• Earthquakes and Structures
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• v.18 no.3
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• pp.367-377
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• 2020

Incremental dynamic analysis (IDA) widely uses for the collapse risk assessment procedures of buildings. In this study, an IDA-based collapse risk assessment methodology is proposed, which employs a novel approach for detecting the near-collapse (NC) limit state. The proposed approach uses the modal pushover analysis results to calculate the maximum inter-story drift ratio of the structure. This value, which is used as the upper-bound limit in the IDA process, depends on the structural characteristics and global seismic responses of the structure. In this paper, steel midrise intermediate moment resisting frames (IMRFs) have selected as case studies, and their collapse risk parameters are evaluated by the suggested methodology. The composite action of a concrete floor slab and steel beams, and the interaction between the infill walls and the frames could change the collapse mechanism of the structure. In this study, the influences of the metal deck floor and autoclaved aerated concrete (AAC) masonry infill walls with uniform distribution are investigated on the seismic collapse risk of the IMRFs using the proposed methodology. The results demonstrate that the suggested modified IDA method can accurately discover the near-collapse limit state. Also, this method leads to much fewer steps and lower calculation costs rather than the current IDA method. Moreover, the results show that the concrete slab and the AAC infill walls can change the collapse parameters of the structure and should be considered in the analytical modeling and the collapse assessment process of the steel mid-rise intermediate moment resisting frames.

• ETRI Journal
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• v.29 no.2
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• pp.153-161
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• 2007

In this paper, we analyze the algorithm of the methodology developed by ITU for the calculation of spectrum requirements of IMT-Advanced. We propose an approach to estimate user density using traffic statistics, and to estimate spectrum efficiencies using carrier-to-interference ratio distribution and capacity theory as well as experimental data under Korean mobile communication environments. We calculate the IMT-Advanced spectrum requirements based on the user density and spectral efficiencies acquired from the new method. In the case of spectral efficiency using higher modulation and coding schemes, the spectrum requirement of IMT-Advanced is approximately 2700 MHz. When applying a $2{\times}2$ multiple-input multiple-output (MIMO) antenna system, it is approximately 1500 MHz; when applying a $4{\times}4$ MIMO antenna system, it is approximately 1050 MHz. Considering that the development of new technology will increase spectrum efficiency in the future, the spectrum requirement of IMT-Advanced in the Korean mobile communication environment is expected to be approximately 1 GHz bandwidth.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.2
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• pp.1-9
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• 2017

Defect dispute in apartment building has become a debating social issue. The system of defect lawsuit and the conciliation process are applicable to solve defect problems in South Korea. Among various defects, painting work defect is a critical issue because it requires large area works and entails a lot of cost. Accordingly, disputes on work procedure and cost calculation are argued oftenly between residents and housing providers. This study reviewed detailed main issues of painting work and propose relevant systems and standards. In this analysis, the main issues are categorized into pre-works, main work, and others. The most recent cases are compared and analyzed for each issue. After the analysis, following conclusions are obtained, (1) In defect lawsuit system, even though surface treatment work in pre-work step is part of main work, it has been separated and regarded as a separate work. (2) Although the main painting work are not significantly different from two systems, it is still necessary to achieve a consensus to close the gap in the methodology of painting area calculation and determining whole painting or partial painting. (3) In addition, unlike the profit rate of general construction works, that of painting work remained the maximum rate and additional charge rate for works carried out in higher place are different among cases. Therefore, it is determined that establishing consistent standards is urgent.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.453-464
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• 2018

Purpose: The purpose of this study is to propose a solution to the case where $V_{50}$ calculation is impossible in the process of bulletproof test. Methods: In this study, we proposed a $V_{50}$ estimation method using logistic regression analysis. Six scenarios were applied by combining the homogeneity of the sample and the speed range. Then, 1,000 simulations were performed per scenario and six assumptions reflecting the reality were applied. Results: The result of the study, it was confirmed that there was no statistical difference between the $V_{50}$ value calculated by the conventional method and the $V_{50}$ value calculated by the improvement method. Therefore, in situations where $V_{50}$ can not be calculated, it is reasonable to use logistic regression analysis. Conclusion: This study develops a methodology that is easy to use and reliable by using statistical model based on actual data.

