• Title/Summary/Keyword: F-ToBI

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Microwave Dielectric Properties of Bi2O3-TiO2 Composite Ceramics

  • Axelsson, Anna-karin;Sebastian, Maladil;McN Alford, Neil
    • Journal of the Korean Ceramic Society
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    • v.40 no.4
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    • pp.340-345
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    • 2003
  • B $i_2$ $O_3$-Ti $O_2$ composite dielectric ceramics have been prepared by a conventional solid state ceramic route. The composite ceramics were prepared with starting materials of different origin and the microwave dielectric properties were investigated. The sintered ceramics were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray microanalysis, Raman and microwave methods. Structural and microstructural analyses identified two separate phases: Ti $O_2$(rutile) and B $i_2$ $Ti_4$0$_{11}$. The separate grains of titania and bismuth titanate were distributed uniformly in the ceramic matrix. The composition 0.88Ti $O_2$-0.12B $i_2$ $Ti_4$ $O_{11}$ was found to have a Q$\times$f of 9300 GHz (measured at a frequency of 3.9 GHz), a temperature coefficient of frequency, $\tau$$_{cf}$ near zero and a high relative permittivity, $\varepsilon$r of 83. The microwave dielectric properties were measured down to 20$^{\circ}$K K. The quality factor increased on cooling the ceramic samples.les.

Bioelectrical Impedance Analysis at Inner Forearms of the Human Body using Bioelectrical Impedance Measurement System

  • Kim, Jae-Hyung;Kim, Soo-Hong;Baik, Sung-Wan;Jeon, Gye-Rok
    • Journal of Korea Multimedia Society
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    • v.19 no.7
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    • pp.1146-1153
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    • 2016
  • The bioelectrical impedance (BI) at the inner forearms was measured using bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, while applying a constant alternating current of 800A to the inner region of the forearms, BI (Z) was measured at nineteen frequencies ranging from 5 to 500 kHz. The prediction marker (PM) was calculated for right and left forearm. The resistance (R) and the reactance (Xc) were simultaneously measured during impedance measurement. Second, a Cole-Cole plot (relationship between reactance and resistance) was obtained for left and right forearm, indicating the different characteristic frequencies (fc). Third, the phase angle was obtained, indicating strong dependence on the applied frequency.

Studies on the Induction of Transformation in Cereal Plants.II. Expression of Gene Transferred into Rice Protoplasts by Electroporation (곡물류의 형질전환에 관한 연구.II. Electroporation에 의해 벼 원형질체로 도입된 유전자의 발현)

  • Hwang, Baik;Hwang, Sung-Jin;Im, Wook-Bin;Im, Hyong-Tak;Kang, Young-Hee
    • KSBB Journal
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    • v.5 no.4
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    • pp.323-327
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    • 1990
  • Protoplasts isolated from embryogenic cell suspensions were electroporated in buffered solutions containing plasmid DNA of pBI121. Transient GUS (beta-glucuronidase) activity measurement and selection for kanamycin resistent showed that expression of foreign genes and stable loransformation were achieved. GUS transient gene expression was increased by increasing DNA concentration of pBI121 plasmid and affected by the level of the applied voltage. An optimal level of GUS activity was obtained after electroporation with a pulse of 200 voltage/1180 uF. Protoplast viability was up to the 60% at the optimal voltage. Cell colonies resistent to 200$\mu\textrm{g}$/ml kanamycin were selected in agar medium and identified by histochemical GUS assay.

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High Performance Current Sensing Circuit for Current-Mode DC-DC Buck Converter

  • Jin, Hai-Feng;Piao, Hua-Lan;Cui, Zhi-Yuan;Kim, Nam-Soo
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.1
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    • pp.24-28
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    • 2010
  • A simulation study of a current-mode direct current (DC)-DC buck converter is presented in this paper. The converter, with a fully integrated power module, is implemented by using sense method metal-oxide-semiconductor field-effect transistor (MOSFET) and bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. When the MOSFET is used in a current sensor, the sensed inductor current with an internal ramp signal can be used for feedback control. In addition, the BiCMOS technology is applied in the converter for an accurate current sensing and a low power consumption. The DC-DC converter is designed using the standard $0.35\;{\mu}m$ CMOS process. An off-chip LC filter is designed with an inductance of 1 mH and a capacitance of 12.5 nF. The simulation results show that the error between the sensing signal and the inductor current can be controlled to be within 3%. The characteristics of the error amplification and output ripple are much improved, as compared to converters using conventional CMOS circuits.

