• Journal of radiological science and technology
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• v.44 no.3
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• pp.173-181
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• 2021

The purpose of this study was to reduce dose while maintaining image quality during digital radiographic examination of paranasal sinus by using the automatic exposure control (AEC) system. The tube voltage was set as six stages that increased by about 10 kVp to 70 kVp, 81 kVp, 90 kVp, 102 kVp, 109 kVp and 117 kVp. And then the AEC system conditions were consisted of 9 setting environments, that change mode of the sensitivity (S200, S400, S800) and the density (+2.5, 0, -2.5). We measured automatically exposed tube current (mAs) under 54 conditions with combined these, and assessed SNR and PSNR through the acquired images. In addition, four radiologists performed a qualitative assessment of the acquired images for each combination on a five-point scale of the Likert. As a result, the lowest dose and the highest values of SNR and PSNR in images with a qualitative assessment more than 4 point were the AEC control factors of 90 kVp, S800, D2.5. We applied this condition to the clinical trial, it showed an effect of 83.1% reduction in exposure radiation dose (mR). Therefore, AEC system could be used as dose reduction technology if it understood and used related regulatory factors and physical characteristics.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.111-116
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• 2022

In this study, the applicability of machine learning for the development of a simulator for general X-ray examination education is evaluated. To this end, k-nearest neighbor(kNN), support vector machine(SVM) and neural network(NN) classification models are analyzed to present the most suitable model by analyzing the results. Image data was obtained by taking 100 photos each corresponding to Posterior anterior(PA), Posterior anterior oblique(Obl), Lateral(Lat), Fan lateral(Fan lat). 70% of the acquired 400 image data were used as training sets for learning machine learning models and 30% were used as test sets for evaluation. and prediction model was constructed for right-handed PA, Obl, Lat, Fan lat image classification. Based on the data set, after constructing the classification model using the kNN, SVM, and NN models, each model was compared through an error matrix. As a result of the evaluation, the accuracy of kNN was 0.967 area under curve(AUC) was 0.993, and the accuracy of SVM was 0.992 AUC was 1.000. The accuracy of NN was 0.992 and AUC was 0.999, which was slightly lower in kNN, but all three models recorded high accuracy and AUC. In this study, right-handed PA, Obl, Lat, Fan lat images were classified and predicted using the machine learning classification models, kNN, SVM, and NN models. The prediction showed that SVM and NN were the same at 0.992, and AUC was similar at 1.000 and 0.999, indicating that both models showed high predictive power and were applicable to educational simulators.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.498-510
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• 2001

Distraction osteogenesis refers to the biological process responsible for new bone formation between bone segments by gradual distraction after osteotomy. For the past several years, various inconveniences including a protracted consolidation period that requires patients to wear a distractor frame longer, as well as higher medical costs, have not been remedied by improvements in osteotomy, distraction rate and monitoring system. Furthermore, side effects such as pin tract infections and soft tissue swelling may arise due to the long treatment period. These drawbacks form the rationale of this study which purports to seek a method by which the consolidation period can be reduced. This paper examines how platelet-rich plasma(PRP), known to facilitate osteogenesis, influences bone formation when applied in distracted area. Ten mongrel dogs, which were made to wear external distractor frames after osteotomy in both sides of the mandible, were used as subjects. After a 7day period of latency, distraction was carried out at a rate of 1mm/day for 14 consecutive days. After the onset of distraction, 2ml of PRP and a mixture of calcium gluconate and thrombine were injected into the center of the distracted callus on the left side of the mandible. The left was injected with PRP while the right side was set as the control site without PRP treatment. Execution at the onset of distraction and in 2 weeks, 4 weeks and 8 weeks after the consolidation period, clinical and radiographic tests, bone mineral density examination, histological examination and histomorphometric analysis were conducted to compare both sides. The results are summarized as follows: 1. Based on the clinical examination at two weeks, more remarkable cortical bone formation was found on the buccal and lingual side of the distracted area in the PRP treatment site than in the control site. No visual difference was found between the PRP treatment site and the control site at four eight weeks. 2. Based on the radiological examination, a distinct increase in the radiopaque appearance of the PRP treatment site was revealed at two weeks, but this increase appeared to slow down at four and eight weeks. 3. Examination of bone mineral density revealed a significant difference at two weeks with the PRP treatment site yielding density two times higher than the control site. This difference lessened after four weeks, and disappeared at eight weeks. 4. The histomorphometric examination revealed that about 20% more bony trabeculae area(20%, higher) was formed in the PRP treatment site than in the control site. In conclusion, it can be said that PRPs effect on stimulating bone formation in the PRP treatment site manifest as early as two weeks. Trabeculae formation likewise increased throughout the whole period. If this result can be applied to humans, the consolidation period can be reduced by injecting PRP into the distracted area.

