• 제목/요약/키워드: biological phenomena

검색결과 203건 처리시간 0.028초

STATISTICAL PHYSICS APPROACH TO BIOLOGICAL PHENOMENA

  • Sung, Wokyng
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1996년도 정기총회 및 학술발표회
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    • pp.7-7
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    • 1996
  • A new trend that emerges at the turn of the century is the physical approach to biological phenomena. It is expected that biology provides novel materials for condensed matter physics and, most importantly, a revolutionary paradigm for physics at large. On the other hand, physics, if properly extended, is expected to provide systematic and quantitative understanding of biological phenomena, and multitude of biotechnological applications. (omitted)

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유전자 프로그래밍을 이용한 생체 신호의 비선형 특성 모델링에 관한 연구 (A study on the Modeling of Nonlinear Properties of Biological Signal using Genetic Programming)

  • 김보연;박광석
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1996년도 추계학술대회
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    • pp.70-73
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    • 1996
  • Many researchers had considered biological systems as linear systems. In many cases of biological systems, the phenomena that show the regular and periodic dynamics are considered the normal state. However, some clinical experiments reported, in some cases, the periodic signals represented the abnormal state. We assume that signals from human body system are generated from deterministic, intrinsic mechanisms and can be represented a simple equation that show nonlinear dynamics dependent on control parameters. The objective of our study is to model a nonlinear dynamics correctly from the nonlinear time series using the genetic programming method; to find a simple equation of nonlinear dynamics using collected time series and its nonlinear characteristics. We applied genetic programming to model RR interval of ECG that shows chaotic phenomena. We used 4 statistic measures and 2 fractal measures to estimate fitness of each chromosome, and could obtain good solutions of which chaotic features are similar.

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심근세포의 동기현상과 그 모델화 (The Syncronization Phenomena and Its Model of Myocardial Cells)

  • 박민용;제승정남
    • 대한의용생체공학회:의공학회지
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    • 제3권2호
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    • pp.101-104
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    • 1982
  • Even one embryonic myocardial cell exhibits a spontaneous, periodic beating phenomena. When these cells come in contact with each other, they beat synchronously with a certain period. In this paper, the mechanism of this phenomena is investigated, and the synchronization model is presented. The physiological experimental results are compared with the simulated results of the model.

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Investigation of Corrosion Fatigue Phenomena in Transient Zone and Preventive Coating and Blade Design against Fouling and Corrosive Environment for Mechanical Drive Turbines

  • Hata, Satoshi;Nagai, Naoyuki;Yasui, Toyoaki;Tsukamoto, Hiroshi
    • International Journal of Fluid Machinery and Systems
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    • 제1권1호
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    • pp.121-139
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    • 2008
  • For mechanical drive steam turbines, the investigation results of corrosion fatigue phenomena in the transient zone are introduced, including basic phenomena on expansion line and actual design and damage experience. These results were analyzed from the standpoint of stress intensity during the start of cracking. In order to resolve such problems, preventive coating and blade design methods against fouling and corrosive environments are developed. Detailed evaluation test results are given for coating performance using a unique test procedure simulating fouling phenomena and washing conditions. Finally, the results of the successful modification of internals and on-line washing results on site are introduced.

Autophagy-Is it a preferred route for lifespan extension?

  • Dwivedi, Meenakshi;Ahnn, Joo-Hong
    • BMB Reports
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    • 제42권2호
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    • pp.65-71
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    • 2009
  • Autophagy, which is a process of self eating, has gained interest in the past decade due to its both beneficial and controversial roles in various biological phenomena. The discovery of autophagy genes (ATG) in yeast has led to focused research designed to elucidate the mechanism and regulation of this process. The role of autophagy in a variety of biological phenomena, including human disease, is still the subject of debate. However, recent findings suggest that autophagy is a highly regulated process with both beneficial and negative effects. Indeed, studies conducted using various model organisms have demonstrated that increased autophagy leads to an extended lifespan. Despite these findings, it is still unknown if all pathways leading to extended lifespan converge at the process of autophagy or not. Here, an overview of modern developments related to the process of autophagy, its regulation and the molecular machinery involved is presented. In addition, this review focuses on one of the beneficial aspects of autophagy, its role in lifespan regulation.

