• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.383-387
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• 2001

The sea flower begins at the water-sediment Interface. In the ocean basins, the sound velocity of the sediments at the interface vary from a few percent less than the sound speed in water just above the interface to somewhat greater. Marine sediments are unconsolidated; that is, the particles are not cemented of fused together. Samples feel like mud, muddy sand, sand, and so on. With the theoretical knowledge, the systematic research on the searching capability of Ultra Sonic Signal will be continued to identify the influence against the sea water subject. In this research, signal will be analyzed according to the influence range, power and sensitiveness of Ultra Sonic Generator. In addition, the radius of Ultra Sonic Signal will be included. The experimental field work will be executed at Nockdong, Pulkyo and other places well known as a habitat of Pan Shell.

• Electronics and Telecommunications Trends
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• v.28 no.6
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• pp.167-179
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• 2013

측면주사음탐기(side scan sonar) 센서는 해저면의 영상을 실시간으로 탐색하는 장비로서 해양탐사 및 지질조사, 해저통신 및 어초조사, 기뢰 및 잠수정 탐색 등 해양탐사와 관련한 대표적 장비라고 할 수 있다. 센서는 해저와 목표물을 표시하기 위해 소나 플랫폼의 움직임을 사용하며, 동작주파수 범위는 20kHz~500kHz이다. 이 주파수는 요구되는 깊이와 목표물의 크기에 의해서 결정된다. 센서는 수직으로 $45^{\circ}$, 수평으로 $2^{\circ}$ 정도의 신호전파 방사각도 폭을 가진다. 최근에는 해양탐사와 개발을 위해 빠른 스캔속도와 정확한 정보, 고해상도의 영상을 얻기 위해 해저면에 대한 다중빔 영상센서의 핵심기술로 활용되면서 그 활용성과 중요성이 점차 증가되고 있다. 본고에서는 측면주사소나 센서의 기본 원리 및 종류, 디중빔측면주사소나 기술동향, 응용분야의 사례를 소개함으로써, 국내 기반기술 및 상용화 개발이 취약한 측면주사 음탐기 센서에 대한 이해를 돕고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.385-391
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• 2001

In this study, we will develop the sea surface interpretation system that can aware the target in the bottom of the sea. we will setup the database whose records would be the signal patterns of formation about mud, sand, rock and sea shell achieved by using supersonic. then we will convert analog signal received in fish detector to digital one using A/D converter So we can process and analyze this signal pattern then compare it to the one in our Database at the real time to identify the target in the bottom of the sea. After enough times of experiments from the background of the results that have been achieved from many studies(including a water tank experiment and a field investigation), we can aware the exact information of the sediment and the sand in the sea. By analyzing the first, second and third signal of the supersonic characters reflected from the body of a fish categorized by its family and from the body of shellfish, muddy sand, sand and rocks, We will develop the sea surface decipherment system which abstracts the first signal that shows the target in the bottom of the sea and makes the second and third signals filtering.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.410-418
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• 2000

In general, the experienced diver go into the water to find out Pan Shell which is spontaneously generated and brought up at the depth of 25-30 meters in the slime along the bank of an inlet of western and southern sea. However, this searching system has caused some problems in terms of economical efficiency and riskiness of diver. To overcome such problems and enhance the competence capability of fishermen, a new Pan Shell searching system is required. If an onboard searching system as a substitute of the way of diving into the deep water to identify the existence of Pan Shell is developed, it would be greatly beneficial to fishermen. The purpose of this research is to develop a new searching system of Pan Shell by making use of 50-200 Khz Ultra Sonic Signal, A/D Converter and computer process program. Based on the fact that Sonic Signal between the soft part of slime and the hard part of sand, pebble and Pan Shell is different, the possibility of this system have been approved in some degree by this time of research. However, to utilize this new system, further research on the establishment of data base and sample data is required. With the theoretical knowledge, the systematic research on the searching capability of Ultra Sonic Signal will be continued to identify the influence against the sea water subject. In this research, signal will be analyzed according to the influence range, power and sensitiveness of Ultra Sonic Generator. In addition, the radius of Ultra Sonic Signal will be included. The experimental field work will be executed at Nockdong, Pulkyo and other places well known as a habitat of Pan Shell.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.308-315
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• 2002

해양구조물 설치(Offshore Engineering)에 대한 수요가 급증함에 따라 보다 정확한 설계와 시공을 위한 해저지형 및 지질환경에 대한 탐사(Geophysical Survey)수요가 급격히 증가하고 있다. 전자기파의 감쇄가 심한 해수로 덮여 있는 해저에 대한원격탐사 매체로는 SONAR(SOund Navigation And Ranging)시스템이 일반적으로 이용되고 있다. (중략)

