• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.35-43
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• 2013

Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. 3D digital methods using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging have been developed for accurate shape and 3D measurements in freeform buildings. In contrast to a conventional building using auto CAD system and others, the proposed digital optimization method is based on a combination of 3D numerical data and parametric 3D model for design and construction. The objective of this paper is therefore to present digital optimization process for constructability of freeform building. The method can be useful in the effective implementation of an error-proofing process of freeform building during design and construction phase. 3D digital coordinate data can be used effectively to identify correct size of structural and finish members and installation location of each members in construction field. In addition, architects, engineers and contractors can evaluate design, materials, constructability and identify error-proofing opportunities. Other project participants can also include representatives from all levels of management, departments as well as workers and key subcontractors' personnel, if necessary. The 3D digital optimization process is therefore appropriate to serious variations in freeform shape. For future study, the developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability in construction field.

• Restorative Dentistry and Endodontics
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• v.31 no.1
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• pp.66-71
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• 2006

To evaluate the ratio of gutta-percha area in the canal after canal obturation with Continuous Wave of Condensation Technique (CWCT) with varying depths of plugger penetration, forty root canals of extracted human teeth were prepared up to size 40 of 0.06 taper with $ProFile^{(R)}$. Canals of three groups were filled with CWCT with System $B^{TM}$ (Analytic Tech. , USA) and different plugger penetration depths of 3, 5, or 7 mm from the apex. Canals of one group were filled with lateral condensation technique as a control The felled teeth were cross-sectioned at 1, 2 and 3 mm levels from the apical foramen. The ratio of gutta-percha area in the canal was analyzed using $Auto^{(R)}$ Cad 2000. Data were analyzed with one-way ANOVA and Duncan's multiple range test. At all levels, higher gutta-percha area ratio was found with deeper plugger penetration depth in CWCT, and cold lateral condensation group showed higher ratio than group of plugger penetration to apical 7 mm in CWCT. At apical 1 mm and 2 mm levels, group of plugger penetration to apical 3 mm showed significantly high or gutta-percha area ratio than those of apical 7 mm and lateral condensation (p<0.05). It is concluded therefore that, under the conditions of the present study, deeper plugger penetration depth results in more favorable and efficient obturation in CWCT.

• The Journal of Advanced Prosthodontics
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• v.5 no.1
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• pp.9-15
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• 2013

PURPOSE. The purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients. MATERIALS AND METHODS. 150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane ($OT_1$-OP), Eye-Ear plane and ala-superior border of tragus ($OT_1-AT_1$), Eye-Ear plane and ala-middle border of tragus ($OT_1-AT_2$) and Eye-Ear plane and ala-inferior border of tragus ($OT_1-AT_3$) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane ($OT_1$ or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane ($OT_1$) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant. RESULTS. The mean of base line angle i.e. $OT_1$-OP angle ($11.96{\pm}4.36$) was found to be close to $OT_1-AT_2$ angle ($13.67{\pm}1.93$) and $OT_1-AT_3$ angle ($10.31{\pm}2.03$), but $OT_1$-OP angle was found to be more closer to $OT_1-AT_3$ angle. Comparison of mean angles showed that $OT_1$-OP angle in both males (11.68) and females (12.51) is close to $OT_1-AT_3$ angle (males- 11.01, females- 11.95). CONCLUSION. The line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.20-28
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• 2006

Statement of problem: The titanium has advantages of a high biocompatibility, a corrosion resistence, low density, and cheep price, so it is focused as a substituted alloy But it is quite difficult to cast with the tranditional method due to the high melting point, reacivity with element at, elevated temperature. By using the CAD-CAM system for the crown construction, it is possible to reduce the errors while proceeding the wax-up, investing, and casting procedure Purpose: The purposes of this study were to measure the marginal adaptation of the casting titanium coping and machine-milled titanium coping according to the casting methods and the marginal configurations. Material and method: The marginal configurations were used chamfer shoulder, and beveled shoulder. The total 30 copings were used, and these are divided into 6 groups according to the manufacturing method and marginal configuration. The gap between margin of the model and the restoration was measured with 3-dimensional measuring microscope. Results: The following results were obtained; 1. casting gold coping demonstrated the best marginal seal, followed by casting titanium coping finally machine-milled titanium copings. 2. In casting titanium coping, chamfer demonstrated the best marginal seal, followed by shoulder and beveled shoulder. There was no significantly difference in shoulder and beveled shoulder. But all margin form has clinically acceptable 3. In machine-milled titanium copings, chamfer demonstrated the best marginal seal, followed by shoulder and beveled shoulder. Beveled shoulder show large and uneven marginal gap Conclusions: Above result revealed that marginal adaptation of the titanim coping is avail able in the clinical range, it can be used as an alternative metal and it is prefered especially in chamfer or shoulder margin during implant superstructure fabrication. But there should be more research on machine-milled titanium in order to use it in the clinics.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.91-106
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• 2010

