• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.151-151
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• 2019

Because drought is a complex and stochastic phenomenon in nature, statistical approaches for drought assessment receive great attention for water resource planning and management. Generally drought characteristics such as severity, duration and intensity are modelled separately. This study aims to develop a relationship between drought characteristics using a bivariate copula model. To achieve the objective, we calculated the Standardized Precipitation Index (SPI) using rainfall data at 6 rain gauge stations for the period of 1961-1999 in Jehlum River Basin, Pakistan, and investigated the drought characteristics. Since there is a significant correlation between drought severity and duration, they are usually modeled using different marginal distributions and joint distribution function. Using exponential distribution for drought severity and log-logistic distribution for drought duration, the Galambos copula was recognized as best copula to model joint distribution of drought severity and duration based on the KS-statistic. Various return periods of drought were calculated to identify time interval of repeated drought events. The result of this study can provide useful information for effective water resource management and shows superiority against univariate drought analysis.

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.76-83
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• 2018

The electron energy probability function (EEPF) is of significant importance since the plasma chemistry such as the rate of ionization is determined by the electron energy distribution function. It is usually assumed to be Maxwell distribution for 0-D global model. Meanwhile, it has been observed experimentally that the form of EEPF of Ar plasma changes from being two-temperature to Druyvesteyn like as the gas pressure increases. Thus, to apply the 0-D global model of Maxwellian distribution to the non-Maxwellian plasma, we investigated the relative contribution of two distinct electrons with different temperatures. The contributions of cold/hot electrons to the equilibrium state of the plasma have attracted interest and been researched. The contributions to the power and particle balance of cold/hot electrons were studied by comparing the result of the global model considering all combinations of electron temperatures with that of 1-D Particle-in-Cell and Monte Carlo collision (PIC-MCC) simulation and the results of studies were analyzed physically. Furthermore, comparisons term by term for variations of the contribution of cold/hot electrons at different driving currents are presented.

• Restorative Dentistry and Endodontics
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• v.44 no.2
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• pp.15.1-15.8
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• 2019

Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. $135^{\circ}$ angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results: The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions: The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.

• Journal of Distribution Science
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• v.19 no.4
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• pp.37-51
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• 2021

Purpose: The purpose of this study is to provide a basis for establishing a policy to promote the export of Korean goods through the economic ripple effect of the Korean Wave. From 2001 to 2017, cultural goods exports and consumer goods exports data to 102 countries were used to estimate the effect of cultural goods exports on domestic consumer goods exports. Research design, data and methodology: Based on the Gravity Model, we analyzed the effects of domestic film, publishing, music, broadcasting, clothing, cosmetics, processed food, IT products, and automobiles on the export of consumer goods. Results: The empirical analysis estimated the trade creation effect of exports of cultural products driving exports of consumer goods and found that a 1% increase in exports of cultural products increased 0.136% in exports of consumer goods. Conclusions: The average rate of change in consumer goods exports due to changes in cultural product exports was 22.44, which could be interpreted as an increase of $2,244 in exports of consumer goods such as IT products, cosmetics, clothing, and processed foods. According to the analysis of export-driven effects of each consumer item by dividing cultural products by sector, the effects of export of processed foods, clothing, cosmetics, IT products, and film, music, publishing exports were statistically significant.

• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.680-688
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• 2011

This study was performed to find out the distribution aspect of benthic macroinvertebrates according to altitude in a mountain stream (a main stream: Buk stream, a tributary: Hangye stream) of Seoraksan. The survey was conducted from August to November in 2010. All survey sites were very sound because the mountain was being maintained as a protection area of the national park. Water quality and the composition of substrata were similar in all sites. Benthic macroinvertebrates of 3 phyla, 4 classes, 9 orders and 84 species occurred in the stream. Along with the decline of altitude, shredders of the functional feeding groups (FFGs) decreased, while collector filterers increased. In particular, collector filterers increased sharply at the altitude of 600 ~ 500 m (S.E.L.). Benthic macroinvertebrates showed low similarity between the uppermost site and the lower sites. Altitude appeared to be a significant factor that influence the structure and distribution of benthic macroinvertebrate community.

