• Journal of Conservation Science
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• v.38 no.4
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• pp.347-359
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• 2022

Gongsanseong Fortress was registered of a World Heritage Site in 2015 as a representative cultural heritage from the Woongjin Baekje period, and it has been used throughout the entire period from Baekje Kingdom to the Joseon Dynasty. Within Gongsanseong Fortress, the area around Ssangsujeong is presumed the site of royal palace of the Woongjin Baekje. Also, the excavated culture layers of the Baekje Kingdom, the Unified Silla period, and the Joseon Dynasty were confirmed. In this study, paleotopography was modeled by digitally converting the elevation data obtained through surveying the excavation process, and the use of the topography in the Ssangsujeong area was considered by examining the variations in the topography according to the periods. As a result, the topography of the slope around the peak changed by periods, and the topography did not change on the flat land. The topography between the Baekje Kingdom and the Unified Silla period appeared to be almost identical, and it seems that the space of the Baekje period was maintained as it is. Also, during the Joseon Dynasty, it is confirmed that flat surfaces in the previous period were used. However, sediments on the slopes flowed down, reducing the area of the flatland, and architectural techniques that could utilize the natural topography of the changed slope were applied to interpret it as having a different topography from the previous period. In order to model and interpret the paleotopography, excavation data, geological and topographic analysis, and digital data must be secured. It is expected that location conditions and ancient human life can be identified if the analysis technique in the study is applied to other archaeological sites in the future.

• International Journal of Computer Science & Network Security
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• v.22 no.5
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• pp.375-380
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• 2022

Virtual and augmented reality technologies provide access to learning materials and improve the organization of a modern library's media space. This article aims to identify the significance and role of virtual and augmented reality technologies in the modern library's media space organization. Methodology. The research uses a university library case study methodology to empirically investigate virtual and augmented reality technologies. Results. Virtual and augmented reality technologies provide research and improve learning outcomes by engaging students and learners with significant interest in such technologies. Libraries offer users the opportunity to create their VR content through available software. Students can test their VR content in the libraries' labs. Libraries support access to a variety of virtual and augmented reality content. The content is accessed using "virtual reality headsets" for viewing and workstations with "authoring software and loanable 360 cameras" for creating. The library lab is a space to support students' digital creativity and research through virtual and augmented reality. There are 3D Design Labs within the libraries as a medium to large group design learning spaces with virtual reality technology. Libraries form a media space where users can create videos, podcasts, portfolios, edit media, and book tours, and students and researchers can explore different scientific knowledge. In this way, technology ensures that risks in learning are minimized as opposed to hands-on seminars and classes.

• Journal of Conservation Science
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• v.38 no.4
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• pp.277-288
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• 2022

'Eve 58-1', the subject of this study is a statue made of plaster and its structural stability was evaluated by utilizing the CAE program in order to prevent the risk of damage arising from impact and vibration that are generated during the packaging and transportation process given its material characteristics. CAE is an abbreviation for Computer Applied Engineering for realization by predicting changes at the time of application of virtual physical energy. It is applied by reflecting the physical property conditions and each boundary condition of plaster, and the digital images of the internal and external structure of the work were acquired through 3D scanning and CT analysis for interpretation by executing finite element modeling. When acceleration is applied to the work in the direction of its own weight, the left-right side and the front-rear side, it was possible to confirm a maximum displacement value of 15.24 mm in the head section of the front-rear side direction that has been tilted by approximately 27° from the Y-axis and the largest stress value of 12.46 MPa was at the left ankle section. The corresponding results confirmed that the left ankle section is the most vulnerable area and the section for which precautions need to be exercised and supplemented at the time of transporting the work by means of objective values.