Recently, interest in supply chain management is rising along with the increasing oil prices and traffic congestion. In particular, people started studying the issue, but realized that advantageous strategies for suppliers and retailers are not always advantageous to a carrier. Therefore, in this study the atuhors set up a simulation scenario to understand delivery vehicle routing problems under various inventory policies, namely Economic Order Quantity (EOQ) and Periodic Order Quantity (POQ) and network configurations. First, the authors made a virtual supply chain. Then they analyzed characteristics of delivery vehicle routing under various inventory policies (EOQ and POQ) and network configurations. As a result, the POQ inventory policy decreases the number of vehicles, the number of drivers, and the service time of vehicles. Also, the centralized network increases the load factor of vehicles and decreases the service time of vehicles. In other words, the centralized network and the POQ inventory policy are better for the carrier. These results show a savings of 15,556,806 won ($13,389.10) in a month: a reduction of 17%.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.83-88
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• 2008

Purpose: To design an anamorphic aspherical prism lens for the HMD optical system. Methods: First, we get the initial data, needed in design, which are distances between each surface etc., by analyzing user's demended specifications and by drawing geometrically the shape of prism lens by using CAD. Based on these data and using 'ode V' which is an optical design software, we could progress the optimization in which we treat the coefficients of the anamorphic aspherical surface as the principal variables. To reduce the cost in DTM manufacturing, we would optimize the optical system with the transmitting surface, existed in the direction of video device among 3 surfaces of the prism lens, remaining as a plane. Results: we could design one anamorphic aspherical prism lens which has the finite ray aberration of 15 ${\mu}m$, the distortion of 0.5%, and the MTF value of 0.3 over at 36 lp/mm for the video device of 12 mm ${\times}$ 9 mm size. Conclusions: We designed a prism lens used for HMD. This prism lens has the optical capacities of 15 ${\mu}m$ finite ray aberration and 0.5% distortion for the video device of 12 mm ${\times}$ 9 mm size, and become the optical system having the MTF value of 0.3 over at 36 lp/mm.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.617-623
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• 2012

This study was performed to measure the accuracy of different gypsum materials by a white light dental scanner. A master model with the prepared lower full arch tooth was used. The type IV and scannable stone were used for 20 stone casts (10 casts each) duplicated a master model of mandible. The distance between the reference points were measured and analyzed by the Delcam $Copycad^{(R)}$ (Delcam Plc, UK) 3D graphic software. The t-student test for paired samples were used for statistical analysis. The mean differences to master model for type IV stone and scannable stone model were 0.29~0.56 mm, and 0.17~0.35 mm, respectively. There were statistical differences in dimensional accuracy for full arch impression between the master model and type IV/scannable stone (p<0.05). Two different gypsum materials showed clinically acceptable accuracies of full arch digital impression produced by them. Besides, in both gypsum materials, the differences to the master model detected appear to provide enough accuracy for clinical application.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.439-444
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• 1993

The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.179-183
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• 2019

The system stability must be ensured from the switching noise due to the power conversion efficiency and power conversion system miniaturization. Therefore, countermeasures to reduce switching noise during power conversion are essential. Thus, in the previous paper, we constructed the DC / DC Buck Converter circuit using MPQ4432 driver of MPS, and simulated the switching noise characteristics which occurs when the components are arranged differently in the 4 - layer PCB circuit structure with reference plane. In this paper, two different simulated circuits are fabricated and the characteristics of the conducted emission and the radiated emission are analyzed in the same way as the simulation. As a result, it was confirmed that the Conducted Emission characteristic was reduced by 2 ~ 9dB in the low frequency band and 6 ~ 7dB in the high frequency band depending on the configuration of the current return path. And the radiated emission characteristic is reduced by 9 dB. Conducted emission simulation results show that 6 ~ 7dB in the low frequency range and 2 ~ 9dB in the measurement result are somewhat different. In the high frequency band, it is confirmed that the experimental and simulation results are about 7dB. And Radiated Emission confirmed 12dB decrease in simulation, but confirmed decrease of 9dB in measurement result. It is confirmed that there is a slight difference in the amount of reduction, but the design of the power conversion circuit improves the noise characteristics according to the configuration of the current return path.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.639-645
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• 2018

The objective of this research was to compare the precision of scanning the digital abutment impression and gypsum model according to 3-dimensional superimposing different skills. There were made with the abutment impression and gypsum model of a maxillary 1st premolar, blue light scanner scanned to obtain the stereolithography (STL) file. After the same process was performed 10 more times without moving them on the scanner table about the abutment impression and gypsum model, respectively (n=11, per types). By superimposing the date of scanning the abutment impression and gypsum model used with no control and best-fit-alignment skills, 10 color-difference maps and root mean square (RMS) data were obtained. The independent t-test was performed to compare RMS data between the each other groups (${\alpha}=0.05$). In the scanning abutment impressions, $RMS{\pm}SD$ of no control, best-fit-alignment showed $6.86{\pm}0.94$, $5.04{\pm}0.24$. in the scanning gypsum model, $4.98{\pm}1.16$, $3.39{\pm}0.07$, all groups showed a significant difference (P<0.001). Trough the this study's result, not only best-fit-alignment but no control is used with digital dental computer-aided design/computer-aided manufacturing (CAD/CAM) research and clinical part.