• 한국물환경학회지
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• 제29권6호
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• pp.790-798
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• 2013

Benthic macroinvertebrates are widely used as biological indicators for assessing the integrity of aquatic ecosystem. However, sampling has usually been done with fixed sample size due to time consuming and costly process. This study was conducted to find out the influence of sample size on the biological indices (H' DI, R1, J, EPT, ESB and BMI) of benthic macroinvertebrates. The 15 replicate samples were quantitatively collected from each 3 different site of two mountain streams in May, 2011. With the replicate data, we combined the abundance of each species with all the possible combinations of the sample size. Along with the increase of sample size, the number of species increased continuously and did not converge. BMI showed little difference whereas other biological indices increased or decreased.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.110-113
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• 2002

Statistical- based, principal component analysis (PCA) was applied to chemical data from two underground storage systems containing LPG to assess the usefulness of such technique at the initial stage (Pyeongtaek) or middle stage (Ulsan) of hydrochemical studies. For the first case, both natural and anthropogenic contamination characterize regional groundwater. Saline water buffered by Namyang lake affects as a natural factor, whereas cement grouting influence as an artificial factor. For the second study area, contaminations due to operation of LPG caverns, such as disinfection activity and cement grouting effect, deteriorate groundwater quality. This study indicates that principal component analysis would be particularly useful for summarizing large data set for the purpose of subsurface characterization, assessing their vulnerability to contamination and protecting recharge zones.

• Asian Journal of Atmospheric Environment
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• 제8권2호
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• pp.69-80
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• 2014

It is often assumed that atmospheric observations at remote sites represent long-range transport of airborne material, and local influences are overlooked. We evaluated the impact of local input on the rainwater composition at Gosan Station, a strategic site for monitoring the continental outflow from Asia. We analyzed a 14-year record of rainwater chemical composition archived by the Korea Meteorological Administration and detected local terrestrial contribution for nitrate, sulfate and ammonium. We also measured the chemical composition of rainwater sampled simultaneously at multiple locations within the premises of the Gosan Station, from which local influence with meter-scale spatial heterogeneity could be discerned. We estimate that the local input accounted for at least ~10% of the wet deposition of nitrogen and ~12% of the wet deposition of sulfur during the 14 years. This highlights the significance of the local influence, which should be carefully assessed when interpreting atmospheric observations at this site.

• 대한건축학회논문집:계획계
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• 제35권6호
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• pp.3-12
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• 2019

Current risk assessment methods typically determine accident risks embedded in construction projects by combining severity and frequency; however, they do not reflect the characteristics of construction projects. To solve the problem, this study aims to develop a novel risk assessment method that combines severity, frequency, and disaster influence factors (i.e., weather conditions and worker's characteristics) for assessing risks of activities occurring on a construction site actually. In this study, a severity was estimated by death against victims, and a frequency was estimated by the victim rate. The frequency was then converted to probability taking disaster influence factors into account. Thus, instead of considering severity and frequency for assessing the original risks (RO), the proposed method uses severity and probability to yield adjusted risks (RA) for each activity. A case study was conducted to determine if the proposed method works as intended in a real setting. The results show that RA is more sensitive to disaster influence factors than RO and, therefore, is able to assess the actual risks reflecting the working environment and conditions of a construction site. This study contributes to risk management of construction projects by offering a risk assessment method that measures a possibility of potential disasters from the probabilistic perspective. This method would help project managers assess accident risks in a more systematic and quantitative manner.

• 한국안전학회지
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• 제30권4호
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• pp.51-55
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• 2015

There are various studies on the fire suppression process but the study on second pollution from fire products is not enough yet. Therefor, in this study verify that environmentally-friendly properties($LC_{50}$) of foam extinguishing agent with increases its amount used through with Fish-Acute Toxicity Test using a fish named Misgurnus anguillicaudatus that is appointed by OECD Test Guideline. In conclusion, proven that environmentally friendly properties of the agent of hoseo university through 16 times of LC50 than that of market.

