• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.1-8
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• 1999

This study was conducted to collect data concerning the preferred driving postures and adopted seat adjustment levels and to grasp relationships among drivers' body sizes, postural angles, and adopted seat positions and angles. Also optimum driving posture and seat adjustment level estimation models were constructed. An experiment was conducted to investigate observed optimum driving posture, and seat adjustment level. Thirty-six subjects (male=20, female=16) was selected to include a wide range of percentiles in the dimensions important for automotive driving workstation design and to be representative of the automotive driving population in Korea. New guidelines and estimation models for optimum postural comfort were developed. There were significant differences between male and female in postural angles but not in seat adjustment levels. Taller subjects preferred a more open and reclined posture. Estimation models enable us to estimate the quantitative optimum driving posture and seat adjustment level with some drivers' physical dimensions.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.379-387
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• 1998

HVAC systems are used to maintain comfort conditions in occupied spaces. Like rolling noise and aerodynamic noise, noise from the HVAC system of train increases interior noise level. For an appropriate interior noise level, it is necessary not to find noise sources and their propagation paths. Noise emission from the sources and propagation through the propagation paths should be regulated in order to reduce their effect to the interior noise level. In general, the main noise source in the HVAC system is blower which operates at high static pressure. This noise propagates through ducts which are directly connected to the residential area. Since the blower noise can be reduced only to some degree, it is necessary for the propagation paths to have enough noise attenuation. Acoustic properties of ducts are usually found by experimental methods but it is rather difficult and expensive to set up such test equipments. In this thesis, the design and the noise characteristics of TGV-K HVAC system are studied. Finite element method in accordance with experimental method is used to study the acoustic properties of TGV-K duct system.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.3
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• pp.480-491
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• 2010

This study investigates the body satisfaction and fitness apparel depending on age and silhouette. The subjects were 254 females 20~50 years of age living in Chungju South Korea. There are various body types in women over the age of 35, the lower part of the body-development type, regular type, the upper part of the body-development type, and the rectangular body type. In addition, there is a lower satisfaction level in circumferences related with apparel fit, especially in the sleeve length, armhole, and crotch length. Therefore, a size system is needed that considers various body types in ready-to-wear clothing for middle-aged women. Design, color, and pattern are most important in clothing purchases by unmarried women, but the ease of laundry management and price discounts are the most significant for clothing purchases by married women. The upper part of the body-development type is unsatisfactory in the size-fit of sleeve length and shoulder width, but the lower part of the body-development type is unsatisfactory in the circumference of the waist, hip, abdominal, girth of skirt, and crotch length. The rectangular body type and the lower part of the body-development type are unsatisfactory in movement comfort, especially in hip girth and crotch length. The upper part of the body-development type is unsatisfactory in the movement comfort of the chest and elbow girth.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.333-339
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• 2008

When a vessel is underway in a heavy weather, passengers and crew suffer from seasickness caused by ship motions such as pitch, heave or roll, or all combined Sickness induces drowsiness, dizziness, headache, stomachache etc, in extreme conditions, they are met with a serious trouble which is physiologically unrecoverable. It results in weakening of spiritual activities or making errors from decrease of motivation, dropping off skills, poor recognition and poor judgement. In this paper, it was examined the international standards concerning the occurrence of sickness and the execution of works, also evaluated the boarding comfort by conducting several times of questionnaire on cadets boarding on the training ship HANBADA As a result, it was confirmed that the main factor of occurring the sickness was the vertical acceleration and the level was more than 0.2g. Also, it was presented the way how to reduce the sickness by changing the speed and/or course in relation to the encounter period.

• The Research Journal of the Costume Culture
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• v.13 no.3 s.56
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• pp.406-413
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• 2005

This study performed the evaluation of skin temperature, heart rate, temperature and relative humidity of microclimate, and subjective sensation, such as thermal sensation, wet sensation and comfort sensation to estimate physiological responses of the human body and its comfortable feeling to the vitamin E fabric. Experiments were performed on the five healthy adult women whose average age was 21, at climate chamber in which temperature, relative humidity and air current were set up below $30{\pm}\;1^{\circ}C$, $50{\pm}\;15\%$ and 0.2m/s, respectively. Two kinds of clothes were used for experiments: unfinished sports clothes, with the same form and the same size, of short-sleeved knit shirt and long trousers made with $100\%$ cotton, and finished sports clothes printed with the vitamin E solution of the level of $0.88\%$. Exercises of walking (about 105 steps/minute) with the exercise intensity of 2.5 were performed for 20 minutes using treadmill. In result, the study showed significant difference (p<0.01) in average skin temperature between unfinished and finished sport clothes, and represented higher value with having unfinished sport clothes in wear than with finished one. The study also showed significant difference (p<0.01) in heart rate only during the period of exercise, and represented higher value generally with unfinished sport clothes than with finished one. There were significant differences not only in temperature of microclimate (p<0.01) but also in humidity of microclimate (p<0.05) between two sport clothes. As for the evaluation of subjective sensation, the study showed significant difference (p<0.05) in thermal sensation between the two kinds of sport clothes, significant difference in wet sensation only during the period of exercise, and significant difference (p<0.05) in comfort sensation only during the period of recovery.

