• Wind and Structures
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• v.1 no.4
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• pp.287-302
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• 1998

This paper formulates a probabilistic model which is able to represent the maximum instantaneous wind velocity. Unlike the classical methods, where the randomness is circumscribed within the mean maximum component, this model relies also on the randomness of the maximum value of the turbulent fluctuation. The application of the FOSM method furnishes the first and second statistical moments in closed form. The comparison between the results herein obtained and those supplied by classical methods points out the central role of the turbulence intensity. Its importance is exalted when extending the analysis from the wind velocity to the wind pressure.

• Advances in Computational Design
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• v.1 no.3
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• pp.221-234
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• 2016

The present study dictates the behavior of shear wall under a seismic event in slender high rise buildings, and studies the effect of height, location and distribution of shear wall in slender high rise building with and without boundary elements induced by the effect of an earthquake. Shear walls are located at the sides of the building, to counter the earthquake forces. This study is carried out in a 12 storeys building using SAP2000 software. The obtained results disclose that the behavior of the structure is definitely affected by the height and location of shear walls in slender high rise building. The stresses are concentrated at the limit between the shear wall region and the upper non shear wall especially for shear walls without columns. Displacements are doubled between the shear wall region and the upper non shear wall especially for shear walls without columns.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.2
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• pp.50-56
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• 2002

In this study, we establish bootstrap control limits for EWMA chart by applying the bootstrap method, called resampling, which could not demand assumptions about pre-distribution when the process is skewed and/or the normality assumption is doubt. The results obtained in this study are summarized as follows : bootstrap EWMA control chart is developed for applying bootstrap method to EWMA chart, which is more sensitive to small shifts of process. With the purpose of eliminating a skewness of the resampling distribution, the bootstrap control limits are established by using a modified residual, and its performance is analyzed by ARL. It is shown that the bootstrap EWMA control chart developed in this study includes the properties of standard EWMA control chart that is sensitive to a small shift, and detects process in out of control more quickly than standard EWMA chart.

• Journal of Microbiology
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• v.45 no.3
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• pp.205-212
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• 2007

Anoxygenic photosynthesis, performed primarily by anoxygenic photosynthetic bacteria (APB), has been supposed to arise on Earth more than 3 billion years ago. The long established APB are distributed in almost every corner where light can reach. However, the relationship between APB phylogeny and source environments has been largely unexplored. Here we retrieved the pufM sequences and related source information of 89 pufM containing species from the public database. Phylogenetic analysis revealed that horizontal gene transfer (HGT) most likely occurred within 11 out of a total 21 pufM subgroups, not only among species within the same class but also among species of different phyla or subphyla. A clear source environment feature related phylogenetic distribution pattern was observed, with all species from oxic habitats and those from anoxic habitats clustering into independent subgroups, respectively. HGT among ancient APB and subsequent long term evolution and adaptation to separated niches may have contributed to the coupling of environment and pufM phylogeny.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.13-21
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• 2001

The effect of water spray for the fire sprinkler depends on droples distribution over maximum possible floor area. The present study are carried out for the characteristics of water spray and droplets experimentally and numerically km two fire sprinkler heads which are CHM head and CHl heal CHl head is self-production and CHl head is widely used up to date. As the result of using CHM head, water spray and droplets are distributed over large area because CHM head has smooth surface and non-flamed shape. When the pressure of fire sprinkler head is low, SMD(sauter mean diameter) is large and when the pressure of fire sprinkler head is high, SMD is small.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.546-549
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• 2004

This paper describes the electrical characteristics of the polymer lightning arresters(L.As) used to protect distribution lines and power facilities from surge. For the relative comparison, the characteristics assessment was done for 2 states of L.As before and after water immersion treatment. The L.As for the comparative test were immersed with water of $95[^{\circ}C]$ considered a severe condition. After the immersion treatment, the assessment was carried out for material analyses in chemical structure(FTIR : fourier transform infrared spectrophotometer). Electrical performance measured insulation resistance measurement, leakage current measurement, critical operation voltage measurement etc.. In addition to, the results were compared with those for the L.As deteriorated in the field. Thus, the accelerative deterioration degree of polymer materials by immersion treatment was evaluated, by which the structural defects of the polymer L.As could be inferred.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2803-2810
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• 2007

Three dimensional numerical studies were carried out to investigate the effect of aspect ratio on gas slip flow in rectangular microchannels. We focused on aspect ratio effect on slip velocity, pressure distribution and mass flow rate. As aspect ratio decreases the wall slip velocity also decreases. As a result nonlinearity of pressure distribution increases. The slip velocities on sides and top/bottom walls are different and this difference decreases with increasing aspect ratio. These two velocities are equal when aspect ratio is 1. The ratios of slip mass flow rate over noslip mass flow rate increases with increasing aspect ratios.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.59-63
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• 2007

Each country uses its own datum which well represent its topography. The uses of the space technology such as GPS and the effort of establishing the consistent data over the world, Korea changed the survey act to use a world geodetic system from January 1, 2007. In this study, spatial analysis carried out to transform the GIS DB of electric power distribution system based on the old Tokyo datum the new world geodetic system, KGD 2002. Based on the study, problems on the transformation had been identified and efficient solutions are suggested. The data used for the 7 parameter similarity transformation in this study is the blueprints of the electric equipment and base maps. It is expected that this study provide general scheme and procedure for efficient GIS DB transformation to the new world geodetic system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.396-401
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• 2003

Electrical impedance tomography(EIT) is a relatively new imaging modality in which the internal impedivity distribution is reconstructed based on the known sets of injected currents and measured voltages on the surface of the object. In this paper, an effective dynamic EIT imaging scheme is presented based on the projection filtering to estimate the unknown resistivity distribution. In particular, pre-integration (pre-grouping) technique is employed to stabilize the inverse algorithm. We carried out computer simulations with synthetic data to illustrate the reconstruction performance of the proposed algorithm.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.579-584
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• 2008

The importance and the interest of wind load have emphasized since the damage of the Jeju World cup Stadium and Main Stadium of Busan Asiad in 2002, and the appearance of high-rise buildings. In general, a evaluation for the wind load acting on structures have been carried out mainly through the wind tunnel test, but this technique has the huge shortcomings that consume too much cost and experimental time. However, with the rapid advances on computers, it is possible to analyze the wind pressure distribution acting on structures by numerical scheme. In this paper, to predict the wind pressure distribution acting on shell structures having the various shape by numerical simulation, governing equations of fluid flow and turbulent model is formulated. Also, evaluates the wind pressure coefficient in accordance with the structural shape for shell structures like as a membrane structures and dome structures.