• Title/Summary/Keyword: Ph.D

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An Analysis of the Differences in Research-related Constructs: Serial Comparson of the Graduate Students in Global Ph. D Fellowship and Brain Korea 21 Projects (대학원생들의 연구관련 성과 변인들의 차이 분석: 글로벌 박사양성 프로젝트와 두뇌한국21사업을 중심으로)

  • Jang, Deok-Ho
    • Journal of Engineering Education Research
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    • v.16 no.3
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    • pp.20-27
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    • 2013
  • The purpose of this study is to compare the key research-related constructs, research insterest, research self-efficacy, research productivity, and research outcome expectation of the graduate students, who are participating in Global Ph.D Fellowship (GPF) and Brain Korea (BK) 21 projects. The overall results show that the mean scores of GPF students in research interest, research self-efficacy, research productivity, and research outcome expectation are higher than those of BK21. However, the higher mean scores of doctoral students in both GPF and BK21 projects imply that the longer you stay in graduate program, the better researcher you can be. Although GPF program selected higher potential students and they seem to work very hard with high expectation to be competent researchers, compatible outcome also could be possible by BK21 project.

Development of Neuro-Fuzzy System for Cold Storage Facility (저온저장고의 뉴로-퍼지 제어시스템 개발)

  • 양길모;고학균;홍지향
    • Journal of Biosystems Engineering
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    • v.28 no.2
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    • pp.117-126
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    • 2003
  • This study was conducted to develop precision control system fur cold storage facility that could offer safe storage environment for green grocery. For that reason of neuro-fuzzy control system with learning ability algorithm and single chip neuro-fuzzy micro controller was developed for cold storage facility. Dynamic characteristics and hunting of neuro-fuzzy control system were far superior to on-off and fuzzy control system. Dynamic characteristics of temperature were faster than on-off control system by 1,555 seconds(123% faster) and fuzzy control system by 460 seconds(36.4% faster). When system was arrived at steady state. hunting was ${\pm}$0.5$^{\circ}C$ in on-off control system, ${\pm}$0.4$^{\circ}C$ in fuzzy control system, and ${\pm}$0.3$^{\circ}C$ in neuro-fuzzy control system. Hunting of humidity and wind velocity was also controlled precisely by 70 to 72.5% and 1m/s For storage experiment with onion, characteristics of neuro-fuzzy control system were tested. Dynamic characteristics of neuro-fuzzy control system made cold storage facility conducted precooling ability and minimized hunting.

A reliable method for evaluating upper molar distalization: Superimposition of three-dimensional digital models

  • Nalcaci, Ruhi;Kocoglu-Altan, Ayse Burcu;Bicakci, Ali Altug;Ozturk, Firat;Babacan, Hasan
    • The korean journal of orthodontics
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    • v.45 no.2
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    • pp.82-88
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    • 2015
  • Objective: The aim of this study was to evaluate the reliability of measurements obtained after the superimposition of three-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs and photocopies of plaster models for the evaluation of upper molar distalization. Methods: Data were collected from plaster models and lateral cephalometric radiographs of 20 Class II patients whose maxillary first molars were distalized with an intraoral distalizer. The posterior movements of the maxillary first molars were evaluated using lateral cephalometric radiographs (group CP), photocopies of plaster models (group PH), and digitized 3D models (group TD). Additionally, distalization and expansion of the other teeth and the degrees of molar rotation were measured in group PH and group TD and compared between the two groups. Results: No significant difference was observed regarding the amount of molar distalization among the three groups. A comparison of the aforementioned parameters between group PH and group TD did not reveal any significant difference. Conclusions: 3D digital models are reliable to assess the results of upper molar distalization and can be considered a valid alternative to conventional measurement methods.

Sodium Metaarsenite (KML001) Induces G1 Phase Arrest in HCT116 Colorectal Cancer Cells (대장암 세포주에서 메타아비산 나트륨에 의한 G1 세포주기 정지)

  • Hong, Yun-Kyung;Kim, Sun-Mi;Lee, Seung-Hoon;Kang, Jae-Seon;Hong, Yong-Geun
    • YAKHAK HOEJI
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    • v.55 no.5
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    • pp.391-397
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    • 2011
  • KML001 reduced the proliferation of HCT116 cells in a concentration- and time-dependent manner without change of cell viability. Beclin-1 expression was significantly attenuated by KML001 (P<0.05), but no significant changes were observed in KML001-treated cells. The number of cells in G1 phase was increased 48 hr after KML001 treatment. Furthermore, a dramatic reduction in the frequency of beating and the number of embryoid bodies of the cells was noted after treatment. Taken together, KML001 suppresses the proliferation of HCT116 cells, which might be due to G1 phase arrest.

