• Steel and Composite Structures
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• v.37 no.1
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• pp.1-14
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• 2020

Composite beams with corrugated steel webs represent a new innovative system which has emerged in the past decade for medium span in the construction technology. The use of composite beams with corrugated steel webs results in a range of benefits, including flexible spaces and reduced foundation costs in the construction technology. The thin corrugated web affords a significant weight reduction of these beams, compared with hot-rolled or welded ones. In the current research, an optimal designed I-girder beam with corrugated web has been proposed to improve the structural performance of continuous composite girder under bending moment. The experimental program has been conducted for six simply supported composite beams with different loading conditions. The tested specimens are designed by using one of the stochastic techniques called hunting search algorithm. In the optimization process, besides the thickness of concrete slab and studs, corrugated web properties are considered as design variables. The design constraints are respectively implemented from Eurocode 3, BS-8110 and DIN 18-800 Teil-1. The last part of the study focuses on performing a numerical study on composite beams by utilizing finite element analysis and the bending behavior of steel girders with corrugated webs experimentally and numerically verified the results. A nonlinear analysis was carried out using the finite element software ANSYS on the composite beams which were modelled using the elements ten-node high order quadrilateral type.

• Knowledge Management Research
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• v.21 no.2
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• pp.21-40
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• 2020

Korea Credit Guarantee Fund(KODIT) is a public financial institution under the provision of the Korea Credit Guarantee Fund Act. Facing the waves of change both locally and globally, KODIT will serve as 'social value creator' in making a paradigm shift from a large corporation(Conglomerate-dominated) economy to a social enterprise-oriented one based on social economy. This study focuses on the supporting service programs for social enterprises and job creation how it affects the performance of social value creation of KODIT. There is currently no detailed research of the social value in terms of the business and management academic agenda. Therefore, the present study describes the importance of social value creation on the policy financial institution. This study conducted in-depth case study for social value performance. As a public policy financial institution, KODIT exert diverse efforts to correct market failure and achieve inclusive growth. For example, KODIT extends credit guarantee services for the liabilities of promising corporations and stimulates financial and non-financial supporting programs for social enterprises. Although the role of social value and social economy has gained business field attention, few investigations have been conducted to explain how social value is achieved. The present study can thus act as the foundation for exploring the social value creation in the circumstances of public financial institution.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.106-114
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• 2000

An investigation was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The contents of the investigation consisted of actual state of structures, maintenance status, meteorological disaster, and corrosion characteristics of pipe framework in greenhouses. the number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standared 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column , and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient. After about 7 years in grounds, 8 years in joints, 10 years in bending parts. and 13 years in columns. pipe surface was mostly rusted. Most weak parts in corrosion were pipes in contact with the ground, joints, roll-up shaft pipes, and pipes close to the gutter. Almost all of the greenhouse farmers didn't pay any attention to maintenance affair in a regular interval for pipe framed grenhouses. Many greenhouses have experienced the meteorologicla diaster such as uplift of foundation, partial or complete failure by the hyphoon and/or high winds.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.17-22
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• 2009

Reliability analyses were performed to quantify the risk in axially loaded large-scale pile foundations in consideration of pile-soil interaction and uncertainties on various design variables. The finite difference method based on an equivalent soil spring model and a load transfer method and Monte Carlo simulation method are integrated in the framework of reliabilty analysis. The applicability and efficiency of the proposed method in the safety assessment of axially loaded pile-soil system was verified using a realistic example. Since the proposed method can explicitly consider uncertainties in various design variables, and quantify failure probability of a pile foundation, it can be used to estimate risk, to obtain basic informations for life cycle cost analysis, and to develop code requirements for a reliability-based design of pile foundations.

• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.71-76
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• 2012

Shear strength of soil is power that resists failure and sliding according to any face in soils and one of the most important factors during engineering properties of soil. Shear strength is used for engineering science problems as bearing capacity methods of foundation or piles, slope stability after dam or Cutting Embankment and stability problem analysis of soils as lateral earth pressure of soil structures, ets. This study has analyzed shear strength change of samples classified 2.00mm(10sieve)와 0.85mm(20sieve), 0.475mm(40sieve) using direct shear tester after removing and drying cohesive soil ingredient of Weathered granite soil Therefore, this study would help studies about shear strength properties by particle size.

