• Geophysics and Geophysical Exploration
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• v.24 no.4
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• pp.158-163
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• 2021

The frequency-domain induced polarization (IP) response based on Cole-Cole model is expressed as a simple equation in close form. However, it is difficult to compute the time-domain IP response based on Cole-Cole model or any other relaxation model because it cannot be written in closed form. In this study, using numerical experiments, we compared three numerical methods for calculating the time-domain IP response of the Cole-Cole model asymptotically: series expansion, digital linear filtering and Fourier transform. The series expansion method is inadequately accurate for certain time values and converges very slowly. A digital linear filter specially designed to calculate the time-domain IP response does not present the desired accuracy, especially at later times. The Fourier transform method can overcome the abovementioned problems and present the time-domain IP response with adequate accuracy for all time values, even though more computing time is required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.63-70
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• 1994

This study presents the nonlinear dynamic analysis method of the multi-span continuous bridge considering the friction of the expansion bearings. Also the numerical analysis is performed for estimating the effect of the friction on the seismic response of the multi-span continuous bridge under the longitudinal ground motion compatible to Korean bridge design response spectra. It is found that even small friction coefficient of the expansion bearings has significant effect on reducing the superstructure displacement due to energy dissipation and distributing the inertia force of the superstructure to the substructures due to frictional force. It is observed that such favorable friction effects increase as the friction coefficient increases and the magnitude of the ground motion decreases. Therefore, the friction of the expansion bearings can be effectively used for the safe and economic design of the continuous span bridge with many spans and large superstructure weight under the small to medium scale longitudinal ground motions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.161-168
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• 2013

Nowadays, one of the most interested area of automobile industry is the production of vehicle which has collision safety and ability to produce less amount of $CO_2$. The achievement of such a dual performance is done by choosing the materials like dual phase steel, ferrite bainite steel, etc. These steels have been used in automotive chassis and body parts, and also used to be formed by hole flanging to meet the goal of strength and design requirement. The formability of sheet material was experimented by hole expansion test and the judgement relies on human eye and his experience. This manual judgement involves many errors and large deviation. This paper develops the automatic crack recognition system which finds a crack based on CCD image to complement the problem of the current method depending on human's sense.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.3
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• pp.289-304
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• 2006

The purpose of this pilot study is to construct a searching thesaurus with word association test in the library and information science field and to confirm it's functionality as searching aids through query expansion experiments. The test results were analyzed to four types of relationship between stimulus words and response words, and the terms of association thesaurus were compared with descriptors of an existing thesaurus. The test results show that the word association test is a fruitful method to identify many related terms and narrower and equivalent terms in some degree to the stimulus terms. Furthermore. in the query expansion experiment. the Performance of association thesaurus was better than that of an existing thesaurus, This result demonstrates that word association thesaurus can apply to query expansion.

• Journal of Korean Society of Transportation
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• v.32 no.4
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• pp.401-409
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• 2014

This study deals with capacity expansion planning of airport infrastructure in view of economic validation that reflect construction costs and social benefits according to the reduction of passengers' delay time. We first forecast the airport peak-demand which has a seasonal and cyclical feature with ARIMA model that has been one of the most widely used linear models in time series forecasting. A discrete event simulation model is built for estimating actual delay time of passengers that consider the passenger's dynamic flow within airport infrastructure after arriving at the airport. With the trade-off relationship between cost and benefit, we determine an economic quantity of conveyor that will be expanded. Through the experiment performed with the case study of Incheon international airport, we demonstrate that our approach can be an effective method to solve the airport expansion problem with seasonal passenger arrival and dynamic operational aspects in airport infrastructure.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.143-147
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• 2010

Purpose: Nostril stenosis is an uncommon deformity that develops as a consequence of smallpox, chickenpox, tuberculosis, syphilis, congenital malformations etc. There have been several studies on the surgical techniques to treat it. However, it is difficult to maintain the result for a long time. The goal of this study is to evaluate the use of Wplasty, perialar flap as an operative techniques and expansion exercise using Foley catheter as a method to keep the patency of nostril. Methods: This is a retrospective review of the senior surgeon's (Y.L.) patients who underwent W-plasty and a perialar flap. Patients treated from 2005 to 2009 were reviewed and the postoperative results were evaluated. Average patient age was 24 years, ranged from 1 to 61 years, average follow-up period was 27.5 months, ranged from 3 to 77 months. The mild deformity was released with an incision and expansion by the ballooning of a Foley catheter and corrected by W-plasty only. However, a severe deformity required an additional procedure including perialar flap transposition. During the postoperative period, the patients maintained a nasal stent and exercise using a Foley catheter to prevent recurrence. Results: Five cases of nostril stenosis in four patients were treated using this technique. One case was corrected with W-plasty only, but four cases were more severe and were corrected with W-plasty and a perialar flap. There were no perioperative complications. The patients were satisfied with the results and retained a good shape during the follow-up periods. Conclusion: Nostril stenosis can be corrected with W-plasty and a perialar flap. A perialar flap is added if W-plasty is unable to correct the deformity. A postoperative nasal stent and expansion with a Foley catheter can help in preventing recurrences.

