• 전기학회논문지
• /
• 제57권12호
• /
• pp.2249-2254
• /
• 2008

A non-thermal micron size plasma needle is applicable for medical treatment because it includes radicals, charged particles, ultraviolet emission, and strong electric fields. The electric fields around the plasma needle device driven by a radio frequency wave are investigated in order to calculate the power delivered to the cell. A commercial multi-physics code, CFD-ACE, was utilized for the calculation of electric fields for the optimization of the needle structure. The electric field and energy absorption profiles are presented with the variation of the device structure and the distance between the needle and tissues. The living tissues effectively absorb the radio frequency power from the plasma needle device with the covered pyrex structure.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권2호
• /
• pp.99-106
• /
• 2003

In this paper, an intelligent fault location and diagnosis system is proposed. The proposed system identifies the fault location in two-step procedure. The first step identifies candidates of fault location using an fault distance calculation using an iterative method. The second step is diagnosis the actual fault location in the candidates by comparing the current waveform patterns with the expected operation of the protective devices and considering the interrupted load after the operation protective device. The simulations results in the case study demonstrates a good performance of the proposed fault location and diagnosis system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 B
• /
• pp.1390-1392
• /
• 2000

In this paper, a numerical calculation method based on CSM has been described. The electric field must be nonuniform even close to railway feed system. In that case, to calculate induced voltage, this paper uses the mutual capacitances between a conductor and railway feed system. The induced voltages of a conductor located at point (height=4m, distance=8m) near by railway feed system are calculated from 370V to 668V.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.439-441
• /
• 2003

In this study the formula of electro magnetic fields under 3-phase power lines with vertical or horizontal line-configurations were deduced and the effect of the earth was considered in the formula. Using the formula the electric field and the magnetic flux density under distribution and transmission lines constucted currently in our country were calculated and the components of each field were investigated with horizontal distance from tower and height above the earth.

• Steel and Composite Structures
• /
• 제20권1호
• /
• pp.71-89
• /
• 2016

In steel and concrete composite girders, the load transfer between the steel beam and the concrete slab is commonly ensured by installing shear connectors. In this paper, to investigate the nonlinear behavior of perfobond connectors, a total of 60 push-out specimens were fabricated and tested with the variables for the hole diameter, the concrete strength, the thickness of concrete slab, the diameter, strength and existence of perforating rebar, the thickness, height and distance of perfobond ribs. The failure mode and the load-slip behavior of perfobond connectors were obtained. A theoretical model was put forward to express the load-slip relationship. Analytical formulas of shear capacity and peak slip were also proposed considering the interaction between the concrete dowel and the perforating rebar. The calculation results of the proposals agreed well with the experimental values.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 춘계학술대회 논문집
• /
• pp.431-436
• /
• 2002

Train driving should be satisfied to run fixed distance within given time, and it is desirable to minimize energy consumption. Minimizing energy consumption depends on the train operation modes by driver or automatic operation. In this article, an optimal operation to minimize energy consumption by changing modes of train operation by a driver is investigated. First, powering model, braking model and consumed energy calculation model are introduced by using Matlab software. The accuracy of the model established by simulation is compared with the real experimental data, which is obtained from an authorized institution. Second, several simulations under a variety of operations in the ideal track are executed, and then the optimal pattern of train driving is found.

• Geomechanics and Engineering
• /
• 제4권1호
• /
• pp.67-78
• /
• 2012

Soil foundations exhibit significant creeping deformation, which may result in excessive settlement and failure of superstructures. Based on the theory of viscoelasticity and fractional calculus, a fractional Kelvin-Voigt model is proposed to account for the time-dependent behavior of soil foundation under vertical line load. Analytical solution of settlements in the foundation was derived using Laplace transforms. The influence of the model parameters on the time-dependent settlement is studied through a parametric study. Results indicate that the settlement-time relationship can be accurately captured by varying values of the fractional order of differential operator and the coefficient of viscosity. In comparison with the classical Kelvin-Voigt model, the fractional model can provide a more accurate prediction of long-term settlements of soil foundation. The determination of influential distance also affects the calculation of settlements.

• Nuclear Engineering and Technology
• /
• 제49권4호
• /
• pp.801-809
• /
• 2017

The purpose of this study is to assess the additional neutron effective dose during passive scattering proton therapy. Monte Carlo code (Monte Carlo N-Particle 6) simulation was conducted based on a precise modeling of the National Cancer Center's proton therapy facility. A three-dimensional neutron effective dose profile of the interior of the treatment room was acquired via a computer simulation of the 217.8-MeV proton beam. Measurements were taken with a $^3He$ neutron detector to support the simulation results, which were lower than the simulation results by 16% on average. The secondary photon dose was about 0.8% of the neutron dose. The dominant neutron source was deduced based on flux calculation. The secondary neutron effective dose per proton absorbed dose ranged from $4.942{\pm}0.031mSv/Gy$ at the end of the field to $0.324{\pm}0.006mSv/Gy$ at 150 cm in axial distance.

• KIEAE Journal
• /
• 제9권1호
• /
• pp.61-68
• /
• 2009

In this study, computer simulation program was using to identify the effects of road traffic noise propagation depending on the road types which are very variable in dense city. To achieve this goal, the roads should adjacent to housing complex were categorized into 7 types and propagation noise level should predicted then after simulation of noise exposure population calculation are carried out. Followings the results. First, the road types producing the higher noise level are R1, R2, R3 and R7. The lowest one is R6. And R4, R5 showed that some amount of noise level reduction. Second. the R6 road type which is tunnel shaped showed the highest noise level reduction in vertical distance gap. Last, the order of noise exposure population ratio is R1>R2>R7 and R6 showed the lowest.

• 한국해양공학회지
• /
• 제8권2호
• /
• pp.124-130
• /
• 1994

This paper compared with the hydrodynamic interference acting on the semi-submersible element model with 1-lowerhull and 2-columns. In this case, calculation are applying the strip method and 3-dimensional source distribution method. As the wave frequency and the distance between increase, the influence effects of parts upon each other decrease and approach the results calculated by using the strip method. Thus, it can be prepared for the investigation of new practical method of investigation of new practical method of hydrodynamic forces acting on huge structures.