• 제어로봇시스템학회논문지
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• 제22권2호
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• pp.110-116
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• 2016

Autonomous vehicles must obey the traffic laws in order to drive actual roads. Traffic signs erected at the side of roads explain the road traffic information or regulations. Therefore, traffic sign recognition is necessary for the autonomous vehicles. In this paper, color characteristics are first considered to detect traffic sign candidates. Subsequently, we establish HOG (Histogram of Oriented Gradients) features from the detected candidate and recognize the traffic sign through a SVM (Support Vector Machine). However, owing to various circumstances, such as changes in weather and lighting, it is difficult to recognize the traffic signs robustly using only SVM. In order to solve this problem, we propose a tracking algorithm with RANSAC-based motion estimation. Using two-point motion estimation, inlier feature points within the traffic sign are selected and then the optimal motion is calculated with the inliers through a bundle adjustment. This approach greatly enhances the traffic sign recognition performance.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.185-192
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• 2006

인터넷 웜과 같은 DDoS(Distribute Denial of Service Attack) 공격에 사용되는 네트워크 트래픽과 정상적인 서비스를 위한 네트워크 트래픽을 구분해 내는 것은 쉽지 않다. 정상적인 패킷을 유해 트래픽으로 판단하고 유해 트래픽의 공격자의 의도대로 서비스를 못하는 경우가 발생하므로, 인터넷 웜과 DDoS 공격으로부터 시스템을 보호하기 위해서는 공격 트래픽에 대한 정확한 분석과 탐지가 우선되어야 한다. IPv6 환경으로 전환될 때 발생하는 유해 트래픽에 대한 연구가 미약한 상태이므로, 본 논문에서는 IPv6 환경에서 NETWIB로 공격을 수행하고 공격 트래픽을 모니터링한 후 MIB(Management Information Base) 객체를 지수평활법을 적용하여 예측치 구한 후 임계치를 산정하여 공격을 판별한다.

• 한국전자통신학회논문지
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• 제5권1호
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• pp.44-50
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• 2010

무선 센서 네트워크는 다수의 센서 노드로 구성되며, 센서 노드들의 협력 작업을 통해 하나의 공통 작업을 수행한다. WSN 의 트래픽은 주기적인 모니터링 트래픽, 이벤트 발생 트래픽 및 쿼리 기반 트래픽으로 분류된다. 주기적인 트래픽은 발생 빈도는 낮지만, 다수의 센서노드들이 일정한 간격으로 트래픽을 생성하기 때문에 전체 트래픽 관점에서 볼 때 많은 비중을 차지하고 있다. 본 논문에서는 이러한 주기적 트래픽에 대해 에너지 효율적으로 처리하는 네트워크 프로토콜의 트래픽 제어 알고리즘을 제안하고, 이에 대한 성능 분석을 수행한다.

• 한국환경보건학회지
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• 제8권1호
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• pp.13-23
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• 1982

This Study was designed to investigate Traffic condition, Traffic Noise level, Traffic Noise Index (TNI) and Response for dissatisfactions of residents as part of assesment of Noise by 12 Sites in Seoul from July 1st to the end of August 1981. As the resut of this Study, the following Conclusion were obtained 1. The mean traffic Volume of Seoul was 3076/hour ranging 1440/hour to 5772/hour. 2. The range of Road Traffic Noise Level in Residential area was from 73.0dB (A) to 80.2dB (A). The highest level was 80.2dB (A) on Heugseog-dong and the lowest level was 73.0dB (A) on Suyu-dong. 3. Comparision of Road traffic noise level in the day and evening, the range of traffic noise level in day was from 73.9dB (A) to 80.2dB (A), and evening was ranging 73.0 to 79.9dB (A). 4. The range of TNI in Residential area was from 77.5 to 100.0. The highest TNI was 100.0 on Suyu-dong including Heugseog-dong, the lowest TNI was 77.5 on Hyuikyung-dong. 5. Respose of Noise by 360 householders has been examined in Residential Area: Sourse of Noise Causing bothersome to residents was 52.5% of traffic, the types of road traffic Cousing annoyance to residents residents were 84.8% of passing cars and 81.1% of horns, and 71.7% of reading interfered and 68.1% appeal dissatisfactions due to the sleeping disturbance by road traffic noise.

• 한국항공운항학회지
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• 제28권1호
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• pp.22-33
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• 2020

Due to recent increased air traffic,, air traffic controllers in charge of en-route and approach control have faced huge increase in both workload and its intensity. The purpose of this paper is to analyze how much safety culture of air traffic controllers has effect on their complexity mitigation strategies during their duties. It could be expected complexity mitigation improve air traffic flow resulting in enhancing safety eventually. According to empirical analysis against air traffic controllers in civil aviation and air force in South Korea, it was proven safety culture had a statistically positive effect on complex mitigation strategies through safety behavior. In safety culture among air traffic controllers, intrinsic culture had a positive effect on extrinsic value of safety culture. Intrinsic value of safety culture led to air traffic controllers' safety behavior which created work complexity mitigation strategies. Among work complexity mitigation strategies, communication and cooperation was proven to be the most important factor effected by safety culture and behavior. It was implied that enhancing the intrinsic values of safety culture would cause to improve extrinsic safety culture and air traffic controller's work efficiency.

