http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이창용,곽한성,이동은,Yi, Chang-Yong,Gwak, Han-Seong,Lee, Dong-Eun 大韓建築學會 2014 大韓建築學會論文集 : 構造系 Vol.30 No.8
Reducing greenhouse gas(GHG) emissions is a worldwide concern. Low carbon construction is an important operation management goal. Construction resources(i.e., equipment and laborer) are major contributors to producing GHG, and they are the main target for achieving low carbon construction. The amount of Carbon emissions varies depending on the operating conditions. This paper introduces a method which measures the variability of carbon emissions amounts. First, it allows creating construction operation models of which the level of detail is breakdown into the work task level. It makes use of the equipments' hourly fuel consumption and laborers' hourly respiration rate. Second, the method implements sensitivity analysis along with ranges of resources that are allocated in an operation model. It facilitates to find the optimal resource combination using the operation performances such as the amount of emissions, operation completion time, operation completion cost, and productivity. Third, it identifies the best fit probability distribution functions of performance criteria given a certain resource combination. It allows project manager to query the chance to complete the operation within limitations of multiple performance criteria specified by the system users.
이창용,조겸래,이대우,조윤철,Yi, Chang-Yong,Cho, Kyeum-Rae,Lee, Dae-Woo,Cho, Yun-Cheol 한국항공운항학회 2016 한국항공운항학회지 Vol.24 No.2
A GPS/SDINS/ST(Star Tracker) integrated sensor algorithm is more robust than the GPS/SDINS and the ST/SDINS systems on exploration of other planets. Most of the advanced studies shown that GPS/SDINS/ST integrated sensor with centralized Kalman filter was more accurate than those 2 integrated systems. The system, however, consist of a single filter, it is vulnerable to defects on failed data. To improve the problem, we work out a study using federated Kalman filter(No-Reset mode) and centralized Kalman filter with adaptive measurement fusion which known as robustness on fault. The simulation results show that the debasing influences are reduced and the computation is enable at least 100Hz. Further researches that the initial calibration in accordance with observability and applying the exploration trajectory are needed.
광역 네트워크 트래픽의 장거리 상관관계와 1/f 노이즈
이창용,Lee, Chang-Yong 한국정보과학회 2010 정보과학회논문지 : 정보통신 Vol.37 No.1
본 논문에서는 네트워크 트래픽의 수동적 측정치 분석을 통해 잘 알려진 장거리 상관관계가 광역 네트워크의 능동적 측정치에도 존재하는지 여부를 관련 분석법을 통하여 검정하고자 한다. 이를 위하여 PingER 프로젝트를 통하여 측정된 광역 네트워크 트래픽의 대표적인 능동적 측정치인 RTT(Round Trip Time)와 RTT의 변동성 시계열 데이터에 대하여 분석을 수행하였다. RTT 시계열 데이터는 장거리 상관관계 혹은 1/f 노이즈의 특성을 보였으며, RTT의 고차원 변화량으로 정의된 변동성은 로그정규분포를 따르며 변동성에 대한 장거리 상관관계는 고려하는 시간 간격이 짧은 경우 장거리 상관관계를 보이고, 시간 간격이 긴 경우에는 장거리 상관관계 혹은 1/f 노이즈를 따름을 밝혔다. 본 연구를 통해 볼 때 장거리 상관관계는 비단 패킷 도착의 시간 간격 등과 같은 수동적 측정뿐만 아니라 RTT와 같은 능동적 측정에서도 나타나는 특징이며, 특히 능동적 측정에는 수동적 측정에는 잘 나타나지 않는 1/f 노이즈 특성이 존재함을 밝혔다. In this paper, we examine a long-range dependence in an active measurement of a network traffic which has been a well known characteristic from analyses of a passive network traffic measurement. To this end, we utilize RTT(Round Trip Time), which is a typical active measurement measured by PingER project, and perform a relevant analysis to a time series of both RTT and its volatilities. The RTT time series exhibits a long-range dependence or a 1/f noise. The volatilities, defined as a higher-order variation, follow a log-normal distribution. Furthermore, volatilities show a long-range dependence in relatively short time intervals, and a long-range dependence and/or 1/f noise in long time intervals. From this study, we find that the long-range dependence is a characteristic of not only a passive traffic measurement but also an active measurement of network traffic such as RTT. From these findings, we can infer that the long-range dependence is a characteristic of network traffic independent of a type of measurements. In particular, an active measurement exhibits a 1/f noise which cannot be usually found in a passive measurement.