• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.44-51
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• 2019

Objectives : Teaching the standardized acupuncture point locations and improving the accuracy of acupoint locations through objective evaluation is a very important part of Korean medicine education. The aim of this study is to develop a dummy system for evaluation and support of teaching acupoint location in meridian and acupoints classes and to introduce the developed system. Methods : We established a protocol for the development of the system. The protocol included definition of usage purpose, definition of its essential performance, and set of scope. The system compares the amount of light at the target acupoint with the amount of light at the other sites to determine whether the target acupoint is properly specificated. Results : A prototype of the system was built according to the protocol and consists of light emitter, dummy, control/operation, input part and output part. The light emitter projects laser beam passing through the skin of the dummy. Light sensors were attached inside the acupoints of the dummy. Three types of light sensors were selected depending on the location of the acupoints. The arithmetic, input, and output parts were constructed using Arduino and Raspberry pi boards. The developed system was applied in class. Conclusions : It is thought that the dummy system for evaluation and support of teaching acupoint location can be used as a training model in order to help teach standardized acupoint locations and objective evaluation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.717-723
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• 2020

Determination of local tie vectors between the space geodetic techniques such as VLBI (Very Long Baseline Interferometer), SLR (Satellite Laser Ranging), DORIS (Doppler Orbit determination and Radiopositioning Integrated on Satellite), GNSS (Global Navigation Satellite System) is essential for combination of ITRF (International Terrestrial Reference Frame). Therefore, it is required to compute IVP (Invariant Point) position of each space geodetic technique with high accuracy. In this study, we have computed Sejong VLBI IVP position by using updated mathematical model for adjustment computation so that the improvement on efficiency and reliability in computation are obtained. The measurements used for this study are the coordinates of reflective targets on the VLBI antenna and their accuracies are set to 1.5 mm for each component. The results show that the position of VLBI IVP together with its standard deviation is successfully estimated when they are compared with those of the results from previous study. However, it is notable that additional terrestrial surveying should be performed so that realistic measurement errors are incorporated in the adjustment computation process.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.183-194
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• 2020

Recently, the number of hip dysplasia (DDH) that occurs during infant and child growth has been increasing. DDH should be detected and treated as early as possible because it hinders infant growth and causes many other side effects In this study, two modelling techniques were used for multiple training techniques. Based on the results after the first transformation, the training was designed to be possible even with a small amount of data. The vertical flip, rotation, width and height shift functions were used to improve the efficiency of the model. Adam optimization was applied for parameter learning with the learning parameter initially set at 2.0 x 10e-4. Training was stopped when the validation loss was at the minimum. respectively A novel image overlay system using 3D laser scanner and a non-rigid registration method is implemented and its accuracy is evaluated. By using the proposed system, we successfully related the preoperative images with an open organ in the operating room

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.72-81
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• 2021

We developed smartphone application and web application server to acquire and effectively manage tree measurement information. Smartphone applications can measure tree height, diameter at breast height (DBH), azimuth, altitude, slope, and positional coordinates using augmented reality (Google AR core) and motion sensors. The web application server effectively manages and stores measurement information. To evaluate the accuracy of information acquired using a smartphone, 90 Korean pine trees (Pinus koraiensis) were randomly selected from a natural mixed forest, with a total of 90 representative trees randomly collected from a natural mixed forest. Then, height and DBH were measured using a Haglof Vertex Laser Hypsometer and caliper. Comparisons of the results indicated significant results at the 95% level and a very high average correlation of 0.972 for both tree height and DBH. In terms of DBH, the average errors were 0.6745 cm and 1.0139 cm for artificial coniferous and natural mixed forests, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.43-50
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• 2022

In this paper, we designed and verified a Far-field measurement system for measuring the performance of an antenna operating in millimeter wave(W-band). For the antenna test, a measurement system should be selected according to the type of antenna, measurement items, measurement environment and period, etc. In the case of near-field measurement, it takes a lot of time because the number of measurement items increases when the antenna has multiple channels or various beams. Such an antenna can reduce the measurement time through Far-field measurement, and only necessary measurement items can be measured. Therefore, this study secured precise alignment of the far-field measurement system using a high-power laser and improved the measurement accuracy by applying a double amplifier system. The designed system was built in the anechoic chamber and verified by comparison with the verified Near-field measurement system.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.136-136
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• 2023