• Asian Journal of Business Environment
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• 제9권1호
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• pp.13-20
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• 2019

Purpose - The purpose of this paper is to find out the determinants of the quality of financial information in the financial environment of the cement companies of Bangladesh. Research design, data and methodology - This study considers a total of fifty-eight firm years as the sample from the seven listed cement companies of Bangladesh during the period of 2007 to 2015. This study applies the multivariate regression analysis including the pooled OLS, panel and controlling time. Results - This study finds that profitability and external financing are the two major explanatory variables in determining the quality of financial information. This study also finds that firm size and accrual quality don't have any significant influence on quality of financial information. Conclusion - This study observed that profitability of this sector which is much volatile and prone to be manipulated. Thus, this paper suggests that higher profitability needs more scrutiny while assessing quality of financial information. Finally, this study provides some indications for future research such as considering the listed firms of other sectors of Bangladesh or cross country comparison in different country setting.

• 한국경영과학회지
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• 제41권1호
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• pp.71-85
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• 2016

Service channel environments have changed dramatically with the advent of new, online digital channels. This article studies the effects of perceived multi-channel service quality on customer satisfaction and loyalty in the banking industry and the moderating role of age, which is a characteristic of customers. The objective is to identify the quality factors that affect the overall satisfaction and loyalty of a multi-channel customer. A quantitative study was conducted on 900 customers, with the main targets being users of the nine primary Korean retail banks. Results show that perceived service quality of the physical environment, human service, Internet banking, mobile banking, and ATM has a positive influence on overall satisfaction and loyalty. Age moderates the relationship among physical environment quality, human service, and customer loyalty.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.855-862
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• 2022

Environmental stressors considerably influence the health and safety of humans and must thus be continuously monitored to enhance the urban environments and associated safety. Environmental stressors typically act as stimuli and lead to behavioral changes that can be easily identified. These behavioral responses can thus be used as indicators to clarify people's perceptions of environmental stressors. Therefore, in this study, a framework for assessing environmental stressors based on human behavioral responses was developed. A preliminary experiment was conducted to investigate the feasibility of the framework. Human behavioral and physiological data were collected using wearable sensors, and a survey was performed to determine the psychological responses. Humans were noted to consistently exhibit changes in the movement and speed in the presence of physical environmental stressors, as physiological and psychological responses. The results demonstrated the potential of using behavioral responses as indicators of the human perceptions toward environmental stressors. The proposed framework can be used for urban environment monitoring to enhance the quality and safety.

• Structural Engineering and Mechanics
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• 제85권6호
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• pp.825-835
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• 2023

The effective buckling length factor is an important parameter in the elastic buckling analysis of steel structures. The present article aims at developing a new method that allows the determination of the buckling factor values for frames. The novelty of the method is that it considers the interaction between the bracing and the elastic supports for asymmetrical frames in particular. The approach consists in isolating a critical column within the frame and evaluating the rotational and translational stiffness of its restraints to obtain the critical buckling load. This can be achieved by introducing, through a dimensionless parameter 𝜙_i, the effects of coupling between the axial loading and bending stiffness of the columns, on the classical stability functions. Subsequently, comparative, and parametric studies conducted on several frames are presented for assessing the influence of geometry, loading, bracing, and support conditions of the frame columns on the value of the effective buckling length factor K. The results show that the formulas recommended by different approaches can give rather inaccurate values of K, especially in the case of asymmetric frames. The expressions used refer solely to local stiffness distributions, and not to the overall behavior of the structure.

• 환경영향평가
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• 제21권1호
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• pp.71-80
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• 2012

Against the backdrop of the clear impact of climate change, it has become essential to analyze the influence of climate change and relevant vulnerabilities. This research involved evaluating the impact of heat waves in Seoul, from among many local autonomous bodies that are responsible for implementing measures on adapting to climate change. To carry out the evaluation, the A1B scenario was used to forecast future temperature levels. Future climate scenario results were downscaled to $1km{\times}1km$ to result in the incorporation of regional characteristics. In assessing the influence of heat waves on people-especially the excess mortality-we analyzed critical temperature levels that affect excess mortality and came up with the excess mortality. Results of this evaluation on the impact of climate change and vulnerabilities indicate that the number of days on which the daily average temperature reaches $28.1^{\circ}C$-the critical temperature for excess mortality-in Seoul will sharply increase in the 2050s and 2090s. The highest level of impact will be in the month of August. The most affected areas in the summer will be Songpa-gu, Gangnam-gu, and Yeongdeungpo-gu. These areas have a high concentration of residences which means that heat island effects are one of the reasons for the high level of impact. The excess mortality from heat waves is expected to be at least five times the current figure in 2090. Adaptation plan needs to be made on drawing up long-term adaptation measures as well as implementing short-term measures to minimize or adapt the impact of climate change.