• Journal of Power Electronics
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• 제12권3호
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• pp.439-447
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• 2012

In this paper, an input-series auxiliary power supply scheme is proposed, which is suitable for high input voltage and multiple-output applications. The power supply scheme is based on a two-transistor forward topology, all of the series modules have a common duty ratio, all the switches are turned on and off simultaneously, and the whole circuit has a single power transformer. It does not require an additional controller but still achieves efficient input voltage sharing (IVS) for each series module through its inherent transformer-integration strategy. The IVS process of this power supply scheme is analyzed in detail and the design considerations for the related parameters are given. Finally, a 100W multiple-output auxiliary power supply prototype is built, and the experimental results verify the feasibility of the proposed scheme and the validity of the theoretical analysis.

• 한국수자원학회논문집
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• 제33권5호
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• pp.647-658
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• 2000

본 연구에서는 공급측면 산업연관분석모형을 사용하여 물공급지장이 끼치는 산업의 전방효과를 분석하고자 하였다. 여기서 분석된 공급지장비용은 수도사업의 신뢰도 결정에 사용될수 있으며 물의 공급부족이 발생할 경우 물의 효율적 배분을 위한 정책적 기초를 제공할 수 있다. 따라서 산업연관분석을 이용하여 수도부문이 차지하는 국민경제적 위치를 확인하고 공급지장으로 인한 산업간 직·간접 피해를 분석하였다. 또한 가뭄시 중요한 공급우선 순위 결정을 위한 공급지장지수를 제안하였다. 한편 가뭄의 발생은 지역적인 특성을 가지고 있어서 전국산업연관표를 이용한 지역수준의 공급지장비용이 과대 도는 과소평가될 여지가 있다. 따라서 경남지역산업연관표를 통해 산정한 공급지장비용을 전국산업관표와 비교·분석하였다.

• Journal of electromagnetic engineering and science
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• 제16권2호
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• pp.126-133
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• 2016

Wireless power transfer (WPT) efficiencies for multiple-input multiple-output (MIMO) systems are formulated with a goal of achieving their maximums using Z matrices. The maximum efficiencies for any arbitrarily given configurations are obtained using optimum loads, which can be determined numerically through adequate optimization procedures in general. For some simpler special cases (single-input single-output, single-input multiple-output, and multiple-input single-output) of the MIMO systems, the efficiencies and optimum loads to maximize them can be obtained using closed-form expressions. These closed-form solutions give us more physical insight into the given WPT problem. These efficiencies are evaluated theoretically based on the presented formulation and also verified with comparisons with circuit- and EM-simulation results. They are shown to lead to a good agreement. This work may be useful for construction of the wireless Internet of Things, especially employed with energy autonomy.

• 대한기계학회논문집
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• 제18권8호
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• pp.1997-2004
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• 1994

A model analysis method has been developed in the paper. The method estimates the modal parameters of multiple input-output systems, assesses their quality, and seperates structural modes form computation ones. The modal parameter extraction algorithm is the least squares method with a finite difference model relating input and output time data. The quality of the estimated system model can be assessed in narrow frequency bands by comparing the measured and model predicted responses in time domain with the aid of digital filters. Structural modes can be effectively separated from computational ones using the convergence factor which represents the pole convergence rate. The modal analysis method has been applied to simulated and experimental vibration data to evaluate its utility and limitations.

• 한국IT서비스학회지
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• 제17권3호
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• pp.37-51
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• 2018

Recently, cloud computing market is growing geometrically in both private and public area, and many global companies in various domains have developed and provided cloud computing services. In such situation, Korean government made multiple plans for domestic cloud computing industry. However, most research institutes have focused on market size and status information, which makes actual effectiveness of cloud computing service hard to recognize. In this study, we define cloud computing Industry by rearranging Input-Output table published by the Bank of Korea to use Input-Output Analysis. The Input-Output Analysis was devised in 1963 by Leontief and it is used in many fields of study until now. It produces various coefficients that are able to identify production-inducing effect, value-added effect, labor-inducing effect, front and rear chain effect. The analysis results show that production-inducing effect, front and rear chain effect of cloud computing industry is low compared to other industries. However, cloud computing Industry possesses relatively high value-added effect and labor-inducing effect. It is because industry magnitude of cloud computing is smaller than other industries such as manufacturing, chemical industries. The economic effects of the cloud computing industry are not remarkable, but this result is significant to emerging markets and industries and presents the fresh way of analyzing cloud computing research field.