• Geotechnical Engineering
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• v.10 no.3
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• pp.97-110
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• 1994

Interaction between an unlined tunnel may cause a serious stability both the tunnel and the overlying and unli Red tunnel interaction meta study on the three dimensional bets a three dimensional elasto plastic the program, a wide range of blur puter analysis such as stress distr menu and tunnel deformation were footing and unlined tunnel. The yes traces the ultimate bearing capacity only on the tunnel size and location revealed is that an unlined tunnel under a square footing is subjected to three dimensional stress pattern along the tunnel axis, and that the magnitudes of stresses in the foundation soil and around tunnel perimeter are considerably smaller when loaded with a square than with a strip footings and the difference varies with the location and the type of stress. It is also revealed that the footing failure mechanism varies with the degree of footing and tunnel interaction.

• Geomechanics and Engineering
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• v.3 no.2
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• pp.117-130
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• 2011

The methods of design available for geocell-supported embankments are very few. Two of the earlier methods are considered in this paper and a third method is proposed and compared with them. In the first method called slip line method, plastic bearing failure of the soil was assumed and the additional resistance due to geocell layer is calculated using a non-symmetric slip line field in the soft foundation soil. In the second method based on slope stability analysis, general-purpose slope stability program was used to design the geocell mattress of required strength for embankment. In the third method proposed in this paper, geocell reinforcement is designed based on the plane strain finite element analysis of embankments. The geocell layer is modelled as an equivalent composite layer with modified strength and stiffness values. The strength and dimensions of geocell layer is estimated for the required bearing capacity or permissible deformations. These three design methods are compared through a design example. It is observed that the design method based on finite element simulations is most comprehensive because it addresses the issue of permissible deformations and also gives complete stress, deformation and strain behaviour of the embankment under given loading conditions.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.171-189
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• 2005

In order to improve inefficient and unproductive factors and in response to criticisms of the failure in harbor privatization introduced in 1997, the Korean government introduced the Port Authority system, which is commonly adopted in advanced harbors in the world. This research examined the theoretical background of harbor management system and various cases of harbor management in foreign countries. The desirable introduction of Port Authority system must be preceded by the settlement of problems in harbor structure and operation. In addition, the Port Authority Act, which restricts the autonomy of harbor corporations, should be improved for user-centered Port Authority system. Strategies for the successful introduction of Incheon Port Authority are as follows. Firstly it is required to establish consumer-centered harbor operation system. The second requirement is to activate the harbor logistics industry through the development of nearby logistic complexes led by Port Authority and, by doing so, to promote the development of local economy. Thirdly it is essential to lay the foundation of mutual prosperity through developing profitable businesses by linking localities and harbors, and to suggest a crisis control network for Port Authority and local self-governing bodies to cope jointly with crises in logistics and natural disasters.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.65-73
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• 2012

We studied the risk analysis of fire and explosion caused by gas leak in underground-parking of gas vehicle. However, an entrance regulation of gas vehicles (H2/LPG/CNG etc.) to underground garages has not been enacted in Korea. Incase, a gas explodes in an underground parking garage placed in overcrowded residential area, such as an apartment, the scale of the damage would cause tremendous disaster. Faults of vehicle parts and management problems were evaluated by using the Failure mode and effect analysis (FMEA), which is a qualitative analysis method. The range of the damaged area by the explosion and the damage scale by the explosion pressure were analyzed by using the process hazard analysis software tool (PHAST). The study is expected to facilitate enactment of the regulation for the underground parking to restrict the gas vehicle.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.94-100
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• 2002

As the use of automatic handling equipment for sensitive semiconductor devices is rapidly increased, manufacturers of electronic components and equipments need to be more alert to the problem of electrostatic discharges(ESD). In order to analyze damage characteristics of semiconductor device damaged by ESD, this study adopts a new charged-device model(CDM), field-induced charged model(FCDM) simulator that is suitable for rapid, routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. High voltage applied to the device under test is raised by the field of non-contacting electrodes in the FCDM simulator, which avoids premature device stressing and permits a faster test cycle. Discharge current and time are measured and calculated. The characteristics of electrostatic attenuation of domestic semiconductor devices are investigated to evaluate the ESD phenomena in the semiconductors. Also, the field charging mechanism, the device thresholds and failure modes are investigated and analyzed. The damaged devices obtained in the simulator are analyzed and evaluated by SEM. The results obtained in this paper can be used to prevent semiconductor devices form ESD hazards and be a foundation of research area and industry relevant to ESD phenomena.