• 한국항해항만학회지
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• 제46권4호
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• pp.331-337
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• 2022

2021년 UN 자문 연구기관인 해양환경전문가그룹(GESAMP)은 해운 부문의 해양쓰레기 발생원 여섯 가지 중 하나로 컨테이너 해상유실을 지목했다. 대표적으로 2021년 5월 발생한 X-Press Pearl호 침몰은 유실된 컨테이너가 해안으로 떠밀려와 내부에 적재된 플라스틱 펠릿이 스리랑카 연안을 뒤덮은 대형 환경오염 사고로 이어졌다. 이러한 배경으로 국제해사기구(IMO)는 2022년 9월 개최하는 제8차 화물 및 컨테이너 운송 전문위원회 회의를 기점으로 선박 운항 중 컨테이너 해상유실의 방지 및 후속대책을 논의한다. 본 연구는 IMO 회의에서 우리나라의 대응 방향을 수립하고자 컨테이너 해상유실 주요 사고 조사보고서 및 관련 전문 자료 분석을 통해 유실 사고의 주요 요인을 식별하고 대응에 대해 고찰하였다. 그 결과, 운항 중 컨테이너 해상유실의 주요 요인으로 컨테이너 선박의 대형화, 기상악화 그리고 컨테이너 적재 불량이 파악되었다. 특히, 기상악화에 따른 대형 컨테이너 선박의 운항 안전성 저하에 대한 대책 마련 필요성이 식별되었다. 또한, 컨테이너의 안전한 해상운송을 위해 국제협약 이행에 대한 통합 모니터링이 요구된다. 그리고 해양환경 보전 관점에서 유실 컨테이너의 회수에 대한 제도적 보완이 필요하다. 마지막으로 컨테이너 해상유실 사고의 근본적인 방지를 위해 선박의 건조와 운항 측면에서 조선과 해운이 상호보완 가능한 체계 구축이 필요함이 식별되었다. 운항 중 컨테이너 해상유실 사고의 여러 요인은 개별 관점의 대응으로 해결하기 어렵다고 판단된다.

• 한국항해항만학회지
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• 제48권1호
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• pp.49-54
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• 2024

본 연구는 조선산업 경기가 선박용 도료업체의 경영성과에 미치는 영향을 분석하는 것을 목적으로 한다. 조선기자재는 조선산업의 후방산업으로 우리나라 조선산업의 경쟁력을 좌우하는 중요한 요소이다. 이처럼 밀접한 관계에도 불구하고, 조선기자재산업에 대한 연구는 경쟁력 확보 방안 및 기술개발 위주로 진행되어 왔으며, 조선산업과 연계한 경영성과에 대한 연구는 부족한 편이다. 이에 본 연구에서는 우리나라 조선산업 경기가 선박용 도료업체의 경영성과에 미치는 영향을 성장성과 수익성의 관점에서 분석하였다. 이를 위해서 우리나라에서 영업중인 주요 선박용 도료업체 6개사의 영업실적을 2003-2022년 기간 동안 수집하여 패널 회귀분석을 실시하였다. 분석 결과, 우리나라 조선소의 선박 인도량으로 측정한 조선산업 경기는 선박용 도료업체의 성장성과 수익성에 양(+)의 영향을 미치는 것으로 나타났다. 그러나, 선박인도량 지표에 따라 통계적 유의성이 상이한 것으로 나타났는데, 표준화물선환산톤수, 총톤수, 금액 기준의 지표는 통계적 유의성이 있지만, 재화중량톤수는 통계적 유의성이 없었다. 이러한 결과는 조선산업의 규모가 아니라 조선산업이 창출하는 부가가치에 따라 선박용 도료업체들의 경영성과가 영향을 받는다는 시사점을 제공한다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1121-1121
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• 2001

