• Title/Summary/Keyword: 시점 추적

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Mean-field-Bias Correction of the Rainfall Forecasts Using Backward-Forward Storm Tracking (호우의 역방향-정방향 추적기법을 이용한 예측강우 편의보정)

  • Na, Wooyoung;Kim, Gildo;Song, Sung-uk;Yoo, Chulsang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.202-202
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    • 2020
  • 산지 및 도시에서 발생하는 돌발홍수가 대상인 예경보는 홍수 도달시간이 짧고, 수위가 급격하게 상승하는 특성 때문에 1시간 선행시간 확보를 목표로 한다(MOLIT, 2016). 그러나 현재 돌발홍수 예경보 process에 소요되는 시간은 그 이상으로 확인되고 있다. 또한, 돌발홍수 예경보시스템으로부터 출력된 예측 결과를 사람이 직접 확인해야 한다는 단점도 있다. 본 연구에서는 돌발홍수 예경보 선행시간 1시간 확보를 목표로 backward-forward tracking 기법 기반 예측강우 편의보정기법을 제안하고자 한다. 이 기법은 현재 시점보다 이전에 보정계수를 결정함으로써 돌발홍수 예경보 소요시간을 크게 줄여 돌발홍수 대피시간을 확보할 수 있게 한다. 또한, 보정계수의 결정과 적용이 연속적으로 이루어짐에 따라 10분 간격으로 생성되는 MAPLE의 지속적인 편의보정이 가능하다. 예측강우에 대한 보정계수는 현재보다 10분 이전에 결정한다. 즉, 10분 이전 시점에 생성된 10분, 70분 선행 예측강우에 backward tracking을 적용하여 현재 시점의 호우 위치인 target window를 찾는다. 그리고 target window에서 보정계수를 결정한다. 결정된 보정계수는 돌발홍수발령 대상지역인 correction window의 현재 생성된 60분 선행 예측강우에 적용한다. 이 과정에서 과거 시점 10분 선행 예측강우와 현재 시점에 생성된 60분 선행 예측강우와의 forward tracking이 수행된다. Storm tracking 기법으로는 두 예측강우의 호우패턴에 대한 유사성을 정량화한 패턴상관계수를 이용하였다. 대상 호우사상으로는 2016년에 발생한 주요 호우사상을 선정하였다. 본 연구에서 제안하는 기법을 적용하고, 편의보정 결과를 기존 편의보정기법 적용 결과와 비교하였다.

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Implementation of View Point Tracking System for Outdoor Augmented Reality (옥외 증강현실을 위한 관측점 트래킹 시스템 구현)

  • Choi, Tae-Jong;Kim, Jung-Kuk;Huh, Woong;Jang, Byung-Tae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.4
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    • pp.45-54
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    • 2004
  • In this paper, a view point tracking system has been realized for outdoor augmented reality including broad area monitoring. Since the surroundings of the moving view point are changing, it is necessary to track the position and observation moment of the view point system for consistency between real and virtual images. For this reason, the GPS(Global Positioning System) is applied to the realized system for tracking the information on position and direction of the moving system. In addition, an optical position tracking system that is able to track view point in a limited area is used, because the local tracking system has to trace the image variation, seen to the observer in a moving vehicle, at a particular position and time. It was found that the realized outdoor augmented reality system, which combined the virtual information tracked in real time with the real image, can be very practical in various application area.

The Study on Coordinate Transformation of the Tracking Radar in NARO Space Center (나로우주센터 추적레이더의 좌표 변환에 관한 연구)

  • Shin, Han-Seop;Choi, Jee-Hwan;Kim, Dae-Oh;Kim, Tae-Hyung
    • Aerospace Engineering and Technology
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    • v.10 no.1
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    • pp.116-121
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    • 2011
  • The tracking radar systems in NARO space center are used in order to acquire the TSPI (Time, Space, and Position Information) data of the launch vehicle. The tracking radar produce the measurements of tracked targets in the radar-centered coordinate system. When the tracking radar is in the Cartesian/Polar tracking mode, the state vector data is sent in radar-centered Cartesian/Polar coordinate system to RCC. RCC also send the slaving data in Test Range coordinate system to the tracking radar. So, the tracking radars have to transform the slaving data in Test Range coordinate system into in radar-centered coordinate system. In this study, we described the coordinate transformation between radar-centered coordinate system and Test Range coordinated system.

