진행하는 동안 반사파에 의한 전파경로는 직접파에 비해 0.1[m]$\sim$5.1[m]정도 더 길었다. 또한 전파경로 손실을 비교한 결과 벽면에 의한 반사의 경우 -0.8[dB]$\sim$-4.2[dB], 차량에 의한 반사의 경우 -0.8[dB]$\sim$-1[dB] 정도 더 손실이 커짐을 알 수 있었다. 이상의 결과 벽면에 의해 발생한 반사파의 경로손실이 인접 차량에 의해 발생한 경로 손실 보다 -3.2[dB] 정도 더 큼을 알 수 있었다.

• 한국전산유체공학회지
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• 제21권2호
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• pp.47-53
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• 2016

This study investigated natural convection flow behavior in airflow path designed in concrete dry storage cask to remove the decay heat from spent nuclear fuels. Using FLUENT 16.1 code, thermal analysis for natural convection was carried out for three dimensional, 1/4 symmetry model under the normal condition that inlet ducts are 100% open. The maximum temperatures on other components except the fuel regions were satisfied with allowable values suggested in nuclear regulation-1536. From velocity and temperature distributions along the flow direction, the flow behavior in horizontal duct of air inlet and outlet duct, annular flow-path and bent pipe was delineated in detail. Theses results will be used as the theoretical background for the composing of airflow path for the designing of passive heat removal system by understanding the flow phenomena in airflow path.

• 한국생활과학회지
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• 제16권4호
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• pp.745-759
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• 2007

The study aims at investigating the causal relationships among leisure expenditures, leisure activity participation and leisure satisfaction of adult consumers. Data were collected from 415 adult consumers in Ulsan. ANOVA, multiple regression, and path analysis were used for the statistical analysis. The results indicated that marital status, household income and subject's attitude toward leisure had significant impacts on leisure expenditures, while their satisfaction with financial status, household income, leisure plan, their attitudes toward leisure and personal acquaintanceship significantly affected leisure activity participation. To leisure satisfaction, their satisfaction with financial status, the attitudes toward leisure, leisure expenditures and leisure activity participation were positively related, and leisure plan was negatively related. The results of path analysis showed that marital status, household income, the satisfaction with financial status, their attitude toward leisure, leisure plan, personal acquaintanceship, leisure expenditures, and leisure activity participation had direct or indirect effects on leisure satisfaction.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.280-289
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• 2005

A single degree of freedom system and transmissibility are key concepts in many problems of vibration isolation. In order to apply this approach, however, several assumptions must be satisfied, which are often not realistic. For examples, in practical systems, vibration transmissions at multi-point with multi-degree of freedom(translational and rotational DOF) take place and mobilities or impedances of receiver structures cannot be ignored any more especially over high frequency range. Therefore, a multi-dimensional treatment is required for accurate estimation of dynamic behavior of the system. In this paper, an approach using vibrational power flow is introduced to deal with analysis of multi-dimensional vibration isolation system in a more practical way and in aspects of vibration isolations and vibration path analysis. Procedures of this approach and some results of research for vibrational power path analysis with rotational terms included are presented. Difficulties in this method are also discussed.

• 한국강구조학회 논문집
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• 제21권6호
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• pp.563-574
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• 2009

본 논문은 기하학적 비선형성을 가진 보존적 단일 하중 매개변수의 탄성 상태 공간구조의 탄성 분기 좌굴이론에 관한 수치 해석적 기본 방법 및 경로 추적, pin-pointing, 경로 전환을 기술하고 있다. 비선형 탄성 불안정 상태는 극한점과 분기점으로 분류될 수 있으며, 평형경로상의 평형점의 계산 및 평형경로상의 특이점을 찾기 위한 pin-pointing 반복계산을 수행하는 일반적인 비선형 수치해석법으로 극한점을 계산할 수 있다. 그러나 분기좌굴 해석을 위해서는 좌굴 후 분기경로의 추적을 위한 분기경로 전환 알고리즘이 추가적으로 필요하다. 본문에서는 에너지이론에 기초한 일반 탄성안정이론을 소개하고, 평형경로 추적, 다분기 좌굴점을 찾기 위한 간접법과 다분기의 경로 전환에 관한 이론을 전개한다. 분기좌굴 해석예제로 트러스로 이루어진 스타돔, 핀지지의 평면아치의 분기좌굴 해석을 수행하여 본문에서 제시한 수치해석법의 정확성 및 적용성을 검증한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.585-587
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• 2004

Diameter base protocol is intended to provide an AAA framework for applications such as IP mobility. Currently Diameter base protocol is standardized to RFC 3588, but there are some problems. One of them, path authorization is already argued at IETF WG Mailing List. According to RFC 3588, path authorization function causes inefficient data traffic and conflicts with RFC 3588 itself. In this paper, we analysis these problems about path authorization function and propose more improved solution.

