• Safety and Health at Work
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• v.8 no.3
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• pp.322-326
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• 2017

In 1992, the quality control program was introduced in Republic of Korea to improve the reliability of the work environment monitoring, which was introduced in the 1980s. The commission entrusted by the Ministry of Employment and Labor, the Occupational Safety and Health Research Institute has conducted the program for industrial hygiene laboratories including designated monitoring institutions and spontaneously participating agencies. The number of institutions that participated in the program has increased from 30 to 161. The initial conformance ratio in the participants was 43% (organic solvents) and 52% (metals). Thereafter, the conformance ratio increased rapidly and it has remained in a stable state at more than 89% since 1996. As subject materials, 13 kinds of organic solvents and 7 kinds of metals were used. To improve the capability of measurement and analysis of private institutions, educational courses were conducted annually. An assessment at the actual sites of participants was additionally introduced into the program in 2013. Thus, the program turned into a system that administrates the overall process of participants. For the future, the scope of target materials will be extended through additional items. Thus, the reliability of the results of the work environment monitoring is expected to increase accordingly.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.288-296
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• 2009

We conducted validation for asbestos quality control (QC) samples made by the developed method which was presented in our published paper. The main results of the validation study are as follows. The pooled coefficient variations of analytical results in three different concentrations (low, medium, and high concentration) for amosite and chrysotile were less than 20 %, which met the sample homogenicity criteria of NIOSH. Also we confirmed the homogenicity of asbestos samples by using the relocatable field slide. To evaluate the field applicability of the developed asbestos QC samples, the field validation was performed with four proficient asbestos analysts by using the statistical methods of AIHA asbestos PAT program. All analytical results from four asbestos analysts were located in the acceptable range.

• Analytical Science and Technology
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• v.23 no.4
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• pp.363-370
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• 2010

This study was performed to validate reference materials (RMs) for proficiency testing (PT) in waste inter-laboratories. Dioxin RMs were prepared from fly ash in industrial incinerators. The relative standard deviations (RSDs) of analytical results were 2.6~15.7% for the dioxin RMs in 10 replicates (between and withinbottles). Data were collected and statistical analysis was performed by the One-way ANOVA test. The combined uncertainties of target isomers in dioxin analysis were 0.114~7.091.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.61-68
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• 2024

In the quest for advancing diabetes diagnosis, this study introduces a novel two-step machine learning approach that synergizes the probabilistic predictions of Logistic Regression with the classification prowess of Random Forest. Diabetes, a pervasive chronic disease impacting millions globally, necessitates precise and early detection to mitigate long-term complications. Traditional diagnostic methods, while effective, often entail invasive testing and may not fully leverage the patterns hidden in patient data. Addressing this gap, our research harnesses the predictive capability of Logistic Regression to estimate the likelihood of diabetes presence, followed by employing Random Forest to classify individuals into diabetic, pre-diabetic or nondiabetic categories based on the computed probabilities. This methodology not only capitalizes on the strengths of both algorithms-Logistic Regression's proficiency in estimating nuanced probabilities and Random Forest's robustness in classification-but also introduces a refined mechanism to enhance diagnostic accuracy. Through the application of this model to a comprehensive diabetes dataset, we demonstrate a marked improvement in diagnostic precision, as evidenced by superior performance metrics when compared to other machine learning approaches. Our findings underscore the potential of integrating diverse machine learning models to improve clinical decision-making processes, offering a promising avenue for the early and accurate diagnosis of diabetes and potentially other complex diseases.

• Analytical Science and Technology
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• v.21 no.4
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• pp.284-295
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• 2008

For plastics samples, a method using combustion ion chromatography was selected as a method for rapid low-cost analysis to test whether hazardous substances are contained or not. Using combustion ion chromatography, a verification test for F, Cl and Br compounds generated a linear calibration curve with a correlation coefficient of $r^2$ = 0.999~1.000 in the calibration range from 0.5 to 4.0 mg/kg. The detection limits were found to be 0.005~0.024 mg/kg and quantitative limits were found to be 0.014~0.073 mg/kg. The recoveries of combustion ion chromatography using certified reference material (CRM) were found to be 95.5~104.9%. Based on these results, a proficiency test was conducted together with several laboratories in and out of the country, to make comparative analysis of the results from each laboratory. As a result, the data supported the use of combustion ion chromatography as an effective analysis method to deal with regulations for halogen-free electronic products and for other hazardous substances in the electronic products.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.243-249
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• 2013

Objectives: This study assessed the status of domestic industrial hygiene laboratories using data from on-site investigation for revision of quality control systems in 2012-2013. Methods: The target laboratories were 60 industrial hygiene laboratories chosen by random selection and nationwide distribution which had participated in on-site investigations for revision of quality control systems from March 2012 to August 2013. The investigation was performed on-site following standard quality control procedures. The score between each group was compared using Mann-Whitney and Kruskal-Wallis tests, and the correlation between analytical career, sex, academic major of analyst and score of analytical performance was expressed as Spearman's rank correlation coefficient. Results: The assessment revealed that the items to be improved, in sequence, were effort at staff training (score 65.5), ability to calculate data (score 73.4), establishment of internal quality control guidelines (score 75.7), laboratory facilities (score 77.1), degree of understanding and skill at gas chromatography (score 77.1). Analysis performance showed a positive correlation with career of analyst (r=0.56, p<0.01). Conclusions: The practice of on-site investigation for quality control systems showed the current status of industrial hygiene laboratories in the first trial. There were many laboratories which needed improvement and development of analytical systems. This assessment can provide information for the systematic operation and improvement of facilities at each laboratory. Further practice of this investigation will lead to a proficiency testing and accreditation system for autonomous quality control as is the practice in many countries, rather than mandatory practice by legal regulation.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.1-10
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• 2018

