• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.41-46
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• 2012

The flash point the lowest temperature at which the concentration of vapor of the substance in the air reaches the lower flammability limit(LFL), and is one of the most important physical properties used to determine the potential for fire and explosion hazards of industrial materials. The most published flash point data was for pure components and the flash points of the binary solutions that have flammable components, appear to be scarce in the literature. In the present study, the flash points of tert-pentanol+n-decane system were measured by Tag open-cup tester. The measured data were compared with the values calculated by the Raoult's law and the optimization methods based on the Wilson and NRTL equations. The calculated values by optimization methods were found to be better than those based on the Raoult's law.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.1-8
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• 2001

This study was performed to evaluate a local exhaust ventilation system capability and welding fume concentration in welding laboratory at 5 technical high schools. Results of the study are as follows; 1. The personal exposure of welding fume in welding laboratory was measured. The geometric mean of 73 personal samples was $6.27mg/m^3$($3.85{\sim}9.88mg/m^3$), and 68.5% of these exceeded TLV of the Korea Ministry of Labor. 2. The geometric mean of welding fume at outside of booth was $2.27mg/m^3$($1.57{\sim}2.58mg/m^3$). All of measured concentrations were lower than TLV of the Korea Ministry of Labor. 3. Local exhaust ventilation system in welding laboratory could not remove hazardous substance effectively because of inappropriate canopy hood and absurd design. 4. The possibility of exposure risk was estimated to be high because of working point under breathing zone, misplacement of working table and insufficient supply of respiratory protector. 5. The mean values of capture velocity and transportation velocity of local exhaust ventilation system in welding laboratory were 0.38m/sec, 4.27m/sec respectively. These values were satisfied the guideline of the Korea Ministry of Labor. 6. The efficiency of performance of local ventilation system was anticipated to be decreased because of accumulated dust and alien substance on fan and duct.

• Clinical and Experimental Pediatrics
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• v.58 no.8
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• pp.301-308
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• 2015

Purpose: We evaluated three blood glucose self-monitoring for measuring whole blood glucose levels in preterm and low-birth-weight infants. Methods: Between December 1, 2012 and March 31, 2013, 230 blood samples were collected from 50 newborns, who weighed, ${\leq}2,300g$ or were ${\leq}36$ weeks old, in the the neonatal intensive care unit of Eulji University Hospital. Three blood glucose self-monitoring (A: Precision Pcx, Abbott; B: One-Touch Verio, Johnson & Johnson; C: LifeScan SureStep Flexx, Johnson & Johnson) were used for the blood glucose measurements. The results were compared to those obtained using laboratory equipment (D: Advia chemical analyzer, Siemens Healthcare Diagnostics Inc.). Results: The correlation coefficients between laboratory equipment and the three blood glucose self-monitoring (A, B, and C) were found to be 0.888, 0.884, and 0.900, respectively. For glucose levels ${\leq}60mg/dL$, the correlation coefficients were 0.674, 0.687, and 0.679, respectively. For glucose levels>60 mg/dL, the correlation coefficients were 0.822, 0.819, and 0.839, respectively. All correlation coefficients were statistically significant. And the values from the blood glucose self-monitoring were not significantly different from the value of the laboratory equipment, after correcting for each device's average value (P>0.05). When using laboratory equipment (blood glucose ${\leq}60mg/dL$), each device had a sensitivity of 0.458, 0.604, and 0.688 and a specificity of 0.995, 0.989, and 0.989, respectively. Conclusion: Significant difference is not found between three blood glucose self-monitoring and laboratory equipment. But correlation between the measured values from blood glucose self-monitoring and laboratory equipment is lower in preterm or low-birth-weight infants than adults.

