• Journal of Technologic Dentistry
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• v.42 no.3
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• pp.220-227
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• 2020

Purpose: This study aims to investigate the cusp variation pattern of the Korean mandibular second premolar and to determine the difference in tooth diameter and surface area using a virtual three-dimensional model. Methods: Dental casts from 69 students were scanned as a virtual dental models with a three-dimensional dental model scanner. Tooth diameter, absolute and relative individual areas, total crown area, the number of lingual cusps and central groove pattern were analyzed using RapidForm 2004. The Mann-Whitney U-test and the Kruskal-Wallis test were performed to verify sexual dimorphism, the difference in tooth diameter and surface according to the cusp variation pattern (α=0.05). Results: There was no significant difference except in buccolingual diameter (p<0.05) and buccolingual diameter at the cervix (p<0.05). The relative surface area of the total clinical crown was 65.76% for the buccal half and 34.24% for the lingual half, with a ratio of 2:1. In the case of the presence of two lingual cusps, the ratio was 21.47% for the mesiolingual half and 14.12% for the distaolingual half, with a ratio of 3:2. The dominant central groove patterns of the second premolar were the H-pattern (42.0%), followed by the Y-pattern (37.7%), then the U-pattern (20.3%). The relative buccal half was largest in the U-pattern central groove and the relative lingual half was largest in the Y-pattern central groove (p<0.05). Conclusion: This study is significant in that it measured quantitative surface areas and the findings could be a meaningful reference to comprehend dental anatomy in Koreans.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.59-67
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• 2023

Recently, interest in flight simulators based on HMD and mixed reality is increasing. However, they have limitations in providing various interactions and a sense of presence to pilot wearing HMD. To overcome these limitations, a mixed reality image corresponding to the interaction under the actual cockpit environment must be generated in real time and provided to the pilot. For this purpose, we proposed a mixed reality image generation method, in which the cockpit area including the pilot's body could be extracted from real image obtained from the camera attached to the HMD and then composed with virtual image to generate a high-resolution mixed reality image. Simulation results showed that the proposed method could provide mixed reality images to HMD at 30 Hz frame rate with 99% image composition accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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• pp.1216-1233
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• 2023

Conventional occupational therapy (OT) is conducted under the observation of an occupational therapist, and there are limitations in measuring and analyzing details such as degree of hand tremor and movement tendency, so this important information may be lost. It is therefore difficult to identify quantitative performance indicators, and the presence of observers during performance sometimes makes the subjects feel that they have to achieve good results. In this study, by using the Unity3D and artificial intelligence (AI) speaker, we propose a system that allows the subjects to steadily use it by themselves and helps the occupational therapist objectively evaluate through quantitative data. This system is based on the OT of the sensory integration approach. And the purpose of this system is to improve children's activities of daily living by providing various feedback to induce sensory integration, which allows them to develop the ability to effectively use their bodies. A dynamic OT cognitive assessment tool for children used in clinical practice was implemented in Unity3D to create an OT environment of virtual space. The Leap Motion Controller allows users to track and record hand motion data in real time. Occupational therapists can control the user's performance environment remotely by connecting Unity3D and AI speaker. The experiment with the conventional OT tool and the system we proposed was conducted. As a result, it was found that when the system was performed without an observer, users can perform spontaneously and several times feeling ease and active mind.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.581-587
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• 2023

During the global pandemic period, The world has created a new paradigm using digital technology, aligning one direction with the highest value of life and survival. Untact has changed from a convenience value to an essential value with quarantine and sanitation. And the industry process has shifted from face-to-face to non-face-to-face. The platform formed an community in a virtual space, and companies started a new service based on presence. For a sense of reality, information is expressed and stored from 2D centered on images to 3D multifaceted. Companies are marketing using 3D modeling, focusing on augmented reality, virtual world, and mirror world of Metaverses. The purpose of this study is to analyze the current status and examples of 3D modeling in the E-commerce environment of domestic and foreign jewelry brands in this era of change, and present ways to use 3D modeling in jewelry industries.

• Atmosphere
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• v.29 no.1
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• pp.41-51
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• 2019

The characteristics of the sea breeze were investigated using the wind and temperature data collected from 300-m tower at Boseong from May 2014 to April 2018. Sea breeze day was detected using following criteria: 1) the presence of a clear change in wind direction near sunrise (between 1 hour after sunrise and 5 hours before sunset) and sunset (from 1500 LST to midnight), 2) presence of thermal forcing of sea breeze and 3) no heavy precipitation (rain < $10mm\;d^{-1}$). Sea breeze days occurred on 569 days for 4 years. The monthly distribution of sea breeze day occurrence shows maxima in May and September and minimum in December. The average onset and cessation times of the sea breeze are 0942 LST and 1802 LST, respectively. Although the 10-m wind shows clockwise rotation with time in the afternoon, the observed hodograph does not show an ideal elliptical shape and has different characteristics depending on the upper synoptic wind direction. Vertical structure of sea breeze shows local maximum of wind speed and local minimum of virtual potential temperature at 40 m in the afternoon for most synoptic conditions except for southeasterly synoptic wind ($60^{\circ}{\sim}150^{\circ}$) which is in the same direction as onshore flow. The local minimum of temperature is due to cold advection by sea breeze. During daytime, the intensity of inversion layer above 40 m is strongest in westerly synoptic wind ($240^{\circ}{\sim}330^{\circ}$) which is in the opposite direction to onshore flow.

