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        검색결과 91

        61.
        2002.10 구독 인증기관 무료, 개인회원 유료
        We developing for Gate-Container Yard model to execute the Input & Output process of containers which are waiting in container yard effectively and fast. The optimal model is developed to manage and trace the containers in yard. We developed the put-away strategies which considered the storage time for volume of transportation and the distance between blocks and gates using the MICRO-CRAFT (Computerized Relative Allocation Facilities Technique).
        4,200원
        62.
        2002.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,100원
        63.
        2002.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        5,800원
        65.
        1992.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Among various Power converters, a variable voltage variable frequency (VVVF) three-phase PWM inverter is regarded as most promising power converter due to its capabilities, which permits the control of voltage, frequency and harmonic contents in a single power stage employing only on DC source. As a modulating technique of the PWM inverter, the regular sampling technique has rendered possible the on-line computation and generation of PWM control waveforms with a reasonably high switching frequencies. In this paper, microprocessor based three-phase regular samping PWM inverter with real-time control algorithm and control circuits for driving three phase AC motor has been developed. Harmocic components of PWM waveform were analized theoretically in terms of Bessel function series and then calculated by digital computer and observed with spectrum analyzer
        4,300원
        66.
        1981.12 구독 인증기관 무료, 개인회원 유료
        A scheme for installing the digital printing devices as an additional output system of photoelectric photometry is discussed. The digital printing devices consist of counter/integrator and printer interfaces for the digital printer HP 5055A. The integration gate time could be adjusted from 1 second to 99 seconds.
        3,000원
        67.
        2020.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The study aims to measure the productivity of the Saudi banking sector at the retail level using secondary data for 11 local banks from the period 2015-2019. The study uses an extended version of the Cobb-Douglas production function to account for the fact that as banks openup more retail branches, they will need to employ more labor. The extended Cobb-Douglas production function was estimated using the two-way fixed effect model to account for unobserved heterogeneity across Saudi banks resulting from differences in labor competencies and leadership style. Besides, the model accounts for unobserved heterogeneity among Saudi banks due to the advancement in electronic services over time. The results showed that labor, branches, customers’ deposits, and fixed deposits have a positive effect on the total value of generated loans. Conversely, ATM has an insignificant effect on generated loans. The average scale elasticity shows that the Saudi banks at the retail level are operating under decreasing returns to scale. The average marginal rate of technical substitution shows that Saudi banks need at least one ATM to replace one unit of labor at the retail level while keeping the same level of output.
        68.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The effect of research and development (R&D) expenditure on firm output is an interesting topic, but hardly explored in developing countries due to the unavailability of data. This study investigates this topic in the context of Vietnam by utilizing a novel dataset of 343 firms listed on the Vietnam Stock Exchange in the 2010-2018 period. The effect of R&D expenditure is examined under the production function framework. In order to obtain the robustness of the quantitative results, we estimate the production function with two coherent techniques including the OLS and 2-SLS. An instrumental variable regression technique is adopted to avoid the endogeneity problem between R&D expenditure and other variables. In our empirical analysis, we find that R&D expenditure has a positive and significant impact on output growth. The finding is robust in both OLS and 2-SLS frameworks. Besides, the output elasticity to R&D expenditure of our result is much higher than the estimated elasticity of other countries. The results imply that a 1% increase in R&D expenditure in Vietnam will help to expand the output more than a 1% increase in R&D investment in other countries. The findings from our paper provide important implications for firm managers, investors, and policymakers in Vietnam.
        69.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study attempts to analyze trade flows between Vietnam and China in order to understand the mutual influence of bilateral trade relations. China is a country with the world’s leading economic potential. China and Vietnam are neighboring countries sharing a border of 1,281 km. Trade relations between the two countries are a necessity and, with a right policy, are beneficial to both. Vietnam has a trade deficit with China. This situation is exacerbated by the continuing rise in the gap. Vietnam trade deficit from China was USD12.5 billion in 2010, increasing to USD24 billion in 2018. Data are extracted from the 2015 national input-output tables of Vietnam and China as well as Vietnam Household Living Standard Survey statistics. The research identified 36 sectors of bilateral input-output trade between Vietnam and China. A bilateral output-input model is applied to analyze how final demand and use of input in the production of this country induces output and value added of the other country. The results show that China benefits more from Vietnam’s production and consumption than Vietnam does. Vietnam’s inter-sector structure does not stimulate domestic production due to the absence of supporting products as inputs in the production process.
