• 제목/요약/키워드: fundamental research

검색결과 4,477건 처리시간 0.032초

Interaction at the nanoscale of fundamental biological molecules with minerals

  • Valdre, Giovanni;Moro, Daniele;Ulian, Gianfranco
    • Advances in nano research
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    • 제1권3호
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    • pp.133-151
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    • 2013
  • The availability of advanced nanotechnological methodologies (experimental and theoretical) has widened the investigation of biological/organic matter in interaction with substrates. Minerals are good candidates as substrates because they may present a wide variety of physico-chemical properties and surface nanostructures that can be used to actively condense and manipulate the biomolecules. Scanning Probe Microscopy (SPM) is one of the best suited techniques used to investigate at a single molecule level the surface interactions. In addition, the recent availability of high performance computing has increased the possibility to study quantum mechanically the interaction phenomena extending the number of atoms involved in the simulation. In the present paper, firstly we will briefly introduce new SPM technological developments and applications to investigate mineral surfaces and mineral-biomolecule interaction, then we will present results on the specific RNA-mineral interaction and recent basics and applicative achievements in the field of the interactions between other fundamental biological molecules and mineral surfaces from both an experimental and theoretical point of view.

내부품질 판정을 위한 수박의 음파특성 (Acoustic Characteristics of Watermelon for Internal Quality Evaluation)

  • 최동수;최규홍;이강진;이영희;김만수
    • Journal of Biosystems Engineering
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    • 제27권1호
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    • pp.59-66
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    • 2002
  • The objectives of the study were to analyze the acoustic characteristics related to the internal quality factors of watermelon(Citrulus Vulgaris Schrad). Among the various internal quality factors, only four factors such as ripeness, inside cavity, yellow belt and blood flesh were considered in this study. Relationships between the internal quality factors, the day after fruit set and the day after harvest were also investigated. Test apparatus was the same as the apparatus described in the previous study(Choi et at., 2000). The selected sample was divided into four groups; 69 samples used for ripeness tests 56 samples for ripeness test along the day after fruit set and for yellow belt detection, 60 samples for ripeness along the day after harvest 44 samples fur blood flesh detection. It was shown that the first peak frequencies shifted to the lower range and the energy ratios of the bandwidths between 0∼550 Hz to the bandwidths between 850∼2500 Hz increased as the day after fruit set elapsed. Since the acoustic responses of the watermelon such as frequency and magnitude began to change from 10 days after harvest, the storage period of watermelon in a normal temperature condition seemed to be approximately 10 days after harvest. The ratios of the first peak amplitude to the maximum peak amplitude fur the sound watermelon showed the higher value than that fur watermelon with cavity inside, and the separation between the sound and cavity inside could be accomplished by the ratio value of 0.25. The energy ratios (0∼550 Hz/850∼2,500 Hz) for the watermelon with cavity inside showed the higher value than 2.3. The frequency characteristics of the yellow belt watermelon appeared mostly in the range of 600∼900 Hz frequencies. The yellow belt watermelon showing the energy spectral density function at this frequency range to be over 70 seemed to be not a marketable commodity, The energy ratios(0∼550 Hz/850∼2,500 Hz) for the blood flesh watermelon showed the higher value than 3.5.

블렌디드 러닝(blended learning)을 적용한 기본간호학 실습교육에서 성찰일지의 작성이 간호학생의 메타인지와 문제해결능력에 미치는 효과 (Effects of Writing Reflective Journal on Meta-cognition and Problem Solving Ability in Nursing Students taking a Fundamental Nursing Skills Course Applying Blended Learning)

