• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.720-731
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• 2003

Statement of problem. The importance of fixture design and surface treatment. Purpose. The clinical success of dental in plants is affected by many factors such like as degree of osseointegration, the effective load dispersion for the prostheses, and a lot of attempts have been made to overcome the difficulties. In this study, efforts were made to find the possibility of clinical acceptance of the dental implants of newly designed surface and resorbable blast media surcace. Materials and methods. In this study, two groups of custom-made, screw-shaped implants were prepared. The first with the consisting of Branemark clone design and the other with the new design. These implants were divided into four groups according to the kinds of surface treatment. Four implants($AVANA^{(R)}$, Osstem, Busan, Korea)of each group were installed in twenty rabbits. Group A was consisted of Branemark done implant left as machined, Group B with Branemark clone implants with RBM(Resorbable blast media) surface, Group C with newly designed implants left as machined and Group D with newly designed implants with RBM surface. One of the twenty rabbits died from inflammation and the observation was made for six weeks. Specimens from four groups were observed using scanning electron microscopy with 40, 100, 1000 magnification power and microsurface structures were measured by white-light scanning interferometry for three dimensional surface roughness measurements(Accura $2000^{(R)}$, Intek-Plus, Korea.). Removal torque was measured in 17 rabbits using digital torque gauge(MGT 12R, Mark-10 corp., NY, U.S.A.) immediately after the sacrifice and two rabbits were used for the histologic preparation(EXAKT $310^{(R)}$, Heraeus Kulzer, wehrheim, Germany) of specimens and observed under light microscope. Resonance frequency measurement($Osstell^{(R)}$) was taken with the 19 rabbits at the beginning of the implant fixation and immediately after the sacrifice. Results. Following results were taken from the experiment. 1. The surface of the RBM implants as seen with SEM had rough and irregular pattern with reticular formation compared to that of fumed specimens showing different surface topographies. 2. The newly designed implant with RBM surface had high removal torque value among four groups with no statistical significance. The average removal torque was $49.95{\pm}6.70Ncm$ in Group A, $51.15{\pm}4.40Ncm$ in Group B, $50.78{\pm}9.37Ncm$ in Group C, $51.09{\pm}4.69Ncm$ in Group D. 3. The RFA values were $70.8{\pm}4.3Hz$ in Group A, $71.8{\pm}3.1Hz$ in Group B, $70.9{\pm}2.5Hz$, $72.7{\pm}2.5Hz$ in Group D. Higher values were noted in the groups which had surface treatment compared to the untreated groups with no statistical significance. 4. The results from the histomorphometric evaluation showed a mean percentage of bone-to-implant contact of $45{\pm}0.5%$ in Group A, $55{\pm}3%$ in Group B, $49.5{\pm}0.5%$ in Group C, and $55{\pm}3%$ in Group D. Quite amount of newly formed bone were observed at the surface RBM-treated implants in bone marrow space.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.206-214
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• 2009

Statement of problem: There are common clinical cases in which the mandibular first and second molars are missing unilaterally. Purpose: This study was designed to compare and evaluate the magnitude and distribution of stress produced by four kinds of mandibular unilateral free-end removable partial dentures that could be applied clinically in Kennedy class II cases. Material and methods: Four unilateral free-end removable partial dentures using clasp, Konus crown, resilient attachment, and flexible resin were fabricated on the photoelastic models of the Kennedy class II cases. The vertical load of 6㎏ was applied on the central fossa of the first molar of every removable partial denture in the stress freezing furnace and the photoelastic models were frozen according to the stress freezing cycle. After these models were sliced mesio-distally to a thickness of 6mm, the photoelastic isochromatic white and black lines of the sliced specimens were examined with the transparent photoelastic experiment device and photographs were taken with a digital camera. The fringe order numbers at eight measuring points in the photograph were measured with the naked eye. Results: The maximum fringe order number of each sliced specimen and the fringe order number at the residual ridge just below the loading point were in the decreasing order of the unilateral removable partial dentures using flexible resin followed by clasp, resilient attachment, and Konus crown. The fringe order number at the root apex of the second premolar was in the decreasing order of the unilateral removable partial dentures using clasp followed by flexible resin, Konus crown, and resilient attachment. Conclusion: The removable partial denture using Konus crown showed the most equalized stress distribution to the supporting alveolar bone of abutment teeth and residual ridge under the vertical loads. The removable partial denture using flexible resin can be applied to the case that has a better state of residual ridge than abutment teeth.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.124-133
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• 2009