        70.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        This paper presents cable-hydraulic driven 3DoF (Degree-of-Freedom) manipulator for cooperative robot with high output/low inertia and enhancing lager workspace of hydraulic manipulator. Hydraulic actuation could be solution to design more higher output manipulator than the one of electric motor actuation due to install actuation source and robot joint separated. In spite of this advantage, the conventional hydraulic driven manipulator using cylinder or vane actuator is not suitable for the candidate of cooperative robot because smaller workspace owing to small RoM (Range of Motion) hydraulic actuator. In this paper, we propose 3DoF manipulator with cable-hydraulic actuation which is more larger ratio of payload-to-weight than the one of conventional cooperative manipulator and larger workspace than the one of existing hydraulic driven manipulator. The performance of proposed manipulator was demonstrated by the experiments for confirming overall workspace task, high payload operation task under worst situation and comparing repeatability between developed manipulator and existed cooperative robots. The results of experiments showed that the appropriate performance of proposed manipulator for cooperative robot.
        71.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        Phosphorus (P) is an essential and major nutrient for both plants and animals. However, anthropogenic P in the environment may cause severe problems such as the deterioration of water quality. Therefore, it is essential for the Korean government to manage P in the agricultural sector. The annual P budget for Korea was 46 kg P ha-1 in 2013, placing Korea in second among Organication for Economic Co-operation and Development (OECD) countries. P surplus and deficiency in agricultural lands can be estimated according to the P budget, which is one of the OECD agri-environment indicators. In the P budget, it is important to ensure consistency in the input-output data sources, in order to apply national and regional policies for the environmentally sound management of agricultural P. This study examines the impacts on the input-output data sources in the regional P budget in Korea. P budgets were between 99-145 kg-P/ha, depending on different data sources. We suggest two recommended data combinations (DC 1 and DC 2) for reliability of the data. P budgets calculated using DC 1 and DC 2 were 128 kg-P/ha and 97 kg-P/ha, respectively. According to the results, one of the core factors affecting P budgets was crop production. In this study, DC 2 was recommended rather than DC 1 in order to consider the cultivated areas for various crops. It is also necessary to analyze the sensitivity of the coefficients used in P budget in the future.
        72.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        Purpose - The purpose of this paper is to analyze the relationship between the real exchange rate and the output, which is based on the macroeconomic equilibrium theory in China. Its aim will be to verify whether the change in the real exchange rate has a significant effect on the output or not. Research design, data, and methodology - This study endeavors triestoinvestigatethecorrelationamongeconomicvariablesunder the macroeconomic market (the commodity market and the money market) equilibrium. So, time-series data from 1990 to 2016 is applied to establish a vector auto-regression (VAR) model so as to perform an empirical analysis. Results - The empirical results reveal that an increase in the real exchange rate will result in an increase in the output in the short run. However, the empirical results also indicate that this kind of mechanism cannot work in the long run. Conclusions - The effect of a decrease of real exchange rate on output is significant in the short run. Also, this paper suggests that the total supply and the total demand can promote economic growth. The fiscal and money policy play a significant role in economic growth in China as well.
        73.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        In the offshore crane system, the requirements on the operating safety are extremely high due to many external factors. Rope extension is one of the factors producing vertical vibration of load. In this study, the load is carried by the motor-winch actuator control and the rope is modeled as a mass-damper-spring system. To control the load position and suppress the vertical vibration of the load, a control system based on input-output linearization method is proposed. By the simulation and experiment results with pilot crane model, the effectiveness of proposed control method is evaluated and verified.
        74.
        2017.05 서비스 종료(열람 제한)
        우리나라는 반도체, 철강, 자동차, 선박 등의 제조업을 토대로 경제규모를 성장시켜왔으며, 성장에 비례하여 에너지 수입 의존도 또한 증가했다. 현재 우리나라는 에너지의 95% 이상을 수입하여 사용하고 있는 에너지 다소비 국가로써 2013년 기준 제조업 원자재의 전체 수입량은 하루 평균 약 1조원에 이르는 것으로 집계되었다. 하지만 국내에서 발생되는 폐기물의 약 50% 이상이 에너지 회수에 이용될 수 있음에도 불구하고 단순히 소각 및 매립으로 처리가 되고 있어 에너지 다소비 국가의 현실과는 대조적인 폐기물처리가 이루어지고 있음을 알 수 있다. 이에 환경부는 「자원순환기본법(2018.01.01. 시행)」을 마련하여 폐기물의 에너지화를 계획하고 있으며, 이와 관련해 소각으로부터 발생되는 열원, 온수, 증기 등의 에너지를 최대한 활용하여 그 효율에 따라 폐기물처분부담금을 감면해주는 방안을 구상하고 있다. 따라서 소각시설의 열에너지 회수효율 산정 및 산정을 위한 주요인자들의 과학적인 접근방법이 요구되었으며, 이에 본 연구에서는 열에너지 회수효율의 주요인자인 저위발열량 및 출열항목에 대하여 산정하고, 산정된 저위발열량 결과와 각 시설의 저위발열량 설계 값 및 발열량계측정값을 비교하여 타당성에 대하여 검토하고자 한다. 본 연구는 1차(2016.05.09.~2016.08.31.) 7개 시설(8호기), 2차(2016.09.05.~2016.10.30.) 4개 시설(9호기)로 진행하였으며, 대상 시설의 선정은 폐기물의 종류, 보일러의 설치형태, 소각로의 형태를 고려하여 선정하였다. 열에너지 회수효율의 산정을 위한 계측항목에 관련한 데이터를 일별로 수집하였으며, 계측 외 항목은 직접 측정하여 저위발열량 및 출열항목 등을 산정하였다. 대상 시설의 저위발열량 산정결과는 1차의 경우 2,776.6~3,881.4kcal/kg, 2차의 경우 1,921.5~5928.7kcal/kg으로 분포되는 것으로 나타났으며, 2차 대상시설 중 저위발열량 결과 값이 5928.7kcal/kg으로 산정된 시설의 경우 사업장폐기물 소각시설로 지정폐기물 투입비율이 100%인 것으로 나타났다. 연구결과, 지속적인 데이터 수집을 통해 출열항목을 산정하여 열에너지 회수효율을 극대화 시킬 방안을 마련해야 하며, 또한 과학적 근거를 수반한 저위발열량 산정방법을 마련해야 할 것으로 판단된다.
