• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.164-171
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• 2019

Focusing on the bridge facilities, which occupy the largest proportion among SOC public facilities in Korea, it is possible to reduce the cost compared to existing wired measurement systems or wireless measurement systems developed by domestic telecommunications companies, and to increase the technical perfection to be applied to many bridges. We developed a wireless measurement system for bridges. Using LoRa, one of the unlicensed LPWAN technologies, we have developed an optimized MEMS-based LoRa smart sensor node considering the domestic ISM band and the existing wired sensor LoRa DAQ sensor node that can communicate with the LoRa network. Application server was developed for the test bed performance verification and efficient management of the developed sensor node.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.33-41
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• 2018

The idea of the Internet of Things as a platform on the Smart Campus has become increasingly popular. It requires an infrastructure consisting of communication networks, sensor nodes and gateways to connect to the Internet. Each sensor node is responsible for gathering data from the environment. This document outlines a network of wireless sensors on the Internet for the application of Smart Campus monitoring. Wireless sensor network Monitoring have become a complete solution to using a low power implementation and integrated systems. The numerous restrictions however result from the low communication range, the limited computing power, the lack of availability of the network protocol, the lack of programming security and the security failures in the areas of confidentiality, integrity and availability. A new security technique and its functionality for WSNM nodes developed. Development in the research of a secure network and suggestions for avoiding denial of service (DOS) and complexity attacks. These systems if properly implemented can provide an energy efficiency mechanism through pre-allocation and a new key from key management models with a secure routine algorithm.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.27-29
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• 2012

본 논문에서는 최근 사용량이 급증한 스마트폰을 이용한 증강현실 시스템을 제안한다. 이 시스템은 스마트폰 기기의 GPS와 센서 기능을 활용하여 현재 위치를 탐색하고, 무선 네트워크를 사용하여 주변 위치정보를 다운로드 하여 표시한다. 또한 이 시스템은 다운로드한 위치정보의 내용을 활용하여 사용자에게 정보를 제공한다. 애플리케이션이 수행 중인 동안 계속하여 현재 위치탐색과 위치 정보 다운로드 및 갱신이 이루어져 사용자로 하여금 정보 인식에 편의성을 제공하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.73-76
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• 2013

기존의 보안장치에서 주로 사용하는 방법인 센서 또는 카메라 중 하나를 이용하는 방법이 아닌 센서와 카메라 모두를 이용한 보안 시스템을 제안한다. 센서를 사용한 방법의 단점인 현장을 확인 할 수 없다는 것을 보안하여 카메라를 이용하였으며, 사용자는 이를 서버에서 모니터링 되는 화면을 직접 확인 하거나 혹은 서버에서 보내오는 데이터를 사용자의 스마트 폰에서 확인 할 수 있도록 개선하였다. 그리고 이를 구현하기 위해서 통신을 위한 노드 구성 및 이상 감지시 노드에서 서버로, 서버에서 사용자에게 상황 통보를 위한 스마트폰 알고리즘 구성에 대해 설명하고 이를 실험적으로 구현하였다.

• Smart Media Journal
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• v.6 no.4
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• pp.24-31
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• 2017

In wireless sensor networks, sensor nodes are deployed in a remote, harsh environment. When the power of the sensor node is consumed in such a network, the sensor nodes become useless together with the deterioration of the quality and performance of the sensor network which may save human life. Although many clustering protocols have been proposed to improve the energy consumption and extend the life of the sensor network, most of the previous studies have shown that the overhead of the cluster head is quite large. It is important to design a routing protocol that minimizes the energy consumption of each node and maximizes the network lifetime because of the power limitations of the sensor nodes and the overhead of the cluster heads. Therefore, in this paper, we propose an efficient clustering scheme that reduces the burden of cluster heads, minimizes energy consumption, and uses algorithms that maximize network lifetime. Simulation results show that the proposed clustering scheme improves the energy balance and prolongs the network life when compared with similar techniques.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.131-135
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• 2011

In this paper, we describe the design and implementation of wireless smart plug having AC power sensor and intelligent standby power control algorithm for energy sensor network. The adaptive standby power control algorithm has function to apply different threshold of standby power by using learning algorithm depending on electric equipments. As using the proposed algorithm, user convenience will be more better and power consumption can be more reduced. The implemented prototypes of wireless smart plug and wireless access point were tested to verify the required functions and performance. As a result, we confirmed practicality of wireless smart power sensor and satisfaction of given design specifications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.479-485
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• 2013

In this paper, we propose a smart farming system using the visible light communication based on the software defined radio (SDR) technology and the conventional RF radio. The proposed system can continuously monitor growth environments of the LED plant factory and automatically control the LED plant factory to keep optimal growth environments. Furthermore, by creating a database from various growth factors, the LED plant factory can be efficiently managed.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.918-931
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• 2013

The conventional object tracking techniques using PTZ camera detects object movements by analyzing acquired image. However, this technique requires expensive hardware devices to perform a complex image processing. And it is occasionally hard to detect object movements, if an acquired image is low quality or image acquisition is impossible. In this paper, we proposes a smart security CCTV system applying to wireless sensor network technique based on IEEE 802.15.4 standard to overcome the problems of conventional object tracking technique, which enables to track suspicious objects by detecting object movements and GPS data in sensor node. This system enables an efficient control of PTZ camera to observe a wide area, decreasing image processing complexity. Also, wireless sensor network is implemented using mesh networks to increase the efficiency of installing sensor node.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.135-141
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• 2011

A smart home provides services that its inhabitant needs or wants, by integrating and simultaneously controlling various devices and sensors. In this study, we focused on a smart-home system for people with disabilities and for elderly people. We introduced a new type of system for real-time analysis of body posture of the inhabitants of a smart home. The system includes the concept that offers remote healthcare or medical services by using a 3D tilt sensor for recognizing the static and dynamic postures of inhabitants in real time. It consists of a smart-home server and a 3D tilt sensor, and it uses wireless technology to communicate with the inhabitants and thus enhance their mobility. The smart-home server includes the inference engine that differentiates the dynamic postures from the static ones. Finally, we also demonstrate the usefulness of the proposed system by applying it to a real environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.66-72
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• 2016

An LED lighting control system was developed to combine information technology and LED lights for efficient management and energy savings. The system can monitor and control the status of an LED luminaire using Bluetooth wireless communication, sensor technology, and smart phones. An LED lighting control circuit was designed using a temperature sensor, illumination sensor, and Bluetooth module with a fuzzy constant-current control circuit. We extended the lifetime and prevented damage to the LED by optimizing the supply current of the LED luminaire based on the heat-generation temperature of $70^{\circ}C$ of an LED heat sink. We also automatically adjusted the ON/OFF time depending on the ambient illumination of the LED luminaire. By allowing easy control of the LED luminaires on a smartphone, we improved the efficiency and achieved energy savings. The control system was validated through experiments for normal operation.