• Journal of Auto-vehicle Safety Association
• /
• v.15 no.1
• /
• pp.35-44
• /
• 2023

The purpose of this study is to predict how the actual accident changes by reconstructing the accident with an Autonomous Emergency Braking system (AEB) based on the actual accident of the LTAP-OD (Left Turn Crossing Path - Opponent Direction) intersection. A virtual AEB sensor was developed, and 150 head-on collision accident reports were secured to the insurance company to reconstruct the accident. As a result of the accident type analysis, a total of 13 types of head-on collision accidents were derived, and it is the LTAP-OD intersection accident with the highest frequency. In the LTAP-OD intersection accident, the simulation was conducted by applying the virtual AEB of each vehicle, the accident rate decreased by 90% or more when the AEB of the left-turn vehicle was applied, and the accident rate decreased by 50%. In addition, the most frequent collision types in LTAP-OD accidents were the front bumper on the driver's side of a vehicle going straight and the front bumper on the passenger's side of a vehicle turning left.

• Journal of Korean Society of Transportation
• /
• v.25 no.1 s.94
• /
• pp.93-105
• /
• 2007

To raise transit ridership, it is necessary to expand transit facilities in long term Plans and to raise passengers' satisfaction by improving bus service qualify in short term Plans. In this study, the relationship between bus driver job satisfaction and Passenger service Performance is analyzed. The results of the study indicate that a driver s job satisfaction has an influence on accident rates. However, even when job satisfaction is not very high, if food resting facilities and Policies ave Provided then the Probability of an accident tends to decrease. To improve job satisfaction, several things should be done, such as stabilizing employment, creating fair company policies, improving overall employee welfare, and enhancing driver achievement from working. The satisfaction from salary is also an important factor and drivers are satisfied when they earn more money relative to other companies' drivers and when they aye satisfied with their salary increases. Therefore, creating appropriate monetary incentives would be a food policy for improving bus driver job satisfaction. This study serves as pilot research to make a foundation for further research about job satisfaction in the public transit field.

• Journal of the Korean Society for Railway
• /
• v.20 no.1
• /
• pp.128-141
• /
• 2017

This paper analyzes the under-researched field of the characteristics of th Chosun private railway, such as laws, systems, human resources, and subsidies associated with this railway, in an effort to increase our understanding of these characteristics. It was found that the private railway shared strong identity resemblance with a national project, as it served to assist the roles of the main national railway. General patterns of change of the company indicate that the private railway received increased subsidies consequent to the amendment of a related law and that it was strongly influenced by Japan's railway policies. The private railway system during the Chosun period more subsidies than those administered by Japan, and they tended to depend on fund raising for external capital. A tendency of many board members to be from the Chosun bureau was also noted. Profits in the private railway system were relatively low compared to those of the national railway such that the deficits were supplemented by the subsidies redeived. Based on corroborating examples, the private railway system can be said to have been an organization that had strong connections with national projects. It was especially related to regional industries according to an examination of the distribution of lines, which shows that most assisted the main railway or coincided with regions undergoing industrial development. Typically, northern areas were for resource development while southern areas were for agricultural production and/or passenger transportation. The company carried dual traits as it operated as a subsidiary enterprise for peripheral profit while also playing a role in transportation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.7
• /
• pp.607-612
• /
• 2019

The softness of the crashpad part is one of the important factors which affect the interior perceived quality of the vehicle interior. And while improving the softness of the crashpad part, every effort to lower the production cost has been going on. The PU foaming process for the crashpad part depends on the understanding of a lot of processes, tools and material properties. Therefore, to achieve the requirement of the customer for the interior part's visual quality, the integrated design techniques are investigated to correlate the processes, tool design, material design and the computer aided analysis. In this paper, IMG (In Mold Grain) designed concept is firstly developed to integrate the skin preforming, plastic injection molding of the substrate and the foaming process in a tool within reduced processes. Through the application of this technology, softness of crashpad is improved by 40% compared to the conventional vacuum molding method, and the existing process is reduced by 50% by integrating the injection process and the manufacturing process. And by integrating the injection mold and the skin mold and removing the foaming mold, the number of molds are reduced from 3 to 1, resulting in 20% reduction in the cost of applying a medium-sized passenger car.

• Journal of Korean Society of Transportation
• /
• v.26 no.3
• /
• pp.7-16
• /
• 2008

The immigration procedure at airports is vital to making passenger and cargo transport faster. The rapid procedure of immigration could be an important determining factor when passengers select an air transport company, one that should have high satisfactory in terms of their service level and efficiency. Therefore, the advanced airport makes it easy for customers and their cargo to proceed. The coordination between authorities related to the Korean international airport is not satisfactory for customers. This paper analyzes the factors necessary to enhance the airport immigration procedure with the movement of aircrafts, passengers, cargo, and post, using the CK(Cook and Kress) model of DEA(Data Envelopment Analysis). From this study, the author found that research and development will be needed to improve the immigration procedure, especially on facilities and their operating systems. There are needed, also, performance indicators and a continuous monitoring system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.4
• /
• pp.65-71
• /
• 2006

The number of elevator installation increases every year about 15,000. The number of confine-disease of elevator increases every year and then sudden in, sudden stop, error of level indication, stand; those can bring to uneasiness of elevator passenger and malfunction related life accident is increasing. Therefore we researched elevator repair diary of elevator repairing company, APT management office and 119 life rescue for elevator confine-disease during 2004. 1. 1.${\sim}$12. 31. we analyzed the content and the time type and cause of the malfunction and fault for APT elevator. Form the result of 119 life rescue, only power reset is 24[%] and only power failure is 8.2[%] by cause of confine-disease. This paper will be used data of the analysis for mutual relation between Power Quality and malfunction and fault of elevator.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.2
• /
• pp.498-503
• /
• 2012

It happens that the fuel is not injected when the driver doesn't push the acceleration pedal of vehicle with engine speed higher than 1,500rpm above the mid range of vehicle speed. This is called "fuel-cut function" and almost every modern vehicle is equipped with this function. This is activated frequently on the downhill area of highway and the quantity of vehicle-exhausted $CO_2$ gas can be zero on this area. With this fuel-cut function on the test highway, $CO_2$ gas from passenger car(2,000cc engine volume) can be reduced up to 4%. The fuel-cut function with CRUISE made in company AVL is simulated to find the most effective driving pattern on the downhill area. By simulating with CRUISE software, it is found that the lower limit of vehicle speed for fuel-cut should be raised to improve the fuel economy on the steeper downhill road. The fuel economy can be most economical when fuel-cut driving and reacceleration are completed on the section of downhill road.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.9
• /
• pp.979-988
• /
• 2014

Recently, the interest in the thermal comfort is ever increasing as the time people stay in the automobile is gradually increasing. So far, however, the cooling performance of the HVAC(heating and ventilation air conditioning) system is evaluated by thermal environment criteria such as indoor air velocity and temperature, not by a thermal comfort index. Furthermore, the precise criteria has not been established yet when the thermal comfort for the automobile is evaluated using numerical analysis. In this study, the numerical analysis of automobile indoor thermal comfort according to various parameters such as HVAC operating mode, airflow, passenger boarding conditions is performed during the HVAC system's initial operating time(20 minutes). The solar ray tracing model and S2S radiation model are used and validated to simulate an external heat source. Based on this study, an evaluation model which can predict the thermal comfort index for the combination of the above parameters is presented.

• Tribology and Lubricants
• /
• v.30 no.3
• /
• pp.183-188
• /
• 2014

In this paper, we present our analysis of tribological failure examples for an anti-lock brake system(ABS) in a car. The study range of this paper is to improve the quality of ABS system by analyzing with sensor, computer, actuator and oil lines. In the first example, the brake leak from hydraulic supply line in a caliper on the rear left side of the ABS hydraulic modulator. This produces the sponge phenomenon, where the car does not brake even when the driver operates the brake pedal. The hydraulic unit operating ABS is actuator that play role regulating drive condition according with the oil pressure supplied with wheel of a car. In the second example, the service man does not completely tighten the fixed bolt after repairing the car. This causes the ABS warning lamp to light up as the ABS wheel speed sensor cannot detect whether the ABS has been activated. In the third example, the ABS electronic control unit is separated from the soldered part of the inner circuit board. Consequently, the ABS fails in control because the ABS motor pump receives no-signal for the hydraulic unit. The wheel speed sensor has to large durability because of giving signal of acting condition to computer by detected the acceleration and deceleration of wheel of a car. In the fourth example, the ABS warning lamp lights up of when cracks propagate in the circuit board soldering part. The circuit of this computer is very important part for input and output the operating signal of system. Such failures can aggravate the durability of the ABS. Thus, the ABS needs to be optimized to eliminate malfunction phenomenon.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.6
• /
• pp.4002-4006
• /
• 2014

The automotive exhaust gases generated by the vehicles containing carbon monoxide, hydrocarbons and lead, is a large concern because of their harm to human health or the living environment. To reduce exhaust gas, it is important to develop a variety of techniques that are currently being used by elemental analysis to determine the optimal conditions. In this study, the anti-freeze coolant contained in the exhaust gas was examined, which can affect the emissions. The effects of the commercially available coolant from five domestic companies on the HC, NOx and $CO_2$ emissions were analyzed to determine the optimal amount of antifreeze. In addition, antifreeze products from the five companies were analyzed with respect to driving time of the cooling fan and the correlation of the NOx emission analysis. The temperature of the engine oil was matched using a manual gear of small passenger inspection standard speed $40{\pm}2Km/h$ so the vehicle could meet the specifications for inspection $90{\sim}93^{\circ}C$. The Company D fan operation time resulted in the shortest antifreeze, $CO_2$ and NOx emissions.