• Journal of IKEEE
• /
• v.24 no.4
• /
• pp.1129-1135
• /
• 2020

The effects of battery aging limit the rechargeable capacity, State of Health(SoH). It is very important to estimate the SoH in the battery monitoring system(BMS) and many algorithms of measuring the internal resistance of the battery were proposed. A method is used by applying a current source of a specific frequency to the battery and measuring the voltage response. When charging harmonic noise is generated in the voltage response, it results in poor resistance measurement accuracy. In this paper, a robust battery internal resistance measurement algorithm is proposed to eliminate the effect of charging noise by integrating the current source and voltage response signals for a certain period. It showed excellent accuracy and stable measurement results. Applying to the BMS for uninterruptible power supply, the usefulness of the proposed method is verified.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.1
• /
• pp.7-12
• /
• 2001

Three Pseudomonas strains (Bk8, Bk9, Bk10) selected from soil for their ability to degrade herbicide diuron were tested for their heavy metal resistance. The growth of these catabolic strains on a minimal medium with various concentrations of $Cd^{2+},\;Zn^{2+},\;Ni^{2+}$, and $Hg^{2+}$ revealed a minimal effect on the carbon source for the inhibitory effect of the metals. One of these strains, namely, Bk8, exhibited a high resistance to the heavy metals as compared to the two other strains. This strain harbors plasmid pBk8 (110 kb) and contains at least fur determinants encoding heavy metal resistance. Nickel and zinc resistance are encoded by genes located on the chromosome, while cadmium and mercury resistance are on plasmid pBk8. Accordingly, the characteristics of strain Bk8 suggest that it would be useful in the bioremediation of aromatic compounds in the presence of toxic heavy metals as co-contaminants.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.49 no.2
• /
• pp.9-14
• /
• 2012

In this study, multi-finger RF MOSFET substrate parameters are accurately extracted by using S-parameters measured from common source-bulk and common source-gate test structures. Using this extraction method, the accuracy of an asymmetrical model with three substrate resistances is verified by observing better agreement with measured Y-parameters than a simple model with a single substrate resistance. The modeled S-parameters of the asymmetrical model also show excellent agreement with measured ones up to 20GHz.

• Journal of Satellite, Information and Communications
• /
• v.11 no.4
• /
• pp.27-32
• /
• 2016

A conventional double diffused drain n-type MOSFET (DDD_NMOS) device shows SCR behaviors with very low snapback holding voltage and latch-up problem during normal operation. However, a modified DDD_NMOS-based silicon controlled rectifier (DDD_NSCR_CPS) device with a counter pocket source (CPS) structure is proven to increase the snapback holding voltage and on-resistance compare to standard DDD_NSCR device, realizing an excellent electrostatic discharge protection performance and the stable latch-up immunity.

• Journal of the Korean institute of surface engineering
• /
• v.44 no.5
• /
• pp.190-195
• /
• 2011

Diamond-like carbon (DLC) has many outstanding properties such as low friction, high wear resistance and corrosion resistance. However, it is difficult to achieve enough adhesion on the metal substrates because of weak bonding between DLC film and the metal substrate. The purpose of this study is to enhance an adhesion of DLC film. For improving adhesion, the substrate was treated by active screen plasma nitriding before DLC film deposing. Nitrided substrates were investigated by Glow Discharge Spectrometer (GDS), Micro-Vickers Hardness. DLC films were deposited on several metals by linear ion source, and characteristics of the films were investigated using nano-indentation, Field Emission Scanning Electron Microscope (FESEM). The adhesion was measured by scratch tester. The adhesion of DLC films was increased when nitriding layer was formed before DLC deposition. Therefore, the adhesion of DLC film can be enhanced as increasing the hardness of materials.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.8 no.3
• /
• pp.251-263
• /
• 2008

In this paper, we report an analytical modeling and 2-D Synopsys Sentaurus TCAD simulation of ion implanted silicon carbide MESFETs. The model has been developed to obtain the threshold voltage, drain-source current, intrinsic parameters such as, gate capacitance, drain-source resistance and transconductance considering different fabrication parameters such as ion dose, ion energy, ion range and annealing effect parameters. The model is useful in determining the ion implantation fabrication parameters from the optimization of the active implanted channel thickness for different ion doses resulting in the desired pinch off voltage needed for high drain current and high breakdown voltage. The drain current of approximately 10 A obtained from the analytical model agrees well with that of the Synopsys Sentaurus TCAD simulation and the breakdown voltage approximately 85 V obtained from the TCAD simulation agrees well with published experimental results. The gate-to-source capacitance and gate-to-drain capacitance, drain-source resistance and trans-conductance were studied to understand the device frequency response. Cut off and maximum frequencies of approximately 10 GHz and 29 GHz respectively were obtained from Sentaurus TCAD and verified by the Smith's chart.

