• Ocean Systems Engineering
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• v.1 no.4
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• pp.337-353
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• 2011

In the present study, an offshore platform having large partial porous cylindrical members, which are composed of permeable and impermeable cylinders, is suggested. In order to calculate the wave force on large partial porous cylindrical members, the fluid domain is divided into three regions: a single exterior region, N inner regions and N beneath regions, and the scattering wave in each fluid region is expressed by an Eigen-function expansion method. Applying Darcy's law to the porous boundary condition, the effect of porosity is simplified. Wave excitation forces and wave run up on the structures are presented for various wave conditions. For the idealized three-dimensional platform having large partial porous cylindrical members, the dynamic response evaluations of the platform due to wave forces are carried out through the modal analysis. In order to examine the effects of soil-structure interaction, the substructure method is also applied. The displacement and bending stress at the selective nodal points of the structure are computed using various input parameters, such as the shear-wave velocity of soil, the wave height and the wave period. Applying the Monte Carlo Simulation (MCS) method, the reliability evaluations at critical structure members, which contained uncertainties caused by dynamic forces and structural properties, are examined by the reliability index with the results obtained from MCS.

• Steel and Composite Structures
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• v.13 no.4
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• pp.343-365
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• 2012

Steel suspension members subjected to tension and bending offer an economical and efficient alternative for many structural problems. This paper is concerned with the elastic and elastic-plastic behaviour of suspension members with bending stiffness subjected to vertical point and uniformly distributed loads. An experimental study is described which focuses on the response of three suspension members with various T-shaped steel hot rolled sections and geometric configurations. The tests enable direct assessment of the influence of a key parameter such as the sag-to-span ratio on the response of suspension members. Detailed nonlinear finite-element models are generated to provide a tool for theoretical analyses and to facilitate further understanding of the behaviour. Results demonstrate that experimentally obtained responses can generally be closely predicted numerically because there are relatively good agreements between finite element and tests results. The results and observations of subsequent numerical parametric studies offer an insight into the key factors that govern the behaviour of suspension members with bending stiffness in the elastic-plastic range.

• Smart Structures and Systems
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• v.19 no.6
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• pp.643-652
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• 2017

Pitched roof frames are widely used in construction of the industrial buildings, gyms, schools and colleges, fire stations, storages, hangars and many other low rise structures. The weight and shape of the gable frames with tapered members, as a familiar group of the pitched roof frames, are highly dependent on the properties of the member cross-sectional. In this work Enhanced Colliding Bodies Optimization (ECBO) is utilized for optimal design of three gable frames with tapered members. In order to optimize the frames, the design is performed using the AISC specifications for stress, displacement and stability constraints. The design constraints and weight of the gable frames are computed from the cross-section of members. These optimum weights are obtained using aforementioned optimization algorithms considering the cross-sections of the members and design constraints as optimization variables and constraints, respectively. A comparative study of the PSO and CBO with ECBO is also performed to illustrate the importance of the enhancement of the utilized optimization algorithm.

• Korean Journal of Human Ecology
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• v.13 no.3
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• pp.329-343
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• 2004

The purpose of this study was to investigate the changes of family relations following the Internet use of housewives. The survey was performed on-line and off-line. 582 housewives who used the Internet at home gave valid responses to the questionnaire. The findings of tills study were as follows. First, after having started using the Internet, housewives felt that intimacy among family members has increased while the level of equality between couples unchanged. Second, the change in intimacy among family members has significant differences according to family adaptability and family cohesion. Whether or not other family members used the Internet also affected the intimacy among family members. Third, the change in equality between couples depended on their ability to use the Internet. This suggested that the ability to use the Internet was the core element to an equality. The results of this research suggested several implications for the public policy.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.56-64
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• 2004

Several types of steel structures which are employed in offshore petroleum activities are constructed with tubular members. These structures are usually subjected to various types of loads such as normal functional loads and environmental loads. Furthermore, accidental loads may also act on the leg or bracing members due to supply boat collisions and objects droppings from platform decks. The extent of damage caused by these loads ranges from total collapse of the structure to small damage which may not have serious consequence at the time of accident. To make optimal design decisions regarding structural safety and economical efficiency, it is very important to be able to assess the influence of damages on the performance of damaged structural members. In the End report, a series of calculations is performed to study the effects of different parameters on the load carrying capacity of such damaged members under pure bending. And the results of analysis are compared with experiment results.

