• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.167-174
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• 2022

This study investigates the behavior of a jointless bridge that integrates superstructure and abutment without an expansion joint. Based on the sensitivity analyses conducted in previous studies, a shell-based model was determined to be the most suitable numerical analysis model for jointless bridges due to the similarity of the model's results compared with the obtained displacement shape, which was influenced by relative errors, precision, and practical aspects. Accordingly, the behavior of a jointless bridge was analyzed at various wall depths using shell element-based and solid element models. In addition, the results of MIDAS Civil and ABAQUS analysis programs were compared. In the case of semi-integrated bridges (A and B), the displacement decreased as the wall depth increased due to the ground reaction force in Case 1 under a linear spring condition and +30℃. In the case where temperature was -30℃, the change in displacement was small because the ground reaction did not occur. As for bridge C (a fully integrated alternating bridge) and bridge D (an integrated chest wall alternating bridge), the displacement decreased as the wall depth increased at both +30 and -30℃ due to pile resistance. As for the comparison between the analysis programs used, the relative error in Case 1 was small, whereas a significant difference in Case 2 was observed. The foregoing variation is possibly due to the difference in the application of the nonlinear spring in the programs.

• Composites Research
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• v.37 no.3
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• pp.238-245
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• 2024

In this study, as part of the development of a monitoring system for the efficient maintenance of steel pipes, an experimental study was conducted to evaluate the performance of steel pipes treated with modified polyethylene coating. In the case of the conventional mechanical pre-coating method, there was a deterioration in polyethylene adhesion during expansion testing, which led to the application of a chemical pre-treatment process using a calcium-mixed phosphate zinc film to resolve this issue. SEM and EDX analyses showed that the densest structure was observed at a Zn/Ca ratio of 1.0, and improved heat resistance compared to the conventional method was confirmed. Additionally, to prevent coating detachment during expansion, an evaluation of adhesion and elongation was conducted on steel pipes with modified polyethylene coating, incorporating materials such as elastomers based on maleic anhydride grafting, metal oxides, blocking agents, and slip agents. Experimental results showed that the specimen (S4) containing all modified materials exhibited more than a 25% performance improvement compared to the specimen (S2) containing only metal oxides. Lastly, the development and performance evaluation of wedge-shaped socketing and pressing wheels, which are part of the pipe fixing accessories, were conducted to prevent surface coating damage on the completed pipes.

• Journal of Korean Biological Nursing Science
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• v.1 no.1
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• pp.1-24
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• 1999

The purpose of this study was to define the content of requisite human structure and function knowledge needed for clinical knowledge of nursing practice. Subjects of human structure and function were divided into 10 units, and each unit was further divided into 21 subunits, resulting in a total of 90 items. Contents of knowledge of human structure and function were constructed from syllabus of basic nursing subjects in 4 college of nursing, and textbooks published by nurse scholars prepared with basic nursing sciences. The degree of need of 90 items was measured with a 4 point scale. The subjects of this study were college graduated 136 nurses from seven university hospitals in Seoul and three university hospitals located in Chonnam Province, Kyungbook Province, and Inchon. They have been working at internal medicine ward, surgical ward, intensive care unit, obstetrics and gynecology ward, pediatrics ward, opthalmology ward, ear, nose, and throat ward, emergency room, rehabilitation ward, cancer ward, hospice ward, and their working period was mostly under 5 years. The results were as follows: 1. The highest scored items of human structure and function knowledge necessary for nursing practice were electrolyte balance, blood clotting mechanism and anticoagulation mechanism, hematopoietic function, body fluid balance, function of plasma, and anatomical terminology in the order of importance. The lowest scored items of human structure and function knowledge necessary for nursing practice was sexual factors of genetic mutation. 2. The highest order of need according to unit was membrane transport in the living unit, anatomical terminology in movement and exercise unit, mechanism of hormone function in regulation and integration unit, component and function of blood in oxygenation function unit, structure and function of digestive system in digestive and energy metabolism unit, temperature regulation in temperature regulation unit electrolyte balance in body fluid and electrolyte unit, concept of immunity in body resistance unit, and genetics terminology in genetics unit. The highest order of importance according to subunit was membrane transportation in cell subunit, classification of tissues in tissue unit, function of skin and skin in skin subunit, anatomical derivatives of the skeleton subunit, classification of joints in joint subunit, an effect of exercise on muscles in muscle subunit, function of brain in nervous system subunit, special sense in sensory subunit mechanism of hormone function in endocrine subunit, structure and function of female reproductive system in reproductive system unit, structure and function of blood in blood unit, structure of heart, electrical and mechanical function in cardiovascular system unit, structure of respiratory system in respiratory system subunit, structure and function of digestive system in digestive system subunit, hormonal regulation of metabolism in nutrition and metabolism subunit, function of kidney in urologic system subunit, electolyte balance in body fluid, electolyte and acid-base balance subunit. 3. The common content of human structure and function knowledge need for all clinical areas in nursing was structure and function of blood, hematopoietic function, function of plasm, coagulation mechanism and anticoagulation mechanism, body fluid, electrolyte balance, and acid-base balance. However, the degree of need of each human structure and function knowledge was different depending on clinical areas. 4. Significant differences in human structure and function knowledge necessary for nursing practice such as skin and derivatives of the skin, growth and development of bone, classification of joint, classification of muscle, structure of muscle, function of muscle, function of spinal cord, peripheral nerve, structure and function of pancrease, component and function of blood, function of plasma, structure and function of blood, hemodynamics, respiratory dynamics, gas transport, regulation of respiration, chemical digestion of foods, absorption of foods, characteristics of nutrients, metabolism and hormonal regulation, body energy balance were demonstrated according to the duration of work. 5. Significant differences in human structure and function knowledge necessary for nursing practice such as classification of tissue, classification of muscles, function of muscles, muscle metabolism, classification of skeletal muscles, classification of nervous system, neurotransmitters, mechanism of hormone function, pituitary and pituitary hormone, structure and function of male reproductive organ, structure and function of female reproductive organ, component and function of blood, function of plasma, coagulation mechanism and anticoagulation mechanism, gas exchange, gas transport, regulation of respiration, characteristics of nutrients, energy balance, function of kidney, concept of immunity, classification and function of immunity were shown according to the work area. Based on these findings, all the 90 items constructed by Korean Academic Society of Basic Nursing Science should be included as contents of human structure and function knowledge.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.771-785
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• 2021

