• Title/Summary/Keyword: D D C

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Design of a 12-bit, 10-Msps SAR A/D Converter with different sampling time applied to the bit-switches within C-DAC (C-DAC 비트 스위치에 다른 샘플링 시간을 인가하는 12-bit, 10-Msps SAR A/D 변환기 설계)

  • Shim, Minsoo;Yoon, Kwangsub;Lee, Jonghwan
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1058-1063
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    • 2020
  • This paper proposes a 12-bit SAR A/D(Successive Approximation Register Analog-to-Digital) converter that operates at low power for bio-signal and sensor signal processing. The conventional SAR A/D converter utilized the reduction of the dynamic current, which resulted in reducing total power consumption. In order to solve the limitation of the sampling time due to charging/discharging of the capacitor for reducing dynamic current, the different sampling time on the C-DAC bit switch operation was applied to reduce the dynamic current. In addition, lowering the supply voltage of the digital block to 0.6V led to 70% reduction of the total power consumption of the proposed ADC. The proposed SAR A/D was implemented with CMOS 65nm process 1-poly 6-metal, operates with a supply voltage of 1.2V. The simulation results demonstrate that ENOB, DNL/INL, power consumption and FoM are 10.4 bits, ±0.5LSB./±1.2LSB, 31.2uW and 2.8fJ/step, respectively.

Evaluation of Skin Dose and Image Quality on Cone Beam Computed Tomography (콘빔CT 촬영 시 mAs의 변화에 따른 피부선량과 영상 품질에 관한 평가)

  • Ahn, Jong-Ho;Hong, Chae-Seon;Kim, Jin-Man;Jang, Jun-Young
    • The Journal of Korean Society for Radiation Therapy
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    • v.20 no.1
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    • pp.17-23
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    • 2008
  • Purpose: Cone-beam CT using linear accelerator attached to on-board imager is a image guided therapy equipment. Because it is to check the patient's set-up error, correction, organ and target movement. but imaging dose should be cause of the secondary cancer when taking a image. The aim of this study is investigation of appropriate cone beam CT scan mode to compare and estimate the image quality and skin dose. Materials and Methods: Measurement by Thermoluminescence dosimeter (TLD-100, Harshaw) with using the Rando phantom are placed on each eight sites in seperately H&N, thoracic, abdominal section. each 4 methods of scan modes of are measured the for skin dose in three time. Subsequently, obtained average value. Following image quality QA protocol of equipment manufacturers using the catphan 504 phantom, image quality of each scan mode is compared and analyzed. Results: The results of the measured skin dose are described in here. The skin dose of Head & Neck are measured mode A: 8.96 cGy, mode B: 4.59 cGy, mode C: 3.46 cGy mode D: 1.76 cGy and thoracic mode A: 9.42 cGy, mode B: 4.58 cGy, mode C: 3.65 cGy, mode D: 1.85 cGy, and abdominal mode A: 9.97 cGy, mode B: 5.12 cGy, mode C: 4.03 cGy, mode D: 2.21 cGy. Approximately, dose of mode B are reduced 50%, mode C are reduced 60%, mode D are reduced 80% a point of reference dose of mode A. the results of analyzed HU reproducibility, low contrast resolution, spatial resolution (high contrast resolution), HU uniformity in evaluation item of image quality are within the tolerance value by recommended equipment manufacturer in all scan mode. Conclusion: Maintaining the image quality as well as reducing the image dose are very important in cone beam CT. In the result of this study, we are considered when to take mode A when interested in soft tissue. And we are considered to take mode D when interested in bone scan and we are considered to take mode B, C when standard scan. Increasing secondary cancer risk due to cone beam CT scan should be reduced by low mAs technique.

