• 제목/요약/키워드: mechanism

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An Emerging New Paradigm of the Control Mechanism of Cellular Functions

  • Park, Chun-Sik
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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    • pp.14-15
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    • 1999
  • The control mechanism of cellular functions has been classified into two modes: one rapid mechanism occurring within minutes by kinetic alterations of effector proteins without changing the number of effector molecules and another slow mechanism occurring over hours and days by changes in the number of effector molecules without kinetic alterations.(omitted)

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보행공간과 안정성 향상을 위한 병렬기구 보행로봇의 설계 (Design of Parallel Typed Walking Robot for Improvement of Walking Space and Stability)

  • 김치효;박근우;김태성;이민기
    • 대한기계학회논문집A
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    • 제32권4호
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    • pp.310-318
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    • 2008
  • This paper presents a parallel typed walking robot to improve walking space and stability region. The robot is designed by inserting an intermediate mechanism between upper leg mechanism and lower leg mechanism. The leg mechanism is composed of three legs and base, which form a parallel mechanism with ground. Seven different types of walking robot are invented by combining the leg mechanisms and an intermediate mechanism. Topology is applied to design the leg mechanism. A motor vector is adopted to determine Jacobian and a wrench vector is used to analyze dynamics of the robot. We explore the stability region of the robot from the reaction force of legs and compute ZMP including the holding force to contact the foot to a wall. This investigates a walking stability when the robot walks on the ground as well as on the wall. We examine the walking space generated by support legs and by swing legs. The robot has both a large positional walking space and a large orientational walking space so that it can climb from a floor up to a wall.

Design of Multilayered Suspension Mechanism for Differential Type Mobile Robot

  • Park, Jin-Ho;Roh, Se-Gon;Park, Ki-Heung;Kim, Hong-Seok;Lee, Ho-Gil;Choi, Hyouk-Ryeol
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.859-864
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    • 2003
  • This paper presents a design for the novel suspension mechanism of a two-wheeled mobile robot having two casters which is used for indoor environment. Although the indoor environment is less rough than the outdoor one, the fixed caster mechanism has some problems such as causing the robot to be immovable because robot's driving wheels do not have contact with the ground. Therefore, we tried installing a spring-damper suspension mechanism to keep driving capability and to remove pitching phenomenon. However, this suspension mechanism also has the problem, which the robot body inclined by disturbances does not return to the initial position. To deal with above problems and to accomplish desired performances, we designed the Multilayered Suspension Mechanism, which has springs and dampers working partially according to the inclined angle and angular velocity of robot body concerned with pitching. To analyze design, the equations of motion describing their dynamics were developed. Using the equations, simulation results show the improved performance. We confirm the usefulness of the Multilayered Suspension Mechanism by construction and test of a actual prototype.

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예인체의 투하 및 인양 자동화를 위한 사변형 Overboarding Mechanism의 최적설계 (Optimal Design of Quadrilateral Typed-Overboarding Mechanism for Drop/Lift Automation of Towed Object)

  • 강석정;정원지;박성학;최종갑;김효곤;이준구
    • 한국생산제조학회지
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    • 제26권1호
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    • pp.74-81
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    • 2017
  • A crane is typically used as a means to lift and load equipment or materials. A surface vessel uses a towed object for underwater activity. Such a mechanism for dropping and lifting of equipment is necessary, and is called an overboarding unit. The present study is focused on the overboarding unit used for a crane structure. This paper deals with new overboarding mechanism design and GA-based $MATLAB^{(R)}$ optimization. By using a quadrilateral link mechanism, it is possible to set the constraint function for optimizing the GA method. The optimization with $MATLAB^{(R)}$ is followed by the $SolidWorks^{(R)}$ simulation and verification. When applying the proposed mechanism, the operator is expected to have a big advantage in safety and efficiency of operations. Furthermore, the technology developed in this study will be helpful in similar circumstances and in the proposed mechanism.

에너지 효율적인 이더넷에서 개선된 LPI 제어 메커니즘 (An Enhanced LPI Control Mechanism in Energy Efficient Ethernet)

  • 이성근;장용재;유남현
    • 한국전자통신학회논문지
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    • 제7권5호
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    • pp.983-989
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    • 2012
  • IEEE 802.3az LPI 메커니즘은 전송할 데이터가 없을 경우 취침 모드로 천이하여 다수의 컴포넌트들을 저전력 상태를 유지하게 함으로써 에너지 효율성을 향상시킨다. LPI는 소량의 데이터가 주기적으로 전송되는 상황에서는 잦은 전송 모드 변환에 따른 오버헤드 때문에 에너지 효율이 크게 개선되지 못하는 문제점이 있다. 본 논문에서는 전송계층 트래픽 특성 및 네트워크 상태에 따라 LPI 모드 상태 천이를 적응적으로 수행하는 개선된 LPI 메커니즘을 제안한다. 시뮬레이션 방법에 의한 성능 분석을 통해 제안한 메커니즘이 다양한 트래픽 부하에 대해서 기존 방법보다 에너지 효율성을 향상시키는 것으로 나타났다.