        75.
        2017.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Based on a simultaneous-equation model consisting of aggregate demand and short-run aggregate supply, this paper estimates a reducedform equation specifying that the equilibrium real GDP is a function of the real effective exchange rate, the government deficit as a percent of GDP, the real interest rate, foreign income, labor productivity, the real oil price, the expected inflation rate, and the interactive and intercept binary variables accounting for a potential change in the slope of the real effective exchange rate and shift in the intercept. Applying the exponential GARCH technique, it finds that aggregate output in Australia has a positive relationship with the real effective exchange rate during 2003.Q3 – 2013.Q2, the government deficit as a percent of GDP, U.S. real GDP, labor productivity and the real oil price and a negative relationship with the real effective exchange rate during 2013.Q3 – 2016.Q1, the real lending rate and the expected inflation rate. These results suggest that real appreciation was expansionary before 2013.Q3 whereas real depreciation was expansionary after 2013.Q2 and that more government deficit as a percent of GDP would be helpful to stimulate the economy. Hence, the impact of real appreciation or real depreciation on real GDP may change overtime. Keywords: Exchange Rates, Government Deficit, Interest Rates,
        76.
        2016.11 서비스 종료(열람 제한)
        현재 국내의 주된 폐기물 처리 방식은 발생억제(Reduce), 재이용(Reuse), 재활용(Recycle)을 통한 물리적인 처리방식으로써 대량으로 발생하는 폐기물을 효율적으로 처리하기에는 한계가 있다. 이에 폐자원 에너지화(Recovery) 개념의 도입으로 폐기물의 단순한 처리가 아닌 효율적인 에너지 자원으로 활용함으로써 자원순환사회를 구축하기 위한 정책적 방안이 마련되었으며, 구체적인 방안의 하나로 2018년 1월 1일부터 시행되는 자원순환기본법을 통하여 소각시설에 발생되는 열에너지를 적극적으로 활용할 예정이다. 따라서 소각시설로부터 실질적으로 회수되어 사용되는 에너지의 정확한 수치화가 요구되었으며, 현재 국내에서 운영 중인 소각시설을 대상으로 시범사업을 진행하여 소각열에너지 회수・사용률의 실증에 노력을 기울이고 있다. 이에 본 연구에서는 폐자원에너지 회수・사용률 산정에서 가장 중요하게 작용되는 저위발열량을 도출하기 위한 핵심요소인 출열항목을 실측하여 소각열에너지 회수・사용률 산정을 위한 기초자료로 활용하고자 한다. 본 연구에서는 현재 운영 중인 생활폐기물 소각시설 2곳(A, B 소각시설)의 3개 호기와 사업장폐기물 소각시설 5곳(C, D, E, F, G 소각시설)의 5개 호기를 대상으로 5월부터 16주 동안 TMS 데이터 수집과 현장측정 및 시료분석을 병행하였으며, 종합적인 결과 값을 환경부 고시 제 2015-251호 폐자원에너지 회수・사용률 산정방법에 대입하여 소각로에서 발생되는 각각의 출열항목을 산출하였다. 또한 산출된 결과를 종합하여 생활폐기물 소각장과 사업장폐기물 소각장의 출열분포를 비교하여 보았다. 소각시설의 출열항목의 산정결과, 생활폐기물 소각시설 3개 호기의 출열 총합은 A시설 1호기가 13.54GJ/ton, 2호기가 14.12GJ/ton으로 산정되었으며, B시설 1호기는 12.72GJ/ton으로 산정되었다. 이 중 가장 높은 비율을 차지하는 출열항목은 증기 흡수열로 A시설 1호기는 9.57GJ/ton, 2호기는 9.82GJ/ton, B시설 1호기는 9.77GJ/ton을 차지하여 평균 72%의 분포를 보이는 것으로 나타났다. 또한 사업장폐기물 소각시설의 출열 총합은 C시설 16.65GJ/ton, D시설 15.48GJ/ton, E시설 13.35GJ/ton, F시설 12.49GJ/ton, G시설 11.79GJ/ton으로 산정되었으며, 사업장폐기물 소각시설 또한 생활폐기물 소각시설과 동일하게 증기 흡수열이 평균 65%의 분포를 보여 가장 높은 비율을 차지하는 것으로 나타났다. 연구결과, 지속적인 시범사업을 통해 실측값을 축적하여 소각열에너지 회수・사용률 제고를 위한 연구 등의 기초자료로 활용하여야 할 것으로 판단된다.
