• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.569-579
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• 2011

Reinforced concrete walls subjected to cyclic loading show complicated inelastic behaviors varying with aspect ratio, re-bar detail, and loading condition. In the present study, a macro model for nonlinear analysis of reinforced concrete walls was developed. For exact prediction of inelastic flexure-compression and shear behaviors, the macro model of the wall was idealized with longitudinal and diagonal uniaxial elements. The uniaxial elements consist of concrete and re-bars. Simplified cyclic models for concrete and re-bars under uniaxial loading was used. For verification, the proposed model was applied to slender, lowrise, and coupled walls subjected to cyclic loading. The results showed that the proposed method predicted the nonlinear behaviors of the walls with reasonable precision.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.305-312
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• 2014

The current American Concrete Institute(ACI), Canadian Standard Associate(CSA) and CEB-FIP Model Code 2010 provisions on the shear strength of a simply supported deep beam suggest that deep beams should be designed using the strut-and-tie model. Although this is a useful methodology to design members in disturbed regions, the quality of the design is highly dependent on the truss model that designers create. However, Hong et al. derived the shear strength equations of reinforced concrete deep beams. This thesis investigates the validity of the current ACI, CSA and CEB-FIP code provisions on the shear strength of simply supported reinforced concrete deep beams by comparing them with the shear strength equations proposed by Hong et al. The comparison shows that all of these code provisions provide reasonable estimates on the shear strength of concrete deep beam members and the selection of an internal truss model plays an important role on the estimation of shear strength.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.216-223
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• 2019

The objective of this study is to propose a reliable stress-strain model in compression for lightweight concrete using bottom ash aggregates and air foam(LWC-BF). The slopes of the ascending and descending branches in the fundamental equation form generalized by Yang et al. were determined from the regression analyses of different data sets(including the modulus of elasticity and strains at the peak stress and 50% peak stress at the post-peak performance) obtained from 9 LWC-BF mixtures. The proposed model exhibits a good agreement with test results, revealing that the initial slope decreases whereas the decreasing rate in the stress at the descending branch increases with the increase in foam content. The mean and standard deviation of the normalized root-square mean errors calculated from the comparisons of experimental and predicted stress-strain curves are 0.19 and 0.08, respectively, for the proposed model, which indicates significant lower values when compared with those(1.23 and 0.47, respectively) calculated using fib 2010 model.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.6
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• pp.3-14
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• 2018

The aim of this study is to propose a method for calculating the weight of walking energy in ERAM model by calculating it for the analysis of vertical and horizontal spaces in a building. Conventional theories on the space analysis in the field of architectural planning predict the pedestrian volume of network spaces in urban street or in two-dimensional plane within a building, however, for vertical and horizontal spaces in a building, estimates of the pedestrian volume by those theories are limited. Because in the spatial syntax and ERAM model have been applied weights such as the spatial depth, adjacent angles, and physical distances available only to the two-dimensional same layer or plane. Therefore, the following basic assumptions and analysis conditions in this study were established for deriving a predictor of pedestrian volume in vertical and horizontal spaces of a building. The basic premise of space analysis is not to address the relationship between the pedestrian volume and the spatial structure itself but to the properties of spatial structure connection that human beings experience. The analysis conditions in three-dimensional spaces are as follows : 1) Measurement units should be standardized on the same scale, and 2) The connection characteristics between spaces should influence the accessibility of human beings. In this regard, a factor of walking energy has the attributes to analyze the connection of vertical and horizontal spaces and satisfies the analysis conditions presented in this study. This study has two implications. First, this study has shown how to quantitatively calculate the walking energy after a factor of walking energy was derived to predict the pedestrian volume in vertical and horizontal spaces. Second, the method of calculating the walking energy can be applied to the weights of the ERAM model, which provided the theoretical basis for future studies to predict the pedestrian volume of vertical and horizontal spaces in a building.

• Architectural research
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• v.21 no.2
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• pp.41-48
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• 2019