• Journal of the Korean Home Economics Association
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• v.29 no.3
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• pp.23-34
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• 1991

With 10 subjects of 6-year-old children residing in Pusan, I analyzed the relation of walking types(step angle, step width, step and stride) and wear comfort according to the style and size fo shoes in order to reveal the fitness of children's shoes centered on the relationship of shoes size and walking. Three styles of children's shoes(laced and unlaced formal shoes, magic-taped sports shoes) ranging in five different size were used. The following are conclusions. 1. As to step angle, there was no conceivable change in the left side, while the right side had a significance in accordance with the shoes size at p<0.001. As the size grew, right step angle of all shoes increased, with unlaced shoes having more influence than others. Step angle were the smallest when all the sampled shoes made the difference of 5mm between foot size and shoes size. 2. As to step width, there was no conceivable change in the style of shoes, while shoes size had a significance at p<0.001. As the size grew, step width also increased. Step width were the smallest when all the sampled shoes made the difference of 5mm between foot size and shoes size. 3. Step and stride, however, took no significance at all, since they were not influenced by the size or style of the shoes. 4. Wear comfort had a significance at the level of p<0.001. Since it was influenced by the size or style of the shoes. The best wear comfort was felt when all the sampled shoes had laces and magic tapes as well as the size with the difference of 5-10mm between foot size and shoes size.

• Smart Structures and Systems
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• v.21 no.5
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• pp.705-713
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• 2018

High-speed rail (HSR) has been in operation and development in many countries worldwide. The explosive growth of HSR has posed great challenges for operation safety and ride comfort. Among various technological demands on high-speed trains, vibration is an inevitable problem caused by rail/wheel imperfections, vehicle dynamics, and aerodynamic instability. Ride comfort is a key factor in evaluating the operational performance of high-speed trains. In this study, online monitoring data have been acquired from an in-service high-speed train for condition assessment. The measured dynamic response signals at the floor level of a train cabin are processed by the Sperling operator, in which the ride comfort index sequence is used to identify the train's operation condition. In addition, a novel technique that incorporates salient features of Bayesian inference and time series analysis is proposed for outlier detection and change detection. The Bayesian forecasting approach enables the prediction of conditional probabilities. By integrating the Bayesian forecasting approach with time series analysis, one-step forecasting probability density functions (PDFs) can be obtained before proceeding to the next observation. The change detection is conducted by comparing the current model and the alternative model (whose mean value is shifted by a prescribed offset) to determine which one can well fit the actual observation. When the comparison results indicate that the alternative model performs better, then a potential change is detected. If the current observation is a potential outlier or change, Bayes factor and cumulative Bayes factor are derived for further identification. A significant change, if identified, implies that there is a great alteration in the train operation performance due to defects. In this study, two illustrative cases are provided to demonstrate the performance of the proposed method for condition assessment of high-speed trains.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.565-575
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• 2016

Wheel reprofiling is frequently conducted to remove faults such as flange wear, flat areas, and cracks that occur in railway vehicle operation. We analyzed the dynamic performances of a vehicle before and after wheel reprofiling to grasp the influence of reprofiling on the dynamic behavior of the vehicle. We measured the wheel profile of the test vehicle and conducted a running test to analyze the vibration and comfort characteristics of the test vehicle. The result of the test indicated that vibration of the test vehicle after wheel reprofiling was reduced compared to that before wheel reprofiling. And, comfort level of the test vehicle after wheel reprofiling was improved by about 3dB laterally and vertically. Consequently, the positive effect of wheel reprofiling on the dynamic performance of vehicle was verified.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.59-68
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• 2014

Objective: The aim of this study is to investigate the effect of BackJoy on how it effectively reduces the physical load generated in a posture in which the user sits, increases user's comfort and satisfaction, and maintains the correct posture. Background: Because of development of science and economic development, most office workers and students spend about 75% of their working time in chairs. However most of them have a poor posture. Method: This experiment conducted measurement using a pressure mat and surveyed to evaluate fatigue level, satisfaction and comfort of sit. The study is experimented 20 male and 14 female participants. The participants carried out four different types of tasks and each task took 20 minutes long. Results: In the case of experiment results before and after the use of BackJoy, average pressure, contact area and pressure per unit area appear to prove that using BackJoy is more effective. Conclusion: Through this study, the BackJoy's effects for the maintenance of good posture and loads that occur in the body are reduced. In the future study, there are some researches needed for various verifications using an EMG sensor that shows loads of vertebrae and we need to analyze each group of the participants by dividing them. Application: The evaluation method used in this study can be applied to evaluating ergonomic chairs.

• Safety and Health at Work
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• v.9 no.1
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• pp.10-16
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• 2018

Background: A detailed evaluation of the underground mine climate requires extensive measurements to be performed coupled to climatic modeling work. This can be labor-intensive and time-consuming, and consequently impractical for daily work comfort assessments. Therefore, a simple indicator like a heat stress index is needed to enable a quick, valid, and acceptable evaluation of underground climatic conditions on a regular basis. This can be explained by the unending quest to develop a "universal index," which has led to the proliferation of many proposed heat stress indices. Methods: The aim of this research study is to discuss the challenges in identifying and selecting an appropriate heat stress index for thermal planning and management purposes in underground mines. A method is proposed coupled to a defined strategy for selecting and recommending heat stress indices to be used in underground metal mines in the United States and worldwide based on a thermal comfort model. Results: The performance of current heat stress indices used in underground mines varies based on the climatic conditions and the level of activities. Therefore, carefully selecting or establishing an appropriate heat stress index is of paramount importance to ensure the safety, health, and increasing productivity of the underground workers. Conclusion: This method presents an important tool to assess and select the most appropriate index for certain climatic conditions to protect the underground workers from heat-related illnesses. Although complex, the method presents results that are easy to interpret and understand than any of the currently available evaluation methods.