• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.271-278
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• 1999

Soil filters are commonly used to protect the soil structures from eroding and piping. When filters are clogged by fine particles which are progressively accumulated, these may lead to buildup of excessive pore pressures also leading to instability in subsurface infrastructure. A filter in the backfill of a retaining wall, a filter adjacent to the lining of a tunnel, or a filter in the bottom of an earth dam can be clogged by transported fine particles. This causes reduction in the permeability, which in turn may lead to intolerable decreases in their drainage capacity. In this thesis, the extent of this reduction is addressed using results from both experimental and theoretical investigations. In the experimental phase, the permeability reduction of a filter is monitored when an influent of constant concentration flows into the filter (uncoupled test), and when the water flow through the soil-filter system to simulate an in-situ condition (coupled test), respectively. The results of coupled and uncoupled test are compared with among others. In the theoretical phase of the investigation, a representative elemental volume of the soil filter was modeled as an ensemble of capillary tubes and the permeability reduction due to physical clogging was simulated using basic principles of flow in cylindrical tubes. In general, it was found that the permeability was reduced by at least one order of magnitude, and that the results from the uncoupled test and theoretical investigations were in good agreement. It is observed that the amount of deposited particles of the coupled test matches fairly well with that of the uncoupled test, which indicates that the prediction of permeability reduction is possible by preforming the uncoupled test instead of the coupled test, and/or by utilizing the theoretical model.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.56-66
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• 1993

The Langerhans cells are dendritic nonkeratinocytes found suprabasally in most stratified squamous epithelia, such as human epidermis and the epithelium of the oral mucosa including that of gingiva. After Paul Langerhans found it in the skin in 1968, there have been sturdies of it's function and distribution . Stingle et al. reported that the Langerhans cells seem able to present antigens and to stimulate T-lymphocytes. Shelley et al. discovered that they can take up contact allergens. Accordingly it has been suggested that Langerhans cells are important elements of p Peripheral cell mediated immune system. In this study, the gingival tissue of a adult periodontitis patient was taken and freeze dried. In one specimen, we used the CD1 monoclonal antbody to staining the Langerhans cell. The other specimen, we embedded in paraffin and staining it with S-100 monoclonal antibody. The purpose of this study was to use these specimens to find out the distribution, orientation, morphology of the Langerhans cell and to discover the increase or decrease of Langerhans cell in an increased inflammatory state. The results were obtained as follows : 1. Langerhans cells were distributed between the basal cell layer and spinous cell layer against the CD1 & S-100 monoclonal antibody. 2. Langerhans cessl were plentiful in the oral eptihelium, and there was very little in the sulcular epithelium. 3. There were no Langerhans cell in the junction epithelium and pocket lining epithelium. 4. The number of Langerhans cells that responsed to the CD1 & S-100 monoclonal antibody had a statistically difference. 5. As the infiltration of the lymphocyte into the connective tissue were increased, the number of Langerhans cells in the epithelium were increased. 6. As the inflammation was increased, Langerhans cells in the spinous cell layer were more increased than those of the basal layer.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.307-316
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• 2009

Seoul, the capital of Korea, is worldwide city; Seoul is 600 year-old city as a capital and more than 10 millions of population live in Seoul, Image of Seoul has began to be known to the peoples in the world through 1988 Seoul Olympic Games and 2002 World Cup. However, in the public design and trees lining street system, Seoul hasn't been escaped from the image of a city which lacks of the characterization in the culture and identity aspects. This paper applied a protective fence designing simulation for Cultural Street in Seoul to develop much more the identity of Seoul and characterization of local culture. Also, It's examined and analyzed R&D data, and applied traditional patterns to design to set developmental capacity of design and a direction of fence design in the past, present and future. It's analyzed the present condition of domestic manufacturers and examples for installation, selected randomly 7 places of domestic cultural places as an alternative to compare the previous design to the present design with 3D design and photos composing method, and developed the related situation. Also, It's visualized this method to let the citizens and all levels of society determine the design. besides that, developed the traditional patterns to apply the patterns to the design, considering the characteristic of each region and characteristic of each road. It's suggested this fence design to apply the image of advanced Korea and Seoul as a creative cultural city, and the international status of Korea and Seoul to the trees on the historical and traditional street. Also, put an importance to bring the identity of Seoul and Korea in the world into relief.

• Tunnel and Underground Space
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• v.21 no.4
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• pp.287-296
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• 2011

We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than $1.0{\times}10^{-18}\;m^2$ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 MPa. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.339-351
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• 1999

