• 베이커리
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• no.9 s.398
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• pp.66-67
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• 2001

• Journal of Korean Society for Quality Management
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• v.40 no.4
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• pp.599-614
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• 2012

Purpose: We measure service quality based on service process, and examine relationships among product quality, product and service loyalty. Methods: We develop a construct to evaluate process based service quality. We collect data from customers of auto maintenance centers to measure perceived product quality, service and product quality. We test relationships between constructs using structural equation model and regression analysis. Results: Relationships among perceived-product quality, service quality, service loyalty, and product loyalty are all significant. Conclusion: Perceived-product quality has a indirect impact through service quality and loyalty in addition to a direct impact on product loyalty.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.584-590
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• 2015

Objectives: The purpose of this study was to evaluate quartz concentrations in airborne total and respirable dusts. Materials: Respirable dust samples were collected using a 10 mm aluminum cyclone equipped with a 37 mm$5{\mu}m$ pore size PVC filter. Total dust samples were collected with a three stage cassette from three work sections at earthwork sites located in the South Chungcheong-do Province area. Results: The geometric means of quartz concentrations were $0.008mg/m^3$ and $0.004mg/m^3$ in total dust and respirable dust, respectively. The geometric means of quartz contents analyzed by FTIR were 3.74% in total dust and 3.16% in respirable dust. The geometric mean of quartz concentrations and contents in secondary blasting operations were higher than those in other operations. Conclusions: Given that secondary blasting operations had higher quartz concentrations, there is a need to reduce respirable dust, such as through wet operations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.390-397
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• 2017

Objectives: The purpose of this study was to evaluate concentrations in airborne total and respirable dusts in the cement manufacturing and handling industries. Methods: Fifty-three total dust and 42 respirable dustsamples were collected from 24 work places. Total dust samples were collected using a three-stage cassette. Respirable dust samples were collected using a cyclone equipped with a 37 mm, $5{\mu}m$ pore size PVC filter. Results: The geometric means of the dust concentrations were $0.10mg/m^3$ and $0.08mg/m^3$ in total dust and respirable dust, respectively. The Korean Occupational Exposure Limit($10mg/m^3$) was not exceeded, but the rate of exceeding the American Conference of Governmental Industrial Hygienist(ACGIH) Threshold Limit Value($1mg/m^3$) was 16.7%. Conclusion: When measuring the level of dust at cement manufacturers, the airborne concentration of respirable dust should be evaluated. In order to protect the health of workers exposed to cement dust, it is necessary to actively consider strengthening the Korean Occupational Exposure Limit.

• Education of Primary School Mathematics
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• v.9 no.1 s.17
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• pp.43-58
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• 2005

The objective of the present study was designed to examine that metacognition education had any promoting effects on the development of students' reasoning ability. Two classes in the 5th grade were asked to participated for the present study. Prior to the metacognition teaching, both the experimental and control group classes were given to the preliminary test in which students' basic ability for mathematical reasoning was graded. Then, the students in the experimental group were given 8hour teaching for the topics on the symmetric properties of geometric figures. The present findings indicate that educational application which motivates metacognition can improve mathematical reasoning ability in elementary students. It is widely accepted that metacognition is an active and conscious mental activity, helps the students perceive voluntarily the study items, and further plays an important role in constructing independent and active thinking processes. Accordingly, the present results implicate that the practical performance of metacognition education into the class indeed contributes to build up or strengthen students' voluntary ways of reasoning.

• Journal of Environmental Science International
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• v.24 no.5
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• pp.699-708
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• 2015

This study was performed to identify the state of the exposure and characteristics of pollutants by each process at 4 casting sites located in Gyeongsang-do from April to November 2013. The concentrations of methanol, crystallized silica glass, formaldehyde and phenol were analyzed by different process - casting process, molding process, core process, and shakeout & finishing process. The highest concentration of methanol was found in casting and molding process, whereas the highest concentration of crystalline quartz(Silica) was observed in core process. The most oxidized steel dusts and the highest concentration of fume were found in shakeout & finishing process. As a result of this study, those labors working at the casting site were found to be constantly exposed to various forms of hazardous chemicals; therefore, it is considered that this is the time to manage and plan how to reduce them. In addition, it is required to thoroughly manage the local exhauster, and improve the process and working environment to reduce various forms of hazardous chemicals.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.462-470
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• 2014

