• Title/Summary/Keyword: Location correction

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A Study on Marker-based Detection Method of Object Position using Perspective Projection

  • Park, Minjoo;Jang, Kyung-Sik
    • Journal of information and communication convergence engineering
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    • v.20 no.1
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    • pp.65-72
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    • 2022
  • With the mark of the fourth industrial revolution, the smart factory is evolving into a new future manufacturing plant. As a human-machine-interactive tool, augmented reality (AR) helps workers acquire the proficiency needed in smart factories. The valuable data displayed on the AR device must be delivered intuitively to users. Current AR applications used in smart factories lack user movement calibration, and visual fiducial markers for position correction are detected only nearby. This paper demonstrates a marker-based object detection using perspective projection to adjust augmented content while maintaining the user's original perspective with displacement. A new angle, location, and scaling values for the AR content can be calculated by comparing equivalent marker positions in two images. Two experiments were conducted to verify the implementation of the algorithm and its practicality in the smart factory. The markers were well-detected in both experiments, and the applicability in smart factories was verified by presenting appropriate displacement values for AR contents according to various movements.

Location Correction of multiple low-cost GPS receivers (저가형 GPS 를 활용한 위치 정밀도 향상 연구)

  • Chan-Hwi Lim;Young-Soo Do;Jae-Wook Jeon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.11a
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    • pp.1155-1156
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    • 2023
  • 본 논문은 다수의 저정밀 GPS(Global Positioning System) 센서를 활용하여, 보다 정밀하고 정확한 GPS 좌표 보정 모델을 설계하고자 한다. 제안 모델에서는 다수의 저정밀 센서에서 GPS 좌표를 수합한 뒤, 최소자승법과 선형칼만필터로 값을 보정한다. 본 논문에서는 Horizontal Accuracy 가 2m 인 저정밀 GPS 센서를 활용하여 제안 모델을 설계하였으며, 저정밀 센서와 제안 모델 비교 실험에서 제안 모델의 46% 정밀도 향상을 확인하였다.

Evaluation on the Accuracy of Targeting Error Correction Through the Application of Target Locating System in Robotic CyberKnife (로봇 사이버나이프에서 위치인식시스템을 이용한 Targeting Error값 보정의 정확성 평가)

  • Jeong, Young-Joon;Jung, Jae-Hong;Lim, Kwang-Chae;Cho, Eun-Ju
    • The Journal of Korean Society for Radiation Therapy
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    • v.21 no.1
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    • pp.1-7
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    • 2009
  • Purpose: The purpose is to evaluate the accuracy of correcting the targeting error through the Target Location System (TLS) for the location change error of the reference point which arises from the movement or motion of patient during the treatment using the CyberKnife. Materials and Methods: In this test, Gafchromic MD-55 film was inserted into the head and neck phantom to analyze the accuracy of the targeting, and then the 6 MV X-ray of CyberKnife (CyberKnife Robotic Radiosurgery System G4, Accuray, US) was irradiated. End to End (E2E) program was used to analyze the accuracy of targeting, which is provided by Accuray Corporation. To compute the error of the targeting, the test was carried out with the films that were irradiated 12 times by maintaining the distance within the rage of $0{\pm}0.2\;mm$ toward x, y, z from the reference point and maintaining the angle within the rage of $0{\pm}0.2^{\circ}$ toward roll, pitch, yaw, and then with the films which were irradiated 6 times by applying intentional movement. And the correlation in the average value of the reference film and the test film were analyzed through independent samples t-test. In addition, the consistency of dose distribution through gamma-index method (dose difference: 3%) was quantified, compared, and analyzed by varying the distance to agreement (DTA) to 1 mm, 1.5 mm, 2 mm, respectively. Results: E2E test result indicated that the average error of the reference film was 0.405 mm and the standard deviation was 0.069 mm. The average error of the test film was 0.413 mm with the standard deviation of 0.121 mm. The result of independent sampling t-test for both averages showed that the significant probability was P=0.836 (confidence level: 95%). Besides, by comparing the consistency of dose distribution of DTA through 1 mm, 1.5 mm, 2 mm, it was found that the average dose distribution of axial film was 95.04%, 97.56%, 98.13%, respectively in 3,314 locations of the reference film, consistent with the average dose distribution of sagittal film that was 95.47%, 97.68%, 98.47%, respectively. By comparing with the test film, it was found that the average dose distribution of axial film was 96.38%, 97.57%, 98.04%, respectively, at 3,323 locations, consistent with the average dose distribution of sagittal film which was 95.50%, 97.87%, 98.36%, respectively. Conclusion: Robotic CyberKnife traces and complements in real time the error in the location change of the reference point caused by the motion or movement of patient during the treatment and provides the accuracy with the consistency of over 95% dose distribution and the targeting error below 1 mm.

