• KIPS Transactions on Software and Data Engineering
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• v.8 no.12
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• pp.507-516
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• 2019

Costs invested in road maintenance and road development are on the rise. However, due to accidents such as portholes and ground subsidence, the risks to the drivers' safety and the material damage caused by accidents are also increasing. Following this trend, we have developed a system that determines road damage, according to the magnitude of vibration generated without directly intervening the driver when driving. In this paper, we implemented the system using a remote control car (RC car) simulator due to the limitation of the environment in which the actual vehicle is not available in the process of developing the system. In addition, we attached a vibration sensor and GPS sensor to the body of the RC car simulator to measure the vibration value and location information generated by the movement of the vehicle in real-time while driving, and transmitting the corresponding data to the server. In this way, we implemented a system that allows external users to check the damage of roads and the maintenance of the repaired roads based on data more easily than the existing systems. By using this system, we can perform early prediction of road breakage and pattern prediction based on the data. Further, for the RC car simulator, commercialization will be possible by combining it with business in other fields that require flatness.

• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.42-57
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• 2023

In this paper, to increase the research capability of flight missions and maintenance in operating military aircraft, we studied the requirements for additional mounting of flight video and data recorders and safety verification methods. The verification process of the recorder equipment itself, structural safety in the aircraft system, power and electrical safety, electromagnetic compatibility, and impact of airworthiness are described in accordance with military standards and operating environment requirements. In addition, through ground/flight tests, the results of functional operation suitable for the influence and demand of interference between the flight video and data recorder and other systems are also presented.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.351-355
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• 2023

The need for Advanced LOSA arises from the limitations and drawbacks of traditional LOSA. Amended LOSA aims to address some of the shortcomings of the original methodology and make it more effective and relevant to current aviation safety needs. Some of the key reasons for developing Advanced LOSA include Enhancing the scope, Improving data collection and analysis, Providing more targeted safety recommendations. First, Traditional LOSA mainly focuses on flight deck operations, but Advanced LOSA expands the scope to include other operational areas such as cabin operations, ground handling, and maintenance. Second, Advanced LOSA can build a Forecasting System that can predict the future through data collection and data analysis. Third, Advanced LOSA aims to provide more specific and targeted safety recommendations based on the Aviation data collection and Aviation data analysis. Overall, Advanced LOSA seeks to improve aviation safety by addressing the limitations of traditional LOSA and providing a more comprehensive and effective methodology for identifying and mitigating safety risks in aviation operations.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.451-454
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• 2007

There is an inseparable relation between human race and engineering work. As world developed into highly industrialized society, a diversity of large structures is being built up correspondently to limited topographical circumstance. Though large structures are national establishments which provide us with convenience of life, there are some disastrous possibilities which were never predicted such as ground subsidence and degradation. It is very difficult to analyze the volume of total metamorphosis with the relative displacement measurement system which is now used and it is impossible to know whether there is structural metamorphosis within a permissible range of design or not. In this research with an object of 13-year-old earthen dam, through generating point-cloud which has 3D spatial coordinates(x, y, z) of this dam by means of 3D Laser Scanning, we can get real configuration data of slanting surface of this dam with this method of getting a number of 3D spatial coordinates(x, y, z). It gives 3D spatial model to us and we can get various information of this dam such as the distance of slanting surface of dam, dimensions and cubic volume. It can be made full use of as important source material of reinforcement and maintenance works to detect previously the bulging of the dam through this research.

• Journal of the Korean Geotechnical Society
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• v.38 no.7
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• pp.5-24
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• 2022

