• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.891-897
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• 2021

There is a need for a technology that can quickly and accurately analyze soil carbon contents. Existing soil carbon analysis methods are cumbersome in terms of professional manpower requirements, time, and cost. It is against this background that the present study leverages the soil physical properties of color and water content levels to develop a model capable of predicting the carbon content of soil sample. To predict the total carbon content of soil, the RGB values, water content of the soil, and lux levels were analyzed and used as statistical data. However, when R, G, and B with high correlations were all included in a multiple regression analysis as independent variables, a high level of multicollinearity was noted and G was thus excluded from the model. The estimates showed that the estimation coefficients for all independent variables were statistically significant at a significance level of 1%. The elastic values of R and B for the soil carbon content, which are of major interest in this study, were -2.90 and 1.47, respectively, showing that a 1% increase in the R value was correlated with a 2.90% decrease in the carbon content, whereas a 1% increase in the B value tallied with a 1.47% increase in the carbon content. Coefficient of determination (R²), root mean square error (RMSE), and mean absolute percentage error (MAPE) methods were used for regression verification, and calibration samples showed higher accuracy than the validation samples in terms of R² and MAPE.

• The Mathematical Education
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• v.56 no.4
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• pp.407-434
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• 2017

The purpose of this study is to develop and verify the TPACK measurement tool for middle and high school mathematics teachers in the Korean context. Also, by clarifying the relationship between subordinate factors of Mathematics teachers' TPACK, an attempt was made to provide suggestions on the designs and directions for the in-service and pre-service teacher education and the programs for improving mathematics teachers' TPACK in the future. In order to achieve this goal, TPACK factors of mathematics teachers were extracted by reviewing literature on PCK, MKT, and TPACK. Then, content validity, basic statistical survey, reliability verification, exploratory factor analysis, confirmatory factor analysis, and structural equation model verification were conducted sequentially. At first, preliminary analysis was carried out on 79 mathematics teachers, and 76 items excluding the items with extreme value and reliability were included in the basic statistical analysis. And secondly, an exploratory factor analysis was conducted on 376 mathematics teachers, and this instrument consisted of 7 subordinate factors(CK, PK, TK, PCK, TCK, TPK, TPACK) and 61 items. Also by conducting confirmatory factor analysis and structural equation model test with 254 mathematics teachers, the measurement tool was confirmed the validity and reliability through statistically significant analysis. Then, the importance of integrated knowledge was confirmed by looking at the relationship between the TPACK factors of in-service mathematics teachers. The integrated knowledge(PCK, TCK, TPK) has played a crucial role in the formation of TPACK rather than the knowledge of CK, PK, and TK alone. Finally, the validity of TCK was confirmed through the structural equation modeling of TPACK. TCK not only directly affected TPACK, but also indirectly through TPK. According to these affirmative results, this measurement tool is claimed to be suitable for measuring the factors of Mathematics teachers' TPACK, and also the structural equation model can be regarded as a suitable model for analyzing the structural relationship of mathematics teachers' TPACK.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.85-91
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• 2021

This study is a methodological study that explains the procedure for verifying effectiveness in developing practical guidelines for cognitive programs suitable for dementia patients. Based on the development of evidence-based new clinical practice guidelines, a preliminary recommendation for the domestic dementia patient care guidelines was developed. The practical guidelines consisted of the final four types, and the content validity score of the configuration items was 0.87 to 1 point. In the sub-categories of field applicability, appropriateness score was 3.95 to 4.34 points, applicability score was 3.57 to 4.27 points, and predicted effect score was 3.84 to 4.22 points. Through the examination of the content validity and field applicability of experts, it was confirmed that the practical guidelines developed in this study can be used as the basis for establishing an intervention plan for dementia cognitive program managers engaged in clinical practice. In future studies should further facilitate the development of evidence-based treatment guidelines to select appropriate treatment activities for dementia patients.

• Safety and Health at Work
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• v.2 no.3
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• pp.218-228
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• 2011

Objectives: The objective of this study was to test the feasibility and acceptability of a new workers' health surveillance (WHS) for fire fighters in a Dutch pilot-implementation project. Methods: In three fire departments, between November 2007 and February 2009, feasibility was tested with respect to i) worker intent to change health and behavior; ii) the quality of instructions for testing teams; iii) the planned procedure in the field; and iv) future WHS organisation. Acceptability involved i) satisfaction with WHS and ii) verification of the job-specificity of the content of two physical tests of WHS. Fire fighters were surveyed after completing WHS, three testing teams were interviewed, and the content of the two tests was studied by experts. Results: Feasibility: nearly all of the 275 fire fighters intended to improve their health when recommended by the occupational physician. The testing teams found the instructions to be clear, and they were mostly positive about the organisation of WHS. Acceptability: the fire fighters rated WHS at eight points (out of a maximum of ten). The experts also reached a consensus about the optimal job-specific content of the future functional physical tests. Conclusion: Overall, it is feasible and acceptable to implement WHS in a definitive form in the Dutch fire-fighting sector.