• Geomechanics and Engineering
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• v.28 no.2
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• pp.181-195
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• 2022

Roughness and joint inclination angle are the important factors that affect the strength and deformation characteristics of jointed rock mass. In this paper, 3D printer has been employed to make molds firstly, and casting the jointed specimens with different joint roughness coefficient (JRC), and different joint inclination angle (α). Conventional triaxial compression tests were carried out on the jointed specimens, and the influence of JRC on the strength and deformation parameters was analyzed. At the same time, acoustic emission (AE) testing system has been adopted to reveal the AE characteristic of the jointed specimens in the process of triaxial compression. Finally, the morphological of the joint surface was observed by digital three-dimensional video microscopy system, and the relationship between the peak strength and JRC under different confining pressures has been discussed. The results indicate that the existence of joint results in a significant reduction in the strength of the joint specimen, JRC also has great influence on the morphology, quantity and spatial distribution characteristics of cracks. With the increase of JRC, the triaxial compressive strength increase, and the specimen will change from brittle failure to ductile failure.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.240-249
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• 2007

Statement of problem: A phenomenon of screw-loosening in implant abutment is frequently occurred in a single and multiple implant restoration. Purpose: This study was performed to evaluate an effect of abutment material on screw-loosening before and after a cyclic loading. In a single-tooth implant, different materials of abutment, Type III Gold alloy and Zirconium composite$(ZrO_2/Al_2O_3)$ were used. Material and method: The Gold alloy(Type III) and Zirconium composite$(ZrO_2/Al_2O_3)$ were used to make a superstructure of implant, the one of types of UCLA, Each group was constituted of 5 sample with a 30-degree offset angulated loading platform. The external hexagonal fixture was rigidly hel d in a special holding zig to ensure solid fixation without rotation during the tightening and a cyclic loading. A Titanium-alloy screw was used to connect and controlled to be tighten in 20Ncm torque by a digital torque gauge. A 20 times of consecutive closing/opening cycle were performed to evaluate the immediate torque loss. In 5 sample of each material group, an initial opening torque was recorded during 3 closing/opening cycle, then 2Hz, 200N, 1,000,000 cyclic loadings were performed, then a opening torque was evaluated. Result & Conclusion: 1. In this limited study, titanium alloy screw tightened in 20Ncm, a cold-welding phenomen on was not observed during the 20 times of closing/opening cycle(p=0.11, p=0.18). 2. In titanium alloy abutment screw, repeated opening and closing of the screw caused to progressive decrease of opening torque(p=0.014). 3. The difference in preload of screw between gold alloy abutment and ceramic$(ZrO_2/Al_2O_3)$ abutment was not significant(p=0.78). 4. The difference in torque loss of screw between gold alloy abutment and ceramic$(ZrO_2/Al_2O_3)$ abutment was not significant after 2Hz,200N, 1,000,000 cyclic loading(p=0.92). 5. In titanium alloy abutment screw tightened by 20Ncm, the screw loosening was not significant on each group after 2Hz, 200Ncm, 1,000,000 cyclic loading(p=0.59).

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.101-112
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• 2005

As we perceive the world as 3-dimensional through our two eyes, we can extract 3-dimensional information from stereo images obtained from two or more cameras. Since stereo images have a large amount of data, with recent advances in digital video coding technology, efficient compression algorithms have been developed for stereo images. In order to compress stereo images and to obtain 3-D information such as depth, we find disparity vectors by using disparity estimation algorithm generally utilizing pixel differences between stereo pairs. However, it is not unusual to have stereo images having different intensity values for several reasons, such as incorrect control of the iris of each camera, disagreement of the foci of two cameras, orientation, position, and different characteristics of CCD (charge-coupled device) cameras, and so on. The intensity differences of stereo pairs often cause undesirable problems such as incorrect disparity vectors and consequent low coding efficiency. By compensating intensity differences between left and right images, we can obtain higher coding efficiency and hopefully reduce the perceptual burden of brain to combine different information incoming from two eyes. We propose several methods of intensity compensation such as local intensity compensation, global intensity compensation, and hierarchical intensity compensation as very simple and efficient preprocessing tool. Experimental results show that the proposed algerian provides significant improvement in coding efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1170-1174
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• 2009

