• Clean Technology
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• v.25 no.2
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• pp.147-152
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• 2019

Electrostatic precipitator that shows a good performance for the removal of particulate matter is important for controlling emissions from industrial facilities and power plants. The efficiency of the electrostatic precipitator on the removal of particulate matter is highly affected by the flow pattern inside the electrostatic precipitator. A number of studies have been conducted to obtain uniform flow distribution inside electrostatic precipitators. An electrostatic precipitator (ESP) with a length of 3.5 m and a height of 0.875 m was designed and installed in this study. The ESP included an inlet duct, diffuser, body, and contractor. Three perforated plates were installed in the diffuser of the ESP. Five pitot tubes were installed vertically and used to measure flow distribution in the cross section of the ESP body. Root mean square deviation value (RMS%) was used to examine the flow distribution inside the ESP when the perforated plates were installed in the diffuser. Flow distribution was also investigated in relation to the porosity of the perforated plate. The results showed that the perforated plates improved greatly the flow distribution inside the electrostatic precipitator. In addition, the most uniform flow distribution was found with 40%, 50%, and 50% porous perforated plates located from the inlet of the diffuser.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.9-20
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• 2019

The number of natural disasters in Korea, such as earthquakes, is increasing. As a result, there is growing need for temporary residences or shelters for disaster conditions. The aim of this study was to produce post-disaster refugees housing differentiated from existing shelters using lightweight composite panels. To accomplish this, the structural performance of lightweight composite panels was validated, and an in-plane shear strength test was conducted according to the ASTM E72 criteria among the performance test methods for panels. As a result of the experiment, the maximum load for each specimen under an in-plane shear load was determined. All the experiments ended with the tear of the panel's skin section. The initial stiffness of the specimens was consistent with that predicted by the calculations. On the other hand, local crushing and tearing, as well as the characteristics of the panel, resulted in a decrease in stiffness and final failure. Specimens with an opening showed a difference in stiffness and strength from the basic experiment. The maximum load and the effective area were found to be proportional. Through this process, the allowable shear stress of the specimens was calculated and the average allowable shear stress was determined. The average ultimate shear stress of the lightweight composite panels was found to be $0.047N/mm^2$, which provides a criterion of judgement that could be used to expect the allowable load of lightweight composite panels.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.60-67
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• 2019

In general, a reinforced concrete slabs are known to have a high fire resistance performance due to thermal properties of concrete materials. However, according to previous research, the thermal behavior of voided slabs is reported to be different from that of conventional RC solid slabs, and the differences seem to be caused by the air layer formed inside the voided slab. Therefore, it is difficult to estimate the temperature distribution of the voided slab under fire by using the existing methods that do not take into account the air layer inside the voided slab. In this study, a numerical analysis model was proposed to estimate the temperature distribution of voided slabs under fire, and evaluated. Heat transfer of slabs under fire is generally caused by conduction, convection and radiation, and time-dependent temperature changes of slab can be determined considering these phenomena. This study proposed a numerical method to estimate the temperature distribution of voided slabs under fire based on a finite difference method in which a cross-section of the slab is divided into a number of layers. This method is also developed to allow consideration of heat transfer through convection and radiation in air layer inside of slabs. In addition, the proposed model was also validated by comparison with the experimental results, and the results showed that the proposed model appropriately predicts the temperature distribution of voided slabs under fire.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.561-564
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• 2016

If using crime map which represents criminal section that violent crimes targeting women frequently happened, the police could prevent additional crimes by positioning themselves intensively in expected crime zones and each individual could avoid being damaged by referring information of criminal zones. In this paper, by analyzing crimes targeting women and offender information which is provided in public-opened datum portal, we suppose a system which prevents crimes that calculates locational danger and, by considering location and age group of users, provides user-customized information of danger. By crawling the criminals datum which is provided in public-opened datum portal, It collects them. About the areas which happened sexual crimes, calculating danger of crime based on statistical crime information including criminal information, residence of offenders, areas which happened sexual crimes, sentences and the number of crime, this system is able to visualize the areas which sexual crimes happened based on information of danger grade representing on user's location. The score of danger calculated in location unit can provide criminal information according to location and ages of users by interacting GIS.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.241-258
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• 2019

