• 제목/요약/키워드: Ins Choi

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Study and Implementation on Compensation of Step Jump Errors and Integrated Filter in the INS/GPS System

  • Hong, Woon-Seon;Choi, Sang-Wook;Park, Heung-Won;Kim, Chen-Jung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.114.3-114
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    • 2001
  • The pure navigation system using Inertial Navigation Unit(INU) which has very accurate short term stabilities but not long term gives rise to position errors propotional to time. On the contrary, Global Positioning System(GPS) which is bounded its errors to some fixed ranges shows higher accuracy in the long term, and lower accuracy in the short term than that of INS. Recently the integration of these two systems is one of the main topic in the field of navigation system. In this thesis, the implementation of kalman filter on the real time navigation computer and step jump error compensation method is suggested.

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Design and Implementation of 4S-Van: A Mobile Mapping System

  • Lee, Seung-Yong;Choi, Kyoung-Ho;Joo, In-Hak;Cho, Seong-Ik;Park, Jong-Hyun
    • ETRI Journal
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    • v.28 no.3
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    • pp.265-274
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    • 2006
  • Recent advances in positioning and photogrammetry technologies have made it possible to build a mobile mapping system (MMS) that can obtain 3D coordinates of geographic objects from stereo images recorded from a moving vehicle. In this paper, we present a design and detailed implementation of an MMS called a 4S-Van. Furthermore, we present four issues that have made major contributions to the performance of an MMS: 1) CCD camera calibration, 2) GPS signal condition, 3) integrating a GPS, inertial navigation system (INS), distance measurement indicator (DMI), and CCD cameras, and 4) the orientation angle of CCD cameras. In the experimental results, the performance of an MMS was analyzed for each component, giving an idea of how to effectively design and integrate each component in developing an MMS to get a maximal accuracy of 3D coordinates.

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Mosaic image generation of AISA Eagle hyperspectral sensor using SIFT method (SIFT 기법을 이용한 AISA Eagle 초분광센서의 모자이크영상 생성)

  • Han, You Kyung;Kim, Yong Il;Han, Dong Yeob;Choi, Jae Wan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.2
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    • pp.165-172
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    • 2013
  • In this paper, high-quality mosaic image is generated by high-resolution hyperspectral strip images using scale-invariant feature transform (SIFT) algorithm, which is one of the representative image matching methods. The experiments are applied to AISA Eagle images geo-referenced by using GPS/INS information acquired when it was taken on flight. The matching points between three strips of hyperspectral images are extracted using SIFT method, and the transformation models between images are constructed from the points. Mosaic image is, then, generated using the transformation models constructed from corresponding images. Optimal band appropriate for the matching point extraction is determined by selecting representative bands of hyperspectral data and analyzing the matched results based on each band. Mosaic image generated by proposed method is visually compared with the mosaic image generated from initial geo-referenced AISA hyperspectral images. From the comparison, we could estimate geometrical accuracy of generated mosaic image and analyze the efficiency of our methodology.

Cytoprotective Effect of Lespedeza Cuneata Extract on Glucose Toxicity (야관문(夜關門)의 포도당 독성에 대한 세포 보호 효과)

  • Choi, Jeong-Sik;Cho, Chung-Sik;Kim, Cheol-Jung
    • The Journal of Korean Medicine
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    • v.31 no.4
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    • pp.79-100
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    • 2010
  • Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

Compensation of Magnetometer in the Navigation System for Unmanned Helicopter using an Electric Motor (전기모터를 사용한 소형 무인헬리콥터에 활용될 항법장치용 자장계의 보상)

  • Lee, Gilho;Jo, Sungbeom;Kim, Jungsung;Choi, Keeyoung;Kee, Changdon;Song, Yongkyu;Koo, Wheonjoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.11
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    • pp.997-1003
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    • 2012
  • GNSS and ARS are the most common sensors in low-end UAVs. However, these sensors are vulnerable to built-in errors and cannot measure the body heading independently. The GNSS/INS cannot fully compensate the IMU errors in initial alignment process and rectilinear flights. For an unmanned helicopter, a magnetometer can be more useful than any other sensors to obtain heading information. However, the electric motor which drives small helicopter UAV keeps the magnetometer from reading the pure magnetotelluric vector. This paper shows the effects of electric motor on the magnetometer readings, and presents a method to compensate the effects. The results are verified with flight test data. The simulation and experimental results in this paper proves that aiding GNSS/INS with magnetometer increases observability and improves accuracy.