Biotechnology Development Collaboration System and Limitations of Domestic Physician Scientists

  • Yu, Tae Gyu
    • International journal of advanced smart convergence
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    • v.11 no.4
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    • pp.247-252
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    • 2022
  • The purpose of the domestic physician scientist support program is to promote the development of various biotechnology. Therefore, it can be said that examining whether the purpose of support is being faithfully implemented has an important meaning for the future domestic biotechnology development ecosystem. Therefore, this study limited the subject of analysis to 79 MD-PhD experts who participated or participated in doctor scientist programs at major universities in Korea. Among them, a total of 25 researchers, one researcher from each classroom in parasitology, microbiology, pharmacology, biochemistry, physiology, and anatomy, which had the highest paper citations in the last five years (2016-2021), were selected to examine the relationship between joint research. It was selected as the subject of review. As a result, 25 selected pseudo-scientists(MD-PhD) identified domestic and foreign researchers who participated as co-researchers when publishing in overseas academic journals for the last 5 years(2016-2021), and identified the affiliation and name of the top 5 among them, as well as the pseudo-scientist(MD-PhD), it was possible to identify the relationship of a total of 123 co-researchers(excluding 2 missing values) of the top 5 co-researchers with a high degree of cooperation with respect to the researcher(25 in total), and the collaboration of pseudo-scientists. Relationships, major researchers, and research institutes were examined. Nodexl Basic 2018 ver. (Microsof) was used for the analysis, and the relationship between researchers could be visualized by applying network analysis techniques.

A Kinetic Study on Solvolysis of Diphenyl Thiophosphorochloridate

  • Koh, Han-Joong;Kang, Suk-Jin;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.383-388
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    • 2009
  • Rates of solvolyses of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone and 2,2,2-trifluoroethanol (TFE) are reported. For four representative solvents, studies were made at several temperatures and activation parameters were determined. The 30 solvents gave a reasonably precise extended Grunwald-Winstein plot, correlation coefficient (R) of 0.989. The sensitivity values (l = 1.29 and m = 0.64) of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) were similar to those obtained for diphenyl phosphorochloridate ($(PhO)_2$POCl, 2), diphenylphosphinyl chloride ($Ph_2$POCl, 3) and diphenylthiophosphinyl chloride ($Ph_2$PSCl, 4). As with the previously studied of 3~4 solvolyses, an $S_N$ pathway is proposed for the solvolyses of diphenyl thiophosphorochloridate (1). The activation parameters, ${\Delta}H^{\neq}\;(=11.6{\sim}13.9\;kcal{\cdot}mol^{-1})\;and\;{\Delta}S^{\neq}\; (=\;-32.1\;{\sim}\;-42.7\;cal{\cdot}mol^{-1}{\cdot}K^{-1})$, were determined, and they were in line with values expected for an $S_N$2 reaction. The large kinetic solvent isotope effects (KSIE, 2.44 in MeOH/MeOD and 3.46 in $H_2O/D_2$O) are also well explained by the proposed $S_N$2 mechanism.

Characterization of Amylolytic Activity by a Marine-Derived Yeast Sporidiobolus pararoseus PH-Gra1

  • Kwon, Yong Min;Choi, Hyun Seok;Lim, Ji Yeon;Jang, Hyeong Seok;Chung, Dawoon
    • Mycobiology
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    • v.48 no.3
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    • pp.195-203
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    • 2020
  • Marine yeasts have tremendous potential in industrial applications but have received less attention than terrestrial yeasts and marine filamentous fungi. In this study, we have screened marine yeasts for amylolytic activity and identified an amylase-producing strain PH-Gra1 isolated from sea algae. PH-Gra1 formed as a coral-red colony on yeast-peptone-dextrose (YPD) agar; the maximum radial growth was observed at 22 ℃, pH 6.5 without addition of NaCl to the media. Based on the morphology and phylogenetic analyses derived from sequences of internal transcribed spacer (ITS) and a D1/D2 domain of large subunit of ribosomal DNA, PH-Gra1 was designated Sporidiobolus pararoseus. S. pararoseus is frequently isolated from marine environments and known to produce lipids, carotenoids, and several enzymes. However, its amylolytic activity, particularly the optimum conditions for enzyme activity and stability, has not been previously characterized in detail. The extracellular crude enzyme of PH-Gra1 displayed its maximum amylolytic activity at 55 ℃, pH 6.5, and 0%-3.0% (w/v) NaCl under the tested conditions, and the activity increased with time over the 180-min incubation period. In addition, the crude enzyme hydrolyzed potato starch more actively than corn and wheat starch, and was stable at temperatures ranging from 15 ℃ to 45 ℃ for 2 h. This report provides a basis for additional studies of marine yeasts that will facilitate industrial applications.

Improved Synthesis of the Tetrasaccharide Repeat Unit of the O-Antigen Polysaccharide from Escherichia coli O77

  • Lee, Bo-Young;Baek, Ju-Yuel;Jeon, Heung-Bae;Kim, Kwan-Soo
    • Bulletin of the Korean Chemical Society
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    • v.28 no.2
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    • pp.257-262
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    • 2007
  • The efficient synthesis of a tetrasaccharide, the suitably protected form of the repeat unit, →2)-α-D-Manp-(1→2)-β-D-Manp-(1→3)-α-D-GlcpNAc-(1→6)-α-D-Manp-(1→, of the O-antigen polysaccharide of the lipopolysaccharide from E. coli O77 has been accomplished. Glycosylation reactions for the coupling of four monosaccharide building blocks of the tetrasaccharide were carried out employing the CB glycoside method, the mannosyl 4-pentenoate/PhSeOTf method, and the glycosyl trichloroacetimidate method with complete stereoselectivities in excellent yields.