• Title/Summary/Keyword: avoid

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A Method to Adjust the Optimal Phase Angle of Resolver Excitation Signal (레졸버 여자신호의 최적 위상 조정 방법)

  • Kim, Kyung-Seo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.15 no.3
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    • pp.252-258
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    • 2010
  • If the speed measurement of resolver and the generation of PWM signals are implemented with single microcontroller, it is easy to reduce the system cost and to avoid the switching noise of inverters. To avoid the switching noise and to improve the accuracy of measurement, PWM switching and A/D sampling of the resolver should be synchronized. Phase angle of the resolver excitation signal is increased in stepwise manner, then, the output signal of the resolver is measured in each step. From the measured data, the optimal phase angle of resolver excitation signal is estimated using the least square approximation method.

The Path Planning for Mobile Robot Using the Line Segment Information (선소 정보를 이용한 로봇의 경로계획)

  • Kim, Byung-Gon;Lee, Kwae-Hi
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.514-516
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    • 1998
  • A Mobile Robot should be able to navigate safely in the workspaces without any additional human's helps. In this paper, a method to generate the safe path to avoid the unknown obstacles using the pre-knowledge of the workspaces was proposed. For the efficiency of the algorithm, it is proposed to model the obstacles as the line segments in numerical map, which can reduce the required memory size and give the simple forms. To make the environments map, we used the Hough transform and the sonar measurements is converted to the set of line segments by Hough transform. In this algorithm, the subgoals are generated to avoid the obstacles until a mobile robot arrives the final position using the proposed environmental model.

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Construction of Expression Vector for Functional Analysis of Target Protein in Streptomyces sp.

  • Lee, Yong-Jik;Ryu, Jae-Ki;Kim, Hyun-Soo
    • Biomedical Science Letters
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    • v.18 no.1
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    • pp.29-34
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    • 2012
  • Streptomycetes are gram-positive filamentous bacteria that are well-known for producing a vast array of bioactive compounds, including more than 70 % of commercially important antibiotics. For the research about Streptomyces sp., the protoplast and electroporation transformation method have been the general techniques for the construction of transformants. However, these techniques have low efficiency and are time-consuming. Another option is intergenic conjugation, which is used for DNA transfer using methylation-deficient E. coli as a DNA donor to avoid the methylated-DNA-dependent restriction systems of actinomycetes. This conjugation method has been widely improved and applied to many other actinomycetes. In this research, an effective transformation procedure for the construction of expression vector by using gateway system was established to avoid limit of restriction enzyme site for cloning of target gene based on transconjugation by Escherichia coli ET12567/pUZ8002 with a pSET152 integration vector.

Estimation of longitudinal velocity noise for rail wheelset adhesion and error level

  • Soomro, Zulfiqar Ali
    • Multiscale and Multiphysics Mechanics
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    • v.1 no.3
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    • pp.261-270
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    • 2016
  • The longitudinal velocity (forward speed) having significant importance in proper running of railway wheelset on track, depends greatly upon the adhesion ratio and creep analysis by implementation of suitable dynamic system on contamination. The wet track condition causes slip and slide of vehicle on railway tracking, whereas high speed may also increase slip and skidding to severe wear and deterioration of mechanical parts. The basic aim of this research is to design appropriate model aimed estimator that can be used to control railway vehicle forward velocity to avoid slip. For the filtration of disturbance procured during running of vehicle, the kalman filter is applied to estimate the actual signal on preferered samples of creep co-efficient for observing the applied attitude of noise. Thus error level is detected on higher and lower co-efficient of creep to analyze adhesion to avoid slip and sliding. The skidding is usually occurred due to higher forward speed owing to procured disturbance. This paper guides to minimize the noise and error based upon creep coefficient.

Gustatory Receptors Required for Avoiding the Toxic Compound Coumarin in Drosophila melanogaster

  • Poudel, Seeta;Lee, Youngseok
    • Molecules and Cells
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    • v.39 no.4
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    • pp.310-315
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    • 2016
  • Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms.

