• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3637-3641
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• 2014

In this study, we analyzed the toxicity of mixtures of dimethylformamide (DMF) and methyl ethyl ketone (MEK) or DMF and toluene (TOL) and predicted their toxicity using quantitative structure-activity relationships (QSAR). A QSAR model for single substances and mixtures was analyzed using multiple linear regression (MLR) by taking into account the statistical parameters between the observed and predicted $EC_{50}$. After preprocessing, the best subsets of descriptors in the learning methods were determined using a 5-fold cross-validation method. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP), flash point (FP), low explosion limit (LEL), and octanol/water partition coefficient (Pow) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of DMF and TOL was significantly lower than that of DMF. The mixture toxicity was directly related to the mixing ratio of TOL and MEK (MLR $EC_{50}$ equation = $1.76997-1.12249{\times}TOL+1.21045{\times}MEK$), as well as to SG, VP, and LEL (MLR equation $EC_{50}=15.44388-19.84549{\times}SG+0.05091{\times}VP+1.85846{\times}LEL$). These results show that QSAR-based models can be used to quantitatively predict the toxicity of mixtures used in manufacturing industries.

• Therapeutic Science for Rehabilitation
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• v.12 no.4
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• pp.23-37
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• 2023

Objective : This study systematically reviewed the collaborative team interventions of the Individualized Education Plan (IEP) using the International Classification of Functioning, Disability, and Health-Children and Youth (ICF-CY) framework to establish the professional domain of occupational therapists in Korea and their role as experts in IEP cooperative team interventions in special education. Methods : Articles were collected from the EBSCOhost, ProQuest, and PubMed databases. International search terms included "Special education," "Individualized education plan (IEP)," "IEP process," "IEP implementation," and "Occupational therapy." The study period was limited from January 2013 to February 2023, and the final 10 studies were analyzed using secondary classification. Results : Most studies were randomized experiments targeting individuals with autism, and often employed environmental improvements. The IEP collaborative team interventions using the ICF-CY framework emphasized goals related to activity (five studies), participation (four studies), and body structure/function (one study). Conclusion : Occupational therapists play a crucial role in collaborative IEP team interventions. This study established expertise in the context of special education in South Korea.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.309-315
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• 2018

The study analyzed convergent influence on occupational stress(KOSS-SF: Korean Occupational Stress Scale-Short Form) and its association with Organizational Justice(OJ), Self Esteem(RSE :Rosenberg Self-Esreem) and Self Efficacy(GSE: Generalized Self-Efficacy) among some regional General Hospital Administrative Staff(GHAS). The survey was administered to 221 staff from 11 general hospitals located in J city from Nov. 1st, 2016 to Jan. 31st, 2017, by structured self-administered questionaries. Occupational stress was negatively correlated with two sub-domains of OJ, RES and GSE. With the analysis of covariance structure, we identified the causal relationship of OJ, RES, GSE and occupational stress among GHAS. The study found the higher OJ, RES and GSE tend to decrease occupational stress. The results indicate that the efforts, to increase OJ, RSE and GSE, are required to decrease the occupational stress of GHAS. The results are expected to be useful for organization & HR management to decrease the occupational stress of GHAS. In the following study, the analysis about convergent additional factors of influence on occupational stress of GHAS will be needed.

• The Journal of Korean society of community based occupational therapy
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• v.5 no.1
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• pp.45-53
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• 2015

Objective : The purpose of this study is to investigate the awareness and interest rate of residential environment and to establish basic data for further development of occupational therapy through the results. Methods : This survey was conducted between April 1th and May 31st 2015 and 165 questionnaires were public. The questionnaires of 165 respondents were analyzed through Cosstabs, Descriptive statistics, Frequency study and t-test, ANOVA analysis using SPSS ver. 18.0 Results : Looking for recognition percentage of residential environment improvement, 44.8% of people reply the changing the house structure and 26.8% of people reply the cure method. in contrast to 28.5% of people reply the architect, the only 9.1% of people reply occupation therapist. the most people agree that residential environment improvement is important. but there is no difference about answer between sex and age. 5.9% of people reply that improving live environments may be good for improving life quality but 7.6% of people reply independency may increase, it is not important because it must need lot of money for improving live environments Conclusion : The awareness of the residential environment improvement in short supply, but Things that are significant in the distance, the need for further residential environment improvement was broad consensus. residential environment improvement for people with disabilities in economic assistance and occupational therapists and incursion of correlated to require institutional support.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.137-147
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• 2020

This study is aimed to develop and validate the clinical competence scale of occupational therapy student. The development of clinical competence scale analyzed the definition of clinical performance and previous studies. preliminary examinations were conducted on 203 occupational therapy departments in 3rd and 4th grade to verify item analysis and job validity. After exploratory factor analysis, eight factors of professional consciousness, 11 items of occupational therapy evaluation factors, 4 items of occupational therapy intervention factors, and 4 items of communication factors were extracted into a total of 27 factors. As a result of verifying the reliability of each factor through the internal consistency coefficient Cronbach's α, it was found to be .87~.94 and the overall reliability was .96. The correlation between the total score and the factors of the clinical competence scale was statistically significant. Through the confirmatory factor analysis, the model fit test of the factor structure for 27 items of 4 factors (χ²=.76, df = .31, CFI = .81, TLI = .80, RMSEA = .79) is considered acceptable. Through this study, The clinical competence scale is a valid and reliable scale that can be useful for objectively assessing.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.21-28
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• 1993

