• 한국ITS학회 논문지
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• 제9권2호
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• pp.33-40
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• 2010

본 논문에서는 거시교통류 모니터링을 위한 세 가지 지표를 다루고 신뢰성 있는 지표산출에 필요한 적정 프로브차량 비율을 결정하기 위해 샘플링 기법을 이용하는 방법에 대하여 연구한다. 모니터링 세 가지 지표로는 Travel Time Index(TTI), Acceleration Noise(AN) 그리고 Two Fluid(TF)를 살펴보고, 적정 프로브 차량 비율의 결정방법으로는 절대오차를 이용한 표본크기의 결정방법과 상대오차를 이용한 표본크기의 결정방법에 대하여 고찰한다. 그리고 표본추출비율에 따른 지표 값 변동을 비교 검토하기 위해 서울시 강남지역의 대규모 자료를 이용하여 모의실험을 실시하였다. 모의실험 결과 교통수요 단계(Demand Level)가 증가함에 따라 상대오차를 이용한 표본 추출비율이 줄어들며, 추출비율은 허용오차, 링크통과차량의 수와 반비례 관계이므로 추출비율을 증가시킬수록 허용오차를 줄일 수 있음을 알 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.546-548
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• 2011

네트워크 트래픽이나 정보를 이용하여 실시간으로 자원을 모니터링하는 기술들이 발전하고 있다. 대표적인 트래픽 정보 중의 하나인 PING 메시지는 단순하지만 강력한 네트워크 감시에 사용되고 있는데, 본 논문에서는 PING 메시지 및 트래픽 정보를 활용하여, 실시간으로 정보를 확인하고, 이를 그래프 등을 이용하여 효율적으로 자원을 감시하고, 이에 대한 통계 자료를 제공하는 기술에 대하여 기술하다. 또, 최근 트래픽 관리의 추세인 웹 기반의 서비스 제공을 통하여, 관리자의 접근성을 제공하고, 데이터베이스화함으로써 네트워크의 감시 기능을 제공한다.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.1017-1021
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• 2013

The traffic signal has been widely used in the transport system with a fixed time interval currently. This kind of setting time was determined based on experience for vehicles to generate a waiting time while allowing pedestrians crossing the street. However, this strict setting causes inefficient problems in terms of economic and safety crossing. In this research, we propose a monitoring algorithm to detect, track and check pedestrian crossing the crosswalk by the patterns of behavior. This monitoring system ensures the safety for pedestrian and keeps the traffic flow in efficient. In this algorithm, pedestrians are detected by using HOG feature which is robust to illumination changes in outdoor environment. According to a complex computation, the parallel process with the GPU as well as CPU is adopted for real-time processing. Therefore, pedestrians are tracked by the relationship of hue channel in image sequence according to the predefined pedestrian zone. Finally, the system checks the pedestrians' crossing on the crosswalk by its HOG based behavior patterns. In experiments, the parallel processing by both GPU and CPU was performed so that the result reaches 16 FPS (Frame Per Second). The accuracy of detection and tracking was 93.7% and 91.2%, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3946-3965
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• 2018

Network anomaly detection in Software Defined Networking, especially the detection of DDoS attack, has been given great attention in recent years. It is convenient to build the Traffic Matrix from a global view in SDN. However, the monitoring and management of high-volume feature-rich traffic in large networks brings significant challenges. In this paper, we propose a moving window Principal Components Analysis based anomaly detection and mitigation approach to map data onto a low-dimensional subspace and keep monitoring the network state in real-time. Once the anomaly is detected, the controller will install the defense flow table rules onto the corresponding data plane switches to mitigate the attack. Furthermore, we evaluate our approach with experiments. The Receiver Operating Characteristic curves show that our approach performs well in both detection probability and false alarm probability compared with the entropy-based approach. In addition, the mitigation effect is impressive that our approach can prevent most of the attacking traffic. At last, we evaluate the overhead of the system, including the detection delay and utilization of CPU, which is not excessive. Our anomaly detection approach is lightweight and effective.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.96-103
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• 2012

Ambient particulate matter (PM) and particle-bound polycyclic aromatic hydrocarbon (PAH) concentrations were measured continuously for 70 days at a Korean elementary school located near a highway. The $PM_{10}$, $PM_{2.5}$, and $PM_1$ values were measured with a light-scattering, multi-channel, aerosol spectrometer (Grimm, Model 1.107). The number concentrations of the particles were measured using a scanning mobility particle sizer and counter (SMPS+C) which counted particles from 11.1 to 1083.3 nm classified in 44 channels. Particle-bound PAHs were measured with a direct reading, photoelectric aerosol sensor. The daily $NO_2$, $SO_2$, and CO concentrations were obtained from a national air-monitoring station located near the school. The average concentrations of $PM_{10}$, $PM_{2.5}$, and $PM_1$ were 75.3, 59.3, and $52.1{\mu}g/m^3$, respectively. The average number concentration of the ultrafine particles (UFPs) was $46,307/cm^3$, and the averaged particle-bound PAHs concentration was $17.9ng/cm^3$ during the study period. The ambient UFP variation was strongly associated with traffic intensity, particularly peak concentrations during the traffic rush hours. Particles <100 nm corresponded to traffic-related pollutants, including PAHs. Additional longterm monitoring of ambient UFPs and high-resolution traffic measurements should be carried out in future studies. In addition, transient variations in the ambient particle concentration should be taken into consideration in epidemiology studies in order to examine the short-term health effects of urban UFPs.

