• 제목/요약/키워드: firefly

검색결과 146건 처리시간 0.023초

Developmental Characteristics and Life History of the Korean Native Firefly, Pyrocoelia rufa

  • Kim, Jong-Gill;Kim, Keun-Young;Choi, Young-Cheol;Choi, Ji-Young;Kim, Sam-Eun;Jin, Byung-Rae;Lee, Sang-Mong;Lee, Jong-Eun;Lee, Ki-Yeol;Lee, Sang-Ho
    • 한국잠사학회:학술대회논문집
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    • 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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    • pp.62-62
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    • 2003
  • The Korean native firefly, P. rufa, is widely distributed in Korea and only at Tsushima in the case of Japan. P. rufa is known to occur in various habitats such as stream area, wet fields and mountain area. Development and life history of the Korean native firefly, Pyrocoelia rufa, were investigated throughout the indoor rearing. (omitted)

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Amyloid Polymorphism of α-Synuclein Induced by Active Firefly Luciferase

  • Yang, Jee Eun;Hong, Je Won;Kim, Jehoon;Paik, Seung R.
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.425-430
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    • 2014
  • Amyloidogenic proteins often exhibit fibrillar polymorphism through alternative assembly processes, which has been considered to have possible pathological implications. Here, firefly luciferase (LUC) is shown to induce amyloid polymorphism of ${\alpha}$-synuclein, the major constituent of Lewy bodies found in Parkinson's disease, by acting as a novel template. The drastically accelerated fibrillation kinetics of ${\alpha}$-synuclein with LUC required the nucleation center produced by the active enzyme of LUC. Fluorescent dye binding, transmission electron microscopy, and Fourier transformed infrared spectroscopy revealed the morphologically distinctive amyloid fibrils of ${\alpha}$-synuclein prepared in the absence or presence of LUC. As the altered morphological characteristics became inherent to the mature fibrils, those properties were inherited to next-generations via nucleation-dependent fibrillation process. The seed control, therefore, would be an effective means to modify amyloid fibrils with different biochemical characteristics. In addition, the LUC-directed amyloid fibrillar polymorphism also suggests that other cellular biomolecules including enzymes in general are able to diversify amyloid fibrils, which could be self-propagated with diversified biological activities, if any, inside cells.

The effect of surface charge balance on thermodynamic stability and kinetics of refolding of firefly luciferase

  • Khalifeh, Khosrow;Ranjbar, Bijan;Alipour, Bagher Said;Hosseinkhani, Saman
    • BMB Reports
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    • 제44권2호
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    • pp.102-106
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    • 2011
  • Thermodynamic stability and refolding kinetics of firefly luciferase and three representative mutants with depletion of negative charge on a flexible loop via substitution of Glu by Arg (ER mutant) or Lys (EK mutant) as well as insertion of another Arg in ER mutants (ERR mutant) was investigated. According to thermodynamic studies, structural stability of ERR and ER mutants are enhanced compared to WT protein, whereas, these mutants become prone to aggregation at higher temperatures. Accordingly, it was concluded that enhanced structural stability of mutants depends on more compactness of folded state, whereas aggregation at higher temperatures in mutants is due to weakening of intermolecular repulsive electrostatic interactions and increase of intermolecular hydrophobic interactions. Kinetic results indicate that early events of protein folding are accelerated in mutants.

Power System Oscillations Damping by Robust Decentralized DFIG Wind Turbines

  • Surinkaew, Tossaporn;Ngamroo, Issarachai
    • Journal of Electrical Engineering and Technology
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    • 제10권2호
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    • pp.487-495
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    • 2015
  • This paper proposes a new robust decentralized power oscillation dampers (POD) design of doubly-fed induction generator (DFIG) wind turbine for damping of low frequency electromechanical oscillations in an interconnected power system. The POD structure is based on the practical $2^{nd}$-order lead/lag compensator with single input. Without exact mathematical model, the inverse output multiplicative perturbation is applied to represent system uncertainties such as system parameters variation, various loading conditions etc. The parameters optimization of decentralized PODs is carried out so that the stabilizing performance and robust stability margin against system uncertainties are guaranteed. The improved firefly algorithm is applied to tune the optimal POD parameters automatically. Simulation study in two-area four-machine interconnected system shows that the proposed robust POD is much superior to the conventional POD in terms of stabilizing effect and robustness.

