• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.205-212
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• 2017

Chronic diffuse hepatopathy is one of the important clinical tasks to reduce mortality and morbidity due to liver cirrhosis, liver failure, and liver cancer. The purpose of this study was to evaluate the criteria for predicting liver and chronic liver disease using Fibroscan based on ultrasound diagnosis. Serum and liver stiffness measurement(kPa) were analyzed in 280 patients and cut-off values of liver stiffness measurement for predicting fatty liver and chronic diffuse hepatopathy were determined using ROC curve analysis. Bilirubin and PT(prothrombin time) were not related to disease prediction(p=0.243, p=0.115). Serum glucose and triglyceride levels were significantly higher in the liver (p<0.05). The cut-off value for predicting chronic diffuse hepatopathy was determined as 10.3 kPa(AUC 0.98, sensitivity 94.94%, specificity 94.93%) in the order of control group, fatty liver and chronic diffuse hepatopathy. Therefore, it will be used as a primary tool for the diagnosis of chronic liver disease patients with quantitative evaluation.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.112-121
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• 2020

Organic pollution due to coastal development increases the distribution of organic pollution indicators (OPI) and disturbs benthic ecosystems by increasing the number of organic pollution indicators dominant in the target area. However, there is a little researches on the organic pollution levels of benthic ecosystems in subtidal target coast of all over Korea. Therefore, this study analyzed the distribution of macrobenthos in subtidal around the coast development sites of EIA, confirmed the distribution of OPI, and produced the benthic health index-map (organic pollution level) of all coasts of Korea. The benthic health index of the sites was calculated using the density of each OPI, and the image program was used for the benthic health index-map. Organic pollution levels varied by projects for EIA and OPI. Lumbrineris sp. was found to be dominant throughout the coast and correlated with the benthic health index in Korea. Through this study, we will be able to confirm the future organic pollution level in the subtidal ecosystems of the project for EIA through the results of research to macrobenthos in subtidal for EIA. In addition, the distribution of Lumbrineris sp. OPI can be used as an indicator to indirectly evaluate the organic pollution level of the development site.

• Convergence Security Journal
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• v.13 no.3
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• pp.9-15
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• 2013

Calculating of matching cost is an important for efficient stereo matching. To investigate the performance of matching process, the concepts of the existing methods are introduced. Also we analyze the performance and merits of them. The simplest matching costs assume constant intensities at matching image locations. We consider matching cost functions which can be distinguished between pixel-based and window-based approaches. The Pixel-based approach includes absolute differences (AD) and sampling-intensitive absolute differences (BT). The window-based approach includes the sum of the absolute differences, the sum of squared differences, the normalized cross-correlation, zero-mean normalized cross-correlation, census transform, and the absolute differences census transform (AD-Census). We evaluate matching cost functions in terms of accuracy and time complexity. In terms of the accuracy, AD-Census method shows the lowest matching error ratio (the best solution). The ZNCC method shows the lowest matching error ratio in non-occlusion and all evaluation part. But it performs high matching error ratio at the discontinuities evaluation part due to blurring effect in the boundary. The pixel-based AD method shows a low complexity in terms of time complexity.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.289-299
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• 2009

Objective: The purpose of the present study was to evaluate the effectiveness of the use of Head Posture Aligner (HPA) during cone-beam computed tomography (CBCT) scan in generation of frontal cephalograms using 3D CBCT images. Methods: CBCT scans and frontal cephalograms were made in 30 adult individuals. While a couple of CBCT scan was made for one subject, one was made with conventional method, without use of HPA, the other was acquired with the use of HPA. After creation of virtual frontal cephalogram from each 3D CBCT image, it was traced and compared with the tracing of real frontal cephalogram. Results: In the comparison of the measurements, the virtual cephalograms with the use of HPA did not show statistically significant differences with the real cephalograms whereas the virtual cephalograms without the use of HPA presented significant differences with real cephalograms in many measurements. In the correlation analysis with the measurements of the real cephalograms, the virtual cephalograms with the use of HPA showed higher correlations in all measurements than the virtual cephalograms without the use of HPA. Conclusions: Measurements from CBCT-generated cephalograms become similar to those from real cephalograms with the use of HPA during CBCT scan. Thus, the use of HPA is suggested during the CBCT scan in order to construct accurate virtual frontal cephalograms using 3D CBCT images.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.251-257
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• 2017

