• Journal of the Korea Computer Graphics Society
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• v.24 no.5
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• pp.21-30
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• 2018

In this paper, we use Sound-tracing, a 3D sound technology based on ray-tracing that uses geometric method as auditory technology to enhance realism. The Sound-tracing is costly in the sound propagation stage. In order to reduce the sound propagation cost, we propose a method to calculate the average effective frame number of previous frames using the frame coherence property and to adjust the depth according to the space based on the calculated number. Experimental results show that the path loss rate is 0.72% and the traversal & Intersection test calculation amount is decreased by 85.13% and the frame rate is increased by 4.48% when the sound source is indoors, compared with the result of the case without depth control. When the sound source was outdoors, the path loss was 0% and the traversal & Intersection test calculation amount is decreased by 25.01% and the frame rate increased by 7.85%. This allowed the rendering performance to be increased while minimizing the path loss rate.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.1
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• pp.63-70
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• 2017

On the spatial information open platform, the national spatial data are released to provide services that the people can use freely. Recently, the demand for high quality 3D geospatial information and indoor spatial information is increasing. However, open platform is not able to provide seamless service because spatial data of indoor and outdoor are composed of different formats and storage structures. In addition, the 3D data format used in the current service does not reflect the recent changes in service environment and new technology. Therefore, in this study, we proposed new format of 3D data used in service to improve interoperability and service of open platform 3D data. The proposed format is lighter than the existing format and the rendering speed is improved.

• Science of Emotion and Sensibility
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• v.22 no.4
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• pp.3-14
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• 2019

The café has become an important representative "third place" where people study and rest. Hence, it is worthwhile for researchers to understand the needs of individual users as well as the requirements of people who visit such venues in groups. The identification of strategies that can help achieve larger, wider, higher, or deeper interior spaces in small and compact locations can generate benefits for both users and designers. In this study, where 56 interior design students participated, we used an eye-tracker and images of cafes to explore the relationships between spatial depth and the intention to visit a cafe space. The researchers digitally developed fifteen different conditions of space and measured the eye movements of the participants using an eye-tracker when they examined images that appeared to convey the most depth. Participants were also asked to imagine the proposed space images as cafes and to select one of the 15 images as the location that they would be most likely to visit individually and one that they would frequent in the company of other people. The research results revealed that certain ways of using interior design elements altered the participants' perceptions of spatial depth without any change being effected to the actual volume or the size of the space. The participants tended to perceive a space with a small decorative artwork on a dark toned wall with unconnected furniture as deeper than a space with no or large artwork on a light toned wall with contiguous furniture. Spatial depth was a more important consideration for an individual visit than for a group visit. The results of this exploratory study will help scholarly understanding of the role played by spatial depth in customer intentions to visit a cafe.

• Journal of KIISE
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• v.44 no.3
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• pp.332-337
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• 2017

When using IFC data consisting of STEP schema based on the EXPRESS language, it is not easy for collaborating project stakeholders to share BIM modeling shape information. The IFC viewer application must be installed on the desktop PC to review the BIM modeling shape information defined within the IFC, because the IFC viewer application not only parse STEP structure information model but also process the 3D feature construction for a 3D visualization. Therefore, we propose a lightweight data structure design for web visualization by parsing IFC data and constructing 3D modeling data. Our experimental results show the weight reduction of IFC data is about 40% of original file size and the web visualization is able to see the same quality with all web browsers which support WebGL on PCs and smartphones. If applied research is conducted about the web visualization based on IFC data of the last construction phase, it could be utilized in various fields ranging from the facility maintenance to indoor location-based services.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.161-166
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• 2006

Purpose: Recently, the incidence of early gastric cancer (EGC) patients is rapidly increased in Korea. However, they're often not perceptible by surgical palpation or inspection. The aim of this study is 1) to develope a software that can locate the tumor and measure the mucosal distance from an anatomic landmark to the tumor using CT gastrography and 2) to compare the distance measured by the developed software with the distance measured by the pathologic findings. Materials and Methods: Between January 2004 and September 2005, sixty patients (male=45, female=15, mean 57.8 years old) estimated for EGC with preoperative CT scans and undergone gastrectomies in Kyungpook National University Hospital were enrolled in this study. Preoperative CT scans were performed after insufflations of room air via 5 Fr NG tube. The scans included the following parameters: (slice thickness/reconstruction interval: 0.625 mm, kVp: 120, mAs: 200). 3D volume rendering and measurement of the surface distance from the pylorus to the EGC were performed using the developed software. Results: The average difference between the lesion to pylorus distances measured from pathologic specimens and CT gastrography was $5.3{\pm}2.9\;mm(range,\;0{\sim}23\;mm)$. The lesion to pylorus distance measured from CT gastrography was well correlated with that measured from the pathologic specimens (r=0.9843, P<0.001). Conclusion: These results suggest that the surface distance from an anatomic landmark to the EGC can be measured accurately by CT gastrography. This technique could be used for preoperative localization of early gastric carcinomas to determine the optimal extent of surgical resection.