• International conference on construction engineering and project management
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• 2020.12a
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• pp.3-12
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• 2020

Nowadays, as-is BIM generation has been popularly adopted in the architecture, engineering, construction and facility management (AEC/FM) industries. In order to generate a 3D as-is BIM of a structural component, current methods require a registration process that merges different sets of point cloud data obtained from multiple locations, which is time-consuming and registration error-prone. To tackle this limitation, this study proposes a registration-free 3D point cloud data acquisition technique for as-is BIM generation. In this study, small-size mirrors that rotate in both horizontal and vertical direction are used to enable the registration-free data acquisition technique. First, a geometric model that defines the relationship among the mirrors, the laser scanner and the target component is developed. Second, determinations of optimal laser scanner location and mirror location are performed based on the developed geometrical model. To validate the proposed registration-free as-is BIM generation technique, simulation tests are conducted on key construction components including a PC slab and a structural wall. The result demonstrates that the registration-free point cloud data acquisition technique can be applicable in various construction elements including PC elements and structural components for as-is BIM generation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.143-144
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• 2023

The compressive strength of concrete varies depending on various factors. Among them, based on the curing temperature, the KCS 14 20 10 Standard Specification for General Concrete calculates the nominal strength by applying the temperature correction value (Tn) based on the compressive strength of the standard cured concrete at 20±2℃ when designing the formulation strength. However, Tn is a correction value that considers only the temperature, and the correction of strength difference due to heat of hydration is not applied. Therefore, in this study, one-component and two-component concrete are mixed in the summer, structural concrete are manufactured, standard concrete specimen are manufactured, and coring is performed on the central and boundary parts of the structural concrete to calculate the correction value applied to the nominal strength by comparing the compressive strength of standard cured concrete on the 28th day of curing and the compressive strength of structural concrete on the 91st day of curing.

• Journal of the Korea Institute of Building Construction
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• v.10 no.4
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• pp.75-82
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• 2010

As structures become larger, taller, and more diverse, a high degree of technology and expertise are required in the construction industry. However, it has been becoming difficult to construct under severe conditions and to fulfill the high performance needs of structures due to a lack of skilled construction engineers. To compensate for these weak points, high-performance concrete and performance specifications have been developed. The application of reliable high-fluidity concrete, which is one of these efforts, is expected to be effective in terms of overcoming severe conditions, reducing the number of workers required, and shortening the construction period. In order to apply high fluidity concrete in the field, practical mock-up tests were carried out to estimate whether self-compaction concrete could satisfy constructability needs. From the results, it was verified that the multi-component high fluidity concrete has excellent flowability in practical structures. In addition, it was shown that the temperature distribution in the concrete due to hydration heat is satisfactory. As a result, it is judged that multi-component high fluidity concrete can be utilized as an effective building material for various structures, including structures related to the electric power industry.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.2
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• pp.131-136
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• 2004

According to development of media, various information is recorded in media, expression is one during interesting information. Because expression includes of relationship of human inside. Intention of inside is expressed by gesture, but expression has more information. And, expression can manufacture voluntarily, include plan of inside on the man. Also, expression has unique character in a person, have alliance that do division possibility. In this paper, to analyze expression of USB camera animation, wish to detect facial building block. Because characteristic point by person's expression change exists on face component. For component detection, in animation one frame with Capture, grasp facial position, and separate face area, and detect characteristic points of face component.

• Journal of Internet Computing and Services
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• v.3 no.4
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• pp.71-82
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• 2002

Recently. component-based software development is getting accepted in industry as a new effective software development paradigm, Since an introduction of component-based software engineering(CBSE) at later 90's, the CBSD research has focused largely on component modeling, methodology, architecture and platform, However. as the number of components available on the market increases, it becomes more important to make metrics to measure the various characteristics of components. In this paper. we propose metrics for measuring the complexity, customizability, and resuability of software components, Complexity of metrics can be used to evaluate the complexity of components Customizability is used to measure how efficiently and widely the components can be customized for specific requirements organization, Resuability can be used to measure the degree of features that is reused in building applications.

