• 제목/요약/키워드: Uncertain Measure

검색결과 103건 처리시간 0.032초

AKARI-SDSS-GALEX SURVEYS: SPECTRAL ENERGY DISTRIBUTIONS OF NEARBY GALAXIES

  • Buat, V.;Yuan, F.T.;Takeuchi, T.T.;Giovannoli, E.;Heinis, S.
    • 천문학논총
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    • 제27권4호
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    • pp.317-320
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    • 2012
  • A sample of nearby galaxies was built from the AKARI/FIS all sky survey cross-correlated with the SDSS and GALEX surveys. The spectral energy distributions from 0.15 to 160 microns of these galaxies are analysed to study dust attenuation and star formation properties. The calibrations of the amount of dust attenuation as a function of the IR-to-UV flux ratio and the FUV-NUV colour are re-investigated: the former one is confirmed to be robust and accurate whereas the use of the FUV-NUV colour to measure dust attenuation is found highly uncertain. The current star formation rate given by the SED fitting process is compared to that directly obtained from the UV and total IR luminosities. It leads to an accurate estimate of dust heating by old stars. We emphasize the importance of such a sample as a reference for IR selected star forming galaxies in the nearby universe.

오차 감소를 위한 이동로봇 Self-Localization과 VRML 영상오버레이 기법 (Self-localization of a Mobile Robot for Decreasing the Error and VRML Image Overlay)

  • 권방현;손은호;김영철;정길도
    • 제어로봇시스템학회논문지
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    • 제12권4호
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    • pp.389-394
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    • 2006
  • Inaccurate localization exposes a robot to many dangerous conditions. It could make a robot be moved to wrong direction or damaged by collision with surrounding obstacles. There are numerous approaches to self-localization, and there are different modalities as well (vision, laser range finders, ultrasonic sonars). Since sensor information is generally uncertain and contains noise, there are many researches to reduce the noise. But, the correctness is limited because most researches are based on statistical approach. The goal of our research is to measure more exact robot location by matching between built VRML 3D model and real vision image. To determine the position of mobile robot, landmark-localization technique has been applied. Landmarks are any detectable structure in the physical environment. Some use vertical lines, others use specially designed markers, In this paper, specially designed markers are used as landmarks. Given known focal length and a single image of three landmarks it is possible to compute the angular separation between the lines of sight of the landmarks. The image-processing and neural network pattern matching techniques are employed to recognize landmarks placed in a robot working environment. After self-localization, the 2D scene of the vision is overlaid with the VRML scene.

Remaining service life estimation of reinforced concrete buildings based on fuzzy approach

  • Cho, Hae-Chang;Lee, Deuck Hang;Ju, Hyunjin;Kim, Kang Su;Kim, Ki-Hyun;Monteiro, Paulo J.M.
    • Computers and Concrete
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    • 제15권6호
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    • pp.879-902
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    • 2015
  • The remaining service life (RSL) of buildings has been an important issue in the field of building and facility management, and its development is also one of the essential factors for achieving sustainable infrastructure. Since the estimation of RSL of buildings is heavily affected by the subjectivity of individual inspector or engineer, much effort has been placed in the development of a rational method that can estimate the RSL of existing buildings more quantitatively using objective measurement indices. Various uncertain factors contribute to the deterioration of the structural performance of buildings, and most of the common building structures are constructed not with a single structural member but with various types of structural components (e.g., beams, slabs, and columns) in multistory floors. Most existing RSL estimation methods, however, consider only an individual factor. In this study, an estimation method for RSL of concrete buildings is presented by utilizing a fuzzy theory to consider the effects of multiple influencing factors on the deterioration of durability (e.g., concrete carbonation, chloride attack, sulfate attack), as well as the current structural condition (or damage level) of buildings.

