• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.14-28
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• 2018

Thanks to technical improvement on the vehicle to vehicle communication and the intelligent transportation system, gradual introduction of the autonomous vehicles is expected soon in the market. The study analyzes the autonomous vehicles' impacts on the network efficiencies. In order to measure the network efficiencies, the study applies the sequential procedures that combines the microscopic and macroscopic simulations. The microscopic simulation attends to the capacity changes due to the autonomous vehicles' proportions on the roadway while the macroscopic simulation utilizes the simulation results in order to identify the network-wide improvement. As expected, the autonomous vehicles efficiently utilizes the existing capacity of the roadway than the human driving does. Particularly, the maximum capacity improvements are expected by the 190.5% on the expressway. The significant capacity change is observed when the autonomous vehicles' proportions are about 80% or more. These improvements are translated into the macroscopic model, which also yields overall network efficiency improvement by the autonomous vehicles' penetration. However, the study identifies that the market debut of the autonomous vehicles does not promise the free flow condition, which implies the possible needs of the system optimal routing scheme for the era of the autonomous vehicles.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.71-78
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• 2002

Driving involves a series of complicated precesses requiring various human capacities, such as perception, will decision, and athletic functions. Consequently, it induces a high degree of continuous concentration of mind and tension from external stimulation, bringing fatigue to the driver, and driver fatigue is counted as one of the major causes of traffic accidents. Nevertheless, because of the complicated urban lives, traffic congestion, job characteristics, and so on, the drivers have to spend a longer time inside a vehicle, and the fatigue and stress thereof is almost unavoidable. We haute, therefore, turned our attention to the reduction in the fatigue during driving by supplying oxygen, and investigated in this research the drivers subjective fatigue evaluations and reaction time when oxygen is supplied in different rates. As a result, we have found that the subjective fatigue feeling is highest at low-rate O/Sub 2/ supply (18%), and fatigue feeling was comparatively reduced at high-rate O/Sub 2/ (30%). The sleepiness also showed the tendency to be reduced at high-rate O/Sub 2/ supply in the case of driving for 1 hour or more. The time for reaction to braking after the sign for urgent stop is given tends to show more substantial reduction at high-rate O/Sub 2/ supply than at low-rate O/Sub 2/ supply after 2 hours driving. It can, therefore, be deduced from the aforesaid results that the subjective responses and behavioral reactions tend to show reduced fatigue at the condition of high-rate O/Sub 2/ supply. Hence, it was suggested that drivers felt subjective fatigue while driving at low-rate O/Sub 2/ and the subjective fatigue and reaction time were reduced at high-rate O/Sub 2/. These findings suggest that the oxygen supply will reduce driver fatigue.

• The tire
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• s.144
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• pp.8-20
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• 1989

이 자료는 일본자동차타이어협회에서 타이어의 이상발열에 의한 손상, 즉 트럭 및 버스용 타이어의 Heat Separation Brust의 발생요인을 규명하기 위해 실제의 사용조건에서 재현시험을 실시하여 얻은 결과를 토대로 작성한 보고서이다. 이 시험의 목적은 타이어의 이상발열에 의한 손상의 발생요인을 해석함과 동시에 안전주행을 확보하기 위한 타이어의 올바른 사용법의 계몽자료로서 활용하려는 데 두었다. 이번 호에 그 내용을 번역ㆍ전재한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.438-439
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• 2013

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.138-149
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• 2016

The study reviewed the effects of the variable speed limit under adverse weather conditions by using a driving simulator. The study assumed that the display of the reduced speed limit without any change of the weather condition and the display of the same speed limit under the change of the weather conditions violate the expectancy of drivers, so it brings the negative effects on the safety. The study regards drivers conformance as the index of the degree of the compliance of driver expectancy, and utilizes the cumulative probability density within the certain range of the speed including displayed speed limit as the quantitative measure of effectiveness. The study reviewed this assumptions by using a driving simulator. As the results, the cases assumed to violate the expectancy of drivers showed the negative effects on the driving behaviour of driver relatively.

• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.19-26
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• 2002

The purpose of this paper is to study the fundamental characteristics of bicycle flows. Several experiments were conducted to obtain the characteristics of bicycle flows, speed variation along a curve radius, bicycle driver's travelling territory and saturation flow rate at signalized intersection. Bicycle facilities are categorized into uninterrupted and interrupted, the capacity of uninterrupted is approximately 5000bic/h, and that of the interrupted (at signalized intersection) is approximately 3000bic/h, when a curve radius is over 20m, bicycle speed is not increasing. Bicycle driver's travelling territory is used to occupancy area, it is the same concept as pedestrian's. Bicycle occupancy area is to be divided into circulation zone, comfort zone. and collision zone. Circulation zone is over 2.21$\times$4.1m and collision zone is less than 0.96$\times$2.47m. Comfort zone is defined as intermediate state between two zones.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.58-66
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• 1979