Rank Tracking Probabilities using Linear Mixed Effect Models (선형 혼합 효과 모형을 이용한 순위 추적 확률)

  • Kwak, Minjung
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.241-250
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    • 2015
  • An important scientific objective of longitudinal studies involves tracking the probability of a subject having certain health condition over the course of the study. Proper definitions and estimates of disease risk tracking have important implications in the design and analysis of long-term biomedical studies and in developing guidelines for disease prevention and intervention. We study in this paper a class of rank-tracking probabilities to describe a subject's conditional probabilities of having certain health outcomes at two different time points. Linear mixed effects models are considered to estimate the tracking probabilities and their ratios of interest. We apply our methods to an epidemiological study of childhood cardiovascular risk factors.

Case Study on Business Model for Indoor Positioning System (실내 위치추적 시스템의 비즈니스 모델 사례 연구)

  • Park, Sang Hyuk;Park, Young Sik;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.64-69
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    • 2013
  • Recently, users who are interested in the service at indoor spaces is increasing. An indoor positioning system can minimize a range of positioning error using a variety of wireless communication infrastructure. Also, the system improves an indoor positioning accuracy by combining a mobile communication network. However, flexible positioning technologies regardless of an environment are insufficient. Therefore, this is time for a systematic study on an indoor positioning system business model. This paper classify differences between an indoor positioning system technology and outdoor positioning system technology. And we research a construction and application of the indoor positioning system that is adapted a wireless communication system (Wi-Fi, Bluetooth, RFID, UWE, Fingerprint, etc.) in domestic and foreign. We present a successful model of indoor positioning system and the development for future systems.

Efficient Polling Structure for Pipeline Viterbi Decoder Using Backtrace Prediction Algorithm (역추적 예견 알고리즘을 적용한 파이프라인 비터비 복호기의 효율적인 Polling 구조 제시)

  • You, Ki-Soo;Song, Oh-Young
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.04b
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    • pp.1627-1630
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    • 2002
  • 본 논문은 역추적 예견 알고리즘을 사용한 비터비 복호기에서의 TB단의 Polling 구조의 단순화 방법을 제시한다. 비터비 복호기의 3대 Unit중 하나인 Trace Back에서 역추적 예견 알고리즘을 사용할 경우 복호화 시점에서의 최소 State Metric 값을 찾아야 하는 번거로움을 줄일 수 있다. 하지만 복호 신호의 신뢰도 분산에 따라 Polling Unit 이 추가되어야 함에 따라 실제 하드웨어 복잡도에서의 이득은 미미한 것으로 알려져 있다. 제시된 구조에서는 Polling Unit을 단순화 할 수 있는 방법을 적용하였다. 기존 하드웨어와의 비교 평가를 위하여 IEEE802.11a의 표준에 따른 부호화율 1/2, 구속장 7을 갖는 비터비 디코더에 대하여 역추적 예견 알고리즘과 파이프라인 구조만을 갖는 경우와 제안된 단순화한 Polling Unit을 적용한 구조와의 비교에서 Trace Back Unit에서 약 45%의 감소 효과를 보였다.

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3D Display Method for Moving Viewers (움직이는 관찰자용 3차원 디스플레이 방법)

  • Heo, Gyeong-Mu;Kim, Myeong-Sin
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.4
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    • pp.37-45
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    • 2000
  • In this paper we suggest a method of detecting the two eyes position of moving viewer by using images obtained through a color CCD camera, and also a method of rendering view-dependent 3D image which consists of depth estimation, image-based 3D object modeling and stereoscopic display process. Through the experiment of applying the suggested methods, we could find the accurate two-eyes position with the success rate of 97.5% within the processing time of 0.39 second using personal computer, and display the view-dependent 3D image using Fl6 flight model. And through the similarity measurement of stereo image rendered at z-buffer by Open Inventor and captured by stereo camera using robot, we could find that view-dependent 3D picture obtained by our proposed method is optimal to viewer.