호텔개발사업의 불확실성에 전략적으로 대응하기 위한 실물옵션 적용 연구 (A Study on Application of Real Option for Strategic Response to Uncertainty in Hotel Development Project)

  • 권태인;이상효;김재준
    • 한국디지털건축인테리어학회논문집
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    • 제10권2호
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    • pp.5-12
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    • 2010
  • Unlike housing development project that can ensure profit by selling built units, a hotel development depends on long-term business operation to be profitable due to characteristics of service industry. The expected cash flow has substantial uncertainty depending on room occupancy rate and room charge. Thus, even after construction is complete, business risk tends to rise. It is necessary to ensure strategic response to uncertainty in future value of a hotel. The objective of the study is to explore strategic measures to deal with risk and uncertain future value in hotel development project by adopting abandonment option, which is a type of real options. The case in analysis had sevenyears of project period: Two years for construction, and five years for operation; a plan was made to sell the hotel after five years' of operation. For the research purpose, option value ofrecoverable investment amount was estimated, and value of abandonment option was KRW 124.921 billion. When abandonment option is applied, the project value was deemed to be KRW 120.592 billion. Generally, the amount of loss is enormous when a real estate project like a hotel development fails, and therefore, application of option is expected to be an effective measure to leverage uncertainty of a project.

A Critical Review of Current Crisis Simulation Methodology

  • Kim, Hak-Kyong;Lee, Ju-Lak
    • International Journal of Contents
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    • 제7권1호
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    • pp.58-64
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    • 2011
  • This paper is concerned with simulation exercises used to train key response agencies for crisis situations. While 'multi-agency' simulations are increasingly acknowledged as a necessary and significant training tool for emergency response organisations, many current crisis simulations are still focused on the revision of existing response plans only. However, a crisis requires a rapid reaction, yet in contrast to an 'emergency', the risks for critical decision makers in crisis situations are difficult to measure, owing to their ill-structure. In other words, a crisis situation is likely to create great uncertainty, unfamiliarity and complexity, and consequently should be managed by adaptive or second order expertise and techniques, rather than routine or structured responses. In this context, the paper attempts to prove that the current practices of simulation exercises might not be good enough for uncertain, unfamiliar, and complex 'crisis' situations, in particular, by conducting case studies of two different underground fire crises in Korea (Daegu Subway Fire 2003) and the UK (King's Cross Fire 1987). Finally, it is suggested that the three abilities: 'flexibility', 'improvisation' and 'creativity' are critical in responding to a crisis situation.

변위 제한 조건하에서의 신뢰성 기반 형상 최적화 (Reliability-Based Shape Optimization Under the Displacement Constraints)

  • 오영규;박재용;임민규;박재용;한석영
    • 한국생산제조학회지
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    • 제19권5호
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    • pp.589-595
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    • 2010
  • This paper presents a reliability-based shape optimization (RBSO) using the evolutionary structural optimization (ESO). An actual design involves uncertain conditions such as material property, operational load, poisson's ratio and dimensional variation. The deterministic optimization (DO) is obtained without considering of uncertainties related to the uncertainty parameters. However, the RBSO can consider the uncertainty variables because it has the probabilistic constraints. In order to determine whether the probabilistic constraint is satisfied or not, simulation techniques and approximation methods are developed. In this paper, the reliability-based shape design optimization method is proposed by utilization the reliability index approach (RIA), performance measure approach (PMA), single-loop single-vector (SLSV), adaptive-loop (ADL) are adopted to evaluate the probabilistic constraint. In order to apply the ESO method to the RBSO, a sensitivity number is defined as the change of strain energy in the displacement constraint. Numerical examples are presented to compare the DO with the RBSO. The results of design example show that the RBSO model is more reliable than deterministic optimization.

슬라이딩 섭동 관측기를 이용한 수술용 로봇 인스트루먼트의 반력 추정 가능성 평가 (Evaluation of a Possibility of Estimation of Reaction Force of Surgical Robot Instrument using Sliding Perturbation Observer)

  • 윤성민;이민철;김지언;강병호
    • 로봇학회논문지
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    • 제7권1호
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    • pp.20-28
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    • 2012
  • In spite of the difficulties and uncertain characteristic of cable driven method, surgical robot instrument has adopted it as driving mechanism for various reasons. To overcome the problem of cable system, previous research applied SMCSPO (sliding mode control with sliding perturbation observer) algorithm as robust controller to control the instrument and found that the value of SPO (sliding perturbation observer) followed force disturbance, reaction force loaded on the tip very similarly. Thus, this paper confirms that the perturbation observer is sufficient estimator which finds out the mount of loaded force on the surgical robot instrument. To prove the proposition, simulation using the similar model with an actual instrument and experimental evaluation are performed. The results show that it is possible to substitute SPO for sensors to measure the reaction force. This estimated reaction force will be used to realize haptic function by sending the reaction force to a master device for a surgeon. The results will contribute to create surgical benefit such as shortening the practice time of a surgeon and giving haptic information to surgeon by using it as haptic signal to protect an organ by making force boundary.