웨이블릿 변환을 이용한 원자로 제어봉구동장치 동작 감시 방법 (A Monitoring Method of Movements in Control Rod Drive Mechanism using Wavelet Transform)

  • 천종민;김춘경;이종무;박민국;권순만
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.270-272
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    • 2005
  • In this paper, we proposed a new method detecting actions of some components driven by the coil excitation. Nuclear power reactors are typically controlled by the movement of several neutron-absorbing control rods into or out of the reactor core. For moving control rods, we use an electromagnetic-jack-typed mechanism, which is called Control Rod Drive Mechanism. This mechanism moves control rods by the step composed of sequential actions of components. In case any mechanical problems happen in the mechanism, the orders for the control rod movement from the higher system cannot be performed properly. This abnormal state must be monitored and the sequential actions of the components can be the monitoring target. The actions of components generate some deviations in the profiles of the currents flowing into the coils in the mechanism. We focused on this phenomena and devised a new method of detecting the actions of the components in Control Rod Drive Mechanism by using the wavelet transform for observing the current profile.

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하이브리드 데이터마이닝 메커니즘에 기반한 전문가 지식 추출 (Extraction of Expert Knowledge Based on Hybrid Data Mining Mechanism)

  • 김진성
    • 한국지능시스템학회논문지
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    • 제14권6호
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    • pp.764-770
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    • 2004
  • This paper presents a hybrid data mining mechanism to extract expert knowledge from historical data and extend expert systems' reasoning capabilities by using fuzzy neural network (FNN)-based learning & rule extraction algorithm. Our hybrid data mining mechanism is based on association rule extraction mechanism, FNN learning and fuzzy rule extraction algorithm. Most of traditional data mining mechanisms are depended ()n association rule extraction algorithm. However, the basic association rule-based data mining systems has not the learning ability. Therefore, there is a problem to extend the knowledge base adaptively. In addition, sequential patterns of association rules can`t represent the complicate fuzzy logic in real-world. To resolve these problems, we suggest the hybrid data mining mechanism based on association rule-based data mining, FNN learning and fuzzy rule extraction algorithm. Our hybrid data mining mechanism is consisted of four phases. First, we use general association rule mining mechanism to develop an initial rule base. Then, in the second phase, we adopt the FNN learning algorithm to extract the hidden relationships or patterns embedded in the historical data. Third, after the learning of FNN, the fuzzy rule extraction algorithm will be used to extract the implicit knowledge from the FNN. Fourth, we will combine the association rules (initial rule base) and fuzzy rules. Implementation results show that the hybrid data mining mechanism can reflect both association rule-based knowledge extraction and FNN-based knowledge extension.

공압 실린더 및 단순 링크기구를 이용한 충돌 보행자 보호 장치에 관한 연구 (Study on Pedestrian Protection device in collision using Pneumatic cylinder and simple link mechanism)

  • 노상현;이동렬
    • 동력기계공학회지
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    • 제12권4호
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    • pp.64-71
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    • 2008
  • This study is on pedestrian protection device using pneumatic cylinder and simple link mechanism when vehicle collide with pedestrian. This study ensured the safety space between engine and hood after it applies to simple link mechanism and pneumatic cylinder. It can absorb the damage which measure the specific device if vehicle collide with pedestrian. Combination of simple link mechanism and pneumatic cylinder was more superior than the present pedestrian protection device. Simple link mechanism could confirm superior height and survival probability than when only cylinder operated. It also ensured enough space between engine and hood. And if a cylinder is not working because of old cylinder, poor repair or damage of accident vertical cylinder would be difficult to execute because there exists the irregular space between engine and hood. If simple link mechanism operates with only one cylinder it could ensure the regular space because simple link mechanism set up at the middle of hood. So this device could confirm high safety for pedestrian.

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구형 3자유도 병렬 메커니즘의 기구학 해석 및 구현 (Kinematic Analysis and Implementation of a Spherical 3-Degree-of-Freedom Parallel Mechanism)

  • 이석희;김희국;오세민;소병록;이병주
    • 한국정밀공학회지
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    • 제22권11호
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    • pp.72-81
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    • 2005
  • A new spherical-type 3-degree-of-freedom parallel mechanism consisting of a two degree-of-freedom parallel module and a serial module is proposed. Two alternative designs for the serial sub-chain are suggested and compared. The first design employs RU joint arrangement for the serial sub chain structure. The second design incorporates a gear chain to drive the distal revolute joint of the serial sub-chain from the base platform of the mechanism. This modification significantly improves kinematic characteristics of the mechanism within its workspace. Firstly, the closed-form solutions of both the forward and the reverse position analysis are derived. Secondly, the first-order kinematic model with respect to three inputs which are located at the base is derived. Thirdly, it is confirmed through simulation that the modified mechanism has much more improved isotropic characteristic throughout the workspace of the mechanism. Lastly, the proposed mechanism is implemented to verify the results from this analysis.