접근로별 포화도를 고려한 Roundabout Signal Metering 운영방법에 관한 연구

안우영,이소영 한국도로학회 2013 한국도로학회논문집 Vol.15 No.5

PURPOSES: Under the capacity conditions with balanced approach flows, roundabouts give less delay than existing signalized intersections;however, flows over 450 vehicles/hour/lane with unbalanced approach flow conditions, roundabouts efficiency drops due to the short time difference between the critical gap and the follow-up headway. The purpose of this study is developing a roundabout Signal Metering operation method by considering approach lanes degree of saturation. METHODS : A four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of 16different unbalanced flow conditions. Based on these traffic conditions, the performance is evaluated for 64 different cases of Signal Metering combinations by using SIDRA software. A degree of saturation(V/C ratio) sum for two adjoined approaches is used for the performance index of choosing Metered Approach and Controlling Approach. RESULTS : When the V/C ratio sum is 0.29~0.81 and Metered Approach flow is less than Controlling Approach flow, the average delay saving per vehicle is about 7 seconds; however, after this rage the delay saving decreases gradually until the V/C ratio sum reaches around 1.0. The range of V/C ratio sum 0.93~1.09 provides average delay saving per vehicle about 3 seconds. In case of V/C ratio sum is grater than 1.0and the flows of Metered Approach is grater than Controlling Approach, the average delay per vehicle increases 3~11 times respectively. CONCLUSIONS : As expected, the Signal Metering provides substantial improvements in delay saving for the case of V/C ratio sum is 0.3~1.0 under the traffic flow conditions of Metered Approach is less than Controlling Approach.

진입교통량을 고려한 회전교차로 Signal Metering 운영에 관한 연구

안우영 한국도로학회 2012 한국도로학회논문집 Vol.14 No.2

Under unsaturated capacity conditions with balanced approach flows, roundabout gives less delay and queue length than existing signalized intersections; however, over capacity conditions with unbalanced approach flows(flow above 450 pcu/h/lane), roundabouts efficiency drops due to the short gap between entering vehicles and circulating vehicles. This study provides a roundabout Signal Metering transfer standard and operation method. In this study, a four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of unbalanced flow conditions. The performance is evaluated by using SIDRA software in terms of average delay and queue length. The result shows that the Signal Metering provides substantial improvements for the case of total approach flow is 1,800~2,000 pcu/h in which the main approach flow ratio is 60~70% gives 30~40% less delay and 30~60% less queue length than normal roundabout operation. Also, it is approved that operational performance saving can be achieved when the Metered Approach is selected adjoining to the main approach in pair. 회전교차로(roundabout)는 용량 이하의 상태에서 접근로별 교통류가 균등할 경우 기존 신호교차로에 비해 운영효율성이 증대되나 토지이용변화로 교통량이 증가하면서 접근로별 교통류가 불균등 해질 경우(차로 당 450대/시 이상) 주접근로에서 회전교차로 내부로의 진입이 어려워져 효율성이 떨어지게 된다. 본 연구에서는 1차로형 4지 회전교차로를 대상으로 회전교차로 설치이후 교통량 증가로 신호교차로 설치에 대한 재검토를 하기 전에 회전교차로를 효율적으로 운영할 수 있는 Signal Metering 전환기준 및 운영방법을 제시하고 효과분석(지체 및 대기행렬)은 SIDRA를 활용하였다. 본 연구결과 총 진입교통량이 1,800~2,000pcu/시 이고 주접근로의 진입교통량비가 60~70%일 때 지체는 30~40% 그리고 대기행렬은 30~60% 감소하였다. 또한 주접근로에 가장 인접한 부접근로에 Metered Approach를 설치하고 한 쌍(pair)으로 묶어서 운영하는 것이효과적인 것으로 분석되었다.

The Analysis of Safety Impacts of “Near-Site” Traffic Signals

장일준 대한토목학회 2011 KSCE Journal of Civil Engineering Vol.15 No.7

Many approaches have been performed to reduce traffic accidents at signalized urban intersections in Korea. Among them installing red-light running cameras have been the most popular and simplest approach. Recently, on the other hand, engineering approaches have been tried and as a result, some provinces in Korea have started to install “near-site” traffic signals. Near-site signals are installed before crossing the intersection, aiming to reduce traffic violations and accidents at intersections. This new approach,however, has been performed without any in depth studies. Thus, this research attempts to verify the impact of near-site signals on traffic safety based on collected field data of drivers’ behaviors. Accident rates at signalized intersections with near-site traffic signals have been collected to study the direct effects of near-site signals. This study also collects violation rates of stop lines and traffic signals, and approach speed to examine the rate of reduction of possible risks at intersections. A simple comparison method has been applied. By comparing violation rates, approach speed, and accident rates, while excluding adjustment periods, this research finds that intersections with near-site signals can enhance traffic safety. Furthermore, this research suggests near-site signals should be installed at intersections that has the number of intersecting lanes are less than 6 lanes to maximize the impact on traffic safety.

