• Journal of Broadcast Engineering
• /
• v.25 no.6
• /
• pp.944-953
• /
• 2020

Object detection plays a crucial role in a self-driving system. With the advances of image recognition based on deep convolutional neural networks, researches on object detection have been actively explored. In this paper, we proposed a lightweight model of the mask R-CNN, which has been most widely used for object detection, to efficiently predict location and shape of various objects on the road environment. Furthermore, feature maps are adaptively re-calibrated to improve the detection performance by applying an attention module to the neural network layer that plays different roles within the mask R-CNN. Various experimental results for real driving scenes demonstrate that the proposed method is able to maintain the high detection performance with significantly reduced network parameters.

• Korean Journal of Remote Sensing
• /
• v.37 no.3
• /
• pp.475-491
• /
• 2021

With the recent increase in available high-resolution (< ~1 m) satellite SAR images, the demand for precise registration of SAR images is increasing in various fields including change detection. The registration between high-resolution SAR images acquired in different look angle is difficult due to speckle noise and geometric distortion caused by the characteristics of SAR images. In this study, registration is performed in two stages, coarse and fine, using the x-band SAR data imaged at staring spotlight mode of TerraSAR-X. For the coarse registration, a method combining the adaptive sampling method and SAR-SIFT (Scale Invariant Feature Transform) is applied, and three rigid methods (NCC: Normalized Cross Correlation, Phase Congruency-NCC, MI: Mutual Information) and one non-rigid (Gefolki: Geoscience extended Flow Optical Flow Lucas-Kanade Iterative), for the fine registration stage, was performed for performance comparison. The results were compared by using RMSE (Root Mean Square Error) and FSIM (Feature Similarity) index, and all rigid models showed poor results in all image combinations. It is confirmed that the rigid models have a large registration error in the rugged terrain area. As a result of applying the Gefolki algorithm, it was confirmed that the RMSE of Gefolki showed the best result as a 1~3 pixels, and the FSIM index also obtained a higher value than 0.02~0.03 compared to other rigid methods. It was confirmed that the mis-registration due to terrain effect could be sufficiently reduced by the Gefolki algorithm.

• Journal of Korea Water Resources Association
• /
• v.54 no.6
• /
• pp.365-379
• /
• 2021

Hydrological model parameters are essential for model simulation and can vary over time due to topography, climatic conditions, climate change and human activity. Consequently, the use of fixed parameters can lead to inaccurate stream flow simulations. The aim of this study is to investigate an appropriate method of estimating time-varying parameters using stream flow observations, and how the simulation efficiency changes when stream flow data are assimilated into the model. The data assimilation method can be used to automatically estimate the parameters of a hydrological model by adapting to a variety of changing environments. Stream flow observations were assimilated into a two parameter monthly water balance model using a particle filter. The simulation results using the time-varying parameters by the data assimilation method were compared with the simulation results using the fixed parameters by the SCEM method. First, we conducted synthesis experiments based on various scenarios to investigate if the particle filter method can adequately track parameters that change over time. After that, it was applied to actual watersheds and compared with the predictive performance of stream flow when using parameters that change with time and fixed parameters. The conclusions obtained through this study are as follows: (1) The predictive performance of the overall monthly stream flow time series was similar between the particle filter method and the SCEM method. (2) The monthly runoff prediction performance in the period except the rainy season was better in the simulation by the periodically changing parameters using the data assimilation method. (3) Uncertainty in the observational data of stream flow used for assimilation played an important role in the predictive performance of the particle filter.

• Journal of Information Technology Applications and Management
• /
• v.28 no.3
• /
• pp.59-75
• /
• 2021

