• Korean Journal of Ecology and Environment
• /
• v.40 no.3
• /
• pp.449-458
• /
• 2007

Fish community and its temporal-spacial variation in the Lagoon Hwajinpo, Korea were seasonally investigated with different types of fishing gears from November, 2005 to August, 2006. Total 35.812 fishes caught during the period were belonged to 24 families 37 species. Dominant species was H. nipponensis(60.8%), T, hakonensis (19.8%), and K. punctatus (5.5%) ana these species were peripheral freshwater fish. Among 37 species, primary freshwater and seawater fish were 8 species (21.6%), respectively and peripheral freshwater fish were 21 species (56.8%). Total biomass of collected fish was 279.3kg, and biomass of each species was T. hakonensis 152.9 kg, H. nipponensis 40.0 kg, K. punctatus 31.4 kg and C. haematochelius 25.3 kg, respectively. Hence, productivity of the Lagoon Hwajinpo was much higher than those of inland reservoirs. The aspect of community classified by surveyed period was changed according to the 'Breaking-sandbar', but some of peripheral freshwater fish populations made stable community in their life cycle in the lagoon. In conclusion, the Lagoon Hwajinpo seems to be maintained more natural ecosystem better than other lagoons in Korea. Therefore, the findings provide consideration of the management and restoration for this lagoon and others through the continuous observation and monitoring in future.

• Korean Journal of Heritage: History & Science
• /
• v.44 no.2
• /
• pp.46-57
• /
• 2011

The aim of this study was to examine the current situation of otter inhabitation and conservation and to collect basic information for establishing appropriate policies. We conducted the study around the Bukhan river from April to October 2009, mostly focusing on otter distribution, feeding habits, threats, and conservation measures. We divided the study area into 2 sectors: the dam area and the stream. We found 39 spraint sites in the dam area and 70 in the stream area. A significant difference was observed in the number of spraint sites between the upper stream and the lower stream. To evaluate the feeding habit, we collected and analyzed the frequency and bulk occurrence of the spraints. Among the prey items, fish were the most numerous (36.99%) followed by amphibians (17.22%). Fish showed the highest bulk occurrence in the dam area, and the bulk occurrence of amphibians and insects seemed to increase in the stream area. However, the bulk occurrence in the dam area seemed to be lower than that in the stream area (ANOVA, F = 3.99, p < 0.05). Fyke nets and abandoned fishing nets were found to be the most threatening factors. Further research on the systematic management of otters and the use of stop grids is required for better conservation of otters.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.5
• /
• pp.542-549
• /
• 2019

Maritime accidents, such as the collision of a fishing boat in Incheon's Yeongheung Island, result in several casualties and property damage, even if they occur just once. To prevent such accidents, the Incheon Metropolitan Government is implementing safety management policies; further, they will provide ship collision warning services to prevent collisions on WAVE (Wireless Access in Vehicular Environment) communication-based ship safety operation pilot projects. However, to realize these objectives, a service standardization method is required that defines specific service types, configurations, and systems, which should be prepared based on user requirement analyses. In this study, a standardization method of WAVE communication-based collision warning service was developed by analyzing the requirements of the vessel operators subject to the services and related authorities. This will help improve the quality of service, ensuring professionalism and reliability through continuous improvement and efforts for standardization, as well as data derived from demonstration projects. Therefore, it is expected to help prevent maritime accidents to a considerable extent.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.4
• /
• pp.549-566
• /
• 2022

Recently, artificial intelligence (AI) technology has progressed rapidly, and industries using this technology are significantly increasing. Further, analysis research using text mining, which is an application of artificial intelligence, is being actively developed in the field of social science research. About 125 laws, including joint laws, have been enacted under the Ministry of Oceans and Fisheries in various sectors including marine environment, fisheries, ships, fishing villages, ports, etc. Research on the laws under the Ministry of Oceans and Fisheries has been progressively conducted, and is steadily increasing quantitatively. In this study, the domestic research trends were analyzed through text mining, targeting the research papers related to laws of the Ministry of Oceans and Fisheries. As part of this research method, first, topic modeling which is a type of text mining was performed to identify potential topics. Second, co-occurrence network analysis was performed, focusing on the keywords in the research papers dealing with specific laws to derive the key themes covered. Finally, author network analysis was performed to explore social networks among authors. The results showed that key topics have been changed by period, and subjects were explored by targeting Ship Safety Law, Marine Environment Management Law, Fisheries Law, etc. Furthermore, in this study, core researchers were selected based on author network analysis, and the tendency for joint research performed by authors was identified. Through this study, changes in the topics for research related to the laws of the Ministry of Oceans and Fisheries were identified up to date, and it is expected that future research topics will be further diversified, and there will be growth of quantitative and qualitative research in the field of oceans and fisheries.

