• Journal of radiological science and technology
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• v.5 no.1
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• pp.15-19
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• 1982

Authors made an experiment to know the relation of surface doses and multiple factors of exposure by using grids, fields, tube voltages objects and distances and obtained the results as follows: 1. Surface doses were increased in proportion to the thickness of objects. 2. Surface doses were more influenced when irradiated fields were small and tube voltages were low. 3. Surface doses were a logarthmic proportion to the focus-object distance. 4. Multiple factors of exposure by using grid were under the control of the thickness of objects, irradiated fields and tube voltages but the relation of them were not fixed.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.45.4-45
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• 2002

In EIT, an array of disjoint electrodes is attached on the boundary of the object and a set of small alternating electrical currents is injected into the object through these electrodes, and then the corresponding set of voltages is measured on the same array of the electrodes. The objective in EIT is to estimate the resistivity distribution inside the object based on the set of measured voltages and injected currents. In this paper, we proposed a new dynamic EIT reconstruction scheme based on the interacting multiple model (IMM) algorithm. The main contribution of the proposed scheme is that multiple models are employed for the state evolution to get around the modeling uncertainty. Extensi...

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1866-1868
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• 2004

This paper deals with the device for measuring the time-varying magnetic fields and induced voltages caused by lightning discharges. The system consists of two loop antennas for the measuring the magnetic flux density and induced voltages caused by the lightning current, an integrator a data acquisition and a personal computer with a software package that was developed for the analysis of the measurements.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.32-39
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• 2008

Tunnel oxide of non-volatile memory (NVM) devices would be very difficult to downscale if ten-year data retention were still needed. This requirement limits further improvement of device performance in terms of programming speed and operating voltages. Consequently, for low-power applications with Fowler-Nordheim programming such as NAND, program and erase voltages are essentially sustained at unacceptably high levels. A promising solution for tunnel oxide scaling is tunnel barrier engineering (TBE), which uses multiple dielectric stacks to enhance field-sensitivity. This allows for shorter writing/erasing times and/or lower operating voltages than single $SiO_2$ tunnel oxide without altering the ten-year data retention constraint. In this paper, two approaches for tunnel barrier engineering are compared: the crested barrier and variable oxide thickness. Key results of TBE and its applications for NVM are also addressed.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1112-1115
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• 1990

Described is a new control signal transmission system which utilizes an optical fiber to transmit 2-bit control signals from the transmitter to receiver. In the transmitter the DC series control voltages are converted into the multiple frequency signals by voltage controlled oscillator (VCO). The multiple frequency signals can easily be transmitted by optical fiber. In the receiver the multiple frequency signals can be detected by analog or digital circuits and then be converted into 2-state control signals which can be used for a variety of applications.

• Journal of IKEEE
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• v.22 no.2
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• pp.384-392
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• 2018

A multiple-output LDO regulator is a good choice in terms of the efficiency in embedded systems requiring various supply voltages. A small feedback factor in LDO incurs the long settling time, resulting in large ripples in the time-multiplexing strategy. A new proposed topology enhances the settling time, and hence the ripples by incorporating the constant feedback factor with different reference voltages. The simulation results of a prototype design in a standard $0.35{\mu}m$ CMOS process verify that the proposed strategy enhances the settling time and ripple characteristic by more than doubled than a conventional circuit using the feedback factor of less than 0.4.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.184-191
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• 2016

In recent years, there are a number of studies that have been carried out to explore the alternative for Mineral Oil (MO) as dielectric insulating fluid in transformers due to the increasing tight regulation on safety and environment. Vegetable oils have been identified as suitable candidate since it is biodegradable, non-toxic and high flash/fire points which ensure more in-service safety. Among the types of vegetable oils considered for transformers application are Palm Oil (PO) and Coconut Oil (CO). This paper presents an experimental study on the lightning breakdown voltages of PO and CO under non-uniform electric field based on needle-sphere electrodes configuration at 3 small gap distances. The type of PO used in this study is Refined Bleached and Deodorized Palm Oil (RBDPO) Olein. The main focus of this study is to examine the lightning breakdown performance of RBDPO and CO under different test conditions and assess its suitability as dielectric insulating fluid in transformers. The effect of voltage polarities (positive and negative) and testing methods (rising-voltage, up-and-down and multiple-voltage) were investigated. The data obtained from all tests were analysed by Weibull distribution in order to determine the withstand voltages for each type of oils. It was found that the breakdown voltages of RBDPO and CO are comparable with MO under positive lightning impulse. Under negative lightning impulse, the breakdown voltage of MO is slightly higher than RBDPO and CO. There is no significant effect of testing methods and voltage polarities on lightning breakdown voltages of RBDPO and CO. Based on the statistical analysis, it is found that the breakdown voltages of RBDPO and CO at 1% probability are slightly lower than MO.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.13-14
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• 2013

Multiple output converters (MOCs) are widely used for applications which require various kinds of the output voltages due to its advantages in cost, volume, and efficiency. However, most of the MOCs developed so far can regulate only one output tightly and require as many secondary windings in the transformer as the number of the outputs. In this paper, a novel Time Division Multiple Control (TDMC) method to regulate all the outputs in high precision is proposed and applied to the double ended forward converter for the multiple battery charger. Additional benefit of the proposed topology is to require only one secondary winding in the transformer for all the outputs. The proposed converter can charge two different kinds of batteries or same kind of batteries in different state of charges (SOCs) by CC/CV mode independently with the even degree of tight regulation, thereby satisfying the ripple requirements for each battery.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.802-805
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• 2007

A hardware architecture is presented of a wavelet based multiple line addressing driving scheme for passive matrix displays using the FPGA (Field Programmable Gate Arrays), which will be integrated in the scalable video coding $architecture^{[1]}$. The incoming compressed video data stream will then directly be transformed to the required column voltages by the hardware architecture without the need of employing the video decompression.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.6 s.348
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• pp.9-17
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• 2006

We proposed a new High-speed CMOS Level Up/Down Shifter circuits that can be used with Dynamic Voltage and Frequency Scaling(DVFS) algorithm, for low power system in the SoC(System-on-Chip). This circuit used to interface between the other voltage levels in each CMOS circuit boundary, or between multiple core voltage levels in a system bus. Proposed circuit have advantage that decrease speed attenuation and duty ratio distortion problems for interface. The level up/down shifter of the proposed circuit designed that operated from multi core voltages$(0.6\sim1.6V)$ to used voltage level for each IP at the 500MHz input frequency The proposed circuit supports level up shifting from the input voltage levels, that are standard I/O voltages 1.8V, 2.5V, 3.3V, to multiple core voltage levels in between of $0.6V\sim1.6V$, that are used internally in the system. And level down shifter reverse operated at 1Ghz input frequency for same condition. Simulations results are shown to verify the proposed function by Hspice simulation, with $0.6V\sim1.6V$ CMOS Process, $0.13{\mu}m$ IBM CMOS Process and $0.65{\mu}m$ CMOS model parameters. Moreover, it is researched delay time, power dissipation and duty ration distortion of the output voltage witch is proportional to the operating frequency for the proposed circuit.