• Interaction and multiscale mechanics
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• v.1 no.1
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• pp.33-51
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• 2008

This paper investigates the modelling of coupled soil-structure interaction problems by domain decomposition techniques. It is assumed that the soil-structure system is physically partitioned into soil and structure subdomains, which are independently modelled. Coupling of the separately modelled partitioned subdomains is undertaken with various algorithms based on the sequential iterative Dirichlet-Neumann sub-structuring method, which ensures compatibility and equilibrium at the interface boundaries of the subdomains. A number of mathematical and computational characteristics of the coupling algorithms, including the convergence conditions and choice of algorithmic parameters leading to enhanced convergence of the iterative method, are discussed. Based on the presented coupling algorithms a simulation environment, utilizing discipline-oriented solvers for nonlinear structural and geotechnical analysis, is developed which is used here to demonstrate the performance characteristics and benefits of various algorithms. Finally, the developed tool is used in a case study involving nonlinear soil-structure interaction analysis between a plane frame and soil subjected to ground excavation. This study highlights the relative performance of the various considered coupling algorithms in modelling real soil-structure interaction problems, in which nonlinearity arises in both the structure and the soil, and leads to important conclusions regarding their adequacy for such problems as well as the prospects for further enhancements.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1706-1712
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• 2014

The OH($X^2{\Pi}$, ${\upsilon}^{\prime\prime}=0,1$) internal state distribution following the reaction of electronically excited oxygen atom ($O(^1D_2)$) with cyclo-$C_3H_6$ has been measured using laser-induced fluorescence, and compared with that following the reaction of $O(^1D_2)$ with $C_3H_8$. The overall characteristics of the OH internal energy distributions for both reactions were qualitatively similar. The population propensity of the ${\Pi}(A^{\prime})$ ${\Lambda}$-doublet sub-level suggested that both reactions proceeded via an insertion/elimination mechanism. Bimodal rotational population distributions supported the existence of two parallel mechanisms for OH production, i.e., statistical insertion and nonstatistical insertion. However, detailed analysis revealed that, despite the higher exoergicity of the reaction, the rotational distribution of the OH following the reaction of $O(^1D_2)$ with $C_3H_8$ was significantly cooler than that with cyclo-$C_3H_6$, especially in the vibrational ground state. This observation was interpreted as the effect of the flexibility of the insertion complex and faster intramolecular vibrational relaxation (IVR).

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1496-1503
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• 2005

The study on the lateral earth pressure is briskly preformed for various conditions such as type of retaining walls, ground condition, and type of supporting systems. It is not simple to determine the distribution of lateral earth pressure accurately, however, because the lateral earth pressure is affected by various factors. This study is performed to analyze the behavior of earth retaining walls for new excavation contacting with existing excavation by comparing with the site measuring values before and after new excavation. On the base of observation, the distribution of strut axial forces is similar to that of ganeral earth retaining walls, but strut axial forces is increased by removal of existing earth anchors. When new excavation is performed contacting with existing excavation, the axial force of strut is decreased because of soil exclusion in the behind walls, but that force is increased after new exeavation. The analysis result show that the installation of strut in middle part makes a effect to not only 1 adjacent strut, but 3-5 adjacent struts. Also during new excavation strut axial forces is decreased by relaxation of total earth retaining wall system.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.114-114
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• 2010

In this study, structural properties and photoluminescent characteristics of thin film rhombohedral zinc orthosilicate doped with manganese ($Zn_2SiO_4:Mn$) were investigated. The $Zn_2SiO_4:Mn$ films showed a pronounced absorption edge in the near ultraviolet wavelength region and a high optical transparency in the visible spectral range. The maximum transmittance reached 0.922 at 597 nm, which was very close to the transmittance of the fused quartz substrate alone (0.935). The $Zn_2SiO_4:Mn$ films were composed of rhombohedral polycrystalline grains with random crystallographic orientation. The broad-band photoluminescence emission peaked at around 525 nm was observed from the $Zn_2SiO_4:Mn$ films, which was ascribed to the radiative relaxation from the $^4T_1$ lowest excitation state to $^6A_1$ ground state of 3d5 electrons in divalent manganese ion. The excitation band exhibited a peak maximum at 259 nm in the near ultraviolet region, which was considered to be associated with the charge transfer transition of divalent Mn ion in the $Zn_2SiO_4$ system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.468-471
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• 2003

Fault of under ground power cable occurs usually from the water tree such as the vented tree, the bow tree and the water-rich halo. The water tree penetrates to the polyethylene cable insulations. Sometimes, the water tree also diffuses to mother cable in the substation. In this paper, instead of replacement of the faulty cable, we tried to cure an electrical power cable degraded by the water trees with silicon injection method. And measured the results with the isothermal relaxation current analysis method. After cable cure, Chonil line was improved from 2.27 to 1.96 in a phase, from 2.148 to 2.020 in b phase, and from badness to 2.192 in c phase. And Keumam line was also improved from 2.419 to 1.920 in a phase, from 2.301 to 2.000 in b phase, and from badness to 1.957 in c phase.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.35-40
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• 1987

Higenamine, a benzyltetrahydroisopuinoline analog isolated from aconite tuber, has potent isotropic action. Recent studies suggest it may have beta receptor agonistic property in that its inotropic action is blocked by propranolol in isolated rabbit heart. However, no study has been carried out on other organs than heart. Higenamine is expected to have pharmacological actions on smooth muscle on the ground that it has catecholamine moiety and tetrahydrosioquinoline nucleus in its chemical structure, both of which are well known to have smooth muscle relaxation effects. Therefore present study was aimed at determining whether higenamine has bronchodilating effect in isolated guinea pig trachea smooth muscle rich in adrenergic beta receptor and if any, it has agonistic effect on beta receptor. The results were summarized as follows : 1. Higenamine had remarkable bronchodilating effect in guinea pig tracheal smooth muscle in a dose-dependent manner. 2. Bronchodilator effect of higenamine in isolated guinea pig tracheal smooth muscle was blocked competitively by propranolol. The $pD_2$ value of higenamine in isolated guinea pig tracheal smooth muscle was 5.65 and the $pA_2$ value of propranolol against higenamine in the same preparation was 7.97.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.3
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• pp.133-149
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• 2021

