• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.2
• /
• pp.192-198
• /
• 2013

The rapidly growing demand for electric power systems in electric vehicles (EVs) and hybrid electric vehicles (HEVs) require simpler, cost-effective, and higher performance components. In this paper, a novel power conversion system for hybrid electric vehicles is proposed for these needs. The proposed power conversion system reduces the conversion system cost while preserving same functionality. The proposed power conversion system can boost multi-sources to drive a traction motor and to store energy at the same time reducing number of switching components. In this paper, all operational modes of the proposed converter are explained in detail and verified by a computer simulation first. Then, the topology and operational modes are experimentally verified. Based on the results, the feasibility of the proposed multi-mode single leg power conversion system for EV and HEV applications is discussed.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.2
• /
• pp.199-204
• /
• 2013

Recently, the demand for fuel efficient electric vehicles (EVs) and hybrid electric vehicles (HEVs) has been growing globally. Due to the increased number of switching devices in the electrified vehicles, the probability of the semiconductor device failure is much higher than in other application areas. A sudden failure in one of the power switches and insufficient power management ability in the systems not only decreases system performance, but also leads to critical safety problems. In this paper, novel switch open circuit fault detection method is proposed, and the proposed approach is verified by experiments.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.171.1-171
• /
• 2001

This paper describes the design and implementation of a new type of a force reflective joystick. It has single degree of freedom that is actuated by motor and brake pair. The use of motor and brake allows various objects to be simulated without the stability problem and related safety issues involved with high torque motors only. The joystick performance is measured by its ability to simulate various test objects. Simple test objects are modeled as a benchmark test of the system´s performance and to evaluate different control approaches for hybrid motor/brake actuator. The force output joystick is capable of simulating forces in a variety of virtual environments. This device demonstrates the effectiveness of a hybrid motor/brake haptic actuator.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.673-678
• /
• 2011

For the wind-diesel hybrid electric power generation system equiped with two diesel generators, the diesel power sharing is studied analytically and a power sharing technique of less fuel consumption is developed. Based on the technique, as example, a diesel power sharing algorithm is suggested for two diesel generators of capacity 500Kw(200Kw+300Kw).

• Journal of ILASS-Korea
• /
• v.9 no.3
• /
• pp.42-49
• /
• 2004

The present article investigates the influence of droplet drag models on predictions of diesel spray behaviors under ultra-high injection pressure conditions. To consider drop deformation and shock disturbance, this study introduces a new hybrid model in predicting drag coefficient from the literature findings. Numerical simulations are first conducted on transient behaviors of single droplet to compare the hybrid model with earlier conventional model. Moreover, using two different models, extensive numerical calculations are made for diesel sprays under ultra-high pressure sprays. It is found that the droplet drag models play an important role in determining the transient behaviors of sprays such as spray tip velocity and penetration lengths. Numerical results indicate that this new hybrid model yields the much better conformity with measurements especially under the ultra-high injection pressure conditions.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.408-411
• /
• 1995

In this paper, we discuss the force control of flexible manipulators. Since the force control of flexible manipulators with planar one or two links using the distributed-parameter modeling has been the subject of a considerable number of publications until now, real time computations of the force control schemes are possible. But, application of those control schemes to multi-link spatial manipulators is fairly complicated. In this paper, we apply a concise hybrid position/force control scheme for a flexible manipulators. We use a lumped-parameter modeling for the flexible manipulators. The Hamilton's principle is applied to derive the equations of motion for the system and then, state-space model is obtained by the Lagrange's method. Finally, comparison of simulation results with experimental results is given to show the performance of our method.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.448-451
• /
• 1995

A general task execution with hybrid impedance control method is addressed. The target impedance is expressed in the constraint frame. For the computational simplicity and the robustness improvement, disturbance observer scheme is used. To make stable contact with the environment, the large value of desired inertia gain for the force-controlled subspace is suggested. Numerical examples are given to show the performance of the proposed controller.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.730-734
• /
• 2007

National projects on renewable energy and new energy are driven more actively than ever in many countries for the exhaustion of fossil fuel energy from the turn of the century. Such activities began to spread out in railway industry with centering around west European countries. Electric energy is generated on the hybrid vehicle itself, which contributes to reduction of the cost for construction of the infrastructure required for the supply of electric power. Hybrid tram is mainly composed of propulsion system to control electric energy, automatic guidance system to control steering and operation, and central vehicle unit to control and monitor major electronic devices. Generation and supply of electric power are made by the combination of engine generator and battery, or fuel cell and super capacitor.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.4
• /
• pp.209-218
• /
• 2016

This paper proposes a new lifetime aware buffer mapping method of a synchronous dataflow (SDF) graph on a hybrid memory system with DRAM and PRAM. Since the number of write operations on PRAM is limited, the number of written samples on PRAM is minimized to maximize the lifetime of PRAM. We improve the utilization of DRAM by mapping more buffers on DRAM through buffer sharing. The problem is formulated formally and solved by an optimal approach of an answer set programming. In experiment, the buffer mapping method with buffer sharing improves the PRAM lifetime by 63%.

• Genomics & Informatics
• /
• v.6 no.2
• /
• pp.87-90
• /
• 2008

During the last four years, the pyrosequencing-based 454 platform has rapidly displaced the traditional Sanger sequencing method due to its high throughput and cost effectiveness. Meanwhile, the Sanger sequencing methodology still provides the longest reads, and paired-end sequencing that is based on that chemistry offers an opportunity to ensure accurate assembly results. In this report, we describe an optimized approach for hybrid de novo genome assembly using pyrosequencing data and varying amounts of Sanger-type reads. 454 platform-derived contigs can be used as single non-breakable virtual reads or converted to simpler contigs that consist of editable, overlapping pseudoreads. These modified contigs maintain their integrity at the first jumpstarting assembly stage and are edited by fragmenting and rejoining. Pre-existing assembly software then can be applied for mixed assembly with 454-derived data and Sanger reads. An effective method for identifying genomic differences between reference and sample sequences in whole-genome resequencing procedures also is suggested.