A previous study (Berzaghi et al., 2001) evaluated the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural networks (ANN) on the prediction of the chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with reference values for moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected using 10 different Foss NIR Systems instruments, only some of which had been standardized to one master instrument. The aim of the present study was to evaluate the behaviour of these different calibration methods when predicting the same samples measured on different instruments. Twenty-two sealed samples of different kind of forages were measured in duplicate on seven instruments (one master and six slaves). Three sets of near infrared spectra (1100 to 2500nm) were created. The first set consisted of the spectra in their original form (unstandardized); the second set was created using a single sample standardization (Clone1); the third was created using a multiple sample procedure (Clone6). WinISI software (Infrasoft International Inc., Port Mathilda, PA, USA) was used to perform both types of standardization, Clone1 is just a photometric offset between a “master” instrument and the “slave” instrument. Clone6 modifies both the X-axis through a wavelength adjustment and the Y-axis through a simple regression wavelength by wavelength. The Clone1 procedure used one sample spectrally close to the centre of the population. The six samples used in Clone 6 were selected to cover the range of spectral variation in the sample set. The remaining fifteen samples were used to evaluate the performances of the different models. The predicted values for dry matter, protein and neutral detergent fibre from the master Instrument were considered as “reference Y values” when computing the statistics RMSEP, SEPC, R, Bias, Slope, mean GH (global Mahalanobis distance) and mean NH (neighbourhood Mahalanobis distance) for the 6 slave instruments. From the results we conclude that i) all the calibration techniques gave satisfactory results after standardization. Without standardization the predicted data from the slaves would have required slope and bias correction to produce acceptable statistics. ii) Standardization reduced the errors for all calibration methods and parameters tested, reducing not only systematic biases but also random errors. iii) Standardization removed slope effects that were significantly different from 1.0 in most of the cases. iv) Clone1 and Clone6 gave similar results except for NDF where Clone6 gave better RMSEP values than Clone1. v) GH and NH were reduced by half even with very large data sets including unstandardized spectra.

• 한국환경농학회지
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• 제24권2호
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• pp.164-168
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• 2005

인삼의 휘발성 성분 분석 시 SFSI를 이용한 분석법의 최적화를 일하여 실험을 수행하였다. 최적화를 위하여 세 가지 시료조제방법인 생체시료, oven건조와 동결건조를 검토하였고, GC injector 온도는 100, 150, 200, 250, $300^{\circ}C$에서의 휘발성분 분석효율을 검토하였으며, 모세관에서 시료의 기화 시간인 preheating time은 3, 5, 7, 10, 15 min의 조건에서 검토한 결과, 시료 조제방법은 생체시료를 그대로 사용 시, GC injector 온도는 $250^{\circ}C$일 때 preheating time은 10min일 때 가장 분석효율이 높았다. 휘발성분 분석을 위해 사용된 인삼은 금산에서 재배한 6년근 삼으로 수삼, 백삼, 홍삼을 사용하였으며, SFSI가 장착된 CC/MS에 의해 휘발성분을 분석, 동정하였다. 분석결과 수삼에서는 33종, 백삼에서는 36종, 홍삼에서는 38종의 휘발성분이 분석되어져 SFSI에 의한 분석법이 인삼의 휘발성분을 분석, 동정하는 방법으로 이용될 수 있음을 보여주고 있다.

• 한국전자파학회논문지
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• 제21권4호
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• pp.417-426
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• 2010

본 논문에서는 근접 거리에서 평면파를 생성할 수 있는 도파관 배열 안테나의 급전부로 활용이 가능한 6-way 전력 분배기에 대하여 기술하고 있다. 원형으로 배치된 방사 소자를 급전하기 위하여 분배기의 중앙에 SMA 커넥터의 입력 단자가 존재하고, 분배기를 둘러싼 원형의 주변에 도파관 형태의 출력 단자가 존재한다. 본 논문은 분배기의 반사 손실을 낮추기 위하여 유도성 포스트를 활용하는 방법을 제안한다. 급전 핀의 높이, 유도성 포스트의 지름, 급전 핀과 유도성 포스트간의 간격에 대한 파라미터 분석을 수행하여 최적의 분배기를 설계하였다. 모의실험과 실제 측정을 수행한 결과, 약 -40 dB의 낮은 반사 손실을 가진다. 6개의 출력 단자의 계산 및 측정된 투과량은 각각 -7.78 dB와 -8.06 dB로써, 동진폭 및 동위상의 전력 분배가 이루어짐을 확인하였다. 본 논문에서 제안한 분배기는 다수 개의 출력 단자를 갖는 분배기로 손쉽게 확장이 가능하므로 다양한 형태의 배열 안테나의 급전 구조로 활용될 수 있다.

