• Tunnel and Underground Space
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• v.14 no.6 s.53
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• pp.440-449
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• 2004

Rock mass includes natural discontinuities such as joints and faults during its formation. Discontinuities are also referred as planes of weakness because of their weak mechanical characteristics. In the design of underground structures, it is necessary to consider the properties of discontinuities to insure the stability. During the excavation of a tunnel, these discontinuities have to be identified as early as possible so that proper change in excavation method or support design can be made accordingly. The excavation of the tunnel in a stable rock mass causes a 3-dimensional arching effect around the excavation face. It was revealed by previous studies that the existence of a weak zone or a fault zone ahead of tunnel foe induces a typical displacement tendency of convergence. For better understanding of the meaning of influence/trend lines of various displacement components, three-dimensional numerical analyses were conducted while varying deformation moduli, thicknesses and orientations of discontinuities. Numerical results showed that the changes in influence/trend lines of various displacement components were very similar to those by measurements. The discrepancies from the expected values were dependent on the physical properties, thicknesses and orientations of discontinuities.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.479-486
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• 2017

Steel beams with corrugated web have been widely used in the steel structures. However, it is challenging to weld the section between the corrugated web and the flange straight, which increases the cost of production. In order to solve this issue, steel beam with intaglio and embossed web (It is called an IEB) was invented. A web with embossment is produced by cold pressing and welded to flange by automatic welding machine. The loading tests were conducted to investigate the load-carrying capacity of IEB, and its test result was compared with that of H-shaped beam having a same size of flange and web. The test results of IEB series showed about 40% higher load capacities than H-shaped series. As a result of comparing the IEB specimen with Eurocodes for steel beams with corrugated web, all of specimens tested in this study did not meet the design value. Therefore, it is difficult to apply existing formula to IEB and new design formula should be presented for field application.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.3
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• pp.291-303
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• 2016

Recently, various forms of diverging sections in tunnels have been designed as the demand for underground passageway in urban areas increases. Therefore, the complexity of the ventilation system in tunnels with diverging sections requires a ventilation analysis method different from the conventional method for the straight tunnels. None of the domestic and foreign tunnel ventilation design standards specifies the method for the ventilation network analysis, and the numerical analysis methods have been most widely used. This paper aims at reviewing the ventilation network analytical method applicable as the design standard. The proposed method is based on the characteristic equations rather than the numerical analysis. Thanks to the advantages of easy application, the Hardy-Cross method has been widely applied in the fields of mine ventilation and tunnel ventilation. However, limitations with the cutting errors in the Taylor series expansion and the convergence problem mainly caused by the mesh selection algorithm have been reported. Therefore, this paper examines the applicability of the ventilation analysis method for network-type tunnels with the gradient method that can analyze flow rate and pressure simultaneously without the configuration of mesh. A simple ventilation analysis method for network-type tunnels is proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.618-624
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• 2017

In Seoul and most metropolitan cities, urban trains are delayed due to high congestion during commute times. The delay effect of passengers boarding and disembarking is also significant. In this study, a wide passenger door system was developed as a way to improve the scheduled speed of urban trains by decreasing the passengers' flow time. The door size was defined experimentally to shorten the entrance time. The optimum door size was also determined to improve the stop precision performance of the train while considering the interference effect with peripheral devices. Because the change in door size changes the structural characteristics of the vehicle, the structural stability of a train was analyzed numerically. A prototype of the wide door system was made, and the proposed design was verified using functional and endurance tests. The systematic development process can be used as design data for door size definition and system production when applying a wide door to improve the scheduled speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.370-378
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• 2020

The Construction Operations Building Information Exchange (COBie) collects and documents a large amount of information from different paths in one place during design and construction projects. This documented information is readily available as a means of continuously transferring data to the facility management systems used by building engineers. In this process, the COBie Worksheet, an open standard form, is used to input the information by simplifying the list required by the user. As a result, COBie was developed to improve dramatically how relevant information is obtained and updated to support operations, maintenance, and asset management at the design and construction stages. On the other hand, to use COBie, a great deal of manual work is required for information linkage and quality inspection with heterogeneous data models. These issues become obstacles to COBie-based facility management system development. This study analyzed the COBie information system and defined the framework for simpler operating maintenance information from BIM (Building Information Modeling). Moreover, the rules for facility management information submission, quality inspection, role definition of framework components, and information linkage were derived. COBie DB schema and support data linkages could be generated effectively based on the proposed framework in prototype development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.340-347
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• 2016