Variation in Chromosome Number in Early Generation from Cross between Hexaploid Triticale(X Triticosecale Wittmack) and Wheat (Triticum aestivum L.) (6배체 트리티케일X밀 잡종 초기 세대의 염색체수 변이)

  • 황종진;이홍석
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.36 no.4
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    • pp.310-318
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    • 1991
  • This experiment was carried out to obtain the information on the variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results were summarized as follows: Number of uni-, bi- and tri-valent in PMC was 11.9, 14.4 and 0.44, respectively, in the F$_1$ between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate, pollen fertility and bivalent number of PMC, and seed set rate and bivalent number of PMC, and negative correlation between pollen fertility and uni-or tri-valent of PMC in the cross between triticale and wheat were detected. F$_1$ (crossed seed) had 42 chromosomes, F$_2$ and F$_1$/P$_1$ showed high frequency of hyperploid (42-49) and F$_1$/P$_2$ showed high frequency of hypoploid (36- 42), which suggest non-random segregation for somatic chromosome number. in the cross between the triticale and wheat.

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THE CEPHALOMETRIC STUDY OF KOREAN MANDIBULAR ANGLE (한국인 성인 하악각에 대한 두부계측 방사선학적 연구)

  • Park, Jung-Ha;Hwang, Kyung-Gyun;Kim, Yong-Jae;Woo, Soon-Seop;Yoo, Eem-Hak;Shim, Kwang-Sup
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.4
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    • pp.226-231
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    • 2003
  • The contour of mandibular angle is important for facial esthetics in the oriental population, because the wide and square face is thought to have had an unhappy life. A prominent mandibular angle produces a characteristics quardrangle, coase, and muscular appearance. So, uni- or bi-lateral mandibular angle reduction is usually performed. However, there is little guideline for bi-lateral angle reduction. So, this study was to investigate the pattern of Korean mandibular angle for bi-lateral mandibular angle reduction as guideline. This study was included 66 adult men and women over 19 years old who are having the normal mandibular angle. We measured the posterior border, angle, and inferior border of mandible using cephalometric view. The results of study was as followed : 1. The ratio of posterior mandible was 96.6, 97.3% in male, and 103.0, 106.0% in female. 2. The ratio of mandibular angle(R1-Go/R1-R2) was 120.2% in male, and 117.3% in female. 3. The ratio of inferior mandible(D5, 6, 7, E, F, G/D4) was 97.3, 90.9, 79.5, 65.2, 57.8, 46.9% in male, and 98.5, 91.2, 80.5, 67.6, 59.1, 50.2% in female. The results of this study should be useful to decide accurate amount of reduction.

Design of an Planar Inverted -F Antenna With Wide band Characteristic (광대역 특성을 갖는 역 F형 내장형 안테나의 설계)

  • Jung, Hee-Kyung;Park, Hoon;Choi, Jae-Hoon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.249-254
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    • 2005
  • This paper presents the design of a novel small and wide band planar inverted F-antenna which simultaneously covers GSM900/GPS/DCS1800/DCS1900/DMB service. The proposed antenna consisting of a main patch with rectangular slit, strip 1 and strip 2, occupied the total volume of.$15\times36\times6mm^3$. A very wide impedance bandwidth characteristic was achieved by optimizing both the distance between the feed line and short strip and the length of rectangular slit on the main patch. The commercial electromagnetic software, CST Microwave Studio, is used to design the structure. The maximum gains at the frequencies of 900, 1575, 1800, 1900, and 2600 MHz were 2.07, 1.07, 1.69 and 0.55, -1.99 dBi, respectively. The overall shape of the radiation patterns is suitable for mobile communication application.

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The biblographical study on $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine -(Comparative study between Oriental and Western Medicine)- (두풍(頭風)과 편두통(Migraine)에 대(對)한 동서의학적(東西醫學的) 문헌고찰(文獻考察))

