• Title/Summary/Keyword: improving accuracy

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Improving Satellite Derived Soil Moisture Data Using Data Assimilation Methods (자료동화 기법을 이용한 위성영상 추출 토양수분 자료 개선)

  • Hwang, Soonho;Ryu, Jeong Hoon;Kang, Moon Seong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.152-152
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    • 2018
  • Soil moisture is a important factor in hydrologic analysis. So, if we have spatially distributed soil moisture data, it can help to study much research in a various field. Recently, there are a lot of satellite derived soil moisture data, and it can be served through web freely. Especially, NASA (National Aeronautics and Space Administration) launched the Soil Moisture Aperture Passive (SMAP) satellite for mapping global soil moisture on 31 January 2015. SMAP data have many advantages for study, for example, SMAP data has higher spatial resolution than other satellited derived data. However, becuase many satellited derived soil moisture data have a limitation to data accuracy, if we have ancillary materials for improving data accuracy, it can be used. So, in this study, after applying the alogorithm, which is data assimilation methods, applicability of satellite derived soil moisture data was analyzed. Among the various data assimilation methods, in this study, Model Output Statistics (MOS) technique was used for improving satellite derived soil moisture data. Model Output Statistics (MOS) is a type of statistical post-processing, a class of techniques used to improve numerical weather models' ability to forecast by relating model outputs to observational or additional model data.

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A Study on Improving Design of Ferrule Grinding Spindle for Higher Stiffness and Accuracy (페룰연삭용 주축의 강성 및 정밀도 개선설계에 관한 연구)

  • 편영식;이건범;요꼬이요시유끼;박정현;여진욱;정일용;안건준
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.7
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    • pp.20-25
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    • 2003
  • 21세기 초고속 통신시스템 구축의 핵심 부품인 고정밀도의 광페룰(Fig. 1)의 수요는 획기적으로 증가할 것으로 전망된다. 전 세계 광페룰 생산량의 90% 정도를 일본에서 생산하고 있으며, 현재 국내 업체들도 일본산 가공설비를 대부분 도입하여 광페룰을 생산하고 있으나 품질 수준이나 생산량에서 아직 미미한 형편이다. 광페룰의 품질수준은 통신 품질의 향상 욕구에 따라 점점 높은 정밀도와 동심도가 요구되고 있으며 정밀도에 따른 가격의 차는 수배에 달하고 있다.(중략)

Molecular Dynamics Simulations for Transport Coefficients of Liquid Argon : New Approaches

  • Lee, Song-Hi;Park, Dong-Kue;Kang, Dae-Bok
    • Bulletin of the Korean Chemical Society
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    • v.24 no.2
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    • pp.178-182
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    • 2003
  • The stress and the heat-flux auto-correlation functions in the Green-Kubo formulas for shear viscosity and thermal conductivity have non-decaying long-time tails. This problem can be overcome by improving the statistical accuracy by N (number of particles) times, considering the stress and the heat-flux of the system as properties of each particle. The mean square stress and the heat-flux displacements in the Einstein formulas for shear viscosity and thermal conductivity are non linear functions of time since the quantities in the mean square stress and the heat-flux displacements are not continuous under periodic boundary conditions. An alternative to these quantities is to integrate the stress and the heat-flux with respect to time, but the resulting mean square stress and heat-flux displacements are still not linear versus time. This problem can be also overcome by improving the statistical accuracy. The results for transport coefficients of liquid argon obtained are discussed.

Precision Calibration of Gyroscopes for Improving Dead-Reckoning Accuracy in Mobile Robots (이동로봇의 추측항법 정확성을 개선하기 위한 자이로스코프의 정확도 교정)

  • Ko Jae-Pyung;Yun Jae-Mu;Lee Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.463-470
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    • 2005
  • This paper describes a method aimed at improving dead-reckoning accuracy with gyroscopes in mobile robots. The method is a precision calibration procedure for gyroscopes, which effectively reduces the ill effects of nonlinearity of the scale-factor and temperature dependency. This paper also describes the methods of gyro data collection fur all ambient temperature$(-40^{\circ}C{\~}+80^{\circ}C)$ using cubic spline interpolation and defining the error function. The sensor used was a vibrating gyroscope called the EWTS82NA21, which is low lost and commonly used in car navigation system, made by Panasonic. This angular rate sensor utilizes Coriolis force generated by a vibrating tuning fork. The paper also provides experimental results to check the performance and the effectiveness of the proposed method.

A Method of Improving Accuracy of Histogram Specification (정확성을 향상시킨 히스토그램 명세화 방법)

  • Huh, Kyung Moo
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.2
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    • pp.175-179
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    • 2014
  • The histogram specification turns the shape of a histogram into that we want to specify. This technique can be applied usefully in various image processing fields such as machine vision. However, the histogram specification technique has its basic limits. For instance, the histogram does not have location information of pixels. Also, the accuracy of the specification drops because of quantization errors of the digitized image. In this paper, we proposed a multiresolution histogram specification method in order to improve the accuracy of specification in terms of resemblance between destination and source image. The experimental results show that the proposed method enhances the accuracy of the specification compared to the conventional methods.

