• Radiation Oncology Journal
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• v.16 no.1
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• pp.71-79
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• 1998

Purpose : The objective of this study is to introduce our installation of a non-commercial 3D Planning system, Plunc and confirm it's clinical applicability in various treatment situations. Materials and Methods : We obtained source codes of Plunc, offered by University of North Carolina and installed them on a Pentium Pro 200MHz (128MB RAM, Millenium VGA) with Linux operating system. To examine accuracy of dose distributions calculated by Plunc, we input beam data of 6MV Photon of our linear accelerator(Siemens MXE 6740) including tissue-maximum ratio, scatter-maximum ratio, attenuation coefficients and shapes of wedge filters. After then, we compared values of dose distributions(Percent depth dose; PDD, dose profiles with and without wedge filters, oblique incident beam, and dose distributions under air-gap) calculated by Plunc with measured values. Results : Plunc operated in almost real time except spending about 10 seconds in full volume dose distribution and dose-volume histogram(DVH) on the PC described above. As compared with measurements for irradiations of 90-cm 550 and 10-cm depth isocenter, the PDD curves calculated by Plunc did not exceed $1\%$ of inaccuracies except buildup region. For dose profiles with and without wedge filter, the calculated ones are accurate within $2\%$ except low-dose region outside irradiations where Plunc showed $5\%$ of dose reduction. For the oblique incident beam, it showed a good agreement except low dose region below $30\%$ of isocenter dose. In the case of dose distribution under air-gap, there was $5\%$ errors of the central-axis dose. Conclusion : By comparing photon dose calculations using the Plunc with measurements, we confirmed that Plunc showed acceptable accuracies about $2-5\%$ in typical treatment situations which was comparable to commercial planning systems using correction-based a1gorithms. Plunc does not have a function for electron beam planning up to the present. However, it is possible to implement electron dose calculation modules or more accurate photon dose calculation into the Plunc system. Plunc is shown to be useful to clear many limitations of 2D planning systems in clinics where a commercial 3D planning system is not available.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.418-421
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• 2007

It is important to maintain information by application or 3D modeling through the satellite and UAV image which is a real world. The prevention business has recognized the need for accurate 3-D geospatial information around the disaster region to identify objects to 3D modeling. In this paper, we presented an approach to create 3D model and loading, processing the image using GIS techniques, and the digital topographic maps were used for the DEM and the features of the area. The result is a implementation of the simple application that illustrates the objects in 3-D. The presented approach will be used for identifying objects and assisting in regional planning around the airfields.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.191-197
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• 2013

Conventional CT and MRI scans produce cross-section slices of body that are viewed sequentially by radiologists who must imagine or extrapolate from these views what the 3 dimensional anatomy should be. By using sophisticated algorithm and high performance computing, these cross-sections may be rendered as direct 3D representations of human anatomy. The 2D medical image analysis forced to use time-consuming, subjective, error-prone manual techniques, such as slice tracing and region painting, for extracting regions of interest. To overcome the drawbacks of 2D medical image analysis, combining with medical image processing, 3D visualization is essential for extracting anatomical structures and making measurements. We used the gray-level thresholding, region growing, contour following, deformable model to segment human organ and used the feature vectors from texture analysis to detect harmful cancer. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR and CT image data. The 3D visualization of human anatomy and segmented human organ provides valuable benefits for radiation treatment planning, surgical planning, surgery simulation, image guided surgery and interventional imaging applications.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.201-207
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• 2018

Purpose: To develop the reliability growth planning for a subsystem of guided weapon system using PM2-Continuous model. Methods: The target MTBF of the subsystem is set by allocating the system target MTBF to the lower level, where ARINC method is applied. Other model parameters such as initial MTBF, management strategy ratio and average fix effectiveness factor are chosen from historical growth parameter estimates. Given the values of model parameters, the reliability growth planning curve using PM2-Continuous model is constructed and the sensitivity analyses are performed for the changes of model parameters. Results: We have developed the reliability growth plan for a subsystem of guided weapon system using PM2-Continuous model. It was found that the smaller the ratio of initial MTBF to target MTBF, the smaller the management strategy ratio, the smaller the average fix effectiveness factor, and the shorter the development test period, the higher reliability growth is required. Conclusion: The result of this study will be used as a basis for establishing the reliability growth plan, the test period setting and the budget appropriation for the similar system entering the system development stage in the future.

• Journal of The Korea Institute of Healthcare Architecture
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• v.13 no.2
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• pp.27-36
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• 2007

Recently, hospital patients experience anxiety, confusion, and stress about wayfinding as the spacial layout and treatment circulatory system of hospitals have become complicated due to their oversized and complex structure. As part of finding a solution to the problem, this study seeks to examine what are the essential elements of the wayfinding planning of O.P.D. in general hospitals, to develop the model of wayfinding, and to suggest the methods of improving the wayfinding system. The research methods of this study adopted were literature review in wayfinding cognition, plan analysis of ten general hospitals, space analysis of these hospitals through space syntax, analysis of the system of visual-perceptual information through a field study, and analysis of surveys and follow-up surveys conducted to support the results. Based on these results, the proposals for finding decision points, providing the information, and developing a model planning are listed as follows. 1) The comprehensive understanding of O.P.D. spacial layout and the visual-perceptual information system is necessary to find the essential elements of wayfinding. 2) The decision points are found through the full understanding of spacial functions, circulation systems, and facility configuration, considering the spacial layout, the bound of the visual-perceptual information system, and the circulatory system. Furthermore, the information decision points could be confined by space syntax. 3) The checklist and color compound & color codes, developed through the planning of signage system and color system could be applied to the methods of providing the information. 4) The planning of wayfinding system according to the whole process of practices for outpatients was mentioned above. The system of visual-perceptual information developed through the process of this study should be integrated in the spacial layout of the whole O.P.D.

