• Journal of Korean Society for Geospatial Information Science
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• v.23 no.4
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• pp.49-55
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• 2015

This paper explains major considerations for integrated GPS/GLONASS/BDS positioning, and then analyzes integrated GNSS positioning accuracies based on low-cost receivers in open-sky and poor reception environments. In an open-sky environment, horizontal RMSE of the integrated system positioning is about 1.2m. It shows improved result compared with single system positioning, the improvement ratio was 17-55%. In poor reception environments, we sometimes could not do positioning because the number of visible satellites gets below four. In an integrated positioning mode, the number of visible satellites was always higher than four, allowing us to find positions all the time. The horizontal RMSE of the integrated system positioning in poor reception environments is about 6.4m. Compared with single system positioning;the integrated system positioning shows better performance and the improvement ratio was 8-47% for the horizontal directions.

• Journal of Ocean Engineering and Technology
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• v.23 no.3
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• pp.59-64
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• 2009

Bridge types such as the suspension bridges and the cable stayed bridges maintained by cables present the dangerous possibility of a ship running through the bottom of the bridge. Due to hangers and main cables in the upper structural system, the bridge is also susceptible to disasters. However, these cable bridges are usually used for long span bridges over the sea. This structure is relatively more exposed to disasters, such as wind, hail, and earthquake, than other structures. This structure also has the potential to cause car accidents on account of the poor visibility due to foggy conditions. If a fire breaks out because of a car accident due to wind, a car explosion will likely occur.

• The Journal of Korea Robotics Society
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• v.7 no.2
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• pp.142-149
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• 2012

The camera has limitations of poor visibility in underwater environment due to the limited light source and medium noise of the environment. However, its usefulness in close range has been proved in many studies, especially for navigation. Thus, in this paper, vision-based object detection and tracking techniques using artificial objects for underwater robots have been studied. We employed template matching and mean shift algorithms for the object detection and tracking methods. Also, we propose the weighted correlation coefficient of adaptive threshold -based and color-region-aided approaches to enhance the object detection performance in various illumination conditions. The color information is incorporated into the template matched area and the features of the template are used to robustly calculate correlation coefficients. And the objects are recognized using multi-template matching approach. Finally, the water basin experiments have been conducted to demonstrate the performance of the proposed techniques using an underwater robot platform yShark made by KORDI.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.829-830
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• 2008

In modern days, many of the images are captured by using various devices, such as PDA, digital camera, or cell phone camera. Because all these devise have a limited dynamic range, images captured in real world scenes with high dynamic ranges usually exhibit poor visibility and low contrast, which may make important image features lost or hard to tell by human viewers. In this paper, the efficient color image enhancement method is presented. Experimental result show that the proposed method yields better performance of color enhancement over the previous work for test color images.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.10
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• pp.975-981
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• 2006

This paper shows a feasibility analysis results on RFID for car positioning system. Usually, a car navigation is mainly based on GPS combined with map-matching. However, in the case of poor visibility of satellites, GPS can not supply accurate position information continuously. In recent years, RFID has been considered to be one of key technologies in positioning and localization area. But its application and research results in the area of vehicular positioning are not popular. RFID system consists of tag, reader, antenna and software such as drivers and middleware. The main function of RFID system in a vehicular positioning is to retrieve ID recorded position information from tags which set on the center of road. We propose a positioning method for vehicles using RFID and we present some indoor and outdoor experiment results to show that the proposed method is available in vehicle operational environments.

• Journal of the Korea Safety Management & Science
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• v.22 no.3
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• pp.9-14
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• 2020

A forklift accident occurs in the logisitcs center. there are many kinds of accidents such as a casualty accident or a minor accident, etc. there are many other causes of accident, including poor visibility and habitual operational mistakes The result of the accident is the phenomenon of cutting, falling, scratching of the product. In the case of minor accidents, workers do not report accidents, so the occurrence of accidents is unknown. The customer receives the goods and then notifies them that they are defective product. After the product is returned, we can see that the forklift accident caused the problem of the product The result of the late response affects the image of the enterprise. In this study, we recognized the need for safety education to prevent accidents and found out which of the education items could raise awareness of safety. As result of the study, disinfection and forklift maneuverability regarding speed were mentioned as the most important items in education.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.161-176
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• 2002

Collision avoidance is the most important part of a small vessel. Small and mediurn sized ships are surprisingly poor targets for radar reflection and are frequently in danger of being overrun by large vessels, even under good condition of visibility. One of the best way to prevent collisions at sea is to use as large and well designed a radar reflector. Thus, RCS(Radar Cross Section) increase is key element in the design of radar reflector. Radar Reflectors are normally classified into active-type and passive-type. In this paper, the RCS increase methods for passive-type reflector through shaping are explained, and analyzed with RCS performance test by computer simulation. As results from analysis, It is shown that the effective diameter of radar reflector is over 10 λ to provide a return above the threshold RCS of 25m$^2$, lower limit of detectability using X-band radar in a moderate sea.

• Journal of Drive and Control
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• v.17 no.4
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• pp.15-22
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• 2020

With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.267-278
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• 2020

Although the theater performance industry is a typical cultural content industry, the support at the national level has been poor and the theater workers tend to focus on individual efforts rather than active interaction with the theater environment. Therefore, there is a growing need for effective revitalization of the theater industry, which should be found in improving the quality of interaction between the theater and the theater environment. Therefore, the purpose of this study is to analyze the effects of theater actors (theaters, theater organizations) on the activation of plays by the interaction of politics, business, and technology, the main environment of the plays. For this, social network analysis was performed. As a result of the study, it was found that mediation centrality significantly influenced the visibility of theater actors. This means that the more the theater actors are at the center of information and resource flows to the elements of the theater environment, the more visibility becomes. This shows that the theater must actively acquire technology, create an avant-garde, and endeavor to expand its influence and outreach through active interaction with politics and corporations.

• Human Ecology Research
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• v.56 no.4
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• pp.347-360
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• 2018

We surveyed 223 road workers between 2017 July-August about wearing and satisfaction in order to find basic data to develop safety clothing that enhances visibility of motion and comfort while meeting international standards. It was found that most of the current warning clothing owned by road cleaners and about 2/3 of policemen clothes were provided by public institutions. The purpose of wearing, color, properties, satisfaction and protectiveness differed significantly by occupation. Second, the most popular response for the type and quantity of warning clothing was 2 sets of spring/autumn, summer, and winter type for road cleaners, whereas policemen chose 2 sets of all types plus a safety vest. Therefore, a top-level (3rd class) warning clothing study is required. Third, satisfaction ranked Moderate>Good>Poor; in addition, the main reason for satisfaction was that 'retroreflective tape increases safety at night (54.4%)' for road cleaners and 'the fluorescent color stands out (43.7%)' for policemen. Thus, it was accepted that visibility contributed to safety. Fourth, body-protectiveness was evaluated higher compared to wearing satisfaction, and it was recognized more by road cleaners than policemen. Overall satisfaction was higher for road cleaners versus policemen both in Seoul than Incheon. Fifth, the main dissatisfaction in both groups was 'low sweat absorbency' showing improving the air permeability, moisture regain and permeability was the highest priority. Finally, those working 8 hours a day tended to evaluate more positively the 6 properties of the material.