• Title/Summary/Keyword: Research frontier

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Ferroelectric-gate Field Effect Transistor Based Nonvolatile Memory Devices Using Silicon Nanowire Conducting Channel

  • Van, Ngoc Huynh;Lee, Jae-Hyun;Sohn, Jung-Inn;Cha, Seung-Nam;Hwang, Dong-Mok;Kim, Jong-Min;Kang, Dae-Joon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.427-427
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    • 2012
  • Ferroelectric-gate field effect transistor based memory using a nanowire as a conducting channel offers exceptional advantages over conventional memory devices, like small cell size, low-voltage operation, low power consumption, fast programming/erase speed and non-volatility. We successfully fabricated ferroelectric nonvolatile memory devices using both n-type and p-type Si nanowires coated with organic ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] via a low temperature fabrication process. The devices performance was carefully characterized in terms of their electrical transport, retention time and endurance test. Our p-type Si NW ferroelectric memory devices exhibit excellent memory characteristics with a large modulation in channel conductance between ON and OFF states exceeding $10^5$; long retention time of over $5{\times}10^4$ sec and high endurance of over 105 programming cycles while maintaining ON/OFF ratio higher $10^3$. This result offers a viable way to fabricate a high performance high-density nonvolatile memory device using a low temperature fabrication processing technique, which makes it suitable for flexible electronics.

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An Investigation on the Efficiency of Research Collaborations: Data Envelopment Analysis and Stochastic Frontier Analysis on Bio-technology R&D Projects

  • Og, Joo-Young;Hwang, Jung-Tae
    • Asia-Pacific Journal of Business
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    • v.10 no.2
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    • pp.1-12
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    • 2019
  • Collaborative research and development (R&D) has been encouraged based on the belief that knowledge spill-over is mutually beneficial for partners. Although the benefits are supported by science and technology policy research, the risk of R&D collaboration has not been extensively discussed. Two independent studies suggest that there are risks associated with the overuse of collaborative research frameworks. Two sets of R&D collaboration data were analyzed: between the national bio-technology research program and 1) Data Envelop Analysis (DEA), and 2) between Stochastic Frontier Analysis (SFA). In the case of SFA, output measures were integrated into a single output, with weights extracted from research programme managers' responses to the questionnaire. While the DEA result demonstrated the inefficiency of collaborative research, SFA did not. Unlike previous research highlighting risks associated with disclosing proprietary R&D and potential conflict of interest, our study indicates that the transaction's social cost affects collaborative research efficiency. Therefore, governments promoting R&D collaborations should be carefully managed, and policy makers must reconsider the strict conditions governing compulsory collaborative R&D programs.

A New Pruning Method for Synthesis Database Reduction Using Weighted Vector Quantization

  • Kim, Sanghun;Lee, Youngjik;Keikichi Hirose
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.4E
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    • pp.31-38
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    • 2001
  • A large-scale synthesis database for a unit selection based synthesis method usually retains redundant synthesis unit instances, which are useless to the synthetic speech quality. In this paper, to eliminate those instances from the synthesis database, we proposed a new pruning method called weighted vector quantization (WVQ). The WVQ reflects relative importance of each synthesis unit instance when clustering the similar instances using vector quantization (VQ) technique. The proposed method was compared with two conventional pruning methods through the objective and subjective evaluations of the synthetic speech quality: one to simply limit maximum number of instance, and the other based on normal VQ-based clustering. The proposed method showed the best performance under 50% reduction rates. Over 50% of reduction rates, the synthetic speech quality is not seriously but perceptibly degraded. Using the proposed method, the synthesis database can be efficiently reduced without serious degradation of the synthetic speech quality.

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Global Fast Food Brands: The Role of Consumer Ethnocentrism in Frontier Markets

  • MUKUCHA, Paul;JARAVAZA, Divaries Cosmas
    • The Journal of Industrial Distribution & Business
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    • v.12 no.6
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    • pp.7-21
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    • 2021
  • Purpose: Modern globalization and Western markets saturation has catalyzed the growth of culinary globalization into developing countries. The question was whether fast food consumers in frontier markets of Sub-Saharan Africa (Zimbabwe), either upholds national gastronomic tendencies in terms of consumer ethnocentrism and buy local or they adopt global fast food brands. Demographic consumer profiles were also analyzed as antecedents of consumer ethnocentrism. Research design, data and methodology: A sample size of 400 fast food-adult consumers was surveyed in the City of Harare. Data was captured on SPSS and Analysis of Moment Structure (AMOS). Hypothesis testing was done using sample t test (H1), logistic regression (H2) and multiple regression (H3, 4, 5) analysis. Results: Consumer ethnocentrism in Zimbabwe was marginally above average and no statistically significant relationship between the levels of consumer ethnocentrism and adoption of foreign fast food brands was noted. Age had an inverse relationship; income had a positive association whilst gender had no statistical significance with consumer ethnocentrism. Conclusions: Despite the Zimbabwean consumers being marginally ethnocentric, international restaurateurs should invest in the Zimbabwean fast food market since their nature of being foreign has got an exotic appeal to the Zimbabwean consumers thereby enhancing their likelihood of success.