우리나라의 강우 특성은 하절기에 집중되어 있으며 최근 이상강우와 기상이변에 따른 집중호우 발생으로 여를철 탁수 문제 발생 빈도가 높아지고 있는 추세이다. 과거 '02년 태풍 루사', '03년 태풍 매미', '06년 에위니아'부터 20년 마이삭, 하이선과 같은 태풍 및 장마에 의해 탁수 유입이 급증되어 수중 탁도가 높아지며 저수지 탁수 문제가 발생하였다. 특히 우리나라 경우 하천 및 저수지에서 물 사용량의 대부분을 이용하고 있기에 탁수 문제가 장기화 될 시 댐 하류 지역의 농업, 공업, 수생태 등 사회적, 비용적, 환경적 문제를 발생시킨다. 이러한 문제를 파악, 대응을 위한 탁수 모의에 대한 연구가 활발히 진행되고 있다. 탁수를 모의하기 위해서는 유량, 수온, SS, 탁도 데이터가 필요하며 이를 위해 국가측정망에서 하천 및 댐 저수지 내 SS를 측정하여 탁수를 측정 하고 있다. 하지만 현재 측정의 경우 채수를 통한 점단위의 측정으로 데이터 해상도가 낮다는 한계점이 있다. 이러한 데이터 취득의 한계로 기존 조사를 통한 탁도-SS 관계식을 통해 탁수를 예측하고 있으나 과거 2003년 이후 자료를 바탕으로 산정된 식으로 불확도가 존재한다. 탁수 모의 정확도 개선을 위한 데이터 해상도 및 탁도-SS 관계식 문제를 해결 하기 위해 기존 데이터 분석을 통한 미계측 기간에 대한 보간을 필요로 하며 현장 계측을 통한 탁도, SS 자료를 취득하여 탁도-SS 관계식을 최신화 할 필요가 있다. 따라서, 본 연구에서는 탁도를 측정 센서 YSI와 SS 측정센서 레이저부유사측정기(LISST: Laser In-Situ Scattering and Transmissometry)를 활용하여 자료를 취득하고 탁도-SS 산정식을 최신화 하였다. 또한 기존 국가 수질 측정망 데이터 및 기상 자료 데이터를 취득하여 데이터 분석을 통해 미계측 기간에 대한 데이터를 보간하여 탁수 모의 입력자료를 개선하였고 이를 기반으로 탁수 모의 정확도를 개선하고자 하였다.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.383-387
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• 2023

The quartz crystal microbalance (QCM), commonly used in high vacuum deposition, becomes difficult to use when a thick film is deposited on the quartz, affecting the crystal's inherent vibration. In this study, a non-destructive optical measurement method was developed to measure the film's deposition rate during the in-situ film deposition process. By measuring the scattered laser intensity caused by the dimer in the parylene gas passing through the gas flow path, it was successfully confirmed that the ratio of the dimer in the parylene gas increases as the pyrolysis temperature decreases. Additionally, it was noted that the film's thickness and haze increase as the pyrolysis temperature decreases by confirming the characteristics of the visible parylene films. Through the research results, we aim to utilize the stable in-situ film deposition rate measurement system to control the precise film deposition rate of parylene films.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.669-676
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• 2023

In this paper, a multi-purpose golf putting range finder based on an IR razer sensor and an inertial sensor was designed and made. It was designed to measure distance and slope within a 50m outdoor measurement range for the main purpose of golf putting distance measurement, and at the same time, it is designed to measure temperature information that affects putting. In addition, the distance meter supports house maintenance work by providing length and horizontality measurement values within the indoor 80m measurement range, and provides safety from indoor or vehicle fires by providing indoor temperature measurement values to mobile phones through linkage with the web server. In order to evaluate the accuracy of the proposed method and its interworking performance with a smartphone, a prototype was produced and a web server was built, and the usefulness was confirmed by showing an acceptable error rate within 5% in repeated experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.101-103
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• 2022

CCTV is mainly used as a real-time detection system for critical facilities. In the case of CCTV, although the accuracy is high, the viewing angle is narrow, so it is used in combination with a sensor such as a radar. LiDAR is a technology that acquires distance information by detecting the time it takes to reflect off an object using a high-power pulsed laser. In the case of lidar, there is a problem in that the utilization is not high in terms of cost and technology due to the limitation of the number of simultaneous processing sensors in the server due to the data throughput. The detection method by the optical mesh sensor is also vulnerable to strong winds and extreme cold, and there is a problem of maintenance due to damage to animals. In this paper, by using the 1550nm wavelength band instead of the 905nm wavelength band used in the existing lidar sensor, the effect on the weather environment is strong and we propose to develop a system that can integrate and control multiple sensors.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.154-160
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• 1996

The control of diamond turning is usually achieved through a laser-interferometer feedback of slide position. The limitation of this control scheme is that the feedback signal does not account for additional dynamics of the tool post and the material removal process. If the tool post is rigid and the material removal process is relatively static, then such a non-collocated position feedback control scheme may surfice. However, as the accuracy requirement gets tighter and desired surface cnotours become more complex, the need for a direct tool-tip sensing becomes inevitable. The physical constraints of the machining process prohibit any reasonable implementation of a tool-tip motion measurement. It is proposed that the measured force normal to the face of the workpiece can be filtered through an appropriate admittance transfer function to result in the estimated dapth of cut. This can be compared to the desired depth of cut to generate the adjustment control action in additn to position feedback control. In this work, the design methodology on the admittance model-based control with a conventional controller is presented. The recursive least-squares algorithm with forgetting factor is proposed to identify the parameters and update the cutting process in real time. The normal cutting forces are measured to identify the cutting dynamics in the real diamond turning process using the precision dynamoneter. Based on the parameter estimation of cutting dynamics and the admitance model-based nanodynamic control scheme, simulation results are shown.