• IE interfaces
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• v.22 no.3
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• pp.278-286
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• 2009

The anti-collision algorithms to identify a number of tags in real-time in RFID systems are divided into the anti-collision algorithms based on the Framed slotted ALOHA that randomly select multiple slots to identify the tags, and the anti-collision algorithms based on the Tree-based algorithm that repeat the questions and answer process to identify the tags. In the hybrid algorithm which is combined the advantages of these algorithms, tags are distributed over the frames by selecting one frame among them and then identified by using the Query tree frame by frame. In this hybrid algorithm, however, the time of identifying all tags may increase if many tags are concentrated in a few frames. In this study, to improve the performance of the hybrid algorithm, we suggest an improved algorithm that the tags select a specific group of frames based on the earlier bits of the tag ID so that the tags are distribute equally over the frames. By using the simulation and mathematical analysis, we show that the suggested algorithm outperforms traditional hybrid algorithm from the viewpoint of the number of queries per frame and the time of identifying all tags.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.117-139
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• 1999

This paper is concerned about the hybrid tandem configuration as the design of the automated guided vehicle system(AGVs). The hybrid tandem configuration is that the manufacturing system is divided into several non-overlapping zones, workstations of each zone are linked by network configuration including loop. That is, the manufacturing system is divided into several non-overlapping small size networks, and at most two automated guided vehicles can be available in each network. The transit point is located at proper point between adjacent networks. The parts are transported to workstations in other network through the transit points. One of the objective functions in dividing into the hybrid tandem configuration is to minimize the maximum travel time of the divided networks, and other is to minimize the total travel distance of parts moved to workstations in other networks for the next processing. The model formulation is presented, and a numerical example is shown. Also, the performances of system for the hybrid tandem, tandem and network configuration are compared through the simulation. The results of this research will contribute to the development of material handling systems in the manufacturing system. Also, it will be applied in determining the transportation area of transportation vehicles and the number and size of the transportation fleet in the transportation problem of logistics management.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.159-166
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• 2014

The study is conducted on the subject of optimization of components sizing for series hybrid electric propulsion systems. The components sizing of series type hybrid system is very important because each component of series type is larger than the corresponding component of the parallel type or series-parallel type. If the components sizing is greater or less than what is required to this system, the performance of the system is getting worse. The methodology for the sizing of a driving motor is introduced based on the foundation of determined system configuration and performance target. And the sizing of an engine/generator and a battery is achieved based on simulation results using Dynamic Programming. It is possible to find the optimal sizing of these components by comparing fuel efficiency of hybrid electric propulsion system for 8 driving cycles.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.1
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• pp.17-29
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• 2003

This paper preliminarily investigates the effectiveness of various control systems, such as passive, active, semiactive and hybrid control, for seismic protection of cable-stayed bridges by examining the ASCE first generation benchmark problem for a cable-stayed bridge. This benchm.0.00000ark problem considers the cable-stayed bridge that is scheduled for completion in Missouri, USA In 2003. Seismic considerations were strongly considered in the design of this bridge due to location of the bridge and its critical role as a principal crossing of the Mississippi River. Based on detailed drawings of this cable-stayed bridge, a three-dimensional linearized evaluation model has been developed to represent the complex behavior of the bridge. A set of eighteen evaluation criteria has been developed to evaluate the capability of each control system. In this study, four passive control systems, one active control system, two semiactive control systems and three hybrid control systems are considered. Numerical simulation results show that all the control systems are effective in reducing the responses of the benchmark cable-stayed bridge under the historical earthquakes. To get good performance, however, the passive control systems need quite large control forces compared to other control systems. The simulation results also demonstrate that the passive, semiactive and hybrid control systems are robust to the stiffness uncertainty of the structure. Therefore, the semiactive and hybrid control systems are more appropriate in real applications for full-scale civil infrastructures.

