• Korean Journal of Cognitive Science
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• v.21 no.1
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• pp.1-24
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• 2010

The stationary image appears to move after we view a moving stimulus for a long time. The motion aftereffect(MAE) can spread to an adjacent region if there is no contrast discontinuity between two regions. In this study, it is investigated whether a phenomenon of MAE spreading to an adjacent non adapting area is affected by the depth discontinuity defined by binocular disparity. In the first experiment a disparity defined slanted pattern was presented in an unadapted region, and in the second experiment, a disparity defined pattern with a different depth was presented on the fronto-parallel plane. Although MAE duration in the condition with slanted pattern was not different from that in the non-slanted pattern condition, MAE durations in the pattern presented on pronto-parallel plane was vividly reduced, but not completely disappeared. These results suggest that a phenomenon of MAE spreading might be affected by depth discontinuity, and could be occurred after binocular information converges.

• Journal of the Korean institute of surface engineering
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• v.30 no.6
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• pp.382-390
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• 1997

Good appearance of insulation coating is required for non-oriented silicon steel sheets, The property is influenced by both the chemical composition of coating solution and the species of resin. The composition of inorganic-organic coating was studied to obtain good surface quality for non-oriented silicon steel. The greenish degree of coating surface depended on $Cr^{3+}$ content in the coating layer, which was satisfied when chromate content was more than 54.60 wt. %, in the coating solution. The homogeneous pattern and roughness of the coating surface depended on spreading property of the resin. Surface appearance of the coating could be improved by using resin with good spreading property at the chemical composition of chromate 59.00 wt.%.. resin 34.23wt.%, and etyhylene glycol 6.67 wt.% without colloidal sillica.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.182-187
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• 2022

This study aims to study non-rechargeable wrist-type smart bands for those vulnerable to the digital environment. The transition to the digital age means improving the efficiency of human life and the convenience of management. In the digital age, it can be a very convenient infrastructure for the digital generation, but otherwise, it can cause inconvenience. COVID-19 is spreading non-face-to-face culture. The reality is that the vulnerable are complaining of discomfort in non-face-to-face culture. The core of the digital environment is smartphones. Digital life is spreading around smartphones. Technology that drives the digital environment is the core technology of the Fourth Industrial Revolution. The technologies are lot, big data, Blockchain, Smart Mobility, and AI. Related technologies based on these technologies include digital ID cards, digital keys, and nfc technologies. Non-rechargeable wrist-type smart bands based on related technologies can be conceptualized. Through these technologies, blind people can easily access books and manage their ID cards conveniently and efficiently. In particular, access authentication is required wherever you go due to COVID-19, which can be used as a useful tool for the elderly who feel uncomfortable using smartphones. It can also eliminate the inconvenience of the elderly finding or losing their keys.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.513-518
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• 2010

In the present work the second-order perturbation solutions of the simple physical model for liquid pool spreading is obtained for the case of instantaneous spill. To generalize the solution governing equations are non-dimensionalized, and two dimensionless parameters, dimensionless evaporation rate and aspect ratio of the initial pool, are identified to control the governing equations. The dimensional governing equations have three parameters. The second-order solution improves fairly the first-order solution for the pool volume.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.628-632
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• 2001

We propose time-frequency (TF) tools for analyzing linear time-varying (LTV) systems and nonstationary random processes. Obtained warping the narrowband Weyl symbol (WS) and spreading function (SF), the new TF tools are useful for analyzing LTV systems and random processes characterized by generalized frequency shifts, This new Weyl symbol (WS) is useful in wideband signal analysis. We also propose WS an tools for analyzing systems which produce dispersive frequency shifts on the signal. We obtain these generalized, frequency-shift covariant WS by warping conventional, narrowband WS. Using the new, generalized WS, we provide a formulation for the Weyl correspondence for linear systems with instantaneous of linear signal transformation as weighted superpositions of non-linear frequency shifts on the signal. Application examples in signal and detection demonstrate the advantages of our new results.

• Journal of the Korean Society of Visualization
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• v.11 no.3
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• pp.12-16
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• 2013

The impact and spreading behaviors of silicon dioxide nanoparticle colloidal suspension droplets were quantitatively visualized using a high-speed imaging system. Millimeter-scale droplets were generated by a syringe pump and a needle. Droplets of different velocity were impacted on a non-porous solid surface. Images were consecutively recorded using a CMOS high-speed camera at 5000 fps (frames per second) for millimeter-scale droplets. Temporal variations of droplet diameter, velocity and maximum spreading diameters were evaluated from the sequential images captured for each experimental condition. Effects of Reynolds number, Weber number, and particle concentration were investigated experimentally.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.638-643
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• 2013

Chaos communication system has a sensitive characteristic to initial conditions, because completely another signal is generated when initial condition of chaos equation is changed subtly. Also, chaos communication systems have the characteristics of non-periodic, non-predictability, the broadband signal, such as ease of implementation. Due to these characteristics, security of chaos communication system generally is evaluated better than other systems. However, BER(Bit Error Rate) performance is evaluated worse than other digital system, because existing chaos communication system's transmitter and receiver are strong influence by interference signal and noise. So, research to improve the BER performance of the chaotic communication system is performed continuously. In this paper, We will propose a new CDSK(Correlation Delay Shift Keying) receiver for BER performance improvement. After we compare to the performance of existing CDSK receiver and proposed CDSK receiver, BER performance of proposed CDSK receiver evaluate. Also, when using the new CDSK receiver, we evaluate the BER performance according to the spreading factors and find an optimum spreading factor. If chaos communication system use a new CDSK receiver, BER performance is improved than existing CDSK receiver. Also, if spreading factor's value is increased, BER performance is improved, because it is not nearly affected by interference signal and noise.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.511-517
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• 1998

In this paper a new technique to generate spreading code sequences in the CDMA communication is introduced. It is an effective method to generate optimal code sequences using the orthogonality of wavelet packet basis set of subspaces. With a three-stage Quadrature Mirror Filter(QMF), generation of optimal code sequences has been demonstrated. Since these generated optimal code sequences are non-binary and have an arbitrary waveform which is different from that of the conventional PN-based Gold code sequences, a strong security against the intended interceptor is feasible. Encouraging good correlation properties are also achieved with this new method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1686-1692
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• 2012

Spreading sequence play an important role in wireless communications, such as in a CDMA(code division multiple access) communication system and multi-carrier spectrum communication system. Spreading sequences with low cross-correlation, in a direct-sequence spread spectrum communication system, help to minimize multiple access interference and to increase security degree of system. Analysis of cross-correlations between the sequences is a necessary process to design sequences. However it require lots of computing time for analysis of cross-correlations between sequences. In this paper we propose a method which is possible to compute effectively cross-correlation using subfield in the process of practical computation of cross-correlation between nonlinear binary sequences.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.1015-1025
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• 2010

In this present study, we experimentally investigated the effects of electric fields on the characteristics of flames spreading over electric-wires with AC fields. The dependence of the rate at which a flame spreads over polyethylene-insulated wires on the frequency and amplitude of the applied AC electric field was examined. The spreading of the flame can be categorized into linear spreading and non-linearly accelerated spreading of flame. This categorization is based on the axial distribution of the field strength of the applied electric field. The rate at which the flame spreads is highly dependent on the inclined direction of the wire fire. It could be possible to explain the spreading of the flame on the basis of thermal balance.