• Journal of Navigation and Port Research
• /
• v.42 no.4
• /
• pp.245-252
• /
• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Geophysics and Geophysical Exploration
• /
• v.11 no.1
• /
• pp.34-40
• /
• 2008

Underwater seismic refraction with advanced interpretation approaches makes important contributions to shallow marine exploration and geotechnical investigations in Australia's coastal areas. A series of case studies are presented to demonstrate the recent applications of continuous and static USR methods to river crossing and port infrastructure projects at various sites around Australia. In Sydney, static underwater seismic refraction (USR) with bottom-placed receivers and borehole seismic imaging assisted the development of improved geotechnical models that reduced construction risk for a tunnel crossing of the Lane Cove River. In Melbourne, combining conventional boomer reflection and continuous USR with near-bottom sources and receivers improved the definition of a buried, variably weathered basalt flow and assisted dredging assessment for navigation channel upgrades at Geelong Ports. Sand quality assessment with continuous USR and widely spaced borehole information assisted commercial decisions on available sand resources for the reclamation phase of development at the Port of Brisbane. Buried reefs and indurated layers occur in Australian coastal sediments with the characteristics of laterally limited, high velocity, cap layers within lower velocity materials. If these features are not recognised then significant error in depth determination to deeper refractors can occur. Application of advanced refraction inversion using wavefront eikonal tomography to continuous USR data obtained along the route of a proposed offshore pipeline near Fremantle allowed these layers and the underlying bedrock refractor to be accurately imaged. Static USR and the same interpretation approach was used to image the drowned granitic regolith beneath sediments and indurated layers in the northern area of Western Australia at a proposed new berthing site where deep piling was required. This allowed preferred piling sites to be identified, reducing overall pile lengths. USR can be expected to find increased application to shallow marine exploration and geotechnical investigations in Australia's coastal areas as economic growth continues and improved interpretation methods are developed.

• Journal of Animal Environmental Science
• /
• v.16 no.2
• /
• pp.153-160
• /
• 2010

Recently, the treatment of dead poultry has become more important issue because, the infected poultry, which was buried under the ground, causes environmental contaminations such as steep water and reek occurrence, etc. Therefore, in this study, we investigated the type of treatment and the composting methods influencing to the characteristics on decomposition and fermentative disinfection of dead poultry with poultry manure and sawdust. The results of the port tests showed that amputated poultry treated by the cut-sterilization were not only more decomposed, with less smell compared to the non-treated poultry carcass. When we treated thermophilic microorganism such as bacillus in this amputated poultry, the temperature of treated poultry increased much fester, the fermentation temperature didn't rise and not maintained constantly for long time due to the small size of the fermentation port. On the other hand, we did fermentation test by the layered disposal method with more poultry. In this experiment, the temperature of fermented poultry rose to $54^{\circ}C$ in a day and maintained around $55^{\circ}C$ during four weeks period. With less odor outside the experiment room. further. Also, we inoculated AI virus, ND virus in the excrement for studying the effect of fermentative disinfection. The result of the test revealed that AI virus was destructed within 60 minutes and ND virus was destructed within 30 minutes at the temperature of $56^{\circ}C$. Therefore, the investigations revealed scope of composting method for steam sterilized infected poultry in the originated area mixed with poultry manure, sawdust by thermophilic microorganism could increase the effectiveness of fermentative disinfection and decrease the environmental contamination.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.1
• /
• pp.201-210
• /
• 2019

Recently, due to the efforts to mitigate traffic congestion and expansion of space efficiency, the construction of underground roads has been increased in big-scale cities. Since tunnels in the city have a higher chance for a fire leading to a great tragedy during a severe traffic jam than mountain tunnels, it is highly likely that it will be constructed as a tunnel, having a small cross section, for small vehicles. However, if they are constructed as such small-vehicle tunnels, it would be possible to reduce the design fire intensity while the concentration of harmful gases would increase due to a reduction in the small cross sectional area, led by a decrease in the tunnel height. In this study, behaviors of fire smoke by the installation interval and format of large-scale exhaust-gas ports were examined and compared in the analysis of temperatures and CO concentrations of a tunnel and its results were as the following. Although there were no significant differences in the smoke spreading distance between installation intervals, but in this study, 100 m was found to be the most effective installation interval. The smoke exhaustion performance was found to be excellent in the order of $4m{\times}3m$, $6m{\times}2m$, and $3m{\times}2m$ (2 lane) of the smoke spreading distance. Although there was no significant difference in the smoke spreading distance between formats of large-scale exhaust-gas ports, it was found that the smoke spreading distance was larger than other cases when it was $3m{\times}2m$ in the fire growing process. The analysis of smoke spreading distances by the aspect ratio showed that a smoke spreading distance was shorted when its the smoke spreading distance was found to be shorter when its traverse distance was relatively longer than its longitudinal distance.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.2
• /
• pp.87-97
• /
• 2023

