• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.121-127
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• 2003

The Korea Maritime Police Agency(KMPA) is the national maritime Search and Rescuee (SAR) authority with the responsibility to promote an efficient organization of SAR services and to coordinate the conduct of SAR operations within the Korean Search and Rescue Region(SRR). The maritime SAR operations shall provide an adequate and effective search and rescue services to minimize the loss by rendering aid to persons in distress and property in the marine environment. The essence of a successful search and rescue operation is the speed with which it is planned and carried out because survivors who need assistance and whose chances of survival diminish rapidly with time. This paper aims to propose an optimal allocation model of maritime SAR fleet in view of minimizing the search and rescue time. When maritime accidents occur, rescue units have to reach to the distress scene within the specified time. For this, SAR units must be redeployed to an advanced base so that Rescue Units(RU) can reach to the scene of distress in the shortest possible time. The Korean maritime SRR is divided into 180 sub-areas in consideration of an operational and technical ability of SAR units. The suggested model is verified through an empirical application to the Korean maritime SRR. And also the Rescue Vessels(RV) required is estimated for each Rescue Co-ordination Center(RCC).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1114-1125
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• 2013

License Plate Detection (LPD) is a key component in automatic license plate recognition system. Despite the success of License Plate Recognition (LPR) methods in the past decades, the problem is quite a challenge due to the diversity of plate formats and multiform outdoor illumination conditions during image acquisition. This paper aims at automatical detection of car license plates via image processing techniques. In this paper, we proposed a real-time and robust method for license plate detection using Heuristic Energy Map(HEM). In the vehicle image, the region of license plate contains many components or edges. We obtain the edge energy values of an image by using the box filter and search for the license plate region with high energy values. Using this energy value information or Heuristic Energy Map(HEM), we can easily detect the license plate region from vehicle image with a very high possibilities. The proposed method consists two main steps: Region of Interest (ROI) Detection and License Plate Detection. This method has better performance in speed and accuracy than the most of existing methods used for license plate detection. The proposed method can detect a license plate within 130 milliseconds and its detection rate is 99.2% on a 3.10-GHz Intel Core i3-2100(with 4.00 GB of RAM) personal computer.

• The Journal of Fisheries Business Administration
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• v.45 no.1
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• pp.95-107
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• 2014

This study is aimed to analyze the economic performance of black rockfish aquaculture by standardizing cost structures by region and farming size. The result of survey on farming and sale condition in each region, stocking density, survival rate, juvenile price, and unit production was the highest at Yeosu and Tongyeong, Heuksando showed the lowest. While rearing period was the longest at Tongyeong, the shortest region was Yeosu and Wando. In farming cost structure by region, amount of feeing was the highest at Tongyeong and Yeosu, and the lowest was Heuksando. Cost of medicine was high in Wando and Taean region, Yeosu and Hecksando was low. In case of farm size, feed cost ratio was high in the order of medium(0.75ha), small(0.25ha) and large(1.25ha) size. Standard production cost at every farm size of Heuksando showed the lowest among these regions. Taean and Yeosu was middle, and Tongyeong and Wando was the highest. According to the income, profit rate and investment return of farm size in all regions, as the bigger farm size, the higher income and profit rate was revealed. However, in case of Wando, Taean, and Heuksando which regions has high investment return, medium farm size was higher than large size. The result of economic analysis according to various factors, economic feasibility of black rockfish aquaculture in marine floating cage was showed significant changes by rearing and market condition.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.181-181
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• 2016

Hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films have attracted much attention as materials of the bottom-cells in Si thin film tandem photovoltaics due to their low bandgap and excellent stability against light soaking. However, in PECVD, the source gas $SiH_4$ must be highly diluted by $H_2$, which eventually results in low deposition rate. Moreover, it is known that high-rate ${\mu}c-Si:H$ growth is usually accompanied by a large number of dangling-bond (DB) defects in the resulting films, which act as recombination centers for photoexcited carriers, leading to a deterioration in the device performance. During film deposition, Si nanoparticles generated in $SiH_4$ discharges can be incorporated into films, and such incorporation may have effects on film properties depending on the size, structure, and volume fraction of nanoparticles incorporated into films. Here we report experimental results on the effects of nonoparticles incorporation at the different substrate temperature studied using a multi-hollow discharge plasma CVD method in which such incorporation can be significantly suppressed in upstream region by setting the gas flow velocity high enough to drive nanoparticles toward the downstream region. All experiments were performed with the multi-hollow discharge plasma CVD reactor at RT, 100, and $250^{\circ}C$, respectively. The gas flow rate ratio of $SiH_4$ to $H_2$ was 0.997. The total gas pressure P was kept at 2 Torr. The discharge frequency and power were 60 MHz, 180 W, respectively. Crystallinity Xc of resulting films was evaluated using Raman spectra. The defect densities of the films were measured with electron spin resonance (ESR). The defect density of fims deposited in the downstream region (with nonoparticles) is higher defect density than that in the upstream region (without nanoparticles) at low substrate temperature of RT and $100^{\circ}C$. This result indicates that nanoparticle incorporation can change considerably their film properties depending on the substrate temperature.

• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.203-216
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• 2015

This paper examined the changes of urban system through the network and the flow pattern reflected in daily movement in Korea. Because daily movement reflects trip pattern, urban system formed by inter-city linkages can be recognized in terms of living sphere. While population movements between cities have the number of linkage systems of city network and the number of traffic regions composed of the origin and destination has increased respectively. Nevertheless, spatial extent of Capital region and Busan region has been expanded. In Gangwon-do in which Seoul-oriented high-speed transportation network has developed, separation of living sphere between Yeongdong area and the Soyanggang cultural region formed around Chuncheon was intensified. Living sphere that includes Daejeon and the surrounding cities has been expanded to the southern Gyeonggi-do. The existing living sphere formed in Jeollanam-do was fragmented into the east and west around Mokpo and Suncheon due to the weakened centrality of Gwangju. Living spheres formed by spatial interaction were consistent with regional administrative boundary. Considering the increased interaction between Seoul and its surrounding cities, the development of global city-region centered on Seoul is expected.

• Journal of the Korean Society of Earth Science Education
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• v.1 no.1
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• pp.41-51
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• 2008

For teaching-learning to geological region of earth science part in science education, middle school, the practical uses of natural science museum are very effective. So, the appropriate uses of the natural science museum are necessary for the teaching and learning of Science Education. This study aims to consider the presentation characteristics of the natural science museum and to examine how is effective it to geological region in middle school science curricula on those uses. From the results, the natural science museum is low in multi-sided and open-endedness presentation characteristics but high in ones of accessible characteristic. And its presentations are good in multimodal characteristics using supported materials but relatively low in relevant and multimedia ones. In the museum, diorama and self-performing presentation types are not but internet ones are most. The presentations of the natural science museum are mainly assigned to knowledge region linked to basic science concepts but relatively insufficient in STS aspects, on the basis of connection the presentations with middle school science curricula. It is respected that these insufficiencies might be diminished by variable arrangements of and explanations to the presentations for understanding improvements. And, applies to the presentations in STS may be encountered, if multi-sided observations to them is available.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.845-850
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• 2018

In this paper, we propose a method to estimate the number of biofouling attached to the surface of marine structures. This method estimates the number of biofouling by calculating the region maxima using images taken in underwater. To do this, we analyze the correlation between the region maxima and the number of biofouling. The analysis showed that there is a significant correlation between the number of region maxima and the number of biofouling. By using the results of this analysis, the experiments were conducted on images taken in the underwater. Experimental results show that the higher the region maxima of the image, is greater than the number of biofouling in the image. The proposed method can be used as an important technology in computer vision for underwater images.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.3
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• pp.230-237
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• 2017

In this study, electrochemical methods were used to determine the optimum protection potential of S355ML steel for the cathodic protection of offshore wind-turbine-tower substructures. The results of potentiodynamic polarization experiments indicated that the anodic polarization curve did not represent a passivation behavior, while under the cathodic polarization concentration, polarization was observed due to the reduction of dissolved oxygen, followed by activation polarization by hydrogen evolution as the potential shifted towards the active direction. The concentration polarization region was found to be located between approximately -0.72 V and -1.0 V, and this potential range is considered to be the potential range for cathodic protection using the impressed current cathodic protection method. The results of the potentiostatic experiments at various potentials revealed that varying current density tended to become stable with time. Surface characterization after the potentiostatic experiment for 1200 s, by using a scanning electron microscope and a 3D analysis microscope confirmed that corrosion damage occurred as a result of anodic dissolution under an anodic polarization potential range of 0 to -0.50 V, which corresponds to anodic polarization. Under potentials corresponding to cathodic polarization, however, a relatively intact surface was observed with the formation of calcareous deposits. As a result, the potential range between -0.8 V and -1.0 V, which corresponds to the concentration polarization region, was determined to be the optimum potential region for impressed current cathodic protection of S355ML steel.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.185-189
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• 2008

This study was conducted to find out the effects of relationship between ocean conditions and snowfall when cold and dry continental air mass passes through the West Sea of Korea. Route of continental high atmospheric pressure can cause effect on snowfall at the west regions (Inchoen, Gunsan, Mokpo) of the Korean Peninsula. The continental high atmospheric pressure extend from the southern China to western coastal region of the Korean Peninsula during the December, and it extend from the north side of China through Bohai Sea and Yodong Peninsula to central area of the Korean Peninsula during the February. Therefore, more snowfall recorded in Incheon is higher during Feb. than Dec.. whereas Gunsan and Mokpo is the opposite. The heavy snowfall at the western coastal region of Korea was caused by loss of the heat from the ocean to air when it's higher than $100W/m^2$. the heavy snowfall was also observed when the arrangement of continental high atmospheric pressure and low pressure was high at the West and low at the East, which formed a front in West and when the wind blow from the North or North West at the speed of $4\sim8m/sec$. There were not much relation between salinity in the western sea and snowfall in the western coastal region of Korea.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.982-987
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• 2012

In this paper, the SNR estimation error of Decision Directed SNR estimation method in AWGN is investigated, which uses samples received in reference decision region. In communication system receiver, when SNR estimation scheme using error vectors between ideal sample points and received sample points of reference region is adopted, the samples contain incorrectly received samples due to AWGN. Consequently, the mean of estimated reference constellation point is shifted and Decision Directed SNR estimation is inaccurately performed. These effects are explained by modified probability density function and difference between actual SNR and estimated SNR is theoretically derived and quantatively analyzed. It is proved that SNR estimation error obtained through computer simulation is matched up with derived one, and SNR estimation performance is enhanced significantly by adopting suggested correction scheme.