• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.413-420
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• 2006

The construction of a submerged breakwater has become increasing due to their multiple effects on the coastal zone. Recently, marker rocks have been installed on the submerged breakwater to indicate its position to the vessels instead of buoy systems, since a buoy is not only improper for the ocean view, but also its mooring system may be damaged by the impulsive wave force caused by wave breaking on the breakwater. The accurate estimation of wave forces on such rocks is deemed necessary for their stability design. In this study, the characteristics of irregular wave forces acting on a marker rock, which was installed on a submerged breakwater, was investigated on the basis of laboratory experiments. It was revealed that the dimensionless highest one-third wave force tends to decrease with increasing the installation distance of a marker rock from the leading crown edge of a submerged breakwater. Also, the drag and inertia coefficients for irregular wave forces, which were obtained using the Morison equation, were investigated in relation to K.C. number.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.617-626
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• 2006

The purpose of contingency estimate is to manage the increase in construction cost and the extension of the term of works due to the inevitable occurrence of uncertain situations. The aim of contingency strategies have two intentions. One thing, can be called a passive strategy, gets ready for construction cost increase due to uncertainty factors, the other thing, can be called a active strategy, gets rid of the obstruction factors of work prior to construction performance. Therefore, from the view point of medium and long term, there is necessary to accumulate data in conjunction with design modification cases and carefully analyze uncertainty factors from construction types and characters. Therefore, this thesis will analyze design modification case at a special work such as highway and select factors that affect construction cost and present contingency estimate process using regression analysis.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.35-57
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• 2011

Minor erosional forms in the bedrock river, like potholes, are not just research subject for the professional geomorphologis. In addition, these features attract general public and make them understand the social contribution and importance of geomorphologic research activities. In this paper, the studies on bedrock minor forms in Korea was reviewed. For further researches, some of major erosional processes and minor forms in bedrock rivers were discussed in detail. Cavitation, plucking, hydro-wedging, and abrasion by passing sediment particles are the major processes to create the longitudinal or transverse minor forms like pothole, furrows, flutes, and runnels. Especially the definition of furrows and runnels are explained to prevent the confusion with pothole, weathering pits and grooves. To make a progress in research on bedrock minor forms the quantitative relationship between the variables should be studied. New techniques for scientific estimation of erosion rates and exposure ages of bedrock surfaces should be used in this field.

• Journal of the Korea Computer Graphics Society
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• v.30 no.2
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• pp.11-19
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• 2024

Demand for small biomimetic robots that can carry out reconnaissance missions without being exposed to the enemy in underground spaces and narrow passages is increasing in order to increase the fighting power and survivability of soldiers in wartime situations. A small compound eye image sensor for environmental recognition has advantages such as small size, low aberration, wide angle of view, depth estimation, and HDR that can be used in various ways in the field of vision. However, due to the small lens size, the resolution is low, and the problem of resolution in the fused image obtained from the actual compound eye image occurs. This paper proposes a compound eye image quality enhancement algorithm based on Image Enhancement and ESRGAN to overcome the problem of low resolution. If the proposed algorithm is applied to compound eye image fusion images, image resolution and image quality can be improved, so it is expected that performance improvement results can be obtained in various studies using compound eye cameras.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.123-133
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• 2024

Existing autonomous driving technology has been developed based on sensors attached to the vehicles to detect the environment and formulate driving plans. On the other hand, it has limitations, such as performance degradation in specific situations like adverse weather conditions, backlighting, and obstruction-induced occlusion. To address these issues, cooperative autonomous driving technology, which extends the perception range of autonomous vehicles through the support of road infrastructure, has attracted attention. Nevertheless, the real-time analysis of the 3D centroids of objects, as required by international standards, is challenging using single-lens cameras. This paper proposes an approach to detect objects and estimate the centroid of vehicles using the fixed field of view of road infrastructure and pre-measured geometric information in real-time. The proposed method has been confirmed to effectively estimate the center point of objects using GPS positioning equipment, and it is expected to contribute to the proliferation and adoption of cooperative autonomous driving infrastructure technology, applicable to both vehicles and road infrastructure.

