• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.5-19
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• 2016

This paper presents the results from three-dimensional finite element (FE) analysis undertaken to provide insight into the lateral behaviors of piled gravity base foundation (GBF) for offshore wind turbine. The piled GBF was originally developed to support the gravity based foundation in very soft clay soil. A GBF is supported by five piles in a cross arrangement to achieve additional vertical bearing capacity. This study considered four different cases including a) single pile, b) three-by-three group pile (with nine piles), c) cross-arrangement group pile (with five piles), and d) piled GBF. All the cases were installed in homogenous soft clay soil with undrained shear strength of 20 kPa. From the numerical results, p-y curves and thus P-multiplier was back-calculated. For the group pile cases, the group effect decreased with increasing the number of piles. Interestingly, for the piled GBF, the P-multipliers showed a unique trend, compared to the group pile cases. This study concluded that the global lateral behaviour of the piled GBF was influenced strongly by the interaction between GBF and contacted soil surface.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.230-234
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• 2011

The present study describes the synthesis of 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives. The synthesis of the first target compound, 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone (1), was achieved by Friedel-Crafts acylation of o-cresyl methyl ether with succinic anhydride and subsequent cyclization of the intermediary g-keto acid with hydrazine hydrate. Condensation of compound 1 with aromatic aldehydes in the presence of sodium ethoxide affords the corresponding 4-substituted benzyl pyridazinones (3a-d). The dihydropyridazinone 1 underwent dehydrogenation upon treatment with bromine/acetic acid mixture to give (4). Pyridazine (5) has been synthesized upon the reaction of pyridazinone (1) with 1,3-diphenyl-2-propen-1-one under the Michael addition reaction. N-dialkylaminomethyl derivatives 6a-b have been obtained from the reaction of pyridazinone 1 with formaldehyde and secondary amine, whereas reaction of 1 with formaldehyde gives N-hydroxymethyl derivative (7). This study also includes the synthesis of the 3-chloropyridazine derivative 8 in excellent yield by heating pyridazinone 3b in phosphorus oxychloride. The behaviour of the chloro derivative toward sodium azide, benzyl amine and anthranilic acid was also studied. The proposed structures of the products were confirmed by elemental analysis, spectral data and chemical evidence.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.533-542
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• 2014

In design standards such as AASHTO LRFD and Korea Highway Bridge Design, the dynamic behaviors under the impact loading has not been considered and it recommends of using a static force for designing bridge column against vehicle collisions. Accordingly, in this study, models of vehicle collisions to concrete bridge column were developed with various boundary conditions in order to take into account dynamic behaviour of the column. Cargo trucks of 10tons, 16tons and 38tons were selected and a typical type of concrete bridge pier column along the Kyungbu highway in Korea was selected for this study. Results from this study indicate that the static load specified in the design standards are too small compared to results obtained in this study. It was also found that a consideration of the bridge superstructure allowed smaller damages of concrete bridge pier column under truck impact loadings. Furthermore, a comparison study of direct impact analysis of vehicle to bridge-column with in-direct impact analysis using load-time history functions was performed. The in-direct impact analysis shows that the use of load-time history graph improves the computational cost up to 92% and predict the behaviors of the bridge column under the impact loadings well. The obtained load-time history graph could be easily applied to several existing models.

• Management & Information Systems Review
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• v.39 no.1
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• pp.75-91
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• 2020

The purpose of this study is to examine the application of in-depth interviews in terms of exploration on the basis of the theoretical basis of various aspects of consumer empathy, and the question of whether the consumer can expand to the process of self empathy. Most studies related to consumer empathy divide the responsive dimension of consumer empathy into rational and emotional dimension based on empathy theory, and look at the empathic response perceived by consumers to the stimulus presented from the current point of view. In this study, however, we want to go one step further and confirm that the consumers themselves can ultimately go to the self-empathy stage by forming a creative street of reproduction and redevelopment. As a result of exploratory research through in-depth interviews, it was indirectly confirmed that consumer's empathetic response to specific marketing stimulus exists at the level of creative and self-empathetic as well as the emphasis of previous studies. Based on these findings, this study confirmed that consumer empathetic responses could go beyond a single dimension to form a multidimensional structure and move toward an expanded structure of empathic self-creation. This suggests that consumers' empathic responses should be grasped in terms of continuity of empathic responses rather than explained in a specific dimension. Although this study is meaningful as an early research of exploratory nature, it is necessary to supplement various content validity and refine the research method through subsequent studies. This study is expected to expand the understanding that consumer's empathy can be extended to other people's empathy and to be self-empathy.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.1-12
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• 2004

