• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.429-434
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• 2013

This paper proposes a CPSO (Cooperative Particle Swarm Optimization)-based MPC (Model Predictive Control) scheme to deal with formation control problem of multiple nonholonomic mobile robots. In a distributed MPC framework, each robot needs to optimize control input sequence over a finite prediction horizon considering control inputs of the other robots where their cost functions are coupled by the state variables of the neighboring robots. In order to optimize the control input sequence, a CPSO algorithm is adopted and modified to fit into the formation control problem. Experiments are performed on a group of nonholonomic mobile robots to demonstrate the effectiveness of the proposed CPSO-based MPC for multi-robot formation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.03a
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• pp.127-130
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• 1998

In this paper, we propose a method of cooperative control(T-cell modeling) and selection of group behavior strategy(B-cell modeling) based on immune system in distributed autonomous robotic system(DARS). Immune system is living body's self-protection and self-maintenance system. Thus these features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For the purpose of applying immune system to DARS, a robot is regarded as a B cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-call respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control scheme is based of clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

• Smart Structures and Systems
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• v.25 no.3
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• pp.323-335
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• 2020

Magnetorheological elastomer (MRE), a smart material, is an innovative material for base isolation system. It has magnetorheological (MR) effect that can control the stiffness in real-time. In this paper, a new hybrid base isolation system combining two electromagnetic closed circuits and the roller bearing is proposed. In the proposed system, the roller part can support the vertical load. Thus, the MRE part is free from the vertical load and can exhibit the maximum MR effect. The MRE magnetic loop is constructed in the free space of the roller bearing and forms a strong magnetic field. To demonstrate the performance of the proposed hybrid base isolation system, dynamic characteristic tests and performance evaluation were carried out. Dynamic characteristic tests were performed under the extensive range of strain of the MRE and the change of the applied current. Performance evaluation was carried out using the hybrid simulation under five earthquakes (i.e., El Centro, Kobe, Hachinohe, Northridge, and Loma Prieta). Especially, semi-active fuzzy control algorithm was applied and compared with passive type. From the performance evaluation, the comparison shows that the new hybrid base isolation system using fuzzy control algorithm is superior to passive type in reducing the acceleration and displacement responses of a target structure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.147-154
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• 2021

In this paper, the configuration and design of the test equipment are presented to examine the impact of rapid temperature change in cooling-air that may occur during the operation of the fixed wing aircraft Environmental Control System (ECS) on avionic electronic equipment. At the start of the ECS, the temperature of the air supplied by the aircraft ECS may be increased to 5.0℃ per second. In order to ensure operating of the avionic electronic equipment that is mounted on the aircraft and receives cooling-air from the ECS, testing equipment that can implement the cooling-air characteristic test environment is required. During design of test equipment was verified cooling-air rapid rate of temperature change by performing a thermal/flow analysis, performance of the test equipment implemented was verified by applying an avionic electronic equipment.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.58-66
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• 2006

Environmental Sensitivity Index Map(ESI Map) is useful information for efficient and prompt contolling of oil spill accident. Environmental sensitivity information relating to oil spill is very various, so efficient access and utilization for environmental sensitivity information at control field is required. In order to improve the efficiency of controlling accident at the field, it is necessary to building digital ESI Map and GIS program. In this study, GIS database was built to utilize environmental sensitivity information at Yeosu and Gyunggi bay. And the ESI Map program which is focused on the control job was developed. IMO/IPIECA's guide to make the ESI Map and Korea Coast Guard's guide to collect information for the control information map were referenced to capture environmental sensitivity data and build GIS database. The symbology of environmental sensitivity layers was defined and functions for supporting control job were implemented in ESI Map program. For the future works, the program in this study could be applied to ESI Map program for the whole coastal area of Korea and it could be the essential element technology in marine pollution control supporting system.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.61-67
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• 2018

