• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.204-212
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• 2002

The ride comfort is one of the important dynamic performances of railway vehicle and is affected by the various factors, such as vibration, sound, temperature, humidity, etc. In general, vibration is known to be a major effect of rode comfort. There are many studies on the evaluation methods of ride comfort in the railway vehicle vibration. Each of the evaluation methods suggested by Spelling and in the standards recommends a different evaluation method and guidance. So users must review whether they can apply it to their railway system or not. In this study, we have suggested the relationship between several evaluation methods using the statistical vibration model based on the experimental data.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1566-1573
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• 2009

Although the riding comfort of tilting trains has been managed by setting allowable limits of roll motion in Korea, it is impossible for this approach to express the psychophysical relationship between various vibrational factors and riding comfort. in order to propose a function to evaluate the riding comfort of tilting train on transition curves, an experiment was performed with the Korea Tilting Tran eXpress(TTX). As a result, by referring to some international standards on the method of evaluating ride comfort, a modified method was proposed to evaluate the lateral vibration in addition to the roll motion on carve transitions.

• Smart Structures and Systems
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• v.24 no.1
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• pp.141-155
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• 2019

This work evaluates the influence of negative stiffness on the performances of various vehicle suspension systems, and proposes a re-centering negative stiffness device (NSD). The re-centering NSD consists of a passive magnetic negative stiffness spring and a positioning shaft with a re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of static spring deflection. The numerical simulations reveal that negative stiffness can improve the ride comfort of a vehicle without affecting its road holding abilities for either passive or semi-active suspension systems. In general, the improvement degree of ride comfort increases as negative stiffness increases. For passive suspension system, negative stiffness brings in negative stiffness feature in the control forces, which is helpful for the ride comfort of a vehicle. For semi-active suspensions, negative stiffness can alleviate the impact of clipped damping in semi-active dampers, and thus the ride comfort of a vehicle can be improved.

• Advances in Automotive Engineering
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• v.1 no.1
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• pp.1-20
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• 2018

The aim of this study is the optimization of the parameters of interconnected Hydro-Pneumatic (HP) suspension system of a three-axle vehicle for ride comfort and handling. For HP suspension systems of equivalent vertical stiffness and damping characteristics, interconnected HP suspension systems increase roll and pitch stiffness and damping characteristics of the vehicle as compared to unconnected HP suspension systems. Thus, they result in improved handling and braking/acceleration performances of the vehicle. However, increased roll and pitch stiffness and damping characteristics also increase roll and pitch accelerations, which in turn result in degraded ride comfort performance. Therefore, in order to improve both ride comfort and vehicle handling performances simultaneously, an optimum parameter set of an interconnected HP suspension system is obtained through an optimization procedure. The objective function is formed as the sum of the weighted vertical accelerations according to ISO 2631. The roll angle, one of the important measures of vehicle handling and driving safety, is imposed as a constraint in the optimization study. Upper and lower parameter bounds are used in the optimization in order to get a physically realizable parameter set. Optimization procedure is implemented for a three-axle vehicle with unconnected and interconnected suspension systems separately. Optimization results show that interconnected HP suspension system results in improvements in both ride comfort and vehicle handling performance, as compared to the unconnected suspension system. As a result, interconnected HP suspension systems present a solution to the conflict between ride comfort and vehicle handling which is present in unconnected suspension systems.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.6 s.111
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• pp.619-626
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• 2006

Body-on-frame type vehicle has a set of frame bushes between body and frame for vibration isolation. Such frame bushes are important vibration transmission paths to passenger space for excitations during driving. In order to reduce the vibration level of passenger space, therefore, change of complex stiffness of the frame bushes is more efficient than modification of other parts of the vehicle such as body, frame and suspension. The purpose of this study is to reduce the vibration level for ride comfort by optimization of complex stiffness of frame bushes. In order to do this, a simple finite element vehicle model was constructed and complex stiffness of the frame bushes was set to be design variables. The objective function was defined to reflect frequency dependence of passenger ride comfort. Genetic algorithm and sub-structure synthesis were applied for minimization of the objective function. After optimization level at a position of interest on the car body was reduced by about 43.7 % in RMS value. Causes for optimization results are discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.2
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• pp.321-341
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• 2020

