• Title/Summary/Keyword: Port state control

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RCGA-Based State Feedback Control for Seesaw Systems (시소 시스템을 위한 RCGA 기반의 상태피드백 제어)

  • Ryu, Ki-Tak;So, Myung-Ok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.307-308
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    • 2007
  • In general, most physical systems are complex, highly non-linearity, affected by disturbance, incomplete knowledge, and even interactive change with the operating points. To solve this problem, the research of modem control theory and controller is proceeding. Before appling the proposed controller to the real system, however, it needs an apparatus which can verify the proposed controller for being not damaged the plant. In this paper, therefore, a RCGA-based PI-type state feedback controller using reduced-order observer is implemented and applied to the seesaw system and a series of simulation are carried out to verify the effectiveness of the control system.

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A posture control for underwater vehicle with nonholonomic constraint (비 홀로노믹 구속조건을 이용한 수중 이동체의 자세제어에 관한 연구)

  • 남택근;노영오;안병원;김철승
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.135-140
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    • 2004
  • In this paper, we study the posture control of an underwater vehicle with nonholonomic constraint. Generally, systems with nonholnomic constraints cannot be stabilized to an equilibrium points by smooth state feedback control. Therefore, we proposed a control strategy for posture control of the underwater vehicle using backstepping control. The proposed control scheme is applied to the posture control of an underwater vehicle and verified the effectiveness of control strategy by numerical simulation.

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Design of an RCGA-based Linear Active Disturbance Rejection Controller for Ship Heading Control

  • Ahn, Jong-Kap;So, Myung-Ok
    • Journal of Navigation and Port Research
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    • v.44 no.5
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    • pp.423-429
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    • 2020
  • A ship's automatic steering system is the basis for addressing control difficulties related to course-changing and course-keeping during navigation through heading angle control, and is a link in realizing unmanned and autonomous ships. This study proposes a robust RCGA-based linear active disturbance rejection controller (LADRC) design method considering environmental disturbances, measurement noise, and model uncertainties in designing a ship heading controller for use when the ship is sailing. The LADRC consisted of a transient profile, a linear extended state observer, and a PD controller. The control gains in the LADRC with the linear extended state observer were adjusted by RCGAs to minimize the integral of the time-weighted absolute error (ITAE), which is an evaluation function of the control system. The proposed method was applied to ship heading control, and its effectiveness was validated by comparing the propulsive energy loss between the proposed method and a conventional linear PD controller. The simulation results showed that the proposed method had the advantages of lower propulsive energy loss, more robustness, and higher tracking precision than the conventional linear PD controller.

A PI-type State Feedback Control of Seesaw System Using Reduced-order Observer (축소차수 관측기를 이용한 시소시스템의 Pl형 상태피드백 제어)

  • Ryu, Ki-Tak;Lee, Yun-Hyung;Yoo, Heui-Han;Jung, Byung-Gun;Kim, Jong-Su;So, Myung-Ok
    • Journal of Navigation and Port Research
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    • v.31 no.10
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    • pp.853-858
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    • 2007
  • In this paper, a seesaw system composed with a moving cart on the rail and seesaw frame is made to demonstrate the effectiveness of the control theory. The control aim is to maintain an equilibrium of seesaw frame in spite of various initial conditions and an allowable disturbance. To solve this control problem, a PI-type state feedback controller using reduced-order observer is implemented and applied to the seesaw system. The reduced-order observer can be used to estimate the state variables in the case of the limit of sensor number or the constraint on setting sensors and the cost. A series of simulation are carried out to verify the effectiveness of the control system.

A Vibration Control of the Strcture using Immune Response Algorithm (면역반응 알고리즘을 이용한 구조물의 진동제어)

  • 이영진;이권순
    • Journal of Korean Port Research
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    • v.13 no.2
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    • pp.389-398
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    • 1999
  • In the biological immunity, the immune system of organisms regulates the antibody and T-cells to protect the attack from the foreign materials which are virus, germ cell, and other antigens, and supports their stable state. It has similar characteristics that has the adaptation and robustness to overcome disturbances and to control the plant of engineering application. In this paper, we build a model of the T-cell regulated immune response mechanism. We have also designed an immune response controller(IRC) focusing on the T-cell regulated immune response of the biological immune system that include both a help part to control the response and a suppress part to adjust system stabilization effect. We show some computer simulation to control the vibration of building structure system with strong wind forces excitation also demonstrate the efficiency of the proposed controller for applying a practical system even with existing nonlinear terms.

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Two-port machine model for discrete event dynamic systems (이산현상 시스템을 위한 두개의 입력을 가진 모델)

  • 이준화;권욱현
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.212-217
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    • 1992
  • In this paper, a two ports machine(TPM) model for discrete event dynamic systems(DEDS) is proposed. The proposed model is a finite state machine which has two inputs and two outputs. Inputs and outputs have two components, events and informations. TPM is different from other state machine models, since TPM has symmetric input and output. This symmetry enables the block diagram representation of the DEDS with TPM blocks, summing points, multiplying points, branch points, and connections. The graphical representation of DEDS is analogous to that of control system theory. TPM has a matrix representation of its transition and information map. This matrix representation simplifies the analysis of the DEDS.

