• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.512-516
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• 2005

Home-Network is an integrated network of the PC and all electric home appliances in the home so that they can communicate with each other. In the 21th century, here are various technology for home Network environment such as HomePNA, IEEE1394, Ethernet Lan and Bluetooth. For Home Network construction, generally, the standard series interface 'RS232' is used to make communication possible between electric home appliances. However Home network using RS232 has a problem. That is, All machines have to be connected to each other with RS232 using Point-to-Point mode. In this case, the system becomes complicated because we have to use circuits as much as there are machines and increased expenses. To improve this problem, In this thesis, designed home network using RS422 Multi-drop mode serial communication and controled it with embedded linux system. And connected RS422 with motors and sensors using PIC to make the home network virtual environment.

• Smart Media Journal
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• v.8 no.4
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• pp.9-16
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• 2019

In order to realize IoT(Internet of Things) service, it is necessary to manage sensing data and build a service with respect to its scalability. However, existing internet services use unique protocols and non-standardized functions for each service provider, and it is difficult to provide data management and service because they use short-range communication technology such as Bluetooth. In addition, plurality of APs and gateways must be taken into consideration in establishing a wide area network. In this paper, we propose a sensing data management system using LoRa(Long Range) communication based on Mobius platform. The end device that drives Tas is configured to collect sensing data, configure an application gateway that drives &Cube, and transmit sensing data to the server. In addition, a server that manages the Mobius is configured to handle the sensing data transmitted from the application gateway to provide a monitoring service. We establish a wide area network through LoRa communication between the end device and the gateway and provide data management and service corresponding to the internet through the Mobius platform.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1411-1416
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• 2018

Currently, most of the industrial areas like chemistry, manufacturing, shipbuilding, and steel, perform the work related to gas, and the staffs who are in charge of this work have a risk of suffocation without cognizing incidents like gas leak. For example, when the nitrogen gas leaked in 2015 at Paju, two people were killed and four people were injured. In 2018 at Pohang, four workers were suffocated to death from nitrogen gas. In order to solve this problem, this study realized the system in which workers could immediately cognize the gas leak and also deliver the situation to the staff in charge of safety at the same time, by installing the IoT device composed of gas sensor and communication module on the safety helmet that should be worn by field workers. This study is expected to be able to reduce the casualties caused by gas leak in industrial sites.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1199-1206
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• 2022

In this paper, unlike door locks that are controlled only by the existing keypad because electronic devices can be easily operated through apps on smartphones in modern society, an app was created using app inventory so that door locks can be controlled using smartphones. Through the Bluetooth module experiment, the communication distance with the smartphone was controlled up to 10m when there were no obstacles, and through the voice recognition experiment, the recognition rate was 85% and 90% at 500~1000Hz and 1000~1500Hz, respectively, and 70% and 80% at 80dB noise. Through the results of the experimental evaluation, it was confirmed that convenience and security could be improved.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.231-238
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• 2022

In this paper, among short-range wireless communication technologies such as Beacon, Bluetooth, UWB (Ultra-wideband), ZigBee, NFC (Near Field Communication), Z-Wave, 6LoWPAN (IPv6 over Low power WPAN), D2D (Device to Device), etc., proposed an IoT service platform based on a beacon that can provide indoor positioning. And, a beacon-linked web server was designed by blocking indiscriminate beacon spam signals and applying REST web service technology with flexibility and scalability. Data accessibility between different devices was verified by testing the success rate of data transmission, the success rate of blocking beacon push, the success rate of IoT interlocking processing, the accuracy of location positioning, and the success rate of REST web service-based data processing. Through the designed IoT service platform, various proposals and research on short-distance-based business models and service platforms will be conducted in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.313-316
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• 2021

In the IoT(IoT: Internet of Things) environment, network configuration is essential to collect data generated from objects. Various communication methods are used to process data of objects, and wireless communication methods such as Bluetooth and WiFi are mainly used. In order to collect data of objects, a communication module must be installed to collect data generated from sensors or edge devices in real time. And in order to deliver data to the database, a software architecture must be configured. Data generated from objects can be stored and managed in a database in real time, and data necessary for industrial safety can be extracted and utilized for industrial safety service applications. In this paper, a network environment was constructed using a LoRa(LoRa: Long Range) gateway to collect object data, and a client/server data collection model was designed to collect object data transmitted from the LoRa module. In order to secure the resources necessary for data collection and storage management without data leakage, data collection should be possible in real time. As an application service, location data required for industrial safety can be stored and managed in a database in real time.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.16-25
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• 2023

There are various types of foreign object debris (FOD) in the aviation industry. Tools lost by workers can act as a risk factor throughout aircraft operation, manufacturing, and maintenance fields. Accidents caused by tools lost due to workers' carelessness continue to occur throughout the aviation industry. Aviation-related institutions such as FAA and EASA have established tool control regulations and systems to prevent FOD occurrence. However, in Korea, related regulations and procedures are insufficient. A systematic and effective tool control system is required for reliable manufacturing, airworthiness, operation, and maintenance of aircraft. In this paper, tool control regulations and procedures of domestic and foreign air traffic authorities and aviation industry-related organizations were studied. A wireless communication-based tool control system was proposed based on the NAS 412's tool control regulations certified by the National Standards Association.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.6
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• pp.461-466
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• 2021

Drone can be controlled by the method such as Bluetooth communication for close distance and can be controlled through network communication for long distance. Especially, the coordinate is set using GPS and drone is controlled using network communication and video communication when the activity range is long distance. However, the drone should be controlled by receiving control authority accordingly in response about it appropriately when the drone leaves the control area after arriving at the destination if there is a problem with network communication and video communication. So, this study proposes a method to control a drone with a simple mutually promised simple gesture and the drone can be controlled in the proposed method even if the drone leaves from the control authority in above situation. The reference posture was established for mutually promised simple gesture algorithm and automatically handed over the control authority of drone to a person who takes the reference posture when the drone recognizes it to implement this. And all the movements of the drone could be controlled by starting the beginning of all commands from the reference posture (The hovering posture of the drone). Lastly, the control authority of the drone should be returned after achieving the purpose, and the algorithm was implemented to make the drone can perform next action of its own, and it was confirmed that the drone was operating normally by the mapped instruction.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.245-252
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• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Korean Journal of Remote Sensing
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• v.31 no.3
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• pp.215-226
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• 2015

Normally, aero photography using UAV uses about 430 MHz bandwidth radio frequency (RF) modem and navigates and remotely controls through the connection between UAV and ground control system. When using the exhausting method, it has communication range of 1-2 km with frequent cross line and since wireless communication sends information using radio wave as a carrier, it has 10 mW of signal strength limitation which gave restraints on life my distance communication. The purpose of research is to use communication technologies such as long-term evolution (LTE) of smart camera, Bluetooth, Wi-Fi and other communication modules and cameras that can transfer data to design and develop automatic shooting system that acquires images to UAV at the necessary locations. We conclude that the android based UAV filming and communication module system can not only film images with just one smart camera but also connects UAV system and ground control system together and also able to obtain real-time 3D location information and 3D position information using UAV system, GPS, a gyroscope, an accelerometer, and magnetic measuring sensor which will allow us to use real-time position of the UAV and correction work through aerial triangulation.