• Journal of the Korea Computer Graphics Society
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• v.10 no.4
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• pp.27-36
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• 2004

본 논문에서는 뇌의 하부구조인 해마를 정확하게 분석하기 위한 형상 정규화 방법과 정상인과 간질 환자의 해마를 분류하기 위한 방법을 제시한다. 해마에 대한 형상 분석 과정은 크게 형상 표현을 구축하는 과정, 형상의 유사도를 측정하는 과정, 정상인 집단과 환자 집단을 분류하는 과정으로 이루어진다. 본 연구에서는 해마의 형상 표현으로 메쉬, 골격, 복셀로 이루어진 하이브리드 옥트리 자료구조를 구축하였다. 또한 Iterative Closest Point (ICP) 알고리즘을 사용하여 해마 골격을 기반으로 한 정규화를 수행하였다. 그리고 정규화된 해마 형상을 전역적, 국부적으로 분석하여 최종적으로 입력된 해마가 정상인 또는 간질 환자에 속하는지를 학습된 데이터를 이용하여 분류하였다. 본 논문에서 제시한 ICP 기반의 정규화 방법은 3차원 해마 형상을 정확하게 분석하게 해주고, 골격의 정점 수를 조절함으로써 정규화 시간을 감소시킬 수 있다. 뿐만 아니라 3차원 해마 모델의 형상을 신경망을 통하여 학습시킴으로써 해마의 형상이 변형된 환자 집단과 정상인 집단을 분류하는데 이용할 수 있다.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.73-80
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• 2012

Recently, medical equipments are developed and used for diagnosis or studies. In addition, demand of techniques which automatically deal with three dimensional medical images obtained from the medical equipments is growing. One of the techniques is automatic bone segmentation which is expected to enhance the diagnosis efficiency of osteoporosis, fracture, and other bone diseases. Although various researches have been proposed to solve it, they are unable to be used in practice since a size of the medical data is large and there are many low contrast boundaries with other tissues. In this paper, we present a fast and accurate automatic framework for bone segmentation based on multi-resolutions. On a low resolution step, a position of the bone is roughly detected using constrained branch and mincut which find the optimal template from the training set. Then, the segmentation and the registration are iteratively conducted on the multiple resolutions. To evaluate the performance of the proposed method, we make an experiment with femur and tibia from 50 test knee magnetic resonance images using 100 training set. The proposed method outperformed the constrained branch and mincut in aspect of segmentation accuracy and implementation time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2312-2317
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• 2017

Museums are converging with digital technology to convey information to viewers in various ways. Augmented reality technology enhances virtual objects seamlessly in the real world, and provides a high sense of immersion and realism because it can use various senses of users in combination with information providing role of exhibits. However, the location-based augmented reality may cause the inaccurate registration of the virtual object with the real world due to the error of the GPS information, and the vision-based augmented reality can be enhanced at the position where the marker is placed. To solve this problem, we implemented the exhibition contents that interact with the real world by using the developed project tango. The exhibited contents were based on Lenovo Phab 2 Pro and Project Tango SDK in Unity 3D. Visitors were able to improve immersion and realism in exhibition contents, and it would be able to combine with various exhibition fields such as shopping malls as well as museums.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.378-384
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• 2020

For patients with unstable mandibular movements and centric relation of the mandible due to long-term use of ill-fitting dentures, the successful fabrication of new dentures is challenging. Before fabrication new dentures, registration of centric relation is the critical point in such cases. In this case, treatment dentures with a flat occlusal table were used to stabilize mandibular movements and to register centric relation. In order to reflect the patient's jaw relation and vertical dimension obtained through the treatment dentures to the final denture, the treatment dentures were digitally duplicated, and impressions and jaw relations were obtained using the duplicated therapeutic dentures. The clinical results were satisfactory on the aspect of aesthetic and masticatory functioned.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.238-242
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• 2007

Today's commercial high resolution satellite imagery such as that provided by IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Digital maps supply the most generally used GIS data probiding topography, road, and building information. Currently, the building information provided by digital maps is incompletely constructed for GIS applications due to planar position error and warped shape. We focus on extracting of the accurate building information including position, shape, and height to update the building information of the digital maps and GIS database. In this paper, we propose a new method of 3D building information extraction with a single high resolution satellite image and digital map. Co-registration between the QuickBird image and the 1:1,000 digital maps was carried out automatically using the RPC adjustment model and the building layer of the digital map was projected onto the image. The building roof boundaries were detected using the building layer from the digital map based on the satellite azimuth. The building shape could be modified using a snake algorithm. Then we measured the building height and traced the building bottom automatically using triangular vector structure (TVS) hypothesis. In order to evaluate the proposed method, we estimated accuracy of the extracted building information using LiDAR DSM.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.284-287
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• 2010

