• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.33-41
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• 2014

Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. When two pieces of materials, pressed together by an external static load, are subjected to a transverse cyclic loading or various vibrations, so that one contacting face is relatively displaced cyclically parallel to the other face, wear of the mating surfaces occurs. These fretting damages may be observed in electrical connectors for automotive components, where there are special environments and various vibration conditions. This study aims to evaluate the usefulness of fretting test equipment that was developed for reliability test of electrical connector. Fretting tests were carried out using tin coated connectors and friction force, contact resistance, contact area and roughness of contact region were investigated. The following results that will be helpful to understand the fretting wear mechanism, increase process the contact resistance and contact area were obtained. (1) In the same frequency and slip amplitude, the friction force, roughness and contact area increased rapidly until about $10^3$ cycles, after which it was slightly changed. (2) In the various frequency and slip amplitude, the contact area increased with slip amplitude and cyclic numbers, but it did not depend on cyclic frequency. (3) The surface roughness of contact region did not depend on the cyclic frequency. From these results, the applicability of the fretting wear test equipment and reliability of connector were discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1279-1292
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• 2022

This study proposes a non-contact input method based on face recognition and Pyautogui mouse control as a system that can help users who have difficulty using input devices such as conventional mouse due to physical discomfort. This study includes features that help web surfing more conveniently, especially screen zoom, scroll function, and also solves the problem of eye fatigue, which has been suggested as a limitation in existing non-contact input systems. In addition, various set values can be adjusted in consideration of individual physical differences and Internet usage habits. Furthermore, no high-performance CPU or GPU environment is required, and no separate tracker devices or high-performance cameras are required. Through these studies, we intended to contribute to the realization of barrier-free access by increasing the web accessibility of the disabled and the elderly who find it difficult to use web content.

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.25-34
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• 2021

This study develops a new device system for measuring a slope of object with non-adhesive, non-contact and non-face-to-face, namely Inclinometer Slope Laser Measuring (ISLM), that is applicable in the field. This system includes cradle, laser, camera, and computer and the filming and is performed after laser projection at programmed intervals. After measuring the amount of displacement converted to numerical values, these values can then be transferred to the office using the selected data transmission method. The obtained results from the test carried out to verify the reliability of the ISLM system indicated that the ISLM system can measure with accurately level of 0.1mm/Pixel at 1m distance and when increasing the camera resolution, the precision might increase proportionally. Therefore, the proposed measure system may widely apply on-site for various constructions, especially, in the case of object with very high surface temperature where exhibits difficulty to directly measure the adjacent structures. However, due to the sensitive reaction to the illuminance, this method can be applied with caution at times of large changes in illuminance, such as at dawn and at dusk.

• Journal of Families and Better Life
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• v.33 no.4
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• pp.105-118
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• 2015

This study examined whether structural (coresidence, proximity) and associational (frequency of face-to-face contact, frequency of contact via phone, email or letter) solidarity between adult children and older parents may influence older parents' cognitive functioning. Adult children may help delay older parents' cognitive decline by promoting healthier lifestyle, engaging parents in complex everyday problem solving, and providing emotional support. The data consisted of men and women 65+ at Wave 1 who had at least one child 20+ and participated in at least two waves of the Korean Longitudinal Study of Ageing (KLoSA, N=3,961). Cognitive functioning was measured with the Korean version of the Mini Mental State Examination. Fixed effects models were estimated using the xtreg procedure in STATA. Findings suggest that increases in proximity with at least one adult child may lead to enhanced cognitive functioning among older parents. Neither transitioning to coresidence with at least one adult child nor increases in frequency of contact with at least one non-resident adult child was associated with changes in older parents' cognitive functioning. With older parents' increasing preference for living close by, but not necessarily living with adult children, greater proximity may provide more opportunities for reciprocal support exchanges between the two generations, leading to better cognitive functioning of older parents.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.323-324
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• 2021

This study is to develop a non-contact construction project management solution that can reduce cost and construction period through on-site information sharing, minimizing contact with others by COVID19, and improving the productivity of the construction industry. Decisions, checklists, and execution rates of construction costs can be checked with smart devices through sharing on-site photos and videos, exchanging opinions. Details and checklist data stored on cloud servers of sites that apply non-face-to-face construction project management solutions will be used as data for analyzing amounts and construction periods depending on the size of the construction. Real-time field information sharing will reduce expected problems and waste factors, expand communication channels with users to prevent or minimize construction disputes and claims, and contribute to the expansion and growth of new research industry markets in construction technology.

