• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.81-89
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• 2015

This study takes shear wall of reinforced concrete structure as study object, and the purpose of this study is to suggest structure BIM based on automatic reinforcing bar placement system applying set-based design through the most optimum reinforcing bar placement group that was selected by applying AHP (analytical hierarchy process) method from design step. For this, the most optimum reinforcing bar placement group was selected by pairwise comparison analysis on complex standard of multiple alternatives. And shear wall automatic reinforcing bar placement system has been developed, which can automatically generate members and arrange reinforcing bar by structure design algorithm and using open API (application programming interface) provided by a BIM software vendor. As a result, the most optimum reinforcing bar placement group of the highest weight, ALT1, was selected and was generated using Tekla Structure program.

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.119-126
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• 2004

Generally, reinforced concrete is one of the most commonly used structural materials and it prevents corrosion of steel bar by high pH of interior, But, as time elapsed, reinforced concrete structure become deteriorated by many of combined deterioration factors and environmental conditions. And, there are large number of deteriorate mechanism of the reinforced concrete structure and it acts complexly. It is recognized that steel bar corrosion is the main distress behind the present concern regarding concrete durability. In this study, to institute combined deterioration environments, established acceleration condition and cycle for combined deterioration environments has a resemblance to environments which are real structures placed. After that to confirm corrosion properties of reinforced concrete due to permeability with covering depth and types of surface cover under combined deterioration environments, measured carbonation velocity coefficients, chloride ion diffusion coefficients, water absorption coefficients, air permeability coefficients and electric potential, corrosion area ratio, weight reduction, corrosion velocity of steel bar. The results showed that an increase in age also decrease carbonation velocity coefficients, increase Chloride ion diffusion coefficients and increases water absorption coefficients. As well, an increase in age also increases corrosion of steel bar. Data on the development of corrosion velocity of steel bar with types of surface cover made with none, organic B, organic A, inorganic B, and inorganic A is shown. As well, permeability and corrosion velocity of steel bar with covering depth is superior to 10mm than 20mm. And it is confirmed permeability and corrosion properties of steel bar are closely related.

• Korean Journal of Heritage: History & Science
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• v.33
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• pp.182-208
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• 2000

Kwan-gyongdo is a pictorial presentation of a $s{\bar{u}}tra$ that teaches the Buddhist way for a person to be reincarnated in the paradise of $Amit{\bar{a}}bha$ Buddha. It consists of a preface (Kwan-gyong sobun pyonsangdo) and 16 scenes of $S{\bar{a}}kyamuni$ preaching. The preface, a painting illustrating the motivation behind the production of tile kwan-gyongdo, illustrates the "Legend of King $Aj{\bar{a}}tasatru$", a tragic story in which the prince of India's Magadha kingdom murders his father, the king, to usurp the throne. The 16 subsequent scenes show $S{\bar{a}}kyamuni$ teaching the distressed queen how a person can be reborn in paradise through meditation and praying. In the kwan-gyongdo in the Mogao Cave No. 17 in Dunhuang, China, painted during the Tang dynasty (618-907), the preface and the 16 scenes are presented in one painting, whereas they are presented in two paintings in those painted in Korea during the Koryo period (918-1392). The difference is attributed to the stylistic disparity of the two periods. Despite the temporal gap between the Koryo paintings and the Mogao Cave paintings, a comparison of the two can show the characteristic development of kwan-gyongdo. Kwan-gyongdo of the Koryo period do not have the "enmity created in the previous life" scene featuring a heavenly figure and a hare, a result that shows the influence of the Tang school that deleted the scene. The scene of $S{\bar{a}}kyamuni$ preaching on the Mountain of Spirit is included in kwan-gyongdo of both the Koryo period and the Mogao Cave, but the scene of $S{\bar{a}}kyamuni$ emerging from the earth to the Magadha palace is not included in Koryo kwan-gyongdo. Kwan-gyongdo of Koryo are generally a simpler but more faithful rendering of the $s{\bar{u}}tra$.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.66-73
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• 2015

Alveolar bone loss and deformation can be a risk factor in removable prosthetic restoration treatment for partially or fully edentulous patients. The use of implants to solve this problem could improve the support, retention and stability of removable restoration. Attachments used in implant overdenture are versatile. The attachment should be selected according to the patients' conditions. Milled bar has been chosen when readymade bar could not be used because of the narrow distance between implants or firm stability and support of supra-structure were needed. Milled bar design is able to provide cross arch stabilization and comfortability to patients. However, it needs skilled laboratory procedures. Recently, the fabrication of milled bar has become simple and its suitability has been improved through the development of CAD/CAM system. In a 67-year-old female Alzheimer's disease patient with 8 implant fixtures on the fully edentulous site of mandible, implant overdenture with using milled bar and magnet attachment was planned. As rapid treatment was required, CAD/CAM system was used to make a simple laboratory procedure instead of a traditional fabrication process. With this system, implant overdenture with milled bar can be fabricated esthetically and functionally.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.205-208
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• 2006

