• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.37-41
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• 2008

According to the recent rapidly increasing that construction works are gradually Manhattanized mainly the grand scaled residential buildings, the foundation of the building that is related to safety is increasing for building as a grand scaled mat concrete. Because mat concrete can not be simultaneously placing of concrete in a great quantity due to the circumstance at the field, the inequal deformation of the tensile stress that according to the time lag of hydration heat between the upper layer and the lower layer is affecting as a cause that is the possibility of crack occurrence by increasing. Accordingly, this research checked the efficiency of super retard concrete in applying real structures, and we implemented the preparatory experiment to settle up the inequal deformation of the tensile stress substantially that is according to the time lag of placement between the upper layer and the lower layer by controlling the setting time using the super retarding agent. As the result of test, the more target of delay time lengthened, the more fluidity increased and air content indicated a little differences. There was from 2 to 10 hours between the standard curing and the outside curing at the setting time and in case of calculating the rate of mixing at real structure is required that mix promotion, increasing the amount of mixing, by setting up the curing temperature. The super retard concrete showed the result that in compressive strength, early-age strength was smaller than normal concrete whereas it was same or more figures from at the aging 28days because of the super retarding agent.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.57-60
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• 2008

According to the recent tendency that the buildings in the downtown concerning rising land prices and efficient use of building are gradually Manhattanized mainly the grand scaled residential buildings, structure of the buildings relates to safety and so the very thick mat concrete is selected as the foundation of architectures. Because mat concretes can not be simultaneously pour in a great quantity due to the circumstance at the field, not only the questions on the unification between the concretes pour on the upper layer and the lower layer are presented but also the cracks by the internal force from the difference of hydration exothermic period are occurred because of the time lag. Thus, this study checked the efficiency to apply "The hydration heat controlling method of mass concrete for horizontal partition pouring construction" to the skyscraper sites under construction at Haiundai in Busan. After applying this method, the result of observation that the cracks by hydration heat in all over the placement surface did never be founded. Also, in case of the economic analysis that the hydration heat reduction method using super retarding agent by difference of setting time is approximately 80% cheaper than the hydration heat reduction method by pipe cooling in the construction expenses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2379-2384
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• 2015

Bellows product is an important part in the area of plant engineering, shipbuilding and petrochemistry. For safety and durability it is necessary to consider lots of factors when designing it. This research developed a U-shaped metal bellows design software based on EJMA 9th Edition manual. This GUI software was developed by using Matlab software and can be able to design four types of bellows, Unreinforced Single Bellows, Unreinforced Double Bellows, Reinforced Single Bellows and Reinforced Double Bellows. The already proven bellows model was designed to verify this software. We investigated the behavior while changing the thickness of the bellows. As the thickness of bellows increases, spring rate, thrust force, stress increase and fatigue life decreases. This software will be helpful design engineers save time and effort.

• Journal of the Korean Geosynthetics Society
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• v.6 no.1
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• pp.1-7
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• 2007

In order to improve the bearing capacity of soft ground for the purpose of getting a trafficability of construction vehicles, the geosynthetics-sandmat system has often been used. Yamanouchi had proposed the equation of calculating the bearing capacity about this kind of bearing mechanism, which has a soft ground-geosynthetics-sandmat system. The bearing capacity equation by Yamanouchi has been widely using in our country. However this equation includes an important contradictory concept because if the contact width of vehicles is incresed to reduce the contact pressure, the bearing capacity is decresed on the contray according to this equation. In order to investigate this contradictory concept, the bearing capacity test has been performed on the soft model ground with geosynthetics-sandmat system. From the test results about various kinds of models, the principle that explain the contradictory concept has been found and on the basis of this principle the new bering capacity equation has been proposed by modifying Yamanouchi equation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2661-2669
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• 2010