Recently, hybrid positioning system combining GPS, vision sensor, and inertial sensor has drawn many attentions to estimate accurate vehicle positions. Since accurate multi-sensor fusion requires efficient time synchronization, this paper proposes an efficient method to obtain time synchronized measurements of vision sensor, inertial sensor, and OBD device based on GPS time information. In the proposed method, the time and position information is obtained by the GPS receiver, the attitude information is obtained by the inertial sensor, and the speed information is obtained by the OBD device. The obtained time, position, speed, and attitude information is converted to the color information. The color information is inserted to several corner pixels of the corresponding image frame. An experiment was performed with real measurements to evaluate the feasibility of the proposed method.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.66-76
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• 2002

The purpose of this study is to evaluate the effectiveness of customized master cone on apical sealing in various apical size of prepared root canals, that is MAF(Master Apical File) and to know at which apical size the apical leakage is to be significantly reduced using customized master cone. 120 extracted single rooted premolars were divided into four groups according to their apical size(MAF), #30, 40, 50 and 60. And then, each group was subdivided into three in accordance with three obturation methods, lateral condensation with standardized master cone, lateral condensation with chloroform-dipped customized master cone, and continuous wave of obturation technique. Resorcinol-formaldehyde resin was used for the microleakage test of this study. Teeth were sectioned horizontally at 1.5mm(Level 1), 2.5mm(Level 2), and 3.5mm(Level 3) from the anatomical root apex using low speed microtome. All sections were examined under $\times$40 magnification with a stereomicroscope, photographed, and then scanned. With the scanned images, resin-infiltrated area presenting the microleakage was calculated using SigmaScan/Image, and the ratio of leakage to the total root canal area of each group was analyzed statistically(one way ANOVA). The results were as follows ; 1. In groups of MAF #30, there was no significant difference of mean leakage ratio among three obturation methods at all three levels. 2. In groups of MAF #40, the group using lateral condensation with customized master cone had the low-est mean leakage ratio at all three levels, but there was no significant difference among three obturation techniques. 3. In groups of MAF #50, the mean leakage ratio of the group using lateral condensation with standard master cone was the highest among those of three obturation techniques at level 1, and this difference was statistically significant(p<0.05). 4 In groups of MAF #60, the groups using lateral condensation with standard master cone had also the highest mean leakage ratio at all levels, but there was no significant difference at level 1 and 2. At level 3, the leakage of the group using lateral condensation with standard master cone was significantly higher than that of the group using continuous wave of obturation(p<0.05). The results of this study suggested that the obturation method using customized master cone or the continuous wave of obturation is more effective for apical sealing than that using standardized master cone when MAF is larger than ＃50.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.155-160
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• 2006

Purpose: To evaluate the results of meniscal repair and partial meniscectomy of lateral meniscus injury associated with tibial plateau fracture. Materials and Methods: Between February 1993 and August 2004, 24 cases (23 patients) of lateral meniscus tear with tibial plateau fracture were evaluated retrospectively. The most frequent type of tear was the longitudinal tear of the meniscocapsular junction (14 cases, 66.7%). All fractures were reduced under the control of arthroscopic and image intensifier. Arthroscopic repair of the longitudinal tear of the lateral meniscus or arthroscopic partial meniscectomy was performed. The final results were evaluated with the Ikeuchi criteria and Lysholm score. Results: At the final follow-up, the outcome was excellent in 12 cases (85.7%), good in 1 case (7.1%) and fair in 1 case (7.1%) among 14 cases of meniscal repair, and the excellent in 4 cases (66.7%) and good in 2 cases (33.3%) among 6 cases of partial meniscectomy according to the Ikeuchi criteria, There was a significant improvement of Lysholm score after surgery, 92.3 postoperatively compared with 56.6 preoperatively (p<0.0001, paired t-test). Conclusion: The fracture of the lateral tibial plateau did not seem to affect on the healing of the meniscus repair and partial meniscectomy.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.71-80
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• 1993