• 한국조경학회지
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• 제30권1호
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• pp.61-74
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• 2002

The purpose of this study is to propose vegetation management devices through analyzing the actual vegetation, flora, plant community structure and soil chemical concentrations in Weolmi urban nature park, Incheon. The actual vegetation of Weolmi Park in various areas is composed of urbanization area(2 types, 25.9%), landscape planting area(4 types, 16.1%), grass and marsh area(5 types, 7.6%) and mountain forest areal(14 types, 50.4%). The flora is composed of 295 taxa with 80 families, 253 species, 35 varieties and 7 formas, and among them there are 16 naturalized plant families, 39 species, 3 varieties. In reflection of size, the number of the species seems high but most of the them are under influence of human disturbance. Nine survey plots of plant community structure are classified into two groups. One is the semi-natural plant community(Prunus sargentii-Acer palmatum, Quercus accutissma-Prunus sargentii, Quercus serrata-Quercus accutissma-Prunus sargentii, Prunus sargentii, and Zelkova serrata-Prunus sargentii) that migrated finn the planting forest to the natural forest and the other is planting forest(Pinus koraienssis-Pinus thunbergii-Abies holophylla-Chamaectparis obtusa, Prunus sargentii, Pinus thunbergii-Alnus firma, Zelkova serrata). The average pH is 4.65 which means the soil acidity is quite high. The concentration of K, Ca, Mg and base saturation is very low. It seems that the environmental pollutants from Incheon Port and industrial plants near by survey site and long-distance transport of air pollutants from China made the soil condition worse. On the basis of the results above, six vegetation management devices are suggested: 1) removing the hazard plants(Pueraia thunbergiana and Humulus japonica), 2) natural landscape management of the middle and long term, 3) increasing species diversity, 4) Robinia pseudoacacia management, 5) keeping the naturalized plants from being distributed any further inside the mountain forest, 6) improving soil acidification.

• Journal of Gastric Cancer
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• 제20권1호
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• pp.50-59
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• 2020

Purpose: The objective of the present retrospective analysis was to describe the experience of intraperitoneal (IP) paclitaxel and systemic chemotherapy in patients with peritoneal metastasis (PM) of advanced gastric cancer (AGC) in a multicenter setting in Korea. Materials and Methods: The medical records of patients with AGC, who were diagnosed with PM between January 2015 and December 2018, were reviewed. IP catheter was placed in the pouch of Douglas and was used for the administration of IP paclitaxel chemotherapy. Results: We reviewed the clinical outcomes of IP paclitaxel and systemic chemotherapy administration in 82 patients at six institutions in Korea. Mean number of IP chemotherapy cycles was 6.6. The mean peritoneal cancer index (PCI) was 21.9. Postoperative complications related to IP catheter and port were observed in 15 patients. The overall median survival was 20.0 months. A significant difference was observed in the survival rate according to the ascites grade (grade I and II, 24.1 months; grade III and IV, 15.3 months; P=0.014) and PCI grade (grade I, 25.6 months; grade II and III, 16.3 months; P=0.023). Conclusions: The feasibility of IP paclitaxel and systemic chemotherapy administration was demonstrated in this experience-based retrospective analysis suggesting that the procedure is beneficial in patients with PM of AGC.

