• Magazine of the Korean Society of Agricultural Engineers
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• v.20 no.2
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• pp.4645-4687
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• 1978

This study was attempted to investigate the mechanical properties of concrete and crack control effects of reinforced concrete with steel and glass fiber. The experimental program includes tests on the properties of fresh concrete containing fibers, compressive strength, tensile strength, flexural strength, Young's modulus, Shrinkage and deformation of steel or glass fiber reinforced concrete. Also this study was carried out to investigate the effect of steel or glass fiber to retard the development in reinforced concrete subject to uniaxial tension and thus facilitate the use of steels of higher strength. The major conclusions that can be drawn from the studies are as follows: 1. The effect of the fibers in various mixes on fresh concrete confirmed that fibers do have a significant effect on the properties of fresh concrete, bringing much more stable and exhibiting a signiflcant reduction in surface bleeding, and that the cohesion is greatly improved and the internal resistance increases with fiber concentration. But the addition of an excess contents and length of fibers brings about the reduction of workability. 2. With the addition of steel fibers(1.5% Vol.) to concrete, the compressive strength as compared with plain concrete showed a very slight increase, but excess addition, over 1.5% Vol. of steel and glass fiber reduced its strength. 3. Splitting tensile strength of fiber reinforced concrete showed a significant increase tendency, as compared with plain concrete. In case of containing steel fiber (2.5%, 30mm), it showed that the maximum increase rate of 1.48 times as much rate, and in case of containing glass fiber (2.5%, 30mm), the increase rate of strength was 1.25 times as much rate. 4. Flexural strength of fiber reinforced concrete showed a significant tendency, as compared with plain concrete. Containing steel fiber (2.5%, 30mm) showed the maximum increase rate of 1.64 times as much rate and containing glass fiber (2.5%, 30mm) showed the increase rate of strength of 1.32 times as much rate, and in general, the 30mm length brougth the best results. 5. The strength ratio ($\sigma$b/$\sigma$c and $\sigma$t/$\sigma$c) increased, when steel fiber's average spacing was up to 3.05mm, but decreased when beyond 3.05mm, and it was confirmed that tensile or flexural strengths of steel fiber reinforced concrete are apparently governed by fiber's average spacing. 6. The compressive strain of fiber reinforced concrete showed a significant increasing tendency as the fiber was added, but Young's modulus. with the addition of steel and glass fibers, showed a slight decrease tendency. And according to the increase of flexural strength, a considerable increase was seen in toughness. 7. With the addition of fiber's the shrinkage of concrete was significantly decreased, in both case of adding steel fibers 12.5%, 30mm, and showed a significant decrease ratio, in average 30.4% and 36.7%, as compared with plain concrete. 8. With the increase of fiber volume fraction and length, the gained stress in reinforcing bar in concrete specimens increased in all crack widths, but at different rates, with the decrease of fiber diameter, the stress showed a considerable increasing tendency. And the duoform steel fibers showed the greatest improvement, as compared with the other types tested. 9. The influence of fiber dimensions in order of significanse on the machanical properties of concrete and the crack control of reinforced concrete was explained as follows: content, length, aspect ratio and dimeter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.121-123
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• 2002

The design of an air seat cushion for preventing decubitus ulcer includes many design factors such as the even distribution of interface pressure, the minimization of mean and peak interface pressure values, and the reduction of interface shear force and pressure gradient. It involves the anatomic condition of plegia's buttock as well as air pressure in air cells of cushion. As a result, a suitable design of the cushion satisfying the all requirements is a difficult problem. Therefore, an appropriate and effective numerical tool to develop an air cushion orthosis is required. The purpose of the present study was to develop an air seat cushion orthosis having optimized air cells for evenly distributed interface pressure between the buttock and cushion surface. For the purpose, an advanced finite element (FE) model for the design of air cushion was developed. Since the interface pressure and shear force behavior, as well as stress analyses were primary concern, a FE air cell model was developed and verified by the experiments. Then, the interactions of two cells were checked. Also, the human part of the developed numerical model includes every material property and geometry related to buttock and femoral parts. For construction of dimension data of buttock and femoral parts, CT scans were performed. A commercial FE program was employed for the simulation representing the seating process on the orthosis. Then, sensitive analyses were performed with varying design parameters. A set of optimal design parameters was found satisfying the design criteria of the orthosis. The results were utilized to produce a prototype of the orthosis. Experimentally, the buttock interface pressure distributions from the optimized and previous ones were compared. The new seat orthosis showed a significantly improved interface pressure characteristics compared to the most popular one in the market. The new orthosis will be used for the development of the AI(artificial intelligent) controlled seat orthosis fur prevention of decubitus ulcer fur various plegic patients and the elderly.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.635-641
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• 2019

Domestic southwest offshore wind farms have problems such as the reduction in fishing rights by prohibiting vessel traffic, which delays their development. As such, there is a need to develop offshore windfarms in Europe to permit the passage of vessels and fishing operations in specific offshore windfarm areas. In this study, we used the environmental stress (ES model) and the IALA Waterway Risk Assessment Program (IWRAP) to determine the ratio of risk to the route type (cross pattern, grid pattern) and traffic volume (present, 3 times, 5 times and 10 times) to derive the risk factors of specific vessels for offshore windfarms. As a result, ship operators' risk related to offshore windfarms did not rise in both route types and there was no significant difference in the annual probability of collision in the present traffic volume. In conditions that increased traffic volume by 3 times, 5 times and 10 times, the risk ratio increased as ship operator risk and collision probability increased at the crossing points. Furthermore, when the traffic volume of the ship increased, the risk could be more effectively distributed in the grid route compared to the cross route. The results of this study are expected to apply to the operation type, route operation method, safety measures, etc. in offshore wind farms.

