• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1988-1998
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• 2008

Performed was a survey to find the level of interest on passenger services using IT and smart sensor technology in connection with High Speed Train development in Korea. The survey respondents were sampled from the KTX passengers, KTX crews, Korail employees, IT or sensor experts, and rolling stock experts. The results of the survey were categorized as importance, urgency/necessity, importance vs urgency/necessity, improvement measure, preferable activities based on the trip length, and inconveniencies. By analyzing the results, service items that can be implemented to the High Speed Train were recognized. The results showed that a passenger tends to expect to have his/her comfort and convenience, an attendant safety and serviceability, a Korail employee information provision and serviceability, an IT/sensor expert technological implementation done, and a rolling stock expert implementation done in practical level.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.2
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• pp.113-118
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• 2011

In this paper, we develop a speaker gender classification technique using collaborative sensor fusion for use in a wireless sensor network. The distributed sensor nodes remove the unwanted input data using the BER(Band Energy Ration) based voice activity detection, process only the relevant data, and transmit the hard labeled decisions to the fusion center where a global decision fusion is carried out. This takes advantages of power consumption and network resource management. The Bayesian sensor fusion and the global weighting decision fusion methods are proposed to achieve the gender classification. As the number of the sensor nodes varies, the Bayesian sensor fusion yields the best classification accuracy using the optimal operating points of the ROC(Receiver Operating Characteristic) curves_ For the weights used in the global decision fusion, the BER and MCL(Mutual Confidence Level) are employed to effectively combined at the fusion center. The simulation results show that as the number of the sensor nodes increases, the classification accuracy was even more improved in the low SNR(Signal to Noise Ration) condition.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.201-206
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• 2022

In this paper, a flushing system with automatic opening and closing function of the toilet cover was studied. It works by an infrared sensor attached to the cover is detected or not. When the infrared sensor of the open function detects it, the servomotor is driven on the toilet cover to raise the cover, and when the infrared sensor with the close function detects the infrared sensor, the cover is set to be lowered. A tilt sensor is attached to the inside of the cover to operate when the cover goes down, and when this is activated, the servomotor connected to the toilet lever opens the stopper of the supply port and sends water down. In addition, we minimized the inconveniences for the next user when they use the toilet by using the non-contact water level sensor and LED function to notice the water is clogged during the flushing process. Also, we implemented UV-LED function to prevent bacterial growth while the toilet is closed.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.668-671
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• 2004

This paper proposes a new method of sensor fusion of an ultrasonic sensor and a vision sensor at the sensor level. In general vision system, the vision system finds edges of objects. And in general ultrasonic system, the ultrasonic system finds absolute distance between robot and object. So, the method integrates data of two different types. The system makes perfect output for robot control in the end. But this paper does not propose only integrating a different kind of data but also fusion information which receives from different kind of sensors. This method has advantages which can simply embody algorithm and can control robot on real time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.747-752
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• 2008

Fiber-guided sensor system using a generator and a receiver can detect the amplitude of load or pressure. However, this type of sensor can show some difficulties in detecting the location of damages and pressure loadings. To overcome this weakness of this type, the ultrasonic active fiber sensor, which has an integrated ultrasonic generator and sensing part, was developed in this study. By using this sensor system, the location of mechanical loads can be exactly detected. Moreover, the ultrasonic active fiber sensor is more cost-effective than an ultrasonic fiber sensor using two piezoelectric transducers which are used as a generator and a receiver, respectively. Two applications of the ultrasonic active fiber sensor are demonstrated: cure monitoring of lead and measurement of liquid level. Present results showed that the active fiber sensor can be applied for various environmental sensing.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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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.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.107-111
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• 2022

In this paper, a plastic film type submersion sensor capable of measuring submersion speed was developed. This submersion sensor is designed as a capacitive type, and it is a sensor that outputs the change in capacitance between the electrode of the submersion sensor and the grounded body as a voltage through a C-V(capacitance-voltage) converter. We developed an submersion sensor in which two electrodes of different lengths are connected in parallel to measure the submersion speed accurately by minimizing the influence of noise such as contamination. When both electrodes of the submersion sensor are exposed to water, the rate of change of water level suddenly increases, so the submersion speed is measured by measuring the time to this point. Since the difference in length between the two electrodes of the submersion sensor does not change in any case, it is possible to accurately measure the submersion speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.174-183
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• 2008

In this paper we design and implement a sensor network management framework(SNMF) for ubiquitous sensor networks(USNs). The SNMF employs the policy-based management approach for the autonomous and energy-efficient management of USNs. Moreover, a new light-weight policy distribution protocol called TinyCOPS-PR is designed and USN PIB for low-level policy is also defined. This allows the high-level policies defined by an administrator to translate into the specific low-level policies. The low-level policies are executed on sensor nodes so it can fulfill the proper management actions. The sensor nodes that receive some policies from an administrator perform local management actions according to those policies. SNMF can therefore realize small energy consumption and bring long network lifetime. It can also manage USNs automatically with a minimum of human interference.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.93-98
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• 2023

As semiconductor devices become highly integrated and process difficulty increases, the need for highly sensitive sensors that can detect micro leaks is increasing. However, the noise contained in the CCD sensor itself acts as an obstacle to detecting fine leaks. In this study, integration time was changed for each condition, the sensor was cooled to 0℃, and the dark voltage level was measured to confirm through experiment the characteristics of the temporal noise included in the CCD sensor, a component of OES (Optical Emission Spectroscopy). When integration time was reduced from 30msec to 10msec, the dark voltage level decreased by about 20.5 % from an average of 151.5mV to 120.5mV. In the case of cooling device, Peltier elements were selected because of their simple structure and small size. During temperature cooling, the target temperature was controlled to within ±0.5℃ through PID control. When cooled from 20℃ to 0℃ using this cooling device, it was confirmed that the dark voltage level decreased by about 7% from an average of 147.0mV to 137.0mV.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1316-1321
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• 1990

Molten steel level information of ladle is very important for process control in steelmaking process. At secondary refining process, measuring lance and snokel have to keep constant thier depth from molten steel surfaces. But, there is much slag on the molten steel surface. Besides, not only the thickness of slag is varied with refining condition, but also molten steel level is largely affected by firebrick errosion. Then, optical measuring method and/or by human eyes cannot detect true molten steel surface, but slag surface. This slag thickness is 300mm at maximum, then huge diameter eddy current sensor will be needed if that type sensor is applied. In addition to, cooling system is necessary because the molten steel and slag temperature is high. This is not practically. To solve this problem, immersion type levelmeter is developed. This sensor is made up from primary and secondary cylindrical coils. High frequency current is applied to primary coil. Electro-motive force from secondary coil is measured, which is varied with molten steel level. This complete set is installed within stainless steel long capsule and attached to top of lance. This sensor is immersed into molten steel bath of ladle or tundish with protection of expendable paper sleeve.