• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.3
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• pp.127-134
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• 2018

Electric transmission towers are facilities to transport electrical power from a plant to an electrical substation. The towers are connected using power lines that are installed with a proper sag by loosening the cable to lower the tension and to secure the sufficient clearance from the ground or nearby objects. The power line sag may extend over the tolerance due to the weather such as strong winds, temperature changes, and a heavy snowfall. Therefore the periodical mapping of the power lines is required but the poor accessibility to the power lines limit the work because most power lines are placed at the mountain area. In addition, the manual mapping of the power lines is also time-consuming either using the terrestrial surveying or the aerial surveying. Therefore we utilized multiple overlapping images acquired from a low-cost drone to automatically reconstruct the power lines in the object space. Two overlapping images are selected for epipolar image resampling, followed by the line extraction for the resampled images and the redundant images. The extracted lines from the epipolar images are matched together and reconstructed for the power lines primitive that are noisy because of the multiple line matches. They are filtered using the extracted line information from the redundant images for final power lines points. The experiment result showed that the proposed method successfully generated parabolic curves of power lines by interpolating the power lines points though the line extraction and reconstruction were not complete in some part due to the lack of the image contrast.

• Journal of IKEEE
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• v.22 no.3
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• pp.645-650
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• 2018

IT-based automatic controller that control the temperature and humidity to prevent dew condensation of distributing board was designed and implemented in this paper. The dew condensation temperature was deduced from room temperature and humidity of distributing board. Based on the comparisons between the deduced dew condensation temperature and the temperature of surface condensation, the facilities that can prevent the condensation was implemented to be operated in due order. Also, the remote monitoring module to monitor operation status of controller was implemented using LoRa technique. The performances for controller operation and data transmission were validated from the transmission and operation test for dew condensation prevention. The controller can be put to good use at the facilities that requires the condensation prevention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1229-1235
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• 2014

At the LPG vehicle air intake system, most of dust particles in the air cleaner are removed. However very small particles are not removed and accumulated. The accumulation of carbon in air intake system is going to affect the idle speed control and sensor signal. It also causes engine chattering and transmission troubles of automatic transmission. This is study about cleaning up intake system using cleaning chemical. We can clean up the intake system by spraying cleaning liquid onto intake device when the engine is idling after intake hose is removed from warmed up vehicle. We can obtain the following experimental results by cleaning up ISC, surge tank, intake manifold, intake valves and combustion chamber. According to this results, the stroll valve works correctly and power rate of engine is up to the standard, it is smoothy to control the idling speed when a vehicle pulls up. After cleaning up CO grow down about 0.15%, HC does about 20~100 ppm.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.71-79
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• 2020

In this paper, we propose a theft prevention technology based on beacon and smart device for smart stroller. The smart stroller has two Bluetooth devices. One is for data transmission and the other is for distance measurement as beacon. Thus, smart device uses a Bluetooth for strength level setting, manual locking and data transmission of smart stroller. Furthermore, smart device can do automatic locking of smart stroller using Bluetooth beacon when the stroller go further away from smart device. At this time, we apply a distance measurement algorithm and theft prevention algorithm with improved beacon distance measurement technique. To show usefulness of the proposed technology, we make a smart stroller and developed a smart device application. We did two distance measurement experiments and a theft prevention experiment with the proposed technology and the result shows 91.3% accuracy for theft prevention. Therefore, the proposed technology would be more usefulness technology for smart stroller.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.389-393
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• 2007

The distribution of donated blood for medical purpose is an area that presents many challenges. In order to establish a comprehensive solution, the current patterns of distribution must be reviewed and problems related to it need to be clearly understood. This paper introduces 'Radio Frequency Identification (RFID) System', as a potential solution to some of the problems which arise in the process of blood supply distribution, and a way to systematically manage the blood supply. For the various possible RFID systems, the reader and tag must be suitable for the purpose of blood distribution. A database has been designed that can recognize tags and objects in a ubiquitous RFID blood distribution system. In this paper, we design the real-time software to control the RFID reader system and transponder, using the EEPROM memory by RFID. The experimental results confirm that the transmission rate of 3.9kbps for RF is 125 KHz. The electric power usage of transponder chip is $100{\mu}W$, with the recognition distance is about 7cm range.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.355-362
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• 2009

In real-time communication services, delay constraints are among the most important QoS (Quality of Service) factors. In particular, it is difficult to guarantee the delay requirement over wireless channels, since they exhibit dynamic time-varying behavior and even severe burst-errors during periods of deep fading. Channel throughput may be increased, but at the cost of the additional delays when ARQ (Automatic Repeat Request) schemes are used. For real-time communication services, it is very essential to predict data deliverability. This paper derives the delay distribution and the successful delivery probability within a given delay budget using a priori channel model and a posteriori information from the perspective of queueing theory. The Gilbert-Elliot burst-noise channel is employed as an a Priori channel model, where a two-state Markov-modulated Bernoulli process $(MMBP_2)$ is used. for a posteriori information, the channel parameters, the queue-length and the initial channel state are assumed to be given. The numerical derivation is verified and analyzed via Monte Carlo simulations. This numerical derivation is then applied to a rate control scheme for real-time video transmission, where an optimal encoding rate is determined based on the future channel capacity and the distortion of the reconstructed pictures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.739-744
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• 2005

For the structure of AVLS is required to the GPS-MDT for realtime acquisition the position reporting of vehicle and traffic management S/W. It is necessary that the MODEM using VHF transceiver base on GPS and monitoring program for display base on GIS the traffic status by vehicles position report in management system. The other wise, vehicles among management system that is required the automatic communications protocol for GPS information and mobile's ID. In his paper have studied the VHF modem for transmission the voice and data at same time and S/W for management system using GIS-tool.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5C
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• pp.265-275
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• 2011

In this paper, we propose a Multi-Strata Space Time Code(MSSTC) for MIMO retransmissions. Since MSSTC is constructed by superimposing two OSTBC matrices, there are no intra-stratum interferences, but there exist inter-strata interferences. In MIMO retransmission environment, the transmitter switches adaptively the phases of strata at each transmission by using 1-bit feedback sent from the receiver in order to reduce the inter-strata interferences efficiently. We also propose a power allocation scheme between strata to improve error performance. Simulation results show that the proposed scheme achieves better performance than other conventional schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.256-260
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• 2005

For the structure of AVLS is required to the GPS-MDT for realtime acquisition the position reporting of vehicle and traffic management S/W. It is necessary that the MODEM using VHF transceiver base on GPS and monitoring program for display base on GIS the traffic status by vehicles position report in management system. The other wise, vehicles among management system that is required the automatic communications protocol for GPS information and mobile's ID. In this paper have studied the VHF modem for transmission the voice and data at same time and S/W for management system using GIS-tool.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.172-178
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• 2022

In this paper, water meter AMR(automatic meter reading), one of the core technologies of smart water grid, using LoRa IoT network is studied. The main content of the research is to develop the network system and show the test results that one PC server receives the readings of water meters from multiple households through LoRa communication and stores them in the database, and at the same time sends the data to the web server database through internet. The system also allows users to monitor the meter readings using their smartphones. The hardware and firmware of the main board of the digital water meter are developed. For a PC server program, MDMS(meter data management system) is developed using Visual C#. The app program running on the user's smartphone is also developed using Android Studio. By connecting each developed parts, the total network system is mounted on a flow test bench in the laboratory and tested. For the fields test, 5 places around the university are selected and the transmission distances are tested. The test result show that the developed system can be applied into the real field. The developed system can be expanded to various social safety nets such as monitoring the living alone or elderly with dementia.