Two frequency-reconfigurable antennas have been designed and combined in a space with limited volume, i.e., 40mm ${\times}$ 20mm ${\times}$ 6mm. Each antenna can be reconfigured to operate at different frequency bands depending on the state of an embedded switch, which is implemented using a PIN diode. The first antenna can be switched between 0.82GHz ${\sim}$ 0.96GHz band (GSM/ CDMA) and 1.7GHz ${\sim}$ 2.17GHz band (DCS/ PCS/ WCDMA), which are cellular bands. The second antenna can be switched between 3.4GHz ${\sim}$ 3.6GHz band (mWiMax) and 2.3GHz ${\sim}$ 2.5GHz, 5.15GHz ${\sim}$ 5.35GHz bands (WiBro/ WLAN 11a/b/g/n), which are connectivity bands. The proposed combined antenna operates both over cellular bands and connectivity bands concurrently. The choice of the operation bands is made independently by the states of the two switches.

• Journal of Oriental Neuropsychiatry
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• v.16 no.1
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• pp.1-17
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• 2005

Objective : This empirical research is performed to recognize diagnostic concept, pattern identification, and clinical features of Hwa-byung. In other words, the aims of this research are to examine the differences of the diagnosis between Hwa-Byung and the other psychiatric disorders, and to find out pattern identification, and clinical characteristics of Hwa-Byung for prescriptions of this syndrome. Method : In the experiment, there were participated 30 patients who were met for our criterions according to HBDIS (Hwa-Byung Diagnostic interview Schedule). These patients were diagnosed as Axis1 according to criterions of DSM-IV with administering SCID-I. OMS-prime was utilized for finding out pattern identification of oriental medicine. Symptom Check List-90-Revision(SCL-90-R), Hemilton rating Scale for Depression(HRSD), Heart Rate Variability(HRV), and Digital Infrared Thermographic imaging(D.I.T.I.) were also utilized to discover clinical characteristics of Hwa-Byung Patients. Results : 1. Regarding Sex-ratio, male subjects were 3(10%), and female subjects are 27(90%). The age of subjects ranged from 22 year old to 75 $(51.87{\pm}11.04;\:Mean{\pm}SD)$ 2. In the results of diagnosis on the basis of DSM-IV, the 17(56.67%) patients were MOD (Major Depressive Disorder), the 5(16.67%) patients were USD (Undifferentiated Somatoform Disorder), the 4(13.33%) patients were Dysthymic Disorder, the 3(10%) patients were GAD (Generalized Anxiety Disorder), and the 1(3.33%) was Panic Disorder. Two of the patients who diagnosed as MOD were diagnosed as Panic Disorder too, and one of them was diagnosed as Pain Disorder too. 3. Regarding pattern identification, Hwa-Byung is positively correlated to deficiency of Heart(心). and then to stagnancy of Liver-Gall bladder. Hwa-Byung is correlated deficiency symptom-complex rather than excessiveness symptom-complex. That is also correlated positively to Pathological heat and fire. 4. In SCL90-R, the mean of PSDI was $(75.3{\pm}10.7;\:Mean{\pm}SD)$. The each mean of the other 11 factors was distributed between50-70. 5. The mean of HRSD was $(17.9{\pm}5.6;\:Mean{\pm}SD)$ in the entire subject's group. Then the group of MDD was $20.9{\pm}4.4$ and the group of USD was $12.0{\pm}4.8$ 6. In the results of HRV. the mean of TP is $972.4{\pm}1174(Mean{\pm}SD)$, this is lower than normal range 1000-200. The other factors were within normal range. Then, there were no significant differences between them (p<0.05). 7. The temperatures of each acupoint have significant differences between HNl(印堂) and PC6(內關), between CV17(顫中) and PC6(內關), between HN1(印堂) and CV8(神闕), between CV17(顫中) and CV8(神闕) in comparison with the average of body temperature in the use of D.I.T.I. (p<0.01) 8. In the analysis of correlation between SCL-90-R, HRSD, HRV. and D.I.T.I. there were no significant results. According to results that the correlation was analyzed with only the MDD group as subjects, there was negative correlation between RMSSD of HRV and HRSD, between LF of HRV and PDSIof SCL-90-R, and between LF/HF of HRV and ANX, PSY, and PDSI of SCL-90-R. Conclusion : In the observation of clinical features of 30 cases of Hwa-Byung patients by using diverse structured tests, there could make diverse diagnosis as depressive disorder, anxiety disorder, and Somatoform Disorder. Particularly. MDD was highly distributed. Considering oriental medicine's pattern identification of Hwa-Byung, this syndrome is related strongly to Heart, and there were demonstrated deficiency symptom-complex, and Pathological heat and fire. One of the limits of this study is lack of control subject's group, therefore, in the future study, it requires reexamination through a comparative research with these data to complete this study.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.97-104
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• 2014

