• Journal of the Korea Computer Graphics Society
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• v.29 no.5
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• pp.1-9
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• 2023

The control technology of animatronics is an interesting topic explored in various fields, including engineering, medicine, and art, with ongoing research efforts. The conventional method for controlling the movement of animatronics is to use electric motors installed inside the body. However, this method is difficult to apply when expressing a narrow space inside the body. In this study, a method of using external forces instead of installing mechanical devices inside the body was proposed to control the movement of a thin and long tentacle organism. Specifically, in this study, the joint body of animatronics was made of magnetic metal material so that it could be affected by the force of an externally installed electromagnet. The strength of the electromagnet was controlled by a PID controller to enable real-time control of the position of the animatronics body. In addition, the magnet was made to rotate, and the speed of rotation was changed to create various movements. Through virtual environment simulations, our experiments demonstrate the superiority of the proposed method, showcasing real-time control by users and the creation of animations in various styles.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.160-172
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• 2023

The metaverse, derived from the fusion of "meta" and "universe," encompasses a three-dimensional virtual realm where avatars actively participate in a range of political, economic, social, and cultural activities. With the recent development of the metaverse, the traditional way of experiencing services is changing. While existing studies have mainly focused on the technological advancements of metaverse services (e.g., scope of technological enablers, application areas of technologies), recent studies are focusing on evaluating the quality of experience (QoE) of metaverse services from a customer perspective. This is because understanding and analyzing service characteristics that determine QoE from a customer perspective is essential for designing successful metaverse services. However, relatively few studies have explored the customer-oriented approach for QoE evaluation thus far. This study conducted an online review analysis using text mining to overcome this limitation. In particular, this study analyzed 227,332 online reviews of the Roblox service, known as a representative metaverse service, and identified points for improving the Roblox service based on the analysis results. As a result of the study, nine service features that can be used for QoE evaluation of metaverse services were derived, and the importance of each feature was estimated through relationship analysis with service satisfaction. The importance estimation results identified the "co-experience" feature as the most important. These findings provide valuable insights and implications for service companies to identify their strengths and weaknesses, and provide useful insights to gain an advantage in the changing metaverse service environment.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1165-1172
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• 2023

Recently, Korea has declared carbon neutrality by 2050. The Korea Forest Service is promoting the precision and high technology of forest resource surveys. As such, the demand for forest resource management is increasing, and the need to build a digital twin of forest space is increasing. However, to date, digital twin has only built and provided virtual city services, which are city and nationwide digital twin environments. Three-dimensional digital twin services targeting forest space are not operated and provided. Therefore, in this study, we aimed to implement a forest digital twin environment to provide 3D forest spatial information services corresponding to vertical information such as tree-level height and thorax diameter. By lightweighting realistic 3D tree models and applying 3D Tiles, we confirmed the feasibility of implementing a forest digital twin environment for 3D forest spatial information services. Through continuous research, we plan to implement a forest digital twin that can deploy and service 3D tree models for trees nationwide, including street trees in urban areas. This is expected to enable the development of forest digital twin services for forest resource management.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.1
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• pp.57-68
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• 2023

With the technological development in the era of the 4th Industrial Revolution, technologies using HMD are being applied in various fields. HMD is especially useful in virtual reality fields such as AR/VR, and is very effective in receiving vivid impressions from users located in remote locations. According to these characteristics, the frequency of using HMD is increasing in the field related to collaboration. However, when HMD is applied to collaboration, communication between experts located in remote locations and workers located in the field is not smooth, causing various problems in terms of usability. In this paper, remote experts and workers in the field use HMD to solve various problems arising from collaboration, design/propose new types of HMD structures and functions that enable more efficient collaboration, and verify their usability using SUS evaluation techniques. As a result of the SUS evaluation, the new type of HMD structure and function proposed in this paper was 86.75points, which is believed to have greatly resolved the restrictions on collaboration and inconvenience in use of the existing HMD structure. In the future, when the HMD structure and design proposed in this paper are actually applied, it is expected that the application technology using HMD will expand rapidly.

• Journal of the Korean Chemical Society
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• v.67 no.6
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• pp.441-461
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• 2023

This study explore characteristics of teaching orientation and pck of science teachers in online-offline mixed learning environment. Data consisted of open-ended survey, semi-structured interview, class observation, field notes from 12 science teachers. We categorized teaching orientation considering both science education goals and science teaching·learning orientation. There were 8 different teaching orientations such as 'understanding science concepts-lecture centered' 'constructing science concepts-inquiry based' 'applying science concepts and inquiry-inquiry based' 'applying science concepts and inquiry-lectured centered' 'analyzing and judging science information-inquiry based' 'developing scientific attitude-inquiry based' 'developing scientific attitude-lecture centered' and 'developing perception of interrelationships among science, technology, and society-inquiry based'. Teachers with inquiry based teaching·learning orientation seemed to have knowledge of science curriculum specific to online learning environment for student inquiry. While teachers with 'understanding science concepts-lecture centered' teaching orientation appeared to have questioning strategy of checking student understanding and strategy of repeating a lecture, teachers with 'constructing science concepts-inquiry based' teaching orientation appeared to have knowledge of instructional strategies to perform online group activities targeting student construction of knowledge and to replace face-to-face group activities with virtual experiments and individual experiments. While teachers with 'understanding science concepts-lecture centered' teaching orientation did not show knowledge of student science learning, teachers with 'constructing science concepts-inquiry based' teaching orientation appeared to have knowledge of student difficulties in inquiry based learning.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.130-144
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• 2023

