• Title/Summary/Keyword: 3D(three-dimensional)

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Reproducibility of asymmetry measurements of the mandible in three-dimensional CT imaging (전산화단층사진을 이용한 하악골 3차원 영상에서 비대칭진단 계측항목의 재현도에 관한 연구)

  • Kim, Go-Woon;Kim, Jae-Hyung;Lee, Ki-Heon;Bwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.38 no.5
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    • pp.314-327
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    • 2008
  • Objective: The purpose of this study was to evaluate the reproducibility of measurements representing asymmetry of the mandible and to identify which landmarks would be more useful in 3-dimensional (3D) CT imaging. Methods: Facial CT images were obtained from forty normal occlusion individuals. Eighteen landmarks were established from the condyle, gonion, and menton areas, and 25 measurements were constructed to represent asymmetry of the mandible; 8 for ramus length, 12 for mandibular body length, 1 for condylar neck length, 2 for frontal ramal inclination, and 2 for lateral ramal inclination. Inter- and intra-examiner reproducibility of the measurements was evaluated. Results: Inter-examiner reproducibility of the measurements proved to be high except for 3 measurements. Intra-examiner reproducibility also proved to be high except for 2 measurements. Inter- and intra-examiner reproducibility of the measurements including Gonion proved to be low. Conclusions: The results of the present study indicate that the landmarks and measurements constructed in 3D CT images can be used for the diagnosis of facial asymmetry.

Performances and Electrical Properties of Vertically Aligned Nanorod Perovskite Solar Cell

  • Kwon, Hyeok-Chan;Kim, Areum;Lee, Hongseuk;Lee, Eunsong;Ma, Sunihl;Lee, Yung;Moon, Jooho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.429-429
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    • 2016
  • Organolead halide perovskite have attracted much attention over the past three years as the third generation photovoltaic due to simple fabrication process via solution process and their great photovoltaic properties. Many structures such as mesoporous scaffold, planar heterojunction or 1-D TiO2 or ZnO nanorod array structures have been studied to enhance performances. And the photovoltaic performances and carrier transport properties were studied depending on the cell structures and shape of perovskite film. For example, the perovskite cell based on TiO2/ZnO nanorod electron transport materials showed higher electron mobility than the mesoporous structured semiconductor layer due to 1-D direct pathway for electron transport. However, the reason for enhanced performance was not fully understood whether either the shape of perovskite or the structure of TiO2/ZnO nanorod scaffold play a dominant role. In this regard, for a clear understanding of the shape/structure of perovskite layer, we applied anodized aluminum oxide material which is good candidate as the inactive scaffold that does not influence the charge transport. We fabricated vertical one dimensional (1-D) nanostructured methylammonium lead mixed halide perovskite (CH3NH3PbI3-xClx) solar cell by infiltrating perovskite in the pore of anodized aluminum oxide (AAO). AAO template, one of the common nanostructured materials with one dimensional pore and controllable pore diameters, was successfully fabricated by anodizing and widening of the thermally evaporated Al film on the compact TiO2 layer. Using AAO as a scaffold for perovskite, we obtained 1-D shaped perovskite absorber, and over 15% photo conversion efficiency was obtained. I-V measurement, photoluminescence, impedance, and time-limited current collection were performed to determine vertically arrayed 1-D perovskite solar cells shaped in comparison with planar heterojunction and mesoporous alumina structured solar cells. Our findings lead to reveal the influence of the shape of perovskite layer on photoelectrical properties.