The current performance evaluation of slope anchors qualitatively determines the physical bonding between the anchor head and ground as well as cracks or breakage of the anchor head. However, such performance evaluation does not measure these primary factors quantitatively. Therefore, the time-dependent management of the anchors is almost impossible. This study is an evaluation of the 3D numerical model by SfM which combines UAS images with terrestrial LiDAR to collect numerical data on the damage factors. It also utilizes the data for the quantitative maintenance of the anchor system once it is installed on slopes. The UAS 3D model, which often shows relatively low precision in the z-coordinate for vertical objects such as slopes, is combined with terrestrial LiDAR scan data to improve the accuracy of the z-coordinate measurement. After validating the system, a field test is conducted with ten anchors installed on a slope with arbitrarily damaged heads. The damages (such as cracks, breakages, and rotational displacements) are detected and numerically evaluated through the orthogonal projection of the measurement system. The results show that the introduced system at the resolution of 8K can detect cracks less than 0.3 mm in any aperture with an error range of 0.05 mm. Also, the system can successfully detect the volume of the damaged part, showing that the maximum damage area of the anchor head was within 3% of the original design guideline. Originally, the ground adhesion to the anchor head, where the z-coordinate is highly relevant, was almost impossible to measure with the UAS 3D numerical model alone because of its blind spots. However, by applying the combined system, elevation differences between the anchor bottom and the irregular ground surface was identified so that the average value at 20 various locations was calculated for the ground adhesion. Additionally, rotation angle and displacement of the anchor head less than 1" were detected. From the observations, the validity of the 3D numerical model can obtain quantitative data on anchor damage. Such data collection can potentially create a database that could be used as a fundamental resource for quantitative anchor damage evaluation in the future.

• Journal of Information Technology and Architecture
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• v.11 no.2
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• pp.157-173
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• 2014

As Air Base Defence, Anti-Aircraft Defence and Nuclear-Biological-Chemical Protection model considered as ground operation models in Republic of Korea Air Force are designed as the voice-centered system between participant nodes, there is a problem communicating accurately. In recent years, the military is developing a command and control capability using data communication technology to solve the problem. Therefore, this paper proposes new model to maximize efficiency of performance improvement through the Data Communication-based Future Air Base Defence Model. We refer to a research paper that is related existing and developed new model. and then we really experimented under WiBro Network that is constructed to Air Base for maintenance control. Based on the analysis and the test result of new Air Base Defence Model, we have concluded that the performance improvement effect is reached.

• The Journal of Engineering Geology
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• v.22 no.2
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• pp.233-241
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• 2012

The objectives of this study were to test geothermal conductivity (k), water velocity, water quantity, and pipe pressure from a ground heat exchanger in the field, and then to analyze these data in relation to the effectiveness and economical efficiency for application of geothermal energy. After installation of the apparatus required for field tests, geothermal conductivity values were obtained from three different cases (second, third, and fourth). The k values of the second case (506 m depth) and third case (151 m depth) are approximately 2.9 and 2.8, respectively. The k value of the fourth case (506 m depth, double pipe) is 2.5, which is similar to the second and third cases. This result indicates that hole depth is a critical factor for geothermal applications. Analysis of the field data (k, water velocity, water quantity, and pipe pressure) reveals that a single geothermal system at 506 m depth is more economically efficient than three geothermal systems at depths intervals of 151 m. Although it is more expensive to install a geothermal system at 506 m depth than at 151 m depth, test results showed that the geothermal system of the fourth case (506 m, double pipe) is more economically efficient than the system at 151 m depth. Considering the optional cost of maintenance, which is a non-operational expense, the geothermal system of the fourth case is economically efficient. Large cities and areas with high land prices should make greater use of geothermal energy.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• 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 Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.401-409
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• 2003

Recently, the development of underground structures is to be inevitably necessary due to the increase in population and traffic volume that has caused to the limit of urban land use and the heavy traffic jams. Therefore, underground structures such as subway, underground shopping centers, lifeline facilities and so on, have been increasingly constructed, On the other hand, several social problems have occurred during construction, i.e., ground subsidence, noise, and vibration. Therefore, safer and more beneficial methods for underground construction are on the demand. In this research, N.T.R.(New Tubular Roof) method has been modified and utilized for solving those problems and overcoming the difficulties connected with the bored tunnel construction of large underground openings in unfavorable ground, often under the water table, and with overburdens that are too shallow to solve problems of stability using traditional methods. The N.T.R. method has been modified to suit for Korean geotechnical conditions, and was made up for the weak points-the water leakage from walls and tops, the maintenance and the lack of stability-of the conventional methods. This paper dealt with the features and the applicability of N.T.R. Method based on the results from numerical analysis and data from in-situ monitoring system.