• Steel and Composite Structures
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• 제30권4호
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• pp.365-382
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• 2019

In steel frame-tube structures (SFTSs) the application of flexural beam is not suitable for the beam with span-to-depth ratio lower than five because the plastic hinges at beam-ends can not be developed properly. This can lead to lower ductility and energy dissipation capacity of the SFTS. To address this problem, a replaceable shear link, acting as a ductile fuse at the mid length of deep beams, is proposed. SFTS with replaceable shear links (SFTS-RSLs) dissipate seismic energy through shear deformation of the link. In order to evaluate this proposal, buildings were designed to compare the seismic performance of SFTS-RSLs and SFTSs. Several sub-structures were selected from the design buildings and finite element models (FEMs) were established to study their hysteretic behavior. Static pushover and dynamic analyses were undertaken in comparing seismic performance of the FEMs for each building. The results indicated that the SFTS-RSL and SFTS had similar initial lateral stiffness. Compared with SFTS, SFTS-RSL had lower yield strength and maximum strength, but higher ductility and energy dissipation capacity. During earthquakes, SFTS-RSL had lower interstory drift, maximum base shear force and story shear force compared with the SFTS. Placing a shear link at the beam mid-span did not increase shear lag effects for the structure. The SFTS-RSL concentrates plasticity on the shear link. Other structural components remain elastic during seismic loading. It is expected that the SFTS-RSL will be a reliable dual resistant system. It offers the benefit of being able to repair the structure by replacing damaged shear links after earthquakes.

• 한국자동차공학회논문집
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• 제18권6호
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• pp.130-137
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• 2010

Due to test facility and specialty, it is physically difficult to conduct the modal tests of large-sized structures such as truck, bus and airplane. So, in case of a large-sized truck, the mode analysis on a full vehicle model comprised of reliable cabin, frame, and deck has been generally performed. However, the reliability of overall vibrational characteristics of the analytic model has not been fairly guaranteed by the testified models of each subsystem owing to the existence of cab suspension and the nonlinear mounting between a chassis frame and a special deck system. In this paper, a method to find out the modal characteristics of a large-sized military truck is presented. New modal test equipment is developed to set the boundary conditions of three military truck variants as close as a free-free condition. And the mode analysis method using coupled structure and dynamic models is established to consider the above-mentioned dynamic non-linearities of the vehicle itself. The usefulness of the suggested method is verified by comparing with the modal test results. Finally, the modal parameters of the final variant are extracted using the proved analytic method.

• Journal of Korea Trade
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• 제25권6호
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• pp.34-56
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• 2021

Purpose - This study presents strategies to overcome the COVID-19-induced crisis in Korea's meetings, incentives, conferences, and exhibitions (MICE) industry. It aims to quantitatively identify the environmental factors affecting the industry and their degree of influence, and derive optimal countermeasures. Design/methodology - The study applied the SWOT-AHP-TOWS framework. An AHP analysis was first performed within the SWOT frame, and then a TOWS analysis was conducted using the results of the SWOT-AHP analysis. In the AHP analysis, the number of pairwise comparison questions was limited to four for each SWOT factor to increase the consistency of responses by reducing the burden on respondents. Findings - The plunge in demand (threats factor) has had an overwhelming impact on the MICE industry, more than any other environmental factor. To overcome the crisis, the ST alternative that takes advantage of dynamic pop culture to minimize the business damage caused by the plunge in demand was the top priority measure. Based on the results, this study presents suggestions for overcoming the crisis in the MICE industry. First, the industry should develop profitable business models to supplement scarce financial resources by exploiting Korea's success with quarantine management. Second, the government must provide emergency relief funds or bailout support to protect MICE facilities and employees. Originality/value - Unlike previous work on the MICE industry, this study utilized the SWOT-AHPTOWS framework to derive quick research results in an abnormal situation. This approach can be expanded to other countries with different industrial environments and situations. Additionally, when applying this method to MICE sub-sectors, countermeasures should be tailored to each field.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3806-3825
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• 2016

This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose we intent to hitch on BOVW and Mapreduce in 3D framework. Here, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook. Further, matching is performed using soft weighting scheme with L₂ distance function. As a final step, retrieved results are ranked according to the Index value and produce results .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we fiture the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy.

• KIEAE Journal
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• 제16권3호
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• pp.77-82
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• 2016

Purpose: The aim of this study is to calculate U-factor of the window using international standard methods and compare quantitative and tendency difference focused on ISO standard 15099 and ISO standard 10077. And the result of ISO standard calculation methods is verified using thermal performance experiment to evaluate applicability of domestic certification system. This study is utilized a basis for activation of domestic window certification system. Method: First, 16 cases are selected that is combined a variety of frame, Glazing, spacer, etc. The selected cases were simulated using WINDOW&THERM based on ISO 15099 and 10077 calculation method. Second, experiment was conducted based on Korean standard condition. Then, it was compared the error of experiment and simulation results. Through this process, ISO 15099 and 10077 calculation methods were evaluated accuracy and utilization. Result: The results show that the difference of ISO 15099 and ISO 10077-2 is maximum 5.4%. The results of comparing U-factor errors based on the Korea standard experiment test found 2.4%. Consequently, it will be possible to combination calculation methods of ISO 15099 and ISO 10077 for a single window.