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NOTES ON THE SPACE OF DIRICHLET TYPE AND WEIGHTED BESOV SPACE

  • Choi, Ki Seong
    • Journal of the Chungcheong Mathematical Society
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    • v.26 no.2
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    • pp.393-402
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    • 2013
  • For 0 < $p$ < ${\infty}$, ${\alpha}$ > -1 and 0 < $r$ < 1, we show that if $f$ is in the space of Dirichlet type $\mathfrak{D}^p_{p-1}$, then ${\int}_{1}^{0}M_{p}^{p}(r,f^{\prime})(1-r)^{p-1}rdr$ < ${\infty}$ and ${\int}_{1}^{0}M_{(2+{\alpha})p}^{(2+{\alpha})p}(r,f^{\prime})(1-r)^{(2+{\alpha})p+{\alpha}}rdr$ < ${\infty}$ where $M_p(r,f)=\[\frac{1}{2{\pi}}{\int}_{0}^{2{\pi}}{\mid}f(re^{it}){\mid}^pdt\]^{1/p}$. For 1 < $p$ < $q$ < ${\infty}$ and ${\alpha}+1$ < $p$, we show that if there exists some positive constant $c$ such that ${\parallel}f{\parallel}_{L^{q(d{\mu})}}{\leq}c{\parallel}f{\parallel}_{\mathfrak{D}^p_{\alpha}}$ for all $f{\in}\mathfrak{D}^p_{\alpha}$, then ${\parallel}f{\parallel}_{L^{q(d{\mu})}}{\leq}c{\parallel}f{\parallel}_{\mathcal{B}_p(q)}$ where $\mathcal{B}_p(q)$ is the weighted Besov space. We also find the condition of measure ${\mu}$ such that ${\sup}_{a{\in}D}{\int}_D(k_a(z)(1-{\mid}a{\mid}^2)^{(p-a-1)})^{q/p}d{\mu}(z)$ < ${\infty}$.

A Study on the Standardization of Kimchi for the Children -The Proper Red Pepper Powder for Children대s Kimchi- (어린이 김치 표준화에 대한 연구 -어린이 김치에 적합한 고추가루-)

  • 송영옥;빈성미;문정원
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.6
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    • pp.893-898
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    • 1996
  • This study is a continuous work for the standardization of children's kimchi preparation. In order to find out the proper red pepper powder for children's kimchi, four kinds of red pepper powder(A, B, C, D) sold in Kyungsang province were used as samples. The proximate composition, color value, capsaicinoids concentration and sugar content in four kinds of the red pepper powder were determined, and sensory evaluation of kimchi Prepared with those was carried out for different fermentation times. Moisture contents of red pepper powder A, B, C and D were in the range of 11.59~13.48%. Lipid and ash contents of samples were in the range of 7.59~8.39% and 4.34~7.45%, respectively. In comparision of color values measured by a Hunter colorimeter, red pepper powder A showed the highest value for a and b values. Also A showed the brightest color as measured in ASTA color and L value. Capsaicin concentration of D and dihydrocapsaicin concentration of C were found to be the highest among the sanlples. The capsaicin equivalent was in tile order of D>C>A>B. The content of total sugar was in the order of B>A>D>C. In the sensory evaluation of children's kimchi prepared with four kinds of red pepper powder, the color and total acceptability of kimchi prepared with A were found to be the best. The results of sensory evaluation between kimchi prepared with A and school supplied kimchi showed that the former was better. And the composition of A red pepper powder was as follows: capsaicin equivalent 24.l5mg%, total sugar content 15.79% and ASTA color value 178.2.

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Deuterium oxide stabilizes conformation of tubulin: a biophysical and biochemical study

  • Das, Amlan;Sinha, Sharmistha;Acharya, Bipul R;Paul, Pinaki;Bhattacharyya, Bhabatarak;Chakrabarti, Gopal
    • BMB Reports
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    • v.41 no.1
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    • pp.62-67
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    • 2008
  • The present study was aimed to elucidate the mechanism of stabilization of tubulin by deuterium oxide ($D_2O$). Rate of decrease of tryptophan fluorescence during aging of tubulin at 4$^{\circ}C$ and 37$^{\circ}C$ was significantly lower in $D_2O$ than in $H_2O$. Circular dichroism spectra of tubulin after incubation at 4$^{\circ}C$, suggested that complete stabilization of the secondary structure in D2O during the first 24 hours of incubation. The number of available cysteine measured by DTNB reaction was decreased to a lesser extent in $D_2O$ than in $H_2O$. . During the increase in temperature of tubulin, the rate of decrease of fluorescence at 335 nm and change of CD value at 222 nm was lesser in $D_2O$. Differential Scanning calorimetric experiments showed that the $T_m$ values for tubulin unfolding in $D_2O$ were 58.6$^{\circ}C$ and 62.17$^{\circ}C$, and in $H_2O$. those values were 55.4$^{\circ}C$ and 59.35$^{\circ}C$.

