• Journal of Advanced Navigation Technology
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• v.14 no.4
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• pp.489-494
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• 2010

According to the recent increase in air traffic more efficient air traffic control automation is required. Aeronautical traffic environment is different from the common traffic environment since it exist controller for control of aircraft And controller have to control jurisdiction hand-off by manual when aircraft move to the other sector. This paper proposes the automatic control jurisdiction hand-off algorithm for efficient air traffic flow management. It is sector distinction algorithm that aircraft move sector to the other sector it recognized sector and then give permission to authorized controller. As a simulation result, so unlilke simply manual control sector hand-off of existing algorithm. we confirmed that proposed algorithm in this paper can do air traffic control more efficiently by performing automatic aircraft. control sector hand-off.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.1
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• pp.43-52
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• 2018

This paper presents the performance of a Phase Shift Full Bridge (PSFB) converter with inductive load and a new current control scheme to improve dynamic response of output current with various inductive loads. Enhanced dynamic model is used which includes leakage inductance and inductive load. Effect of changing of inductive load was analyzed in detail. Proposed current control scheme is designed based on phase margin specifications. As a result, the proposed current control scheme helps to improve the dynamic response in comparison with the existing current control scheme. The performance of the designed controller is verified by a 500 A PSFB converter. The results will be utilized for high current applications with high inductive load such as superconducting devices.

• Journal of KIISE
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• v.44 no.6
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• pp.601-606
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• 2017

Recently, we have frequently encountered flying drones with the growth of drone industry. However, it is difficult for a driver to stabilize the motor speed of drones, since the voltage of a Lithium polymer battery used in drones may suddenly drop or rise when its power is exhausted. The instability of the motor speed precludes the drone from maintaining a flight altitude, so that the fuselage of a drone performs ascending and descending repeatedly. For solving this problem, existing techniques either add a compensator considering voltage drop of battery or change the control model. Since these techniques use hardware-implemented modules or depend on motor type and experimental results, there is a problem that new suitable modules should be implemented in accordance with the used motor of the fuselage. For solving this problem, in this paper, we implement a motor speed controller in the firmware of drones by considering voltage drop of battery to enhance drone flight stability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.491-498
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• 2016

The software defined networks implement a software network control plane, which is physically separated from the data plane. For wide area software defined network deployments, multiple controllers are required, and the placement of these controllers influences importantly the performance of the software defined networks. This paper proposes a Tabu search algorithm, which is one of the meta heuristic algorithms, for an efficient controller placement in software defined networks. In order to efficiently obtain better results, we propose new neighborhood generating operations, which are called the neighbor position move and the neighbor number move, of the Tabu search algorithm. We evaluate the performances of the proposed algorithm through some experiments in terms of the minimum latency and the execution time of the proposed algorithm. The comparison results show that the proposed algorithm outperforms the existing genetic algorithm and random method under various conditions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.85-90
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• 2015

Work environments within the firm with a concept of mobile office is growing divided into two sections. It's Wi-Fi FMC(Fixed Mobile Convergence) field Which are implemented in a telephone service available from existing fixed-line service in the center of the smart phones and the EMS(Enterprise Mobility Service) field to make people will be able to handle PC the center of the information system within an enterprise using a smart phone instead of terminal facility connects to a system in the workplace and external. This paper developed FMC controller to allow execution IMS(IP Multi-Media Subsystem) services to complement the issues of the FMC corporation, telephony service associated. The controller includes FMC automatic enrollment services, voice quality enhancement of the mobile phone, anywhere within the firm on his mobile phone calls can provide mobility and is also implemented FMC LCR function that use status information from mobile soft-phone within the IP-PBX.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.99-106
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• 2017

Audible Pedestrian Signal(APS) is an additional equipment to provide information about pedestrian signals in non-visual formats such as audible tones and verbal messages. It can provide information to pedestrians about the location and directions of a crosswalk, and the traffic signal status. In general, a pedestrian who is visually impaired uses a 358.5MHz wireless remote controller to activate the APS and crosses at the crosswalk with the help of the APS. The existing APS can only receive an activation message from the remote controller. Therefore, the APS has an issue, especially at intersections, that all APSs within the communication range of the remote controller are activated simultaneously. It makes to confuse the visual impaired pedestrians. In this paper, we propose a BLE-enabled APS that can enable two-way communication via Bluetooth with a smartphone. The proposed system solves the problem and provides them with additional information, so that visually impaired pedestrians can cross at the crosswalk more conveniently.

• The Journal of the Acoustical Society of Korea
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• v.23 no.5
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• pp.390-399
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• 2004

In this paper, we design and implement a multiple-view VoiceXML editor to improve editing efficiency of the VoiceXML. The VoiceXML multiple-view Editor uses a MVC framework to support multiple views and paradigm. Our multiple-view editor consists of Model. View and Controller using MVC framework. A model, core data structure. is constructed of abstract syntax tree and abstract grammar. A view. user interface. is formalized in unparsing rules and unparser. A controller. to control model and view. is made of command interpreter and tree handler. The VoiceXML multiple-view editor overcomes a drawbacks of existing XML editors by showing document structure and context concurrently. as well as document flows. Our VoiceXML multiple-view editor. which MVC framework has been applied, provides various editing views concurrently to users. Thereby. it supports efficient and convenient editing environments for voice-web documents to users and it guarantees transparency of editors. as various views have a same consistent model.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.97-104
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• 2015

A fuzzy controller and a 2-dimensional wire-driven heavy material lifting system helping human operator are proposed in this paper. The 2-dimensional wire-driven heavy material lifting system is a kind of human-assistive systems in which a human is involved in the control loop. Most of the existing human-assistive control systems cannot consider human operator's characteristic. To consider human operator's characteristic, human's operating motion and requirement of reducing operator's force to lift a heavy material are considered in the design process of the proposed fuzzy controller. The performance of the proposed system is verified by experiments.

• Journal of Practical Engineering Education
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• v.6 no.2
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• pp.135-139
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• 2014

In this study, the new model of presentation remote controller in which has improved the conventional function and deteceted the level of human's tension on a real time basis is suggested and tested. Existing presentation remote controller was just used turning the pages. But new model controls presentation and check tension level on real time using the smart phone's bluetooth interface. The proposed system is comprised with the PPG (Photo-Plethysmo-Graphy) sensor, Bluetooth and Wi-Fi modules. The configured system is to process (within 150 ms) the pulse signals of the presenter and stored the data. As a result, it can check and make up for the week presentation part and used as sources for improving self-confidence. This is the result obtained from the process of capstone design irregular course for 20 weeks of a graduate-to-be in four-year college.

• Journal of Power Electronics
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• v.18 no.1
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• pp.225-233
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• 2018

This paper proposes a universal system control strategy for voltage source converter (VSC) based high voltage direct current (HVDC) systems. The framework of the designed control strategy consists of five layer structures considering the topology and control characteristics of the VSC-HVDC system. The control commands sent from the topmost layer can be transmitted to the next layer based on the existing communication system. When the commands are sent to each substation, the following transmission of commands between the four lower layers are realized using the internal communication system while ignoring the communication delay. This hierarchical control strategy can be easily applied to any VSC-HVDC system with any topology. Furthermore, an integrated controller for each converter is designed and implemented considering all of the possible operating states. The modular-designed integrated controller makes it quite easy to extend its operating states if necessary, and it is available for any kind of VSC. A detailed model of a VSC-HVDC system containing a DC hub is built in the PSCAD/EMTDC environment. Simulation results based on three operating conditions (the start-up process, the voltage margin control method and the master-slave control method) demonstrate the flexibility and validity of the proposed control strategy.