This study was performed to provide detailed and comprehensive information on inflammation-related blood indicators, joint range of motion, pain scale, and psychological indicators by patient characteristics by performing a 12-week home-based exercise program for ankylosing spondylitis patients. For the purpose of this study, 10 patients with ankylosing spondylitis were selected by age (30s vs. 40s vs. 50s), gender (male vs. female), and duration (less than 5 years vs. 5 years or more). The home-based exercise program was a combination of aerobic exercise and Pilates-based resistance exercise, and was performed 4 times a week for 12 weeks at an intensity of 50-70% of maximal heart rate (MHR). As a result, after 12 weeks of home-based exercise intervention, the blood C-reactive protein (CRP) concentration of patients with ankylosing spondylitis decreased (-35.6%, p=.002), and the blood inflammation level was improved, and each joint (hip, lumbar, cervical) improved mobility (p<.05). In addition, the bath ankylosing spondylitis disease activity index (BASDAI) was decreased by -67% (p=.001) and the visual analogue scale (VAS) was decreased by -64.8% (p=.001), stiffness and pain has been alleviated. In particular, as the degree of depression decreased by -65.5% (p=.001) and the degree of anxiety by -55.2% (p=.003), 12 weeks of home-based exercise improved not only physical changes but also psychological factors. On the other hand, there was no difference in exercise effect according to age, gender, and disease duration in ankylosing spondylitis patients (p>.05). These results suggest that the 12-week home-based exercise applied in this study can be an effective exercise program that can be universally used for ankylosing spondylitis patients regardless of patient characteristics.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.21-30
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• 2011

As well known, dowel bars are used to transfer traffic load acting on one edge to another edge of concrete slab in concrete pavement system. The dowel bars widely used in South Korea are round shape steel bar and they shows satisfactory performance under bending stress which is developed by repetitive traffic loading and environment loading. However, they are not invulnerable to erosion that may be caused by moisture from masonry joint or bottom of the pavement system. Especially, the erosion could rapidly progress with saline to prevent frost of snow in winter time. The problem under this circumstance is that the erosion not only drops strength of the steel dower bar but also comes with volume expansion of the steel dowel bar which can reduce load transferring efficiency of the steel dowel bar. To avoid this erosion problem in reasonable expenses, dowers bars with various materials are being developed. Fiber reinforced plastic(FRP) dower that is presented in this paper is suggested as an alternative of the steel dowel bar and it shows competitive resistance against erosion and tensile stress. The FRP dowel bar is developed in tube shape and is filled with high strength no shrinkage. Several slab thickness designs with the FRP dowel bars are performed by evaluating bearing stress between the dowel bar and concrete slab. To calculated the bearing stresses, theoretical formulation and finite element method(FEM) are utilized with material properties measured from laboratory tests. The results show that both FRP tube dowel bars with diameters of 32mm and 40mm satisfy bearing stress requirement for dowel bars. Also, with consideration that lean concrete is typical material to support concrete slab in South Korea, which means low load transfer efficiency and, therefore, low bearing stress, the FRP tube dowel bar can be used as a replacement of round shape steel bar.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.1-9
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• 2000

