• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.4
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• pp.121-127
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• 2022

β-Gallium oxide (Ga₂O₃), an ultra-wide bandgap semiconductor, has attracted great attention due to its promising applications for high voltage power devices. The most stable phase among five different polytypes, β-Ga₂O₃ has the wider bandgap of 4.9 eV and higher breakdown electric field of 8 MV/cm. Furthermore, it can be grown from melt source, implying higher growth rate and lower fabrication cost than other wide bandgap semiconductors such as SiC, GaN and diamond for the power device applications. In this study, β-Ga₂O₃ bulk crystals were grown by the edge-defined film-fed growth (EFG) process. The growth direction and the principal surface were set to be the [010] direction and the (100) plane of the β-Ga₂O₃ crystal, respectively. The spectra measured by Raman an alysis could exhibit the crystal phase an d impurity dopin g in the β-Ga₂O₃ ingot, and the crystallinity quality and crystal direction were analyzed using high-resolution X-ray diffraction (HRXRD). The crystal quality and various properties of as-grown β-Ga₂O₃ ribbon was systematically analyzed in order to investigate the spatial variation in entire crystal grown by EFG method.

• Explosives and Blasting
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• v.40 no.4
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• pp.15-26
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• 2022

With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.897-906
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• 2017

Projection Mapping, also known as Spatial Augmented Reality(SAR) has attracted much attention recently and used for many division, which can augment physical objects with projected various virtual replications. However, conventional approaches towards projection mapping have faced some limitations. Target objects' geometric transformation property does not considered, and movements of flexible objects-like paper are hard to handle, such as folding and bending as natural interaction. Also, precise registration and tracking has been a cumbersome process in the past. While there have been many researches on Projection Mapping on static objects, dynamic projection mapping that can keep tracking of a moving flexible target and aligning the projection at interactive level is still a challenge. Therefore, this paper propose a new method using Unity3D and ARToolkit for high-speed robust tracking and dynamic projection mapping onto non-rigid deforming objects rapidly and interactively. The method consists of four stages, forming cubic bezier surface, process of rendering transformation values, multiple marker recognition and tracking, and webcam real time-lapse imaging. Users can fold, curve, bend and twist to make interaction. This method can achieve three high-quality results. First, the system can detect the strong deformation of objects. Second, it reduces the occlusion error which reduces the misalignment between the target object and the projected video. Lastly, the accuracy and the robustness of this method can make result values to be projected exactly onto the target object in real-time with high-speed and precise transformation tracking.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.38-43
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• 2012

Purpose: Patients injected with FDG use the bathroom that Measured surface contamination level and spatial dose rate. This study about the effect that result affects workers in same part. Materials and Methods: Group1 is St. Vincent' s hospital's 60case. Group 2 is Bucheon St. Mary's hospital's 50case. Last case is lower the average daily number of patients than group 2. Measured time is 8:00, 10:00, 13:00, 15:00 and 17:00. Measured part is 4 point of toilet, basin and wastepaper basket, also measured accumulation dose of toilet during 3 month. Hospitals is installed PET/CT ware surveyed on presence of bathroom that used only by patient and worker has been using the bathroom. Results: The highest average surface contamination level of toilet is group1($8.38{\pm}4.56$), but the highest spatial dose rate is group3. Cumulative exposure dose measured by TLD during 3months is St.Vincent's hospital 0.78 mSv and Bucheon St.Mary's hospital 0.37 mSv. And result of survey is 16.12% worker using the bathroom. Conclusions: The more daily number of patient, the higher surface contamination level of bathroom. Especially, wastepaper basket's surface contamination level is exceed the reference value $4Bq/cm^2$. Based on This survey, Bathroom require special attention and proper decontamination.

• Journal of The Korea Institute of Healthcare Architecture
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• v.19 no.2
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• pp.19-30
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• 2013

Purpose: The planning and design of hospital generally requires the participation and consultation of skilled experts since it has more complex space program than any other buildings. Therefore, the BIM systems for the planning of hospital have been tried continuously. The purpose of this study is to identify the precondition for space Program validation of healthcare architecture based on BIM, which is recently receiving wide attention. Method: For this study, United States, Australia and Finland's guidelines were analyzed among the description space program validation system in 14 overseas BIM Guidelines. And the propose precondition that can be applied to healthcare architecture from among these description of space program validation items, target, process etc for General building. Result: 1) spatial program validation is the following four evaluation phase. Step 1: Standard setting phase Step 2: BIM model accuracy assessment phase Step 3: space validation phase Step 4: Performance evaluation phase 2) The standards for the building elements at Standards Setting stage is considered to the standards for the architectural elements of General building. 3) Healthcare Architecture Area calculation method is considered to be reasonable that borrowing the area calculation standard of general architecture according to the UIA of international standards. However, Be proposed of measuring method that reflect the efficiency of the design process step-by-step area calculation method. The performance assessment indicators of reflect the Hospital uniqueness have to developed. And the research needs to be carried out continuously according to the purpose for healthcare architecture of feature-oriented. Implications: In this paper like to understanding that precondition of space program validation considering the BIM. As a result, understanding to condition about step of the evaluation, the evaluation standards. Is expected to keep the focus on the development of performance indicators that reflect the uniqueness of the hospital for the efficient evaluation of the Hospital building.