• Progress in Medical Physics
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• v.28 no.1
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• pp.27-32
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• 2017

We investigated the effect of a commercial iterative reconstruction technique (iDose, Philips) on the image quality and the dose calculation for the treatment plan. Using the electron density phantom, the 3D CT images with five different protocols (50, 100, 200, 350 and 400 mAs) were obtained. Additionally, the acquired data was reconstructed using the iDose with level 5. A lung phantom was used to acquire the 4D CT with the default protocol as a reference and the low dose (one third of the default protocol) 4D CT using the iDose for the spine and lung plans. When applying the iDose at the same mAs, the mean HU value was changed up to 85 HU. Although the 1 SD was increased with reducing the CT dose, it was decreased up to 4 HU due to the use of iDose. When using the low dose 4D CT with iDose, the dose change relative to the reference was less than 0.5% for the target and OARs in the spine plan. It was also less than 1.1% in the lung plan. Therefore, our results suggests that this dose reduction technique is applicable to the 4D CT image acquisition for the radiation treatment planning.

• The Journal of the Korean dental association
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• v.50 no.11
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• pp.660-669
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• 2012

We describes the process of 3D virtual treatment planning and of CAD/CAM for surgical splint in orthognathic surgery. The potential benefits and disadvantages of 3D virtual approach and the use of CAD/CAM system for the treatment of the patient with a maxillofacial deformity are discussed. For the more convenient applications,3D software should be improved.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.272-277
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• 2005

Initial mixing characteristics in near field regions were analyzed by FLOW-3D, for analyzing mixing behavior of submerged discharge from freshwater lake in sea water. FLOW-3D model was applied to the region near Geum-ho dike for its verification. Simulation results from FLOW-3D were compared to the observed data for the verification periods. FLOW-3D showed resonable prediction results compared to the observed data, except underestimation in area near outfall. Particularly, FLOW-3D showed a good prediction for movement of buoyancy jets. In addition, FLOW-3D model was applied to the region near Saemangeum dike, which is to be constructed in near future. It was expected that the results of model application to Saemangeum area could provide substantial information in planning submerged discharge facilities. Based on the model applications to Saemangeum area, it was recommended that outfall should be located to the distance which gave an enough depth of outfall from water surface.

• Archives of Plastic Surgery
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• v.47 no.5
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• pp.428-434
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• 2020

Background Three-dimensional (3D) model printing improves visualization of anatomical structures in space compared to two-dimensional (2D) data and creates an exact model of the surgical site that can be used for reference during surgery. There is limited evidence on the effects of using 3D models in microsurgical reconstruction on improving clinical outcomes. Methods A retrospective review of patients undergoing reconstructive breast microsurgery procedures from 2017 to 2019 who received computed tomography angiography (CTA) scans only or with 3D models for preoperative surgical planning were performed. Preoperative decision-making to undergo a deep inferior epigastric perforator (DIEP) versus muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flap, as well as whether the decision changed during flap harvest and postoperative complications were tracked based on the preoperative imaging used. In addition, we describe three example cases showing direct application of 3D mold as an accurate model to guide intraoperative dissection in complex microsurgical reconstruction. Results Fifty-eight abdominal-based breast free-flaps performed using conventional CTA were compared with a matched cohort of 58 breast free-flaps performed with 3D model print. There was no flap loss in either group. There was a significant reduction in flap harvest time with use of 3D model (CTA vs. 3D, 117.7±14.2 minutes vs. 109.8±11.6 minutes; P=0.001). In addition, there was no change in preoperative decision on type of flap harvested in all cases in 3D print group (0%), compared with 24.1% change in conventional CTA group. Conclusions Use of 3D print model improves accuracy of preoperative planning and reduces flap harvest time with similar postoperative complications in complex microsurgical reconstruction.

• The korean journal of orthodontics
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• v.43 no.2
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• pp.62-73
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• 2013

Objective: The purpose of this study was to assess new three-dimensional (3D) cephalometric variables, and to evaluate the relationships among skeletal and dentoalveolar variables through 3D cephalometric analysis. Methods: Cone-beam computed tomography (CBCT) scans were acquired from 38 young adults (18 men and 20 women; $22.6{\pm}3.2$ years) with normal occlusion. Thirty-five landmarks were digitized on the 3D-rendered views. Several measurements were obtained for selected landmarks. Correlations among different variables were calculated by means of Pearson's correlation coefficient values. Results: The body of the mandible had a longer curve length in men ($102.3{\pm}4.4$ mm) than in women ($94.5{\pm}4.7$ mm) (p < 0.001), but there was no significant difference in the maxillary basal curve length. Men had significantly larger facial dimensions, whereas women had a larger gonial angle ($117.0{\pm}4.0$ vs. $113.8{\pm}3.3$; p < 0.001). Strong-to-moderate correlation values were found among the vertical and transverse variables (r = 0.71 to 0.51). Conclusions: The normative values of new 3D cephalometric parameters, including the maxillary and mandibular curve length, were obtained. Strong-to-moderate correlation values were found among several vertical and transverse variables through 3D cephalometric analysis. This method of cephalometric analyses can be useful in diagnosis and treatment planning for patients with dentofacial deformities.