• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권9호
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• pp.2173-2193
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• 2013

In order to reduce the distribution cost of sensor nodes, a mobile sensor deployment has been proposed. The mobile sensor deployment can be solved by finding the optimal layout and planning the movement of sensor nodes with minimum energy consumption. However, previous studies have not sufficiently addressed these issues with an efficient way. Therefore, we propose a new deployment approach satisfying these features, namely a tree-based approach. In the tree-based approach, we propose three matching schemes. These matching schemes match each sensor node to a vertex in a rake tree, which can be trivially transformed to the target layout. In our experiments, the tree-based approach successfully deploys the sensor nodes in the optimal layout and consumes less energy than previous works.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.33-37
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• 2008

The evidence of the Cargo tank volume is very important between Buyer and Seller for agreement each other for LNG Ship. CTS(Custody Transfer System) Radar type level gauging sensor to be measured for cargo volume. The data of Trim & List sensor to be compensated for measuring data which is original data of the CTS sensor. The latest days, the Buyer would have posed a problem both the location and the accuracy of trim/list sensor specially neared final stage of the ship's delivery. So, we would like to report the introducing to the trim/list sensor and the confirmation of actual location for the trim/list sensor.

• 한국인터넷방송통신학회논문지
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• 제12권1호
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• pp.239-243
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• 2012

본 논문에서는 전기 저항식 수분 측정 방식을 선택한 토양수분센서를 제안하였다. 이 방식은 토양내의 수분량에 따라 저항의 변화가 생기는 것을 전기적인 신호로 변환하여 토양수분량과의 관계를 비교하여 수분량을 측정하는 방식으로 방법이 간단하며 저렴한 비용으로 간단하게 장치를 구현하였으며, 시리얼통신을 이용하여 여러 개의 센서를 하나의 네트워크에 묶어 사용하였다. 이 센서 네트워크를 사용하여 IMS(Internet Management System)에 적용하였으며, 센서 네트워크가 웹에서도 잘 작동함을 보였다.

• ETRI Journal
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• 제35권4호
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• pp.617-624
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• 2013

Low power consuming and highly responsive semiconductor-type microelectromechanical systems (MEMS) gas sensors are fabricated for real-time environmental monitoring applications. This subsystem is developed using a gas sensor module, a Bluetooth module, and a personal digital assistant (PDA) phone. The gas sensor module consists of a $NO_2$ or CO gas sensor and signal processing chips. The MEMS gas sensor is composed of a microheater, a sensing electrode, and sensing material. Metal oxide nanopowder is drop-coated onto a substrate using a microheater and integrated into the gas sensor module. The change in resistance of the metal oxide nanopowder from exposure to oxidizing or deoxidizing gases is utilized as the principle mechanism of this gas sensor operation. The variation detected in the gas sensor module is transferred to the PDA phone by way of the Bluetooth module.

• 센서학회지
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• 제21권2호
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• pp.121-126
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• 2012

Piezoresistive type contact force sensor array is fabricated by (111) Silicon bulk micromachining for continuous blood pressure monitoring. Length and width of the unit sensor structure is $200{\mu}m$ and $190{\mu}m$, respectively. The gap between sensing elements is only $10{\mu}m$. To achieve wafer level packaging, the sensor structure is capped by PDMS soft cap using wafer molding and bonding process with $10{\mu}m$ alignment precision. The resistance change over contact force was measured to verify the feasibility of the proposed sensor scheme. The maximum measurement range and resolution is 900 mm Hg and 0.57 mm Hg, respectively.

• 전기학회논문지
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• 제57권8호
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• pp.1371-1376
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• 2008

A Steer-by-Wire system has so many advantages comparing with conventional mechanical steering system that it is expected to take key role in future environment friendly vehicle and intelligent transportation system. The mechanical connection between the hand wheel and the front axle will become obsolete. SBW system provides many benefits in terms of functionality, and at the same time present significant challenges - fault tolerant, fail safety - too. In this paper, failure analysis of SBW system will be performed and than sensor fusion technique will be proposed for fail safety of SBW system. A sensor fusion logic of steering angle sensor by using steering angle sensor, torque sensor and rack position sensor will be developed and simulated by fault injection simulation.

• 전기학회논문지
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• 제57권4호
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• pp.686-691
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• 2008

This paper proposes the concept of "virtual sensor data" and its application for real time obstacle avoidance. The virtual sensor data is virtual distance which takes care of the movement of the obstacle as well as that of the robot. In practical application, the virtual sensor data is calculated from the odometry data and the range sensor data. The virtual sensor data can be used in all the methods which use distance data for collision avoidance. Since the virtual sensor data considers the movement of the robot and the obstacle, the methods utilizing the virtual sensor data results in more smooth and safer collision-free motion.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.360-361
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• 2006

This paper describes a wire and wireless network sensor for temperature and humidity measurements. The network sensor comprises PLC(Power Line Communication) and RF transmitter(433MHz) for acquiring an internal (on-board) sensor signal, and measured data is transmitted to a main processing unit. The network sensor module is consist of MEMS sensor, 10-bit A/D converter, pre-amp., gain-amp., ADUC812 one chip processor and PLC/RF transmitting unit. The temperature and humidity sensor is based on MEMS piezoelectric membrane structure and is implemented by using dual function sensor for smart home and smart building.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.525-543
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• 2010

Testing and validation processes are critical tasks in developing a new hardware platform based on a new technology. This paper describes a series of experiments to evaluate the performance of a newly developed MEMS-based wireless sensor node as part of a wireless sensor network (WSN). The sensor node consists of a sensor board with four accelerometers, a thermometer and filtering and digitization units, and a MICAz mote for control, local computation and communication. The experiments include calibration and linearity tests for all sensor channels on the sensor boards, dynamic range tests to evaluate their performance when subjected to varying excitation, noise characteristic tests to quantify the noise floor of the sensor board, and temperature tests to study the behavior of the sensors under changing temperature profiles. The paper also describes a large-scale deployment of the WSN on a long-span suspension bridge, which lasted over three months and continuously collected ambient vibration and temperature data on the bridge. Statistical modal properties of a bridge tower are presented and compared with similar estimates from a previous deployment of sensors on the bridge and finite element models.

• 대한임베디드공학회논문지
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• 제6권2호
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• pp.68-75
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• 2011

This paper describes the development of an open source motion sensor emulator. It helps developers to understand the motion sensor and its data better. Through this emulator, the realtime or stored motion sensor data can be applied to the applications that utilize motion sensors. The data of motion sensors which include accelerometer sensor, magnetic field sensor, gyro sensor, GPS, and so on, can be collected by using smart phones or motion sensors. We also describe a visualizer which shows various graphs, video and 3D animations based on the data sent by the emulator. It helps developers to understand motion sensors and how to use the sensors. The developed emulator is compatible with Android sensor simulator.