This study analyzed the domestic patent trends of brassiere to provide fundamental data for promising technology. Relevant patents were searched by inputting the key words of "brassiere" and IPC code "A41C" on patent information search service of KIPRIS. A search for bras patents from 1985 to 2019 revealed 533 registered applications out of the total 744 listed. The IPC code with the highest portion (40%) was A41C3/00 (brassiere), followed by A41C3/14 (forming inserts, 21.6%), and A41C3/12 (component parts, 13.3%). To arrange the guidelines of the content of brassiere patents, we carried out a qualitative technology analysis on 744 patents, to extract 850 technology cases applied in patents. From the technological features of each case, main categories were classified into two parts (function and structure) and function was divided into 7 sub-categories that included physiological comfort, physical comfort, utility, healthcare, appearance, and economic value. As for the structure, cup showed the highest portion (37.9%), followed by pad (16.5%), and wings (13.2%). From the aspect of function, appearance showed the highest portion (30.8%), followed by usability (22.2%), physiological comfort (14.6%), physical comfort (14.6%), economic value (10.7%), and health care (7.4%).

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.8
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• pp.1179-1189
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• 2008

The purpose of this study is to investigate the satisfaction of the adolescents' school backpack bag and the important criteria when purchasing for developing comfort and functional backpack. The questionnaire was composed and surveyed with 245 middle school students and the data were analyzed through SPSS 13.0. Purchasing criteria were grouped into 5: practical, shop environment, comfort, aesthetic and maintenance. Satisfaction factors were function/comfort, fashion/aesthetic and durability/A.S. 50.2% of students recognized the inappropriate wearing backpack might cause the deformation of body shape. And the wrong habit of wearing bag was found to affect the body posture of students. Main symptoms caused by wearing it for long time are ‘sweating around shoulder and back' and ‘feeling stiff in shoulders and waist'. Needs arise to develop the bag which could prevent them and to educate students how to wear bags. According to the result from MDS of purchasing criteria, one axis is product vs. environment, and other is functional vs. psychological aspects. According to the result from MDS of bag satisfaction, one axis is function/durability vs. fashion/appearance, and other is gestalt quality vs. part quality. They wanted the improvement in the aspects of shape/design, material, maintenance, comfort and usability of the bags. Specially it is required that we research the adolescent customer-oriented way and develop the new materials or shapes pursuing both shoulder comfort and characteristics.

• Journal of The Korea Institute of Healthcare Architecture
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• v.11 no.3
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• pp.75-85
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• 2005

Recently the number of women's hospitals of a small scale are increasing in seoul and the other cities although the surroundings of these sites are so inferior. Those hospitals need the space of comfort as like family home. This study suggests that the encirclement space is one of the design methods to make comfort to patients. The encirclement is the form of hugging a baby to a mother's arms. Analysing six woman hospitals, encirclement space is categorized about the six types of square, open square, right-angled, linear, dispersed, etc. The characteristics of "right-angled" is featured as the form of L, and "square" type is characterized as the relationship of functional circulation among doctors, nurses and patients. And all types are organized as the relationship between the encirclement space and the enclosed space about how the functional space and the comfort space are made up. The properties of encirclement space are appeared by the interactions about function, circulation, sight, form, access, recognition through transparent, three-dimensional experience, etc. Encirclement space is recommended as a vital factor to make comfort space for designing women's hospital in city.

• Korean Journal of Human Ecology
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• v.22 no.1
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• pp.141-155
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• 2013

The purpose of this study is to identify consumers' needs and purchase intention of high-functional sportswear according to sports participation motivations. Internet survey was done for data collection and the subjects were 300 consumers in their 20-39's who participated in sport activities at least once a week. Factors of sport participation motivations were ostentation, social interaction, self development, mental health, and physical health. Consumers were segmented into the motivation retard group, the multi-purpose pursuit group, the health pursuit group, and the extrinsic motivation pursuit group. And factors of consumers' needs for high-functional sportswear were practicality and comfort function, body protection and physical function, and skin protection and health function. The multi-purpose pursuit group showed strong needs for active and comfort, body protection and physical function, and skin protection and health function but the motivation retard group showed the lowest needs for high functional sportswear. Purchase experiences of high-functional sportswear, accomplishment, and duration period of sport activity affected positively on the purchase intention of high-functional sportswear.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.5
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• pp.714-723
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• 2000

The purpose of this study is to develop functional and sensible brassiere for middle-aged women. As a methodology, engineering design process, especially, QFD(Quality Function Deployment) was adopted to translate consumer's needs into product design parameters. Wearing tests of commercial brassiere were performed for the development o subjective measurement scale. The environmental condition was controlled at 28$\pm$1$^{\circ}C$, 65$\pm$3%RH. As results, subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. Regression equations with the subjective evaluation descriptors were developed for the prediction of wearing comfort of brassiere. (R2=.82) The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap.