• Title/Summary/Keyword: Point Landmark

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Study on Characteristics of Visual-Perception by Presence of Object in Exhibition Hall (전시공간 홀에서 대상체의 유무에 따른 시지각 특성 연구)

  • Choi, Gae-Young
    • Korean Institute of Interior Design Journal
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    • v.26 no.6
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    • pp.106-115
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    • 2017
  • This study has analysed the characteristics of observation by presence of objects in exhibition spaces through eye-tracking. The area with prevailing observation by the change of observation time with visual-perception response to the presence of objects has been analyzed to figure out the mechanism of sensibility estimation which can take place while the visual-perception is being estimated in spaces. Research results are able to ascertain that First, it was very characteristic that the signs right and left were observed more when there were no objects while when there were objects they were observed prevailingly. Second, the characteristics by section when there were any objects showed that there were more high observation scale I (more than 1000ms). When there were any objects with the number of areas where all the participants prevailed commonly, the scale was more, also. Third, in the process of acquiring any visual-perception information in spaces, the element of landmark can be regarded as a control point for space cognition, where the objects (people) became landmark when there were the objects but the signs became landmark when there were no objects. Fourth, the polynomial trend line of the changes to prevailing observation frequency by observation time shows that there was a gradual average value in general when there were any objects and then after the time range[8] the prevailing observation frequency increased. Without any objects, after a particular time range the value sharply dropped along with the increase of observation time because no objects to be observed prevailingly couln't be seen. The gradual average value means that some elements in the space were prevailingly observed all the time.

Setting the Stomach Transection Line Based on Anatomical Landmarks in Laparoscopic Distal Gastrectomy

  • Hosogi, Hisahiro;Kanaya, Seiichiro;Nomura, Hajime;Kinjo, Yousuke;Tsubono, Michihiko;Kii, Eiji
    • Journal of Gastric Cancer
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    • v.15 no.1
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    • pp.53-57
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    • 2015
  • Laparoscopic distal gastrectomy has become widespread as a treatment for early gastric cancer in eastern Asia, but a standard method for setting the stomach transection line has not been established. Here we report a novel method of setting this line based on anatomical landmarks. At the start of the operation, two anatomical landmarks along the greater curvature of the stomach were marked with ink: the proximal landmark at the avascular area between the last branch of the short gastric artery and the first branch of the left gastroepiploic artery, and the distal landmark at the point of communication between the right and left gastroepiploic arteries. Just before specimen retrieval, the stomach was transected from the center of these two landmarks toward the lesser curvature. Then, about two-third of the stomach was reproducibly resected, and gastroduodenostomy was successfully performed in 26 consecutive cases. This novel method could be used as a standard technique for setting the transection line in laparoscopic distal gastrectomy.

Verification of stereotactic target point and CT image transfer (정위적 target point 및 CT 영상전환 입증)

  • 유명진
    • Progress in Medical Physics
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    • v.10 no.1
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    • pp.47-54
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    • 1999
  • Purpose: To verify the BRW coordinates of target located within the limit of XKnife hardware, and to verify the successful transfer of image data, rod detection, anatomical structure when CT images are transferred into a XKnife computer. Materials and Methods: Target coordinates of 13 patients were calculated by SCS1 computer through the rod image on the console screen and film. BRW coordinates of target and landmark calculated by SCS1 computer were compared to those acquired by XKnife localizer. Results : Vertical components of BRW coordinates of target for 13 patients are larger than -50 mm, and then the vertical components of BRW coordinates of target are localized within the limit of XKnife hardware. Average differences between XKnife and SCS1 for BRW coordinates of target and landmark were within 1 mm for AP and LAT components, 0.5 mm for VERT component. Conclusion : It was verified that the SCS1 computer is adequate tool to calculate BRW coordinates of target quickly. And by the comparison between SCS1 computer and XKnife localizer, it was verified that the image transfer into the XKnife computer was performed successfully.

