• 한국해양학회지
• /
• v.4 no.1
• /
• pp.9-16
• /
• 1969

The sand drift movement at Young Il Bay area was tentatively investigated using Co-60 glass sand. Grain size and specific gravity of the glass sand which has originally contained natural cobalt, Co-59, was made similar to those of the real coastal sand, and was irradiated in a beam port of the reactor Triga Mark II to make the glass sand radioactive by the reaction of 59Co(n, r)60Co. The radioactive cobalt glass sand was deposited on the preselected point of sea bed, and, after a couple of weeks, the drift of sand was traced by means of specially designed water-proof G-M detector. Net counts at each point were plotted to figure out equicount lines and consequently such aspects as the direction of sand drift movement, the scope of distribution and the relative drift velocity etc. were indicated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.2 no.1
• /
• pp.17-33
• /
• 1984

This work represents results of analysis of tidal observations at twelve major ports(Inchon, Kunsan, Mokpo, Daeheuksando, Jeju, Yeosu, Jinhae, Busan, Pohang, Ulsan, Mugho, Sogcho) around Korean coast for the years up to 1979. The reduction of hourly tide gauge sea level records provided by Korean Hydrographic Office was performed in systematic manner resulting digitised hourly observed series, predicted series and residual series. As a first step the application of an extended harmonic method of analyzing the tidal observations leads to the identification of 42 new constituents including 60 orthodox Doodson's constituents at major ports. The sea level statistics including sea level frequency distribution are presented and the tidal emersion curves showing the percentage of time for which different levels are covered by water and exposed are also presented to provide useful design input for coastal development. This study has teen undertaken in association with the programme of sea level research at Korean Hydrographic Office and the programme of adjustment of first order levelling network at National Geographic Institute.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.11
• /
• pp.13-18
• /
• 2022

In this study, the suitability of the grouting method will be evaluated by analyzing seismic reinforcement methods for the stability of gravity structure in Port. The evaluation categories are liquefaction, sliding, toppling and circular failure. To compare the appropriateness of the seismic reinforcement method, the low mobility mortar injection, one of the grouting method and the SPC file and GRB method, which are pile wall type reinforcement methods, were evaluated and compared respectively. The object of the evaluation is the gravitational structure of Po-Hang old port. As a result of the evaluation, both the grouting method and the pile wall type reinforcement method are considered to have sufficient stability. Therefore, in the case of the gravity structure, the grouting method is more efficient than the seismic reinforcement method considering construction efficiency, economic efficiency, maintenance and similar construction cases.

• Journal of the Korean Institute of Navigation
• /
• v.21 no.2
• /
• pp.47-58
• /
• 1997

The purpose of this study is to find out the impacts of VTS on the marine safety and users' opinion on the VTS which have been being operated in the port of Pohang for the last 3 years and is to suggest a guideline to the successful operation of VTS in the future. This study is based upon the questionnaire survey and the respondents include 236 masters/mates of merchant vessels who have visited the port of Pohang and 6 pilots who have been working in the port. From the questionnaire results, this study notes the following conclusions related to the VTS operations. (1) A few of the respondents (mainly foreigners) do not understand the entering procedure of the port and the fundamental concept of VTS. Accordingly, the more active VTS services have to be provided for the mariners. (2) It was found that themost dangerous factors in tehvicinity of the port were the floating materials, fishing nets, andillegal fishing activities inthe fairway. Therefore, the proper surveillance, stricter enforcement of Acts and the instructive education for the fishermen are required to avoid the risks. (3) A majority of the respondents agreed the VTS has contributed to the safety of vessel traffic, and they pointed out ' the assiatances in reduced visibililty conditions' is the most important task of VTS. The amount of 75.6% of the respondents answered that they have experienced the assistance from VTS more than 1 time since the system was established in the port of Pohang . Also 44.2% of the respondents considered they were able to avoid marine casualties such as collision, ramming or agrounding with the VTS assistances. (4) 49.2% of the respondents preferred the passive information services , while, 38.8% of them preferred the positive control advices in the case of encountering any potential risks. VTS iperators have to consider seriously when they provide the positive control advices of ship's course and speed. (5) A majority of the respondents confirmed that the prot and its approaches is suitable for the VTS coverge . To extend the service areas of the VTS and to improve radar detecting ability, the use of radar transponders are seen as the ideal method. (6) A minority of the respondents pointed out 'the improper orders or recommendatinos caused by the poor decision making' firstly, ' the language problem(sea-speaking in English)' secondly, as the deficiency of personal qualification. It seems, therefore, theat the personal efforts of the operators and systematic training programmes for them are necessary to solve the problems.

