• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.878-885
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• 2011

A kinematically-hybrid 5-axis machine tool is analyzed from the perspective of machine tool design. Its kinematic characteristics are pointed out, which should be considered during the conceptual design process. A result of the structural analysis of the machine is presented, which is performed during the detailed design process. It is also presented how we improve the thermal characteristics of the machine tool by changing the installation position of the actuators.

• Structural Engineering and Mechanics
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• v.65 no.3
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• pp.251-261
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• 2018

Self-centering concentrically braced frames (SCCBFs) are emerging as high performance seismically resistant braced framing system, due to the capacity of withstanding strong earthquake attacks and promptly recovering after events. To get a further insight into the seismic performance of SCCBFs, systematical evaluations are currently conducted from the perspective of modal contributions. In this paper, the modal pushover analysis (MPA) approach is utilized to obtain the realistic seismic demands by summarizing the contribution of each single vibration mode. The MPA-based results are compared with the exact results from nonlinear response history analysis. The adopted SCCBFs originate from existing buckling-restrained braced frames (BRBF), which are also analyzed for purpose of comparison. In the analysis of these comparable framing systems, interested performance indices that closely relate to the structural damage degree include the interstory drift ratio, floor acceleration, and absorbed hysteretic energy. The study shows that the MPA approach produces acceptable predictions in comparison to the exact results for SCCBFs. In addition, the high-modes effect on the seismic behavior increases with the building height, and is more evident in the SCCBFs than the BRBFs.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.188-192
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• 2007

This paper presents a current perspective on advanced fusion research trends in the construction industry as reflected in the proceedings of International Symposium on Automation and Robotics in Construction (ISARC) which has focused on advanced fusion technology in last decades. The paper reports the results of a 7-year analysis of papers between 2000 and 2006. The analysis focused on such data as research topics of the proceedings. The paper summarizes the data extracted from the paper and uses it to analyze advanced fusion research trends. The research result shows that the top research topics in advanced fusion research areas are construction robots and automation and intelligent construction management. The research also found that research related to advanced fusion technology is increasing throughout the world and topics are changing as current needs change.

• Smart Structures and Systems
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• v.15 no.3
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• pp.913-929
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• 2015

Hybrid simulation is increasingly being recognized as a powerful technique for laboratory testing. It offers the opportunity for global system evaluation of civil infrastructure systems subject to extreme dynamic loading, often with a significant reduction in time and cost. In this approach, a reference structure/system is partitioned into two or more substructures. The portion of the structural system designated as 'physical' or 'experimental' is tested in the laboratory, while other portions are replaced with a computational model. Many researchers have quite effectively used hybrid simulation (HS) and real-time hybrid simulation (RTHS) methods for examination and verification of existing and new design concepts and proposed structural systems or devices. This paper provides a detailed perspective of the enabling role that HS and RTHS methods have played in advancing the practice of earthquake engineering. Herein, our focus is on investigations related to earthquake engineering, those with CURATED data available in their entirety in the NEES Data Repository.

• Earthquakes and Structures
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• v.3 no.5
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• pp.629-647
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• 2012

Multiple acceleration sequences of earthquake ground motions have been observed in many regions of the world. Such ground motions can cause large damage to the structures due to accumulation of inelastic deformation from the repeated sequences. The dynamic analysis of inelastic structures under repeated acceleration sequences generated from simulated and recorded accelerograms without sequences has been recently studied. However, the characteristics of recorded earthquake ground motions of multiple sequences have not been studied yet. This paper investigates the gross characteristics of earthquake records of multiple sequences from an engineering perspective. The definition of the effective number of acceleration sequences of the ground shaking is introduced. The implication of the acceleration sequences on the structural response and damage of inelastic structures is also studied. A set of sixty accelerograms is used to demonstrate the general properties of repeated acceleration sequences and to investigate the associated structural inelastic response.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.981-989
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• 2006