• Journal of Distribution Science
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• v.21 no.3
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• pp.13-23
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• 2023

Purpose: Low-Cost Carrier airlines attempt to provide the best service for their customers. However, the pandemic has forced airline companies to keep developing new strategies. Moreover, in this digital era, airlines must intensely market their service through social media to reach as many customers as possible. This research aims to study the impact of advertisements on Instagram and the customer experience concerning customer loyalty and satisfaction in the aviation industry. Research design, data, and methodology: This study uses a quantitative explanatory with the combination of the positivism paradigm. The data collection technique is by distributing questionnaires to related airline Instagram followers. Meanwhile, the sample calculation uses using the Slovin formula in which 414 respondents are gained. The collected data is analyzed with Structural Equation Model and using Smart-PLS software. Results: The study results indicate that advertising on Instagram and customer experience significantly positively affect customer satisfaction and loyalty. In addition, the variable customer satisfaction has a significant positive on customer loyalty. Conclusions: The study results indicate that the ease of obtaining information via Instagram can affect satisfaction and will increase when customers have made a flight so that they will become loyal customers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.42-48
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• 2023

Abstract: In this study, an induction heating system using resonance is developed to remove remaining moisture and contaminations which could be generated during fabricating secondary batteries. This system is composed of power supply and induction coil. Power supply needs an oscillator, zero crossing detection, frequency tracking function, and induction coil needs a dummy coil to obtain a uniform temperature distribution. It is very important to obtain a uniform heating temperature distribution of battery cell case in the induction heating system before pouring electrolyte into battery cell. Experimental results show a temperature distribution deviation of below 1℃ in the external position of battery cell cases. As well, the temperature of battery cell itself shows distribution of 40℃±3℃.

• Progress in Superconductivity and Cryogenics
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• v.12 no.2
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• pp.17-20
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• 2010

A considerable amount of research material discussing designs and properties of High Temperature Superconducting Fault Current Limiter (HTS FCL) is available. However, a shortage of research concerning positioning of HTS FCL in power grid is felt. In this paper a feasibility study of HTS FCL positioning in Smart Grid through simulation analysis is carried out. A complete power network (including generation, transmission and distribution) is modeled in Simulink / SimPowerSystems. A generalized HTS FCL is also designed by integrating Simulink and SimPowerSystem blocks. The distribution network of the model has a wind turbine attached to it forming a micro grid. Three phase fault have been simulated along with placing FCL models at key points of the distribution grid. It is observed that distribution grid, having distributed generation sources attached to it, must not have a single FCL located at the substation level. Optimized HTS FCL location regarding the best fault current contribution from wind turbine has been determined through simulation analysis.

• Journal of Distribution Science
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• v.20 no.4
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• pp.9-19
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• 2022

Purpose: Mothers determines all household requirements and decides almost all their related things. The purpose of this study was to examine several independent variables on customer loyalty among mothers in The Asian Parents Indonesia community. The independent variables include advertising on Instagram, brand image, word-of-mouth, community cohesiveness, while the dependent variable is purchasing decisions. Research design, data, and methodology: This quantitative study uses a survey method for the Asian Parents Indonesia community members, listed on its website. The population of this community was recorded at 1,310, with a sample of 135 respondents. Data processing is done by using Structural Equation Model using Smart-PLS software. Results: Variables that significantly affect purchasing decisions and customer loyalty are word-of-mouth,summarized in a testimony, advertising on Instagram, and brand image. However, community cohesiveness does not affect customer loyalty to a brand. Conclusion: The results of this test propose significant implications for developing the relationship between baby toiletries producers and customers through word-of-mouth testimonials and advertisements on Instagram while community cohesiveness in maintaining customer loyalty using a brand is not influential, but interactions that occur within the community become a reference for mothers to choose a baby toiletries product.

• Journal of The Geomorphological Association of Korea
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• v.28 no.1
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• pp.67-81
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• 2021

Geomorphological development and distribution at the macro scale provide a clue to the geotectonic characteristics that have affected the geomorphological system. This is because the developmental characteristics and distribution of the landform at the macro scale remain spatial characteristics due to tectonic processes, such as fault activity. From the perspective of tectonic geomorphology, this study identified the developmental characteristics and distribution of the Quaternary landforms in central-southern Yangsan fault and discussed its relevance to fault activity. In this paper, we presented examples and results of morphotectonic analysis of the Yangsan fault, and will present the results of age dating, stratigraphic relationship of the Quaternary landforms, and calculation of cumulative slip rate in the next paper.