• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.6
• /
• pp.344-353
• /
• 2006

In this paper, we present a new algorithm which imitate real pencil strokes. The purpose of research on NPR(Non-Photorealistic Rendering) is simulating automatically manmade artistic expressions such as pen-and-ink illustrations, watercolor paintings, pencil sketches and pastel drawings with computers. Recently, there has been a great deal of research works on NPR. One of them is researching in pencil illustration methods for NPR, and a lot of researchers have investigated into the LIC(Linear Integral Convolution) techniques which would change the initial images into the output images by directional vector field images for generating effects of pencil. However, the LIC techniques can not be applied to real-time drawing tools because they are post processing techniques. This paper presents a real-time pencil strokes algorithm which is based on an observation of how pencils(from 6B to 6H) draw lines. Although this algorithm using some pencil variables and noise generation is simple, it is fast and also can draw real-time pencil strokes similar to real manmade pencil strokes in a GUI drawing tool.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.8 no.1
• /
• pp.77-85
• /
• 1988

A stochchastic analysis procedure of generating floor response spectra for proportionally damped linear systems subject to earthquake loading is presented. Theories of random vibration and mode acceleration method are used in the formulation of governing equations. The structure-oscillator interaction is not considered. It is assumed that the input motions and oscillator responses are stationary Gaussian processes with mean zero. The nonstationary characteristics of earthquake motion are incorporated in the peak factor which is based on Vanmarcke's theory. Floor response spectra for both resonance and non-resonance cases are calculated under the assumption that the peak factors for structure and oscillator are equal to that for ground response spectrum. The validity of this method is demonstrated by comparing the results obtained by proposed method with those by time history analyses. The results obtained by this method are conservative and accurate with tolerable precision. This method saves much computing time compared with time history analysis method.

• Journal of Advanced Navigation Technology
• /
• v.13 no.5
• /
• pp.669-676
• /
• 2009

HTTP or audio/video streaming services are good candidates for future centralized navigation system and in order to provide stability for such services, service providers use a cluster of web servers. In this paper, we provide the criteria for web server cluster design of vehicular users with consideration of differentiated access per different user classes. Several feasible scenarios are examined and their performance analysis using queueing theory is presented to provide the foundation for web server cluster design using traffic load balancer. Through the thorough analysis, efficient criteria for traffic load balancer design is derived. In order to satisfy users' service requirements, priority services controlled by traffic load balancer are considered and analyzed. We also provide the evaluation of the accuracy of the analytical model through simulation.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.11 no.2
• /
• pp.5-11
• /
• 1974

Theoretical analysis is carried out for the beat frequency generation phenomena in the IMPATT diodes an4 the experimental studies are given in parrallel. The theory is based on the space charge modulation effect introduced to the multiplication process by the input signal. Computed results show that the beat frequency output power is linearly dependent upon the signal power and self oscillating power. Also the strong dependence of the output power with respect to the diode negative resistance is found and it turns out that the larger the negative resistance, the stronger the beat frequency output power. Experimental results show a good agreement with the theoretical values. Calculated conversion gain is about -0.4[db] at 10[GHz] and the experimental value shows -6.2[db] below this value. This difference between the theoretical and the experimental values is considered to be the results of the ineffective injection of signal power.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.3
• /
• pp.105-112
• /
• 2002

Increases in excess pore water pressure without change of surcharge load were reported in clay underneath embankment at Berthierville and Olga sites after the end of construction. These abnormal phenomena could not be explained by classical consolidation theory. This paper presents a nonlinear viscoplastic model to interpret an increase in pore water pressure on natural clay, The proposed model can consider the combined processes of pore water pressure dissipation according to Darcy's law and pore water pressure generation due to viscoplastic strain, as well as time-dependent viscoplastic behaviour and strain rate dependency of preconsolidation pressure. The calculated results using numerical analysis are compared with measured ones under embankments built on soft clay at Berthierville and Olga in Quebec, Canada. It may be possible to explain the phenomenon of excess pore water pressure increase after the end of construction using the proposed nonlinear viscoplastic model.