• Journal of Information Technology Services
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• v.17 no.2
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• pp.1-16
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• 2018

Large corporations have the work and roles of employees clearly defined in accordance with their established internal structure whereas small and mid-sized firms may lack an official job specification or a written job description, causing ambiguity in the role of employees. In IT service companies, especially, there is a relatively large number of tasks requiring one person to play multiple roles and they are often highly dependent on few key players. In this reality where about 80% of the job seekers end up in SMEs, it is therefore necessary to look into how the turnover factors such as job strain and occupational burnout caused by the role ambiguity from extra work affect the turnover intentions of small and medium sized IT service firm employees. The outcome of this study is as follows. First, the relationship between job strain and turnover intention has been examined to find that a weak inverted U shaped relationship exists between role overload, which is a subset of job strain, and turnover intention. Second, the hypothesis based on the competing values framework has been tested that the fitness with organizational leadership and culture would moderate the relationship between job strain and turnover intention and it has been confirmed that the degree of relationship between role conflict and role ambiguity, the subsets of job strain, and turnover intention has changed. In conclusion, in order to discourage turnover intention, it is necessary to increase the fitness with the organization and leadership or generate a sufficient level of strain in case of an organization with low fitness.

• Journal of the Korean Society of Safety
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• v.33 no.3
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• pp.39-45
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• 2018

The occupational safety and health act defines how to evaluate the explosion hazardous areas according to KS (Korean Industrial Standards). Current KS have to follow IEC (International Electrotechnical Commission) 60079-10-1 1st edition and there has been no change since 2008. And its 2nd edition has been revised in 2015. In this study, IEC 1st Ed. (IEC 60079-10-1 1st edition) is compared with IEC 2nd edition. Total 112 case studies including four materials (methane, propane, benzene, methanol) are selected to test and explosion hazardous ranges evaluated by IEC 1st and 2nd Ed. are analyzed according to various leakage pressures and hole sizes. In order to verify the results calculated by them, PHAST, which is one of the most representative consequence analysis programs, is employed. As a result, it can be concluded that there are many differences between IEC 1st and 2nd Ed. due to the discharge and the ventilation parameters. As comparing with PHAST, it is confirmed that IEC 1st provides more conservative values than PHAST. Even if IEC 2nd Ed. provides more conservative for gases, this fails to provide more conservative values for liquids. Therefore, it is worth to note that a large value between the explosion hazardous ranges value calculated by the IEC 1st Ed. and 2nd Ed. should be selected until further investigation and analysis is made. Morevover, the full consideration for IEC 2nd Ed. have to be needed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.336-346
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• 2009

As a follow-up survey of A Study of Monitoring Method on Exposure Level and Biomarkers of Environmental Pollutants-Focused on Ulsan Industrial Comlpex Area, published in 2005, a close examination of the health status was conducted for selected Ulsan residents. Based on the previous study, a total number of 129 subjects were divided into two groups: the exposure group consisted of 39 residents whose blood levels of lead, mercury and/or cadmium were higher than international reference values, and 90 residents of control group with normal levels. Environmental exposure level and its association with health condition were examined by various methods such as questionnaire, analyses of lead, mercury and cadmium in blood and medical examinations. The geometric mean concentrations of lead, mercury and cadmium in blood were respectively $2.07{\mu}g/d{\ell}$ (exposure $2.54{\mu}g/d{\ell}$, control $1.90{\mu}g/d{\ell}$), $5.94{\mu}g/L$ (exposure $8.57{\mu}g/L$, control $5.07{\mu}g/L$), $1.32{\mu}g/L$ (exposure $1.30{\mu}g/L$, control $1.33{\mu}g/L$). The concentrations of the three heavy metals in blood showed lower levels than internationally recommended values except for blood mercury. Also, any abnormal or, peculiar disease, or target tissue damage related to the heavy metals was not observed among the all subjects. Therefore, it can be said that no significant difference of heavy metal concentrations and health conditions was found between the two groups.

