• 제목/요약/키워드: Multi-sensing System

검색결과 417건 처리시간 0.027초

편심하중 요소를 활용한 방수형 다분력 검력계 개발 (Development of a Multi-Component Waterproof Type Force Sensor Devised with Column Elements Under Eccentric Load)

  • 김효철;신창환;유성선;함연재
    • 대한조선학회논문집
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    • 제61권3호
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    • pp.200-207
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    • 2024
  • A multi-component force sensor has been developed to measure force and moment components in high-speed flow media for submerged models. The size of the test model is determined based on the Reynolds number of the model at the test speed and expected blockage effect. A two-component force sensor unit has been created by assembling pairs of column elements arranged symmetrically under an eccentric load. The six-component force sensor is constructed with symmetric arrangements of two-component force sensor units in a rectangular plane. The signals generated from the strain gauges attached to the surface of the elements can be converted into force signals. The performance of the waterproof six-component force sensor has been evaluated through calibration. A simplified interference decomposition procedure has been introduced to increase the accuracy of measurement.

Sentinel 위성기반 한반도 연속 지반변화 관측체계 개발 (Development of Continuous Ground Deformation Monitoring System using Sentinel Satellite in the Korea)

  • 유정흠;윤혜원
    • 대한원격탐사학회지
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    • 제35권5_2호
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    • pp.773-779
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    • 2019
  • 본 연구에서는 유럽에서 운영 중인 Sentinel-1 위성레이더 자료를 기반으로 하여 한반도 전역의 지반변화를 자동으로 분석하는 체계 구축을 수행하였다. 장시간에 걸려 발생하는 지반변화 자연재난은 광역적 지역에서 발생하게 되어 관측의 어려움과 분석을 위한 대용량의 자료가 요구되었다. 하지만, 인공위성의 발달로 광역지역을 주기적으로 관측할 수 있는 방법이 개발되었으며, 이렇게 축적된 다년간의 위성 관측 자료를 활용하여 시계열적인 지반의 변화를 분석할 수 있게 되었다. 이에 연구원에서는 한반도 전 지역을 대상으로 위성레이더 관측자료 취득에서 부터 지반변위 분석 및 분석 결과 표출까지 모든 과정을 자동화 하는 체계를 구축하였다. 본 연구에서 개발된 체계를 기반으로 한반도 전 지역에 대한 주기적인 지반변화 자료의 갱신이 가능하게 되었으며, 변화 우려지역에 대한 사전적 정보제공을 통하여 대형 재난에 대한 예방단계의 대응이 가능하게 될 것으로 기대된다. 향후 지역별 자동화 분석 체계와 동일대상 지역의 다 채널 분석 및 3차원 변화 분석체계에 대한 연구가 진행된다면, 보다 다양한 지반변위 정보를 제공할 수 있을 것이다.

SURFACE DEFORMATION MONITORING USING TERRASAR-X INTERFEROMETRY

  • Kim, Sang-Wan;Wdowinski, Shimon;Dixon, Tim
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.422-425
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    • 2008
  • TerraSAR-X is new radar satellite operated at X-band, multi polarization, and multi beam mode. Compared with C-band or L-band SAR, the X-band system inherently suffers from more temporal decorrelation, but is more sensitive to surface deformation monitoring due to short wavelength (3.1 cm) and high spatial resolution (1m-3m). It is generally expected that sensitivity to estimate surface movement using TerraSAR-X will be increased by the factor of 10, compared to current C-band system with low spatial resolution such as ERS-2, Envisat. Many urban areas are experiencing land subsidence due to water, oil and natural gas withdrawal, underground excavation, sediment compaction, and so on. Monitoring of surface deformation is valuable for effectively limiting damage areas. In addition high accuracy and spatially dense subsidence map can be achieved by X-band InSAR observation, promoting identification and separation of various subsidence processes and leading to enhanced understanding via mechanical modeling. In this study we will introduce some initial InSAR results using new TerraSAR-X SAR data for surface deformation monitoring.

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INTRODUCTION OF NUC ALGORITHM IN ON-BOARD RELATIVE RADIOMERIC CALIBRATION OF KOMPSAT-2

  • Song, J.H.;Choi, M.J.;Seo, D.C.;Lee, D.H.;Lim, H.S.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.504-507
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    • 2007
  • The KOMPSAT-2 satellite is a push-broom system with MSC (Multi Spectral Camera) which contains a panchromatic band and four multi-spectral bands covering the spectral range from 450nm to 900nm. The PAN band is composed of six CCD array with 2528 pixels. And the MS band has one CCD array with 3792 pixels. Raw imagery generated from a push-broom sensor contains vertical streaks caused by variability in detector response, variability in lens falloff, pixel area, output amplifiers and especially electrical gain and offset. Relative radiometric calibration is necessary to account for the detector-to-detector non-uniformity in this raw imagery. Non-uniformity correction (NUC) is that the process of performing on-board relative correction of gain and offset for each pixel to improve data compressibility and to reduce banding and streaking from aggregation or re-sampling in the imagery. A relative gain and offset are calculated for each detector using scenes from uniform target area such as a large desert, forest, sea. In the NUC of KOMPSAT-2, The NUC table for each pixel are divided as HF NUC (high frequency NUC) and LF NUC (low frequency NUC) to apply to few restricted facts in the operating system ofKOMPSAT-2. This work presents the algorithm and process of NUC table generation and shows the imagery to compare with and without calibration.

