• Spatial Information Research
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• 제18권3호
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• pp.73-83
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• 2010

본 연구는 정지장면의 연속영상간 각 픽셀위치에서 일어나는 통계적 특성을 활용하여 영상을 분할하는 기법을 제안한다. 공간정보의 획득과 분석에서 디지털 영상 처리 기법의 활용은 아주 중요한 의미를 가진다. 특히 디지털 영상의 영역 구분을 위해 다양한 영상 분할(image segmentation) 기법들이 활용되고 있다. 본 연구에서는 선행 연구한 연속프레임 영상의 분광학적 특성 분석의 결과를 바탕으로 연속 프레임 간 Randomness를 활용한 이미지 분할 방법을 제안하였다. 우선 연속 프레임 간 각 화소에 통계학적인 분석 방법을 적용하여 각 화소의 평균과 표준편차 값을 구하고, 이를 통하여 대상 영상에서 가장 신뢰할 만한 화소들을 찾아 씨앗 점(seed point)을 결정하였다. 그리고 이 씨앗 점들을 시작으로 이웃 화소 간 T-test를 실시하였으며, 이를 기반으로 영역 성장(region growing)의 개념을 적용하여 영상을 분할 할 수 있는 기법을 연구하였다. 제안방식의 성능을 검증하기 위하여 실험을 통하여 기존의 방식과 비교분석을 수행하였다. 이러한 실험의 결과 영상분할에서 영상의 단일 프레임을 활용한 것보다 연속 프레임을 활용한 경우가 유리함을 확인 할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.363-372
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• 2017

This paper presents a novel face recognition algorithm based on the deep convolution neural network and key point detection jointed local binary pattern methodology to enhance the accuracy of face recognition. We firstly propose the modified face key feature point location detection method to enhance the traditional localization algorithm to better pre-process the original face images. We put forward the grey information and the color information with combination of a composite model of local information. Then, we optimize the multi-layer network structure deep learning algorithm using the Fisher criterion as reference to adjust the network structure more accurately. Furthermore, we modify the local binary pattern texture description operator and combine it with the neural network to overcome drawbacks that deep neural network could not learn to face image and the local characteristics. Simulation results demonstrate that the proposed algorithm obtains stronger robustness and feasibility compared with the other state-of-the-art algorithms. The proposed algorithm also provides the novel paradigm for the application of deep learning in the field of face recognition which sets the milestone for further research.

• 대한공간정보학회지
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• 제23권2호
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• pp.97-104
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• 2015

최근 스마트폰을 비롯한 각종 IT 장치의 도입과 차량항법시스템의 보편화로 인하여 위치기반 공간정보 서비스의 활용이 활발해 짐에 따라, 공간정보 사용자가 요구하는 품질의 수준이 높아지게 되었다. 본 연구에서는 지상 MMS 측정자료와 항공측량자료를 통합함으로써 정밀한 3차원 공간정보 구축하는 방법을 연구하였다. 이를 위해 실험지역에서 관측한 지상 MMS 측정자료와 항공측량자료 간의 편차경향을 분석하였고 각 데이터의 편차경향이 일관되지 못한걸 확인하였다. 편차 보정 모델 결정을 위해 GPS/INS 처리결과에 포함되어 있는 외부표정정보를 직접 수정하는 방법을 선택하였고 보정모델이 사용하는 기준인 보정용 기준점 좌표의 취득방법을 분류하여 각각의 장단점을 분석하였다. 항공사진 프로젝트에서 취득한 기준점 정보를 사용하여 지상 MMS 측정자료를 보정하는 방법을 통해 지상 MMS 측정자료 사이에 존재하는 편차를 소거하였을 뿐만 아니라 항공측량자료와 지상 MMS 측정자료 사이에 존재하던 편차도 대부분 소거된 것을 확인할 수 있었다.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.19-28
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• 2022

