• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.247-253
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• 2011

In this paper, we propose and implement the automated brightness control system using distance measuring sensor for reducing the power consumption of emotional lighting device. In order to reduce the power consumption of emotional lighting devices which express continuous color changes, the proposed device measures the distance continuously using ultrasonic sensor and by using this, it also performs PWM Dimming control. The lighting device is composed of micro controller, LED driver, ultrasonic sensor, communication module and so on. And the device performs the real time brightness control by adapting the measured distance information from ultrasonic sensor to PWM signals. From this experiment, we implement the active lighting system which minimizes unnecessary power consumption during user's absence by adapting existing energy reducing techniques.

• Journal of Advanced Navigation Technology
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• v.23 no.4
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• pp.316-321
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• 2019

In this paper, by applying the constant current principle we develop an impedance measurement system which can measure the high precision impedance of various electric materials by using microprocessor. This measurement system board has an interface device for acquiring digital data from an external device including an impedance measuring device, and system software is also developed by a firmware program executed on such an embedded board. It can measure the high precision impedance of a specific band with 1/32768 precision by using 15-bit ADC(analog to digital converter) and calculate it to the five digits to the right of the decimal point(fraction part). Data is transmitted through a USB interface of a general computer and a measuring device to manage digital data. An impedance measurement system equipped with a communication function capable of a more general and easy-to-use interface than other equipment is developed and verified.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.191-198
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• 2022

The most basic thing to measure the condition of a companion animal is to check the breathing and pulse. There are several methods to measure the breathing and pulse of a companion animal, and the PPG method is generally used to measure the oxygen saturation (SpO₂) in a companion animal. However, since the input PPG signal is inputted with various information as well as oxygen saturation, it is necessary to separate and extract oxygen saturation information from the PPG signal in order to measure the oxygen saturation. Therefore, in this paper, a wearable measuring device for companion animals that can be measured by applying the PPG method was designed and implemented, and an algorithm for separating oxygen saturation information from the PPG signal input through the wearable measuring device was proposed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1615-1620
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• 2003

Kinematic calibration is a process whereby the actual values of geometric parameters are estimated so as to minimize the error in absolute positioning. Measuring all components of Cartesian posture, particularly the orientation, can be difficult. With partial pose measurements, all parameters may not be identifiable. This paper proposes a new device that can identify all kinematic parameters with partial pose measurements. Study is performed for a six degree-of-freedom fully parallel Hexa Slide manipulator. The device, however, is general and can be used for other parallel manipulators. The proposed device consists of a link with U joints on both sides and is equipped with a rotary sensor and a biaxial inclinometer. When attached between the base and the mobile platform, the device restricts the end-effector's motion to five degree-of-freedom and can measure position of the end-effector and one of its rotations. Numerical analyses of the identification Jacobian reveal that all parameters are identifiable. Computer simulations show that the identification is robust for the errors in the initial guess and the measurement noise. Intrinsic inaccuracies of the device can significantly deteriorate the calibration results. A measurement procedure is proposed and formulations of cost functions are discussed to prevent propagation of the inaccuracies to the calibration results.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.279-282
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• 2020

In this study, body pressure was quantitatively detected using built-in optical sensors, inside an air cushion seat. The proposed system visualizes the effect of the body pressure distribution on the air cushion seat. The built-in sensor is based on the time-of-flight (ToF) optical method, instead of the conventional electrical sensor. A ToF optical sensors is attached to the bottom surface of the air-filled cells in the air cushion. Therefore, ToF sensors are durable, as they do not come in physical contact with the body even after repeated use. A ToF sensor indirectly expresses the body pressure by measuring the change in the height of the air-filled cell, after being subjected to the weight of the body. An array of such sensors can measure the body pressure distribution when the user sits on the air cushion seat. We implemented a prototype of the air cushion seat equipped with 7 ToF optical sensors and investigated its characteristics. In this experiment, the ToF optical pressure sensor successfully identified the pressure distribution corresponding to a sitting position. The data were accessed through a mobile device.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.3
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• pp.97-106
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• 2000

This paper proposes on-line based a deterioration diagnosis device for diagnosis pole transformers using tan$\delta$ and FFT(fast Fourier transform). We measured tan$\delta$ and temperature to diagnose pole transformer insulating oil, diagnostic results are processed by FFT. For measuring convenience, we use R/F(radio frequency) wireless data communication module operating by secondary voltage of pole transformer. We have voltage variation test and oil temperature variation test to prove usability of proposed diagnosis device. The result of this paper shows that the proposed device can be used as deterioration diagnosis device of pole transformers.

• Journal of Information Processing Systems
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• v.6 no.3
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• pp.347-358
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• 2010

This paper presents a measurement system for 3D hand-drawn gesture motion. Many pen-type input devices with Inertial Measurement Units (IMU) have been developed to estimate 3D hand-drawn gesture using the measured acceleration and/or the angular velocity of the device. The crucial procedure in developing these devices is to measure and to analyze their motion or trajectory. In order to verify the trajectory estimated by an IMU-based input device, it is necessary to compare the estimated trajectory to the real trajectory. For measuring the real trajectory of the pen-type device, a PHANToMTM haptic device is utilized because it allows us to measure the 3D motion of the object in real-time. Even though the PHANToMTM measures the position of the hand gesture well, poor initialization may produce a large amount of error. Therefore, this paper proposes a calibration method which can minimize measurement errors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.689-694
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• 2016

The objective of this study is to identify the requirements for a energy metering device and develop a real-time energy metering device for measuring energy (electricity) consumption of the electric railway vehicle during its operation. The study also evaluated the performance of the AC voltage sensor, current sensor, and data meter for the device and performed EMC tests such as surge and EFT (Burst). The performance tests showed that the percent errors of the AC voltage sensor and current sensor were ${\leq}0.1%$, and ${\leq}0.5%$ under 10~127V, and 10~250A, respectively. The result of surge and EFT (Burst) tests also indicated that the device had no malfunction in any wave (combination and ring waves) under the treat level with 2kV. The result of the field test also confirmed that the device had no malfunction in data metering.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.59-66
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• 2006

In laser welding, automatic seam tracking is important to adjust the laser head position in real time as it moves along the seam. Also if the joint gap is occurred, filling the missing material into the joint gap is necessary to prevent welding defects and bad welding quality. In general, the joint gap width is not constant along the seam due to a variety of reason. So it is essential to control the filler wire speed into the joint gap to acquire good welding quality. This paper describes an intelligent filler wire feeding device which can control 3-dimensional seam tracking and the filler wire speed by measuring the gap position and the joint gap width in laser welding. We call this device as Smart Micro Control system(SMC). To achieve this objective, we assessed weld quality in 2mm sheets of A16061 which had various gap width by using the developed device. From the experimental results, It was found the possibility that the developed device could be used in welding various 3-dimensional structures.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.219-229
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• 2021

In this study, the new electrochemical cell device using Arduino and sensor was developed, and experiments of changes in voltage at the time of serial and parallel connection of electrochemical cells were conducted to verify the effectiveness of the device. In addition, in order to examine the educational effects of the device, student's inquiry activities of measuring voltage of electrochemical cells and making objects using the voltage difference were conducted. As a result, it was confirmed that the electrochemical device using Arduino and sensor could not only perform automatic measurements and visualize data but also have a possibility to seek various educational effects through easy coding and modification of the device. Based on the results of students' performance, it was found that experimental activities using the device impart a positive effect not only on the understanding of scientific concepts, but also on the development of the practical ability to apply scientific knowledges to the real life. Educational implications are discussed in terms of 'learning by making'.