• 한국대기환경학회지
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• 제19권5호
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• pp.491-502
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• 2003

In the present work, the distribution characteristics of ambient volatile organic compounds (VOCs) were investigated at high temporal resolution from a monitoring station located in a mid-eastern area of Seoul. A total number of 587 samples were collected during December 2002 to January 2003. The measurements of VOC were conducted by a combination of on-line air sampling and thermal desorption unit (TDU) coupled with capillary GC/FID analysis. A total of five aromatic compounds (BTEX: benzene, toluene, ethylbenzene, m, p-xylene, and o-xylene) were measured routinely at hourly intervals during the whole study period. The mean concentrations of BTEX measured in our study period were found in the order: toluene (8.99 $\pm$5.38 ppb) > benzene (0.92$\pm$0.52 ppb) > m, p-xylene (0.51$\pm$0.34 ppb) > 0- xylene (0.48$\pm$0.35 ppb) > ethyl benzene (0.43$\pm$ 0.32 ppb). The BTEX concentrations were generally higher during the daytime than the nighttime, exhibiting certain patterns on a weekly basis. Results of our analysis indicate that the unusually high concentrations of toluene, while showing good correlations with other VOCs, can be a good indicator of air pollution in the study area.

• Smart Structures and Systems
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• 제11권1호
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• pp.35-51
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• 2013

Over the last two decades Wavelet Transformation (WT) method has been widely utilized for the damage identification of structures. The main objective of this paper is to discuss and present some of common shortcomings and limitations of mathematical software, as well as other precautionary measures that need to be considered when using them for wavelet analysis applications. Due to popular usage of MATLABMATLAB(R) comparing to other mathematical tools among researchers for data processing of structural responses through WT analysis, this software was chosen for specific study. To the best of the authors' knowledge, these limitations and observations have not been previously identified or discussed in the literature. In this work, a square plate with a severe damage, in form of a crack, parallel to the left edge of the plate is selected for a pilot study. The steady state harmonic response is used for measuring the deflection shape across the line parallel to one edge and perpendicular to the damage. Several criteria and cases such as the smallest size damage that can be detected, correlation between the crack width and the number of sampling points, and the influence of the damage thickness on the accuracy of the result are investigated.

• Asian Journal of Business Environment
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• 제4권4호
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• pp.13-18
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• 2014

Purpose - This study aims to analyze changes in attitudes towards women's political leadership and the social factors related to such changes. The study reviews the field of women's political leadership, specifically the political and economic participation of women in the world, and the impact of variables such as the changes in attitude on such participation. Research design, data, and methodology - The population for this study comprises 99 countries that are members of the United Nations and have participated in the third and fifth waves of the World Values Surveys. The sample consists of 31 such countries selected for sampling. Results - This study is a secondary analysis to examine the hypotheses regression and the LISREL model are used. The findings of the study indicate that the correlation between two variables, namely women's political participation and leadership of women, is statistically significant. Conclusions - The changing rate of women's economic participation is also significant. The significance of these coefficients indicates that the results, with a 95% confidence level, can be extended to all member states.

• Journal of Multimedia Information System
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• 제7권3호
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• pp.231-238
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• 2020

This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4^th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E1호
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• pp.17-24
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• 2001

For the purpose of collecting fog droplets as a function of size a new sampling method was developed in this study. Formation of 100$\pm$10㎛ thickness of polymeric water absorbent film (PWAF) on a nuclepore filter could be successfully realized. Also applicability of particle induced X-ray emission (PIXE) method to the chemical analysis of size-segregated fog droplets collected on PWAF was examined experimentally with synthetic fog droplets generated from a nebulizer. Absorption capacity of S-PAAS polymeric water absorbent shows marked decreases in the range less than 1 wt% and slight decrease between 1 and 3.5 wt% of every salt concentration. Dependency of absorption capacity on pH shows the maximum at pH 7. No apparent peak which can influence the quantitative analysis of elements dissolved and suspended in fog droplets was found at PIXE spectrum of PWAF blank. PWAF kept the original shape without rupture under the PIXE analytical conditions of beam intensity for 10 to 60 nA and irradiation time of 4∼5 min. It should be said that the proposed new technique in the work is helpful to get more detailed information of fog droplets, to clarify the fog formation processes, and to develop a model of acid deposition process.