동력경운기용 두류의 무경운 파종기에 부착하여 사용하는 구절기중에서 소요견인력이 작고 구절작업정도가 양호한 구절기의 개발을 위한 기초자료를 얻기 위하여 구동식 토조에 인공강토를 채우고 원판형 및 호우형 구절기의 소요견인력과 이에 영향을 미치는 인자들의 관계를 구명코자 실내모형 확험을 실시하여 다음과 같은 결과를 얻었다. 원판형 구절기에 대하여 직경별로 조립각을 $8^{\circ}$ 와 $16^{\circ}$, 경심을 3 cm 와 6cm로 변화시키면서 2.75cm/sec의 속도로 견인력을 측정한 결과 원판의 직경이 약 28cm인 경우에 견인력이 최소로 나타났고, 직경이 이보다 크거나 작은 때는 견인력이 증가하는 경향을 나타냈으며 비저항도 대체로 비슷한 경향이었으나 원판의 직경이 약 30cm 일 때 최소로 나타났다. 종자파종의 심도조절을 목적으로 작구심(3cm 및 6 cm)과 견인력과의 관계를 조사하였던바, 경심과 견인력과의 관계는 거의 직선적인 변화를 나타냈으며 견인력에 영향을 미치는 인자중에서 경심의 영향이 가장 컸음을 알 수 있었다. 일반적으로 조립각 미 주행속도에 별 영향없이 경심 3cm 및 6 cm 공히 견인력은 직경 약 28 cm에서 , 비저항은 약 30cm에서 최소의 값을 나타내었다. 파종기의 작업성능과 관계가 깊은 주행속도 및 파시의 조절을 목적으로 원판의 조립각과 주행속도가 견인력에 미치는 영향을 조사했던 바, 조립각과 주행속도가 증가함에 따라 모두 견인력이 증가하는 경향을 나타내었으나 견인력에 미치는 영향은 주행속도가 더욱 크게 나타났다. 원판형 구절기와 호우형 구절기를 비교하기 위하여 쐐기각이$16^{\circ}$ 이고 리프트 각이 $20^{\circ}$ 인 호우형 구절기와 조건이 비슷한 조립각$16^{\circ}$ 의 원판형 구절기의 견인특성을 비교한 결과 직경 30cm 인 원판형의 경우는 비저항이 0.35-0.5kg/$cm^2$인데 비해 호우형의 경우는 0.71-1.02kg/$cm^2$로 나타나 호우형의 견인저항력이 평균 2 배정도 크게 나타났고 작구상태고 원판형의 경우보다 불량하였다.

• Journal of Internet of Things and Convergence
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• v.9 no.1
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• pp.65-70
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• 2023

In this paper, we propose an autonomous driving system using an end-to-end model to improve lane departure and misrecognition of traffic lights in a vision sensor-based system. End-to-end learning can be extended to a variety of environmental conditions. Driving data is collected using a model car based on a vision sensor. Using the collected data, it is composed of existing data and data with outlayers removed. A class was formed with camera image data as input data and speed and steering data as output data, and data learning was performed using an end-to-end model. The reliability of the trained model was verified. Apply the learned end-to-end model to the model car to predict the steering angle with image data. As a result of the learning of the model car, it can be seen that the model with the outlayer removed is improved than the existing model.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1370-1378
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• 2007

High speed railway bridge is affected on safety of bridge by dynamic amplification effect, when dynamic response of bridge is equal to effect cycle load for rolling stock axle according to high speed operation train. And excessive deformation of structure has negative effect on operation safety of train and comfort of passenger due to fluctuation of wheel load by torsion of track etc. and decrease of contact force on vehicle wheel-rail. To ensure the safety of track and train operation safety, it is have to perform the study on resonance and deformation of structure. That criteria and requirement of railway bridge is limitation of vertical acceleration on deck for dynamic behavior of structure, contact of vehicle wheel and rail, limitation of face distortion and rotation angle of end deck, and limitation of vertical displacement by train. Unlike KYEONGBU High Speed Railway, New constructed HONAM High Speed Railway have to applied the new requirement for dynamic behavior safety according to change of condition which is type of ballast (slab ballast), interval of track, and actual rolling stock load. Therefore, in this paper, it was conformed the dynamic characteristic due to parameter, which related with above mentioned criteria, for steel composite bridges.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.111-122
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• 2018

At present, the ground transportation system is saturated in many countries including Korea. To overcome this problem, many researches of developing a roadable personal air vehicle (PAV) are being carried out to alleviate traffic congestion and to accomplish door-to-door mobility through three-dimensional traffic system. In this study, the thrust-to-weight ratio, the wing loading, and the power-to-weight ratio that are major design parameters for the sizing of roadable PAVs were calculated under the constraints of ground roll, climb rate, maximum cruise speed, service ceiling, stall speed. Also, in the sizing process, the study was conducted to determine the design point using the graphs of thrust-to-weight ratio, wing loading, power-to-weight ratio, and brake horse power for the mission profiles considering domestic environments and the FAR PART 23 which is the GA class aircraft certification standard.