• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.989-996
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• 2021

In the case of an unmanned aerial vehicle using a battery as a power source, there are restrictions in performing the mission because the battery capacity is limited. To extend the mission capability, it is important to minimize battery usage while the flight to the mission area. In addition, by using the battery usage prediction model, the possibility of mission completeness can be determined and it can be a criterion for selecting an emergent landing point in the mission planning stage. In this paper, we propose a battery usage prediction model considering as one of the environmental factors in the three-dimensional space. The required power is calculated according to the flight geometry of an unmanned aerial vehicle. True battery usage which is predicted from the required power is verified through the comparison with the battery usage prediction model. The optimal flight trajectory that minimizes battery usage is produced and compared with the shortest travel distance.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.1-16
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• 2020

The purpose of this study is to promote package tourism. The value perceived as a sub-factor of tourism motivation and inducement was divided into emotional and functional values. And the variables of tourism constraints, satisfaction and behavior were addedly presented. The analysis proved that all factors have a positive effect on perceived values (emotional and functional) of the sub-factors of tourism motivation (daily escape, harmony, service appeal, convenience). The perceived value (emotional and functional) has also established a positive impact on the satisfaction, and tourism restrictions have been proven to have a negative impact on satisfaction and behavior intention. Finally, it was confirmed that there was a positive relationship between the two variables of satisfaction and behavior. Based on these research results, the implications and future research directions were presented, and it could be useful for promoting package tourism.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.38.4-39
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• 2021

The Local Volume Mapper (LVM), for the Sloan Digital Sky Survey V, consists of four 16 cm telescopes with three fiber spectrographs in the Las Campanas Observatory in Chile. With the fixed telescopes on optical tables, the Alt-Alt mounted siderostats point and guide targets during spectrograph exposures. We are developing the integrated LVM instrument control software. Considering international travel restrictions caused by the COVID-19 pandemic in 2021, we decided to make a simplified version of siderostat to test the LVM telescope control system in Korea. The prototype siderostat consists of two aluminum flat mirrors, optomechanical housing structures made by aluminum profiles, and the Planewave L-350 mount. We designed the optical mirrors and the optomechanical structure of the siderostat. From structural analysis at various pointing cases, we estimated the tilt misalignments of mirrors within 4 arcsec, which would affect the telescope pointing errors.

• Journal of Preventive Medicine and Public Health
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• v.56 no.6
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• pp.523-532
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• 2023

Objectives: During the second coronavirus disease 2019 (COVID-19) surge, cases increased sharply due to low awareness and compliance with measures to limit disease spread. Health literacy (HL) is an important component of public health initiatives, and schools are potential sources of health education to increase HL via the presentation of COVID-19 educational modules. Methods: This cross-sectional study involved an online questionnaire administered to students from 5 high schools in Surabaya and Sidoarjo, Indonesia, 6-7 weeks after the start of government-issued directives restricting public gatherings. We collected data on each respondent's age, gender, parental education, and socioeconomic variables. HL was determined by the Health Literacy Measure for Adolescents. We additionally measured their attitudes and behaviors related to preventing the spread of COVID-19. The students were asked if they watched the COVID-19 module at school, their feelings about vaccination, and preferred online sources of COVID-19-related information. Results: Most of the 432 respondents had viewed COVID-19 modules at school. Module exposure was associated with significantly higher total and domain-specific HL and more positive attitudes toward government-issued COVID-19 restrictions on travel and public gatherings (p<0.05). However, behaviors to prevent COVID-19 spread and vaccine acceptance were not associated with module exposure. Most students chose social media as their source of COVID-19-related information. Conclusions: Schools can provide information to increase adolescents' HL and the public's support for health initiatives to prevent or limit the spread of COVID-19.

