• 아태비즈니스연구
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• 제11권2호
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• pp.27-43
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• 2020

Purpose - This study explores the impact of the real estate industry on related industries for the perspective of Chinese steel companies. Design/methodology/approach - The impact of housing prices on the 41 listed steel companies' performance was analyzed by using the panel data model. We used two kinds of housing price indexes that are set in the panel data models to estimate the range of the real estate market, driving the performance growth of steel listed companies. Moreover, the net profit of steel companies is used as the dependent variable. To test the stability of the model, ROA used as a dependent variable for the robustness test. Also, to avoid the time trend of housing prices, this paper selects the growth rate of housing prices as the primary research variable. After Fisher-type testings, there is no unit root problem in both independent and dependent variables. Findings - The results indicated that the rise in the housing price has a positive influence on the steel company performance. When the housing price increases by 1%, the net profit of steel enterprises will increase by 5 to 20 million yuan. Research implications or Originality - In this paper, empirical data at the micro-level and panel model are used to quantify China's real estate industry's driving effect on the iron and steel industry, providing evidence from the microdata level. It helps us to understand further the status and role of China's real estate industry in the economic structure.

• 한국BIM학회 논문집
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• 제11권2호
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• pp.43-53
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• 2021

The 'public agency oil joint purchase system' was introduced to lower public sector oil prices and contribute to the stability of the overall consumer oil market. The present study used spatial regression to analyze the factors affecting domestic gasoline price, focusing on the impact of potential implicit collusion among gas stations in determining domestic gasoline prices. Also, this study investigated the effect the location characteristics of the market convention gas stations and government offices on the pressure of price competition in the market and the gasoline price at general gas stations. To summarize the results of the spatial lag model (SLM), the individual characteristics of gas stations such as convenience stores (+), self-fuelling (-), commercial areas (+), subway stations (+), population density (-), and sales (-) are correlated to gasoline prices at gas stations, and the institutional location factors of gas stations (+) affected the average of 9 won per liter, 11 won per liter. In order to solve these problems, the establishment of a monitoring system reflecting the location characteristics of the region and the ongoing review of the system should be carried out. In addition, separate, expanded and promotional measures should be prepared for the convenience of general and public oil buyers.

• 대한가정학회지
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• 제18권4호
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• pp.65-73
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• 1980

The purpose of this study is ti find out a desirable way to stability and improvement of household economy by studying the changes of consumption level and consumption pattern of urban salary and wage earners' households during the years from 1970 to 1978. For this study, "Annual Report on the Family Income and Expenditure survey" (Published by the Bureau of Statistics, Economics Planning Board) has been used as basic material, and the methods of analysis used here are the time series analysis. We have gained the results as follows: 1) From 1970 to 198, the total income level increased at the rate of 416.2% in nominal price, but only 74.4% in reql price, while the total expenditure level showed 338.5% increase in nominal price, but its real increased proved only 418.2% in consideration of inflation. APC decreased from 95.1%(in 1970) to 80.7%(in 1978). 2) As for the expenditure pattern for the above mentioned nine years, the rate of food expenditure increased until 1975 under the price influence, but it trended to decease there after on . The rate of housing expenditure showed a gradual increase while that of fuel and light expenditure was on the decrease. The rate of clothing expenditure had been on the decease until 1974 but it began to increase gradually thereafter on. The trend of miscellaneous expenditures was irregularly up and down, educational expences being the first rank among them, Non-living expenditure had been constant until 1974 but it decreased a little after that. From the results it was found that the consumption level of the salary and wage earners' household in all cities from 1970 to 1978 was not practically improved because of rise in prices, nor was the Engel's coefficient and the rate of miscellaneous expenditure changed distinctively. However, as the successive decrease of APC suggests the possibility of economic development, we must try to put stress on economy in consumption and on encouraging. This will help run our household economy in safety and stability.

• 수산해양교육연구
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• 제28권1호
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• pp.198-210
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• 2016

This study firstly aims to estimate a leading-price of Jeju flounders with various price-classes by fish weight and secondly plans to provide policy implications of flounder purchase projects by understanding dynamic changes and interactions among flounder producer price-classes caused by price impulses in the market. This study applies an unit root test for stability of data, uses a Granger causality test to estimate the leading-price among producer prices by fish weight, employs the vector autoregressive model to analyze statistical impacts among t-1 variables used in models, and finally utilizes impulse response analyses and forecast error variance decomposition analyses to understand dynamic changes and interactions among change rates of the producer prices caused by price impulses in the market. The results of the study are as follows. Firstly, KPSS, PP, and ADF tests show that the change rate of Jeju flounder monthly producer prices by fish weight differentiated by logarithm is stable. Secondly, the Granger causality test presents that the change rate of the 1kg flounder producer price strongly leads it of 500g, 700g, and 2kg flounder producer prices respectively. Thirdly, the vector autoregressive model indicates that the change rate of the 1kg producer price in t-1 period statistically, significantly influences it of own weight in t period and also slightly affects price change rates of other weights in t period. Fourthly, the impulse response analysis indicates that impulse responses of structural shocks for the change rate of the 1kg producer price are relatively more powerful in its own weight and in other weights than shocks emanating from price change rates of other weights. Fifthly, the variance decomposition analysis points out that the change rate of the 1kg producer price is relatively more influential than it of 500g, 700g, and 2kg producer prices respectively. In conclusion, the change rate of the 1kg Jeju flounder producer price leads the change rates of other ones and Jeju purchase projects need to be targeted to the 1kg Jeju flounder producer price as the purchase project implemented in 2014.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1994년도 가을 학술발표회 논문집
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• pp.119-122
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• 1994