The purpose of this study is to research and development of 'Korea B(Benefit)-impact Model' for Sustainable Development. A concept evaluation model is 'B(Benefit)-impact model' in U.S.A. We use the results of surveys that examined the importance of social value issues to stakeholders in Korea to implement the benefit-impact model in Korea. In particular, in this paper, we use the KSI(Korean Sustainability Index) survey data conducted by the Korea Standards Association to evaluate the social value of the construction industry for representative stakeholders in the construction industry. The social value pool and the activity indicator pool used for the survey are created based on relevant International Standards; ISO 26000, ISO 14001, ISO 37001. As a result, Korea B-impact model for construction industry included the following five core social value issues; Strengthen transparency of corporate management, Ensure fair employment and employment relations, Efforts to prevent corruption, Conduct fair competition, Efforts to prevent environmental pollution. In addition, the US B-impact model has three limitations. First, it is unclear whether the key indicators have been derived while considering all issues of social value. Second, US B-impact model indicators are developed by the social responsibility experts, so it is necessary to review by stakeholders in each industry. Finally, it would be more effective for companies to use the B-impact model index as a more detailed activity indicator. When developing a Korea B-impact model, the following methods are used to supplement it. First, we reviewed all social value issues using international standards. Secondly, we used the KSI(Korean Sustainability index) survey results to derive the importance of the social value issue of construction industry in Korea. Finally, we have clearly matched the activity indicators by social value core issues based on the GRI Standard so that companies can actually use the Korea B-impact model for the construction sector. The detailed development stages and results of this study are as follows;.

• Solar Energy
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• v.20 no.4
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• pp.31-43
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• 2000

A model house with a "Ondol" heating working with solar energy and supplied by circulation air was investigated both experimentally and theoretically, A calculation method was developed for interpreting the measured values and for comparing several variants, This calculation method together with the measurement result is presented in the following. The gain in energy of the collector(Trombe wall type with TWD) measured on a particularly selected winter day with plenty of radiation amounted to approximately 31 % of the total solar radiation.

• Information Systems Review
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• v.12 no.2
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• pp.1-23
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• 2010

Most enterprise information systems today are silo systems in that they are not properly aligned nor integrated with one another. Such silo systems result because enterprises lack an architectural perspective in the planning and development of the systems. This paper proposes an Enterprise Architecture Orientation Model as a framework for the analysis, planning and design of the architectural quality of enterprise information systems. The model decomposes enterprise architecture into two dimensions-alignment and integration, and specifies for each dimension the general development and evolution stages enterprises may traverse. The alignment dimension represents the vertical strategic alignment of the systems with the vision, mission, strategy and goals of the enterprise, and is analyzed in terms of the performance, capability, and strategy of the enterprise. The integration dimension, on the other hand, represents the horizontal and functional integration among the systems that span organizational functions and boundaries, and is analyzed in terms of such technological components as IT infrastructure, data, application, and business processes. The model combines the alignment and integration dimensions to form a two-dimensional conceptual space for mapping the architectural quality of the enterprise. It is proposed that an enterprise use the model to identify and understand its position now and in the future in the architectural quality of the enterprise information systems. It is also proposed that the model provides a tool for the planning and design of the transition from one stage to the next in the alignment and integration of the systems to reach an architectural maturity. At the end, the paper discusses how the model can be applied differently according to the strategic orientation of the enterprise. An example of the usage of the model is presented.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.69-74
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• 2004

This study is to suggest a performance assessment model for fire safety protection of office building 34 asessment elements were chosen by interviewing with experts, reviewing several codes and existing relevant models, assessment elements included in this model are comprised of five categories which are 'performace of protected area', 'performance of fire partition', 'safety performance of fire escape', 'performace of smoke control system' and 'performace of fire fighting equipment'. The weight of each element was computed by systematic approach like an AHP (analytical hierarchy process), which was conducted by experts who work in the field of fire protection. This model would be utilized as a part of assessment model for the overall performace of domestic office building.

• International Journal of Concrete Structures and Materials
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• v.1 no.1
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• pp.19-28
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• 2007

A dynamic constitutive damage model for reinforced concrete (RC) structures and formulations of blast loading for contact or near-contact charges are considered and adapted from literatures. The model and the formulations are applied to the input parameters needed in commercial finite element method (FEM) codes which is validated by the laboratory blast tests of RC slabs from literature. The results indicate that the dynamic constitutive damage model based on the damage mechanics and the blast loading formulations work well. The framework on the dynamic constitutive damage model and the blast loading equations can therefore be used for the simulation of failure of bridge components in engineering applications.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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• pp.177-186
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• 2014

Depending on the change of lifestyle and the improvement of people's living standards and rapid industrialization, urbanization of recent, demand for water is increasing rapidly. So emissions of domestic wastewater and various industrial waste water has increased, and water quality is worsening day by day. Therefore, in order to provide a measure against the occurrence of water pollution accident, this study was tried to simulate water pollution accident. This study simulated 2008 Gimcheon phenol accident using 1,2-D model, and analyze scenario for prevent of water pollution accident. Consequently the developed 1-D model presents high reappearance when compared with 2-D model, and has been able to obtain results in a short simulation run time. This study will contribute to the water pollution incident response prediction system and water quality analysis in the future.