Objectives: The purpose of this study was to evaluate quartz concentrations in airborne respirable dust and particle size-related quartz concentrations. Methods: Respirable dust samples were collected using a 10 mm Dorr-Oliver nylon cyclone equipped with a 37 mm, $5{\mu}m$ pore size PVC filter. Dust samples were collected with a Marple's personal cascade impactor from stone grinding operations in five stone-related business located in the Gyeongsangbuk-do area. Results: The geometric mean of quartz concentration in the respirable dust was $0.170mg/m^3$, and the rate of exceeding the Korean Occupational Exposure Limit(KOEL) was 93.3%. The quartz concentration by particle size shows that it was the highest($0.115mg/m^3$) in stage 5($3.50-6.00{\mu}m$), which corresponds with the size of respirable particle. The smaller the particle sizes were, the higher quartz the content became. The mass fractions of inhalable, thoracic, and respirable dust were 72.1%, 36.0%, and 14.4%. Conclusions: The rate of the quartz concentration in respirable dust from stone grinding operations exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values was 100%, which means proper work environmental management is required through regular working environmental measurements. Given that the stone grinding operations had a higher small size dust concentrations, there is a need to reduce respirable dust, such as through wet operation and local exhaust ventilation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.75-83
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• 2013

Objectives: This study was conducted to estimate quartz concentrations in the airborne respirable dust from concrete manufacturing industries and to compare performance of two analytical methods, direct on filter(DOF) and the transfer methods in the Fourier Transform Infrared Spectroscopy(FTIR). Methods: Total 36 area samples were collected from 8 concrete manufacturing industries. Each respirable dust sample was collected by a 25 mm cassette attached to a 10 mm Dorr-Oliver nylon cyclone. The quartz content was estimated using the intensity of the absorption peak of quartz at $799cm^{-1}$ by FTIR. Results: By the comparison of quartz content in respirable dust between the two methods, the results of using DOF method were higher than that of transfer method. And the result of quartz concentrations in respirable dust estimated by DOF method were mostly higher than those by transfer method. Statistically significant difference of quartz concentrations in respirable dust were not found in shakeout, input, loading and transporting processes by two methods. But quartz concentrations in the molding process had the statistically significant difference between DOF and transfer method. Conclusions: The results of the study is suggested that, it be needed to correct the influence of the interferences in order to establish the DOF method when interfering minerals have an effect on quantitative analysis of quartz in respirable dust by the direct on filter method with FTIR.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.3
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• pp.163-169
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• 2017

Objectives: This study was conducted toestimate quartz concentrations and contents in the airborne respirable dust from various industries. Methods: A total of 818 samples were collected from 174 industries. Respirable dust samples were collected using a cyclone equipped with a 37 mm, $5{\mu}m$ pore size PVC filter. The quartz concentrations were identified using the intensity of the absorption peak of quartz at $799cm^{-1}$ by Fourie Transformed Infrared Spectroscopy(FTIR). Results: The respective geometric means for quartz concentrations in the respirable dust were 0.0050, 0.0049, 0.0025, and $0.0019mg/m^3$ in foundries, ceramics, construction, and cement/stone. The geometric mean of quartz contents analyzed by FTIR were respectively 3.43, 1.99, 1.04, and 0.82% for ceramics, foundries, cement/stone, and construction. The rate of exceeding the Korean Occupational Exposure Limit($0.05mg/m^3$) was 2.03%, but rate of exceeding the American Conference of Governmental Industrial Hygienist(ACGIH) Threshold Limit Value($0.025mg/m^3$) was 7.12%. Conclusions: Given that foundries had a higher quartz concentration, there is a need to reduce respirable dust, such as through wet operation. In order to protect the health of workers exposed to mineral dust, it is necessary to actively consider strengthening the Korean Occupational Exposure Limit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.155-159
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• 2016

The objective of this study was to investigate the effect of fermentation temperature on quality characteristics of apple wine. Apple wine mashes were fermented in 15, 20, and $25^{\circ}C$ water bathes for 9 days. The pH levels of all samples were below 4 from 24 h of fermentation until the end. Total acidities of 0.05% acetic acid solution were 7.8, 7.4, and 7.0% in the 15, 20, and $25^{\circ}C$ fermented samples, respectively. The evaporation of esters generated by combining alcohol and organic acids might be the reason for lower total acidity for high temperature fermentation. Alcohol contents of the 20 and $25^{\circ}C$ fermented samples were 6.5 and 6.6% (v/v), respectively, whereas that of the $15^{\circ}C$ fermented sample was 5.6% (v/v) and significantly lower than the others (P<0.05). Methanol contents were 0.68, 0.82, and 1.69 mg/L in the 15, 20, and $25^{\circ}C$ fermented samples, respectively. Fermentation at higher temperatures generated higher methanol content in apple wine. On the other hand, acetaldehyde contents were 3.43, 2.39, and 1.02 mg/L in the 15, 20, and $25^{\circ}C$ fermented samples, respectively, due to the lower boiling point of acetaldehyde ($20.2^{\circ}C$). Based on the results, a fermentation temperature of $20{\sim}25^{\circ}C$ is effective for apple wine fermentation.