Scientometric Analysis for Pilot Study of Smart Grid (스마트 그리드 예비 연구를 위한 계량정보분석)

  • Park, Jong-Kyu;Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.1
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    • pp.97-105
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    • 2012
  • In order to avoid duplication in patents, papers and research subjects, many researchers have to review previous research work and patents with various methods. To reduce the our efforts in preview of research work, in this paper, we present scientometric analysis including Analysis of Index Level, International Cooperation Research Network, Analysis of Key Organizations and their Authors to help researchers to avoid duplication problems in field of smart grid.

A Study on Choice Behavior of Theme Park Visitors - Application of Nested Logit Model - (주제공원 이용자들의 선택행동 추정에 관한 연구 -Nested Logit Model의 적용)

  • 홍성권
    • Journal of the Korean Institute of Landscape Architecture
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    • v.24 no.4
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    • pp.96-111
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    • 1997
  • This study was carried out to identify users' choice behavior of theme parks. overland. Lotte World, Seoul Land, Dreamland and Children's Grand Park were selected as study areas. Both multinomial logic model(MNL), nested logic model(NMNL) and joint logit model wet$.$e test using a choice-based sample collected on study areas. Hausman-McFadden test showed that the MNL is not appropriate because the IIA assumption is violated. To avoid the problematic IIA assumption, the NMNL was tested. It splits similar alternatives into groups and nests separate decisions into hierarchical order to avoid the IIA assumption. Cluster analysis and discriminant analysis were conducted to find applicable nest structures. The inclusive value coefficient was 0.7788. It meant that sufficient condition of this model is met and users' choice behavior can be better understood by NMNL than MNL. The $\rho$2 value and accuracy of prediction of this model were 0.402 and 46.33% , respectively. Several comments were suggested to make the NMNL to be more reliable for future research on users' choice behavior of theme park.

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Parallel Control of Mini Ice Storage Air Conditioner Using LonWorks System (LonWorks 시스템을 이용한 소형빙축열 에어컨의 병렬 제어)

  • Kim, Hong-Ryeol;Cho, Sung-Kyu;Chung, Nam-Jong;Kim, Dae-Won
    • Proceedings of the KIEE Conference
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    • 2003.07d
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    • pp.2358-2361
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    • 2003
  • In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.

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Perception of small-obstacles using ultrasonic sensors and its avoidance method in robot (초음파센서를 이용한 로봇의 소형장애물 감지 및 회피방법연구)

  • Kim, Gab-Soon
    • Journal of Sensor Science and Technology
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    • v.14 no.2
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    • pp.101-108
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    • 2005
  • The research on the avoidance of the large-obstacles such as a wall, a large box, etc. using ultrasonic sensors has been generally progressed up to now. But the mobile robot could meet a small-obstacle such as a small plastic bottle, a small sphere, and so on in its designated path, and could be disturbed by them in the locomotion of the mobile robot. So, it is necessary to research on the avoidance of a small-obstacle. In this paper, a robot's small-obstacle perceiving system was designed and fabricated by arranging four ultrasonic sensors on the plastic plate to avoid small-obstacles. The system was installed on the upper part of the mobile robot with the slope angles between $40.7^{\circ}$ and $23.3^{\circ}$ to a horizontal line and the dynamic characteristic test of the robot was performed. As the result, it was confirmed that the mobile robot with the system could avoid small-obstacles in indoor environment safely.

Effect of Wandering Characteristics in Traffic Lanes (차로 위치가 차량의 원더링 특성에 미치는 영향 평가)

  • Jo, Myoung-Hwan;Jin, Jung-Hoon;Cho, Gyu-Tae;Kim, Nak-Seok
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.525-528
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    • 2008
  • The research was conducted to investigate the characteristics of lateral wheel path distributions (wandering) in different traffic lanes. The Wandering may affect pavement life and various distress types. To achieve results presented that the normal distribution curve with symmetry was observed in the 3-lane roads. In the case of the 3-lane road (on one direction), 50-60cm, 65-85cm, and 80-95cm for the 1st, 2nd, and 3rd lanes, respectively. In addition, the 1st lane vehicles tended to pass on the right side to avoid th opposite side vehicles, while the outside lane vehicles tended to pass on the left side to avoid the walkway.

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