In this study, we examined the effects of a large wildfire in the coastal area of Uljin-gun. The analysis of water quality and the dominant species, species composition, and community structure of marine algal was conducted quarterly in 2022 at Nagok (F-1), Hujeong (F-2), Bongpyeong (F-3), and Gongse Port (F-C) in Uljin-gun. As a result of water quality analysis, the pH, a factor of wildfire impact was 8.07~8.30 and 8.12~8.48 in surface and bottom layers, respectively, which are normal values in coastal waters of the East Sea, suggesting no direct impact from wildfires. By marine algal species composition, the coastal areas show the following order: Rhodophyta (58.1%) > Ochrophyta (25.8%) > Chlorophyta (14.5%) > Magnoliophyta (1.6%). By season, Undaria pinnatifida was the most dominant at Nagok and Hujeong in March and June, which in September and November, Gelidium elegans and Lithophyllum sp. were the most dominant in Bongpyeong and Gongse Port, respectively. In the cluster analysis, the stations were divided into two groups according to presence and absence of specific marine algal by season. The dominant species were U. pinnatifida, G. elegans and D. divaricata in group A, and Lithophyllum sp. was mainly present in group B. Thus, the species composition and group structure reflected the normal seasonal change pattern with water temperature variation and showed little significant difference from the control site, suggesting no direct effects of the wildfire on algae distribution in Uljin.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.28 no.3
• /
• pp.160-170
• /
• 2016

In this study, the bottom tracking observation in the tidal entrance within Mokpo coast is performed using ADCP in order to estimate net flux of water mass and tidal prism. First of all, observed rawdata was conducted coordinate rotation considering rotation of the cross-section in order to derive the predominant velocity component. And observed rawdata is converted into Sigma coordinate with normalization and blank zone data near the water surface and bottom is interpolated using von-Karman equation. Net flux of water mass is calculated quantitively from the interpolated data, calculated results show that these represent well characteristic of ebb superiority at Mokpo coast as well as change of net flux of water mass with tide. Also, by complementing the definition of tidal prism proposed in past studies, the definition of tidal prism including tidal condition was re-established. Based on the new definition, tidal prism at a tidal entrance using bottom tracking data with ADCP is estimated quantitively for the first time domestically. The results are compared with those for results of previous study, calculated results were in good agreement with previous studies.

• International Commerce and Information Review
• /
• v.18 no.3
• /
• pp.47-72
• /
• 2016

The Government of Korea has always focused on developing and maintaining a surplus on the balance of payments as a successful trade policy. The focus should now be on spatial information hiding, revealing patterns in trade activities that enable viewing trade in a more sophisticated manner. This study utilizes trade statistical data such as the United States-South Korea imports and exports from 2003 to 2015 officially released by the two countries. It allows us to analyze and extract the spatial information pertaining to the origin, transit, and destination. First, in the case of export data to the United States, the origin of the trade goods has expanded and decentralized from the metropolitan area. With regard to transit, in 2003, most of the exported goods were shipped by ocean vessels and arrived at the ports on the western coast of the United States. However, trade patterns have changed over the 12-year period and now more of that trade has moved to the southern ports of the United States. In terms of destination, California and Texas were importing goods from South Korea. With the development of the automotive industry in Georgia and Alabama, these two states also imported huge volumes of automobile parts. Second, in case of import data, most imported goods from the United States originated from California and Texas. In this case, 40% of goods were shipped by air freight and arrived at the Incheon-Seoul International Airport; most ocean freight was handled at the Port of Busan. The purpose of this study is to decompose the spatial information from the trade statistics data between Korea and the United States and to depict visualized bilateral trade structure by origin, transit, and destination.

