• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.1
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• pp.36-45
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• 2010

This paper shows a multiplexing technique to maximize the application of a moire-fringe based fiber optic sensor to lots of structure. Especially, a novel fringe-based fiber optic sensor was proposed to overcome the difficulty of multiplexing of a previous moire-fringe-based fiber optic sensor. The novel fringe-based fiber optic sensor is composed of a single reflective fringe and two optical fibers. Therefore, the multiplexing is easily realized because of the simplicity of optic structure inside the sensor. This paper also proposed four models of the multiplexing techniques. The models are based on a wavelength division multiplexing(WDM) technique and a time division multiplexing(TDM) one. Basically, the models would be profitable for a general extrinsic fiber optic sensor such as the fringe-based fiber optic sensor. Finally, the real optic system was manufactured by using the proposed model and successfully examined to prove the feasibility of the model for the application.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.33-39
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• 2014

Domestic and international researches, about intelligent systems based on a variety of location recognitions using location information, have actively proceeded. The representative location recognition method based on PTMP(Point To Multi Point) communication uses TOA(Time Of Arrival) to calculate distances to a fixed node that you want to recognize a position. The method is used to obtain the fixed node location information from three nodes location information that is applied by the triangulation method. There are disadvantages, an infrastructure should be established at a specific space and the system established cost is needed, in the location recognition method based on the PTMP communication, In this paper, the ranging based PTP(Point To Point) location recognition method is proposed to revise the disadvantage of PTMP location recognition method. And then it is compared with PTMP communication location recognition to evaluate performance. In this way, PTMP and PTP communication location recognition systems based on ranging were constructed and tested in an indoor environment. Experiment results show that the proposed PTP location recognition method could be confirmed to improve accuracy more than 3 times when it was compared with the existed PTMP location recognition method.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.474-477
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• 2009

본 연구에서는 5MW급 수평축 풍력발전 블레이드에 대한 정격풍속과 낮은 풍속 영역을 고려하여 풍속에 대한 다점 최적설계를 수행하였다. 다점 최적설계를 수행하기 위해 블레이드 해석은 Blade Element and Momentum theory를 이용 하였으며, 설계 시 적용된 기저형상은 NREL에서 제안한 5MW급 풍력터빈 블레이드이다. 최적화 과정을 통해 얻어진 최적해의 집합에 대하여 L2 Norm을 통한 파레토분석을 하였으며, 이를 통해 기저형상의 연간 에너지생산량과 설비 이용률을 보다 향상 시킬 수 있었다.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.5
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• pp.87-102
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• 2018

The purpose of this study is to determine the impact of food service franchise's support system on franchisee's trust, financial performance and intention of multi-store operation. For this purpose, the results of the survey were collected for 111 small and mid-sized food service franchisees in Korea with less than 100 brand franchises, referring to article 9 of the act on Fair Trade. Structural equation model analysis was used for hypothesis testing. The results of the study are as follows; First, a support for store development, education, logistics, and supervisors among franchise's support system were found to have a significant impact on the franchisee's trust, but public relations support was not significantly affected. Second, a support for store development had significant influence on the financial performance, but the support for education, logistics, supervisors and public relations did not significantly affect the financial performance. Third, franchisee's trust has been shown to have a significant impact on financial performance and intention of multi-store operation. Fourth, financial performance was shown to have a significant impact on the intention of multi-store operation. Finally, confirming the mediated effects of financial performance on the effect of franchisee's trust and intention of multi-store operations also proved to have indirect effects. This study identified the impact relationship between the small and medium-sized food service franchise support system, franchisee's trust, financial performance and intention of multi-store operation. In particular, it is deemed meaningful that the performance of Korea's small and medium-sized food service franchises and the relationship of influence that can grow together through the qualitative growth of the franchise's system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1661-1667
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• 1999

In this paper, we propose an efficient VP extension algorithm for ABR multipoint-to-point connection in ATM networks. The VC merging or VP merging is used to implement ABR multipoint-to-point connection. We use the VP merging technique. To solve the scarcity problem of VP resources, we propose an efficient VP extension algorithm. Since the proposed scheme follows the standard VPI/VCI format, it doesn’t require another table according to the VP extension. We compare the proposed scheme with VC merging algorithm. The result shows that the proposed method can provide fair bandwidth allocation among the sources in multipoint-to-point connection.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.71-73
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• 2012

본 연구는 선형이론에 기반한 상용코드를 이용하여 불규칙파중에서 다점계류중인 해양구조물의 계류력과 운동응답특성을 추정하였다. 경험적인 실험에 의존했던 방법의 병행하여 해를 갖을 필요성을 인식하지만 초기설계단계에서 계류력의 추정과 설치해역의 자연환경조건에서 해양구조물의 생명주기에 대한 추정을 하는 것은 충분한 의미를 가질 수 있다. 설치해역은 연안해역의 환경조건을 적용하였으며 해석대상은 길이 200미터, 폭 30미터 높이 10미터의 강구조물에 대해서 선정하였다. 해석결과 대형구조물의 운동응답은 계류삭과 현수선의 의존도가 높게 나타났다. 불규칙 파랑하중에 대한 종횡강도에 대한 추가연구가 필요하다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.625-628
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• 1989

광섬유와 micro변형기를 이용하여 다점 압력 계측 system을 구성하여 실험을 행하였다. 그 결과 pulse generator와 analog switch를 이용함으로써 100ns의 광 pulse를 쉽게 얻을 수 있었으며, 또한 3개의 광 pulse를 analog switch를 이용하여 쉽게 분리할 수 있었다. 한편 변형기에 가한 힘과 광 손실간의 상관관계를 이론치와 비교하여 조사한 결과 힘과 광손실간의 상관관계는 이론치와 실험치가 유사한 경향을 나타내는 것을 알 수 있었다.

• 베이커리
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• no.12 s.329
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• pp.108-109
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• 1995

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.119-126
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• 2019

For rockets using cryogenic liquid hydrogen or liquid oxygen, chilling is required to avoid cavitation and surge problems. Chilling is categorized by the initial chilling/filling stage and the low-temperature maintenance stage. In addition, to improve satellite insertion capability, a multi-ignition capability is required and accordingly chilling to prepare for the next ignition during low-gravity coasting is also required. This paper describes the overall aspects of filling and low temperature maintain marinating for the booster and the upper stage engine including chilling for multi-ignition.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.3
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• pp.195-201
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• 2001

The time simulation of slow drift motions of moored FPSO in waves is presented. The equation of motion based on Cummin's theory of impulse responses are employed, and are consisted of horizontal plane motions such as surge, sway and yaw. The added mass, wave damping coefficients, first order wave exciting forces and the second order wave drift forces involved in the equations are obtained from three-dimensional panel method in the frequency domain. The mooring lines are modeled as quasi-static catenary cable. As a numerical example, time domain analyses are carried out for a box-type FPSO in long crest irregular wave condition.