Topology optimization of nonlinear single layer domes by a new metaheuristic

  • Gholizadeh, Saeed;Barati, Hamed
    • Steel and Composite Structures
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    • 제16권6호
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    • pp.681-701
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    • 2014
  • The main aim of this study is to propose an efficient meta-heuristic algorithm for topology optimization of geometrically nonlinear single layer domes by serially integration of computational advantages of firefly algorithm (FA) and particle swarm optimization (PSO). During the optimization process, the optimum number of rings, the optimum height of crown and tubular section of the member groups are determined considering geometric nonlinear behaviour of the domes. In the proposed algorithm, termed as FA-PSO, in the first stage an optimization process is accomplished using FA to explore the design space then, in the second stage, a local search is performed using PSO around the best solution found by FA. The optimum designs obtained by the proposed algorithm are compared with those reported in the literature and it is demonstrated that the FA-PSO converges to better solutions spending less computational cost emphasizing on the efficiency of the proposed algorithm.

A Study on Parameter Estimation for General Aviation Canard Aircraft

  • Kim, Eung Tai;Seong, Kie-Jeong;Kim, Yeong-Cheol
    • International Journal of Aeronautical and Space Sciences
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    • 제16권3호
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    • pp.425-436
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    • 2015
  • This paper presents the procedures used for estimating the stability and control derivatives of a general aviation canard aircraft from flight data. The maximum likelihood estimation method which accounts for both process and measurement noise was used for the flight data analysis of a four seat canard aircraft, the Firefly. Without relying on the parameter estimation method, several aerodynamic derivatives were obtained by analyzing the steady state flight data. A wind tunnel test, a flight test of a 1/4 scaled remotely controlled model aircraft, and the prediction of aerodynamic coefficients using the USAF Stability and Control Digital Data Compendium (DATCOM), Advanced Aircraft Analysis (AAA), and Computer Fluid Dynamics (CFD) were performed during the development phase of the Firefly and the results were compared with flight determined derivatives of a full scaled flight prototype. A correlation between the results from each method could be used for the design of the canard aircraft as well as for building the aerodynamic database.

Theoretical Study of the Relationships between Excited State Geometry Changes and Emission Energies of Oxyluciferin

  • Li, Zhong-Wei;Min, Chun-Gang;Ren, Ai-Min;Guo, Jing-Fu;Goddard, John D.;Feng, Ji-Kang;Zuo, Liang
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.895-900
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    • 2010
  • In order to find a relationship between firefly luciferases structure and bioluminescence spectra, we focus on excited substrate geometries which may be affected by rigid luciferases. Density functional theory (DFT) and time dependent DFT (TDDFT) were employed. Changes in only six bond lengths of the excited substrate are important in determining the emission spectra. Analysis of these bonds suggests the mechanism whereby luciferases restrict more or less the excited substrate geometries and to produce multicolor bioluminescence.

Adaptive Firefly Algorithm based OPF for AC/DC Systems

  • Babu, B. Suresh;Palaniswami, S.
    • Journal of Electrical Engineering and Technology
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    • 제11권4호
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    • pp.791-800
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    • 2016
  • Optimal Power Flow (OPF) is an important operational and planning problem in minimizing the chosen objective functions of the power systems. The recent developments in power electronics have enabled introduction of dc links in the AC power systems with a view of making the operation more flexible, secure and economical. This paper formulates a new OPF to embrace dc link equations and presents a heuristic optimization technique, inspired by the behavior of fireflies, for solving the problem. The solution process involves AC/DC power flow and uses a self adaptive technique so as to avoid landing at the suboptimal solutions. It presents simulation results of IEEE test systems with a view of demonstrating its effectiveness.

하이브리드 메타휴리스틱 기법을 사용한 트러스 위상 최적화 (Truss Topology Optimization Using Hybrid Metaheuristics)

  • 이승혜;이재홍
    • 한국공간구조학회논문집
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    • 제21권2호
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    • pp.89-97
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    • 2021
  • This paper describes an adaptive hybrid evolutionary firefly algorithm for a topology optimization of truss structures. The truss topology optimization problems begins with a ground structure which is composed of all possible nodes and members. The optimization process aims to find the optimum layout of the truss members. The hybrid metaheuristics are then used to minimize the objective functions subjected to static or dynamic constraints. Several numerical examples are examined for the validity of the present method. The performance results are compared with those of other metaheuristic algorithms.