• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.347-348
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• 2014

In this paper, we describe the methods for quantitative evaluation of placement of aids to navigations (AtoN). AtoN is the additive devices for navigation that inform navigators using human vision and guide navigators to safe watercourse. Therefore the effectiveness of placement of AtoN can be quantified according to the grade of visibile recognition to navigators. In order words, the placement of AtoN can be quantified in the sense of visibility. In this study, we describe the methods for quantifying the visibility about the placement of AtoN. Using AtoN simulator which has been developed by Korea Research Institute of Ships and Ocean Engineering (KRISO), the quantitative method is investigated for the pre-installed placement of AtoNs.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.247-253
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• 2006

NSW in Australia is famous for beautiful beaches and water activities. There are now almost 450,000 people who hold a NSW power boat driving licence and 200.000 registered boat owners. The popularity of boating continues to grow with licence and registration figures increasing by 3-4 per cent each year. This is a survey about the guide book for boating licence in NSW. This study outlines the essential information such as the types of licence, registration of vessels, choosing the right boat, maintain vessel, safety equipment and preparing for a safe boating trip. In addition, it touches the technical side like boat handling, water traffic rules, navigation markers, emergency and the ways to avoid them. Recently, more and more people are interested in boating. It forms an important part of recreational and tourism activities. To manage these demands effectively and to provide the orderly and safe leisure hours, it is necessary to induce more organizational and serviceable boating licence system.

• Journal of Navigation and Port Research
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• v.35 no.10
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• pp.799-804
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• 2011

The hydrodynamic interaction effects between the multi-bodies can not be neglected when vessels are close to each other in congested and confined waters, such as in a harbour or narrow channel. Increase in speed and size of modern vessels make it necessary to consider this interaction effects when designing harbours and navigation channels. In this research, the hydrodynamic interaction effects of the spacing between vessels and water depth along with ship's velocity are summarized and discussed. The goal of this research is to propose a guideline of appropriate speed and distance between passing and moored vessels to avoid the influence of hydrodynamic forces and to navigate safely in confined sea areas.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.208-209
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• 2023

Intelligent maritime traffic information service for maritime traffic safety operates a service that provides safe and efficient optimal safety routes considering information such as water depth, maritime safety law, weather information, and fuel consumption. However, from a service user's point of view, they prefer a route that suits their personal navigation experience and style, such as unnecessary detours and conservative safety distances for maritime objects. In this study, the optimal safety route can be extracted based on the experience of service users without reflecting the separate maritime environment by adjusting the weight of the trunk line for the area where the ship frequently navigates with the ship's track data collected through LTE-M model was studied.

• Annals of Coloproctology
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• v.34 no.6
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• pp.292-298
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• 2018

Purpose: This study compared the perioperative clinical outcomes of reduced-port laparoscopic surgery (RPLS) with those of conventional multiport laparoscopic surgery (MPLS) for patients with sigmoid colon cancer and investigated the safety and feasibility of RPLS performed by 1 surgeon and 1 camera operator. Methods: From the beginning of 2010 until the end of 2014, 605 patients underwent a colectomy for sigmoid colon cancer. We compared the characteristics, postoperative outcomes, and pathologic results for the patients who underwent RPLS and for the patients who underwent MPLS. We also compared the clinical outcomes of single-incision laparoscopic surgery (SILS) and 3-port laparoscopic surgery. Results: Of the 115 patients in the RPLS group, 59 underwent SILS and 56 underwent 3-port laparoscopic surgery. The MPLS group included 490 patients. The RPLS group had shorter operating time ($137.4{\pm}43.2minutes$ vs. $155.5{\pm}47.9minutes$, P < 0.001) and shorter incision length ($5.3{\pm}2.2cm$ vs. $7.8{\pm}1.2cm$, P < 0.001) than the MPLS group. In analyses of SILS and 3-port laparoscopic surgery, the SILS group showed younger age, longer operating time, and shorter incision length than the 3-port surgery group and exhibited a more advanced T stage, more lymphatic invasion, and larger tumor size. Conclusion: RPLS performed by 1 surgeon and 1 camera operator appears to be a feasible and safe surgical option for the treatment of patients with sigmoid colon cancer, showing comparable clinical outcomes with shorter operation time and shorter incision length than MPLS. SILS can be applied to patients with favorable tumor characteristics.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.385-393
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• 2022

Hydrogen has reduced greenhouse gas (GHG) emissions, the main cause of global warming, and is emerging as an eco-friendly energy source for ships. Hydrogen is a substance with a lower flammability limit (LFL) of 4 to 75% and a high risk of explosion. To be used for ships, it must be sufficiently safe against leaks. In this study, we analyzed the effect of changes in the area of the air inlet / vent port on the ventilation performance when hydrogen leaks occur in the hydrogen tank storage room. The area of the air inlet / vent port is 1A = 740 mm × 740 mm, and the size and position can be easily changed on the surface of the storage chamber. Using ANSYS CFX ver 18.1, which is a CFD commercial software, the area of the air inlet / vent port was changed to 1A, 2A, 3A, and 5A, and the hydrogen mole fraction in the storage chamber when the area changed was analyzed. Consequently, the increase in the area of the air inlet port further reduced the concentration of the leaked hydrogen as compared with that of the vent port, and improved the ventilation performance of at least 2A or more from the single air inlet port. As the area of the air inlet port increased, hydrogen was uniformly stratified at the upper part of the storage chamber, but was out of the LFL range. However, simply increasing the area of the vent port inadequately affected the ventilation performance.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.497-502
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• 2007