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A THREE DIMENSIONAL FINITE ELEMENT STRESS ANALYSIS OF SINGLE IMPLANT PROSTHESES ACCORDING TO THE HEX-LOCK TYPE (단일 임플랜트 보철물의 Hex-lock 형태에 따른 3차원 유한요소법적 응력분석)

  • Hwang, Young-Pil;Kay, Kee-Sung;Cho, Kyu-Zong
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.2
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    • pp.385-402
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    • 1996
  • The purpose of this study was to analyze how the stability of the implant prostheses and the loosening of the fastening screw was affected when the various types of Hex structure provided for the effect of anti-rotation of the single prostheses were given. Three dimensional finite element model was designed with which the implants with the external hex type of 0.75mm, 1.5mm and the implant with the internal hex type of 0.75mm, 1.5mm and the implant with the external hex type of $15^{\circ}$ tapered shape of 0.75mm were supposed to completely osseointegrate to the mandible. After fininshing the finite element model, the preload of 10N at the fastening screw was applied and then the vertical and $30^{\circ}$ lateral load of 200N was applied respectively at the cusp tips of the prostheses. The following results were obtained : 1. In case of displacement, the amount of displacement was increased at the internal hex type(model C, D) than at the external hex type(model A, B, E) when the vertical and lateral load was applied. 2. Less equivalent stress was represented at the model B with increased external hex height than at the model A when the vertical and lateral load was applied. 3. Much stress was represented at the model E with increased hex angle than at the model A in case of the stress happened to the implant body and the fastening screw when the vertical and lateral load was applied. 4. Much equivalent stress was represented at the model D with deepened internal hex height than at the model C when vertical and lateral load was applied. 5. The least stress was taken at the model B and the most stress was taken at the model D in case of the stress happened to the implant when the vertical and lateral load was applied. 6. The least stress was taken at the model C at the vertical load. And the least stress was taken at the model B at lateral load in case of the stress happened to the fastening screw. As a results of this study, the good lateral stability of prostheses and less stress of the component of implant was taken when the external hex height was increased, and the risk of neck fracture of implant and fastening screw was increased when the internal hex height was deepned because of long screw neck portion and thin implant neck portion.

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Comparison of Diagnostic Accuracy of Three-Dimensional MR Cholangiopanceatography and ERCP in Various Extrahepatic Biliary Lesions (여러 간외담도 질환에서 삼차원적 자기공명 췌담관 조영술과 내시경적 역행성 췌담관 조영술과의 비교: 진단적 정확성을 중심으로)

  • 김경숙;이문규;김명환;이승규;김표년;오용호
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.148-153
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    • 1997
  • Purpose: To evaluate the diagnostic role of a three-dimensional MR cholangiopancreatography (MRCP) over endoscopic retrograde cholangio-pancreatography (ERCP) in various extrah-epatic biliary disease. Materials and Methods: MRCP and ERCP were performed in 45 consecutive patients with suspected extrahepatic biliary diseases. MRCP was obtained using a reverse fast imaging with a steady-state free precession (reverse FISP: PSIF) sequence, and then images were reconstructed by standard MIP algorithm. The predictability of biliary dilatation and level of obstruction of MRCP was evaluated using ERCP as a gold standard. The accuracy distinguishing malignant from benign lesions, and overall diagnostic accuracy were compared between MRCP and ERCP. Results: The sensitivity, specificity and accuracy of MRCP in predicting biliary dilatation were 94.6%, 75.0% and 91.1%, respectively. The level of obstruction was accurate in 87.0% with MRCP. The sensitivity, specificity and accuracy of MRCP and ERCP in distinguishing malignant from benign lesions were 76.2%, 87.5% and 82.2% and 71.4%, 83.3% and 77.8%, respectively. The overall diagnostic accuracy was 60.0% with MRCP and 55.6% with ERCP. Conclusion: 3D MRCP shows a good diagnostic value compared to that of ERCP, and can replace a ERCP.

