• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.571-575
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• 2002

An immersion-type on-line refractometer useful for the in-situ measurement of salinity and temperature of sea water is developed, and its performance is examined by applying the refractometer to known salt solution having salt concentration between 2 and 4 % similar to practical sea water salinity. Since refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of salinity measurement for the different concentrations of salt solution indicates that the device is suitable for the salinity measurement by yielding stable and reproducible reading.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.240-242
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• 2012

2011년 6월 '해상교통안전법'이 '해사안전법'으로 전부 개정된 후 진단시행지침의 전부 개정을 통해 선박안전기술공단 해사안전연구센터가 진단전문기관으로 지정되었다. 하지만 국가업무를 대행 또는 위탁하는 형식이 아닌 진단서에 대한 의견을 제시하는 수준으로 전문기관의 설립 및 역할이 불명확하여 정부의 예산지원이나 수수료 등의 징수 근거로 한계가 있는 것으로 조사되었다. 따라서 본 연구에서는 도로교통안전진단, 시설물안전진단, 환경영향평가 등 유사제도의 전문기관 운영현황을 분석한 결과, 법에서 전문기관의 존재 및 역할을 명확히 규정하여 정부의 예산지원이나 수수료 등 징수근거가 명확한 상태에서 전문기관의 역할을 수행하고 있으며, 담당 공무원의 업무 연속성 및 전문성 부재로 제도의 효율적 운영을 위해서는 전문기관의 역할 및 권한 확대와 더불어 진단기술관련 역량 강화를 통해 전문성 향상이 필요한 것으로 조사되었다. 향후과제로 안정적인 전문기관의 역할 수행을 위해 관련법령을 정비하여 전문기관의 설립 및 업무 위탁을 명확히 규정할 필요가 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.210-212
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• 2019

위성항법시스템의 취약성에 따른 보완 시스템의 필요가 높아지면서, eLoran 시스템이 가장 현실적인 대안으로 인정받고 있다. 우리나라도 서해 일부 지역에서 eLoran 시스템의 테스트베드 구축 사업을 진행 중에 있다. 전 해양지역에 안정적인 서비스를 제공하기 위해서는 추가적인 송신국 설치가 필요하지만. 여러가지 현실적인 이유로 인해 추진되기 어렵다. 이런 문제를 해결하기 위해 기존의 NDGNSS 기준국을 활용한 측위기술이 개발되고 있다. 이미 운영 중인 NDGNSS 기준국을 활용하면 전 해상에서 탄력적 항법시스템 운용이 가능해질 수 있다. 본 논문에서는 eLoran 시스템과 NDGNSS의 기준국을 활용한 지상파 통합항법시스템의 성능을 예측할 수 있는 시뮬레이션 툴을 제작 하였다. ITU에서 배포한 송출 주파수와 거리에 따른 신호 세기, 대기잡음 등을 고려해 Cramer-Rao Lower Bound로 수신 신호의 측정 거리 오차를 계산하였다. 또한 한빛호가 항해하면서 수집한 DGPS 신호를 통해 실질적인 대기잡음을 추정하는 방법을 사용해 기존보다 정확한 SNR 계산이 가능해졌다. 해당 결과는 추후 진행될 지상파통합항법시스템 개발에 유용하게 활용될 것으로 기대된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.575-578
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• 2009

자연하천에 적용가능한 수치모형은 지형의 변화를 합리적으로 계산할 뿐 아니라, 하도의 초기상태가 마름상태이거나 혹은 계산과정 중에 마름상태가 나타나더라도 충분히 계산할 수 있을 만큼 안정적이어야 한다. 본 연구에서는 비정형 및 비구조적 격자를 사용하여 지형변화를 고려한 흐름해석의 정확성과 효율성을 높이기 위해 보존변수의 재구성을 수면경사법과 MUSCL 기법을 연계하였으며, 하상경사항은 발산정리를 이용하여 이산화 하였다. 개발 모형의 정확성, 적용성 그리고 보존특성 등을 검증하기 위하여 해석해가 존재하는 불규칙 하상이 존재하는 하도 및 실험자료가 존재하는 실험하도에서의 댐 및 제방 붕괴와 같은 다양한 조건의 흐름에 적용하였다. 그리고 자연하천에 대한 적용 및 검증을 위해 Malpasset 댐 붕괴 모의를 수행하여 계산결과를 관측자료와 비교하였다.

• The Korean Journal of Zoology
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• v.31 no.4
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• pp.300-308
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• 1988

Human placental alkaline phosphatase (PLAP), one of the oncofetal antigen was purified from placentas through the procedures including butanol extraction, concanavalin A-Sephar-ose, DEAE-cellulose and Sephadex G-200 gel chromatography. Monoclonal antibodies (fibs) against human PMP were produced by hybridizing SP 210-Ag 14 mouse myeloma cells with spleen ceils of Balblc mice immunized with PLAP. Six stable monoclones uvere obtained by cloning tuvice in serial dilutions, and the monoclonal speclfidty of these MAbs was confirmed by biochemical and immunonogical criteria. Tumor marker의 하나인 태반형 alkaline phosphatase(PLAP)에 대한 단일 클론항체의 생산과 분석을 위하여, 태반조직을 재료로 butanol 추출법 및 concanavaline A-Sepharose, DEAE-cellulose, Sephadex G-200 gel 크로마토그라피법에 의하여 PLAP를 순수 분리하였다. 이를 항원으로 하여 하이브리도마 방법에 의해 항-PLAP 단일 클론항체를 생산 분비하는 안정된 6클론세포를 얻었으며 생화학적 및 면역학적 분석방법으로 이들의 단일 클론성을 확인하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.134-134
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• 2009

