• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.213-230
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• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.15-24
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• 2003

The purpose of this study is to investigate the sterilization effect of Er:YAG laser against the intraoral acid producing bacterium, S. mutans, by irradiating the culture solution containing S. mutans KCTC 3065 with Er:YAG laser having a $650{\mu}m$ diameter beam through the non-contact method. We obtained the following results after examining the temperature changes of the culture solution, numbers of bacterial colonies, and acid-producing ability and attaching ability on teeth by measuring the amount of extracellular polysaccharide produced by S. mutans. The number of bacterial colony was decreased in $10{\mu}l$ culture solution irradiated with laser in overall compared to the control solution. The number decreased as the irradiation intensity and pulse repetition rate were larger and as the exposure time was increased. However, it did not change significantly in $100{\mu}l$ culture solution compared to the control solution. Although the acid-producing ability of S. mutans was inhibited for a certain duration after laser irradiation in 10r1 bacterial culture solution, it did not change in $100{\mu}m$ solution compared with the control solution. The amount of extracellular polysaccharide synthesized by S. mutans was partially decreased through laser irradiation in $10{\mu}m$ culture solution but did not change in $100{\mu}m$ culture solution. Based on these findings, we concluded that Er:YAG laser has an sterilization effect on S. mutans in which we presume that the mechanism is through the heat effect rather than the mechanical effect from development of ultrasound.

• The Korean Journal of Elementary Counseling
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• v.9 no.1
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• pp.41-58
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• 2010

The purpose of this study was to invent anger-inducing automatic thoughts examination for elementary school children based on its investigation for Korean one. I made the anger-inducing Automatic Thoughts Questionnaire(I, II) and made an examination of the contents of the automatic thoughts with it. Based on it, with preliminary questionnaire 90, I did principal component analysis varimax rotation and then final anger-inducting automatic thoughts examination of 40 question in 2 primary factor construction was consisted. I made 300 students carry out it to know its reliability, propriety and made 100 students carry it out at 2-week intervals test-retest. I divided them in three groups as low, middle and high according to its soore regarding anger-inducting automatic thoughts, I confirmed the variation of each group in positive thoughts, self-esteem, life satisfaction, anger, the result is same as follows; First, the content of Anger-inducting Automatic thoughts for elementary school students is revealed as unreasonableness(56.4%), retailation and passive, active offense(16.3%), blame and contempt(11.9%), injured pride and refusal(9.2%), absurd(3.9%), abandonment and avoidance(2.1%), self-abasement in turn. Second, said inventory is consist of 2 notion; first(20 questions) is blame, retaliation and second(20 questions) is injustice. Inner-item consistency of total 40 question is .97, Split-half reliability is .93, Test-retest reliability is .86. Third, criterion validity is revealed fine by reviewing the correlation between existing index related to the inventory of Anger-inducting Automatic thoughts of the elementary school students. Moreover, to find out discriminant validity, I divided three classes(low, middle, high) according to the score of said thoughts. As a result, there is certain variations when I confirmed variations in groups by reviewing the self-esteem, positive way of thinking, life satisfaction, anger.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.251-258
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• 2017

The objective of this study was to analyze patient satisfaction and perception of nutritional counseling services quality. A patient satisfaction and perception survey was conducted for 1,095 patients from 43 tertiary hospitals and 20 general hospitals. The number of returned questionnaires was 656 (response rate: 60.0%). Data from 633 questionnaires were analyzed after the questionnaires with unanswered items were excluded. Five domains were identified from the result of the factor analysis using the maximum likelihood and oblique rotation. The five domains were named empathy, responsiveness, tangibles, reliability, and skill and specialty. Patient perception mean score of nutritional counseling was 4.54/5.00. Patient satisfaction scores were significantly higher in empathy (P<0.001), responsiveness, and skill and specialty (P<0.01) with a college or graduate school education than in patients with a middle school education. There was no statistically significant difference between satisfaction scores in tertiary hospitals and those in general hospitals, but patients in capital hospitals reported significantly higher scores than their local counterparts in empathy, responsiveness, reliability, skill and specialty (P<0.001), and tangibles (P<0.05). In responsiveness, significantly higher (P<0.01) scores were observed in patients who received nutritional counseling only once compared to patients who received counseling two times. Patients perception of nutritional counseling services was significantly correlated with their satisfaction of five domains, reliability (r=0.721), responsiveness (r=0.697), empathy (r=0.690), skill and specialty (r=0.678), and tangibles (r=0.622).

