• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2000.11a
• /
• pp.179-182
• /
• 2000

This paper investigates characteristics of spiral charge for charge simulation method to calculate electric fields of spiral conductor bundles with spiral rods in 765 kV transmission line. We finds the simulating spiral charge as constant charge density give less potential calculation error than sinusoidal charge density. When a spiral rod is simulated as spiral charge, we also knows two spiral charge can simulate spiral rod best.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.7
• /
• pp.532-541
• /
• 2003

In a memory, most power is dissipated in high capacitive lines such as predecoder lines, word lines, and bit lines. To reduce the power dissipation in these high capacitive lines, this paper proposes three techniques using charge recycling and charge sharing. One is the charge recycling predecoder (CRPD). The second one is the charge recycling word line decoder (CRWD). The last one is the charge sharing bit line (CSBL) for a ROM. The CRPD and the CRWD recycle the previously used charge in predecoder lines and word lines. Theoretically, the power consumption in predecoder lines and word lines are reduced to a half. The CSBL reduces the swing voltage in the ROM bit lines to very small voltage using a charge sharing technique. the CSBL can significantly reduce the power dissipation in ROM bit lines. The CRPD, the CRWD, and the CSBL consume 82%, 72%, and 64% of the power of previous ROM designs respectively. A charge recycling and charge sharing ROM (CRCS-ROM) with the CRPD, the CRWD, and the CSBL is implemented. A CRCS-ROM with 8K16bits was fabricated in a 0.3${\mu}{\textrm}{m}$ CMOS process. The CRCS-ROM consumes 8.63㎽ at 100MHz with 3.3V. The chip core area is 0.1 $\textrm{mm}^2$.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.2 no.2
• /
• pp.139-148
• /
• 1998

The charge densities of humic acid and humic extract have been determined by back titration using spectrophotometry as the method of end point detection and several cationic polymers of different charge density(copolymers of acylamide and dimethylaminoethylacrylate and polydiallyidimethylammonium chloride, PDDA), and a cationic indicator o-toluidine blue(o-Tb). The charge densities of humic acid and humic extract obtained depend on the charge densities of cationic polymers used. When the polymers of lower charge density are used, lower apparent charge density values are obtained, but for polymers of high charge density(above 2.5 meq/g), the measured values are almost identical, but also are nearly the same as that obtained for PDDA which has a high charge density(about 6 meq/g). For polymers of lower charge density, it is considered that the optimum dosage does not correspond to 1 :1 charge neutralization between anionic and cationic groups. Polymers of high charge density should be used in order to achieve a complete charge neutralization. As humic acid and humic extract are dissociable acids, their ionization is heavily pH dependent and so higher charge density values are obtaines with increasing pH.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.2 no.2
• /
• pp.267-273
• /
• 1998

In this paper, we designed a charge pump with a differential current switching structure and it was made of a MESFET with high speed switching Property compared with CMOSFETs. The charge pump with a differential current switching structure is analyzed about operating property of circuit in high frequency band. Also we propose a method on it's characteristics estimation. The designed circuit is simulated by HSPICE simulator, and in view of the results we think that the charge pump of this study can be used in circuits of 1 GHZ frequency band grade.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.5
• /
• pp.50-57
• /
• 2008

In this paper, a high-efficiency charge pump for use in CMOS image sensor(CIS) is proposed. The proposed charge pump pursues high pumping efficiency by minimizing the switching and reversion losses by taking advantage of operation characteristics of CIS. That is, the proposed charge pump minimizes the switching loss by dynamically controlling the size of clock driver, pumping capacitor, and charge transfer switch based on the operation phase of CIS pixel sensor. The charge pump also minimizes the reversion loss by guaranteeing a sufficient non-overlapping period of local clocks using a tri-state local clock driver adapting the schmitt trigger. Comparison results using a 0.13-um CMOS process technology indicate that the proposed charge pump achieves up to 49.1% reduction on power consumption under no loading current condition as compared to conventional charge pump. They also indicate that the charge pump provides 19.0% reduction on power consumption under the maximum loading current condition.

• Journal of the Semiconductor & Display Technology
• /
• v.18 no.4
• /
• pp.138-142
• /
• 2019

As the NAND flash memory goes to 3D vertical Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) structure, the lateral charge migration can be critical in the reliability performance. Even more, with miniaturization of flash memory cell device, just a little movement of trapped charge can cause reliability problems. In this paper, we propose a method of predicting the trapped charge profile in the retention mode. Charge diffusivity in the charge trapping layer (Si₃N₄) was extracted experimentally, and the effect on the trapped charge profile was demonstrated by the simulation and experiment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.4
• /
• pp.31-36
• /
• 2001

This paper investigates characteristics of spiral charge for 3 dimensional charge simulation method to calculate electric fields of special conductor bundles with spiral rods in 765kV transmission line. We finds the simulating spiral charge as constant charge density give less potential calculation error than sinusoidal charge falsity. When a spiral rod is simulated as spiral charge, we also knows two spiral charge can simulate spiral rod best.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.8
• /
• pp.672-679
• /
• 2007

The combustion characteristics of a liquefied petroleum gas-di-methyl ether (LPG-DME) compression ignition engine was investigated under homogeneous charge and stratified charge conditions. LPG was used as the main fuel and injected into the combustion chamber directly. DME was used as an ignition promoter and injected into the intake port. Different LPG injection timings were tested to verify the combustion characteristics of the LPG-DME compression ignition engine. The combustion was divided into three region which are homogeneous charge, stratified charge, and diffusion flame region according to the injection timing of LPG. The hydrocarbon emission of stratified charge combustion was lower than that of homogeneous charge combustion. However, the carbon monoxide and nitrogen oxide emission of stratified charge combustion were slightly higher than those of the homogeneous charge region. The indicated mean effective pressure was reduced at stratified charge region, while it was almost same level as the homogeneous charge combustion region at diffusion combustion region. The start of combustion timing of the stratified charge combustion and diffusion combustion region were advanced compared to the homogeneous charge combustion. It attributed to the higher cetane number and mixture temperature distribution which locally stratified. However, the knock intensity was varied as the homogeneity of charge was increased.

• Environmental Engineering Research
• /
• v.16 no.1
• /
• pp.29-34
• /
• 2011

The electric charge on a membrane was investigated by analyzing the experimental rejection of various monovalent and divalent ionic solutes. The characteristics of the separation of ionic solutes using various nanofiltration membranes were obtained from an experimental nanofiltration set-up, with a surface area of $40cm^2$ under the operational pressures between 0.25-0.3 MPa. The state of the membrane electric charge was observed using separation coefficients, i.e., the permeation ratio of monovalent to divalent ions. To confirm the state of the membrane charge observed via the separation coefficient, a calculation using the extended Nernst-Planck equation, coupled with the Donnan equilibrium, assuming different electric charge states of the membrane, was compared with the experimental rejection of ionic solutes. The examination of the characteristics of separation using three types of nanofiltration membranes showed that one of the membranes carried a negative/positive double charge density inside, while other two membranes carried either a positive or negative charge density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.497-500
• /
• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current.