This study aims to report the behavioral mechanism of steel pipe reinforcement grouting, which is being actively used to ensure the stability of the excavation surface during tunnel excavation, based on measurements taken at the actual site. After using a 12 m steel pipe attached with a shape displacement meter and a strain gauge to reinforce the actual tunnel surface, behavioral characteristics were identified by analyzing the measured deformation and stress of the steel pipe. Taking into account that the steel pipes were overlapped every 6 m, the measured data up to 7 m of excavation were used. In addition, the behavioral characteristics of the steel pipe reinforcement according to the difference in strength were also examined by applying steel pipes with different allowable stresses (SGT275 and SGT550). As a result of analyzing the behavior of steel pipes for 7 hours after the first excavation for 1 m and before proceeding with the next excavation, the stress redistribution due to the arching effect caused by the excavation relaxation load was observed. As excavation proceeded by 1 m, the excavated section exhibited the greatest deformation during excavation of 4 to 6 m due to the stress distribution of the three-dimensional relaxation load, and deformation and stress were generated in the steel pipe installed in the ground ahead of the tunnel face. As a result of comparing the behavior of SGT275 steel pipe (yield strength 275 MPa) and SGT550 steel pipe (yield strength 550 MPa), the difference in the amount of deformation was up to 18 times and the stress was up to 12 times; the stronger the steel pipe, the better it was at responding to the relaxation load. In this study, the behavior mechanism of steel pipe reinforcement grouting in response to the arching effect due to the relaxation load was identified based on the measured data during the actual tunnel excavation, and the results were reported.

• Journal of the Korean GEO-environmental Society
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• v.16 no.10
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• pp.15-22
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• 2015

In this study, to evaluate the long-term behavior characteristics and the loss of prestress force, the long-term measurement of the tensile anchors in the actual construction was performed and the results were analyzed comparing with the existing estimation. As the reinforcement member used for the purpose of slope stability or uplift-resisting of the permanent structure, etc, the permanent anchor should maintain the functions during the performance period of the structure differently from the temporary anchor. However, as the time passes by, since the relaxation and the creep of the anchor occur constantly, the management for the loss of tensile force is essential to perform the functions stably. So far, the loss of the tensile force has been estimated according to the reduction of the prestress using elasticity theory and using the relaxation value according to the type of tension member and the test using the long-term measurement is limited. Therefore, in this study, the site condition and the ground were investigated for the tensile anchor in the actual construction and the long-term measurement results more than 500 days was analyzed by installing the loadcell, inclinometer and the groundwater level gauge. In addition, the long-term behavior characteristics were evaluated by comparing the disposition of the measured earth retaining wall and the tension force loss of the anchor with the existing interpretation results. In the evaluation results, the most of the tension force loss occurs within 90 days and the loss was measured less than the estimated values.

• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.323-327
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• 2008

Systemic lupus erythematosus (SLE) is a multisystem disorder where the etiology is not clearly known. Symptomatic chronic interstitial pneumonitis is an uncommon manifestation, with a reported prevalence of 3~13%. Achalasia is rare disease that presents with failure in the relaxation of the esophagus sphincter. A 22-year-old woman was admitted to our hospital because of fever, cough and dyspnea. The patient had a history of pericardial effusion and Raynaud's phenomenon. The results of laboratory tests indicated the presence of lymphopenia and included positive antibody tests for antinuclear antibody and anti Sm antibody. A chest X-ray demonstrated the presence of peribronchial infiltration on both lung fields. A Chest CT image showed interlobar septal thickening, ground-glass opacity and a honeycomb appearance in both lung fields and esophageal dilatation with air fluid level. An esophagogram showed the presence of dilated esophagus ends that represented the non-relaxed lower esophageal sphincter. Manometry demonstrated incomplete sphincter relaxation. The case was diagnosed as systemic lupus erythematosus associated with interstitial pneumonia and achalasia.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.100-105
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• 2021

Contactless service is rapidly emerging as a new growth strategy due to consumers who are reluctant to the face-to-face situation in the global pandemic of coronavirus disease 2019 (COVID-19), and various technologies are being developed to support the fast-growing contactless service market. In particular, the restaurant industry is one of the most desperate industrial fields requiring technologies for contactless service, and the representative technical case should be a kiosk, which has the advantage of reducing labor costs for the restaurant owners and provides psychological relaxation and satisfaction to the customer. In this paper, we propose a solution to the restaurant's store operation through the unmanned kiosk using a state-of-the-art artificial intelligence (AI) technology of image recognition. Especially, for the products that do not have barcodes in bakeries, fresh foods (fruits, vegetables, etc.), and autonomous restaurants on highways, which cause increased labor costs and many hassles, our proposed system should be very useful. The proposed system recognizes products without barcodes on the ground of image-based AI algorithm technology and makes automatic payments. To test the proposed system feasibility, we established an AI vision system using a commercial camera and conducted an image recognition test by training object detection AI models using donut images. The proposed system has a self-learning system with mismatched information in operation. The self-learning AI technology allows us to upgrade the recognition performance continuously. We proposed a fully automated payment system with AI vision technology and showed system feasibility by the performance test. The system realizes contactless service for self-checkout in the restaurant business area and improves the cost-saving in managing human resources.