• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.12 s.354
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• pp.1-7
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• 2006

An on chip voltage down converter (VDC) using the self temperature-compensation techniques is proposed. At a different gate bias voltage, PMOSFET shows different source to drain current characteristic according to the temperature variation. The proposed VDC can reduce its temperature dependency by the source to drain current ratio of two PMOSFET with different gate bias respectively. Proposed circuit is fabricated in Dongbu-anam $0.18{\mu}m$ CMOS process and experimental results show its temperature dependency of $-0.49mV/^{\circ}C$ and external supply dependency of 6mV/V. Total current consumption is only $1.1{\mu}A@2.5V$.

• Korean Journal of Materials Research
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• v.7 no.3
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• pp.234-243
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• 1997

The crystal structure of arc melted $ZrV_{x}Mn_{1-x}Ni_{1.0},\;ZrV_{x}Mn_{0.8-x}Ni_{1.2},\;ZrV_{x}Mn_{0.6-x}Ni_{1.4}$ alloys which are known to have AB2 type Laves structure was investigated. They had mixed phases of C14 and C15. The radius ratio ($r_{A}/r_{B}$) of atoms in A site to that of B site was found to be an important parameter in explaining the omposition dependence of the crystal structure The C15 structure showed a linear increase with the ratio in as-cast conditions. However, the annealed alloys revealed a definite ratio at which the stability of both phases are divided distinctly. The composition of the alloys could be closely controlled by maintaining the argon pressure in the chamber over 1 arm during arc melting. In contrast, the alloy ingot melted in VIM showed a significant loss of hln.

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.700-705
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• 2006

Present studies were performed to determine the physiology of seed germination in Viola species native to Korea. Twelve species, 1 variety and 1 form were collected, classified and used as materials: V. collina, V. blandaefomis, V. rosii, V. chaerophylloides, V. phalacrocarpa, V. patrinii, V. mandshurica, V. mandshurica for. albescence, V. seoulensis, V. yedoensis, V. keiskei, V. variegata, V. variegata var. chinensis, and V. verecunda. V. tricolor 'Helen Mount' was also used to compare wild with cultivated species. In order to investigate the effect of temperature on seed germination, seeds stored at $4{\pm}2^{\circ}C$ for 10 months or 4 years were incubated at 10, 15, 20, $25^{\circ}C$ under 16h illumination with 4 replicates per treatment. Seeds which had not germinated at $10^{\circ}C$ were transferred to $30^{\circ}C$ to assess the effect of temperature change in germination. Germination percent and the days of first, 40% and 80% germination were assessed. Capability of seed germination varied with taxon; Species belonging to subsection Patellares had high ability of germination, compared to species in the other subsections, and series Chinensis was the best among subsection Patellares. Species capable of high germination germinated in all temperatures with reasonably high germination rate, but the other species responded sensitively to temperature with different germination patterns. Higher the temperature, shorter the incubation time required for first, 40% and 80% of germination. Therefore, high temperature was effective in almost all species, not only for inducing high rate of germination but also the uniformity of germination. Temperature change from $10^{\circ}C\;to\;30^{\circ}C$ had a positive effect on seed germination.

• KSBB Journal
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• v.17 no.6
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• pp.586-589
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• 2002

Lipomyces starkeyi KSM 22 produces dextranase and amylase (DXAMase). The addition of 0.02％ (w/v) 2-deoxy-D-glucose or 0.5% (w/v) glycerol into a 1% (w/v) starch medium increased the final activity of DXAMase produced 2.5 fold or 2.4 fold, respectively, compared to that of a 1% (w/v) starch medium. This activity was similar to that produced with 1% (w/v) dextran. The stability of purified OXAMase at 40$\^{C}$ for 3 weeks was tested using the various enzyme stabilizers. With the addition of 25% (v/v) glycerol, 90.9% of initial activity was left after 3 weeks. For practical use, the addition of 1% (v/v) glycerol with 50 mM of CaCl$_2$ or KH$_2$PO$_4$was adequate and maintained 73.4% of the initial activity under the test conditions used.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.4
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• pp.36-46
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• 1979

Using N_ Ch silicon gate technology . the capacitors and transistors with various dimenssion were fabricated. Although the applied process was somewhat standard the conditions of ion implantation for the gate were varied by changing the implant energies from 30keV to 60keV for B and from 100 keV to 175keV for P . The doses of the implant also changed from 3 $\times$ 10 /$\textrm{cm}^2$ to 5 $\times$ 10 /$\textrm{cm}^2$ for B and from 4$\times$ 10 /$\textrm{cm}^2$ to 7 $\times$ 10 /$\textrm{cm}^2$ for P . The D. C. parameters such as threshold voltage. substrate doping level, the degree of inversion, capacitance. flat band voltage, depletion layer width, gate oxide thickless, surface states, motile charge density, electron mobility. leakage current were evaluated and also compared with the corresponing theoretical values and / or good numbers for application. The threshold voltages measured using curve tracer and C-V plot gave good agreements with the values calculated from SUPREM II which has been developed by Stanford University process group. The threshold vol tapes with back gate bias were used to calculate the change of the substrate doping level. The measured subthreshold slope enabled the prediction of the degree of inversion The D. C. testing results suggest the realized capacitors and transistors are suited for the memory applications.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.451-463
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• 2004