• Journal of Acupuncture Research
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• v.31 no.1
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• pp.159-165
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• 2014

Background and objectives : Social phobia is a nervous anxiety characterized by one or more constant fear in social activity or specific situation which causes serious damage to individual's social functions leading to chronic functional impairment when it is untreated. The objective of this study is to report a new finding of a possible subtype of social phobia according to a case survey and study of sufferers found via online support group. Methods : A single case review using survey and interview on patient was employed. Following a no-treatment baseline period for examination and interview, biweekly acupuncture treatment with interview for in-depth examination was delivered for 6months. Also, for in-depth investigation of peripheral vision phobia, survey questionnaire was done by the members of a Korean support group on on-line social group forum. Result : A new type of social phobia which has not yet been reported nor mentioned in any journals, namely called 'peripheral vision phobia' has been identified. Biweekly acupuncture treatment reached a comfort state of mental status on one case of patient with social phobia. Limitation : Due to the shift of environment on patient's part, the termination of the school session at where the phobia occur the most, the reoccurrence of the phobia is yet to be examined. Also, the generalization of the new type of phobia as a subtype only by reviewing one case alone with survey interview of on-line social group has limitation. Conclusion : The result of the case review suggests that 'peripheral vision phobia' is strictly concentrated on malfunctioning of peripheral vision without functional or organic hindrance of pupils or of any parts of eyes including eye muscles due to peripheral vision phobia. PVP is similar to social phobia and it may be a subtype of social phobia, however, since etiology, diagnosis, medical treatment methods are under researched, investigation is yet to be done.

• Journal of radiological science and technology
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• v.46 no.2
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• pp.99-106
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• 2023

The height of the table should be considered important during computed tomography (CT) examination, but according to previous studies, not all radiology technologists set the table at the patient's center at the examination, which affects the exposure dose and image quality received by the patient. Therefore, this study intends to study the image quality exposure dose according to the height of the table to realize the optimal image quality and dose during the brain CT scan. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. For the exposure dose measurement, optically stimulated luminescence dosimeter (OSLD) was attached to the front, side, eye, and thyroid gland of the head phantom. In the signal to noise ratio (SNR) measurement result, The SNR values for each table height were all lower than 915 mm. As a result of exposure dose, the exposure dose on each area increased as the table height decreased. The height of the table has a close relationship with the patient's radiation exposure dose in the CT scan.

• 월간산업보건
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• s.5
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• pp.4-15
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• 1988

In order to proffer the fundamental data for the better working environment and the effective establishment of hearing conservation program on workers exposed to industrial noise, author assessed noise levels on the 42 noisy processes among 84 manufactures of 9 industries and measured noise gearing loss by the type of industries on 3,104 workers at these noisy processes from March, 1986 to Februry, 1987. The results were summarized as follows: 1. The averge of A-weight sound level of 23 processes(54.8%) and the avergae of sound level at each octave band of 14 processes(33.3%) exceeded the permissible exposure limits in 8 hours per day. 2. The noise level was the highest in process of cocking of ship building(109.1dBA), and followed by plating of steel rolling(104.3dBA), rivet of manufacture of motor vehicles(102.5dBA), shot of ship building(98.5dBA), aciding(95.7BA) and steel tubing(95.0dBA) of steel rolling, weaving of textiles(95.0dBA). 3. The permissible exposure time for the average of sound level at each octave band was only 30 minutes in the process of cocking of ship building, plating of steel rolling and rivet of manufacture of motor vehicles. 4. As a result of audiometric examination in 3,104 workers, the rate of hearing loss over 50dB at 4,000Hz was 7.3%(227 workers) and the rate of hearing loss over 41dB at 60average method was 2.9%(89 workers). 5. The prevalence of occupational hearing loss in ship building and manufacture of motor vehicle was 5.2% and it was the highest among prevalence of these 9 industries. 6. As a result of this suvery, the noise control and gearing conservation program were required especially in the industry of ship building and manufacture of motor vehicle.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.300-305
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• 2008

