• 소음진동
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• 제8권6호
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• pp.1121-1129
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• 1998

This research is concerned with the multiple PPF and the modified LQG controller design for active vibration control of intelligent structures. The intelligent structure is defined as the structure equipped with smart actuators and sensors. Various control techniques aimed for the piezoceramic sensors and actuators have been proposed for the active vibration control of smart structures and some of them prove their effectiveness experimentally. In this paper, the multiple PPF controller and the modified LQG controller are developed and applied to the smart grid structure. The multiple PPF control and the modified LQG control can be classified as the classical and the modern control techniques. respectively. The experimental results show that both control techniques are effective in suppressing vibrations. Two control techniques are compared with respect to the design process. the ease of implementation and the effectiveness

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.505-512
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• 2005

MR damper is one of the most promising control devices for civil engineering applications to earthquake hazard mitigation. However, a control system including a power supply, controller, and sensors is required to maximize the performance of the MR damper and this complicated control system is not effective to most of large civil structures. This paper proposes and experimentally verified a smart passive damping system using MR(Magnetorheological) dampers by introducing electromagnetic induction(EMI) system as an external power source to MR damper. It is easy to build up and maintain EMI system, because it does not require any control system such as a power supply, controller, and sensors. Numerical simulations using experimental model of EMI system are carried to verify the effectiveness of the proposed EMI system. The performances of smart passive damping system are compared with those of passive and semiactive MR dampers.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1201-1208
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• 2008

Ubiquotuous technology should be adopted in railroad business to provide passenger's security and convenience. In this project, IT and smart sensor technologies are reviewed, benchmarked, designed, and implemented. The target system is the next generation high speed train to be developed and operated in Korea with the maximum speed of 400km/h. Wireless sensor network with smart sensors is implemented around a train car. PC-like IT terminal will be designed and implemented so an individual passenger can use it to do information retrieval through the Internet, personal data processing, the e-learning, shopping on the railroad, and so on. These provision will give comfort, convenience, and safety of a passenger during his/her trip.

• 전기학회논문지P
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• 제64권2호
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• pp.50-56
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• 2015

This paper presents a smart monitoring technique for photovoltaic power systems by using wire and wireless communication networks in which the RS-232/484 and the Zigbee communication networks are inherently established respectively. In the proposed monitoring systems, environmental data sequences and the output power measured by sensors in photovoltaic systems are transferred to PC systems via two communication networks. We made electronic hardware boards for sensors and communication networks to construct its real-time monitoring system and carry out experiments for demonstrating reliability of the proposed monitoring system.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.9-17
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• 2023

Recently, IoT technology has been widely used in many industries. Also research on integrating IoT technology with IoT sensors is actively underway. One of the important challenges in IoT is to support low-latency communication. With the development of communication networks and protocols, a variety of protocols are being used, and their performance is improving. In this paper, we compare the performance and analyze the characteristics of some of the major communication protocols in IoT application, namely MQTT, HTTP, and HTTPS. IoT sensors acquired data by connecting an Arduino equipped with ESP8266 and a temperature and humidity sensor (DHT11). The server measured the performance by building servers for each protocol using AWS EC2. We analyzed the packets transmitted between the Arduino and the server during the data transmission. We measured the amount of data and transfer time. The measurement results showed that MQTT had the lowest data transmission time and data amount among the three protocols.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1321-1326
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• 2000

This paper is concerned with the making of smart structrures by means of piezoceramic wafers and its performance tests. It is also concerned with the implementation of the PPF controller by using the quad operational amplifier, which includes the charge and bridge amplifiers. The problems regarding the implementation of the piezoceramic sensors and actuators are discussed. The experimental process for smart structures is explained in detail. The technology demonstration which can show the effectiveness of smart structure technology is built up. Experimental results will follow.

• 한국정밀공학회지
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• 제28권2호
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• pp.176-184
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• 2011

As modern megalopolises become more complex and huge, convenience and safety of citizens are main components for a welfare state. In order to make safe society, telemetrics technology, which remotely measures the information of target system using electronic devices, is an essential component. In general, telemetrics technology consists of USN (ubiquitous sensor network) based on a wireless network, smart sensor, and SoC (system on chip). In the smart sensor technology, the following two problems should be overcome. Firstly, because it is very difficult for transducer manufacturers to develop smart sensors that support all the existing network protocols, the smart sensor must be independent of the type of networking protocols. Secondly, smart sensors should be modular so that a faulty sensor element can be replaced without replacing healthy communication element. To solve these problems, this paper investigates the feasibility of an IEEE 1451 based ZigBee smart sensor system. More specifically, a smart sensor for large network coverage has been developed using ZigBee for active telemetrics.

• 스마트미디어저널
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• 제12권3호
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• pp.120-128
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• 2023

산업재해로 인한 피해를 줄이기 위해 다양한 ICT 기술이 지속적으로 개발되고 있으며, 센서, IoT, 빅데이터, 머신러닝 및 인공지능 등을 활용하여 산업재해 발생 시 피해를 최소화하고자 하는 연구가 진행되고 있다. 본 논문에서는 산업 현장의 밀폐구간, 산악, 해양, 탄광 등의 통신 음영지역에서 디바이스 간 다자간 통신 및 스마트 중계기와의 통신이 가능한 스마트 디바이스의 설계 방안을 제안한다. 제안된 스마트 디바이스는 작업자 위치, 이동 속도 등 작업자 정보와 지형, 풍향, 온도, 습도 등 환경정보를 수집하고 작업자 상호 간의 안전거리를 확보하여 위험 상황 발생 시 경고가 가능하며 헬멧에 부착할 수 있도록 설계하였다. 이를 위해, 스마트 디바이스에 필요한 기능적 요구사항과 스마트 디바이스 내의 센서와 모듈을 이용하여 요구사항을 구현하기 위한 설계 방안과 스마트 디바이스의 성능평가를 위한 지표를 도출하고 산악지역에서의 성능평가를 위한 평가환경을 제안한다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.124-127
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• 2000

In this study, a technique for monitoring of fatigue damage of composite laminates by measuring the stiffness change using embedded intensity-based optical fiber sensors was investigated. Firstly, the underlying measurement principle and structure of intensity-based sensors and then a simple stiffness conversion process was explained. The monitoring technique was evaluated by fatigue tests of composite laminates with an embedded intensity-based sensor. From the test results, the response of the intensity-based sensor showed good correlation with that of surface mounted extensometer. Therefore, it can be concluded that the intensity-based sensors have good potential for the monitoring of fatigue damage of composite structures under fatigue loading. In addition, it could be confirmed that the intensity-based sensors have higher resistance to fatigue than the commercial electrical strain gauge.

• 정보와 통신
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• 제30권10호
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• pp.79-85
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• 2013

By interacting with external wireless sensors, smartphones can gather high-fidelity data on the surrounding environment to develop various environment-aware, personalized applications. In this work we introduce the sensor virtualization module (SVM), which virtualizes external sensors so that smartphone applications can easily utilize a large number of external sensing resources. Implemented on the Android platform, our SVM simplifies the management of external sensors by abstracting them as virtual sensors to provide the capability of resolving conflicting data requests from multiple applications and also allowing sensor data fusion for data from different sensors to create new customized sensors elements. We envision our SVM to open the possibilities of designing novel personalized smartphone applications.