• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2181-2202
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• 2016

In Wireless Sensor Networks (WSNs) and even in the Internet of Things (IoT) ecosystem, the reconfiguration of sensor variables is an important problem when the role of a system (or application) program's sensor nodes needs to be adjusted in a particular situation. For example, the outdoor temperature in a volcanic zone, which is usually updated in a system every 10 s, should be updated every 1 s during an emergency situation. To solve this problem, this paper proposes a novel approach based on changing only a set of sensor variables in a part of a program, rather than modifying the entire program, in order to reduce both network congestion and the sensor nodes' battery consumption. To validate our approach, we demonstrate an implementation of a proof-of-concept prototype system and also present results of comparative studies showing the performance and effectiveness of our proposed method.

• 한국컴퓨터정보학회논문지
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• 제23권9호
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• pp.113-122
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• 2018

In this paper, IoT(Internet of things) technology, which is the core of the 4th industrial revolution, was applied to the study of reduction of consumption current. The IoT is a sensor that collects data, a sensor communication, a gateway that processes and stores the collected data. Data application of IoT technology is applied to smart home, smart city, healthcare, smart factory, etc. and it needs to be applied to various industrial fields. By sensing the location of the sensor device, the specific functions of the gateway and the platform are turned ON and OFF to reduce the consumption current of the equipment during the OFF period. When the sensor device accesses the gateway, the specific function of the gateway is turned ON and When the device is separated from the gateway, it senses the sensitivity of the wireless signal and automatically turns off the certain functions. As a resurt, it has reduced the consumption of current. In this paper, we propose a novel system for detecting the location of sensor devices by applying IoT technology. The system implementation is realized by software based, and defines the requirements for the implementation of the sensor device gateway. The gateway automatically detects the location, movement of the device and performs necessary functions. Finally verifies the automatic detection performance of the gateway according to the location of the device. It will contribute greatly to the development of the smart city and office.

• Journal of Information Processing Systems
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• 제14권2호
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• pp.286-308
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• 2018

The availability of powerful and sensor-enabled mobile and Internet-connected devices have enabled the advent of the ubiquitous sensor network (USN) paradigm. USN provides various types of solutions to the general public in multiple sectors, including environmental monitoring, entertainment, transportation, security, and healthcare. Here, we explore and compare the features of wireless sensor networks and USN. Based on our extensive study, we classify the security- and privacy-related challenges of USNs. We identify and discuss solutions available to address these challenges. Finally, we briefly discuss open challenges for designing more secure and privacy-preserving approaches in next-generation USNs.

• 대한임베디드공학회논문지
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• 제10권3호
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• pp.119-127
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• 2015

In the IoT(Internet of Things) environment, methods that user can access sensor node directly to collect sensing data or manage sensor in a gateway have a limitations. To solve this problem, cloud based sensor network architectures are proposed. In this paper, we proposed CoAP based IoT architecture that a lightweight gateway is used for data gathering instead of using a heavy traditional one and users can request sensing data through IoT applications running in the cloud environment and analyze signaling message cost. By doing so, our system can reduce message cost compared to the traditional gateway based system.

• 전기학회논문지
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• 제65권1호
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• pp.122-127
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• 2016

In this paper, new spectrum sensing schemes based on analog/RF front-end processing are introduced for IoT wireless sensor networks. While the conventional approaches for wireless channel cognition have been issued in signal processing area, the RF spectrum cognition concept makes it feasible to achieve cognitive wireless sensor networks (C-WSNs). The spectrum cognition at RF processing is categorized as four kinds of sensing mechanisms. Two recent reseaches are described as promising candidates for the C-WSN. One senses spectrum by the frequency discriminating receiver, the other senses and detects from the frequency selective super-regenerative receiver. The introduced systems with simple and low-power RF architectures play dual roles of channel sensing and demodulation. simultaneously. Therefore, introduced spectrum sensing receivers can be one of the best candidates for IoT wireless sensor devices in C-WSN environments.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.36-41
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• 2022

In the 21st century, information collection and information provision based on digital informatization and intelligent automation are emerging as one of the social problems in the society for the elderly and the vulnerable groups in the welfare society including the disabled, and various methods are being studied to find realistic alternatives. Among these factors, the problem of the elderly living alone is emerging as the most serious, and as a realistic approach to solve some problems by applying information devices, it is a monitoring system using the Internet of Things(IoT). The need for an optimized system is emerging. In this study, the state of the elderly and the elderly living alone can be measured remotely by applying IoT technology. We present the research cases of a Breathing Sensor-based Smart Monitoring System that is used as a smart information system and used as a monitoring system for the elderly and infirm when it is identified as deceased through state detection

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권6호
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• pp.268-277
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• 2016