• Journal of the Korean Geotechnical Society
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• v.39 no.11
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• pp.53-62
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• 2023

The characteristics of unfrozen water content in frozen soils significantly impact the thermal, hydraulic, and mechanical behavior of the ground. A thorough analysis of the unfrozen water content characteristics of the target subsoil material is crucial for evaluating the stability of frozen ground. This study conducted indoor experiments to measure the freezing point and unfrozen water content of sandy soil while considering pore water salinity. Utilizing the experimental data, we introduced a novel empirical model to conveniently estimate the unfrozen water retention curve. Furthermore, the validity of the unfrozen water retention curve was assessed by comparing the experimental data with the results of a simulation model that utilized the proposed empirical model as input data.

• Water for future
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• v.28 no.6
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• pp.193-202
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• 1995

The subjective research attempts to apply a rainfall-runoff model capable of considering time-variation of soil water contents which are highly correlated to the river flows on the qpqyungchang river basin and to evaluate its performance for flow forecasting. The model used in this study is a physically-based conceptual time-continuous model, which is composed of the Sacramento soil moisture accounting model and the nonlinear multiple conceptual reservoirs model. The daily precipitation and evaporation data for 7 years and for 3 years were used for the parameter estimation and the model verification, respectively. As a result, the flows including a significant flood event were well simulated, and the cross-correlation coefficient between observed flows and computed flows for the verification periods was 0.87, but in general computed flows were underestimated for the low-flow periods. Also, the effects of precipitation and soil water content to the river flows were analysed for the flood and the drought.

• Women's Health Nursing
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• v.16 no.4
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• pp.370-380
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• 2010

Purpose: The purpose of this study was to develop an uncertainty scale for infertile women. Methods: The process included construction of a conceptual framework, generation of 12items, verification of content validity, selection of secondary items, verification of construct validity and extraction of final items. In order to verify the reliability and validity of the preliminary instrument, data were collected from 50 infertile women in an In Vitro Fertilization (IVF) clinic. Data were analyzed by item analysis, Varimax factor analysis and Cronbach's alpha. Results: There were 10 items in the final instrument categorized into 2 factors labeled as "personal (6 items)" and "relational (4 items)" The total variance explained was 73.36%. The instrument was shown to have good reliability with a Cronbach's alpha of .899. Conclusion: Validity and reliability of the scale were confirmed in this study showing its utility to measure uncertainty for infertile women. The instrument can help understand sterility and accurately measure uncertainty for infertile women. The instrument can also be used to evaluate nursing interventions designed for mitigating uncertainty for infertile women.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.5
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• pp.509-520
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• 2003

In this paper, we developed a new and robust algorithm for a practical and very efficient MPEG-4 video coding. The MPEG-4 video group has developed the video Verification Model(VM) which evolved through time by means of core experiments. And in the standardization process, MS-FDAM was developed based on the standard document of ISO/IEC 14496-2 and VM as a reference MPEG-4 coding system. But MS -FDAM has drawbacks in practical MPEG-4 coding and it does not have the VOP extraction functionality. In this research, we implemented a preprocessing system for a real-time input and the VOP extraction for a practical content-based MPEG-4 video coding and also implemented the motion detection to achieve the high compression rate of 180:1.

• Women's Health Nursing
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• v.25 no.1
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• pp.99-111
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• 2019

Purpose: To develop nurses' educational needs scale for woman with infertility. Methods: A total of 201 nurses in charge of infertility health services in 4 infertility hospitals and 1 public health center were enrolled for this study. The scale was developed through literature review, in-depth interview, development of preliminary items, verification of content validity, development of secondary items, verification of construct validity, and extraction of final items. Data were analyzed using item analysis, exploratory factor analysis, Pearson's correlation coefficients, and Cronbach's ${\alpha}$. Results: Nurses' educational needs scale for women with infertility consisted of 41 items. Three factors (education for disease and symptom of infertility, supporting and counselling for infertility patients, and education for daily life of infertile patients) explained 63.7% of the total variance. Conclusions: Nurses' educational needs scale for woman with infertility demonstrated acceptable validity and reliability. Its items could be used to assess the level of educational needs for nurses in charge of infertility health services.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.60-66
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• 2021

Blockchain is a technology that enables trust-based consensus and verification based on a decentralized network. Distributed ID (DID) is based on a decentralized structure, and users have the right to manage their own ID. Recently, interest in self-sovereign identity authentication is increasing. In this paper, as a method for transparent and safe sovereignty management of data, among data pseudonymization techniques for blockchain use, various methods for data encryption processing are examined. The public key technique (homomorphic encryption) has high flexibility and security because different algorithms are applied to the entire sentence for encryption and decryption. As a result, the computational efficiency decreases. The hash function method (MD5) can maintain flexibility and is higher than the security-related two-way encryption method, but there is a threat of collision. Zero-knowledge proof is based on public key encryption based on a mutual proof method, and complex formulas are applied to processes such as personal identification, key distribution, and digital signature. It requires consensus and verification process, so the operation efficiency is lowered to the level of O (log_eN) ~ O(N²). In this paper, data encryption processing for blockchain DID, based on zero-knowledge proof, was proposed and a one-way encryption method considering data use range and frequency of use was proposed. Based on the content presented in the thesis, it is possible to process corrected zero-knowledge proof and to process data efficiently.