Stability of $Pr_{6}O_{11}$-Based ZnO Varistors Doped with $Y_{2}O_{3}$ under d.c. Stresses ($Y_{2}O_{3}$가 첨가된 $Pr_{6}O_{11}$계 ZnO 바리스터의 d.c. 스트레스에 따른 안정성)

  • 윤한수;류정선;남춘우
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.551-554
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    • 2000
  • The stability of $Pr_6$$O_{11}$-based ZnO varistors doped with $Y_2$$O_3$ was investigated under various d.c. stresses. The varistors were sintered at $1350^{\circ}C$ for 1h in the addition range of 0.0 to 4.0 mol% $Y_2$$O_3$. The varistors doped with $Y_2$$O_3$ exhibited much higher nonlinearity than that without $Y_2$$O_3$. In Particular, the varistors containing 0.5 mol% $Y_2$$O_3$ showed very excellent V-I characteristics, which the nonlinear exponent was 51.19 and the leakage current was 1.32 $\mu\textrm{A}$. And these varistors also showed an excellent stability, which the variation rate of the varistor voltage and the nonlinear exponent were -0.80% and -2.17%, respectively, under 4th d.c. stress, such as (0.80 $V_ {1mA}$/$90^{\circ}C$/12h)+(0.85 $V_{1mA}$/$115^{\circ}C$/12h)+(0.90 $V_{1mA}$/$120^{\circ}C$/12h)+(0.95 $V_{1mA}$/$125^{\circ}C$/12h). Consequently, since $Pr_ 6$$O_{11}$-based ZnO varistors doped with 0.5 mol% $Y_2$$O_3$ have an excellent stability as well as good nonlinearity, it is expected to be usefully used to develop the superior varistors in future.

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NMR Studies on Ferrocytochrome $C_3$ and its Interaction with Ferredoxin I

  • Kim, Andre;Park, Jang-Su
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.1
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    • pp.12-26
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    • 1999
  • The 1H NMR signals of the heme methyl, propionate and related chemical groups of cytochrome C3 from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were assigned by means of 1D NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the assignments of the hemes with the highest and second-lowest redox potentials reported by Gayda et al. [Reference: 15]. The heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val-18, All the results contradicted the heme assignments for D.v. MF cytochrome C3 made on the basis of NMR [Reference: 11]. Based on these assignments, the interaction of cytochrome C3 with ferredoxin I was investigated by NMR. The major interaction site of cytochrome C3 was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochrome C3 molecules per monomer of ferredoxin I and 108 M-2 (at 53 mM ionic strength and $25^{\circ}C$), respectively.

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Control of Diatrype stigma occurred on the bed-log of Shiitake by resistant Shiitake strains (표고골목 해균인 주홍꼬리버섯을 방제하기 위한 저항성 표고균주 선발)