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Results of Three-Dimensional Conformal Radiation Therapy for the Treatment of a Solitary Sternal Relapse of Breast Cancer (흉골에 단독 전이된 유방암의 삼차원 입체조형 방사선 치료 성적)

  • Kim, Hae-Young;Huh, Seung-Jae;Park, Won;Choi, Do-Ho;Kang, Min-Kyu;Yang, Jung-Hyun;Nam, Seok-Jin;Im, Young-Hyuck
    • Radiation Oncology Journal
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    • v.26 no.2
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    • pp.91-95
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    • 2008
  • Purpose: To evaluate the response and survival rate after three-dimensional conformal radiation therapy(3D-CRT) of patients with a solitary sternal relapse of breast cancer. Materials and Methods: Seventeen patients between May 1996 and June 2005 were evaluated with the salvage 3D-CRT treatment of a solitary sternal relapse of breast cancer. The treatment fields included the gross tumor volume with 2 cm margins. The total radiation dose was $35.0{\sim}61.5$ Gy(biologic effective dose of $43.7{\sim}76.9Gy_{10}$ using an $\alpha/\beta$ ratio of 10 Gy), with a daily dose of $1.8{\sim}3.0$ Gy. The tumor response was evaluated by the change in maximum tumor size via follow up CT scans $1{\sim}3$ months after the completion of treatment. Results: An objective tumor response was achieved in all patients, with a complete response in 5 patients and a partial response in 12 patients. The 5-year overall survival rate was 51.9%(median survival time: 27 months), and the most important factor affecting overall survival was the disease-free interval(interval from primary surgery of breast cancer to the development of sternal metastasis): The 5-year overall survival rate was 61.8% for patients with a disease-free interval ${\geq}12$ months and 0.0% for patients with disease-free interval <12 months(p=0.03). Conclusion: The response to 3D-CRT was good in patients with solitary sternal relapse of breast cancer. Particularly, patients with long disease-free interval from primary surgery survived significantly longer than patients with short disease-free interval from primary surgery.

A Design for Extension Codec based on Legacy Codec (레거시 코덱 기반 확장 코덱 설계)

  • Young, Su Heo;Bang, Gun;Park, Gwang Hoon
    • Journal of Broadcast Engineering
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    • v.20 no.4
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    • pp.509-520
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    • 2015
  • A design for the merge mode of three dimensional High Efficiency Video Coding (3D-HEVC) is proposed in this paper. The proposed design can reduce the implementation complexity by removing the duplicated modules of the HEVC. For the extension codec, the implementation complexity is as crucial as coding efficiency, meaning if possible, extension codec needs to be easily implemented through by reusing the design of the legacy codec as-is. However, the existing merging process of 3D-HEVC had been built-in integrated in the inside of the HEVC merging process. Thus the duplicated merging process of HEVC had to be fully re-implemented in the 3D-HEVC. Consequently the implementation complexity of the extension codec was very high. The proposed 3D-HEVC merge mode is divided into following two stages; the process to reuse the HEVC modules without any modification; and the reprocessing process for newly added and modified merging modules in 3D-HEVC. By applying the proposed method, the re-implemented HEVC modules, which accounted for 51.4% of 3D-HEVC merge mode confirmed through the operational analysis of algorithm, can be eliminated, while maintaining the same coding efficiency and computational complexity.

Preparation of Flexible 3D Porous Polyaniline Film for High-Performance Electrochemical pH Sensor (고성능 전기 화학 pH 센서를 위한 유연한 3차원 다공성 폴리아닐린 필름 제조)

  • Park, Hong Jun;Park, Seung Hwa;Kim, Ho Jun;Lee, Kyoung G.;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • v.31 no.5
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    • pp.539-544
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    • 2020
  • A three-dimensional (3D) porous polyaniline (PANI) film was fabricated by a combined photo-and soft-lithography technique based on a large-area nanopillar array, followed by a controlled chemical dilute polymerization. The as-obtained 3D PANI film consisted of hierarchically interconnected PANI nanofibers, resulting in a 3D hierarchical nanoweb film with a large surface and open porous structure. Using electrochemical measurements, the resulting 3D PANI film was demonstrated as a flexible pH sensor electrode, exhibiting a high sensitivity of 60.3 mV/pH, which is close to the ideal Nernstian behavior. In addition, the 3D PANI electrode showed a fast response time of 10 s, good repeatability, and good selectivity. When the 3D PANI electrode was measured under a mechanically bent state, the electrode exhibited a high sensitivity of 60.4 mV/pH, demonstrating flexible pH sensor performance.