• Proceedings of the KIEE Conference
• /
• 2000.11d
• /
• pp.675-678
• /
• 2000

This paper has proposed a new digital ground resistance tester for electrical systems. It features automatic operation with an injected current source. Without climbing electric power poles a worker can measure safely and quickly a ground resistance and current along the ground line.

• Korean Journal of Materials Research
• /
• v.13 no.1
• /
• pp.43-47
• /
• 2003

As and BF$_2$dopants are implanted for the formation of source/drain with dose of 1${\times}$10$^{15}$ ions/$\textrm{cm}^2$∼5${\times}$10$^{15}$ ions/$\textrm{cm}^2$ then formed cobalt disilicide with Co/Ti deposition and doubly rapid thermal annealing. Appropriate ion implantation and cobalt salicide process are employed to meet the sub-0.13 $\mu\textrm{m}$ CMOS devices. We investigated the process results of sheet resistance, dopant redistribution, and surface-interface microstructure with a four-point probe, a secondary ion mass spectroscope(SIMS), a scanning probe microscope (SPM), and a cross sectional transmission electron microscope(TEM), respectively. Sheet resistance increased to 8%∼12% as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{V}$ , while sheet resistance uniformity showed very little variation. SIMS depth profiling revealed that the diffusion of As and B was enhanced as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{＋}$ . The surface roughness of root mean square(RMS) values measured by a SPM decreased as dose increased in $CoSi_2$$n^{＋}$ , while little variation was observed in $CoSi_2$$p^{＋}$ . Cross sectional TEM images showed that the spikes of 30 nm∼50 nm-depth were formed at the interfaces of $CoSi_2$$n^{＋}$ / and $CoSi_2$/$p^{＋}$, which indicate the possible leakage current source. Our result implied that Co/Ti cobalt salicide was compatible with high dose sub-0.13$\mu\textrm{m}$ process.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.407-408
• /
• 2015

The existing (q)Z-source PWM AC-AC converters have limited voltage gain because of the equivalent series resistance in the Z-source inductor. In order to obtain higher voltage gain than (q)Z-source AC-AC converters, a coupled inductor (or transformer) based Z-source AC-AC converter is proposed in this paper. By increasing turns ratio of the coupled inductor more than 1, the proposed converter can obtain higher output voltage than (q)Z-source converters with the same duty ratio. A 120 W prototype AC-AC converter is built and tested to verify performances of the proposed converter.

• Information Systems Review
• /
• v.11 no.3
• /
• pp.125-146
• /
• 2009

The emergence of open source software(OSS) with its most prominent advantages creates a vast interest among practitioners. A study on Linux, the most well-known OSS, estimated that it would cost as 5.4 billion Euros taking over 73,000 person-years if it had been developed by conventional means. However, Linux has achieved only 0.65 percent of the operating system market for individual users while Microsoft windows family counts for nearly 90 percent of the market. Much of the effort being spent in the development of OSS is going to waste and potential value that OSS can bring to users is not being realized. Adoption of OSS is often accompanied by the discontinuance of existing software that is already in place. If users resist changing, they may not adopt OSS. Using the case of Linux, this study examines user resistance to change from the commercial operating software to the free operating system. This study identifies six sub-types of switching costs (uncertainty, emotional, setup, learning, lost benefit, and sunk costs) and tests their effects on user resistance to change based on a survey of 201 users. The results show that user resistance to change has a negative impact on the adoption of OSS. Further, this study shows that uncertainty and emotional costs have significant effects on user resistance to change. Beyond previous research on technology adoption, this research contributes towards an understanding of the switching costs leading to user resistance to change and offers suggestions to OSS practitioners for developing strategies to improve the adoption of OSS.