The performance of disk-type catalytic filters impregnated by TiO$_2$ or TiO$_2$-3Al$_2$O$_3$ㆍ 2SiO$_2$ supports and V$_2$O$_{5}$ catalyst was evaluated for selective catalytic reduction (SCR) of NO with ammonia as a reductant. XRD, FT -IR, BET and SEM were used to characterize the catalytic filters prepared in this work. Optimal V$_2$O$_{5}$ loading and reaction temperature for V$_2$O$_{5}$/TiO$_2$ catalytic filters were 3-6 wt.% and 350-40$0^{\circ}C$ at GHSV 14,300 $hr^{-1}$ in the presence of oxygen, respectively. With increasing the V$_2$O$_{5}$ loading from 0.5 to 6 wt%, NO conversion increased from 24 to 96% at 40$0^{\circ}C$ and 14.300$hr^{-1}$, and maintained at 80% over in the V$_2$O$_{5}$ loading range of 3-6 wt.% and then dropped at V$_2$O$_{5}$ loading of 7wt.% over. In comparing V$_2$O$_{5}$/ TiO$_2$ and V$_2$O$_{5}$/ TiO$_2$-3Al$_2$O$_3$ㆍ2SiO$_2$ catalytic fillers, which have same 3wt.% V$_2$O$_{5}$ loading, the V$_2$O$_{5}$/ TiO$_2$-3A1$_2$O$_3$ㆍ2SiO$_2$ catalytic filter showed higher activity than V$_2$O$_{5}$/ TiO$_2$ catalytic filter, but higher differential pressure drops owing to its low air permeability. low air permeability.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.2
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• pp.115-122
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• 2007

As the genome of B.mori is available in GenBank and the EST database of B.mori is expanding, identification of novel genes of B.mori is conceivable by data-mining techniques. We used the in silico cloning method to get the vacuolar-type $H^+-ATP$ synthetase (V-ATPase) c subunit (16 kDa proteolipid subunit) gene of B.mori and analysed with bioinformatics tools. The result was confirmed by RT-PCR and sequencing. The V-ATPase c subunit cDNA contains a 468 bp ORF. The ORF encoded a 155-residue protein that showed extensive homology with V-ATPase c subunits from other 15 species and contained four membrane-spanning helices. Tissue expression pattern analysis revealed that V-ATPase c expressed strongly in Malpighian tubules, not in fat body. This gene has been registered in GenBank under the accession number EU082222.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.938-940
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• 1999

We have fabricated SiC Schottky diode for high temperature applications. SiC thin film for drift region has been deposited by ICP-CVD. In order to establish metallization conditions, we have extracted the device parameters of the Schottky diode from the forward I-V characteristics and the C-V characteristics as a function of temperature. The ideality factor was varied from 2.07 to 1.15 and the barrier height was also varied from 1.26eV to 1.92eV with increase of temperature. The reverse blocking voltage was 183 V.

• Elastomers and Composites
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• v.7 no.1
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• pp.53-58
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• 1972

Sublimatographic study on the method of test for sulfur in the petroleum and rubber products was as following results: (1) The relation between the heating temperature$(t_h)$ and the vacuum condensing point(V.C.P.) of sulfur at different degree of vacuum appeared as Fig.4. The results were in good agreement with those expected from the $t_h-V.C.P$ curves of sublimatographic separation of sulfur. (2) The relation between the degree of vacuum and the V.C.P. at different heating temperature of sulfur appeared as follows; $$tv.c.p.=\alpha+{\beta}logP_{va}$$ (3) The V.C.P of sulfur could be physical property comparing with melting point and boiling point. (4) The relation between the V.C.P. and the quantity of sublimation of sulfur becomes quantitative as Fig.7.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.19-24
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• 2003

We carried out studies on development and characteristic of ultrasound brast training biopsy phantom. the major finding were of follow ; (1) C type TMM was shown good homogeneity, brightness and attenuation as like human soft tissue. (2) $TiO_2$ 4.10%w/v TMM was shown good homogeneous echo texture and propagated speed as like the human Tissue. (3) $TiO_2$ type TMM was appeared lower brightness and higher penetration rate than C type TMM. Therefor, Breast TM phantom and target material TMM will be useful $TiO_2$ 4.10 %w/v TMM and C 2.09 %w/v TMM.