This paper introduces an automatic steering system for straight traveling capable of being mounted on drivable agricultural machinery which user can handle it such as a tractor, a transplant, etc. The modular automatic steering device proposed in the paper is composed of RTK GNSS, IMU, HMI, hydraulic valve, and wheel sensor. The path generation method of the automatic steering system is obtained from two location information(latitude and longitude on each point) measured by GNSS in advance. From HMI, a straight path(AB line) can be created by connecting latitude and longitude on each point and the device makes the machine able to follow the path. During traveling along the reference path, it acquires the real time position data every sample time(0.1s), compares the reference with them and calculates the lateral deviation. The values of deviation are used to control the steering angle of the machine using hydraulic valve mounted on the axle of front wheel. In this paper, Pure Pursuit algorithm is applied used in autonomous vehicles frequently. For the analysis of traveling characteristics, field tests were executed about these conditions: velocity of 2, 3, 4km/h which is applied to general agricultural work and ground surface of solid(asphalt) and weak condition(soil) such as farmland. In the case of weak ground state, two experiments were executed about no-load(without work) and load(with work such as plowing). The maximum average deviations were presented 2.44cm, 7.32cm, and 11.34cm during traveling on three ground conditions : asphalt, soil without load and with load(plowing).

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.186-195
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• 2021

In Korea, groundwater quality is monitored through National Groundwater Quality Monitoring Network (NGQMN) administered by Ministry of Environment. For a given contaminant, compliance to groundwater quality standards is assessed on a annual basis by monitoring the number of incidents that concentration exceeds the regulatory limit. However, this approach provides only a fractional information about groundwater quality degradation, and more crucial information such as location and severity of the contamination cannot be obtained. For better groundwater quality management on a watershed, a more spatially informative and intuitive method is required. This study presents two statistical methods to convert point-wise monitoring data into information on groundwater quality status of a watershed by using a proposed grading scale. The proposed grading system is based on readily available reference standards that classify the water quality into 4 grades. The methods were evaluated with NO₃^-, Cl^-, and total coliform data in Geum River basin. The analyses revealed that groundwater in most watersheds of Geum River basin is good for domestic or/and drinking with no treatment. But, there was notable quality degradation in Bunam seawall and So-oak downstream standard watersheds contaminated by NO₃^- and Cl^-, respectively.

• 제어로봇시스템학회논문지
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• 제18권8호
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• pp.713-718
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• 2012

Lumber spine range of motion has been used to measure of physical and functional impairment by various tools from a ruler to 3D kinematic devices. However, pre-existing tools have problems in either movement or accuracy and reliability limitations. Accurate devices are limited by fixed space whereas simple devices are limited in measuring complex movements with less accuracy. In order to solve the location, movement and accuracy limitations at once, we have developed a novice measurement device equipped with accelerometer sensor and gyroscope sensor for getting three-dimensional information of motion. Furthermore, Kalman filter was applied to the algorithm to improve accuracy. In addition, RF wireless communication was added for the user to conveniently check measured data in real time. Finally, the measurement method was improved by considering the movement by a reference point. An experiment was conducted to test the accuracy and reliability of the device by conducting a test-retest reliability test. Further modification will be conducted to used the device in various joints range of motion in clinical settings in the future.

• 한국도로학회논문집
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• 제2권4호
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• pp.111-122
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• 2000

우리나라 도로중 PMS가 구축된 도로는 현재, 고속도로와 국도가 있다. 그러나 많은 시(市)에서 도로의 효율적인 관리를 위해 요구되는 시도로 PMS는 아직 없는 실정이다. 따라서, 본 논문에서는 시단위에 적용가능한 Prototype PMS 전산시스템을 개발 제시하였다. 개발한 PMS는 기본적으로 PC 수준에서 운영 가능하도록 구성하였으며 GIS 기능을 이용하여 사용자가 쉽게 포장상태나 유지보수 현황 및 계획을 이해할 수 있게 하였다. 본 PMS의 기능상 구성은 크게 조회, 분석, 자료관리, 출력 부분으로 구축하였다. 특히, 분석과정의 주논리(보수우선순위결정, 보수공법결정)부분은 필요시 사용자가 각 항목의 criteria 값을 수정 할 수 있게 하여 시스템운영이 경직되지 않도록 배려하였다. PMS 데이터베이스의 항목은 시도로 PMS의 규모 및 목적을 고려하여 선정하였다. 또한 PMS에서 사용된 도로 관리길이 및 위치 지정체계는 노선을 기준으로 기본 100m길이의 section으로 분할관리하였으며, 위치 지정체계 방식은 reference points 방식을 기본으로 사용하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권1호
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• pp.41-52
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• 2012

