• 한국전자통신학회논문지
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• 제16권6호
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• pp.1223-1230
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• 2021

최근 에너지 자원관리는 전 세계적인 주요 관심사이다. 에너지원 생산의 한계 조건 속에서, 효과적인 에너지 관리 활동은 에너지 수요 및 생산을 최소화하고 이는 환경이 미치는 영향을 최소화할 수 있다. 본 논문은 주거형 건물에서 에너지 소비자에게 전기 사용에 대한 실시간 정보를 제공할 수 있는 가정용 전기에너지 모니터링 시스템의 프로토타입 설계를 제안하고자 한다. 제안된 시스템은 자체 개발된 센싱 시스템, 데이터처리시스템, 원격 모니터링 서버 시스템으로 구성된다. 주거형 건물내에 설치 적용된 센싱 시스템은 전원 공급을 제어하는 릴레이, 부하 전기기기의 전류를 감지하는 CT센서, Kmote로 구성된 무선 스마트 플러그로 구성된다. 공동/단독 주거형 건물에서 3개월 동안의 가전제품별 에너지 소비량 데이터를 분석하여 제시하였으며, 실험결과는 에너지 소비 패턴과 현황을 추정할 수 있는 가능성을 확인하여 제시하고 있다.

• Computers and Concrete
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• 제31권5호
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• pp.457-468
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• 2023

Buildings, bridges, and dams are examples of civil infrastructure that play an important role in public life. These structures are prone to structural variations over time as a result of external forces that might disrupt the operation of the structures, cause structural integrity issues, and raise safety concerns for the occupants. Therefore, monitoring the state of a structure, also known as structural health monitoring (SHM), is essential. Owing to the emergence of the fourth industrial revolution, next-generation sensors, such as wireless sensors, UAVs, and video cameras, have recently been utilized to improve the quality and efficiency of building forensics. This study presents a method that uses a target-based system to estimate the dynamic displacement and its corresponding dynamic properties of structures using UAV-based video. A laboratory experiment was performed to verify the tracking technique using a shaking table to excite an SDOF specimen and comparing the results between a laser distance sensor, accelerometer, and fixed camera. Then a field test was conducted to validate the proposed framework. One target marker is placed on the specimen, and another marker is attached to the ground, which serves as a stationary reference to account for the undesired UAV movement. The results from the UAV and stationary camera displayed a root mean square (RMS) error of 2.02% for the displacement, and after post-processing the displacement data using an OMA method, the identified natural frequency and damping ratio showed significant accuracy and similarities. The findings illustrate the capabilities and reliabilities of the methodology using UAV to evaluate the dynamic properties of structures.

• 한국통신학회논문지
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• 제40권10호
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• pp.2006-2013
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• 2015

본 논문에서는 저전력 무선통신 기반 다중 프로토콜 게이트웨이 시스템 설계를 제안한다. 제안 된 멀티 프로토콜 게이트웨이 시스템은 가로등 전력 제어 및 환경 모니터링을 위한 정보를 수집하여 무선 네트워크와 유선 네트워크를 통해 현장 상황을 실시간으로 모니터링 및 제어 할 수 있도록 설계하였다. 코드분할 다중접속 및 이더넷, 위성 항법장치, 저전력 무선통신 등의 유선 또는 무선통신을 선택적으로 사용한 복합처리와 함께 다중 센서를 이용하여 수집 된 데이터를 저전력 무선통신을 통해 서버로 전송하는 중개 역할을 하도록 설계하였다. 그리고 유지보수 비용 및 하드웨어 교체 용이성을 위해 CPU 및 베이스 보드로 분리하여 설계하였다. 본 논문에서 제안된 다중 프로토콜 게이트웨이 시스템의 전원, 충격, 연속동작 신뢰성 검증결과, 95% 이상의 정상동작 성공률 및 정상적인 연속동작 결과를 얻을 수 있었다. 그리고 전압 강하 및 순간 내성시험, 전도성 RF 전자기장 내성시험에서 평균 A등급의 평가결과를 얻을 수 있었다.

• International journal of advanced smart convergence
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• 제1권2호
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• pp.1-11
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• 2012

IP-based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health care, home automation, environmental monitoring, industrial control, vehicle telematics, and agricultural monitoring. In all these applications, a fundamental issue is the mobility in the sensor network, particularly with regards to energy efficiency. Because of the energy inefficiency of network-based mobility management protocols, they can be supported via IP-WSNs. In this paper, we propose a network-based mobility-supported IP-WSN protocol called mSFP, or the mSFP: "Multicasting-supported Inter-Domain Mobility Management Scheme in Sensor-based Fast Proxy Mobile IPv6 Networks". Based on [8,20], we present its network architecture and evaluate its performance by considering the signaling and mobility cost. Our analysis shows that the proposed scheme reduces the signaling cost, total cost, and mobility cost. With respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 7% and the total cost by 3%. With respect to the number of hops, the proposed scheme reduces the signaling cost by 6.9%, the total cost by 2.5%, and the mobility cost by 1.5%. With respect to the number of IP-WSN nodes, the proposed scheme reduces the mobility cost by 1.6%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3064-3094
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• 2018

Currently, the Underwater Sensor Networks (UWSNs) is mainly an interesting area due to its ability to provide a technology to gather many valuable data from underwater environment such as tsunami monitoring sensor, military tactical application, environmental monitoring and many more. However, UWSNs is suffering from limited energy, high packet loss and the use of acoustic communication. In UWSNs most of the energy consumption is used during the forwarding of packet data from the source to the destination. Therefore, many researchers are eager to design energy efficient routing protocol to minimize energy consumption in UWSNs. As the opportunistic routing (OR) is the most promising method to be used in UWSNs, this paper focuses on the existing proposed energy efficient OR protocol in UWSNs. This paper reviews the existing proposed energy efficient OR protocol, classifying them into 3 categories namely sender-side-based, receiver-side-based and hybrid. Furthermore each of the protocols is reviewed in detail, and its advantages and disadvantages are discussed. Finally, we discuss potential future work research directions in UWSNs, especially for energy efficient OR protocol design.

