• Journal of Aerospace System Engineering
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• v.16 no.6
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• pp.54-63
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• 2022

Recently, electric propulsion aircraft with various propeller mounting positions have been under construction. The position of the propeller relative to the wing can significantly affect the aerodynamic performance of the aircraft. Placing the propeller in front of the wing produces a complex swirl flow behind or around the propeller. The up/downwash induced by the swirl flow can alter the wing's local effective angle of attack, causing a change in the aerodynamic load distribution across the wing's spanwise direction. This study investigated the influence of the distance between a propeller and a wing on the aerodynamic loads on the wing. The swirl flow generated by the propeller was modelled using an actuator disk theory, and the wing's aerodynamics were analysed with the VSPAERO tool. Results of the study were compared to wind tunnel test data and established that both axial and spanwise distance between the propeller and the wing positively affect the wing's lift-to-drag ratio. Specifically, it was observed that the lift-to-drag ratio increases when the propeller is positioned higher than the wing.

• The Korean Journal of Coaching Psychology
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• v.6 no.2
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• pp.75-92
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• 2022

There are many studies that intrinsic learning motivation and social support play an important role in the study of children and adolescents. However, studies examining the effects of intrinsic learning motivation and social support by measuring the actual academic performance of elementary school students are rare. This study attempted to verify the effect of intrinsic learning motivation on Korean language performance and moderating effect of social support in 5th and 6th graders in elementary school. 122 elementary school students in local county-level areas participated in this study. The Korean language test was conducted about 5 months after intrinsic learning motivation and social support of families and teachers were measured. The results revealed that Korean language performance showed a significant positive correlation with intrinsic learning motivation and social support, and also showed a significant correlation between learning motivation and social support. In the regression analysis with control variables, it was found that intrinsic learning motivation had a significant effect on Korean language performance. The moderating effect of social support was analyzed by dividing it into family support and teacher support. The interaction effect of learning motivation and social support was significant only in teacher support, not in family support. In specific, when teacher support was high, Korean language performance was high regardless of the student's learning motivation level, but when teacher support was low, the student's learning motivation mattered in the performance. Based on the results of this study, implications and limitations were discussed.

• The Korean Journal of Coaching Psychology
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• v.5 no.1
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• pp.67-83
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• 2021

The purpose of this research is verifying the effects born by reading-based learning coaching programs on Korean language performance and the psychological variables of middle school students. A reading-based learning coaching program applied alongside a coaching model was developed and presented to first grade middle school students living in a local county-level city. The psychological variables were measured three times: prior to the program, immediately following the end of the program, and one month after the end of the program. Korean language performance was only measured twice: prior to the program and following the end of the program. Results revealed that compared to the control group, the experiment exhibited showed significant improvement in the scores of learning efficacy and self-regulation efficacy after the program. As well, these changes lasted for up to one month after the program. The future time perspective didn't show any significant interaction effects between time and group. The experimental group's performance in terms of Korean language was also significantly improved after completing the program. Based on these results, implications and limitations are discussed.

• Journal of Korean Society of Archives and Records Management
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• v.22 no.2
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• pp.1-25
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• 2022

Today, most archives provide recording services through social media; however, their effectiveness is very low. This study aimed to analyze the causes of insufficient social media recording service, focusing on Gyeongnam Archives and Seoul Metropolitan Archives, which are permanent records management institutions and local government archives, and design ways to create synergy by mutual growth with classical recording service. Through literature research, the characteristics and mechanisms of each social medium were identified, and the institutions' current status of social media operations and internal documents were reviewed to analyze the common problems. An in-depth analysis was conducted by interviewing the person in charge of recording services at each institution. In addition, a plan that can be applied to archives was proposed by reviewing the cases of social media operations of domestic-related institutions and overseas archives. Based on this, a new recording service process was established, strategic operation plans for each social medium were proposed, and a plan to mutually grow with the existing recording service was designed.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.95-102
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• 2023

This study aims to empirically verify the moderating effect of population drop on the relationship between demographic changes and crime decline in local cities facing population decline in Korea. The study employs changes in the population of young adults, men, elderly, foreign residents, and population movement as factors of demographic changes, including types of the city as a control variable in the research model. The rate of change in population drop is used as a moderator variable and the rate of change in crime decline as a dependent variable. Data are collected from 155 cities with declining populations from 2010 to 2022 through KOSIS, the National Statistics Portal, and information disclosure requests. Data collected are analyzed using moderated regression analysis. In the first and second stages of the analysis, they show that changes in the population of young adults, population movement, foreign people, population drop, and the type of city affect the change in crime. Moderated regression analysis shows that only the interaction terms among changes in the population of young adults, changes in population movement, and changes in the population of foreigners and the population drop affects change in crime significantly.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.45-52
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• 2019

