• The Journal of Korean Academy of Prosthodontics
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• v.32 no.1
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• pp.120-147
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• 1994

This study was performed for the purpose of evaluating the stress distribution around threaded type implants, cylindrical type implants and teeth connected with rigid or non-rigid connector. The stress distribution around the surrounding bone was analyzed by three-dimensional photoelastic method. Twelve mandibular photoelastic epoxy resin models and a circular polariscope were used to record the isochromatic fringes. After the stress distribution around the implant and tooth was observed, the results were as follows ; 1. In threaded type implants, stress concentrated patterns were observed at the neck either vertical or 25 degree lateral force. 2. The stress concentrated patterns were observed at the tooth apical portion and neck portions of the implant and tooth when a threaded implant was connected with the tooth by either a rigid or non-rigid connector. More force was generated at the tooth neck portion by a rigid connector and more force at the implant neck portion by a non-rigid connector. 3. The stress concentrated patterns were observed at the apical portion of the implant and tooth when a cylindrical type ,implant was connected with the tooth either by a rigid or non-rigid connector. More force was generated at the tooth apical portion by a rigid connector and more force at the neck portion of the tooth and implant by a non-rigid connector. 4. The stress around the tooth was more equally distributed in a threaded type implant than in a cylindrical implant when the tooth was connected with either a rigid or non-rigid connector. 5. The stress around a threaded type implant was progressively more equally distributed in the following order : 1) when used a single implant, 2) a non-rigid connection with the implant and tooth, 3) a rigid connection with the implant and tooth, 4) a rigid connection with two implant fixtures.

• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.49-54
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• 2000

Background: Echocardiography is rapidly establishing itself as the primary diagnostic technique for investigation of children with heart diseases, and referrals are increasing to the pediatric cardiology clinic for investigation. However, because there is a lack of analyzed data on the patients referred to the pediatric cardiology clinics, we have proceeded to compare and analyze their characteristics to provide basic data base. Methods: From Oct. 1, 1998 to Jul. 10, 1999, total 443 cases referred to the pediatric cardiology clinic of Yeungnam University Hospital were studied retrospectively by medical records, chest X-ray, EKG and echocardiography, etc. Results: The results were as follows. 1. The proportion of male was 61.0%(261 cases) and that of female was 39.0%(67 cases). The ratio of male to female was 1.6:1. The proportion infants less than 1 year-old was 62.6% (26R cases) of all patients. 2. Cardiac murmur was present in 248 cases(57.9%), which was the most common case of referral ed to the pediatric cardiology clinic. The impression at referral was more congenital heart disease(70.6%) than acquired heart disease(17.8%) and arrhythmia01.6%). 3. The final diagnosis was as follows : congenital heart disease was present in 212 cases(49.5%), acquired heart disease, 59 cases(13.9%); arrhythmia. 13 cases(3.0%); normal heart. 144 cases(33.6%). Conclusion: Among the patients referred to pediatric cardiology clinic, 33.6%(144 cases) had normal hearts and why these patients were referred may be possibly due to more dependence on echocardiography than on auscultation instruction. Therefore, clinical and auscultatory skill should be emphasized to minimize dependence on expensive echocardiography for evaluation of pediatric heart disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.264-273
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• 2012

This cross-sectional study was investigated musculoskeletal discomfort symptoms and related factors on some middle high school teachers. Self-questionnaire of KOSHA CODE H-30-2003 was done with 250 teachers from 1st to 15th October, 2010, the data from 231 teachers (68 male, 163 female) was statistically analyzed to search the factors related to musculoskeletal discomfort symptoms. According to NIOSH rate of musculoskeletal discomfort symptoms by body parts was 36.8%. Musculoskeletal discomfort symptoms related to age, school types, subjective health status, housekeeping time, VDT work time and regular rest. After adjusting for related variables, odds ratio (OR) of musculoskeletal discomfort symptoms was correlation significantly to subjective health status unhealthy (OR 11.75, 95% Confidence Interval, CI, 3.56-378.78). In addition, ORs (95% CI) of age (40-49) and housekeeping time (${\geq}3$) were 4.63 (1.82-26.18) and 4.33 (1.97-19.34). Analysis of the factors influencing the musculoskeletal discomfort symptoms vary in different parts of the body. The most discomfort symptoms by parts was neck (26.0%) and shoulder (30.0%). In the neck region was related to subjective health status and regular rest. In the shoulder and waist region was subjective health status and sex. Age was wrist/finger, leg/foot was related to subjective health status, sex and VDT work time. Age, school types, subjective health status, housekeeping time, VDT work time and regular rest related to musculoskeletal discomfort symptoms and the most discomfort symptoms by parts was neck and shoulder.