• IE interfaces
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• v.20 no.3
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• pp.353-362
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• 2007

This paper proposed the calculation method of the avoided cost for natural gas and district heating DSM programs. And the proposed method is applied to real DSM programs. The avoided cost for natural gas consists of commodity avoided cost, supply equipment avoided cost, storage equipment avoided cost, and electric power avoided cost. In case of the district heating, avoided cost consists of heat generation equipment avoided cost, heat energy avoided cost, environment avoided cost, and electric power avoided cost. This method can be used to evaluate the benefit of DSM programs quantitatively in cost. Therefore, this method can contribute to make the cost-effectiveness evaluation system and to operate the DSM programs for natural gas and district heating effectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1822-1828
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• 2008

This paper presents design parameter calculation methodology and its realization to construction for the 10/350${\mu}s$ lightning impulse current generator(ICG) modelled as double exponential function waveform with characteristic parameters ${\alpha},{\beta}$. Matlab internal function, "fzero" was applied to find ${\lambda}={\alpha}/{\beta}$ which is solution of nonlinear equation linearly related with two wave parameter $T_1$ and $T_2$. The calculation results for 10/350${\mu}s$ lightning impulse current show very good accuracy with error less 0.03%. Two type of 10/350${\mu}s$ ICGs based on the calculated design circuit parameters were fabricated by considering the load variation. One is applicable to the MOV based Surge protective device(SPD) for less 15 kA and the other is to test small resistive devices such as spark gap arrester and bonding device with maximum current capability 30 kA. The tested waveforms show error within 10% in comparison with the designed estimation and the waveform tolerance recommended in the IEC 61643-1 and IEC 60060-1.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.8
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• pp.341-350
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• 2006

This paper presents a new methodology to draw the components of locational marginal price (LMP) in electricity market. Recently, the changing environments surrounding electricity industries resulted in the unbundled services provided by electricity market players, which may require the new pricing mechanisms based on the LMP. The changed pricing mechanisms will provide the price signals of time and location to the market participants. Most of the existing studies of LMP are based on the Lagrangian multipliers as shadow prices to evaluate the equivalent values of constraints or factors for security, reliability and quality. However, the shadow prices cannot provide enough information for components of LMP. In this paper, therefore, we proposed a new approach that LMP is divided into three components. To do this, we first present the method for shadow prices calculation and then break down LMP into a variety of parts corresponding to the concerned factors. The proposed approach is applied to 5-bus and modified IEEE 14-bus sample system in order to verify its validity.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.3
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• pp.339-349
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• 2017

This paper is related to structural design evaluation of 19,000 TEU ultra large container ship, dealing with hydroelastic response, i.e. springing and whipping. It illustrates application of direct calculation tools and methodologies to both fatigue and ultimate strength assessment, simultaneously taking into account ship motions and her elastic deformations. Methodology for springing and whipping assessment within so called WhiSp notation is elaborated in details, and in order to evaluate innovative container ship design with increased loading capacity, a series of independent hydroelastic computations for container ship with mobile deckhouse and conventional one are performed with the same calculation setup. Fully coupled 3D FEM - 3D BEM model is applied, while the ultimate bending capacity of hull girder is determined by means of MARS software. Beside comparative analysis of representative quantities for considered ships, relative influence of hydroelasticity on ship response is addressed.

• The KSFM Journal of Fluid Machinery
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• v.17 no.6
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• pp.89-94
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• 2014

The 4th generation SFR is being designed with a milestone of construction by 2028. It is important to understand the subchannel flow characteristics in fuel assembly through the experimental investigations and to estimate the calculation uncertainties for insuring the confidence of the design code calculation results. The friction coefficient and the mixing coefficient are selected as primary parameters. The two parameters are related to the flow distribution and diffusion. To identify the flow distribution, an iso-kinetic method was developed based on the previous study. For the mixing parameters, a wire mesh system and a laser induced fluorescence methods were developed in parallel. The measuring systems were adopted on 37 rod bundle test geometry, which was developed based on the Euler number scaling. A scaling method for a design of experimental facility and the experimental identification techniques for the flow distribution and mixing parameters were developed based on the measurement requirement.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.295-300
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• 2001

Additional costs as well as schedule delay are occurred due to change orders in today's construction projects. Additional costs, overhead calculation methods are of various types. In a foreign country cases, many claims related to the loss of labor productivity quote research statistics data. In domestic cases, the study of the reason why the loss of labor productivity occurs and its effect have not been performed. Therefore, this paper analyzes factors affecting lost productivity and a methodology is presented to estimate the lost productivity.