• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.150-154
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• 2013

Objective : To evaluate the effect of electromagnetic (EM) navigation system on ventriculoperitoneal (VP) shunt failure rate through comparing the result of standard shunt placement. Methods : All patients undergoing VP shunt from October 2007 to September 2010 were included in this retrospective study. The first group received shunt surgery using EM navigation. The second group had catheters inserted using manual method with anatomical landmark. The relationship between proximal catheter position and shunt revision rate was evaluated using postoperative computed tomography by a 3-point scale. 1) Grade I; optimal position free-floating in cerebrospinal fluid, 2) Grade II; touching choroid or ventricular wall, 3) Grade III; tip within parenchyma. Results : A total of 72 patients were participated, 27 with EM navigated shunts and 45 with standard shunts. Grade I was found in 25 patients from group 1 and 32 patients from group 2. Only 2 patients without use of navigation belonged to grade III. Proximal obstruction took place 7% in grade I, 15% in grade II and 100% in grade III. Shunt revision occurred in 11% of group 1 and 31% of group 2. Compared in terms of proximal catheter position, there was growing trend of revision rate according to increase of grade on each group. Although infection rate was similar between both groups, the result had no statistical meaning (p=0.905, chi-square test). Conclusion : The use of EM navigation in routine shunt surgery can eliminate poor shunt placement resulting in a dramatic reduction in failure rates.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.529-539
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• 1999

This paper suggests a new image analysis method and indoor navigation control algorithm of mobile robots using a mono vision system. In order to reduce the positional uncertainty which is generated as the robot travels around the workspace, we propose a new visual landmark recognition algorithm with 2-D graph world model which describes the workspace as only a rough plane figure. The suggested algorithm is implemented to our mobile robot and experimented in a real corridor using extended Kalman filter. The validity and performance of the proposed algorithm was verified by showing that the trajectory deviation error was maintained under 0.075m and the position estimation error was sustained under 0.05m in the resultant trajectory of the navigation.

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.65-70
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• 2009

In-vehicle route guidance information(RGI) systems have been developed with the advancement of the information and communication technologies. However, the RGI is provided by a pre-determined option, drivers occasionally pass the target intersection owing to non- or late- recognizing it. The purpose of this experiment is to examine the position of driver's tum signal operation and intersection recognition approaching at the target intersection which is difficult to identify as a preliminary research on developing the additional RGI connecting with the tum signal control. The field experiment was conducted to measure distances of the turn signal operation and intersection recognition from the target intersection according to driving lanes and landmarks at adjacent intersection. And, glance behavior to the car navigation display was evaluated by using an eye camera. The results indicate that drivers operate the turn signal after confirming a landmark in the case of the intersection with it. However, most case of driving, drivers operate the tum signal at 40 to 50m before coming to the target. To provide the additional RGI, when drivers do not operate the tum signal approaching at the target intersection based on the results, is expected to improve the traffic safety and the comfort for drivers.

• Culinary science and hospitality research
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• v.14 no.2
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• pp.293-302
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• 2008

The objective of this study is to suggest development methods of marine tour complexes by specializing and modernizing the renowned Jagalchi Fish Market. This study tries to suggest the ways of overcoming limitations of the traditional market place and making a unique tourism destination with affluent attractive culture elements. To preserve its position as the most famous fish market in Korea, Jagalchi market needs to more differentiate its position over competitors. To do that, it needs to avoid over-lapping of product categories among different sectors and specializing each zone according to the assigned theme. Improving tourism environments by expanding entertaining aspects, building landmark facilities and a seaside park, and tourism infrastructures. In addition, the development scheme needs to be planned unified with other city development plans to create a unified image, and a connection program with other tourism resources surrounding the target area needs to be created in order to pursue synergy effects. In the aspect of food, a large seafood center which offers various seafood from all around the world, a traditional night market street, various theme restaurants can be suggested. Successful development of the Jagalchi marine tour complexes not only has ripple effects on the region's culture, society, and other related industries but directly influences related regional tourism and commercial industry.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.75-81
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• 2001

