• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.337-352
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• 2023

In general, Rainfall-Runoff model parameter set is optimized using the entire data to calculate unique parameter set. However, Korea has a large precipitation deviation according to the season, and it is expected to even worsen due to climate change. Therefore, the need for hydrological data considering seasonal characteristics. In this study, we conducted regional sensitivity analysis(RSA) using the conceptual Rainfall-Runoff model, GR4J aimed at the Soyanggang dam basin, and clustered combining the RSA results with hydrometeorological data using Self-Organizing map(SOM). In order to consider the climate characteristics in parameter estimation, the data was divided based on clustering, and a calibration approach of the Rainfall-Runoff model was developed by comparing the objective functions of the Global Optimization method. The performance of calibration was evaluated by statistical techniques. As a result, it was confirmed that the model performance during the Cold period(November~April) with a relatively low flow rate was improved. This is expected to improve the performance and predictability of the hydrological model for areas that have a large precipitation deviation such as Monsoon climate.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.189-217
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• 2023

The metaverse is a virtual world where individuals engage in social, economic, and cultural activities using avatars, which represent an alternate version of oneself within the virtual realm. While the metaverse has garnered global attention recently, research exploring the identity manifested through avatars within the metaverse remains limited. This study investigates the influence of four IT artifact characteristics related to avatar usage in the metaverse-avatar representation, avatar copresence, avatar profiling, and avatar-space interaction-on perceived avatar identity verification. A survey was conducted with 196 experienced users of the Zepeto platform, and hypotheses were tested using structural equation modeling. The analysis results indicate that the use of IT artifacts enabling avatar representation, avatar copresence, and avatar-space interaction has a positive impact on perceived avatar identity verification. This achieved self-verification indirectly influences the satisfaction and subsequent intention to continue using the metaverse. This study contributes to the academic field by empirically verifying the metaverse technological factors that influence the projected identity onto avatars within the metaverse. Furthermore, it is expected to provide effective guidelines for metaverse platform companies in designing and implementing the metaverse.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.141-157
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• 2023

Start-ups are the driving force of economic development and play an important role in improving national competitiveness. The country's start-up support policies are increasing every year, but indicators that do not challenge them and do not consider future start-ups can predict employment reduction and unemployment can increase further. You can. The increase in the number of young people doing nothing is causing economic hardship and neglect of future precious human resources, which calls for a more realistic national entrepreneurship policy. Accordingly, this study sought to identify bias and environmental factors in order to reveal factors that influence the will to start a business among potential entrepreneurs in Korea. For this purpose, descriptive statistical analysis was performed using SPSS on a sample of 227 responses from the general public who are potential entrepreneurs interested in starting a business. As a result, prejudice decreased the will to start a business and increased fear of failure. On the other hand, the entrepreneur's environmental factors reduced the fear of failure and increased the will to start a business. Lastly, fear of failure was found to play a mediating role between the two independent variables and the will to start a business. The results of this study showed that prejudice was a negative factor in the will to start a business, and the environment was a positive factor. These research results suggest that in order to revitalize entrepreneurship, positive environmental factors that can provide entrepreneurs' correct recognition and support for entrepreneurship are necessary.

• The Transactions of the Korea Information Processing Society
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• v.13 no.6
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• pp.269-277
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• 2024

With the advancement of modern IT technologies, the operation of autonomous vehicles is becoming a reality, and route planning is essential for this. Generally, route planning involves proposing the shortest path to minimize travel distance and the quickest path to minimize travel time. However, the quality of these routes depends on the topological characteristics of the road network graph. If the connectivity structure of the road network is not rational, there are limits to the performance improvement that routing algorithms can achieve. Real drivers consider psychological factors such as the number of turns, surrounding environment, traffic congestion, and road quality when choosing routes, and they particularly prefer routes with fewer turns. This paper introduces a simple path algorithm that seeks routes with the fewest turns, in addition to the traditional shortest distance and quickest time routes, to evaluate the characteristics of road networks. Using this simple path algorithm, we compare and evaluate the connectivity characteristics of road networks in 20 major cities worldwide. By analyzing these road network characteristics, we can identify the strengths and weaknesses of urban road networks and develop more efficient and safer route planning algorithms. This paper comprehensively examines the quality of road networks and the efficiency of route planning by analyzing and comparing the road network characteristics of each city using the proposed simple path algorithm.

