• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.295-296
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• 2015

We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

• 한국해양공학회지
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• 제30권4호
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• pp.260-267
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• 2016

Considering the effect of dynamic response amplification, a reliability analysis of an offshore wind turbine support structure under an earthquake is presented. A reliability analysis based on the dynamic response requires a large amount of time when using not only a level 3 approach but also level 2 such as a first order reliability method (FORM). Moreover, if a limit state is defined by using the maximum stress at a structural joint where stress concentration occurs, a three-dimensional element should be used in the finite element analysis. This makes the computational load much heavier. To deal with this kind of problem, two techniques are suggested in this paper. One is the application of a quasi-static structural analysis that takes the dynamic amplification effect into account. The other is the use of a stress concentration factor to estimate the maximum local stress. The proposed reliability analysis is performed using a level 2 FORM and verified using a level 3 simulation approach.

• Journal of Welding and Joining
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• 제30권1호
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• pp.72-77
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• 2012

Recently, according to the increase of income and development of quality of life, the leisure industry has been developed. In particular, the interest of design and manufacture technology of leisure yacht has significantly increased. However, domestic market of leisure ships is currently in its initiating stage. So research and development for structural strength of leisure yacht need to be investigated. In this study, lug of yacht's mast which is known for a critical damage region is explicitly considered. This paper deals with the estimation of stress concentration factors (SCFs) for lug of yacht's mast depending on dimensions of lug using hot spot stress. Also, SCF formulae is suggested using parametric study.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.254-254
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• 2004

Final disposal of radioactive waste generated from Nuclear Power Plant (NPP) requires the detailed information about the characteristics and the quantities of radionuclides in waste package. Most radionuclides are difficult to measure and expensive to assay. Thus it is suggested to the indirect method by which the concentration of the Difficult-to-Measure (DTM) nuclide is estimated using the correlations of concentration-it is called the scaling factor-between Easy-to-Measure (Key) nuclides and DTM nuclides with the measured concentration of the Key nuclide.(omitted)

• 대한화학회지
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• 제30권2호
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• pp.224-230
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• 1986

알킬처리된 실리카(ODS)칼럼을 이용하여 역상 이온쌍 크로마토그래피방법으로 방향족 술폰산들의 분리 인자를 조사하였으며 또한 분리를 시도하였다. 반대이온으로서 브롬화 도데실 트리메틸암모늄(DTAB)을 사용하였으며, 시료의 분리인자는 반대이온의 농도, 메탄올의 농도, 전해질의 종류 및 농도, 시료 분자에 붙어있는 작용기의 종류 및 위치등에 의하여 영향을 받았다. 최적 조건하에서 몇 가지 혼합시료를 분리할 수 있었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 제7회 압연 심포지엄
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• pp.13-16
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• 2009

In order to investigate the effects of geometry factors such as a roil diameter ratio and backup roll crown of the stress concentration factor on the edge of backup roil end, 3-dimensional FEM analyses of stress at the contact of backup roll and work roll assembled in a 4-high strip mill were carried out, It was made clear that the peak stress at the edge is about 2 to 3 times of that at the longitudinal center of the roll barrel and the peak stress proportionally increase with decreasing the ratio of backup roll diameter to work roll diameter Furthermore a crowning on the backup roll is effective to decrease the maximum edge stress.

• Fibers and Polymers
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• 제3권2호
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• pp.73-79
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• 2002

Nanoscaled PVA fibers were prepared by electrospinning. This paper described the electrospinning process, the processing conditions fiber morphology, and some potential applications of the PVA nato-fibers. PVA fibers with various diameters (50-250 nm) were obtained by changing solution concentration, voltage and tip to collector distance (TCD). The major factor was the concentration of PVA solution which affected the fiber diameter evidently. Increasing the concentration, the fiber diameter was increased, and the amount of beads was reduced even to 0%. The fibers were found be efficiently crosslinked by glyoxal during the curing process. Phosphoric acid was used as a catalyst activator to reduce strength losses during crosslinking. Scanning electron micrograph (SEM) and differential scanning calorimetric (DSC) techniques were employed to characterize the morphology and crosslinking of PVA fibers. It was fecund that the primary factor which affected the crosslinking density was the content of chemical crosslinking agent.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.87-91
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• 1998

In this paper, We analyzed the current-voltage characteristics with n-type silicon substrates concentration and temperature variations (Room temperature, 50$^{\circ}C$, 75$^{\circ}C$) in platinum silicide and silicon junction. The electrical parameters of measurement are turn-on voltage, saturation current, ideality factor, barrier height, dynamic resistance in forward bias and reverse breakdown voltage according to variations of junction concentration of substrates and measurement temperature variations. As a result, the forward turn-on voltage, reverse breakdown voltage, barrier height and dynamic resistance were decreased but saturation currents and ideality factor were increased by substrates increased concentration variations in platinum silicide and n-silicon junction. In increased measurement temperature (RT, 50$^{\circ}C$, 75$^{\circ}C$), the extracted electrical parameter values of characteristics were rises by increased temperature variations according to the forward and reverse bias.

• International journal of advanced smart convergence
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• 제12권3호
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• pp.157-162
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• 2023

This study analyzed the relationship between ESG performance and corporate value using panel data from Chinese equipment manufacturing companies spanning from 2012 to 2021, and it also examined whether ownership structure moderates this relationship. We have contributed to filling the gap in existing research. The main conclusions of this study are as follows: Firstly, similar to previous researches, ESG performance was found to have a positive and statistically significant impact on corporate value. Secondly, when the three dimensions of ESG - Environmental (E), Social (S), and Governance (G) - were analyzed separately, it was observed that E and S have a positive and statistically significant impact on corporate value, while G has a negative and statistically significant impact. Thirdly, ownership concentration emerged as a significant moderating factor in explaining the connection between ESG performance and corporate value. Lastly, when the three dimensions of ESG were analyzed separately, ownership concentration was found to serve as a positive moderating factor in the relationship between corporate value and E and S, but it did not play a statistically significant role for G.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.3935-3939
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• 2023

The paper presents the results of a study of radioactive noble gases and from decay products in the atmosphere of the reactor hall of the research nuclear reactor IVV-2M. The distribution of short-lived ⁸⁸Rb and ¹³⁸Cs activity by sizes of aerosol particles was measured in the range of 0.5-1000 nm. It is shown that radioactive aerosols are characterized by three main modes with AMTD 2-3 nm, 7-15 nm and 400 nm. About 70% of aerosol activity is due to ⁸⁸Rb. The equilibrium factor between ⁸⁸Kr and ⁸⁸Rb is 0.2 ± 0.1. The total concentration of aerosols particles was measured using an aerosol diffusion spectrometer. The value of unattached fraction of radioactive aerosols in the atmosphere of reactor hall IVV2M was f = 0.15-0.25 at the average total aerosol particles concentration from 20,000 cm³ to 53,000 cm³.