• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.

• Journal of Gifted/Talented Education
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• v.10 no.2
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• pp.47-69
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• 2000

One of the most controversial issues in contemporary research of creativity, whether a person"s creativity is domain-specific or domain-general, was investigated with 109 second grade children in the present study. The purposes of this study sere to empirically examine (1) the relationships among children's creative performances measured by three product-based assessments (story-telling, collage-making, and math word problems) in three domains, and (2) the relationships between children's general creative thinking sills, measured by two divergent thinking tests, and children's creative performances. The findings of this study support the position that creative ability in young children is rather (but not absolutely0 domain-specific. Children exhibited a range of creative ability across different domains rather than a uniform creative ability in diverse domains, indicating there is considerable intra-individual variation in creative ability by domain. Divergent thinking measures did not have great power in predicting creative performance in at least two of three, if not all, domains assessed in the study. It is implied from the study that it is not possible to reliably predict a child"s creative ability in one domain based on his/her creative ability in other domains or his/her overall divergent thinking ability. Implication of the study in connection with educational practices for gifted children is discussed.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.549-559
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• 2005

Sustainable industrial development which can minimize an ecological effect by the mankind exertion is recently interested due to an environmental contamination and a resource exhaustion problem. An eco-industrial park (EIP) is a community of manufacturing and service businesses seeking enhanced environmental and economic performance through collaboration in managing environmental and resource issues, including energy, water, and materials. EIP developments which improve a production plant within an eco-friendly greenfield and design a new industrial ecosystem are accomplished recently, which can efficiently re-use the waste and resources from each company within EIP. In this review, the outside and domestic case studies of EIP and cornerstone technologies to develop the EIP, such as energy integration, waste reuse, mass flow analysis, water pinch, and life cycle assessment, are summarized.

• Journal of Science and Technology Studies
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• v.19 no.3
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• pp.119-166
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• 2019

The risk of electromagnetic field(EMF) from power lines has been heavily disputed whenever high-voltage power line towers were built in South Korea. Local communities and civic groups had regarded burying the lines in the ground as an alternative to building power line towers. In 2014, however, when an elementary school science teacher reported the results of EMF measurements over the underground power lines to the Asian Citizens' Center for Environment and Health (ACCEH), the risk controversy over underground power lines took a whole new turn. The level of EMF from underground power lines turned out to be higher, and therefore more harmful than that from power line towers. In the debates that took place from then on over the EMF risk, ACCEH and NIER(National Institute of Environmental Research) presented conflicting topographies of EMF risk. This paper examines measuring practices of ACCEH and NIER by analyzing the measuring sites, measuring devices, and measuring heights chosen by each organization. This paper further examines how ACCEH and NIER mobilized various standards(EMF exposure limit, measurement guideline, categorization of carcinogens) differently. This controversy on the EMF from underground power lines of Seoul has raised concerns on the non-thermal effects of EMF in the long-term exposure and has led people to question whether burying the power lines is the safe alternative to building power line towers. Furthermore, this suggests conflicting answers on whether Seoul, where 90 % of transmission lines were already buried, is a safely managed place or not.

• Nuclear Engineering and Technology
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• v.26 no.4
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• pp.471-483
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• 1994

A sodium fire facility with a test chamber of 1.7㎥ volume was constructed and operated to carry out experiments of sodium fires such as pool, spray, and columnar fires which might take place in sodium-related facilities. The experimental results of pool fires showed that the increase of temperature and pressure in the test chamber was much smaller than that of spray and columnar fires even though their amount of sodium injection in the chamber was much larger compared to other types of fires. And it was found in pool fires that the temperatures of sodium pool and the gas temperature in the test chamber had been maintained much longer than other types of fires, and that the chamber pressure had come to vacuum due to depletion of the oxygen for a large amount of sodium injection in the chamber. The experimental results of spray fires showed that sprayed sodium of small particles instantly reacted with oxygen, and that its reaction heat increased gas temperature and pressure of the test chamber rapidly and decreased them shortly. And the maximum gas temperature and pressure of the test chamber in spray fires ore greatly changed according to the inlet sodium temperature in the test chamber. The characteristics of the columnar fires were almost similar to those of spray fires, but the maximum temperature and pressure of the test chamber were much smaller even for a large amount of sodium injection. And it was shown in spray and columnar fires that the temperatures at each measurement position in the test chamber were quite different due to the instantaneous sodium oxidation in comparision with pool fires. Finally, the graphex powder was proved to be a very effective extinguisher against sodium pool fires.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.73-85
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• 2021

