• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.300-303
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• 1991

Sulphur-hexafluoride has extensively been used as an insulating gas of electric power equipment in substation for its high dielectric strength, non-toixity and non-flammable properties. But it is very expensive and is liquidizable under the condition of low temperature and high pressure. And it is very sensible to the locally high electric field strength. To resolve these problems, we studied 50% FOV and V-t characteristics of $SF_6-N_2$ mixtures under positive and negative lightning impulses using a 25mm rod-plane gap. 50% FOV of $SF_6-N_2$ 50% mixture was about 85% of pure $SF_6$ and it was known that $SF_6-N_2$ mixtures can be used as an economic substitution insulating gas for $SF_6$.

• The Journal of Asian Finance, Economics and Business
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• 제5권3호
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• pp.7-17
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• 2018

This paper examines short-run and long-run dynamic relationships between selected macroeconomic variables and stock prices in the Korea Stock Exchange. The data is restricted to the period for which monthly data are available from January 1986 to October 2016 (370 observations) retrieved from the Economic Statistics System database sponsored by the Bank of Korea. The study employs unit root test, cointegration test, vector error correction estimates, impulse response test, and structural break test. The results of the Johansen cointegration test indicate at least three cointegrating equations exist at the 0.05 level in the model, confirming that there is a long-run equilibrium relationship between stock prices and macroeconomic variables in Korea. The results of vector error correction model (VECM) estimates indicate that money supply and short-term interest rate are not related to stock prices in the short-run. However, exchange rate is positively related to stock prices while the industrial production index and inflation are negatively related to stock prices in the short-run. Furthermore, the VECM estimates indicate that the external shock, such as regional and global financial crisis shocks, neither affects changes in the endogenous variables nor causes instability in the cointegrating vector. This study finds that the endogenous variables are determined by their own dynamics in the model.

• 전기학회논문지
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• 제59권2호
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• pp.369-373
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• 2010

Modem electronic circuits are of importance for the function of communication, traffic systems and security systems. An intentional threat to these systems could be of big casualties and economic disasters. This paper has shown damage effect of microcontroller device with coupling caused by UWB-HPEM(Ultra Wideband-High Power Electromagnetics). The UWB measurements were done at an Anechoic Chamber using a RADAN UWB voltage source, which can generate a transient impulse of about 180 kV. The susceptibility level for microcontroller has been assessed by effect of various operation line lengths. The results of susceptibility analysis has showed that the effect of the reset line length on the MT(Ma1function Threshold) is larger than the effect of the different line length(Data, Power, Clock). With the knowledge of these parameters electronic system can be designed exactly suitable concerning the system requirements. Based on the results, susceptibility of microcontroller can be applied to protection plan to elucidate the effects of microwaves on electronic equipment.

• 동아시아경상학회지
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• 제8권1호
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• pp.57-69
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• 2020

Purpose - This study examines what are the asset market fluctuations in Europe and how each economic variable affects major variables, and explore the dynamics of housing and stock market through Greece. The variables under consideration are balance on current account (BCA), index of stock (STOCK), gross domestic product (GDP), housing price indices (HOUSING), M3, real rate of interest (IR_REAL) and household credits (LOAN). We investigate the functional and causal relationships between housing and stock market. Research design, data, and methodology - Vector error correction model (VECM) is used to figure out the dynamic relationships among variables. This study also contains the augmented Dickey-Fuller unit root, cointegration, Granger causality test, and impulse response function and variance decomposition analysis by EViews 11.0. Results - The statistical tests show that all variables under consideration have one unit root and there is a longterm equilibrium relationship among variables for Greece. GDP, IR_REAL, M3, STOCK and LOAN can be considered as causal factors to affect real estate market, while GDP, LOAN, M3, BCA and HOUSING can bring direct effects to stock market in Greece. Conclusions - It can be judged that the policy that affects the lending policy of financial institutions may be more effective than the indirect variable such as monetary interest rate.

