• Earthquakes and Structures
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• v.8 no.5
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• pp.995-1016
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• 2015

The reliability or the safety index is a measure of how far a structure is from the state of collapse. Also it defined as the probability that a structure will not fail in its lifetime. Having any increase in the reliability index is typically interpreted as increasing in the safety of structures. On the other hand most of researchers acknowledged that one of the most effective means of increasing both the reliability and the safety of structures is to increase the structural redundancy. They also acknowledged that increasing the number of vertical seismic framing will make structural system more reliable and safer against stochastic events such as earthquakes. In this paper the reliability index and the behavior factor of a numbers of three dimensional RC moment resisting frames with the same story area, equal lateral resistant as well as different redundancy has been evaluated numerically using both deterministic and probabilistic approaches. Study on the reliability index and the behavior factor in the case study models of this research illustrated that the changes of these two factors do not have always the same manner due to the increasing of the structural redundancy. In some cases, structures with larger reliability index have smaller behavior factor. Also assuming the same ultimate lateral resistance of structures which causes an increase to a certain level of redundancy can enhance behavior factor of structures. However any further increase in the redundancy of that certain level might decrease the behavior factor. Furthermore, the results of this study illustrate that concerning any increase in the structural redundancy will make the reliability index of structure to be larger.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.253-261
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• 2018

The purpose of this study is to find the theories of public policy in Confucian politics during Choson Dynasty. As a result of the analysis, there are five implications. First, the area of Confucian policy of Choson consisted in authority, organization, financial policy, affection for the people, and li(ritual propriety). Second, major political context had been maintained from King Se-Jong, through King Sung-Jong and King Yeong-Jo to King Jeong-Jo in the perspective of dynasties' characteristic. Third, there were major ideas on Confucius's idea for li in early period, $Zh{\bar{u}}z{\check{i}}^{\prime}s$ idea for the authority in late period and Mencius's idea for financial policy in major risk situation. Fourth, there were five periods with establishment, foundation, crisis, restoration and collapse in the change of public policy. Fifth, $Zh{\bar{u}}z{\check{i}}^{\prime}$ and $Ch{\acute{e}}ng{\cdot}zi$ had influenced bigger than Confucius as a factors of policy making. This study has been promoted the complement of context analysis and understanding of semantic analysis with implementing dictionary using two language with Korean and Chinese.

• The Journal of the Petrological Society of Korea
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• v.28 no.4
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• pp.237-249
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• 2019

The volcanic rocks around the Jayang caldera are classified in an order such as Jukjang Volcanics, Doil Rhyolite, Unjusan Tuff and Rhyolite intrusions. By the SHRIMP U-Pb zircon datings from zircons, eruption ages of the Unjusan Tuff are constrained as 66.65±0.96 Ma in the intracaldera, and 66.08±0.62 Ma in the extracaldera outflow, and intrusion age of the ring dike is investigated as 60.74±0.66 Ma. The age data indicate that the caldera was collapsed between 66.08 Ma and 60.74 Ma, just before the dike intruded after the explosive eruption of the Unjusan Tuff. The Jayang caldera shows the composite igneous process of a perfect volcanic cycle passing from ash-flow tuffs through caldera collapse into ring dikes in the Jayang area.

• Journal of The Korean Astronomical Society
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• v.24 no.1
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• pp.71-94
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• 1991

With the 14 m radio telescope at DRAO and the 4 m at Nagoya University, we have made detailed maps of $^{12}CO$ and $^{13}CO$ emissions from two Barnard objects B133 and B134 in the $J=1{\rightarrow}O$ rotational transition lines. Usual LTE analyses of the CO observations led us to determine the distribution of column densities over an entire area encompassing both globules. Total gas masses estimated from the column density map are $90\;M_{\odot}$ and $20\;M_{\odot}$ for B133 and B134, respectively. The radial velocity of B133 is red shifted with respect to B134 by $0.8\;km\;s^{-1}$, which is too lagre to bind the two clouds as a binary system. We have shown that the usual stability analysis based on the simplified version of virial theorem with the second time-derivative of the moment of inertia term $\ddot{I}$ being ignored could mislead us in determining whether a given cloud eventually collapses or not. The lull version of the scalar virial theorem with the $\ddot{I}$ term is shown to be useful in following up the time-dependent variations of the cloud size R and its streaming velocity $\dot{R}$ as functions of time. Results of our stability analysis suggest that B133 will eventually collapse in $(2{\sim}4){\times}10^6$ years.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.592-599
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• 2004

Talus topography is that weathered rock clasts were accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope. it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short because of short resolution of aerophoto and difficulties of research about huge talus. In this Study, Our research team analgize the wetness index using the geomorphogical data. Lineament through wetness index is simillar with distribution of the talus. And, the aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy- shaped clasts dominate the proximal and intermediate parts of the talus, wheres blocky-shaped clasts is more common in the distal part. we carry out Rock Fall Simulation. And, We install criteria of the rockfall protective barrier using talus and geomorphological characteristics.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.729-736
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• 2006