• The Mathematical Education
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• v.63 no.1
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• pp.1-18
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• 2024

This study aims to analyze low-performing high school students' difficulties in constructed response (CR) mathematics assessments and explore ways to use writing activities to support student learning. The participants took CR assessments, engaged in guided writing activities across 15 lessons, and provided responses to our interviews. The study identified 20 types of student difficulties, which were sorted into two main categories: "mathematical difficulties" and "CR difficulties." The difficult nature of mathematics as a school subject included a lack of understanding of mathematical concepts, students' difficulty with mathematical symbols and notations, and struggles with word problems. Challenges specific to CR assessments included students' difficulties arising from the testing conditions unlike those of multiple-choice items, and included issues related to constructing appropriate responses and psychological barriers. To address these challenges in CR assessments, the study conducted guided writing activities as an intervention, through which six themes were identified: (1) internalization of mathematical concepts, (2) mathematical thinking through relational understanding, (3) diverse problem-solving methods, (4) use of mathematical symbols, (5) reflective thinking, and (6) strategies to overcome psychological barriers.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.60-74
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• 2018

This study was to investigate the pedestrian's thermal environments in the North Sidewalk of E-W Street during summer heatwave. We carried out detailed measurements with four human-biometeorological stations on Dongjin Street, Jinju, Korea ($N35^{\circ}10.73{\sim}10.75^{\prime}$, $E128^{\circ}55.90{\sim}58.00^{\prime}$, elevation: 50m). Two of the stations stood under one row street tree and hedge(One-Tree), two row street tree and hedge (Two-Tree), one of the stations stood under shelter and awning(Shelter), while the other in the sun (Sunlit). The measurement spots were instrumented with microclimate monitoring stations to continuously measure microclimate, radiation from the six cardinal directions at the height of 1.1m so as to calculate the Universal Thermal Climate Index (UTCI) from 24th July to 21th August 2018. The radiant temperature of sidewalk's elements were measured by the reflective sphere and thermal camera at 29th July 2018. The analysis results of 9 day's 1 minute term human-biometeorological data absorbed by a man in standing position from 10am to 4pm, and 1 day's radiant temperature of sidewalk elements from 1:16pm to 1:35pm, showed the following. The shading of street tree and shelter were mitigated heat stress by the lowered UTCI at mid and late summer's daytime, One-Tree and Two-Tree lowered respectively 0.4~0.5 level, 0.5~0.8 level of the heat stress, Shelter lowered respectively 0.3~1.0 level of the heat stress compared with those in the Sunlit. But the thermal environments in the One-Tree, Two-Tree and Shelter during the heat wave supposed to user "very strong heat stress" while those in the Sunlit supposed to user "very strong heat stres" and "exterme heat stress". The main heat load temperature compared with body temperature ($37^{\circ}C$) were respectively $7.4^{\circ}C{\sim}21.4^{\circ}C$ (pavement), $14.7^{\circ}C{\sim}15.8^{\circ}C$ (road), $12.7^{\circ}C$ (shelter canopy), $7.0^{\circ}C$ (street funiture), $3.5^{\circ}C{\sim}6.4^{\circ}C$ (building facade). The main heat load percentage were respectively 34.9%~81.0% (pavement), 9.6%~25.2% (road), 24.8% (shelter canopy), 14.1%~15.4% (building facade), 5.7% (street facility). Reducing the radiant temperature of the pavement, road, building surfaces by shading is the most effective means to achieve outdoor thermal comfort for pedestrians in sidewalk. Therefore, increasing the projected canopy area and LAI of street tree through the minimal training and pruning, building dense roadside hedge are essential for pedestrians thermal comfort. In addition, thermal liner, high reflective materials, greening etc. should be introduced for reducing the surface temperature of shelter and awning canopy. Also, retro-reflective materials of building facade should be introduced for the control of reflective sun radiation. More aggressively pavement watering should be introduced for reducing the surface temperature of sidewalk's pavement.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.825-833
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• 2017

The Korean Ministry of Education has emphasized human resource development with creative and convergent ability for future science and technology development. Korean STEAM Education aims to enhance students' interest and their understanding of science and technology as well as to develop students' creative problem-solving skills. Through STEAM R&E project, students experience self-directed research in order to solve the problem in the context of everyday life. In this study, we aim to find out whether the creative leader competency of high school students changed after they experienced the STEAM R&E project. The creative leader competency consisted of three domains: cognitive, affective, and societal domain. We measured the creative leader competency using the questionnaire scales. The questionnaire was administered to 612 high school students who participated in the 2016 STEAM R&E project. Pre- and post- test scores were collected, and we analyzed it. We compared the mean difference between pre- and post- test scores as well as the mean differences among science high school, gifted school, science core school, and general high school. From the result, we found that all student' creative leader competency improved after participating in the STEAM R&E project in all three domains. The result also showed that students' test scores of science high school and gifted school showed no significant mean differences, while student's scores of both science core school and general high school improved significantly. From the results, we concluded that STEAM R&E activities could be an effective tool in cultivating creative leader competency, especially for general high school students and science core school students. We also suggested that further researches are needed to find how we could enhance students' creative leader competency.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.42-55
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• 2011