This study focuses on analyzing rhythms revealed in music songs of Korean third-generation idol girl groups. The development of genre and development of rhythm continues and the rhythm of Third World music is strong worldwide. The development of genres and rhythms continues and the rhythms of the Third World music are winning big popularity world wide. In the past, Third World rhythms were used only in countries where rhythm originated and neighboring countries, and the rhythms between countries were combined to occur in various conersence composite forms. In the past, the Third World rhythms were used only in rhythm-oriented countries and neighboring countries, and the rhythms between countries were combined in various and composite forms The changes in the global music market and the structure of the Korean pop music market show the same pattern in the local pop music genre. This study analyzes the phenomenon in which the Dembow rhythm and the tresillo rhythm, one of the rhythms of the Third World music, are concentrated in third-generation idol music, and notes that a certain number of combinations appear in rhythms and melodies. Moreover, this study identifies and compares the origin, the structure and the application cases of the Dembow rhythm and the tresillo rhythm by analyzing 12 songs of Korean third-generation idol girl groups. A game, as a sort of media like a movie, may be subjected to an ambivalent evaluation in accordance with the quality of each content. In this regard, it is necessary to have an active discussion about which game has desirable contents. Emotion which is an influential factor on interaction among players in game design needs to be approached from a social perspective. Also, based on social emotions associated with players, a significant relationship between emotional vocabularies and game emotions should be understood in comparison with social emotions within the game. based on social emotions regarding players As a result, social emotions within the game exhibited differences from the meaning of the terms. It is supposed that this result was caused by the ethical standards and differences in the real world. Accordingly, for qualitative enhancement of games, it is required to utilize the contents of this study, since emotions within the game are based on social emotions regarding players.

• Korean Journal of Legislative Studies
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• v.26 no.2
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• pp.35-71
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• 2020

The purpose of this study is to verify the effect of electoral competition on voters deciding on strategic split-ticket voting under the mixed-member electoral system. As result, the more competitive the constituencies are, the more voters choose to vote for the major parties. The results of logistic regression analysis including interaction terms showed that the more competitive the constituencies are, the more voters choose for candidates from the major parties. Also, the finding shows that major party supporters are less affected by electoral competition than minor party supporters in choosing a candidate in the single-seat districts. In the case of minor party supporters, the more competitive the constituencies were, the more likely they were to choose the major party candidate instead of the minor party candidate. Based on these results, it can be inferred that voters are affected by the presence or behavior of other voters in local constituencies under the first-past-the-post rule. Because of the psychology of not wanting their votes to be useless, voters cast their ballots more strategically as the competition in constituencies intensifies, and as the competition in constituencies slackens, such tendencies weaken, and this trait is particularly evident among minor party supporters.

• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.99-111
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• 2008

In recent years, the needs for WLANs(Wireless Local Area Networks) technology which can access to Internet anywhere have been dramatically increased particularly in SOHO(Small Office Home Office) and Hot Spot. However, unlike wired networks, there are some unique characteristics of wireless networks. These characteristics include the burst packet losses due to unreliable wireless channel. Note that burst packet losses, which occur when the distance between the wireless station and the AP(Access Point) increase or when obstacles move temporarily between the station and AP, are very frequent in 802.11 networks. Conversely, due to burst packet losses, the performance of 802.11 networks are not always as sufficient as the current application require, particularly when they use TCP at the transport layer. The high packet loss rate over wireless links can trigger unnecessary execution of TCP congestion control algorithm, resulting in performance degradation. In order to overcome the limitations of WLANs environment, MAC-layer LDA(Loss Differentiation Algorithm)has been proposed. MAC-layer LDA prevents TCP's timeout by increasing CRD(Consecutive Retry Duration) higher than burst packet loss duration. However, in the wireless channel with high packet loss rate, MAC-layer LDA does not work well because of two reason: (a) If the CRD is lower than burst packet loss duration due to the limited increase of retry limit, end-to-end performance is degraded. (b) energy of mobile device and bandwidth utilization in the wireless link are wasted unnecessarily by Reducing the drainage speed of the network buffer due to the increase of CRD. In this paper, we propose a new retransmission module based on Cross-layer approach, called BLD(Burst Loss Detection) module, to solve the limitation of previous link layer retransmission schemes. BLD module's algorithm is retransmission mechanism at IEEE 802.11 networks and performs retransmission based on the interaction between retransmission mechanisms of the MAC layer and TCP. From the simulation by using ns-2(Network Simulator), we could see more improved TCP throughput and energy efficiency with the proposed scheme than previous mechanisms.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.3
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• pp.61-102
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• 2007

