• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1043-1048
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• 2017

Since year 2016, in Korea, the police department started to use drones to patrol violated vehicles on the highway area. They monitor vehicle drivers who use side ways on the highway during traffic congested hours of the season, drunken drivers, or violent drivers. They use the 'Spot Mobility' method which floats the drones for 30 minute period. However, this method is inefficient since it requires manually charging batteries, gathering data, and operate drones with many numbers of policeman. Therefore, in this paper, for the efficient patrol in this purpose, I have suggested an effectively manageable network system consists of many drones as the wireless network nodes and with small numbers of policeman in a wide highway area. To accomplish this, the two topologies of effective drone patrol network systems are designed and simulated in OPNET simulator for performance evaluation.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.9-16
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• 2017

Researchers are now faced with a limited flight time of the hoverable UAV due to the sluggish technological advances of the Li-Po energy density and try to find a bypassing solution for the fully autonomous hoverable UAV mission planning. Although there are several candidate solutions, automated wireless charging is the most likely and realistic candidate and we are focusing on the autolanding strategy of the hoverable UAV in this paper since it is the main technology of it. We developed a hoverable UAV flight simulator including Li-Po battery pack simulator using MATLAB/Simulink and UAV flight and battery states are analyzed. The maximum motor power measured as 1,647 W occurs during the takeoff and cell voltage decreases down to 3.39 V during the procedure. It proves that the two Li-Po battery packs having 22 Ah and connected in series forming 12S1P are appropriate for the autolanding mission planning.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.288-294
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• 2018

The entertainment system of the aircraft has changed its paradigm in the form of using passenger electronic devices instead of using a fixed monitor. This has simplified the on-board equipment while the risk of safety has increased with the electric charging of portable electronic devices. Unlike personal portable electronic devices that do not have a transmission function, the use of Wi-Fi enabled electronic devices(T-PED) is allowed and the battery is required to be charged in the cabin. In this study, we used the NASA Aviation Safety Reporting System to investigate the effects of changes in wireless environment and entertainment service. Based on this, we analyzed the risks of personal electronic devices by sharing event occurrence cases caused by in-flight electronic equipment or passenger portable electronic devices(especially smart phones) from the viewpoint of aircraft safety management. This analysis includes identification of potential hazards and risk assessment, and finally the strategies for risk mitigation for safe use of portable electronic devices are suggested.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.11-19
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• 2007

A ubiquitous network environment is a system where the user can avail of the network's services anytime, anywhere. To establish such an environment, studies continue being conducted on wireless communication technology and mobile terminals. The company that provides such services should have an established system for authentication, authorization and charging for users. This service is referred to as Authentication, Authorization, Accounting(AAA), and its aspects have been consistently studied. On the other hand, existing studies have been promoted with regard to the authentication and efficiency of the mobile terminal. One of the method is that the mobile terminal contacts to the home authentication server through the external authentication server every time it is required and; another one is to use a medium server to provide authentication in the middle between them. Thus, this study aims to determine the best method to use ticketing, where tickets are provided through a mobile terminal, complete with authentication and authorization features. Also, as it uses ticket, it can efficiently provide mobile verification processing.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1121-1128
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• 2022

Information about the present invention is made available for business use. You are helping to use the LCD, you can't use the LCD screen. During software configuration, Raspbian was used to provide the system environment. We made our way through the menu and made our financial through play. It provides various information such as weather, weather, apps, streamer music, and web browser search function, and it can be charged. Currently, the 'Google Assistant' will be provided through the GUI within a predetermined time.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.543-554
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• 2022

In this study, the government's investment, laws, regulations, and difficulties related to IoT radio technology in the energy and medical fields are mainly analyzed. Also, plans for dissemination, technology preemption, and commercialization are derived to enhance global competitiveness. Research on ways to secure and predict radio wave application technologies in energy and medical fields, and to alleviate barriers to entry for new business operators. Analyzes the efficiency of support measures using expert groups in each energy and medical field, analyzes the utilization value of accumulated data, and proposes mid- to long-term promotion systems and support measures, as well as utilization measures of data held by external agencies related to radio waves.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.466-473
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• 2013

In this paper, a compact planar multi-loop self-resonant coil of high quality factor with a coaxial cross section is proposed for effective wireless charging. The proposed coil has high Q-factor and a resonant frequency of a coil can be easily controlled by adjusting distributed capacitance. For designing the coil, a self-inductance and a distributed capacitance are calculated theoretically. The self-inductance is calculated from the sum of the mutual energies between small circular loops that are made by dividing the cross section of the coil. To verify its properties and calculation results, the self-resonant coils are fabricated by using a coaxial cable with characteristic impedance of $50{\Omega}$. The measured frequencies are very consistent with the calculated ones. In addition, the resonant frequency can be adjusted slightly by the tuning parameter ${\gamma}$. The resonant coils are applied to a tablet PC, the Q-factors of the Tx and Rx resonant coils are 282 and 135, respectively. As a result of measurement when height between the two resonant coils is 4.4 cm, the power transfer efficiency is more than 80 % within a radius of 5 cm.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.289-298
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• 2014

Recently, the traditional paradigm in railroad technology is changing as more efficient and cost-effective electric vehicle (EV) technologies have emerged. The original concept of PRT (Personal Rapid Transit) proposed in the past has come to be regarded as unrealistic, but its feasibility is improving through the utilization of an EV platform. In particular, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. However, based on the inductive power transfer (IPT) technology, the fast charging of supercapacitors with high energy density can contribute to overcoming this technical challenge and promote the transition to electric-powered ground transportation by improving the appearance of cities. This study discusses the development process of a power supply system for PRT, including concept design, numerical analysis, and device manufacturing, along with performance predictions and evaluations. In terms of results, the system was found to meet the performance requirements for power supply modules on a test-bed.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.86-92
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• 2022

Recently, the bio-healthcare market is enlarging worldwide due to various reasons such as the COVID-19 pandemic. Among them, biometric measurement and analysis technology are expected to bring about future technological innovation and socio-economic ripple effect. Existing systems require a large-capacity battery to drive signal processing, wireless transmission part, and an operating system in the process. However, due to the limitation of the battery capacity, it causes a spatio-temporal limitation on the use of the device. This limitation can act as a cause for the disconnection of data required for the user's health care monitoring, so it is one of the major obstacles of the health care device. In this study, we report the concept of a standalone healthcare monitoring module, which is based on both triboelectric effects and electromagnetic effects, by converting biomechanical energy into suitable electric energy. The proposed system can be operated independently without an external power source. In particular, the wireless foot pressure measurement monitoring system, which is rationally designed triboelectric sensor (TES), can recognize the user's walking habits through foot pressure measurement. By applying the triboelectric effects to the contact-separation behavior that occurs during walking, an effective foot pressure sensor was made, the performance of the sensor was verified through an electrical output signal according to the pressure, and its dynamic behavior is measured through a signal processing circuit using a capacitor. In addition, the biomechanical energy dissipated during walking is harvested as electrical energy by using the electromagnetic induction effect to be used as a power source for wireless transmission and signal processing. Therefore, the proposed system has a great potential to reduce the inconvenience of charging caused by limited battery capacity and to overcome the problem of data disconnection.