• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.213-218
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• 2019

In this paper, we study autonomous navigation system for path guide system by using RFID that is enable to navigate and load in hotel. In case of a mobile robot used in a general autonomous navigation guidance system, a large amount of sensors are added to the system in order to improve the accuracy, resulting in cost problems. Therefore, to reduce the number of sensors, and to increase the accuracy and recognition rate, an autonomous driving guidance system was implemented using one of the inexpensive small micro controller units (MCU) such as Raspberry Pi3.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.399-399
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• 2000

In this paper, path generation using the sensor platform is proposed. The sensor platform is composed two electric motors which make panning and tilting motions. An algorithm fur a real path form and an obstacle length is realized using a scanning algorithm to rotating the sensors on the sensor platform. An ARV (Autonomous Robot Vehicle) is able to recognize the given path by adapting this algorithm. In order for the ARV to navigate the path flexibly, a kinematic model needed to be constructed. The kinematic model of the ARV was reformed around its body center through a relative velocity relationship to controllability, which derives from the nonholonomic characteristics. The optimal controller that is based on tile kinematic model is operated purposefully to track a reference vehicle's path. The path generation algorithm is composed of two parks. On e part is the generating path pattern, and the other is used to avoid an obstacle. The optimal controller is used for tracking the reference path which is generated by recognizing the path pattern. Results of simulation show that this algorithm for an ARV is sufficient for path generation by small number of sensors and for low cost controller.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.4
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• pp.477-484
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• 2009

An Integrated Management Platform, which plays a core role in managing u-City, intelligently control various infra-structure components by accommodating a large number of sensors and devices; and analyzing data received from these sensors and devices through wired/wireless sensor networks. In this paper, the services provided by the integrated management platform for u-City are classified into common application service, operational management service, and platform gateway service, and furthermore detailed functions for each service are defined. These functions, through their roles and information flows, will clarify the requirements of the integrated management platform, and through their addition and modification will be utilized as a reference model for the functional organization of the integrated management platform.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.905-914
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• 2016

This paper proposes a new phase current reconstruction technique for interleaved three-phase bidirectional dc-dc converters using a single current sensor. In the proposed current reconstruction algorithm, a single current sensor is employed at the dc-link, and the dc-link current information is sampled at either the peak or valley point of the pulse-width modulation (PWM) carriers regularly. From the obtained current information, all phase currents are reconstructed in a single PWM cycle. After that, the digital current controller is applied to achieve current balancing in each phase. Compare to the previous multiple current sensor method, the proposed strategy reduces the number of the current sensors in the interleaved three-phase bidirectional converter as well as reducing potential current sensing error caused by non-ideal characteristics of the multiple current sensors. The effectiveness of the proposed method is verified from the experiments based on a 3kW three-phase bidirectional converter prototype for the automotive battery charging application.

• Journal of Platform Technology
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• v.8 no.4
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• pp.11-19
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• 2020

In an autonomous driving environment, dynamic recognition of objects is essential as the situation changes in real time. In addition, as the number of sensors and control modules built into an autonomous vehicle increases, the amount of data the central control unit has to process also rapidly increases. By minimizing the output data from the sensor, the load on the central control unit can be reduced. This study proposes a dynamic object recognition algorithm solely using the embedded processor on a LiDAR sensor. While there are open source algorithms to process the point cloud output from LiDAR sensors, most require a separate high-performance processor. Since the embedded processors installed in LiDAR sensors often have resource constraints, it is essential to optimize the algorithm for efficiency. In this study, an embedded processor based object recognition algorithm was developed for autonomous vehicles, and the correlation between the size of the point clouds and processing time was analyzed. The proposed object recognition algorithm evaluated that the processing time directly increased with the size of the point cloud, with the processor stalling at a specific point if the point cloud size is beyond the threshold

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.508-514
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• 2005

This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi input and multi output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments..

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.151-156
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• 2016

The IoT technology and sensors used for collecting the environment information has rapidly increased the number and type. With the increasing need for this type of sensor effective system for selecting and testing the sensor nodes for the IoT to develop products and services. In this study, we design and implement IoT sensor testing system for IoT service and product. In order to support rapid prototyping, the proposed system provides testing and management tools for IoT sensor nodes. We analyze the requirements of the proposed system and design the system based on the functional component-specific design. Finally, we implement testing application to verify the functional elements of the proposed system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.9 s.102
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• pp.1037-1044
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• 2005

This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi-input and multi-output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block-inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments.

• Korean Journal of Artificial Intelligence
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• v.9 no.2
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• pp.29-34
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• 2021

In this paper, for efficient parking control, in an Arduino environment, an intelligent parking control prototype was implemented to provide parking control and parking guidance information using HC-SR2O4 and RC522. The main elements of intelligent parking control are vehicle recognition sensors, parking control facilities, and integrated operating software. Whether the vehicle is parked on the parking surface may be confirmed through sensor or intelligent camera image analysis. Parking control equipment products include parking guidance and parking available display devices, vehicle number recognition cameras, and intelligent parking assistance systems. This paper applies and implements ultrasonic sensors and RFID concepts based on Arduino, recognizes registered vehicles, and displays empty spaces. When a vehicle enters a parking space to handle this function, the automatic parking management system distinguishes the registered vehicle from the external vehicle through the RC522 sensor. In addition, after checking whether the parking slot is empty, the HC-SR204 sensor is displayed through the LED so that the driver can visually check it. RFID is designed to check the parking status of the server in real time and provide the driver with optimal route service to the parking slot.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.115-122
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• 2008

Mostly used sensors have wired powering and two-way cable systems. It is difficult to employ wired sensor network in ubiquitous era because of a number of sensors and cables. Therefore, sensor networks move from wired systems to wireless systems for the future. However, the power source is a critical obstacle for wireless sensornodes. This research represents the new power source which supplies energy sensor node, maintains over 10 years, and thus replaces batteries with limit of lifetime. The system with piezo materials scavenges extra energies such as vibration and acceleration from the environment. Then it converts the scavenged mechanical energy to electrical energy for powering a sensor, a controller and a circuit for regulating voltage and transmitting sensor value. This study explains the properties of piezo material through theoretical analysis and experiments, and demonstrates powering sensor and transmitting data with stored energy (35mJ) for 14 sec. The developed system provides a solution to overcome the critical problem of making up wireless sensor networks.