• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.6
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• pp.591-598
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• 1984

The results of measurements showing normal vibrations and rubbing noise generated during unlubricated smooth sliding between metal surfaces are presented. The measurements were made on pin-on-disc type apparatus instrumented with piezoelectric acceleration transducers and microphones. Spectral analysis of the both signals up to frequency of 10kHz indicates that they are closely correlated. The major components of both signals in this frequency range are primarily associated with the normal contact vibrations which are excited by surface irregularities being swept through the contact region during sliding. As an approximation to the seismic input of surface irregularities, an effective surface wavenumber spectrum was assumed in the form of an inverse vibration and noise measurements for a number of surface finishes and mean loads. The predominant frequency component of which levels of the normal vibration and noise are close to overall levels of the both signals is induced by contact resonance between the two bodies and its frequency can be calculated from the Hertzian theory.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.97-104
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• 2014

Automobile trunk latches enable trunks to be opened and closed by a latch mechanism, which can be selectively positioned between a locked condition and an open condition. To maintain structural and electronic performance of the trunk latch, the latch needs to endure impact load that occurs in its open and close motion, and a dynamic mechanism needs to be electronically controled by a contact switch connected with a small DC motor. A base plate, which is the most important component relating to the structural safety, commonly uses a high stiffness material SAPH440-P with high manufacturing cost. In this paper, through structural analysis and optimization, production cost is significantly reduced by replacing SAPH440-P used in some region of the base plate with engineering plastic PBT GF 20%. The optimized contact switch reduces difference between distributed pressures of its two legs, which leads to improve the electronic performance of the trunk latch.

• 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 KIEE Conference
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• 1998.07e
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• pp.1614-1616
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• 1998

Insulation performance of major components of prefabricated joint such as epoxy insulation unit and premolded rubber cone are guaranteed by material selection design and proper manufacturing. On the other hand insulation performance of the interfaces between the premolded rubber cone and the epoxy insulation unit and the cable insulation is maintained by keeping the premolded rubber cone to close contact with such insulation by spring. Electric characteristics of a interface depend on the contact pressure, but the required characteristics are assured so far as a proper contact pressure is maintained. In this report, the interfacial pressure by pressure sensors both in the early stage and after heating cycle were measured and the simulation by FEM program were presented. The comparison of these two results show that interfacial pressure could be controlled optimally by changing the spring length and lubricant state of the interface.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.232-239
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• 2011

Fabric fibrous filter has been used in various industrial applications owing to the low cost and wide generality. However, the basic properties of fabric materials often limit the practical utilization including hot gas cleaning. This study attempts to find new coatings of porous fibrous filter media in order to overcome its insufficient thermal resistance and durability. Teflon was one of the plausible chemicals to supplement the vulnerability against frequent external thermal impacts. A foaming agent composed of Teflon and some organic additives was tentatively coated on the glass fiber mat. The present test Teflon foam coated filter was fount to be useful for hot gas cleaning, up to $250^{\circ}C$-$300^{\circ}C$. Close examination using XPS(X-ray Photoelectron Spectroscopy) and Contact angle proved the binding interactions between carbon and fluorine, which implies coating stability. The PTFE/Glass foam coated filter consisted of more than 95% (C-F)n bond, and showed super-hydrophobic with good-oleophobic characteristics. The contact angle of liquid droplets on the filter surface enabled to find the filter wet-ability against liquid water or oil.

• Journal of The Korean Astronomical Society
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• v.39 no.1
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• pp.25-30
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• 2006

We completed four color light curves of the near-contact binary CN And during three nights from September to December 2004 using the 61-cm reflector and BV RI filters at Sobaeksan Observatory. We determined four new times of minimum light (two timings for primary eclipse, two for secondary). Newly obtained BV RI light curves and the radial velocity curves from Rucinski et a1. (2000) were simultaneously analyzed to derive the system parameters of CN And. We used the semi-detached mode 4 of the 2003-version of the Wilson-Devinney binary model, and interpreted the asymmetry of the light curve by introducing two spots; a cool spot on the primary component and a hot spot on the secondary component. New photometric parameters are not much different from those of Cicek et a1. (2005), and it is considered that the system is in the era of broken contact. From the orbital period study with all available timings including our data, we found a continous period decrease with a rate of $P_{obs}=--1.82{\times}10^{-7}\;d\;yr^{-1}$ that can be explained with two possible mechanisms. We think the most likely cause of the period decrease is a thermal mass transfer from the primary to the secondary component, rather than angular momentum loss due to a magnetic stellar wind.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.132-137
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• 2005

Installation art(I.A.), which has appeared since 1940s against the loss of human nature and hackneyed art caused by materialism, is in pursuit of contact with audience and various artistic experiments. Many features of I.A. - to try contact with audience, to do experiments connecting different genres of art, to regard time and nature as elements of art and to use high technology - could give good ideas for contemporary display(S.W.D.) design. This study is a basic work to suggest new S.W.D. design through artistic principles of I.A.. First, I.A. and S.W.D. design were studied theoretically. Next, spatial expressions were extracted from I.A. and the case study was proceeded to seek the co-relationship of spatial expressions and display design. For a case of Shiseido, it could be evaluated very high because it adapted spatial expressions of I.A. successively. The S.W.D design could be more effective presentation when it has close contact with audience and various experimetal and artistic ways of Installation art.

• Journal of Drive and Control
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• v.18 no.1
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• pp.31-38
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• 2021

This study presents a new principle for driving the robot aimed at reducing the position error for the boresonic examination of turbine rotor. The conventional method of inspection is performed by installing manipulator onto the flange of the turbine rotor and connecting a pipe, which is then being pushed into the bore. The longer the pipe gets, the greater sagging and distortion appear, making it difficult for the ultrasonic sensor to contact with the internal surface of the bore. A pneumatic pressure will ensure the front or rear feet of the robot in close contact with the inner wall to prevent slipping, while the ball screw on the body of the robot will rotate to drive it in the axial direction. The compression force required for tight contact was calculated in the form of a three-point support, and a static structural simulation analysis was performed by designing and modeling the robot mechanism. The driving performance and ultrasonic detection ability have been tested by fabricating the robot, the test piece for ultrasonic calibration and the transparent mock-up for robot demonstration. The tests have confirmed that no slipping occurs at a certain pneumatic pressure or over.

• Journal of Platform Technology
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• v.11 no.1
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• pp.52-59
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• 2023

The importance of spatio-temporal trajectories for contact tracing has increased due to the recent COVID-19 pandemic. Spatio-temporal trajectories store time and spatial data of moving objects. In this paper, I propose query processing for spatio-temporal trajectories of moving objects. The spatio-temporal trajectory model of moving objects has point type spatial data for storing locations and timestamp type temporal data for time. A trajectory query is a query to search for pairs of users who have been in close contact by boarding the same bus. To process the trajectory query, I use the Geolife dataset provided by Microsoft. The proposed trajectory query processing method divides trajectory data by date and checks whether users' trajectories were nearby for each date to generate information about contacts as the result.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.478-482
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• 2010

Considering the globalization and the development of regional culture, culture and design become more and more closely connected. It is obvious that every country, based on politics, economy, society, industry, has a different understanding to the design. With the popularity of mobile phone, it has been in close contact with our lives. Mobile phone is changing our way of life, it also has become a culture, and is reflected in a period in different countries and different ethnic's cultural traditions and lifestyle. In this paper, the study is about the impact of culture on mobile telephone design and application, especially for appearance and input for mobile telephone.