Purpose: Triangulation is the process of determining the location of a point by measuring angles to it from known points at either end of a fixed baseline. This point can be fixed as the third point of a triangle with one known side and two known angles. The aim of this study was to find a clinically adaptable method for applying an optical tracking navigation system to orthognathic surgery and to estimate its accuracy of measuring the bone displacement by use of triangulation methods. Methods: In orthognathic surgery, the head position is not fixed as in neurosurgery, so that a head tracker is needed to establish the reference point on the head surface byusing an optical tracking system. However, the operation field is interfered by its bulkiness that makes its clinical use difficult. To solve this problem, we designed a method using an Aquaplast splinting material and a mini-screw in applying a head tracker on a patient's forehead. After that, we estimated the accuracy of measuring displacements of the ball marker by an optical tracking system with a conventional head tracker (Group A) and with a newly designed head tracker (Group B). Measured values of ball markers' displacements by each optical tracking system were compared with values obtained from fusion CT images for an estimation of accuracy. Results: The accuracy of the optical tracking system with a conventional head tracker (Group A) is not suitable for clinical usage. Measured and predictable errors are larger than 10 mm. The optical tracking system with a newly designed head tracker (Group B) shows 1.59 mm, 6.34 mm, and 9.52 mm errorsin threeclinical cases. Conclusion: Most errors were brought on mainly from a lack of reproducibility of the head tracker position. The accuracy of the optical tracking system with a newly designed head tracker can be a useful method in further orthognathic navigation surgery even though the average error is higher than 2.0 mm.

• 한국정보통신학회논문지
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• 제17권11호
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• pp.2541-2546
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• 2013

본 논문에서는 가시선 데이터링크용 추적안테나 시스템에 적용하기 위한 방위각 보정 알고리즘에 대해 연구한다. 이동하는 물체와 가시선 통신링크를 유지하기 위해서는 추적안테나 시스템이 필수적이다. 방위각과 고각계산을 위해서는 이동체와 안테나시스템의 GPS값을 이용하는데, 이때 두 좌표계의 동일성을 유지하기 위해서 초기에 지자기센서나 beacon등을 이용하여 보정을 하게 된다. 하지만 지형적으로 지자기교란이 생기기 쉬운 장소에서는 정확한 보정이 어렵다. 따라서 본 논문에서는 초기에 RF신호의 수신세기추적을 통해서 신호의 발생 위치를 검출하고 검출된 위치까지의 방위각 보정 값을 계산하여 통신링크개설 후 수신된 GPS값에 보정 값을 적용함으로서 주변의 영향을 최소화하면서 쉽고 빠르게 보정할 수 있다.

• 방사선산업학회지
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• 제9권2호
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• pp.69-75
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• 2015

Purpose: The gonad shielding is used to minimize the impact of the exposure to gonads when Abdomen, Pevis and Hip X-ray inspections are conducted on radiation impressionable pediatric patients. By the way, the gonad is palpable difficult and impossible to check visually because it's a sensitive area, so tests are conducted with the approximate location of shielding, thereby appearing problems of not shielding gonads accurately. Accordingly, this study produced shields by age and gender of pediatric patients and studied the method of positioning shields with ASIS as a reference point without palpable sensitive areas, and tried to evaluate its usability. Materials and methods: The study surveyed 30 pediatric patients by gender and age, who came and got inspected in Department of Radiology, our hospital from February 2012 to January 2014 and obtained the value of tolerance by measuring the average size of the pelvis using the distance measurement function of Infinitt Piview with the images stored in the PACS and producing shields by age and gender of pediatric patients and specifying the areas at random for the comparative analysis of pre- and post-using. It calculated the technology statistics($mean{\pm}SD$) with the value of tolerance measured the length using SPSS 12.0 statistical program. Results: As for boys, differences in the tolerance range of pre- and post-using shields were 2.69 mm in case of 1 year old, 2.58 mm in 2 years, 2.37 mm in 3 years, 2.815 mm in 4~5 years, 2.043 mm in 7~10 years, and as for girls, 1.92 mm in 1~2 years, 1.75 mm in 3~4 years, 2.52 mm in 5~6 years and 1.93 mm in 7~10. After analyzing the pre- and post-using shields for all of boys and girls, there were statistically significant differences(P<0.050). Conclusions: It is considered that we can minimize the exposure to gonads and get a better video for diagnosis in testing high biological impressionable pediatric, if we use shields correctly with ASIS as a reference point considering its shape and size by age and gender in Abdomen, Pevis and Hip X-ray inspections.