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Invasive strategies for rhythm control of atrial fibrillation: a narrative review

  • Hong-Ju Kim;Chan-Hee Lee
    • Journal of Yeungnam Medical Science
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    • v.41 no.4
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    • pp.279-287
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    • 2024
  • Atrial fibrillation (AF) is the most common sustained tachyarrhythmia and its increasing prevalence has resulted in a growing health-care burden. A recent landmark randomized trial, the EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial), highlighted the importance of early rhythm control in AF, which was previously underemphasized. Rhythm control therapy includes antiarrhythmic drugs, direct-current cardioversion, and catheter ablation. Currently, catheter ablation is indicated for patients with AF who are either refractory or intolerant to antiarrhythmic drugs or who exhibit decreased left ventricular systolic function. Catheter ablation can be categorized according to the energy source used, including radiofrequency ablation (RFA), cryoablation, laser ablation, and the recently emerging pulsed field ablation (PFA). Catheter ablation techniques can also be divided into the point-by-point ablation method, which ablates the pulmonary vein (PV) antrum one point at a time, and the single-shot technique, which uses a spherical catheter to ablate the PV antrum in a single application. PFA is known to be applicable to both point-by-point and single-shot techniques and is expected to be promising owing to its tissue specificity, resulting in less collateral damage than catheter ablation involving thermal energy, such as RFA and cryoablation. In this review, we aimed to outline catheter ablation for rhythm control in AF by reviewing previous studies.

A Study on Optimal Location Selection and Analytic Method of Landmark Element in terms of Visual Perception (시각적 측면에서 랜드마크 요소의 최적입지선정 분석방법에 관한 연구)

  • Kim, Suk-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6360-6367
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    • 2015
  • The location selection of the element that should guarantee easy visual perception, like the landmark, is the a topic that appears much in the design process. Recently, a graph analysis technique using computers has been applied in order to evaluate the visibility of the visual element, but the analytic frame is flat and the setting of the visual pont and the matrix are fixed so there were great limitations in obtaining the results of the practical analysis. Thus, this study presented Nondirectional Multi-Dimensional Calculation (MDVC-N), an analytic methodology available for the analysis of the dynamic visual point in the 3D environment. It thus attempted to establish the analytic application using the 3D computer graphics technology and designed a script structure to set the visual point and the matrix. In addition to that, this study tried to verify the analytic methodology by applying the complex land as an example model, where buildings in various heights of terrains with a high-differences are located, verifying the same analytic methodology. It thus tried to identify the visual characteristics of each alternative location. The following results were gained from the study. 1) The visibility can be measured quantitatively trough the application of the 6-alternatives. 2) Using the 3dimensional graph, intuitive analysis was possible. 3) It attempted to improve the analytic applicability by calculating the results corrected as a variable behavior from the local integration variable of the space syntax.

Three‐Dimensional Automatic Measurement Extraction Algorithms for Neck‐base Part of Females in Their Twenties (20대 여성의 목밑둘레 부위에 대한 3차원 자동 측정 알고리즘)

  • Hwang, Keun-Young;Nam, Yun-Ja;Park, Jae-Kyung
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.2
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    • pp.35-43
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    • 2005
  • The purpose of this study is to suggest computer assisted neck-base's landmark identification algorithms and measurement extraction methods from three-dimensional human scan data. So we developed the algorithms for automatic identification of landmarks related to the neck-base types. The subjects were 58 women $18{\sim}24$ years of age. Their body were measured directly and indirectly by using camera and three-dimensional body scanner. They were measured during the months of October in 2001. Based on the characters of classified neck-base types, algorithms for the automatic identification of landmarks and methods of automatic measurement are developed. The three-dimensional automatic measuring program is made by $C^{++}$ language. Using this program, 4 landmarks are identified and 6 items are measured. In the verifying the precision of automatic measurement, the height measurements(cervicale, side neck point, front neck point) were relatively accurate, but neck-base width measurement was measured wide.

Determining the Position of a Mobile Robot Using a Vanishing Point Neural Networks (소실점과 신경회로망을 이용한 이동 로봇의 위치 결정)

  • 이효진;이기성
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.11a
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    • pp.165-170
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    • 1997
  • During the navigation of mobile robot, one of the essential task if to determine the absolute position of mobile robot. In this paper, a method to determine the position of the camera using a vanishing point and neural networks without landmark if proposed. In determining the position of the camera on the world coordinate, there are differences between the real value and the calculated value because of uncertainty in pixels, incorrect camera calibration and lens distortion etc. This paper describes the solution of the above problem using BPNN(Back Propagation Neural Network) and experimental results show the capability to adapt for a mobile robot.

