• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.155-161
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• 2005

Up to now, a lot of unmanned demining systems have been developed. However, some inferiority surely exist by reason of their large platform and explosive mechanism. To settle this inferiority, non-explosive demining system adaptable to a mobile robot already has been developed. Brief experiment indoors showed that developed demining system can remove landmines well. But, out of doors, several problems are detected. In this research, a study on the performance improvement of developed non-explosive demining system is mainly discussed. To overcome downhill effect, mechanical sensor composed of shaft and spring is used. It is confirmed that clearance depth control using the mechanical sensor is a good solution for the inclination of the system.

• Journal of Industrial Technology
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• v.30 no.B
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• pp.55-59
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• 2010

The number of elderly people living alone increases with the trend of nuclear family in recent aging society and advances of health and medical technologies, where the safety of the elderly people becomes a big social issue. One of the safety system for them these days is that security guards regularly visit homes of the elderly living alone to check their safety. However, it is an inefficient system since it costs a great deal. So, a new efficient system with low cost using modern advanced technologies needs to be developed. In this paper, we implement a monitoring system for elderly living alone using ubiquitous sensor and zigbeX. The system can remotely determine the health status of elderly people and report to their hospitals. Since the system can be implemented with low cost and do the same job as security guards do, we expect that it should replace the existing expensive monitoring system.

• Journal of Sensor Science and Technology
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• v.14 no.6
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• pp.444-454
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• 2005

The IEEE 1451.4 standards defines an architectural model for interfacing smart transducers for sensors & actuators. This standard allows analogue transducers to communicate their identification and calibration data in a digital format. A digital format is called the TEDS (transducer electronic data sheet). However, the standard template TEDS of IEEE 1451.4 do not supports sensors to use in electronic tongue system, such as arrayed-potentiometric and voltametric sensors. In this paper, a solution to standardize sensors for E-Tongue (electronic tongue) and electronic tongue systems is presented.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.676-682
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• 2011

Sybil attack can disrupt proper operations of wireless sensor network by forging its sensor node to multiple identities. To protect the sensor network from such an attack, a number of countermeasure methods based on RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) have been proposed. However, previous works on the Sybil attack detection do not consider the fact that Sybil nodes can change their RSSI and LQI strength for their malicious purposes. In this paper, we present a Sybil attack detection method based on a transmission power range. Our proposed method initially measures range of RSSI and LQI from sensor nodes, and then set the minimum, maximum and average RSSI and LQI strength value. After initialization, monitoring nodes request that each sensor node transmits data with different transmission power strengths. If the value measured by monitoring node is out of the range in transmission power strengths, the node is considered as a malicious node.

• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.265-271
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• 2005

In this study, a variable capacitive pressure sensor is fabricated for TPMS (Tire Pressure Monitoring System). This study is for developing sensors which consecutively measure the tire pressure given as 30 psi from the industrial standard. For improving non-linearity of the prior capacitive pressure sensors, it is suggested that touch mode capacitive pressure sensor be applied. In addition, initial capacitance is designed as small as possible for the conformity to the wireless sensor. ANSYS, commercial FEA package, is used for designing and simulating the sensor. The device is progressed by MEMS (Micro Electro Mechanical Systems) fabrication and packaged with PDMS. The result is obtained sensitivity, 1 pF/psi, through a pressure test. The simulation result is discrepant from experiment one. Wafer's uniformity is presumed as the main reason of discrepancy.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.127-134
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• 2012

Stroke patients must do the rehabilitation exercise to recover their fingers' function using a rehabilitation robot. But the rehabilitation robots mostly have not the force sensors to control the applied force to each finger. Thus, in this paper, the development of a force sensor for thumb rehabilitation robot and four two-axis force sensors for four-finger rehabilitation robot were developed. The force sensor and four two-axis force sensors could be used to measure the applied force to each finger, and the forces could be used to control the applied forces to each sensor in rehabilitation exercise using in the rehabilitation robot. The developed sensors have non-linearlity error of less than 0.05 %, repeatability error of less than 0.03 %, and the interference error of two-axis force sensor is less than 0.2 %.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.141-145
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• 2008

Wireless sensor network (WSN) is expected to be used in many applications. However, sensor nodes still have some secure problems to use them in the real applications. They are typically deployed on open, wide, and unattended environments. An adversary using these features can easily compromise the deployed sensor nodes and use compromised sensor nodes to inject fabricated data to the sensor network (false data injection attack). The injected fabricated data drains much energy of them and causes a false alarm. To detect and drop the injected fabricated data, a filtering-based security method and adaptive methods are proposed. The number of different partitions is important to make event report since they can make a correctness event report if the representative node does not receive message authentication codes made by the different partition keys. The proposed methods cannot guarantee the detection power since they do not consider the filtering scheme. We proposed clustering method for filtering-based secure methods. Our proposed method uses fuzzy system to enhance the detection power of a cluster.

• Journal of Electrochemical Science and Technology
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• v.10 no.3
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• pp.294-301
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• 2019

The quasi-solid-state hybrid electrolytes were synthesized by chemical cross-linking reaction of methacrylate-functionalized $SiO_2$ ($MA-SiO_2$) and tetra (ethylene glycol) diacrylate in aqueous electrolyte. A quasi-solid-state electrolyte synthesized by 6 wt.% $MA-SiO_2$ exhibited a high ionic conductivity of $177mS\;cm^{-1}$ at room temperature. The electrochemical $H_2$ sensor assembled with quasi-solid-state electrolyte showed relatively fast response and high sensitivity for hydrogen gas at ambient temperature, and exhibited better durability and stability than the liquid electrolyte-based sensor. The simple construction of the sensor and its sensing characteristics make the quasi-solid-state hydrogen sensor promising for practical application.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.43-44
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• 2010

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.150-158
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• 2007

The IEEE 1451 publication are available, this standard defines interface between sensor and processor, and plug and play in processor is possible. Also, Intelligence of sensor was possible because sensor includes transducer electronic data sheet (TEDS). In IEEE 1451 standards, IEEE 1451.4 is suitable standard in single sensor, and IEEE 1451.2 is suitable standard in multi-sensors (array sensor). In this paper, apply IEEE 1451 to electronic tongue system. In the case of electronic tongue system, because array sensor is used, it is that complex and difficult to apply IEEE 1451.4 that is standard for single sensor. In this paper, apply IEEE 1451.2 for array sensor to design of electronic tongue system. Communication interface method of IEEE 1451.2 for electronic tongue system is presented, and implemented TEDS of electronic tongue system.