• Progress in Medical Physics
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• v.16 no.2
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• pp.82-88
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• 2005

In this study, the physical compensator made with the high density material, Cerrobend, and the electronic compensator realized by the movement of a dynamic multileaf collimator were analyzed in order to verify the properness of a design function in the commercial RTP (radiation treatment planning) system, Eclipse. The CT images of a phantom composed of the regions of five different thickness were acquired and the proper compensator which can make homogeneous dose distribution at the reference depth was designed in the RTP. The frame for the casting of Cerrobend compensator was made with a computerized automatic styrofoam cutting device and the Millennium MLC-120 was used for the electronic compensator. All the dose values and isodose distributions were measured with a radiographic EDR2 film. The deviation of a dose distribution was $\pm0.99 cGy\;and\;\pm1.82cGy$ in each case of a Cerrobend compensator and a electronic compensator compared with a $\pm13.93 cGy$ deviation in an open beam condition. Which showed the proper function of the designed compensators in the view point of a homogeneous dose distribution. When the absolute dose value was analyzed, the Cerrobend compensator showed a $+3.83\%$ error and the electronic compensator showed a $-4.37\%$ error in comparison with a dose value which was calculated in the RTP. These errors can be admtted as an reasonable results that approve the accuracy of the compensator design in the RTP considering the error in the process of the manufacturing of the Cerrobend compensator and the limitation of a film in the absolute dosimetry.

• The Korean Journal of Nuclear Medicine
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• v.36 no.3
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• pp.155-165
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• 2002

Purpose: The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using ${H_2}^{15}O-PET$. Materials and Methods: 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was peformed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Results: During the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal legions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal legions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Conclusion: Epilepsy induced changes were found not only in relative increase/decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.381-392
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• 2000

Purpose: We compared the reproducibility of $^{201}Tl\;and\;^{99m}Tc$-sestamibi (MIBI) gated SPECT measurement of myocardial function using the Germano algorithm Materials and Methods: Gated SPECT acquisition was repeated in the same position in 30 patients who received $^{201}Tl$ and in 26 who received $^{99m}Tc$-MIBI. The quantification of end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) on $^{201}Tl\;and\;^{99m}Tc$-MIBI gated SPECT was processed independently using Cedars quantitative gated SPECT software. The reproducibility of the assessment of myocardial function on $^{201}Tl$ gated SPECT was compared with that of $^{99m}Tc$-MIBI gated SPECT Results: Correlation between the two measurements for volumes and EF was excellent by the repeated gated SPECT studies of $^{201}Tl$ (r=0.928 to 0.986; p<0.05) and $^{99m}Tc$-MIBI (r=0.979 to 0.997; p<0.05). However, Bland Altman analysis revealed the 95% limits of agreement (2 SD) for volumes and EF were tighter by repeated $^{99m}Tc$-MIBI gated SPECT (EDV: 14.1 ml, ESV: 9.4 ml and EF: 5.5%) than by repeated $^{201}Tl$ gated SPECT (EDV: 24.1 ml, ESV: 18.6 ml and EF: 10.3%). The root mean square (RMS) values of the coefficient of variation (CV) for volumes und EFs were smaller by repeated $^{99m}Tc$-MIBI gated SPECT (EDV: 2.1 ml, ESV 2.7 ml and EF: 2.3%) than by repeated $^{201}Tl$ gated SPECT (EDV: 3.2 ml, ESV: 3.5 ml and EF: 5.2%). Conclusion: $^{99m}Tc$-MIBI provides more reproducible volumes and EF than $^{201}Tl$ on repeated acquisition gated SPECT. $^{99m}Tc$-MIBI gated SPECT is the preferable method for the clinical monitoring of myocardial function.

• Journal of the Korean Arthroscopy Society
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• v.6 no.1
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• pp.1-6
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• 2002

Purpose : Evaluation and analysis of the incidence and causes of intraoperative and postoperative complications after arthoscopic anterior cruciate ligament(ACL) reconstruction using bone-patella. tendon-bone (BPTB) auto graft. Materials and Methods : We reviewed 85 cases of arthroscopic ACL reconstruction using BPTB autograft which had been followed up for more than 1 year. Intraoperative complications had been recorded and corrected during the operation. Postoperative complications were analyzed and compared between 3 groups which were classified by the last follow-up period after the operation. Results : There were a few intraoperative complications including patellar fracture(1 case), contamination of harvested graft(1 case), impingement of graft(2 cases), blow-out of tile posterior wall of the femoral tunnel(1 case) and intraarticular retraction of the screw(1 case). The result of the comparison of postoperative complications among the groups shows that the incidence of anterior knee pain, donor site pain and patellofemoral crepitation were significantly decreased after 2 years. But there was no significant decrease in these complications after 3 years. Conclusion : Intraoperative complications after arthroscopic ACL reconstruction using BPTB autograft were due to incorrect technique and carelessness of the operation team, and can be prevented by improvement of surgical technique and accumulation of experience. Postoperative complication were somewhat unavoidable but gradually improved with time; hence, we should consider it for the selection of graft donor.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.206-214
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• 2003

