• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.637-638
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• 2017

MQTT broker는 트래픽에 따라 네트워크 성능이 저하되어 패킷 손실, 지연 등의 문제가 발생한다. 하지만 MQTT broker는 트래픽 측정을 위한 별도의 인터페이스를 지원하지 않아 네트워크 성능 저하에 대처할 수 없다. 본 논문에서는 MQTT broker의 트래픽 측정을 위한 시스템을 제안한다. 제안하는 시스템은 jnetpcap 라이브러리를 사용하여 MQTT broker로 송수신되는 모든 트래픽을 측정한다.

• 한국ITS학회 논문지
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• 제21권6호
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• pp.266-283
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• 2022

자율주행자동차 기술이 급속히 발전함에 따라 예상치 못한 사고가 발생하고 있어 자율주행 교통안전교육 개발을 통해 이용자 사고 피해를 최소화 시켜야 한다. 현실적 교육을 위해 엣지케이스, 사고 사례, 위험요인 분석이 중요하므로 해외 사례 연구와 실증을 진행하였고, 이를 기반으로 서비스 제공자, 일반이용자 2가지 교육 과정을 개발하였다. 서비스 제공자 과정은 사물인지대응, 급정지, 끼어들기, 제어권 전환, 방어운전, 시스템오작동, 정책 및 정보보안 교육으로 구성하였고 일반이용자 과정은 주의의무, 제어권 전환, 운행설계범위, 사고유형, 법규, 기능, 정보보안 교육으로 구성하였다.

• 대한안전경영과학회지
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• 제13권1호
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• pp.127-131
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• 2011

Even if there are no causing factors such as car crash and road works, traffic congestion come from traffic growth on the road. In this case, estimation of traffic flow helps find the solution of traffic congestion problem. In this paper, we present a optimization model which used on traffic equilibrium problem and studied the problem of inverting shortest path sets for complex traffic system. And we also develop pivotal decomposition algorithm for reliability function of complex traffic system. Several examples are illustrated.

• Wind and Structures
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• 제37권4호
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• pp.303-314
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• 2023

In this study, two steady RANS turbulence models (SST k-ω and Realizable k-ε) and four unsteady turbulence models (URANS SST k-ω and Realizable k-ε, SST-SAS, and SST-IDDES) are evaluated with respect to their capacity to predict crosswind characteristics on high-speed trains (HSTs). All of the numerical simulations are compared with the wind tunnel values and LES results to ensure the accuracy of each turbulence model. Specifically, the surface pressure distributions, time-averaged aerodynamic coefficients, flow fields, and computational cost are studied to determine the suitability of different models. Results suggest that the predictions of the pressure distributions and aerodynamic forces obtained from the steady and transient RANS models are almost the same. In particular, both SAS and IDDES exhibits similar predictions with wind tunnel test and LES, therefore, the SAS model is considered an attractive alternative for IDDES or LES in the crosswind study of trains. In addition, if the computational cost needs to be significantly reduced, the RANS SST k-ω model is shown to provide relatively reasonable results for the surface pressures and aerodynamic forces. As a result, the RANS SST k-ω model might be the most appropriate option for the expensive aerodynamic optimizations of trains using machine learning (ML) techniques because it balances solution accuracy and resource consumption.

• 한국도로학회논문집
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• 제20권2호
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• pp.97-107
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• 2018

PURPOSES : The effects on traffic accidents change with the changing environment. Accordingly, this study analyzes the characteristics of traffic accidents based on the personal characteristics (gender and age) of drivers, and those of 25 autonomous districts in Seoul, and suggests improvements. METHODS : Based on data pertaining to traffic accidents in Seoul, the analysis of accident characteristics was conducted by categorizing the types of traffic accidents according to the drivers' gender and age, and characteristics of 25 autonomous districts in Seoul. Further, for statistical verification, the SPSS software was used to derive influence variables through a multinomial logistic regression analysis, and a method for reducing traffic accidents was proposed. RESULTS : Analysis results show that males tend to be more involved in speed-related accidents and females in low-experience driving-related accidents such as those during parking and alleyway driving. In addition, variables such as age, automobile type, district, and day of the week are found to influence accident types. CONCLUSIONS : This study analyzed the accident characteristics based on personal and city characteristics to reflect the sociological characteristics that influence traffic accidents. The number of traffic accidents in Korea could be decreased drastically by implementing the results of this study in customized safety education and traffic maps.

• 수산해양교육연구
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• 제5권1호
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• pp.15-22
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• 1993

The Maritime Traffic Safety Law of P. R. China has not the legal nature of navigation rule which regulates the vessel traffic directly but has the legal nature of management to ensure the safety and good order of the whale marine traffic. For that reason, the legal status of this Law is a general basic norm for the marine safety regulations rather than a definite enforcement regulation. This Law does not have any clear statements on adaptation of the steering and sailing rules of the International Regulations for Preventing Collisions at Sea, but it can be presumed the Convention would be applied on the viewpoint of the international practice. The subject matter of this Law is easily understandable, because the IMO and shipping countries have already made similar legislation. Since the maritime traffic condition of the P. R. China also has a direct effect upon the Korean coastal waters, it is essential to observe closely the process of enforcement and development of the P. R. China's Maritime Traffic Safety Law.