An analytical procedure is described to estimate the mobilized tensile forces along the effective lengths of nails. Based on the horizontal focing displacements of a nailed-soil wall experiencing outward tilt about the toe with granular soil deposit, the variation of nail-soil friction coefficient is modeled. Also, the method of overall stability analysis of a nailed-soil wall is presented using the Morgenstem-Price limit-equilibrium slice method. The results predicted by the developed procedure are compared with test measurements. The comparisons show in general good agreement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.962-963
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• 2015

This paper proposes a sensorless V/f control method of the interior mounted permanent magnet synchronous motor without damper winding. Arithmetic computation is simpler than vector control. And the lower cost price, dynamics and stability is guaranteed. When the loss of synchronization occurs with the load disturbances, the stability loop with a reduced order observer is applied quickly and accurately to improve the speed error.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1313-1323
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• 2008

The purpose of this study is to understand behaviors of slopes and determine soil parameters of slopes through the triaxial compression test and the direct shear test. Following results were obtained by comparing and analyzing model tests and analysis programs of slope stability. The safety factors of the Bishop's simple method, the Morgenstern Price method, the Spencer method and the GLE method were similar to each other but safety factors of the Fellenius method and the Janbu method were different from the formers. It was found that the Bishop's simple method, the Morgenstern Price method, the Spencer method and the GLE method could be used for design but attention should be paid to the Fellenius method and the Janbu method since they underestimated safety factor.

• 수산해양기술연구
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• 제55권3호
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• pp.264-272
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• 2019

The aim of this study is to analyze the relationship between international oil price as a fuel cost in overseas fisheries and skipjack tuna price as a part of main products in overseas fisheries using monthly time series data from 2008 to 2017. The study also tried to analyze the change of fishing profits by fuel cost. For a time series analysis, this study conducted both the unit-root test for stability of data and the Johansen cointegration test for long-term equilibrium relations among variables. In addition, it used not only the Granger causality test to examine interactions among variables, but also the Vector Auto Regressive (VAR) model to estimate statistical impacts among variables used in the model. Results of this study are as follows. First, each data on variables was not found to be stationary from the ADF unit-root test and long-term equilibrium relations among variables were not found from a Johansen cointegration test. Second, the Granger causality test showed that the international oil prices would directly cause changes in skipjack tuna prices. Third, the VAR model indicated that the posterior t-2 period change of international oil price would have an statistically significant effect on changes of skipjack tuna prices. Finally, fishing profits from skipjack would be decreased by 0.06% if the fuel cost increases by 1%.

• 한국전자통신학회논문지
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• 제6권2호
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• pp.280-287
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• 2011

연구의 목적은 서민주거안정정책이 주택가격에 미치는 영향을 분석하는 것이다. 이에 대한 실증분석을 실시한 결과 다음과 같은 결론을 얻었다. 첫째, 그랜저인과관계를 검증한 결과 전 지역의 주택시장은 서민주거안정정책에 영향을 주고 있는 것으로 나타났다. 둘째, 충격반응은 전 지역에서 부(-)의 반응을 보이며, 서민주거안정정책은 주택시장안정에 어느 정도 기여한 것으로 나타났다. 셋째, 로짓회귀분석결과 서민주거안정정책은 노무현 정부의 강남지역을 제외하고 주택시장안정에 상당한 효과가 있는 것으로 나타났다.

• 대한기계학회논문집
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• 제19권6호
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• pp.1469-1478
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• 1995

PWM control is a kind of nonlinear control. The merits of PWM control of hydraulic equipment are the robustness of the high speed on-off valve and its low price. And it is easily implemented to hydraulic equipments with microcomputer. The high speed on-off valve is directly digitally controlled without any D/A converter. The objectives of this study is to analyze the limit cycle which regularly appear in the position control system using high speed on-off valve, and to give a criterion for the stability of this system. To do this, the nonlinear characteristics of PWM and cylinder friction of this system are described by harmonic linearization and the effects of parameter variations to the system stability are examined theoretically and experimentally. Consequently, the availability of the proposed method is confirmed well.