• Title/Summary/Keyword: baseline model

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Performance Improvement in GPS Attitude Determination Using Unscented Kalman Filters (GPS를 이용한 자세결정에서 Unscented Kalman Filter를 이용한 성능 향상)

  • Chun Sebum;Lee Eunsung;Kang Taesam;Jee Gyu-In;Lee Young Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.7
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    • pp.621-626
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    • 2005
  • With precise GPS carrier positioning result, we can get attitude information if GPS antenna has adequate attaching position on the vehicle. In this case, baseline length information can be bandied as an additional measurement or constraint. In this paper, we have proposed a method to improve the attitude accuracy. To overcome nonlinearity of baseline observation model, we analyze attitude estimation result using existing estimation method like a least square method and Kalman filter, and apply a new nonlinear estimation method an unscented Kalman filter Finally we confirm the improvement of attitude estimation result in the case of appling the unscented Kalman filter.

AERODYNAMIC DESIGN OPTIMIZATION OF ROTOR AIRFOIL WITH MULTIPLE CONSTRAINTS (다중제약조건을 가진 로터익형의 공력 최적 설계)

  • Lee, S.M.;Sa, J.H.;Jeon, S.E.;Kim, C.J.;Park, S.H.;Chung, K.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.55-59
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    • 2010
  • Aerodynamic design optimization of rotor airfoil has been performed with advanced design method for improved aerodynamic characteristics of ONERA airfoils as a baseline. A multiple response surface method is used to consider various consider various constraints in rotor airfoil design. Airfoil surface and mean camber line are modified using various shape functions. Numerical simulations are performed using KFLOW, a Navier-Stokes solver with shear stress transport turbulence model. The present design method provides favorable configurations for the high performance rotor airfoil. Resulting optimized air foils give better aerodynamic performance than the baseline airfoils.

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A Survey of Use of Computers in Mathematics Education (수학교육 현장에서 교육 정보화의 현황과 과제)

  • 김민경;노선숙
    • School Mathematics
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    • v.3 no.1
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    • pp.45-74
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    • 2001
  • In this paper, an analysis of survey questions relating to educational technology which was extracted from a more general survey of 1-12 mathematics teachers in Korea is reported. The general survey was conducted to provide a baseline for evaluating and developing recommendations for mathematics curriculum that is consistent with the knowledge based information society model of the future. The basic requirements for technology based education are availability of hardware and the ability of teachers to use technology for education. Therefore, the availability and use of technology by mathematics teachers in today’s curriculum was analyzed. The computer ability of teachers, the amount of computer use in the classroom, and the attitude of teachers about the use of technology for education was analyzed. The analysis is intended to provide a baseline of information for understanding and developing plans for better implementing technology for mathematic education.

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AERODYNAMIC DESIGN OPTIMIZATION OF ROTOR BLADE OA AIRFOILS (로터 블레이드 OA 익형의 공력 최적 설계)

  • Sa, J.H.;Park, S.H.;Kim, C.J.;Yun, C.Y.;Kim, S.H.;Kim, S.;Yu, Y.H.
    • Journal of computational fluids engineering
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    • v.14 no.2
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    • pp.25-31
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    • 2009
  • Numerical optimization of rotor blade airfoils is performed with a response surface method for helicopter rotor. For the baseline airfoils, OA 312, OA 309, and OA 407 airfoils are selected and optimized to improve aerodynamic performance. Aerodynamic coefficients required for the response surface method are obtained by using Navier-Stokes solver with k-$\omega$ Shear Stress Transport turbulence model. An optimized airfoil has increased drag divergence Mach number. The present design optimization method can generate an optimized airfoil with multiple design constraints, whenever it is designed from different baseline airfoils at the same design condition.

MODELING QUANTITATIVE VARIATION - In the Kyungnam Dialect of Korean -

  • Cho, Yong-Hyung
    • Speech Sciences
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    • v.1
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    • pp.137-152
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    • 1997
  • The objectives of this paper are to see how the declination is realized in the different positions/lengths of the utterance, to see if the $F_0$ value throughout the utterance changes in a predictable way, and if so, to find out the best quantitative model which fits the declination. The experiment results are as follows. First, the peak value over the utterance can be affected by the position of the peak and length of the utterance. Second, the choice of quantitative models is dependent on the different list lengths. Third, in everyone's speech, there is a baseline (the lowest $F_0$ value a speaker can use), and the $F_0$ will not fall below the baseline. Forth, the peak $F_0$ of the last word in each list shows little variation in pitch value (target $F_0$) while the number of words in the list affects the starting $F_0$ values.