• 한국자기공명학회논문지
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• 제24권2호
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• pp.53-58
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• 2020

Free radicals including reactive oxygen species (ROS) are important chemicals in the research area of biology, pharmaceutical, medical, and environmental science as well as human health risk assessment as they are highly involved in diverse metabolism and toxicity mechanisms through chemical reactions with various components of living bodies. Electron spin resonance (ESR) spectroscopy is a powerful tool for detecting and quantifying those radicals in biological environments. In this work we observed the ESR signal of 2,2,6,6-Tetra-methyl piperidine 1-oxyl (TEMPO) in aqueous solution at various concentrations to estimate the uncertainty factors arising from the experimental conditions and signal treatment methods. As the sample position highly influences the signal intensity, dual ESR tube geometry (consists of a detachable sample tube and a position fixed external tube) was adopted. This type of measurement geometry allowed to get the relative uncertainty of signal intensity lower than 1% when triple measurements are averaged. Linear dependence of signal intensity on the TEMPO concentration, which is required for the quantification of unknown sample, could be obtained over a concentration range of ~10³ by optimizing the signal treatment method depending on the concentration range.

• Safety and Health at Work
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• 제7권3호
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• pp.225-230
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• 2016

Background: This study seeks to examine the relationship and impact of occupational health and safety on employees' organizational commitment in Ghana's mining industry. The study explores occupational health and safety and the different dimensions of organizational commitment. Methods: A cross-sectional survey design was used for this study. The respondents were selected based on simple random sampling. Out of 400 questionnaires administered, 370 were returned (77.3% male and 22.7% female) and used for the study. Correlation and multiple regression analysis were used to determine the relationship and impact between the variables. Results: The findings of this study revealed positive and significant relationship between occupational health and safety management, and affective, normative, and continuance commitment. Additionally, the results revealed the significant impact of occupational health and safety on affective, normative, and continuance commitment. Conclusion: Management within the mining sector of Ghana must recognize the fact that workers who feel healthy and safe in the performance of their duties, develop emotional attachment and have a sense of obligation to their organization and are most likely committed to the organization. Employees do not just become committed to the organization; rather, they expect management to first think about their health and safety needs by instituting good and sound policy measures. Thus, management should invest in the protection of employees' health and safety in organizations.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.668-674
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• 2002

Structural integrity assessment is indispensable for preventing catastrophic failure of industrial structures/components/facilities. This diagnosis of operating components should be done periodically for safe maintenance and economical repair. However, conventional standard methods for mechanical properties have the problems of bulky specimen, destructive and complex procedure of specimen sampling. Especially, the mechanical properties at welded zone including weldment and heat affected zone could not be evaluated individually due to their size requirement problem. So, an advanced indentation technique has been developed as a potential method for non-destructive testing of in-field structures. This technique measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation such as yield strength, tensile strength and work-hardening index. Also indentation technique can evaluate a residual stress based on the concept that indentation load-depth curves were shifted with the direction and the magnitude of residual stress applied to materials. In this study, we characterized the tensile properties and welding residual stress of various industrial facilities through the new techniques, and the results are introduced and discussed.

• 대한가정학회지
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• 제8권1호
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• pp.159-180
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• 1970

Forty-five home account books were randomized by electing "prize for good home manager" in 1967 through all over the country in korea. With this sampling analyzed monthly home expenditure in different item by test of significance, and compared with model of home expenditure and this results. Hope this analysis will help to the house wife for better plan home expenditure and will develope in scientific way of life in home managing. 1. Significance test of home account books in their items and in months indicated that there were significant statistical differences in the total living expenses. In other words, they did not work out a budget, and their home account books were nothing but a record expenses. 2. There was a significant difference in the monthly expenditure for food caused by the preparation of cabbage pickle (kim Jang) in November. This payment in a lump to the cabbage pickle brought about unbalance to home economic. 3. Compared with others, in November and in December we could find a meaningful difference in the monthly expenditure for clothing. 4. It was noted that there were not such comparable significant differences in months as to be mentioned for housing light and heating, education, saving, transportation and communication culture, taxes.

• 간호행정학회지
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• 제17권4호
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• pp.493-507
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• 2011

Purpose: The aim of this study was to investigate the effect of sense of coherence (SOC) on occupational stress, psychosocial stress and quality of life (QOL) of nurses working in a hospital. Methods: The participants were 401 nurses working in S hospital in Seoul. A stratified random sampling was performed for the all nurses in S hospital which were grouped by age and work unit. Data were collected by a self-report survey. Data analyses included descriptive statistics, t-test, Pearson correlations, multiple linear regressions, and ANOVA. Results: This study showed nurses' occupational stress was at high risk and their psychosocial stress, at low risk. It also showed that those two types of stress are mutual predictors for each other and that SOC was a predictor for both types of stress. For QOL, SOC was also a predictor in SF-36 and MCS (Mental Component Summary). Therefore, SOC may be considered as a major controlling factor for stress and QOL. Conclusion: The results indicate the need to develop programs that enhances nurses' SOC, programs that could be utilized as an intervention to reduce nurses' stress and to promote nurses' QOL.