• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.176-180
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• 2007

In this study, we deployed the cable tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway can be applied to cable tunnel monitoring system. Sensors considered herein are flame detection sensor, flood detection sensor, intruder detection sensor, and temperature sensor, etc. It is also found that the wireless sensor network can deliver sensing data reliably by wireless sensing technology. The gateway system that can transmit sensed data to server by CDMA is developed. Monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. The system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system is infeasible.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.549-552
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• 2008

In this study, we deployed the cable tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway can be applied to cable tunnel monitoring system. Sensors considered herein are flame detection sensor, flood detection sensor, intruder detection sensor, and temperature sensor, etc. It is also found that the wireless sensor network can deliver sensing data reliably by wireless sensing technology. The gateway system that can transmit sensed data to server by CDMA is developed. Monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. The system provides an alternative to inspecting and monitoring the tunnel efficiently where the conventional wired system is infeasible.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.128-135
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• 2000

This paper presents a polishing expert system integrated with sensor information which can modify the polishing sequence and conditions initially determined by the system depending on the on-site polishing status. A practical system using AE sensor to detect the on-line polishing status is developed for the rotational polishing and the smoothly curved sur-face. Database and knowledge base for polishing processes are established by using the results of experiments and also expert's experience. Evaluations are performed for a die of headlight lamp by using both the sensor integrated expert sys-tem and the expert system without sensor. The test results show that the sensor integrated expert system provides more optimal polishing conditions since the proposed system takes advantage of on-line sensor information.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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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.

• Journal of Sensor Science and Technology
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• v.23 no.5
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• pp.310-313
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• 2014

We report a way to improve the ability of graphene to operate as a gas sensor by applying single stranded deoxyribonucleic acid (DNA). The sensitivity and recovery of the DNA-graphene sensor depending on the different DNA sequences are analyzed. The different sensor responses to reactive chemical vapors are demonstrated in the time domain. Because of the chemical gating effect of the deposited DNA, the resulting devices show complete and rapid recovery to baseline unlike the bare graphene at room temperature. The application of the pattern recognition technique can increase the potential of DNA-graphene sensors as a chemical vapor classifier.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.425-430
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• 2015

The Sensor Registry System(SRS) provides sensor metadata to a user for instant use and seamless interpretation of sensor data in a heterogeneous sensor network environment. The existing sensor registry system cannot provide sensor metadata in case that the network connection is not available or is unstable. To resolve the problem, this paper proposes an extension of sensor registry system using network coverage information. The extended system sends a set of sensor metadata to the user by using network coverage open data (mobile vendors, signal strength, communication type). The extended SRS proposed in this paper supports a safer sensor metadata provision than the existing SRS, and it thus improves the quality of application services.

• Journal of Mechanical Science and Technology
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• v.15 no.10
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• pp.1369-1379
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• 2001

This paper focuses on a development of a sensor system measuring locations of a vehicle to localize a mobile robot while it tracks on the track (location sensor) . Also it focuses on a system configuration identifying the vehicle's orientation and distance from the object while it is stationary at certain station (position sensor) . As for the location sensor it consists of a set of sensors with a combined guiding and counting sensor, and an address-coded sensor to localize the vehicle while moving on the rail. For the position sensor a PSD (Position Sensitive Device) sensor with photo-switches sensor to measure the offset and orientation of the vehicle at each station is introduced. Both sensor systems are integrated with a microprocessor as a data relay to the main computer controlling the vehicle. The location sensor system is developed and its performance for a mobile robot is verified by experiments. The position measuring system is proposed and is robust to the environmental variation. Moreover, the two kinds of sensor systems guarantee a low cost application and high reliability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.998-1013
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• 2013

Wireless wearable sensor networks have emerged as a promising technique for human motion tracking due to the flexibility and scalability. In such system several wireless sensor nodes being attached to human limb construct a wearable sensor network, where each sensor node including MEMS sensors (such as 3-axis accelerometer, 3-axis magnetometer and 3-axis gyroscope) monitors the limb orientation and transmits these information to the base station for reconstruction via low-power wireless communication technique. Due to the energy constraint, the high fidelity requirement for real time rendering of human motion and tiny operating system embedded in each sensor node adds more challenges for the system implementation. In this paper, we discuss such challenges and experiences in detail during the implementation of such system with wireless wearable sensor network which includes COTS wireless sensor nodes (Imote 2) and uses TinyOS 1.x in each sensor node. Since our system uses the COTS sensor nodes and popular tiny operating system, it might be helpful for further exploration in such field.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.103-109
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• 2015

This paper introduces a multi-purpose smart fusion sensor. Normally, this type of sensor can contribute to energy savings specifically related to lighting and heating/air conditioning systems by detecting individuals in an office building. If a fire occurs, the sensor can provide information regarding the presence and location of residents in the building to a management center. The system consists of four sensors: a thermopile sensor for detecting heat energy, an ultrasonic sensor for measuring the distance of objects from the sensor, a fire detection sensor, and a passive infrared sensor for detecting temperature change. The system has a wireless communication module to provide the management center with control information for lighting and heating/air conditioning systems. We have also demonstrated the usefulness of the proposed system by applying it to a real environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1861-1868
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• 2008

In this paper, Passive Telemerty RF Sensor System using Unscented Kalman Filter algorithm(UKF) is proposed. General Passive Telemerty RF Sensor System means that it should be "wireless", "implantable" and "batterless". Conventional Passive Telemerty RF Sensor System adopts Integrated Circuit type, but there are defects like complexity of structure and limit of large power consumption in some cases. In order to overcome these kinds of faults, Passive Telemetry RF Sensor System based on inductive coupling principle is proposed in this paper. Because passive components R, L, C have stray parameters in the range of high frequency such as about 200[KHz] used in this paper, Passive Telemetry RF Sensor System considering stray parameters has to be derived for accurate model identification. Proposed Passive Telemetry RF Sensor System is simple because it consists of R, L and C and measures the change of environment like pressure and humidity in the type of capacitive value. This system adopted UKF algorithm for estimation of this capacitive parameter included in nonlinear system like Passive Telemetry RF Sensor System. For the purpose of obtaining learning data pairs for UKF Algorithm, Phase Difference Detector and Amplitude Detector are proposed respectively which make it possible to get amplitude and phase between input and output voltage. Finally, it is verified that capacitive parameter of proposed Passive Telemetry RF Sensor System using UKF algorithm can be estimated in noisy environment efficiently.