The purpose of this study is to provide a cost effective usability test model for business web site development. In this study, we present a usability test model that combines Concurrent Think Aloud, performance measurement, coaching method, and remote test method. Testing target was the consortium website of electronic information joint licensing. Test participants were actual users selected by their task roles and proficiency in different levels. We improved the system by reflecting the results of user test analysis and re-tested usability test again. The result showed that usability of all participants was improved in the aspect of the time required and the complexity of mouse trajectory. It is expected that the usability test model presented in this study can be used to cost-effectively evaluate and analyze business web sites. We suggest that research various usability test model considering the characteristics of websites.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.217-225
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• 2019

Objectives: The aim of this study is to evaluate the quality management systems of domestic asbestos survey and monitoring service providers and the relationships with the number of licenses or designations and sales performances. Methods: Data on quality management systems were collected by assessors who were assigned by the Korea Occupational Safety and Health Agency(KOSHA) during a pilot evaluation program for designated asbestos survey and monitoring service providers in 2016 using evaluation criteria developed by KOSHA. Basic characteristics, evaluated scores, and sales performance were gathered and statistically analyzed. Results: The median and arithmetic mean of the total scores were 0.64 and 0.66. Evaluation fields that scored highly with the highest percentages were sales performance, installation and availability of equipment, compliance with the mandatory minimum number of airborne samples, laboratory independence, and results of proficiency analytical testing, in that order. Evaluation fields that received low marks with the highest percentages were the training of personnel, blank field samples, calibration of flow rates, preliminary check and visual inspection of the work area prior to the clearance test, and review and approval of final reports, in that order. Comparison of normalized scores between service providers registered for asbestos and other tasks and those designated for only asbestos showed significant differences in their evaluated scores. Sales performance did not show a positive correlation with evaluated scores. Conclusions: The quality management systems of domestic asbestos survey and monitoring service providers were poor. High scores were recorded mostly in evaluation fields related to regulatory requirements. Low scores were recorded mostly in evaluation fields related to documentation and recordkeeping. Considering the low influence of quality on sales performance, the government needs to evaluate the quality management of asbestos survey and monitoring service providers and provide the results to public in order to address their low levels of quality management.

• Structural Engineering and Mechanics
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• v.86 no.5
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• pp.673-686
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• 2023

Determining the properties of pile from cone penetration test (CPT) is costly, and need several in-situ tests. At the present study, two novel hybrid learning models, namely PSO-RF and HHO-RF, which are an amalgamation of random forest (RF) with particle swarm optimization (PSO) and Harris hawks optimization (HHO) were developed and applied to predict the pile set-up parameter "A" from CPT for the design aim of the projects. To forecast the "A," CPT data along were collected from different sites in Louisiana, where the selected variables as input were plasticity index (PI), undrained shear strength (S_u), and over consolidation ratio (OCR). Results show that both PSO-RF and HHO-RF models have acceptable performance in predicting the set-up parameter "A," with R² larger than 0.9094, representing the admissible correlation between observed and predicted values. HHO-RF has better proficiency than the PSO-RF model, with R² and RMSE equal to 0.9328 and 0.0292 for the training phase and 0.9729 and 0.024 for testing data, respectively. Moreover, PI and OBJ indices are considered, in which the HHO-RF model has lower results which leads to outperforming this hybrid algorithm with respect to PSO-RF for predicting the pile set-up parameter "A," consequently being specified as the proposed model. Therefore, the results demonstrate the ability of the HHO algorithm in determining the optimal value of RF hyperparameters than PSO.

• Journal of KIBIM
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• v.13 no.3
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• pp.21-29
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• 2023

ChatGPT, a chatbot based on GPT large language models, has gained immense popularity among the general public as well as domain professionals. To assess its proficiency in specialized fields, ChatGPT was tested on mainstream exams like the bar exam and medical licensing tests. This study evaluated ChatGPT's ability to answer questions related to Building Information Modeling (BIM) by testing it on Korea's BIM expertise exam, focusing primarily on multiple-choice problems. Both GPT-3.5 and GPT-4 were tested by prompting them to provide the correct answers to three years' worth of exams, totaling 150 questions. The results showed that both versions passed the test with average scores of 68 and 85, respectively. GPT-4 performed particularly well in categories related to 'BIM software' and 'Smart Construction technology'. However, it did not fare well in 'BIM applications'. Both versions were more proficient with short-answer choices than with sentence-length answers. Additionally, GPT-4 struggled with questions related to BIM policies and regulations specific to the Korean industry. Such limitations might be addressed by using tools like LangChain, which allow for feeding domain-specific documents to customize ChatGPT's responses. These advancements are anticipated to enhance ChatGPT's utility as a virtual assistant for BIM education and modeling automation.