Recently, various positioning technologies are being researched based on signal-based positioning and image-based positioning to obtain accurate indoor location information. Among these, various studies are being conducted on image positioning technology that determines the location of a mobile terminal using images acquired through cameras and sensor data collected as needed. For video-based positioning, a method of determining indoor location is used by matching mobile terminal photos with virtual landmark images, and for this purpose, it is necessary to build indoor spatial information about various landmarks such as billboards, vending machines, and ATM machines. In order to construct indoor spatial information on various landmarks, a panoramic image in the form of a road view and accurate 3D survey results were obtained through c 13 buildings of the Electronics and Telecommunications Research Institute(ETRI). When comparing the 3D total station final result and the terrestrial lidar panoramic image coordinates, the coordinates and distance performance were obtained within about 0.10m, confirming that accurate landmark construction for use in indoor positioning was possible. By utilizing these terrestrial lidar achievements to perform 3D landmark modeling necessary for image positioning, it was possible to more quickly model landmark information that could not be constructed only through 3D modeling using existing as-built drawings.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.205-216
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• 2024

Recently, seismic Probabilistic Safety Assessment (PSA) methods have been developed for process plants, such as gas plants, oil refineries, and chemical plants. The framework originated from the PSA of nuclear power plants, which aims to assess the risk of reactor core damage. The original PSA method was modified to adopt the characteristics of a process plant whose purpose is continuous operation without shutdown. Therefore, a fault tree, whose top event is shut down, was constructed and transformed into a Bayesian Network (BN), a probabilistic graph model, for efficient risk-informed decision-making. In this research, the fault tree-based BN from the previous research is further developed to consider the multi-hazard of earthquake-induced fire and explosion (EQ-induced F&E). For this purpose, an event tree describing the occurrence of fire and explosion from a release is first constructed and transformed into a BN. And then, this BN is connected to the previous BN model developed for seismic PSA. A virtual plot plan of a gas plant is introduced as a basis for the construction of the specific EQ-induced F&E BN to test the proposed BN framework. The paper demonstrates the method through two examples of risk-informed decision-making. In particular, the second example verifies how the proposed method can establish a repair and retrofit strategy when a shutdown occurs in a process plant.

• Journal of Industrial Convergence
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• v.22 no.6
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• pp.51-59
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• 2024

The purpose of the paper is to suggest government policies that are practically helpful to small business owners in pandemic situations such as COVID-19. To this end, keyword frequency analysis and word cloud analysis of text mining analysis were performed by crawling news articles centered on the keywords "COVID-19 Support for Small Businesses", "The Impact of Small Businesses by Response System to COVID-19 Infectious Diseases", and "COVID-19 Small Business Economic Policy", and major issues were identified through LDA topic modeling analysis. As a result of conducting LDA topic modeling, the support policy for small business owners formed a topic label with government cash and financial support, and the impact of small business owners according to the COVID-19 infectious disease response system formed a topic label with a government-led quarantine system and an individual-led quarantine system, and the COVID-19 economic policy formed a topic label with a policy for small business owners to acquire economic crisis and self-sustainability. Focusing on the organized topic label, it was intended to provide basic data for small business owners to understand the damage reduction policy for small business owners and the policy for enhancing market competitiveness in the future pandemic situation.

• Smart Media Journal
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• v.13 no.1
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• pp.36-44
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• 2024

Metaverse is attracting attention as the development of virtual environment technology and the emergence of untact culture due to the COVID-19 pandemic. In this study, by analyzing users' reviews on the "Zepeto" application, which has recently attracted attention as a metaverse service, we tried to confirm changes in the requirements for the metaverse after the COVID-19 pandemic. To this end, 109,662 reviews of "Zepeto" applications written on the Google Play Store from September 2018 to March 2023 were collected, topics were extracted using LDA topic modeling technique, and topics were analyzed using the Causal Impact technique to examine how topics changed before and after based on "March 11, 2020" when the COVID-19 pandemic was declared. As a result of the analysis, five topics were extracted: application functional problems (topic1), security problems (topic 2), complaints about cryptocurrency (Zem) in the application (topic 3), application performance (topic 4), and personal information-related problems (topic 5). Among them, it was confirmed that security problems (topic 2) were most affected by the COVID-19 pandemic.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.421-435
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• 2017

Recently, due to the saturation of ground structures and the overpopulation of pipeline facilities requires to development of underground structures as an alternative to ground structures. Thus, mechanized tunnel construction of the shield TBM method has been increasing in order to prevent vibration and noise problems in construction of the NATM tunnel for the urban infrastructure construction. Tunnel construction plan for the tunnel line should be formed in a sharp curve to avoid building foundation and underground structures and it is inevitable to develop a shield TBM technology that suits the sharp curve tunnel construction. Therefore, this study is about the structural stability technology of the articulation jack, shield jack and skin plate for the shield TBM thrust in case of the mechanized tunnel construction that is a straight and sharp curve line. The construction case study and shield TBM operation principle are examined and analyzed by the theoretical approach. The torque of the cutter head, the thrust of the articulation jack and the shield jack, the amount of over cutting for curve is important respectively in shield TBM construction of straight and sharp curve line. In addition, it is very important to secure the stability of the skin plate structure to ensure the safety of the inside worker. This study examines the general structure and construction of the equipment, experimental simulation was carried out through numerical analysis to examine the main factors and structural stability of the skin plate structure. The structural stability of the skin plate was evaluated and optimizes the shape by comparing the loads of the articulation jack by selecting the virtual soil to be applied in a straight and sharp curve line construction. Since the present structure and operation method of the shield TBM type in domestic constructions are very similar, this study will help to develop the localized shield TBM technology for the new equipment and the vulnerability and stability review.