Purpose : Spine is one of the most common sites of the metastatic bone tumors. Conservative management such as chemotherapy or radiotherapy has been preferred in most cases. However, the neurologic deficit has not been usually improved, and the quality of life was poor. The purpose of this study was to show the efficacy of the surgical treatments for metastatic spinal tumors in terms of postoperative improvements of neurologic deficit and survival time. Materials and Methods : Authors have reviewed the literatures and analyzed 14 patients of metastatic spinal tumors who were received operative treatments between August 1991 and June 1999 at the our department of orthopaedic surgery. Results : The most frequent primary tumor was breast cancer in women and lung cancer in men. The thoracic region was the most common site. There was a preponderance of females over males, and the age ranged between 4th and 8th decade. The indications of surgical treatment comprised instability, progressive neurologic findings, resistance to radiotherapy, pathological fracture, long life expectancy( >6weeks), isolated metastasis and need for pathological diagnosis. The degree of preoperative neurological deficit might influence on the improvement of clinical symptoms after surgery. Conclusion : The surgical treatment reduced the neurological deficit and pain regardless of the operative methods. In the early stage of neurological deficit, the surgical treatment was important for better prognosis. Recently early active operative treatment was performed for metastatic spinal tumor to minimize the intractable pain and to prevent the progression of the neurologic deficit. Early intervention can improve the quality of life and long term survival.

• Science of Emotion and Sensibility
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• v.18 no.4
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• pp.25-34
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• 2015

TThis study explored the requirement of fabric sensor that can measure the motion of the joint effectively by measuring and analyzing the variation in electric resistance of a sensor in accordance with bending and stretching motion of the arm by the implementation of a motion sensor utilizing conductive fabric. For this purpose, on both sides of two kinds of knitted fabric, namely 'L' fabric and 'W' fabric Single Wall Carbon Nano-Tube(SWCNT) was coated, fabric sensor was developed by finishing them in a variety of ways, and the sensor was attached to the arm band. The fabric sensor consisted of total 48 cases, namely background fabric for coating, the method of sensor attachment, the number of layer of sensors, the length of sensor, and the width of sensor. The performance of fabric motion sensors in terms of a dummy arm, that is, a Con-Trex MJ with 48 arm bands around it was evaluated. For each arm band, a total of 48, fastened around the dummy arm, it was adjusted to repeat the bending and stretching at the frequency : 0.5Hz, ROM : $20^{\circ}{\sim}120^{\circ}$, the voltage was recorded for each case after conducting three sets of repeat measurement for a total of 48 cases. As a result of the experiment, and as a consequences of the evaluation and analysis of the voltage based on the uniformity of the base line of the peak-to-peak voltage(Vp-p), the uniformity of Vp-p within the same set, and the uniformity of the Vp-p among three sets, the fabric sensors that have been configured in SWCNT coated 'L' fabric / welding / two layers / $50{\times}5mm$, $50{\times}10mm$, $100{\times}10mm$, and SWCNT coated 'W' fabric / welding / two layers / $50{\times}10mm$ exhibited the most uniform and stable signal value within 5% of the total variation rate. Through all these results of the experiment, it was confirmed that SWCNT coated fabric was suitable for a sensor that can measure the human limb operation when it was implemented as a fabric sensor in a variety of forms, and the optimal sensor types were identified.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.709-734
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• 2001

The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerzing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity ($40.0{\times}25.0mm$, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly(methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued bench-curing up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at $50^{\circ}C$, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn: 1. The mean shrinkage strains reached $-3095{\mu}{\epsilon},\;-1796{\mu}{\epsilon}$ and $-2959{\mu}{\epsilon}$ for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached $56.7^{\circ}C,\;41.3^{\circ}C$ and $56.1^{\circ}C$ for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly(methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to $-31.8{\mu}{\epsilon}/sec,\;-15.9{\mu}{\epsilon}/sec$ and $-31.8{\mu}{\epsilon}/sec$ for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. From the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly(methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly(methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.129-138
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• 2014

Purpose: Streptococcus pyogenes is an important cause of invasive diseases in children. We aimed to describe the clinical characteristics of invasive infections due to S. pyogenes in children in Korea. Methods: A retrospective study of children under 18 years of age with invasive infections due to S. pyogenes at Seoul National University Children's Hospital between March 1992 and December 2012, and Seoul National University Bundang Hospital between March 2003 and December 2012 was conducted. Demographic factors, clinical characteristics, laboratory findings, treatment, mortality and morbidity of all patients were reviewed. Results: A total of 30 among 36 cases identified as invasive disease due to S. pyogenes were available for review. There was a predominance for male subjects (male:female=2.75:1). The median age was 50 months (range 12 days to 15 years) and 53.3% were under 5 years of age. Skin and soft tissue infections (9/30, 30.0%), bacteremia without identified focus (4/30, 13.3%) and bone and joint infections (6/30, 20.0%) were the most frequent clinical presentations. Streptococcal toxic shock syndrome (3/30, 10.0%) pulmonary, abdomen and central nervous system infections (2/30, 6.7%) were also seen. There was a peak in number of patients in year 2012 (9/30, 30.0%). There were no cases of mortality. Erythromycin and clindamycin resistance rates were low by 3.8% and 7.5%, respectively. Conclusion: We studied the clinical presentations of invasive infections due to S. pyogenes during the past 20 years in Korean children. The findings of this study help us understand the characteristics of the disease, enhancing early recognition and prompting adequate antibiotic therapy which is important in reducing morbidity and mortality.