• 소음진동
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• 제11권2호
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• pp.329-335
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• 2001

The analytical model of the ground wave can be used for the prediction of the noise level from a source above a plain and homogeneous ground surface with no obstacles nearby. Sound propagation along the surface of the ground can be affected by the roughness of the ground surface and the direction of the wind. The effects of the ground surface and the wind can be formulated in terms of the ground coefficient and the noise source parameter. Upward and downward conditions can also be addressed by considering the direction of the wind. The ground coefficient and the noise source parameter are estimated using the measured noise levels of two points under particular environmental condition, and the noise levels of arbitrary points under the same environmental condition can be estimated. The proposed method can be utilized to estimate the noise level of specific noise environment and its validity was confirmed with the results of actual field measurement.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1014-1019
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• 2009

The optimal control system for heat source and HVAC system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters are supply air temperature and chilled or hot water temperatures. The optimal control study has been implemented for biosafety laboratory by using TRNSYS simulation program in order to investigate energy performance for heat source and HVAC system.

• Journal of information and communication convergence engineering
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• 제18권1호
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• pp.22-27
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• 2020

Content centric networking (CCN) is regarded as promising internet architecture because it can provide network efficiency in terms of bandwidth consumption by separating contents from a specific network location and decrease network congestion events. However, the application of a CCN does not widely consider the side effects of mobile devices, particularly mobile content sources. For content source mobility, a full routing update is required. Therefore, in this study, a route optimization scheme is proposed for mobile content sources in a CCN environment to provide low communication overhead, short download time, and low resource consumption. The proposed scheme establishes a direct path between content requesters and a mobile content source for the exchange of interest and data packets using interest-piggybacked data packets. Based on the inherent CCN naming characteristics, the content source does not know the name prefix of the content consumer, and thus the proposed optimized CCN scheme utilizes the content router in the home domain of the content source.

• 가정과삶의질연구
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• 제15권4호
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• pp.27-40
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• 1997

The purpose of this study was to investigate adolescents' maladjustment in terms of type and source of social support. The main results of this study were as follows; 1. In social support source the mean score of peer support was higher than family support. In social support type the mean score of expressive support was higher than other support type. 2. Social support source was found significantly different according to sex of the children educational level of the father and mother. Malajustment were found significantly different according to sex of the children educational level of the father and mother income and marital satisfaction of the mother. 3. In social support source it was significantly different according to all maladjustment subscale in family support and to over-anxiousness social withdrawal and hyperactivity in peer support. In social support type it was significantly different according to over-anxiousness and social withdrawal in expressive support to socia withdrawal over-anxiousness hyperactivity and delinquency in esteem support and to over-anxiounsness in informational support.

• Journal of Electrical Engineering and information Science
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• 제1권1호
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• pp.91-97
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• 1996

This paper proves by straightforward computation an interesting property of a recursive indexing: it preserves the entropy of a geometrically-distributes stationary memoryless source. This result is a pleasant surprise because the recursive indexing though one-to-one, is a symbol-to-string mapping and the entropy is measured in terms of the source symbols. This preservation of the entropy implies that the minimum average number of bits needed to represent a geometric memoryless source by the recursive indexing followed by a good binary encoder of a finite imput alphabet remains the same as that by a good encoder of an infinite input alphabet. Therefore, the recursive indexing theoretically keeps coding optimality intact. For this reason recursive indexing can provide an interface for a binary code with a finite code book that performs reasonably well for a source with an infinite alphabet.

• 천문학회지
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• 제17권1호
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• pp.15-22
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• 1984

The transverse velocities of the gravitational lens system (galaxy plus a 'disturbing star') and their dependences on unkown properties of the source and the deflecting object are discussed. We have derived an analytic expression for the transverse velocity in terms of the velocities of the light source, the gravitational lensing galaxy and the 'disturbing star', and the observer. The results are then further applied to an estimate of the expectation value of the absolute transverse velocity and of the probable time scales of flux changes of the double QSO 0957+561A, B.

• 한국수학사학회지
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• 제15권3호
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• pp.83-93
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• 2002

We investigate a history of reseahches of a nonlinear elliptic equation with jumping nonlinearity, under Dirichlet boundary condition. The investigation will be focussed on the researches by topological methods. We also add recent researches, relations between multiplicity of solutions and source terms of tile equation when the nonlinearity crosses two eigenvalues and the source term is generated by three eigenfunctions.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.272-275
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• 2003

A mixed analytical/numerical method is developed here to solve the low Reynolds number kepsilon turbulence model. In this method the advection-diffusion part is solved numerically, while the source terms are split into two parts: one part is solved analytically and the next is solved numerically.

• 대한전자공학회논문지
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• 제23권2호
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• pp.131-148
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• 1986

A field ploblem of a grounded dielectric slab covered by a conducting plane with periodecally spaced arbitrary number of slots excited by an aperiodis source is analyzed. The problem is formulated in terms of simultaneous integral equations for unknown electric fields at each slot. A sampling technique is introduced to reduce the system equations to a matrix equation equation involving Green's function matrix. The solution obtained in the form of infinite series is transformed, into a more rapidly convergent one in its final stage. Theoretical results agree closesly with the experimental results.

• 한국해양공학회지
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• 제14권2호
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• pp.53-59
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• 2000

A numerical method to predict responses of very large floating structures in wave is suggested using source-dipole distribution method. The deflection of the plate is calculated by the finite element method in terms of rigidity matrix of each node. The calculated results for a plate are compared with the experimental ones.