• 한국군사과학기술학회지
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• 제22권3호
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• pp.369-381
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• 2019

As tactical networks are gradually shifting toward IP-based flexible operation for diversified battlefield services, QoS(Quality-of-Service) coordination for service differentiation becomes essential to overcome the heterogeneous and scarce networking resources limitations. QoS coordination for tactical network traffic should be able to monitor and react the dynamic changes in underlying network topology and service priorities. In this paper, by adopting the emerging cloud-native service mesh concept into tactical network context, we study the feasibility of intelligent QoS coordination by employing tactical service mesh(TSM) as an additional layer to support enhanced traffic quality monitoring and control. The additional TSM layer can leverage distributed service-mesh proxies at tactical mesh WAN(Wide Area Network) nodes so that service-aware differentiated QoS coordination can be effectively designed and integrated with TSM-assisted traffic monitoring and control. Also, by validating the feasibility of TSM layer for QoS coordination with miniaturized experimental setup, we show the potential of the proposed approach with several approximated battlefield traffics over a simulated TSM-enabled tactical network.

• 한국대기환경학회지
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• 제32권6호
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• pp.575-582
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• 2016

Seoul city has high population density as well as high traffic congestion, which are vulnerable to exposure of environmental pollutions caused by car traffic. However, recent studies are only on local regions about road traffic and air pollution or health effect of road traffic on residents. Thus, comprehensive study data are needed in terms of overall Seoul regions. In this study utilized the nitrogen dioxide concentration through the national air pollution monitoring network data, 2012 to 2013. It also divided regions into high and low exposure districts via the Origin destination data developed by the Korea transport institute to quantify and evaluate the effect of transport policies and analyzed a correlation of asthma symptoms with high and low exposure districts through raw data of community health survey from the Korea centers for disease control and prevention. Based on the collected data, the pearson's correlation analysis was conducted between air pollution substance concentration and high exposure district and multiple logistic regression analysis was conducted to determine the effect of traffic environment and factors on asthma symptoms of residents. Accordingly, the following results were derived. First, the high exposure district was higher concentrations of nitrogen dioxide ($NO_2$) as per time compared to those of the low exposure district (p<0.01). Second, analysis on correlation between average daily environmental concentration in the air pollution monitoring network and road traffic showed that nitrogen dioxide had a significant positive correlation (p<0.01) with car traffic and total traffic as well as with truck traffic (p<0.05) statistically. Third, an adjusted odds ratio about asthma doctor's diagnosis in the high and low exposure districts was analyzed through the logistic regression analysis. With regard to an adjusted model 2 (adjusted gender, age, health behavior characteristics, and demographic characteristics) odds ratio of asthma doctor's diagnosis in the high exposure district was 1.624 (95% CI: 1.269~2.077) compared to that of the low exposure district, which was significant statistically (p<0.001).

• 한국정보전자통신기술학회논문지
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• 제5권1호
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• pp.1-6
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• 2012

본 논문에서는 HMM(Hidden Markov Model)방법에 기초하여 전경과 배경영역 뿐만 아니라 그림자 까지도 분할 할 수 있는 교통모니터링 방법을 제안하였다. 움직이는 물체의 그림자는 시각적 추적을 방해하기 때문에 이러한 문제점을 해결하기 위한 방법으로 각 화소나 영역을 3개의 카테고리 즉, 그림자, 전경, 배경물체로 분할하였다. 교통 모니터링 영상의 경우, 실험결과를 통해 제안된 방법의 효율성을 입증 할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.528-533
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• 2000

원거리에 분산되어 있는 다수의 농축수산업 양식시설을 원격으로 감시하고 관리하기 위한 시스템으로 각각의 시설에 대한 온도, 습도, 전원 등의 환경 데이타를 수집한 후, 전화회선을 통하여 관리자측으로 전송하면 관리자측에서는 수신된 데이터를 수치로 표시하므로써 시설들의 환경상태를 원거리에서 항상 파악할 수 있는 시스템을 연구하였단. 시스템의 구성을 위하여 환경상태를 정확하게 검출할 수 있는 센싱회로와 멀티프로쎄싱을 위한 통신회로 그리고 데이터의 전송과 취득에 대한 알고리즘을 실험적으로 구현하였다. 즉, 저가의 설치와 운용비용으로 시설을 효율적으로 관리할 수 있으며, 생산성 의 향상은 물론 재해를 사전에 예방할 수 있는 효과를 기대하는 시스템이다.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.16-22
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• 2011

This paper presents the potential of in-vehicle data recorder system for monitoring aggressive driving patterns and providing feedback to drivers on their on road behaviour. This system can detect 10 risky types of drivers' driving patterns such as aggressive lane change, sudden brakes and turns with acceleration etc. Vehicle dynamics simulation and vehicle road test have been performed in order to develop driving pattern recognition algorithms. Recorder systems are installed to 50 buses in a single company. Drivers' driving behaviour are monitored for 1 month. The drivers' risky driving data collected by the system are analyzed. Aggressive lane change in 50km/h below is a cause in overwhelming majority of risky driving pattern.