• 한국해양학회지
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• v.30 no.4
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• pp.320-331
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• 1995

The closely spaced cores were analyzed to find detailed reconstruction of paleoenvironments and sealable changes along the Delaware Bay coast. Three areas, Kitts Hummock Beach mars, the St. Jones River marsh, and Bowers marsh near the St. Jones River's mouth, were chosen because these areas are compose of their own geomorphic characteristics and sea-level history. since significance of the stratigraphic correlations was to determine sedimentary fancies and paleoenvironments, multidisciplinary methods such as lithological description, grain-size analysis, organic/inorganic content, water content, mineral composition, botanical analysis, micropaleontological analysis, and /SUP 14/C datings were performed. Five major divisions of marsh environments were recognized in the stratigraphic sections: freshwater marsh, initialfreshwater marsh, slightly brackish marsh, brackish marsh, and salt marsh. Most of the lower part in the stratigraphic sections show freshwater marsh. On the top of this, either brackish marsh or tidal flat/tidal stream was recorded. The pro-Holocene sediments consist of sand, mud, and sandy mud, The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene sediments consist of sand, mud, and sandy mud. The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene surface within short distances permitted the concurrent development of variable environments such as freshwater marsh, brackish marsh or salt marsh at similar elevations. The freshwater marsh in this case was formed in the areas of isolation, so saline-water cannot encroach upon these areas. This complex development of paleoenvironments leads to a difficulty in stratigraphic correlation and interpretation of local relative sea-level changes. The deposition of subsurface sediments was affected by sediment supply, compaction, fluvial activity, biological competition, local tectonics and isostacy, climate and local relative sea-level changes. It was interpreted that the positions in the changes from freshwater environments to brackish environments or ice versa are the turning points of transgressions and regressions. Therefore, multiple transgressions and regressions were identified in the stratigraphic sections of the study area.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.593-598
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• 1996

The large number of past investigation on extended myocardial protection clearly indicates that cold potassium cardioplegia and topical cooling have limited capabilities. Accordingly, more recent experimen- tal approaches have focused on the modalities of reperfusion and their implication on postischemic myo- cardial recovery. Oxygen may play a crucial role in the development of ischemic and reperfusion injury. Reactive oxygen radicals may be produced during ischemia or reperfusion after incomplete reduction of molecular oxygen or from other pathway and then induce fatal injury of the heart. The important obser- vation of oxygen-induced myocardial damage during reperfusion has led to the concept of applying oxy- gen free radical scavengers. So, this study is on dietary vitamin C supplementation as antioxidant in rats to determine whether or not they have a higher tolerance against cardiac ischemia-reperf'usion injury under Langendorff system. Male or female Sprague-Dawley rats (190-33Og) were randomly separated into two groups. Group A was not treated(n=10). Group B received vitamin C supplement (n=10). Experiment was performed 24 hours after vitamin C 200mg fed orally as injectable ascorbic acid. There were significant differences in contractile parameters between control and vitamin C-treated group. The RLVP (r te of post/preischemic left ventricular pressure) and Rdp/dt (rate of post/preischemic dp/dt) were significant statistically between two groups (p<0.05). But, RHR (rate of post/preischemic heart rate), time to first beat and sta'utilization were not significant. In conclusion, pretreatment with the antioxidant, ascorbic acid, was found to preserve left ventricular contractile function. But the precise mechanism of action of ascorbic acid has not as yet been determined, so further study will be required.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.1-9
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• 2001

