• 한국식품저장유통학회지
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• 제6권1호
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• pp.29-36
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• 1999

Using Fuji apple fruits cultivated in Kyungpook prefecture, the calibration model for firmness evaluation of fruits by near infrared(NIR) reflectance spectroscopy was developed, and the various influence factors such as instrument variety, measuring method, sample group, apple peel and selection of firmness point were investigated. Spectra of sample were recorded in wavelength range of 1100∼2500nm using NIR spectrometer (InfraAlyzer 500), and data were analyzed by stepwise multiple linear regression of IDAS program. The accuracy of calibration model was the highest when using sample group with wide range, and the firmness mean values obtained in graph by texture analyser(TA) were used as standard data. Chemometrics models were developed using a calibration set of 324 samples and an independent validation set of 216 samples to evaluate the predictive ability of the models. The correlation coefficients and standard error of prediction were 0.84 and 0.094kg, respectively. Using developed calibration model, it was possible to monitor the firmness change of fruits during storage frequently. Time, which was reached to firmness high value in graph by TA, is possible to use as new parameter for freshness of fruit surface during storage.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.92-95
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• 2008

The Geostationary Ocean Color Imager (GOCI) is under development to provide a monitoring of ocean-color around the Korean Peninsula from geostationary platforms. It is planned to be loaded on Communication, Ocean, and Meteorological Satellite (COMS) of Korea. The GOCI has been designed to provide multi-spectral data to detect, monitor, quantify, and predict short term changes of coastal ocean environment for marine science research and application purpose. The target area of GOCI observation covers sea area around the Korean Peninsula. Based on the nonlinear radiometric model, the GOCI calibration method has been derived. The radiometric model of GOCI has been validated through radiometric ground test. From this ground test result, GOCI radiometric model has been changed from second order to third order. In this paper, the radiometric test performed to evaluate the radiometric nonlinearity is described and the GOCI radiometric error propagation is analyzed. The GOCI radiometric calibration is based on onboard calibration devices; solar diffuser, DAMD (Diffuser Aging Monitoring Device). The radiometric model error due to the dark current nonlinearity is considered as a systematic error. Also the offset correction error due to gain/offset instability is considered. The radiometric accuracy depends mainly on the ground characterization accuracies of solar diffuser and DAMD.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.814-822
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• 2022

The deployment of sensors for Structural Health Monitoring requires a complicated network arrangement, ground truthing, and calibration for validating sensor performance periodically. Any conventional sensor on a structural element is also subjected to static and dynamic vertical loadings in conjunction with other environmental factors, such as brightness, noise, temperature, and humidity. A structural model with strain gauges was built and tested to get realistic sensory information. This paper investigates different deep learning architectures and algorithms, including unsupervised, autoencoder, and supervised methods, to benchmark blind drift calibration methods using deep learning. It involves a fully connected neural network (FCNN), a long short-term memory (LSTM), and a gated recurrent unit (GRU) to address the blind drift calibration problem (i.e., performing calibrations of installed sensors when ground truth is not available). The results show that the supervised methods perform much better than unsupervised methods, such as an autoencoder, when ground truths are available. Furthermore, taking advantage of time-series information, the GRU model generates the most precise predictions to remove the drift overall.

• 한국측량학회지
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• 제36권6호
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• pp.443-449
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• 2018

SLAM (Simultaneous Localization and Mapping) 기반 모바일 매핑 시스템을 활용한 실내 공간의 포인트 클라우드 취득은 건축물의 유지, 관리를 위한 as-built BIM (Building Information Model) 구축의 기초 공정이다. 본 연구에서는 다중 2D 레이저 스캐너로 구성된 모바일 매핑 시스템의 구축을 위한 시뮬레이션 기반 검정(calibration) 표적의 구조 결정 방법을 제안하였다. 2D 레이저 스캐너의 외부 표정요소 검정을 위해 (1) 원형, (2) 사각형, (3) 이중 원형, (4) 이중 사각형 형태의 표적을 구성하였다. 시뮬레이션을 통해 얻어진 각 표적 관측 값을 토대로, 최소제곱법 기반의 외부 표정요소 검정을 수행하였다. 그 결과 사각형 형태의 표적 구조가 주어진 시스템의 검정에 가장 적합한 형태임을 확인하였다. 또한 외부 표정요소 간의 높은 상관성을 확인할 수 있었으며, 표적의 구조에 따른 외부 표정요소의 검정 결과가 상이한 것으로 나타났다.