• 한국가스학회지
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• 제13권2호
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• pp.7-13
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• 2009

관망 내 배관의 간섭 거동에 따른 지하 매설 배관의 영향선 분석을 위하여 실제 환경에 부합 하도록 지하의 상부와 하부에 각각 하수관거와 가스관을 매설하여 유한요소모델을 구현하였으며, 두 배관의 교차 정도에 따라 하부 가스 배관의 영향선을 분석하였다. 하수관거와 가스관은 각각 1.0m와 3.39m의 매설심도를 가지며, 두 배관이 이루는 교차각은 $0{\sim}90^{\circ}$에 대하여 해석을 실시하였다. 본 연구에서는 Ring Deflection과 Bending Stress의 결과로부터, 교차각에 따른 영향선을 분석하였으며, 그 결과 두 배관이 이루는 교차각과 하부 배관의 영향선은 일치함을 알 수 있었다. 따라서 배관의 간섭 거동에 따른 하부 배관의 영향선은 두 배관의 교차각과 깊은 관계가 있다고 판단된다.

• 분석과학
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• 제26권2호
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• pp.120-124
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• 2013

본 연구에서는 대기오염 및 화산활동에 의한 분출가스의 원거리 가스검출에 제한적으로 사용된 개방형 푸리에 변환 분광 분석기(open path FT-IR spectrometer)를 사용하여 적외선광원을 사용하지 않는 passive mode로 $CO_2$, CO, $SO_2$에 대한 정량 분석을 시도하였다. 표준가스를 이용하여 제작된 적외선흡수 스펙트럼으로 $CO_2$, CO, $SO_2$ 다중 회귀 곡선(MLR)을 사용한 농도 별 검량선 작업 결과, $CO_2$, CO는 결정 계수가 0.90 이상으로 선형성이 좋았으나, $SO_2$는 0.88로 비교적 낮은 선형성을 확인할 수 있었다. 실제 화재 실험을 통하여 3가지 가스에 대해서 측정한 결과 $CO_2$는 높은 농도를 확인하였으나, CO, $SO_2$는 확인되지 않았다. 이 결과를 통해서 적외선 광원 없이 개방형 푸리에 변환 분광 분석기를 활용하여 화재시 배출되는 가스의 원거리측정이 가능함을 확인하였다.

• 한국조경학회지
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• 제33권4호
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• pp.33-44
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• 2005

In order to reveal the geographical landscape's features of the East Sea-gateway(東海口), which has existed only in the era of Shilla as unique east path, we have carried out analysis of the old maps(邑誌圖) and satellite imagery, and geographical features analysis in the application of digital maps, and the result is as follows. 1. Analysis of materials from the Chosun dynasty describes landscapes called sea gates(海口) (note that this should not be capitalized); a place where the river meets the sea and the sea comes far into the land. Sea gate landscapes may have an island, but this is not a prerequisite. 2. According to the satellite imagery, the capital city of Shilla Dynasty had five passages. four or them are broad corridors, but one of them is narrow. The east side of the capital city is blocked by mountains and there was an important path which leads into the East Sea. 3. According to the cross section of the mountains, there is the only rule East-path. There was no alternative way. There was only one way-out to the east side from the capital city. This is the unique path which reaches a length of 28km. Judging from this, it seems that this path was called the East Sea-gateway. 4. The landscape of the East Sea-gateway was shaped like the letter 'V' and reached to the landscape of the sea gate. However, the route was blocked - part by the mountains, and also the part in the crisis of loss of path-landscape which has lost its own character of closure as several valleys are merged together.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3604-3613
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• 2022

The Physical Protection System (PPS) plays an important role and must effectively deal with various adversary attacks in nuclear security. In specific single adversary path scenarios, we can calculate the PPS effectiveness by EASI (Estimated Adversary Sequence Interruption) through Probability of Interruption (P_I) calculation. EASI uses a single value of the probability of detection (P_D) and the probability of alarm communications (P_C) in the PPS. In this study, we develop a multi-path analysis code based on EASI to evaluate the effectiveness of PPS. Our quantification method for P_I considers the variability and uncertainty of P_D and P_C value by Monte Carlo simulation. We converted the 2-D scheme of the nuclear facility into an Adversary Sequence Diagram (ASD). We used ASD to find the adversary path with the lowest probability of interruption as the most vulnerable paths (MVP). We examined a hypothetical facility (Hypothetical National Nuclear Research Facility - HNNRF) to confirm our code compared with EASI. The results show that implementing the variability extension can estimate the P_I value and its associated uncertainty. The multi-path analysis code allows the analyst to make it easier to assess PPS with more extensive facilities with more complex adversary paths. However, the variability of the P_D value in each protection element allows a significant decrease in the PI value. The possibility of this decrease needs to be an important concern for PPS designers to determine the P_D value correctly or set a higher standard for PPS performance that remains reliable.