• Structural Engineering and Mechanics
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• 제47권4호
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• pp.531-544
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• 2013

Compared with pavement structures of ordinary road sections, pavement structures in the intersection are exposed to more complex traffic characteristics which may exacerbates pavement distresses such as fatigue-cracking, shoving, shear deformation and rutting. Based on a field survey about traffic characteristics in the intersection conducted in Shanghai China, a three dimensional dynamic finite-element model was developed for evaluating the mechanistic responses in the pavement structures under different traffic characteristics, namely uniform speed, acceleration and deceleration. The results from this study indicated that : (1) traffic characteristics have significant effects on the distributions of the maximum principal strain (MPS) and the maximum shear stress (MSS) at the pavement surface; (2) vehicle acceleration or deceleration substantially impact the MPS and MSS at pavement surface and could increase the magnitude of them by 20 percent to 260 percent; (3) in the vertical direction, with the increase of vehicle deceleration rate, the location of the MPS peak value and the MSS peak value changes from the sub-surface layer to the pavement surface.

• 한국게임학회 논문지
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• 제12권6호
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• pp.5-14
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• 2012

일상생활을 살아나가면서 발생하는 안전사고 중에 어린이에게 가장 위협적인 사고는 보행 중 발생하는 교통사고이다. 사고발생 후의 대책이나 처리보다 사고를 미연에 방지하기 위해 어린이 스스로 몸을 유지할 수 있는 안전에 대한 바른 습관 및 태도를 형성시켜주는 교통안전 교육이 강조되야 한다. 본 논문에서는 기능성게임으로서 교통안전교육을 가장 효율적으로 학습할 수 있는 방안의 하나로 어린이의 몸을 활용해 교통안전 준수체험 교육훈련을 할 수 있는 체감형 교통안전교육게임을 설계해보고 3차원 동작인식기술을 다양한 기능성게임에 적용할 수 있는 가능성을 제시하였다.

• 보건교육건강증진학회지
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• 제16권1호
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• pp.31-43
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• 1999

Increase of automobiles become today's environmental problem decreasing space for our children's playground. The traffic situation around us shows automobiles over filled the public roads and started to intrude even on the side walks. Children's traffic safety education for the awareness of the danger from traffic mishaps, and for the behavior to cope with preventives measure by continual learning programs in systematized method is very important need in current health education. For this research, the subject was represented by 243 students from 4th grade in D Elementary School located at Daechi-dong, Seoul. During total of 5 weeks (September 4, 1997 to September 30, 1997), lessons were taught to the subject. Lessons consist of traffic safety education and customized education program that were designed and developed specificially for the subject level. In this research, Case group of 3 classes and control group of 3classes were predetermined before subject's degree of knowledge, attitude, and practice was analized. The difference before and after the training of this education was observed to verify the effectively and to find the influential factors of this education program. On September 2-3, survey study was performed after the training. the results of this study were as follows: 1. The knowledge analysis from the comparison between before and after of the training shows case group and control group scored(8.36, 8.86) before the traning, but scored(10.36, 8.52) after the traning. the difference from the result of the case group is statistically significant(p〈0.001). 2. The attitude analysis from the comparison between before and after of the training shows case group and control group scored(48.23, 49.87) before the training, but scored (51.05, 48.45) after the traning. the difference from the result of the case group is statistically significant(p〈0.001) 3. The practice analysis from the comparison between before and after of the training shows case group and control group scored (27.42, 28.08) before the training, but scored(30.49, 28.25) after the training. The differece from the result of the case group is statistically significant (p〈0.001). 4. The correlation analysis of traffic safety education's influence on traffic safety knowledge, attitude, and practice before training shows the relationship between attitude and practice was satistically significant(p〈0.05). The result after the training shows the relationship between knowledge and attitude, attitude and practice, and knowledge and practice was all statistically significant(p〈0.001).

• 해양환경안전학회지
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• 제25권7호
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• pp.874-880
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• 2019

우리나라는 2000년 고령화 사회에 진입한 이후 2019년 현재 고령사회로 분류되고 있다. 이에 따라 고령선원의 수는 해를 거듭할수록 증가하는 추세이고, 고령선원의 해양사고 건수도 해마다 증가하고 있다. 도로 교통분야에서도 운전자의 고령화가 해운분야와 동일하게 나타나고 있다. 하지만, 도로 교통분야에서는 이러한 문제를 해결하려는 연구와 정책 등이 해운분야에 비해 활발하게 진행되었다. 이에 본 연구에서는 도로 교통분야에서 고령운전자에 의한 교통사고 발생원인을 줄이기 위한 노력 중 교육분야에 한정하여 살펴보고 이를 해기교육에 벤치마킹하였다. 국내·외 도로 교통분야에서는 인적요인 등의 발생원인을 줄이기 위한 방안의 하나로 고령운전자 교통안전교육을 시행하고 있다. 고령화에 따른 교육분야 문제 현황을 분석하고 도로 교통분야의 해결방안과 접목하였으며, 그에 따른 해기교육 개선방안은 다음과 같다. 첫째, 전문적인 면허취득교육을 시행하는 방안이다. 둘째, 고령선원의 면허갱신 시 직무 보수교육을 시행하는 방안이다. 마지막으로 고령선원 연령전환 교육을 시행하는 방안이다. 다만, 본 연구는 선원고령화에 따른 해기교육분야의 개선방안에 한정된 연구인 만큼 향후 다양한 분야에서의 연구가 필요할 것으로 판단된다.