이동로봇의 거리측정을 위한 고성능 일체형 초음파 모듈 개발 (Development of Robust Single Ultrasonic Module for Distance Measurement of Mobile Robot)

  • 최종훈;심현민;유제군;이응혁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.418-420
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    • 2005
  • This paper proposed ultrasonic distance measurement module development for correct distance detection with collision escaping or obstacle of mobile robot is traveling self-regulation. Representative ultrasonic module applied in existing was Polaroid company's 6500 series and Devantech company's SRF04/SRF08 series. This ultrasonic sensors are corrupted by systematic errors due mainly to the dependency of sound speed upon surrounding conditions and random errors of uncertain origin. Therefore Ultrasonic distance detecting means of error compensation method and high definition, narrow beam angle, board area distance detecting means to apply to ultrasonic mobile robot control urgently need. In this paper use internal type temperature compensation method to improve problem of ultrasonic distance measurement method instead of that volume that have shortcoming of used correct temperature compensation methods applied big addition device. Compensate error by environment change of temperature. Humidity density etc. and is applicable to mobile robot offering various interface and real-time processing developed possible distance measurement module.

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불안 및 우울 장애에 있어서 불확실성에 대한 불내성의 역할 (The Role of Intolerance of Uncertainty in Anxiety and Depressive Disorders)

  • 이준엽;이상혁;서호석
    • 대한불안의학회지
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    • 제9권1호
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    • pp.3-9
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    • 2013
  • Intolerance of uncertainty (IU) is defined as the tendency to react negatively on an emotional, cognitive, and behavioral level to uncertain situations and events. However, this definition is somewhat categorical and does not explain the phenomenology of IU. Intolerance of uncertainty scale (IUS), the standard measure of IU, was considered to have two factors : 'unacceptability and avoidance of uncertainty' and 'uncertainty leading to the inability to act'. IU may be a cognitive vulnerability factor for clinical worry and generalized anxiety disorder (GAD). A number of moderators and mediators including cognitive avoidance, experiential avoidance and rumination influence the relationship between IU, worry, obsessive-compulsive symptoms, anxious and depressive symptoms. IU may be more strongly related to the symptoms of GAD than to symptoms of other anxiety disorders including obsessive-compulsive disorder (OCD), and major depressive disorder. IU may serve as an important transdiagnostic feature across anxiety and depressive disorders. Incorporating IU-specific treatment components into therapeutic protocols may result in pervasive benefits, and not only for those with GAD or OCD, but for people with any anxiety disorder or with depression.

VRML 영상오버레이기법을 이용한 로봇의 Self-Localization (VRML image overlay method for Robot's Self-Localization)

  • 손은호;권방현;김영철;정길도
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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    • pp.318-320
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    • 2006
  • Inaccurate localization exposes a robot to many dangerous conditions. It could make a robot be moved to wrong direction or damaged by collision with surrounding obstacles. There are numerous approaches to self-localization, and there are different modalities as well (vision, laser range finders, ultrasonic sonars). Since sensor information is generally uncertain and contains noise, there are many researches to reduce the noise. But, the correctness is limited because most researches are based on statistical approach. The goal of our research is to measure more exact robot location by matching between built VRML 3D model and real vision image. To determine the position of mobile robot, landmark-localitzation technique has been applied. Landmarks are any detectable structure in the physical environment. Some use vertical lines, others use specially designed markers, In this paper, specially designed markers are used as landmarks. Given known focal length and a single image of three landmarks it is possible to compute the angular separation between the lines of sight of the landmarks. The image-processing and neural network pattern matching techniques are employed to recognize landmarks placed in a robot working environment. After self-localization, the 2D scene of the vision is overlaid with the VRML scene.

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