Accuracy Estimation of Laser scanning Mobile Mapping System using Lynx Mobile Mapper (Lynx Mobile Mapper를 이용한 레이저스캐너 기반 차량 MMS의 정확도 평가)

  • Jeong, Tae-Jun;Yun, Hong-Sic;Hwang, Jin-Sang;Kim, Yong-Hyun;Wi, Gwang-Jae;Lee, Ha-Jun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.69-71
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    • 2010
  • In this paper, we focus on the accuracy estimation of laser scanning mobile mapping system using Lynx Mobile Mapper. For this, we surveyed checkpoints(181 points) in study areas. A method to estimate the accuracy of laser scanning mobile mapping system based on the measurement range, interval of control points and gps signal environments. As a result, to ensure reliable measurement results, we must be made a plan considering Measure range(60m or under) and operation. The estimation results showed the need for improving accuracy using control points about 150m interval according to environment error source.

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Development of CNC machine Pre-processor for temperature compensation (CNC공작기계의 온도차보정을 위한 Pre-Processor개발)

  • Shin, Hyun-Myung;Im, Moon-Hyuk
    • Journal of Korean Institute of Industrial Engineers
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    • v.24 no.4
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    • pp.601-611
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    • 1998
  • The machining accuracy of CNC machine tools will decrease the production lead time because the coordinate compensation of the tool path will be unnecessary to meet design specifications. Improving the accuracy of machined parts enhances the reliability and functionality of the assembly as well as the life of the product. Among various factors affecting the accuracy of machined parts, the ambient temperature is the major factor that refers to the temperature surrounding the machine and workpiece. In this study, an experiment was conducted to confirm the dimensional variations caused by changes in the ambient temperature. The ambient temperature resulted in overcutting when it increased. A developed pre-processor converts the CNC program to compensate the dimensional variations caused by temperature changes. This methodology can be used to determine the machining accuracy and improve the positioning accuracy of a machine tool.

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A Consideration of Accuracy Correction Methods in RTLS for Indoor Facility Management with Drones

  • Yeo, ChangJae;yu, Jungho
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.210-213
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    • 2017
  • The construction industry has witnessed an exponential growth of drones used in the field over the past few years. Likewise, the field of maintenance has paid increasing attention to using drones with a view to improving the efficiency of condition checks in high-rise buildings and major space. Although operators manipulate drones to inspect buildings at present, drones are expected to autonomously move around without operators in a few years. Also, for indoor maintenance, it is important for drones to find accurate locations, which is implemented by real-time locating systems(RTLS). Yet, the accuracy of RTLS varies across the types of systems and indoor settings, which warrants a locating system suitable for indoor space and a location correction system designed to improve the accuracy. Hence, the current study investigated the accuracy of real-time locating systems(RTLS) for the maintenance of indoor space of buildings with drones and delved into the methods of correcting the location information to improve the accuracy of RTLS.

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Optimization of Model based on Relu Activation Function in MLP Neural Network Model

  • Ye Rim Youn;Jinkeun Hong
    • International journal of advanced smart convergence
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    • v.13 no.2
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    • pp.80-87
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    • 2024
  • This paper focuses on improving accuracy in constrained computing settings by employing the ReLU (Rectified Linear Unit) activation function. The research conducted involves modifying parameters of the ReLU function and comparing performance in terms of accuracy and computational time. This paper specifically focuses on optimizing ReLU in the context of a Multilayer Perceptron (MLP) by determining the ideal values for features such as the dimensions of the linear layers and the learning rate (Ir). In order to optimize performance, the paper experiments with adjusting parameters like the size dimensions of linear layers and Ir values to induce the best performance outcomes. The experimental results show that using ReLU alone yielded the highest accuracy of 96.7% when the dimension sizes were 30 - 10 and the Ir value was 1. When combining ReLU with the Adam optimizer, the optimal model configuration had dimension sizes of 60 - 40 - 10, and an Ir value of 0.001, which resulted in the highest accuracy of 97.07%.

Inter-expert Agreement and Diagnostic Accuracy of Sasang Constitution Medicine (사상체질 진단 연구의 전문가 일치도와 진단 정확률)

  • Han, Eunkyung;Kwon, Young Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.32 no.4
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    • pp.185-196
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    • 2018
  • The purpose of this study is to evaluate the current inter-expert agreement of Sasang Constitution Medicine (SCM), to expand the current knowledge on the causes of imperfect inter-expert agreement, and to explore possible solutions for improving inter-expert agreement. A literature search was conducted to gather data on the studies on diagnosis of SCM. The 127 articles included in this analysis had a mean 4.1 publications per year, 56.0% published in the Journal of Sasang Constitutional Medicine between the year of 1987 and 2017. SCM specialist participated in 96.3% of all the expert judgment cases. Inter-expert agreement was reported in 14.8% of the cases that had two or more experts. We recommend that expert panels integrate the results of current status of diagnostic consensus into guideline development and strengthen expert education and training with the aim of improving SCM diagnostic accuracy.