• Journal of Navigation and Port Research
• /
• v.46 no.3
• /
• pp.209-215
• /
• 2022

On the Jeju coast, international cruise ships, passenger ships, and other ships pass frequently, as well as many fishing boats. Thus, there is a high risk of marine accidents and frequent ship collisions. Accordingly, it is urgent to establish a coastal VTS for systematic safety management of ships passing through the coastal waters of Jeju. The purpose of this study was to set the area of the VTS to be newly established. In this study, to calculate the workload of the VTS operators, a formula was proposed that reflects the monitoring workload considering the monitoring frequency and required time for target as well as non-target ships and the workload for ship collision situations. The proposed formula was applied to the newly established VTS area in Jeju. Three control sectors were set up in each VTS center. The average number of workstations per hour was approximately 1, so the division between sectors was appropriate. Thus, it was deduced that there would be no workload for the VTS operators. It is expected that the method proposed in this study can be used as primary data for calculating the appropriate number of workstations for the current VTS, and setting the VTS area for a new coastal VTS in the future.

• Korean Journal of Remote Sensing
• /
• v.39 no.1
• /
• pp.77-86
• /
• 2023

Ship detection is widely used in areas such as maritime security, maritime traffic, fisheries management, illegal fishing, and border control, and ship detection is important for rapid response and damage minimization as ship accident rates increase due to recent increases in international maritime traffic. Currently, according to a number of global and national regulations, ships must be equipped with automatic identification system (AIS), which provide information such as the location and speed of the ship periodically at regular intervals. However, most small vessels (less than 300 tons) are not obligated to install the transponder and may not be transmitted intentionally or accidentally. There is even a case of misuse of the ship'slocation information. Therefore, in this study, ship detection was performed using high-resolution optical satellite images that can periodically remotely detect a wide range and detectsmallships. However, optical images can cause false-alarm due to noise on the surface of the sea, such as waves, or factors indicating ship-like brightness, such as clouds and wakes. So, it is important to remove these factors to improve the accuracy of ship detection. In this study, false alarm wasreduced, and the accuracy ofship detection wasimproved by removing wake.As a ship detection method, ship detection was performed using machine learning-based random forest (RF), and convolutional neural network (CNN) techniquesthat have been widely used in object detection fieldsrecently, and ship detection results by the model were compared and analyzed. In addition, in this study, the results of RF and CNN were combined to improve the phenomenon of ship disconnection and the phenomenon of small detection. The ship detection results of thisstudy are significant in that they improved the limitations of each model while maintaining accuracy. In addition, if satellite images with improved spatial resolution are utilized in the future, it is expected that ship and wake simultaneous detection with higher accuracy will be performed.

• Journal of Korean Port Research
• /
• v.11 no.2
• /
• pp.321-337
• /
• 1997

Rapid change in the technological environment of marine transportation and the development of the ocean shipping industry have fostered a revolution in the port system. This in turn has caused major changes in the function and use of port in Korea. Aside from this. Mokpo Port, however continues to decline, because the existing port facilities and related subsystem are already obsolete with no chance of regaining operational effectiveness and treatment for proper implementation. Although a few studies have been done on the Mokpo Port, has not been found, any reseach for the analytical approach to the transportation system of it. This paper aims to make an extensive analysis of the physical distribution system in Mokpo Port focusing on the coordination of subsystems such as navigational aids system, quay handling and transfer system, storage system and inland transport system. The base of introduced simulation tool here is the queueing theory. The overall findings are as follows; 1. Among those vessels called at Mokpo Port in 1994, the average size of oceangoing vessels is 4,922.1 G/T, and the domestic is 317.8 G/T. The average arrival interval and service time of the domestic vessels are 6.0 hours and 24.1 hours respectively marking the berth occupation rate over 100%. Those for oceangoing vessels are 34.5 hours, 120.0 hours and 37.2%. In order to maintainin the berth occupation rate to 70% the capacity considering the 1994 of domestic piers must be extended to 145% and oceangoing vessels must be increased to 165% year called. 2. The capacity of approaching channel is enough to handle the total traffic volume. 3. Tugs are sufficiently being provided to handle all ships requiring their services 4. The capacity of storage and inland transportation systems are sufficient to handle the throughput and the yard stroage utilization rate of No.1 $\cdots$ No.5 is 4.5% and No.6 1S 30% of 1993's. 5. The utilization rate of LLc(Level Looping Crane) and PNT(PNeumaTic) are 2.7% and 18.8%, respectively. Practical solution and proposal for improvement of Transportation System in Mokpo Port are as follows; 1. To avoid the congestion in domestic pier introduction of a new port operation system is necessary allowing the domestic vessel to use the oceangoing pier. 2. To establish the port management information system to improve the efficiency of port operation. 3. To build a new storage system for high valued cargos including modernization of the present storage and handling system. 4. To insure the safety of navigation in approaching channel, The Vessel Traffic System including separation scheme is introduced. 5. To interest enormously on public relation to ship owner's association, shippers and consignees by showing that they can save cost and ship turnaround time in order to promote the call to Mokpo Port. At last, to be strategically change the function of Mokpo Port to the Leisure, Fishing & Ferry as well as Maritime port.