• 한국농공학회논문집
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• 제47권4호
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• pp.65-74
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• 2005

AnnAGNPS model was applied to a catchment mainly occupied with bushland for modeling non-point source pollution. Since the single event model cannot handle events longer than 24 hours duration, the event-based calibration was carried out using the continuous mode. As event flows affect sediment and nutrient generation and transport, the calibration of the model was performed in three steps: Hydrologic, Sediment and Nutrient calibrations. The results from hydrologic calibration for the catchment indicate a good prediction of the model with average ARE(Absolute Relative Error) of $24.6\%$ fur the runoff volume and $12\%$ for the peak flow. For the sediment calibration, the average ARE was $198.8\%$ indicating acceptable model performance for the sediment prediction. The predicted TN(Total Nitrogen) and TP(Total Phosphorus) were also found to be acceptable as the average ARE for TN and TP were $175.5\%\;and\;126.5\%$, respectively. The AnnAGNPS model was therefore approved to be appropriate to model non-point source pollution in bushland catchments. In general, the model was likely to result in underestimation for the larger events and overestimation fur the smaller events for the water quality predictions. It was also observed that the large errors in the hydrologic prediction also produced high errors in sediment and nutrient prediction. This was probably due to error propagation in which the error in the hydrologic prediction influenced the generation of error in the water quality prediction. Accurate hydrologic calibration should be hence obtained for a reliable water quality prediction.

• 산업기술연구
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• 제36권
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• pp.9-16
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• 2016

In the face of increasing impact of climate change due to human activities, there has been an urgent need to resolve the problem in water resources planning management and environmental engineering. Therefore SWAT model was used to identify the impacts and change in hydrological cycle and environmental aspect. The most important step for the development of SWAT model is calibration procedure. Therefore, SWAT-CUP automatic calibration module was used to find some optimal parameters in SWAT model. After calibration in the cheongmicheon basin, SWAT model is used for the projected precipitation and temperature of RCP 4.5 and 8.5 climate change scenarios in AR5. The quantity and quality using SWAT model from 2014 to 2100 were identified. Finally, this study can provide the reasonable finding on impact by climate change.

• 한국군사과학기술학회지
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• 제5권4호
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• pp.67-77
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• 2002

This paper introduces the calibration results of the fatigue crack growth models for damage tolerance analysis of the aircraft structures. Generalized Willenborg model and Wheeler model are calibrated with experimental data tested under the load spectrum of a trainer. The retardation factors such as, shut-off ratio in Generalized Willenborg model and shaping exponent in Wheeler model, are evaluated for aluminum alloys AL2024-T3511, AL7050-T7451 and AL7075-T73511. It is shown that the retardation effect of the crack growth rate depends on the yield strength of material and the maximum stress in the load spectrum. Generalized Willenborg model and Wheeler model give satisfactory prediction of crack growth life but the calibration of the experimental parameters with test is required.

• 천문학논총
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• 제12권1호
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• pp.1-21
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• 1997

We have obtained theoretical calibration curves to convert the amount of polarization into the strength of magnetic field, by a numerical calculation of radiation transfer for the polarized spectral line of FeI $6303{\AA}$. In our calculation, three kinds of atmospheric models (VAL-C, penumbra, umbra) have been used to make a proper calibration for an active region composed of quiet, penumbral and umbral areas. It was found that firstly, the results of our calculation depend highly on a kind of atmospheric model rather than on any other input parameters used in a model. Secondly, observed line profile showed m solar spectrum atlas proved to be very similar to the calculated profiles obtained by using a penumbra model. Finally, another method except this calibration curve should be developed to estimate correctly the distribution of magnetic field in solar active region from the observation of polarized spectral line.

• 품질경영학회지
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• 제19권1호
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• pp.83-94
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• 1991

The purpose of this study is to analyze the economic efficiency of the investment for calibrating measurement instruments in manufacturing industries, and to propose the administration scheme of measurement instruments. To investigate the efficieny of calibration, we estimate a multiple regression model composed of variables - product inferiority-rate, calibration rate, etc-, and verify fitness of the model. According to the statistical analysis by LOGIT method, a forecasting model of product inferiority-rate with calibration-related variables is proposed, and its validity is investigated.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.947-952
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• 2021

In this paper, the simplified kinematic error model for Delta parallel robot is presented, which can enable the analytical forward kinematics essentially for kinematic calibration calculations instead of the numerical one. The simplified kinematic error model is proposed and the forward kinematics including the error parameters is analytically derived. The kinematic calibration algorithm of the Delta parallel robot with 90 degree arrangement using laser tracker and the experiment result are presented.