• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.3
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• pp.102-113
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• 2017

A new index for the buckling strength of non-structured plates is proposed. The external work or the deformation energy caused by the external loads or the boundary displacement controled by a load parameter is calculated along an equilibrium path of the member under consideration. If the second variation of the energy with respect to the parameter loses its positiveness, it defined as the limit of the stability. In contrast to the current method given in codes where the stability limit is evaluated by using only representative internal forces, the evaluation of the stability limit is always consistent even with the change of the distribution of the internal forces on the boundary. If the elasticity is concerned, the result from this proposed approach becomes identical to that from the classical methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.333-340
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• 2018

Recently, free-form buildings have been designed with complex shapes due to digitization of the construction industry. Exterior and interior components of free-form buildings have free cross sections and curved shapes. Therefore, structural members with curvature are frequently seen. In the modeling and stability evaluation of these structures, commercial programs using classical finite element analysis are not able to perform rapid shape modeling, resulting in a decrease in productivity. Therefore, in this study, pre- and post-processing modules were developed using a prior study to rapidly model the surface of a free-form building and to automatically generate frame structures that make up the cladding. The developed modules use a subdivision algorithm with spline curves. This algorithm is used to automatically generate analytical elements from the configuration information of NURBS curves. In addition, the deformation after analysis can be viewed more realistically. The modules can quickly construct complex curved surfaces. An analysis model of the frame structure was also automatically generated. Therefore, the modules could contribute to the productivity improvement of free-form building design.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.127-135
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• 2020

As the importance of the use and analysis of big data is emerging, there is a growing interest in natural language processing techniques for unstructured data such as news articles and comments. Particularly, as the collection of big data becomes possible, data mining techniques capable of pre-processing and analyzing data are emerging. In this case study with a telecom company, we propose a methodology how to formalize unstructured data using text mining. The domain is determined as equipment failure and the data is about 2.2 million equipment check ledger data. Data on equipment failures by 800,000 per year is accumulated in the equipment check ledger. The equipment check ledger coexist with both formal and unstructured data. Although formal data can be easily used for analysis, unstructured data is difficult to be used immediately for analysis. However, in unstructured data, there is a high possibility that important information. Because it can be contained that is not written in a formal. Therefore, in this study, we study to develop digital transformation method for unstructured data in equipment check ledger.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.36-36
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• 2010

본 연구에서는 다이아그리드 구조시스템의 기술 현황 동향을 파악, 분석하고 향후발전과제를 제시하였다. 비정형 건물을 표현하기에 적합한 구조 시스템인 다이아그리드의 개념 및 원리를 설명하고 높이, 유형, 지역별로 건물 적용사례를 살펴보았다. 또한 국내의 연구 동향을 변수별로 정리하여 추가적인 연구개발 사항을 파악하고 이를 위한 구체적인 방안을 제시하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.3
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• pp.49-57
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• 2010

Most previous research on the seismic response of structures with plan irregularities have focused on the relationship between the eccentricity and the amount of torsion. This approach cannot provide the direct relationship between the irregularity and the damage. Therefore, an investigation on the relationship between the eccentricities of buildings with plan irregularities and the damage index was performed. Inelastic dynamic time-history analyses were performed on one-story buildings with various eccentricities. For the damage assessment, a 3D damage index was adopted to reflect the effect of the bi-directional response and torsion. Based on the analysis results, buildings with eccentricities of 10%, 20% and 30% will suffer 3~5%, 13~18%, and 33~47% more damage than their regular counterparts, respectively.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.11
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• pp.521-526
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• 2016

