• Title/Summary/Keyword: Modification function

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Salsolinol, a tetrahydroisoquinoline-derived neurotoxin, induces oxidative modification of neurofilament-L: protection by histidyl dipeptides

  • Kang, Jung-Hoon
    • BMB Reports
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    • v.45 no.2
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    • pp.114-119
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    • 2012
  • Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is a compound derived from dopamine metabolism and is capable of causing dopaminergic neurodegeneration. Oxidative modification of neurofilament proteins has been implicated in the pathogenesis of neurodegenerative disorders. In this study, oxidative modification of neurofilament-L (NF-L) by salsolinol and the inhibitory effects of histidyl dipeptides on NF-L modification were investigated. When NF-L was incubated with 0.5 mM salsolinol, the aggregation of protein was increased in a time-dependent manner. We also found that the generation of hydroxyl radicals (${\bullet}OH$) was linear with respect to the concentrations of salsolinol as a function of incubation time. NF-L exposure to salsolinol produced losses of glutamate, lysine and proline residues. These results suggest that the aggregation of NF-L by salsolinol may be due to oxidative damage resulting from free radicals. Carnosine, histidyl dipeptide, is involved in many cellular defense processes, including free radical detoxification. Carnosine, and anserine were shown to significantly prevent salsolinol-mediated NF-L aggregation. Both compounds also inhibited the generation of ${\bullet}OH$ induced by salsolinol. The results indicated that carnosine and related compounds may prevent salsolinol-mediated NF-L modification via free radical scavenging.

A Study on the Optimum Modification of Dynamic Characteristics of Stiffened Plate Structure of Ship (선박의 보강판 구조물의 동특성의 최적 변경법에 관한 연구)

  • 박성현;박석주;고재용
    • Journal of the Korean Institute of Navigation
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    • v.25 no.1
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    • pp.45-52
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    • 2001
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization, finite element method(FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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The study on the military utilization of weather modification techniques and inducing their research priority (기상조절기술의 군사적 활용방안과 연구 우선순위 도출에 관한 연구)

  • Han, Seung Jo;Shin, Jin
    • Convergence Security Journal
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    • v.18 no.2
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    • pp.77-88
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    • 2018
  • The purposes of this paper are to research the military utilization of weather modification techniques and to induce their research priority when considering the Korean Peninsular environment and technical level. To achieve these goals, the advantages and disadvantages of weather modification technologies have been discussed, and the evaluation index evaluation was derived through the Delphi method, and the weight of the evaluation index and the final research priority were induced through analytic hierarchical process. Analysis shows that the ionospheric modulation technology has the highest priority in terms of effectiveness as a weapon system and compatibility in the Korean Peninsula environment. It is expected that Korean ionosphere modification can disturb C4ISR function of the enemy and guarantee ours reliably when operating PGM, military satellite, surveillance & reconnaissance equipments, etc. Other weather modification technologies except for ionosphere modification should be developed gradually in that potential threat can be expanded to neighboring countries after the Unification of the Korea.

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A Fuzzy Traffic Controller Considering Spillback on Crossroads

  • Park, Wan-Kyoo;Lee, Sung-Joo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.1-5
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    • 2001
  • In this paper, we propose a fuzzy traffic controller that is able to cope with traffic congestion appropriately. In order to consider such situation as loss of green time caused by spillback of upper crossroad, it imports a degree of traffic congestion of upper roads which vehicles on a crossroad are to proceed to. We constructed the equal-partitioned fuzzy traffic controller that uses the membership functions of the same size and shape, and modified the size and shape, and modified the size and shape of its membership functions by the membership function modification algorithm. In experiment, we compared and analyzed the fixed signal controller, the fuzzy traffic controller with the membership of the same size and shape, and the modified fuzzy traffic controller by using the delay time, the proportion of entered vehicles to occurred vehicles and the proportion of passed vehicles to entered vehicles. As a result of experiment, the modified fuzzy controller showed more enhanced performance than others.

