• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.135.1-135.1
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• 2014

Silicon nanoparticles can be synthesized in a standard radio-frequency glow discharge system at low temperature (${\sim}200^{\circ}C$). Plasma synthesis of silicon nanoparticles, initially a side effect of powder formation, has become over the years an exciting field of research which has opened the way to new opportunities in the field of materials deposition and their application to optoelectronic devices. Hydrogenated polymorphous silicon (pm-Si:H) has a peculiar microstructure, namely a small volume fraction of plasma synthesized silicon nanoparticles embedded in an amorphous matrix, which originates from the unique deposition mechanism. Detailed discussion on plasma synthesis of silicon nanoparticles, growth mechanism and photovoltaic application of pm-Si:H will be presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.362-370
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• 1996

Even if the shock absorber is developed to Variable S/A or Active S/A, it is necessary to construct data-base or build the dynamic performance characteristic program of Oil S/A. Since both Variable S/A and Active S/A are based on the principle of Oil S/A. To obtain the design technique of Oil S/A, we model the damping mechanism and characteristics of an Oil S/A whose performance was testified. And then it is analyzed the dynamic behaviour characteristics of damping mechanism.

• Tribology and Lubricants
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• v.12 no.2
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• pp.20-31
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• 1996

Pressures in compression pockets consists of two identical spiral scrolls are influenced by gas flow resistance in discharge process and leakages in radial and tangential directions between two scroll wraps. In this paper, considering geometrical characteristics of these members, flow resistance and refrigerant gas leakage losses, pressure variations in compression pockets are calculated. For a scroll compressor model with fixed crank mechanism, acting load on crankshaft is analyzed. And, for a vertical type crankshaft-journal bearing system used in scroll compressor, nonlinear transient response is calculated including nonlinear fluid film reaction forces of journal bearings.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.9
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• pp.956-963
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• 1990

The general shapes of prebreakdown pulses in a discharge gap were calculated and the current pulses due to avalanche were detected in SF6 by changing the polarity of the protrusion placed on an electrode at pressures up to about 400 Kpa. The mathematical model of prebreakdown pulse development with a negative protrusion shows agreement with the observed pulses. No evidence of intense bursts of field-emitted electrons was observed. Breakdown probably results from a single avalanche developing to a critical size. However the calculated shape of prebreakdown current pulse does not agree with the observed pulses with a positive protrusion. The breakdown is preceded by multiple avalanche development at pressures less than about 200 Kpa. This observation has been interpreted as due to the formation of negative ions following photoionization in the gas which drift into the critical volume near a positive protrusion.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.877-878
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• 2006

The sintered parts are mainly used for automobile industry, and a part of air conditioners. In automobile industry, the application range of sintered parts is very broad and use for a driving and a lubricating system. And air conditioner uses them for compressor. Grinding of compressor and pump parts is very difficult these days, because these parts use High hardness materials and require high precision grinding. Tool life has to be extended to decrease production cost. We analyzed processing mechanism and developed new grinding wheels for Double Disk Grinding. And, we introduce new truing technology that improved tool-life and precision.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.28-36
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• 1997

Even if the shock absorber is developed to Variable S/V or Active S/A, it is necrssary to construct database or bulid the dynamic performance characteristic program of Oil S/A. Since both Variable S/A and Active S/A are based on the principle of Oil S/A. To obtain the design technique of Oil S/A, we model the daping mechanism and characteristics of an Oil S/A whose performance was testified. And then it is analyzed the dynamic behaviour characteristics of damping mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.65-72
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• 2020

A refrigerator equipped with an ice dispenser has ice cubes in its ice bucket to discharge the required amount of ice. On the other hand, the ice cubes in the bucket may clump together if the refrigerator is filled with ice and is not used for a long time or during normal operation. Although a mechanism for separating the ice mass is provided, the ice mass cannot be removed completely if the ice blocking is severe. To solve this problem, after investigating the existing research on the process of ice entanglement and the separation force, this study tested ice extraction under a range of conditions of artificially entangled ices. In this process, new mechanisms are proposed to resolve the problem of existing ice storage features that prevent the extraction of ice and to expand the working radius of the icebreaking mechanism for full extraction. The prototype of the proposed mechanism was also fabricated in an actual refrigerator. As a result, the proposed shape and mechanism could extract the ice cubes in the bucket completely, while the existing ice dispenser could extract only 65%.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.384-390
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• 2001

The hollow cathode discharge is a kind of plasma formation scheme in which plasma is formed inside a hollow structure, the cathode, with current to a nearby anode of arbitrary shape. In this scheme, electrons reflex radially within the hollow cathode, establishing an efficient ionization mechanism for gas within the cavity. An existence condition for the hollow cathode effect is that the electron mean-free-path for ionization is of the order of the cavity radius. Thus the size of this kind of plasma source must decrease as the gas pressure is increased. In fact, the hollow cathode effect can occur even at atmospheric pressure for cathode diameters of order 10-100 $\mu\textrm{m}$. That is, the "natural" operating pressure regime for a "micro hollow cathode discharge" is atmospheric pressure. This kind of plasma source has been the subject of increasing research activity in recent years. A number of geometric variants have been explored, and operational requirements and typical plasma parameters have been determined. Large arrays of individual tiny sources can be used to form large-area, atmospheric-pressure plasma sources. The simplicity of the method and the capability of operation without the need for the usual vacuum system and its associated limitations, provide a highly attractive option for new approaches to many different kinds of plasma applications, including plasma surface modification technologies. Here we review the background work that has been carried out in this new research field.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.295-301
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• 2017

$SF_6$ decomposition products can be used to detect partial discharge (PD), but the metal materials in a PD area can significantly affect $SF_6$ decomposition characteristics. Disregarding the effect of metal materials on such characteristics inevitably result in certain errors when using them to diagnose the internal insulation faults of gas-insulated switchgears. This paper investigates the influence regularity on the main stable decomposition components of $SF_6$ (namely $SO_2F_2$ and $SOF_2$) of the commonly metal materials uesd in GIS, such as aluminum (Al), copper (Cu) and stainless steel (SS). Firstly, an experimental platform is constructed to simulate $SF_6$ decomposition under a PD area, and the influence regularities of Al, Cu and SS on the concentration, formation rate and saturation time of $SO_2F_2$ and $SOF_2$ are obtained. Secondly, the influence mechanism of Al, Cu and SS are preliminary explored combined with the chemical activity of the metal materials.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.167-174
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• 2010

In this paper, the ultraviolet rays images and aging judgement caused by surface contamination on 22.9[kV] class insulators was defined. UV images represented by the corona discharge are divided 3 types such as sunflower, jellyfish, amoeba and in detail, there are classified the progress mechanism of eight. In the field which is installed the power facilities, immediately, this judgement method can be found out the deteriorated parts of the power facilities. These steps are possible to judge the deterioration of power facilities through reliable data. Hereafter, this study as the diagnostic technology suitable for the sites is used.