A new standard rose cv. 'Honey Lemon' was bred by the cross between white standard cv. 'Escimo' and light pink standard cv. 'Medeo' at the National Institute of Horticultural Research Institute. The cross was made in 1999 and 'Honey Lemon' was finally selected in 2003 after investigating characteristics for three years from 2001 to 2003. 'Honey Lemon', a white standard cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are $248.0stems/m^2/year$ in yield, 53.0 cm in length of cut flower, 8.0 cm in flower diameter, 17.0 in petal number, and 16.9 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cv., 'Tineke'. (Registration number: 1151).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.437-444
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• 2008

In the paper, a methodology is verified to integrate IKONOS-2 satellite imagery and ALS dataset by compensating biases of RPC models. To achieve this, conjugate features from both data should be extracted in advance. For this purpose, linear features are chosen as conjugate features because they can be accurately extracted from man-made structures in urban area and more easily extracted than point features from ALS data. Then, observation equations are established from similarity measurements of the extracted features. During the process, several kinds of transformation functions were selected and used to register them. In addition, it was also analyzed how the number of linear features used as control features affects the accuracy of registration results. Finally, the results were evaluated by using check-points obtained from DGPS surveying techniques and it was clearly demonstrated that the proposed algorithms are appropriate to integrate these data.

• Radiation Oncology Journal
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• v.38 no.2
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• pp.109-118
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• 2020

Purpose: Hypofractionated radiotherapy (RT) is becoming a new standard in postoperative treatment of patients with early stage breast cancer after breast conservation surgery. However, data on hypofractionation in patients with advanced stage disease who undergo mastectomy followed by local and regional nodal irradiation (RNI) is lacking. In this retrospective study, we report late-term effects of 3 weeks post-mastectomy hypofractionated local and RNI with two-dimensional (2D) technique in patients with stage II and III breast cancer. Methods: Between January 1990 and December 2007, 1,770 women with breast cancer who were given radical treatment with mastectomy, systemic therapy and RT at least 10 years ago were included. RT dose was 35 Gy/15 fractions/3 weeks to chest wall by two tangential fields and 40 Gy in same fractions to supraclavicular fossa (SCF) and internal mammary nodes (IMNs). SCF and IMNs dose was prescribed at d_max and 3 cm depth, respectively. Chemotherapy and hormonal therapy was given in 64% and 74% patients, respectively. Late-term toxicities were assessed with the Radiation Therapy Oncology Group (RTOG) scores and LENT-SOMA scales (the Late Effects Normal Tissue Task Force-Subjective, Objective, Management, Analytic scales). Results: Mean age was 48 years (range, 19 to 75 years). Median follow-up was 12 years (range, 10 to 27 years). Moderate/marked arm/shoulder pain was reported by 254 (14.3%) patients. Moderate/marked shoulder stiffness was reported by 219 (12.3%) patients. Moderate/marked arm edema was seen in 131 (7.4%) patients. Brachial plexopathy was not seen in any patient. Rib fractures were noted in 6 (0.3%) patients. Late cardiac and lung toxicity was seen in 29 (1.6%) and 23 (1.3%) patients, respectively. Second malignancy developed in 105 (5.9%) patients. Conclusion: RNI with 40 Gy/15 fractions/3 weeks hypofractionation with 2D technique seems safe and comparable to historical data of conventional fractionation (ClinicalTrial.gov Registration No. NCT04175821).

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.1
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• pp.8-16
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• 2012

An image obtained from a low light environment results in a low-exposure problem caused by non-ideal camera settings, i.e. aperture size and shutter speed. Of particular note, the multiple color-filter aperture (MCA) system inherently suffers from low-exposure problems and performance degradation in its image classification and registration processes due to its finite size of the apertures. In this context, this paper presents a novel method for the color enhancement of low-exposure images and its application to color shift model-based MCA system for image refocusing. Although various histogram equalization (HE) approaches have been proposed, they tend to distort the color information of the processed image due to the range limits of the histogram. The proposed color enhancement algorithm enhances the global brightness by analyzing the basic cause of the low-exposure phenomenon, and then compensates for the contrast degradation artifacts by using an adaptive histogram specification. We also apply the proposed algorithm to the preprocessing step of the refocusing technique in the MCA system to enhance the color image. The experimental results confirm that the proposed method can enhance the contrast of any low-exposure color image acquired by a conventional camera, and is suitable for commercial low-cost, high-quality imaging devices, such as consumer-grade camcorders, real-time 3D reconstruction systems, digital, and computational cameras.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.193-199
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• 2011

It is necessary to register precisely Digital Elevation Model (DEM) generated from SPOT -5 stereo images in order to monitor the topographic and environmental changes of important topographic features such as Mt. Baekdu. The SPOT-5 DEM is registered taking SRTM DEM as a reference DEM. If SPOT-5 DEM is transformed with single 3D rigid equation, it has many errors. Therefore, this study extracted uniformly ground control points over study area and estimated locally adapted transformation equation. The accuracy of proposed method was evaluated with comparison to scale-based and GCP-based transformation method.