• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.141-148
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• 2016

This paper employed finite element method (FEM) to study the dynamic response of Steel Fiber-Reinforced Concrete(SFRC) panels subjected to impact loading by spherical projectiles. The material properties and non-linear stress-strain curves of SFRC were obtained by compression test and flexural test. Various parametric studies, such as the effect of fiber volume fraction and thickness of panels, are made and numerical analyses are compared with experiments conducted. It is shown that protective performance of concrete panels will be improved by adding steel fiber. Area loss rates and weight loss rates are decreased with increasing fiber volume fraction. Also, penetration modes can be expected by FEM, showing well agreement with experiment. Results can be applied for designing the protection of military structures and other facilities against high-velocity projectiles.

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.62-72
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• 2011

Currently, The failure of construction project is increasing to be caused by a changing construction environment. According to this circumstances, Researches of project success factors affecting performance have been presented to develop strategies for efficient construction project management in the construction industry. However, Conducting efficient construction project management is difficult because project manager could not know which project success factors can be improved or not. Especially, although the project characteristics were derived the level of difficulty for performance, research of the project characteristics which could not be improved as influence factor to performance is lacking. Therefore, This paper has developed the Performance Predicting System(PPS) with Fuzzy set theory to establish. PPS has been developed to establish efficient project management strategies and to save time and effort. As Contractor inputs the project characteristics, PPS can predict the level of difficulty of performance.

• KIEAE Journal
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• v.9 no.2
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• pp.43-52
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• 2009

The aim of this study is to find out the solutions for an improvement of residential environment through the relation between satisfaction of residential environment and amenity awareness of the local residents in Chonnam Mokpo city. For this purpose, it is conducted a questionnaire survey of 203 local residents on the attributes of residential environment. The satisfaction factors of residential environment consist of 8 types of factors such as housing structure, stability, green tract of an avenue, convenience, housing environment, sanitary conditions, waterside facilities, and familiarity. It is analyzed that there is a great difference of the satisfaction between new town dwellers and old town dwellers in three satisfaction factors of a housing structure, convenience, and housing environment. The attributes of amenity awareness consist of 6 types of factors such as fitness, comfort, intimacy, vitality, naturalness, and brilliance. The new town dwellers have a high satisfaction in fitness and vitality factors, and the old town dwellers have a high satisfaction in naturalness factors. Through the analysis to the importance on the satisfaction factors of residential environment related to amenity awareness, it is founded that intimacy factor have importance in order of stability, familiarity, green tract of an avenue and sanitary conditions. Naturalness factor have importance in order of stability, waterside facilities, familiarity and green tract of a avenue. Fitness factor have importance in order of housing structure and sanitary conditions. Comfort factor have importance in order of stability, housing environment and sanitary conditions. And vitality factor have importance in order of housing environment, convenience and green tract of an avenue. Therefore, it is needed that the development plan of residential environment take into consideration in accordance with the importance on the satisfaction of residential environment in Mokpo city.

• Tunnel and Underground Space
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• v.25 no.1
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• pp.24-36
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• 2015

The Geochang granite widely used in construction works is one of the most popular dimension stones in Korea. In order to evaluate the physical properties of rock, a lot of laboratory tests for the Geochang granite were conducted to find unit weight, absorption ratio, P wave velocity, S wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, cohesion, friction angle and point load strength index. The uniaxial compressive strength of the Geochang granite was 19.5 times tensile strength and also 8.6 times cohesion, besides P wave velocity was 1.5 times S wave velocity. Correlation analyses were also conducted to find the correlation among 11 different physical properties, where the uniaxial compressive strength showed Pearson correlation coefficient of more than 0.8 with Poisson's ratio, point load strength index and Young's modulus, respectively. Regression analyses were finally conducted by means of both linear and multiple analysis and the brief results including coefficient of determination of more than 0.7 were presented.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.76-81
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• 2004

From September 1, 2003 to November 30, 2004, 20 mineral water wells were selected for some area in east Europe and the study on their water quality was analized. It revealed that mineral water contained considerable quantity of magnesium ions which helps the smooth activities of vascular muscles, nervous systems and protects skins from allergic reactions. It also lowers cholesterol level and contains high concentration of calcium ions which is one of the vital components of teeth and bone like phosphorus. Thus it is concluded that it is not qualified as boiler feed water as it has overall high degree of hardness by the presence of four times content of $Mg^{2+}\;and\;Ca^{2+}$.

