• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.32 no.1
• /
• pp.49-60
• /
• 2024

This study used the Unified Theory of Acceptance and Use of Technology(UTAUT) model to find factors that influence consumer acceptance intention toward Vertiport, a physical ground support technology required to implement AAM services. The analysis showed that among the four independent variables, Vertiport's social influence and facilitating conditions have a significant impact on future Vertiport usage behavior. At this point, the public has not yet had actual experience with Vertiport, so there is a limitation of considering it as a future concept based on speculation and measuring acceptance by actual behaviors related to its use (inquiries, information gathering, interest, etc.). Research on acceptance and attitudes toward new transportation methods should be further activated and developed along with future service development. Through the results of this study, we aim to understand the initial public acceptance of Vertiport as a ground-based infrastructure in the AAM field (or UAM) and propose strategic implications for the direction of service development.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.10 no.1
• /
• pp.91-99
• /
• 2007

The research was carried out to define the morphological and growth characteristics of Poa pratensis L. (Kentucky bluegrass) 'Pureundul' native to Korea. Poa pratensis 'Pureundul' was collected from the belt highway around Mt. Uam located in Naedeok-dong, Cheongju City, Chungcheongbuk-do Province on May 5, 1995. The morphological characteristics of 'Pureundul' were compared with those of 205 individuals of native Poa pratensis collected throughout the nation from June 11, 2000 to June 21, 2003. The findings were as follows : The height of plant was 28.2cm but increased to 40.0cm at the flowering time. The height of first node from the base was 6.8cm and the length and width of leaf were 17.3cm and 2.9mm, respectively. The length of a spike was 7.9cm. Based on these morphological characteristics, 'Pureundul' was defined medium type Kentucky bluegrass. Visual quality(1~9), visual color and visual density were measured. The visual quality, color and density of 'Pureundul' were not superior to those of introduced species but above the average other native species. The damages from the diseases during summer resulted in poorer visual quality of color of 'Pureundul'. But the spread of the diseases was slower in 'Pureundul' than other native species, and accordingly 'Pureundul' didn't suffer from more quality deterioration from July to September during which the diseases broke out. Entering fall, 'Pureundul' showed high quality comparable to that of the introduced species. If 'Pureundul' is put to breeding by implementing pest control in summer and introducing disease tolerant genes, it will be used to make greens of greater quality than now.

• Journal of Navigation and Port Research
• /
• v.29 no.10 s.106
• /
• pp.921-926
• /
• 2005

The purpose of this paper is to conduct a comparative analysis of container terminal operation in Busan and Kwangyang port. The research method used for this study is DEA(Data Envelopment Analysis} and among DEA methods CCR and BCC model has been used. According to the results of CCR model Gamman in 2004 and Gamcheon in 2004 are found to be the most efficient terminals in the sample and the inefficient terminals include Gwangyang Phase 2 terminal. Based on BCC model Gamcheon and Uam are identified as the most efficient terminals in three consecutive years including Gamman terminal in 2004. The inefficient terminals include New Gamman in 2002 and Hutchison in 2002. The research findings show that inefficient terminals need to fully utilise their terminal facilities and increase container throughput through effective marketing activities.

• Journal of Advanced Navigation Technology
• /
• v.24 no.5
• /
• pp.348-357
• /
• 2020

An important challenge in commercialization of eVTOL PAV is to reduce noise for urban air mobility (UAM) operation. Therefore, in this paper, noise priority routes were created to minimize the number of people affected by noise using aviation environmental design tool (AEDT) software and population distribution data for administrative districts, and noise analyses during operation were performed. Also, it was analyzed how much noise exposure could be reduced compared to the number of people affected by noise in the shortest route. Considering that the eVTOL PAV developers do not provide data, the analysis was conducted using a helicopter model. As a result, it was shown that the noise priority route that minimized the amount of noise exposure was more efficient than other routes.

• Journal of Korea Port Economic Association
• /
• v.26 no.1
• /
• pp.1-19
• /
• 2010

This paper focuses measuring the efficiency of container yards on container terminals in Busan (Gasungdae, Shinsundae, Gamman, New Gamman, Uam, Gamchon, PNC) and Gwangyang(GICT, KEC, Dongbu, KIT) using Data Envelopment Analysis(DEA) approach. Container terminals in Busan and Gwangyang play an important role in the region's economic development. The results show that Shinsundae was an efficient DMU during the period of 2007 to 2009, while Gamman, New Gamman and PNC were efficient terminals in 2009. The very inefficient terminals were shown to be GICT, KEC, Dongbu and KIT. GICT(2009), KEC(2009), Dongbu(2008-2009), KIT(2009) on Gwangyang Port were found to be relatively the inefficient terminals in terms of the returns to scale. This study also finds that the efficiency of Shinsundae terminal was so high as to be abel to keep its efficiency in spite of the additional increase of the inputs from 2007 to 2009. Gamman terminal was in the decreasing returns to scale in 2009, while the other terminals were in the increasing returns to scale. It means that we are able to improve the efficiency of the Gamman terminal with increasing returns to scale through enlarging the scale.

