• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.3
• /
• pp.102-110
• /
• 2008

It is well known that the acoustic cavity inside the tire-wheel assembly contributes to vehicle interior noise and ride comfort. In this paper, we performed acoustic and structural modal testings by varying the temperature ranging from $20^{\circ}\;to\;45^{\circ}C$ to investigate the effects of temperature on acoustic cavity resonance and structural vibration characteristics for unloaded and loaded tires. The testing has given us some findings, which are reported in this paper.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.26-31
• /
• 2000

There are various noises generated by friction. Among the rest, eliminating squeal noise generated during braking is an important task for the improvement of vehicle passengers' comfort. The parameters affecting brake squeal noise are the material properties of the braking pad, the dynamic properties of the brake parts and the dimensions of the brake assembly etc. Also, the squeal noise changes its inherent form with the normal load and sliding speed. In this study, the characteristics of brake squeal noise generated by friction is analyzed experimentally. The experiment focused on the analysis of friction self-excited vibration and squeal noise level. Friction self-excited vibration is caused by the dry friction between pads and rotor, and occurs as a function of their relative sliding speeds. And Friction self-excited vibration is raised the brake squeal noise.

• Journal of the Optical Society of Korea
• /
• v.4 no.1
• /
• pp.58-61
• /
• 2000

Viewing zone shape and size perform a key role in creating viewing comfort for the viewer. The horizontal and vertical sizes of viewing zones, formed by a full color transmission type holographic screen with a stereoscopic image projection are investigated. The screens have been recorded as holograms of a narrow stripe shaped object with different width; to extend the vertical size of the viewing zone the holograms were exposed two times with the hologram shifting between exposures. The viewing zone parameters were measured as a function of the stripe width of the object and of the exit pupil size of projection optics for several holographic screens having the size of the 30 $\times$ 40 $\textrm{cm}^2$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.1004-1006
• /
• 2014

This study was conducted to improve the understanding of factors affecting an automobile seat cushion in dynamic conditions. When there are two dummies on the seat to measure each places respectively at once, the shape of the transfer function changes because the dummies affect each other as if they are linked with some kind of a spring when under excitation. A simple two-degree-of-freedom linear model is used to define a translational stiffness of dynamic coupling phenomenon. The cushion deflection model was created to find the relation between dynamic coupling and distance. Experimental set-up was made to compare with the two-degree-of-freedom linear model. The dynamic coupling factor could be utilized to improve the dynamic comfort of automobile seats.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.17 no.4
• /
• pp.602-607
• /
• 1993

Concept of the comfort and fitness becomes a major concern in the basic function of the ready-made clothes. This research was performed to classify and characterize Korean adult males anthropometrically. Sample size was 1290 subjects and their age range was from 19 to 54 years old. Sampling was carried out by the stratified sampling method. 75 variables in total were applied to classify the bodytypes. Data were analyzed by the multivariate method, especially factor and cluster analysis. The high factor loading items extracted by factor analysis were based to determine the variables of the cluster analysis for the similar bodytypes respectively. In the part of the lower body, 14 variables from the data were applied to classify the bodytypes of lower part by Ward's minimum variance method. The group fanning a cluster were subdivided into 5 sets by cross-tabulation extracted by the hierarchical cluster analysis. Type 3 and 4 in lower body were composed of the majority of 53.1% of the subjects. The Korean adult males had relatively well-balanced in lower body.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.28 no.5
• /
• pp.690-700
• /
• 2004

The purposes of this research were to segment consumer groups according to sportswear benefits sought and to find the differences among the groups in regard to domestic vs imported brand attitudes, internet vs department store attitudes, and sportswear purchasing behavior. The subjects used for the research were 773 male and female consumers who were residents in Seoul. The data were analyzed by factor analysis, cluster analysis, ANOVA, and Duncan test. The results showed that there were four sportswear benefit segments: figure compensation/ ostentation, individuality, comfort/function, and youth-oriented groups. Statistical analyses showed that the four sportswear benefit segments were different in regard to imported brand attitudes, department store attitudes, and sportswear purchasing behavior. For example, figure compensation/ ostentation segment had more positive attitude toward imported brands and department stores, considered design and advertisement important as sportswear selection criteria, and had a highest expenditure on sportswear purchase. The implications of the research were discussed.

• Fibers and Polymers
• /
• v.7 no.2
• /
• pp.195-202
• /
• 2006

Tight-fitting clothing pattern reflecting the accurate information of the 3D body shape has been one of the challenges for garment industry, however, fitting problems still exist. The objectives of the paper is to develop a 2D pattern which fits tightly to the 3D human scan data for sports suits that need comfort and function for maximum performance. In this study, the user graphic interface application software for the semi-automatic garment pattern generation has been implemented using the triangle simplification scheme together with 2D projections of free-falling of 3D surface polygons keeping the original 3D surface area preservation. A typical application of the developed pattern to the functional body suits is presented and verification of the proposed method is also provided.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.372-374
• /
• 2001

An automatic operation of train is executed by an automatic train operation(ATO) system. The main function of ATO system is to control train speed as well as train brake system. So that train can stop at its programed position on platform and run with passenger comfort. In this paper, the gain scheduled control is designed for speed control considering the disturbances. The simulation is executed to verify the speed control performance and to compare its performance with the conventional PI and general Fuzzy control.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.2094-2100
• /
• 2008

The indoor PMV(Predicted Mean Vote) in rolling stock is very important for the enhancement of the amenity and health of passengers. Many researchers have studied it not for train but for building. Thermal comfort in Rolling Stock is function of temperature, relative humidity, air current, radiation temperature, etc. So, in this study, we have performed thermal environment in rolling stock(Electric motor car, Saemaeul, Mugunghwa train), and verified the relation between the PMV from Nov.2007 and Feb.2008. As a result, the average PMV value for each trains are 0.2, -0.3 Electric motor car, 0.5, 0.1, 0.1, 1.1 for Mugunghwa, 0.3, 0.5 for Saemaeul.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.283-289
• /
• 2004

Rail defects(Corrugation, shelling, etc) are occurred by the Rail with wheel contact stress. Rail grinding is maintaining of optimal rail profile to use special rail grinding machine to remove rail defect. The benefits of rail grinding enforcement, improve track safety, improve track steering and rail life, improve ride comfort and reduce noise, etc. Actually when rail grinding plan apply to field track, we should consider a lot of function before determination, such as grinding method, grinding pass number, removing metal volume, etc. because each track has various characteristics. Therefore it is important that the determination of rail grinding strategy for optimum and economic before enforcement.