• Journal of IKEEE
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• v.23 no.1
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• pp.224-229
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• 2019

Seat of automobile is required to support the comfort to driver and passenger during the driving. The control method of the seat position is changed from manual type to power type, which means using the motor to increase the comfort of the driver. By using the motor, several problems, such as vibration, noise, and over-current, appeared. These problems can be reduced through the control of seat motor. In this study, a control technology of four control variables, which determine profile of the input voltage applying to the seat motor, is proposed to generate the current profile having soft-start and soft-stop. The current flowing through the coil by input voltage is described by mathematical modeling of power seat. It is confirmed that optimized current profile having soft-start and soft-stop can be generated from simulation using the mathematical model.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.87-92
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• 2007

KTX (Korea Train eXpress) is launched as the $5^{th}$ develop a ride-comfort model for high-speed rail pasengers using structural equation model (SEM). Both qualitative and quantitative factors affecting ride-comfort were investigated, and employed to construct a comprehensive ride-comfort model. The SEM model was built with twenty measurement variables and seven latent variables for the evaluation of ride-comfort of high-speed train passenger. A total of six hundreds thirty two subjects participated in the evaluation using face-to-face survey method. As a result, the proposed SEM model model fitnes (GFI=0.93). According to the results, overall ride-comfort was significantly affected by the seat-, fatigue-, interior-related, and customer satisfaction variables such as fare. Among the engineering design variables of high-speed train, seat-related variables were identified as critical factors of the ride-comfort. It is expected that the result of this study could be useful for the enhancement of ride comfort in next generation KTX.

• Journal of the Ergonomics Society of Korea
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• v.33 no.3
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• pp.215-227
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• 2014

Objective: The purpose of this study was to evaluate Korea's Honam express train's first- and second-class seat discomfort by using pressure measurement, subjective discomfort rating, and physical compatibility. Background: Over the years, the demand for an express train service is continually increasing. A comfortable ride is important to achieving passenger satisfaction. A train seat plays a significant role in fulfilling passenger seating comfort. With this in view, a field survey and pressure measurements were performed on the selected train seat. Method: The pressure ratio at the body-seat interface (thigh and buttock regions) was measured by the pressure mat system. The interface pressure ratio was calculated and compared. The subjective discomfort rating scale was used to evaluate the subjects' overall feeling. The dimensions of train seats were analysed according to the anthropometric and demographic characteristics of the population data from Size Korea. Results: The results highlighted that the interface pressure ratio was greater while participants sat on the second-class seat than the first-class seat in the left- and right-side thigh regions. Also the pressure ratio was greater for the participants in the 1st~25th percentile height groups (149.8~160.8cm). The subjects rated higher discomfort for the second-class seat than the first-class seat. The physical compatibility results showed that the second-class seat's breadth was inadequate for the 95th and 99th percentile male. Conclusion: Overall, interface pressure measurement, subjective discomfort score and physical compatibility results showed that the second-class seat was more uncomfortable for the passengers than the first-class seat. Application: The adopted methodologies could be used to measure the seating comfort of the train seats.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.3
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• pp.149-157
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• 2018

In this research, the psychological and physiological reactions of the driver were measured during winter to evaluate thermal comfort. The experiment was conducted using 3 different cases which are hot air heating, warm-wire seat heating and hot air & warm-wire seat heater operating simultaneously. With regard to psychological reaction, the warm-wire heating mode was the most preferred. The reason is that it is dry in other cases. With regard to EEG response, thermal comfort increased by 37% in warm air mode heating. In addition, when the warm-wire heating mode and the hot air & warm-wire heating mode were simultaneously operated, the thermal comfort continuously increased by between 17% and 20% for 20 minutes after boarding. Under the change of the autonomic nervous system, the thermal stress level increased by 23% after 15 minutes on board in the hot air heating mode and decreased continuously by 13% during the warm-wire seat heating mode. We recommended the hot air heating mode is only used for a short time to raise the inside temperature during the early boarding period and that warm-wire seat heating mode be actively utilized.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.210-218
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• 2000