• Journal of the Korea Society of Computer and Information
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• v.29 no.6
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• pp.201-209
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• 2024

The COVID-19 pandemic has significantly impacted the aviation industry, leading to worldwide changes in travel restrictions and security measures. This study analyzes 59,818 reviews of 147 airlines from the SKYTRAX website between 2016 and 2023 to understand the changes in airline service satisfaction before and after the pandemic. Using sentiment analysis, the study compares overall satisfaction, review sentiment, and attributes influencing satisfaction. The results show a statistically significant (p<0.001) decrease in overall satisfaction post-COVID-19, with reduced positive sentiment and increased negative sentiment for all airline selection attributes, except cabin and in-flight services. Flight operation services had the most significant impact on overall satisfaction during both periods. This quantitative analysis of global major airlines' satisfaction attributes before and after COVID-19 contributes to enhancing future service satisfaction in the airline industry.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.179-187
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• 2009

Currently, the signalized intersections in Korea are operated without providing an emergency vehicle preemption control strategy. Thus, it might threaten the safety of the pedestrians and drivers on highways when an emergency vehicle faces congested traffic conditions. The existing preemption control is activated when an emergency vehicle is detected along a path. This enables emergency vehicles to progress uninterrupted, but it also increases the delay of other vehicles. In this paper, a revised preemption control strategy considering queue length restrictions is proposed to make both a progressive movement of an emergency vehicle and reduce delay of other vehicles simultaneously. By applying the preemption control strategy through a simulation study, it was shown that delay of an emergency vehicle decreased to 44.3%-96.1% and speed increased to 8.8%-42.0% in all 9 cases as compared with a conventional signal control. The existing preemption control is superior for oversaturated conditions (v/c >1.0) or a link length less than 200m. However, the preemption control considering queue length constraints shows better performance than the existing preemption control when the v/c is less than 0.8 and a link length is longer than 500m.

• Journal of Christian Education in Korea
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• v.63
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• pp.13-37
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• 2020

The World Health Organisation(WHO), paying attention to the spread and fatality of the coronavirus(COVID-19), which first occurred in Wuhan, China, declared a global emergency. Although many countries implement strict measures to slow down the spread, WHO officially declared a pandemic. COVID-19 has sparked fears of an impending economic crisis and recession. Due to the economic crisis caused by social distancing, self-isolation and travel restrictions, the collapse of the world economic system centered on free trade and the decline of globalization are mentioned. Political leadership that has not responded properly to the pandemic is challenged, and nearly all of society is rapidly changing to a non-contact and immobile culture. COVID-19 has seriously affected all levels of the education system, from preschool to tertiary education. The so-called old concept of deschooling is realizing in the field of education through digital media paradoxically. Church education is facing a serious crisis as well. Churches are seeking now a new normal that includes theological reflection on the pandemic, online worship, education, and non-face-to-face ministry to overcome the worst unexpected crisis. In the post-corona era, church education must actively seek alternatives in response to rapidly changing surrounding conditions and reconstruct educational philosophy(theology) that focuses on Christian values. In addition, it is necessary to start operating a mobile(or online) church school that combines offline and online. It is necessary to introduce 'Blended Learning' method that combines non-face-to-face and face-to-face learning, and by combining church school and homeschooling, churches and families need to share the responsibility of education in faith.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.4
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• pp.189-196
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• 2017

BIS(Bus Information System) provides the different information related to buses including predictions of arriving times at stations. BIS have been deployed almost all cities in our country and played active roles to improve the convenience of public transportation systems. Moving average filters, Kalman filter and regression models have been representative in forecasting the arriving times of buses in current BIS. The accuracy in prediction of arriving times depends largely on the forecasting algorithms and traffic conditions considered when forecasting in BIS. In present BIS, the simple prediction algorithms are used only considering the passage times and distances between stations. The forecasting of arrivals, however, have been influenced by the traffic conditions such as traffic signals, traffic accidents and pedestrians ets., and missing data. To improve the accuracy of bus arriving estimates, there are big troubles in building models including the above problems. Hidden Markov Models have been effective algorithms considering various restrictions above. So, we have built the HMM forecasting models for bus arriving times in the current BIS. When building models, the data collected from Sunchean City at 2015 have been utilized. There are about 2298 stations and 217 routes in Suncheon city. The models are developed differently week days and weekend. And then the models are conformed with the data from different districts and times. We find that our HMM models can provide more accurate forecasting than other existing methods like moving average filters, Kalmam filters, or regression models. In this paper, we propose Hidden Markov Model to obtain more precise and accurate model better than Moving Average Filter, Kalman Filter and regression model. With the help of Hidden Markov Model, two different sections were used to find the pattern and verified using Bootstrap process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.57-64
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• 2021

