• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1327-1332
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• 2011

In the mobile meteorological information services, an existing sensor system should be expanded to serve precise information. This is because of large cost problem to add the existing sensors. This thesis proposes a system architecture to construct scalable mobile meteorological information services and suggests mobile phone, sensor network, and public traffic vehicle as expended sensors. The proposed scalable sensors are compared each other and analysed the results to evaluated their strength and weakness. In this system, based on the characteristics of the sense data collected at server, a data processing methods are proposed to support efficient query processing. The proposing data processing methods have several benefits. They compress some data volume sensed by various sources on some area at some time to a logical unit. Still it could preserve same services quality.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.237-246
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• 2022

This paper proposes a method to adjust the turn ratio of a transformer for the high-efficiency operation of an LLC converter with a wide input range in a wired/wireless integrated charging system for electric vehicles. The characteristics of the inductive power transfer converter in the integrated charging system are analyzed to design the LLC converter, and the DC-link voltage range is derived. The aspect of voltage gain following each parameter of the LLC converter is analyzed, and the resonant network and transformer are designed. Based on the designed parameters, the feasibility of the design and control method is verified by implementing the operation of the LLC converter according to the DC-link and battery voltages.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.199-203
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• 2017

In this paper, we developed an underwater localization system for underwater robot docking using the electromagnetic wave attenuation model. Electromagnetic waves are generally known to be impossible to use in water environment. However, according to the conclusions of the previous studies on the attenuation characteristics in underwater, the attenuation pattern is uniform and its model was accurately proposed and verified in 3-dimensional space via the omnidirectional antenna. In this paper, a docking structure and localization sensor system are developed for a widely used cone type docking mechanism. First, we fabricated electromagnetic wave range sensor transmit modules. And a mobile sensor node is equipped with unmanned underwater vehicle(UUV)s. The mobile node senses the four different signal strength (RSS: Received Signal Strength) from fixed nodes, and the obtained RSS data are transformed to each distance information using the 3-Dimensional EM wave attenuation model. Then, the relative localization between the docking area and underwater robot can be achieved according to optimization algorithm. Finally, experimental results show the feasibility of the proposed localization system for the docking induction by comparing the errors in the actual position of the mobile node and the theoretical position through the model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.47-56
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• 1998

This paper describes a moving path generation method for the Autonomous vehicles (AV) to search for paths in an unknown environment by using fixed obstacle information. Algorithms for the AV which were recently proposed have some problems, so it was difficult to utilize these algorithms in the real world. The purpose of this research is to examine the applicability of real-time control and efficient improvement by reducing calculation iterations. In the network which is constructed by the cell-decomposition method, a gate is installed in each cell. By verifying the possibility of gate pass-over, the number of cells which should be considered to find the solution can be reduce. Therefore, algorithm iterations can be dramatically improved. In this paper we have proven that path-generated algorithms are efficient by using simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.238-245
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• 2023

As technologies have been more quickly developed in this 4th Industry Revolution era, their application to defense industry has been also growing. With these much advanced technologies, we attempt to use Manned-Unmanned Teaming systems in various military operations. In this study, we consider the Location-Routing Problem for reconnaissance surveillance missions of the maritime manned-unmanned surface vehicles. As a solution technique, the two-phase method is presented. In the first location phase, the p-median problem is solved to determine which nodes are used as the seeds for the manned vehicles using Lagrangian relaxation with the subgradient method. In the second routing phase, using the results obtained from the location phase, the Vehicle Routing Problems are solved to determine the search routes of the unmanned vehicles by applying the Location Based Heuristic. For three network data sets, computational experiments are conducted to show the performance of the proposed two-phase method.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.411-418
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• 2003

The proposed system in this paper uses a camera attached to a mobile device in order to inquire a car and track its location anywhere. To do this, the system recognizes and verifies license plates on the front and back of a cu. The plates are scanned by the camera attached to a mobile device. The technology enables us to detect a car registration number and to transmit the number along with the location of the device to a server through a wireless communication network. The information of a car obtained through the terminal is encoded and transmitted to a server in a remote place through a wireless communication network also. The car registration number and its location information are decoded and transmitted as a text to the server in a remote place. In order to track a user´s location through spatial relative distance estimated in real-time, the server uses the spatial and attribute information which are the most prior to the desired data value. With this property information, the right location can be calculated.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.122-124
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• 2008

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. In order to maximize the efficiency in such applications, this paper proposes the Adaptive-FNIS(Fuzzy Neural Network Inference System). The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal d-axis current $i_d$. This paper considers the parameter variation about the motor operation. The operating characteristics controlled by efficiency optimization control are examined in detail.

• The Journal of Information Systems
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• v.21 no.3
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• pp.99-116
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• 2012

As a way to allocate lots of orders to many participants for vehicle allocation problem, this study has used an agent negotiation based reverse auction model. This agent negotiation provides coordination functions allowing all participants to make a profit, and accomplishing Pareto optimum solution from the viewpoint of a whole trucking cargo transportation network. In order to build a strategic cooperation relationship based on information sharing, this agent negotiation provides a coordination mechanism in which all the participants including consignors, brokerage firms, and car owners are able to attain their own profits, and also that ensure a competitive market. This study has tried to prove that the result of an agent-based negotiation is the Pareto optimal solution under the present market environment. We established a mathematical formulation for a comparison with the Integer Programming model, and analysing e-Marketplace, structure of shipping expenses and brokerage system in the trucking cargo transportation industry.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.5
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• pp.422-428
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• 2007

This paper presents a neural network based adaptive control approach to a reconfigurable flight control law that keeps handling qualities in the presence of faults or failures to the control surfaces of an aircraft. This approach removes the need for system identification for control reallocation after a failure and the need for an accurate aerodynamic database for flight control design, thereby reducing the cost and time required to develope a reconfigurable flight controller. Neural networks address the problem caused by uncertainties in modeling an aircraft and pseudo control hedging deals with the nonlinearity in actuators and the reconfiguration of a flight controller. The effect of the reconfigurable flight control law is illustrated in results of a nonlinear simulation of an unmanned aerial vehicle Durumi-II.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.83-91
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• 2012

In recent days, the study on hybridization of the heavy-duty is going on, actively. Especially, the improvement of fuel economy can be maximized in the intra-city bus because it drives the fixed route. For developing the hybrid electric intra-city bus, optimized control strategy which is possible to be applied with real vehicle is necessary. If the real-time control strategy is developed based on the HILS, it is possible to verify the real-time ability and fail-safety function which has the vehicle stay in safe state when the functional errors are occurred. In this study, the HILS system of series hybrid electric intra-city bus is developed to verify the real time control strategy and the fail-safety functions. The main objective of the paper is to build the HILS system for verifying the control strategy (rule-based control) which is implemented to reflect the Dynamic Programming results and fail-safety functions.