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DSM Potential Evaluation and Procedures on Commercial Sector (업무용 부문의 DSM 잠재량 평가절차 및 절전잠재량 추정)

  • Rhee, Chang-Ho;Park, Jong-Jin;Jo, In-Seung
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.5
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    • pp.531-537
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    • 1999
  • This paper presents the evaluaton procedures and the estimation model for DSM potential on commercial sector in Korea. In general, the evaluation process of the potential savings for DSM measures or programs consists of baseline electricity consumption forecast and potential evaluation such as technical potential(TP), economic potnetial(EP), and achievable potential(AP). A library of energy conservation measures applicable to each end-use or apparatus is developed, and energy savings and other factors are applied to the baseline demand estimates of consumption to produce potential savings estimates. The purpose of this paper is to establish the evaluation process of those DSM potential for commercial sector. In case study, we applied it to commercial sector for horizon years by end-use.

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Determination of Research Octane Number using NIR Spectral Data and Ridge Regression

  • Jeong, Ho Il;Lee, Hye Seon;Jeon, Ji Hyeok
    • Bulletin of the Korean Chemical Society
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    • v.22 no.1
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    • pp.37-42
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    • 2001
  • Ridge regression is compared with multiple linear regression (MLR) for determination of Research Octane Number (RON) when the baseline and signal-to-noise ratio are varied. MLR analysis of near-infrared (NIR) spectroscopic data usually encounters a collinearity problem, which adversely affects long-term prediction performance. The collinearity problem can be eliminated or greatly improved by using ridge regression, which is a biased estimation method. To evaluate the robustness of each calibration, the calibration models developed by both calibration methods were used to predict RONs of gasoline spectra in which the baseline and signal-to-noise ratio were varied. The prediction results of a ridge calibration model showed more stable prediction performance as compared to that of MLR, especially when the spectral baselines were varied. . In conclusion, ridge regression is shown to be a viable method for calibration of RON with the NIR data when only a few wavelengths are available such as hand-carry device using a few diodes.

Impacts Of 3 Baselines(Scope, Schedule, Cost) Caused by PMMM Level Under Software Projects. (소프트웨어 프로젝트에서 프로젝트 관리 성숙도가 3Baseline(범위, 일정, 원가)에 미치는 영향 연구)

  • Kim, IlSoo;Lee, SeoukJoo;Choi, JinYoung
    • Annual Conference of KIPS
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    • 2012.04a
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    • pp.1159-1162
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    • 2012
  • 프로젝트 관리 성숙도(Project Management Maturity Model)란 프로젝트 관리 관련 업무 성숙도를 측정하는 것으로, 프로젝트 성공을 위해 관련 있는 업무가 어느 정도 수준으로 진행되고 있는가를 평가하는 목적으로 주로 사용된다. 본 논문에서는 프로젝트 관리 성숙도를 활용하여 프로젝트 관리 성숙도가 범위, 일정, 그리고 원가에 미치는 영향을 연구 하였다. 연구 결과로 프로젝트 관리 성숙도가 낮으면 범위 변경률이 커지고, 일정이 지연되며, 비용 또한 초과되는 것으로 나타났다. 본 연구의 성과를 토대로 기업이 프로젝트 관리 성숙도 향상을 위해 투자와 노력을 해야 한다는 것을 알 수 있다.

Crack detection in concrete slabs by graph-based anomalies calculation

  • Sun, Weifang;Zhou, Yuqing;Xiang, Jiawei;Chen, Binqiang;Feng, Wei
    • Smart Structures and Systems
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    • v.29 no.3
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    • pp.421-431
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    • 2022
  • Concrete slab cracks monitoring of modern high-speed railway is important for safety and reliability of train operation, to prevent catastrophic failure, and to reduce maintenance costs. This paper proposes a curvature filtering improved crack detection method in concrete slabs of high-speed railway via graph-based anomalies calculation. Firstly, large curvature information contained in the images is extracted for the crack identification based on an improved curvature filtering method. Secondly, a graph-based model is developed for the image sub-blocks anomalies calculation where the baseline of the sub-blocks is acquired by crack-free samples. Once the anomaly is large than the acquired baseline, the sub-block is considered as crack-contained block. The experimental results indicate that the proposed method performs better than convolutional neural network method even under different curvature structures and illumination conditions. This work therefore provides a useful tool for concrete slabs crack detection and is broadly applicable to variety of infrastructure systems.

Improving Detection Range for Short Baseline Stereo Cameras Using Convolutional Neural Networks and Keypoint Matching (컨볼루션 뉴럴 네트워크와 키포인트 매칭을 이용한 짧은 베이스라인 스테레오 카메라의 거리 센싱 능력 향상)

  • Byungjae Park
    • Journal of Sensor Science and Technology
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    • v.33 no.2
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    • pp.98-104
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    • 2024
  • This study proposes a method to overcome the limited detection range of short-baseline stereo cameras (SBSCs). The proposed method includes two steps: (1) predicting an unscaled initial depth using monocular depth estimation (MDE) and (2) adjusting the unscaled initial depth by a scale factor. The scale factor is computed by triangulating the sparse visual keypoints extracted from the left and right images of the SBSC. The proposed method allows the use of any pre-trained MDE model without the need for additional training or data collection, making it efficient even when considering the computational constraints of small platforms. Using an open dataset, the performance of the proposed method was demonstrated by comparing it with other conventional stereo-based depth estimation methods.