• 한국정보전자통신기술학회논문지
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• 제13권2호
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• pp.113-122
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• 2020

Noise affects the accuracy of three-dimensional shape recovery. Its occurrence is unpredictable and depends on several mechanical, environmental, and other factors. When two-dimensional image sequences are obtained for shape from focus (SFF), mechanical vibration occurs in the translational stage, causing an error in the three-dimensional shape recovery. To address this issue, mechanical vibration is modeled using Newton's second law and the principle of the rack and pinion gear. Then, an optimal sampling step size considering the mechanical vibration is suggested through theoretical demonstration. Experiments conducted with real objects verify the effectiveness of the proposed sampling step size. In this paper, in a realistic environment with noise, the potential of obtaining more accurate three-dimensional reconstruction results of the objects is explored by acquiring the optimal sampling step size, which improves the sampling step size relative to those reported in a previous study performed under similar conditions.

• Journal of Korean Neurosurgical Society
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• 제50권6호
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• pp.532-534
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• 2011

Temple trauma that appears initially localized to the skin might possess intracranial complications. Early diagnosis and management of such complications are important, to avoid neurologic sequelae. Non-penetrating head injuries with intracranial hemorrhage caused by a driven bone fragment are extremely rare. A 53-year-old male was referred to our hospital because of intracerebral hemorrhage. He was a mechanic and one day before admission to a local clinic, tip of metallic rod hit his right temple while cutting the rod. Initial brain computed tomography (CT) and magnetic resonance imaging demonstrated scanty subdural hematoma at right temporal lobe and left falx and intracerebral hematoma at both frontal lobes. Facial CT with 3-D reconstruction images showed a small bony defect at the right sphenoid bone's greater wing and a small bone fragment at the left frontal lobe, crossing the falx. We present the unusual case of a temple trauma patient in whom a sphenoid bone fragment migrated from its origin upward, to the contralateral frontal lobe, producing hematoma along its trajectory.

• Journal of the Optical Society of Korea
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• 제20권2호
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• pp.239-244
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• 2016

Mugshot face images, routinely collected by police, usually contain both frontal and profile views. Existing automated face recognition methods exploited mugshot databases by enlarging the gallery with synthetic multi-view face images generated from the mugshot face images. This paper, instead, proposes to match the query arbitrary view face image directly to the enrolled frontal and profile face images. During matching, the 3D face shape model reconstructed from the mugshot face images is used to establish corresponding semantic parts between query and gallery face images, based on which comparison is done. The final recognition result is obtained by fusing the matching results with frontal and profile face images. Compared with previous methods, the proposed method better utilizes mugshot databases without using synthetic face images that may have artifacts. Its effectiveness has been demonstrated on the Color FERET and CMU PIE databases.

• Archives of Plastic Surgery
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• 제38권3호
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• pp.222-227
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• 2011

Purpose: Autogenous particulate bone grafting is a type of autogenous bone graft that consists of small particles of cortical and cancellous bone. Autogenous particulate bone grafting has been used for calvarial bone defect after calvarial defect of craniosynostosis and prevention of temporal depression after fronto-orbital advancement. The results were followed up and studied for effectiveness of autogenous calvarial particulate bone grafting. Methods: Cranial vault remodeling and fronto-orbital advancement was performed for six craniosynostosis patient from August 2005 to October 2007. Autogenous particulate bone grafting was harvested from endocortex of separated cranial vault and if insufficient, from extocortex of occipital region using Hudson brace & D'Errico craniotomy bit and was grafted on the calvarial bone defect of cranial vault and temporal hollow. Fibrin glues were added to the harvested particulated bone for adherence and shaping of paticles. Results: Autogenous particulate bone grafting was followed-up at least longer than I year. The calvarial bony defects following primary cranial remodeling were successfully covered and postoperative temporal depressions after fronto-orbital advancement were also well prevented by grafted particulated bone. Conclusion: Autogenous calvarial particulate bone graft can be harvested in infants and young children with minimal donor site morbidity. It effectively heals cranial defects in children and during fronto-orbital advancement reduces the prevalence of osseous defects independent of patient age. It's easy and effective method of reconstruction of calvarial defect.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.302-320
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• 2017

In this paper, an innovative robust feature detection and matching strategy for visual odometry based on stereo image sequence is proposed. First, a sparse multiscale 2D local invariant feature detection and description algorithm AKAZE is adopted to extract the interest points. A robust feature matching strategy is introduced to match AKAZE descriptors. In order to remove the outliers which are mismatched features or on dynamic objects, an improved random sample consensus outlier rejection scheme is presented. Thus the proposed method can be applied to dynamic environment. Then, geometric constraints are incorporated into the motion estimation without time-consuming 3-dimensional scene reconstruction. Last, an iterated sigma point Kalman Filter is adopted to refine the motion results. The presented ego-motion scheme is applied to benchmark datasets and compared with state-of-the-art approaches with data captured on campus in a considerably cluttered environment, where the superiorities are proved.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.496-502
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• 1998

