• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.381-382
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• 2022

흘수는 선체가 물속에 얼마나 잠겨있는지를 나타내는 용어로, 선박에서는 화물의 양을 계산하거나 안정성을 평가하기 위해 흘수를 측정한다. 흘수를 측정하는 방법으로는 항해사가 부두에서 육안으로 확인하거나, 사다리를 타고 내려가 직접 확인하는 방법이 있다. 이러한 방법들은 경우에 따라 흘수 측정이 불가능하거나, 추락의 위험이 항상 존재한다는 문제가 있다. 이러한 문제를 해결하기 위해 드론 등을 통해 카메라로 선박의 흘수선 부근을 촬영하고, 필터링 및 이미지 검출 기법을 사용하여 선박의 흘수선을 탐지하는 방안을 제시하였다.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.110-110
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• 2010

본 연구에서는 대규모 항만시설물을 계획함에 따라 발생될 수 있는 인근 소규모 어항의 안정성에 대하여 일예를 들어 검토하였다. 제주해군기지 건설로 인해 인근어항(강정항)의 기축조분 84m를 제외한 잔량분 126m에 대한 평면수정이 불가피할 것으로 판단됨에 따라 수치모형실험(SWAN)을 통해 강정항의 현 상태 및 기지건설 후의 항내파고 분포에 대하여 검토하였다. 또한 남방파제 잔량분이 미 시행됨에 따라 발생할 수 있는 항내정온도를 확보하기 위하여 대안을 연구한 결과 제주해군기지 서방파제 시점부에 파제제 50.0m를 설치함으로써 보다 효율적이고 경제적으로 인근어항(강정항)의 항내정온도를 크게 개선시킬 수 있을 것으로 판단된다.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.389-394
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• 2017

In this paper, the captive model test of a submarine using the RA test was carried out in a square basin. The target model submarine consisted of four types varying according to the position of conning tower and control planes. Hydrodynamic derivatives were acquired by multi-regression analysis. As a result, horizontal dynamic stability indexes of the four types presented positive values and satisfied dynamic stability requirements. In addition, the stability index of type 1 and type 4 - each with the same cruciform configuration of the aft planes - scored within the acceptable range of motion stability.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.116-118
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• 2021

초고속 해상무선통신망(LTE-Maritime)은 바다 어민의 안전과 항해 중인 선박의 편의 서비스 제공을 위해 대한민국 연안으로부터 최대 100km 까지 해역을 LTE(Long Term Evolution) 통신 체계로 구축한 세계 최초의 해상 무선통신망이다. 본 논문은 초고속 해상무선통신망의 활용성을 높이기 위해 다용한 용도로 개발된 무선설비의 호환성, 신뢰성, 안정성을 확보하기 위한 상호운용성 시험 방안을 논의해보고자 한다. 본 논문은 이종 통신장비 및 이종 무선설비 간의 상호운용성을 단말(무선설비)과 시스템의 종단간 통신품질 측정을 통해 서비스 커버리지 성능, 무선데이터 전송 속도 및 전송성공률 등을 검토해 보고, 각 품질 지표를 검증할 수 있는 시험 구성 방안, 시험 항목 및 절차, 측정 결과 분석 방법 등을 다각도로 살펴보고자 한다.

• Journal of Korea Port Economic Association
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• v.30 no.1
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• pp.1-21
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• 2014

Recently, GTO's rate of return to investment is decreasing. Therefore, the main purpose of this paper is to analyze empirically on enhancement of competitiveness of global port container terminal. This study deals with the terms of three competitiveness enhancement factors which are a GTO's subjective factors, a management environment factors, and a government policy factors. According to analysis results of the three competitiveness enhancement factors, a GTO's subjective factors(4.21 score) are scored at the most ones of competitiveness enhancement factors of GTO, to be compared with a management environment factors(3.94 score). with a government policy factors(3.90 score). Therefore, first of all, it is important to enhance competitiveness of GTO through as follows, a GTO's subjective factors : (1) to procure local and tranship cargo volume, (2) to promote port logistics service, (3) to retain resonable port rate by promoting terminal productivity, (4) to procure container ship firms and alliance. And, the next, we have to enhance GTO's competitiveness through considering a management environment factors, that is, fluctuation of container cargo volume, port awareness, whether function of hub port, etc., and a government policy factors, that is, smart policy of port development, smart policy of port rate, incentive policy for procuring tranship cargo, etc.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.71-83
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• 2014

Busan is located at the mouth of Nakdong River and if an earthquake occurs, it is very likely that the damage by the earthquake will be worse as liquefaction can happen in the sand layer, builtup soil, and landfill ground due to amplification in the lower sedimentary layer that is well developed in the river mouth. Therefore, this study first examined the possibility of liquefaction in the replaced sand layer under breakwater using 14 earthquakes in 5.6-7.9 scale and artificial earthquakes including the seismic wave suggested in the standard specifications for seismic design of ports and fishing port facilities to evaluate the stability of breakwater which is the primary protective structure for port facilities against earthquakes. Second, analysis on characteristics of the seismic energy and acceleration response spectrum by size of earthquake was performed to suggest the most appropriate size of seismic wave for the condition in Korea. Third, finite element analysis was performed using the suggested seismic wave to study the characteristics of earthquake by finding the dynamic lateral displacement of breakwater and verifying the stability of structure and the displacement and forces occurring at geotextile. Results of the study showed that the possibility of liquefaction in the landfill and replaced sand layer, the dynamic lateral displacement of breakwater, and changes of geotextile are greatly affected by the subsurface ground (replaced sand layer).