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Geometric Correction of Lips Using Lip Information (입술정보를 이용한 입술모양의 기하학적 보정)

  • 황동국;박희정;전병민
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.6C
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    • pp.834-841
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    • 2004
  • There can be lips transformed geometrically in the lip images according to the location or the pose of camera and speaker. This transformation of the lip images changes geometric information of original lip phases. Therefore, for enhancing global lip information by using partial information of lips to correct lip phases transformed geometrically, in this paper we propose a method that can geometrically correct lips. The method is composed of two steps - the feature-deciding step and the correcting step. In the former, it is for us to extract key points and features of source image according to the its lip model and to create that of target image according to the its lip model. In the latter, we decide mapping relation after partition a source and target image based on information extracted in the previous step into each 4 regions. and then, after mapping, we unite corrected sub-images to a result image. As experiment image, we use fames that contain pronunciation on short vowels of the Korean language and use lip symmetry for evaluating the proposed algorithm. In experiment result, the correcting rate of the lower lip than the upper lip and that of lips moving largely than little was highly enhanced.

Non-stationary statistical modeling of extreme wind speed series with exposure correction

  • Huang, Mingfeng;Li, Qiang;Xu, Haiwei;Lou, Wenjuan;Lin, Ning
    • Wind and Structures
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    • v.26 no.3
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    • pp.129-146
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    • 2018
  • Extreme wind speed analysis has been carried out conventionally by assuming the extreme series data is stationary. However, time-varying trends of the extreme wind speed series could be detected at many surface meteorological stations in China. Two main reasons, exposure change and climate change, were provided to explain the temporal trends of daily maximum wind speed and annual maximum wind speed series data, recorded at Hangzhou (China) meteorological station. After making a correction on wind speed series for time varying exposure, it is necessary to perform non-stationary statistical modeling on the corrected extreme wind speed data series in addition to the classical extreme value analysis. The generalized extreme value (GEV) distribution with time-dependent location and scale parameters was selected as a non-stationary model to describe the corrected extreme wind speed series. The obtained non-stationary extreme value models were then used to estimate the non-stationary extreme wind speed quantiles with various mean recurrence intervals (MRIs) considering changing climate, and compared to the corresponding stationary ones with various MRIs for the Hangzhou area in China. The results indicate that the non-stationary property or dependence of extreme wind speed data should be carefully evaluated and reflected in the determination of design wind speeds.

The antenna azimuth correction method for a special purpose mobile video terminal tracking antenna system implementation (특수목적을 위한 이동형 영상 터미널 장비의 추적안테나 시스템에 적용하기 위한 방위각보정 알고리즘 구현)

  • Kim, Nam-Woo;Hur, Chang-Wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.11
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    • pp.2541-2546
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    • 2013
  • In this paper, we proposed on the azimuth correction method for a line-of-sight data-link tracking antenna system. Tracking antenna system is essential to maintain line-of-sight between moving object and data-link equipment. In order to calculate the azimuth and elevation between the moving object and antenna system, we used GPS data. also to match the each coordinate systems, we used geomagnetic sensor or beacon. However, the geomagnetic disturbance-prone terrain in places difficult to correct calibration. The first step, finds the location of the strongest RF signal, we should remember the difference between the reference point and the detected position of the antenna. The second step, we could communicate each other. And the azimuth angle is calculated by GPS values. Despite the geomagnetic interference, we can correct the azimuth angle quickly and easily.