It is absolutely important to design passenger seat so that train passengers can satisfy because passenger seat is one of the most important parts in tile determination of passenger's satisfaction for train.. So, it is necessary to consider passengers' characteristics, requirements, and dissatisfactions in seat design. However, passengers' dissatisfactions for the seat of Mugunghwa-ho train have been often raised through various routes. It is necessary to resolve their dissatisfactions to provide comfortable trip to passengers. So, we designed a seat of new Mugunghwa-ho train that resolved passengers' dissatisfactions. Our focusing design parts were the seat pan and the backrest of passenger seat. We investigated passengers' dissatisfactions for the seat of Mugunghwa-ho train through various methods and the human factors design guidelines of passenger seat through literature survey. We designed a new seat on the basis of investigated results. For newly designed seat, we evaluated comfort, sensible satisfaction, and fitness in comparison with the existing seat. An experimental method and a subjective method were used in this evaluation. In all aspects, new seat was superior to the existing.

• IE interfaces
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• v.14 no.2
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• pp.210-217
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• 2001

Because passenger seat is one of the most important parts in the determination of passengers' satisfaction for train, it is absolutely important to design the passenger seat so that train passengers can satisfy. So, in the seat design it is necessary to consider passengers' characteristics, requirements, and dissatisfactions. However, passengers' dissatisfactions for the seat of Mugunghwa-ho train have been often raised through various routes. It is necessary to resolve their dissatisfactions to provide comfortable trip to passengers. So, we designed a new seat of Mugunghwa-ho train that resolved passengers' dissatisfactions. Our focusing design parts were the seat pan and the backrest of passenger seat. We investigated passengers' dissatisfactions for the seat of Mugunghwa-ho train through various methods and the human factors design guidelines through literature survey. We designed a new seat on the basis of investigated results. For newly designed seat, we evaluated comfort and sensible satisfaction in comparison with the existing seat. An experimental method and subjective methods were used in this evaluation. In all aspects, the new seat was superior to the existing.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2004.11a
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• pp.24-24
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• 2004

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.102-109
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• 2003

Safety and comfort are importance concepts for designers of vehicle seats and instrument panels. There have been a lot of researches on comfortable sitting postures, however, relatively a few researchers have tried to find a desirable driving posture in consideration of both comfort and safety. This study investigates a relationship between comfort and safety of sitting posture of a driver. Since a seat is closely related to comfort, the angular data of comfortable sitting posture were obtained through the correlation between the seat and the driver. In order to acquire the data of safe sitting posture, computer simulations were performed for various seatback angles. Based on comparing and analyzing the data obtained, the optimal sitting posture is suggested for both comfort and safety aspects.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.71-79
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• 2000

In this study, through the roadside interview, drivers'feeling about fatigue has been evaluated synthetically and systematically when they drive a vehicle according to their sex, vehicle type, driving career, etc. Also, with the human sensibility evaluation technique, we grasped the human sensibility structure for the fatigue in a vehicle and as an objective evaluation index for comfort and fatigue in a vehicle, we developed a sensibility database. Through the survey and research, extracting and understanding the importance of factors which have influence on the fatigue in driving can be used as basic data that can suggest more comfort and pleasant driving environment to drivers. Also, human sensibility database regarding to the comfort and fatigue in a vehicle can be used as basic data in ergonomic vehicle design, evaluation for seat , comfort seat development, development of vibration reduction method and so on.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1736-1740
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• 2003

There have been various studies to find out the correlation between subjective and objective evaluation ride comfort in vehicle. To be proper, subjective evaluation considers the signal pattern of vibration generated by vehicle. In this study, driving test is carried out to extract the correlation between subjective evaluation by subjects and vibration signals measured on the seat when a test vehicle is passing over test bumpers, which have two sorts of width change and height change respectively. A unique reference bumper is used to be compared with the relative comfort of test bumpers.