• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.682-685
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• 2011

An engine oil sensor based on multiwall carbon nanotubes was fabricated with screen printing method. Since carbon nanotubes are generally intertwined, dispersion of the carbon nanotubes in the binding agent (ethyl cellulose, a-terpineol, frit) is a key factor for large yield of engine oil sensor. By conventional dispersion method, a hand-mill method, the maximum yield was 80% at most. However, we used the hand ultrasonic, in order to increase the yield of the sensors. As a results, our engine oil sensor fabricated by the screen printing method shows excellent yield rate of 97%, when we dispersed a paste by the hand ultrasonic method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.41-47
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• 2012

In this paper, we proposed a new method which analyzes and eliminates errors occurring by multi-reflection of ultrasonic firing in mobile robot application. This new method allows ultrasonic sensors to fire at rates that are three times faster than those customary in conventional applications readings due to ultrasonic noise disturbance. It is possible them to collect and predict sensor data much faster than conventional methods. Furthermore, this method's capability allows mobile robot to navigate in a complex and unknown environment and to collaborate in the same environment with multiple mobile robot, even if their ultrasonic sensors operate. And it's usefulness to avoid moving obstacles by capability of rapid collecting data. Finally, we present experimental results that demonstrate the performances of the new proposed method by experiments in a multi-reflective environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.96-100
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• 2010

In this paper we present a position tracking system that checks the locations of moving targets in real-time. The system confirms that unknown object invades in watch area using 2 infrared sensors and detect the distance from each sensor to object using 4 ultrasonic sensors, and calculate the position of moving object in x-y coordinate. We specially present an algorithm that decide the location of target in case of target is detected in 2 sensors because of radiation beam width of ultrasonic sensor. We established the algorithm to hardware system and tested the system within a laboratory, and confirmed that the designed system tracked an object exactly in real-time.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1227-1232
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• 2017

In this study, we have studied a system to reduce the inconvenience and the accident rate at the intersection when the visually impaired use traffic information by using pressure sensor and ultrasonic sensor. By using the pressure sensor to light the strip LED, the driver recognizes the pedestrian, thereby reducing the accident rate. In addition to the pedestrian signal light information, the ultrasonic sensor and Bluetooth transmit the bus position information to the application so that the user can listen to the voice.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.247-252
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• 2013

An intelligent light emitting diode (LED) dimming system is designed and implemented for energy-saving lighting systems. An LED light bulb is powered by an LED driver controlled by a microcontroller using pulse width modulation (PWM) signals. By changing the duty cycle of the PWM signals, the LED driver generates a driving current of up to 1,000 mA. The current consumption by the LED light bulb exhibits a very linear characteristic that indicates that the level of LED dimming can be finely tuned. Multiple sensors-lighting intensity and ultrasonic range sensors-are combined with the LED dimming system to realize an automatically controllable LED lighting system. The light intensity sensor is capable of sensing ambient light. The ultrasonic range sensor can detect objects from 0.15 to 5.6 m at a resolution of 0.0254 m. The collected information by the light intensity and ultrasonic range sensors is processed by the microcontroller that in turn automatically controls the brightness of the LED light bulb. The algorithm of the software for the LED dimming system is also described.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.411-413
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• 2002

In this paper we researched about the ultrasonic cane which aids the blind to walk. We used ultrasonic in recognizing the object and implemented pulse counting method in measuring the distance. The distance measuring system consists of transmitter unit, receiver unit and micro-processor. We used broadband ultrasonic sensors in transmitter unit and receiver unit. The blind is able to recognize the distance between obstacles and himself as it used a vibration system.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.1-10
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• 1996

In this paper, describe the automatic climbing wheelchair system use an articulated crawler mobile robot. This wheelchair system(call system) is composed of sensor detecting part and wireless communication part with PC. The sensor parts are consisted of sloping sensor and ultrasonic sensor part. The sloping sensor measures the sloping angle of system, and the ultrasonic sensor measures the distance of system's front wheel center from stair. PC will generate the operation data to climb up the stair using the measured data and make primitives for the system. At firsts This system transfer from sensor data to the PC. PC calculate the operation data to climb up the stair from the internal algorithm. We simulated the system in various stair angle slope($25^{\circ}$, $30^{\circ}$, $45^{\circ}$), and tested it on the real staircase with width 37cm, highlt 18cm, Angle $26^{\circ}$ . There were $0.350^{\circ}$ - $1.060^{\circ}$ Angle errors while climbing because adapted sensor has a precision $0.35^{\circ}$ in resolution. Finally, We implemented the sensor detecting part and the wireless communication park and practiced our system in 4cm/sec speed.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.595-597
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• 2004

In this paper range measurement systems using ultrasonic and visual sensors are designed. By varying the focus of a camera, the range to a target pattern is computed. Pour different methods are tested for the focusing-based range measurement. The best result is obtained when counting edge pixels found by Laplacian operator. Higher accuracy can be obtained by fusing the measurement of camera focusing with that of ultrasonic sensor. The system designed is experimented within the range of 300-450mm.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.119-124
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• 1993

This paper describes a method of producing maps of an indoor environment with an autonomous mobile robot equipped with sonar array. This method uses the certainty grid suitable for accommodation of inaccurate sensor data and real-time navigation. Each grid contains a certainty vale that indicates the measure of confidence that an obstacle exists within th grid area. The scheduled firing method is used to eliminate the crosstalk between ultrasonic sensors. The effectiveness of the method is verified by a series of experiments.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1484-1486
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• 2001

In this study, The underwater object recognition using ultrasonic sensor fabricated with porous PZT-Polymer 3-3 type composites and invariant moment vector and SOFM(Self Organizing Feature Map) neural networks are presented. The recognition rates for the training data and the testing data were 98% and 94%, respectively.