In this study, a finite element formulation based first-order shear deformation theory is developed for non-linear behaviors of laminated composite plates containing matrix cracking. The multi-directional stiffness degradation is developed for adopting the stiffness variation induced from matrix cracking, which is proposed by Duan and Yao. The matrix cracking can be expressed in terms of the variation of material properties, such as Young's modulus, shear modulus and Possion ratio of plates, and sequently it is possible to predict the variation of the local stiffness. Using the assumed natural strain method, the present shell element generates neither membrane nor shear locking behavior. Numerical examples demonstrate that the present element behaves quite satisfactorily either for the linear or geometrical nonlinear analysis of laminated composite plates. The results of laminated composite plates with matrix cracking may be the benchmark test for the non-linear analysis of damaged laminated composite plates.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.55-64
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• 2008

When the structure is constructed on the soft ground, the embankment is settleed into the soft ground. At this time, the settlement of the structure is needed to predict. We are using bamboo mats construction only as a way of test construction. Under this circumstance, using the equation of Janbu and Perloff, we calculated the settlement, and analyzed the problem, suggesting proper theoretical equations showing the settlement of soft ground using bamboo mat. Using this equations the settlement was calculated and compared with the result of FEM. The result of the application was very close to the numerical value and the trend of theoretical equations. Using the existing equations, the settlement in Janbu's and Perloff's methods were calculated to be 40% of the actual settlement.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.807-812
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• 2001

This study is peformed for checking the limitation and application of each curing/heating methods on cold-weathering mat foundation construction, considering temperature control, early strength security and temperature declination range limit, by means of concrete material properties and thermal analysis technique that were published previously. In the result of this analysis, we checked the open air temperature and mat depth that are possible to apply each curing/heating methods on cold-weathering construction and found curing/heating time of each methods that is able to prevent early aged freezing damage and thermal crack

• Proceedings of the Technology Innovation Conference
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• 2009.02a
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• pp.205-230
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• 2009

기술지식으로서의 특허가 과학지식으로서의 과학논문을 많이 인용하면 할수록 과학지식과 기술지식의 상호작용이 많다고 해석할 수 있고, 또한 인용까지의 평균시차가 짧으면 짧을수록 과학지식과 기술지식의 확산속도가 그만큼 빠른 것으로 해석할 수 있다. 과학논문과 특허를 대상으로 과학집약도가 높은 기술분야, 여러 학문분야를 가장 많이 인용하고 있는 기술분야, 그리고 여러 기술분야에서 가장 많이 인용되는 학문분야를 발견할 수 있다. 또한 하나의 특허가 다른 특허에 인용되는 관계를 통해 피인용특허의 기술분야와 인용특허의 산업분야에 대한 연계 매트릭스를 구성함으로써 기술지식이 파급 연계되는 산업분야를 확인할 수 있다. 여기에서는 이러한 과학기술 지식의 연계관계를 규명함으로써 어떤 유형의 지식이 기술혁신에 있어 가장 기초가 되는지, 어떤 기술 분야가 과학적 지식을 가장 역동적으로 활용하는지, 그리고 산업계의 요구와 가장 긴밀한 관계를 맺고 있는 학문분야는 어떤 분야인지를 분석하고자 한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.144-147
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• 2004

In this paper, field application of mass concreting using super retarding agent(SRA) are discussed based on setting. time difference with SRA in big discount market in Chongju. Mechanical and physical properties of .concrete are investigated. Temperature history of concrete is also measured. Slump and air content meet the requirement of target value. Compressive strength of concrete exceeded the nominal strength with 24MPa. Compressive strength of SRA concrete is higher than that of plain concrete by about $3\~4\%$. For temperature history, peak temperature of concrete at middle section at top concrete layer reached $49.6^{\circ}C$ within 24hours, and at bottom concrete layer, $54.6^{\circ}C$ within 42hours. Based on the naked eye's observation, no crack was found at mass concrete.

• Cartoon and Animation Studies
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• s.9
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• pp.220-234
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• 2005

The article deals with the reality subject of animations. Animations are created on the basis of fantasy. Disney's introduction of the narratives and styles of live action film into the field of animation, which laid a foundation for the hyper-reality animation, has produced an unintended consequence of marginalizing other animation genres which have emphasized fantasy through free experimentations of various images. A combination of Disney's world view of hyper-reality with later-developed 3D computer animation technology has made fantastic figures and spaces much more real than the real ones, and succeeded in creating a matrix of simulacre, a world of mere copies without the original.