Housing and Domestic Living ; An Analysis of Housing Plans for Goryo-in Immigrant Workers in Korea (우리나라에 거주하는 고려인(高麗人)의 주거 및 주생활 - 재한(在韓) 고려인 이주 노동자의 주거 지원을 위한 탐색 -)

  • Lee, Young-Shim;Choi, Jung-Shin
    • Journal of the Korean Home Economics Association
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    • v.46 no.4
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    • pp.47-59
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    • 2008
  • With increasing numbers of immigrant workers in Korea, the supply of socially and culturally acceptable housing has become an important issue. The purpose of this study was to analyze the state of Goryo-in housing and domestic living conditions in metropolitan areas of Korea. This study will present essential information directly relevant to the establishment of practical housing policy for Goryo-in in Korea. Furthermore, data collected and analyzed here will enable comparative investigation with Goryo-ins who live in Russia and Central Asia. Using ethnographic methodologies, we examined 20 Goryo-in households in relation to their usage of domestic space. The following conclusion were established; 1). The most popular L D K(Living Dining Kitchen)type consisted of kitchen plus one or two bedrooms. The majority of households lived in quarters with separated kitchen and living room areas. 2). Most households had a washing machine in the bathroom due to a lack of space, and they regarded the bathtub and the drain hole of the bathroom as very necessary. The Goryo-ins interviewed preferred quarters with separate bathroom and toilet areas, in order to allow simultaneous use. 3). Their most preferred seating style was chairs, while making Kimchi at home was not very popular. 4). All respondents took their shoes off and wore slippers at home, while also indicating a preference for designated shoes space at the entrance to the house. 5) Half of the households had a carpet or mat in the bedroom or living room, both for keeping warm and aesthetic reasons. 6). All households had modified Ondol heating system and demonstrated satisfaction with this. The majority of Goryo-ins interviewed had a different living style compared to households in Russia and Central Asia which were related to less favorable economic conditions in Korea.

Chemical Vapor Deposition of Tungsten by Silane Reduction (사일린 환원반응에 의한 텅스텐 박막의 화학증착)

  • Hwang, Sung-Bo;Choi, Kyeong-Keun;Rhee Shi-Woo
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.10
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    • pp.113-123
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    • 1990
  • Tungsten film was deposited on the single crystal silicon wafer in a low pressure chemical vapor deposition reactor from silane and tungsten hexafluoride in the temperature range of $250-400^{\circ}C$ Deposition rate was found to be determined by the mass transfer rate of reactants from the gas phase to the safter surface. It was found out that tungsten films deposited contained about 3 atomic $\%$ of silicon and that the crystallinity and the grain size increased as the deposition temperature was increased. The resistivity of the film was measured to be in the range of $7~25{\mu}{\Omega}-cm$ and decreased with increasing deposition temperature. The adhesion of the tungsten film on a silicon surface was measured by the tape peel off test and it was improved with increasing deposition temperature. From the analysis of the gas composition, the reaction pathway to form $SiF_{4}$ and $H_{2}$ was found to be more favorable than HF formation.