• Journal of the Korean Society of Costume
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• v.67 no.4
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• pp.131-152
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• 2017

The purpose of this study is to analyze modern fashion culture in the 20th century through changes in transmedia in order to better understand characteristics of fashion contents. The study also strived to identify the characteristics of remediation in modern fashion and media by exploring the cultural code, and use it to establish an integrated view. The subjects and the method of the study are as follows. First, the study analyzed the development of transmedia and fashion culture since the 20th century. Second, it identified the transitional characteristics of transmedia. Third, the study analyzed the characteristics of remediation in modern fashion culture by using the characteristics of mediation, which appeared with the transitional characteristics of transmedia. The study results are as follows. First, the types of remediation are 'borrowing,' 'Representation,' 'Expansion,' 'Refashion,' and 'Absorb.' In old and new media, each type can be aesthetically experienced in 'transparency,' opaqueness,' 'Hypermediacy,' and 'Immediacy.' Second, fashion culture can undergo a transformation from its original form to a second and a third iteration, and this process allows for possibility of an expansion of multiple plots and well-rounded character settings. This opens up the possibility for fashion consumer participation, and signifies a transition into an environment where expansion of time and space is possible. The third finding is the non-mediation of fashion objects. The mediating relationship between clothes and media is directly connected to the development of new media. The immersion of new media by fashion consumers has the characteristics of 'transparency'/'Non-mediation,' and the reinterpretation and reproduction of original fashion styles have the characteristics of 'opaqueness'/'Hyper-mediation.' Fourth, fashion culture has data variability. Through 'Borrowing,' 'Representation,' 'Expansion,' 'Remodeling,' and 'Absorption,' the cultural hierarchy of reproduced fashion forms a multi-layered integrated network. Mediation code, which repurposes fashion culture contents, also creates new media fashion through transmedia.

• Fire Science and Engineering
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• v.24 no.6
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• pp.139-144
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• 2010

Fire fighting foam is expanded when it mix with many water in mechanical method. It have adaptability, mass production possibility, long-time storage possibility. But foam isn't recommended that it use for extinguish the fire in winter. Because of, expansion ratio is changed according to exterior temperature and environment. In this study, we analysis to effect of expansion according to temperature and develop auto mixing system available for fire engine. As a result of non-standard drug mixture is 3.0% up to 30.08% depending on the temperature of the fire showed that the difference in performance occurs. In addition, analysis of the applicability of automatic mixing system design values and actual experimental data as 0.012% maximum error of the applicability of the system obtained according nataname was judged.

• PNF and Movement
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• v.15 no.2
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• pp.159-166
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• 2017

Purpose: This study attempts to determine the effects of applying three kinds of breathing exercises for four weeks on the neck muscle activation of subjects with a forward head posture. Methods: A total of 30 adults aged in their twenties (15 men and 15 women) with a forward head posture who voluntarily agreed to participate after listening to the purpose and procedure of this research were chosen as the subjects of this study. The subjects were randomly divided into either the diaphragmatic breathing exercise (DBE) group, the abdominal drawing-in maneuver (ADIM) group, or the abdominal expansion method (AEM) group according to the breathing intervention scheme. Each group included ten subjects. The muscle activity of the sternocleidomastoid, scalenus anterior, and splenius capitis was measured in all the groups prior to the intervention, two weeks after the intervention, and four weeks after the intervention. All the interventions were implemented for 30 minutes a day, three times a week, for a total of four weeks. Results: No significant between-group difference was observed in terms of the change in neck muscle activity according to the four-week intervention scheme. Further, there was no interaction between the intervention period and the intervention scheme in relation to the change in neck muscle activity. Conclusion: The results of this study suggest that abdominal expansion exercise is as effective as other breathing exercise methods for subjects with a forward head posture. We therefore expect that abdominal expansion exercise can be used as a scheme for the prevention of symptoms as well as therapy for patients with a forward head posture.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.701-704
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• 2008

The case of failure of Alkali-silica reaction (ASR) on the cement concrete pavement was reported in Korea. In the United States America, the fly ash has less than 10 percent Cao reported that prevent expansion by ASR. Most of all fly ash in Korea have less than 10 percent CaO, therefore it is similar ASTM F fly ash in the USA. Crushed aggregates of the test section had expansion behavior by potential ASR that the ASTM C 1260 test method tested expansion 0.17 percent during 14 days. The test section of concrete pavement used crushed aggregate was constructed that fly ash have 20 percent weight of cementitious materials to prevent expansion by ASR. This study was performed flexural strength test for elapsed days and durability by freeze-thaw test. It was shown that flexural strength was increased elapsed days and good performed freeze-thaw test. This study shown that fly ash concrete pavement was good performance in the test section.