• Journal of Digital Convergence
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• v.17 no.12
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• pp.219-228
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• 2019

Thanks to the development of information technology and the vitalization of smart services, the Internet of Things (IoT) technology, in which various smart devices are connected to the network, has been continuously developed. In the legacy IoT architecture, data processing has been centralized based on cloud computing, but there are concerns about a single point of failure, end-to-end transmission delay, and security. To solve these problems, it is necessary to apply decentralized blockchain technology to the IoT. However, it is hard for the IoT devices with limited computing power to mine blocks, which consumes a great amount of computing resources. To overcome this difficulty, this paper proposes an IoT architecture based on the edge computing technology that can apply blockchain technology to IoT devices, which lack computing resources. This paper also presents an operaional procedure of blockchain in the edge computing-based IoT architecture.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.4
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• pp.441-448
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• 2010

This paper estimates the tree height using Airborne LiDAR that is obtained for each season to analyze its influence based on a canopyclosure and data fusion. The tree height was estimated by extracting the First Return (RF) from the tree and the Last Return (LR) from the surface of earth to assume each tree via image segmentation and to obtain the height of each tree. Each data on tree height that is collected from seasonal data and the result of tree height acquired from the data fusion were compared. A tree height measuring device was used to measure on site and its accuracy was compared. Also, its applicability on the result of fused data that is obtained through the Airborne LiDAR is examined. As a result of the experiment, the result of image segmentation for an individual tree was closer to the result of site study for 1 meter interval when compared to the 0.5 meter interval of point cloud. In case of the tree height, the application of fused data enables a closer site measurement result than the application of data for each season.

• Journal of Ocean Engineering and Technology
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• v.34 no.5
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• pp.351-360
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• 2020

Of late, demand for test sites for marine equipment such as ASV, AUV, ROV, and various underwater sensors is increasing. The authors have focused on an oscillating water column (OWC), which is being constructed near Chagwido Island Jeju, as one of the test-sites. The main objective of the OWC is to produce wave energy and develop technologies. It has been built in the sea approximately 1 km off the coast. It has berth accommodation and some rooms that can be used as laboratories. To investigate the feasibility of its usage as a test site for marine equipment, we acquired bathymetric data around the OWC by using a multi-beam echo sounder and a single-beam scanning sonar. The accessibility of the OWC from nearby ports and the use of support vessels or ships were also investigated. 3D point cloud data from the multi-beam echo sounder and 2D acoustic images from the scanning sonar are expected to be used as references for identifying changes over time. In addition, through these experiments, we derived a procedure to use this facility as a test site by using the IDEF0 functional modelling method. Based on this preliminary investigation and previously reported examples, we determined the general conditions and preferences for evaluating the performance of various marine equipment heuristically. Finally, we developed five applications that were derived from this investigation.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.69-79
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• 2012

The aim of this study is to analyze the mid-term changes of beach and dune morphology at Sohwang beach, Korea using by Total Station. Measurements executed 4 times during two year. Based on ArcInfo as point cloud obtained through precise measurement data by Total Station, alteration of beach and dune was analyzed at DEM, of which cell size is about 1m. Since these artificial constructions have influenced current systems of this region, the large-scale sand movements above mentioned have occurred around the jetty and the sea-wall. There occurred sedimentation in the north of the Jetty and erosion in the south of the Jetty, which is installed at the central part of object area. The direction of recent topographic development does not coincide with that of wind, and, rather, topographic changes occurred mainly at beaches and dunes due to the transformation of coastal water flow caused by artificial structure nearby. If precise measurement is conducted periodically, and long term monitoring is carried out by installing equipment measuring movement pattern of sediment around artificial structure, cause of topographic change around the object area could be discovered.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.545-550
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• 2012

