• 제목/요약/키워드: Data Sets

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주성분 분석을 활용한 재현자료 생성 (Synthetic data generation by probabilistic PCA)

  • 박민정
    • 응용통계연구
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    • 제36권4호
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    • pp.279-294
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    • 2023
  • 재현자료를 생성할 때 순차회귀 다중대체(SRMI)를 이용하는 방식이 가장 널리 알려져 있으며, 이를 구현한 소프트웨어로 R-패키지 synthpop이 활용되고 있다. 본 논문에서는 확률적 주성분 분석(PPCA)을 이용하여 재현자료를 생성하는 방안을 제안하고 2개의 데이터 세트를 이용한 모의실험으로 SRMI 방식과 PPCA 방식을 비교하였다. 모의실험에서 PPCA 방식으로 생성한 재현자료는 쌍별 상관계수를 기준으로 원자료와의 유사성이 가장 우수함을 확인하였다. 향후 PPCA 방식을 이용하여 시계열 자료에 대한 재현자료 생성을 연구하고자 한다.

ACCURATE ESTIMATION OF GLOBAL LATENT HEAT FLUX USING MULTI-SATELLITE DATA

  • Tomita Hiroyuki;Kubota Masahisa
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.14-17
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    • 2005
  • Global latent heat flux data sets are crucial for many studies such as those related to air-sea interaction and climate variation. Currently, various global latent heat flux data sets are constructed using satellite data. Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO) includes one of the satellite-derived global latent heat flux data (Kubota et aI., 2000). In this study, we review future development of J-OFURO global latent heat flux data set. In particular, we investigate usage of multi-satellite data for estimating accurate global latent heat flux. Accurate estimation of surface wind speeds over the global ocean is one of key factors for the improved estimation of global latent heat flux. First, we demonstrate improvement of daily wind speed estimation using multi-satellites data from microwave radiometers and scatterometers such as DMSP/SSMI, ERS/AMI, QuikSCAT/SeaWinds, AqualAMSR-E, ADEOS2/AMSR etc. Next, we demonstrate improvement of global latent heat flux estimation using the wind speed data derived from multi-satellite data.

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AGV Navigation Using a Space and Time Sensor Fusion of an Active Camera

  • Jin, Tae-Seok;Lee, Bong-Ki;Lee, Jang-Myung
    • 한국항해항만학회지
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    • 제27권3호
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    • pp.273-282
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    • 2003
  • This paper proposes a sensor-fusion technique where rho data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent only on the current data sets. As the results, more of sensors are required to measure a certain physical promoter or to improve the accuracy of the measurement. However, in this approach, intend of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples md the effectiveness is proved through the simulation. Finally, the new space and time sensor fusion (STSF) scheme is applied to the control of a mobile robot in the indoor environment and the performance was demonstrated by the real experiments.

A Study on Mobile Robot Navigation Using a New Sensor Fusion

  • Tack, Han-Ho;Jin, Tae-Seok;Lee, Sang-Bae
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.471-475
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    • 2003
  • This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. Finally, the new space and time sensor fusion (STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.

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Control of the Mobile Robot Navigation Using a New Time Sensor Fusion

  • Tack, Han-Ho;Kim, Chang-Geun;Kim, Myeong-Kyu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권1호
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    • pp.23-28
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    • 2004
  • This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. Finally, the new space and time sensor fusion(STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.

Deformable image registration in radiation therapy

  • Oh, Seungjong;Kim, Siyong
    • Radiation Oncology Journal
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    • 제35권2호
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    • pp.101-111
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    • 2017
  • The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

A Study on Indoor Mobile Robot Navigation Used Space and Time Sensor Fusion

  • Jin, Tae-Seok;Ko, Jae-Pyung;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.104.2-104
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    • 2002
  • This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system , the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is il lustrated by examples and...

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Rough 집합 이론을 이용한 원격 탐사 다중 분광 이미지 데이터의 특징 추출 (Features Extraction of Remote Sensed Multispectral Image Data Using Rough Sets Theory)

  • 원성현;정환묵
    • 한국지능시스템학회논문지
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    • 제8권3호
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    • pp.16-25
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    • 1998
  • 본 논문에서는 초 다중 밴드 환경의 효과적인 데이터 분류를 위해서 Roungh 집합 이론을 이용한 특징 추출 방법을 제안한다. 다중 분광 이미지 데이터의 특성을 분석하고, 그 분석 결과를 토대로 Rough집합이론의 식별 능력을 이용하여 가장 효과적인 밴드를 선택할 수 있도록 한다. 실험으로는 Landsat TM으로부터 취득한 데이터에 적용시켰으며, 이를 통해 전통적인 밴드 특성에 의한 밴드 선택 방법과 본 논문에서 제안하는 러프 집합 이론을 이용한 밴드 선택 방법이 일치됨을 보이고 이를 통해 초다중 밴드 환경에서의 특징 추출에 대한 이론적 근거를 제시한다.

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지진파 스펙트럼특성과 선형판별분석을 이용한 자연지진과 인공지진 식별 (Discrimination between earthquake and explosion by using seismic spectral characteristics and linear discriminant analysis)

  • 제일영;전정수;이희일
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2003년도 추계 학술발표회논문집
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    • pp.13-19
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    • 2003
  • Discriminant method using seismic signal was studied for discrimination of surface explosion. By means of the seismic spectral characteristics, multi-variate discriminant analysis was performed. Four single discriminant techniques - Pg/Lg, Lg1/Lg2, Pg1/Pg2, and Rg/Lg - based on seismic source theory were applied to explosion and earthquake training data sets. The Pg/Lg discriminant technique was most effective among the four techniques. Nevertheless, it could not perfectly discriminate the samples of the training data sets. In this study, a compound linear discriminant analysis was defined by using common characteristics of the training data sets for the single discriminants. The compound linear discriminant analysis was used for the single discriminant as an independent variable. From this analysis, all the samples of the training data sets were correctly discriminated, and the probability of misclassification was lowered to 0.7%.

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퍼지-라프 집합을 이용한 관계 데이터베이스 구성 (Design and Implementation of Relational Database model Using Fuzzy-rough Sets)

  • 강전근;정환묵
    • 한국정보처리학회논문지
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    • 제4권1호
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    • pp.1-10
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    • 1997
  • 본 논문에서는 의미적으로 접근되어 애매성이 있으며 구별하기 힘든 자료를 효과 적으로 관리하기 위한 방안의 하나로 퍼지 집합과 라프 집합을 통합한 퍼지-라프 집 합(Fuzzy-Rough Sets:FRS)을 이용, 관계 데이터베이스를 구성하고 구현하였다. 먼저 불완전한 정보를 데이터베이스로 구성, 표현하는 방법에 대하여 일반적 관계 데이터 베이스를 확장시킨 퍼지 데이터베이스와 라프 데이터베이스를 간략히 살펴본다. 그리 고 퍼지 집합과 라프 집합을 통합한 퍼지-라프 집합을 근거로 퍼지-라프(Fuzzy -Rough:FR)관계데이터베이스를 구성한 후, 펜티엄 컴퓨터(166Mhz)상에서 데이터베이 스 관리 시스템인 엑세스(access)와 비쥬얼베이직(visual)을 도구(tool)로 구현하고 분석 하였다. 본 논문에서는 퍼지 집합의 특성과 라프 집합의 특성을 가진 집합을 기 반으로 한 데이터베이스를 구성, 구현함으로서 데이터의 감소를 유도하였다.

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