사물인터넷이 대중화되면서 주차장에도 사물인터넷 환경을 구축해 이용객이 주차한 차량의 위치 식별 및 주차 위치 안내 서비스를 제공하려는 연구가 진행되고 있다. 기존 시스템들은 차량을 식별하기 위해 식별 장치를 차량에 부착하거나 이용객이 소지하는 방법 또는 고화질 카메라를 이용하여 주차된 차량의 번호판을 인식하는 방법 등을 이용하고 있다. 하지만 이 방법들은 이용 방법과 비용 측면에서 아쉬운 면을 보였다. 본 논문에서는 초음파 센서와 블루투스 통신을 이용한 스마트 실내 주차장 관리 시스템을 제안한다. 제안하는 시스템은 각 주차공간에 설치된 주차장 센서 모트의 초음파센서를 이용하여 차량의 점령을 판단하고 블루투스의 RSSI를 이용하여 주차된 차량의 위치 식별이 가능하다. 또한 블루투스 RSSI를 이용한 실시간 실내 위치 인식을 통해 주차된 차량까지의 길 안내 서비스가 가능하다. 시스템의 성능평가를 위해 주차된 차량의 위치 인식률과 RSSI를 변환해 얻은 거리의 정확도를 측정하였다.

• 한국위성정보통신학회논문지
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• 제10권1호
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• pp.56-61
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• 2015

본 논문에서는 사물인터넷(IoT, Internet of Things) 사용자가 안드로이드 플랫폼 기반의 홈 허브가 유니티 3D 모델링으로 사물인터넷 센서의 3D 위치표출 방안이 제안되었다. 특별히, 3차원 공간에서 IoT 센서는 설치 공간별로 클러스링을 통해 IoT센서 속성과 배터리 상태를 모니터링 방식을 설계한다. 또한, 3차원 공간상에서 신규 설치한 IoT 센서가 인접 센서들의 무선신호의 비콘신호 및 도착시간 분석에 따른 센서의 위치를 추적하는 방식은 센서의 무선신호세기(RSSI, received signal strength indicator)와 방위각을 기반으로 3차원 공간상에서 수신 각도에 따른 센서의 3D 위치를 표출할 수 있다. 이때 유니티 런쳐가 탑재된 스마트 허브 플랫폼은 사물인터넷 센서의 동작상태 모니터링이 가능하며, 다양한 센서의 생애주기를 관리할 수 있도록 동영상이 3차원 텍스쳐가 동시에 연동하도록 활용할 수 있다.

• 농촌계획
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• 제21권4호
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• pp.177-186
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• 2015

The main objective of this study was to assess the applicability of IoT (Internet of Things)-based flood management under climate change by developing intelligent water level monitoring platform based on IoT. In this study, Arduino Uno was selected as the development board, which is an open-source electronic platform. Arduino Uno was designed to connect the ultrasonic sensor, temperature sensor, and data logger shield for implementing IoT. Arduino IDE (Integrated Development Environment) was selected as the Arduino software and used to develop the intelligent algorithm to measure and calibrate the real-time water level automatically. The intelligent water level monitoring platform consists of water level measurement, temperature calibration, data calibration, stage-discharge relationship, and data logger algorithms. Water level measurement and temperature calibration algorithm corrected the bias inherent in the ultrasonic sensor. Data calibration algorithm analyzed and corrected the outliers during the measurement process. The verification of the intelligent water level measurement algorithm was performed by comparing water levels using the tape and ultrasonic sensor, which was generated by measuring water levels at regular intervals up to the maximum level. The statistics of the slope of the regression line and $R^2$ were 1.00 and 0.99, respectively which were considered acceptable. The error was 0.0575 cm. The verification of data calibration algorithm was performed by analyzing water levels containing all error codes in a time series graph. The intelligent platform developed in this study may contribute to the public IoT service, which is applicable to intelligent flood management under climate change.

• 한국정보통신학회논문지
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• 제21권5호
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• pp.936-944
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• 2017

현재 산업 분야 전반에 걸쳐 다양한 IoT 기술들이 연구되고 있으며 이 기술들을 효과적으로 적용하는 중이다. 그러나 IoT 대부분의 연구들은 센서 디바이스, 게이트웨이, 네트워크 서버, 그리고 어플리케이션 서버로 연결되는 복잡한 구조에 의존한다. 물론 유연성과 확장성 측면에서 이들은 분명한 장점이 있다. 문제는 이와 같은 복잡한 구성은 구현상의 어려움과 추가적인 비용을 초래하기 때문에 소규모 네트워크 환경의 산업 분야에서 IoT 도입을 저해하는 결과로 나타나고 있다. 따라서, 본 논문에서는 소규모/저비용의 IoT 환경이 필요한 산업분야에 적용 가능한 시스템 구조를 제안 한다. 또한 RF433 기반의 무선 센서 네트워크, 아두이노 윤 기반의 게이트웨이, APM (Apache, PHP, MySQL)을 적용한 어플리케이션 서버를 구현하고 이들 간의 효율적인 전력관리 방안을 제시한다.