• Journal of Oral Medicine and Pain
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• v.38 no.4
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• pp.357-366
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• 2013

This study is designed to evaluate the treatment outcome of occlusal stabilizing splint and to assess follow-up study of condylar bony changes using cone beam computed tomography(CBCT) in adolescents patients (12-19 years) with TMJ osteoarthritis(OA). 167 eroded condyles in 149 subjects were chosen among the patients who presented to the Department of Oral Medicine of Pasan National University Hospital, diagnosed as TMJ osteoarthritis by clinical exam, x-ray and CBCT from 2009 to 2012. They were treated conservatively with physical therapy, medication, behavioral therapy and occlusal stabilizing splint therapy. After average 9 months, CBCT was retaken and subjective symptoms and clinical findings were investigated. Condyle bony changes were classified by unchanged, less severe and more severe. The obtained results were as follow: 1. Pain, Noise, LOM(Limitation of motion) and MCO(Maximum comfortable opening) measurement of TMJ OA patients were markedly improved after conservative treatment. 2. In the occlusal stabilizing splint therapy group, Pain and LOM were statistically significant improved than non-occlusal stabilizing splint therapy group. 3. In the acute occlusal stabilizing splint therapy group, Pain and LOM were remarkably improved. 4. In comparison of CBCT1 and CBCT2 images, the transition of bone changes to lesser severe was most commonly in joint with erosive change. 5. In the non-occlusal stabilizing splint therapy group, the transition of condylar bone changes from erosion to more severe was many than occlusal stabilizing splint therapy group.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.50-55
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• 2013

Purpose: The purpose of this study was to compare the clinical results of absorbable knot-tying and absorbable knotless suture anchors in arthroscopic Bankart repair. Materials and Methods: This study compared the patients who underwent arthroscopic Bankart repairs using absorbable knottying suture anchors (59 patients: KT Group), and absorbable knotless suture anchors (52 patients: KL Group). Preoperative and postoperative evaluations were performed by Rowe scores, patient satisfaction score, visual analogue scale (VAS), American shoulder and elbow surgeons (ASES) score, range of motion (ROM), and re-dislocation rate. Results: Postoperative VAS, Rowe scores, ASES score were significantly not different between the 2 groups (VAS: p=0.250, Rowe score: p=0.412, ASES: p=0.052). Mean postoperative VAS was 0.5 in KT Group and 0.8 in KL Group (p=0.250), and limited ROM was noted only in one patient in KL Group. Mean Rowe score was 94.3 in KT Group and 96.3 in KL Group (p=0.412), and mean ASES score was 97.3 in KT Group and 94.0 in KL Group (p=0.052). Re-dislocation rate were no different between the 2 groups. Conclusion: There were no differences in clinical outcomes and re-dislocation rate between Knot-Tying and Knotless repairs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.1-13
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• 2018

Divers types of Personal Mobility(PM) are appeared on the market after the Segway is introduced. PMs have propagated very rapidly with their ease of use, and accidents related with PM show a sudden increase. Many studies on the PM are performed as its trend, but dring safety of passengers are excluded. In this study, criteria which can be adopted for PM's driving safety evaluation are reviewed. Also result of driving safety evaluation on 3 types of PM(wheel chair, kickboard, scooter(seating/standing) and walking using deducted criteria is given. COG(Center of the gravity) and SM(Stability Metric) are finally selected two criteria among many of them used in other fields. COG indicates how the center of mass deviates from the direction of the gravity. SM is a normalized value of generated force when PM moves as internal force, angular momentum, and ground reaction force. 0 means stop, and negative value means rollover, so it can be used for safety evaluation of PM. Average and standard deviation of measurement are standard of safety on the COG analysis. Wheel chair is the most safe and kickboard is the most unstable on the COG analysis. Wheel chair is also ranked as top safe on the SM analysis. Among two riding types(seating and standing) on the scooter, seating type is evaluated more safer than standing type. It is proposed that more various type of PMs are need to get safety evaluation for drivers and devices themselves together.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.7-10
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• 2013