• The Journal of Asian Finance, Economics and Business
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• 제6권2호
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• pp.269-275
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• 2019

This study intended to examine the relationship between inflation and unemployment rate in Indonesia during 1987 to 2018 period. The study applied a quantitative method using Vector Error Correction Model (VECM) in order to comprehensively understand the causality between inflation and unemployment rates. The data were collected from various main sources including the World Bank, Central Bank of Indonesia, and Central Bureau of Statistics (BPS). The findings showed that inflation has a one-way relationship toward unemployment in Indonesia and it occurs at the third lag. Impulse Response Function (IRF), shows that the inflation rate are fluctuating in response to the shock of unemployment. The unemployment rate responses to shocks from inflation initially increased until it is eventually diminished. It shows that the shocks caused by the impact of inflation were only in the short term. Further, inflation in the three previous lags will have consequences for the unemployment rate in the year. Lastly, both in the long run and short run, unemployment did not affect inflation rates. These findings suggest that high inflation in Indonesia is determined the rising price of basic commodities and fuel. In addition, most companies in Indonesia applying capital intensive so that employment growth in Indonesia is small.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.91-101
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• 2021

The paper examines the impact of the COVID-19 pandemic on the stock market prices. The vector autoregression model (VAR) has been used in this analysis to survey 341 stocks on the Ho Chi Minh City Stock Exchange (HOSE) for the period from January 23, 2020 to December 31, 2020. The empirical results obtained from the analysis of 11 economic sectors suggest that there is a statistically significant impact relationship between COVID-19 and the healthcare and utility industries. Additional findings show a statistically significant negative impact of COVID-19 on the utility share price at lag 1. Analysis of impulse response function (IRF) and forecast error variance decomposition (FEVD) show an inverse reaction of utility stock prices to the impact of COVID-19 and a gradual disappearing shock after two steps. Major findings show that there is a clear negative effect of the COVID-19 pandemic on share prices, and the daily increase in the number of confirmed cases, indicate that, in future disease outbreaks, early containment measures and positive responses are necessary conditions for governments and nations to protect stock markets from excessive depreciation. Utility stocks are among the most severely impacted shares on financial exchanges during a pandemic due to the high risk of immediate or irreversible closure of manufacturing lines and poor demand for basic amenities.

• The Journal of Asian Finance, Economics and Business
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• 제9권3호
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• pp.33-42
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• 2022

Oil prices have become more volatile as a result of global economic contraction and control measures. Before and during the COVID-19 crisis, this study examines the relationship between oil price swings and daily stock returns in the power sector. The impact is investigated using a panel Vector Autoregressive (VAR) model. Granger causality tests are used to see if oil prices are effective in predicting returns. The dynamic impact of supply shocks is studied using Impulse Response Functions (IRFs). From January 2011 to May 2021, the study used daily data from all listed power sector enterprises on the Pakistan stock exchange. To investigate the differences in reactions between the Pre-COVID and COVID eras, the sample was separated into two groups. Oil shocks are inversely associated with daily firm stock returns. The conclusions are further supported by the lack of impact of stock prices on oil prices. The relationship, however, deteriorates during the COVID pandemic. We could not uncover any evidence of a significant relationship. In developing countries that rely on oil imports, the study sheds light on the utility of oil price shocks in daily stock return predictions.

• 한국가스학회지
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• 제27권4호
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• pp.56-61
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• 2023

플랜트는 사회기반시설로써 중요한 보호시설이고, 여기서 발생 가능한 가스 누출 및 폭발과 같은 사고에 대한 안전성 확보는 설계 시 반드시 고려해야 한다. 하지만 플랜트에서의 폭발압력에 대한 연구는 경제성 등의 이유로 거의 없으며, 이에 대한 데이터가 부족한 실정이다. 본 연구에서는 플랜트에서 발생할 수 있는 폭발 시나리오를 고려한 실험 설계안을 제시하고 폭발 실험을 통해 폭압을 확인하였다. 가연성 물질로 수소-메테인 혼합 가스가 이용되었으며, 밀폐도와 밀집도가 폭압에 주는 영향에 대해 연구하였다. 밀폐도에 따라 압력파의 중첩이 폭압에 주는 영향과 밀집도에 따른 난류 영향을 구분하여 논의한다. 본 연구에서의 결과는 다양한 안전설계 시 입력자료로 활용될 수 있다.

