• Resources Recycling
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• v.26 no.5
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• pp.29-38
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• 2017

This study suggests optimal policy options for collection of used diapers through benchmarking of foreign countries and perception surveys. By conducting a survey, this study can identify the actual problems involved in the collection process and enhance the social acceptance toward diaper recycling policies. As a perception survey result, the economic burden of emission bags and sanitary issues were most important for the collection pilot test. Respondents thought that twice-a-week collection frequency was appropriate and that free emission bags might be preferable to participants. Currently municipal wastes are subject to waste management laws, which are applied by local governments. Diaper waste is categorized with municipal waste, so it seems to be treated by municipal waste systems. In terms of connection with government, possible alternatives were suggested to identify the relevant local government. Useful data could be obtained, to determine the economical viability of any future diaper recycling system implementation in the entire Seoul metropolis and adjacent areas of dense population.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.3
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• pp.51-65
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• 2009

The seismic design concept of RC bridges is to attain the proper ductility of piers, yielding a ductile failure mechanism. Therefore, seismic design force for moment is determined by introducing a response modification factor (R), and lateral reinforcements to confine core concrete are specified in the current design code. However, these design provisions have irrationality, which results in excessive amounts of lateral reinforcements for columns in Korea, which are generally designed with large sections. To improve on these provisions, a new design method based on seismic performance has been proposed. To apply this to hollow sectional columns, however, further investigations and improvements must be performed, due to the different seismic behaviors and confinement effects. In this study, hollow sectional columns with different lap-splice of longitudinal bars and lateral reinforcements have been tested. Seismic characteristics and performance were investigated quantitatively. These research results can be used to derive a performance-based design for hollow sectional columns.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.255-264
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• 2007

In the current domestic and overseas standards concerning seismic design, especially on the capacity & demand spectra in the multi-story building, failure is caused more by story drift than by displacement; and the existing capacity spectrum method (CSM) does not make a close estimate of story drift because response is derived using displacement. Therefore, this paper proposes an improved CSM to estimate story drift and its direct effect on the collapse of structures, yet still maintaining the same advantage and convenience of the existing CSM about a most basic model of multi-story building: shear building. To establish its reliability, the proposed method is applied to an example model and results are then compared with those obtained through nonlinear time-history analysis.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.449-458
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• 2016

The temperature data were measured for two years in a bridge specimen and the bridge in service nearby in order to calculate the effective temperature for thermal loads in steel box girder bridge. The maximum and minimum effective temperatures were calculated in the bridge specimen and the bridge according to air temperature in 2014, 2015 and 2years. The effective temperatures calculated in this study were compared the Euro code and the Highway Bridge Design Criteria. The coefficients of determination in the maximum effective temperature and the Euro code for 2 year were calculated from R = 0.927, R = 0.894 in a bridge specimen and the bridge respectively. Those of minimum temperature and the Euro code were analyzed from R = 0.992, R = 0.813 in two bridge respectively. Also, the results were evaluated as being very similar, or slightly increased as compared with the maximum temperature of the Korean Highway Bridge Design Code(Limit State Design).

• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.229-240
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• 2004

Many experiments have been performed to investigate eccentric shear strength and unbalanced moment-carrying capacity of flat plate-column connections under combined gravity and lateral load. However, each existing experiment used different test setup, and the shear strength of the connection was different depending on the test setup. Current design methods which were based on the experimental results might not accurately explain the shear strength of the flat plate. In a companion study, based on results of nonlinear finite element analyses, an alternative design method for the plate-column connection was developed. However, in this method, eccentric shear strength of the connection which was required for assessing unbalanced moment-carrying capacity was evaluated by an empirical formula. In the present study, a theoratical approach using Rankine's failure criterion was attemped to investigate failure mechanism of the eccentric shear. Based on the results, an improved strength model of the eccentric shear was developed, and it was verified by comparison with the existing experimental results. By means of the strength model, the design method developed in the companion study was re-verified.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.11-17
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• 2007

