• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.521-532
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• 2007

Elastic wave propagations in the semi-infinite transversely isotropic cylinder under various kinds of longitudinal impact loads are analyzed using the axisymmetric finite element method and Houbolt time-integration scheme. For which the finite element program is newly constructed and verified through the comparison of present numerical results with those by other researchers. E-type glass-epoxy composite cylinders with different fiber volume fractions are adopted and studied in detail with dynamic responses of the isotropic cylinder. Three dimensional wave motions are given in graphic form to show the realistic view of the wave propagation. Nondimensionalized dynamic characteristic variables which relate the size of finite element mesh, the time step, and the wave speed are presented for obtaining accurate and stable numerical results.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1796-1800
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• 1991

Picture Archiving and Communication Systems(PACS) provide an integration of digital imaging information in a hospital, which encompasses various imaging equipment, viewing workstations, database archive systems, and a high speed fiber optic network. One of the most important requirements for integration is the standardization of communication protocols to connect devices from different vendors. Since 1985, the ACR-NEMA standard provides a hardware interface, a set of software commands, and a consistent set of data formats for point-to-point interconnection of medical equipment. However, it has been shown to be inadequate for PACS networking environments, because of its point-to-point nature and its inflexibility to allow other services and protocols in the future. Based on previous experience of PACS developments in The University of Arizona, a new communication protocol for PACS networks has been suggested to the ACR-NEMA Working Group VI. The defined PACS protocol is intended to facilitate the development of PACS's capable of interfacing with other hospital information systems. Also, it is intended to allow the creation of diagnostic information data bases which can be interrogated by a variety of distributed devices. A particularly important goal is to support communications in a multivendor environment. The new protocol specifications are defined primarily as a combination of the International Organization for Standardization / Open Systems Interconnection (ISO/OSI) protocols and the data format portion of ACR-NEMA standard. This paper addresses the specification and implementation of the proposed PACS protocol into network node. The protocol specification, which covers Presentation, Session, Transport, and Network layers, is summarized briefly. The implementation has natural extentions to Global PACS environments. The protocol implementation is discussed based on our implementation efforts in the UNIX Operating System Environment. At the same time, results of performance evaluation are presented to demonstrate the implementation of defined protocol. The testing of performance analysis is performed on the PACS prototype node.

• The Korean Journal of Community Living Science
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• v.15 no.4
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• pp.177-184
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• 2004

This study performed compositional analyses of a genetically modified herbicide-tolerant red pepper (GMHT), developed by the Rural Development Administration, and a parental red pepper cultivar 'Subicho', and compared the nutrient composition of them. Using the Association of Official Analytical Chemists (AOAC) methods, the study measured the concentration of nutrients, including the proximate components (protein, fat, fiber, ash, and carbohydrates) and minerals (Ca, K, Na, Fe, Mg, Zn) of GMHT and 'Subicho'. Nutritional composition of GMHT and 'Subicho' were compared with the nutritional composition of conventional red peppers. The nutrient composition of GMHT and 'Subicho' were found similar, and GMHT's nutrient contents were in the range of those of the conventional red peppers. These results showed that GMHT's nutrient contents were equivalent to those of the parental red pepper and other conventional red peppers.

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.159-169
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• 2014

This study generalizes the lateral load-displacement relationship of reinforced concrete shear walls from the section analysis for moment-curvature response to straightforwardly evaluate the flexural capacity and ductility of such members. Moment and curvature at different selected points including the first flexural crack, yielding of tensile reinforcing bar, maximum strength, 80% of the maximum strength at descending branch, and fracture of tensile reinforcing bar are calculated based on the strain compatibility and equilibrium of internal forces. The strain at extreme compressive fiber to determine the curvature at the descending branch is formulated as a function of reduction factor of maximum stress of concrete and volumetric index of lateral reinforcement using the stress-strain model of confined concrete proposed by Razvi and Saatcioglu. The moment prediction models are simply formulated as a function of tensile reinforcement index, vertical reinforcement index, and axial load index from an extensive parametric study. Lateral displacement is calculated by using the moment area method of idealized curvature distribution along the wall height. The generalized lateral load-displacement relationship is in good agreement with test result, even at the descending branch after ultimate strength of shear walls.

• Journal of the Korean housing association
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• v.23 no.3
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• pp.71-78
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• 2012

This study analyzed metaphorical characteristics of composite materials in terms of a visual aspect on a new material that is applicable for housing space. The results are as follows. First, the recent trend of housing space tends to stimulate emotions of residents through visual finishing materials, and for this reason, visual expression of a new material that is applicable to finishing materials plays an important role. Second, convertibleness, association and duplicity were selected as items of metaphorical expressions through the precedent studies. Third, most of combinations of materials were shown different from the existing materials in an expressive characteristic of composite materials through analysis, and application of a technology showed a different visual effect of patterns and textures from the existing materials. This implies that visual expression and directing are being attempted using such technology on finishing materials of housing space with development of digital technologies. Fourth, for metaphorical characteristics of composite material for housing space, combination of various materials and a digital technology were applied on convertibleness. For association, a combination of materials that have each different characteristic associated with the third material, and combination with subsidiary material of optical fiber and a digital technology were appled for duplicity. Data obtained from the results of this study has high efficiency in planning finishing materials for emotional housing space in future, and it will be basic data for a study on development of new finishing materials.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.357-375
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• 1994