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A study on the establishment a point of reference for the improvement of a dweller's life environment at skyscraper (초고층 건축물의 거주자 생활환경을 위한 평가기준 개선에 관한 연구)

  • Lee, Gun;Kim, Gil-Jung;Lee, Hyun-Chul;Park, Hyeon-Ku;Go, Seong-Seok
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.04a
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    • pp.355-360
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    • 2009
  • Nowadays, the condition of overcrowded cities has raised a question which is insufficient land in cities, and has gotten worse because of the influx of the population continuously. It has rapidly constructed a skyscraper increasingly that the solution to secure a living space against these overcrowded cities until 2000, but these are already positioning itself as one of the new type of residence. The necessity of skyscraper as facilities of residence inside cities has be available both a solution for overcrowded cities and a meaning for a symbol of its represented a landmark. However, constructing skyscrapers indiscreetly can not guarantee dweller's life environment, and it contains risks unless design and facilities criteria are provided. Now, a skyscraper as a new substitute constituting a living space in the future for overcrowded cities deals with a systematic correlation between a city and construction. Therefore the aim of this study were to indicate a method for improvement of dweller's life environment at skyscraper through establishing a point of reference to inculcate them for a sustainable skyscraper from now on.

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Three-Dimensional Active Shape Models for Medical Image Segmentation (의료영상 분할을 위한 3차원 능동 모양 모델)

  • Lim, Seong-Jae;Jeong, Yong-Yeon;Ho, Yo-Sung
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.5
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    • pp.55-61
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    • 2007
  • In this paper, we propose a three-dimensional(3D) active shape models for medical image segmentation. In order to build a 3D shape model, we need to generate a point distribution model(PDM) and select corresponding landmarks in all the training shapes. The manual determination method, two-dimensional(2D) method, and limited 3D method of landmark correspondences are time-consuming, tedious, and error-prone. In this paper, we generate a 3D statistical shape model using the 3D model generation method of a distance transform and a tetrahedron method for landmarking. After generating the 3D model, we extend the shape model training and gray-level model training of 2D active shape models(ASMs) and we use the integrated modeling process with scale and gray-level models for the appearance profile to represent the local structure. Experimental results are comparable to those of region-based, contour-based methods, and 2D ASMs.

A fully deep learning model for the automatic identification of cephalometric landmarks

  • Kim, Young Hyun;Lee, Chena;Ha, Eun-Gyu;Choi, Yoon Jeong;Han, Sang-Sun
    • Imaging Science in Dentistry
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    • v.51 no.3
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    • pp.299-306
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    • 2021
  • Purpose: This study aimed to propose a fully automatic landmark identification model based on a deep learning algorithm using real clinical data and to verify its accuracy considering inter-examiner variability. Materials and Methods: In total, 950 lateral cephalometric images from Yonsei Dental Hospital were used. Two calibrated examiners manually identified the 13 most important landmarks to set as references. The proposed deep learning model has a 2-step structure-a region of interest machine and a detection machine-each consisting of 8 convolution layers, 5 pooling layers, and 2 fully connected layers. The distance errors of detection between 2 examiners were used as a clinically acceptable range for performance evaluation. Results: The 13 landmarks were automatically detected using the proposed model. Inter-examiner agreement for all landmarks indicated excellent reliability based on the 95% confidence interval. The average clinically acceptable range for all 13 landmarks was 1.24 mm. The mean radial error between the reference values assigned by 1 expert and the proposed model was 1.84 mm, exhibiting a successful detection rate of 36.1%. The A-point, the incisal tip of the maxillary and mandibular incisors, and ANS showed lower mean radial error than the calibrated expert variability. Conclusion: This experiment demonstrated that the proposed deep learning model can perform fully automatic identification of cephalometric landmarks and achieve better results than examiners for some landmarks. It is meaningful to consider between-examiner variability for clinical applicability when evaluating the performance of deep learning methods in cephalometric landmark identification.