• Communications for Statistical Applications and Methods
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• v.24 no.2
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• pp.143-154
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• 2017

A variable selection method based on probabilistic principal component analysis (PCA) using penalized likelihood method is proposed. The proposed method is a two-step variable reduction method. The first step is based on the probabilistic principal component idea to identify principle components. The penalty function is used to identify important variables in each component. We then build a model on the original data space instead of building on the rotated data space through latent variables (principal components) because the proposed method achieves the goal of dimension reduction through identifying important observed variables. Consequently, the proposed method is of more practical use. The proposed estimators perform as the oracle procedure and are root-n consistent with a proper choice of regularization parameters. The proposed method can be successfully applied to high-dimensional PCA problems with a relatively large portion of irrelevant variables included in the data set. It is straightforward to extend our likelihood method in handling problems with missing observations using EM algorithms. Further, it could be effectively applied in cases where some data vectors exhibit one or more missing values at random.

• Journal of Korean Association for Spatial Structures
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• v.9 no.1
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• pp.69-78
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• 2009

Recent earthquake, such as the Northridge(1994), the Kobe(1995) and the Izmit(1990) earthquakes, gave serious damage in various buildings and bridges by the vertical seismic component. Most of the seismic designs neglect the vertical seismic component for usual frame structures. The purpose of this study is to evaluate the effects of the vertical seismic component and to compare the axial force of columns and plastic rotation angle of the analytical models in these effects. The vertical seismic component produced a large increment of axial force in columns. And the vertical seismic component caused a significant increase of the damage in the columns. As analysis result, increase of axial force cause the damage of columns and give possibility of story collapse mechanism of the structure system. Therefore, area that near fault ground motion is expected may be consider the effect of vertical component of seismic ground motions.

• Journal of KIISE:Software and Applications
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• v.33 no.6
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• pp.525-538
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• 2006

Component-Based Software Engineering (CBSE) is widely accepted as new paradigms for building applications with reusable assets. Mismatch problems occur while integrating the assets and make a burden in CBSE. Therefore, a larger-grained reuse unit than a component such as a framework is required, and it consists of relevant components, connectors and domain-specific architecture. The benefits of frameworks over components are commonly known, however, the key elements and internal structure of framework has not been clearly defined. We believe most of the framework models proposed in recent works remain at conceptual level. In this paper, we propose a practical-level framework reference model, and define key elements of frameworks. The research goal is to precisely identify concrete elements of a framework, inter-connection of components within a framework, extended notion of connectors, and tailored meaning of architecture In a framework. Hence, the proposed framework can be practically implemented in common object-oriented languages and with middleware such as lava, J2EE, CORBA Component Model (CCM) and NET.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.6
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• pp.11-18
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• 2017

Education facilities have much affect to make a good condition for the learning environment. Therefore, various approaches have been conducted to improve the physical, social and educational achievement. Especially, the physical aspect is very important to get rid of the building defect and improve the student their learning environment. For these, it needs to explain the performance and function of components and materials, which is linked with the deterioration degree. The deterioration degree is a imperative factor to make a decision whether the component would be repaired or not and to provide the repair scope of its component. In this paper, it aimed at making the deterioration degree model of roof proof under the hypothesis of which deterioration degree would be equal the repair cost at this time. Results of the study are shown that first, the $3^{rd}$ function is most proper to explain the deterioration degree model among 11 functions in view of resulted statistics. Second, the inflection of deterioration is shown at 15yr of the elementary school and 13yr of the middle and high school. This study has a limit of disclassification of the component or materials and it is, therefore, favorable to include the classification of waterproof material and work. These results would make a change from the breakdown maintenance to preventive maintenance and give a decent the learning environment for student.

• Wind and Structures
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• v.5 no.2_3_4
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• pp.291-300
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• 2002

An efficient large eddy simulation algorithm is used to compute surface pressure distributions on an eleven story (target) building on the NIST campus. Local meteorology, neighboring buildings, topography and large vegetation (trees) all play an important part in determining the flows and therefore the pressures experienced by the target. The wind profile imposed at the upstream surface of the computational domain follows a power law with an exponent representing a suburban terrain. This profile accounts for the flow retardation due to friction from the surface of the earth, but does not include fluctuations that would naturally occur in this flow. The effect of neighboring buildings on the time dependent surface pressures experienced by the target is examined. Comparison of the pressure fluctuations on the single target building alone with those on the target building in situ show that, owing to vortices shed by the upstream buildings, fluctuations are larger when such buildings are present. Even when buildings are lateral to or behind the target, the pressure disturbances generate significantly different flows around this building. A simple grid-free mathematical model of a tree is presented in which the trunk and the branches are each represented by a collection of spherical particles strung together like beads on a string. The drag from the tree, determined as the sum of the drags of the component particles, produces an oscillatory, spreading wake of slower fluid, suggesting that the behavior of trees as wind breakers can be modeled usefully.