• Environmental and Resource Economics Review
• /
• v.31 no.4
• /
• pp.451-480
• /
• 2022

The Japanese Flying Squid (Todarodes pacificus) is a commercially important species in South Korea and the most popular species among consumers. However commercial catches of Japanese Flying Squid have been declining since 2000. In this study, we conducted a stock assessment to identify stock status. This study differed from previous studies in two aspects: a greater amount of available fishing effort data was used, and data from China, Japan, and Korea were included. A CMSY (catch-maximum sustainable yield) model was used to estimate MSY, biomass and exploitation with Bayesian state-space implementation of the Schaefer (BSS) model for the method of stock assessment, and evaluated the species by dividing into two groups, 'Korea' and ' Korea·China·Japan'. In all cases, Japanese flying squid biomass showed a general decreasing trend. Additionally, the biomass estimated for 2020 was lower than the biomass necessary to achieve the maximum sustainable yield. To manage Japanese Flying Squid effectively, it is necessary to strengthen the resource management strategies of individual countries and prepare a cooperative plan among countries.

• Korean Journal of Environment and Ecology
• /
• v.36 no.6
• /
• pp.575-581
• /
• 2022

Brown rats (Rattus norvegicusBerkenhout, 1769) were eradicated from Sasudo Island (33°55'13.04" N, 126°38'19.98" E), an uninhabited island designated as Natural Monument No. 333 and the largest breeding site for the streaked shearwater (Calonectris leucomelasTemminck, 1835) in South Korea. Twelve eradication studies were conducted from November 2015 to February 2021. The survey was conducted using a line census method that entailed slow wandering throughout the island and identifying starting and returning points. Capture traps were installed around traces of Rattus norvegicus,such as excrement and identified holes. As a result, 2 to 6 individuals were captured at each instance, except for the last time, when no individuals were captured. It is hypothesized that brown rats arrived at Sasudo Island via vessels arriving at the island for leisure and fishing. After the damage to streaked shearwater caused by brown rats was confirmed in 2006, entry to Sasudo Island was strictly prohibited through security measures, and marine clean-up programs that began in 2013 and continuous capturing since 2015 have been successful in eradicating brown rats. To maintain and manage the condition in Sasudo Island, preservation and management measures, such as strict visitor control, are necessary to prevent the inflow of new brown rats in the future.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.1
• /
• pp.112-130
• /
• 2006

In order to improve the waste management system for the unit of small villages, we visited 14 counties nationwide and investigated the present conditions of the farming and fishing villages on waste management. First, we selected one concentrated residential type village and one separated residential type village. Then we investigated the quantities and the characteristics of the domestic wastes generated from the 2 sample villages that we chose early on. The concentration of 7 heavy metals in open burned residuals was analyzed. The results are as follows: (1) We distributed the 799 questionnaires to public servants (83 Gun, 716 Myon) and 337 questionnaires to residents. In accordance with a result of questionnaire on the Volume-Based Waste Fee System, the rate of participated questionnaire was 70.3% from public servants and 31.8% from residents. (2) From the survey on two chosen villages, the generation of municipal waste was 48.6g/person/day in A Village, 54.3g/person/day in B Village. This amount was smaller than that of national average of 1.05kg because of excluding recyclable wastes and some of incinerated combustible waste. (3) The 14 counties entered the aged society. There were 2 aging societies, 8 aged societies and 4 super-aged societies. And the average ratios of Public financial independence and waste budget of financial independence were 16.1% and 17.9% respectively. These are lower than that of national average of 57.2% and 31.4%. This indicates that these factors seemed to be operated with the hindrance insettling Volume-Based Waste Fee System in the small villages.