Occupational Safety & Health Code requires to calculate Design Load and stress for the approval within thirty working days prior to initiating each construction site work This study is to develop an easy and useful program that each safety manager. Controller or engineers are able to make output for the above mentioned form structure analyses without knowledge or engineering background of it. Therefore. three, randomly selected. different major student and engineers verified if they could make output. really without the engineering background. And then some deficiencies are corrected after finding those from the program operation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.146-151
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• 2014

Objectives: Chrysotile is mineralogically distinct from amphiboles, displaying a notably different chemical structure. The thin sheets that form chrysotile fiber lead to the ability of the lung/macrophage system to decompose the chrysotile fibers. This study was performed in order to compare the physicochemical characteristics of Korean asbestos with those of Canadian amphiboles. Materials: An acid solubility test for each test substance was done to compare pH 4.5 and pH 1.2 distilled water. Asbestos fibers which had been placed in acid solutions for five days, five weeks and weeks were analyzed with a transmission electron microscope equipped with an energy dispersive X-ray spectrometer (TEM-EDS). Results: The composition element (Mg) of Korean chrysotile, Korean anthophyllite and Canadian amosite significantly decreased from 5 days and also decreased significantly after 5 weeks and 10 weeks. Only the composition (Mg) of Canadian crocidolite did not change under any conditions. From 5 days, the Mg of Korean chrysotile, Korean anthophyllite and Canadian amosite were significantly lower than before the acid treatment, but there were no changes over time or by the pH of the acid solutions. Particularly after 10 weeks, the composition (Mg) of Korean chrysotile in the pH 1.2 acid solution showed a rapid reduction of 15.86%. Conclusions: Korean chrysotile was very weak in an acid environment, beginning to show significant changes after 5 days. The Mg component rapidly decreased after 10 weeks in the pH 1.2 acid solution.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.500-509
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• 2009

Passive samplers have been used for many years for the sampling of organic vapors in work environment atmospheres. Currently, all passive samplers used in domestic occupational monitoring are foreign products. This study was performed to evaluate variable parameters for the development of passive organic samplers, which include the geometry of the device and diffusive length for the sampler design. Four prototype diffusive lengths; A-1(4.5 mm), A-2(7.0 mm), A-3(9.5 mm), A-4(12.0 mm) were tested for adsorption performances to a chemical mixture (benzene, toluene, trichloroethylene, and n-hexane) according to the US-OSHA's evaluation protocol. A dynamic vapor exposure chamber developed and verified by related research was used for this study. The results of study are as follows. The results in terms of sampling rate and recommended sampling time test indicate that the most suitable model was A-3 (9.5 mm diffusive lengths on both sides) for passive sampler design in time weighted average (TWA) assessment. Sampling rates of this A-3 model were 45.8, 41.5, 41.4, and 40.3 ml/min for benzene, toluene, trichloroethylene, and n-hexane, respectively. The A-3 models were tested on reverse diffusion and conditions of low humidity air (35% RH) and low concentrations (0.2 times of TLV). These conditions had no affect on the diffusion capacity of samplers. In conclusion, the most suitable design parameters of passive sampler are: 1) Geometry and structure - 25 mm diameter and 490 $mm^2$ cross sectional area of diffusion face with cylindrical form of two-sided opposite diffusion direction; 2) Diffusive length - 9.5 mm in both faces; 3) Amount of adsorbent - 300 mg of coconut shell charcoal; 4) Wind screen - using nylon net filters (11 ${\mu}m$ pore size).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1348-1354
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• 2020

The purpose of this study is to discover the occupational identity by examining the narrative of the life of a TVET teacher using the project method in programming fields. Teacher S, a participant in the study, started as a part-time lecturer at university and has been teaching programs for the past 20 years. As a result, six kinds of occupational identities of a programming teacher who teach by project method were found. S experienced pride and pride as a teacher through the project method. The project method served as a motive for continuous self-development to lead S to an expert. His experience as a positive teacher made him wish to maintain this life and live as a teacher as long as his health permits, even after retirement. This study has significance in exploring the structure of the occupational identity of a TVET teacher using the project method in programming fields, which have not been studied yet.

• Safety and Health at Work
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• v.13 no.3
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• pp.357-363
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• 2022

Background: Refractory ceramic fibers (RCFs) are a suspected carcinogen but have been widely used as insulations. Depending on the temperature, RCFs can transform into crystalline SiO₂, which is a carcinogen that can be present in the air during bulk RCF handling. This study analyzed the physicochemical and morphological characteristics of RCFs at high temperatures and determined the exposure levels during the semiconductor scrubber maintenance. Methods: Sampling was conducted at a company that manufactures semiconductor scrubbers using RCFs as insulation. Bulk RCF samples were collected both before and after exposure to a scrubber temperature of 700℃. Airborne RCFs were collected during scrubber maintenance, and their characteristics were analyzed using microscopes. Results: The components of bulk RCFs were SiO₂ and Al₂O₃, having an amorphous structure. Airborne RCFs were morphologically different from bulk RCFs in size, which could negatively affect maintenance workers' health. 58% of airborne RCFs correspond to the size of thoracic and respirable fibers. RCFs did not crystallize at high temperatures. The exposure caused by airborne RCFs during the scrubber frame assembly and insulation replacement was higher than the occupational exposure limit. Conclusion: Workers conducting insulation replacement are likely exposed to airborne RCFs above safe exposure limits. As RCFs are suspected carcinogens, this exposure should be minimized through prevention and precautionary procedures.