In order to evaluate the scintigraphic features of choledochal cyst and these diagnostic value, authors investigated the findings of fourteen patients with choledochal cyst undergone hepatobiliary scan with $^{99m}Tc$-DISIDA before surgery. Five cases demonstrated the decreased hepatic uptake at 5-minute image of which four cases revealed severe jaundice. Seven cases demonstrated visualization of the cystic dilated common bile duct within 1 hour after injection. Two cases showed the cyst activity between 1 and 12 hours, but the cyst activity was not visible in five cases. Nonvisualization of the gall bladder was noted in ten cases, while four cases demonstrated visualization of the gall bladder within 1 hour. The time of visualization of gut activity was variably delayed. The intestinal activity was found in three cases within 1 hour and appeared in three cases between 1 and 2 hours and eight cases showed no visible gut activity. In four cases, intrahepatic ductal prominence was visible on the scintigram. Seven cases showed early and persistent accumulation of tracer in the common bile duct. Three cases showed persistent photon-deficient area in the gall bladder region. Two cases showed early photon-deficient area around gall bladder region with progressive accumulation of tracer in the same region. Two cases showed no evidence of activity in the biliary tract but noted late excretion into the small intestine. We concluded that hepatobiliary scan using $^{99m}Tc$-DISIDA is a noninvasive test useful in the evaluation and the diagnosis of choledochal cyst.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.15-21
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• 1995

To evaluate availability of cerebral radionuclide imaging for diagnosis of brain death, we examined 25 patients with a suspected clinical diagnosis of brain death. 8 patients were studied by $^{99m}Tc$ DTPA and 15 patients were studied by $^{99m}Tc$ HMPAO (Hexamethyl propyleneamine oxime). Seven patients with $^{99m}Tc$ DTPA studies revealed absence of cerebral blood flow and sagittal sinus activity. All of 15 patients with $^{99m}Tc$ HMPAO studies revealed complete absence of cerebral perfusion. The results of the cerebral radionuclide studies of brain death correlated with other clinical conditions, such as intracranial pressure(ICP), EEG, transcranial doppler sonography(TCDS), and neurologic examination. The ICP of 8 patients, who are confirmed by brain death with $^{99m}Tc$ HMPAO study are elevated in all cases. In conclusion, cerebral radionuclide imaging for diagnosis of brain death is available. $^{99m}Tc$ HMPAO imaging is unequivocal, easily interpreted, well reflect the physiologic state of increased ICP, and provides adequate assessment of posterior fossa activity. In addition, the SPECT imaging with $^{99m}Tc$ HMPAO produces more accurate results due to it's superiority of image contrast and proper localization of radiopharmaceutical distribution than conventional planar imaging.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.184-193
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• 2016

Purpose: To evaluate marginal leakage of bulk fill flowable composite resin filling with different curing time by using microcomputed tomography technology. Materials and Methods: 30 previously extracted human molars were randomly divided into 6 groups based upon restorative system and different curing time. Class II cavities (vertical slot cavities) were prepared. An individual metallic matrix was used to build up the proximal wall. The SonicFill or SureFil SDR flow was inserted into the preparation by using 1 bulk increment, followed by light polymerization for different curing times. The different exposure times were 20, 40, and 60 seconds. All specimens were submitted to 5,000 thermal cycles for artificial aging. Micro-CT scanning was performed by using SkyScan 1272. One evaluator assessed microleakage of silver nitrated solution at the resin-dentin interface. The 3D image of each leakage around the restoration was reconstructed with CT-Analyser V.1.14.4. The leakage was analyzed with the Mann-Whitney test. Results: Significant differences were observed between the light curing times, but no significant differences were found between the bulk fill composite resins. Increasing in the photoactivation time resulted in greater microleakage in all the experimental groups. Those subjected to 60 seconds of light curing showed higher microleakage means than those exposed for 20 seconds and 40 seconds. Conclusion: Increasing the photoactivation time is factor that may increase marginal microlekage of the bulk fill composite resins. Further, micro-CT can nondestructively detect leakage around the resin composite restoration in three dimensions.