• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.131-135
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• 2020

In this study, the models with three, five and ten wings of the propeller which made a light aircraft fly were performed by air flow analyses. As for the flow model A with the shape with five wings, Model A can be seen to be the most ideal flow of air. The flow of air through the number of wings, which is not too many or too few, shows the most smooth flowing form. The smaller the number of propeller blades, the smaller the flow of air. Model A is applied under pressure of up to 0.5631 MPa at the front of air flow. Also, models B and C are applied under pressures of 0.5758 MPa and 0.5589 MPa, respectively. Comparing the pressure contours for each model of flux, model B can be shown to have the highest pressure distribution. The result of this study can be used to investigate the air flow without actual testing. It also seems to be helpful in the aesthetic convergent design of light aircraft propeller.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.7
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• pp.99-106
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• 2018

The purpose of this study is to examine adaptation types of urban tissue in Ipjeong-dong area, Seoul. Ipjeong-dong area has urban tissue those were made during Joseon dynasty and this is remaining even in the present time. This area was originally urban hanok residential districts till late 1950s. However, it has changed into machinery manufacture business area after demolition of Cheonggyechon shantytown. After several workshops and stores moved in this area, manufacturer and merchants required for more spaces due to lack of room for machinery. To place more workshops in the block, lot alteration were happened and accessibility to workshops inside the block were required. Adaptive road network which is main form of adaptative urban tissue were made to adapt in this kind of poor urban condition. To research about adaptive urban tissue making, distribution were explored and comparison tasks between various cadastral map of 1940, 1964, 1970s and 2017 were conducted. From these tasks, certain types of adaptive urban tissues and characteristics of these elements were found. First of all, forms of adaptive road depend on the surrounded environment. Connecting internal building corridor with original road system is categorized as Type A. Altering a portion of the buildings to make adaptive roads is categorized as Type B. Second, there were two types of formation of adaptive road. Type 1 is for adaptive road which is independent gesture from original road network. Type 2 is for adaptive road which is altering the form of original road network by lengthening or connecting two different dead-end roads.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.5
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• pp.61-72
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• 2019

The purpose of this study is to propose the clue of planning guideline for the elderly welfare center supporting the healthy life of the elderly through deriving the planning element of the elderly welfare center based on the Salutogenic Model(SM). The research method was proceeded with literature review. The meaning of Sense of Coherence(SOC) and Generalised Resistance Resources(GRR) which constitute Salutogenic Model is established. The correlation between SOC and GRR is analyzed. The conclusions of this study are as follows. First, EBD, BD, HD, UD, and BFD were studied as planning theories that could enhance the SOC of space. Second, based on the five planning theories, 43 planning elements needed for the elderly welfare center plan were derived. Third, as a result of classifying the plan elements based on the SOC, 'Manageability' is divided into 22 elements, 'Meaningfulness' is 11 and 'Comprehensibility' is 10 elements. Fourth, the details of the SOC items for each theory are as follows: BFD focuses on 'Manageability' with 'Manageability'(74%) and 'Comprehensibility'(26%), but 'Meaningfulness' does not exist. And UD regards 'Comprehensibility'(66%) as important, and 'Manageability' and 'Meaningfulness' as 17%. BD, on the other hand, has a high percentage of 'Meaningfulness'(70%), 'Comprehensibility'(21%) and 'Manageability'(9%). Next, the 'Manageability' of HD and EBD is 46%. And HD was 'Meaningfulness'(34%), 'Comprehensibility'(20%), and EBD was 'Meaningfulness'(30%) and 'Comprehensibility'(24%). The three items of SOC showed different distribution according to the spatial planning theory. As a result of the analysis, the spatial planning theory with the 'Comprehensibility' was related to Universal Design(UD), and the spatial planning theory with the 'Manageability' was related to Barrier-Free Design(BFD). In addition, the spatial planning theory of 'Meaningfulness' was related to Bio-philic Design(BD). Therefore, the plan of the elderly welfare center needs to approach the multidimensional design methodology to enhance the SOC(Sense of Coherence).