• Korean Institute of Interior Design Journal
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• v.23 no.2
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• pp.117-124
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• 2014

As the contemporary times entered, the attention focused on the 'human's perception on a space' as much as on that a space's physical structure, so the meaning of a space became defined depending on how a person thought over and behaved in the space. As this age is the times of consilience and integration, a space accepts new technologies beyond being defined simply based on the space's structure and its shape and tries to provide different, 'strange experiences' from tho se felt by the human until now. Recently in the filed of space design, it can be seen that the spae design's connection with various technologies affects on considerable influence on the all fields of culture and arts like space marketings, media arts, exhibitions and performances as well as the buildings. Especially. the fusion of digital images and architecture is actively developed. Images possessing the moving light's attributes shine a city night and day and a building changes a city's appearance itself by adding new materials on the surface of building. It is the purpose of this study to study what new experiences the human gets and creates from his interaction with spaces based on such technological fusion. By studying some cases that used the digital media as a mediating instrument as the way presenting spatial experiences to the human, this study intended to identify what design factors were applied and to find appropriate directions for space desig in relation to what new trials can be done.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.141-148
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• 2020

Unilateral neglect is associated with stroke, a neurological disorder caused by cerebrovascular injury, and is a symptom of not recognizing or responding to the opposite stimulus of the cerebral hemisphere, mainly in the right cerebral hemisphere injury. In this paper, we implemented contents using Virtual Reality based on 10 items and contents of Korean Catherine Bergego Scale(K-CBS), which is used as a behavioral evaluation scale for unilateral neglect. Implemented contents can evaluate body disregard, motility disregard, visual and spatial disregard, auditory attention, etc., which are symptoms of unilateral neglected patients, and can confirmed progression of disease quantitatively by measuring time and rotation angle of head during visual recognition. This method is expected to be useful for rehabilitation training using convenient unilateral neglect diagnosis and its applied contents.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.106-117
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• 2018

The purpose of the study is to present the social welfare center planning factors of space for promoting intergenerational exchanges between the elderly and children. To achieve the purpose, the study conducted a survey of professionals on the importance of planning factors. The results are as follows. First, it is surveyed that less high are Korean social welfare center planning and availability extents of space for intergenerational exchanges, while less no profound are the necessity and concern of such spaces. The result suggests that social welfare centers need a concrete planning of space for intergenerational exchanges. Second, it is identified that in order to promote intergenerational exchanges, there need to plan planning factors of each space, especially with focus on 'outdoor space' and 'specific space.' Third, it is revealed that regarding the importance of factors of 'specific space,' physical supports account for the high rates; architectural factors providing free space contribute to the supports of physical development; and decorative factors giving visual effects could be helpful for behaviors. Fourth, it is unveiled that the supports of physical behaviors are of the most importance in 'connecting space'. This would be planned as a path that gives a free access in spaces, with attention being paid to safety. Lastly, it is shown that in the case of 'outdoor space,' the supports of physical development are of the most importance. Given the fact that 'outdoor space' offers a wider scope of activities, and accommodates various available elements in connection with surrounding environments, it is considered that the space would be of help for intergenerational interactions. The study is expected to be utilized as the preliminary data which proposes the social welfare center planning factors of space for promoting intergenerational exchanges between the elderly and children.

• Communications of Mathematical Education
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• v.31 no.3
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• pp.257-277
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• 2017

The purpose of this research is divide into two kinds. First, develop the mathematical modeling program for mathematically gifted students focused on Voronoi diagram and Delaunay triangulation, and then gifted teachers can use it in the class. Voronoi diagram and Delaunay triangulation are Spatial partition theory use in engineering and geography field and improve gifted student's mathematical connections, problem solving competency and reasoning ability. Second, after applying the developed program to the class, I analyze gifted student's core competency. Applying the mathematical modeling program, the following findings were given. First, Voronoi diagram and Delaunay triangulation are received attention recently and suitable subject for mathematics gifted education. Second,, in third enrichment course(Student's Centered Mathematical Modeling Activity), gifted students conduct the problem presentation, division of roles, select and collect the information, draw conclusions by discussion. In process of achievement, high level mathematical competency and intellectual capacity are needed so synthetic thinking ability, problem solving, creativity and self-directed learning ability are appeared to gifted students. Third, in third enrichment course(Student's Centered Mathematical Modeling Activity), problem solving, mathematical connections, information processing competency are appeared.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.5-11
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• 1999

This paper reviews recent major activities on instrumentation and methodology of PET. The performance of the PET instrumentation can be expressed by four physical characteristics, 1) spatial resolution, 2) coincidence resolving time, 3) energy resolution, and 4) detection efficiency. The physical and technical aspects of PET systems are briefly discussed along with these characteristics. Toward high resolution PET the recent trend has been to design multiple rings of densely packed detector arrays with scintillators. In order to satisfy the sampling requirement in reconstruction, continuous detector units has been developed. Iterative image reconstruction algorithms have received considerable attention for improvement of both the sampling requirement and image quality toward the stationary PET. Better resolving time improves the maximum true coincidence rate, which is also increased with more detectors placed in coincidence with each other. It suggests that volume PET is promising for enhancement of detection efficiency. The scattered coincidence event rate may be reduced by using detectors with better energy resolution. The use of interplane septa, however, takes over improvement of energy resolution in 2D PET. Energy resolution becomes an important factor for image quality under the condition of septa removal such as volume PET. Toward full utilization of emitting photons, 3D reconstruction incorporating oblique rays has been studied, and volume reconstruction algorithms have been developed. Practical volume PET systems impose heavy burden not only to detector sets and coincidence circuits, but also to computers in the memory requirements and the data processing. In conclusion, there have been many ingenious methods in development of PET instrumentation, which are based on unique capability of PET. They will be expected to overcome technical limitations, and to approach the fundamental limits.