• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.618-626
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• 2019

Stem cell therapy is not expected to bestow any therapeutic benefit because of the low engraftment rates after transplantation.Various cell-carrying scaffolds have been developed in order to overcome this problem. When the scaffold is formed by 3-dimensional (3D) printing, it is possible to create various shapes of scaffolds for specific regions of injury. At the same time, scaffolds provide stem cells as therapeutic-agents and mechanically support an injured region. PCL is not only cost effective, but it is also a widely used material for 3D printing. Therefore, rapid and economical technology development can be achieved when PCL is printed and used as a cell carrier. Yet PCL materials do not perform well as cell carriers, and only a few cells survive on the PCL surface. In this study, we tried to determine the conditions that maximize the cell-loading capacity on the PCL surface to overcome this issue. By applying a plasma treated condition and then collagen coating known to improve the cell loading capacity, it was confirmed that the 3% collagen coating after plasma treatment showed the best cell engraftment capacity during 72 hours after cell loading. By applying the spheroid cell culture method and scaffold structure change, which can affect the cell loading ability, the spheroid cell culture methods vastly improved cell engraftment, and the scaffold structure did not affect the cell engraftment properties. We will conduct further experiments using PCL material as a cell carrier and as based the excellent results of this study.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.381-389
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• 2013

Two patients with partial edentulous maxilla were scheduled to undergo installation of implant fixtures using a tooth-supported surgical template based on computer assisted treatment planning. After 3-dimensional (3D) computed tomographic scanning was transferred to the OnDemand3D (Cybermed Co., Seoul, Korea) software program for virtual planning, fixtures of MK III Groovy RP implant of the Br${\aa}$nemark System (Nobel Biocare AB Co., G$\ddot{o}$teborg, Sweden) was installed using the In2Guide (CyberMed Co., Seoul, Korea) tooth-supported surgical template with a Quick Guide Kit (Osstem Implant Co., Seoul, Korea) system in the posterior maxilla of each patient. Sinus floor elevation with a xenogenic bone graft procedure was also performed simultaneously in one patient. Fixture installations were completed successfully without complications, such as sinus mucosa perforation, bony bleedings, fenestrations, or others. During the last two-year follow-up period after prosthetics delivery, each implant was found to be fine with no other minor complications. The entire procedures are reported and the literatures on use of tooth-supported surgical template was reviewed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5148-5154
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• 2012

The purpose of this study was to analyze the kinematic characteristics of the thrower's center of mass (COM) and the shot that her performance hits record high for the 29th National Athletic Competition. Two S-VHS video cameras were used to visualize. The Direct Linear Transformation technique was employed to paint a clear picture in the three dimensional coordination. Kwon3D was used to analyze the data. The results showed that release velocity and height were 13.73 m/s and 198.6 cm(119% by height ratio), respectively, which is considered as peak performance comparing an extensive review of previous literature on the shot put. Release angle was $34^{\circ}$, which is lower than the previous studies. The path of thrower's center of mass is needed to travel in a release direction during the flight phase. The vertical movement of the thrower's center of mass during the driving should be controlled. At release, the perfact timing is required without vertical and horizontal movements of the thrower's center of mass.

• Journal of the Korea Computer Graphics Society
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• v.2 no.1
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• pp.77-85
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• 1996

Using a series of medical tomograms, we can reconstruct internal organs or other objects of interest and generate 3-D images. It is generally accepted that the axial resolution determined by two sequential image slices is lower than the planar resolution in one image slices. Therefore, various methods of interpolation were developed for an accurate display of reconstructed images. In this paper, a new algorithm for 3-D reconstruction of the medical images such as MRI and X-ray CT is suggested. The algorithm is shape-based and utilizes parts of the gray-level information. We extend the conventional shape-based interpolation of the binary images to the gray-scale images using the shortest distance map. Using this new algorithm, We could reduce the execution time for interpolation while keeping similar high quality of the reconstructed images with reduced execution time and is applicable to the various medical tomograms.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.56-65
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• 2009

