• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2339-2355
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• 2021

In this paper, a joint probabilistic data association algorithm based on loss function (LJPDA) is proposed so that the computation load and accuracy of the multi-target tracking algorithm can be guaranteed simultaneously. Firstly, data association is divided in to three cases based on the relationship among validation gates and the number of measurements in the overlapping area for validation gates. Also the contribution coefficient is employed for evaluating the contribution of a measurement to a target, and the loss function, which reflects the cost of the new proposed data association algorithm, is defined. Moreover, the equation set of optimal contribution coefficient is given by minimizing the loss function, and the optimal contribution coefficient can be attained by using the Newton-Raphson method. In this way, the weighted value of each target can be achieved, and the data association among measurements and tracks can be realized. Finally, we compare performances of LJPDA proposed and joint probabilistic data association (JPDA) algorithm via numerical simulations, and much attention is paid on real-time performance and estimation error. Theoretical analysis and experimental results reveal that the LJPDA algorithm proposed exhibits small estimation error and low computation complexity.

• Korean Journal of Childcare and Education
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• v.19 no.6
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• pp.1-19
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• 2023

Objective: The aim of the present study was to develop and validate a recognition scale for childcare teachers' rights. Methods: Statistical methods for data analysis involved the use of SPSS 20.0 and AMOS 20.0. To confirm the reliability and validity of the developed scale, various analyses, including item quality assessment, item discrimination, exploratory factor analysis, confirmatory factor analysis, and Pearson correlation analysis, were conducted. The maximum likelihood estimation method was employed for model fitting. Goodness of fit was assessed using SRMR, RMSEA and its 90% confidence interval, CFI, and TLI. Through these analyses, the scale's reliability and validity exceeded the standard. Consequently, 5 factors and 30 questions were ultimately selected as the recognition scale for childcare teachers' rights. Results: First, a recognition scale for childcare teachers' rights was developed to reflect changes in childcare settings. Second, an objective measurement was incorporated into the recognition scale of childcare teachers' rights. Third, the analysis using the proposed scale revealed a correlation between the recognition of childcare teachers' rights and life satisfaction. Conclusion/Implications: The study developed a scale capable of objectively measuring the recognition of childcare teachers' rights.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.783-788
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• 2011

Different from the main land of South Korea, Jeju Island has been in difficulties for measuring discharge. Due to high infiltration rate, most of streams in Jeju Island are usually in the dried state except six streams with the steady base flow, and the unique geological characteristics such as steep slope and short traveling distance of runoff have forced rainfall runoff usually to occur during very short period of time like one or two days. While discharge observations in Jeju Island have been conducted only for 16 sites with fixed electromagnetic surface velocimetry, effective analysis and validation of observed discharge data and operation of the monitoring sites still have been limited due to very few professions to maintain such jobs. This research is sponsored by Ministry of Land, Transport and Maritime Affairs to build water cycle monitoring and management system of Jeju Island. Specifically, the research focuses on optimizing discharge measurement techniques adjusted for Jeju Island, expanding the monitoring sites, and validating the existing discharge data. First of all, we attempted to conduct discharge measurements in streams with steady base flow, by utilizing various recent discharge monitoring techniques, such as ADCP, LSPIV, Magnetic Velocimetry, and Electromagnetic Wave Surface Velocimetry. ADCP has been known to be the most accurate in terms of discharge measurement compared with other techniques, thus that the discharge measurement taken by ADCP could be used as a benchmark data for validation of others. However, there are still concerns of using ADCP in flood seasons; thereby LSPIV would be able to be applied for replacing ADCP in such flooded situation in the stream. In addition, sort of practical approaches such as Magnetic Velocimetry, and Electromagnetic Wave Surface Velocimetry would also be validated, which usually measure velocity in the designated parts of stream and assume the measured velocity to be representative for whole cross-section or profile at any specified location. The result of the comparison and analysis will be used for correcting existing discharge measurement by Electromagnetic Wave Surface Velocimetry and finding the most optimized discharge techniques in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2511-2520
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• 2011

This paper describes the parameter adjustment method of fuzzy membership function to improve the performance of multi-sensor fusion system using adaptive fuzzy-Kalman filter and cross-validation. The adaptive fuzzy-Kanlman filter has two input parameters, variation of accelerometer measurements and residual error of Kalman filter. The filter estimates system noise R and measurement noise Q, then changes the Kalman gain. To evaluate proposed adaptive fuzzy-Kalman filter, we make the two-axis AHRS(Attitude Heading Reference System) using fusion of an accelerometer and a gyro sensor. Then we verified its performance by comparing to NAV420CA-100 to be used in various fields of airborne, marine and land applications.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2655-2661
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• 2012

