• Journal of Environmental Science International
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• v.28 no.6
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• pp.553-559
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• 2019

In this study, zeolitic materials at $Na_2CO_3/CFA$ ratio of 0.6 - 1.8 were synthesized from coal fly ash from a thermal power plant using a fusion/hydrothermal method. The zeolitic materials were found to have cubic crystals structure and X-ray diffraction (XRD) peaks of Na-A zeolite by XRD and SEM analysis. When the zeolitic materials were synthesized from the coal fly ash, the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratios of 0.9-1.8 had the same location as the XRD peaks of commercial Na-A zeolite. The XRD peaks of the Na-A zeolite ($Na_{12}Al_{12}Si_{12}O_{48}27.4H_2O$) were confirmed in the $2{\theta}$ in the range of 7.18-34.18. However, it was also confirmed that peaks of $CaCO_3$, an impurity inhibiting synthesis of Na-A zeolite from CaO and $Na_2CO_3$ in the coal fly ash, occurred in the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratio of 1.5-1.8. The crystallinities of the zeolitic materials tended to increase gradually within the $Na_2CO_3/CFA$ ratio range of 0.6-1.8.

• Fire Science and Engineering
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• v.33 no.1
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• pp.164-170
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• 2019

This paper discusses the characteristics of the fire service organization structure in the Republic of Korea. The subjects of the study were selected by the fire service organization consisting of public firefighters in the Republic of Korea. The characteristics of the fire service organization structure (complexity, centrality, and officiality) were confirmed by various articles and previous references. The fire service organization showed a mechanical structure and bureaucratic organization. The levels of complexity, centrality, and officiality in the characteristics of fire service organization structure were higher than those of a general administration organization or company organization. In conclusion, this paper contributes to the development of fire service organization theory by confirming the characteristics of fire service organization structure.

• Journal of Information Technology Applications and Management
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• v.25 no.4
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• pp.1-21
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• 2018

Due to the increase in the use of the Internet, it is becoming more common to provide or use a social login for registering for services. Herein, the purpose of this study is to analyze the influence of security, individual innovativeness, ubiquity and brand awareness on the use of social log-in service through the individuals' attitude who have memorized various IDs and passwords by using Technology Acceptance Model (TAM). In addition, the effect of individual innovativeness on the relationship between social login characteristic factors and attitudes toward social login services are examined. Based on the statistical results, it is found that the significant factors affecting the attitude toward the social login service are the security, ubiquity, brand awareness and perceived usefulness. Moreover, the individual innovativeness is found to have the moderating effects in the relationship between the three factors (the perceived usefulness, and perceived ease of use, and security) and attitude toward the social login service. Positive attitudes increase with the usefulness, ease of using social login serive when individual innovativeness is high. On the other hand, when individual innovativeness is low, the stronger the effect of security on attitude toward the social login services. In accordance with these results, the implications and limitations of this study are discussed.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.87-100
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• 2020

Economic Development Zone(EDZ) in the province is one of the foreign policy for economic development of North Korea. North Korea has promulgated 27 Economic Development Zones(5 EDZs as central level and 22 EDZs as provincial level) to promote economic growth through the expansion of external opening policy. EDZs of the provinces play an important role in North Korea's national and regional economic growth. The purpose of this study is to select analytical criteria that can be quantified when considering the location conditions of North Korean economic development zones when domestic companies advance into North Korea according to the progress of inter-Korean economic cooperation, and derive the relative importance between the criteria. After that, based on this, we intend to quantify the evaluation of the location priority of the economic development zone. In this study, through AHP analysis results, when domestic companies enter North Korea, we derive the importance and preference of location selection factors when considering the location conditions of North Korean economic development zones. Taking into account the reality of North Korea when the Korean company entered the North economic development zone following location for evaluation. That is, logistics and transportation, industrial infrastructure, competitiveness, and management incentives. And 14 sub-factors were selected and AHP analysis was performed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.66-77
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• 2021

Companies widely use survey to identify customer requirements, but the survey has some problems. First of all, the response is passive due to pre-designed questionnaire by companies which are the surveyor. Second, the surveyor needs to have good preliminary knowledge to improve the quality of the survey. On the other hand, text mining is an excellent way to compensate for the limitations of surveys. Recently, the importance of online review is steadily grown, and the enormous amount of text data has increased as Internet usage higher. Also, a technique to extract high-quality information from text data called Text Mining is improving. However, previous studies tend to focus on improving the accuracy of individual analytics techniques. This study proposes the methodology by combining several text mining techniques and has mainly three contributions. Firstly, able to extract information from text data without a preliminary design of the surveyor. Secondly, no need for prior knowledge to extract information. Lastly, this method provides quantitative sentiment score that can be used in decision-making.

• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.146-154
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• 2021

Conspicuous consumption is often investigated in Korea and consumers purchase a product to publicly display economic power or social status. The existing studies argue that brand loyalty and luxury brand preferences escalate conspicuous consumption, and it is important to identify different visual perception to understand irrational consumers' behavior. Car emblem as brands' visual identity represents the brand's image, mission and message. Irrational consumers thus are expected have different visual perception to the emblem or logo. To understand the impact of irrational consumer behavior on visual perception, this study explored how brand loyalty and luxury brand preferences impact on the visual perception of car emblems between Korean domestic brand and imported brand. This study used eye tracking technology to measure the respondents' attention on an emblem of the cars. Eye tracking tools analyze fixations and measure the attention on a specific area of interests (AOI). This study explored the maintaining time and frequency on AOI, as well as explored the size of pupil to identify the respondents' attention on the AOI. In this experiment, the logos of domestic cars (i.e., Hyundai and Kia) and foreign cars (i.e., Mercedes-Benz and BMW) were swapped to see how irrational consumer behavior impact on visual perception of car emblem.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.88-95
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• 2021

In aviation meteorology, the low level wind shear is defined as a sudden change of head windbelow 1600 feet that can affect the departing and landing of the aircraft. Jeju International Airport is an area where low level wind shear is frequently occurred by Mt. Halla. Forecasting of such wind shear would be useful in providing early warnings to aircraft. In this study, we investigated the performance of statistical downscaling model, called Korea Meteorological Administration Post-processing (KMAP) with a 100 m resolution in forecasting wind shear by the complex terrain. The wind shear forecasts was produced by calculating the wind differences between stations aligned with the runways. Two typical wind shear cases caused by complex terrain are validated by comparing to Low Level Wind Shear Alert System (LLWAS). This has been shown to have a good performance for describing air currents caused by terrain.

• Asia-Pacific Journal of Business
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• v.12 no.4
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• pp.87-105
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• 2021

Purpose - The purpose of this study was to explores how CEO general human capital, one of the most critical issues in recent research, affects compensation schemes. Design/methodology/approach - This study collected the CEOs of S&P500 companies from 2001 to 2009 and contains 4,155 CEO-firm-year observations and 704 different CEOs. Findings - First, only contingent bonus is affected by general human capital and reputation. Second, the career concerns of CEOs are relevant, especially when explaining CEO tenure. Third, we offer an alternative view of what determines the level of cash compensation schemes and the factors that affect the running of a firm. Fourth, we also suggest that the increase in general human capital can be explained by the increase in its relative importance in managing a modern firm. Overall, the results of this study do not only contribute to academics but also important to boards and shareholders. Research implications or Originality - This study intends to fill the gap in the extant literature by examining the relationship between general human capital and compensation schemes.First, we add to the compensation literature by arguing that a cash compensation scheme is efficient for generalist CEOs. We break down CEO cash compensation schemes into fixed and contingent bonus compensation and investigate whether general human capital differentially affects CEO cash compensation schemes, and thus, the sensitivity to unequal pay for human capital. Second, we contribute to the reputation literature by arguing that CEO perceived reputation also affects CEO compensation schemes.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.343-353
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• 2023

A zeolite material (ZCH) was synthesized from coal fly ash in an HD thermal power plant using a fusion/hydrothermal method. ZCH with high crystallinity could be synthesized at the NaOH/CFA ratio of 0.9. Ion-exchanged ZCH adsorbents for ammonia removal were prepared by ion-exchanging various cation (Cu²⁺, Co²⁺, Fe³⁺, and Mn²⁺) on the ZCH. They were used to evaluate the ammonia adsorption breakthrough curves and adsorption capacities. The ammonia adsorption capacities of the ZCH and ion-exchanged ZCHs were high in the order of Mn-ZCH > Cu-ZCH ≅ Co-ZCH > Fe-ZCH > ZCH according to NH₃-TPD measurements. Mn-ZCH ion-exchanged with Mn has more Brønsted acid sites than other adsorbents. The ion-exchanged Cu²⁺, Co²⁺, Fe³⁺, or Mn²⁺ ions uniformly distributed on the surface or in the pores of the ZCH, and the number of acidic sites increased on the alumina sites to form the crystal structure of zeolite material. Therefore, when the ion-exchanged ZCH was used, the adsorption capacity for ammonia gas increased.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.355-363
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• 2023

This study used a batch DAF (dissolved air flotation) jar tester to evaluate the algae removal efficiency of alum and PAC coagulants during coagulation, flocculation, and flotation. Optimal coagulant dosages were 0.06 ~ 0.15 mL/L (12.0 ~ 26.0 mg Al/L,17%), 0.08 ~ 0.20 mL/L (10.0 ~ 24.0 mg Al/L, 12%), 0.25 ~ 0.30 mL/L (25.0 ~ 30.0 mg Al/L, 10%) for PAC, and 3.0 ~ 5.0 mL/L (81.0 ~ 135.0 mg Al/L, 2.7%) for alum. Turbidity of treated water was 1.0 ~ 2.0 NTU in optimal coagulation, flocculation, and flotation conditions for the four coagulants types. The amount of coagulant injected tended to decrease with increasing Al content in the coagulant, as follows : 17% PAC < 12% PAC < 10% PAC < 2.7% alum. Turbidity removal efficiencies were in the order of 12% PAC (93.6%) > 10% PAC (92.7%) > 17% PAC (91.3%) > 2.7% Alum (88.1%).