• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.6
• /
• pp.822-831
• /
• 2021

Although programs have been developed to evaluate the risk of dragging anchors, it is practically difficult for VTS(vessel traffic service) operators to calculate and evaluate these risks by obtaining input factors from anchored ships. Therefore, in this study, the gross tonnage (GT) that could be easily obtained from the ship by the VTS operators was set as an independent variable, and linear and nonlinear regression analyses were performed using the input factors as the dependent variables. From comparing the fit of the polynomial model (linear) and power series model (nonlinear), the power series model was evaluated to be more suitable for all input factors in the case of container ships and bulk carriers. However, in the case of tanker ships, the power supply model was suitable for the LBP(length between perpendiculars), width, and draft, and the polynomial model was evaluated to be more suitable for the front wind pressure area, weight of the anchor, equipment number, and height of the hawse pipe from the bottom of the ship. In addition, all other dependent variables, except for the front wind pressure area factor of the tanker ship, showed high degrees of fit with a coefficient of determination (R-squared value) of 0.7 or more. Therefore, among the input factors of the dragging anchor risk assessment program, all factors except the external force, seabed quality, water depth, and amount of anchor chain let out are automatically applied by the regression analysis model formula when only the GT of the ship is provided.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.4
• /
• pp.483-491
• /
• 2021

The identification of regional collision risks in water areas is significant for the safety of navigation. This paper introduces a new method of collision risk assessment that incorporates a clustering method based on the distance factor - hierarchical clustering - and uses real-time data in case of several surrounding vessels, group methodology and preliminary assessment to classify vessels and evaluate the basis of collision risk evaluation (called HCAAP processing). The vessels are clustered using the hierarchical program to obtain clusters of encounter vessels and are combined with the preliminary assessment to filter relatively safe vessels. Subsequently, the distance at the closest point of approach (DCPA) and time to the closest point of approach (TCPA) between encounter vessels within each cluster are calculated to obtain the relation and comparison with the collision risk index (CRI). The mathematical relationship of CRI for each cluster of encounter vessels with DCPA and TCPA is constructed using a negative exponential function. Operators can easily evaluate the safety of all vessels navigating in the defined area using the calculated CRI. Therefore, this framework can improve the safety and security of vessel traffic transportation and reduce the loss of life and property. To illustrate the effectiveness of the framework proposed, an experimental case study was conducted within the coastal waters of Mokpo, Korea. The results demonstrated that the framework was effective and efficient in detecting and ranking collision risk indexes between encounter vessels within each cluster, which allowed an automatic risk prioritization of encounter vessels for further investigation by operators.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.4
• /
• pp.507-514
• /
• 2022

Jinhae Bay is used as a major typhoon shelter in the southeastern region of Korea. However, when a typhoon strikes, the Jinhae Bay is facing the possibility of marine accidents caused by dragging anchors and the increased number of ships. This paper suggested ways to safely and efficiently manage the port of Jinhae Bay when a typhoon strikes from Vessel traffic service operators in the sea, derived relative importance by conducting an Analytic Hierarchy Process assessment to ship operators, and suggested safety measures reflecting manager and user opinions. In order to select safety measures factors for the AHP survey, VTS operators analyzed the evaluation of measures when a typhoon strikes in Jinhae Bay. As a result of conducting a survey based on the selected safety measure factors, it was found that ship operators consider the safety of ships more than twice as important as efficient management, and comprehensively consider them in the order of management of evacuated ships, management of anchorage area, management of evacuation information, preparation regulations and guidelines, improvement of system equipment, education, publicity, and notification activities. Through the measures and relative importance identified in this paper, it is believed that Jinhae Bay can serve as the basis for safely and efficiently managing typhoon shelters.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.2
• /
• pp.127-138
• /
• 2023

A variety of decarbonized energy sources are being developed globally to realize carbon neutrality (Net Zero) by 2050 as a measure to address the global climate crisis. As the Korean government has also established a Renewable Energy 3020 policy and promoted energy development plans using solar or wind power, large-scale offshore development projects not present before in coastal waters, such as offshore wind farms, are being promoted. From ships' point of view, offshore facilities present obstacles to safe navigation, and with the installation of marine facilities, ship collisions or contact accidents between ships and marine facilities may occur in the narrowed water areas. In addition, there are concerns about environmental pollution and human casualties caused by marine accidents. Accordingly, we review overseas and domestic offshore wind farm development plans, analyze whether institutional devices are in place to ensure the safe passage of ships in wind farm areas, and study the safe operation of large-scale offshore wind farms and safe passage of ships along the Korean coast by comparing overseas legislative cases with domestic laws and presenting a proposal to illuminate the legal blind sectors.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1A
• /
• pp.1-9
• /
• 2006

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgment. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. More researches on the allocation model of AF and the determination of impact resistance are required.