  • Lee, Bong-Hun;Bak, Won-Chull;Ka, Kang-Hyeon;Yoon, Kab-Hee;Park, Hyun;Cha, Byeong-Jin
    • Journal of Mushroom
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    • v.3 no.3
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    • pp.109-114
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    • 2005
  • Attempts were made to control Diatrype stigma occurred on the bed-log of shiitake by resistant shiitake strains. In selection test of resistant shiitake strains, 67 out of 77 strains tested were proved to be resistant to D. stigma. Among them, 13 strains including KFRI 5 were effective to inhibit the access of D. stigma, and 7 strains including KFRI 180 remarkably invaded the territory of D. stigma. Among 31 shiitake strains made by hybridization of resistant strains for D. stigma, 8 strains including KFRI 537 inhibited the access of D. stigma, and 4 strains including KFRI 545 invaded the territory of D. stigma. The effects of temperatures and inoculation orders to the resistance were confirmed in PDA plates and test tubes filled with sawdust of Quercus acutissima. Four kinds of temperature treatments as follows were tested: (1) continuous incubation at $14^{\circ}C$, (2) continuous incubation at $25^{\circ}C$, (3) changing of incubation temperature from $14^{\circ}C$ to $25^{\circ}C$ as soon as mycelia of both shiitake and D. stigma meet together, (4) changing of incubation temperature from $25^{\circ}C$ to $14^{\circ}C$ as soon as mycelia of both shiitake and D. stigma meet together. Three kinds of inoculation procedure were tested: (1) inoculation of shiitake 3 days ahead of D. stigma inoculation, (2) inoculation of D. stigma 3 days ahead of shiitake inoculation, (3) simultaneous inoculation of both fungi. In PDA plate test, the strain KFRI 137 showed outstanding ability to inhibit mycelial growth of D. stigma and the strain KFRI 180 invaded into the territory of D. stigma in most of treatments. Hybrid strains, KFRI 545, 546, and 547 were more resistant than their parent strains, KFRI 488 and 405. In test tube examinations, all the strains of shiitake showed high resistance at the treatment of change in temperature from $14^{\circ}C$ to $25^{\circ}C$ when mycelia of both shiitake and D. stigma meet together. On the other hand, resistance of all the strains growing at $25^{\circ}C$ decreased when the temperature was changed into $14^{\circ}C$ after mycelia of both fungi. In these cases, the resistance reached to 7~20% of the highest resistance. The strain KFRI 259 invaded the territory of D. stigma, contrary to PDA plate test. Among the strains, KFRI 393 strain was the most resistant under the continuous incubation at $25^{\circ}C$.

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Effect of Fermentation Temperature on the Physicochemical Properties of Mustard Leaf(Brassica juncea) Kimchi during Various Storage Days (발효숙성온도를 달리한 갓 김치의 저장중 이화학적 특성 변화)

  • 박삼수;장명숙;이규환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.5
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    • pp.752-757
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    • 1995
  • The effect of fermentation temperature on the changes of pH, acidity, salt content, color and vitamin C of mustard leaf kimchi during various storage days was investigated. The conditions of fermentation temperature were set at $4^{\circ}C$ (sample A) and $20^{\circ}C$ (sample B), and $4^{\circ}C$ after keeping at $20^{\circ}C$ for 12 hours(sample C) and $20^{\circ}C$ for 36 hours(sample D). As the fermentation proceeded, pH of sample stored at low temperature(sample A) was drop ped gradually from initial pH of 5.24 but there was great pH drop in the sample stored at high temperature(sample B, D). The salt content of the sample B at high temperature increased remarkably, and then the values showed D > A > C. The Humter values of L and a increased at the optimum ripening period, the higher the initial fermentation temperature(B) and the later the initial fermentation time at $20^{\circ}C$ those values, then decreased. The Hunter value of b constantly increased until day of 108. As fermentation time passed, the content of total vitamin C decreased to the range of 9.0mg% to 14.0mg% up to 24 days of fermentation, and at the optimum ripening period, it increased to the range of 14.0mg% to 22.0mg%, and at the fermentation period(until day 108), it decreased gradually.

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MARTENS' DIMENSION THEOREM FOR CURVES OF EVEN GONALITY

  • Kato, Takao
    • Journal of the Korean Mathematical Society
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    • v.39 no.5
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    • pp.665-680
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    • 2002
  • For a smooth projective irreducible algebraic curve C of odd gonality, the maximal possible dimension of the variety of special linear systems ${W^r}_d$(C) is d-3r by a result of M. Coppens et at. [4]. This bound also holds if C does not admit an involution. Furthermore it is known that if dim ${W^r}_d(C)qeq$ d-3r-1 for a curve C of odd gonality, then C is of very special type of curves by a recent progress made by G. Martens [11] and Kato-Keem [9]. The purpose of this paper is to pursue similar results for curves of even gonality which does not admit an involution.