• Journal of the Korean Society of School Health
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• v.11 no.1
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• pp.123-130
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• 1998

The Korean society of School Health was opened to research school health, publish a Journal, survey activities, educate members, and exchange information etc This society has operated these services actively since 1987. The objectives of this study are (1) To review the quantitative development process of the society of school health (2) To review the qualitative development process of the society. (3) To suggest improvement and new directions of the society The quantitative aspects include number of members, number of conferences, and number of journals published; the qualitative aspects deal with comprehension and sufficiency of these activities A literature review method was used for this study The results are as follows. (1) The number of members increased to 987 from 200 (2) The number of conferences total led 15 at an average of 1 5 per year since 1987 (3) The journal of the Korean society of school health was published a total of 20 times at an average of 2 per year. (4) Many health behavior and student-oriented articles were published (5) There are few activities that exchange international information, suply data to members, and investigate the opinions of society concerning school health Consequently, positive activities concerning major school health themes, research concerning the health rights of teachers in a school environment, and a more systematic management of members should be developed. Also, it is necessary to develope an in-service education program for those same members.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.387-390
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• 2003

Direct tensile tests were carried out for the tensile members of steel-reinforced polymer concrete with different steel diameters and steel ratios to figure out the effect of tensile strength of polymer concrete. In the experiments, polymer concrete with $1000kgf/cm^2$ of compressive strength, steel with $5200kgf/cm^2$ of tensile strength, and the tensile members with 100 cm of constant length were used. Experimental results showed that, regardless of steel diameters and steel content, the strain energy exerted by concrete till the initial crack was 14-15% of the total energy till the point of yield: The energy was much larger than the one of high-strength cement concrete. The behaviors of tensile members of steel-reinforced polymer concrete were in relatively good agreement with the model suggested by Gupta-Maestrini (1990), which was idealized by the effective tensile stress-strain relationship of concrete and the load-strain relationship of members, while those showed a big difference from CEB-FIP model and ACI-224 equation suggested for the load-displacement relationship that was defined as the cross sectional stiffness of effective axis. Modified ACI-224 model code about the load-displacement relationship for the tensile members of steel-reinforced polymer concrete and theoretical equation for the polymer concrete tensile stiffness of polymer concrete suggested through the results of this study are expected to be used in an accurate structural analysis and design for the polymer concrete structural members.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.93-102
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• 1999

Increased height of buildings causes severe shortening of vertical structural members due to the accumulated axial load. It not only decreases the serviceability of a structure but also affects significantly the stability of a structure itself due to the secondary stress. The main purpose of estimating the shortening of vertical structural members is to compensate the differential shortening of adjacent members. This paper presents the comparison of stresses between the vertical structural members compensated during construction process and these compensated during design process under the seismic load and represents that the precise compensation of vertical structural members is important.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.301-310
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• 2006

In this short paper, an elasto-plastic repair and retrofit element is developed for the investigation of the seismic performance of damaged reinforced concrete members. The developed element is capable of reflecting the increased characteristics due to both repair and retrofitting for degraded strength and stiffness of the members. The element having both birth and death time can freely be activated within the user-defined time intervals during static and dynamic time-history analysis. Comparative studies are conducted for reinforced concrete members being repaired and retrofitted. Analytical predictions including the developed element display reasonable correlation with experimental results. In short, it is concluded that the developed element is capable of providing salient features for the healthy assessment of seismic performance of RC members being repaired and retrofitted.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.212-223
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• 2020

We study to confirm the relationship between leadership trust and job satisfaction on the leadership style of managers recognized by ICT organization members. To this end, the research hypothesis established by using SPSS23.0 for the survey results of 230 ICT organization members was analyzed as follows. First, the hypothesis 1 person leadership type (individual consideration: H1-1, intellectual stimulation: H1-2, charisma: H1-3, conditional compensation: H1-4, exceptional reward: H1-5) had a significant effect on leader trust. The results were obtained. Second, the hypothesis 2 manager's leadership type (individual consideration: H21-1, intellectual stimulation: H2-2, charisma: H2-3, conditional compensation: 2-4, expected compensation: H2-5) is based on job satisfaction. As a result of verifying the impact relationship, all showed significant effect on job satisfaction. Third, it acted as a positive factor in the job satisfaction of the leader of the hypothesis 3-member organizational member. It was confirmed that the job satisfaction of organizational members started based on the trust of actual leaders. Fourth, the role of leadership trust was partially confirmed between leadership type and job satisfaction. Through this study, in order to improve job satisfaction of ICT organizational members, the importance of exerting competency on the leadership type of managers and trusting the leaders on the characteristics consistent with ICT organizational characteristics was emphasized.