• Journal of Arbitration Studies
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• v.19 no.2
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• pp.155-178
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• 2009

The ODR can be categorized into four distinctive types. First type is the asynchronous non-demeanour method. Second type is the asynchronous demeanour method. Third type is the synchronous demeanour method. Fourth type is the synchronous demeanour method. A typical example of the asynchronous and non-demeanour method is e-mail. The example of the synchronous and non-demeanour method is tele conference. The example of the asynchronous demeanour method is video recordings. The example of synchronous and demeanour method is video conference. The primary benefit of e-mail is to avoid the physical violence. But the costs of email is the lack of emotional aspects of disputants. The benefits of tele conference is ease of use, and reduces the negative aspects of face to face communication. but the costs are limitation of the exchange of written information. The benefits of video conference is the approximation of face to face communication by providing oral as well as visual communication. but it is insufficient to represent eye contact. The common limitations of ODR are as follows. First is the lack of human face. Second is the neutrality of arbitrators and mediators. Third is the authenticity of electronic document. Fourth is the digital divide across South and North and generations. Fifth is the cross-cultural communication. The development strategy of ODR is the training and education of arbitrators and mediators in the area of writing skill. Furthermore, it is necessary to supplement the weakness of email via diverse kinds of expressions to show emotions. Finally, it is necessary to train neutrals in the area of cross-cultural communication.

• Journal of the Korea Computer Industry Society
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• v.5 no.1
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• pp.157-166
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• 2004

Consequently substantial research has been done on the development of the bio-metric recognition method as well as technical research in the field of authentication. As a method of bio-metric recognition, personal and unique information such as fingerprints, voice, face, Iris, hand-geometry and vein-pattern are used. The face image system in bio-metric recognition and information authentication reduces the denial response from the users because it is a non-contact system the face image system operates through a PC camera attached to a computer base this makes the system economically viable as well as user friendly. Conversely, the face image system is very sensitive to illumination, hair style and appearance and consequently creates recognition errors easily, therefore we must build a stable authentication system which is not too sensitive to changes in appearance and light. In this study, I proposed user authentication protocol to serve a confidentiality and integrity and to obtain a least Equal Error Rate to minimize the wrong authentication rate when it authenticates the user.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.161-163
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• 2021

In an apartment or private building, it is difficult for the user to operate the elevator button in a similar situation with luggage in both hands. In an environment where human contact must be minimized due to a highly infectious virus such as COVID-19, it is inevitable to operate an elevator based on untact. This paper proposes an operating system capable of operating the elevator by using the user's voice and image processing through the user's face without pressing the elevator button. The elevator can be operated to a designated floor without pressing a button by detecting the face of a person entering the elevator by detecting the person's face from the camera installed in the elevator, matching the information registered in advance. When it is difficult to recognize a person's face, it is intended to enhance the convenience of elevator use in an untouched environment by controlling the floor of the elevator using the user's voice through a microphone and automatically recording access information.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.456-463
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• 2007

It is important to improve the initial launch conditions of golf ball at impact between golf club and ball to get a long flight distance. The flight distance is greatly influenced by the initial launch conditions such as ball speed, launch angle and back spin rate. It is also important to analyze the mechanism of ball spin to improve the initial conditions of golf ball. Back spin rate is created by the contact time and force. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of ball, and the tangential force creates the spin. Especially, the tangential force is known to take either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail in the literature. In this paper, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and time at impact between golf club head and ball are computed using FEM and compared with previous results. In addition, we investigate the impact phenomenon between golf club head and ball by FEM and clarify the mechanism of ball spin creation accurately, particularly focusing on the effect of negative tangential force on ball spin rate.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1017-1022
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• 2007

It is important to improve the initial launch conditions of golf ball at impact between golf club and ball to get a long flight distance. The flight distance is greatly influenced by the initial launch conditions such as ball speed, launch angle and back spin rate. It is also important to analyze the mechanism of ball spin to improve the initial conditions of golf ball. Back spin rate is created by the contact time and force. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of ball, and the tangential force creates the spin. Especially, the tangential force is known to take either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail in the literature. In this paper, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and time at impact between golf club head and ball are computed using FEM and compared with previous results. In addition, we investigate the impact phenomenon between golf club head and ball by FEM and clarify the mechanism of ball spin creation accurately, particularly focusing on the effect of negative tangential force on ball spin rate.