• The korean journal of orthodontics
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• v.51 no.6
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• pp.375-386
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• 2021

Objective: To evaluate the accuracy of a one-piece bracket jig system fabricated using computer-aided design and manufacturing (CAD/CAM) by employing three-dimensional (3D) digital superimposition. Methods: This in vitro study included 226 anterior teeth selected from 20 patients undergoing orthodontic treatment. Bracket position errors from each of the 40 arches were analyzed quantitatively via 3D digital superimposition (best-fit algorithm) of the virtual bracket and actual bracket after indirect bonding, after accounting for possible variables that may affect accuracy, such as crowding and presence of the resin base. Results: The device could transfer the bracket accurately to the desired position of the patient's dentition within a clinically acceptable range of ± 0.05 mm and 2.0° for linear and angular measurements, respectively. The average linear measurements ranged from 0.029 to 0.101 mm. Among the angular measurements, rotation values showed the least deviation and ranged from 0.396° to 0.623°. Directional bias was pronounced in the vertical direction, and many brackets were bonded toward the occlusal surface. However, no statistical difference was found for the three angular measurement values (torque, angulation, and rotation) in any of the groups classified according to crowding. When the teeth were moderately crowded, the mesio-distal, bucco-lingual, and rotation measurement values were affected by the presence of the resin base. Conclusions: The characteristics of the CAD/CAM one-piece jig system were demonstrated according to the influencing factors, and the transfer accuracy was verified to be within a clinically acceptable level for the indirect bracket bonding of anterior teeth.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.469-476
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• 2022

As the 3D modeling technology and conversational algorithm is developed, digital humans are being used in various fields, and also virtual bankers have begun to appear in banks, including major banks such as Shin-Han Bank and Nong-Hyup Bank. However, most of the research of digital human mainly focus on its appearance, and research on robot persona that should be considered in anthropomorphizing a robot is insufficient. In this study, an experiment was conducted to find out the user experience of three scenarios (student ID receipt, deposit and withdrawal account opening, leasehold loan consultation) in which the level of anthropomorphism of the speech strategy and the level of personal information use differed in the specific context of banking. As a result of the study, social presence and usefulness had an interactive effect on the scenario and the level of anthropomorphism. There was no interaction effect on intimacy, trustworthiness, and perceived intelligence, but a tendency could be confirmed.

• Knowledge Management Research
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• v.23 no.2
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• pp.61-82
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• 2022

Metaverse is a combination of Meta and Universe, which refers to a world in which users or avatars engage in social, economic, and cultural activities. This study attempted to compare the four worldviews proposed by the Acceleration Studies Foundation (ASF) based on the five evaluation factors of SPICE, which are factors for promoting customer experience. 227 samples were used in the analysis, and as a result, seamlessness was the highest in augmented reality, interoperability in lifelogging, presence in the mirror world, and concurrence in virtual reality. This study is meaningful in that it presents a model design plan according to the classification of the metaverse platform and the worldview, and presents detailed strategic directions to existing metaverse platform operators or new entrants.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.519-529
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• 2022

Many consumers are opting for online booking over traditional booking systems. Customers can actively seek out information about hotels and lodging services, as well as book rooms, at any time and from any location. Customers also feel more supported when they interact with virtual assistants or professionals. Recognizing this issue, several hotels have focused on improving their websites by incorporating aspects that encourage customers to book directly through the hotel's website. The study's goal is to discover what factors impact people's decisions to book a hotel stay through the hotel's website. Therefore, hotel managers and owners can make decisions to improve the hotel website to attract residents to Can Tho City. The factors are website quality, affective commitment, social presence, and e-trust that affect customers' decision to book through the hotel website. The study uses quantitative methods to collect data from 180 residents living in Can Tho. Through data analysis on SPSS and Amos software, the research results show that three factors considered, namely website quality, affective commitment, and social presence, positively influence customers' booking decisions. This finding also suggests that e-trust is less critical to residents in Can Tho City, different from what the study had predicted.

• Trans-
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• v.15
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• pp.25-56
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• 2023

VR is a dynamic image simulation technology with very high information density. Among them, spatial depth, temporality, and realism bring an unprecedented sense of immersion to the experience. However, due to its high information density, the information contained in it is very easy to be manipulated, creating an illusion of objectivity. Users need guidance to help them interpret the high density of dynamic image information. Just like setting up navigation interfaces and interactivity in games, interactivity in virtual reality is a way to interpret virtual content. At present, domestic research on VR content is mainly focused on technology exploration and visual aesthetic experience. However, there is still a lack of research on interactive storytelling design, which is an important part of VR content creation. In order to explore a better interactive storytelling model in virtual reality content, this paper analyzes the interactive storytelling features of the VR animated version of <Wolves in the walls> through the methods of literature review and case study. We find that the following rules can be followed when creating VR content: 1. the VR environment should fully utilize the advantages of free movement for users, and users should not be viewed as mere observers. The user's sense of presence should be fully considered when designing interaction modules. Break down the "fourth wall" to encourage audience interaction in the virtual reality environment, and make the hot media of VR "cool". 2.Provide developer-driven narrative in the early stages of the work so that users are not confused about the ambiguous world situation when they first enter a virtual environment with a high degree of freedom. 1.Unlike some games that guide users through text, you can guide them through a more natural interactive approach that adds natural dialog between the user and story characters (NPC). Also, since gaze guidance is an important part of story progression, you should set up spatial scene user gaze guidance elements within it. For example, you can provide eye-following cues, motion cues, language cues, and more. By analyzing the interactive storytelling features and innovations of the VR animation <Wolves in the walls>, I hope to summarize the main elements of interactive storytelling from its content. Based on this, I hope to explore how to better showcase interactive storytelling in virtual reality content and provide thoughts on future VR content creation.