• Journal of Korean Association for Spatial Structures
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• v.10 no.2
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• pp.61-68
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• 2010

The collapsing accidents of pipe greenhouses in the farmhouse have been increased duo to heavy snow load. However, the study on exact structure analysis to prevent the collapse of pipe greenhouses is rare and the damage of the farmhouse is annually repeated. The method of existing structure analysis is basically made of linear elastic analysis based on the micro displacement. But the actual stiffness of the pipe greenhouse is significantly weaker than the stiffness of buildings and the load acting on the greenhouses gets to become relatively bigger. It means that the geometry shape of greenhouses changes so that the relation of strain-displacement gets to indicate a nonlinear behavior. Therefore, this study is performed to evaluate the structural safety so as to prevent the collapse of pipe greenhouses, which are the single-span greenhouse(farmhouse guidance shape, G) and multi-span greenhouse(farmhouse supply shape, 1-2W), by performing the large-displacement analysis considering nonlinear effects.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.255-266
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• 1999

The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames having non-seismic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional practice was selected. A 1:12 scale plane frame model was manufactured according to similitude law. A reversed lateral load test and a monotonic pushover test were performed under the displacement control. To simulate the earthquake effects, the lateral force distribution was maintained to be an inverse triangle by using a whiffle tree. From the tests, base shears, crack pattern, local rotations in the ends of critical members and the relations between interstory drift versus story shear are obtained. Based on test results, conclusions are drawn on the implications of the elastic and inelastic behaviors of a high-rise reinforced concrete frame having non-seismic details.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.105-111
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• 2004

This study is aiming at examining the possibilities to develop eco-friendly waterfront, and discusses characteristics of the organic worldview which has been emerged as new development or eco-friendly paradigm in recent science against the mechanical worldview of modem times. The orientation of waterfront development is characterized as unity, diversity, dynamics and mutuality. In addition, I examined the factors for waterfront design according to the locational, decorativeand visual properties of urban$.$architecture to find out concrete factors of its design. This study suggests the factors for waterfront design making use of organic properties, by examining the orientation for organic development of eco-friendly waterside environment and showing correlation between the factors of specific design, and their examples.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.3-10
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• 2011

Currently, technologies for industrialization and dissemination for Han-Ok are developed actively. Also BIM technologies are actively developed. However, it is difficult to find the research and study cases for construction method and process for Han-Ok. BIM is the technology for managing information with element as a unit for building design, construction and management, and it is closely related to Han-Ok using assembling method for building construction. We analyzed the basic construction processes for IK-Gong and MinDoRi house, typical types of Han-Ok. Also we developed the Work Breakdown Structure of construction process for Han-Ok and suggested the method for construction simulation using BIM. Simple BIM model of Han-Ok which is Ik-Gong type is used for case study. It was possible to link automatically between 3D elements objects and construction activities about 95% in the case study. More studies of construction method for various type of Han-Ok and rules for link between elements and construction activities are required for Industrialization and dissemination of Han-Ok.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.22-30
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• 2011

In the planning phase of domestic urban environment maintenance and improvement projects, a particular problem is the increase in service expenses and project cost with the establishment of plans under circumstances that exclude the residents or have incomplete consent from them and the public organization. This delays the promotion of the project. This study aims to resolve such problems by proposing a measure to introduce a privatepublic consultative body for residents and the relevant departments of the public sector, to encourage them to participate and establish plans together from the beginning. This is expected to contribute to the smooth promotion of the project, as it would remove the conflicting factors that are expected to be generated in the project implementation phase before they could emerge.