• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.575-580
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• 2013

The IMU(Inertial Measurement Unit) which is the expensive equipment has been used as a special limited area, usually in measurement of posture of applying to the areas of ship, submarine, aircraft and military equipment application. However, in the current situation, MEMS AHRS technology can replace the high-priced IMU in MEMS AHRS selected application field. In this paper, wireless hull motion measurement system was suggested for measuring key elements of ship's movement such as rolling, pitching and yawing using gyro, acceleration and magnetic sensors of AHRS. In order to reduce the error such as instantaneous acceleration, effects and vibration of geomagnetic, we have adopted the sensors equipped with Kalman filtering. The Wireless hull motion measurement system using AHRS sensors was tested in actual ship and it could easily be applied in limited installation circumstances of the ship. In the future, this system can be useful in the navigation safety and marine accident analysis by using with ship equipment such as INS or VDR in the maritime.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1524-1532
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• 2015

This study analyzed traffic accident characteristics in Chungcheong Region through the factor analysis, cluster analysis and questionnaire survey using traffic accident analysis data for Chungcheong Region in order to improve Korea's traffic safety level. Based on the analysis results, this study suggests traffic safety technologies suitable for the situation of Chungcheong Region. According to the results of the questionnaire survey carried out for transporters in Chungcheong Region, 'the passage of pedestrians and aged people' and 'a problem of lacking visibility' were the biggest threatening factors of major traffic accidents in Chungcheong Region. The facilities required the most were 'lighting equipment in driving at night', and the expected effect by the equipment installation was high. As a result of the factor analysis and cluster analysis using the traffic accident analysis data, traffic accident risk by city type in Chungcheong Region was higher in rural areas, compared to urban areas. Especially, this study confirmed the risks of pedestrian and agricultural machine traffic accidents were high. Therefore, this study suggests three technologies to improve traffic safety level in Chungcheong Region, based on the analysis results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.35-43
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• 2016

Recently, the pipeline system for waste transportation has been increasingly constructed as new solution for the waste collection and disposal system by constantly increasing domestic waste which issued as social problem. The pipeline system is constructed through long distance, so proper long-term monitoring system is necessary which available to detect the damage location for the effective maintenance. In this paper, the experimental study is carried out to evaluate the applicability of optical strain gauge sensor based on FBG for the long-term monitoring system. Three test parameters such as pressure leaking, blockage and deformation are considered as typical damages for real-scale pipeline test specimen. In order to measure flexural and volumetric strain and temperature, three FBG sensors are installed at each monitoring sections. From the test results, this study suggested effective methods of sensor installation and arrangement. Also the sensor spacing for the design of monitoring system using FBG sensor is derived by the correlation of distances from deformation between sensor responses.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.210-219
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• 2017

Electric vehicles, which are attracting attention as eco-friendly vehicles, have been increasing in number since 2011 in Korea. The purpose of this study is to analyze the efficient operation of existing charging stations and factors to consider when installing additional charging stations based on the case of Jeju Island where the electric vehicle penetration rate is high and the charging infrastructure is relatively well established. The characteristics of using electric car charging stations by region, type of facility, and time of day are analyzed. As a result of analyzing the frequency of using the charger installed in Jeju Island, the utilization of both the fast charger and the slow charger is found to be concentrated in a specific area. The usage rate of charger installed in a business facility and a public parking lot is high in both fast charger and slow charger. However, according to the usage rate by time of day, the fast charger has a high utilization rate throughout the afternoon, while the use of a slow charger is concentrated in the morning. In order to enable users to utilize the electric vehicle charging station efficiently, it is necessary to provide a publicity guide for the charging station having a low utilization rate, a notice for using the charger, and a notification of completion of charging. Considering the charging demand, the area where the charger is not yet installed should be considered as the area to install the charger, and in addition, the additional installation should be considered in the area and the facility where the amount of charge is large. Service improvement is expected to be possible by utilizing actual electric vehicle charging behavior analysis result.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.55-65
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• 2008

For obtaining telematics traffic information(travel time or speed in an individual link), there are many kinds of devices to collect traffic data. Since the GPS satellite signals have been released to civil society, thank to the development of GPS technology, the GPS has become a very useful instrument for collecting traffic data. GPS can reduce the cost of installation and maintenance in contrast with existing traffic detectors which must be stationed on the ground. But. there are Problems when GPS data is applied to the existing filtering techniques used for analyzing the data collected by other detectors. This paper proposes a method to provide users with correct traffic information through filtering abnormal data caused by the unusual driving in collected data based on GPS. We have developed an algorithm that can be applied to real-time GPS data and create more reliable traffic information, by building patterns of past data and filtering abnormal data through selection of filtering areas using Quartile values. in order to verify the proposed algorithm, we experimented with actual traffic data that include probe cars equipped with a built-in GPS receiver which ran through Gangnam Street in Seoul. As a result of these experiments, it is shown that link travel speed data obtained from this algorithm is more accurate than those obtained by existing systems.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1080-1091
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• 2003