It has been shown that many Reinforced Concrete(RC) structures designed without seismic details have experienced brittle shear failures in the beam-column joint area and resulted in large permanent deformations and structural collapse. In this study, experimental investigations into the performance of exterior reinforced concrete beam-column joints strengthened with the carbon fiber-reinforced polymer(CFRP) under cyclic loading were presented. The CFRP has been applied by choosing different combinations and locations to determine the effective way to improve structural performances of joints. Eight beam-column joints were tested to investigate behaviors of each specimen under cyclic load and to compare performances of seismic retrofit. According to the experimental study, the retrofit strengthened with the CFRP provides significant improvements of flexural capacity and ductility of beam-column joints originally built without seismic details.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.290-301
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• 2002

The purpose of this study was to evaluate new bone formation and healing process in rat calvarial bone defects using $BioMesh^{(R)}$. membrane and DFDB. Forty eight rats divided equally into 4 groups of 1 control group and 3 experimental groups. Standardized transosseous circular calvarial defects (8 mm in diameter) were made midparietally. In the control group, the defect was only covered with the soft tissue flap. In the experimental group 1, it was filled with DFDB only, in the experimental group 2, it was covered $BioMesh^{(R)}$. membrane only, and in the experimental group 3, it was filled DFDB and covered with membrane. At the postoperative 1, 2, 4, 8 weeks, rats were sacrificed and histologic and histomorphometric analysis were performed. These results were as follows. In histomorphometric analysis, It showed the greatest amount of new bone formation through experimental in the experimental group 3 (P<0.001). The amount of new bone formation at the central portion of the defect was greater in the experimental group 3 than experimental group 2. $BioMesh^{(R)}$. membrane began to resorb at 1 week and resorbed almost completely at 8 weeks after operation. The collapse of membrane into the defect was observed through the experimental periods in the experimental group 2. In the area of collapsed membrane, new bone formation was restricted. These results suggest that maintenance of some space for new bone to grow is required in the use of $BioMesh^{(R)}$. membrane alone in the defect. It is also thought that use of the membrane may promote new bone growth in DFDB graft.

• Childhood Kidney Diseases
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• v.17 no.1
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• pp.13-18
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• 2013

Podocytopathy is glomerular lesions characterized by podocyte injury. It is observed in various glomerular diseases, but minimal change disease and focal segmental glomerulosclerosis (FSGS) are the prototypes. In this review, morphologic features of podocyte injury and subtypes of FSGS will be reviewed briefly. Effacement of podocyte foot processes is the most common feature of podocyte injury. As podocytic injury progresses, intracytoplasmic vacuoles, subpodocytic cyst, detachment of podocytes from the glomerular basement membrane and apoptosis develop. Glomerular capillary loops in epithelium-denuded area undergo capillary collapse. Synechia and hyalinosis may accompany this lesion. To manifest segmental sclerosis, podocyte loss above a threshold level may be required. Injured podocytes can injure neighboring intact podocytes, and thereby spread injury within the same lobule. FSGS can be categorized into five subtypes by morphologic characteristics; not otherwise specified (NOS), perihilar, cellular, tip, and collapsing types. Each subtype has been reported to show different clinical courses and associated conditions, but there are controversies on its significance. With recent progress in the discovery of genetic abnormalities causing FSGS and plasma permeability factors, we expect to unravel pathophysiology of FSGS and to understand histological sequences leading to FSGS in near future.

• Earthquakes and Structures
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• v.18 no.5
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• pp.527-542
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• 2020

In traditional eccentrically braced steel frames, damages and plastic deformations are limited to the links and the main structure members are required tremendous sizes to ensure elasticity with no damage based on the force-based seismic design method, this limits the practical application of the structure. The high strength steel frames with eccentric braces refer to Q345 (the nominal yield strength is 345 MPa) steel used for links, and Q460 steel utilized for columns and beams in the eccentrically brace steel frames, the application of high strength steels not only brings out better economy and higher strength, but also wider application prospects in seismic fortification zone. Here, the structures with four type eccentric braces are chosen, including K-type, Y-type, D-type and V-type. These four types EBFs have various performances, such as stiffness, bearing capacity, ductility and failure mode. To evaluate the seismic behavior of the high strength steel frames with variable eccentric braces within the similar performance objectives, four types EBFs with 4-storey, 8-storey, 12-storey and 16-storey were designed by performance-based seismic design method. The nonlinear static behavior by pushover analysis and dynamic performance by time history analysis in the SAP2000 software was applied. A total of 11 ground motion records are adopted in the time history analysis. Ground motions representing three seismic hazards: first, elastic behavior in low earthquake hazard level for immediate occupancy, second, inelastic behavior of links in moderate earthquake hazard level for rapid repair, and third, inelastic behavior of the whole structure in very high earthquake hazard level for collapse prevention. The analyses results indicated that all structures have similar failure mode and seismic performance.

• The Journal of Engineering Geology
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• v.17 no.2 s.52
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• pp.235-251
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• 2007

Baeknokdam rock mass at the crest of Halla mountain is composed of Baeknokdam trachybasalt in the eastern region and Hallasan trachyte in the western region. On-going weathering, rockfall and collapse of Baeknokdam wall rock are closely linked to the weathering of trachyte distributed in the western region of Baeknokdam, though within the restricted area of eastern region trachybasalt blocks has been naturally formed and may be rolled down neering properties have been conducted. Based on the results of these experiments variations of mineralogical-petrographical characteristics of trachyte together with chemical and physical properties with respect to the degree of weathering have been analyzed. Weathering mechanism of Baeknokdam trachyte has been delineated by investigating the environmental cause of weathering and the peculiar features of weathered rock mass.