The purpose of this study was to investigate the differences of histochemical characteristics in inflammatory fibrous gingival hyperplasia (FGH), phenytoin-induced gingival hyperplasia(PIGH), idiopathic gingival hyperplasia(IDGH) and control groups (healthy and inflammatory gingiva) by immunohistochemical method with various antibodies and histomorphological analysis. In immunohistochemical finding, antibodies to inflammatory cells (T/B lymphocytes, macrophages, other monocytes), proliferating cell nuclear antigen(PCNA), epidermal growth factor(EGF), factor VIII, and type I collagen were used. 1. The inflammatory infiltrates in FGH were less than those in inflammatory gingiva. The composition of inflammatory cells of PIGH was similar with that of FGH. IDGH showed a similar histologic findings with healthy gingival tissue. 2. In FGH, the number of fibroblasts and newly-formed collagen fibers was increased. No significant increase of fibroblasts and the dense accumulation of thick collagen fibers were seen in PIGH. The increase of fibroblasts and the dense accumulation of thick collagen were seen in IDGH. 3. PCNA-positive cells were localized mainly in the area accumulated with inflammatory cells and blood vessels, significantly increased in all hyperplastic tissue groups, and distributed evenly in IDGH. 4. The distribution of EGF were not observed in healthy gingiva but detected locally in area with confluent blood vessels,without significant difference between the other tissue groups. This results suggest that inflammation plays a significant role in inducing hyperplastic change of gingival tissue. While in DIGH, drug itself as well as inflammation seems to attribute to hyperplastic change.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.107-112
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• 2004

Many studies have showen that Letinus edodes have a reducing effects on blood pressure and lipid levels in animals with high blood pressure and hyperlipidemia. But the only cap has been on the market as goods and the stipe has been wasted. The price is very variable and is based on harvest time and the part of the plant currenty, there is not much information about the nutritional composition and bio-fuctional effects of Letinus edodes based on harvest time and part. Some farmers have been selling the powder seasoning by drying and pulverizing Letinus edodes including stipe to develop value added, late harvested Letinus edodes and its stipe these days. This study was conducted to investigate and compare the nutritional composition of Letinus edodes harvested at different times (early: E, late: L) and separated by part (cap: C, stipe: S). The 4 kinds of materials were named as early harvested cap (EC) and stipe (ES), and late harvested cap (LC) and stipe (LS) samples were obtained from Mungyeong City Agricultural Technology & Extension Center. The composition analysis of the nutrients in the 4 materials was conducted by using the AOAC method. The proximate components (moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamin content were measured. Nutritional composition of Lentinus edodes did not show any significant difference between early and late harvested mushrooms. Nutritional compositions were different according to part. The results demonstrate that the late harvested stipe can also be used as a quality food material.

• Composites Research
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• v.13 no.3
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• pp.9-20
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• 2000

Free vibration characteristics of a cantilevered laminated composite beam with multiple non-propagating transverse open cracks are investigated. In the present analysis a special ply-angle distribution referred to as asymmetric stiffness configuration inducing the elastic coupling between chord-wise bending and extension is considered. The multiple open cracks are modelled as equivalent rotational springs whose spring constants are calculated based on the fracture mechanics of composite material structures. Governing equations of a composite beam with open cracks are derived via Hamilton's Principle and Timoshenko beam theory encompassing transverse shear and rotary inertia effect is adopted. The effects of various parameters such as the ply angle, fiber volume fraction, crack numbers, crack positions and crack depthes on the free vibration characteristics of the beam with multiple cracks are highlighted. The numerical results show that the existence of the multiple cracks in an anisotropic composite beam affects the free vibration characteristics in a more complex fashion compared with the beam with a single crack.

• Composites Research
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• v.33 no.5
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• pp.288-295
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• 2020

Fiber-reinforced composite laminates have high specific stiffness and strength and are expected to be useful for weight reduction in weight-sensitive industries, such as automotive and aerospace. However, designing composite laminates is often dependent on designer's experience and intuition because of difficulties in determining the number of plies and stacking sequence, which tends to lead to over-design. In this study, optimal design of composite laminates was performed to minimize weight, while withstanding the given load. Based on the enumeration method, all combinations of stacking sequence satisfying the design guideline for composite laminates were considered. Composite laminates were discretized into panels. Optimal number of plies and stacking sequence for each panel were determined considering local load on each panel and contiguity across adjacent panels. Failure index from Tsai-Wu criteria was optimized for strength and buckling analysis was performed for compressive load. Stacking angles of 0, ±45 and 90° were used.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.4
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• pp.363-370
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• 2020

This paper reports the results of an experimental study using the BOTDR sensor to detect the unbonded location of attached CFRP sheet for structural rehabilitation. A specimens with the unattached CFRP sheet were fabricated for this study, on which BOTDR sensor was attached with a nylon net. During the flexural test of the specimens, the strain of the CFRP sheet was measured using the BOTDR sensor and electric resistance gauges. From the results, it was confirmed that the strain distribution obtained through the BOTDR sensor can be effectively used to visualize and detect the unbonded position of the CFRP sheet. In addition, In addition, the strain measured by the BOTDR sensor was found to be more effective in analyzing the overall structure behavior than the electric resistance strain gauge. The development of a BOTDR sensor with a measuring longth of less than 100 mm will enable accurate detection of the local unbonded position of the CFRP sheet.