Since the 1970s, manufacturing has been one of the key driving forces that has led to Korea's economic growth. However, this growth rate has been reduced significantly since the 2000s, and shows that revenues and employment are steadily decreasing. In addition, while manufacturing investment in Korea has dropped sharply, the United States, Germany, Japan, and other major countries have increased investment in manufacturing. These countries have promoted manufacturing innovation strategies that include the convergence of information and communications technologies (ICT) and manufacturing. For manufacturing innovation, it is important for time and cost savings required for product development to be achieved by changes in the production process, especially product design. Modeling and simulation (M&S) is a process that replaces physical product design, mockup making, and testing, with virtual product creation (modeling) and engineering analysis (simulation). In this paper, we analyze the economic ripple effect of supercomputing M&S using an input-output model technique based on the input-output tables published by the Bank of Korea. When we set the M&S budget (about US$16 million for the last 10 years) of the Korea Institute of Science and Technology Information (KISTI) as input coefficients, the effect on production inducement, value-added inducement, and employment inducement was analyzed to be US$24 million, US$13.4 million, and 267, respectively.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.637-643
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• 2014

The purpose of this study was twofold: 1) to analyze the impact factor of clothing and textile-related journals by utilizing the average number of cross-citation that evaluates the relative importance of an academic journal and 2) to provide a list of journals with higher impact factor by analyzing closeness and betweenness among individual journals through graph networks. To fulfill this, a total of 10 clothing and textile-related journals, which are accredited by National Research Foundation of Korea, were analyzed. For analysis of the average number of cross-citation, the targeted research papers were limited to those published between 2008 and 2011 and they were derived from the Korea Citation Index. The software used for network analysis was R ver. 2.15. The results of the study were as follow: First, 'The Korean Society of Knit Design' was indicated as the highest rate of self-citation, followed by 'Journal of the Korean Fashion & Costume Design Association.' Secondly, the average impact power of clothing & textile-related journals was relatively lower (0.681) compared to that (1.00) of 23 journals under the human ecology discipline. 'Korean Journal of Human Ecology' was found to have impact factor of 1.24, which was higher than the average impact factor of human ecology-related journals. Lastly, together with 'Journal of the Korean Society of Clothing and Textiles.'

• Journal of Digital Convergence
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• v.11 no.4
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• pp.383-389
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• 2013

The purpose of this study was to investigate evidence-based practice (EBP) for sensory integration (SI) intervention in children with cerebral palsy (CP) through a systematic review and meta analysis. The screening strategy was performed to select studies for analysis after that, a meta-analysis was implemented for calculating the effect size (ES) in group studies. Twenty-four studies were included for a systematic review and included seven case reports, three single-subject designs, and fourteen group experimental design studies(three randomized controlled trials, three two groups nonrandomized studies, and six one group nonrandomized studies). The ES of the experimental group studies was moderate size of 0.272. The results of the ES according to the dependent variables, the ES was the largest in the fine motor development. The effect size of the published papers was greater than the unpublished paper's and two groups nonrandomized studies' size effect was the largest in the design. The ES of the infants was larger than the children. The ES for a period of 8 weeks, the number of five times a week, and time in 90 minutes showed the biggest in SI program. Although the ES of SI intervention in children with CP showed moderate effect, accumulation of research well be needed.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.527-538
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• 2020

This research measures the urgency and importance listening to experts' opinions as a proposal for vitalization of folk modern dance groups. Firstly, the open type FGI(Focus Group Interview) was implemented for five groups of an expert by applying the new industry foster theory, and total 24 types of second questionnaire were developed through importantly referred or repeated contents. They were distributed to 20 people including a dance group representative, a planner, a university professor and etc to measure experts' importance and urgency. In the research result, For big list, Financial aid for both importance and urgency appear first, and for comparative analysis of importance and urgency for small list, differences in infrastructure construction are shown. "expansion of dance program's advertisement channels" and "rank 1" appeared in "Secure space for dancers". Suggestions for analyzing such results are as follows. It is shown that "detailed financial aid for the operation of dance groups" and etc in the aspect of financial aid, "the employment of professional human resources including design and producing etc" in that of performance and education related production development, "training a dancer who can assimilate a complex genre" in that of manpower training, "arrangement of exclusive space for a dance group" in that of infrastructure building, and "the employment of professional human resources including design and producing etc" in that of consulting support are important and urgent matters considered by experts.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.3
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• pp.19-25
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• 2009

In this thesis, design effective elimination interference algorithm of ICS repeat system for repeater that improve frequency efficiency. Error convergence speed and accuracy of LMS Algorithm are influenced by reference signal. For improve LMS Algorithm, suggest Adaptive channel estimate algorithm. For using channel characteristic, adaptive channel estimate algorithm make reference signal similar interference signal by convolution operation and complement LMS algorithm demerit. For make channel similar piratical channel, apply Jake's Rayleigh multi-path model that random five path with 130Hz Doppler frequency. LMS algorithm and suggested adaptive channel estimate algorithm that have 16 taps apply to ICS repeat system under Rayleigh multi-path channel, so simulate with MATLAB. According to simulate, ICS repeat system with LMS algorithm show -40dB square error convergent after 150 datas iteration and ICS repeat system with adaptive channel estimate algorithm show -80dB square error convergent after 200 datas iteration. Analyze simulation result, suggested adaptive channel estimate algorithm show more three times iteration performance than LMS algorithm, and 40dB accuracy.