Surgical Correction of Congenital Type III Atresia ani with Rectovaginal Fistula in a Cat (고양이의 직장질루가 병발한 Type III 선천성 항문무형성증의 수술적 교정)

  • Kim, Minkyung;Hwang, Yong-Hyun;Choi, Woo;Lee, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.30 no.5
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    • pp.376-379
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    • 2013
  • A four-week-old female Scottish Fold cat weighting 0.6 kg was admitted for vaccination. During the physical examination, the liquid feces were observed from the vulva and the anus was imperforate. The location of a narrow fistula and distended colon were identified on the contrast radiography. Definitive diagnosis was made as type III atresia ani with rectovaginal fistula. Anal reconstruction and ligation of the fistula were successfully undertaken to treat atresia ani. After surgery, the cat was treated with lactulose and a special diet consisting of high fiber was fed to increase digestibility. The cat was able to control defecation after 2 weeks post-operation. There was no complication for 8 months after surgery.

Implementation of Precise Drone Positioning System using Differential Global Positioning System (차등 위성항법 보정을 이용한 정밀 드론 위치추적 시스템 구현)

  • Chung, Jae-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.14-19
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    • 2020
  • This paper proposes a precise drone-positioning technique using a differential global positioning system (DGPS). The proposed system consists of a reference station for error correction data production, and a mobile station (a drone), which is the target for real-time positioning. The precise coordinates of the reference station were acquired by post-processing of received satellite data together with the reference station location data provided by government infrastructure. For the system's implementation, low-cost commercial GPS receivers were used. Furthermore, a Zigbee transmitter/receiver pair was used to wirelessly send control signals and error correction data, making the whole system affordable for personal use. To validate the system, a drone-tracking experiment was conducted. The results show that the average real-time position error is less than 0.8 m.

Availability Evaluation of Network DGPS Positioning for Various Facilities Management In Dense Housing Area (주택가 밀집지역에서의 각종 시설물 관리를 위한 네트워크 DGPS 측위의 가용성 평가)

  • Kim, In-Seup
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.4
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    • pp.93-99
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    • 2010
  • Since the facility management for various facilities in urban area are conducted by general managers who have poor knowledge for surveying technology, it is not easy to trace the exact location of the facility in a short time with the GIS map only by themselves in the field. In order to improve it, VRS-RTK or SBAS DGPS system integrated with UMPC and PDA which is uploaded GIS field software are being used recently however lot of difficulties are still existed with the GPS positioning in urban area due to the lack of visible satellites, no reception of correction data and multipath error by the interruption of the high buildings and houses etc. Therefore, in this study, we applied with Network DGPS system which allows better reception of satellite signal and correction data even in dense housing areas with the use of GNSS receiver and CDMA mobile phone. Based on the analysis of field data, it was confirmed that standard deviations of the Network DGPS positioning are 0.3 to 0.84m with a very high positioning rate even in dense housing areas. Therefore, it was concluded that the Network DGPS system could be used widely to fast and accurate positioning for various facilities management works in dense housing areas in the future.

A STUDY OF THE DEVIATION-MEASURING METHOD & AUTOMATIC DEVIATION-CORRECTING APPARATUS (자차측정 방법 및 자동 자차수정 장치에 대한 연구)

  • Park, Hyuk;Park, Jin-woo;Kim, Boo-il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.181-184
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    • 2016
  • This study is to compensate for inaccuracies in accordance with the change in the deviation correction value due to the movement and location of the ship cargo, equipment of the vessel, and eliminating the inconvenience of hand. By modifying the deviation through the simplification and automation was planned for accuracy and ease of modification of the modified value. The main method used is charted by measuring 24 direction and inputting the value of magnetic compass direction in automatic deviation-correcting apparatus manually or automaticallyThe measured values are exhibited in Table data and made it possible to calculate accurate correction value deviation. From this it can make deviation table having the margin of error within ${\pm}3^{\circ}$in all regions of the world And this table will help to navigational safety and economy under the unavailable or limited gyro contion.

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