• Title/Summary/Keyword: genetic instability

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Implementation of the Controller for a Stable Walking of a Humanoid Robot Using Improved Genetic Algorithm (개선된 유전 알고리즘 기반의 휴머노이드 로봇의 안정 보행을 위한 제어기 구현)

  • Kong, Jung-Shik;Lee, Eung-Hyuk;Kim, Jin-Geol
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.5
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    • pp.399-405
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    • 2007
  • This paper deals with the controller for a stable walking of a humanoid robot using genetic algorithm. A humanoid robot has instability during walking because it isn't fixed on the ground, and its nonlinearities of the joints increase its instability. If controller isn't robust, the robot may fall down at the ground during walking because of its nonlinearities. To solve this problem, robust controller is required to reduce the effect of nonlinearities and to gain the good tracking performance. In this paper, motion controller that is based on fuzzy-sliding mode controller is proposed. This controller can remove the effect of the saturation by limitation of the input voltage. It also includes compensator for reducing the effect of the nonlinearity by backlash and PI controller improving the tracking performance. In here, genetic algorithm is used for searching the optimal gains of the controller. From the given controller, a humanoid robot can moved more preciously. All the processes are investigated through simulations and are verified experimentally in a real joint system for a humanoid robot.

Fast Genetic Variation among Coliphage Quasispecies Revealed by a Random Amplified Polymorphic DNA (RAPD) Analysis

  • Kwon, Oh-Sik;Lee, Jae-Yung
    • Journal of Microbiology
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    • v.34 no.2
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    • pp.166-171
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    • 1996
  • Genetic analysis was conducted on newly isolated coliphages form soil by using a RAPD assay. From the initial result, the coliphages were turned out to be different form one another but were closely related to .psi..lambda. due to the fact that they shared the samed RAPD maker in which other T phage testings failed to show. By using the primers EC01 or EC02, a fast genetic mutation of .psi.C1 was found by producing specific RAPD markers on the phages from the first filial progeny to the second filial progeny. When we made a RAPD assay with combined primers (EC01, EC05 and EC08), the genetic mutation was again confirmed in .psi.C1. The assay detection showed mutations in other coliphages such as .psi.C2 and .psi.C3 by revealing specific RAPD bands among different progeny phages, where genetic instability of the coliphages in implied.

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GENETIC POLYMORPHISMS AND CHROMOSOMAL INSTABILITY TO LUNG CANCER IN THE KOREAN POPULATIONS

  • Eom, Mi-Ok;Oh, Hye-Young;Min, Soo-Jin;Kim, Jong-Won;Park, Mi-Sun;Han, Eui-Sik;Jung, Hai-Kwan;Jong, Won-Sang;Kim, Ok-Hee
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.191-192
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    • 2001
  • Although the incidence rates of gastric cancer and liver cancer, the most common cancers in Korea, are tending decrease, lung cancer is on the increase every year as cause of cancer death as well as incidence rate in Korea. And cigarette smoke is believed to be responsible for 90% of lung cancer. Many investigators have reported an association between genetic polymorphism of cytochromes P-450 (CYPs) or glutathoine S-transferase (GSTs) and susceptibility to lung cancer.(omitted)

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A Study on the Joint Controller for a Humanoid Robot based on Genetic Algorithm (유전 알고리즘을 이용한 휴머노이드 로봇의 관절 제어기에 관한 연구)

  • Kong, Jung-Shik;Kim, Jin-Geol
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.5
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    • pp.640-647
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    • 2007
  • This paper presents a joint controller for a humanoid robot based on genetic algorithm. h humanoid robot has basically instability during walking because it isn't fixed on the ground. Moreover nonlinearities of the joints increase its instability. If one of them isn't satisfied, the robot may fall down at the ground during walking. To attack one of those problems, joint controller is proposed. It can perform tracking control preciously and reduce the effect of nonlinearities by gear, limitation of the input voltage, coulomb friction and so on. This controller is based on fuzzy-sliding mode controller (FSMC) and compensator and control gains are searched by a proposed genetic algorithm. It can reduce the effect by nonlinearities. Also, to improve the tracking performance, the proposed controller has motion controller. From the given controller, a humanoid robot can moved more preciously. Here, all the processes are investigated through simulations and it is verified experimentally in a real joint system for a humanoid robot.

Interplay between Epigenetics and Genetics in Cancer

  • Choi, Jae Duk;Lee, Jong-Soo
    • Genomics & Informatics
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    • v.11 no.4
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    • pp.164-173
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    • 2013
  • Genomic instability, which occurs through both genetic mechanisms (underlying inheritable phenotypic variations caused by DNA sequence-dependent alterations, such as mutation, deletion, insertion, inversion, translocation, and chromosomal aneuploidy) and epigenomic aberrations (underlying inheritable phenotypic variations caused by DNA sequence-independent alterations caused by a change of chromatin structure, such as DNA methylation and histone modifications), is known to promote tumorigenesis and tumor progression. Mechanisms involve both genomic instability and epigenomic aberrations that lose or gain the function of genes that impinge on tumor suppression/prevention or oncogenesis. Growing evidence points to an epigenome-wide disruption that involves large-scale DNA hypomethylation but specific hyper-methylation of tumor suppressor genes, large blocks of aberrant histone modifications, and abnormal miRNA expression profile. Emerging molecular details regarding the modulation of these epigenetic events in cancer are used to illustrate the alterations of epigenetic molecules, and their consequent malfunctions could contribute to cancer biology. More recently, intriguing evidence supporting that genetic and epigenetic mechanisms are not separate events in cancer has been emerging; they intertwine and take advantage of each other during tumorigenesis. In addition, we discuss the collusion between epigenetics and genetics mediated by heterochromatin protein 1, a major component of heterochromatin, in order to maintain genome integrity.

