• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.49-56
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• 2022

In this study, numerical simulations for reducing noise between floors in an apartment building was carried out using Active Noise Control (ANC) technology. In order to examine the feasibility of using ANC to reduce noise between floors, accelerometers and microphones for noise collection were installed in the inter-floor noise test facility to measure noise and vibration caused by the impact ball drop test. By using the measured data, Filtered-x Least Mean Square (Fx-LMS) algorithm-based ANC simulations were carried out. In the simulations, after deriving optimal simulation conditions including the adaptive control convergence coefficient, the noise reduction effect was analyzed through numerical simulations using the number of installed accelerometers and speakers as variables. Finally, it was confirmed that the noise between floors could be reduced using ANC technology under limited conditions.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.39-50
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• 2022

The Purpose of this study was to confirm the effects of Active learning application on thecritical thinking disposition, problem-solving ability, and self-leadership of nursing students in the online health assessment practice course in the COVID-19 pandemic situation. Data collection was conducted from September 1st to December 17th, 2021 for 78 nursing students in the Department of Nursing at University D, and the collected data was analyzed using the SPSS/WIN 20 program. As a result of this study, the critical thinking disposition (t=-2.11 p=.038) and self-leadership (t=-2.07 p=.042) were statistically significantly increased after active learning was applied to the online nursing health assessment practice class. SOAP, Outcome-Present-Test(OPT) worksheet, clinical reasoning webs, mind map writing are confirm to improve critical thinking disposition, problem solving ability, self-leadership of nursing student, so research to confirm the effect in face to face classed should be conducted.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.966-978
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• 2002

There are two important problems in improving text classification systems based on machine learning approach. The first one, called "selection problem", is how to select a minimum number of informative documents from a given document collection. The second one, called "composition problem", is how to reorganize selected training documents so that they can fit an adopted learning method. The former problem is addressed in "active learning" algorithms, and the latter is discussed in "boosting" algorithms. This paper proposes a new learning method, called AdaBUS, which proactively solves the above problems in the context of Naive Bayes classification systems. The proposed method constructs more accurate classification hypothesis by increasing the valiance in "weak" hypotheses that determine the final classification hypothesis. Consequently, the proposed algorithm yields perturbation effect makes the boosting algorithm work properly. Through the empirical experiment using the Routers-21578 document collection, we show that the AdaBUS algorithm more significantly improves the Naive Bayes-based classification system than other conventional learning methodson system than other conventional learning methods

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.293-297
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• 2012

Of the 169 strains of microorganisms stored in Polar and Alpine Microbial Collection of Korea Polar Research Institute, 27 strains were selected for their chitinase activity on ZoBell plates supplemented with 0.4% colloidal chitin. Among them, PAMC 21693 strain have shown the highest chitinolytic enzyme activity toward pNP-$(GlcNAc)_1$ at low temperature and the highest growth rate at $4^{\circ}C$. We cloned a full-length chitinase gene of 2,857 bp which contains an open reading frame of 2,169 bp encoding 872-amino acid polypeptide. Recombinant chitinase protein was expressed in E. coli and its molecular weight was confirmed 96 kDa. In this paper, we suggest the potential use of cold-active chitinase from polar microorganisms in the field of biotechnology.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.5
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• pp.748-759
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• 2000

The purposes of this study were 1) to classify wearing situation of male adolescents and 2) to classify self-image and CPI(Clothing Preference Image) of male adolescents and 3) to segment consumer group by self-image and to find the differences in self-image and CPI by situation among groups. For the data collection a questionnaire was distributed to male adolescents who were residents in Seoul and Taejeon. The statistics used for the data analysis were factor analysis, multiple dimensional scale, mean, percentage, peason-correlation, cluster analysis, one-way ANOVA, Duncan-test by the SPSSWIN program. The results of this study are as follows: 1) The self-image of male adolecents is categorized by seven factors; sophisticate and fashion conscious, active, practical and realistic, flank and pure, young-looking, feminine, and slender. Based on seven factors, the consumer group is categorized to five groups; practical and realistic Group1, young-looking and feminine Group2, characterless Group3, active Group4, sophisticate and flank Group5. 2) Wearing situations are divided into three categories; in downtown, in urban, at festival. In downtown, CPI are divided into six elements; ornamental, simplex, sexy, feminine, neat, young, and sophisticate. In urban, CPI are divided into five elements; ornamental, simple, sexy, feminine, young-looking, and sophisticate. At festival, CPI are divided into four elements; unique, simple, feminine, and formal. To conclude, the male adolescent consumers are categorized by self-image, and the different CPIs are sought by different wearing situations.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1173-1177
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• 2004