Purpose: Gastroesophgeal reflux (GER) is defined as involuntary movement of gastric contents into esophagus. Relaxation of lower esophageal sphincter caused by immature anatomical development in newborn and young infants produces GER frequently. We wanted to know whether the frequency of GER is influenced by feeding types and position or not. We studied in 16 subjects according to feeding types (breast feeding group: BFG-7, formula feeding group: FFG-9) who admitted to the Soonchunhyang university hospital for recurrent regurgitation with 24 hr esophageal pH monitoring from August 1996 to July 1999. Methods: We compared two groups by number of reflux episode, reflux rate, longest episode, numbers of episodes lasting >5 minutes, longest episode in upright position and longest episode in supine position. We used Mann-Whitney test for statistical analysis. Results: 1) The subjects were 7 infants in BFG and 9 infants in FFG, 16 in total, and mean age was 2.1, and 2.6 months for BFG and FFG, respectively. 2) The reflux numbers were $244{\pm}151/day$, $275{\pm}155/day$ for BFG and FFG, respectively. 3) The reflux rate was $14{\pm}15%$ for BFG and $28{\pm}22%$ for FFG. It was lower in BFG. 4) The longest episode was $20{\pm}28$ minutes for BFG and $58{\pm}66$ minutes for FFG. It was significantly longer in FFG. 5) The numbers of episodes lasting >5 minutes were $5{\pm}6$ for BFG and $9{\pm}3$ for FFG. 6) The longest episode in upright position was $10{\pm}8$ minutes for BFG and $40{\pm}47$ minutes for FFG. It was significantly shorter in BFG. 7) The longest episode in supine position was $18{\pm}29$ minutes for BFG and $52{\pm}66$ minutes for FFG. It was significantly shorter in BFG. Conclusion: Breast feeding is strongly recommended to reduce the regurgitation in infancy. It is an another benefit of breast feeding.

• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.330-335
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• 2010

This study was performed to compare the anesthetic and cardiorespiratory effects of the tiletamine/zolazepam/xylazine (TZX) combination and tiletamine/zolazepam/midazolam (TZM) combination. Eight healthy Landrace $\times$ Yorkshire pigs were randomly assigned to two groups. Each group was composed of four pigs. The pigs in group 1 (TZX) received tiletamine/zolazepam (2 mg/kg, IM) and xylazine (2 mg/kg, IM). The pigs in group 2 (TZM) received tiletamine/zolazepam (2 mg/kg, IM) and midazolam (0.5 mg/kg, IV). Induction time, anesthesia time and standing time were recorded for each pig. The scores of anesthetic effects were subjectively evaluated every 15 minutes during anesthesia. Cardiopulmonary parameters (heart rate, arterial blood pressure, respiratory rate and rectal temperature) were monitored and recorded 0, 5, 15, 30, 45 and 60 minutes after administration of drugs. Arterial blood gases ($pH_a$, $P_aCO_2$ and $P_aO_2$) and oxygen saturation ($SO_2$) were analyzed at same times. The scores of anesthetic effects decreased in the TZX group compare with the TZM group. From 5 to 85 minutes the mean heart rate in the TZX group was significantly lower than those in the TZM group. Mean arterial blood pressure in the TZX group was significantly higher than those in the TZM group at 5, 15 and 30 minutes. Both drug combinations provided a smooth induction and good immobilization. Scores of anesthetic effects in the TZM group were better than those in the TZX group. The effects to the cardiorespiratory function and temperature were lesser in the TZM group than those in the TZX group. In conclusion, when the two drug combinations were compared, the TZM group showed better anesthetic effects and less cardiorespiratory effects.

• PNF and Movement
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• v.19 no.3
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• pp.423-433
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• 2021

Purpose: Proprioceptive neuromuscular facilitation (PNF) is a method for promoting functional movements by facilitating neuromuscular responses through the stimulation of proprioceptors in the body using spiral and diagonal patterns. Irradiation, a basic principle of PNF, is a phenomenon in which the muscle activity of a body part caused by resistance is increased or spread into muscles in other parts via their connected muscles. Resistance training can be divided by body alignment into closed and open chain exercises. Methods: In this study, 19 healthy men in their 20s and 30s were selected as subjects. They performed PNF hip flexion, abduction, and internal rotation motions on their dominant side in an open chain exercise posture in which the nondominant sole was away from the wall, and in a closed chain exercise posture in which the sole was fixed to the wall. The nondominant leg's muscle activity was measured while resistance was maintained with applied pressure at 0%, 25%, 50%, 75%, and 100% of the maximum muscle strength in the last range of motions. A two-way analysis of variance (ANOVA) was conducted for a comparative analysis of the contralateral leg's muscle activity according to the chain exercise postures and the intensity of resistance intensity during PNF hip flexion, abduction, and internal rotation. In addition, an independent sample T-test was conducted for a comparative analysis of each chain exercise posture according to the intensity of resistance. A one-way ANOVA and a Scheffe post-hoc test were also performed to analyze the contralateral leg's muscle activity according to the intensity of resistance in the closed and open chain exercise postures. Results: Results of the two-way ANOVA found that the gluteus medius and the biceps femoris had statistically significant differences in both the chain exercise postures and resistance intensity (p<0.05), and that the vastus medialis and the gastrocnemius did not exhibit statistically significant differences in the chain exercise postures (p>0.05) but showed statistically significant differences in resistance intensity (p<0.05). As a result of the independent sample T-test, the application of the PNF hip flexion-abduction-internal rotation pattern led to a statistically significant difference in the contralateral gluteus medius during the closed chain exercise posture (p<0.05). According to the results of the one-way ANOVA and the Scheffe post-analysis, statistically significant differences were observed in the gluteus medius at 50%, biceps femoris at 75%, vastus medialis at 100%, and gastrocnemius at 100% during the closed chain exercise posture based on a resistance intensity of 0% (p<0.05). In the open chain exercise posture, statistically significant differences were found in the gluteus medius at 50%, biceps femoris at 50%, and vastus medialis at 75% based on the resistance intensity of 0% (p<0.05). In the same posture, there was no significant difference in the gastrocnemius's resistance intensity (p>0.05). Conclusion: When the PNF leg pattern is applied, each muscle requires effective chain exercise postures and resistance intensity to generate the contralateral leg muscle's irradiation.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.667-685
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• 2022

