• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.207-214
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• 2011

In this paper, using Zigbee-based wireless sensor networks and Lego MindStorms NXT robot, a remote monitoring and navigation system for mobile robot has been developed. Mobile robot can estimate its position using encoder values of its motor, but due to the existing friction and shortage of motor power etc., error occurs. To fix this problem and obtain more accurate position of mobile robot, a ultrasound module on wireless sensor networks has been used in this paper. To overcome disadvantages of ultrasound which include straightforwardness and narrow detection coverage, we rotate moving node attached to mobile robot by $360^{\circ}$ to measure each distance from four fixed nodes. Then location of mobile robot is estimated by triangulation using measured distance values. In addition, images are sent via a network using a USB Web camera to smart phone. On smart phones we can see location of robot, and images around places where robot navigates. And remote monitoring and navigation is possible by just clicking points at the map on smart phones.

• Electronics and Telecommunications Trends
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• v.28 no.5
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• pp.83-92
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• 2013

IT 기술이 발달함에 따라 저전력, 초소형 센서노드를 설치하여 무인으로 정보를 얻을 수 있는 시스템의 도입이 점차 확대되는 추세이며, 이것을 위하여 온도, 습도, 가스 등 환경정보를 획득할 수 있는 센서뿐만 아니라 초소형 저전력 복합환경센서 ROIC(Read-Out Integrated Circuit)의 중요성이 증가하고 있다. 또한 휴대폰, 노트북, 스마트폰, 태블랫 PC 등의 모바일 IT 제품들은 빠르게 소형화, 슬림화, 저전력화 되고 있다. 이런 시스템의 요구에 따라 음향부품도 기본적인 음향감지/출력 성능 이외에 크기 및 소모전력이 중요한 기능요소로 크게 부각되고 있으며, 이것을 위하여 소형화, 저가격화가 가능한 MEMS(Microelectromechanical Systems) 음향센서 및 ROIC 개발이 요구되고 있다. 따라서 본고에서는 복합환경센서 ROIC 및 MEMS 마이크로폰 ROIC의 기술동향 등에 대해서 고찰하고자 한다.

• Journal of Internet of Things and Convergence
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• v.6 no.4
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• pp.81-87
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• 2020

This paper creates a standard node for acquiring sensor data from various industrial sensors (IoT/non-IoT) for the establishment of Smart Factory Digital Twin, and provides inter-compatible data by linking zones by group/process to secure data stability and to ensure the digital twin (Digital Twin) of Smart Factory. The process of the Zone Master platform contains interface specifications to define sensor objects and how sensor interactions between independent systems are performed and carries out individual policies for unique data exchange rules. The interface for execution control of the Zone Master Platform processor provides system management, declaration management for public-subscribe, object management for registering and communicating status information of sensor objects, ownership management for property ownership sharing, time management for data synchronization, and data distribution management for Route information on data exchange.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.185-188
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• 2021

본 논문에서는 기술의 빠른 발전에도 불구하고 줄어들지 않는 화재 사고, 그 중에서도 많은 인명피해를 내는 실내 화재 사고에 대하여 기존 실내 화재 알림 시스템의 한계점인 알림의 양치기 소년화로 인한 안전 불감증 증가와 알림의 사각지대 문제를 해결하고자 새로운 대안 시스템을 설계 및 구현하고, 실험 검증을 진행하였다. 위 두 가지 문제점을 해결하기 위해, 본 연구에서는 스마트폰이 매우 대중적으로 보급되어 있다는 점을 기반으로 IoT, 엣지 컴퓨팅, 비콘 등을 응용한다. 비콘 신호를 broadcasting 하는 엣지 노드의 신호 범위 내에 진입하면 사용자 정보를 수집하여 대상 건물에 출입한 대상을 특정한다. 말단 센서 노드와 엣지 노드 간의 무선 RF 통신으로 화재를 모니터링하며 화재가 발생했을 시 특정된 대상들에게만 스마트폰 어플의 푸시 알림으로 화재 발생 상황을 전송하는 시스템을 설계 및 구현하였다. 시스템 성능 평가를 위해 동국대학교 건물 내에서 수평, 수직으로 이동하며 실험을 진행하였고, 그 결과를 통해 대안 시스템의 성능과 한계를 분석하여 이를 실내 공간에 적용하기 위한 적합성을 평가하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1263-1266
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• 2006

센서 네트워크는 환경 정보를 이용하여 재난방제, 스마트홈, 환경감시 등의 다양한 서비스를 제공할 수 있으며, 특히 위치인식 기반 서비스에 관한 연구가 활발히 진행되고 있다. 위치인식을 하기 위해 기본적이고 가장 중요한 기술은 센서와 사물 사이의 거리를 측정하는 것이다. 초음파와 RSSI, GPS 등 위치인식을 위해 거리를 측정하는 방식은 여러 가지가 있다. 본 논문에서는 소리와 RF신호를 이용하여 거리를 측정하는 시스템을 구현하고 평가한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.111-116
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• 2018