Studies on the Management and Utilization of Reed Canarygrass III. Effect of harvest time on the dry matter yeild, nutritive value, and weed development in four cultivars of reed canarygrass pasture (Reed Canarygrass 초지의 관리 및 이용에 관한 연구 III. 수확시기가 주요 Reed Canarygrass 목초의 수량과 사료가치 및 잡초발생에 미치는 영향)

  • Seo, Sung;Lee, Joung-Kyong;Shin, Dong-Eun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.15 no.2
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    • pp.112-117
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    • 1995
  • A field experiment was canied out to determine the effects of harvest time (grazing, soiling and hay stage) on the grass growth, dry matter (DM) yield, nutritive value, and weed development in reed canarygrass (Phalaris arundinacea L.) pasture. The cultivars of reed canarygrass used in this study were Palaton, Venture, Castor, and Frontier (control). The grass was harvested 3 times at hay stage, 4 times at soiling stage, and 6 times at grazing stage in 1992. The average plant height was 31-41cm at grazing, 47-59cm at soiling, and 76-86cm at hay stage. Similar DM yield was observed in Palaton(12,567 kglha), Venture(l2,435kg), and Frontier(12,762kg), and the yields of 3 cultivars were significantly higher than that of Castor(ll,025kg) (P<0.05). Total yields affected by harvest time were lO,O6 1, 1 1,832, and 14,699 kg/ha at grazing, soiling, and hay stage, respectively(P<0.05). The content of crude protein (CP) was not significantly different among cultivars. CP contents by harvest time were 21.6% at grazing, 19.3% at soiling, and 18.8% at hay stage, regardless of cultivm(P<0.05). The contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among cultivars and harvest time. However, slightly higher NDF and ADF contents were found in Frontier. The contents of Ca, P, K, and Mg were not affected by cultivars and harvest time. The appearance of weeds was high in Castor, and low in Frontier. The weeds at grazing stage(33.3-60.0%) were remarkably higher than those at soiling and hay astage (ca 10%). In conclusion, it is suggested that 3-4 times (soiling and hay stage) of harvest was recommended for grass production, nutritive value, and weed control in reed canarygrass pasture, regradless of cultivars of Palation, Venture and Frontier, except Castor.

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Analysis of Expressed Sequence Tags from the Antarctic Psychrophilic Green Algae, Pyramimonas gelidicola

  • Jung, Woongsic;Lee, Sung Gu;Kang, Se Won;Lee, Yong Seok;Lee, Jun Hyuck;Kang, Sung-Ho;Jin, Eon Seon;Kim, Hak Jun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.7
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    • pp.902-906
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    • 2012
  • Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control ($4^{\circ}C$) and cold-shock conditions ($-2^{\circ}C$), respectively. The complete EST sequences were deposited to the DDBJ EST database (http://www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms.

Selection of Frontier Green Construction Product

  • Hyounseung Jang;Seokin Choi;Boknam Lee;Wooyoung Kim;Chulki Chang;Younghwan Lee
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1426-1432
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    • 2009
  • Green growth is summarized as the national growth strategies to enhance the quality of life as a whole by converting not only the lifestyle but the economic and industrial structures into the low carbon and eco-friendly environments with the green growth industries with low carbon as the momentum for new growth, based on green technologies including renewable energy technologies, energy and resource efficient technologies, converging technologies related to technologies to reduce the environmental pollution. Roles of the construction industry along with other industries are very important in securing justifications for the cooperation between our government and industries for challenges to this green growth as well. The national effects of economy are very large from leading the construction industry to the green construction from the national level. Accordingly, this study suggested responsive plans for both government and companies for the activation of green construction by selecting 15 frontier green construction products and analyzing them by the type of strategy in Korea, as well as analyzing recent trends of overseas green construction.

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A Preliminary Study of the Association between SOX17 Gene Variants and Intracranial Aneurysms Using Exome Sequencing

  • Park, Jeong Jin;Kim, Bong Jun;Youn, Dong Hyuk;Choi, Hyuk Jai;Jeon, Jin Pyeong
    • Journal of Korean Neurosurgical Society
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    • v.63 no.5
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    • pp.559-565
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    • 2020
  • Objective : Conflicting results regarding SOX17 genes and the risk of intracranial aneurysms (IA) exist in the Korean population, although significant positive correlations were noted in genome-wide association studies in European and Japanese populations. Therefore, we aimed to investigate an association between SOX17 gene variants and IA using exome sequencing data. Methods : This study included 26 age-gender matched IA patients and 26 control subjects. The SOX17 gene variants identified from whole-exome sequencing data were examined. Genetic associations to estimate odds ratio (OR) and 95% confidence interval (CI) were performed using the software EPACTS. Results : The mean age of the IA and control groups were 51.0±9.3 years and 49.4±14.3 years, respectively (p=0.623). Seven variants of SOX17, including six single nucleotide polymorphisms and one insertion and deletion, were observed. Among these variants, rs12544958 (A>G) showed the most association with IA, but the association was not statistically significant (OR, 1.97; 95% CI, 0.81-4.74; p=0.125). Minor allele frequencies of the IA patients and controls were 0.788 and 0.653, respectively. None of the remaining variants were significantly associated with IA formation. Conclusion : No significant association between SOX17 gene variants and IA were noted in the Korean population. A large-scale exome sequencing study is necessary to investigate any Korean-specific genetic susceptibility to IA.