The present study was carried out to determine the possible use of cTn-I in the cardiac myofibrillar architecture, as a potential target for in vivo radioimmunodetection of cardiac damage in a brain death pig model. Radioiodiantion of the anti-cTn-I 5F4 McAb was carried out by lactoperoxidase method. the percentage iodine incorporation achieved was 70-75%. The radioiodinated McAbs were purified on Sephadex G-25 column and characterised by Paper chromatography, Phast Gel electrophoresis and electroimmunoblotting. Radioiodinated anticTn-I 5F4 McAbs were employed alongside Pyrophosphate($Tc_{99m}$-PPi$) and $Thallium^{201}$ chloride($TI^{201}$) in 24 landrace pigs (brain-dead=18 & sham-operated=6). The percentage cardiac uptake of the radiolabelled antibody injected dose was significantly higher in the brain dead animals(0.196%) as compared to that of sham-operated animals (0.11%). Specific in vivo localization of radiolabelled McAbs in the infarcted cardiac tissue was confirmed by computer-aided reconstruction of 3-D images of the isolated heart. The preliminary results of the study revealed preferential uptake of radiolabelled antibody at the site of myocyte damage resulting from artificially induced brain death.

• 제어로봇시스템학회논문지
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• 제22권11호
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• pp.877-882
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• 2016

Disaster robots have accepted tele-operation in order to share the intelligence of human operators and robot systems. Virtual wall is one of the tele-operation technology to support recognition of human operator. If the virtual wall can block the robot from dangers, the operator will feel comfortable and can concentrate on fundamental missions. In this paper, we proposes and compares three methods for virtual wall visualization in tele-operation using 3D reconstruction. First is a virtual wall visualized only with edges. A wall filled with transparent color is the second method. Finally, third method is a texture-mapped virtual wall. In the experiments, we discuss their merits and demerits in view of robot tele-operation.

• ETRI Journal
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• 제33권4호
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• pp.537-546
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• 2011

This paper introduces an automated method for building height recovery through the integration of high-resolution satellite images and digital vector maps. A cross-correlation matching method along the vertical line locus on the Ikonos images was deployed to recover building heights. The rational function models composed of rational polynomial coefficients were utilized to create a stereopair of the epipolar resampled Ikonos images. Building footprints from the digital maps were used for locating the vertical guideline along the building edges. The digital terrain model (DTM) was generated from the contour layer in the digital maps. The terrain height derived from the DTM at each foot of the buildings was used as the starting location for image matching. At a preset incremental value of height along the vertical guidelines derived from vertical line loci, an evaluation process that is based on the cross-correlation matching of the images was carried out to test if the top of the building has reached where maximum correlation occurs. The accuracy of the reconstructed buildings was evaluated by the comparison with manually digitized 3D building data derived from aerial photographs.

• ETRI Journal
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• 제33권4호
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• pp.517-527
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• 2011

Currently, there is a considerable interest in 3D object reconstruction using terrestrial laser scanner (TLS) systems due to their ability to automatically generate a considerable amount of points in a very short time. To fully map an object, multiple scans are captured. The different scans need to be registered with the help of the point cloud in the overlap regions. To guarantee reliable registration, the scans should have large overlap ratio with good geometry for the estimation of the transformation parameters among these scans. The objective of this paper is to propose a registration method that relaxes/eliminates the overlap requirement through the utilization of photogrammetrically reconstructed features. More specifically, a point-based procedure, which utilizes non-conjugate points along corresponding linear features from photogrammetric and TLS data, will be used for the registration. The non-correspondence of the selected points along the linear features is compensated for by artificially modifying their weight matrices. The paper presents experimental results from simulated and real datasets to illustrate the feasibility of the proposed procedure.

• Journal of the Optical Society of Korea
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• 제18권1호
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• pp.37-44
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• 2014

The use of a laser interferometer as a metrological tool in micro-optics measurement is demonstrated. A transmissive interferometer is effective in measuring an optical specimen having a high angle slope. A configuration that consists of an optical resolution of 0.62 micron is adapted to measure a specimen, which is a micro-Fresnel lens-shaped lenticular lens. The measurement result shows a good repeatability at each fraction of facets, however, a reconstruction of the lens shape profile is disturbed by a known problem of $2{\pi}$-ambiguity. To solve this $2{\pi}$-ambiguity problem, we propose a two-step phase unwrapping method. In the first step, an unwrapped phase map is obtained by using a conventional unwrapping method. Then, a proposed unwrapping method based on the shape modeling is applied to correct the wrongly unwrapped phase. A measured height of each facet is compared with a profile result measured by AFM.