Numerical Study on the Side-Wind Aerodynamic Forces of Chambered 3-D Thin-Plate Rigid-Body Model (캠버가 있는 3차원 박판 강체 모형의 측풍 공기력에 대한 수치 연구)

  • Shin, Jong-Hyeon;Chang, Se-Myong;Moon, Byung-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.2
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    • pp.97-108
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    • 2015
  • In the design of sailing yachts, para-glider, or high-sky wind power, etc., the analysis of side-wind aerodynamic forces exerted on a cambered 3-D model is very important to predict the performance of various machinery systems. To understand the essential flow physics around the three-dimensional shape, simplified rigid-body models are proposed in this study. Four parameters such as free stream velocity, angle of attack, aspect ratio, and camber are considered as the independent variables. Lift and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization of post-processed flow fields are analyzed in the viewpoint of fluid dynamics.

Development of 3-D Flow Model for Porous Media with Scenario-based Ground Excavation (지반굴착 시나리오 기반의 다공성 매질에 대한 3차원 유동해석모델 구축)

  • Cha, Jang-Hwan;Lee, Jae-Young;Kim, Woo-Seok
    • Journal of Korean Society of Disaster and Security
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    • v.10 no.1
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    • pp.19-27
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    • 2017
  • In recent years, ground subsidence has been frequently occurred by underground cavities due to the excessive groundwater inflow, caused by poor construction and management, during tunnel excavation and underground structure construction. In this study, a numerical model (SEEFLOW3D) was developed to estimate groundwater fluctuations for saturated-unsaturated poros media, evaluates the impact on ground excavation with open cut and non-open cut scenarios. In addition, the visual MODFLOW was applied to demonstrate the verification of the model compared with both results. Our results indicated that the RMSE and NRMSE was obtained to range over -3.95~5.7% and 0.56~4.62%, respectively. The developed model was expected to estimate groundwater discharges and apply analysis tool for optimum design of waterproof wall in future.

Laparoscopic Operation for Superior Mesenteric Artery Syndrome and Follow-up with 3-Dimensional Reconstructive CT - 1 Case Report - (상장간막동맥 증후군의 복강경 수술 및 3차원재건 복부 전산화단층촬영 영상을 이용한 추적관찰 -1예보고-)

  • Kim, Seong-Min;Kim, Sung-Hoon;Kwon, In-Kyou;Kim, Myoung-Joon;Hyoung, Woo-Jin;Choi, Seung-Hoon
    • Advances in pediatric surgery
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    • v.11 no.2
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    • pp.180-185
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    • 2005
  • Superior mesenteric artery (SMA) syndrome is a rare disorder caused by extrinsic compression of the third portion of the duodenum by the SMA. The operative treatment of choice is bypassing the obstructed duodenal segment by duodenojejunostomy. We report one case of SMA syndrome treated by laparoscopic duodenojejunostomy and followed up by 3D-reconstructive CT scan. A fifteen-year-old boy with intermittent vomiting and weight loss was admitted. Ultrasonography showed narrowing of the distance between the SMA and aorta. Hypotonic duodenography showed dilatation of duodenal third portion and barium stasis. On 3Dreconstructive CT scan, the angle between SMA and aorta was $37^{\circ}$. The postoperative course was uneventful. Three months later, he had gained 3 kg of weight and the angle between SMA and aorta increased to $38-39^{\circ}$ on 3D reconstructive CT scan. Laparoscopic duodenojejunostomy for bypassing the obstructive duodenum in SMA syndrome is a feasible and safe method.

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