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Design of Carrier Recovery Circuit for High-Order QAM - Part II : Performance Analysis and Design of the Gear-shift PLL with ATC(Automatic Transfer-mode Controller) and Average-mode-change Circuit (High-Order QAM에 적합한 반송파 동기회로 설계 - II부. 자동모드전환시점 검출기 및 평균모드전환회로를 적용한 Gear-Shift PLL 설계 및 성능평가)

  • Kim, Ki-Yun;Kim, Sin-Jae;Choi, Hyung-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.4
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    • pp.18-26
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    • 2001
  • In this paper, we propose an ATC(Automatic Transfer mode Controller) algorithm and an average-mode-change method for use in Gear shift PLL which can automatically change loop gain. The proposed ATC algorithm accurately detects proper timing or the mode change and has a very simpler structure - than the conventional lock detector algorithm often used in QPSK. And the proposed average mode change method can obtain low errors of estimated frequency offset by averaging the loop filter output of frequency component in shift register. These algorithms are also useful in designing ASIC, since these algorithms occupy small circuit area and are adaptable for high speed digital processing. We also present phase tracking performance of proposed Gear-shift PLL, which is composed of polarity decision PD, ATC and average mode change circuit, and analyze the results by examining constellation at each mode.

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Follow - up Study on Functional Change and Aspect of Physical Therapy in Stroke Patients (뇌졸중환자의 물리치료양상 및 기능변화에 관한 추적연구)

  • Yi Seung-Ju
    • The Journal of Korean Physical Therapy
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    • v.10 no.2
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    • pp.41-55
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    • 1998
  • An analysis of 87 stroke Patients who were enrolled in 7 hospitals in cities of Pusan, Taegu, Kumi, and Andong from January 1 to May 31, 1998 was conducted using the modified Barthel Index(BI) and the adapted PULSES profile index(PS) to evaluate their function. Patients were examined at the following intervals : Initial assessment, one month after initial, at discharge, and ore month after discharge. The mean BI score of patients initial assessment was 26.32. and that of PS was 17.34. There were statistically significant between initial score and one month after initial (16.61 : p<0.001), at discharge(33.51 : p<0,001), one month after discharge(43,56 : p<0.001). PS scores were also improved significantly(-2.1, -3. 94, and -5.52(p<0.001), and BI score between discharge and one month after discharge wag significant improvement(10.06 : p <0.001) and in PS score(-1,57 : p<0.001). Age and BI scone were significantly associated with the improved in BI score between initial and discharge (T3-T1)(p<0.05). Below age forty and the lower initial BI score showed significantly higher improvement(T3-T1) after physical therapy(p<0.05). Initial BI score, BI score at discharge, and religion were significantly associated with the improvement of BI score between initial and one month after discharge(T4-T1)(p<0.05). The lower initial BI score, the high. BI score at discharge, and the religious showed significantly higher improvement(T4-T1)(p<0.05). BI score at discharge and religion were significantly associated with the improvement of BI score between at discharge and one month after discharge(T4-T3)(p<0.05). The lower BI score at discharge, the religious showed significantly higher improvement(T4-T3)(p<0.05) Initial PS score were significantly associated with the improved in PS score between initial and discharge(T3-T1)(p<0.05). The higher initial PS score showed significantly hier improvement(T3-T1)(p<0.05). Initial PS score, Bi score at discharge, and patient's attitude for physical therapy after discharge were significantly associated with the improvement of PS score between initial and one month after discharge(T4- T1)(p <0.05). The higher initial PS scorer the lower PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T1)(p<0.05). PS score at discharge, Patient's attitude for Physical therapy after discharge were significantly associated with the improvement of PS score between discharge and one month after discharge(T4-T3)(p<0.05). The higher PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T3)(p<0.05). In conclusion, Initial BI score, BI score at discharge, age, and religion were significantly associated with BI score improvement. initial PS score, BI score discharge, and patient's attitude for physical therapy after discharge were significantly associated with PS score improvement in stroke patients.

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Feature point extraction using scale-space filtering and Tracking algorithm based on comparing texturedness similarity (스케일-스페이스 필터링을 통한 특징점 추출 및 질감도 비교를 적용한 추적 알고리즘)

  • Park, Yong-Hee;Kwon, Oh-Seok
    • Journal of Internet Computing and Services
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    • v.6 no.5
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    • pp.85-95
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    • 2005
  • This study proposes a method of feature point extraction using scale-space filtering and a feature point tracking algorithm based on a texturedness similarity comparison, With well-defined operators one can select a scale parameter for feature point extraction; this affects the selection and localization of the feature points and also the performance of the tracking algorithm. This study suggests a feature extraction method using scale-space filtering, With a change in the camera's point of view or movement of an object in sequential images, the window of a feature point will have an affine transform. Traditionally, it is difficult to measure the similarity between correspondence points, and tracking errors often occur. This study also suggests a tracking algorithm that expands Shi-Tomasi-Kanade's tracking algorithm with texturedness similarity.

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