The high investment is necessary for the new high speed lines. So the KRRI was interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The tilting train system has been developed because the reconstruction of railway for the cant compensation costs very high. The purpose of the tilting system is to compensate the centrifugal acceleration in order to reduce the lateral acceleration of the passenger at high speed on the curves.The pantograph of the tilting train is indispensable in order to supply the electrification equipments with power in safe. The dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force and the contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the active control of pantograph and presents the LQ-servo controller to reduce the contact force variation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.460-461
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• 2009

We studied the effects of post-annealing treatment on poly(3-hexylthiophene)(P3HT, donor):[6,6]-phenyl $C_{61}$ butyric acid methyl ester(PCBM, acceptor) blend film as an active layer in the organic solar cells(OSCs). For the formation of the active layer, 3 wt.% P3HT:PCBM solution in chlorobenzene were deposited by spin-coating method. In order to optimize the performance of OSCs, the P3HT crystallization and the redistribution of PCBM cluster at P3HT:PCBM composition as a function of post-annealing condition from room temperature to $200^{\circ}C$ were measured by the Hall effect and the UV-vis Spectrophotometer. We thought that the improved efficiency in the OSCs with post-annealing treatment at $150^{\circ}C$ can be explained by the efficient separation or collection of the photogenerated excitons at donor-acceptor interface by P3HT crystallization.

• Journal of the Korean Society for Railway
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• v.8 no.4
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• pp.361-366
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• 2005

The high investment is necessary for the new high speed lines. So the KRRI has been interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The pantograph in train is indispensable in order to supply the electrification equipments with power in safe. The pantograph and the overhead wire form a dynamic coupled system and they affect each other through the contact force. Unfortunately, as the operational speed of a train increases, the vibration of the pantograph and the overhead wire also increases. This may lead to a zero contact force between the pantograph head and the overhead wire, which can results in the loss of contact, arching and abrasion. If the arching and spark happen between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper describes the dynamic response between the pantograph and catenary system by the numerical simulations and presents the LQ-servo controller to reduce the contact force variation

• International Journal of Contents
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• v.12 no.4
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• pp.62-68
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• 2016

This paper describes an attempt to integrate flip teaching into a language classroom by adopting wikispaces as an online learning platform. The purpose of this study is to examine student perceptions of the effectiveness of using video lectures and wikispaces to foster active participation and collaborative learning. Flipped learning was implemented in an English writing class over one semester. Participants were 27 low intermediate level Korean university students. Data collection methods included background questionnaires at the beginning of the semester, learning experience questionnaires at the end of the semester, and semi-structured interviews with 6 focal participants. Because of the significance of video lectures in flip teaching, oCam was used for making weekly online lectures as a way of pre-class activities. Every week, online lectures were posted on the school LMS system (moodle). Every week, participants met in a computer room to perform in-class activities. Both in-class activities and post-class activities were managed by wikispaces. The results indicate that the flipped classroom facilitated student learning in the writing class. More than 53% of the respondents felt that it was useful to develop writing skills in a flipped classroom. Particularly, students felt that the video lectures prior to the class helped them improve their grammar skills. However, with respect to their satisfaction with collaborative works, about 44% of the participants responded positively. Similarly, 44% of the participants felt that in-class group work helped them interact with the other group members. Considering these results, this paper concludes with pedagogical suggestions and implications for further research.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.159-165
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• 1997

We collected 3,237 plant samples, mainly leaves of various trees, from many provinces in Korea and a total of 1,925 Bacillus thuringiensis isolates were obtained and characterized. The isolates were characterized in terms of crystal morphology, PAGE pattern of the toxin proteins, plasmids pattern, biochemical characteristics, and bioassay. The microscopic observation showed that 49.1% of the isolates have bipyramidal shape crystals, 7.1% of spherical shape crystals, 1.4% of rhomboidal shape crystals, and others have small or amorphous inclusions. The insecticidal activities of the spore-crystal mixtures of isolates were tested against Plutella xylostella, Bombyx mori, Culex pipiens, and Agelastica coerulea. Bioassay showed that 51.3% of the isolates were shown to be active; lepidopteran-specific (44.8%), dipteran-specific(4.9%) and coleopteran-specific (1.6%). The remainder(48.8%) did not show any activity against the insects we tested. Interestingly though, some of these non-active isolates were shown to have bipyramidal crystals. By serotyping 22 isolates of our collection, we found that there are various kind of subspecies such as aizawai, amagiens, canadensis, darmstadiensis, galleriae, finitimus, kurstaki, morrisoni and neoleonensis, and three isolates have been classified into a new serotype, H49, and one of them, the type strain, named subsp. muju. From this study it was found that phylloplane is a good source for the isolation of Bacillius thuringiensis, and Bacillus thuringiensis is distributed widely in Korea.