• Journal of environmental and Sanitary engineering
• /
• v.5 no.2
• /
• pp.105-116
• /
• 1990

Seungbong Island is situated about 100km away Inchon Port in the western sea of the Korean Peninsula. Field investigations were conducted for two days each from June 30 through July 1, 1981 and from August 20 through 21, 1981. The results obtained are summarized as follows: Plants growing in this island consist of a total of 193 species (70 families, 151 genera, 170 species, 22 varieties and 1 forma). Pinus thunbergii was confirmed to be the dominant species. The natural degree observed in this island was high, as a whole. The coefficient of ferny plants (Pte-Q) is 0.95, lower than grass. Atractylodes japonica Koidz., Miscanthus sinensis Anders. var. purpurascense Rendle, and Rhododendron mucronulatum Turz. are distributed mainly on the forest bed of Pinus thunbergii. The poor distribution of Chenopodium album var. centrorubrum Makino, Setaria viridis (L.) Beauv., Amaranthus mangostanus Linne is considered attributable to the phenomenon of allellopathy caused by a chemical substance secreted from the leaves of Pinus thunbergii. The component ratio of species in this island is lower than that of other islands due probably to the small area of arable land and grassland. The poor growth of plants in the forest of Pinus thunbergii, the dominant species in this island, seems to be attributed to the low relative light intensity of the forest. Seaside plants consisting of a total of 7 species were distributed mainly in the vicinity of sandy beaches. Naturalized plants comprising a total of 11 species were relatively diversified in the number of species.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.31 no.1
• /
• pp.84-92
• /
• 1995

The methods by turning circle test and maneuvering indices have been used to study and evaluate the maneuverability of a ship. However recently many studies utilizing the GPS are made on the measurement of the turning circle and in the fishery and hydrographic survey. In this paper, the author carried out the turning circle test using the differential GPS and dumb card together, and compared the data measured by them and analyzed the accuracies of them to obtain the utility basic ones on the measurement of the turning circle by the DGPS. The main results area s follows : 1) To check the accuracies of the GPS, the circling experiments of 50m radius by the DGPS were made on the ground. The accuracies of turning circle measured by the DGPS were found to be very high as the errors of 1.5m. 2) the turning circle by the DGPS could be measured very accurately, by the seed, rudder angle, starboard and port respectively. 3) The turning circle measured by the dumb card was found to be measured accurately as much as the DGPS, when using large rudder angle, the turning circle was large, the turning circle by the dumb car could not be measured accurately on account of large error of bearing of compass. 4) The tactical diameters by the DGPS in case of the rudder angle 35。~5。, were found to be 2.6。15.0 times the Lpp of S.T HAELIM-3 at her slow speed 2.8~16.6 times her Lpp at her half speed, 3.1~17.4 times her Lpp at her full speed. The tactical diameter by the dumb card was found to be 2.4~9.5 times, 2.6~9.6 times, 3.2~12.2 times her Lpp respectively, in the above case and speed.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.1
• /
• pp.36-42
• /
• 2018

This paper considers the Marine Traffic Risk Assessment for fixed and moving targets, which threaten officers during a voyage. The Collision Risk Assessment Formula was calculated based on a dynamic ship domain considering the length, speed and maneuvering capability of a vessel. In particular, the Navigation Risk Assessment Model that is used to quantitatively index the effect of a ship's size, speed, etc. has been reviewed and improved using a hybrid combination of a vessel's dynamic area and the Collision Risk Assessment Formula. Accordingly, a new type of Marine Traffic Risk Assessment Model has been suggested giving consideration to the Speed Length Ratio, which was not sufficiently reflected in the existing Risk Assessment Model. The larger the Speed Length Ratio (dimensionless speed), the higher the CJ value. That is, the CJ value is presented well by the Speed Length Ratio. When the Speed Length Ratio is large, states ranging from [Caution], [Warning], [Dangerous] or [Very Dangerous] are presented from a greater distance than when the Speed Length Ratio is small. The results of this study, can be used for route and port development, including dangerous route avoidance, optimum route planning, breakwater width, bridge span, etc. as well as the development of costal navigation safety charts. This research is also applicable for the selection of optimum ship routing and the prevention of collisions for smart ships such as autonomous vessels.