• Title/Summary/Keyword: Global/local analysis

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Optimal Design of PM Wind Generator using Memetic Algorithm (Memetic Algorithms을 적용한 영구자석 풍력발전기 최적설계)

  • Park, Ji-Seong;Ahn, Young-Jun;Kim, Jong-Wook;Lee, Chel-Gyun;Jung, Sang-Yong
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.6-8
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    • 2009
  • This paper presents the novel implementation of memetic algorithm with GA (Genetic Algorithm) and MADS (Mesh Adaptive Direct Search), which is applied for optimal design methodology of electric machine. This hybrid algorithm has been developed for obtaining the global optimum rapidly, which is effective for optimal design of electric machine with many local optima and much longer computation time. In particular, the proposed memetic algorithm has been forwarded to optimal design of direct-driven PM wind generator for maximizing the Annual Energy Production (AEP), of which design objective should be obtained by FEA (Finite Element Analysis). After all, it is shown that GA combined with MADS has contributed to reducing the computation time effectively for optimal design of PM wind generator when compared with purposely developed GA implemented with the parallel computing method.

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An analysis of rock mass characteristics which influence the choice of support

  • Bednarek, Lukasz;Majcherczyk, Tadeusz
    • Geomechanics and Engineering
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    • v.21 no.4
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    • pp.371-377
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    • 2020
  • There are currently three common methods for selecting excavation supports in Polish hard coal mines. While many factors are considered when choosing appropriate support, these do not include layering or cracking in the excavation ceiling. Although global classifications of rock mass are rarely used in hard coal mines, they are utilised much more frequently during the construction of underground structures such as tunnels. Mining classifications of rock mass have been developed (e.g., in Germany) and they rely on a number of factors but are often related to local mining and geological conditions. This paper discusses the selected findings of a study carried out on seven excavation sites with diverse mining and geological characteristics. Based on the collected data, two indicators were developed to describe rock mass quality. The first indicator is referred to as the roof lithology index WL and describes the quality of the excavation roof in terms of its layering and lithology. The second indicator is the crack intensity factor n and represents the amount of cracks in an excavation's roof. The correctness of the developed indicators was supported by reliable data from the excavation in which the designed support did not fulfill its task but was changed at a later stage, after calculating the proposed indicators.

Concrete beams submitted to various moisture environments

  • Multon, S.;Seignol, J.F.;Toutlemonde, F.
    • Structural Engineering and Mechanics
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    • v.22 no.1
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    • pp.71-83
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    • 2006
  • This paper deals with the effects of various moisture environments on the structural behavior of concrete beams. The presented results were obtained within a large experimental program carried out at the Laboratoire Central des Ponts et Chauss$\acute{e}$es (LCPC), with Electricit$\acute{e}$ de France (EDF) as a partner. The aim of this paper is to point out and to quantify the strains resulting from unidirectional moisture conditions: a drying gradient applied during 14 months, followed by the re-wetting of the dried surface during 9 months. The effect of reinforcement on the shrinkage and on the deformation due to water absorption is pointed out. Moreover, a lot of tests on companion cylinders and prisms were carried out to determine the mechanical characteristics of the material and help checking analysis methods. The paper focuses on numerous measurements obtained during the 23 months on one plain concrete beam and one reinforced concrete beam: variation of water content, followed by precise weighing and gammadensitometry, relative humidity measurements, local and global deformations in the three directions and deflection of the beams. Thus, the effects of drying and water absorption on the behavior of concrete structures are documented and analyzed in comparison with existing representation of water diffusion.

Non linear seismic response of a low reinforced concrete structure : modeling by multilayered finite shell elements

  • Semblat, J.F.;Aouameur, A.;Ulm, F.J.
    • Structural Engineering and Mechanics
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    • v.18 no.2
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    • pp.211-229
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    • 2004
  • The main purpose of this paper is the numerical analysis of the non-linear seismic response of a RC building mock-up. The mock-up is subjected to different synthetic horizontal seismic excitations. The numerical approach is based on a 3D-model involving multilayered shell elements. These elements are composed of several single-layer membranes with various eccentricities. Bending effects are included through these eccentricities. Basic equations are first written for a single membrane element with its own eccentricity and then generalised to the multilayered shell element by superposition. The multilayered shell is considered as a classical shell element : all information about non-linear constitutive relations are investigated at the local scale of each layer, whereas balance and kinematics are checked afterwards at global scale. The non-linear dynamic response of the building is computed with Newmark algorithm. The numerical dynamic results (blind simulations) are considered in the linear and non linear cases and compared with experimental results from shaking table tests. Multilayered shell elements are found to be a promising tool for predictive computations of RC structures behaviour under 3D seismic loadings. This study was part of the CAMUS International Benchmark.