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.4
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• pp.61-68
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• 2019

As high schools implement credit completion system these days, concerns about the dissolution of classes, which are the original stable groups of studying and living, and the instability of the basal space, is growing due to the extended operation of moving optional classes. The purpose of this research is to understand the effect that environmental features of the basal space within the school and the operation method have on the students' space use and formation of attachment place within the school. For this, the main activity places, attachment places, school life satisfaction and others were investigated at 2 Japanese credit-based comprehensive high schools, which are different in the physical environmental features of school buildings. Based on this, a quantitative analysis about the distribution of activity places and attachment places was implemented. The space use features for each student attribute were compared, and the school life satisfaction for each type of attachment place formation was analyzed. As a result, the change of the territorial consciousness about the class space according to the implementation of moving optional classes could be understood. And it was confirmed that the students' space using behavior and place evaluation change according to the physical environmental feature of the class space and common space, and that this is affecting the life satisfaction of students.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.21-28
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• 2019

Handmade hydrated lime has been used for preservation and repair of architectural heritage in Korea. However, the effect of the amount of water used for slaking quicklime on the physical and chemical properties of the hydrated lime, which is the result of the slaking process, has not been clearly understood. In this study, particle size distribution, chemical composition and crystalline phases of the hydrated lime are investigated by varying the amount of water used for the slaking. In addition, temperature history during the slaking process is examined. For this, various experiments, such as laser diffraction analysis, X-ray fluorescence, X-ray diffraction, thermogravimetric analysis, and temperature recording using a thermocouple, were performed. When the quicklime came into contact with water, its temperature reached $100^{\circ}C$ within 10 min due to sudden exothermic reaction of calcium oxide, and this temperature was maintained for about 30 min. The water to lime ratio influenced the cooling rate during the slaking process; that is, the more water was used, the longer it took to reach an ambient temperature. The amount of water for the slaking did not have a noticeable effect on the contents of major components of the hydrated lime such as calcium hydroxide and calcium carbonate, but when slaked with more amount of water, average particle size of the lime tended to decrease. The experimental results in this study can be used as references for developing guidelines on the safety or appropriate amount of water in the lime slaking process.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.1
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• pp.173-178
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• 2020

In this study, we analyzed space heating and domestic hot water(DHW) charges from 2017 to 2018 for 151,206 households in 202 apartment complexes built from 1997 to 2016, in order to evaluate the effectiveness of Korea's insulation standards reinforcement. The applied insulation standards were revised three times(in 1987, 2001 and 2010). We used the Anderson-Darling test to review the normality of the space heating and DHW charges. As a result, each p-value was greater than 0.05 and it followed the normal distribution. The annual average space heating charges per unit area of apartments with the 1987 insulation standards were 5,237￦/㎡a in 2017 and 5,328￦/㎡a in 2018. The heating charges with the 2001 standards were 4,827￦/㎡a in 2017 and 4,817￦/㎡a in 2018. Compared to previous standards(1987 standards), heating charges decreased by 7.8% and 9.6%. Also the heating charges with the 2010 standards were 3,683￦/㎡a in 2017 and 3,734￦/㎡a in 2018. Compared to previous standards(2001 standards), heating charges decreased by 24.3% and 21.5%. On the other hand, compared to each previous standards, DHW charges were decreased by 12.2%, 13.6% or increased by 4.6%, 6.9%, which means there's no correlation between insulation standards reinforcement and DHW charges.

• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.419-442
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• 2020

The majority of the natural gas demand in South Korea is mainly determined by the heating demand. Accordingly, there is a distinct seasonality in which the gas demand increases in winter and decreases in summer. Moreover, the degree of sensitiveness to temperature on gas demand has changed over time. This study firstly introduces changing temperature response function (TRF) to capture effects of changing seasonality. The temperature effect (TE), estimated by integrating temperature response function with daily temperature density, represents for the amount of gas demand change due to variation of temperature distribution. Also, this study presents an innovative way in forecasting daily temperature density by employing functional principal component analysis based on daily max/min temperature forecasts for the five big cities in Korea. The forecast errors of the temperature density and gas demand are decreased by 50% and 80% respectively if we use the proposed forecasted density rather than the average daily temperature density.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1384-1389
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• 2020

Although the fintech industry is developing rapidly around the world, the domestic development situation is rather slow compared to the speed. Therefore, the future development direction can be set by analyzing the current status of the fintech industry in order to suggest the direction of development in the domestic fintech industry. The main services provided by companies belonging to the domestic fintech industry are in the areas of remittance settlement, financial investment, asset management, crowdfunding, P2P finance, overseas remittance, fintech SI, insurtech, virtual currency, security, and authentication. It is divided into. This study identifies the main technologies used in the service and grasps the current domestic status. In addition, it analyzes the distribution of workers by each service. This study is expected to play an important role in the development of the financial industry through technical analysis of fintech companies.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.125-134
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• 2021

This study aimed to explore the factors affecting the foreign direct investment (FDI) intentions of investors into Quang Ninh province, located in the north-eastern of Viet Nam. Researchers used two main methods, namely, Exploratory Factors Analysis (EFA) and the Structural Equation Model (SEM) based on partial least squares structural equation modeling (PLS SEM) to explore and measure the impact of factors affecting the investors' FDI intentions into Quang Ninh province. The empirical analysis used data from the survey of 206 domestic and foreign investors into Quang Ninh province, including representatives of the Board of Directors, members, and management representatives at the department level, with reliable tools (SPSS 26 and SmartPLS 3.0 software). The research results identified the following factors affecting investment into Quang Ninh: FDI attraction policies have the strongest impact on the investors' FDI intentions; it is followed by infrastructure, public services and human capital with strong effects on intentions of investors' FDI; and finally the standards of living that affects the investors' FDI intentions. There is also a positive relationship between all the factors and the investors' FDI intentions. Several recommendations are further suggested to enhance attraction of foreign direct investment into Quang Ninh province.

• Korean Journal of Plant Taxonomy
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• v.50 no.4
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• pp.385-394
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• 2020

To elucidate the molecular phylogeny of Neottia japonica, which is a terrestrial orchid distributed in East Asia, the internal transcribed spacer (ITS) of nuclear DNA and the matK of chloroplast DNA were used. A total 22 species of 69 accessions for ITS and 21 species of 114 accessions for matK phylogeny were analyzed with the maximum parsimony and Bayesian methods. In addition, we sought to establish a correlation between the distribution, morphology of the auricles and genetic association of N. japonica with phylogenetic data. The phylogenetic results suggest that N. japonica is monophyletic and a sister to N. suzukii in terms of the ITS phylogeny, while it is paraphyletic with N. suzukii in terms of the matK phylogeny. N. japonica and N. suzukii show similar morphologies of the lip and column, they both flower in April, and they are both distributed sympatrically in Taiwan. Therefore, it appears to be clear that N. japonica and N. suzukii are close taxa within Neottia, although there is incongruence between the nrDNA and cpDNA phylogenies of N. japonica. The incongruence between the two datasets may have various causes, meaning that further studies are needed to confirm the evolutionary process of N. japonica. The phylogenetic status of N. kiusiana, which was not included in previous studies, was as a sister to N. nidus-avis. Meanwhile, the ITS and matK phylogenies are unsuitable for identifying genetic associations with the characteristic of auricles. The phylogenetic topologies of Korean, Taiwanese and mainland Chinese individuals suggest that the populations of N. japonica in Korea originated from China's mainland and island areas. The characterization of regional gene differences could provide useful preliminary data for future studies.