• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.213-213
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• 2010

Magnetic random access memory (MRAM), based on magnetic tunnel junction (MTJ) and CMOS, is one of the best semiconductor memories because it can provide nonvolatility, fast access time, unlimited read/write endurance, low operating voltage and high storage density. For the realization of high density MRAM, the etching of MTJ stack with good properties is one of a key process. Recently, there has been great interest in the MTJ stack using MgO as barrier layer for its huge room temperature MR ratio. The use of MgO barrier layer will undoubtedly accelerate the development of MTJ stack for MRAM. In this study, high-density plasma reactive ion etching of MgO films was investigated in an inductively coupled plasma of $Cl_2$/Ar gas mixes. The etch rate, etch selectivity and etch profile of this magnetic film were examined on vary gas concentration. As the $Cl_2$ gas concentration increased, the etch rate of MgO monotonously decreased and etch slop was slanted. The effective of etch parameters including coil rf power, dc-bais voltage, and gas pressure on the etch profile of MgO thin film was explored, At high coil rf power, high dc-bais voltage, low gas pressure, the etching of MgO displayed better etch profiles. Finally, the clean and vertical etch sidewall of MgO films was achieved using $Cl_2$/Ar plasma at the optimized etch conditions.

• The Journal of Korea Robotics Society
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• v.19 no.3
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• pp.236-243
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• 2024

This paper introduces a dual manipulator system designed to automate the packaging process of industrial coils, which exhibit higher variability than other structured industrial fields due to diverse commercial requirements. The conventional solution involves the direct-teaching method, where an operator instructs the robot on a target configuration. However, this method has distinct limitations, such as low flexibility in dealing with varied sizes and safety concerns for the operators handling large products. In this sense, this paper proposes a two-step approach for coil packaging: motion planning and assembly execution. The motion planning includes a Rapidly-exploring Random Tree algorithm and a smoothing method, allowing the robot to reach the target configuration. In the assembly execution, the packaging is considered a peg-in-hole assembly. Unlike typical peg-in-hole assembly handling two workpieces, the packaging includes three workpieces (e.g., coil, inner ring, side plate). To address this assembly, the paper suggests a suitable strategy for dual manipulation. Finally, the validity of the proposed system is demonstrated through experiments with three different sizes of coils, replicating real-world packaging situations.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.268-278
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• 2013

Objectives: The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of seasoned laver products. The hazard analysis examined microbial evaluations and developed a HACCP management plan through the heating process. Methods: In this study we chose three companies and performed the analysis thrice. During this study, general bacteria along with other food poisoning bacteria such as Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, E.coil, O157:H7, Vibrio parahaemolyticus, were studied at varying temperatures from 100 to $300^{\circ}C$. Results: The presence of general bacteria was detected in raw laver in the samples analyzed from all the three companies, and the number ranged from $10^5-10^7$. Bacillus cereus was detected in samples from only two of the three companies analyzed. However, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, E.coil, O157:H7, and Vibrio parahaemolyticus were all negative. General bacteria was reduced to $10^5$ after being subjected to temperatures of $100-250^{\circ}C$, but heating to over $270^{\circ}C$ reduced the number to below $10^3$, and the other microbes such as Bacillus cereus were not detected. Conclusions: In conclusion, the heating process ($270-280^{\circ}C$) along with RPM of 100-1200 were identified as CCP to reduce biological hazards.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.212-217
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• 2000

This study was determined protein reaction, antioxidative activity, nitrite scavening ability and antimicrobial activity of tannins isolated from astringent persimmon fruits. Tannins extracted from green persimmon fruits reacted highly with BSA(bovine serum albumin). Reactions between tannins and BSA were more active when contents of tannin were higher than that of BSA. Antioxidative abilities of green persimmon tannin were comparable to that of BHT(butylated hydroxytoluene). Green persimmon tannins exhibited remarkable nitrite-scavenging activity. Different antimicrobial activities of persimmon tannins were observed depending on the maturity. The growth of V. parahaemolyticus and E coil were highly inhibited by the addition of persimmon tannins. Tannins from soft persimmon did not have antimicrobial activities against B. subtilis and S. typhimurium.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.151-155
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• 2005

Though the nuclear fusion system has been fused into hydro-nuclear based on thermodynamics by tokamak system, there has been no success story. Because it's impossible to confine high temperatured plasma long Time actually. New nuclear-fusion-system using this nuclear-fusion-method will gather toroidal-magnetic-field by putting Core Block(C shaped torus iron) and toroidal-aluminium coil into toroidal magnetic-field-aluminium. That will arrange the nuclear-fusion-route on a gap fallen out by a part of cut torus-core and mkee the toroidal-an electric-current flow and electrolyze the fusioned-material (an electrolyte) into troidal-electrocity. That consists of troidal-magnetic-fild coil, toroidal-coial fusioned- material, series circuit. So toroidal-electocity will be changed into filament-electrocity and be introjected into fusioned-material. In a sapce on filament-electrocity, the magnetic inhaling-powr will enlarge to input-electrocity outside. This will exceed the Coulomb force and reache the nuclear-fusion. By this phenomenon there be quantity-loss. By this process I could confirmed that Einstein euation$(E=mC^2)$ releases into thermal energy.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.349-354
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• 1985

