• Journal of Institute of Control, Robotics and Systems
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• v.22 no.12
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• pp.1061-1067
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• 2016

Position of the vehicle for driving is essential to autonomous navigation. However, there appears GPS position error due to multipath which is occurred by tall buildings in downtown area. In this paper, GPS position error is corrected by using camera sensor and highly accurate map made with 3D-Lidar. Input image through inverse perspective mapping is converted into top-view image, and it works out map matching with the map which has intensity of 3D-Lidar. Performance comparison was conducted between this method and traditional way which does map matching with input image after conversion of map to pinhole camera image. As a result, longitudinal error declined 49% and complexity declined 90%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.465-469
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• 2006

In recent years there has been considerable interest in the construction of super high-rise buildings. From the prior art, various procedures and devices for surveys during and after the phase of erection of a high-rise building are known. High-rise buildings are subject to strong external tilt effects caused, for instance, by wind pressures, unilateral thermal effects by exposure to sunlight, and unilateral loads. Such effects are a particular challenge in the phase of construction of a high-rise building, in as much as the high-rise building under construction is also subject to tilt effects, and will at least temporarily lose its - as a rule exactly vertical - alignment. Yet construction should progress in such a way that the building is aligned as planned, and particularly so in the vertical, when returning into an un-tilted basic state.It is essential that a straight element be constructed that theoretically, even when moving around its design centre point due to varying loads, would have an exactly vertical alignment when all biasing conditions are neutralised. Because of differential raft settlement, differential concrete shortening, and construction tolerances, this ideal situation will rarely be achieved. This paper describes a procedure developed by the authors using GPS observations combined with a network of precision inclination sensor to provide reliable coordinated points at the top of the worldwide highest-rise building under construction in Dubai.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3412-3420
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• 2015

Smartphone has become an essential element in our daily life and built-in sensors of the smartphone can be utilized in order to recognize of user's situation. However, it is lack of research for safety and accident prevention by dynamic situation recognition. In this paper, we propose a technique that can be recognized risk situation dynamically using accelerometer, microphone and GPS sensor of mobile device. We propose an architecture and process for sensing techniques of Dynamic Recognition Technique, and develop the mobile application for verifying the suitability of the architecture.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.991-1000
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• 2019

The flying-disc game has started since 1940. It has been spreading rapidly in Korea since 2007, mainly in elementary schools. Additionally, as sports science has been developed, research on flying discs has been continued to build a monitoring system for technological improvement and efficiency. In this paper, we acquire information on the user's flying-disc using 9-axis motion sensor and GPS. Then we propose a method for wireless transmission using Bluetooth 5.0. Specifically, the HW platform was designed and implemented not only to monitor a real-time data but also to compare and analyze rotational speed, flight trajectory, and a count of disc rotation through post-processing.

• Korean Journal of Applied Biomechanics
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• v.29 no.1
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• pp.1-8
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• 2019

Objective: The purpose of this study was to confirm that the cross-country ski sprint course in PyeongChang, where the 2018 Winter Olympics course was to utilize wearable devices equipped with inertial measurement unit (IMU), global positioning system (GPS) and heart rates sensor. Method: For the data collection, two national level cross-country (XC) skiers performed classic technique on the entire sprint course. We analyzed cycle characteristics, range of motion on double poling (DP) technique, average velocity, and displacement of 3 points according to the terrain. Results: The absolute cycle time gradually decreased during starting, middle and finish sections. While the length of the DP increased and the heart rates tended to increase for men skier. In addition, the results indicated that range of motion of knee joint during starting and finish section decreased more than middle section. The errors of latitude and longitude data collected through GPS were within 3 m from 3 points. Conclusion: Through the first case study in Korea, which analyzed the location and condition of XC skiers in the entire sprint course in real time, confirmed that feedback was available in the field using various wearable sensors.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.314-322
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• 2022

During the shipbuilding process, many blocks are moved between shipyard workshops by block carrying vehicles called a transporter. Because block logistics management is one of the essential factors in enhancing productivity, it is necessary to manage block information with the transporter that moves it. Currently, because a large amount of data per day are collected from sensors attached to blocks and transporters via IoT infrastructure installed in shipyards, automated methods are needed to analyze them. Therefore, in this study, we developed an algorithm that can automatically match the transporter and the working block based on the GPS sensor data. By comparing the distance between the transporter and the blocks calculated from the Haversine formula, the block is found which is moved by the transporter. In this process, since the time of the measured data of moving objects is different, the time standard for calculating the distance must be determined. The developed algorithm was verified using actual data provided by the shipyard, and the correct result was confirmed with the distance based on the moving time of the transporter.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.280-286
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• 2022