The aim of this study was to analyze the factors that affect the habitat of fishes and amphibians in a mountain stream that is part of an experimental forest at Kongju National University, Gongju, Chungcheongnam, Korea, and examine the differences in the presence of fishes and amphibians in the stream before and after construction of an erosion control dam. The results showed that the factors that affect the presence of fishes are pH, electrical conductivity (EC), dissolved oxygen (DO), flow velocity, and step-pool number, and that the factors that affect the presence of amphibians are monthly rainfall, pH, EC, DO, and crown density. Of these factors, pH, EC, flow velocity, and monthly rainfall were significantly different before and after dam construction; however, the differences among the other three factors from dam construction, except EC, might not have been enough to affect the presence of fishes and amphibians. Our results suggest that the difference in the frequency of fishes and amphibians surveyed before and after dam construction in the upper and lower stream sections were not statistically significant. One exception to this was the presence of amphibians in the lower stream section during and after dam construction, which could have been the result of a large amount of sediment produced by excavation that led to high EC.

• Land and Housing Review
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• v.13 no.4
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• pp.73-89
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• 2022

With the spread of COVID-19, the role of parks has been emphasized. Under the quarantine guidelines, including social distancing, people are visiting parks as a safe place. In line with these changes, parks need to be studied as pandemic adaptation measures according to their physical and location characteristics. This study aims to explore the potential of linear parks with accessibility and pass way functions based on the characteristics of surrounding land uses. The case study area was selected from Yeonnam-dong to Yeomni-dong of the Gyeongui Line Forest Park, and the area was divided into 4 sections based on the administrative boundary and surrounding land uses. Multiple regression models were adopted in each section using the total number of de facto population as a dependent variable and factors affecting external activities including COVID-19 as independent variables. The results show that first, the more diverse the interaction between commercial facilities and linear parks, the greater the impact of the pandemic. Second, where various commercial facilities are concentrated people respond more sensitively to short-term weather changes than seasonal ones. This study indicates that there are differences in the use of linear parks according to the surrounding land uses. In addition, it suggests that the linear park has potential as a means to overcome the Pandemic crisis of the city and to increase equity in access to green areas.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.57-78
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• 2022

The disc cutter and cutterbit, which are the most important factors to increase the excavation efficiency of TBM, are key factors in the design and construction of the cutter head. The arrangement, spacing, number, size, and material of disc cutters suitable for the ground conditions determine the success or failure of TBM construction. The disc cutter, which is a representative consumable part in TBM construction, can cause enormous disruption to the construction cost as well as the construction cost unless accurate prediction of wear and replacement cycle is accompanied. Therefore, in this study, the method of calculating the replacement cycle of the disc cutter calculated at the time of design for the slurry shield TBM field, and the depth of wear and replacement location of the disc cutter that occurred during actual construction were compared by analyzing the field data. For a quantitative comparison, weathered soil/weathered rock, soft rock, and hard rock were classified according to the ground in the section showing constant excavation data, and the trajectory of circle was different depending on the location of the disc cutter, so it was compared and analyzed.

• Journal of Korea Trade
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• v.24 no.2
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• pp.31-52
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• 2020