• Journal of the Korean Home Economics Association
• /
• v.45 no.2
• /
• pp.1-22
• /
• 2007

The purpose of this study was to investigate the effect of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression. Subjects of this study consisted of 342 young children drawn from seven preschools in Cheongju city. The pilot study was used to examine the applicability of survey instrument. Data were analyzed by the method of frequency, percentage, Cronbach' ${\alpha}$, factor analysis, T-test. F-test, and Duncan post-hoc test using SPSSWIN program. The test of model was done with analysis of correlational matrix in LISREL VII package using a maximum likehood estimation. The results of this research were as follows: First, there were statistically significant differences in mother's characteristics consisting of neurosis symptom and extroversions, disciplinary methods consisting of coercive-punishment and indifferent-irresponsibility, young children's emotional regulation, and young children's aggression consisting of relation and overtness according to some socio-demographic variables. Girls had the higher emotional regulation than boys. Second, the direct effects of disciplinary methods and emotional regulation on boys' aggression were different in between relational and overt aggression. Third, the variables predicting boys' emotional regulation directly were the same in both relational and overt aggression. Forth, the direct effect of mother's characteristics on disciplinary methods was different in between coercive-punishment and indifferent-irresponsibility. Fifth, the indirect effects of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression were partly supported in this study. Sixth, the theoretical model of the impact of mother's characteristics, disciplinary methods, and young children's emotional regulation on young children's aggression was different according to gender.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.38 no.3
• /
• pp.247-257
• /
• 2001

New methods are proposed for printing a full resolution image on a limited output device. The proposed algorithm uses a dot-pattern database that models overlapping phenomena among neighbor printing dots. To solve the problem of dot-overlap, the gray levels of dot-pattern sets were calculated using a circular dot-overlap model and then measured by a spectrometer. Thereafter, in order to improve the visual quality of the color dithering, the contrast sensitivity function of the human visual system was used. As a result, the optimal dot-pattern can be selected from the database. Consequently, the proposed algorithm can produce high quality images while using low-cost color devices.

• Tunnel and Underground Space
• /
• v.15 no.2 s.55
• /
• pp.102-110
• /
• 2005

○ ○ tunnel that is located at Iksan - Jangsu freeway ○ ○, has collapsed during construction at the valley with shallow depth. Although, the site investigations, such as TSP, drilling exploration and so of indicated the presence of discontinuities in this section. The RMR was upgraded and the construction were carried out because that not only actual rock qualities were relatively good during construction but also the tunnel foe was stabilized. However, the tunnel was collapsed at the same time blasting of full face, and surface and underground water was infiltrated due to the settlement of the upper part of the tunnel face. To restore the collapsed section, 3-d tunnel stability analysis was performed and suitable reinforcement methods were chosen. The cavity of the upper tunnel face was stabilized by means of UAM and ALC injection. And the settlement was restored using L.W grouting method.

• Journal of the Korean Institute of Rural Architecture
• /
• v.21 no.1
• /
• pp.1-8
• /
• 2019

This study is about the research of living environment in residential areas created by the land readjustment projects in the modern era, and recently lifted from Residential Environment Improvement district at the same time. The five criteria for evaluating the residential area are safety, health, convenience, comfort, and sustainability. The level of resident satisfaction in general is as follows. [completely dissatisfy as 5.30%, dissatisfy as 16.29%, neutral as 49.62%, satisfy as 16.29% and completely satisfy as 6.82%]. The results of the five survey items on the residential areas show that residents are aware of the area not as an old residential area to be demolished, but as a comparatively excellent residential area, namely very different results from the designation criteria of the redevelopment area designated by the Urban and Residential Environment Improvement Act. If the road conditions and the deterioration of the buildings are judged to be designated as the redevelopment area and to be removed these settlements, the residential areas with social sustainability could demolished. Based on this study, it is necessary to conduct the research to find out the reason for deriving the results of each evaluation item in the succeeding study. These studies are needed to rediscover, to develop and manage the value of many old residential areas scattered in the city centers of local areas.

• Journal of Advanced Navigation Technology
• /
• v.25 no.3
• /
• pp.203-210
• /
• 2021

In many metropolitan cities around the world, ground and underground transportation networks are saturated due to urbanization. In addition, regulations on carbon emissions to prevent global warming are becoming stricter, and eVTOL, which will be operating in complex cities, is gaining popularity as the next generation of eco-friendly transportation. In this study, the hover lift efficiency and disc loading of eVTOLs for each type were calculated by classifying eVTOLs into following types: multicopter, lift+cruise, and vectored thrust. In addition, using the aerodynamic analysis programs OpenVSP, Fluent and Javaprop, the specific battery energy required for the smooth operation of eVTOL, which will be realized in the near future, was calculated and analyzed base on reports published by Uber and airworthiness authorities of each country.