Excess secretion of goblet cell stimulated by inhalation anesthetics have side effects during operation or postoperative care. Mucosubstances, which are almost secreted by goblet cells in the epithelium of the respiratory tract, are secreted by a direct irritation of inhalation anesthetics. This study was carried out to compare the differences of mucus secretion on lower respiratory tract stimulated by ethyl ether, halothane and isoflurane. Total of 24 rabbits were used as experimental animals. The trachea and the 1st bronchi were fixed in 10% neutral buffered formalin. After embedding in paraffin, the specimens were sectioned to a thickness of 6 ${\mu}{\textrm}{m}$, and PAS-H, Alcian blue pH 2.5 and Alcian blue pH 1.0 stains were performed for the observation of the composition and the quantity of the mucus. The results were as follows; Ethyl ether and isoflurane irritated the mucous membrane of the respiratory tract. Ethyl ether irritated more than isoflurane. Halothane irritated the mucous membrane, but its effect was minimal and had little influences during operation. In the specimens stained with PAS-H, Alcian blue pH 2.5 and Alcian blue pH 1.0, the mucosubstance lining the cilia and in the goblet cells of the trachea and 1st bronchi were the strongly PAS-H reactive mucosubstances, moderately Alcian blue pH 2.5 and Alcian blue pH 1.0. The PAS-H reactive mucosubstance were polysaccharides, neutral mucopolysaccharides, mucoproteins, glycoproteins and glycolipids. Trachea was easily affected than bronchi by inhalation anesthetics. Consequently, it is suggested that because halothane does not irritates respiratory mucosal secretion, its application may be efficient to the depressed respiratory system.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1438-1447
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• 2010

Construction sites are becoming larger and complex with the growth of national economy. Accordingly, It is essential to indentify real-time information about materials, equipments and manpower during construction at job sites. Even though research utilizing cutting-edge sensors has been conducted in architectural engineering field; this area of research is almost nil in civil engineering field. Therefore a feasibility study to find a way to apply cutting-edge sensors to an in-situ tunnel construction site adopting NATM is tried as the first step. After listing all construction materials needed in each activity, the most representative materials were identified so that IT technology can be applied by attaching and monitoring sensors to the selected materials; shotcrete and lining were selected as representative materials. Moreover, a plan to visualize construction process and progress management system using selected representative materials was proposed.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.775-780
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• 2010

In the machinery, the brake system is as important part as machine's working. The situation of emergency stop, the machine doesn't stopped would be occur big accident. This is common things for all of machinery, also for the ships. There are two kind of mooring devices are existed on the ship. One of them, the windlass winch, is used to anchor. The other, the mooring winch is used to moor the ship in pier use the rope tied to bitt on dock. In case of previously been used mooring winch made of a steel plate, and the bolt which was connect brake band and lining broken. In this study, prevent an accident find the position of stress concentration by finite element analysis program. And removed stress concentration. And search the optimum position of the separation angle to be more efficient.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.6
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• pp.718-726
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• 2007

There are many varieties of asbestos: chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophylite. These are widely used in construction materials, brake lining, textile, and so on. Even though non-asbestos fibers such as glassfiber and rockwool have manufactured because asbestos causes asbestosis, lung cancer, mesothelioma, etc., some bad effects of non-asbestos have been also reported. PCM (phase contrast microscopy) and PLM (polarized light microscopy) have been used to qualitatively analyze asbestoses. These techniques have serious drawbacks when identifying and separating various asbestoses. Recently scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX) has been known as an useful tool to analyze airborne particle since it provides physical and chemical information simultaneously. The purpose of the study was to classify both asbestos and non-asbestos fibers and finally to develop their source profiles by using the SEM/EDX. The source profiles characterized by 6 different types of asbestos fibers and 2 types of non-asbestos fibers had been developed by analyzing a total of 380 fibers. Analytical parameters used in this study were length, width, aspect ratio, and shape as physical information, and Na, Mg, Al, Si, K, Ca, Cr, Mn, Fe, and Cu as chemical information. All the parameters were intensively reviewed.

• Tunnel and Underground Space
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• v.19 no.2
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• pp.77-85
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• 2009

Flexible and lined segment air-tight tunnelling technology for Compressed Air Energy Storage-Gas Turbine(CAES-G/T) power generation was introduced. The distinguished characteristics of the air-tight tunnel system can be summarized by two facts. One is that the high inner pressure due to compressed air is sustained by surrounding rock mass with allowing sufficient displacement of lining segment. The other is that the air-tightness of storage tunnel was enhanced by adopting a specially designed rubber sheet. The flexible lined air-tight underground tunnel can be constructed at a comparatively shallow depth and near urban area so that the locally distributed CAES-G/T power generation can be accomplished. In addition, this air-tight tunnelling technology can be applied to a variety of energy underground storage tunnels such as Compressed Natural Gas(CNG), Liquifed Petroleum Gas(LPG), DeMethyl Ether(DME) etc.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.419-433
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• 2009

Pressure grouting is a common technique in geotechnical engineering to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressure grouting has been applied to a soil-nailing system which is widely used to improve slope stability. The soil-nailing design has been empirically performed in most geotechnical applications because the interaction between pressurized grouting paste and the adjacent ground mass is complicated and difficult to analyze. The purpose of this study is to analyze the increase of pullout resistance induced by pressurized grouting with the aid of performing laboratory model tests and field tests. In this paper, two main causes of pullout resistance increases induced by pressurized grouting were verified: the increase of residual stress; and the increase of coefficient of pullout friction. From the laboratory tests, it was found that residual stress in borehole increases by pressurized grouting and dilatancy angle could be estimated by cavity expansion theory using the measured wall displacements. From the field test results, the pullout resistance of soil-nailing with pressurized grouting was found to be 10% larger than that of soil-nailing with gravitational grouting, mainly caused by mean normal stress increase and dilatancy effect. So, the pullout resistance could be estimated by considering these two effects. The radial displacement increases with dilatancy angle increase and the dilatancy angle decreases with injection pressure increase. The measured pullout resistance obtained from field tests is in good agreement with the estimated one from the cavity expansion theory.