  • Oh, So-Jeo;Jeong, Ji-Cheon;Lee, Won-Chul
    • The Journal of Internal Korean Medicine
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    • v.14 no.1
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    • pp.129-138
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    • 1993
  • This report on the $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine comes to conclude, through the study of the Oriental- Western medical references, as follow; 1. First, $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine had some concurrencies that both the two symptoms have appeared severe and recurrent headache and more often to the female. 2 Many of them e.g. Sensory disturbance, Vertigo, Nausea, Vomiting, Tinnitus etc. in the prodrome and main symptom of $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine were identical, especially the symptom of the $f{\bar{e}}ng\;t{\acute{a}}n\;t{\acute{o}}u\;t{\grave{o}}ng$ was similar to the prodrome of the Migraine. We could find out the semilarity of the symptoms through that Migraine is proximately set in unilateral, and $Pi{\bar{a}}nT{\acute{o}}u\;f{\bar{e}}ng$ is so called alias $B{\grave{a}}n\;bi{\bar{a}}n\;t{\acute{o}}u\;t{\grave{o}}ng$. 3. The pathogeny of $T{\acute{o}}u\;f{\bar{e}}ng$ include the case of ‘$f{\bar{e}}ng\;xi{\acute{e}}\;r{\grave{u}}\;n{\bar{a}}o$’, the patient feeling weak condition, $T{\acute{a}}n,\;T{\acute{a}}nshi,\;T{\acute{a}}nhu{\breve{o}},\;Y{\grave{u}}q{\grave{i}}$, etc. and, ‘$t{\acute{a}}n\;zhu{\grave{o}}\;sh{\grave{a}}ng\;y{\acute{a}}o$’, ‘$G{\bar{a}}n\;y{\acute{a}}ng\;hu{\grave{a}}\;f{\bar{e}}ng$’. There were variable that $F{\bar{e}}ng,\;Xu{\grave{e}},\;F{\bar{e}}ngr{\grave{a}},\;F{\bar{e}}ngx{\bar{u}},\;Xu{\grave{e}}x{\bar{u}},\;Hu{\check{o}}$ in the left, and $t{\acute{a}}n,\;R{\grave{e}},\;t{\acute{a}}nr{\grave{e}},\;Qir{\acute{a}}$ in the right partial pathogeny. It was referred $Sh{\grave{a}}o\;y{\acute{a}}ng\;j{\bar{i}}ng$, $Ju{\acute{e}}\;y{\bar{i}}n\;j{\bar{i}}ng$, $Y{\acute{a}}ng\;m{\acute{i}}ng\;j{\bar{i}}ng$, $T{\grave{a}}i\;y{\acute{a}}ng\;j{\bar{i}}ng$ in connection with the Meridian system. And otherwise the primary cause of Migraine is still unknown to us. Heredity is probably important, but the mode of transmission is uncertain. Recently, the important assumption is the vasomotor change caused by vasoconstrictors like that norepinephrine, epinephrine, and serotonin etc.

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A study on the glass fabrication and sintering behaviour of glass/ceramics for SiO2-TiO2-RO(RO: BaO, CaO, SrO) system (SiO$_2$-TiO$_2$-RO(RO: BaO, CaO, SrO)계 고유전율 유리 제조 및 글라스/세라믹스의 소결 거동에 관한 연구)

  • 구기덕;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.4
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    • pp.626-633
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    • 1998
  • For the fabrication of low temperature cofirable glass/ceramic with high dielectric constant, crystallizing glass [$SiO_2-TiO_2-RO (RO:BaO, CaO:SrO)$] was formed. The glass/ceramic composites were made by mixing this glass and alumina ceramic as filler, and its characteristics was investigated. With this glass compositon, it was possible to fabricate the glass which could be crystallized under $900^{\circ}C$. And it was found that the crystallizing temperature was changed in accordance with the composition of RO in glass. By adding $Bi_2O_3$ as flux, using $Al_2O_3$ as filler and sintering at $860^{\circ}C$, low temperature cofirable glass/ceramic with high dielectric constant was fabricated. The density of that composites was 3.96 g/$\textrm{cm}^3$, dielectric constant was 17 and Q. f was 600.

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(Design of RFID Reader Antenna Using Two Orthogonally Oriented 1x2 Sub-Arrays at 433 MHz) (직교형으로 배열된 2개의 1x2서브-어레이를 이용한 433MHz에서 동작하는 RFID 리더용 안테나 설계)

  • Kim Jong-Sung;Park Seung-Mo;Choi Won-Kyu;Seong Nak-Seon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.9 s.339
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    • pp.97-100
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    • 2005
  • An orthogonal antenna is presented for reader application of radio frequency identification (RFID) at 433 MHz. Two 1x2 sub-arrays are orthogonally placed on a ground plane and two different feeding networks are applied to control horizontal and vertical radiation current flows for each sub-array, respectively. Inverted-F structures are used as radiation elements and can generate two linear polarizations by relative current distribution of radiators forming sub-arrays. Antenna gains are 2.7 and 0.4 dBi and isolation between two input ports is less than 25dB.