• 한국환경보건학회지
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• 제17권1호
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• pp.74-78
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• 1991

This study was performed to investigate the effect of heavy metals and CN on BOD$_{5}$ measurement. The results were as follows: 1. The BOD$_{5}$ value decreased 20% in Cd(CdCl$_{2}$) 3.0mg/l, Ni(NiCl$_{2}$) 7.0mg/l, Cu(CuCl$_{2}$) 0.5mg/l, Pb($Pb(NO_{3})_{2}$) 9.0mg/l, Cr($K_{2}Cr_{2}O_{7}$) 1.0mg/l respectively. 2. The BOD$_{5}$ value decreased 10% in Zn($Zn(NO_{3})_{2}$) 5 mg/l, Fe(FeCl$_{3}$) 20mg, /l, and 25% in CN(KCN) 5mg/l, and 40% in Hg(HgCl$_{2}$) 0.2rng/l. 3. In Comparion with BOD Rapid Analyzer, the above mentioned heavy metals concentrations have no effect on BOD$_{5}$ value of that analyzer except CN.

• 반도체디스플레이기술학회지
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• 제5권1호
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• pp.21-25
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• 2006

To improve the performance of organic thin film transistor, we investigated the properties of gate insulator's surface according to the leakage current by I-V measurement. The surface was treated by the dilute n-octadecyltrichlorosilane solution. The alkyl group of n-octadecyltrichlorosilane induced the electron tunneling and the electron tunneling current caused the breakdown at high electric field, consequently shifting the breakdown voltage. The 0.5% sample with an electron-rich group was found to have a large leakage current and a low barrier height because of the effect of an energy barrier lowered by, thermionic current, which is called the Schottky contact. The surface properties of the insulator were analyzed by I-V measurement using the effect of Poole-Frankel emission.

• Journal of Mechanical Science and Technology
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• 제19권10호
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• pp.1885-1890
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• 2005

The contour method relies on deformations that occur when a residually stressed component is cut along a plane. The method is based on the elastic superposition principle. When plasticity is involved in the relaxation process, stress error in the resulting measurement of residual stress would be caused. During the cutting the specimen is constrained at a location along the cut so that deformations are restrained as much as possible during cutting. With proper selection of the constraining location the plasticity effect can also be minimized. Typical patterns of longitudinal welding residual stress state were taken to assess the plasticity effect along with constraining locations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1234-1237
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• 2002

When measuring sound transmission loss (STL) in a laboratory, the specimen location in test aperture affects considerably the measuring accuracy through the influence of so-called “tunneling effect” In this paper, for a single panel and a double panel with air cavity, experimental STL evaluations on various specimen locations on test aperture were carried out to explain the phenomenon. It is shown that the difference of STL is more than 2dB especially at the low frequency region and the case of the center-located panel yielded the lower STL than that of flushing with the end of tunnel, which confirms that the tunneling effect plays an important role in STL measurement.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.208-213
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• 2011

In the former study, it is obtained that thermal storage effect of the apartment structure is the disadvantage to maintain comfort indoor thermal environment. However, because the thermal storage effect can be changed of its aspect in heating season, field measurement at the same apartment with the measurement in summer season was conducted in winter season. As results, thermal storage effect of apartment structure was the disadvantage in winter season, too.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.21-24
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• 2000

lnSb temperature dependent hall effect of multilayerd structures were investigated. According to variation of magnetic field measured hall coefficient, Hall mobility, carrier density and hall voltage. For the measurement of electrical properties of hall device, evaperated InSb thin film fabricated with series and parallel multilayers. We found that the XRD analysis of InSb thin film showed good properties at 20$0^{\circ}C$, 60 minutes. Resistance of ohmic contact increased linearly due to increasing current. Some of device fabrication technique and analysis of Hall effect were discussed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권6호
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• pp.240-245
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• 2002

In this paper, a novel optical measuring system for the measurement of nonuniform electric field was proposed. The electric field distorted by the discharges was detected through proposed optical measuring system based on the Pockets effect and Mach-Zehnder interferometer. In order to produce distorted electric field, corona discharge was generated from needle-plane electrode in air and detected by optical measuring system. This optical measuring system is constructed by He-Ne laser, single mode optical fiber, $2{\times}2$ 50/50 beam splitter, $LiNbO_3$ Pockets cell, photo detector and PC. In this system, output signal of Pockels sensor is measured by digital oscilloscope and transferred to the PC for recording and statistical processing. Through this paper, a promising possibilities of proto-type optical measuring system were evinced.

• 한국안전학회지
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• 제19권1호
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• pp.77-80
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• 2004

The purpose of this study was to examine effects of combustion retardation for paper filter impregnated metal salts by measurement of extinguishing concentration, CO concentration, and limiting oxygen index(LOI, ASTM D 2863). And thermal stability analysis using DSC was carried out. In case of extinguishing concentration, $NH_4H_2PO_4$ showed excellent effect of combustion retardation. The result of LOI measurement showed that metal salts possessed good effect of combustion retardation. And thermal analysis using DSC showed that these metal salts possessed thermal stability. In case of CO concentration, CO concentration was increasing because of imperfect combustion process due to combustion retardation effect of metal salts.

• Journal of Welding and Joining
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• 제20권1호
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• pp.69-75
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• 2002

This study investigated the effect of the system parameters on penetration depth measurement using infrared temperature sensing system. The distance from focusing lens to detector was varied to diminish the error in measuring weld bead width. The effect of bead surface shape on measured surface temperature profile was evaluated using specimen heated by electric resistance. The measuring distance from laser beam was changed to optimize the measuring point. The results indicated that the monitoring device of surface temperature using infrared detector array was applicable to real time penetration depth control.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.726-730
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• 2000

In this article, the scattering effect around a microphone is studied by using boundary element method, because it is hard to find the scattering experimentally. The scattering problem is defined by impinging an obstacle, i.e. a solid cylinder, with an incident plane wave. From this analysis, the scattering is numerically calculated by varying the microphone shape, the incident angle and the distance between microphones. It is found that the scattering effect of a microphone increases as the frequency increases and is not considerable in the low frequency region. However, it is noted that there might be the pressure distortion above 4 kHz due to the scattering in microphone measurement.