Validation of a food frequency questionnaire (FFQ) utilising a short-term measurement method is challenging when the reference method does not accurately reflect the usual food intake. In addition, food group intake that is not consumed on daily basis is more critical when episodically consumed foods are related and compared. To overcome these challenges, several statistical approaches have been developed to determine usual food intake distributions. The Multiple Source Method (MSM) can calculate the usual food intake by combining the frequency questions of an FFQ with the short-term food intake amount data. In this study, we applied the MSM to estimate the usual food group intake and evaluate the validity of an FFQ with a group of 333 Korean children (aged 3-6 y) who completed two 24-hour recalls (24HR) and one FFQ in 2010. After adjusting the data using the MSM procedure, the true rate of non-consumption for all food groups was less than 1% except for the beans group. The median Spearman correlation coefficients against FFQ of the mean of 2-d 24HRs data and the MSM-adjusted data were 0.20 (range: 0.11 to 0.40) and 0.35 (range: 0.14 to 0.60), respectively. The weighted kappa values against FFQ ranged from 0.08 to 0.25 for the mean of 2-d 24HRs data and from 0.10 to 0.41 for the MSM-adjusted data. For most food groups, the MSM-adjusted data showed relatively stronger correlations against FFQ than raw 2-d 24HRs data, from 0.03 (beverages) to 0.34 (mushrooms). The results of this study indicated that the application of the MSM, which was a better estimate of the usual intake, could be worth considering in FFQ validation studies among Korean children.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.104-108
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• 2018

The purpose of this study was to establish valerenic acid as a marker compound for the standardization of ethanol extract of Valerinan officinalis (valerian) root as a functional health food. We established valerenic acid as a marker compound using HPLC. HPLC was used to quantify the marker compound in the valerian extract after validation of methods with linearity, accuracy, and precision. The specificity for retention time was met by comparative analysis of the valerian extract and standard compound using HPLC. The method showed high linearity of the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The limit of quantification (LOQ) was $10{\mu}g/mL$. The accuracy of measurement was 99.88~00.68% and the relative standard deviation (RSD) value was 0.59%. In addition, our analytical method yielded a 29% mean content of valerenic acid in the valerian ethanol extract. These results indicate that the established HPLC method facilitated the determination of marker compounds in the valerian extract for the standardization of health functional foods.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.357-365
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• 2011

Exposure measurement of agricultural worker to pesticide is one of important part of health risk assessment of pesticide. Therefore exposure matrices, apparatus, instruments and methods must be validated in advance to field experiment. In this study, method validation with an organophosphorus insecticide fenthion was carried out for exposure monitoring of agricultural worker. LOD and LOQ were 0.01 and 0.05 ng, respectively. Calibration curve linearity ($R^2$ > 0.999) and reproducibility (C.V. < 3%) were also excellent. Recovery at LOQ, 10LOQ and 100LOQ levels from gloves, socks, mask, patch, solid sorbent, glass fiber filter was 76~113% (C.V. < 3%). Trapping efficiency was 95~105% while no breakthrough was observed. Method validation for the exposure monitoring was established successfully through several experiments. Such method validation can be usually performed in laboratory and not much different for each pesticide so that, this techniques will be applied widely in research for pesticide exposure monitoring by combination with body surface area and respiration rates.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.177-188
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• 2023

The purpose of this study is to develop and validate a scale for measuring digital literacy by identifying the factors consisting of digital literacy and extracting items for each factor. Preliminary items for the Delphi study were developed through the analysis of previous literature and the deliberation of the research team. As a result of two rounds of the expert Delphi study, 65 items were selected for the main survey. The validation of the items was carried out in the process of exploratory and confirmatory factor analyses, reliability test, and criterion validity test using the data collected in the main survey. As a result, a 4-factor structure composed of 31 questions(factor 1: digital technology & data literacy- 9 questions, factor 2: digital content & media literacy- 8 questions, factor 3: digital communication & community literacy- 9 questions, factor 4: digital wellness literacy - 5 questions) was confirmed. Also, the goodness of fit indices of the model were found to be good and the result of reliability test revealed the scale had a very appropriate level of Cronbach's alpha(α=.956). In addition, a statistically significantly positive correlations(p<.001) were found between digital literacy and internet self-efficacy and between digital literacy and self-directed learning ability, which were predicted in the existing evidence, therefore the criterion validity of the developed scale was secured. Finally, practical and academic implications of the study are provided and future study and limitations of the study are discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1054-1061
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• 2016

Development of an accurate infrared signature (IR) measurement system is expected to contribute in the development of low observable technology and the spectroscopic analysis of electromagnetic radiation. Application of a spectroradiometer (SR) allows for the measurement of detailed infrared signature from the exhaust plume due to its own heat source. Establishment of a measurement system using a micro-turbo engine is intended to simulate the modelling of the aircraft plume. The engine was installed on a test stand to measure the engine performance. The IR signature was measured by placing the SR perpendicular to the axis line of the exhaust plume. Reference data from the blackbody were also measured to calibrate the raw data, and the infrared signature of the background was also measured for comparison with that of the plume. The calibrated spectral radiance was obtained through the data reduction process and the results were analyzed in specific bands. The experiments revealed that the measurement system established here showed sufficient performance for further comprehensive analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.29-36
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• 2015

Exact comparisons of the thermal conductivities of the base fluid and a nanofluid are very important in the early stages of nanofluid development. A simple procedure of measuring the thermal conductivity of the two fluids by the transient hot wire method and numerically dividing these values is used for this purpose. However, because the experiments are not performed simultaneously and the physical properties of the measurement system are sometimes not properly known, large errors are incurred during the evaluation process. This article proposes a new apparatus for thermal conductivity comparison where the working principle is mainly based on relative measurement rather than absolute measurement. The measuring circuit and data processing steps are explained in detail; a validation test was performed using the well-known glycerine and engine oil.