• Journal of Korea Port Economic Association
• /
• v.32 no.4
• /
• pp.149-163
• /
• 2016

Seafarers are an essential resource in maritime industries, which provide navigation skills, vessel maneuvering skills and fishing skills in the fishery industry. They also work as a driving force in pilotage, port operation, vessel traffic service, and marine safety. Other areas in maritime services, which rely on seafarer include safety management of ships, supervisory activities, and maritime accident assessment. In these ways, Korean seafarers have contributed to the growth of Korean economy. However, there have been issues of high separation rate, shortage of supply, multi-nationality, multiplicity of culture caused by employment of foreign seafarers, and aging. The present paper finds that maritime officers and fishery officers demonstrate differences in the statistics of on-board job taking and separation: the separation rate of fishery officers is higher than that of maritime officers. The existing data and statistics by the Korea Seafarer's Welfare & Employment Center could be improved by changing its structure from time series to panel data. The Korea Seafarer's Welfare & Employment Center is the ideal institution for collecting the panel data, as it has already accumulated and published relevant statistics regarding seafarer. The basic design method of the panel data is to adopt and improve it by including the information on ratings of maritime and fishery industries, ranks in a ship, personal information, family life, and career goal. Panel data are useful in short- and long-term forecasts of supply of Korean seafarers; demand evaluation of education, training, and reeducation of the seafarers; demographical dynamic analysis on Korean seafarers; inducement policy of long-term on board job taking in harmony with man-power demands in marine industries such as pilotage service; implementation of job attractiveness policy on Korean seafarers; and employment stabilization of Korean seafarers.

• Journal of Chest Surgery
• /
• v.43 no.3
• /
• pp.285-291
• /
• 2010

Background: Thoracic trauma is one of the leading causes of morbidity and mortality in developing countries. A rib fracture that is secondary to blunt thoracic trauma is an important indicator of the severity of the trauma. The purpose of study was to determine the morbidity and mortality rates and the management of rib fractures. Material and Method: We performed a retrospective study that involved all the blunt trauma patients with rib fractures, excluding those that were transferred to other hospital within 3 days, that were seen at our hospital between May 2002 and December 2008. Of the 474 admitted patients, 454 met the inclusion criteria. There were 356 male and 98 females, and their overall mean age was 53 years (range: 5~90 years). The outcome parameters included the mechanism of injury, the number of fractured ribs, the length of stay in the ICU, the Injury Severity Score (ISS), the length of the hospital stay, the pulmonary complications and the mortality. Result: The mechanism of trauma included traffic accidents in 189 (41.7%) cases, slipping down in 103 (22.7%) cases, falls in 85 (18.7%) cases, cultivator accidents in 30 (6.6%) cases, industrial accidents in 32 (7.0%) cases and assault in 15 (3.3%) cases. Intrathoracic injury was noted such as hemothorax in 269 (59.3%) cases, pneumothorax in 144 (31.7%) cases, pulmonary contusion in 95 (20.9%) cases, subcutaneous emphysema in 29 (6.4%) cases and great vessel injury in 5 (0.1%) cases. Conservative treatment was administered to most of the patients. Tube thoracostomy was administered in 234 (51.5%) cases, whereas thoracotomy was performed in 18 (4.0%) cases. The mean duration of thoracostomy was $5.2{\pm}6.2$ days. Most of the cases with rib fracture were treated in wards and their mean duration of hospital stay was $22.5{\pm}20$ days. The mean Injury Severity Score (ISS) was $14.8{\pm}10.9$ (range: 3~75). The mortality rate was calculated to be 4.8% (n=22). The main factors correlated with an adverse outcome were the number of ribs fractured, the duration of thoracostomy and pulmonary disease. Industrial insurance affected the length of hospitalization. Pulmonary contusion and the Injury Severity Score (ISS) affected the mortality. Conclusion: Rib fractures are a indicator of severe injury. Because of the complication and associated injuries, we believe these patients should be admitted for evaluation and treatment. Recent studies on the impact of rib fractures after blunt trauma have shown that patients as young as 40 years of age demonstrate increased morbidity and mortality with similar injuries as compared to that of older patients. The ISS and pulmonary contusion influenced the mortality rate. Patients with isolated rib fractures should be hospitalized if the number of fractured ribs is one or more.