This study empirically analyzed how human resource management(HRM) practices affect the performance of venture firms using The results of the study are as follows: First of all, several HRM practices were found to affect organizational performance significantly. Specifically, ${(1)}$ recruitment and selection practices were negatively related to turnover, which seemed to mean that effective staffing including development of good recruitment pools and rigorous selection process lower turnover, and ${(2)}$ training and development, compensation, and labor-management relations were positively related to subjective performance of the firms, which implied that as the venture firms provide more opportunities of training and development to employees, provide compensation on the basis of performance, and develop cooperative labor-management relations, the subjective performance of the venture firms Increases. Secondly, negative interaction effects were found to exist between competitive strategies and HRM practices on organizational performance. Specifically, ${(1)}$ the interaction between differentiation strategy and compensation were significantly related to turnover, ${(2)}$ HRM planning and training and development interacted with differentiation strategy to significantly affect subjective organizational performance, and ${(3)}$ HRM planning, selection, training and development, compensation and communication practices interacted with technology innovation strategy to affect subjective organizational performance. So far, there have not been many studies which deal with HRM practices of venture firms in Korea. Thus, it is hoped that this study stimulate more research efforts on theory development and empirical studies on HRM practices of venture firms. Also, it is hoped that government conduct more policy studies and provide more resources in HRM area of the venture firms. Specifically, it is suggested that government take proactive steps to improve industrial skilled staff and technical researcher systems in order to alleviate the problems of workforce shortages in venture firms. And it IS also suggested that regional human resource development programs be introduced with the participation of the firms, local governments, and universities.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.2
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• pp.47-65
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• 2020

With the era of the Fourth Industrial Revolution in sight, innovative business models utilizing new technologies are emerging, and startups are enjoying an abundance of opportunities based on the agility to respond to disruptive innovations and the opening to new technologies. However, what is most important in creating a sustainable start-up ecosystem is not the start-up itself, but the process of research-start-investment-investment-the leap to listing and big business-in order to build a virtuous circle of startups that leads to re-investment. To this end, the environment created in the hub area where start-ups were conducted is important, and these material and non-material environmental factors are described as being inclusive by the word "entrepreneurial ecosystem." This study aims to provide implications for Korea's entrepreneurial ecosystem through the study of the interaction of the elements that make up the start-up ecosystem and the relationship of ecosystem participants in Singapore. Singapore has been consistently mentioned as the top two Asian countries in assessing the start-up environment and business environment. In this process, six elements of the entrepreneurial ecosystem presented by Isenberg(2010)-policies, finance, culture, support, human resources, and market-are the best frameworks for analyzing entrepreneurial ecosystems in terms of well encompassing prior studies related to entrepreneurial ecosystem elements, and a model of regional transformation is formed focusing on some elements to suit Singapore, the target area of study. By considering that Singapore's political nature would inevitably have a huge impact on finance, Smart Nation policy was having an impact on university education related to entrepreneurship, and that the entrepreneurial networks and global connectivity formed within Singapore's start-up infrastructure had a significant impact on Singapore's start-up's performance, researches needed to look more at the factors of policy, culture and market. In addition, qualitative research of participants in the entrepreneurial ecosystem was essential to understand the internal interaction of the elements of the start-up ecosystem, so the semi-structured survey was conducted by visiting the site. As such, this study examined the status of the local entrepreneurial ecosystem based on qualitative research focused on policies, culture and market elements of Singapore's start-up ecosystem, and intended to provide implications for regulations related to start-ups, the role of universities and start-up infrastructure through comparison with Korea. This could contribute not only to the future research of the start-up ecosystem, but also to the creation of a start-up infrastructure, boosting the start-up ecosystem, and the establishment of the orientation of the start-up education in universities.