Purpose : To analysis each clinical results after arthroscopic ACL reconstruction with using variable fixatives which are metallic and bioabsorbable interference screw, and RIGIDfix. Therefore, We reported the clinical reliability and safty of ACL reconstruction using RIGIDfix. Materials and Methods : We evaluated the results of arthroscopic ACL resconstruction with patellar tendon autograft among three groups, of which group 1 is used metal interference screw for 44 patients, group 2 used bioabsorbable interference screw for 47 patients, group 3 used RIGIDfix for 42 patients. We compared the clinical results by physical examination (anterior drawer test, Lachman test and pivot shift test), Lysholm score and KT-2000 arthrometer and compared the radiological results by measurement of tunnel and fixatives position and widening and by MRI findings. We analyzed the results by SAS 8.2 Ducan. Tukey and paired t-test Results : Physical instability was in 5 cases, which group 2 had 4 cases and group 3 had 1 case. Lysholm score improved from 59.8. 64.4, 61 to 90.1, 92.3. 92. KT-2000 arthrometer instability improved from 9.20, 10.2, 9.5 to 1.43. 1.62. 2.00 (p=0.478). Radiologically, all cases had excellent tunnel position and cyst change was observed the 8 cases in the group 2, but, all 20 cases 2nd MRI had signal change of peri-fixatives. But, no correlation of clinical results. Conclusion : No statistical difference of clinical instability was found among three groups. And femoral tunnel changes were much observed in group I, II than III. We considered the RIGIDfix has much advantages because the short operation time, better fixation position and much bone contact surface. But, further long term follow up study was needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.867-873
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• 1995

This study was done ot investigate the effect of chronic alcohol feeding and acetylaminofluorene(2-AAF) treatment on hepatic mitochondrial ATPase activity andmembrane lipid composition. Male Sprague-Dawley rats, weighing 120~125g, were fed for 6 weeks on a liquid diet containing 35% of calories as ethanol. After 4 weeks of experiment diet feeding, 2-AAF(100mg/kg body weight) was injected twice a week intraperitoneally. Body weight and percent liver weight per body weight were significantly changed by ethanol feeding. Hepatic mitochondrial ATPase activity significantly decreased by ethanol feedings but not by 2-AAF treatment. In comparison to control, the ATPase activity of ethanol-AAF group decreased 29.3%. Since phospholipid(PL) content of mitochondria has an interaction effect between ethanol and 2-AAF treatment, 2-AAF treatment significantly increased phospholipid content in only ethanol fed group. Total cholesterol(C) level of mitochondria significantly increased by ethanol feeding. Consequently C/PL ratio of ethanol group was significantly higher than that of control group. The analysis of mitochondrial PL composition showed that cardiolipin(CL) significantly increased by 2-AFF treatment in control group. Phosphatidyl choline(PC) significantly increased by ethanol feeding, whereas PC significanlty decreased and phosphatidyl ethanolamine(PE) significantly increased by 2-AAF treatment. 2-AAF treatment also showed a significant increase in PE/PC ratio. Fatty acid patterns of mitochondria were also changed by either ethanol or 2-AAF although the severity of the changes was not great. These data suggest that the reduced mitochondrial ATPase activity in ethanol-AAF group may be a consequence of a changes in mitochondrial membrane lipid composition such as PE/PC ratio, C/PL ration and fatty acid patterns.

• The korean journal of orthodontics
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• v.39 no.6
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• pp.362-371
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• 2009

Objective: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. Methods: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. Results: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. Conclusions: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.560-571
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• 2006