This study aims to establish a foundation for autonomous driving on campus and communication of abundant university information in the HCI environment in a VR environment where college freshmen can freely travel around campus facilities. The purpose of this study is to develop a three-dimensional VR-style campus tour system to establish a media environment to provide abundant university information guidance services to freshmen in non-face-to-face situations. This study designed a three-dimensional virtual reality campus tour system to solve the problem of discontinuity in which VR360 filming space does not lead to space like reality, and to solve many problems of expertise in VR technology by constructing an integrated production environment of tour system. We aim to solve the problem of inefficiency, which requires a large amount of momentum in virtual space, by constructing a GUI that utilizes the motion of the field of view focus. The campus environment was designed as a three-dimensional virtual reality using a three-dimensional graphic design. In non-face-to-face situations, college freshmen freely transformed the HMD VR device, smartphone, FPS operation mode of the gyroscope sensor. The design elements of the three-dimensional virtual reality campus tour system were classified as ①Visualization of factual experiences, ②Continuity of space movement, ③Operation, automatic operation mode, ④Natural landscape animation, ⑤Animation according to wind direction, ⑥Actual space movement mode, ⑦Informatization of spatial understanding, ⑧GUI by experience environment, ⑨Text GUI by building, ⑩VR360, 3D360 Studio Environment, ⑪Three-dimensional virtual space coupling block module, ⑫3D360-3D Virtual Space Transmedia Zone, ⑬Transformable GUI(VR Device Dual Viewer-Gyro Sensor Full Viewer-FPS Operation Viewer) and an integrated production environment was established with each element. It is launched online (http://vautu.com/u1) by constructing a GUI for free driving mode and college information screens to adapt to college life for freshmen, and designing an environment that can be used simultaneously by current media such as PCs, Android, and iPads. Therefore, it conducted user research, held a development presentation, a forum on excellence in university innovation support projects, and applied it as a system on the website of a particular university. College freshmen will be able to experience university information directly from the web and app to the virtual reality campus environment.

• Journal of Advanced Navigation Technology
• /
• v.25 no.4
• /
• pp.280-285
• /
• 2021

The significance of pilots' fatigue and the attributed risk management had continuously increased over time as the airline industry expanded. Research and legislation efforts associated with pilot fatigue are being taking place actively all over the world. In the developed world such as the United States and European Union etc., the airline pilot fatigue is already being managed by considering the show up time, the number of take offs and landings made, resting period, jet lag etc., when computing flight duty time. In Korea, the flight duty time is only limited by the total number of hours per given period regardless of the flight conditions and environment. Such lack of regulation demand development of a fatigue management program. According to the survey taken from the airline pilots in Korea, it has been found that acquiring foreign policies directly may in turn, increase the risk of fatigue. This research suggest future studies regarding fatigue management program adapted exclusively to Korean domestic flight environment and culture.

• The Journal of the Korea Contents Association
• /
• v.22 no.10
• /
• pp.445-459
• /
• 2022

This study presented a plan to improve the life satisfaction and leisure status of the elderly in the With COVID-19 era, and the life satisfaction of the elderly. For this purpose, we investigated life satisfaction and leisure life for 107 senior citizens at the Gyeonggi Senior Welfare Center, and the following results were obtained. First, it can be seen that overall life satisfaction was relatively lower after Corona than before. Second, in the correlation between leisure activity and life satisfaction, there was no significant correlation between the level of leisure activity and life satisfaction before Corona, and a significant positive correlation was found between the level of leisure activity and life satisfaction after Corona. seemed If alternative measures are proposed according to these results, first, it is necessary to seek ways to improve and manage the environment for the elderly in the with Corona era in the local community. In particular, in order to reduce the adaptation gap among the elderly due to the many changes in digital technology, institutions related to the elderly are providing education on how to use smartphones and kiosks, but it needs to be expanded as a community-wide measure. Second, a systematic system for health care for the elderly in the era of With Corona must be provided. Third, the old-age income security system and support are required so that the minimum living security is guaranteed for the elderly who are experiencing economic difficulties due to the corona virus. Fourth, it is necessary to revitalize programs related to talking to the elderly and counseling for the improvement of relationships and location satisfaction due to social distance and relationship atrophy due to Corona.

• Journal of Christian Education in Korea
• /
• v.71
• /
• pp.341-370
• /
• 2022

As COVID-19 has been converted to an endemic with social distancing lifted, people are getting used to new cultures and lifestyles that are different from before. While the world is now adapting to rapidly changing trends, Christian education is facing a crisis without being able to respond to these changes. Therefore, a new Christian education method is now required. The purpose of this study is to suggest a new Christian education method that allows Christians to properly lead a new era as an alternative to Christian education that is experiencing such a crisis. The study also presents the metaverse Christian education platform, which is a detailed and practical method of Christian education, by incorporating the platform and metaverse that are under the spotlight in the post-Corona era into Christian education. Here, the christian educational platform refers to the system, space, and various materials that can make Christian education efficient and smooth. The metaverse Christian education platform consists of 4 stages according to the size of the platform to activate supply and demand within the platform. Stage 1 is a home education platform, Stage 2 is a community education platform, Stage 3 is a regional union education platform, and Stage 4 is an educational mission platform. The last Stage 4, the educational mission platform utilized the metaverse, which is drastically expanding in the present era, as a method of educational mission. It is meaningful that the educational mission has been embodied by providing small churches and the next generation in underdeveloped countries with educational contents, educational materials, online mentors, virtual communities, and real-time educational broadcasts within the educational platform, using virtual spaces in the metaverse.