• Journal of Family Resource Management and Policy Review
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• v.6 no.2
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• pp.31-52
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• 2002

This study classified consumers' behaviors of purchasing gifts, divided groups by the types of similar behaviors, and examined impacts of demographic variables, relevant variables in purchasing processes on those behaviors. Findings of this study can be summarized as follows. First, factors explaining consumers' behaviors of purchasing gifts were the tendency of demonstrative purchase, the level of placing values to the meaning of gifts, the level of altruism and rationality in the purchase of gifts, and the tendency of impulsive purchase. On the basis of these five factors, five distinct consumer groups showing similar behaviors of purchasing gifts based on the results of Cluster analysis were identified. Those groups were impulsiveㆍdemonstrative groups, impulsiveㆍnon-sincere groups, indifferent groups, non-impulsiveㆍdemonstrative groups, non-altruistic'ㆍrational groups, sincere groups, and altruisticㆍrational groups. Second, behaviors of purchasing gifts showed significant differences depending on gender, educational levels, occupational types, and women's employment status. Consumers with high education, professional occupation, high income tended to show the demonstrative purchase. Male consumers were not interested in the purchases of gifts and placed high values on the meanings of gifts. In contrast, female consumers showed rational behavior, but revealed the tendency of demonstrative in the purchase of gifts as well. Finally, behaviors of purchasing gifts were also different depending on the method of gathering consumer information, places of purchasing gifts, experiences of ordering paid wrapping gifts and the relevant costs, consumers' evaluations of the purchases of gifts, and degrees of satisfaction after the purchase of gifts. Impulsive'ㆍdemonstrative groups and non-impulsive'ㆍ demonstrative groups preferred departments as places of purchasing gifts and choose ordering paid wrapping gifts but showed dissatisfactions after purchases of gifts. Consumers who belongs to non-altruistic'ㆍrational groups, sincere groups, and altruistic'ㆍ rational groups tended to prefer local stores in their own villages as places of purchasing gifts and did not order paid wrapping gifts while showing high after the purchase of gifts.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.2
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• pp.33-37
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• 2010

Purpose : We investigated the effects of the insole types on lower leg muscle activation during treadmill walking. The three insole types investigated for this study were normal insole, medial wedge insole, and viscoheel. Methods : Participants were assigned into three groups. People with foot transformation were excluded from this study. Each participant walked for ten minutes. The first day we applied a normal insole. On the second day, a medial wedge insole was applied. Finally, on the last day a viscoheel was applied. After walking on a treadmill for ten minutes, we measured muscle activation in lower leg muscles (gastrocnemius and tibialis anterior). Surface electromyography (EMG) was used to measure muscle activity. The data were analyzed using one-way analysis of variance (ANOVA) with repeated measures to determine the statistical significance. Results : The results of this study were summarized as follows. While walking on the treadmill, root mean square (RMS) values of the gastrocnemius when the viscoheel was applied were significantly lower than the other insole types. There was no significant difference for the RMS values for the tibialis anterior using viscoheel. The normal insole and viscoheel insole were significantly different in a post hoc analysis. However, there was no significant difference for normal insole and medial wedge insole. Conclusion : Using a viscoheel insole decreases muscle activity of the lower leg. Therefore, in conclusion, the viscoheel insole type reduces the load on the lower leg during walking.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.113-120
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• 2018

The purpose of this study is to examine if entrepreneurship that can influence entrepreneurial intention affects job-getting possibility. Particularly, this author has questingly investigated if the entrepreneurship of undergraduates who are supposed to get a job influences job-getting possibility and if sex has regulating effects on job-getting possibility. According to the results, first, undergraduates' entrepreneurship influences job-getting possibility. Second, according to sex, there is difference found in the effects of entrepreneurship on job-seeking skills and job-getting possibility. In other words, sex has significant regulating effects on job-seeking skills and job-getting possibility. Third, according to the results of comparing the mean values of two groups, upper and lower groups of entrepreneurship, regarding their job-getting possibility(work ethic, occupational exploration, & job-seeking skills) in accordance with moderating variables, female undergraduates gained significantly higher mean values than male undergraduates. Based on the results, this author suggests implications and presents proposals for follow-up research.

• Journal of Preventive Medicine and Public Health
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• v.44 no.4
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• pp.185-189
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• 2011

Objectives: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. Methods: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. Results: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). Conclusions: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.