• Ocean Systems Engineering
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• 제8권1호
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• pp.1-20
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• 2018

The target area of the proposed study, Mamaia beach, is a narrow stretch of sand barrier island that sits between the Siutghiol Lake and the Black Sea. In the northern part of the bay, is located the Midia Port, where between 1966 and 1971 a long extension of 5 km of the offshore was built. Because of this extension, the natural flow of sediments has been significantly changed. Thus, the southern part of the Mamaia Bay had less sand nourishment which meant that the coast was eroding and to prevent it a protection of six dikes was built. After approximately forty years of coastal erosion, the south of the Mamaia Bay had in 2016 a new protection scheme, which includes first of all the beach nourishment and a new dike structure (groins scheme for protection) to protect it. From this perspective, the objective of the proposed study is to evaluate the effectiveness of the old Master plan against the new one by modeling the outcome of the two scenarios and to perform a comparison with a third one, in which the protection dikes do not exist and only the artificial nourishment has been done. In order to assess the wave processes and the current patterns along the shoreline, a complex computational framework has been applied in the target area. This joins the SWAN spectral phase averaged model with the 1D surf model. Furthermore, new UAV technology was also used to map out, chart and validate the numerical model outputs within the target zone for a better evaluation of the trends expected in the shoreline dynamics.

• 한국항해학회지
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• 제24권1호
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• pp.13-22
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• 2000

The collisions at sea among marine casualties are not reduced as the tonnage and speed of ship's increase as well as the traffic quantity increase at sea, in spite of the improvement of nautical equipment, enforcement of crew's education and training as well as improvement of quality standard according to the implementation of ISM code. The measures to prevent the collisions at sea are simple, and are composed of six stage.: The first stage is that the officer on duty detect the target from his eye or radar information. The second stage is determining the type and kind of target-ship. The third stage is target tracking; calculation of target speed, course, CPA and TCPA from radar information or visual check. The fourth stage is determination of vessel in danger after calculation of third stage. The fifth stage is the judgement of situation if own ship is stand-on or give way vessel according to the 1972 COLREG. The last stage is to carry out proper action according to 1972 COLREG, under the circumstances. But by the case, the situations are so different under the different external conditions; for example, natural/navigational conditions, crew's human factors, ship's particular, rule or regulation, management system on board, the condition of watch keeping. Therefore the reasons and casualties are so complicated. This study aims to investigate the collision casualty at sea which needs to clarity all these causal factors of afore-mentioned, and to analyze the causes of problems so as to utilize them to establish the measures of preventing marine accidents. This study, described the concepts of causal factors into three groups; environmental factor, and company/on board management system and navigator's act. Also described how to investigate and analyzes the casual factors. Even though it was described in this paper how to detect the causal factors and reasons of collisions, and how to analyze the inter-relation of each causal factors, it is necessary to do further study how to analyze between the liability of concerned parties and the casual factors involved.

• 해양환경안전학회지
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• 제25권3호
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• pp.344-353
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• 2019

The wakes behind a square cylinder were simulated using two-equation turbulence models, $k-{\varepsilon}$ and RNG $k-{\varepsilon}$ models. For comparisons between the model predictions and analytical solutions, we employed three skill assessments:, the correlation coefficient for the similarity of the wake shape, the error of maximum velocity difference (EMVD) of the accuracy of wake velocity, and the ratio of drag coefficient (RDC) for the flow patterns as in the authors' previous study. On the basis of the calculated results, we discussed the feasibility of each model for wake simulation and suggested a suitable value for an eddy viscosity related constant in each turbulence model. The $k-{\varepsilon}$ model underestimated the drag coefficient by over 40 %, and its performance was worse than that in the previous study with one-equation and mixing length models, resulting from the empirical constants in the ${\varepsilon}-equation$. In the RNG $k-{\varepsilon}$ model experiments, when an eddy viscosity related constant was six times higher than the suggested value, the model results were yielded good predictions compared with the analytical solutions. Then, the values of EMVD and RDC were 3.8 % and 3.2 %, respectively. The results of the turbulence model simulations indicated that the RNG $k-{\varepsilon}$ model results successfully represented wakes behind the square cylinder, and the mean error for all skill assessments was less than 4 %.