Due to the 1989 Loma Prieta, 1995 Hyogoken Nambu earthquakes, etc, a number of bridge columns  were collapsed in flexure-shear failures as a consequence of the premature termination of the column longitudinal reinforcement. Nevertheless, previous researches for the performance of bridge columns were concentrated on the flexural failure mode. It is well understood that the seismic behaviour of RC bridge piers was dependent on the performance of the plastic hinge of RC bridge piers, the ductility of which was desirable to be computed on the basis of the curvature. Experimental investigation was made to evaluate the variation of the curvature of the plastic hinge  region for the seismic performance of earthquake-damaged RC columns in flexure-shear failure mode. Seven test specimens in the aspect ratio of 2.5 were made with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading under a constant axial load, $P=0.1f_{ck}A_g$. Residual seismic capacity of damaged specimens was evaluated by analzying the moment-curvature hysteresis and the curvature ductility. Test results show that the biggest curvature was developed around 15cm above the footing, which induced the column failure. It was observed that RC bridge specimens with lap-spliced longitudinal steels appeared to fail at low curvature ductility but significant improvement was made in the curvature ductility of RC specimens with FRP straps wrapped around the plastic hinge region. Based on the experimental variation of the curvature of RC specimens, new equivalent length of the plastic hinge region was proposed by considering the lateral confinement in this study. The analytical and experimental relationship between the displacement and the curvature ductility were compared based on this proposal, which gave excellent result.

• Journal of East-West Nursing Research
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• v.8 no.1
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• pp.50-62
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• 2003

Through this literal study, we have endeavored to provide korea's unique nursing intervention methods based upon Lee Je-Ma's Sasang Constitutional Theory which is a unique korean medical science. The Sasang Constitution Theory lay great emphasis upon health caring medicine to promote health according to self Constitution at normal times, preventive medicine to manage byself body and mind in everyday life, and eventually, ethical medicine to love benevolence and kindness but to dislike jealousy.A variety of methods has been introduced to diagnose a person's Constitution. And yet, appearance, mind and pathological signs are three major criteria. In appearance, comprehensive features such as figure (the shape of the human body), countenance, behavior, mood, and posture are observed. In mind, nature (character), talent, steadiness, personality, and greed are investigated. In pathological signs, physiological conditions when healthy and peculiar symptoms when being ill are diagnosed. By these three criteria, each Constitution is categorised into Taiyang Person, Soyang Person, Taieum Person or Soeum Person. Different healthcaring methods exist for each Constitution such as mind and body healthcaring, diet healthcaring, knowledge and behaviour leathering, age group healthcaring, regional healthcaring, social life hralthcaring, everyday life healthcaring, and materia medication healthcaring. An independent and unique healthcaring method for each person according to self Constitution could be an important nursing intervention strategy, and can product a new nursing theory. To enjoy longevity by inducing positive caring methods, I believe that individual nursing may be the most desirable nursing approach. Lee Je-Ma's Sasang Constitution caring method is not only a general nursing theory but also expected to be an important landmark/milestone/factor in Korean nursing, preventive nursing, developing new nursing intervention methods and forming new nursing theories. Therefore, it is required to conduct thorough, practical and theoretical researches in the field of nursing.

• Spatial Information Research
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• v.12 no.2
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• pp.193-209
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• 2004

The purpose of this study is to analyze the service area of emergency medical centers using GIS-based spatial analysis methods in Seoul, focusing on the behaviour of patients on the choosing of emergency centers. For this analysis, six emergency centers were selected to collect data for the information on the addresses of patients from September to November hi 2003. Analysis on the service area, which was carried out by measuring the distribution of patients in terms of distance from emergency medical centers, clearly reveals that the majority of patients was located within or adjacent districts at the emergency medical center. However, the size of the primary service area f3r six emergency medical centers was much different, implying that the decision to visit specific emergency medical center by patients was closely related to the size, perception, and preference of the emergency medical center. Based on the results of the spatial characteristics of emergency medical service area, this research tries to construct the surface map of the emergency medical service level supplied by 32 regional emergency medical centers located in Seoul. Considering the levels of infrastructure for emergency medical centers, the coverage for the degree of supply of emergency medical service by each emergency medical center was constructed in terms of a distance decaying in the distribution of patients from emergency medical center imposing different weights on distance bands. Spatial overlay utilizing map algebra function was performed in order to calculate total supply level of emergency service. The results clearly show that spatial inequality exists in the supply levels of the emergency medical service among local areas of Seoul.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.4
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• pp.451-460
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• 2014

