• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.2
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• pp.121-129
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• 2011

It is progressing as new advents and remarkable developments of mobile device every year. On the upper line reason, NAND FLASH large density memory demands which can be stored into portable devices have been dramatically increasing. Therefore, the cell size of the NAND Flash memory has been scaled down by merely 50% and has been doubling density each per year. [1] However, side effects have arisen the cell distribution and reliability characteristics related to coupling interference, channel disturbance, floating gate electron retention, write-erase cycling owing to shrinking around 20nm technology. Also, FLASH controller to manage shrink effect leads to speed and current issues. In this paper, It will be introduced to solve cycling, retention and fail bit problems of sub-deep micron shrink such as Virtual negative read used in moving read, randomization. The characteristics of retention, cycling and program performance have 3 K per 1 year and 12.7 MB/s respectively. And device size is 179.32 $mm^2$ (16.79 mm ${\times}$ 10.68 mm) in 3 metal 26 nm CMOS.

• Journal of the Korean institute of surface engineering
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• v.31 no.1
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• pp.24-33
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• 1998

Effects of pH and supporting salts on the characteristics of electrogalvanzied coating in sulfate bath are investigated. The fine grain size is obtained and the whiteness with the amount of supporting salts or pH increased at more than current density of 100A/$dm^2$<\TEX>, With supporting salts increased, the electro-conductivity of the bulk solution increases and the cell voltage decreases, while the width of the cathode burned edge gets wider because it seems that the increased overpotential the vicinity of cathode causes the decreases, of limiting current density. When the amount of supporting salts or pH of sulfate bath decreases, the zinc crystals have preferred orientation (001) planes. However when the amount of supporting salts or pH increase, the crystal texture has less (001) planes and gets to have random crystal planes.

• Journal of Power Electronics
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• v.7 no.4
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• pp.343-352
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• 2007

This paper proposes a modularized charge equalization converter for hybrid electric vehicle (HEV) lithium-ion battery cells, in which the intra-module and the inter-module equalizer are Implemented. Considering the high voltage HEV battery pack, over approximately 300V, the proposed equalization circuit modularizes the entire $M^*N$ cells; in other words, M modules in the string and N cells in each module. With this modularization, low voltage stress on all the electronic devices, below roughly 64V, can be obtained. In the intra-module equalization, a current-fed DC/DC converter with cell selection switches is employed. By conducting these selection switches, concentrated charging of the specific under charged cells can be performed. On the other hand, the inter-module equalizer makes use of a voltage-fed DC/DC converter for bi-directional equalization. In the proposed circuit, these two converters can share the MOSFET switch so that low cost and small size can be achieved. In addition, the absence of any additional reset circuitry in the inter-module equalizer allows for further size reduction, concurrently conducting the multiple cell selection switches allows for shorter equalization time, and employing the optimal power rating design rule allows fur high power density to be obtained. Experimental results of an implemented prototype show that the proposed equalization scheme has the promised cell balancing performance for the 7Ah HEV lithium-ion battery string while maintaining low voltage stress, low cost, small size, and short equalization time.

• Journal of Plant Biology
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• v.17 no.4
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• pp.163-170
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• 1974

Leaf tissue of Glycine max Merr. was fixed in para-formaldehyde-glutarldehyde and postfixed in osmium tetroxide or postassium permanganate for electron microscopy. The origin of cytolysome-like organelles of mesophyll cell was studied and changes of fine structure of the organelles according to treating solutions such as gibberellin (GA), kinethin (KI), 2,4-dichlorophenoxy acetic acid(2, 4-D) or 2, 4-D＋GA(1mg/l, respectively) were observed. The cylolysome-like organelles differentiate in endoplasmic reticulum and plasmalemma, and they drop into vacuoles being isolated from the formers. They seem to change into myelin-like structure and to be degenerated by autodigestion. Cytolysome-like organelles involved in cell walls and vacuoles showed activity of acid phosphatase. In the group of GA and KI treatment, cytolysome-like organelles were similar to that of the control group. But in the treatmental groups of 2,4-D and 2,4-D＋GA, myelin-like structures increased in size and autodigestion of this organelles were similar to that of the control group. But in the treatmental groups of 2,4-D and 2,4-D＋GA, myelin-like structures increased in size and autodigestion of this organelle seemed to be accelerated. In the treatmental group of 2,4-D＋GA, myelin-like structures shown high electron density were observed in cytoplasm and vacuoles together.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3045-3050
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• 2014