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.329-338
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• 2022

This paper provides a case study of development testing and evaluation of design goal of Interferometric SAS (Synthetic Aperture Sonar) system that is developing supported by Civil-Military Technology Cooperation Center in offshore fields. For Deep water operating capabilities evaluation, We have surveyed candidate field, bathymetric mapping and target identification over 200 m depth, East Sea. In testing phase, We have provided environmental information of testing field include water column, seabed and weather condition in real time. And to compare excellency of developing InSAS, we have gather commercial imaging sonar system data with same target. This case study will support the Test Readiness Review of future underwater surveillance system developing via investigate marine testing field environment, testing facilities and planning.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.271-279
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• 2008

Polymetallic sulphides means hydrothermally formed deposits of sulphide minerals which contain concentrations of metals including, inter alia, copper, lead, zinc, gold and silver. Nautilus is the first company to commercially explore the seafloor polymetallic sulphide deposits. The Company holds exploration licences and exploration applications for more than 370,000 $km^2$ in the jurisdictional seas of Papua New Guinea, Fiji, Tonga, the Solomon Islands and New Zealand along the western Pacific Ocean's Rim of Fire. Neptune Minerals is also a leading explorer and developer in this field, with exploration licences awarded totalling more than 270,000 $km^2$ in the territorial seas or EEZ of New Zealand, Papua New Guinea and the Federated States of Micronesia. These two companies now carry out the most active investment activities for seafloor polymetallic sulphide deposits with a goal of commercial production by 2010. China and Japan carry out exploration activities for the seafloor polymetallic sulphide deposits to secure supplies of strategic metals. China carries out national R&D projects relating to deep sea mineral resources in the world ocean through China Ocean Mineral Resources R&D Association(COMRA). And Japan investigates her own EEZ for exploration of the seafloor polymetallic sulphide deposits. In consideration of aforementioned international activities of coastal nations as well as private companies for exploring the sulphide deposits, Korea shall prepare strategic plans : First, consolidation of the authorities concerned and legislative support; second, determination of main entity of the project; third, securing government's decisive investment of sufficient budget; and lastly, establishment of the mid, long-term plan for development of seafloor polymetallic sulphides deposits.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.955-967
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• 2016

As transportation systems for connecting lands and islands, oversea long-span bridges, underwater tunnels, and immersed tunnels have been mainly used so far. Submerged floating tunnels (SFTs) moored under specific water depth are one of the newest oversea transportation system. Compared to other existing systems, the new system requires relatively less construction cost and time. But, there is still no construction example. For reasonable design of the tunnel and mooring lines the rational structural analysis should be firstly performed. Unlike common transportation structures, the submerged tunnels are mainly affected by the wave, vary irregular excitation component. So, the analysis scheme might be difficult because of the characteristics of the submerged structures. This study aims to suggest the rational global performance analysis methodology for the submerged tunnels. Using ABAQUS the dynamic response of the experimental models studied by KIOST (2013) was investigated considering regular waves. By comparing the simulation results with the experimental results, the feasibility of the numerical simulation was verified. Using the suggested method, the effects of initial inclination of the tethers and draft of the tunnel on the dynamic behavior were studied. In addition, dynamic response of a SFT under the irregular wave was examined.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.2
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• pp.143-150
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• 1993

Shallow sub-bottom reflection recorders are obtained using dual frequency (15/100 KHz). The main goal of this study is to enhance the resolving power and penetration for the sub-bottom reflection of the sub-marine seismic exploration. The Fresnel zones of spherical waves for the near-field are of great importance to reach the high resoluton. In case a target to detects than the Fresnel radius, a diffraction hyperbola on the recorder is observed. A larger attenuation of sand makes less penetration than the smaller attenuation of silt and clay. It is found that the selective frequency as well as the seismic energy generation is the most important factors for sub-marine exploration. This technique of using dual frequency sub-marine exploration may be applied to detect the sub-bottom sludge soil, ocean contamination and marine archaeological relics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2162-2166
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• 2016

This paper describes the implementation of AUSV system for sonar image acquisition to survey the seabed. The system is controlled by Feed Forward PID algorithm on the vessel for bearing of the thrusters composed of motion sensor and DGPS which calculates the differences between the current location and the destination location for longitude and latitude based on GPS coordinates. As experimental results, the bearing control performance is good that the error distance from the destination positions are under 6m in total survey track of 1km. And the sonar image deviation of a object is under 12 pixels from the manned survey method, which the comparison with the total image quality is almost the same as the manned survey one. Thus the proposed AUSV system is a new method of system can be utilized at the limited survey areas as the surveyor should not be able to approach on sea surface by onboard vessel.