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Design of Main Computer Board for MSC on KOMPSAT-2

  • Heo, H.P.;Kong, J.P.;Yong, S.S.;Kim, Y.S.;Park, J.E.;Youn, H.S.;Paik, H.Y.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1096-1098
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    • 2003
  • SBC(Single Board Computer) is being developed for MSC(Multi-Spectral Camera) on KOMPSAT-2(Korea Multi-Purpose Satellite). SBC controls all the units of MSC system and gets commands and sends telemetry to and from spacecraft bus via 1553 communication channel. Due to the fact that SBC does very important roles for MSC system operation and SBC operates with 100% duty cycle, SBC is designed to have high reliability. SBC which has Intel 80486 as a main processor includes eight serial communication channels, one mil-std-1553 interface channel and several discrete interfaces. SBC incorporates 2Mbyte radiation hardened SRAM(Static Random Access Memory) and 1Mbyte flash memory. There are also PIC(Programmable Interrupt Controller), counter, WDT(Watch Dog Timer) in the SBC. In this paper, the design result of the SBC is presented.

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다중가스센서를 이용한 화재의 조기검출에 대한 연구 (A Study on the Early Fire Detection by Using Multi-Gas Sensor)

  • 조시형;장향원;전진욱;최석임;김선규;강종위;최삼진;박찬원
    • 센서학회지
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    • 제23권5호
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    • pp.342-348
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    • 2014
  • This paper introduced a novel multi-gas sensor detector with simple signal processing algorithm. This device was evaluated by investigating the characteristics of combustible materials using fire-generated smell and smoke. Plural sensors including TGS821, TGS2442, and TGS260X were equipped to detect carbon monoxide, hydrogen gas, and gaseous air contaminants which exist in cigarette smoke, respectively. Signal processing algorithm based on the difference of response times in fire-generated gases was implemented with early and accurately fire detection from multiple gas sensing signals. All fire experiments were performed in a virtual fire chamber. The cigarette, cotton fiber, hair, polyester fiber, nylon fiber, paper, and bread were used as a combustible material. This analyzing software and sensor controlling algorithm were embedded into 8-bit micro-controller. Also the detected multiple gas sensor signals were simultaneously transferred to the personnel computer. The results showed that the air pollution detecting sensor could be used as an efficient sensor for a fire detector which showed high sensitivity in volatile organic compounds. The proposed detecting algorithm may give more information to us compared to the conventional method for determining a threshold value. A fire detecting device with a multi-sensor is likely to be a practical and commercial technology, which can be used for domestic and office environment as well as has a comparatively low cost and high efficiency compared to the conventional device.

RPS 시스템을 이용한 차량 제어 특성 해석 (Analysis of Control Performance using RPS System)

  • 김효준;이창노
    • 한국산학기술학회논문지
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    • 제19권5호
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    • pp.160-166
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    • 2018
  • 본 연구에서는 주행하는 도로면의 단면 형상 정보를 이용하는 RPS 시스템과 다원형 감쇠 특성을 가지는 MSD 시스템을 기반으로 예견 제어 알고리즘을 적용한 지능형 현가 시스템을 제안하고, 그 결과를 제시하였다. 자동차의 과도한 진동과 조종 불안정성을 유발하는 대표적인 외란 입력은 주행하는 도로면에 돌출되거나 함몰된 불규칙한 주행 장애물이다. 이러한 장애물의 존재 유무만이 아니라 그 형상에 대한 정보를 안다면 이를 활용하여 제어 성능을 개선시킬 수 있다. 선행 연구 결과를 바탕으로 하여, 상용성을 고려한 구조화된 작동 시스템을 적용한 응용 연구를 수행하였다. 이를 위해 RPS 시스템과 예견 제어 기법을 기반으로 한 제어 알고리즘과 다차원화된 감쇠 특성을 가지는 MSD 시스템 간의 스위칭 알고리즘을 개발, 연계성을 제시하였다. 실차 적용성을 파악하기 위하여, 제안된 제어 프레임을 전차량 모델에 구현하여 시뮬레이션을 수행하였다. 구조적 간결성을 목표로 적용된 3-DS 작동기 시스템과 결합된 전자제어식 현가 시스템을 통하여 탑승자의 승차감과 차체의 조종 안정성을 효과적으로 개선할 수 있음과 제 시스템의 유용성을 확인하였다.