In this paper, we examined the problem of the structural stability according to the patch load of a rectangular plate that reflects the material properties of A6082-T6 is used primarily for marine plant structure. it applied to the four patch loading shapes, the effect of aspect ratio, a boundary condition and calculated the critical elastic buckling load. Calculating the critical elastic buckling load, During the eigenvalue buckling analysis it is applied to the shell181 as 4 node shell element. when the plate subjected to patch loading compare to the plate under a uniform axial compression load, it is possible observed to occur the different elastic buckling behaviour and it could be confirmed that it is affected significantly on a variable position and type of loadings, such as the effect of the aspect ratio. Also, Critical elastic buckling load according to th patch loading type in simply supported rectangular plate a/b=1.0, ${\gamma}b$=200mm are calculated 67%(Loading type I), 119 %(Loading type II), 76 %(Loading type III), 160 %(Loading type IV), respectively. Loading type I and III could be determined with the strong elastic buckling behavior much more than Loading type II and IV.

• Steel and Composite Structures
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• v.34 no.1
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• pp.1-15
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• 2020

This paper presents experimental and numerical studies on effects of local damages on the in-plane elastic-plastic buckling and strength of a fixed parabolic steel tubular arch under a vertical load distributed uniformly over its span, which have not been reported in the literature hitherto. The in-plane structural behaviour and strength of ten specimens with different local damages are investigated experimentally. A finite element (FE) model for damaged steel tubular arches is established and is validated by the test results. The FE model is then used to conduct parametric studies on effects of the damage location, depth and length on the strength of steel arches. The experimental results and FE parametric studies show that effects of damages at the arch end on the strength of the arch are more significant than those of damages at other locations of the arch, and that effects of the damage depth on the strength of arches are most significant among those of the damage length. It is also found that the failure modes of a damaged steel tubular arch are much related to its initial geometric imperfections. The experimental results and extensive FE results show that when the effective cross-section considering local damages is used in calculating the modified slenderness of arches, the column bucking curve b in GB50017 or Eurocode3 can be used for assessing the remaining in-plane strength of locally damaged parabolic steel tubular arches under uniform compression. Furthermore, a useful interaction equation for assessing the remaining in-plane strength of damaged steel tubular arches that are subjected to the combined bending and axial compression is also proposed based on the validated FE models. It is shown that the proposed interaction equation can provide lower bound assessments for the remaining strength of damaged arches under in-plane general loading.

• Journal of the Korean Magnetics Society
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• v.18 no.1
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• pp.39-42
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• 2008

[ $AB_2X_4$ ](A, B=Transition Metal, X=O, S, Se) are cubic spinel normal ferrimagnets, in which M ions occupy the tetrahedral sites and Cr ions occupy the octahedral sites. Recently, they have been investigated for behaviour of B site ions and A-B interaction. Polycrystalline $[Co_{0.9}Zn_{0.1}]_A[Cr_{1.98}{^{57}Fe_{0.02}}]_BO_4$ compound was prepared by wet-chemical process. The ferrimagnetic transition was observed around 90K. $M\"{o}ssbauer$ absorption spectra at 4.2K show that the well-developed two sextets are superposed with small difference in hyperfine fields($H_{hf}$). The hyperfine fields of $CoCr_{1.98}{^{57}Fe_{0.02}}O_4$ and $Co_{0.9}Zn_{0.1}Cr_{1.98}{^{57}Fe_{0.02}}O_4$ were determined to be 488, 478 kOe and 486, 468 kOe, respectively. We notice that the one of the magnetic hyperfine field values changes with Zn ion substitution. These results suggest the incommensurate states and spin-reorientation temperature($T_S=18K$) changes with Zn ions substitution below spin-reorientation temperature($T_S=28K$) of $CoCr_{1.98}{^{57}Fe_{0.02}}O_4$