This project provides designs for renewal of the surrounding environment related to old fountains typically located in cities. In many cities, the fountain element has bee located with a strategic position in the city. Located in the central area of Cheongju, the Sajik Fountain Fountain has significant position in the local city. However, due to changes in the surrounding area and the old-fashioned form of the fountain, it has not contributed substantially to the cityscape. Including the historical Seomoon Bridge and Moosim-Cheon(stream) as Wooam-San(mountain) setting, the surrounding environment of our planning site appear to be a locally important place. In respect to building with a broad function, landscape designers focused on the reconsideration of symbolization as landmark, of the image of Cheongju city, of recognition by removing the horizontal line and of the substantial civil´s use rate. Achieved by working with a sculptor, a new function, the main facility, is managed sculpturally and imaged in a drop of water representing clear, fresh Cheongju city. This plan introduces the image of Wooam-San, Moosim-Cheon(stream), Sangdang-SanSung(A mountain fortress) and elicit a sense of peace, symbolic of Cheongju. The significance of this project is that as the current cities are increasingly developed, small areas left alone in city are reconsidered and offered to the public as efficient, resting and active outdoor space.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.108-118
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• 2017

This paper presents experimental results of realtime sonar-based SLAM (simultaneous localization and mapping) using probability-based landmark-recognition. The sonar-based SLAM is used for navigation of underwater robot. Inertial sensor as IMU (Inertial Measurement Unit) and DVL (Doppler Velocity Log) and external information from sonar image processing are fused by Extended Kalman Filter (EKF) technique to get the navigation information. The vehicle location is estimated by inertial sensor data, and it is corrected by sonar data which provides relative position between the vehicle and the landmark on the bottom of the basin. For the verification of the proposed method, the experiments were performed in a basin environment using an underwater robot, yShark.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.183-194
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• 2009

In this paper, we propose a new method for detecting objectionable images with an active shape model. Our method first learns the shape of breast lines through principle component analysis and alignment as well as the distribution of intensity values of corresponding landmarks, and then extracts breast lines with the learned shape and intensity distribution. To accurately select the initial position of active shape model, we obtain parameters on scale, rotation, and translation. After positioning the initial location of active shape model using scale and rotation information, iterative searches are performed. We can identify adult images by calculating the average of the distance between each landmark and a candidate breast line. The experiment results show that the proposed method can detect adult images effectively by comparing various results.

• Radiation Oncology Journal
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• v.37 no.1
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• pp.43-50
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• 2019

Purpose: The aim of this retrospective study was to investigate the use of a radiopaque tissue fiducial marker (TFM) in the treatment of prostate cancer patients who undergo post-prostatectomy radiotherapy (PPRT). TFM safety, its role and benefit in quantifying the set-up uncertainties in patients undergoing PPRT image-guided radiotherapy were assessed. Materials and Methods: A total of 45 consecutive PPRT patients underwent transperineal implantation of TFM at the level of vesicourethral anastomosis in the retrovesical tissue prior to intensity-modulated radiotherapy. Prostate bed motion was calculated by measuring the position of the TFM relative to the pelvic bony anatomy on daily cone-beam computed tomography. The stability and visibility of the TFM were assessed in the initial 10 patients. Results: No postoperative complications were recorded. A total of 3,500 images were analysed. The calculated prostate bed motion for bony landmark matching relative to TFM were 2.25 mm in the left-right, 5.89 mm in the superior-inferior, and 6.59 mm in the anterior-posterior directions. A significant 36% reduction in the mean volume of rectum receiving 70 Gy (rV₇₀) was achieved for a uniform planning target volume (PTV) margin of 7 mm compared with the Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group recommended PTV margin of 10 mm. Conclusion: The use of TFM was safe and can potentially eliminate set-up errors associated with bony landmark matching, thereby allowing for tighter PTV margins and a consequent favourable reduction in dose delivered to the bladder and rectum, with potential improvements in toxicities.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.274-278
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• 2005

Purpose : Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. Material and Methods : 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. Results : 1. Upper lip setback movement. Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84%(p=0.001). 2. Upper lip downward movement. Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). Conclusion : The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.

• The korean journal of orthodontics
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• v.51 no.2
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• pp.77-85
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• 2021

Objective: To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks. Methods: The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction. Results: The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm. Conclusions: Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.