Purpose: The purpose of our study was to evaluate the volume of pre- and post operative masseter muscle and bite force in mandibular prognathic patients treated with SSRO with the use of the 3D CT imaging technique and occlusal force meter. Materials and methods: The study group consisted of 12 patients with mandibular prognathism (5 males and 7 females) who underwent mandibular setback surgery (BSSRO) in the Department of Oral and Maxillofacial Surgery, Samsung medical center. Bite force was measured at pre op, post op 3, 6 and 12 months by occlusal force meter(GM10, Nagano Keiki, Japan) The preoperative CT examination of subjects was performed between one month prior to operation and one year after to operation. And muscle volume was measured. Result: As compared to preoperative measurements at 1 year postoperatively the masseter & internal pterygoid muscle volume were diminished (p<0.05) The bite force steadily recovered, so at postoperatively 6 months reached the preoperative level. And at 1 year after operation, the maximum bite force was significantly greater than preoperative levels. No significant correlation was presented between masseter muscle and bite force (p>0.05), internal pterygoid muscle and bite force (p>0.05). Conclusion: In this study, the results showed that volume and bite force of the masticatory muscles decreased significantly immediate after orthognathic surgery for mandibular set-back. However, reduction of maximum bite force disappears within 6 months after surgery.

• Quality Improvement in Health Care
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• v.6 no.1_2
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• pp.48-79
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• 1999

Background : The clothing is considered as second skin. The patient clothing needs basic clothing demands which are comfortable, functional and aesthetical and special demeands which are associated with medical examination, treatment and management of daily-life inconveniences. The patient is weak and labile to psychic trauma and has limitation of movement. So the help of others is needed. But recent patient clothing does not satisfy above demands. So the design, making and management of patient clothing to satisfy those demands are very important. The purpose of this study' is to develop multipurpose clothing which is comfortable, functional, aesthetical and satisfying patients and medical personnels. Method : The questionnaires of existing patient clothing were tested by patients, medical doctors, and nurses. After analyzing two types of questionnaires, eight types of experimental patient clothing were made. After preference test, shortcomings were removed and merits were adapted. One type of multipurpose patient clothing mixing eight above experimental clothing was made. The state of wearing and moving were videotaped. The videotape-recoding was watched by patient, caregivers(medical doctors, nurses) and clothing specialists. Result : The general reaction for experimental clothing were positive by the group of patients, medical personnels and clothing specialist, there were significant differences among three groups. Conclusion : It was thought that to develop one type of multipurpose clothing is possible. If the studys for patient clothing which are free-size and economic matters that are type of clothes and method of washing are made in depth, the desirable patient clothing will appear.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.127-137
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• 2017

This study aims to identify the awareness and performance level of hospital infection control in medical technicians working in small and medium-sized hospitals. The experiment was conducted in 235 medical technicians (medical laboratory technologist, radiological technologist, and physical therapist), and for statistical processing, SPSS Ver.23.0 was used to conduct mean and standard deviation, analysis of variance, and regression analysis. As a result, it was found that the major cause of improper infection control was lack of experts ($3.17{\pm}1.18$) and performance level was statistically significantly lower than awareness of infection control. "I took no measures after infection accident" was responded the highest at 40.0%(94 persons), and in "I reported to the head of department after disinfection, examination, and/or vaccination," the standardized regression coefficient ${\beta}$ was -0.265, p=0.025, which suggested that there was a significant negative (-) impact. Infection control level showed a significant positive correlation with training and infection control instructions. Therefore, it was found that medical technicians in small and medium-sized hospitals required high skilled manpower in infection control, training, infection control instructions, etc. Through this study, more effective infection control is considered to be possible.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.7 no.1
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• pp.113-120
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• 2012

Objectives : This study was performed to report the effect of oriental medical treatment including chuna manual therapy for the spondylolisthesis patient. Methods : We treated him by oriental medical treatment including acupuncture, herb therapy and chuna manual therapy. And the result was assessed by numerical rating scale(NRS), walking distance at once and radiological examination. Results : After treatment, NRS changed from 8 to 4, walking distance at once changed from 175m to 500m, percent of slip changed from 28.62% to 19.80% and slip angle changed from $20.0^{\circ}$ to $22.8^{\circ}$. Conclusions : In this study, oriental medical treatment including chuna therapy was effective in spondylolisthesis patient. But additional studies will be needed.