• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.93-101
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• 2007

In heterogeneous networks SVC (Scalabile Video Coding) will be used for IPTV service. This paper analyses how to determine the optimal inter-layer reference scheme according to final level to be displayed in hybrid scalable coding which consists of spatial, quality and temporal layer. It determines where to stop layering quality layer stacks in lower spatial layer according to the relationship between noise induced by loss of high frequency component eliminated by filter in order to get rid of aliasing when spatial layering is processed and noise induced by quantization when quality layering is processed. This paper shows the choice of the level of layering between spatial and quality to get better coding efficiency and then presents what is needed for determining it.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1363-1372
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• 2011

Flooding based routing protocols are usually used to disseminate information in wireless sensor networks. Those approaches, however, require message retransmissions to all nodes and induce huge collision rate and high energy consumption. In this paper, HoGoP (Hop based Gossiping Protocol) in which all nodes consider the number of hops from sink node to them, and decide own gossiping probabilities, is introduced. A node can decide its gossiping probability according to the required average reception percentage and the number of parent nodes which is counted with the difference between its hop and neighbors' ones. Therefore the decision of gossiping probability for network topology is adaptive and this approach achieves higher message reception percentage with low message retransmission than the flooding scheme. Through simulation, we compare the proposed protocol with some previous ones and evaluate its performance in terms of average reception percentage, average forwarding percentage, and forwarding efficiency. In addition, average reception percentage is analyzed according to the application requirement.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.191-200
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• 2010

The "intelligent internet power outlets" realized in this study use Internet environment to connect electrical and electronic products to the Net as well as to enable remote monitoring and control. They also have temperature and light sensors, and even offer scheduling options by means of a universal calendar run by an inner real-time timer. Furthermore, they control 4 outlets handling 4 external input conditions and infrared remote control with easy-to-use functions for home automation control. The user interface is equipped with an embedded Web server and UDP protocol handler, and which also allows special control programs be used with the Web browser. Thus, installing this real-time power control function with optimal scheduling and various communication functions will provide you with energy-efficient power outlets outfitted with the increasingly popular "standby power" electric power efficiency.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.5
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• pp.44-51
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• 2009

In this paper, an air conditioner peak power control system using electric power line communication has been developed. The air conditioner power control system using RS-485 communication method is hard to install on the existing buildings due to difficulty in cabling, and the system using wireless communication methods has a weak point of not being able to be used in close space, while the developed system has its own advantages of overcoming the above mentioned obstacles. In addition, the system is extended to support not only single-phase electricity system but also three-phase four-wire electricity system, and therefore can be installed anywhere in the domestic environment. The system also has enhanced the ease of deployment, operational stability and economical efficiency by compact circuit design. Considering the current state requiring the energy sayings, the system would greatly contribute to the widespread use of the air conditioner power control system. The superiority in the performance and stability of the system has been proved by the design verification of each component such as remote air conditioner controller, electric power line gateway and so on, and the field test of the whole system.

• Smart Structures and Systems
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• v.25 no.5
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• pp.605-617
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• 2020

The existence of damages in structures causes changes in the physical properties by reducing the modal parameters. In this paper, we develop a two-stages approach based on normalized Modal Strain Energy Damage Indicator (nMSEDI) for quick applications to predict the location of damage. A two-dimensional IsoGeometric Analysis (2D-IGA), Machine Learning Algorithm (MLA) and optimization techniques are combined to create a new tool. In the first stage, we introduce a modified damage identification technique based on frequencies using nMSEDI to locate the potential of damaged elements. In the second stage, after eliminating the healthy elements, the damage index values from nMSEDI are considered as input in the damage quantification algorithm. The hybrid of Teaching-Learning-Based Optimization (TLBO) with Artificial Neural Network (ANN) and Particle Swarm Optimization (PSO) are used along with nMSEDI. The objective of TLBO is to estimate the parameters of PSO-ANN to find a good training based on actual damage and estimated damage. The IGA model is updated using experimental results based on stiffness and mass matrix using the difference between calculated and measured frequencies as objective function. The feasibility and efficiency of nMSEDI-PSO-ANN after finding the best parameters by TLBO are demonstrated through the comparison with nMSEDI-IGA for different scenarios. The result of the analyses indicates that the proposed approach can be used to determine correctly the severity of damage in beam structures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.95-102
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• 2014