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.97-106
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• 2022

Listeria monocytogenes (L. monocytogenes) is one of gram-positive foodborne pathogens with a very high fatality rate. Unlike most foodborne pathogens, L. monocytogenes is capable of growing at low temperatures, such as in refrigerated foods. Thus, various physical and chemical prevention methods are used in the manufacturing, processing and distribution of food. However, there are limitations to the methods such as possible changes to the food quality and the consumer awareness of synthetic preservatives. Thus, the aim of this study was to evaluate the anti-listeria activity of lactic acid bacteria (LAB) isolated from kimchi and characterize the bacteriocin produced by Lactococcuslactis which is one of isolated strains from kimchi. The analysis on the anti-listeria activity of a total of 36 species (Lactobacillus, Weissella, Lactobacillus, and Lactococcus) isolated from kimchi by the agar overlay method revealed that L. lactis NJ 1-10 and NJ 1-16 had the highest anti-listeria activity. For quantitatively analysis on the anti-listeria activity, NJ 1-10 and NJ 1-16 were co-cultured with L. monocytogenes in Brain Heat Infusion (BHI) broth, respectively. As a result, L. monocytogenes was reduced by 3.0 log CFU/mL in 20 h, lowering the number of bacteria to below the detection limit. Both LAB strains showed anti-listeria activity against 24 serotypes of L. monocytogenes, although the sizes of clear zone was slightly different. No clear zone was observed when the supernatants of both LAB cultures were treated with proteinase-K, indicating that their anti-listerial activities might be due to the production of bacteriocins. Heat stability of the partially purified bacteriocins of NJ 1-10 and NJ 1-16 was relatively stable at 60℃ and 80℃. Yet, their anti-listeria activities were completely lost by 60 min of treatment at 100℃ and 15 min of treatment at 121℃. The analysis on the pH stability showed that their anti-listeria activities were the most stable at pH 4.01, and decreased with the increasing pH value, yet, was not completely lost. Partially purified bacteriocins showed relatively stable anti-listeria activities in acetone, ethanol, and methanol, but their activities were reduced after chloroform treatment, yet was not completely lost. Conclusively, this study revealed that the bacteriocins produced by NJ 1-10 and NJ 1-16 effectively reduced L. monocytogenes, and that they were relatively stable against heat, pH, and organic solvents, therefore implying their potential as a natural antibacterial substance for controlling L. monocytogenes in food.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.84-92
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• 2010

Antibacterial compound from Bacillus subtilis MJP1 was purified using C18 Sep-Pak cartridge, ion exchange chromatography, and gel filtration chromatography. The purified antibacterial compound showed antibacterial activity against Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus subsp. aureus, and Enterococcus faecalis. The purified antibacterial compound was found to be stable at $100^{\circ}C$ for 5 min and in the pH range of 3.0~9.0, but it was unstable at pH 10.0. It was inactivated by proteinase K and pronase E, and heat treatment at $121^{\circ}C$ for 15 min, but it was stable with lipase and $\alpha$-amylase treatment, which indicated its proteineous nature. Ultra performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compound and confirmed the existence of two peptides (3356.54 Da, 3400.5244 Da).

• Journal of Pharmaceutical Investigation
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• v.1 no.1
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• pp.58-61
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• 1971

Comparatives studies were made on stabilities of some hormons, used individually and combined with some stabilizers, and the following results were found. 1. The increasing order of antiallergic hormons (prednisolone, dexamethasone) to the stabilities as follows : Chlorpheniramine>Menadione>Inositol>Ascorbic acid. 2. The increasing order of sulfonylureas in as follows : Chlorpheniramine>Thiamine>Inositol>Ascorbic acid.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.209-223
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• 2007

B2C, B2B와 같은 인터넷 상거래뿐만 아니라, 전자정부를 통한 G2C 등에서 보는 바와 같이, 공공 및 민간 IX(Internet exchange)를 통한 인터넷 상호연동 인프라는 명실상부한 사회 신경망으로 기능한다. 따라서 전통적인 사회간접자본인 도로, 항만, 전력 등에서와 마찬가지로, 그 구축 및 운영에서의 안정성과 신뢰성에 대한 요구가 점차 강화되고 있다 본 연구는 인터넷 상호연동망의 안정성과 신뢰성을 제고하기 위한 방안을 위험관리 관점에서 제안한다. 먼저, 인터넷 상호연동의 강건성(robustness)을 높이기 위한 방어기제와 더불어 상호연동 대안들을 개발한다. 이들 대안은 장애시에 작동하는 별도의 상호연동 비상망을 운영하는 방재형과, 지역적으로 분산된 상호연동 허브(IX)를 운영하여 장애에 따른 피해 확산을 방지하는 분산 허브형으로 구분된다. 본 논문에서는 또한 대안들의 위험효율성(risk efficiency)을 체계적으로 비교/평가하기 위하여 경영공학 방법론에 의한 위험평가 프레임워크를 개발하고, 이를 투자수준이 상이한 여러 대안들에 적용한다. 몬테카를로 시뮬레이션을 통한 ROI(Risk On Investment) 분석 결과, 방재형 대안이 비용 대비 위험효율성 측면에서 최선의 후보로 평가되었다.