The important purposes of research in ship operation are to ensure safe navigation, high efficiency of transportation, high accuracy, and security. IMO, develops a broad strategy for incorporating the use of new technologies in a structured way to ensure that their use is compliant with the various electronic navigational and communication technologies and services that are already available. As a base research for E-Navigation, therefore, this paper proposes a maritime information network based on Mesh Network that is one of the maritime broadband solutions. Firstly, this paper analyzes an international port network system and the requirements of port network for E-Navigation. Finally, it designs the maritime information network system based on Mesh Network and shows its validity for E-Navigation.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.560-566
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• 2010

Port of Samcheonpo, designated as a Trading Port, is constructing New Port for the increase in trade and the requirement of maritime safety is growing. To meet these requirement for maritime safety, hydrographic surveying around south sea area of Samcheonpo using Multibeam Echo Sounder(MBES), DGPS etc was conducted. In this study, major item of hydrographic surveying such as sounding data was acquired and analyzed depth data comparing with vertical uncertainty in the special publication for hydrographic minimum specification published in Feb, 2008 by International Hydrographic Organization. By analyzing the depth data with 3 steps procedure, the port and starboard beam by removing the outskirts of the data processing could improve the efficiency and accuracy. The error of south sea were about 0.2m and the upper central part of the error were within 0.2m. Depth data of the study area are included in the 99% of 1st order and satisfied with a 100% tolerance of special order based on the international hydrograhic survey standard. This study will be a good case to support efficient decision-making for safe navigation, coastal management.

• Advances in pediatric surgery
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• v.20 no.2
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• pp.48-52
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• 2014

Purpose: Currently the substantial clinical benefits of single-port laparoscopic appendectomy (SLA) over conventional three-port laparoscopic appendectomy (CLA) are equivocal. The aim of this study was to compare surgical outcomes between SLA and CLA in children with acute appendicitis. Methods: A single blind prospective randomized single center study was performed to compare the surgical outcomes of SLA and CLA. A total of 105 patients were randomized and various parameters were analyzed, 52 patients with SLA and 53 patients with CLA between July 2013 and March 2014. Patients with sonographically confirmed acute appendicitis were randomly assigned to receive either SLA or CLA. The outcome measurements were operating time, wound complication, and intraperitoneal morbidities, postoperative pain score and cosmetic result score. Results: Operating time is significantly longer in SLA ($70.4{\pm}26.7$ minutes vs. $58.0{\pm}23.4$ minutes; p=0.016). There were no significant differences in the postoperative wound complication rate and intraperitoneal morbidities between two groups. There were no significant differences in postoperative resting pain score ($6.6{\pm}2.5$ vs. $6.3{\pm}2.5$; p=0.317) and activity pain score ($6.9{\pm}2.4$ vs. $6.3{\pm}2.5$; p=0.189), and the cosmetic result score ($9.2{\pm}1.1$ vs. $9.1{\pm}1.4$; p=0.853). Conclusion: Although SLA would be a safe and feasible procedure in children, SLA could not demonstrate the clear benefit over CLA.

• Journal of Gastric Cancer
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• v.20 no.4
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• pp.431-441
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• 2020

Purpose: Various studies have indicated that reduced-port robotic gastrectomies are safe and feasible for treating patients with early gastric cancer. However, there have not been any comparative studies conducted that have evaluated patients with clinically advanced gastric cancer. Therefore, we aimed to compare the perioperative outcomes of D2 lymph node dissections during reduced-port robotic distal subtotal gastrectomies (RRDGs) and conventional 5-port laparoscopic distal subtotal gastrectomies (CLDGs). Materials and Methods: We retrospectively evaluated 118 patients with clinically advanced gastric cancer who underwent minimally invasive distal subtotal gastrectomies with D2 lymph node dissections between February 2016 and November 2019. To evaluate the patient data, we performed a 1:1 propensity score matching (PSM) according to age, sex, body mass index, American Society of Anesthesiologists physical status classification score, and clinical T status. The short-term surgical outcomes were also compared between the two groups. Results: The PSM identified 40 pairs of patients who underwent RRDG or CLDG. The RRDG group experienced a significantly longer operation time than the CLDG group (P<0.001), although the RRDG group had significantly less estimated blood loss (P=0.034). The number of retrieved extraperigastric lymph nodes in the RRDG group was significantly higher than that of the CLDG group (P=0.008). The rate of postoperative complications was not significantly different between the two groups (P=0.115). Conclusions: D2 lymph node dissections can be safely performed during RRDGs and the perioperative outcomes appear to be comparable to those of conventional laparoscopic surgeries. Further studies are needed to compare long-term survival outcomes.