• Earthquakes and Structures
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• v.6 no.5
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• pp.515-537
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• 2014

Current seismic codes (e.g. the NTC08 Italian code and the EC8 European code) adopt a performance-based approach for both the design of new buildings and the assessment of existing ones. Different limit states are considered by verifying structural members as well as non structural elements and facilities which have generally been neglected in practice. The key role of non structural elements on building performance has been shown by recent earthquakes (e.g. L'Aquila 2009) where, due to the extensive damage suffered by infills, partitions and ceilings, a lot of private and public buildings became unusable with consequent significant socio-economic effects. Furthermore, the collapse of infill panels, particularly in the case of out-of-plane failure, represented a serious source of risk to life safety. This paper puts forward an infill model capable of accounting for the effects arising from prior in-plane damage on the out-of-plane capacity of infill panels. It permits an assessment of the seismic performance of existing RC buildings with reference to both structural and non structural elements, as well as of their mutual interaction. The model is applied to a building type with RC framed structure designed only to vertical loads and representative of typical Italian buildings. The influence of infill on building performance and the role of the out-of-plane response on structural response are also discussed.

• Steel and Composite Structures
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• v.22 no.3
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• pp.647-662
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• 2016

This study aims to monitor the variation of modal frequencies of steel buildings during their construction sequence. In this respect, construction of a steel building is followed by vibration based measurements. The monitored building is a three-story educational building within a building group whose structural system consists of steel moment resisting steel frames and eccentric braces. Five different acceleration measurements in two perpendicular directions are taken on five different construction stages, starting from the erection of the columns and beams ending with the completion of the construction. The recorded measurements are transferred into frequency domain and the dominant frequencies for each case have been determined. The change in the dominant frequencies is evaluated with the existing construction stages and performed constructional works between the stages. The last measurement, performed on the building in service, revealed the first two dominant frequencies as mutual in X and Y direction, showing that these dynamic modes are torsional modes. This result is investigated by numerical analysis performed with finite element model of the building constructed for design purpose. Lower frequencies and different mode shapes are determined from numerical analysis. The reason of lower frequencies is discussed and the vibration survey is extended to determine the effects of an adjacent building. The results showed that the building is in strong relation with an adjoining building in spite of a designed construction joint.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.237.1-237.1
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• 2012

We report extensive statistical analyses based on the simultaneous observational results of SiO and $H_2O$ masers toward 166 known both SiO and $H_2O$ maser sources (Kim et al. 2010), 83 known SiO maser sources (Cho & Kim 2012 submitted), and 152 known $H_2O$ maser sources (Kim et al. 2012 in preparation). We investigate mutual relations between SiO and $H_2O$ maser properties (peak and total flux density ratios, full line width ratios, and velocity structures etc.) according to stellar pulsation phases and type of evolved stars. These statistical results are compared with monitoring observational results of some individual stars. In addition, a relation between the full line width of SiO/$H_2O$ masers and stellar mass loss rates is examined. For 401 observed stars, we also investigate characteristics of SiO and $H_2O$ maser properties related with evolutionary stages in the IRAS two-color diagram.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.141-142
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• 2017

New waterproofing technologies have emerged in the field of building waterproofing due to the recent diversification of the size and type of structures, the enhancement of required performance, and the diversification of new technologies (such as materials and methods)(Sheet waterproofing material, coating waterproofing material) is reduced, and composite waterproofing materials that utilize mutual benefits are widely used by compounding them (sheet+coating film, coating film+sheet). However, it is true that there is no evaluation method that can verify these composite waterproof materials, which is the most widely used at present, but the KS standard only specifies tests for individual materials However, there is a situation in which the countermeasures without a test method for composite waterproofing become sudden.

• Journal of electromagnetic engineering and science
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• v.18 no.2
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• pp.108-116
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• 2018

In this paper, a method of designing a Vivaldi type phased array antenna (PAA) which operates at S-band (2.8-3.3 GHz) is presented. The presented antenna uses broadside coupled split ring resonators (BC-SRRs) for high isolation, wide field of view, and good active S-parameter characteristics. As an example, we design a $1{\times}8$ array antenna with various BC-SRR structures using theory and EM simulations. The antenna is fabricated and measured to verify the design. With the BC-SRR implemented between the two radiating elements, the isolation is shown to be enhanced by 6 dB, up to 23 dB. The scan angle is shown to be within ${\pm}53^{\circ}$ based on a -10 dB active reflection coefficient. The operation of the scan angle is possible within ${\pm}60^{\circ}$ with a little larger reflection coefficient (-7 dB to -8 dB). The proposed design with BC-SRRs is expected to be useful for PAA applications.