This paper aims to investigate 4D printing materials for soft robots. 4D printing is a targeted evolution of the 3D printed structure in shape, property, and functionality. It is capable of self-assembly, multi-functionality, and self-repair. In addition, it is time-dependent, printer-independent, and predictable. The shape-shifting behaviors considered in 4D printing include folding, bending, twisting, linear or nonlinear expansion/contraction, surface curling, and generating surface topographical features. The shapes can shift from 1D to 1D, 1D to 2D, 2D to 2D, 1D to 3D, 2D to 3D, and 3D to 3D. In the 4D printing auxetic structure, the kinetiX is a cellular-based material design composed of rigid plates and elastic hinges. In pneumatic auxetics based on the kirigami structure, an inverse optimization method for designing and fabricating morphs three-dimensional shapes out of patterns laid out flat. When 4D printing material is molded into a deformable 3D structure, it can be applied to the exoskeleton material of soft robots such as upper and lower limbs, fingers, hands, toes, and feet. Research on 4D printing materials for soft robots is essential in developing smart clothing for healthcare in the textile and fashion industry.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2015.05a
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• pp.545-570
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• 2015

Korea is among the ten countries with the largest R&D budget and the highest R&D investment-to-GDP ratio, yet the subject of security and protection of R&D results remains relatively unexplored in the country. Countries have implemented in their legal systems measures to properly protect cutting-edge industrial technologies that would adversely affect national security and economy if leaked to other countries. While Korea has a generally stable legal framework as provided in the Regulation on the National R&D Program Management (the "Regulation") and the Act on Industrial Technology Protection, many difficulties follow in practice when determining details on security management and obligations and setting standards in carrying out national R&D projects. This paper proposes to modify and improve security level classification standards in the Regulation. The Regulation provides a dual security level decision-making system for R&D projects: the security level can be determined either by researcher or by the central agency in charge of the project. Unification of such a dual system can avoid unnecessary confusions. To prevent a leakage, it is crucial that research projects be carried out in compliance with their assigned security levels and standards and results be effectively managed. The paper examines from a practitioner's perspective relevant legal provisions on leakage of confidential R&D projects, infringement, injunction, punishment, attempt and conspiracy, dual liability, duty of report to the National Intelligence Service (the "NIS") of security management process and other security issues arising from national R&D projects, and manual drafting in case of a breach. The paper recommends to train security and technological experts such as industrial security experts to properly amend laws on security level classification standards and relevant technological contents. A quarterly policy development committee must also be set up by the NIS in cooperation with relevant organizations. The committee shall provide a project management manual that provides step-by-step guidance for organizations that carry out national R&D projects as a preventive measure against possible leakage. In the short term, the NIS National Industrial Security Center's duties should be expanded to incorporate national R&D projects' security. In the long term, a security task force must be set up to protect, support and manage the projects whose responsibilities should include research, policy development, PR and training of security-related issues. Through these means, a social consensus must be reached on the need for protecting national R&D projects. The most efficient way to implement these measures is to facilitate security training programs and meetings that provide opportunities for communication among industrial security experts and researchers. Furthermore, the Regulation's security provisions must be examined and improved.