        77.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        본 연구는 단경간 교량의 정적하중입력/변위출력관계를 이용한 새로운 교량 유한요소모델 개선 방법을 제안하였고, 실내 모형교량 실험을 통해 검증하였다. 기존의 유한요소모델개선기법은 실험으로부터 얻어진 모드계수와 유한요소모델로부터 예측된 모드계수가 유사해 지도록 유한요소모델을 개선하는데, 이 과정에서 구조계의 질량행렬에 대한 가정을 필요로 한다. 제안된 기법은 질량행렬을 가정하지 않고, 오 히려 질량행렬 추정을 가능하게 하는 장점을 가진다. 제안된 기법은 두 단계로 구성된다. 첫째, 정적 하중입력-변위응답으로부터 강성행렬을 개선하고, 둘째, 실측된 고유진동수를 이용하여 질량행렬을 개선한다. 실험검증을 위하여 실내 모형교량을 제작하였고, 제안된 기법을 이용하 여 모형교량의 탄성계수를 추정하였으며, Universal Testing Machine으로 부터 얻어진 탄성계수와 비교하였다. 또한 기존의 유한요소모델개 선기법으로 추정된 탄성계수와 비교하였다. 실험의 결과들로부터 제안된 기법이 합리적으로 탄성계수와 질량밀도를 추정하는 것이 관찰되었 고, 기존의 유한요소모델개선기법은 고차모드를 사용했을 때 상대적으로 큰 오차를 주는 것이 관찰되었다. 추가적으로 유한요소모델링 오차 에 대하여 토의하였다.
        78.
        2014.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The application of software engineering is not common in the development of astronomical observation system. While there were component-wise developments in the past, large-scale comprehensive system developments are more common in these days. In this study, current methodologies of development are reviewed to select a proper one for the development of astronomical observation system and the result of the application is presented. As the subject of this study, a project of operation software development for an astronomical observation system which runs on the ground is selected. And the output management technique based on Component Based Development which is one of the relatively recent methodologies has been applied. Since the nature of the system requires lots of arithmetic algorithms and it has great impact on the overall performance of the entire system, a prototype model is developed to verify major functions and performance. Consequently, it was possible to verify the compliance with the product requirements through the requirement tracing table and also it was possible to keep to the schedule. Besides, it was suggested that a few improvements could be possible based on the experience of the application of conventional output management technique. This study is the first application of the software development methodology in the domestic astronomical observation system area. The process and results of this study would contribute to the investigation for a more appropriate methodology in the area of similar system development.
        79.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        The purpose of this article is analyzing the economic impacts of abnormal climate on total revenue of red pepper in Korea, with employing the equilibrium displacement model. Our simulation results show the rate of yield change, price change, and total revenue change according to the climate change scenarios. In th case of by RCP 8.5 Scenario, red pepper production volume would be expected to decrease by 77.2% compared to 2012 while price increasing by 29.6%. As a result, total revenue to be returned to farmers would be reduced by 47.6% than it was in 2012. In contrast, total revenue would be expected to decline by 29.6% according to RCP 4.5 scenario.
        80.
        2014.02 서비스 종료(열람 제한)
        본 연구에서는 기상청 초단기 수치예보모델인 KLAPS 예보장을 이 풍수해 예보를 위해 적합하게 이용될 수 있는지를 평가한다. 2011년-2012년의 KLAPS 예보장과 풍수해 발생이력, 그리고 기상청 AWS, ASOS 관측데이터를 이용하여 과연 방재업무 종사자가 KLAPS 예보장 자료를 이용할 경우 풍수해의 발생을 효과적으로 예측하고 대비할 수 있는지 평가한다.
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