• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.362-367
• /
• 2005

Control network adopted in the national power-plant or manufactory are mostly vendor-dependent products, which have their own special specification, components and individual communication methods. These systems not only raise installation cost, but also bring many difficulties to maintenance and extension. To overcome these problems, this paper introduces a development and application case of a new "PC/Ethernet-based fieldbus" architecture and protocol to be used in mid-level fieldbus. The designed system has a basic idea of "3 Layers fieldbus over Standard-LAN" and implemented on PCs. PC gives user friendly environment. By using an open standard Ethernet in layer 1,2, the system has low cost, wide communication bandwidth and high compatibility. Layer 3 protocol designed for large realtime data communication makes user bypass TCP/IP layer and gives user direct access to the Ethernet. This new protocol eliminates potential collision of Ethernet, and transmits large periodic/non-periodic control data by using long-frame/wide-bandwidth of Ethernet effectively, and offers simple API-Services to the upper layer. Since the system have installed in H-power plant simulator and U-nuclear power plant simulator in Korea, it have been proved to be efficient and stable without any trouble in realtime communication service for full-scope plant simulator that has a lot of control elements.

• Journal of Communications and Networks
• /
• v.18 no.3
• /
• pp.420-428
• /
• 2016

In this paper, we investigate the scheduling and power allocation for coordinated multi-point transmission in downlink long term evolution advanced (LTE-A) systems, where orthogonal frequency division multiple-access is used. The proposed scheme jointly optimizes user selection, power allocation, and modulation and coding scheme (MCS) selection to maximize the weighted sum throughput with fairness consideration. Considering practical constraints in LTE-A systems, the MCSs for the resource blocks assigned to the same user need to be the same. Since the optimization problem is a combinatorial and non-convex one with high complexity, a low-complexity algorithm is proposed by separating the user selection and power allocation into two subproblems. To further simplify the optimization problem for power allocation, the instantaneous signal-to-interference-plus-noise ratio (SINR) and the average SINR are adopted to allocate power in a single cell and multiple coordinated cells, respectively. Simulation results show that the proposed scheme can improve the average system throughput and the cell-edge user throughput significantly compared with the existing schemes with limited feedback.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.4
• /
• pp.820-828
• /
• 2016

The sizable electrical load of plug-in electric vehicles may cause a severe low-voltage problem in a distribution network. The voltage drop in a distribution network can be mitigated by limiting the power consumption of a charging station. Then, the charging station operator needs a method for appropriately distributing the restricted power to all plug-in electric vehicles. The existing approaches have practical limitation in terms of the availability of future information and the execution time. Therefore, this study suggests a heuristic method based on priority indexes for fairly distributing the constrained power to all plug-in electric vehicles. In the proposed method, PEVs are ranked using the priority index, which is determined in real time, such that a near-optimal solution can be obtained within a short computation time. Simulations demonstrate that the proposed method is effective in implementation, although its performance is slightly worse than that of the optimal case.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.11
• /
• pp.193-201
• /
• 2018

In this paper, we extracted relevant patent data and conducted statistical analysis to understand the technical development trend related to Wireless Power Transfer (WPT) for Light Rail Transit (LRT). Recently, with the development of WPT technologies, the Light Rail Transit (LRT) industry is concentrating on applying WPT to the power supply system of trains because of their advantages compared wired counterpart, such as low maintenance cost and high stability. This technology is divided into three areas: wireless feeding and collecting technology, high-frequency power converter technology and orbital and infrastructure technology. From each specific area, key words in patent document were extracted by TF-IDF method and analyzed by social network. In the keyword network, core word of each specific technology were extracted according to their degree centrality. Then, the multi-word phrases were also built to represent the concept of core technologies. Finally, based on the analysis results, the development strategies for each specifics technical area of WPT in LRT filed will be provided.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.11
• /
• pp.1589-1597
• /
• 2016