Principal Component Analysis Based Signal-to-noise Ratio Improvement for Inchoate Faulty Signals: Application to Ball Bearing Fault Detection

Moussa Hamadache,이동익 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.2

This paper addresses the development of an algorithm that can improve the signal-to-noise ratio (SNR)in inchoate faulty signals. The removal of noise and preservation of fault information components cannot be easilyachieved. Many techniques for SNR improvement in healthy signals rely on frequency bands. Such techniqueshave been proven to be efficient in improving the SRN by filtering out frequency bands (FoFBs). However, thesetechniques cannot reduce noise and preserve fault information when dealing with inchoate faulty signals. Thus, afeature extraction technique based on statistical parameters, which are free from Gaussian noise, is proposed in thispaper. The proposed signal subspace-based approach for SNR improvement in inchoate faulty signals is based on amodified principal component analysis (PCA), in which the optimal subspace is selected via a cumulative percentof variance (CPV) criterion and the test statistic condition of the true information loss, which has the tendencyto alleviate the impact of Gaussian and non-Gaussian noise and provides useful time domain analysis for nonstationarysignals such as vibration, in which spectral contents vary with respect to time. Furthermore, the modifiedPCA algorithm is combined with a low-pass filter (LPF) to achieve an optimum balance between noise reductionefficiency and the conservation of inchoate fault information. The proposed PCA-LPF algorithm is compared withdifferent filters under different noise levels to find the most efficient approach in terms of optimizing the trade-offbetween noise reduction efficiency and precision of inchoate fault information conservation, with the final goalof improving the fault detection capability. Further, the performance of the proposed PCA-LPF algorithm wasdemonstrated with an experimental study on vibration-based ball bearing fault detection.

돌발상황에 따른 연령별 운전자 생리반응 비교를 위한 생체신호 추출, 선정 및 정량화

배준형(Junhyung Bae),원웅재(Woongjae Won),손준우(Joonwoo Son) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper is to collect young and older ages man driver's physiological signal under unexpected events and quantify physiological variables for diagnostic approach. The physiological signal is collected from driving simulator with measuring devices. The collected data were analyzed by the temporal pattern during simulated driving accident conditions. We investigated status a various physiological signals using autonomic nerve system such as PPG(peripheral plethysmograph), SCL(skin conductance level), SCR(skin conductance response), RSP(respiration), HR(heart rate). Three physiological signal with consistent pattern were selected and quantified in terms of slope and amplitude of the signal. The result of the paper can be used to design a system to monitor the driver's safety and health condition.

신호접근법에 의한 한국의 해운시장 위기 지표 분석

이재규(Jae-Kyu Lee),김일수(Il-Soo Kim) 한국무역연구원 2016 무역연구 Vol.12 No.5

The economic recession has contributed a lot to the shipping market crisis in Korea. When a financial crisis breaks out, crisis indices become useful primarily in shipping markets. Thus, proposing crisis indices predicting the market crisis more accurately means. The purpose of this study is to find crisis indices in shipping markets in Korea using the signals approach proposed by Kaminsky, Lizondo and Reinhart (1998). The signals approach was not originally designed to predict the crisis of shipping markets. However, as the approach is an efficient method to find out indices of an economic crisis, it is assumed to be also useful in predicting risks of shipping markets in Korea. The history of Korea shipping markets is comparatively short compared to those of advanced countries, and the former has its own characteristics. We conduct the analysis of crisis indices of those markets using our revised signals approach. These two approaches are compared. Finally, this study shows that our revised signals approach improved the predictability of the shipping market crisis in Korea.

우리나라 위기 예측과 지역모형의 사용 -신호접근법 분석-

박원암 명지대학교(서울캠퍼스) 금융지식연구소 2017 금융지식연구 Vol.15 No.3

This paper investigates the efficiency of the regional model to predict Korea's financial crisis, using the signal approach. We adopted the widely recognized model of Goldstein, Kaminsky, and Reinhart(2000) that includes 15 leading indicators in 24 countries around the world during 1990.Jan-2009.Dec. and found the implications as follows. It was not helpful to include other regions than the East Asia to predict Korea's crisis. Within the East Asia, the optimal cluster for Korea was Korea and Indonesia according to within and out of sample forecasts. However, the crisis predictability of the Korea and Indonesia cluster was not significantly different from that of the individual Korea model. 국가위기 사례는 많지 않으므로 개별 국가별로 위기를 예측하기 보다는 다른 나라의 사례를 포함한 패널자료를 이용하는 것이 효율적이라는 견해가 있다. 본 고에서는 우리나라의 위기 예측을 위하여 동아시아 국가 및 여타지역의 국가들을 포함한 지역모형을 사용하는 것이 좋은지 신호접근법 모형을 이용하여 실증 분석하였다. 대표적 신호접근법 모형인 Goldstein, Kaminsky, and Reinhart(2000)를 원용하여 4개 지역 24개국의 1990-2009년 중 15개 선행지표에 대한 월별 자료를 이용하여 표본내 및 표본외 예측을 하였다. 그 결과 동아시아 국가이외에 다른 지역의 국가들을 포함하는 것이 한국의 금융위기 예측에 도움이 되지 않았다. 또한 동아시아 국가 중에서는 한국과 인도네시아 두 국가로 구성한 클러스터의 예측력이 전반적으로 우수하였다. 그러나 이 클러스터의 표본내 및 표본외 예측력도 한국 자료만을 사용한 한국모형의 예측력과 유의하게 차이가 나지 않았다.

