• PNF and Movement
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• v.17 no.2
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• pp.215-222
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• 2019

Purpose: The objective of this study was to investigate whether augmented low-dye taping treatment, which consists of low-dye, reverse-six, and calcaneal-sling taping, is effective in alleviating the collapse of the medial longitudinal arch, which is used for physical balancing during one leg standing. Methods: The subjects comprised 27 students in their 20s whose navicular bone height was lowered by 10 mm or more when evaluated using the navicular drop test. Those with interference factors like deformities, fractures, or traumas were excluded. Frequency-division multiplexing was used to measure one leg standing, and the method to avoir the average each time after 3 times of measurement was applied. Results: Significant differences in the center of pressure (COP) path length, COP average velocity, and forefoot force were observed during left leg standing (p<0.05), but for right leg standing, only changes in forefoot force were noted. Conclusion: Based on the changes to the non-dominant leg in terms of COP path length, COP average velocity, and forefoot force, the immediate effect of augmented low-dye taping, which combines three types of anti-pronation taping, on one leg standing balance in people with flat feet was confirmed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.865-868
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• 2001

We designed and fabricated a planner-type thermoelastic microactuator with a latch-up operation for optical switching. Latch-up actuation is prerequisite to implement an optical switch with low power consumption and high reliability. The proposed microactuator consists of four cantilever-shaped thermal actuators, four displacement linkages, two shallow arch-shaped leaf springs, a mobile shuttle mass with a micromirror, and four elastic boundaries. The structural layer of the planar microactuator is phosphorous-doped 12$\mu\textrm{m}$-thick polysilicon, and the sacrificial layer is LTO(Low Temperature Oxide) of 3$\mu\textrm{m}$thickness. The displacement of actuator is as large as 3$\mu\textrm{m}$when the length of actuation bar is 100$\mu\textrm{m}$in length at 5V input voltage. The proposed microactuators have advantages of easy assembly with other optical component by way of fiber alignment in the substrate plane, and its fabrication process features simplicity while retaining batch-fabrication economy.

• Journal of Korean society of Dental Hygiene
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• v.15 no.3
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• pp.399-410
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• 2015

Objectives: The purpose of the study is to investigate the influencing factors of metabolic syndrome on the periodontal disease in the Korean adults over 40 years old. Methods: The data were extracted from the Fifth National Health Nutrition Survey 2010. The subjects were adults over 40 years old. The periodontal diseases were examined by direct survey. The questionnaire consisted of the general characteristics of the subjects, oral health behavior, metabolic syndrome, and relation to periodontal diseases. CPI(community periodontal index) was measured. CPI indicates periodontal condition and classified into alveolar arch of the upper jaw and the lower jaw. A periodontal disease is defined as $CPI{\geq}3$(over 4 mm). The variables for metabolic diseases included hypertension, diabetes mellitus, dyslipidemia, and obesity measured as BMI. Results: Diabetes mellitus is closely related to periodontal diseases prevalence. Low level of HDL increase the periodontal diseases. Number of toothbrushung, use of dental floss and interdental toothbrush as for the number of toothbrushing, more than twice toothbrushing a day, and use of dental floss and interdental toothbrush reduced periodontal diseases. Conclusions: The risk factors of periodontal disease in Korean adults over 40 years old were sex, age, residence, monthly income, education level, smoking, diabetes and low HDL cholesterol.

• Journal of Chest Surgery
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• v.25 no.3
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• pp.335-340
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• 1992

Truamatic aortic rupture is usually fatal if left untreated. Prompt diagnosis is the cornerstone of suscessful management. But the usual screening tests are non specific and the accuracy of computerized tomography is low, Aortography which is a time consuming procedure may result in false-positive interpretations and significant morbidity. Recently transesophageal echocardiography provides a rapid, effective and relatively safe means of evaluating the distal aortic arch and also affords the opportunity to evaluate the heart during the same study, which may be of benefit in cases of suspected cardiac injury. The experience with the traumatic aortic ruptured patient and a critical review of the literature suggests that transesophageal echocardiography is a useful technique for the diagnosis of ruptured aorta following blunt chest trauma.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.121-128
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• 2001

This is a case study of stability analysis and reinforcement design for the tunnel where the collapse of the entrance slops occured along the fault zone developed in the bed rock. According to the site investigation, the main factor of sliding is the influence of fault gouge and heavy rainfall. Considering the in-situ condition, the versatile reinforcement methods is needed, and so the close investigation on the site area was accompanied with the stability analysis of tunnel and slops. The FRP(Fiberglass reinforced plastic) grouting method improved the defect of Steel Umbrella Arch Method, such as oxidation, low work efficiency, the material's heavy weight, is adapted as the reinforcement methods.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1004-1005
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• 2006

The effect of tempering temperature and microstructure on dry sliding wear behavior of quenched and tempered PM with 0.3% graphite and 1-2% Ni steels was investigated. The sintered specimens were quenched from $890^{\circ}C$ and then tempered at $200^{\circ}C$ and $600^{\circ}C$ for 1 hr. Wear tests were carried out on the quenched$\neq$tempered specimens under dry sliding wear conditions using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively increased with increasing tempering temperature and decreased with increasing Ni content.