In this thesis, the range of motion of the joint was measured using a flexible sensor without using a goniometer, and the measured values were transferred to a smart device. Current range of joint motion measurement is measured by a person using a goniometer. Since the method of measuring by a person is different according to the measuring method and position of the measuring person, it is difficult to make consistent measurement, and an error may occur. The sensor for measurement is a flexible sensor that measures the resistance value that changes according to the movement of the joint. The sensed value can be transmitted to the smart device wirelessly through the ROM sensor node. Also, the sensed analog values were converted to digital values using an ADC. The converted value can be transmitted to the smart device wirelessly through the sensor node. The developed ROM measuring device can perform more consistent measurement than the measurement using general articulator and real time monitoring by interlocking with smart device, so that rapid diagnosis according to the movement of the joint can help the patient's rapid treatment and rehabilitation medical advancement will be.

• Magazine of the Korean Society of Hazard Mitigation
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• v.11 no.1
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• pp.95-98
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• 2011

최근 국내에서 사회기반시설물에 대한 안전관리 네트워크 통합시스템 구축을 위한 국가핵심과제가 진행되고 있다. 본 연구에서는, 위 과제의 일환으로 진행 중인 철도교량의 구조건전성 모니터링 시스템 구축 및 운용에 대하여 기술하였다. 효율적인 철도교량 모니터링 시스템 구축을 위하여 다양한 종류의 스마트센서가 적용되었으며, 웹 기반의 네트워킹을 통해 외부에서 모니터링 시스템을 원격으로 접속, 제어 할 수 있도록 하였다. 철도교량의 국부 손상을 모니터링 하기 위해 압전센서를 활용한 무선 임피던스 노드를 적용하였고, 구조물 전체의 거동 분석을 위하여 가속도 센서 및 광섬유 센서를 적용하였다. 구조물의 장기 계측을 통한 철도 주행 및 외부 환경에 따른 거동 분석을 수행하였으며, 손상 평가를 위한 신호처리 알고리즘이 적용되었다.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.7
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• pp.217-224
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• 2022

Today, with the development of technology and industry, fire accidents in special buildings are increasing as special buildings increase. However, despite the rapid development of information and communication technology, human casualties are steadily occurring due to the underdeveloped and ineffective indoor fire alarm system. In this study, we confirmed that the existing indoor fire alarm system using acoustic alarm could not deliver a sufficiently large alarm to the in-room personnel. To improve this, we designed and implemented a fire alarm system using edge computing and beacons. The proposed improved fire alarm system consists of terminal sensor nodes, edge nodes, a user application, and a server. The terminal sensor nodes collect indoor environment data and send it to the edge node, and the edge node monitors whether a fire occurs through the transmitted sensor value. In addition, the edge node continuously generate beacon signals to collect information of smart devices with user applications installed within the signal range, store them in a server database, and send application push-type fire alarms to all in-room personnel based on the collected user information. As a result of conducting a signal valid range measurement experiment in a university building with dense lecture rooms, it was confirmed that device information was normally collected within the beacon signal range of the edge node and a fire alarm was quickly sent to specific users. Through this, it was confirmed that the "blind spot problem of the alarm" was solved by flexibly collecting information of visitors that changes time to time and sending the alarm to a smart device very adjacent to the people. In addition, through the analysis of the experimental results, a plan to effectively apply the proposed fire alarm system according to the characteristics of the indoor space was proposed.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.239-254
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• 2007

Ubiquitous computing supports environment to freely connect to network without restrictions of place and time. This environment enables easy access and sharing of information, but because of easy unauthorized accesses, specified security policy is needed. Especially, ubiquitous sensor network devices use limited power and are small in size, so, many restrictions on policies are bound to happen. This paper proposes double-key based light weight security protocol, independent to specific sensor OS, platform and routing protocol in ubiquitous sensor network. The proposed protocol supports safe symmetric key distribution, and allows security manager to change and manage security levels and keys. This had a strong merit by which small process can make large security measures. In the performance evaluation, the proposed light weight security protocol using double-key in ubiquitous sensor network allows relatively efficient low power security policy. It will be efficient to ubiquitous sensor network, such as smart of ace and smart home.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.55-62
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• 2010

Monitoring systems are able to report certain events at region of interest(ROI) and to take an appropriate action. From industrial product line full of robots to fire detection, intrusion detection, smart grid application, environmental pollution alarm system, monitoring system has widely used in diverse industry sector. Recently, due to advance of wireless communication technology and availability of low cost sensors, intelligent and/or smart monitoring systems such as sensor networks has been developed. Several deployment methods are introduced to meet various monitoring needs and deployment performance criteria are also summarized to be used to identify weak point and be useful at designing monitoring systems. Both efficiency during deployment and usefulness after the deployment should be assessed. Efficiency factors during deployment are elapsed time, energy required, deployment cost, safety, sensor node failure rate, scalability. Usefulness factors after deployment are ROI coverage, connectivity, uniformity, target density similarity, energy consumption rate per unit time and so on.