The basic approach of this study was to take the theory of cultural fluctuations to investigate the early modern and modern patterns of the use of ox carts and@ the social and economic appropriateness and cultural significance of ox carts. The study chose a village that was the only place that used ox carts in Bugye-myeon. The findings will help to understand how traditional cultural elements would continue or change according to the natural, geographical, economical, and cultural characteristics of a village. Located in Gaho-2-ri, Bugye-myeon, Gunwi-gun, Gyeongbuk Province, Dongrim Village started to use ox carts during the Japanese rule and replaced the traditional version with an improved one in 1972 when a reservoir was built. Until the 1970s, they used ox carts to carry agricultural products and luggage and to visit the markets in distant Bugye-myeon or Gunwi-eup. In the early 1980s when a cultivator was first introduced into the village, ox carts gradually disappeared in the village and eventually remained as a mere means of transportation. As the younger generations were active in introducing modern means of transportation, a cultivator became the main means of transportation in the village in the 1980s and a truck since the latter half of the 1990s. Despite those changes, however, the elderly in their seventies or older continued to use ox carts. With aged labor and inability to use modern means of transportation, they grew cows and oxen to cultivate the inclined fields and gain easy access to fields distributed in distant locations and continued to ox carts through reform. In Dongrim Village, the heritage of using reformed ox carts is the practice of appropriate technology by the old farmers and a cultural representation of an aged agricultural society. That is, the elderly recognized the appropriateness and practicality of traditional culture and renewed a traditional means of transportation called an ox cart. The phenomenon of the old men and women frequently using ox carts in an agricultural village in the mountain with geographical limitations has settled down as a cultural representation of the elderly in Dongrim Village. The continuing usage of ox carts in Dongrim Village is attributed to the fact that ox carts well suit the natural, geographical, and economic aspects of the village and the cultural inertia of the elderly with the aging of the farmers. Thus it is once again shown that human beings transmit and alter culture according to their overall situations and conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5271-5283
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• 2012

The purpose of this study was to provide fundamental materials for improving school health promotion programs by investigating the relationships between the change in obesity rate and risk factors of metabolic syndrome among middle school students in Ulsan. We analyzed the routine health check-up data in 58,298 2nd-year middle school students in Ulsan, which conducted by the Planned Population Federation of Korea from 2007 to 2011. The overall and girls obesity rates gradually decreased throughout the first four years but increased again in 2011. The boys obesity rates were highest in 2008 and lowest in 2010. Throughout the research years, the incidence rates of over-weight and obesity were statistically significantly higher in boys compared to girls(P<0.05). Prevalence rates of the metabolic syndrome, assessed with the modified Cook criteria except high blood pressure, were 0.58%, 0%, 0.01%, 0.31% and 4.53%, respectively in total, low, normal, over-weight, and obese groups. It indicates that the prevalence of metabolic syndrome is increasing and directly related to the obesity rate among adolescents. Hypertriglyceridemia was the most common component (36.58%) of the metabolic syndrome among the middles school students followed by low HDL cholesterol (6.47%), abdominal obesity (3.72%), and high blood sugar (0.47%). Prevalence of the various components of the metabolic syndrome were significantly higher in the obese group compared to other groups. In this study we observed the decrease in obesity rates between 2007 and 2010, and developing obesity prevention programs is essential in order to maintain the trend. Additional study should be necessary to find the cause of increase of obesity rate in 2011 and so to create more effective school health promotion programmes.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.151-162
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• 2005

Variable Message Sign (VMS), which provides drivers with direct information about state of traffic congestion and for prevent an accident, is the most effective method among the methods of providing information in Advanced Transportation Management System. Currently establishment and the VMS which is operated foundation lets in Guidelines on the use of Variable message sign (a book of the VMS) of 1999 November the Ministry Construction & Transportation, these contents mean main viewpoint on physical part such as message special quality variable (font, character size and line space, word interval) and position mainly among standard about establishment in general. But, it is true that using without effect verification on the character of VMS display and that using mode of stationary-centered. In this paper, it executed significance test to effort verification on the character of VMS display for more practical and effective information transmission based on the driver viewpoint For the researches; develop 3D-Simulation, select characteristics of driver's visual cognition behavior (the conspicuity, the legibility and the comprehensibility), evaluation each issue (day or night, 80km/h or 100km/h). Especially, that used the Eye Marker Recorder to measure of reading-time (legibility) thus, confirmed objectivity and reduce an observational error. The results showed that the conspicuity is Flashing> Stationary>Scroll. The legibility is not deference that Flashing between stationary form. Also the comprehensibility result showed that Flashing> Stationary>Stroll form.