• Korean Journal of School Psychology
• /
• v.18 no.1
• /
• pp.121-151
• /
• 2021

This study aimed to identify the factors that helped and hindered secondary school teachers who experienced student suicide using the concept-mapping approach. Seven South Korean middle and high school teachers were interviewed from which 113 core statements were elicited. The participants sorted these core statements into categories by meaning. Multidimensional scaling and hierarchical cluster analysis were conducted to identify the underlying structure of the teachers' experiences. Four hindering factor clusters emerged: (1) regret over failing to prevent the suicide, (2) an apathetic atmosphere in the school, (3) a sense of helplessness related to suicide survivors, and (4) approach-avoidance conflicts related to suicide survivors. Six helpful factor clusters emerged: (1) cooperation and care offered between suicide survivors, (2) focusing on the present, busy life, (3) spiritual activity, (4) social support, (5) overcoming grief through altruistic behaviors, and (6) sympathy for the deceased. Two dimensions were found for both the hindering and helpful factors. The hindering factor dimensions were external system-internal experiences and related to suicide survivors-related to suicide decedents. The helpful factor dimensions were distancing from the loss-approaching the loss and professional activities-personal activities. The present study empirically explored and described the underlying structure of teachers' bereavement experiences after student suicides.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.223-231
• /
• 2022

Covid-19, which has made a huge difference in our daily lives, has also brought major changes to our college education. As the class was changed from the traditional face-to-face class to a non face-to-face class, both teachers and students had difficulties in adapting, and problems such as the occurrence of academic achievement gaps due to non face-to-face classes were also raised. Therefore, this study aims to find out what attitudes students have toward non-face-to-face classes at universities caused by Covid-19. Accordingly, this study tried to identify the types of subjective perceptions college students have toward non-face-to-face classes by applying the Q methodology, and to suggest points for reference in the development and improvement of non-face-to-face classes in the future. Five types were found as a result of analysis using 30 P samples and 34 Q samples. First, learning efficiency-oriented type, second, class participation and communication-oriented type, third, non-face-to-face class active acceptance and utilization type, fourth, dissatisfaction type due to remote system and equipment operation errors, fifth, passive response type according to the situation to be. From the results of this study, it seems that it is necessary to develop an educational method for effective non-face-to-face class considering the characteristics of each type, and the merits of non-face-to-face classes, especially recorded lectures, in terms of learning efficiency, are evident. Therefore, even if face-to-face classes are conducted entirely at universities, it is believed that providing video-recorded lectures in class will be of great help to students' learning.

• Journal of Christian Education in Korea
• /
• v.70
• /
• pp.141-173
• /
• 2022

The purpose of this study is to illuminate depersonalization in the flow of technological revolution and to present a Christian SARAMDAUM education that aims for a new human image. It represents the Christian SARAMDAUM education that adapts to, mediates, and offers alternatives to the technological and human evolutionary flow of the machine age. The purpose of education for this purpose is to aim for 'Homo Creators', creative human beings presented as a new human image in the age of technological revolution. The educational goal is to nurture creative human beings through creative interpretation, creative integration between disciplines, and personal dialogue in the post-mechanical/ post-conventional paradigm. The content of the education is a conversation with the SARAMDAUM that consiliences the characteristics of post-machine and post-convention. The educational method utilizes Edu-Tech and AIED(Artificial Intelligence in Education) to realize systemic thinking and SARAMDAUM dialogue of technology. In addition, the composition of teachers and learners, educational environment and educational evaluation is presented. The significance of this study is that from the point of view of Christian education, the identity of human beings in the era of the technological revolution has been identified, and research on the creative image of the human being is newly attempted, and the direction of Christian SARAMDAUM education aimed at this is presented. This can be said to be a Christian education that emphasizes the essential characteristics of human beings while accommodating the era of technological revolution.