• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.279-282
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• 2003

This paper proposes a medium-access control(MAC) protocol designed for wireless multi-hop sensor networks which is used for connecting physical world and cyber computing space. Wireless multi-hop sensor networks use battery-operated computing and sensing device. We expect sensor networks to be deployed in an ad hoc fashion, with nodes remaining inactive for long time, but becoming suddenly active when specific event is detected. These characteristics of multi-hop sensor networks and applications motivate a MAC that is different from traditional wireless MACs about power conservation scheme, such as IEEE 802.11. Proposed MAC uses a few techniques to reduce energy consumption. Result show that proposed MAC obtains more energy sayings.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.401-406
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• 1998

If a mobile robot can be controlled remotely via the internet using wireless IP protocol network, it becomes much useful and convenient. However risk of illegal access is also increased. This paper discusses problems of the illegal access and proposes protection methods against the access.

• Annual Conference of KIPS
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• 2015.10a
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• pp.335-336
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• 2015

Seamless mobility is one of the most crucial feature of telecommunication industry. Researches are going on in full swing to deal with this feature in most efficient manner. Software Defined Networking (SDN) is seen as the next generation paradigm which can facilitate seamless mobility across heterogeneous networks by segregating the control plane and data plane functionalities, and logically centralizing the control plane. In this paper, we propose a simplified Layer 2 handover mechanism for enterprise wireless networks, based on SDN framework. We present a network assisted L2 handover method using the IEEE 802.21 Media Independent Handover (MIH) protocol and SDN concepts, to achieve seamless mobility across heterogeneous networks.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.237-244
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• 2022

Eco-driving of vehicles today presents an advantage that aims to reduce energy consumption and limit CO2 emissions. The application for this option is possible to older vehicles. In this paper, we propose an efficient implementation for IoT (Internet of Things) system for controlling vehicle components that affect the quality of driving (acceleration, braking, clutch, gear change) via Smartphone using Wi-Fi and BLE as communication protocol. The user can see in real-time data from sensors that control driver action on vehicle driving systems such as acceleration, braking, and vehicle shifting through a web interface. Thanks to this communication, the user can control his driving quality and, hence, eco-driving can be achieved

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.1-7
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• 2023

TCP is considered a major candidate transport protocol even for constrained IoT networks due to its ability to integrate into the existing network infrastructures. Since TCP implementations such as uIP TCP often allow only a single TCP segment per connection to be unacknowledged at any given time due to resource constraints, the congestion control relies only on RTO management. In our previous work, to address the problem that uIP TCP performs poorly particularly when a radio duty cycling mechanism is enabled and the hidden terminal problem is severe, we proposed a RTO scheme for uIP TCP and validated the performance through Cooja simulation. In this study, we investigate the effect of other factors that were not considered in our previous work. More specifically, the effect of traffic intensity, the degree of the hidden terminal problem, and RDC is investigated by varying the offered load and the transmission range, and the RDC channel check rate. Simulation results imply that we need to further investigate how to improve TCP performance when the radio duty cycling mechanism is used.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1482-1484
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• 2010

A new TCP protocol can succeed for large bandwidth delay product when it meets network bandwidth utilization efficiency and fair sharing. We introduce a novel congestion control algorithm which employs queueing delay information in order to calculate the amount of congestion window increment in increase phase, and reduces congestion window to optimal estimated bound as packet loss occurs. Combination of such methods guarantees that the proposal utilizes fully network bandwidth, recovers quickly from packet loss in wireless link, and preserves fairness for competing flows mixed short RTT and long RTT. Our simulations show that features of the proposed TCP meet the desired requirements.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2254-2258
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• 2003

In recent years, the case to install small water treatment facility to every local area has increased. A key issue in the successful implementation of the control systems for the water treatment plants is the choice of control architecture. Within the framework of distributed control system(DCS), this paper presents a new development of intelligent control module and its novel application to open control architecture for water treatment plants. This control system so called NCS(Network Based Control System) with standard networks system with LonTalks protocol of ANSI/EIA 709.1, regulatory control function and information dispatch function has suitable functionality to operate these distributed water treatment facility effectively. This paper describes the case where NCS is applied for the filters system in water treatment facility of Heong Sung area.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.820-824
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• 2004

Personal Robot System in developing, have a module architecture, each module are connected through heterogeneors network systems like Ethernet, WLAN (802.11), IEEE1394 (Firewire), Bluetooth, USB, CAN, or RS-232C. In developing personal robot system we think that the key of robot performance is interoperability among modules. Each network protocol are well connected in the view of network system for the interoperability. So we make a bridging architecture that can routing, converting, transporting data packets with matcing each network's properties. Furthermore we suggest a advanced design scheme for realtime / non-realtime and control signal (short, requiring hard-realtime) / multimedia data (large, requiring soft-realtime). By some application systems, we could test performance, interoperability and stability. In this paper, we show our design concept, middleware architecture, and some applications systems using this middleware.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.29-35
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• 2007

This study was designed to investigate the feasibility to utilize the electromyogram (EMG) for estimating the muscle torque. The muscle torque estimation plays an important role in functional electrical stimulation because electrical stimulation causes muscles to fatigue much faster than voluntary contraction, and the stimulation intensity should then be modified to keep the muscle torque within the desired range. We employed the neural network method which was trained using the major EMG parameters and the corresponding knee extensor torque measured and extracted during isometric contractions. The experimental results suggested that (1) our neural network algorithm and protocol was feasible to be adopted in a real-time feedback control of the stimulation intensity, (2) the training data needed to cover the entire range of the measured value, (3) different amplitudes and frequencies made little difference to the estimation quality, and (4) a single input to the neural network led to a better estimation rather than a combination of two or three. Since this study was done under a limited contraction condition, the results need more experiments under many different contraction conditions, such as during walking, for justification.

• KSCI Review
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• v.14 no.2
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• pp.123-127
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• 2006

In this paper, we designed and implemented home gateway system for remote control of home appliances and devices using cellular phone. The system communicate home devices through Zigbee protocol and home server based on Linux operating system communicate cellular phone through external networks. We expect that the system apply various fields as home automations, home network, smart offices, and ubiquious environments.