The construction industry is considered to be a fatal accident industry, accounting for 28.5% of the total industrial accidents in 2017, as the number of industrial accidents in the construction industry has steadily increased over the past decade. So it is necessary to consider introducing Resilience Engineering, which is actively applied to risky industries around the world, to drastically reduce construction accidents. Although Resilience Engineering, which has emerged as the next-generation safety management centered on Hollnagel since the 2000s, claims the importance of strengthening Resilience abilities considering organizational structure and culture, most studies focus only on developing evaluation indicators. The purpose of this study is to analyze the impact of an organization's safety culture on its Resilience abilities in the construction industry. Specifically, it conducted empirical analysis on the impact of safety culture consisting of 'communication, leadership and safety systems' on the Resilience abilities(responding ability, monitoring ability, learning ability, anticipating ability), and the mediation relationship between leadership, communication, and safety system. The survey was conducted on construction workers, and an empirical analysis was conducted on the final 154 responses using SPSS 25 and Smart PLS 3. The results showed that the safety system had a significant impact on all Resilience Abilities, and communication had a significant impact on the remaining three except for anticipating ability among Resilience Abilities. On the other hand, leadership has been shown to have a significant impact on anticipating ability only. In the verifying of the mediation relationship between leadership, communication and safety systems, it was found that leadership affects all Resilience abilities by means of safety systems, but communication can only affect responding ability. This study has practical significance in that it suggests the need for policy-level efforts to introduce and apply Resilience Engineering and then expanded the effective safety management assessment of the construction industry in the future. Moreover, the academic implications are important in that the study attempted to expand the academic scope for a paradigm shift in the future as the safety culture has identified its impact on the Resilience abilities.

• Explosives and Blasting
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• v.39 no.3
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• pp.15-23
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• 2021

Ventilation shafts are pathways in mines and tunnels for the removal of dust or smoke during underground space construction and operation. In mines, blasting with long blast holes is preferred for the excavation of a ventilation shaft in the 10~20m long crown pillar section. In this case, the bottom part of the blast hole is completely drilled in order to determine the drilling error, and this causes a problem of lowering the explosive charge and blasting efficiency. It is possible to solve the problem of explosive loading and to increase the blast efficiency by covering the curb of the blasthole by using stemming material. In this study, simulations for the blasting of a ventilation shaft were performed with various stemming lengths and the blasthole diameters(45, 76mm) using AUTODYN 2D SPH(Smooth particle hydrodynamics) analysis technique. Also the optimal bottom stemming column was derived by checking the size of the boulder and burden line according to blasting. Analysis result, blasting efficiency is lessened in case of stemming length less than 30cm and the optimal length of the stemming material should be 30cm or higher to achieve high efficiency of blasting.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.153-161
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• 2021

This study examined whether the probability of a tax investigation by the general construction industry could reduce the entertainment expenses in order to confirm whether a tax investigation can reduce excessive discretionary expenses of firms. Among the general construction industry listed on the KOSPI and KOSDAQ from 2011 to 2018, 274 firms with sales exceeding 10 billion won in the previous year were targeted at the tax audit selection rate and the tax audit detection rate, which is a proxy for the possibility of a tax investigation. The effect of the ratio of entertainment expenses to sales and the increase rate of entertainment expenses was verified. As a result of the analysis, both the selection rate and the detection rate of the tax investigation have a significant negative effect on the proxy variable of the discretionary expenses measured as the proportion of entertainment expenses and the increase rate of entertainment expenses. The results of this study showed that the tax investigation is a means to curb the excessive expenditure of the firm's discretionary expenses, thus suggesting the direction for the taxation policy and the effectiveness of the tax investigation.