Compton imaging is often recognized as a potentially more valuable 3-D technique in nuclear medicine than conventional emission tomography. Due to inherent computational limitations, however, it has been of a difficult problem to reconstruct images with good accuracy. In this work we show that the row-action maximum likelihood algorithm (RAMLA), which have proven useful for conventional tomographic reconstruction, can also be applied to the problem of 3-D reconstruction of cone-beam projections from Compton scattered data. The major advantage of RAMLA is that it converges to a true maximum likelihood solution at an order of magnitude faster than the standard expectation maximiation (EM) algorithm. For our simulations, we first model a Compton camera system consisting of the three pairs of scatterer and absorber detectors placed at x-, y- and z-axes, and generate conical projection data using a software phantom. We then compare the quantitative performance of RAMLA and EM reconstructions in terms of the percentage error. The net conclusion based on our experimental results is that the RAMLA applied to Compton camera reconstruction significantly outperforms the EM algorithm in convergence rate; while computational costs of one iteration of RAMLA and EM are about the same, one iteration of RAMLA performs as well as 128 iterations of EM.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.451-461
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• 2000

The locus coeruleus(LG) is known to be observed a sexual dimorphism in rat CNS. LC is the largest collections of norepinephrine(NE)-containing neurons in the mammalian brain. Especially in rat, all LC neurons contained NE unlike other mammalians, so that specific reactions were found in the tyrosine-hydroxylase(TH) immunoreactive neurons. Sexual dimorphism of rat LC has affected by genes before sex hormone appeared, thereafter affected by sex hormones. In these day, many scientists founded morphological differences between male and female LC morphology, but differences of entire structure was not founded. Thus we investigated sex differences of the LC neuron's morphology in rat by three-dimensional(3-D) reconstruction using Confocal laser scanning microscopy(CLSM). We reported that neuron's shape was relatively-large multipolar neurons and neuron's processes in dorsal LC proceeded to ventral direction in the male and female rat. Male had a longer anterior-posterior length than female had in dorsal LC. In addition to middle-LC, male rat's LC had a more thicker posterior region but had not viewed in a previous study. In reverse, female rat's LC had a thicker anterior region like a previous study. This results using 3-D reconstruction by CLSM showed that the male's LC was more wide-ranging than female's relatively.

• Journal of Korean Neurosurgical Society
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• v.49 no.6
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• pp.351-354
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• 2011

Objective : This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. Methods : Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement Results : Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. Conclusion : C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.899-905
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• 2013

In this paper, we focus on how to calibrate multi-cameras easily and how to efficiently detect quad-copters with small-numbered particles. Each particle is a six dimensional vector that is composed of 3D position and 3D orientation of a quad-copter in the space. Due to curse of dimensionality, that leads to explosive computational costs with a large amount of high-dimensioned particles. To detect efficiently, we need to put more particles in very promising spaces and few particles in other spaces. Though computational cost is lowered by minimizing particles, in order to track a quad-copter with multiple cameras in real-time, multiple images from the cameras should be synchronized and analyzed. Therefore, lots of the computations still need to be done. Because of this, GPGPU(General-Purpose computing on Graphics Processing Units) is implemented for parallel computing. This method has been successfully tested and gives accurate results in practical situations.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.171-178
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• 2017

A series of novel effector molecules secreted by the type three secretion system (T3SS) of Shigella spp. have been reported in recent years. In this study, a proteomic approach was applied to study T3SS effectors systematically. First, proteins secreted by the S. flexneri wild-type strain after Congo Red induction were separated and identified using two-dimensional electrophoresis to display the relative abundance of all kinds of early effectors for the first time. Then, a gene deletion mutant of known virulence repressor (OspD1) and a gene overexpressed mutant of two known virulence activators (MxiE and IpgC) were constructed and analyzed to discover potential late effectors. Furthermore, the supernatant proteins of gene deletion mutants of two known translocators (IpaB and IpaD), which would constantly secrete effectors, were also analyzed. Among all of the secreted proteins identified in our study, IpaH1.4, IpaH_5, and IpaH_7 have not been reported before. These proteomics data of the secreted effectors will be valuable to understand the pathogenesis of S. flexneri.

• Tunnel and Underground Space
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• v.12 no.4
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• pp.237-247
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• 2002

A total of 18 stress measurements were performed in the rock and rock-like blocks in the laboratory to estimate the influence of anisotropy in rock. Full scale overcoring equipment, which consists of a coring machine and a biaxial loading system by flat jacks, was developed to simulate the in-situ rock stress condition in the laboratory By comparing the isotropic analysis with the anisotropic analysis in measuring the stress, conclusions have been drawn as to the influence of anisotropy. The maximum difference between the isotropic and the anisotropic analysis was 34% and it was shown that the stress measurement considering the anisotropy was needed. To confirm the validity of the observed data, a diagnostic analysis of stress relief curve by overcoring was conducted using the three dimensional finite difference program, FLAC 3D.