The speed change lane is installed at the point where the roads are connected on the urban roads, reducing the relative speed to facilitate traffic communication. However, in the case of the speed limit of 30 km/h in accordance with the implementation of the safe speed "5030" in the city, the standard is ambiguous, and there are criticisms about the installation of the transmission lane. This study conducted a pilot study on the traffic patterns of the speed change lanes, focusing on the section where the safe speed "5030" policy was scheduled to be implemented after theoretical consideration of the speed change lanes. After on-site investigation, as a result of analyzing the traffic pattern according to the travel speed of the main road according to road conditions and traffic conditions, the effectiveness of the speed change lane according to the safety speed "5030" was analyzed. In this study, the installation criteria for speed change lane by speed were presented. The criteria is that "speed change lanes should not be installed when the speed limit is 30 km/h, and speed change lanes should be installed when the speed limit is 50 km/h." The criteria will be considered as a reference when establishing engineering standards for connection of other facilities in urban areas in the future. It is expected that unnecessary restrictions on individuals' exercise of private property rights will be minimized, smooth traffic flow and secure safety by the installation of speed change lanes and expansion of turning radius.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.15-24
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• 2022

The article clarifies the conditions for information, digital and educational accessibility for higher education seekers with disabilities in terms of distance learning caused by quarantine restrictions. It is established that such conditions are regulated by international and Ukrainian legal documents (The Standard Rules on the Equalization of Opportunities for Persons with Disabilities, Convention on the Rights of Persons with Disabilities, Sustainable Development Goals, Law of Ukraine "On Education", Law of Ukraine "On Higher Education", Strategy for the Development of Higher Education in Ukraine 2021-2031, Development Strategy areas of innovation for the period up to 2030, Development strategy of the sphere of innovation activity for the period up to 2030). As a part of information barrierlessness, Higher Education Institutions (HEI) should provide access to information in various formats and using technologies, in particular Braille script, large-type printing, audio description (audio descriptive commenting), sign language interpretation, subtitling, a format suitable for reading by screen access programs, formats of simple speech, easy-to-read formats, means of alternative communication. The experience of Pavlo Tychyna Uman State Pedagogical University is described. In particular, special attention is paid to the study of sign language: in view of this, the initiative group implemented the project "Learning to hear and overcome social isolation together" with the financial support of the British Council in Ukraine. Within the framework of digital accessibility, the official website of the Faculty of Social and Psychological Education has been adapted for the visually impaired in accordance with WCAG 2.0 World Standards. In 2021, Pavlo Tychyna Uman State Pedagogical University implemented the project "Cultural, Recreational and Tourist Cherkasy Region: Inclusive Social 3D Map" funded by the Ukrainian Cultural Foundation; a site with available content for online travel in the region to provide barrier-free access to the historical and cultural heritage of Cherkasy region was created. Educational accessibility is achieved by increasing the number of people with special educational needs, receiving education in inclusive groups; activities of the Center for Social and Educational Integration and Inclusive Rehabilitation Social Tourism "Bez barieriv" ("Without barriers"); implementation of a research topic for financing the Ministry of Education and Science of Ukraine: "Social and psychological rehabilitation of children and youth with special educational needs by means of inclusive tourism"; implementation of the project "Social inclusion of distance educational process"; development of information campaigns to popularize the ideas of accessibility, the need for its implementation, ongoing training programs and competitions, etc.