• Journal of Family Resource Management and Policy Review
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• v.20 no.2
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• pp.119-140
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• 2016

This study objectively analyzes the understanding of changes in North Koreans' home lives and the differences between the home life cultures of South and North Korea. A comparative analysis was conducted of terms related to consumer and family resource management to determine language differences and create a mutual understanding of social convergence unification. First, the analysis revealed that the North Korean language is not developed in certain areas, such as consumer welfare or consumer patterns related to resolving issues or complaints connected to consumptive lifestyles. In financial management, there were terms that referred to the collapsed North Korean economic conditions after the fall of the Soviet Union in 1991 and the North Korean famine. Second, terms reflecting North Korea's social, political, and economic structures were discovered, and it was found that South and North Korean languages differed from each other with regard to terms about kinship, sports, and art.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.44-51
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• 2019

Designing sophisticate ship structures that satisfy several design criteria simultaneously with minimum weight and cost is an important engineering issue. For a ship structure composed of a shell and stiffeners, this issue is more serious because their mutual effect has to be addressed. In this study, a two-stage optimization method is proposed for the conceptual design of stiffeners in a ship's prow. In the first stage, a topology optimization method is used to determine a potential stiffener distribution based on the optimal results, whereupon stiffeners are constructed according to stiffener generative theory and the material distribution. In the second stage, size optimization is conducted to optimize the plate and stiffener sections simultaneously based on a parametric model. A final analysis model of the ship-prow structure is presented to assess the validity of this method. The analysis results show that the two-stage optimization method is effective for stiffener conceptual design, which provides a reference for designing actual stiffeners for ship hulls.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.141-144
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• 2021

Modern concepts of management of construction production systems require solving the problems of harmonization of the distribution of structural elements on the way to overcoming global destabilization processes. An effective ratio of functional subsystems of production in an environment of mutual influence create sustainable opportunities for production management and contribute to the logical development of the system as a whole in achieving the main goal of harmonious management. The purpose of the study is to develop the concept of effective management of production systems in construction with the harmonious formation of organizational structures. The results of the study allowed to reveal the harmonization approach in improving the interaction of structural elements of production and accelerating their functional sensitivity to changes in the environment. Harmonious production system more effectively adapts to the diversity of interests, goals and actions at all levels of management of different subsystems in any environment.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.105-112
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• 2023

We analyze the global market for flexible electronic circuits, technical considerations, and analyze the market for application areas and regions. In the market analysis of the application field, the display field has the greatest influence in terms of market size and annual growth rate, and the OLE D lighting market size is expected to grow by nearly 50% in 2026. The multilayer flexible electronics, which dependently requires the semiconductor technology, has a larger market size than other structures and its growth rate is relatively large, leading the market and will be further analyzed in depth. The market size of multilayer flexible electronics applied to display field is expected to show an annual growth rate of 21.1% from $2.7 billion in 2017 to $9.8 billion in 2026, and the OLED market is expected to grow by 75.2% during the same periods. Recently, as electronic products have been miniaturized and advanced, and robust installation in a small space is required, companies that preoccupy multilayer structure or rigid flexible electronic circuit technology have an advantage in competitiveness, so many companies are trying to obtain this technology. These efforts are systematically supported by many countries because they can achieve mutual growth by strengthening the competitiveness of the application field and the same industry. In the case of Korea, a support system is established, but it is required to expand and activate it, and to localize manufacturing equipment and materials.

• Smart Structures and Systems
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• v.31 no.2
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• pp.155-169
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• 2023

The quasi-static component of the moving vehicle-induced dynamic response is promising in damage detection as it is sensitive to bridge damage but insensitive to environmental changes. However, accurate extraction of quasi-static component from the dynamic response is challenging especially when the vehicle velocity is high. This paper proposes an adaptive quasi-static component extraction method based on the modified variational mode decomposition (VMD) algorithm. Firstly the analytical solutions of the frequency components caused by road surface roughness, high-frequency dynamic components controlled by bridge natural frequency and quasi-static components in the vehicle-induced bridge response are derived. Then a modified VMD algorithm based on particle swarm algorithm (PSO) and mutual information entropy (MIE) criterion is proposed to adaptively extract the quasi-static components from the vehicle-induced bridge dynamic response. Numerical simulations and real bridge tests are conducted to demonstrate the feasibility of the proposed extraction method. The results indicate that the improved VMD algorithm could extract the quasi-static component of the vehicle-induced bridge dynamic response with high accuracy in the presence of the road surface roughness and measurement noise.