Genetic Stability of Magnaporthe oryzae during Successive Passages through Rice Plants and on Artificial Medium

  • Park, Sook-Young;Chi, Myoung-Hwan;Milgroom, Michael G.;Kim, Hyo-Jung;Han, Seong-Sook;Kang, Seog-Chan;Lee, Yong-Hwan
    • The Plant Pathology Journal
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    • v.26 no.4
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    • pp.313-320
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    • 2010
  • Genetic instability of the rice blast fungus Magnaporthe oryzae has been suggested as a major factor underlying the rapid breakdown of host resistance in the field. However, little information is available on the mechanism of genetic instability. In this study, we assessed the stability of repetitive DNA elements and several key phenotypic traits important for pathogenesis after serially transferring two isolates though rice plants and an artificial medium. Using isolate 70-15, we obtained a total of 176 single-spore isolates from 10 successive rounds of culturing on artificial medium. Another 20 isolates were obtained from germ tubes formed at the basal and apical cells of 10 three-celled conidia. Additionally, 60 isolates were obtained from isolate KJ201 after serial transfers through rice plants and an artificial medium. No apparent differences in phenotypes, including mycelial growth, conidial morphologies, conidiation, conidial germination, appressorium formation, and virulence, or in DNA fingerprints using MGR586, MAGGY, Pot2, LINE, MG-SINE and PWL2 as probes were observed among isolates from the same parent isolate. Southern hybridization and sequence analysis of two avirulence genes, AVR-Pita1 and AVR-Pikm, showed that both genes were also maintained stably during 10 successive generations on medium and plants. However, one reversible loss of restriction fragments was found in the telomere-linked helicase gene (TLH1) family, suggesting some telomere regions may be more unstable than the rest of the genome. Taken together, our results suggest that phenotype and genotype of M. oryzae isolates do not noticeably change, at least up to 10 successive generations on a cultural medium and in host plants.

A New Design of Fuzzy controller for HVDC system with the aid of GAs (HVDC 시스템에 대한 유전자 알고리즘을 사용한 새로운 퍼지 제어기의 설계)

  • Wang Zhong-Xian;Yang Jueng-Je;Rho Seok-Beom;Ahn Tae-Chon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.3
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    • pp.221-226
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    • 2006
  • In this paper, we study an approach to design a Fuzzy PI controller in HVDC(High Voltage Direct Current) system. In the rectifier of traditional HVDC system, turning on, turning off, triggering and protections of thyristors have lots of problems that can make the dynamic instability and cannot damp the dynamic disturbance efficiently. In order to solve the above problems, we adapt Fuzzy PI controller for the fire angle control of rectifier. The performance of the Fuzzy PI controller is sensitive to the variety of scaling factors. The design procedure dwells on the use of evolutionary computing(Genetic Algorithms, GAs). Then we can obtain factors of the Fuzzy PI controller by Genetic Algorithms. A comparative study has been performed between Fuzzy PI controller and traditional PI controller, to prove the superiority of the proposed scheme.

Optimum design of direct spring loaded pressure relief valve in water distribution system using multi-objective genetic algorithm (다목적 유전자 알고리즘을 이용한 상수관망에서 스프링 서지 완화 밸브의 최적화)

  • Kim, Hyunjun;Baek, Dawon;Kim, Sanghyun
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.2
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    • pp.115-122
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    • 2018
  • Direct spring loaded pressure relief valve(DSLPRV) is a safety valve to relax surge pressure of the pipeline system. DSLPRV is one of widely used safety valves for its simplicity and efficiency. However, instability of the DSLPRV can caused by various reasons such as insufficient valve volume, natural vibration of the spring, etc. In order to improve reliability of DSLPRV, proper selection of design factors of DSLPRV is important. In this study, methodology for selecting design factors for DSLPRV was proposed. Dynamics of the DSLPRV disk was integrated into conventional 1D surge pressure analysis. Multi-objective genetic algorithm was also used to search optimum design factors for DSLPRV.

Genetically optimized self-tuning Fuzzy-PI controller for HVDC system (HVDC 시스템을 위한 진화론적으로 최적화된 자기 동조 퍼지제어기)

  • Wang, Zhong-Xian;Yang, Jueng-Je;Ahn, Tae-Chon
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.279-281
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    • 2006
  • In this paper, we study an approach to design a self-tuning Fuzzy-PI controller in HVDC(High Voltage Direct Current) system. In the rectifier of conversional HVDC system, turning on, turning off, triggering and protections of thyristors have lots of problems that can make the dynamic instability and cannot damp the dynamic disturbance efficiently. The above problems are solved by adapting Fuzzy-PI controller for the fire angle control of rectifier.[7] The performance of the Fuzzy-PI controller is sensitive to the variety of scaling factors. The design procedure dwells on the use of evolutionary computing(Genetic Algorithms, GAs). Then we can obtain the optimal scaling factors of the Fuzzy-PI controller by Genetic Algorithms. In order to improve Fuzzy-PI controller, we adopt FIS to tune the scaling factors of the Fuzzy-PI controller on line. A comparative study has been performed between Fuzzy-PI and self-tuning Fuzzy-PI controller, to prove the superiority of the proposed scheme.

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