• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.417-426
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• 2000

This paper introduces the ISO 3010 which is the design standard for seismic action of International Standard Organization. Specially this paper focuses on the philosophical background and the weakness of ISO 3010,. The ISO 3010\ulcorner(Bases for design of structures-Seismic action on structure) were made in 1998 by the efforts of ISO/TC98 which is one working group of ISO. TC98 deals with " Bases for design of structures" in the field of architectural and civil engineering. The revised Committee Draft ISO/CD 3010 was made in February 1999. Even if ISO 3010 has not been complete yet this study carry out critical review of this committee draft.tee draft.

• The Journal of the Korean dental association
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• v.21 no.7 s.170
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• pp.573-577
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• 1983

The antimicrobial action of various dental cements evaluated against common micro-organisms most frequenty found within the components of the normal bacterial flora of oral cavity. They include Streptococcus mutans (2 strains), Lactobacillus acidophilus, Actinomyces viscosus, and Streptococcus sanguis. The test was done by the use of brain heart infusion (BHI) agar plates. A standard mix of each cement was made and placed on the plates which were seeded with a standard culture of microorganisms. After incubation, the halo of bacterial growth inhibition around the cement was identified and its size was measured. Some of the cements tested had obvious antibacterial effect. The cements listed in decreasing order of effectiveness are 1) zinc phosphate and oxyphosphate, 2) silicate, 3) zinc oxide-eugenol, 4) calcium hydroxide, and 5) carboxylate.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.543-550
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• 2007

This study is for an effective response as the pre-stage for railway agencies to prepare the rail road kind based emergency response standard operation procedures when the emergency event occurs. Accordingly, I would like to increase the utility in helping the railroad employees to make their decisions. And that is possible through suggesting them to make computerized Emergency situation based activity and Emergency response that is individual based. And of course all of this procedure would be based on the emergency event categorized response scenario.

• Journal of the Korea institute for structural maintenance and inspection
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• v.1 no.2
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• pp.151-156
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• 1997

An experimental study was performed on the pull-out behavior of 90-deg standard hooks from exterior beam-column connections. The effects of the number of hooked bars of joint area were investigated. Under the pull-out action of hooked bars, the damage and cracking of joint area tends to be more extensive as the number of hooks pulling out from a joint increases. The pull-out strength and post-peak ductility of hooked bar are adversely influenced by the increase in number of hooks pulling out from an exterior joint. Current hooked bar anchorage design guidelines may be improved by considering the effect of the number of hooked bars on anchorage conditions at exterior joints.

• Journal of applied mathematics & informatics
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• v.41 no.6
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• pp.1237-1256
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• 2023

The tree products of groups with amalgamation subgroups are generalizations of the free products of groups with amalgamation subgroup. The aim of this paper is to construct a tree called the standard tree where the tree products of groups with amalgamation subgroups act without inversions and then find the quotient of this action. Furthermore, we show that if the amalgamation subgroups are finite and the factor groups act on disjoint trees then there exists a tree called the fiber tree where the tree products of groups with amalgamation subgroups act without inversions and find the quotients of this action. If each factor is a tree products with amalgamation subgroups, we get a new fiber tree and the corresponding factors.

• Computers and Concrete
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• v.1 no.3
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• pp.325-354
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• 2004

Slabs in buildings and bridge decks, which are restrained against lateral displacements at the edges, have ultimate strengths far in excess of those predicted by analytical methods based on yield line theory. The increase in strength has been attributed to membrane action, which is due to the in-plane forces developed at the supports. The benefits of compressive membrane action are usually not taken into account in currently available design methods developed based on plastic flow theories assuming concrete to be a rigid-plastic material. By extending the existing knowledge of compressive membrane action, it is possible to design slabs in building and bridge structures economically with less than normal reinforcement. Recent research on building and bridge structures reflects the importance of membrane action in design. This paper describes the finite element modelling of membrane action in reinforced concrete slabs through optimisation of a simple concrete model. Through a series of parametric studies using the simple concrete model in the finite element simulation of eight fully clamped concrete slabs with significant membrane action, a set of fixed numerical model parameter values is identified and computational conditions established, which would guarantee reliable strength prediction of arbitrary slabs. The reliability of the identified values to simulate membrane action (for prediction purposes) is further verified by the direct simulation of 42 other slabs, which gave an average value of 0.9698 for the ratio of experimental to predicted strengths and a standard deviation of 0.117. A 'deflection factor' is also established for the slabs, relating the predicted peak deflection to experimental values, which, (for the same level of fixity at the supports), can be used for accurate displacement determination. The proposed optimised concrete model and finite element procedure can be used as a tool to simulate membrane action in slabs in building and bridge structures having variable support and loading conditions including fire. Other practical applications of the developed finite element procedure and design process are also discussed.

• East Asian mathematical journal
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• v.19 no.1
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• pp.81-89
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• 2003

There are many algorithms for factoring integers. The trial division algorithm is one of the most efficient algorithms for factoring small integers(say less than 10,000,000,000). For a number n to be factored, the runtime of the trial division algorithm depends mainly on the size of a nontrivial factor of n. In this paper, we create a function named factors that can implement the trial division algorithm in ActionScript and using the factors function we construct an interactive Prime Factorization Movie and an interactive GCD Movie.

• Spatial Information Research
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• v.14 no.1 s.36
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• pp.95-113
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• 2006

The standardization of Intelligent Transport Systems(ITS) technique should secure a interoperability among the different softwares or hardwares on ITS service. The domestic standard research takes the advantage of a preoccupation on the world ITS market through the international standard(IS) reflecting the domestic technique. The objective of this research focused on the database technology for ITS is to introduce the domestic standard activity for adopting ISs and the current interior corresponding situation against ISs. The first step, we analyze the international standardization action through gathering and investigating the up-to-date issues and documentations focused on ISO/TC204 WG3. And then, we look into the domestic situation about TTA ITS PG 310 and ITS Korea. consequently, a synthetic view, we have analyzied, how interior standard corresponds with the international standards, and how the standard establishing process is being done. The expectation of this research is to help understanding the up-to-date domestic/international standardization and the situation of the standard action related with the database technology for ITS. Also, we take advantage of this result to encourage the international competitiveness on ITS market.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1111-1120
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• 2008

In order to study the degree of improved air quality as an outcome of the action plan of Atmospheric Environment Improvement in Gimhae, Gyeongnam Province, we investigated the status and trends of air pollutant before and after the plan. Nitrogen dioxide and ozone, both classified as hazardous substances, were closely monitored with particular attention. The level of sulfur dioxide, nitrogen dioxide, fine particles and ozone (but for carbon monoxide) was decreased after the plan was implemented. The number of days on which ozone exceeded the National Ambient Air Quality Standard has decreased, but the level was still often exceeded. The level of nitrogen dioxide did not surpass until the 2006 standard, but when the revised 2007 standard was implemented, it exceeded 80% of some standards. The yearly level of ozone has decreased since the plan was introduced. The concentration of nitrogen dioxide, however, has reduced in high order area while increased in low order area.

• Steel and Composite Structures
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• v.43 no.3
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• pp.353-362
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• 2022

Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.