• Progress in Medical Physics
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• v.15 no.1
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• pp.30-38
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• 2004

Purpose: To develop a whole body frame for the purpose of reducing patient motion and minimizing setup error for extra-cranial stereotactic radiotherapy, and to evaluate the repositioning setup error of a patient in the frame. Materials and Methods: The developed whole body frame is composed of a base plate, immobilizer, vacuum cushion, ruler and belts. The dimension of the base plate is 130 cm in length, 50 cm in width and 1 cm in thickness. The material used in the base plate of the frame was bakelite and the immobilizer was made of acetal. In addition, Radiopaque angio-catheter wires were engraved on the base plate for a coordinate system to determine the target localization. The measurement for radiation transmission and target localization is peformed in order to test the utilization of the frame. Also, a Matlab program analyzed the patients setup error by using the patient's setup images obtained from a CCTV camera and digital record recorder (DVR). Results: A frame that is useful for CT simulation and radiation treatment was fabricated. The frame structure was designed to minimize collisions from the changes in the rotation angle of the gantry and to maximize the transmission rate of the Incident radiation at the lateral or posterior oblique direction. The lightening belts may be used for the further reduction of the patient motion, and the belts can be adjusted so that they are not in the way of beam direction. The radiation transmission rates of this frame were measured as 95% and 96% at 10 and 21 MV, respectively. The position of a test target on the skin of a volunteer is accurately determined by CT simulation using the coordinate system in the frame. The estimated setup errors by Matlab program are shown 3.69$\pm$1.60, 2.14$\pm$0.78 mm at the lateral and central chest, and 7.11 $\pm$2.10, 6.54$\pm$2.22 mm at lateral and central abdomen, respectively. The setup error due to the lateral motion of breast is shown as 6.33$\pm$ 1.55 mm. Conclusion: The development and test of a whole body frame has proven very useful and practical in the radiosurgery for extra-cranial cancers. It may be used in determining target localization, and it can be used as a patient immobilization tool. More experimental data should be obtained in order to improve and confirm the results of the patient setup error.

• Progress in Medical Physics
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• v.14 no.4
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• pp.211-217
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• 2003

The Principal component analysis (PCA) is a well-known data analysis method that is useful in linear feature extraction and data compression. The PCA is a linear transformation that applies an orthogonal rotation to the original data, so as to maximize the retained variance. PCA is a classical technique for obtaining an optimal overall mapping of linearly dependent patterns of correlation between variables (e.g. neurons). PCA provides, in the mean-squared error sense, an optimal linear mapping of the signals which are spread across a group of variables. These signals are concentrated into the first few components, while the noise, i.e. variance which is uncorrelated across variables, is sequestered in the remaining components. PCA has been used extensively to resolve temporal patterns in neurophysiological recordings. Because the retinal signal is stochastic process, PCA can be used to identify the retinal spikes. With excised rabbit eye, retina was isolated. A piece of retina was attached with the ganglion cell side to the surface of the microelectrode array (MEA). The MEA consisted of glass plate with 60 substrate integrated and insulated golden connection lanes terminating in an 8${\times}$8 array (spacing 200 $\mu$m, electrode diameter 30 $\mu$m) in the center of the plate. The MEA 60 system was used for the recording of retinal ganglion cell activity. The action potentials of each channel were sorted by off­line analysis tool. Spikes were detected with a threshold criterion and sorted according to their principal component composition. The first (PC1) and second principal component values (PC2) were calculated using all the waveforms of the each channel and all n time points in the waveform, where several clusters could be separated clearly in two dimension. We verified that PCA-based waveform detection was effective as an initial approach for spike sorting method.

• Progress in Medical Physics
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• v.19 no.2
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• pp.102-112
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• 2008

We developed a high-resolution micro-CT system based on rotational gantry and flat-panel detector for live mouse imaging. This system is composed primarily of an x-ray source with micro-focal spot size, a CMOS (complementary metal oxide semiconductor) flat panel detector coupled with Csl (TI) (thallium-doped cesium iodide) scintillator, a linearly moving couch, a rotational gantry coupled with positioning encoder, and a parallel processing system for image data. This system was designed to be of the gantry-rotation type which has several advantages in obtaining CT images of live mice, namely, the relative ease of minimizing the motion artifact of the mice and the capability of administering respiratory anesthesia during scanning. We evaluated the spatial resolution, image contrast, and uniformity of the CT system using CT phantoms. As the results, the spatial resolution of the system was approximately the 11.3 cycles/mm at 10% of the MTF curve, and the radiation dose to the mice was 81.5 mGy. The minimal resolving contrast was found to be less than 46 CT numbers on low-contrast phantom imaging test. We found that the image non-uniformity was approximately 70 CT numbers at a voxel size of ${\sim}55{\times}55{\times}X100\;{\mu}^3$. We present the image test results of the skull and lung, and body of the live mice.