Renal cell carcinoma (RCC) is the most lethal of all urological cancers and tumor angiogenesis is closely related with its growth, invasion, and metastasis. Recent studies have suggested that epidermal growth factor-like domain multiple 7 (EGFL7) is overexpressed by many tumors, such as colorectal cancer and hepatocellular carcinoma; it is also correlated with progression, metastasis, and a poor prognosis. However, the role of EGFL7 in RCC is not clear. In this study, we examined how EGFL7 contributes to the growth of RCC using a co-culture system in vitro and a xenograft model in vivo. Downregulated EGFL7 expression in RCC cells affected the migration and tubule formation of HMEC-1 cells, but not their growth and apoptosis in vitro. The level of focal adhesion kinase (FAK) phosphorylation in HMEC-1 cells decreased significantly when co-cultured with 786-0/iEGFL7 cells compared with 786-0 cells. After adding rhEGFL7, the level of FAK phosphorylation in HMEC-1 cells was significantly elevated compared with phosphate-buffered saline (PBS) control. However, FAK phosphorylation was abrogated by EGFR inhibition. The average size of RCC local tumors in the 786-0/iEGFL7 group was noticeably smaller than those in the 786-0 cell group and their vascular density was also significantly decreased. These data suggest that EGFL7 has an important function in the growth of RCC by facilitating angiogenesis.

• Journal of Korea Foundry Society
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• v.31 no.3
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• pp.145-151
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• 2011

Metallic foam has been known as a functional material which can be used for absorption properties of energy and sound. The unique characteristics of Al foam of mechanical, acoustic, thermal properties depend on density, cell size distribution and cell size, and these characteristics expected to apply industry field. Al-Zn-Mg-Cu alloy foams was fabricated by following process; firstly melting the Al alloy, thickening process of addition of Ca granule to increased of viscosity, foaming process of addition of titanium hydride powder to make the pores, holding in the furnace to form of cooling down to the room temperature. Metal foams with various porosity level were manufactured by change the foaming temperature. Compressive strength of the Al alloy foams was 2 times higher at 88% porosity and 1.2 times higher at 92% porosity than pure Al foams. It's sound and vibration absorption coefficient were higher than pure Al foams and with increasing porosity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.19-26
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• 2021

The lattice structure is attracting attention from industry because of its excellent strength and stiffness, ultra-lightweight, and energy absorption capability. Despite these advantages, widespread commercialization is limited by the difficult manufacturing processes for complex shapes. Additive manufacturing is attracting attention as an optimal technology for manufacturing lattice structures as a technology capable of fabricating complex geometric shapes. In this study, a unit cell was formed using a three-dimensional coordinate method. The relative density relational equation according to the boundary box size and strut radius of the unit cell was derived. Simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) with a controlled relative density were designed using modeling software. The accuracy of the equations for calculating the relative density proposed in this study secured 98.3%, 98.6%, and 96.2% reliability in SC, BCC, and FCC, respectively. A simulation of the lattice structure revealed an increase in compressive yield load with increasing relative density under the same cell arrangement condition. The compressive yield load decreased in the order of SC, BCC, and FCC under the same arrangement conditions. Finally, structural optimization for the compressive load of a 20 mm × 20 mm × 20 mm structure was possible by configuring the SC unit cells in a 3 × 3 × 3 array.

• Polymer(Korea)
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• v.25 no.4
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• pp.528-535
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• 2001

Polyurethane specimens were mainly composed of polyol, MDI, silicone surfactant, and water. The effects of ethylene glycol on the cell size, forming magnification, cream time, gel time, take free time, final free rising height, and reactive temperature were investigated. The cyclopentane was used for PU foam as a physical blowing agent. The components were hand-mixed at about 5000 rpm within 4 seconds at room temperature. The mixtures with various ethylene glycol contents were foamed in the wood mold. When the index of isocyanate was fixed, as the amount of ethylene glycol increased, cell size and thermal conductivity were decreased by about 5.1% and 14%, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.166-169
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• 2006

We fabricated hexagonal copper sulfide $Cu_2S$ nanowires to obtain a larger contact area of $Cu_2S/CdS$ solar cell. Copper sulfide nanowires were grown on Cu foil at room temperature by gas-sol id reaction. The size, density and shape of nanowires seemed to be affected by the change or reaction time temperature, crystallographic orientation of Cu foil, and molar ratio of the mixed gas. We controled the length and the diameter of the nanowires and we obtained suitable nanowire arrays which has fitting size for uniform deposition with n-type CdS. CdS layer was deposited on the nanowire array by electrodeposition and it seemed to be uniform. The $Cu_2S/CdS$ nanowires/CdS junction showed diode characteristics, A large contact area is expected with the $Cu_2S/CdS$ nanowire structure as compared with the $Cu_2S/CdS$ thin film.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.425-428
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• 2006

Recently, Direct Methanol Fuel Cell (DMFC) for portable devices has been received much attention because DMFC has a possibility of higher energy density than electrical batteries and smaller size than other fuel cells. This paper presents the fabrication and test of a thermopneumatic microactuator with a phase change for DMFC. A microactuator consists of an inlet an outlet a chamber, a heater and a sensor of resistance temperature detector(RTD). The micoractuator is fabricated by the spin-coating process, the lithograph process, the deep RIE process and so on. The total size of microactuator is $20{\times}20{\times}0.53mm^3$. When the current is applied, the heater heats liquid in chamber. As a result the liquid vaporizes. The response of temperature in the chamber was measured using thermocouple The changed temperature is $3^{\circ}C$ for 5 sec at 0.032W.