• 국제초고층학회논문집
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• 제9권3호
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• pp.273-282
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• 2020

An innovative high-rise timber-concrete hybrid structure was proposed in previous research, which is composed of the concrete frame-tube structure and the prefabricated timber modules as main structure and substructures, respectively. Considering that the timber substructures are built on the concrete floors at a different height, the floor response spectrum is more effective in estimating the seismic response of substructures. In this paper, the floor response spectra of the hybrid structure with different structural parameters were calculated using dynamic time-history analysis. Firstly, one simplified model that can well predict the seismic response of the hybrid structure was proposed and validated. Then the construction site, the mass ratio and the frequency ratio of the main-sub structure, and the damping ratio of the substructures were discussed. The results demonstrate that the peaks of the floor response spectra usually occur near the vibration periods of the whole structure, among which the first two peaks stand out; In most cases, the acceleration amplification effect on substructures tends to be more evident when the construction site is farther from the fault rupture; On the other hand, the acceleration response of substructures can be effectively reduced with an appropriate increase in the mass ratio of the main-sub structure and the damping ratio of the substructures; However, the frequency ratio of the main-sub structure has no discernible effect on the floor response spectra. This study investigates the characteristics of the floor response spectrum of the novel timber-concrete structure, which supports the future applications of such hybrid structure in high-rise buildings.

• Earthquakes and Structures
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• 제19권5호
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• pp.347-359
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• 2020

The Mega-Sub Controlled Structure System (MSCSS), an innovative vibration passive control system for building structures, is improved by adding lead rubber bearings (LRBs) on top of the substructure. For the new system, a genetic algorithm is used to optimize the dynamic parameters and distributions of dampers and LRBs. The program uses various seismic performance indicators as optimization objectives, and corresponding results are compared. It is found that the optimization procedure for maximizing the energy dissipation ratio yields the best solutions, and optimized models have consistent seismic performances under different earthquakes. Seismic performances of optimized MSCSS models with and without LRBs, as well as the traditional Mega-Sub Structure model, are evaluated and compared under El Centro wave, Taft wave and 20 other artificial waves. In both elastic and plastic analysis, the model with LRBs shows significantly smaller story drift and horizontal acceleration than those of the other two models, and fewer plastic hinges are developed during severe earthquakes. Energy analysis also shows that LRBs installed in proper locations increase the deformation and energy dissipation of dampers, thereby significantly reduce the kinetic, potential, and hysteretic energy in the structure. However, LRBs do not have to be mounted on all the additional columns. It is also demonstrated that LRBs at unfavorable locations can decrease the energy dissipation for dampers. After LRBs are installed, the optimal damping coefficient and the optimal damping exponent of dampers are reduced to produce the best damping effect.

• 대한기계학회논문집A
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• 제31권12호
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• pp.1173-1179
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• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• Interaction and multiscale mechanics
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• 제1권1호
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• pp.33-51
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• 2008

This paper investigates the modelling of coupled soil-structure interaction problems by domain decomposition techniques. It is assumed that the soil-structure system is physically partitioned into soil and structure subdomains, which are independently modelled. Coupling of the separately modelled partitioned subdomains is undertaken with various algorithms based on the sequential iterative Dirichlet-Neumann sub-structuring method, which ensures compatibility and equilibrium at the interface boundaries of the subdomains. A number of mathematical and computational characteristics of the coupling algorithms, including the convergence conditions and choice of algorithmic parameters leading to enhanced convergence of the iterative method, are discussed. Based on the presented coupling algorithms a simulation environment, utilizing discipline-oriented solvers for nonlinear structural and geotechnical analysis, is developed which is used here to demonstrate the performance characteristics and benefits of various algorithms. Finally, the developed tool is used in a case study involving nonlinear soil-structure interaction analysis between a plane frame and soil subjected to ground excavation. This study highlights the relative performance of the various considered coupling algorithms in modelling real soil-structure interaction problems, in which nonlinearity arises in both the structure and the soil, and leads to important conclusions regarding their adequacy for such problems as well as the prospects for further enhancements.

• 복식문화연구
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• 제14권2호
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• pp.192-205
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• 2006

This study first aims on preparing a systematic analysis basis for the expression aspects of hairstyle in forms of postmodernism. Secondly, it studies the meanings and aspects the hairstyle trend through a post modernism approach about its expression methods based on the suggestive collection hairstyles. Third, it confirms that hairstyle is also one of fashion that can be represented as modern society and culture by explaining that post modernism appears in hairstyles. This study analyzes the expression aspects of hairstyle in forms of post modernism that appears in modern collections by preparing theoretical theories for this study based on former studies related to post modernism theory and clothes from a qualitative analysis. The results of this study prepared a theoretical analysis frame to study the expression aspects of hairstyle in forms of postmodernism first. Secondly, as a result of analyzing based on the analysis, they show that disoriginality of hairstyle can be freely interpreted by the author through borrowing and restoration, disformation through discord and incompletion, discenterization through non-westernization and sub-culture, and inter-text through many symbols and meanings. Thirdly, as the postmodernism movement that represents modern society, culture, and art movement is reflected on hairstyle, it can be considered as a small culture and a product of the era.