• 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 Arthroscopy Society
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• v.15 no.2
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• pp.92-98
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• 2011

Purpose: We describe a all-arthroscopic technique for decompression of spinoglenoid ganglion cyst and present our clinical results for this procedure. Materials and Methods: From March 2006 to June 2009, eight patients (7 males, 1 female; mean age 40.6 years; range: 21~61) were included who underwent arthroscopic decompression of spinoglenoid ganglion cyst. The most common symptoms were vague shoulder pain and external rotation weakness, which lasted 6.4 months (range: 3~8) on average. Five of eight patients were noted abnormalities on electromyographic (EMG) examination to have suprascapular nerve neuropathy and magnetic resonance imaging (MRI) showed spinoglenoid ganglion cysts in all eight patients and the cyst size was 2.6 cm (range: 1.8~3.6). Labral pathology was identified intraoperatively in all patients and the cysts were decompressed by the posterosuperior capsulotomy under arthroscopic control and labral repair with suture anchors was performed in six patients. Results: The average clinical outcome scores including Constant and Murley, Simple shoulder test (SST) all improved significantly at the time of the final follow-up and there were no complications resulting from the procedures. All patients including the patients with abnormal EMG study recovered strength on isokinetic strength testing. Follow-up MRI scans were performed on all patients at a mean of 5.2 months postoperatively (range: 3~12) revealed complete resolution of the cysts and no evidence of recurrences were seen at an average of 18 months (range: 12~26) of follow-up. Conclusion: Arthroscopic decompression of spinoglenoid ganglion cyst effectively restores patient function and all patients in this study showed improvement in their postoperative MRI findings. Arthroscopic decompression is also useful in the appropriate treatment for labral pathology and may contribute to decreased risk of cyst recurrence.

• Journal of the Ergonomics Society of Korea
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• v.36 no.3
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• pp.183-196
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• 2017

Objective: The purpose of this research was to assess the agreement between job physical risk factor analysis by ergonomists using ergonomic methods and physical examinations made by occupational physicians on the presence of musculoskeletal disorders of the upper extremities. Background: Ergonomics is the systematic application of principles concerned with the design of devices and working conditions for enhancing human capabilities and optimizing working and living conditions. Proper ergonomic design is necessary to prevent injuries and physical and emotional stress. The major types of ergonomic injuries and incidents are cumulative trauma disorders (CTDs), acute strains, sprains, and system failures. Minimization of use of excessive force and awkward postures can help to prevent such injuries Method: Initial data were collected as part of a larger study by the University of Utah Ergonomics and Safety program field data collection teams and medical data collection teams from the Rocky Mountain Center for Occupational and Environmental Health (RMCOEH). Subjects included 173 male and female workers, 83 at Beehive Clothing (a clothing plant), 74 at Autoliv (a plant making air bags for vehicles), and 16 at Deseret Meat (a meat-processing plant). Posture and effort levels were analyzed using a software program developed at the University of Utah (Utah Ergonomic Analysis Tool). The Ergonomic Epicondylitis Model (EEM) was developed to assess the risk of epicondylitis from observable job physical factors. The model considers five job risk factors: (1) intensity of exertion, (2) forearm rotation, (3) wrist posture, (4) elbow compression, and (5) speed of work. Qualitative ratings of these physical factors were determined during video analysis. Personal variables were also investigated to study their relationship with epicondylitis. Logistic regression models were used to determine the association between risk factors and symptoms of epicondyle pain. Results: Results of this study indicate that gender, smoking status, and BMI do have an effect on the risk of epicondylitis but there is not a statistically significant relationship between EEM and epicondylitis. Conclusion: This research studied the relationship between an Ergonomic Epicondylitis Model (EEM) and the occurrence of epicondylitis. The model was not predictive for epicondylitis. However, it is clear that epicondylitis was associated with some individual risk factors such as smoking status, gender, and BMI. Based on the results, future research may discover risk factors that seem to increase the risk of epicondylitis. Application: Although this research used a combination of questionnaire, ergonomic job analysis, and medical job analysis to specifically verify risk factors related to epicondylitis, there are limitations. This research did not have a very large sample size because only 173 subjects were available for this study. Also, it was conducted in only 3 facilities, a plant making air bags for vehicles, a meat-processing plant, and a clothing plant in Utah. If working conditions in other kinds of facilities are considered, results may improve. Therefore, future research should perform analysis with additional subjects in different kinds of facilities. Repetition and duration of a task were not considered as risk factors in this research. These two factors could be associated with epicondylitis so it could be important to include these factors in future research. Psychosocial data and workplace conditions (e.g., low temperature) were also noted during data collection, and could be used to further study the prevalence of epicondylitis. Univariate analysis methods could be used for each variable of EEM. This research was performed using multivariate analysis. Therefore, it was difficult to recognize the different effect of each variable. Basically, the difference between univariate and multivariate analysis is that univariate analysis deals with one predictor variable at a time, whereas multivariate analysis deals with multiple predictor variables combined in a predetermined manner. The univariate analysis could show how each variable is associated with epicondyle pain. This may allow more appropriate weighting factors to be determined and therefore improve the performance of the EEM.