Recently, the distance education has been rapidly proliferated with the rapid growth of the Internet and high speed networks. There has been relatively much research with regard to online lecture (teaching and studying) tools for the distance education, compared to the virtual laboratory tools (for self-study and experiments). In this paper, we design and implement a web-based simulation tool, named as SimDraw, for the virtual laboratory in the distance education. To apply the web-based simulation technology into the distance education, some requirements should be met; firstly, the user interface of the simulation should be very easy for students. Secondly, the simulation should be very portable to be run on various computer systems of remote students. Finally, the simulation program on remote computers should be very thin so that students can easily install the program onto their computers. To meet these requirements, SimDraw adopts the client/server architecture; the client program contains only model development and animation functions so that no installation of a client program onto student's system is required, and it can be implemented by a Java applet in Web browsers. The server program supports client programs by offering the functions such as remote compiling, model storing, library management, and user management. For the evaluation of SimDraw, we show the simulation process using the example experimentation of the RIP(Routing Information Protocol) Internet routing protocol.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.120-125
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• 2016

For the purpose of protecting personal property and lives from incidents, accidents, and threats such as terrorism, video surveillance equipment has been installed and operates in many places. Video surveillance technology has gradually developed into high-quality, high-definition equipment, and a lot of products have been launched. However, closed circuit television (CCTV) equipment for security purposes can invade a person's privacy. In this paper, we propose a way to protect personal video images using meta-data in an intelligent Internet protocol (IP) camera. We designed the system to mask personal video information from meta-data, define the method of image-information access according to user privileges, and show how to utilize the meta-data during storage and recorded data searches. The suggested system complies with guidelines for CCTV installation and operation from Korea's Ministry of the Interior. Installed on only a single server so far, due to the limitations and technical difficulties of hardware performance, it has been difficult to find a method that can be applied to personal image information using real-time protection techniques. Applying the method proposed in this paper can satisfy the guidelines, reduce server costs, and reduce system complexity.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.273-279
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• 2020

In the Korea's SBAS(KASS), reference site is an important infrastructure facility for the collecting and monitoring GPS/GEO signals. The SBAS reference station has an clear requirements than other regular monitoring stations. It requires constant maintenance during the system operation. The development for KRS site should be prepared for site survey, site construction, antenna geodetic survey, equipment installation and operation. Site survey is initially performed as an important step to predict site availability and system performance. The operation center must provide the reference site, equipment room, and appurtenant to satisfy the site requirements. The position of antennas is very important information, and accuracy must be secured through the geodetic survey. Measurement collected at the from precise antenna are provided to the KASS processing station. The position of antenna should be maintained through continuous position checks and updates during the operation. When the development of the KRS site is completed, it performs tasks for installing and operating the KRS equipment. In this paper, we presented the procedures and some results for the development of the 7 KRS sites.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.206-213
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• 2008

Due to the following reasons, the management of curtain wall parts and material is very Important. Firstly, curtain wall work is one of the main works in High-rise building construction for it takes about $10{\sim}15%$ of the total construction cost. Secondly, the whole process of curtain wall work including manu acture, delivery, storage, installation and maintenance is very complicated and sometimes more than 30 companies involve in the process. Thus there are many control points for curtain wall units. Thirdly, there are not enough space on site for material storage and this situation is more serious for sites in urban area. The purpose of this research is to validate an information systems using RFID technology that is developed to manage the curtain wall units following the process of curtain wall work. For the validation, the cycle times of curtain wall work before and a ter the system was used. The results show that using the systems shorten the cycle time of the curtain wall work. Thus it is concluded that the system can increase the efficiency of managing curtain wall work.

• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.38-49
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• 2020

As the quality of life has been improving, people are getting higher interest and higher expectation for safety. However, the accident rate at the construction site is still high. Therefore, it is urgent to secure the safety at the construction work. Due to the nature of the construction industry, construction sites are directly exposed to the external environment. The possibility of accident occurrence is increased due to various factors such as the always variable processes, the diversity of manpower input, the increase in vulnerable class, and the danger of construction equipment..Particularly, the disasters occurring at the small- or medium-sized construction sites (budget ≤ 12 billion KRW) account for 88.9% of the total disasters at construction sites (73.4% for casualty). It was due to the lack of management caused by the absence of supervisors and insufficient safety measures. Moreover, it is difficult for the small- or medium-sized construction sites to apply basic safety measures such as safety education and safety facility installation by themselves in order to prevent disasters because they don't have sufficient safety organizations. It is because they have relatively less safety personnel and poorer technology system than large-sized construction sites. Therefore, in order to reduce accidents in construction, it is necessary to prevent accidents at the small- and medium-sized construction sites. From this point of view, the objectives of this study were to identify the key risk items causing accidents frequently by analyzing the accidents at construction sites and identifying problems associated with safety management, and to secure the safety at the small- and medium-sized construction sites.