As on-line informal text data have massive in its volume and have unstructured characteristics in nature, there are limitations in applying traditional relational data model technologies for data storage and data analysis jobs. Moreover, using dynamically generating massive social data, social user's real-time reaction analysis tasks is hard to accomplish. In the paper, to capture easily the semantics of massive and informal on-line documents with unsupervised learning mechanism, we design and implement automatic topic extraction systems according to the mass of the words that consists a document. The input data set to the proposed system are generated first, using N-gram algorithm to build multiple words to capture the meaning of the sentences precisely, and Hadoop and Spark (In-memory distributed computing framework) are adopted to run topic model. In the experiment phases, TB level input data are processed for data preprocessing and proposed topic extraction steps are applied. We conclude that the proposed system shows good performance in extracting meaningful topics in time as the intermediate results come from main memories directly instead of an HDD reading.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.6
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• pp.81-91
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• 2003

Recently, many high-rise reinforced concrete(RC) bearing-wall structures of multiple uses have been constructed, which have the irregularities of weak(or soft) story and torsion at the lower stories simultaneously. The study stated herein was performed to investigate seismic performance of such a high-rise RC structure through a series of shaking table tests of a 1: 12 model. Based on the observations of the test results, the conclusions are drawn as follows: 1) Accidental torsion due to the uncertainty on the properties of structure can be reasonably predicted by using the dynamic analysis than by using lateral force procedure. 2) The mode coupled by translation and torsion induced the overturning moments not only in the direction of excitations but also in the perpendicular direction: The axial forces in columns due to this transverse overturning moment cannot be adequately predicted using the existing mode analysis technique, and 3) the hysteretic curve and the strength diagram between base shear and torque(BST) clearly reveal the predominant mode of vibrations and the failure mode.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.223-230
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• 2014

In this paper, the wind-induced response characteristics of freeform shaped tall building is studied by using FSI analysis. The analytical models are twist shaped ones at representing type of atypical tall building, and this study focused on the relationship between twist angle and wind acceleration. Firstly, 1-way FSI analysis is performed, so maximum lateral displacement of the analytical model for 100 years return period wind speed is calculated, then the elastic modulus of a structure that satisfies the constraints condition is evaluated. And 2-way FSI analysis is carried out. so acceleration of the analytical model for the evaluated modulus of elasticity and arbitrary density is predicted through time history analysis. The basic model is a set of a square shape, height is 400m, slenderness ratio is 8, and twist model is rotated at square model from 0 to 90 degrees at intervals of 15 degrees and from 90 to 360 degrees at intervals of 90 degrees. According to the result of predicting wind acceleration by the shape of each model, the wind vibration effect of square shape model is confirmed to be sensitive more than a twist shape ones.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.170-171
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• 2017

최근 디지털 사이니지 시장은 정방형 디스플레이로 콘텐츠를 표출하던 초기와 달리 다양한 형태와 크기를 가진 비정형 사이니지를 배치하여 표출하는 기술에 관심이 높아지고 있다. 본 논문에서는 디스플레이의 회전에 따라 변하는 비정형 사이니지 시스템의 구조를 제시한다. 자이로 센서의 출력 값을 입력으로 받아 기울어진 각도를 계산하고, 극좌표계의 특성을 이용하여 회전 각도에 따라 네 꼭짓점의 위치가 가변되는 영상을 영상좌표계로 변환하여 회전형 디스플레이 사이니지로 표출할 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.57-58
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• 2017

사물인터넷 환경의 다양한 기기에서는 매초마다 시스템 로그 데이터, 온도, 습도, 조도 및 위치 정보 등과 같은 데이터를 지속적으로 생성한다. 이렇게 생성된 데이터는 기기 안에서 대부분 소멸되거나 수집된다 하더라도 시스템 개선의 일부 목적으로 활용하는데 그칠 뿐이다. 본 논문에서는 각각의 사물인터넷 기기에서 발생하는 비정형 데이터를 스트리밍 방식을 통해 수집 서버로 전송하고 이를 유연한 스키마 구조를 가지는 NoSQL 데이터베이스에 적재하는 프레임워크 설계를 제안한다. 이렇게 수많은 장비로부터 수집된 로그 및 센싱 데이터는 빅데이터 분석을 통해 산업의 현장에서 생산성 향상을 위해 사용할 수 있으며 공공의 목적으로 도심지의 교통문제 해소와 재난 및 재해 예측에 활용될 수 있다.