• 한국안전학회지
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• 제21권2호
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• pp.128-137
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• 2006

Traffic accidents occur due to complex influences of transportation companies, drivers, and road environment. This study found that education and surroundings for transportation companies, driving habits of drivers, and road safety facilities and accessory facilities were main factors that affected strongly traffic accidents. Also, it found that driving habits of drivers could affect accidents heavily more than two other factors. Road safety and accessory facilities were analysed that they affected traffic accidents independently with transportation companies and their own drivers. Therefore, in order to achieve a traffic accident prevention as our main target, those companies need to produce atmosphere that their own drivers can have safety awareness, and related institutions for the above target should run parallel with policy assistance and strict traffic enforcement. In the end, this study suggests that transportation companies should secure manpower wholly being charged with traffic safety and financial resources investing in it.

• 한국경영과학회지
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• 제28권2호
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• pp.75-89
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• 2003

Media Access Control (MAC) Protocol in IEEE 802.11 Wireless LAN standard supports two types of services, synchronous and asynchronous. Synchronous real-time traffic is served by Point Coordination Function (PCF) that implements polling access method. Asynchronous nonreal-time traffic is provided by Distributed Coordination Function (DCF) based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. Since real-time traffic is sensitive to delay, and nonreal-time traffic to error and throughput, proper traffic scheduling algorithm needs to be designed. But it is known that the standard IEEE 802.11 scheme is insufficient to serve real-time traffic. In this paper, real-time traffic scheduling and admission control algorithm is proposed. To satisfy the deadline violation probability of the real time traffic the downlink traffic is scheduled before the uplink by Earliest Due Date (EDD) rule. Admission of real-time connection is controlled to satisfy the minimum throughput of nonreal-time traffic which is estimated by exponential smoothing. Simulation is performed to have proper system capacity that satisfies the Quality of Service (QoS) requirement. Tradeoff between real-time and nonreal-time stations is demonstrated. The admission control and the EDD with downlink-first scheduling are illustrated to be effective for the real-time traffic in the wireless LAN.

• 대한임베디드공학회논문지
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• 제9권3호
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• pp.145-150
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• 2014

This paper presents an effective vision based method for LED traffic light detection at the daytime. First, the proposed method calculates horizontal coordinates to set region of interest (ROI) on input sequence images. Second, the proposed uses color segmentation method to extract region of green and red traffic light. Next, to classify traffic light and another noise, shape filter and haar-like feature value are used. Finally, temporal delay filter with weight is applied to remove blinking effect of LED traffic light, and state and weight of traffic light detection are used to classify types of traffic light. For simulations, the proposed method is implemented through Intel Core CPU with 2.80 GHz and 4 GB RAM, and tested on the urban and rural road video. Average detection rate of traffic light is 94.50 % and average recognition rate of traffic type is 90.24 %. Average computing time of the proposed method is 11 ms.

• 한국환경과학회지
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• 제16권7호
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• pp.823-830
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• 2007

Traffic noise is a kind of noise caused by cars, trains and aircraft. Among them, noise produced by cars is the most important factor in cities. According to the National Institute of Environmental Research(NIER)'s survey, Road traffic noise levels in Susan are the highest of all the cities in Korea. So, appropriate measures for road traffic noise reduction is required. For this purpose, the construction of a noise map in Susan will playa vital role. However, road traffic noise formulas are constructed considering regional characteristics such as each country road's environment and vehicle quality. Therefore, prior to constructing a noise map in Susan, examination processes about each formula constituent status and estimation process are required preferentially. In this research, the basic first stage is to estimate Susan's road traffic noise. First, investigate characteristics of each road traffic noise estimate and using this, a noise map is constructed for road traffic noise in Susan. Then the adaptation of a road traffic noise formula is evaluated.

• 대한인간공학회지
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• 제18권1호
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• pp.133-147
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• 1999

Traffic signs without a cognitive consideration in their design may cause information-processing problem that could result in a mental confusion among drivers often lead to a serious traffic accident. Therefore, in this study, several traffic signs currently used in Seoul Metropolitan area have been sampled and analyzed to identify design problems that usually caused by neglecting drivers cognitive ability. To classify the practical design problems, five major information-processing problems have been suggested: indistinguishable information, information conflict, missing information, sign-load mismatch, and information overload. In order to solve these cognitive problems, new traffic signs have been suggested in this study. An experiment was also performed to validate the new traffic sign. Twenty-four healthy subjects participated in the experiment. They were asked to answer the Question after observing the traffic signs continuously displayed on computer screen. The result indicated that subjects improved the accuracy in understanding the signs by 1.4 times when they used the suggested traffic sign compared to the old one. Based upon the results, a cognitive guideline was suggested for correct and speedy reading of traffic signs by improving information processing and reducing of human error. In conclusion, the traffic sign may well be applied to design an intelligent traffic sign system to increase the safety and comfort of drivers, especially in complex load condition.