• Journal of Chest Surgery
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• v.27 no.6
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• pp.455-459
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• 1994

We experienced 20 cases of acquired aortic diseases during last 1 year [Sep. 1992-Aug. 1993] with newly developed surgical strategies. There were 13 cases[65%] of aortic dissections, 5 cases[25%] of aortic aneurysms and 2 cases of Takayasu arteritis with mean age of 56 + 16 years[range:5-78].In ten cases of patients requiring ascending aortic replacement, femoral artery and femoral vein &/or RA auricle were used as cannulation site. With deep hypothermic circulatory arrest and retrograde cerebral perfusion of cold oxygenated blood via SVC, we can replace the ascending aorta and part of arch if necessary. The mean duration of circulatory arrest was 30 minutes[17-45 min]. In 5 cases of patients who requiring descending and thoracoabdominal aorta replacement, we used simple aortic crossclamping under normothermia with no heparin. The mean duration of aortic crossclamping was 37 minutes[25-50 min].The results of operation were as follow:Operative mortality[2 cases, 10%], delayed cerebral infarct[1], low extremity weakness[1] and intraoperative myocardial infarct[1]. There are no delayed complication or mortality as yet.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.242-252
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• 2016

Objective: Orthodontic mini-implants (OMI) generate various horizontal and vertical force vectors and moments according to their insertion positions. This study aimed to help select ideal biomechanics during maxillary incisor retraction by varying the length in the anterior retraction hook (ARH) and OMI position. Methods: Two extraction models were constructed to analyze the three-dimentional finite element: a first premolar extraction model (Model 1, M1) and a residual 1-mm space post-extraction model (Model 2, M2). The OMI position was set at a height of 8 mm from the arch wire between the second maxillary premolar and the first molar (low OMI traction) or at a 12-mm height in the mesial second maxillary premolar (high OMI traction). Retraction force vectors of 200 g from the ARH (-1, +1, +3, and +6 mm) at low or high OMI traction were resolved into X-, Y-, and Z-axis components. Results: In M1 (low and high OMI traction) and M2 (low OMI traction), the maxillary incisor tip was extruded, but the apex was intruded, and the occlusal plane was rotated clockwise. Significant intrusion and counter-clockwise rotation in the occlusal plane were observed under high OMI traction and -1 mm ARH in M2. Conclusions: This study observed orthodontic tooth movement according to the OMI position and ARH height, and M2 under high OMI traction with short ARH showed retraction with maxillary incisor intrusion.

• The korean journal of orthodontics
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• v.41 no.6
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• pp.399-410
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• 2011

Objective: The purpose of this study was to evaluate the difference in frictional resistance among metal, ceramic, self-ligation brackets and coated or non-coated Ni-Ti archwires at various bracket-archwire angulations during the sliding movement of an orthodontic archwire, using an orthodontic sliding simulation device. Methods: Four types of bracket (Micro-arch Perpect Clear2 Clippy-C and Damon3 and 5 types of orthodontic archwire (0.014", 0.016", and 0.016" ${\times}$ 0.022" inch coated Ni-Ti, and 0.016" and 0.016" ${\times}$ 0.022" inch Ni-Ti) were used. Further, the bracket- archwire angles were set at 4 different angulations: $0^{\circ}$, $3^{\circ}$, $6^{\circ}$, and $9^{\circ}$. Results: The frictions from all the experimental groups were found to be significantly increased in order of self-ligation brackets, Micro-arch and Perpect Clear2 ($p$ < 0.001). The presence of a coat had no effect on the friction of the same sized archwires at $0^{\circ}$ and $3^{\circ}$ bracket-archwire angles ($p$ < 0.001). Coated archwires had significantly higher frictions than the same sized non-coated archwires at $6^{\circ}$ and $9^{\circ}$ bracket-archwire angles ($p$ < 0.001). The frictions increased significantly as the bracket-archwire angles were increased ($p$ < 0.001). Conclusions: The use of self-ligation brackets will be beneficial in clinical situations where a low frictional force is required. Further, in cases where crowding is not severe, the use of coated archwires should not cause problems. However, more additional explanation is required considering the fact that the damage of coated archwire and exposure of the metal portion in case of binding and notching and the effects of saliva were not taken into account.

• Journal of Acupuncture Research
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• v.28 no.3
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• pp.73-84
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• 2011

Objectives : The purpose of this study is to evaluate the effect of 12 weeks-walking exercise with functional shoes on chronic low back pain. Methods : The subjects of this study were 18 females from thirty to sixty years old who had suffered from low back pain over 12 weeks. They wore S shoes with curved out-sole and soft material in arch of foot We asked them to walk wearing shoes for 1 hour a day over 4 days a week for 12 weeks. Improvement of the symptoms was evaluated by pain rating scale, Oswestry low-back pain disability index. We measured lumbar lordotic angle, Ferguson's angle, bone mineral density, body composition. The measurements were checked before and after exercise. Results : This study showed significant improvement in pain rating scale, oswestry low-back pain disability index, and body composition. And lumbar lordotic angle, Ferguson's angle and bone mineral density decreased. Conclusions : These results showed that walking exercise with functional shoes could decrease the symptoms of chronic low back pain. But, it's too difficult to conclude whether the efficacy was due to functional shoes or walking exercise because we didn't set the control group wearing general shoes.