조광제어 시스템의 포토센서 감지신호 예측 정확도 분석

윤연주(Younju Yoon),문진우(Jin Woo Moon),김수영(Sooyoung Kim) 한국생활환경학회 2015 한국생활환경학회지 Vol.22 No.2

A computational simulation method was discussed in this study in order to predict photosensor signals under a variety of sky conditions. Theoretical approaches for a simulation method were proposed for prediction, and simulation results were compared with the results of field measurements. Results indicate that differences between prediction and measurement of outdoor global illuminance were higher under a clear sky condition compared to that under partly cloud and overcast sky condition. A photosensor positioned closer to window generated less difference between predicted and measured photosensor signals. Percent errors between predicted and measured photosensor signals under overcast sky conditions were higher than those under partly cloudy and clear sky conditions. Prediction models showed that strong correlations existed between predicted and measured photosensor signals.

2008년 위기 예측 가능했나?: 신호접근법 분석

박원암 대외경제정책연구원 2011 East Asian Economic Review Vol.15 No.3

본 연구는 신호접근법을 사용하여 조기경보모형을 구축하고 2008년 우리나라의 위기가 예측 가능했는지를 살펴본다. 특히 1997년 외환위기를 예측하기 위해 구축된 모형의 골격을 바꾸지 않고 2008년 위기를 예측함으로써 우리나라의 1997년 위기와 2008년 위기가 대내외 여건의 비슷한 변화로 인해 발생하였음을 보였다. 또한 2008년 전체를 전반적으로 위기기간으로 간주하는 경우와 실제로 위기가 발생한 2008년 9월 이후로 위기기간을 한정하는 경우에 위기예측이 어떻게 달라지는지도 보였다. 분석 결과, 신호접근법 조기경보모형의 예측력은 매우 양호했던 것으로 나타났다. 위기를 앞두고 신호발생 건수가 급증하고, 위기발생 확률도 급격하게 높아지면서 위기를 조기에 경보할 수 있었다. 가장 중요한 지표는 외채/외환보유액 비율과 예금취급기관 해외부채/총부채 비율이었다. 모형의 표본외 예측력도 양호하였다. 우리나라가 위기 재발을 방지하기 위해 구축한 조기경보시스템이 잘 작동하기 위해서는 조기경보모형의 신뢰도를 높이고 ‘이번은 다르다 신드롬’에 빠지지 않아야 한다. This paper investigates whether the 2008 crisis in Korea was predictable by applying the signal approach. It shows that the early warning model constructed to predict the 1997 crisis in Korea works very well to predict the 2008 crisis, implying the similarity of the two crises. In predicting the 2008 crisis, crisis period is defined two ways. One is to define the whole year of 2008 as the crisis period. The other confines the crisis period to the post September, 2008. The early warning was not sensitive to the crisis period. Both models provide early warning successfully. Well before the crisis period, signals increased rapidly and the conditional probabilities of crisis rose sharply. The most important indicators were the foreign debt/foreign reserves ratio and the foreign debt/total debt ratio of depository corporations. The models performed well in the out-of-sample period. It seems that Korea did not utilize the early warning systems to be ready for the 2008 crisis, although she had built them after the 1997 crisis to be ready for the another crisis. We must overcome the this-time-is-different syndrome and trust the early warning models to rely on early warning.

Cumulative Sum Control Charts for Simultaneously Monitoring Means and Variances of Multiple Quality Variables

Chang, Duk-Joon,Heo, Sunyeong The Basic Science Institute Chosun University 2012 조선자연과학논문집 Vol.5 No.4

Multivariate cumulative sum (CUSUM) control charts for simultaneously monitoring both means and variances under multivariate normal process are investigated. Performances of multivariate CUSUM schemes are evaluated for matched fixed sampling interval (FSI) and variable sampling interval (VSI) features in terms of average time to signal (ATS), average number of samples to signal (ANSS). Multivariate Shewhart charts are also considered to compare the properties of multivariate CUSUM charts. Numerical results show that presented CUSUM charts are more efficient than the corresponding Shewhart chart for small or moderate shifts and VSI feature with two sampling intervals is more efficient than FSI feature. When small changes in the production process have occurred, CUSUM chart with small reference values will be recommended in terms of the time to signal.