• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.22-28
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• 2011

This paper presents an active roll motion control of a passenger vehicle. The roll controller is designed in the framework of $H_{\infty}$ control scheme based on the 3 DOF vehicle model taking into consideration parameter variations, which affect the roll dynamics, and unmodeled high frequency dynamics for robustness and performance. In order to investigate the feasibility of the active roll control system in a car, its performance is evaluated by simulation in a full vehicle model with nonlinear tire characteristics under various operating conditions. Finally, in order to enhance the performance in a transient region taking into account the limited bandwidth of the actuating module, a hybrid control strategy is presented.

• 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.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.36-42
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• 1997

This paper presents a new design technique for performing high quality low bit rate image compression. A hybrid coder(HC) which combines Mean Removed Important Coefficient Selection based JPEG(MR-ICS-JPEG) and Adaptive Vector Quantization (AVQ) is proposed. A new quantization table is developed using the Important Coefficient Selection(ICS) method; the importance of each coefficient is determined using the orthonormal property of the DCT. This quantization table is applied to standard JPEG with mean removal(MR) strategy before processing. This scheme, called MR-ICS-JPEG, produces more than 2 dB enhanced performance in terms of PSNR over standard JPEG. A set of homogeneous codebooks is generated by homogeneous training vectors. Before compression, an image is uniformly divided into 8${\times}$8 blocks. Low detail regions such as backgrounds are roughly coded by AVQ while high detail regions such as edges or curves are finely coded by the proposed MR-ICS-JPEG. This hybrid coder procuces consistently about 3 dB improved performance in terms of PSNR over standard JPEG.

• Journal of the Korea Society for Simulation
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• v.8 no.3
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• pp.17-28
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• 1999

Recently studies have shown that conditional branches can be accurately predicted by recording the path leading up to the branch. But path predictors are more complex and uncompatible with existing pattern branch predictors. In order to solve these problems, we propose a simple path branch predictor(SPBP) that hashes together two most recent branch instruction addresses. In addition, we propose a pattern/path hybrid branch predictor composed of the SPBP and existing pattern branch predictors. Through the trace-driven simulation of six benchmark programs, the performance improvement by the proposed pattern/path hybrid branch prediction is analysed and validated. The proposed predictor can improve the prediction accuracy from 94.21% to 95.03%.

• Journal of Hydrogen and New Energy
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• v.34 no.5
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• pp.490-496
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• 2023

Unmanned aerial vehicles (UAVs) research is recently actively underway. Especially, fuel cell battery hybrid systems are widely used to overcome the limitations of continuous operation. However, fuel cell systems must be operated in combination with a battery due to their low specific output characteristics. Therefore, a hybrid power system model for UAVs is developed. The rule-based strategy is applied to the model to properly distribute power to batteries and fuel cells. As a result, the designed rule-based power distribution control operates UAVs while maintaining battery state of charge(SOC) at an appropriate level.

• The Journal of Korean Association of Computer Education
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• v.18 no.6
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• pp.43-51
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• 2015

In this paper, we develops the hybrid career coaching model combined the face to face and the E-coaching, and applies students of childhood education for career guidance. The presented hybrid career coaching manages a profile and state information and a remote access between the coach and coachee on Internet. Then, online part of hybrid coaching deals with saving the data, and understand of the situation of the coachee if it is necessary. And face to face part of hybrid coaching have a conversation, the checking, counsel and introspection if the coach needs. Presented hybrid career coaching model has th procedure of 6 steps such like career coaching guidance, self-understanding, career decision-making, establishment of the career execution planning, execution plan and action will inspection and execution result inspection. Proposed hybrid career coaching is possible to understand coachee's current state on the career map, realize the importance of the execution strategy and maximize the efficiency and effectiveness self-regulation capacity.

• Proceedings of the CALSEC Conference
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• 2005.03a
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• pp.143-148
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• 2005

The purpose of this paper is to analyze pricing strategies between conventional offline retailers and Internet retailers and discuss which strategy is more profitable when a bricks-and-mortar firm transforms into a clicks-and-mortar firm.

• 한국전기화학회:학술대회논문집
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• 2004.10a
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• pp.37-37
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• 2004

• Earthquakes and Structures
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• v.15 no.3
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• pp.227-241
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• 2018

The present paper deals with the optimum performance of the passive hybrid control system for the benchmark highway bridge under the six earthquakes ground motion. The investigation is carried out on a simplified finite element model of the 91/5 highway overcrossing located in Southern California. A viscous fluid damper (known as VFD) or non-linear fluid viscous spring damper has been used as a passive supplement device associated with polynomial friction pendulum isolator (known as PFPI) to form a passive hybrid control system. A parametric study is considered to find out the optimum parameters of the PFPI system for the optimal response of the bridge. The effect of the velocity exponent of the VFD and non-linear FV spring damper on the response of the bridge is carried out by considering different values of velocity exponent. Further, the influences of damping coefficient and vibration period of the dampers are also examined on the response of the bridge. To study the effectiveness of the passive hybrid system on the response of the isolated bridge, it is compared with the corresponding PFPI isolated bridges. The investigation showed that passive supplement damper such as VFD or non-linear FV spring damper associated with PFPI system is significantly reducing the seismic response of the benchmark highway bridge. Further, it is also observed that non-linear FV spring damper hybrid system is a more promising strategy in reducing the response of the bridge compared to the VFD associated hybrid system.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.247-249
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• 2007

Urban dynamometer driving schedule(FTP-75 mode) plays very significant role on automotive emission test, due to reference point. The overall system energy efficiency of a HEV(Hybrid Electric Vehicle) is highly dependent on the energy management strategy employed. An energy source is the heart of a HEV. In order to applicable to a vehicle component, it must be need to real world test result. But, the present state of things have numerous problems. In this paper, be studied performed based on HEV simulation software in virtual world and chassis dynamometer test in real world and the result make a comparative. Toyota Prius vehicle was adapted as a modeling and real testing to evaluate the hybrid components and energy balancing management. The point at issue is voltage and current analysis for HEV battery SOC(State of Charge), and verification for energy.