The study was performed to investigate the community structure of macrobenthic fauna during June 2005, in Hallyeohaesang National Park from Korea Strait. A total of 284 macrobenthic fauna were collected. The overall average macrobenthic density and biomass were 2,002 individuals m$^{-2}$ and 154.92 gWWt m$^{-2}$, respectively. Based on the Lebris (1988) index, there were 20 species accounting for approximately 47.64% of total individuals. And the highest densities were found in the polychaetes Scoletoma longifolia, Isolda pulchella, Mediomastus californiensis, Minuspio multibranchia, Tharyx sp. 1 and the bivalve Theora fragilis. On the other hand, the top twenty species made up 70.47% of the total biomass while the three most abundant, the echinoderms Schizaster lacunosus, Amphiura vadicola and the bivalve Fulvia mutica. The conventional multivariate statistics (cluster analysis and non-metric Multi-Dimensional Scaling) applied to assess spatial variation in macrobenthic assemblages. As a result of cluster analysis and nMDS ordination, this study area was divided into two different groups of stations and species. In case of station, there are two groups: one is a mud dominated station group and the other is dead shell and sand dominated group. And the 2 faunistic groups were established as follows: 1) a group of relatively higher abundances in mud dominated sediment. There were numerically dominated by the polychaetes Magelona japonica, Sternaspis scutata, Paraprionospio pinnata, Tharyx sp. 1 and the amphipods Monocorophium sinense and Eriopisella sechellensis. 2) a group of relatively higher densities dead shell and sand dominated sediment. These groups were characterized by the polychaetes I. pulchella, M. multibranchiata, the amphipods M. acherusicum, Gammaropsis japonicus and the echinoderm A. vadicola.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.1
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• pp.1-8
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• 2005

Purpose : An effect of a packing to uterine treatment of a cervical cancer using a dose-volume histogram for a point dose and a volume dose of the bladder and the rectum was analyzed by establishing a three-dimensional treatment plan using a CT image. Materials and methods : Reference points of the bladder and the rectum were marked, respectively at a treatment plan device (plato brachytherapy V14.2.4) by photographing CT(marconi, USA) when the packing was used and removed under the same condition and a treatment plan was performed to Apoint depending on ICRU38. However, in case of the rectum, a maximum point was looked up and compared with the above point because the point presented from the ICRU is not proper as a representative value of a rectum point dose. Further, the volume dose depending on volume of $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder was measured. The measured values were used to analyze the effect of the packing through a Wilcoxon Signed Rank Test (a SAS statistical analysis process program). Result : The reference points at the bladder and rectum doses when the packing was removed were $116.94\;35.42\%$ and $117.59\;21.08\%$, respectively. The points when the packing was used were $107.08\;38.12\%$ and $95.19\;21.32\%$, respectively. After the packing was used, the reference points at the bladder and the rectum were decreased by $9.86\%$ and $22.4\%$, respectively. When the packing was removed, the maximum points at the bladder and the rectum were $164.51\;50.89\%,\;128.81\;33.05\%$, respectively. When the packing was used, the maximum points at the bladder and the rectum were $142.31\;44.79,\;110.08\;37.03\%$, respectively. After the packing was used, the maximum points at the bladder and the rectum were decreased by $22.2\%$ and $18.73\%$, respectively. When the packing was removed, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were $48.62{\pm}18.09\%,\;16.12{\pm}11.15\%,\;and\;7.51{\pm}6.63\%$, respectively and its rectum volume were $23.41{\pm}14.44\%,\;6.27{\pm}4.28\%,\;2.79{\pm}2.27\%$, respectively. When the packing was used, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were $40.33{\pm}16.72,\;11.63{\pm}8.72,\;and\;4.87{\pm}4.75\%$, respectively and its rectum volume were $18.96{\pm}8.37\%,\;4.75{\pm}2.58\%,\;and\;1.58{\pm}1.06\%$, respectively. After the packing was used, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were decreased by $8.29\%,\;4.49\%,\;and\;2.64\%$, respectively and its bladder volume were decreased by $4.45\%,\;1.52\%,\;and\;1.21\%$, respectively. Conclusion : Values at Reference point doses of the bladder and the rectum recommended from the ICRU 38 were 0.0781 and 0.0781, respectively and values of their maximum point doses were 0.0156 and 0.0156, respectively, as a result of which an effect of the packing using at the uterine intracavitary treatment of an uterine cervical cancer through the three-dimensional treatment plan used CT were measured. That is, the values at reference point doses and the values at maximum point doses show similar difference. However, P value was 0.15 at over $50\%,\;80\%,\;and\;100\%$ volume doses and the value shows no similar difference. In other words, the effect of the packing looks like having a difference at the point dose, but actually shows no difference at the volume dose. The reason is that the volume of the bladder and the rectum are wide but the volume of the packing is only a portion. Therefore, the effect of decreasing the point dose was not great. Further, the farer the distance is, the more weak the intensity of radiation is because the intensity of radiation is proportional to inverse square of a distance. Therefore, the effort to minimize an obstacle of the bladder and the rectum by using the packing should be made.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.157-168
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• 2008

Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.