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A Study on Ships of KRS Registered the analyses of Detentions for Port State Control (한국선급 입급선 항만국통제의 출항정지 분석에 관한 연구)

  • IM, Myeong-Hwan;LEE, Chang-Hyun;SIN, Ho-Sig
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.1
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    • pp.34-46
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    • 2016
  • This study analyzes inspection results of ships by Port State Control. Particularly, this research focuses on a detention trend of vessels that registered to Korean Register of Shipping. In order to conduct this research, we have searched 170 ships that got a detention with a Code-30 within recent 46 months period. The deficiencies of the detentions are inspected by ship types, ship years, flags, ports inspected, and criteria. Moreover, we categorized the deficiencies for the detentions into 17 types for internal and external inspections. As the results of the comparison study, bulk and general cargo carriers dominate the portion of detentions by almost 66 percent. Self-induced detention due to a lack of preparation by crews and company support are the main reasons of repeated detentions from the same type ships. Ships between six and ten years old show the lowest detention rate by 4 percent whereas ships less than five years old generate the highest detention rate by 22 percent. The main categories of the detentions from ships less than 5 years old are a lack of documentation and certification, and the clues support our opinion that owners and crews may neglect to prepare the inspections because their strong confidence for the ship condition due to young ship age. As a result of a great effort of Korean government and shipping companies to reduce a detention rate, the detention rate has been recently reduced to 0.3 percent. The results also require companies with the flag of convenience ships to spend more effort to reduce the detention rate, too. We expect that using social networking service by Korea Register will lower the detention rate by sharing relevant information real-time to ships and owners.

A Study on the Efficient Operation of VTS in Inchon (인천항 VTS의 효율적인 운영방안에 관한 연구)

  • 김상환;박진수
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10b
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    • pp.11-25
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    • 1998
  • Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

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Current Status and Improvement Measures for the Port State Control of Foreign Vessels in Domestic Port Calls (국내 기항 외국적 외항선 항만국통제 현황 및 개선방안)

  • Jeong, Kyu-Min;Hwang, Je-Ho;Kim, Si-Hyun
    • Journal of Navigation and Port Research
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    • v.46 no.4
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    • pp.338-343
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    • 2022
  • As the revitalization of the global maritime industry continues, the number of foreign ships navigating the maritime territories of maritime neighboring countries has rapidly increased. However, large-scale marine accidents have occurred, caused by the insufficient establishment of a system for management and operation relative to vessels' safety-condition. To address that, the IMO has granted the right to exercise port state control, especially for foreign vessels, to countries with jurisdiction over maritime territories with strengthening regulations and guidelines. In particular, the Republic of Korea, as a member of the TOKYO MOU, is conducting PSC, but as of 2020, the proportion of foreign ships was three times higher than that of national ships that called in domestic ports. However, the inspection rate was low at 9% which has not met the recommended level by the TOKYO MOU. Thus, this study conducted an IPA analysis as well as content analysis, by collecting the practical opinions and views of PSCO through objective questionnaires and written expert interviews, for improving the efficiency and effectiveness of domestic PSC. As a result, it was derived that the importance and performance related to human factors such as life on board, working environment, and response to safety accidents should be improved in to raise the quality of PSC inspection. Additionally, the work environment and performance of PSC in domestic ports for foreign vessels could be improved, if multifaceted support bases are established, for administrative unification of related tests for PSC, recruitment of PSCO, activation of the defection-reporting system, reorganization of the PSC execution group, etc.

Circuit Design and Simulation Study of an RSFQ Switch Element for Optical Network Switch Applications (광 네트워크 스위치 응용을 위한 RSFQ Switch의 회로 설계 및 시뮬레이션)

  • 홍희송;정구락;박종혁;임해용;장영록;강준희;한택상
    • Progress in Superconductivity
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    • v.5 no.1
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    • pp.13-16
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    • 2003
  • In this work, we have studied about an RSFQ (Rapid Single Flux Quantum) switch element. The circuit was designed, simulated, and laid out for mask fabrication. The switch cell was composed of a D flip-flop, a splitter, a confluence buffer, and a switch core. The switch core determined if the input data could pass to the output. “On” and o“off” controls in the switch core could be possible by utilizing an RS flip-flop. When a control pulse was input to the “on” port, the RS flip-flop was in the set state and passed the input pulses to the output port. When a pulse was input to the “off” port, the RS flip-flop was in the reset state and prevented the input pulses from transferring to the output port. We simulated and optimized the switch element circuit by using Xic, WRspice, and Julia. The minimum circuit margins in simulations were more than $\pm$20%. We also performed the mask layout of the circuit by using Xic and Lmeter.

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