• KDI Journal of Economic Policy
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• 제31권1호
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• pp.169-206
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• 2009

본 연구는 1990년대 이후의 한국경제의 성장패턴을 이해하기 위한 노력의 일환이다. 이를 위해, 본 연구에서는 Blanchard and Quah(1989)가 제시한 바와 같이 장기제약식하의 구조적 벡터자기회귀추정법(Structural Vector Auto Regression: SVAR)에 의거하여 우리나라의 경제를 오늘에 이르게 한 다양한 충격들을 식별하고 각각의 상대적 기여도를 구분하고자 하였다. 보다 구체적으로는 Blanchard and Quah의 2-변수 모형과 이를 확장한 3-변수 모형, 그리고 New Keynesian류의 선형모형을 변형시킨 두 개의 모형을 분석하였다. 특히, 후자의 두 모형은 1997년 외환위기 이후 있었던 외환시장체제(고정환율제도에서 변동환율제도)와 통화정책기조(통화총량제에서 물가목표제)의 변화를 반영하도록 구성되었다는 점에서 의의를 갖는다. 이러한 각 모형으로부터의 추정 결과를 충격반응 및 예측오차분해 분석의 형식으로 정리 비교한 결과 다음과 같은 두 가지 공통점을 발견할 수 있었다. 첫째, 경제성장률의 변동은 생산성의 충격에 주로 기인하며, 이와 같은 경향은 2000년대 이후 더 강해진 것으로 보인다. 이는 2000년대 이후 우리 경제의 성장이 잠재성장률과 밀접한 관계를 갖고 있음을 시사한다. 둘째, 2000년대 이후 충격반응의 크기나 지속성이 전반적으로 줄어드는 경향이 있다. 무역의존도가 높은 우리 경제상황에 비추어 2000년대의 전 세계적인 저(低)금리, 저(低)인플레이션 및 견실한 성장세, 그리고 중국경제의 부상이 자본 및 수출 수입 수요의 안정적인 확보를 도모하여 특히 각 부문 충격이 경제에 미치는 영향을 반감시켰을 개연성이 있다. 분석에 사용된 모형과 식별에 사용된 충격의 다양한 조합에도 불구하고 위의 두 가지 패턴은 일관되게 관측되고 있음에 비추어 볼 때, 2000년 이후 우려되고 있는 우리나라의 경제성장률 저하 현상은 잠재성장률 하락에 주로 기인하는 것으로 판단된다.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.5159-5168
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• 2014

본 연구는 문제음주자의 성별에 따른 정신건강, 대사증후군과 영양소 섭취를 비교하기 위해 시도 되었다. 2010-2012년까지 실시된 제5기 국민건강 영양조사를 원시자료를 이용하여, 19세 이상의 음주하는 성인 남, 녀 중 AUDIT (Alcohol Use Disorder Identification Test) 12점 이상 자를 문제음주자로 선별하여, 최종 669명을 대상으로 하였다. 문제음주자의 정신건강은 스트레스, 우울, 자살생각을, 대사증후군은 허리둘레, BMI(body mass index), 공복혈당(fasting blood sugar), HDL(highdensity lipoprotein), Triglyceride, BP(blood pressure) 중 3가지 이상 정상범위에서 벗어나는 경우로 구분하였으며, 영양소 섭취는 에너지와 9개의 영양소의 적정 섭취비(Nutrient adequacy ratio:NAR) 및 평균 영양소 적정 섭취비(Mean adequacy ratio: MAR)를 구하여 확인하였다. SPSS18.0을 이용하여, 빈도와 교차분석, 다중회귀분석을 실시하였다. 연구결과 일반적 특성은 연령, 결혼상태, 직업유무에서, 정신건강은 스트레스, 우울, 자살생각에서 유의한 차이가 있었고. 대사증후군은 대사증후군 여부, FBS, HDL, BP에서 유의한 차이가 있었으며, 영양소 섭취는 Calcium, Vit. A, Thiamine, Riboflavin, Niacin, Vit. C, MAR에서 유의한 차이가 있었다. 각각 유의한 차이를 보인 변수에 대해서 로지스틱 회귀분석을 실시하였다. 스트레스, 우울, 자살생각은 남성의 경우 19-29세, 여성은 30-49세가 유의하게 많았고, 대사증후군은 남성은 직업이 있는 경우와, 여성은 미혼과 경제상태가 '중-하'인 경우가 더 많았다. 평균 영양소 적정 섭취비(MAR)는 남성은 미혼, 기취업, 경제상태가 '중-하' 인 경우, 여성의 경우는 경제상태가 '하'수준일수록 더 많았다. 문제 음주자의 정신건강, 대사증후군, 영양섭취문제를 해결하기 위한 접근과 중재를 계획 할 때 본 연구를 통하여 확인된 유의한 차이를 보인 특성들을 고려한다면, 보다 효과적으로 도움을 줄 수 있을 것이라 생각된다.