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Performance Improvement of the FLC by Membership Function Modification Algorithm (소속함수 수정 알고리즘에 의한 퍼지 제어의 성능 향상)

  • Choe, Wan-Gyu;Jeong, Mun-Jae
    • The KIPS Transactions:PartB
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    • v.8B no.2
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    • pp.123-129
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    • 2001
  • 본 연구에서는 전문가와 운전자의 제어 지식을 더 정확하게 표현하여 퍼지 논리 제어기의 성능을 향상시킬 수 있는 소속함수 수정 알고리즘을 제안한다. 제안된 알고리즘은 제어지식을 더 정확히 표현할 수 있도록 직관적인 지식과 경험으로부터 유추된 대략적인 제어지식을 평가기준으로 하고 입출력 데이터 클러스터링에 의해 소속함수의 형태와 위치를 수정한다. 제안된 방법을 수위 조절 모델과 교통신호 제어 모델에 적용한 실험을 통해서, 제안된 알고리즘이 기존 제어기의 성능을 향상시킬 수 있고, 퍼지 제어기에서 언어적 변수에 대한 구간 설정의 어려움을 해결할 수 있음을 알 수 있었다.

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Structural Dynamic Optimization of Diesel Generator systems Using Genetic Algorithm(GA) (유전자 알고리즘을 이용한 선박용 디젤발전기 시스템의 동특성 해석 및 최적화)

  • 이영우;성활경
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.3
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    • pp.99-105
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    • 2000
  • For multi-body dynamic problems. especially coalescent eigenvalue problems with multiobjective optimization, the design sensitivity analysis is too much complicated mathematically and numerically. Therefore, this article proposes a new technique for structural dynamic modification using a mode modification and homologous structures design method with Genetic Algorithm(GA). In this work, the homologous structure of the resiliently mounted multi-body for marine diesel generator systems is studied and the problem is treated as a combinational optimization problem using the GA. In GA formulation, fitness is defined based on penalty function approach. That include homology, allowable stress and minimum weight of common plate.

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Structural Dynamic Optimization Using a Genetic Algorithm(GA) (유전자 알고리즘(GA)을 이용한 구조물의 동적해석 및 최적화)

  • 이영우;성활경
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.5
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    • pp.93-99
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    • 2000
  • In many dynamic structural optimization problems, the goal is to reduce the total weight of the structure without causing the resonance. Up to now, gradient informations(i.e., design sensitivity) have been used to achieve the goal. For some class of dynamic problems, especially coalescent eigenvalue Problems with multiobjective optimization, the design sensitivity analysis is too much complicated mathematically and numerically. Therefore, this article proposes a new technique fur structural dynamic modification using a mode modification method with Genetic Algorithm(GA). In GA formulation, fitness is defined based on penalty function approach. Design variables are iteratively improved by using genetic algorithm. Two numerical examples are shown, (ⅰ) a cantilevered plate, and (ⅱ) H-shaped structure. The results demonstrate that the proposed method is highly efficient.

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Development of CFD Based Stern Form Optimization Method (CFD 를 이용한 선미선형 최적화 기법 개발)

  • Kim, Hee-Jung;Chun, Ho-Hwan;Choi, Hee-Jong
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.6
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    • pp.564-571
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    • 2007
  • In the present study, stern form optimization has been carried out using computational fluid dynamics (CFD) techniques. The viscous pressure drag has been minimized to optimize stern shape. Parametric modification function has been used to modify the shape of the hull. By the use of the parametric modification function and algebraic scheme to grid manipulation, the initial ship geometry was easily deformed according to change of design parameters. For purpose of illustration, KRISO 319K VLCC (KVLCC) is chosen for example ship to demonstrate stern form optimization. The numerical results indicate that the optimized hull yields a reduction in viscous resistance.

Shape Optimization of a Thomson Coil Actuator for Fast Response Using Topology Modification

  • Li, Wei;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.330-335
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    • 2012
  • The shape optimization of a Thomson coil actuator used in an arc eliminator is done for fast response by adopting topology modification method. The displacement of the plate in a fixed calculation time is taken as the objective function. The objective function and contribution factor are calculated by using an adaptive equivalent circuit method which has been proved accurate and efficient. Both shape optimization and performance analysis are accomplished based on the segmentation of plate. Through the refinement of the sensitive segments a precise optimal plate shape can be obtained. The effectiveness of the proposed method is proved by the comparison of results before and after the shape optimization.

Shape Optimization of a Thomson Coil Actuator for Fast Response Using Topology Modification

  • Li, Wei;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.7 no.1
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    • pp.58-63
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    • 2012
  • The shape optimization of a Thomson coil actuator used in an arc eliminator is done for fast response by adopting topology modification method. The displacement of the plate in a fixed calculation time is taken as the objective function. The objective function and contribution factor are calculated by using an adaptive equivalent circuit method which has been proved accurate and efficient. Both shape optimization and performance analysis are accomplished based on the segmentation of plate. Through the refinement of the sensitive segments a precise optimal plate shape can be obtained. The effectiveness of the proposed method is proved by the comparison of results before and after the shape optimization.