A 4.7 kb Hind III fragment containing $\alpha$-amylase gene of Bacillus stearothermophilus IAM 11062 was cloned in Escherichia coil HB101, using plasmid pBR322 and runaway plasmid pSY343 as a vector. The cloned gene was stably maintained and expressed In E.coli. The constructed strain of E. coli have at least 3 times higher amylase activity than the donor strain, of B. stearothermophilus. About 75％ of the $\alpha$-amylase produced by the constructed strain of E. coli was localized in the periplasm and it was found that the enzymes can be released by an osmotic shock using EDTA. The enzymatic properties of L-amylase produced in E. coli were very similar to those produced by B. stearothermophilus in terms of optimum temperature, heat stability and molecular weight.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.114-118
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• 2014

A total of 122 ESBL-producing intestinal bacteria were collected from regional hospitals in the Chungcheong area. Combination disk test (CDT) was performed for antimaicrobial susceptability using cefotaxime and cefotaxime/clavulanate according to Clinical Laboratory Standard Institute (CLSI). Mutiplex PCR using specific primers was performed for a detection of ESBL-genotypes and enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out for the tracking of molecular epidemiology. In the confirmation test using CDT, 73 out of 76 (96.1%) ESBL-producing Escherichia coli and 43 out of 46 (93.4%) ESBL-producing Klebsiella pnemoniae were positive. In the multiplex PCR, 60.5% of E. coil were positive for CTX-M-2 type gene and 56.5% of K. pneumoniae were positive for VEB -1 type gene. In the ERIC-PCR, E. coil isolates formed 5 clusters and K. pneumoniae isolates were grouped into 4 clusters depending on region. Genotypes of clinical isolates are useful for detection and differentiation of ESBL producing intestinal bacteria. The ERIC-PCR method is thought to be helpful for establishing a regional surveillance system for infection due to its formation of different clusters depending on region.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2374-2376
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• 2004

In this paper, we describe a DSP-based test apparatus for Control Element Drive Mechanism (CEDM). Using this apparatus, we can catch the mechanical and electrical characteristics of CEDM and obtain the information about the improvement of CEDM and the design of CEDM power controller. The test apparatus for CEDM introduced in this paper can input firing angles directly into gate drive circuits of thyristors so that this method can be used to derive the maximum and minimum values of firing angles within available limits for a 3-phase half-wave rectifier. Angle inputs help us understand each coil's response characteristics. Since this apparatus generates a serial sequence for CEDM insertion and withdrawal operations, we may judge whether CEDM works correctly as expected or not in each phase of a step movement.

• Progress in Medical Physics
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• v.16 no.3
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• pp.155-159
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• 2005

As a part of implantable device in body, a transcutaneous energy transmission system has been developed. It would be desirable to tansfer electrical energy to implantable devices transcutaneously. The distance between transcutaneous transformer windings are approximately equal to the thickness of the human's skin, nominally between 10$\~$20 mm. Class-E resonant amplifier is used to drive a primary coil for high efficiency. Maximum current is above 50 mA at any frequency. The developed system shows that the circuit operates correctly at each frequency; 500 kHz, 1 MHz and 4 MHz.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.211-220
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• 1986

Nitrogen fixation (nif) genes of Rhizobium leguminosarum were transferred to nif Klebsiella pneumoniae and E. coli by conjugation after partial heat induction of $RP_4$ :: Mu cts in Rhizobium $R^+$ transconjugant, and the hybrid plasmids in the transconjugant strains were isolated and characterized. In order to transfer the nif genes from Rhizobium, the hybrid plasmid $RP_4$ :: Mu cts was transferred by conjugation from E. coil to the symbiotic nitrogen fixer, R. leguminosarum. After stabillity test, the $RP_4$ :: Mu cts in Rhixobium $R^+$ transconjugant was subjected to partial heat induction by culturing it statically at $38^{\circ}C$ for 16 hours, and then conjugated with the nif defective mutant strains of K. pneumoniae or nif mutant strains of E. coli having whole nif gene plasmid. Recombinant strains of K. pneumoniae, which could grow in a N-free medium and exhibit the nitrogenase activity were selected. However, in the case of E. coli, they could grow well in a NA medium containing antibiotices, but hardly frow in a N-free medium. The hybrid plasmids in these transconjugal strains were isolated by gel electrophoresis and compared their molecular sizes.