High Energy density metal powder has high melting point of oxide film. By this, the ignition source that can make a thermal effect of high-temperature during short time is needed to overcome ignition disturbance mechanism by oxide film. So effective ignition does not occurred with hydrocarbon ignitor, $H_2-O_2$ ignitor, high power laser. But steam plasma can be generate about 5000 K temperature field in short order. Because a steam plasma uses steam as the working gas, it is environmental-friendly and economical. Therefore in this study, we analyze steam plasma temperature field and radical species with optical emission spectroscopy method in order to apply steam plasma ignitor to metal combustion system and cloud particle ignition was identified in visual.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.383-386
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• 2014

Due to the development of communication technology, a conventional major business through PC, laptop or Tablet PC can be performed via a smartphone and it is increasing the user's convenience. At this point, the user prefers to connect to the Internet using the wireless network because it occurs an additional charge according to the amount of data to be transmitted when using a data communication through 3G or 4G. However, when using a wireless network, there is a possibility of several attacks such as easily steal or modulate the information from the outside or to gain access to personal information stored in the user's smartphone with man-in-the-middle attacks by using the fake AP. IIn this paper, we describe how you can detect the AP when you use LAN of the smartphone, were analyzed for this vulnerability, has not been approved. Furthermore, Also, we discuss ways which can enhance the security when user the access to the internet services (i.e., internet, public/private cloud service, etc.) via wireless network in smartphone.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.89-94
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• 2021

Recently, manufacturing companies are introducing many intelligent production processes that apply IIoT/ICT to improve competitiveness, and a system that maintains availability, improves productivity, and optimizes management costs is needed as a preventive measure using environmental data generated from air ejectors. Therefore, in this study, a dedicated control board was developed and LoRa communication module was applied to remotely control it to collect and manage information about compressors from cloud servers and to ensure that all operators and administrators utilize common data in real time. This dramatically reduced M/S steps, increased system operational availability, and reduced local server operational burden. It dramatically reduced maintenance latency by sharing system failure conditions and dramatically improved cost and space problems by providing real-time status detection through wired and mobile utilization by maintenance personnel.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.377-382
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• 2021

In order to advance forest resource management, it is necessary to solve problems such as the aging of forest-related industry workers and the field investigation system centered on manpower. Therefore, in this study, the trend of establishment and utilization of overseas forest geospatial information applied with the latest technology for scientific forest resource management was investigated to identify the domestic application plan. Overseas, photogrammetry and LiDAR technologies were being used to construct and utilize forest geospatial information. In the case of photogrammetry, it was used to measure the volume of vegetation, diameter, and tree height. And LiDAR technology has been applied to the measurement of diameter, and tree height. Through the analysis of overseas cases, it was identified how to construct forest geospatial information using photogrammetry and LiDAR, and it was found that LiDAR showed higher accuracy than photogrammetry. In the future, if the construction of forest geospatial information using various LiDAR sensors are performed and the accuracy and work efficiency are analyzed, it will be possible to present the possibility of using new technologies in the construction of forest geospatial information in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.1-7
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• 2019

When using conventional 3D image scanning methods, it is common for image scanning to be done manually, which is labor-intensive. Scanning a space made up of complicated equipment or scanning a narrow space that is difficult for the user to enter, is problematic, resulting in quality degradation due to the presence of shadow areas. This paper proposes a method to scan an image using a rover equipped with a scanner in areas where it is difficult for a person to enter. To control the scan path precisely, the 3D image remote scan automation method based on the rover move rule definition is described. Through the study, the user can automate the 3D scan plan in a desired manner by defining the rover scan path as the rule base.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.501-511
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• 2018

Geoparks are worth preserving in an environmentally and heritage. Monitoring and public attention are essential for the conservation and protection of geoparks. The use of Unmanned Aerial Vehicles and the Structure from Motion algorithm enables effective monitoring of geoparks that are difficult to manage due to their wide range of manpower, and various spatial data derived from SfM can be utilized to improve awareness of geoparks that have been lacking. In order to prove this, firstly, we created the 3D spatial data by using the UAV and the SfM algorithm, which is one of the National geoparks of the Hantan-Imjin River area. Using this 3D data for Virtual Reality and 3D printing. After that, we verified the possibility of promoting the geopark through a simple online survey. Finally, we propose a method to utilize all the generated data from each step to promote and research for geoparks.