• Korean journal of communication and information
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• v.34
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• pp.196-243
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• 2006

The popularity of Korea pop culture, which called as the name of "Korea wave", has started to spread out in China and other Asian states from late-1990's. The study about "Korea wave" until now, however, have prevailed within an economic point of view. So, I would like to clarify that this dissertation raises a question in exiting argument and explains the identity of "Korea wave" by investigating the details of pop culture contents of Korea, and understanding of chinese receiver. It shows that chinese receiver, watching the movie , has estimated in the affirmative viewpoint after I have analyzed a reply of movie web-site in China. The main features of this analysis prove that there are a lot of good estimation when chinese receiver have seen that movie because it has been well-matched with emotion and fun of story and attraction in the movie. In that order, Some Chinese netizen evaluated that there are some negative point of view as the main actress has a strange and crazy behavior. I have also found that Korea pop culture contents has not given to them good image and chinese receiver had a tendency to view objectively to classify with strength and weakness. Analysis to contrast understanding of Chinese netizen with Korea netizen showed that Korea netizen emphasized fun of story, however, Chinese netizen showed that they had a lot of opinion to be fresh and realistic relatively. In conclusion, I would like herewith to identify that there are some differences between Chinese netizen and Korean netizen after contacting the movie. The reason has showed that understanding about the same object can be a great deal of various consideration in two more diverse cultures which have many different social-cultural and historical situation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.337-345
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• 2023

Estimating the rice heading date is one of the most crucial agricultural tasks related to productivity. However, due to abnormal climates around the world, it is becoming increasingly challenging to estimate the rice heading date. Therefore, a more objective classification method for estimating the rice heading date is needed than the existing methods. This study, we aimed to classify the rice heading stage from various images using a CNN classification model. We collected top-view images taken from a drone and a phenotyping tower, as well as slanted-view images captured with a RGB camera. The collected images underwent preprocessing to prepare them as input data for the CNN model. The CNN architectures employed were ResNet50, InceptionV3, and VGG19, which are commonly used in image classification models. The accuracy of the models all showed an accuracy of 0.98 or higher regardless of each architecture and type of image. We also used Grad-CAM to visually check which features of the image the model looked at and classified. Then verified our model accurately measure the rice heading date in paddy fields. The rice heading date was estimated to be approximately one day apart on average in the four paddy fields. This method suggests that the water head can be estimated automatically and quantitatively when estimating the rice heading date from various paddy field monitoring images.

• Journal of dental hygiene science
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• v.7 no.1
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• pp.25-30
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• 2007

The objective of this study is to suggest the utilization of educated dental hygienist as the solution to the problem of supply and demand in dental clinics that has been brought up recently. Through document research and National Health Personnel Licensing Examination Board homepage, we estimated the number of dental hygienist and the condition of employment as well as gotten a grasp of the current activities carried out by dental hygienists. Furthermore, through discussion of researchers, suggested reform bills to guarantee and extend the work of dental hygienists as well as to train dental assistant. The findings were as follows: As the result of the estimation of dental hygienist, in the year 2009, two dental hygienists structure will be formed in each dental clinic. Currently the practice ratio of non-law activities of dental hygienists is high and in order to increase the practical use of dental hygienists, there is a need to reform bills that guarantee and extend the work of dental hygienists. In order to train new labors, there is a need for cautious consideration to distinguish the activities of existing trained labors, reforming of bills, and considering from various other sectors. From present point of view, solving the problem of existing trained dental hygienists, researching for the plan of utilizing dental hygienists and carrying it into practice must be the priority.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.10-18
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• 2010

This paper proposes an image stabilization algorithm for close watching UAV(Unmanned Aerial Vehicle) using motion separation and stabilization mode. The motion of UAV is composed of its actual navigating motion and unwanted vibrating motion so that image sequences obtained from UAV are shaken randomly. In order to stabilize these images we separate the vibrating motion component from UAV motion and remove the effect caused by it from image sequences. In the proposed algorithm the motion and global intensity change of two consecutive images are modeled with 6 motion parameters and 2 intensity change parameters respectively. These modeled parameters are estimated by non-linear least square method based on Gauss-Newton algorithm. The vibrating motion component is separated from the estimated motion using IIR filtering and the geometric deformation caused by it is removed from image sequences. In order to apply the proposed method to real aerial image sequences with many abrupt changes of camera view, we proposed a stabilizing method using two different modes named as stabilizing and non-stabilizing mode. Experimental results show that the accuracy of motion estimation is 99% and the efficiency of removing the vibrating motion component is 90%. We apply the proposed method to real aerial image sequences and verified its stabilizing performance.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.1
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• pp.93-106
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• 2016

This study aimed to estimate and evaluate the thermal mitigation of the urban tree canopy on the summer outdoor environment by quantitative use of mean radiant temperature. This study applied the SOLWEIG model based $T_{mrt}$ comparison method by using both (1) urban tree canopy presence examples and (2) urban tree canopy absence examples as constructed from airborne LiDAR system based three-dimensional point cloud data. As a result, it was found that an urban tree canopy can provide a decrease in the entire domain averaged daily mean $T_{mrt}$ about $5^{\circ}C$ and that the difference can increase up to $33^{\circ}C$ depending both on sun position and site conditions. These results will enhance urban microclimate studies such as indices (e.g., wind speed, humidity, air temperature) and biometeorology (e.g., perceived temperature) and will be used to support forest based public green policy development.