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Quickly Map Renewal through IPM-based Image Matching with High-Definition Map (IPM 기반 정밀도로지도 매칭을 통한 지도 신속 갱신 방법)

  • Kim, Duk-Jung;Lee, Won-Jong;Kim, Gi-Chang;Choi, Yun-Soo
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.1163-1175
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    • 2021
  • In autonomous driving, road markings are an essential element for object tracking, path planning and they are able to provide important information for localization. This paper presents an approach to update and measure road surface markers with HD maps as well as matching using inverse perspective mapping. The IPM removes perspective effects from the vehicle's front camera image and remaps them to the 2D domain to create a bird-view region to fit with HD map regions. In addition, letters and arrows such as stop lines, crosswalks, dotted lines, and straight lines are recognized and compared to objects on the HD map to determine whether they are updated. The localization of a newly installed object can be obtained by referring to the measurement value of the surrounding object on the HD map. Therefore, we are able to obtain high accuracy update results with very low computational costs and low-cost cameras and GNSS/INS sensors alone.

Integrated Navigation System Design of Electro-Optical Tracking System with Time-delay and Scale Factor Error Compensation

  • Son, Jae Hoon;Choi, Woojin;Oh, Sang Heon;Hwang, Dong-Hwan
    • Journal of Positioning, Navigation, and Timing
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    • v.11 no.2
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    • pp.71-81
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    • 2022
  • In order for electro-optical tracking system (EOTS) to have accurate target coordinate, accurate navigation results are required. If an integrated navigation system is configured using an inertial measurement unit (IMU) of EOTS and the vehicle's navigation results, navigation results with high rate can be obtained. Due to the time-delay of the navigation results of the vehicle in the EOTS and scale factor errors of the EOTS IMU in high-speed and high dynamic operation of the vehicle, it is much more difficult to have accurate navigation results. In this paper, an integrated navigation system of EOTS which compensates time-delay and scale factor error is proposed. The proposed integrated navigation system consists of vehicle's navigation system which provides time-delayed navigation results, an EOTS IMU, an inertial navigation system (INS), an augmented Kalman filter and integration Kalman filter. The augmented Kalman filter outputs navigation results, in which the time-delay of the vehicle's navigation results is compensated. The integration Kalman filter estimates position, velocity, attitude error of the EOTS INS and accelerometer bias, accelerometer scale factor error, gyro bias and gyro scale factor error from the difference between the output of the augmented Kalman filter and the navigation result of the EOTS INS. In order to check performance of the proposed integrated navigation system, simulations for output data of a measurement generator and land vehicle experiments were performed. The performance evaluation results show that the proposed integrated navigation system provides more accurate navigation results.

Measurement Time-Delay Compensation and Initial Attitude Determination of Electro-Optical Tracking System Using Augmented Kalman Filter (Augmented 칼만 필터를 이용한 전자광학 추적 장비의 측정치 시간지연 보상과 초기 자세 결정)

  • Son, Jae Hoon;Choi, Woo Jin;Kim, Sung-Su;Oh, Sang Heon;Lee, Sang Jeong;Hwang, Dong-Hwan
    • Journal of Korea Multimedia Society
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    • v.24 no.12
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    • pp.1589-1597
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    • 2021
  • Due to the low output rate and time delay of vehicle's navigation results, the electro-optical tracking system(EOTS) cannot estimate accurate target positions. If an inertial measurement unit(IMU) is additionally mounted into the EOTS and inertial navigation system(INS) is constructed, the high navigation output rate can be obtained. And the time-delay can be compensated by using the augmented Kalman filter. An accurate initial attitude is required in order to have accurate navigation outputs. In this paper, an attitude determination algorithm is proposed using the augmented Kalman filter in order to compensate measurement delay of the EOTS and have accurate initial attitude. The proposed initial attitude determination algorithm consists of an augmented Kalman filter, an INS, and an integrated Kalman filter. The augmented Kalman filter compensates the time-delay of the vehicle's navigation results and the integrated Kalman filter estimates the navigation error of the INS. In order to evaluate performance of the proposed algorithm, vehicle's navigation outputs and IMU measurements were generated using sensors' model-based measurement generator and initial attitude estimation errors of the proposed algorithm and the conventional algorithm without the augmented Kalman filter were compared for the generated measurements. The evaluation results show that the proposed algorithm has better accuracy.