• 제어로봇시스템학회논문지
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• 제18권8호
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• pp.780-786
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• 2012

Surveillance has become one of promising application areas of wireless sensor networks which allow for pervasive monitoring of concerned environmental phenomena by facilitating context awareness through sensor fusion. Existing systems that depend on a postmortem context analysis of sensor data on a centralized server expose several shortcomings, including a single point of failure, wasteful energy consumption due to unnecessary data transfer as well as deficiency of scalability. As an opposite direction, this paper proposes an energy-efficient distributed context-aware surveillance in which sensor nodes in the wireless sensor network collaborate with neighbors in a distributed manner to analyze and aware surrounding context. We design and implement multi-modal sensor stations for use as sensor nodes in our wireless sensor network implementing our distributed context awareness. This paper presents an initial experimental performance result of our proposed system. Results show that multi-modal sensor performance of our sensor station, a key enabling factor for distributed context awareness, is comparable to each independent sensor setting. They also show that its initial performance of context-awareness is satisfactory for a set of introductory surveillance scenarios in the current interim stage of our ongoing research.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.217-220
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• 2014

무선 센서 네트워크（Wireless Sensor Network, WSN）수많은 로우 코스트 센서 노드로 구성하고 공동으로 배치된 지역 내에서 정보감지, 수집, 처리 및 전송임무를 수행한다. 광범위하게 국방군사, 지능형 교통, 의료구조, 환경감시, 정밀농업 및 공업 자동화등 방면에 응용할 수 있다. 데이터 유지관리 기술은 센서 네트워크의 핵심 기술 중 하나이다. 본 논문은 현재 무선 센서 네트워크 데이터 관리 기술 분석하고 문제점 지적하였다.

• 전자공학회논문지SC
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• 제46권4호
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• pp.28-38
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• 2009

본 연구에서는 비분산적외선(NDIR) 방식의 CO$_2$센서를 이용하여 무선 센서 네트워크 기반의 지하 공기질 모니터링 시스템을 구현하고 실제 지하철 승강장에 설치한 후 성능평가를 수행하였다. 서울 지하철은 하루 650만 명이 이용하는 대표적인 대중교통 수단이다. 따라서 승객뿐만 아니라 지하철 역사의 지하 공간에서 근무하는 많은 근로자들의 건강에 대한 관심이 높아짐에 따라 지하철 역사의 공기질 모니터링에 대한 요구가 매우 높아졌다. 현재 이런 요구를 충족하기 위해 환경부와 지하철 운영기관 측에서는 지하철역 공기질 모니터링 시스템을 일부 설치 운영 중이다. 그러나 고가의 수입 센서 이용으로 장비의 규모가 크고 설치 및 상시 운영에 따른 유지보수 비용이 큰 한계점이 있다. 따라서 본 연구에서는 저비용으로 CO$_2$ 농도를 상대적으로 정밀하게 측정할 수 있는 상용화된 CO$_2$ 센서에 대해 이론적으로 분석하고 신뢰성 검증 테스트를 수행하였다. 또한 무선 공기질 측정 센서 노드 및 게이트웨이 시스템을 개발하여 지하철 승강장의 실시간 공기질 데이터를 주기적으로 수집할 수 있고, 효율적으로 모니터링 할 수 있는 웹서버를 구축하였다. 본 연구 결과는 향후 지하 공간 공기질 관리 시스템의 확산 설치를 위하여 기초 연구 자료로 활용될 것이다.

• Smart Structures and Systems
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• 제14권2호
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• pp.85-104
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• 2014

Damage detection is a challenging, complex, and at the same time very important research topic in civil engineering. Identifying the location and severity of damage in a structure, as well as the global effects of local damage on the performance of the structure are fundamental elements of damage detection algorithms. Local damage detection is essential for structural health monitoring since local damages can propagate and become detrimental to the functionality of the entire structure. Existing studies present several methods which utilize sensor data, and track global changes in the structure. The challenging issue for these methods is to be sensitive enough in identifYing local damage. Autoregressive models with exogenous terms (ARX) are a popular class of modeling approaches which are the basis for a large group of local damage detection algorithms. This study presents an algorithm, called Influence-based Damage Detection Algorithm (IDDA), which is developed for identification of local damage based on regression of the vibration responses. The formulation of the algorithm and the post-processing statistical framework is presented and its performance is validated through implementation on an experimental beam-column connection which is instrumented by dense-clustered wired and wireless sensor networks. While implementing the algorithm, two different sensor networks with different sensing qualities are utilized and the results are compared. Based on the comparison of the results, the effect of sensor noise on the performance of the proposed algorithm is observed and discussed in this paper.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.33-41
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• 2020

Nowadays, distributed mobility management (DMM) approaches have been widely adopted to address the limitations of centralized architectural methods to support seamless data transmission schemes in wireless sensor networks. This paper deals with the end-to-end (E2E) integration of Network Mobility (NEMO) basic support protocol in distributed wireless sensor network systems in structural health and environmental monitoring of social overhead capital (SOC) public infrastructures such as bridges, national highways, tunnels, and railroads. The proposed scheme takes advantage of the features of both the NEMO basic support protocol and partially distributed network-based DMM framework in providing seamless data transmission and robust mobility support. The E2E seamless data transmission scheme allows mobile users to roam from fixed-point network access locations and mobile platforms (i.e., vehicles such as cars, buses, and trains) without disconnecting its current sessions (i.e., seamless handover).