This study proposes a new vibration control approach for adjacent twin structures, which is termed as viscous damper asymmetric coupling system in this paper. The proposed system takes a concept that the diagonal bracing viscous dampers are asymmetrically distributed in two buildings to break the behavior symmetry of the twin buildings and then the coupling viscous damper is additionally installed at the top floor of the two buildings to couple both buildings and interactively transfer the asymmetric behavior-caused damping forces into both buildings. These asymmetric damping distributions and interacting damping forces of the connection damper efficiently suppress the overall vibration of the damper-coupled adjacent twin buildings efficiently. Genetic algorithm (GA) based multi-objective optimization technique is adopted for optimal design of the proposed system. In the numerical example of adjacent twin 10-story building structures, the conventional control approach, that is, uniform damping distribution system (UDS) is also taken into account for comparison purpose. The optimization results verify that the proposed system either can improve the control performance over the UDS with the same damping capacity, or can save the damping capacity significantly while maintaining the similar level of control performance to the UDS.

• Journal of Animal Environmental Science
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• v.20 no.2
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• pp.57-62
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• 2014

It is very important, if necessary, to remotely monitor and control the body conditions and behavior of livestock as well as the environment of stall using ubiquitous ict, in order to improve the health and productivity of livestock. With the aim of developing a stall management system, this study investigated users' needs, analyzed them to design systems, developed a web-system and an app for stall management, then applied them to a test-bed. The use of the app developed will make it easy for livestock farmers to easily monitor and control environment of stall using their smartphones and allow them to take care of stall more efficiently.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.21-24
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• 2002

There has been a growing need for interaction between human operator and a remote system to perform a complex task in an unpredictable environment and to operate an important work at a remote distance. The interaction becomes an important parameter in the teleautonomous operation because it permits the operator to control the system at remote distance. As the environmental uncertainties to be applied are getting increased, so is the difference between the plan of the operator and the execution of the system increased. Since the operator may be difficult to know the latest information from frequently changing environment due to time-varying delays, remote system may be hard to control in accordance with the operators command. Interactive Teleautonomous Control System (ITCS) is an approach based on interactions at these environments. The ITCS can be regarded as a control system using the transmitted a system's intnetion. The interactive teleautonomous control does not mean the interaction from operators point of view only considering feedback environmental information and forward simulation but an interaction between the operator and the system that transmits or receives intentions. The proposed ITCS is based on the intention communication that transmits their intentions to each other. The ITCS can correctly control the system in accordance with the operator's intention. Using the intention communication, a system intention is helpful to the operator. In the interactive teleautonomous control, the intention communication has to be provided by the interaction between the operator and the system.

• Journal of Environmental Impact Assessment
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• v.10 no.3
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• pp.195-209
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• 2001

The objective of this study is intended to propose plans for reforming environmental impact assessment(EIA) systems by reviewing the current legal systems of EIA related laws and their implementation status in Korea, and by comparing the Korean situation to EIA systems in several foreign countries. This study tried to integrate all EIA related systems scattered over several laws into one comprehensive EIA law, and also to develop legal procedures necessary to accomplish the legislative purpose of the integrated EIA law. Therefore, I propose four reforms (1) All EIA systems should be integrated into one comprehensive EIA act. (2) Administrative plans and policies, though environmentally harmful, which are not currently subject to any prior consultation system, should be covered by the prior consultation system. (3) A screening or scoping should be adopted. (4) Widen civil participation should be encouraged and the administrative control enforcement and introduction of group litigation or citizen suits would be considered.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.63-68
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• 2011

Access-control of hazard zone in a steel manufacturing industry is studied in terms of safety management. Based on the results of risk evaluation for hazard zone, three risk zones with low, middle and high level are categorized. These zones have different color door and locking shape depending on their risk levels. At the high level, red door and key-based locking system are employed to accessed-controled path. Furthermore, tagout, lockout, interlock system for emergency stop, warning and flashing are also introduced. New standardized procedure of access-control for various hazard zones, which could help to greatly contribute to the prevention of accidents in advance, is proposed considering the risk level and the condition of given hazard zones. The standardized procedure of access-management suggested in this study will take an effective role as one of safety guide lines for hazardous workshop of manufacturing industries.