In this paper, we propose a system in a large-scale environment, such as desert and ocean, that can reduce the overall transmission power consumption in mobile sensor network. It is known that the transmission power consumption in wireless sensor network is proportional to the square of transmission distance. Therefore, if the locations of mobile sensors are far from the sink node, the power consumption required for data transmission increases, leading to shortened operating time of the sensors. Hence, in this paper, we propose a system that can reduce the power consumption by allowing to transmit data only if the transmission range of the sensors is within a predetermined distance. Moreover, the energy efficiency of the overall sensor network can even be improved by reducing the number of data transmissions at the sink node to gateway based on compressed sensing. The proposed system is actually implemented using Arduino and Raspberry Pi and it is confirmed that source data can be approximately decoded even when the gateway received encoded data fewer than the required number of data from the sink node. The performance of the proposed system is analyzed in theory.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.323-326
• /
• 2006

This paper shows the comparison of operating characteristics between squirrel cage induction generator and DFIG(Double Fed Induction Generator). Because squirrel cage induction generator consume the reactive power due to magnetizing reactance, the capacitor is need to compensate the reactive power. Otherwise, two back-to-back PWM voltage-fed inverters connected between the stator and the rotor allow sub/super synchronous operation with low distortion currents. In this paper, the response characteristics of squirrel cage induction generator and DFIG, were analyzed and investigated using PSCAD/EMTDC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.296-299
• /
• 2004

This paper introduces a supplementary module reducing tile standby-power of Power Line Communication(PLC) modem, one of the network equipments that take up much of tile stand-by power. This supplementary module consists of three parts, such as a compare part, a control part, and a switch part. This supplementary module controls the power going from the power supply element into PLC modem, which brings about the effect of standby-power reduction. It is assured that over 30% standby-power reduction is estimated when we applied this module to a low-speedy PLC control modem.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.6
• /
• pp.695-700
• /
• 2005

In the sensor network, a lot of sensor nodes are scattered sparsely and organizes a united communication network between each node. After that, environmental information around each sensor node are gathered and analyzed. Because each node operates under resource constraint, the efficiency and hardware specification of a node should be maximized. There exist technical constraints until now but recent technical progress in IC fabrication and wireless network enables to construct a tiny embedded system, which has the properties of low cost, low power consumption, multi functions. Wireless sensor network becomes a modern research field with technical improvements, is studied in numerous laboratories, and is called as diverse different project names - Wireless Integrated Network Sensors (WINS), Mobile Ad hoc NETwork (MANET), Ubiquitous Sensor Network (USN). TinyOS is one of leading project and is widely used. In this paper, we suggest a sensor network, which uses TinyOS platforms and aims for context awareness in a home environment.

• Journal of Convergence Society for SMB
• /
• v.6 no.4
• /
• pp.59-64
• /
• 2016

6LoWPAN (IPv6 over Low Power Wireless Sensor Network) standardized by IETF does not support the mobility of wireless sensor nodes. Since the wireless sensor node, subject to a lot of constraints in the CPU, memory, a battery is not easy to apply to existing protocols such as Mobile IPv6. In this paper, we propose a novel mobility management architecture and methods to work with 6LoWPAN based on the analysis on FPMIPv6 (Fast PMIPv6) the host is not a handover procedure performed in order to support the mobility of such sensor nodes. It was suggested the use of a dispatch code pattern that is not currently used in 6LoWPAN for inter-working, MAG and MAC, MAC in order to reduce packet loss caused as the authentication delay in the handover process to minimize the power consumption of a sensor node that is caused by the re-transmission the new concept of temporary guarantee (temporary guarantee) and trust relationships (trust relationship) between AAA and introduced.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.3
• /
• pp.1-6
• /
• 2014

Companies almost don't use an integrated control system using expensive network system in multimedia like TV and DID, despite IP-Broadcasting and communication equipment have expanded rapidly. The proposed integrated TCU(terminal control unit) is a control device that supports TV power On/Off check and remote control, power control reservation function, TV channel change, a variety of interface supports of input/output AC power & Lan port, RS-232C and IR using existing IP network after there is installed the Wake-on -Lan in the set-top box. The TCU can control and monitor 24 hours unlike existing low-cost control system RF method. In existing control equipment markets without expandability and low price, the TCU development including 24 hours monitoring and automatic control functions is expected to secure a wide range of companies.