• 한국해양학회지
• /
• v.27 no.1
• /
• pp.46-54
• /
• 1992

An investigation on the benthic polychaete community in Youngil Bay was conducted during four seasons of 1991. Polychaetes. the dominant macrofaunal group occupying 71.3% in total macro-faunal density, comprised a total of 72 species with a mean density of 1,485 indiv. m/SUP -2/. The highest species number of 54 spp. and density of 3,207 undiv. m/SUP -2/ was recorded in summer, while the lowest in autumn. The most abundant species was Spiophanes nombyx (37.5%), followed by Pseudopolydora sp.(8.4%), Lumbrineris longifolia(7.0%), Madden cristata(6.5%), Polydora ciliata(4.9%) and so on. Maldane cristata was dominated in winter, Polydora ciliata in spring and Spiophanes bombyx in summer and autumn. The density and species number of Polychaetes were high in the southeastern area of Youngil Bay, and poor near the mouth of Hyoungsan River. Based on the species composition, study area was divided into three regions. Each region sustained its specific benthic faunal assemblage; Maldane-Praxillella assemblage from the middle to the southeastern region of Youngil Bay, Spiophanes-Nephtys assemblage in the northwestern region, and Pseudopolydora-Polydora-Capitella assemblage from the mouth of Hyoungsan River to Pohang Hobour. Maldane Praxillella assemblage showed the highest species number of 55 spp.. and the highest species diversity and species richness indices. Spiophanes-Nephtys assemblage had the highest density of 2,675 indiv. m/SUP -2/ and the highest dominance index because of the predominance of Spiophanes bombyx with a density of 2,073 indiv. m/SUP -2/. Pseudopolydora-Polydora-Capitella assemblage was found in the polluted area and it was a specific assemblage mainly composed of the dominance of organic pollution indicator species. The dominant Polychaetes were Pseudopolydora sp., Polydora ciliata, Capitella capitata, and Dorvillea sp.

• Journal of Navigation and Port Research
• /
• v.34 no.8
• /
• pp.603-607
• /
• 2010

The LORAN system had been used widely and it was an essential navigation aid for ships in the ocean until the GPS is adopted actively. In particular, it was essential functionality for the ships to sail the oceans. According to the advancement of industry, however, the current accuracy of traditional Loran is insufficient for the utilization of harbour approach, land navigation, and the field of survey and timing. Therefore it is necessary that the study on the improvement of the positioning accuracy of Loran. The one of the improving methods is to measure and compensate the propagation time delay between the transmitter and user's receiver, which is called as additional secondary factor (ASF). In this study, we measured the ASF between the Pohang master transmitting station (9930M) and four points where locate within 33 km apart from the transmitting station, using the measuring technique of the absolute time delay without a time of coincidence (TOC) table. As the result of measurement, the ranging error caused by the propagation delay was about 210 m at 33 km, however it can be reduced up to 40 m with ASF compensation.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.24 no.1
• /
• pp.58-65
• /
• 2012

In this study, to reduce the motion of the vessels resulting from resonance and secondary undulation by long-period waves, numerical review on the control performance of resonator was carried out by attaching the resonator to the established harbor of real waters. In the numerical analysis, CGWAVE MODULE of commercial software SMS(Surface water Modeling System), a finite element model based on 2-dimensional elliptical mild slope equation was applied, and through comparative analysis of the existing experiments and analysis results on the rectangular model ports, the validity of the friction coefficients in which validity and effectiveness of SMS on the secondary undulation analysis is applied was verified. Based on this, the control performance of resonator was confirmed through comparative review of the secondary undulation according to whether or not to attach the resonator to rectangular harbor. In addition, to reduce long-period motion of the moored vessels and the secondary undulation which may occur in Pohang new port, the method to move the resonant period which causes abnormal motion of the vessels to long-term one was discussed through application of the resonators with various sizes, thereby identifying the availability.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.3
• /
• pp.1770-1777
• /
• 2014

Coastal settlements have a diversity of tangible or intangible local assets and are environmentally sensitive areas. The value of tangible or intangible local assets is often overlooked and there is no enough consideration for the inhabitants who have a various and acute stake in the development process of coastal settlements. The development of coastal settlements without consideration for the local circumstance, resident's needs, and local characteristics makes it difficult to achieve sustainable regeneration. There are also alienation, conflicts, and the loss of a authentic sense of place because of physical oriented development without regard to the social, economic, and cultural aspects. This research defines the components and types of coastal settlements and draws the characteristics of them around the fishery ports in Busan in the aspect of sustainable regeneration. It will be the important methods for an integrated regeneration including not only spatial and physical regeneration but also social and economic regeneration which has the preservation of local culture with living conditions, local economy activation, and community building. It will also provides the bases of sustainable development, attractiveness, and competitiveness of coastal settlements.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.4
• /
• pp.180-188
• /
• 2017

Recently, as the strength of winds and waves increases due to the climate change, abnormal waves such as swells have been also increased, which results in the increase of downtime events of loading/unloading in a harbour. To reduce the downtime events, breakwaters were constructed in a harbour to improve the tranquility. However, it is also important and useful for efficient port operation by predicting accurately and also quickly the downtime events when the harbour operation is in a limiting condition. In this study, numerical simulations were carried out to calculate the wave conditions based on the forecasted wind data in offshore area/outside harbour and also the long-term observation was carried out to obtain the wave data in a harbour. A forecasting method was designed using an auto-regressive (AR) and artificial neural networks (ANN) models in order to establish the relationship between the wave conditions calculated by wave model (SWAN) in offshore area and observed ones in a harbour. To evaluate the applicability of the proposed method, this method was applied to predict wave heights in a harbour and to forecast the downtime events in Pohang New Harbour with highly complex topography were compared. From the verification study, it was observed that the ANN model was more accurate than the AR model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2010.04a
• /
• pp.370-371
• /
• 2010

The Long Range Navigation (LORAN) had been mainly used world-wide until GPS (Global Positioning System) activation. In particular. it was essential junctionality for the ships to sail the oceans. However, according to the industry's developing, the current accuracy of Loran is insufficient for the utilization such as the harbour approach, the land navigation and the field of precise timing. Therefore it is necessary the study on the improvement of the positioning accuracy of Loran. The method of its improvement is to measure and compensate the propagation time delay, that is, additional secondary factor (ASF) between the transmitter and user's receiver. This study shows the technique for the absolute time delay measurement without a time of coincidence (TOC) table, and represents the ASF measurement result between Pohang transmitter station(9930M) and each measure points.