• Structural Engineering and Mechanics
• /
• 제55권5호
• /
• pp.901-911
• /
• 2015

The goal of this study is to investigate computational convergence of optimal solutions, with respect to optimality criteria (OC) method and methods of moving asymptotes (MMA) as optimization model for non-linear programming of material topology optimization using an acceleration method that makes design variables rapidly move toward almost 0 and 1 values. 99 line topology optimization MATLAB code uses loop vectorization and memory pre-allocation as properly exploiting the strengths of MATLAB and moves portions of code out of the optimization loop so that they are only executed once as restructuring the program. Numerical examples of a simple beam under a lateral load and a given material density limitation provide merits and demerits of the present OC and MMA for 99 line topology optimization code of continuous material topology optimization design.

• Architectural research
• /
• 제24권3호
• /
• pp.75-84
• /
• 2022

Scads of earthquake-resistant systems are being invented around the globe to ensure structural resistance against the lateral forces induced by earthquake loadings considering structural safety, efficiency, and economic aspects. Shear wall and Bracing systems are proved to be two of the most viable solutions for seismic strengthening of structures. In the present study, three numerical models of a G+10 storied building are developed in commercial building analysis software considering shear wall and bracing systems for earthquake resistance. Material nonlinearity is introduced by using plastic hinges. Analyses are performed utilizing two dynamic methods: Response Spectrum analysis and nonlinear Time-history analysis using Kobe and Loma Prieta earthquake data and results are compared to observe the nonlinear behavior of structures. The outcomes exposed that a significant increase in the seismic responses occurs due to the nonlinearity in the building systems. It was also found that building with shear wall exhibits maximum resistance and minimum nonlinearity when subjected to dynamic loadings.

• Steel and Composite Structures
• /
• 제47권3호
• /
• pp.365-374
• /
• 2023

This paper presents a new scheme for constructing locking-free finite elements in thick and thin plates, called Discrete Shear Gap element (DSG), using multiphase material topology optimization for triangular elements of Reissner-Mindlin plates. Besides, common methods are also presented in this article, such as quadrilateral element (Q4) and reduced integration method. Moreover, when the plate gets too thin, the transverse shear-locking problem arises. To avoid that phenomenon, the stabilized discrete shear gap technique is utilized in the DSG3 system stiffness matrix formulation. The accuracy and efficiency of DSG are demonstrated by the numerical examples, and many superior properties are presented, such as being a strong competitor to the common kind of Q4 elements in the static topology optimization and its computed results are confirmed against those derived from the three-node triangular element, and other existing solutions.

• 한국건설관리학회논문집
• /
• 제15권3호
• /
• pp.31-37
• /
• 2014

중소기업제품 구매를 확대하여 중소기업의 경영안정을 지원하는 취지에 의해 2006년 제정된 "중소기업제품 구매촉진 및 판로 지원에 관한 법률"은 제도의 활성화를 위해 최근까지 거듭되어 개정되었다. 이에 따라 중소기업청장에 의해 지정된 설계품목에 대해 공공공사 직접구매를 의무화하였다. 그러나 120여개에 달하는 직접구매대상 품목으로 인해 품질확보 및 납기지연, 현장 자재 담당 근무자의 업무과중 등 문제가 발생하고 있다. 법의 제정 취지는 최근 정부의 대기업과 중소기업의 동반성장이라는 여건에는 부합하지만 현장에서 위법을 기반으로 근무를 하는 담당자들의 입장과 자재 품질 확보, 적기 공급, 비용상승 등을 유발하는 것으로 나타났다. 본 논문은 "공사용 자재 직접 구매제도"의 문제점 파악 및 검증을 통해 향후 효율적이고 합리적으로 적용이 될 수 있도록 기여하고자 한다.

• Architectural research
• /
• 제14권4호
• /
• pp.133-141
• /
• 2012

The research started from the consideration that, although many aspects of the Milanese Early Renaissance are well known today, thanks to a vast literature, only few studies, so far, have paid attention to the ordinary world of architectural work - and its obscure protagonists - of this area and this period. Moving from the belief that this topic is crucial for a complete understanding of the 15th century architectural world, characterized by a progressive overlapping of roles and responsibilities in the worksites, this study aims to provide a contribution to expand the understanding of this matter, by focusing on a particular aspect of it: the role of the public administration in the architectural activity. In particular, the paper analyzes the characteristics of the "Office of the engineers of the Municipality of Milan", one of the major public architectural institution of the Duchy of Milan in the 15th century. Through an extensive archival survey, conducted in the major archives of Milan and Lombardy, the research achieves two main findings: a) the reconstruction of the complete Office staff throughout the 15th century and, b) an outline of the role and identity of the Office and its officers, through the elaboration of data collected. In particular, professional roles, technical duties, cultural background and tasks of the officers, together with Office management, appointment procedures and salary conditions are highlighted. This research, not meant as an ultimate study on the topic discussed, is intended to provide some material and reference points for further researches that will aim to expand the understanding of this matter.

