• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.365-368
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• 2007

Millimeter-wave (MMW) imaging radiometer systems have an attractive advantage to obtain an image through low visibility weather conditions such as fog, clouds and light rain compared with visible and infrared imaging systems. Many countries have developed a various kinds of MMW imaging radiometers for the aim of low cost and high performance. In Korea, Millimeter-wave Imaging RAdiometer Equipment (MIRAE) has been developed since the end of 2006. Recently the development of some modules was finished for the test model. This paper describes the design and development of the MIRAE. In addition, the test results of its manufactured modules are presented.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 한국해양공학회 2004년도 학술대회지
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• pp.30-35
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• 2004

Several roll motion reduction devices are reviewed and suggested for the application in FPSO. The firstly suggested solution is the shape of the bilge. The next is a bilge keel. The last suggestion is the ART (anti-rolling tank). Typical U-tube type ART is designed for a FPSO and examined extensively by model experiment. The model section was made of transparent acryl. Free decay test, forced oscillation test and wave test were carried out at a two-dimensional wave flume. U-tube type ART is effective only when the natural periods of ART and ship are same. Therefore, the divided U-tube type ART with split plate is suggested for the reduction of the roll motion of a FPSO over the wide range of the roll period.

• Journal of rehabilitation welfare engineering & assistive technology
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• 제4권1호
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• pp.15-21
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• 2010

Ultrasonic wave stimulator need estimation of quality and security of safety by courtesy call about malfunction or side effect. Need a standard of test method for estimation of safety and performance in type test before marketing or removal examination after marketing for this. In this paper, studied standard of test method for estimation of essential electrical safety and performance for ultrasonic wave stimulator.

• Journal of the Korean Society of Marine Environment & Safety
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• 제25권4호
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• pp.504-510
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• 2019

Practical test items were analyzed to extend the existing scoring method for boat operator licenses to an electronic scoring method. We have attempted to digitize the method within the current practical test system scope and have developed an electronic scoring system using LiDAR sensors and WAVE communication. The results of the study are as follows; the first, the scoring data entered into the LiDAR and examiner score device on the boat were transferred from an integrated processing unit to a land control center through WAVE communication. The system was constructed and verified to store and manage examinee data. Second, when testing the meandering task, accurate distance measurement was achieved by using LiDAR instead of visually observing the stick (3 m), and an accurate distance was displayed through the examiner score device quickly. Finally, we confirmed that it is possible to smoothly transmit and process the WAVE communication used to transfer the score data acquired from the boat to the monitoring center at a high speed without loss.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.608-611
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• 2004

As the use of various electronic equipments has been increased recently according to industrialization and information network establishment, concern about electromagnetic wave exposed environment has also been increased. Therefore, this study aims to verify electromagnetic wave absorbing effects of inorganic paint that is made of carbon, electro-conductive materials with regard to its physical characteristics, its electromagnetic wave absorbing rate through a mock-up test for proving its effects in the indoor condition. The results are as follows: The results of running tests on electromagnetic wave absorbing inorganic paints for checking their requirements as painting material such as adherence degree, resistance to fine crack, resistance to washing, alkali-resistance, discoloration-resistance, etc. show that inorganic paints have the physical characteristics meeting the requirements for painting materials. In addition, it shows that the electromagnetic wave absorbing effect, in line with the number of paintings and the thickness of paintings, secures $75\~89\%$ of efficiency. And the mock-up test shows that the electromagnetic wave absorbing effect inside building is directly proportional to the distance from the source of electromagnetic wave such as electronic equipments.

• Magazine of the Korean Society of Agricultural Engineers
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• 제38권5호
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• pp.85-94
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• 1996

For the geotechnical analysis in the construction and Deign of the coastal structures, one of the most important factors is the existence of waves. The dynamic behavior and deformation of the seabed subjected to wave load must be considered. It is expected that the soil behavior in the seabed subjected to cyclic wave load is much different from that on the ground subjected to dynamic forces such as earthquake. The purposes of this study are as follows ; Firstly, to provide a testing method to generate wave loads in the laboratory and measuring oscillatory pore water pressures in the unsaturated marine silty sand specimen, Secondly, to analyze the mechanism of wave induced pore water pressures and liquefaction potentials under the conditions in the testing. It is shown that the test set-up manufactured especially for the test is good to generate oscillatory wave pressures to the specimen with sine wave type. From the results of this study, it is understood that the pore water pressure due to induced waves is not accumulated as the wave number increases but is periodically varied with wave passage on still water surface. The magnitude of pore water pressures measured tends to be diminished radically with a certain time lag under the action of both high and low waves as depth increases.

• Journal of Ship and Ocean Technology
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• 제10권4호
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• pp.34-48
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• 2006

The visual observation of wave condition depends on the observer's skill and experience. Also, the environmental conditions such as light and cloud heavily influence the visual measurement. In the speed test of sea trial, the wave measurement should be objective and accurate. In this paper, the problems of visual measurement and their effects on speed test are described. To overcome those problems, we developed the wave measurement system using commercial marine X-band radar, WaveFinder. The system installed at inland base was calibrated by waverider buoy and then the system's operability was defined. Onboard tests had also been performed three times for formal wave measurement to correct the ship speed. The results illustrated very good agreement with visual observation by experts. It can be concluded that the system would be useful to measure wave and swell information for the sea trial, irrespective of day and night.

• Journal of Korean Society of Coastal and Ocean Engineers
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• 제32권1호
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• pp.26-38
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• 2020

A statistical test was carried out on the IID (Independently and Identically Distributed) assumption of the AM (Annual Maxima) data used to estimate the design wave height. The test was divided into independence (randomness) test and homogeneity test, and each test was conducted on AM data of 210 and 310 stations in coastal and inner coastal grids in typhoon and non-typhoon (monsoon) conditions. As a result of the independence test, the rejection ratios of the test are in the range of 1.8~5.3% and 1.4~6.0% for the non-typhoon and typhoon data sets, respectively. On the other hand, in the distribution difference test of typhoon data and nontyphoon data, the same distribution hypothesis was found to be rejected in the range of 47~79% according to the test method for both coastal grid and inner coastal grid. Therefore, in estimating design wave height by extreme value analysis, the estimation process by dividing the typhoon and non-typhoon data is appropriate.

• Honam Mathematical Journal
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• 제39권1호
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• pp.27-40
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• 2017

In this paper, we construct exact traveling wave solutions of various kind of partial differential equations arising in mathematical science by the system technique. Further, the $Painlev{\acute{e}}$ test is employed to investigate the integrability of the considered equations. In particular, we describe the behaviors of the obtained solutions under certain constraints.

• Journal of Ocean Engineering and Technology
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• 제14권1호
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• pp.6-10
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• 2000

In this paper various methods of determining of wave loads acting ofshore structures including impact load due to breaking wave are studied and corresponding model test was performed. In the theoretical approach wave load by nonbreaking wave and impact load by breaking wave is determined by Morrison's equation Goda's equation and impact wave equation, In the experimental approach wave load by nonbreaking wave acting on cylindrical pile used in offshore structures is determined by measuring the strain on a cylindrical pile and compared with theoretical calue. in the numerical approach impact load by breaking wave acting on a modeled cylindrical pile is calculated by usign ANSYS FEM program and compared with theoretical value. It is found that the experimental and numerical results are comparable to theoretical results, Thus the determination of wave load acting on offshore structures can be obtained by a proposed methods and it acceptable.