• The Journal of the Acoustical Society of Korea
• /
• v.24 no.8
• /
• pp.431-440
• /
• 2005

The precise measurement of ultrasonic power is important to the qualify assurance and the safety of medical ultrasonic equipments In the Present work, a brier theory was introduced to determine the ultrasonic Power from the time valving balance-indication due to the radiation force acting on an absorbing target and/or other causes such as buoyancy during the repetition of on/off behavior of ultrasonic irradiation. The developed automated system measuring the ultrasonic power was described in detail with the precise mechanical alignment tool , the electric signal generation network, the control and measurement network and the appropriate procedure. The ultrasonic power measured by the developed system was compared to the reference data calibrated by the other national metrology institute at 1 MHz, 5 MHz, 10 MHz, and 15 MHz over the range 10 mW to 10 W. Their relative differences are within $5\%$.

• The Korean Journal of Archival Studies
• /
• no.24
• /
• pp.41-71
• /
• 2010

Reappraisal is a process to examine the past appraisal decision. The reappraisal theory is based on two facts: first, appraisal decision can not be always correct, second, the archival value is changed by time. So, reappraisal policy should complement the limit of the first appraisal results, which is based on the function analysis. To achieve this goal, it is needed to use different process and methods from the first appraisal. However, existing reappraisal system does not meet the essential purpose of reappraisal. This article examined the limit of the reappraisal policy. To complement the problems, this article set a direction and suggested the subject-based reappraisal. The aim of this study is to present the methods to document the society of the generation.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.34 no.4
• /
• pp.93-99
• /
• 2022

Analytical solutions for regular waves generated by bottom wave makers in a 3-dimensional wave basin were derived in this study. Bottom wave makers which have triangular, rectangular and combination of two shapes were adopted. The 3-dimensional velocity potential was derived based on the linear wave theory with the bottom moving boundary condition, kinematic and dynamic free surface boundary conditions in a wave basin. Then, analytical solutions of 3-dimensional particle velocities and free surface displacement were derived from the velocity potential. The solutions showed physically valid results for regular waves generated by bottom wave makers in a wave basin. The analytical solution for obliquely propagating wave generation from bottom wave maker which works like a snake was also derived. Numerical results of the solution agree well with theoretically predicted results.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.11a
• /
• pp.232-234
• /
• 2006

Main purpose of producing animation is to entertain children, however, it is create for adult as an art form. For commercial animation focus on young generation rather than art animation, to make consume all over the world. To extend usability, animation company divert from child only contents to family animation, Especially, not even Disney animation company but many animation productions changed their policy and more stressed on that recently. It, however, can not be detected any research on this subject, So this study can proved a basic theory of defining term of family animation and contents with to overcome the limitation of viewers range as consumers. Firstly, it is investigated the family animation in domestic and overseas, secondly will be clarified the target for animation and compare to market for other country, it also be a basic analysis of understanding a family animation in the ways of producing and merchandising as goods.

• The Journal of the Acoustical Society of Korea
• /
• v.32 no.2
• /
• pp.116-123
• /
• 2013

This paper represents generation of time-varying underwater acoustic channels by performing scattering simulation with time-varying ocean surface and Kirchhoff approximation. In order to estimate the time-varying ocean surface, 1D Pierson-Moskowitz ocean power spectrum and Gaussian correlation function were used. The computed scattering coefficients are applied to the amplitudes of each impulse of BELLHOP simulation result. The scattering coefficients are then compared with measured doppler spectral density of signal components which were scattered from ocean surface and the correlation time used in the Gaussian correlation function was estimated by the comparison. Finally, bit-error-rate and channel correlation simulations were performed with the generated time-varying channel based on passive time-reversal communication scenario.