This study was aimed to compare the radiopacity of four kinds of currently available resin based implant cements using digital radiography. Materials and Methods: Four resin-based implant cements((Estemp $Implant^{TM}$ (Spident, Incheon, Korea), $Premier^{(R)}$Implant (Premier, Pennsylvania, USA), $Cem-Implant^{TM}$ (B.J.M lab, Or-yehuda, Israel), $InterCem^{TM}$ (SCI-PHARM, California, USA)) and control group (Elite Cement $100^{TM}$ (GC, Tokyo, Japan) ) were mixed and cured according to the manufacturer's instructions on the custom made split-type metal mold. A total of 150 specimens of each cement were prepared and each specimen (purity over 99%) was placed side-by-side with an aluminum step wedge for image taking with Intraoral X-ray unit (Esx, Vatech, Korea) and digital X-ray sensor (EzSensor, Vatech, Korea). For the evaluation of aluminum wedge equivalent thickness (mm Al), ImageJ 1.47 m (Wayne Rasband, National Institutes of Health, USA) and Color inspector 3D ver 2.0 (Interaktive Visualisierung von Farbraumen, Berlin, Germany) programs were used. Result: Among the 5 cements, Elite cement $100^{TM}$ (control group) showed the highest radio-opacity in all thickness. In the experimental group, $InterCem^{TM}$ had the highest radio-opacity followed by $Premier^{(R)}$ Implant $Cement^{TM}$, $Cem-Implant^{TM}$ and Estemp $Implant^{TM}$. In addition, $InterCem^{TM}$ showed radio-opacity that met the ISO No. 4049 standard in all the tested specimen thickness. Cem-Implant on 0.5 mm thickness showed radiopacity that met the ISO No. 4049 standard. Conclusion: Among the implant resin-based cements tested in the study, $Premier^{(R)}$ Implant Cement and Estemp $Implant^{TM}$ did not show appropriate radio-opacity. Only $InterCem^{TM}$ and $Cem-Implant^{TM}$ 0.5 mm specimen had the proper radiopacity and met the experiment standard.

• Journal of Korean Neurosurgical Society
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• v.30 no.2
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• pp.131-136
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• 2001

Object : The clinical uses of screws are increasing with broader applications in spinal disorders. When screws are inserted repeatedly to achieve optimal position, tips of screw pitch may become damaged during insertion even though there are significant differences in the moduli of elasticity between bone and titanium. The effect of repeated screw insertion on pullout resistance was investigated. Methods : Three different titanium screws(cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw) were inserted into the synthetic cancellous material and then extracted axially at a rate of 2.4mm/min using Instron(Model TT-D, Canton, MA). Each set of screws was inserted and pulled out three times. There were six screws in each group. The insertional torque was measured with a torque wrench during insertion. Pullout strength was recorded with a digital oscilloscope. Results : The mean pullout force measurements for the cortical lateral mass screws($185.66N{\pm}42.60$, $167.10N{\pm}27.01$ and $162.52 N{\pm}23.83$ for first, second and third pullout respectively : p=0.03) and the cervical vertebral body screws($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024) showed consecutive decrease in pullout resistance after each pullout, whereas the cancellous lateral mass screws did not($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and 199.49N(36.63 : p=0.24). The SEM after insertion and pullout three times showed a blunting in the tip of the screw pitch and a smearing of the screw surface. Conclusions : Repetitive screw insertion and pullout resulted in the decrease of pullout resistance in certain screws possibly caused by blunting the screw tip. This means screw tips suffer deformations during either repeated insertion or pullout. Thus, the screws that have been inserted should not be used for the final construct.