  • 조미영
    • 기본간호학회지
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    • 제23권4호
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    • pp.430-439
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    • 2016
  • Purpose: The purpose of this study was to contribute to the development of an efficient teaching-learning method by analyzing effects of writing reflective journals on meta-cognition and problem solving ability in nursing students in education applying blended learning for fundamental nursing skills. Methods: The research design was a one-group pretest-posttest design, done to assess changes in meta-cognition and problem solving ability. Participants were 63 nursing students taking the fundamental nursing skills course at one college in Gyeonggi Province. The course was offered from March 21 to June 3, 2016. Data were collected using pre and post tests given before and after writing of reflective journals in blended learning. Data were analyzed using t-test, ANOVA, $Scheff{\acute{e}}^{\prime}s$ test and paired t-test with SPSS Statistics version 20.0. Results: The results of this study show that scores for meta-cognition and problem solving ability of these students were all above average. There was a statistically significant difference in meta-cognition between pre and post writing of reflective journals but not for problem-solving ability. Conclusion: The findings indicate that writing a reflective journal in blended learning is an efficient teaching-learning method to improve meta-cognition in nursing students.

패치로 보강된 구형 복합재료 패널의 후좌굴 거동 및 진동 특성해석 (Post-buckling Behavior and Vibration Characteristics of Patched Reinforced Spherical Composite Panels)

  • 이정진;염찬홍;이인
    • Composites Research
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    • 제14권4호
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    • pp.27-34
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    • 2001
  • 토탈 라그랑지안 방법과 변형율을 가정한 Hellinger-Reissner 원리에 기초한 유한요소법을 이용하여 패치로 보강된 구형 복합재료 쉘의 후좌굴 거동 및 진동 특성을 살펴보았다. 패치 요소는 따로 다른 유한요소를 사용하지 않고 쉘의 중앙면과 다른 기준점을 잡아 두께 변수를 택하여 정식화를 하였다. 비선형 해법으로 원통형 호-길이법을 적용하였고, 후 좌굴 진동은 미소 진폭을 갖는다고 가정하였다. 구형 쉘 패넬에서 패치가 비선형 거동 및 진동수에 미치는 영향을 고찰하였고, 그 결과 패치는 하중지지도를 개선시키킨다. 패치로 보강된 패널의 1차 고유진동수는 등가 패널에 비하여 낮으나, 하중을 받는 경우 1차 고유진동수는 급격히 감소하지 않았다.

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Genetic Diversity and Molecular Phylogeny of Cyanobacteria from Sri Lanka Based on 16S rRNA Gene

  • Wanigatunge, R.P.;Magana-Arachchi, D.N.;Chandrasekharan, N.V.;Kulasooriya, S.A.
    • Environmental Engineering Research
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    • 제19권4호
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    • pp.317-329
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    • 2014
  • The diversity of cyanobacteria in Sri Lanka was studied in different water reservoirs, paddy fields, brackish water and tsunami affected areas using light microcopy, 16S rRNA sequences, followed by phylogenetic analysis. Based on light microscopy, 24 genera were identified from environmental samples belonging to the orders Chroococcales, Oscillatoriales, Pleurocapsales and Nostocales. In cultures, 33 genera were identified from all five cyanobacterial orders, including Stigonematales. Based on 16S rRNA gene sequences and their morphology, two isolates were identified up to species level, 72 to genus level, one isolate up to family and 11 up to order level. Twelve isolates couldn't be assigned to any taxonomic level. The results of 16S rRNA gene sequences along with the phylogenetic analysis indicated that some cyanobacterial isolates could be accommodated to genus or order level. The 16S rRNA sequence analysis data in this study confirmed that order Nostocales and order Pleurocapsales cyanobacteria are monophyletic while orders Chroococcales, Oscillatoriales and Stigonematales cyanobacteria are polyphyletic. Polyphasic approach including the combination of light microscopy, cultures and the analysis of 16S rRNA gene sequences provide a promising approach to ascertain the diversity of cyanobacteria in different habitats.