• New & Renewable Energy
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• v.19 no.1
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• pp.22-30
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• 2023

Recently, the use of renewable energy has been increasing to achieve carbon neutrality. The concept of a zero-energy building is also attracting attention. In this study, a preliminary study was conducted to analyze the feasibility of a hybrid wind and solar power generation system between buildings that utilize the building wind generated by the Venturi effect. For this purpose, the wind speed and sunshine hours were monitored in the area where the building wind blows by the Venturi effect, and the power generation depending on system types, areas, and season was estimated. Consequently, the wind power generation system showed a larger amount of power per area than solar power. The wind power systems can generate larger power if wind power blades are installed along the height of the building. As a preliminary study, this study verified the feasibility of the system utilizing building wind and suggested follow-up studies.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1153-1154
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• 2015

In this study, electro-polymerization was used for coating PEDOT:SDS films on CNTs, thereby producing hybrid-type electrodes. The CNTs were deposited on PET substrates using a spray method. For the fabricated hybrid electrodes, their surface morphologies, electric sheet resistances, visible transmittances, and chromatic properties were characterized as functions of the polymerization conditions used for coating PEDOT, and compared with those of conventional CNTs. The experiment results confirmed that the sheet resistance of CNTs was decreased significantly by coating of PEDOT via electropolymerization, and also indicated that the fabricated hybrid electrodes revealed desirable properties as a transparent electrode for touch screen panels.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.325-329
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• 2003

This paper discuss the method of the system's efficient control using a Intelligent hybrid algorithm in nonlinear dynamics systems. Existing neural network and genetic algorithm for the control of non-linear systems work well in static states. but it be not particularly good in changeable states and must re-learn for the control of the system in the changed state. This time spend a lot of time. For the solution of this problem we suggest the intelligent hybrid self-tuning controller. it includes neural network, genetic algorithm and immune system. it is based on neural network, and immune system and genetic algorithm are added against a changed factor. We will call a change factor an antigen. When an antigen broke out, immune system come into action and genetic algorithm search an antibody. So the system is controled more stably and rapidly. Moreover, The Genetic algorithm use the memory address of the immune bank as a genetic factor. So it brings an advantage which the realization of a hardware easy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.175-176
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• 2014

The paper deals with the development of the multi-layer plant production systems using a sunlight and LED. Nowadays most of plant production systems have been developed by plant factory using only LED. In case of plant factory using LED, however, the light quantity is not sufficient for various kinds of medicinal plants. In this paper, authors have tried to apply the both the luminous sources using a natural sunlight and an appropriate LED. During the daytime, a natural sunlight was applied using the Heliostat, while in the nighttime, LED was used. The proposed mixed plant production system was constructed under the various environmental conditions such as $CO_2$ distribution, temperature and humidity. Through the hybrid plant prodution systems, the growth of Ginseng plants were recorded and demonstrated by CCD camera and monitoring program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.18-29
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• 2014

This paper proposes the integration of photovoltaic (PV) and energy storage systems for sustained power generation. In this proposed system, whenever the PV system cannot completely meet load demands, the super capacitor provides power to meet the remaining load. A power management strategy is designed for the proposed system to manage power flows between PV array systems and supercapacitors (SC). The main task of this study was to design PV systems with storage strategies including MPPT with direct control and an advanced DC-link controller and to analyze dynamic model proposed for a PV-SC hybrid power generation system. In this paper, the simulation models for the hybrid energy system are developed using Matlab/Simulink, SimPowerSystems and Matlab/Stateflow tool. This is the key innovative contribution of the research paper. The system performances are verified by carrying out simulation studies using practical load demand profile and real weather data.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.11a
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• pp.602-609
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• 2007

Combining collaborative filtering with some other technique is most common in hybrid recommender systems. As many recommended items from collaborative filtering seem to be similar with respect to content, the collaborative-content hybrid system suffers in terms of quality recommendation and recommending new items as well. To alleviate such problem, we have developed a novel method that uses a diversity metric to select the dissimilar items among the recommended items from collaborative filtering, which together with the input when fed into content space let us improve and include new items in the recommendation. We present experimental results on movielens dataset that shows how our approach performs better than simple content-based system and naive hybrid system