• Women's Health Nursing
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• v.5 no.1
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• pp.133-145
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• 1999

The purposesof the study are to analyze the community nursing center in U.S.A and to develop the model of nursing care system based on nurse-midwifery clinic in community for women's health in Korea. 1. In America nursing center is defined as nurse-anchored system of primary care delivery or neighborhood health center. Nursing centers are identified the following four types: (1) community outreach centers, which are similar to traditional public health clinics: (2) institutional-based centers following the mission of a large institution, such as a hospital or university: (3) wellness/health promotion centers, which offer screening, education, counseling, triage, and health maintenance services: and (4) independent practice. Nursing centers are a concept of services provided by nurses in practice arrangements in a community. Nursing centers offer a variety of services, ranging from primary care provided by advanced practice nurses with medical acute management and nursing care to the more traditional education, health promotion, screening wellness and coordination services. Some services, such as the care provided by advanced practice nurses are reimbursed under various insurance plan in some instances and states, where as others, such as preventive and educational services, are not. Thus, lack of reimbursement has threatened the survival of some centers. Licensing of nursing centers varies by state and program and accreditation of nursing centers is also limited. 52% of centers are affiliated with another facility and 48% are freestanding centers. The number of registered nurse at the nursing centers ranges from just one to 115, with a mean of eight RNs peragency and a median of three. Nursing centers avail ability varies: 14% are open 24 hours, 27% have variable short hours, 23% are open 6-7 days per week, and 36% are open Monday- Friday. As the result of my visiting three health centers in Seattle and San Francisco, the women's primary care nurse practitioners focus on a systematic and comprehensive assessment of the health status of women and diagnosis and management of common physical and psychosocial health concerns of women in ambulatory settings. Therapeutic nursing strategies are directed toward self-care, risk reoduction, health surveillance, stress reduction, healthy nutrition, social support, healthy coping, psychological well-being, and pharmacological therapy. They function as primary care providers for the well ness and illness care of women from adolescence through the older adult years and pregnant families. 2. In Korea a nurse-midwife practices independently for pregnant women's health including childbearing family at her own clinic in community. Her services are reimbursed under national health insurance but they are not paid on a fee-for-service schedule covering items. Analyzing the nursing centers in America, I suggest that nurse-midwifery clinics offer primary care for women and home care for chronic ill patients. The health law and health insurance policy should be reovised in order to expand nurse-midwife's and home care nurse's roles at nurse-midwifery clinic.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.141-146
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• 2005

Ship have cutout inner bottom and girder and floor etc. Ship's structure is used much, and structure strength must be situated, but establish new concept when high stress interacts sometimes fatally the area. There is no big problem usually by aim of weight reduction, a person and change of freight, piping etc. Because cutout's existence grow up in this place, and, elastic buckling strength by load causes large effect in ultimate strength. Therefore, stiffened perforated plate considering buckling strength and ultimate strength is one of important design criteria which must examine when decide structural concept at initial design. Therefore, and, reasonable buckling strength about perforated stiffened plate need to ultimate strength limited design . Calculated ultimate strength varied several web height and cutout's dimension, and thickness in this investigated data. Used program(ANSYS) applied F.E.A code based on finite element method.

• The Korea Journal of Herbology
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• v.33 no.1
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• pp.37-46
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• 2018

Objectives : Liver disease is an inflammatory reaction caused by oxidative stress, viral, alcohol, and drug properties. Inflammatory reaction causes hepatitis and chronic hepatitis is persistent, it progresses to liver fibrogenesis and liver cancer. The aim of this study was to confirm the hepatoprotective effect of Tongyuhwalhyeol-tang(Tongqiaohuoxue Decoction) (TH) and Gamtongyuhawlhyeol-tang(GTH) in TAA-induced liver injury animal model. Methods : The antioxidant activities were evaluated through in vitro experiments, such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays, total polyphenol and total flavonoid content measurement. To confirm the liver protective effect, induced by Thioacetamide (TAA) for 3 days injection at 200 mg/kg rats. TH and GTH were treated 3 days at 200 mg/kg/day. The changes of reactive oxygen species (ROS), peroxynitrite ($ONOO^-$), alanine aminotransferanse (ALT) and aspartate aminotransferase (AST) in serum were analyzed after experiment. Also, expression of anti-inflammation, anti-oxidant related proteins were investigated by western blot analysis. Results : TH was inhibited the antioxidant activities. In the TAA-induced rat, TH decreased ROS, $ONOO^-$, ALT, AST level in serum. Inflammation related protein expressions increased in TAA-induced rat compared to normal rat. However, TH group inhibited the down expression of these proteins. Also, anti-oxidant related protein expressions increased in TH group compared TAA-induced rat. Conclusion : Therefor, these results suggested that TH provided hepatoprotective effects on the hepatic injury leading to the reduction of inflammatory response. In addition, the effect of TH was superior to that of GTH.