• 대한기계학회논문집B
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• 제33권5호
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• pp.349-357
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• 2009

Effect of computational domain size in simulating of periodic obstacle flow has been investigated for the flow past tube banks. Reynolds number, defined by freestream velocity ($U_{\infty}$) and cylinder diameter (d), was fixed as 200, and center-to-center distance (P) as 1.5d. In-line square array and staggered square array were considered. Drag coefficient, lift coefficient and Strouhal number were calculated depending on domain size. Circular cylinders were implemented on a Cartesian grid system by using an immersed boundary method. Boundary condition is periodic in both streamwise and lateral directions. Previous studies in literature often use a square domain with a side length of P, which contains only one cylinder. However, this study reveals that the domain size is improper. Especially, RMS values of flow-induced forces are most sensitive to the domain size.

• 한국경영과학회지
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• 제37권3호
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• pp.1-12
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• 2012

The research mainstream has focused on improving the competitiveness throughout the reinforcement of customer satisfaction and loyalty in the banking industry, but there is still a lack of research that reflects characteristics of banking services. From a customer point of view, this study considers a variety of bank characteristics such as levels of interest rate, numbers of transaction banks, monthly average balance, and age. In line with this observation, the main objective of the current research is to investigate the relationship between bank characteristics and ongoing transaction intentions with a particular bank using a categorial regression analysis and in turn, provide insights for managers. First, the findings show that deposit interest rate is insignificant for leading customers to ongoing transaction intentions, but loan interest rate is significant when customers are satisfied with a loan interest rate. Second, if customers only transact their banking services with a particular bank, they are more likely to deal with the bank, rather than customers who transact additional one or two banks. Third, in the case of monthly average balance, customers who have more than \100 million wons per month are likely to switch other competitors. Finally, old customers are more stable than young customers when they consider to switch the relationship with a bank. The author provides insights for bank managers and discusses research limitations and further directions of the study.

• 응용통계연구
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• 제26권6호
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• pp.959-975
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• 2013

Friendly (1992)의 SAS macro faces 프로그램은 다변량 시각화 표현법 중 하나인 체르노프 얼굴 분석을 위한 프로그램이다. 본 연구에서는 faces에서 사용된 18개 얼굴 특징 변수를 살펴보고 현 시대의 흐름에 맞는 좋은 얼굴의 정의에 따라 수정된 프로그램을 제시하였다. 또한 은행의 안정성, 소비자 만족도, 건전성, 수익성을 나타내는 11개 은행경제지표에 기초한 체르노프 얼굴분석을 통하여 국내 15개 은행에 대해 소비자 입장에서 좋은 은행 평가를 수행하였다.

• 전기학회논문지
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• 제57권12호
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• pp.2147-2152
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• 2008

This paper proposes an algorithm to estimate the circulating currents in the transformers in parallel in an ultra high voltage system. For the Y-Y-${\Delta}$ transformers operated in parallel, there exist two kinds of the circulating currents i.e. one is between the tanks and the other between the banks of the delta side. As the former is 90 deg out of phase of the load current, it is estimated by decomposing the line current into the component 90 deg out of phase of the load current in the frequency domain. The latter is estimated in the time domain from applying the Kirchhoff's voltage law on the delta winding which gives a first-order differential equation in terms of the delta winding currents. To estimate the circulating currents between the tanks, the performance of the proposed algorithm is investigated when the impedances of the two transformer tanks are different or the taps of the on-load tap changer of the transformers are mismatched temporarily. To estimate the circulating currents between the banks, the performance of the proposed algorithm is also examined under magnetic inrush and over-excitation. Test results indicate that the algorithm can estimate the two kinds of the circulating currents successfully.

• 한국통신학회논문지
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• 제30권1A호
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• pp.70-75
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• 2005

이동 멀티미디어 서비스를 위한 통신 시스템에서 고속으로 데이터를 송신하고 수신함에 따라 발생하는 인접 심벌간의 간섭(Inter Symbol Interference : ISI) 왜곡을 줄이기 위한 방식으로 직교 주파수 분할 다중화(Orthogonal Frequency Division Multiplexing : OFDM) 방식에 대한 연구가 활발하게 진행되고 있다. 고속 무선 LAN이 표준방식으로 채택한 OFDM 방식이 부 반송파의 수가 많아짐에 따라 변복조부를 실제 시스템으로 구현하기가 어려운 단점이 있었다. 그러므로 본 논문에서는 파이프라인 방식을 이용해서 변복조부를 설계하여 많은 수의 버터플라이(Butterfly) 연산자를 감소시켰다. 또한 고속의 처리속도를 만족시키기 위해서 64 포인트를 처리하는 버터플라이 구조를 각각 32 포인트씩 병렬처리 하도록 구성하였다.