Purpose : This study evaluated the effects of breathing protocols on matching results of PET and CT images using two breathing protocols such as free breathing and acquisition in holding the breathing after the normal expiration in acquiring CT images. Materials and Methods: Whole body FDG PET and CT images of 200 patients (mean age: 58 (range 20~84), 103 males and 97 females) using Discovery VCT (GE Healthcare, Milwaukee, USA). When taking CT images, subjects were asked to breathe freely (free breathing, n=100) or hold the breathing after the normal expiration (Hold, n=100). In the whole body image coronal section where PET and CT were matched, the matched error of the boundary between diaphragm and liver was measured in length. The matched errors were compared according to breathing protocol by age, sex and disease. The verification of statistical significance was made by SPSS 15.0 (SPSS Inc., Chicago, IL, USA) via one way ANOVA. Results: The matched error in all was 0.87 mm. According to breathing protocol, there was no significant difference in matched error as1.01 mm in free breathing and as 0.73 mm in hold breathing (p=.688). The matched error according to sex did not show significant difference as 1.08 mm of males, and 0.93 mm of females in free breathing (p=.517). In hold breathing, there was no significant difference as 0.79 mm of males and 0.66 mm of females (p=.738). There was no significant difference in matched error by age between free breathing and hold breathing (free breathing (p=.728), hold (p=.465). There was no significant difference in matched error by disease between free breathing and hold breathing (free breathing (p=.197), hold (p=.518) Conclusion: The difference in matched error between free breathing and hold breathing was less than 5 mm at 99%. There was no statistically significant difference in matched error by breathing protocol, age and disease. It was proved that there was no difference in matched error between PET and CT images according to breathing protocol during PET/CT scan.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.309-317
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• 1999

Background: Left ventricular diastolic filling is an important determinant for maintenance of cardiac output during hemodialysis. Few investigators have studied the influence of hemodialysis on diastolic function. To evaluate the change of left ventricular systolic and diastolic function. we performed M-mode and Doppler echocardiographic studies before and after hemodialysis. Methods: The study population consisted of 30 patients(15 patients were male, mean age $45{\pm}10$ years) with CRF on maintenance hemodialysis. They have normal left ventricular systolic function(Fractional shortening>30%) and no evidence of valvular heart disease or regional wall motion abnormalities. The ejection fraction (EF) was measured using M-mode echocardiography and Doppler indices such as peak E velocity, peak A velocity, isovolumetric relaxation time(IVRT), deceleration time(DT). and left ventricular ejection time(LVET) obtained from Doppler echocardiography. The index of myocardial performance (IMP) was calculated from each of the Doppler velocity indices. Results: The weight reduction after hemodialysis was $2.1{\pm}1.0kg$(p<0.0001), After hemodialysis, there was some decrease in blood pressure(p<0.05), but no significant change in heart rate, EF and fractional shortening, mean VCF, peak A velocity, and DT. And significant reduction in peak E velocity, E/A ratio(p<0.0001. p<0.001), and significant increase in IVRT and IMP(p<0.05, p<0.0001) were noted. Conclusion: In conclusion, preload reduction is the main mechanism that accounts for changes in Doppler diastolic indices after hemodialysis. And an increased IMP suggests that diastolic function may be aggravated after hemodialysis, and that implies impaired left ventricular filling and disturbed left ventricular compliance.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.185-190
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• 2008

Purpose: The purpose of this study is to provide the clinical outcomes of arthroscopic type II SLAP repair in non-athletes, and to compare the clinical outcomes between those who had isolated type II SLAP lesion and those who had combined partial thickness supraspinatus tear that did not required a combined repair. Materials and Methods: From July 2005 to January 2007, 142 consecutive type II SLAP lesions were treated with arthroscopic surgery. The inclusion criteria for the study were; (1) younger than 50 years old; and (2) non-athletes. Exclusion criteria were; (1) prior surgery, fracture or combined recurrent dislocation history on the affected shoulder; (2) combined full thickness rotator cuff tear or PTST (>50% thickness) patient that needed repair; and (3) combined infection, arthritis or inflammatory disease. Remaining 19 patients meet the criteria. Among them, 13 had combined PTRCT that did not require repair (Group I), and 6 had isolated type II SLAP lesion without combined supraspinatus tear (Group II). The mean age was 36.7 years (29~49 years), mean symptom duration was 39.1 months (3~216 months) and mean follow-up was 19.0 months (12~27 months). In all patients, the range of motion of affected shoulder, pain and function visual analogue scale (PVAS, FVAS), the Constant score and UCLA score were evaluated preoperatively and postoperatively. Results: In group I, external rotation at side was decreased significantly (p=0.003),but there were no statistical significant change at the remains(p>0.05). And there were no differences between groups (p>0.05). At the final follow-up, all clinical outcome measurements improved after surgery with statistical significance (p<0.05): UCLA score, $22.8{\pm}5.2$ to $32.8{\pm}2.1$; Constant score, $79.4{\pm}8.6$ to $94.9{\pm}4.3$; PVAS $5.4{\pm}2.7$ to $1.1{\pm}1.4$; FVAS $63.2{\pm}15.3$ to $93.4{\pm}7.3$. But, in group comparison of the mean UCLA score and Constant score, there were no statistical significant differences between two groups. Conclusion: Arthroscopic repair of type II SLAP lesion provided good clinical outcomes in nonathletic population. Combined partial thickness supraspinatus tear does not seem to hamper the final outcome at minimal 1 year follow-up.