• Steel and Composite Structures
• /
• 제8권5호
• /
• pp.389-402
• /
• 2008

In December 2005, one(A) of the two pre-engineered warehouse buildings in the port of K City of Korea was completely destroyed and the other(B) was seriously damaged to be demolished. Over-loaded snow and unexpected blast of wind were the causes of the accident and destructive behavior was brittle fracture caused by web local buckling and lateral torsional buckling at the flange below rafter. However, the architectural design technology of today based on material non-linear method does not consider the tolerances to solve the problem of such brittle fracture. So, geometric non-linear evaluation which includes initial deformation, width-thickness ratio, web stiffener and unbraced length is required. This study evaluates the structural safety of 4 models in terms of width-thickness ratio and unbraced length using ANSYS 9.0 with parameters such as width-thickness ratio of web, existence/non-existence of stiffener and unbraced length. The purpose of this study is to analyze destructive mechanism of the above-mentioned two warehouse buildings and to provide ways to promote the safety of pre-engineered buildings.

• 건축역사연구
• /
• 제12권4호
• /
• pp.27-48
• /
• 2003

This paper aims to identify the meaning of architectural form of the East and the West. Ordinarily, we know the visual differences of architectural form between the two cultural families, and the technical reasons of such differences. However, the East and the West have their own views of architectural form that are derived from their own views of architecture, and again the views of architecture are rooted in their own views of the world. The paper maintains a comparative stance between the two cultures in analyzing the different concepts of architectural form, and employ the ideas of 'Form(形象)' and 'Energy-Form(氣形)' as a kind of representative concept of the two views of architectural form. It is discussed that the idea of Form pursued the realization of ultimate substance which is less materialistic but more ideal., while, the idea of Energy-Form pursued the realization of oneness and health through mutual interaction between man, architecture and nature. Architectural form in the West has been the purposeful expression of human ideal, while in the East, it was an expediential device for better energy condition. It seems important to understand such differences of the meaning of architectural form between the East and the West, since, in present time, we tend to think that the Western conception of architectural form is the only possible one. But it is not generally known that the Western conception of form has very particular background reason of its own which is unique to Western culture, and on the other hand, the nature of East Asian conception of architectural form is generally unknown.

• 한국건축시공학회지
• /
• 제18권2호
• /
• pp.117-123
• /
• 2018

건물의 건설 및 운영에 있어서 에너지 효율성을 증가시키는 것은 현재 매우 중요한 이슈이다. 에너지 효율은 기본적으로 열전도율이 낮은 재료를 이용할 때 이루어질 수 있으며, 이를 위한 가장 좋은 방법은 재료 내부의 공극률을 상승시키는 것이다. 일반적으로 시멘트 복합체에 공극률을 상승시키기 위한 방법에는 발포제, 기포제 및 알루미늄 가루와 같은 반응성 분말을 활용하는 것인데 본 연구에서는 이들에 대한 대안으로 과산화수소를 이용하고자 하였다. 과산화수소 혼입 시멘트 모르타르를 제작하고 이의 부피 팽창, 단위용적중량, 압축강도 및 열전도율을 측정하였다. 실험 결과에 따르면 과산화수소의 혼입률이 증가할수록 공극률은 증가하고 이로 인해 압축강도 및 열전도율이 감소하는 것으로 나타났다. 따라서 과산화수소를 이용하여 경량기포 모르타르의 제작이 충분히 가능한 것으로 파악되었다.

• Nuclear Engineering and Technology
• /
• 제52권10호
• /
• pp.2370-2378
• /
• 2020

Building materials contribute significantly to the indoor radon and thoron levels. Therefore, parameters that influence the exhalation rates of radon and thoron from building material need to be analyzed closely. As a preliminary study, the effects of humidity on exhalation rates were measured using a system with an accumulation chamber and RAD7 detector for Korean brick, Korean soil, and Indonesian brick. Resulting doses to a person who resides in a room constructed from the building materials were assessed by UNSCEAR method for different air exchange rates. The measurements have revealed that Korean brick exhaled the highest radon and thoron while Indonesian brick exhaled the lowest thoron. Results showed that for a typical low dense material, radon and thoron exhalation rate will increase until reached its maximum at a certain value of humidity and will remain saturated above it. Analysis on concentration and effective dose showed that radon is strongly affected by air exchange rate (ACH). This is showed by about 66 times decrease of radon dose from 0.00 h^-1 to those of 0.50 h^-1 ACH and decrease by a factor of 2 from 0.50 h^-1 to those of 0.80 h^-1. In case of thoron, the ACH doesn't have significant effects on effective dose.

• 건축역사연구
• /
• 제32권6호
• /
• pp.77-88
• /
• 2023

This research focused on the regional and temporal attributes of tuff architecture in Mokpo, spanning the Japanese colonial period and the post-liberation era. It aimed to uncover the distinct regional and temporal features of tuff architecture by integrating concepts from vernacular architecture and regionalism, framed through a lens of critical regionalism. The study traced the historical progression of tuff architecture in Mokpo within this context. A significant part of the research was an in-depth analysis of four constructions by Son Yang-dong, a renowned technician in post-liberation Mokpo, to closely examine the contemporary relevance and regional significance of his work. Tuff, as an indigenous material, distinctly articulates the local architectural character. In line with regional properties of tuff, the material has adeptly responded to contemporary construction needs. This has laid a foundation for the development of innovative building designs and techniques. Tuff architecture is particularly noted for its exhibition of raw material textures, offering a unique aesthetic that diverges from classical Western architectural styles. Importantly, through the examination of Son Yang-dong's contributions, the study highlights the role of Korean builders in an industry dominated by Japanese influences during the colonial period, underscoring a strong regional identity. As a representation of Mokpo, tuff architecture not only upholds and protects regional identity within the broader scope of Western modernization and Japanese impacts but also plays a role in its progressive enhancement.