• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.74-74
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• 2008

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1016-1018
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• 1995

In this paper, we studied the electrical and the microwave properties of the amorphous $As_{10}Ge_{15}Te_{75}$ thin film. The electrical properties of a-$As_{10}Ge_{15}Te_{75}$ thin film were examined d.c. and a.c. bias with annealing condition. As the result of the electrical properties, we observed the physical characteristics of a-$As_{10}Ge_{15}Te_{75}$ thin film such as the density of defect states, characteristic relaxation time, localized density of states, and localized wave function by using CBH and QMT model. We also examined the microwave conduction properties before and after d.e. switching.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.2
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• pp.20-26
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• 1995

The very rapid cooling problem from $820^{\circ}$C to $20^{\circ}$C on the surface of the steel by thermal conduction including the latent heat of phase transformation of steel and by transient boiling heat transfer of water are considered to principal problem in quenching. The transient boiling process of water at the surface of specimen during the quenching process were experimentally analyzed. Then the heat flux was numerically calculated by the numerical method of inverse heat condition problem. In this report, the simulation program to calculate the cooling curves for large rolls was made using the subcooled transient boiling curve as a boundary condition. By this simulation program, the cooling curves of rolls from D=50mm to D=200mm were calculated and the effects of agitation of circulation of water also investigated.

• Korean Journal of Acupuncture
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• v.21 no.3
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• pp.137-146
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• 2004

Objective : The purpose of this study is to report the patient with peripheral neuropathy, who improved by Oriental medical treatment. Methods : The patient was managed by acupuncture, moxibustion, physical treatment and herbal medicine. We checked digital infrared thermographic imaging(D.I.T.I.), electromyography(E.M.G.), nerve conduction velocity(N.C.V.), deep tendon reflex(D.T.R.), sensory recover area and range of motion(R.O.M.) of knee & ankle. Results : After 6 week treatment, clinical sign(the movement and sense of leg) of improvement was appeared. Also E.M.G., N.C.V., D.T.R. and D.I.T.I. was recovered to nearly normal range. Conclusion : The results suggest that combination of acupunture, moxibustion and herbal medicine is good method for treatment of peripheral neuropathy. But further studies may be required to concretely prove the effectiveness of this methods for treating peripheral neuropathy.

• Genomics & Informatics
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• v.10 no.2
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• pp.110-116
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• 2012

Recent several studies have shown that the genetic variation of SCN5A is related with atrioventricular conduction block (AVB); no study has yet been published in Koreans. Therefore, to determine the AVB-associated genetic variation in Korean patients, we investigated the genetic variation of SCN5A in Korean patients with AVB and compared with normal control subjects. We enrolled 113 patients with AVB and 80 normal controls with no cardiac symptoms. DNA was isolated from the peripheral blood, and all exons (exon 2-exon 28) except the untranslated region and exon-intron boundaries of the SCN5A gene were amplified by multiplex PCR and directly sequenced using an ABI PRISM 3100 Genetic Analyzer. When a variation was discovered in genomic DNA from AVB patients, we confirmed whether the same variation existed in the control genomic DNA. In the present study, a total of 7 genetic variations were detected in 113 AVB patients. Of the 7 variations, 5 (G87A-A29A, intervening sequence 9-3C>A, A1673G-H558R, G3578A-R1193Q, and T5457C-D1819D) have been reported in previous studies, and 2 (C48G-F16L and G3048A-T1016T) were novel variations that have not been reported. The 2 newly discovered variations were not found in the 80 normal controls. In addition, G298S, G514C, P1008S, G1406R, and D1595N, identified in other ethnic populations, were not detected in this study. We found 2 novel genetic variations in the SCN5A gene in Korean patients with AVB. However, further functional study might be needed.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.686-692
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• 2000