무인항공기 기반 해양 감시를 위한 멀티센서 데이터를 활용한 선박 위치 결정 (Ship Positioning Using Multi-Sensory Data for a UAV Based Marine Surveillance)

  • 유형석;아나 클림코브스카;최경아;이임평
    • 대한원격탐사학회지
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    • 제34권2_2호
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    • pp.393-406
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    • 2018
  • 매년 해양에서 많은 사고가 빈번하게 발생하고 불법 조업이 성행하고 있으며, 그 규모와 빈도도 증가하고 있다. 이로 인한 인명이나 재산 피해를 경감시키기 위하여 신속한 원격 감시 수단이 필요하다. 이러한 감시 수단의 효과적인 플랫폼으로써 무인항공기가 주목을 받고 있다. 해양 사고나 불법 조업이 이루어지는 상황에서 주된 감시 대상은 선박이 될 것이다. 이에 본 연구에서는 무인항공기 기반 선박 감시 체계를 제안하고, 무인항공기 센서 데이터를 이용하여 선박 위치를 결정하는 방법을 제시하고자 한다. 제안된 방법에서 먼저 사전에 수행된 시스템 캘리브레이션 결과와 영상 취득 시각에 취득된GPS/INS데이터를 이용해서 개별 영상을 취득한 위치와 자세를 결정한다. 또한, 개별 영상으로부터 선박을 자동 또는 반자동으로 탐지한 후 탐지된 지점들의 절대좌표를 결정한다. 제안된 방법을 200 m, 350 m, 500 m 고도에서 취득된 실측 데이터에 적용한 결과로 각각 4.068 m, 8.916 m, 13.374 m의 정확도로 선박 위치를 결정할 수 있었다. 수로측량의 최소기준에 따라 항해에 덜 중요한 해안선 및 지형 위치 항목에서 200 m 데이터의 선박위치결정 결과는 특등급, 350 m와 500 m 데이터의 결과는 1a등급을 만족한다. 제안된 방법은 다양한 목적의 해양 감시 또는 측량에 효과적으로 활용될 수 있을 것으로 판단한다.

3-D Hetero-Integration Technologies for Multifunctional Convergence Systems

  • 이강욱
    • 마이크로전자및패키징학회지
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    • 제22권2호
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    • pp.11-19
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    • 2015
  • Since CMOS device scaling has stalled, three-dimensional (3-D) integration allows extending Moore's law to ever high density, higher functionality, higher performance, and more diversed materials and devices to be integrated with lower cost. 3-D integration has many benefits such as increased multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging volume, because it vertically stacks multiple materials, technologies, and functional components such as processor, memory, sensors, logic, analog, and power ICs into one stacked chip. Anticipated applications start with memory, handheld devices, and high-performance computers and especially extend to multifunctional convengence systems such as cloud networking for internet of things, exascale computing for big data server, electrical vehicle system for future automotive, radioactivity safety system, energy harvesting system and, wireless implantable medical system by flexible heterogeneous integrations involving CMOS, MEMS, sensors and photonic circuits. However, heterogeneous integration of different functional devices has many technical challenges owing to various types of size, thickness, and substrate of different functional devices, because they were fabricated by different technologies. This paper describes new 3-D heterogeneous integration technologies of chip self-assembling stacking and 3-D heterogeneous opto-electronics integration, backside TSV fabrication developed by Tohoku University for multifunctional convergence systems. The paper introduce a high speed sensing, highly parallel processing image sensor system comprising a 3-D stacked image sensor with extremely fast signal sensing and processing speed and a 3-D stacked microprocessor with a self-test and self-repair function for autonomous driving assist fabricated by 3-D heterogeneous integration technologies.

Accuracy Assessment of Precipitation Products from GPM IMERG and CAPPI Ground Radar over South Korea

  • Imgook Jung;Sungwon Choi;Daeseong Jung;Jongho Woo;Suyoung Sim;Kyung-Soo Han
    • 대한원격탐사학회지
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    • 제40권3호
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    • pp.269-274
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    • 2024
  • High-quality precipitation data are crucial for various industries, including disaster prevention. In South Korea, long-term high-quality data are collected through numerous ground observation stations. However, data between these stations are reprocessed into a grid format using interpolation methods, which may not perfectly match actual precipitation. A prime example of real-time observational grid data globally is the Integrated Multi-satellite Retrievals for Global Precipitation Measurement (GPM IMERG) from National Aeronautics and Space Administration (NASA), while in South Korea, ground radar data are more commonly used. GPM and ground radar data exhibit distinct differences due to their respective processing methods. This study aims to analyze the characteristics of GPM and Constant Altitude Plan Position Indicator(CAPPI),representative real-time grid data, by comparing them with ground-observed precipitation data. The study period spans from 2021 to 2022, focusing on hourly data from Automated Synoptic Observing System (ASOS) sites in South Korea. The GPM data tend to underestimate precipitation compared to ASOS data, while CAPPI shows errors in estimating low precipitation amounts. Through this comparative analysis, the study anticipates identifying key considerations for utilizing these data in various applied fields, such as recalculating design rainfall, thereby aiding researchers in improving prediction accuracy by using appropriate data.