• 한국IT서비스학회지
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• 제17권1호
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• pp.47-58
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• 2018

In this study, we define Fintech services as review previous literatures and identify the traditional Fintech service market for analysing the economic effects of the Fintech Industry by using the 2014 Input-Output Table. We can identify the current market of Fintech industry which consists of VAN, PG, financial SW, mobile banking and Fintech R&D and we conduct Input-Output analysis by using non-competitive import model. The Input-Output analysis results show that production inducement effect and front/rear chain effect of the Fintech Industry are below average of other industries. This is because the Fintech technology and industry were emerging in Korea at that time (2014), and thus the ripple effects are not significant. Especially, due to the existing white risk financial regulation, new business opportunities have not been open to adapt new ICT-financial technologies. Therefore, when the business ecosystem is build through deregulation and platforms of the financial sector, it is expected that the Fintech Industry will have a high ripple effect. In this study, we identify the current market of Fintech industry from ICT indusries and conduct Input-Output analysis. The economic effects of the Fintech industry are not remarkable, but it is significant to identify the emerging market and present the basic analysis of issued research field.

• 물과 미래
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• 제28권1호
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• pp.81-90
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• 1995

본 연구에서는 장기간의 수문기상자료를 보유하고 있으나 유출량자료의 관측년한이 짧은 유역에서 장기간의 월유출량자료를 확장하고 예측할 수 있는 추계학적 시스템 모형을 개발하고자 한다. 그 방법으로 주기성과 경향성을 갖는 월유출량, 월강수량 및 윌증발량자료를 시계열 분석하여 seasonal ARIMA 형태의 단변량 모형을 유도하는 한편, 각 계열간의 교차상관분석으로부터 월강수량 및 윌증발량을 입력변수로 하고 월유출량을 출력변수로 하는 다중 입력-단일 출력관계의 설명모형을 유도하여 단변량 시계열모형과 비교 검토하였다. 본 연구의 결과 월유출량자료의 확장과 예측에 있어서 다중 입출력모형의 정확성과 적용가능성이 매우 높은 것으로 판단되었다.

• 수산경영론집
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• 제46권1호
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• pp.109-119
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• 2015

This paper is to estimate the economic effect of benefits of the R&D and recreational fishing as well as input-output analysis in the Tae-an Trial Sea Farm Project(TTSFP). We use B/C model to indicate the effects of economic valuation. B/C analyses model consists of Benefit Cost Ratio(BCR), Net Present Value(NPV) and Internal Ration of Return(IRR). Using 5.5% discounting rates and the survey data, the sub-models show economically feasible in the all of analysis and analyzed the results as follows. NPV is 42,147 million won, BCR is 3.29 and IRR is 34.30%. This study attempts to apply input-output(I-O) analysis in connecting the economic effect of TTSFP. I-O model was constructed, focusing on three effects; the production-inducing effect, the value-added-inducing effect and employment-inducing effect. There are positive effects on economic value and job creation in Tae-an and Nation.

• 대한기계학회논문집A
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• 제21권7호
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• pp.1127-1140
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• 1997

With the study for identifying the transmission characteristics of vibration and noise generated by operating engine system of a vehicle, recently many engineers have studied actively the reduction of vibration and noise inducing uncomfortableness to the passenger. In this study, output noise was analyzed by multi-dimensional spectral analysis and vector synthesis method. The multi-dimensional analysis method is very effective in case of identification of primary source, but this method has little effect on suggestion for interior noised reduction. For compensation of this, vector synthesis method was used to obtain effective method for interior noise reduction, after identifying primary source for output noise. In this paper, partial coherence function of each input was calculated to know which input was most coherent to output noise, then with simulation of changes for input magnitude and phase by vector synthesis diagram, the trends of synthesized output vector was obtained. As a result, the change of synthesized output vector could be estimated.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1707-1714
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• 2006

In order to enhance sustainable war fighting capabilities, it is important to maintain a good ammunition support system. In this paper, we evaluate the performance of Ammunition companies using Imprecise Data Envelopment Analysis (IDEA)-BCC and IDEA-Additive model, which can deal with imprecise data in DEA. In order to select a list of input and output variables, we used a multiple regression analysis. We could choose input variables that have significant effects on the output performance with stepwise regression model. From the regression analysis, the number of soldiers, officers, and ammunition warehouses were selected as the input variables. Seven out of sixteen Ammunition companies were found to be inefficient by the IDEA-BCC model. And using IDEA-Additive model, we could identify the input excess and the output shortfall in reaching at a point on the efficiency frontier.