A Study on the Optimum Structural Design of High Speed Ships with Twin Hulls (쌍동형 초고속선의 최적 구조 설계에 관한 연구)

  • C.D. Jang;S.I. Seo;S.K. Kim;J.O. Kwon;S.D. Park
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.4
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    • pp.109-118
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    • 1994
  • In this study, an optimization method to design the hull structure of the surface effect ships with twin hulls is proposed for the purpose of minimization of weight based on the regulations of DnV class, and computer programs following the method are developed. The method uses simple formulas as to bending and buckling strength of beams and plates to design local structures, and considers the effect of interaction between longitudinal girders and transverse web frames by grillage analysis and calculates torsional strength of the cross structure by the simplified method. Global optimization of the midship section is attained by integration of optimized substructures. According to optimized results by applying the method to the designed ship, reduction of 20 percent of hull weight can be shown, and optimum transverse frame space can be obtained.

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Mobile Cloud System based on EMRA for Inbody Data

  • Lee, Jong-Sub;Moon, Seok-Jae
    • International Journal of Advanced Culture Technology
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    • v.9 no.3
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    • pp.327-333
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    • 2021
  • Inbody is a tool for measuring health information with high reliability and accuracy to analyze body composition. Unlike the existing method of storing/processing and outputting data on the server side, the health information generated by InBody requires accurate support for health sharing and data analysis services using mobile devices. However, in the process of transmitting body composition measurement information to a mobile service, a problem may occur in data transmission/reception processing. The reason for this is that, since the network network in the cloud environment is used, if the connection is cut off or the connection is changed, it is necessary to provide a global service, not a temporary area, focusing on the mobility of InBody information. In addition, since InBody information is transmitted to mobile devices, a standard schema should be defined in the mobile cloud environment to enable information transfer between standardized InBody data and mobile devices. We propose a mobile cloud system using EMRA(Extended Metadata Registry Access) in which a mobile device processes and transmits body data generated in the inbody and manages the data of each local organization with a standard schema. The proposed system processes the data generated in InBody and converts it into a standard schema using EMRA so that standardized data can be transmitted. In addition, even when the mobile device moves through the area, the coordinator subsystem is in charge of providing access services. In addition, EMRA is applied to the collision problem due to schema heterogeneity occurring in the process of accessing data generated in InBody.

Genomic Insights into the Rice Blast Fungus through Estimation of Gene Emergence Time in Phylogenetic Context

  • Choi, Jaeyoung;Lee, Jong-Joon;Jeon, Junhyun
    • Mycobiology
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    • v.46 no.4
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    • pp.361-369
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    • 2018
  • The rice blast fungus, Magnaporthe oryzae, is an important pathogen of rice plants. It is well known that genes encoded in the genome have different evolutionary histories that are related to their functions. Phylostratigraphy is a method that correlates the evolutionary origin of genes with evolutionary transitions. Here we applied phylostratigraphy to partition total gene content of M. oryzae into distinct classes (phylostrata), which we designated PS1 to PS7, based on estimation of their emergence time. Genes in individual phylostrata did not show significant biases in their global distribution among seven chromosomes, but at the local level, clustering of genes belonging to the same phylostratum was observed. Our phylostrata-wide analysis of genes revealed that genes in the same phylostratum tend to be similar in many physical and functional characteristics such as gene length and structure, GC contents, codon adaptation index, and level of transcription, which correlates with biological functions in evolutionary context. We also found that a significant proportion of genes in the genome are orphans, for which no orthologs can be detected in the database. Among them, we narrowed down to seven orphan genes having transcriptional and translational evidences, and showed that one of them is implicated in asexual reproduction and virulence, suggesting ongoing evolution in this fungus through lineage-specific genes. Our results provide genomic basis for linking functions of pathogenicity factors and gene emergence time.

