• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2047-2050
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• 1999

This paper presents some of the results of current research on 300 kN Suspension Insulator Design. In this paper, authors first used 2-dimensional field calculation to solve the electric field distribution of an insulator unit and insulator strings, and then 3-dimensional field calculation in order to overcome the shortcomings of 2-dimensional field calculation in which an axis-symmetrical coordinate has been used. And, it was found that the environmental configuration of 300 kN Suspension Insulator String gives great roles to the field distribution of the insulators.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.34-40
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• 2004

This paper presents an analysis of SAR(Specific Absorption Rate) distribution characteristics in a head model using FDTD(Finite Difference Time Domain). In this study human head was modelled in four elements-layered structure, consisting of skin, fat, skull and brain. To calculate the electromagnetic fields wihtin the head model, FDTD method was used. In the FDTD method, the electromagnetic wave is analyzed by solving a Maxwell's equations repeatedly. For the calculation, distance between power source and head model increased by 10[m]. Power density and incident electric field intensity were calculated. Based on the incident electric field, the program which calaculated internal electric fields intensity and SAR calculation of the head model were developed. The results of developed program using FDTD were compared with those of a commericial programs, which showed the availability and usefulness of the suggested scheme in this paper.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.5
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• pp.199-204
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• 1986

The breakdown phenomena of N2 gas by 13.56MHz electric field are very different from those under steady field. In this paper we analyzed the breakdown phenomena by using electron distribution function and diffusion equation. The second-order differential equation derived from the Boltzmann equation is solved for the electron distribution function. The ionization rate and diffusion coefficient are calculated using kinetic theory formulas. The breakdown condition is that the number of electrons produced by ionization equal the number diffusing to the walls of the discharge chamber. Theses theoretical breakdown electric fields are calculated by the computer and compared with the experimental values.

• Computers and Concrete
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• v.14 no.3
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• pp.263-277
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• 2014

This study investigated four electric field configurations of two-dimensional accelerate lithium migration technique (ALMT), including line-to-line, plane-to-line, contour-to-line and plane-to-plane, and analyzed the ion migration behavior and efficiency. It was found that the free ion distribution diagram and voltage distribution diagram were similar, and ions migrated in the power line direction. The electrode modules were used for the mortar specimen with w/c ratio of 0.5. The effectively processed areas accounted for 14.1%, 39.0%, 49.4% and 51.4% of total area respectively on Day 28. Larger electrode area was more advantageous to ion migration. In addition, it was proved that the two-dimensional electric field could be divided into different equifield line active regions, and regarded as affected by one-dimensional electric field, and the ion migration results in various equifield line active regions were predicted by using the duration analysis method based on the theoretical model of ion migration obtained from one-dimensional test.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.155-158
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• 1988

The fabrication of devices using plans technology could lend to n serious degradation in the breakdown voltage as a result of high electric field at the edges. An elegant approach to reducing the electric field at the edge is by using field limiting ring. The presence of surface charge has n strong influrence on the depletion layer spreading at the surface region because this charge complements the charge due to the ionized acceptors inside the depletion layer. Surface charge of either polarity can lower the breakdown voltage because it affects the distribution of electric field st the edges. In this paper we discuss the influrences of fixed oxide charge on the breakdown voltage of the p+/n junction with field limiting ring(or without field limiting ring).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1119-1122
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric in water was simulated. The reactor was made up of the spherical dielectric that is diameter 2.5[mm], ${\epsilon}_r$ : 5, 100, 1000, 5000 respectively and one glass plate being 2[mm] thickness, ${\epsilon}_r$ : 5 as electrode. The discharge gap was 7[mm]. As a result of the simulation, in case of being about the same value between the dielectric constant of spherical dielectric and water, when the reactor was applied to high voltage dielectric polarization characteristic was trending toward disappearance. To get more strong electric field, the dielectric constant should be higher comparatively, Increasing the spherical dielectric constant, the location of equippotential line was shifting from the interior to the exterior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1143-1146
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• 2003

This paper was simulated the electric field distribution in dielectric tube with two layers and spherical dielectric in water. The reactor was made up of the spherical dielectric that is diameter : 2.5[mm], ${\epsilon}_r$ : 5, 25, 100, 1000, 5000 respectively and two glass plate being 2[mm] thickness, ${\epsilon}_r$ : 5 as electrode. The discharge gap was 9[mm]. As a result of the simulation, in case of being about the same value between the dielectric constant of spherical dielectric and water, when the reactor was applied to high voltage, dielectric polarization characteristic was trending toward disappearance. To get more strong electric field, the dielectric constant should be higher comparatively, Increasing the spherical dielectric constant, the location of equippotential line was shifting from the interior to the exterior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.44-47
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric($ZrO_2$) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], $ZrO_2(\varepsilon_r:10)$ and one glass plate of thickness(2[mm]), $\varepsilon_r$(10) as electrode. The discharge gap was 8[mm]. To get more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, ozone was measured higher dissolved ozone in water at condition of water rate(l[l/min]) and injector than condition of non-injector or 2~3[l/min].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.40-43
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric(glass) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], glass(${\varepsilon}_r$:5) and one glass plate of thickness(2[mm]), ${\varepsilon}_r$(5) as electrode. The discharge gap was 8[mm). Toget more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, $H_2O_2$ was measured higher generated $H_2O_2$ in water at condition of water rate(1[l/min]) and injector than condition of non-injector or 2-3[l/min])

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.1
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• pp.33-39
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• 1999

This study has been performed to develop an efficient electrocharged scrubber. To improve collection efficiency of the scrubber, electric-charger was installed at the forefront of the packed crossflow scrubbers, and an experiment of changing discharge electrode shape and fluctuating electric field strength was undertaken. After using a light-oil boiler for generation of particles in the about 80% weight of submicron size particles was exhausted. Collection characteristics of the electrocharged scrubber were similar to those of two-stage electrostatic precipitator. In this study the collection efficiency of submicron size particles has been much improved, compared with the previous ones. In an experiment of changing discharge electrode and electric field strength, a needle-spike shape wire electrode showed a higher collection efficiency than round shape wire. The collection efficiency becomes increased with an increase of electric field strength.