실존적 현상학과 돌봄의 실천 (Existential Phenomenology and the Practice of Caring)

  • 공병혜
    • 간호행정학회지
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    • 제19권1호
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    • pp.138-145
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    • 2013
  • Purpose: This study was done to provide fundamental ontological understanding of caring and inquiring into the possibility of a caring practice in nursing based on existential phenomenology. Methods: According to Heidegger's existential phenomenology, caring has been interpreted as a fundamental ontological basis for caring practice in nursing. Further, based on Merleau-Ponty's phenomenology, the meaning of the lived experience of illness and the way of caring practice have been described from the aspect of the existential involvement in the embodied life world. Results: Heidegger's phenomenology provided ontological thinking about caring, which is understood in a basic way as the possibility of human existence and dwelling in oneself in the confrontation of the illness experience. Merleau-Ponty's phenomenology offered a meaning of human existence according to bodily intention and situated freedom in the life world. This perspective of embodiment enables nurses to understand bodily experiences of patients and recovery of their bodily capacity in responding to the situation in caring practice. Conclusion: Existential phenomenology gives insight into fundamental reflection for caring attitude and practice in nursing. Existential phenomenological nursing research can provide descriptions and meaning of the lived experience of illness and a way of coping with the crisis of human existence in caring practice.

가치투자전략과 이동평균법의 결합효과 (An Analysis on Combination Effect of Value Investment Strategy and Moving Average Method)

  • 장경천;김연권;김현석
    • 경영과정보연구
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    • 제27권
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    • pp.53-69
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    • 2008
  • In this paper we analyse performance of value strategy and moving average method among the non-financial listed companies whose fiscal year ends at December in the Korean Stock Exchange between 1996 and 2005. And we analyse combination investment performance of value investment and moving average method. After the analysis objective enterprises divide with the value stock and the growth stock, in accordance with moving average method we divide ascending stock and descending stock. And we compose 6 portfolios with combination of value stock, growth stock, ascending stock and descending stock. Using the difference of investment performance of these portfolios, when fundamental analysis and technical analysis method all considering we measure investment performance. The major findings of this research are as follows: First, the value strategy of buying value stocks and selling growth stocks were effective in the long-term investment. Second, using the moving average method, technical analysis were effective in the case of the short-term investment. Third, the portfolios combined fundamental analysis and technical analysis were more effective than investment performance of technical analysis.

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위상구성행렬식을 이용한 비압축성 순환망 형태의 유로망 해석에 관한 연구 (A Study on the Analysis of Incompressible and Looped Flow Network Using Topological Constitutive Matrix Equation)

  • 유성연;김범신
    • 설비공학논문집
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    • 제22권8호
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    • pp.573-578
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    • 2010
  • Topological matrix which reflects characteristics of network connectivity has been widely used in efficient solving for complicated flow network. Using topological matrix, one can easily define continuity at each node of flow network and make algorithm to automatically generate continuity equation of matrix form. In order to analyze flow network completely it is required to satisfy energy conservation in closed loops of flow network. Fundamental cycle retrieving algorithm based on graph theory automatically constructs energy conservation equation in closed loops. However, it is often accompanied by NP-complete problem. In addition, it always needs fundamental cycle retrieving procedure for every structural change of flow network. This paper proposes alternative mathematical method to analyze flow network without fundamental cycle retrieving algorithm. Consequently, the new mathematical method is expected to reduce solving time and prevent error occurrence by means of simplifying flow network analysis procedure.

기본상수를 이용한 SI 기본단위의 재정의 (Redefinition of the SI Base Units with Fundamental Constants)

  • 이호성
    • 한국광학회지
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    • 제30권4호
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    • pp.133-141
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    • 2019
  • 기본상수를 이용한 국제단위계 개정이 2018년 11월에 개최된 제26차 국제도량형총회에서 채택되었다. 국제단위계에 속한 4개의 기본단위(킬로그램, 암페어, 켈빈, 몰)가 각각 그 값이 고정된 플랑크 상수 h, 기본 전하 e, 볼츠만 상수 k, 아보가드로 상수 $N_A$를 기반으로 재정의되었다. 이 논문에서는 키블 저울을 이용하여 플랑크 상수로부터 킬로그램을 재정의한 원리를 설명한다. 개정된 국제단위계는 2019년 5월 20일부터 발효된다.