In order to efficiently collect data, it is essential to locate the facilities and analyze the movement data. The current technology for location collection can collect data using a GPS sensor, but GPS has a strong straightness and low diffraction and reflectance, making it difficult for indoor positioning. In the case of indoor positioning, the location is determined by using wireless network technologies such as Wifi, but there is a problem with low accuracy as the error range reaches 20 to 30 m. In this paper, using BLE 4.2 built in Raspberry Pi, we implement Bluetooth Smart Ready. In detail, a beacon was produced for Advertise, and an experiment was conducted to support the serial port for data transmission/reception. In addition, advertise mode and connection mode were implemented at the same time, and a 3-count gradual algorithm and a quadrangular positioning algorithm were implemented for Bluetooth RSSI error correction. As a result of the experiment, the average error was improved compared to the first correction, and the error rate was also improved compared to before the correction, confirming that the error rate for position measurement was significantly improved.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.487-488
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• 2021

시설물 점검은 사람이 직접 들어가거나 올라가 확인하는 방식이 일반적이다. 본 연구에서는 시설물 점검을 보다 안전하고 신속하게 하는 것을 전제로 하여 현재 상용화 되고 있는 드론과 아두이노를 이용한 센서를 적용하고자 한다. 본 논문은 기존의 어려운 조작의 드론에 건물 내부에서 호버링이 가능하게 하는 옵티컬 플로어 센서를 장착아여 조작을 보다 쉽게 한다. 또한, 외부 비행 시 GPS센서를 사용하여 좌표지정을 통한 자동비행을 가능하게 하고 아두이노의 센서와 펌프를 적용한 "오토파일럿이 가능한 시설물 관리 드론" 기술을 제안한다. 기존의 드론과 다르게 카메라와 센서를 이용해 시설물 관리를 대신하고, 외부 시설물 관리나 농업 등에서 사용할 때 좌표를 지정해 사용자가 직접 조작하지 않아도 지정한 좌표로 드론이 이동하여 관리 및 임무를 수행한다. 센서들의 값을 앱으로 전송받아 핸드폰으로 받아 볼 수 있다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.1
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• pp.67-75
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• 2010

This paper presents localization algorithm for mobile robot in outdoor environment. Outdoor environment includes the uncertainty on the ground. Magnetic sensor or IMU(Inertial Measurement Unit) has been used to estimate robot's heading angle. Two sensor is unavailable because mobile robot is electric car affected by magnetic field. Heading angle estimation algorithm for mobile robot is implemented using gyro sensor module consisting of 1-axis gyro sensors. Localization algorithm applied Extended Kalman filter that utilized GPS and encoder, gyro sensor module. Experiment results show that proposed localization algorithm improve considerably localization performance of mobile robots.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.57-65
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• 2019

The purpose of this study was to develop an environment field monitoring system to measure crop growth. The environment field monitoring system consisted of sensors, a data acquisition system, and GPS. The sensors used in the environment field monitoring system consisted of an ambient sensor, a soil sensor, and an intensity sensor. The temperature and humidity of the atmosphere were measured with the ambient sensor. The temperature, humidity, and EC of the soil were measured with the soil sensor. The data acquisition system was developed using the Arduino controller. The field monitoring data were collected before a rainy day, on a rainy day, and after the rainy day. The measured data using the environment field monitoring system were compared with the Daejeon regional meteorological office data. The correlation between the data from the environment field monitoring system and the data from the Daejeon regional meteorological office was analyzed for performance evaluation. The correlation of the temperature and humidity of the atmosphere was analyzed because the Daejeon regional meteorological office only provided data for the temperature and humidity of the atmosphere. The correlation coefficients were 0.86 and 0.90, respectively. The result showed a good correlation between the data from the environment field monitoring system and the data from the Daejeon regional meteorological office. Therefore, the developed system could be applied to monitoring the field environment of agricultural crops.