• Journal of Life Science
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• v.20 no.4
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• pp.543-548
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• 2010

The purpose of this study was to examine the differences in kinetics between 6 months of rehabilitation training and 12 months of rehabilitation training after total hip arthroplasty. 10 unilateral THA participants performed kinetic tests. Three dimensional kinematics and hip flexors and abductors electromyography (EMG) were collected during each trial. T-test was used for statistical analysis (p<0.05). There was no significant difference in EMG data between the two groups, but the mean comparison EMG data was higher in the 12 months rehabilitation training group than the 6 months rehabilitation training group. The moment value was found with motion-dependent interaction analyzing method which was used by Feltner and Dapena. There was no significant difference between moment values of the two groups. There was no significant difference between ground reaction forces of the two groups; however, there were some differences shown in Fz (vertical reaction force) between the two groups ($892{\pm}104\;N$, $820{\pm}87\;N$). The first peak impact force was about 9% lower in the 12 months group compared to the 6 months group. The second peak active force was nearly equal between the two groups. More research is necessary to determine exactly what constitutes optimal rehabilitation training biomechanics for patients with total hip arthroplasty.

• Journal of Life Science
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• v.28 no.3
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• pp.307-313
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• 2018

Alopecia cause psychological stress due to their effect on appearance. Thus, the global market size of the alopecia treatment products are growing quickly. Timosaponin A III is the well known active ingredient of Anemarrhenae Rhizoma. In this study, we investigated and compared the binding affinity of timosaponin A III with finasteride (5-beta reductase antagonist) and minoxidil (androgen receptor antagonist) on the target protein active site by in silico computational docking studies. The three dimensional crystallographic structure of 5-beta reductase (PDB ID : 3G1R) and androgen receptor (PDB ID: 4K7A) was obtained from PDB database. In silico computational autodocking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and NX-QuickPharm option based on scoring functions. The timosaponin A III showed optimum binding affinity (docking energy) with 5-beta reductase as -12.20 kcal/mol as compared to the finasteride (-11.70 kcal/mol) and with androgen receptor as -9.00 kcal/mol as compared to the minoxidil (-7.40 kcal/mol). The centroid X, Y, Z grid position of the timosaponin A III on the 5-beta reductase was similar (overlap) to the finasteride, but the X, Y, Z centroid grid of the timosaponin A III on the androgen receptor was significantly far from the minoxidil centroid position. These results significantly indicated that timosaponin A III could be more potent antagonist to the 5-beta reductase and androgen receptor. Therefore, the extract of Anemarrhenae Rhizoma or timosaponin A III containing biomaterials can substitute the finasteride and minoxidil and can be applied to the alopecia protecting product and related industrial fields.

• Archives of design research
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• v.18 no.4 s.62
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• pp.105-118
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• 2005

Housing environment for human beings has been diversified and more convenient due to the development of high technology and civilization brought by industrialization in the 20th century. In the 21st century, how to overcome the ecological limit of biased development-centered advancement, that is, how to preserve and hand over a clean and healthy 'sustainable environment' to our next generations has been one of the most-talked about issues. Environmental symbiosis means a wider range of environmental harmony from micro-dimensional perspective to macro one. The three goals of a environmentally friendly house are to preserve global environment, to harmonize with the environment around, and to offer a healthy and comfortable living environment. From the point of view of environmental symbiosis, houses should be designed to save energy and natural resources for preservation of global environment, to collect such natural energy resources as solar heat and wind force, to recycle waste water, and recycle and reduce the amount of the waste matter. Now, the environmentally-friendly house became a new social mission that is difficult to not only challenge but also realize without conversion to a new paradigm, ecologism.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.553-562
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• 2017

GPS (Global Positioning System) receiver among various sensors mounted on UAV (Unmanned Aerial Vehicle) helps to perform various functions such as hovering flight and waypoint flight based on GPS signals. GPS receiver can be used in an environment where GPS signals are smoothly received. However, recently, the use of UAV has been diversifying into various fields such as facility monitoring, delivery service and leisure as UAV's application field has been expended. For this reason, GPS signals may be interrupted by UAV's flight in a shadow area where the GPS signal is limited. Multipath can also include various noises in the signal, while flying in dense areas such as high-rise buildings. In this study, we used analytical photogrammetry and auto tracking total station technique for 3D positioning of UAV. The analytical photogrammetry is based on the bundle adjustment using the collinearity equations, which is the geometric principle of the center projection. The auto tracking total station technique is based on the principle of tracking the 360 degree prism target in units of seconds or less. In both techniques, the target used for positioning the UAV is mounted on top of the UAV and there is a geometric separation in the x, y and z directions between the targets. Data were acquired at different speeds of 0.86m/s, 1.5m/s and 2.4m/s to verify the flight speed of the UAV. Accuracy was evaluated by geometric separation of the target. As a result, there was an error from 1mm to 12.9cm in the x and y directions of the UAV flight. In the z direction with relatively small movement, approximately 7cm error occurred regardless of the flight speed.