생명현상에 관한 과학적 의문 생성 과정에서 나타나는 생물학자의 두뇌 활성 양상 (The Biologists' Boon Activation Patterns during the Generation of Scientific Questions on Biological Phenomena)

  • 권용주;정진수;이준기;양일호
    • 한국과학교육학회지
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    • 제27권1호
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    • pp.84-92
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    • 2007
  • 이 연구는 생물학자들이 생물학 현상에서 과학적 의문을 생성할 때 나타나는 두뇌의 활성을 분석하고자했다. 이를 위해서 10개의 의문 생성 과제를 개발하여 8명의 생물학자들에 투입하였고, 의문 생성 과정에서 fMRl를 통해 생물학자들의 두뇌 활성을 측정하여 분석하였다. 그 결과, 방추이랑, 전안구운동 영역, 소뇌, 좌측 전두엽, 좌우측 해마와 대상이랑, 복외측전 두피질부 등이 특징적으로 활성화되었다. 이것은 과학적 의문을 생성하는 과정에서 생물학자들의 뇌는 주어진 생물학 현상을 상세히 분석하였고, 언어적 전략을 사용하였으며, 현재의 현상과 비교하기 위해서 과거의 경험상황과 선지식 등의 장기기억을 인출하고 표상했다고 할 수 있다. 특히 복외측전 두피질부의 활성은 의문 생성 과정에서 뇌가 인지적 갈등 및 부조화 단계를 거쳤음을 보여주었다고 할 수 있다.

심근세포의 동기리듬에 관한 공학적 연구 (A Study of the Factors of Synchronization Model on Myocardial Cell Rhythms)

  • 박민용
    • 대한의용생체공학회:의공학회지
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    • 제5권1호
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    • pp.33-38
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    • 1984
  • Biological rhythms are very important phenomena to generate, grow a living thing. However, the origin of rhythms are not disclosed completely until now. Eack myocardial cell has a natural rhythm of itself, and synchronization is happened when two cells are come in contact with each other. In this research, a simple synchronization model has been proposed and studied, refering to the physiological model. The changes of the synchronization rhythms in experimental results are compared with that of the model.

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Molt cycle in Neomysis awatschensis(Crustacea : Mysidacea) based on marsupial development

  • Ma, Chae-Woo;Oh, Chul-Woong;Kim, Jong-Chun
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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    • pp.317-318
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    • 2001
  • In crustacea the molting cycle is the most important physiological process affecting growth, behaviour, reproduction and population dynamics through their life span. Particularly molt cycle is closely related to reproductive cycle, and it is important to determine the successive stages of molt cycle to understand reproductive phenomena including ovarian cycle and the development of the embryos in the marsupium. (omitted)

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Concentration distributions during flow of confined flowing polymer solutions at finite concentration: slit and grooved channel

  • Hernandez-Ortiz, Juan P.;Ma, Hong-Bo;de Pablo, Juan J.;Graham, Michael D.
    • Korea-Australia Rheology Journal
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    • 제20권3호
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    • pp.143-152
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    • 2008
  • Simulations of solutions of flexible polymer molecules during flow in simple or complex confined geometries are performed. Concentrations from ultradilute up to near the overlap concentration are considered. As concentration increases, the hydrodynamic migration effects observed in dilute solution unidirectional flows (Couette flow, Poiseuille flow) become less prominent, virtually vanishing as the overlap concentration is approached. In a grooved channel geometry, the groove is almost completely depleted of polymer chains at high Weissenberg number in the dilute limit, but at finite concentration this depletion effect is dramatically reduced. Only upon inclusion of hydrodynamic interactions can these phenomena be properly captured.