In current seismic design practice, the response modification factor (R-factor) is used as a factor to reduce the elastic base shear demand to the design force level. As is well-known, the R-factor is a committee-consensus factor and, as such, highly qualitative and empirical. The relationship between the R-factor and the connection rotation capacity available in a particular structural system has remained a missing link. In this paper, a rational procedure to evaluate the R-factor is proposed. To this end, the relationship between the available connection rotation capacity and the R-factor is defined and quantified using nonlinear pushover analysis. An RRS steel frame designed according to IBC 2000 was used to illustrate and verify the proposed procedure. Nonlinear time history analysis results indicated that the R-factor definition proposed in this study is generally conservative from design perspective.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.725-734
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• 2014

Modernization projects are actively underway to replace conventional logistics equipment for the development of the 21st century logistics management system. The modernized logistics system is expected to expand to each troops on future. In this paper, we deal with simulation of automated logistics center to analyse the current system. Especially, the alternative to the same scale is designed based on needs of military distinctiveness. As a result, it can be effectively compared the current system. The result obtained in this design process is comprehensively analyzed by the AHP(Analytic Hierarchy Process). The proposed method in this study is allowed to cost-effectively evaluate current and future automated logistics center. And, that is expected to contribute to modernization projects of the military logistics system.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.34-42
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• 2023

Considering the contribution of industrial facilities to the national economy, securing operability against earthquakes is very important. However, the basic concept of current seismic design mainly allows ductile behavior of facilities against large-scale earthquakes and only considers structural safety for the purpose of preventing collapse. In order to secure the operability of industrial facilities, the level of seismic performance to maintain operability may vary depending on the structural behavior characteristics of the industrial facility, and a seismic design method is needed to satisfy this. In this study, a ground storage tanks Nonlinear seismic behavior characteristics(R-μ-T) were analyzed through nonlinear response history analysis, and based on this, a new reliability-based, performance-based seismic design method was proposed.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.55-62
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• 2010

The purpose of this research is to provide an a basic data for setting design standards and proposing improvement for public open space by analysis one which is the factor that quite influences public open space by factor analysis. First, Extract main design factors by survey and field investigation of the Public Open Space of Centum and Seomyeon in Pusan. After the extraction, Control and simulation of main design factors which selected by survey for making better improved public open space and resolving problems of it. Based on simulation data, the five-factors drawed by psychological estimation and factor analysis are Accessibility, Intimacy, Openness, Amenity, Convenience. By use of a result, Multiple Regression Analysis is implemented for correlation analysis between five-factors and user's satisfaction in the public open space. Therefore the it which influenced user's satisfaction in the public open space most was Accessibility. So, the public open space must be designed to improve Accessibility and Intimacy, Openness, Amenity, Convenience which influenced user's satisfaction were reviewed primary.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.271-278
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• 2021

According to the capacity design of eccentrically braced frames (EBFs), non-dissipative members such as columns, link-exterior beams, and braces must remain within the elastic region when a fully-yielded and strain-hardened link transmits force to them. The current AISC 341 standard suggests a strain-hardening factor (SHF) of 1.25 for a link under capacity design, regardless of its properties. However, all the links in an EBF are not likely to yield simultaneously to the extent to which the overstrength corresponding to 1.25 times their expected strength is attained, especially for high-rise buildings. Considering this phenomenon, a technique to predict the SHF of links at the limit state of the structure is proposed in this paper. The exact prediction of the links' SHF could save structural quantities dramatically while achieving the principle of capacity design. To validate the effectiveness of this technique, SHF values predicted by conducting linear analysis were compared with those evaluated by nonlinear analysis. Furthermore, the maximum demand-to-capacity ratios of the non-dissipative members were calculated to verify whether they would remain elastic at the limit state of the structure. Consequently, EBFs designed by the proposed method showed substantially economical quantities through the exact prediction of the SHFs, and the intention of capacity design was successfully achieved.