• Journal of the Korean earth science society
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• v.33 no.4
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• pp.360-375
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• 2012

The purpose of this study was to compare 10th grade students' understanding of concepts about the plates' motions depending on the different spatial ability. Based on previous studies and literature reviews, two instruments were selected and used in this study. The Spatial Perception Test developed in Korean Testing Center was applied to measure students' spatial ability. Another instrument for testing students' understandings of plates' motions consists of a total of 10 items. The instruments were distributed to 118 students who were 10th graders in metropolitan city. The results are as follows: First, a correlation coefficient between conceptual understanding of plates' motions and spatial ability was r=0.439 (p<.01). It indicates that conceptual plates' motions and spatial ability have a moderate relationship. The students were divided into two groups (high and low) by spatial ability. The independent t-test was performed and reveals that the statistically significant difference between high and low groups. On the other hand, the 6 students (3 higher spatial ability students and 3 lowers) were selected and interviewed individually to find the differences in their understanding of the concept of plates' motions. The findings from interviews indicate that most students recognized about concepts of trench and ocean ridge, a rise and drop of the mantle, and divergent and convergent boundaries. However, students had misconceptions about section of trench and ocean ridge. In addition, the students who had higher spatial ability knew the more proper concepts about the creation and extinction of plate, crustal movements, and bottom of the ocean extension, whereas the students who had the lower spatial ability had misconceptions.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.69-76
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• 1996

Purpose : The aim of this study is to investigate the random and systematic errors and tumor movement using electronic portal imaging device in lung cancer patients for the adequate margin in the treatment planning of 3-dimensional conformal therapy. Material and Methods : The electronic portal imaging device is matrix ion chamber type(Portal Vision, Varian). Ten patients of lung cancer treated with chest irradiation were selected for this study. Patients were treated in the supine position without immobilization device. All treatments were delivered by an 10 MV linear accelerator that had the portal imaging system mounted to its ganrty. AP or PA field Portal images were only analyzed. Radiation therapy field included the tumor, mediastinum and supraclavicular lymph nodes. A total of 103 portal images were analyzed for set-up deviation and 10 multiple images were analyzed for tumor movement because of respiration and cardiac motion. Result : The average values of setup displacements in the x, y direction was 1.41 mm, 1 78 mm, respectively. The standard deviation of systematic component was 4.63 mm, 4.11 mm along the x, y axis, respectively while the random component was 4.17 mm in the x direction and 3.31 mm in the y direction. The average displacement from respiratory movement was 12.2 mm with a standard deviation of 4.03 mm. Conclusion : The overall set-up displacement includes both random and systematic component and respiratory movement. About 10 mm, 25 mm margins along x, y axis which considered the set-up displacement and tumor movement were required for initial 3-dimensional conformal treatment planning in the lung cancer patients and portal images should be made and analyzed during first week of treatment, individually.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.73-83
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• 2013

Purpose: The goal of this study is to evaluate the minimum three-year follow-up results of reverse total shoulder arthroplasty (RTSA) for glenohumeral (GH) arthritic and pseudoparalytic patients with severe rotator cuff deficiency. Materials and Methods: We evaluated 13 patients (three males and 10 females) who underwent RTSA from July 2007 to July 2010. The average follow-up duration was 54.2 months (range, 37~74 months). Clinical results were evaluated using the Visual Analog Scale (VAS) for pain, active Range of Motion (ROM): active forward flexion (aFF); active external rotation at the side (aERs); active internal rotation to the back (aIRb), American Shoulder and Elbow Surgeons (ASES) score, Korean Shoulder Score (KSS), and intraoperative and postoperative complications. Results: VAS score improved from 7.5(6~10) points to 1.5(0~4), and ROM of active forward elevation improved from $42.7(10{\sim}100)^{\circ}$ to $129.1(110{\sim}180)^{\circ}$. In addition, ASES score improved from preoperative 32.9 (11.7~46.7) points to 80.2(58.3~95.0) postoperatively, and KSS score improved from 36.8(24~47) points to 78.4 (61~92). Twelve out of 13 cases showed various degrees of scapular notching at the last follow-up. There was one case of intraoperative anterior glenoid fracture and two cases of temporary nerve injury. Revision surgery was performed in two cases for treatment of delayed postoperative deep infection. Conclusion: According to minimum three-year follow-up results, RTSA may be an effective treatment option for glenohumeral (GH) arthritic and pseudoparalytic patients. However, considering the possibility of complications related to delayed deep infection or surgeon's technique, RTSA should be judiciously and carefully indicated by expert surgeons.