Tin-doped In2O3 (ITO) films were fabricated using a d.c. magnetron reactive sputteirng of a In-10 wt% Sn alloy target in an Ar and O2 gas mixture. To understand the behavior of the carrier mobility in ITO films with O2 partial pressure, the resistivity, carrier concentration and mobility, film density, and intrinsic stress in the films were measured with O2 partial pressure. It was found experimentally that the carrier mobility increased rapidly as the film density increased. In the ITO film with the density close to theoretical one, the mean free path was the same as the columnar diameter. This indicated that the mobility in ITO films was strongly influenced by the crystall size. However, in the case where the film density was smaller than a theoretical density, the mean free paths were also smaller the columnar diameter. It was analyzed that the electron scattering at pores and holes within the crystalline was the major obstacle for electron conduction in ITO films. The measurement of intrinsic stress in ITO films also made it clear that the density of ITO films was controlled by the bombardment of oxygen neutrals on the growing film.

• Journal of the Korean Ceramic Society
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• v.35 no.12
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• pp.1323-1328
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• 1998

The electrical conductivities of the yttria (8mol%) stabilizedzirconia-ceria solid solutions were measured as a function of oxygen partial between 80$0^{\circ}C$ and 100$0^{\circ}C$ using 4-probe d.c. method Under pure oxygen atmosphere the oxygen ionic conductivity of CeO2-ZrO2 decreased with the concentration of CeO2 Under reducing condition electronic conduction due to the redox equilibrium of Ce ion was observed. Total ionic and electronic conductivities fitted by a defect model enabled to determine the electronic transference number(tei) which increased with the concentration of CeO2 and with the degree of reduction.

• Korean Journal of Materials Research
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• v.12 no.6
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• pp.431-435
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• 2002

The dark current and photocurrent(PC) spectrum of Mg-doped GaN thin film were investigated with various bias voltages and temperatures. At high temperature and small bias, the dark current is dominated by holes thermally activated from an acceptor level Al located at about 0.16 eV above the valence band maximum $(E_v)$, The PC peak originates from the electron transition from deep level A2 located at about 0.34 eV above the $E_v$ to the conduction band minimum $(E_ C)$. However, at a large bias voltage, holes thermally activated from A2 to Al experience the field-in-duces tunneling to form one-dimensional defect band at Al, which determines the dark current. The PC peak associated with the transition from Al to $E_ C$ is also observed at large bias voltages owing to the extended recombination lifetime of holes by the tunneling. In the near infrared region, a strong PC peak at 1.20 eV appears due to the hole transition from deep donor/acceptor level to the valence band.

• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.679-684
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• 2000

The Sr2Co0.5Nb(Ta)0.5O4 and Sr3CoNb(Ta)O7 compounds, both with Ruddlesden-Popper structures, have been synthesized by the ceramic method at $1150^{\circ}C$ under atmospheric pressure. The crystallographic structure of the compounds was assigned to the tetr agonal system with space group 14/mmm by X-ray diffraction(XRD) Rietveld refinement. The reduced lattice volume and lattice parameters increased as the Ta with 5d substitutes for the Nb with 4d in the compounds. The Co/Nb(Ta)O bond length has been determined by X-ray absorption spectroscopic(EXAFS/XANES) analysis and the XRD refinement. The CoO6,octahedra were tetragonally distorted by elongation of Co-O bond along the c-axis. The magnetic measurement shows the compounds Sr2Co0.5Nb(Ta)0.5O4 and Sr3CoNb(Ta)O7 have paramagnetic properties and the Co ions with intermediate spin sates between high and low spins in D4h symmetry. All the compounds showed semiconducting behavior whose electrical conductivity increased with temperature up to 1000 K. The electrical conductiviy increased and the activation energy for the conduction decreased as the number of perovskite layers increased in the compounds with chemical formula An+1BnO3n+1.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1469-1471
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• 1996

In this paper, We intended to evaluate the characteristics of XLPE/EPDM interface which exists in the cable joint. The fault of practical cable was mainly occurred in this interface. Thus we looked into the electrical characteristics through the conduction current and the breakdown test. Through the experiment, we obtained the result that the conduction current in this interface flowed less than other dielectric materials, that the breakdown strength was higher and that the pressure dependance of the breakdown strength was higher.