• The Korean Journal of Archival Studies
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• no.15
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• pp.141-183
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• 2007

It is not an overstatement that nowadays electronic mails are communicated more frequently as well as conveniently than phones and facsimiles, not only in routine life hot also in business transactions. Also, it is evident that emails will be used more and more as a communication method between internal and external organizations. If the information transferred and received via emails takes a role of business records, it is no wonder that emails should be uniformly managed as public records. Currently, however, specific policies or guidelines for the management of email records are not available, nor do most of public employees realize that emails are the actual records of the organization. In fact, the three research methods have been used for this study in the purpose of the establishment of email records management scheme. First of all, bibliographic research has been conducted in an effort to describes the definition and types of email records indicated in the guidelines of each nation, as well as the differences from the transitory email messages. Secondly, email management guidelines and policies of public institutions of England, The United States, Australia, and Canada, so-called the advanced countries of the records management, have been analyzed to examine the advanced examples of email management. In order to manage email records effectively, the functional requirements - capture, classification, storage, access, tracking, disposition, and role and responsibility were categorized in this thesis, based on the ISO 15489. As the designs of these foreign guidelines vary one another, common factors of them were extracted to be included in the realm of the seven stages. Lastly, this thesis has analyzed characteristics of the email system within the Electronic Document Management System of existing administrative institutions. Also, it has examined the overall environment of the email records management of public institutions and sought out its improvement. In essence, focused on the crucial factors on email management drawn out from the email management guidelines of foreign nations and the analysis of the policies, this thesis proposes an email records management scheme for Korean public intuitions, as well as an email management model suitable for forthcoming e-government era.

• Journal of Construction Engineering and Project Management
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• v.8 no.4
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• pp.1-24
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• 2018

In the last decade, the use of Building Information Modeling (BIM) as a new technology has been applied with traditional Computer-aided design implementations in an increasing number of architecture, engineering, and construction projects and applications. Its employment alongside construction management, can be a valuable tool in helping move these activities and projects forward in a more efficient and time-effective manner. The traditional stakeholders, i.e., Owner, A/E and the Contractor are involved in this BIM system that is used in almost every activity of construction projects, such as design, cost estimate and scheduling. This article extracts major features of the application of BIM from perspective of participating BIM components, along with the different phrases, and applies to them a logistic analysis using a fuzzy performance tree, quantifying these phrases to judge the effectiveness of the BIM techniques employed. That is to say, these fuzzy performance trees with fuzzy logic concepts can properly translate the linguistic rating into numeric expressions, and are thus employed in evaluating the influence of BIM applications as a mathematical process. The rotational fuzzy models are used to represent the membership functions of the performance values and their corresponding weights. Illustrations of the use of this fuzzy BIM performance tree are presented in the study for the uninitiated users. The results of these processes are an evaluation of BIM project performance as highly positive. The quantification of the performance ratings for the individual factors is a significant contributor to this assessment, capable of parsing vernacular language into numerical data for a more accurate and precise use in performance analysis. It is hoped that fuzzy performance trees and fuzzy set analysis can be used as a tool for the quality and risk analysis for other construction techniques in the future. Baldwin's rotational models are used to represent the membership functions of the fuzzy sets. Three scenarios are presented using fuzzy MEAN, AND and OR gates from the lowest to intermediate levels of the tree, and fuzzy SUM gate to relate the intermediate level to the top component of the tree, i.e., BIM application final performance. The use of fuzzy MEAN for lower levels and fuzzy SUM gates to reach the top level suggests the most realistic and accurate results. The methodology (fuzzy performance tree) described in this paper is appropriate to implement in today's construction industry when limited objective data is presented and it is heavily relied on experts' subjective judgment.