The purpose of this study was to determine composition of food groups appropriate for the evaluation of the quality of total diet or food guide, using the data from the 1998 National Health and Nutrition Survey. Twenty-four-hour-dietary recalls of total 1,110 Korean adolescents aged 13 - 19 years (male 543, female 567) were analyzed for food group consumed (Dietary Diversity Score, DDS), intake patterns of food group, mean index of nutritional quality (mINQ) and nutrient adequacy ratio (NAR). Considering Korean food pattern different from the Americans, this study is to check if Korean 5 food groups with both of oil & sugar group and vegetable & fruit group, and a minimum amount of 30 g in grain group and 15 g in meat group modified from Kant's minimum amount, 15 g in grain and 30 g in meat, could also be appropriate for the diet evaluation of Korean adolescents. Combination of food group and minimum food intake per each food group used in the first trial were categorized into 6 kinds of types: 1) American 5 food groups with Kant's minimum amount as control or 2) American 5 food groups with modified Kant's minimum amount 3) Korean 5 food groups excluded by sugar with the modified amount 4) Korean 5 food groups with modified amount 5) American food groups added oil group with the modified amount 6) American food groups added oil & sugar group with the modified amount. In case of oil group or oil and sugar group, 5 g was quoted for the minimum amount. Correlation between DDS and indices of other diet quality in each type of food group composition were analyzed and the best food group composition was traced by comparing the correlation coefficients of DDS and mINQ or MARs at ${\alpha}\;<\;0.01$. There was no meaningful difference in weight length index of the subjects of eating or not-eating oil or oil & sugar, while the values of mINQ showed higher in the subjects eating oil but no difference in the subjects eating oil & sugar, compared to the group not-eating, respectively. In comparison of type 1 and type 2, correlation between DDS and indices of other diet quality showed higher in type 1 using Kant's amount. And comparing the type of a combined group of fruit & vegetable (type 3 and 4) and the type of separated group of fruit and vegetable (type 5 and 6). six groups of separated vegetable and fruit showed the higher correlation of DDSs and indices of diet quality. In case of being classified into six groups with oil, DDS showed correlation of r = 0.293 with INQ. While, being classified into six groups with oil & sugar instead of oil only, DDS showed correlation of r = 0.249 with INQ. Accordingly the type 5 with oil is regarded as the better food group type than the type 6 with oil & sugar. Since better result was shown in the composition of six groups with Kant's minimum amount, the comparative analysis on both of type1 with oil and oil & sugar was finally performed. Then oil added type 1 showed higher correlation of DDS and indices of diet quality. These result indicated that it would be more appropriate to use six food groups with separate vegetable and fruit including oil group (oil-added type 1) rather than oil & sugar group for evaluation of dietary quality of Korean adolescents using DDS.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.211-216
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• 2018

This study was intended to analyze the effects of the selection of excellent design product by the KIDP(Korea Institute of Design Promotion) on the business performance of the company focused on the start-up with relatively low competitiveness. According to the statistics of KIDP in 2013, a design accounted for 27.53% of the factors affecting the sales of products and a design was the most important factor among the factors affecting the sales of products for the small sized company in terms of the scale of company. In addition, looking at the trend by industry in the data collected for this study, the technology-based industry showed a relatively higher growth rate than the retail industry and other industries. In this study, the author surveyed 186 companies of the companies that recognized the importance of design in difficult management conditions and received excellent design product certificate from KIDP(2013, 2014 and 2015) and empirically verified whether there was any difference in business performance between the start-ups with a business history of less than 7 years and the ongoing firms with a business history of more than 7 years. To evaluate the value of design, we used analytical method of measuring related values by comparison between groups. In addition, we also analyzed the difference in business performance(sales) between manufacturing companies, where the role of design was relatively large, and non-manufacturing companies among companies that received the excellent design product certificate. We have established a study hypothesis that the selection of excellent design product by the KIDP would have more positive effect on the business performance(sales) of the start-up compared to the ongoing firm, and conducted an empirical analysis by comparing both the year before and the year after the selected year. As a result, we found that the selection of excellent design product by the KIDP has a positive effect on the business performance of the start-up, and the selection of excellent design product has a significant effect on the difference in business performance between manufacturing and non-manufacturing companies. This study was conducted in the hope that the government actively supports the design-related policies so that the selection of excellent design product become an important indicator of the business performance of the start-up, and thus the design management will be a way to enhance the competitiveness of the start-up.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.31-40
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• 2010

Purpose : To compare the relative values of various fast breath-hold imaging sequences for superparamagnetic iron-oxide (SPIO)-enhanced hepatic MRI for the assessment of solid focal lesions with a 3T MRI unit. Materials and Methods : 102 consecutive patients with one or more solid malignant hepatic lesions were evaluated by spoiled gradient echo (GRE) sequences with three different echo times (2.4 msec [GRE_2.4], 5.8 msec [GRE_5.8], and 10 msec [GRE_10]) for $T2^*$-weighted imaging in addition to T2-weighted turbo spin echo (TSE) sequence following intravenous SPIO injection. Image qualities of the hepatic contour, vascular landmarks and artifacts were rated by two independent readers using a four-point scale. For quantitative analysis, contrast-to-noise ratio (CNR) was measured in 170 solid focal lesions larger than 1 cm (107 hepatocellular carcinomas, nine cholangiocarcinomas and 54 metastases). Results : GRE_5.8 showed the highest mean points for hepatic contour, vascular anatomy and imaging artifact presence among all of the subjected sequences (p<0.001) and was comparable (p=0.414) with GRE_10 with regard to lesion conspicuity. The mean CNRs were significantly higher (p<0.001) in the following order: GRE_10 ($24.4{\pm}14.5$), GRE_5.8 ($14.8{\pm}9.4$), TSE ($9.7{\pm}6.3$), and GRE_2.4 ($7.9{\pm}6.4$). The mean CNRs of CCCs and metastases were higher than those of HCCs for all imaging sequences (p<0.05). Conclusion : Regarding overall performances, GRE using a moderate echo time of 5.8 msec can provide the most reliable data among the various fast breath-hold SPIO-enhanced hepatic MRI sequences at 3T unit despite the lower CNR of GRE_5.8 compared to that of GRE_10.