Association between Solar Variability and Teleconnection Index

  • Kim, Jung-Hee;Chang, Heon-Young
    • Journal of Astronomy and Space Sciences
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    • v.36 no.3
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    • pp.149-157
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    • 2019
  • In this study, we investigate the associations between the solar variability and teleconnection indices, which influence atmospheric circulation and subsequently, the spatial distribution of the global pressure system. A study of the link between the Sun and a large-scale mode of climate variability, which may indirectly affect the Earth's climate and weather, is crucial because the feedbacks of solar variability to an autogenic or internal process should be considered with due care. We have calculated the normalized cross-correlations of the total sunspot area, the total sunspot number, and the solar North-South asymmetry with teleconnection indices. We have found that the Southern Oscillation Index (SOI) index is anti-correlated with both solar activity and the solar North-South asymmetry, with a ~3-year lag. This finding not only agrees with the fact that El $Ni{\tilde{n}}o$ episodes are likely to occur around the solar maximum, but also explains why tropical cyclones occurring in the solar maximum periods and in El $Ni{\tilde{n}}o$ periods appear similar. Conversely, other teleconnection indices, such as the Arctic Oscillation (AO) index, the Antarctic Oscillation (AAO) index, and the Pacific-North American (PNA) index, are weakly or only slightly correlated with solar activity, which emphasizes that response of terrestrial climate and weather to solar variability are local in space. It is also found that correlations between teleconnection indices and solar activity are as good as correlations resulting from the teleconnection indices themselves.

The Strategy of Korean Firms to Enter Vietnam Market (한국 기업의 베트남 유통시장 진출 전략에 관한 연구)

  • Kwak, Su-Young;Kim, Mie-Jung
    • Korea Trade Review
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    • v.44 no.4
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    • pp.1-17
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    • 2019
  • The purpose of this paper is to suggest strategies for Korean companies to overcome the limitation of the international trade structure between Korea and Vietnam. This study examined foreign multinational distribution companies, Korean distribution companies and domestic distribution companies in Vietnam. A SWOT analysis conducted to propose effective strategies revealed that Saigon Mart, Vietnam's largest regional mart company, needs an O/W strategy and to capture market opportunities quickly through strategic alliances with foreign distribution companies, in order to gradually complement their core competencies internally. Lotte mart in Vietnam, one of Korea's three largest marts, needs to establish a T/S strategy in order to overcome the crisis situation in Vietnam market and succeed in business. BIG C Mart has over 40,000 diverse products needs to use a T/S strategy in order to effectively overcome the crisis situation in the Vietnamese market and to increase the possibility of business success. From the study findings and conclusions, various implications are derived. Vietnam is still very strong in socialism and regional characteristics, so it needs to build up close cooperation such as joint venture with local partners in the region and strategic alliances to increase the possibility of investment success.

The Effects of Corporate Social Responsibility Activities on Brand Equity and Consumer Purchasing Intention

  • LEE, Jaemin
    • The Journal of Economics, Marketing and Management
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    • v.7 no.4
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    • pp.10-19
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    • 2019
  • Purpose - The purpose of this survey-based study was to identify the impact of corporate social responsibility (CSR) activities on corporate brand assets and consumer purchasing intentions, and to verify causal relationships between the variables. Research Question - The XCIP is the company's longest running program of its kind, taking a global approach to CSR. Xerox uses this initiative to fund employees in their local communities to make a difference in projects of their own choosing. Research Method-The survey period was conducted for about three months from May 3, 2018 to August 7, 2018, and a random sampling method was used. The total number of samples was 420, with 19 samples excluded from final analysis due to untruthful or erroneous responses. Result - In this study, the general characteristics of the survey participants were investigated as follows in analyzing the impact of CSR activities on brand assets and consumer purchasing intentions. First, male (51.6 percent) college graduates (42.4 percent) outnumbered female participants (40.2 percent), and participants in their 40s (30.7 percent) and 50s (23.8 percent) ranked highest, followed by general office workers (27.6 percent), business people, people in service positions, and people in sales positions.