• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.52-56
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• 2004

The movement of electron in the semiconductor-gap-semiconductor was observed by the variation of V-I characteristic as a distance two ZnO(1010) single crystals. When the resistance between two crystals was $10^2{\sim}10^4{\Omega}$, V-I characteristics had the pattern of the field emission or ohmic contact. On the other hand, when the resistance was larger than $10^7{\Omega}$ by increasing the distance between two crystals, the effect of surface barrier was prominent. This result leads to the conclusion that both the field emission (or ohmic contact) and the surface barrier effect including the tunneling have the influence on V-I characteristics of mechanically contacted crystals.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.127-130
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• 2015

The objective of this study is to investigate the real flame shape and characteristic of annular combustor. To identify the effects of combustor length ratio and equivalence ratio on the flame shape in annular combustion configuration, the employed parameters are combustor length ratio 0.6-1.0, equivalence ratio 0.7-1.1. The flame shape is visualized using DSLR camera and precision optic mirror. The flame intensity is analyzed by $OH^{*}$ chemiluminescence images with ICCD camera. CO and NOx emission performance is also examined using an exhaust gas analyzer. From the visualized images, it is confirmed that the different tendency appeared in combustor length ratio 0.6-0.7 and 0.8-1.0. The results of $OH^{*}$ chemiluminescence show that the flame intensity is the most uniform for equivalence ratio 0.9. The smaller equivalence ratio is, the less emission of CO and NOx will be in this investigation range.

• Journal of the Korean Society of Safety
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• 제19권1호
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• pp.31-37
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• 2004

The mechanical strength and crack propagation of plain woven carbon fiber fabric laminate composites are examined by acoustic emission(AE). AE signals are measured during the tensile test and fracture tests. Thus, the relationship between AE signal and load-displacement curves and crack extension length are shown. Also the fracture mechanisms in terms of AE characteristics are discussed in viewpoint of crack propagation behavior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.76-79
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• 2003

The characteristic of single wall carbon nanotube (SW-CNT) and herringbone nano fiber (HB-CNF) emitters was described. SW-CNT synthesized by arc discharge and HB-CNF prepared by thermal CVD were mixed with binders and conductive materials, and then were formed by screen-printing process. In order to obtain efficient field emissions, the surface treatment of rubbing & peel-off was applied to the printed CNT and CNF emitters. The basic structure of FED was of a diode type through fully vacuum packaging. Also, we proposed a new triode type of field emitter using a mesh gate plate having tapered holes and could achieve the ideal triode properties with no gate leakage currents.

• Proceedings of the KIEE Conference
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.212-215
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• 1995

In this paper, The characteristic of Harmonic spectrum is studied for generally used three-phase diode rectifier. and filter design criteria is showen in the sense of THD, DPF, and PF. As the becoming of Automative and informative era, the demand of critical and stable control becomes more and more important. But much EMI emissions are generated for more critical and stable control in power electronic system these EMI emissions can be measured using LISN(Line Impedance Stabilization Network). So we are to investigate the behavior of Conducted EMI emission in Diode Rectifiers using LISN in frequency domain.

• Journal of Radiation Industry
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• 제8권1호
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• pp.59-63
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• 2014

Proton Induced X-ray Emission (PIXE) is a MeV ion beam analysis method for use with particle accelerators. PIXE uses low-energy charged particles as an excitation mechanism to generate characteristic x-ray emission from each element in a target. In PIXE analysis, the beam current used is from a few nA to several tens of nA. Chosun University (Cyclotron Research Center) designed a $50{\mu}A$ beam line from the 13 MeV cyclotron for use with a PIXE analysis system, as well as performing beam transport line optimization research. In this study, the beam line operation conditions for the optimization process of beam transport and beam characteristics are shown.

• Journal of the Korea Safety Management & Science
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• 제18권4호
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• pp.39-46
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• 2016

In this paper, the relationship between energy consumption in the logistics industry and economic growth of Tumen River region from 1995 to 2014 is empirically analyzed by using the EKC model theory. The results show that there is a turning point in the Kuznets curve of carbon emission in TumenRiverregion. And it has the characteristic sof "invertedU" curve, which conforms to the environmental Kuznets curve hypothesis. Meanwhile it is stil lintherisingstage. According to the analysis results, it is proposed to set up the concept of low carbon logistics, optimize the energy structure, strengthen the information construction, and establish low-carbon development mechanism and so on.

• Special Issue of the Society of Naval Architects of Korea
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• 대한조선학회 2015년도 특별논문집
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• pp.9-13
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• 2015

While environmental concern is urging shipbuilding industry to reduce pollutant emission, it is necessary to design environmental friendly vessels. LNG as fuel for ship propulsion is proven to be effective way to reduce pollutant emission. In this study, we find optimum position of LNG fuel supply system on AHTS by considering vessel characteristic. Three different positions of fuel supply system are studied in this paper. Factors such as stability, strength and safety are examined in each position of fuel supply system.

• Journal of The Korean Astronomical Society
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• 제56권1호
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• pp.41-57
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• 2023

We measured temporal and emission properties of quiescent magnetars using archival Chandra and XMM-Newton data, produced a list of the properties for 17 magnetars, and revisited previously suggested correlations between the properties. Our studies carried out with a larger sample, better spectral characterizations, and more thorough analyses not only confirmed previously-suggested correlations but also found new ones. The observed correlations differ from those seen in other neutron-star populations but generally accord with magnetar models. Specifically, the trends of the intriguing correlations of blackbody luminosity (L_BB) with the spin-inferred dipole magnetic field strength (B_S) and characteristic age (τ_c) were measured to be L_BB ∝ B^1.5_S and L_BB ∝ τ^-0.6_c, supporting the twisted magnetosphere and magnetothermal evolution models for magnetars. We report the analysis results and discuss our findings in the context of magnetar models.

• Journal of the Korean Institute of Gas
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• 제26권6호
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• pp.45-51
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• 2022

Technologies for collecting and treating pollutants from point sources are steadily being developed, but Non-point sources, it is difficult to develop emission treatment technologies and effective emission coefficients. However, since non-point sources make up about 60% of domestic emissions, and first of all, the method of calculating emissions should be reasonable, and the workplace should develop emission reduction technologies based on this. This study suggest the effectiveness and improvement of the emission coefficient currently used for the petrochemical industry with high emissions. The emission characteristics of non-point sources emission were confirmed by analyzing the LDAR (Leak Detection And Repair) data of OO company located in Yeosu, Jeollanam-do over the past five years. As a result, there was no difference in discharge characteristics according to fluid phase, but it was confirmed that there was a difference in the size of the device and the characteristics of each manufacturer. In addition, it was confirmed that the emission coefficient applied in the petrochemical industry was larger than that of the refining industry, and improvement measures were suggested. Through these studies, it is expected that emission coefficients specialized in the petrochemical industry can be applied and that the workplace itself will contribute to the development of technologies that can drastically reduce them.