• Journal of the Korean Data and Information Science Society
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• 제25권6호
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• pp.1591-1598
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• 2014

The reviews of the balance sheet of commercial banks showed that loan item constitutes the largest portion of bank's assets. Although the sector has highest rate of profit, it possesses the greatest risk. Identifying factors that can contribute in lifting-up the loan repayment rate of customers of Hawassa district commercial bank is the major goal of this study. A sample of 183 customers who took loan from October, 2005 to April, 2012 was taken from the bank record. Kaplan-Meier estimation method and univariate Cox proportional hazard model were applied to identify factors affecting bank loan repayment rate. The result from Kaplan-Meier survival estimation revealed that the loan repayment rate is significantly related with loan type, and previous loan experience, educational level and mode of repayment. The log-rank test indicates that the survival probability of loan customers is not statistically different in repaying the loan among groups classified by sex. Moreover, the univariate Cox proportional hazard model result portrayed that educational level, having previous loan experience, mode of repayment, collateral type and purpose of loan are significantly related with loan repayment rate of customers commercial bank. Hence, banks should design loan strategies giving special emphasis on the significant factors while they are giving loans to their customers.

• 대한기계학회논문집B
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• 제30권5호
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• pp.389-396
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• 2006

For the successful design of heat exchangers, it is very important to understand local heat transfer phenomena on the circular tube of heat exchangers. In the present study, experiments are performed for single circular tube and tube banks with and without heat transfer promoters. The naphthalene sublimation technique is employed to measure the local mass transfer coefficients, and the measured local mass transfer data are converted to the local heat transfer data using heat and mass transfer analogy. The distribution pattern of local Nusselt numbers on single circular tube with heat transfer promoters is similar to that without the heat transfer promoter, but average Nusselt numbers are greatly increased. In case of tube banks without the heat transfer promoter, the Nusselt numbers are much lower in the first row than those of other rows, but the local heat transfer coefficients on all rows are equalized when the heat transfer promoter is installed.

• 무역상무연구
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• 제39권
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• pp.105-142
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• 2008

For many companies, selling in an international market place is the ultimate challenge. One of the greatest problems facing exporters is the increasing insistence by importers that trade be conducted on open account terms. This often means that payment is received many weeks or even months after delivery. Unsurprisingly, many organisations find that giving buyers credit in this way can cause severe cash flow problems. Further problems can arise if the importer delays payment beyond originally agreed terms or makes no payment at all because of financial failure. In particular, many SMEs find it difficult to finance their production cycle, since after goods are delivered most buyers demand 30 to 90 days to pay. Therefore, International factoring for SME has been developing very rapidly in the world trade financing markets. Functions of international factoring as trade financing is a comprehensive financial service that includes credit protection, accounts receivable bookkeeping, collection services and financing. Factoring can be a powerful tool in providing financing to high-risk, informationally opaque sellers. International factoring is very helpful for international exporters to get competitiveness in the world markets. In Korea, a few banks are operating international factoring. But International factoring in Korea could not play a key roll as general trade supporting service. So, This study is to suggest importances of international factoring development for trade development and to investigate real operation situations and problems by way of interviews with operators in banks that are operating international factoring and suggest development strategies for international factoring in Korea.

• 무역상무연구
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• 제60권
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• pp.141-175
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• 2013

The purpose of this study aims to the implications by the introduction of TSU/BPO system as a instrument of trade settlement. Jointly with financial messaging provider SWIFT, the ICC Banking Commission has developed the URBPO to take into account the legitimate expectations of all relevant sectors. Once the goods have been shipped, the seller's bank uploads the shipping and logistics data to the TSU to be checked against the baseline. URBPO is the first ever set of standards in supply chain finance that governs BPO transactions worldwide. BPO enables banks to reduce the risks associated with international trade to the benefit of both buyers and sellers. A BPO is an irrevocable undertaking given by an Obliger Bank to a Recipient Bank to pay a specified amount under the condition of a successful electronic matching of data or acceptance of mismatches. The BPO should be viewed as an exercise in collaboration between trading partners and their banks. Drawings upon global standards and incorporating the benefits offered by letters of credit, the new instrument has the potential to benefit all parties in a trade transaction-and bring trade settlement into the 21st century.

• Journal of Advanced Marine Engineering and Technology
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• 제30권4호
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• pp.483-493
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• 2006

A model for a pressure drop of water vapor flow across tube banks in a horizontal tube absorber of an absorption chiller/heater using LiBr solution as a working fluid has been developed based on a commercial 20RT(70kW) absorption chiller/heater. The numerical results show that the characteristic of the pressure drop in the shell side of the horizontal tube absorber is completely different from that in a conventional shell and tube heat exchanger. Especially, solution film thickness has significant influence on the vapor pressure drop in the horizontal tube absorber. In addition, the effects by the tube diameters, the longitudinal pitch to diameter ratio, and Reynolds number of the vapor flow, on the vapor pressure drop have been studied to evaluate the compactness of tube absorber. It was found that the vapor pressure drop decreases as tube diameter increases, the longitudinal pitch to diameter ratio increases, and Reynolds number of the vapor flow decreases. A comparison of the present study results with well-established experimental and numerical results showed a good overall agreement.