Based on SAR signatures for bars, bar transformation is investigated from 2000 to 2005, and monitoring of suspended-silt transportations from terrestrial runoff is tried to understand the morphology during the events of severe rain storm. SAR data did not reveal clearly the bar locations because of most of data acquisitions during high tides form 6.8 m to 9.0 m. Even though the problem, it could be said that in the estuary vegetated area and natural levees are developed well, but bars are shifted after an event like a flood. It is also showed that suspended solids such as silt transported through the estuary could contributed highly to a sedimentation environment around Incheon. A navigational route could be designed with a minimum width of about 200m.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.4
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• pp.787-793
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• 2002

In this study, a bar impact test of low velocity was carried out to gain an insight into the damage mechanism and sequence induced in alumina plates(AD 85 and AD 90) under impact conditions. An experimental setup utilizing an instrumented long bar impact was devised, that can measure directly the impact force applied to the specimen and supply a compressive contact pressure to the specimen. During the bar impact testing, the influences of the contact pressure applied along the impact direction to the specimen on the fracture behavior were investigated. The measured impact force profiles explained well the damage behavior induced in alumina plates. The higher contact pressure to the specimen led to the less damage due to the suppression of radial cracks due to the increase in the apparent flexural stiffness of plate. It had produced the change of damage pattern developed in the specimen; from the radial cracks to the local contact stress dominant damage. It would contribute to the improvement of the ballistic property in ceramic plates. The observed results showed the following sequence in damage developed: The development of cone crack at impact region, the formation of radial cracks from the rear surface of plate depending on the plate thickness, the occurrence of crushing within the cone envelope and the fragmentation.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.109-120
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• 2014

This study is an analysis on gravel and sand of sand-gravel bar that stretches variously in the Duchon stream basin, which is one of Hong-Cheon River(a well-developed sand-gravel bar in upstream river)'s upper stream basin. The purpose of this study was to understand the characteristic of the stream's topographic development that variously occur in the small basin by comparing the differences between the aspects of development and the sediment of sand-gravel bar in each section and by examining the transition of sediments moving from upstream to downstream. Through the analysis on the roundness and flatness of gravel, we observed an irregular trend following the increase in supply of granite gravel and gneiss gravel as we traveled downstream. As for the aspect of change in sand's grain size, the overall ratio of medium-coarse sand was very high, but the results showed no big difference in the change following the inflow of stream from the main stream section to the gneiss and granite zone.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2209-2219
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• 1997

A split hopkinson bar could be used for obtaining the high strain rate material properties of sheet metals for an autobody. In high speed tensile tests of sheet matals, a new design of a tension split Hopkinson bar apparatus is needed. The design of grips and an anvil length are numerically analyzed with ABAQUS/Explicit for the new apparatus of split Hopkinson bars. From the experiments with the new apparatus, the material properties of SPCEN in the high strain rate state have been acquired and compared with quasi-static experimental results. The material properties of SPCEN as well as other sheet metals in an autobody are indispensible for the analysis of crashworthness. Nevertheless the experiment of sheet metal in the high strain rate state has not been done or reported.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.79-88
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• 2012

The purpose of this study is to evaluate the stiffness of the mechanical sleeve reinforcement splices filling high-strength mortar under monotonic loading. For this objective, we analyzed and compared the previous test data of 189 actual-sized mortar-filled sleeve bar splices specimens, including the reinforcing bar splices prepared and tested by the author. The paper results indicated that the minimum values of compressive strength of mortar($f_g$) multiplied by the ratio of reinforcement development length to bar diameter(L/d) were suggested for holding the stiffness of the mortar-filled sleeve reinforcement splices required in AIJ code.

• Journal of ILASS-Korea
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• v.21 no.3
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• pp.121-129
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• 2016

The advantages of the common rail fuel injection system architecture have been recognized since the development of the diesel engine. In common rail systems, a high-pressure pump stores a reservoir of fuel at high pressure up to and above 2000 bar. And solenoid or piezoelectric valves make possible fine electronic control over the fuel injection time and quantity, and the higher pressure that the common rail technology makes available provides better fuel atomization. In this study, the direct needle-driven piezo injector was investigated for accomplishing injection pressure of 1800 bar by optimal design by simplification of component and changing number of springs and plates of DPI. It was found that a direct needle-driven piezo injection system features the prototype DPI for passenger vehicle to operate at 1800 bar of injection pressure.