ITZO 박막은 2개의 캐소드 (DC, RF)를 이용하여 마그네트론 2원 동시 방전법에 의해 고온에서 안정한 polyimide 기판위에 상온에서 증착하고 $200^{\circ}C$에서 어닐링 하였다. XRD 측정 결과 어닐링 과정을 거친 막들은 Zn의 도입에 따란 결정성이 감소하다가 RF파워 280W에서 증착한 박막은 완전한 비정질 구조를 보였다. AFM 측정과 밴딩 테스트 결과, ITO 및 ITZO 박막들은 결정성이 감소할수록 매끄러운 표면과 낮은 저항 변화율을 보여주었다. 전기 비정항은 Zn 함량이 증가함에 따라 증가하였지만, 광학적 투과율은 $200^{\circ}C$ 어닐링 과정을 거친후의 막들에 있어서 증가됨을 보였다.

• Journal of Korea Port Economic Association
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• v.28 no.4
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• pp.59-77
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• 2012

Inland transportation system has been improving inefficiencies and structural problems due to excess of supply. Therefore, inland transportation market needs to reform its regional logistics structure in order to increase its competitiveness. To improve the solution, the research studied efficiencies and productivity of inland transportation systems in regions. In order to obtain specific facts, each cities' five years of (2005-2009) balanced panel data on inland transportation system has been studied. According to CCR and BCC analysis, Ul-San has been evaluated as the most efficient DMU during 2005-2008. In addition, in 2009, Seoul was the most efficient DMU. Also, according to Window analysis, Gwan-Ju and Gwangwon-do scored 0.062. Therefore, they were estimated as stable DMUs. According to Malmquist productivity analysis, average productivity indexes of four terms of Chungcheongnam-do and Chungcheongbuk-do haves been increased to 6.6% and 7.3%. I hope this study contributes to the improvement of regional inland transportation system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.612-620
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• 2012

This study was performed to investigate the 4-week repeated-dose toxicity of $Lactobacillus$ $plantarum$ AF1 ($Lb.$ $plantarum$ AF1), a lactic acid bacteria isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 0.5, 1.0, and 2.0 g/kg/day for 4-weeks. There were no test articlerelated deaths or abnormal clinical signs in either gender of rat during the observation period. Furthermore, no differences were found between the control and treatment groups in terms of body weight changes, food intake, and water consumptions. Hematological parameters, serum biochemical analysis, and any other findings also showed no significant or dose-dependent alterations. There were no alterations in organ weights upon administration of $Lb.$ $plantarum$ AF1. These results suggest that there were no adverse effects of oral application of $Lb.$ $plantarum$ AF1 up to a dosage level of 2.0 g/kg in both male and female rats.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.256-270
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• 2023

In this study, a sliding mode (SM) controller for dynamic positioning (DP) was specifically designed for a turret connection operation of a ship or an offshore structure in which an arbitrary point on the structure could be controlled as the motion center instead of the center of mass. The SM controller allows control of the arbitrary point and provides capability to manage uncertainties in the dynamics of ships and offshore structures, external forces caused by unknown changing marine environments, and transient performance of DP systems. The Jacobian matrix included in kinematic equations of the controlled object was modified to design the SM controller to control based on an arbitrary point of ships or offshore structures. To ensure robustness of the controller, the Lyapunov stability theory was applied in the design of the SM controller. In general, for robustness in DP control, gain scheduling based on a proportional-derivative (PD) control algorithm is employed. However, finding appropriate gains for gain scheduling complicates the application of DP systems. Therefore, in this study, the SM control algorithm was considered to mitigate the complexity of the DP controller for ships and offshore structures. To validate the proposed SM control algorithm, time-domain simulations were conducted and utilized to evaluate the performance of the control algorithm. The effectiveness of the proposed SM controller was assessed by comparing simulation results with results of a conventional PD control algorithm applied in DP control.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.261-268
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• 2014

The route of Korea and China situates stable shipping market by the agreement on maritime transport between two countries. Epecially, the Car-ferry shipping market between Korea and China is growing up the world's largest markets in this situation. But, the rapid growth of markets have the possibility of imbalance between supply and demand. In addition that heavy competition can be arisen. The aim of this study is to analyze the ways to reinforce competitiveness of Car-ferry shipping companies(CFSCs) between Korea and China routes through suggesting importance weights of service factors. Firstly, evaluating service factors of CFSCs between Korea and China routes are selected by reviewing literatures and Delphi method. Secondly, importance weights of service factors are calculated using Fuzzy method. As a result, Shipper and CFSCs between Korea and China routes select 'agility of loading and unloading', 'agility of customs', and 'punctuality of transportation' as the most important factors. On the other hand, the two groups are shown the perception gaps on the factors such as 'reasonable shipping cost', 'voyage speed', 'multimodal transportation', and 'professionality of manpower'. The implication of this study is that Government of Korea and China Have to cooperate agreement for mutual drive towed trailer and customs to speedy transportation.