Purpose - This study mainly investigates two potential legal regimes expected to govern the use of electronic bills of lading: the Rotterdam Rules (2009) and the UNCITRAL Model Law on Electronic Transferable Records (2017). Widespread use of electronic bills of lading has been unsuccessful partly due to the absence of a uniform legal regime and protracted uncertainties. This paper aims to carry out an assessment of the possibilities where either of two potential legal regimes could provide certainty to the effect and validity of the use of electronic bills of lading, and contribute to the facilitation of electronically transferring the rights to goods carried by sea. Design/methodology - This paper first introduces two legal instruments and the relevance to electronic bills of lading. Since neither of these legal instruments has yet entered into force, the following section looks into the ratification or enactment possibilities based on a literature review and track records of the past legal regimes of the same kind. Assessment of the different adoption possibilities further requires comparative work of the two legal instruments, which will be based on an analysis of relevant provisions and a literature review. The literature review on the Rotterdam Rules delves into various studies and data produced since the UNCITRAL's adoption in 2009. The literature review on the UNCITRAL Model Law on Electronic Transferable Records heavily relies on UNCITRAL working group documents from 2011 to 2017 together with the final explanatory note. Findings - The main findings can be summarized as follows. Application of the Rotterdam Rules would negate the role of the UNCITRAL Model Law on Electronic Transferable Records assisting in the implementation of the Rotterdam Rules due to some conflicting issues. Enactment of the UNCITRAL Model Law alone can sufficiently provide a higher level of certainty in the use and effect of electronic bills of lading so long as lawmakers and parties are aware of some issues with the application. What concerns potential users most is the extension of the status quo, where neither of the legal instruments have any effect. It is necessary to take a number of alternatives into consideration, such as promotion of standard clauses and confirmation by a court ruling. Originality/value - Existing studies focus either on the Rotterdam Rules or on the UNCITRAL Model Law, but not both. Not many papers have yet dealt with the Model Law, which was adopted by UNCITRAL only 2 years ago, particularly in the context of a potential legal regime for electronic bills of lading. This paper attempts to introduce the differences between the two legal instruments in regulating the use of electronic bills of lading while providing an assessment of the various possibilities for which parties involved in international trade can be better prepared for the changing legal environment.

• Korean small business review
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• v.42 no.3
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• pp.1-25
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• 2020

To commemorate the 40th anniversary of the foundation of the Korean Association of Small Business Studies, this study reviewed research papers on the subject of entrepreneurship in the Asia Pacific Journal of Small Business. For 40 years, the subjects of entrepreneurship-related studies published in this journal were relatively limited and the number of articles was very few. The research papers mainly focus on defining entrepreneurship as an innovation or as a determinant of innovation and survey-based empirical studies have been conducted since the publication of the Entrepreneurial Orientation(EO) by Lumpkin and Dess(1996). Although entrepreneurship is a research field that can be approached from various perspectives such as economics, sociology, psychology, cultural anthropology, and organization theory, most of the papers published in the Asia Pacific Journal of Small Business do not clearly state their theoretical positions or viewpoints. Moreover, there are few studies that incorporate corporate entrepreneurs or startup teams although they have been major actors or entrepreneurship. Lastly, innovation has been the main focus of research, leaving other arenas such as opportunity recognition and discovery understudied. In order to increase the quantity and improve the quality in the entrepreneurship research, we need to have the entrepreneurship field as one academic section in the Asia Pacific Journal of Small Business.

• Journal of Internet of Things and Convergence
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• v.8 no.4
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• pp.25-40
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• 2022

This study aimed to understand the increasing number of elder abuses in South Korea, where entry into the super-aged society is imminent, by implementing text mining analysis. Korean Academic journals were obtained from 2004, the establishment year of the senior care agency, to 2021. We performed natural language processing of the titles, keywords, and abstracts and divided them into three segments of periods to identify latent meanings in the data. The results illustrated that the first section included 81 papers, the second 64, and the third 104 respectively, averaging 13.8 annually, which increased its numbers from 2014 until the decrease below the annual average in 2020. Word frequency demonstrated that the common keywords of the entire segments were 'elder abuse,' 'elders,' 'influences,' 'factors,' 'recognition,' 'family,' 'society,' 'prevention plans,' 'experiences,' 'abused elders,' 'abuse prevention,' 'depression,' etc., in consecutive order. TF-IDF indicated that 'influences,' 'recognition,' 'society,' 'prevention plans,' 'abuse prevention,' 'experiences,' 'depression,' etc., were the common keywords of all divisions. Network text analysis displayed that the commonly represented keywords were 'elder abuse,' 'elders,' 'influences,' 'factors,' 'characteristics,' 'recognition,' 'family,' 'prevention plans,' 'society,' 'abuse prevention,' and 'experiences' in the entire sections. concor analysis presented that the first segment consisted of 5 groups, the second 7, and the third 6. We suggest future directions for elder abuse research based on the results.