• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.129-138
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• 2023

Acquiring precise coordinates of ground targets can be regarded as the key mission of the tactical-level military UAS(Unmanned Aerial System) operations. The coordinates deviations for the ground targets estimated from UAV (Unmanned Aerial Vehicle) images may depend on the sensor specifications and slant ranges between UAV and ground targets. It has an order of several tens to hundreds of meters for typical tactical UAV mission scenarios. In this paper, we propose a scheme that precisely acquires target coordinates from UAS by mapping image pixels to geographical coordinates based on GCP(Ground Control Points). This scheme was implemented and tested from ground control station for UAS. We took images of targets of which exact location is known and acquired the target coordinates using our proposed scheme. The experimental results showed that errors of the acquired coordinates remained within an order of several meters and the coordinates accuracy was significantly improved.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.149-155
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• 2009

The frequency is widely used to measure the distance. In the warehouse, however, the frequency is apt to be interrupted by various unmade stuffs and cannot be easily applied to that kind of environment. This study will suggest the method to localize a worker in the warehouse exactly with calculating the time difference of arrival from the base position to a node or between each node and with 3-points pin pointer. This study will propose the localizing method using RFID tag and analyze the result using the suggested method. Also, the efficiency of suggested method will be increased with the simulation based on the information from the RFID tag.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.705-714
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• 2019

Precision positioning is necessary for various use of high-resolution UAV images. Basically, GCP is used for this purpose, but in case of emergency situations or difficulty in selecting GCPs, the data shall be obtained without GCPs. This study proposed a method of improving positional accuracy for x, y coordinate of UAV based 3 dimensional point cloud data generated without GCPs. Road vector file by the public data (Open Data Portal) was used as reference data for improving location accuracy. The geometric correction of the 2 dimensional ortho-mosaic image was first performed and the transform matrix produced in this process was adopted to apply to the 3 dimensional point cloud data. The straight distance difference of 34.54 m before the correction was reduced to 1.21 m after the correction. By confirming that it is possible to improve the location accuracy of UAV images acquired without GCPs, it is expected to expand the scope of use of 3 dimensional spatial objects generated from point cloud by enabling connection and compatibility with other spatial information data.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.706-709
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• 2005

The absence of the nipple-areolar complex(NAC) in men are seldom stated, as a result of trauma, burn, mastectomy, or after the correction of extreme bilateral gynecomastia. A total of 50 healthy men aged 21 to 27 years were examined. We recorded the configuration (dimensions and shape) and the location of the NAC with respect to fixed skeletal anatomic landmarks. Of the 50 subjects examined, 44 had oval and 6 had a round NAC. The mean diameter for a round NAC was 24.3 mm. The center of the NAC was in the fourth intercostal space in 41 volunteers and in the fifth intercostal space in 9 of the subjects. To localize the NAC on the chest wall, at least three reproducible measurements proved to be necessary, composed of a horizontal line(distance from the midsternal line to the nipple, A), a medial oblique line(distance from the sternal notch to the nipple, B) and a lateral oblique line(distance from the acromioclavicular joint to the nipple, C). Using these three parameters, we recommend that the appropriate location can be calculated derived from the circumference of the chest.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.5.1-5.9
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• 2017

Many congenital and acquired defects occur in the maxillofacial area. The buccal fat pad flap (BFP) is a simple and reliable flap for the treatment of many of these defects because of its rich blood supply and location, which is close to the location of various intraoral defects. In this article, we have reviewed BFP and the associated anatomical background, surgical techniques, and clinical applications. The surgical procedure is simple and has shown a high success rate in various clinical applications (approximately 90%), including the closure of oroantral fistula, correction of congenital defect, treatment of jaw bone necrosis, and reconstruction of tumor defects. The control of etiologic factors, size of defect, anatomical location of defect, and general condition of patient could influence the prognosis after grafting. In conclusion, BFP is a reliable flap that can be applied to various clinical situations.