The purpose of this article is to depict the relationship between the frames of leadership and the dependent variables such as job satisfaction, respect from subordinates, promotion, and effective attainment of unit objectives. To attain this purpose, for types of multiple leadership frames, such as structural, human resources, political, and symbolic frames were surveyed through questionnaire and analyzed by SPSS. The major findings are : 1) In general, the symbolic frame is an important factor having a stronger influence on job satisfaction, respect from subordinates, promotion, and effective attainment of unit objectives. 2) In details, the human resources frame shows a positive effects on job satisfaction and respect; the structural frame on effective attainment of unit objectives; the political frame, to a certain degree, on promotion; and the symbolic frame, especially on respect from subordinates, promotion, and effective attainment of unit objectives.

• Journal of Information Technology Services
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• v.7 no.4
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• pp.87-99
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• 2008

As the technologies for telecommunication have been evolving, more enhanced information services and integrated information systems have been introduced, which can manage a variety of information from the heterogeneous systems. The major obstacle for the integrated information systems is the integrating heterogeneous databases in the systems and the heterogeneity problems can be classified into the structural and data heterogeneities. However, the previous researches have mainly highlighted into the solving structural heterogeneity problems. This paper identifies the data heterogeneity problems for multi-database schema integrations and proposes a new solving method. We analyze the semantics equivalence in data values based on the functional dependency, primary and candidate keys, and present a procedural solution of data heterogeneity in the perspective of the concept of attribute equivalence, integration key and conceptual integration table.

• Structural Engineering and Mechanics
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• v.20 no.1
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• pp.123-141
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• 2005

Design details pertaining to the connection between some recently developed fiber reinforced polymer (FRP) composite deck systems and the supporting girders require openings through cells of the deck. This significantly changes the stress distribution in these components. As a result, the conventional assumptions that deck designs are controlled by their stiffness, and not strength, needs a closer examination. This paper proposes an analytical method to investigate the stress states and failure mechanisms using a type of "global-local" modeling perspective, incorporating classical lamination theory and first ply failure criterion with use of appropriate stress concentration factors around the cutouts. The use of a "smeared-stress" approach is presented as a potential means of simplifying certain FRP specific complexities, while still enabling prediction of overall failure.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.140-149
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• 2007

Indian construction companies have only 0.05% market share in the 3-4 trillion dollar global construction business and only two Indian construction companies figure in the ENR "Top 225 Global Contractors 2006" list. Hence, while enormous scope for growth exists, international construction experience is limited. This study explores the risks as perceived by Indian companies venturing abroad since risks in international construction differ from home market risks. Literature survey identified a number of risk factors that were evaluated by the experts, highlighting fourteen important risk factors. Interpretive Structural Modelling (ISM) was used to develop a hierarchical model showing the relationships between the different risk factors, thus helping to focus on the key risks for effective risk management. The study shows that poor project management is a key risk forming the hub of the system, while political instability has maximum influence. The results of the study can be used by managers to visualise the risks in perspective and prioritise the mitigation effort.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.367-370
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• 2015

Building deterioration reflects the degradation of basic building performance including structural performance, energy performance, durability, and safety, and it also includes perceived deterioration, which considers a user-based perspective. More than 50% of the existing buildings in Korea are over 15 years old and public buildings compose 2.5% of all buildings domestically. Therefore, there are several different problems, such as poor energy efficiency, structural performance, and safety. To address the challenges of increasing stock in deteriorated buildings, it is necessary to make decisions about reconstruction or renovation. In this study, we propose a new method to evaluate public building value with a contingent valuation method (CVM). By estimating willing-to-pay (WTP) from users of private buildings in similar situation with the public building, it is possible to compare market prices and calculate a correction factor to adjust the WTP data. Finally, we apply the correction factor to the WTP of a public building and estimate market price, willingness to pay (WTP). Finally, we apply the correction factor to willing to pay (WTP) of public building and estimate market price.