In this paper, we propose the high speed PLC-based automatic control system for a smart LED streetlight. The proposed the automatic control system were constructed of a power line modem part and monitoring part, streetlight controller part for the high speed communication frequency band and streetlight ballasts characterization and real-time remote control using a high-speed PLC network, and it was designed to meet to lighting grades conditions of KS road lighting standards. The proposed automatic control system were easy monitoring of the power consumption using PC through to the comparison result of the existing streetlight system. As a result, it was confirmed to the possibility of efficient operation for the real-time monitoring and maintenance by induction of reasonable power consumption through to the LED streetlight state checking and remote-control. In addition, we proved to improvement of expected effects for the power cost savings, the energy efficiency, and streetlight differentiation and advanced.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.40-45
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• 2014

This study examines the system and process of battery stored energy in vehicles and suggest the effective area for the use of V2G(vehicle-to-grid) from Jeju Smart Grid Demonstration Project. V2G means technology of electric power transmission from the battery of electric-drive vehicles to state grid. As for the increasing of effectiveness for demand-side control, V2G is a very good alternative. In the U.S., the utilization of electric vehicles is under 40% on average. In this case, we can use he battery of electric vehicle as role of frequency regulation or generator of demand-side resource. V2G, which is the element of Smart Transportation, consists of electric vehicle battery, BMS(battery management system), OBC(on-board charger), charging infrastructure, NOC(network operating center) and TOC(total operation center). V2G application has been tested for frequency regulation to secure the economical efficiency in the United States. In this case, the battery cycle life is not verified its disadvantage. On the other hand, Demand Response is required by low c-rate of battery in electric vehicle and It can be small impact on the battery cycle life. This paper concludes business area of demand response is more useful than frequency regulation in V2G application of electric vehicles in Korea. This provides the opportunity to create a new business for power grid administrator with VPP(virtual power plant).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1038-1046
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• 2017

In this paper, we propose the design of LED Streetlight Platform with capabilities of weather monitoring and color temperature control. Several previous works are focused on the energy efficiency or data management of streetlight system, but no work has been done on the lighting performance, especially when natural phenomenon such as fog or haze appears on the street and obstructs the visibility of drivers and pedestrians. To solve such issue, we propose the use of two LED lamps with different correlated color temperature, which will be activated interchangeably according to the condition on the street. We also present the design of communication scheme between each devices in the system. Moreover, our experimental results show the LED Streetlight Platform can perform well and the data can be displayed properly at the website.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.489-499
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• 2012

Most roads in Korea are constructed through a riverside or among the mountains due to geographical characteristics, and composed of various connection roads and complex networks, which makes it susceptible to a fog, rainfall and snowfall and causes serious negligent accidents due to misperception of network while driving. This study amis at securing original technology to provide traffic information, utilizing the road surface by grafting LED and optical technology highly recognized in terms of energy efficiency recently onto ITS, thereby developing next-generation ITS service. To support the research development, H/W was developed and field test was conducted. In addition, the customer satisfaction survey towards equipment, an end product of this research development was also carried out to find out what it means to customers potentially.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.435-447
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• 2006

This paper presents an application of the parallel Adaptive Evolutionary Algorithm (AEA) to search an optimal solution of the service restoration in electric power distribution systems, which is a discrete optimization problem. The main objective of service restoration is, when a fault or overload occurs, to restore as much load as possible by transferring the de-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints. This problem has many constraints and it is very difficult to find the optimal solution because of its numerous local minima. In this investigation, a parallel AEA was developed for the service restoration of the distribution systems. In parallel AEA, a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner are used in order to combine the merits of two different evolutionary algorithms: the global search capability of the GA and the local search capability of the ES. In the reproduction procedure, proportions of the population by GA and ES are adaptively modulated according to the fitness. After AEA operations, the best solutions of AEA processors are transferred to the neighboring processors. For parallel computing, a PC cluster system consisting of 8 PCs was developed. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through switch based fast Ethernet. To show the validity of the proposed method, the developed algorithm has been tested with a practical distribution system in Korea. From the simulation results, the proposed method found the optimal service restoration strategy. The obtained results were the same as that of the explicit exhaustive search method. Also, it is found that the proposed algorithm is efficient and robust for service restoration of distribution systems in terms of solution quality, speedup, efficiency, and computation time.