• Journal of Korea Multimedia Society
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• v.24 no.12
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• pp.1682-1692
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• 2021

Digital Twin, one of the core technologies of the Fourth Industrial Revolution, is attracting attention as a very suitable technology for disaster monitoring such as fires and earthquakes. In this paper, we implement a system equipped with UWB RTLS(Ultra-Wideband Real Time Location System), real-time remote control, and video streaming, which are element technologies for disaster monitoring digital twin. Since the proposed system structure is based on a cloud server, the actual location of the UWB indoor positioning-based client is transmitted to the user device in real time and stored on the cloud server for statistical and data analysis. In addition, we demonstrate through experiments that outliers occurs when the value of RSSI(Received Signal Strength Indicator) decreases due to communication collisions between UWB Tags, and propose an RSSI outlier correction algorithm to solve this problem.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.546-555
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• 2009

There is increasingly interested in the measurement of antenna's characteristics for one's manufacture according to one's various application. Due to this, the antenna measurement system need be made with more and more great precision. On measuring of the antenna's characteristic, the conventional system handled by human generates the error due to controlling the position of the system by user. Therefore there need be introduced the automatic measurement system of antenna's characteristic. In this paper, we propose antenna extraction algorithm for the Antenna automatic measurement system of antenna's characteristic. The proposed algorithm gets the antenna image from antenna measurement system, extracts an antenna object from the image, and extracts the parameters for antenna's slant and antenna's location. The extracted parameters is used to correct location and distortions of the antenna and automatic measurement. The proposed algorithm is applied to the patch antenna. The results show that antenna's object is efficiently extracted and the angle for correcting the error is calculated well.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.5
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• pp.382-388
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• 2016

When Flat Panel Display (FPD) is made with backlight module, such as LED TV, it inherently suffers from the non-uniform backlight luminance problem that results in un-even brightness distribution throughout the TV screen. If the luminance of each pixel location of a TV screen as a function of the driving voltage can be measured, it can be used to compensate the non-uniformity of the backlight module. We use a carefully calibrated imaging system to take pictures of a TV screen at different levels of brightness and generate the compensation functions for the driving circuitry to correct the luminance level at each pixel location. Making use of the fact that the luminance of the screen is normally brightest at around the center of the screen and gradually decreases toward the border of the screen, the luminance of the whole TV screen is approximated by a mathematical function of the pixel locations. The parameters of the function are computed in the least square sense by the values of both the pixel luminance sent from the driving circuit and the grayscale value measured from the image taken by the imaging system. To justify the correction system, a simple second order polynomial function is used to approximate the luminance across the screen. When the driving circuit voltage is corrected according to the measured function, the variance of the screen luminance is reduced to one tenth of the one measured from the un-corrected TV screen.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.25-31
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• 2017

The indoor location based service proposed in the study was assigned to target a moving user. Positioning in the outdoor environment is accurate while using GPS. However, in an indoor environment, positioning is inaccurate and difficult. In order to overcome this, studies of various techniques for positioning based on wireless communication such as Wi-Fi, Zigbee and Bluetooth are being performed. The RSSI value and the delivery signal of the bluetooth beacon are measured according to the distance, and to a database. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance. When average and feedback filtering coefficient are set with 0.5, irregular and highly RSSI values are decreased. As the distance increases, the range of error is confirmed to have a reduction when using a distance calculation correction algorithm. Finally, when using the RSSI measurement results filtering, it corrects an unstable signal. Also, the distance correction algorithm is used to reduce a range of errors.

• The Journal of the Korean dental association
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• v.52 no.10
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• pp.623-632
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• 2014

The facial asymmetries include maxillary, mandibular, and chin asymmetries, although the most common deformity is primarily in the mandible. Common causes of this type of asymmetry can include asymmetric growth of the condyle or the mandible. In these patients, the location of the Me would be deviated to the shorter side because of the asymmetric growth of the mandible, and, commonly, the maxillary occlusal plane would be tilted toward the deviated side because the maxilla likely grows asymmetrically according to the pattern of asymmetric mandibular growth. Three-dimensional CT images are ideal for evaluating the size and location of anatomic structures, and such reconstructed images allow the use of software that can show anatomic structures from numerous angles, allowing actual measurements of distances and angles without problems of magnification, distortion, or superimposition caused by 2-dimensional imaging. In the present study using 3D-CT imaging, the 8 parameters, including measurements of the upper midline deviation, maxillary canting in the canine and first molar regions, width of the upper arch, width of the mandible at the Go, vertical length of the ramus, inclination of the ramus, and deviation of the Me were easily measured. The dentition should be orthodontically decompensated and dental midline should ensure incisor midlines positioned in the midline of each jaw before surgical correction. Surgical correction could be considered such as canting or yawing correction in the frontal or horizontal aspect, respectively.