• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1251-1258
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• 2003

This paper presents a nonlinear robust approach to the slip control problem for a torque converter bypass clutch in a passenger car. The proposed nonlinear robust controller builds upon only the measurements avail-able from inexpensive sensors that are already installed in passenger cars for control. The issue of torque estimation problems for the implementation of the proposed controller is addressed. The stability of the internal dynamics is investigated, upon which a nonlinear robust controller is designed using input-output feedback linearization and Lyapunov redesign technique. The performance of the designed controller is validated by simulation studies.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.159-164
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• 2012

The shell & tube heat exchanger is used throughout various industries because of its inexpensive cost and handiness when it comes to maintenance. However, it has many design elements such as the location and the shape of inlet and outlet, the numbers of tubes and baffles, etc. Also, the flow within the shell and the heat transfer are complex. This paper is performed numerical analysis to evaluate capabilities of difference in temperature and pressure drop, which are the performance of channel heat exchanger, one of different types of shell & tube exchanger. Also, factors that affect the performance of channel heat exchanger were selected through design of experiment along with key factors.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.475-475
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• 2014

Dye sensitized solar cells (DSSCs) are regarded as potential inexpensive alternatives to conventional solid-state devices. The flexible version, employing conductive-plastic-film substrates, is appealing for commercialization of DSSCs because it not only reduces the weight and cost of the device but also extends their applications. However, the need for high temperature does not permit the use of plastic-film substrate. So, development of low-temperature methods is therefore realization of flexible DSSCs. In this work, the electrophoretic deposition combined with hydrothermal treatment was employed to prepare nanocrystalline $TiO_2$ thin film at low temperature. We confirmed the prepared $TiO_2$ thin films with different voltages and deposition times in the electrophoretic deposition process. Properties of the $TiO_2$ films were investigated by various analysis method such as X-ray diffraction, field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.450-454
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• 2003

This paper proposes a new driving scheme for single-phase SRM. The driving scheme is very simple and inexpensive. By use of this scheme, simple power devices based on low switching losses enable to high efficiency SRM drive. Starting, One of the main problem in single-phase SRM is overcame by a new starting algorithm with one hall sensor and a parting magnet. The proposed single phase SRM has a high efficiency and robust drive characteristics compared to that of a universal motor.

• KSBB Journal
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• v.27 no.5
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• pp.281-288
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• 2012

Phytoremediation-the use of plants for the in situ treatment of contaminated soil and water-has recently emerged as an inexpensive and user-friendly alternative to traditional methods of environmental clean-up. The present article outlines the characteristics of phytoremediation based on accumulated research evidence, along with discussions on its advantages and disadvantages. It further reviews various mechanisms involved in the phytoremediation processes: phytoextraction, rhizofiltration, phytostabilization, phytovolatilization and phytodegradation. Along the way, the author summarizes examples of its applications to environmental pollution control. These include wastewater treatment, removal of heavy metals, and hydrocarbons, remediation of recalcitrant contaminants, phytoremediation of radionuclides, and application of transgenic plants for enhanced biodegradation and phytoremediation. The remainder of the article briefly concludes with directions for future research.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.405-411
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• 1989

Performance evaluation of inexpensive LCTV to function as a two-dimensional spatial light modulator is performed. Correction of the phase distortion of the device is performed using the substrate of hologram plate and index matching oil. A new method for eliminating electrode grid pattern that incorporates phase conjugation in a BaTiO3 crystal is proposed and experimented.

• Journal of Power Electronics
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• v.13 no.4
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• pp.719-728
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• 2013

A novel hybrid active power filter (NHAPF) that can be adopted in high-voltage systems is proposed in this paper. The topological structure and filtering principle of the compensating system is provided and analyzed, respectively. Different controlling strategies are also presented to select the suitable strategy for the compensation system. Based on the selected strategy, the harmonic suppression function is used to analyze the influence of system parameters on the compensating system with MATLAB. Moreover, parameters in the injection branch are designed and analyzed. The performance of the proposed NHAPF in harmonic suppression and reactive power compensation is simulated with PSim. Thereafter, the overall control method is proposed. Simulation analysis and real experiments show that the proposed NHAPF exhibits good harmonic suppression and reactive power compensation. The proposed compensated system is based on the three-phase four-switch inverter, which is inexpensive, and the control method is verified for validity and effectiveness.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.11
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• pp.527-532
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• 2005

During the last ten years the new interruption techniques, which use the arc energy itself to increase the pressure inside a chamber by the PTFE nozzle ablation, have displaced the puffer circuit breakers due to reduced driving forces and better maintainability. In this paper, we have investigated the thermal flow characteristics inside a thermal puffer type gas circuit breaker by solving the Wavier-Stokes equations coupled with Maxwell's equations for considering all instabilities effects such as turbulence and Lorentz forces by transient arc plasmas. These relative inexpensive computer simulations might help the engineer research and design the new interrupter in order to downscale and uprating the GIS integral.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.149-159
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• 1996

It's required such information as location, size, distribution and abundance of wetlands as well as categorization of adjacent land-uses to manage effectively and to make wise planning decisions about resources of coastal area. Wetland inventory derived from the technology of Geographic Information System and remote sensing is inexpensive compared to the data based on conventional field data collection and cartographic methods. Furthermore, wetland inventory may prove to be useful references in the wetland management.

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.277-283
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• 2010

CoQ with low melting temperature was exploited to improve its solubility by preparing its solid dispersions (SDs) with a meltable polymer, poloxamer 407 (P 407). P407 can be utilized for a relatively simple, quick, inexpensive, reproducible and potentially scalable manner in the low temperature melting method. CoQ 10 solubility and dissolution increased with increasing concentrations of P 407 in SDs. Comparison of the enhanced dissolution of CoQ 10 from different poloxamers suggested that the preparation of CoQ 10 SDs using P 407 as a meltable hydrophilic polymer carrier could be a promising approach to improve its dissolution.