• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4265-4266
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• 2012

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.176-183
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• 2000

In this paper, sixth order hannonic injected PWM for improving‘ input CWTent distortion of single switch t three phase boost converter is presented. Peliodic sixth order hmmonic ${\gamma}$oltage is inj<:ded in the control circuit t to var${\gamma}$ the duty ratio of the converter switch within one switching cycle. In the result, the input phase c currents are forced to track the input voltage and an 해most unity power factor is obtained. Expelimental r results are verified by converter operating at 400V /6kW with three phase 140V ~220V input and by C02 arc w welding machine which was nonlinear load with 3 $\phi$ 220V input.

• Journal of the Korean Mathematical Society
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• v.56 no.6
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• pp.1503-1514
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• 2019

A rank 1 matrix has a factorization as $uv^t$ for vectors u and v of some orders. The arctic rank of a rank 1 matrix is the half number of nonzero entries in u and v. A matrix of rank k can be expressed as the sum of k rank 1 matrices, a rank 1 decomposition. The arctic rank of a matrix A of rank k is the minimum of the sums of arctic ranks of the rank 1 matrices over all rank 1 decomposition of A. In this paper we obtain characterizations of the linear operators that strongly preserve the symmetric arctic ranks of symmetric matrices over nonnegative reals.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.227-233
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• 2017

Pig has been known to be one of the most feasible animals as a bioreactor to produce pharmaceuticals in milk and as a mediator in xenotransplantation research. Previously, we generated transgenic pigs for both purposes, which were expressing Factor 8, vWF, hTPA, and hEPO in milk, along with expression of MCP at GalT gene locus ($GalT^{-MCP/-MCP}$) as well as expressing MCP at GalT gene loci with CD73 expression ($GalT^{-MCP/+}/CD73$). In this study, we performed comparative analyses of sperm parameters between wild type male (WT) pig and those transgenic males to examine the effects of transgenes integrated into the pigs on motility, morphology, viability, and acrosome integrity of the spermatozoa. Our results showed that the rates of actively motile spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, $GalT^{-MCP/+}/CD73$, and $GalT^{-MCP/-MCP}$ pigs were 85.0%, 83.3%, 82.5%, 83.3%, 82.5%, 77.5%, and 78.7%, respectively. Whereas, the rates of morphologically normal spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, $GalT^{-MCP/+}/CD73$, and $GalT^{-MCP/-MCP}$ pigs were 90.0%, 80.0%, 80.0%, 83.3%, 85.0%, 91.8%, and 80.8%, respectively. In addition, the viability in spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, $GalT^{-MCP/+}/CD73$, and $GalT^{-MCP/-MCP}$ pigs were 93.9%, 82.4%, 89.9%, 83.9%, 87.4%, 92.8%, and 83.6%, respectively. The rates of spermatozoa with normal acrosome integrity in WT, Factor 8, vWF, hTPA, hEPO, $GalT^{-MCP/+}/CD73$, and $GalT^{-MCP/-MCP}$ pigs were 98.1%, 98.6%, 98.6%, 98.7%, 98.1%, 99.5%, and 95.1%, respectively. There were no significant differences in motility, morphology, viability, and acrosome integrity of the spermatozoa among WT, Factor 8, vWF, hTPA, and hEPO, $GalT^{-MCP/+}/CD73$, and $GalT^{-MCP/-MCP}$ pigs. These mean that neither random integration nor targeted integration of the transgene into chromosome of pig effect on characteristics of spermatozoa. Ultimately, the transgenic male pigs subjected in this study could apply to propagate their progenies for production of human therapeutic proteins and advancing the xenotransplantation research.

• Journal of applied mathematics & informatics
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• v.36 no.3_4
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• pp.213-229
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• 2018

In this work, we establish oscillation of the second order sublinear neutral delay dynamic equations of the form:$$(r(t)((x(t)+p(t)x({\tau}(t)))^{\Delta})^{\gamma})^{\Delta}+q(t)x^{\gamma}({\alpha}(t))+v(t)x^{\gamma}({\eta}(t))=0$$ on a time scale T by means of Riccati transformation technique, under the assumptions $${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t={\infty}$$, and ${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t$ < ${\infty}$, for various ranges of p(t), where 0 < ${\gamma}{\leq}1$ is a quotient of odd positive integers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.167-168
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• 2007

$CdIn_2S_4$ (110) films were grown on semi-insulating GaAs (100) by a hot wall epitaxy method. Using photocurrent (PC) measurement, the PC spectra in the temperature range of 30 and 10 K appeared as three peaks in the short wavelength region. It was found that three peaks, A-, B-, and C-excitons, correspond to the intrinsic transition from the valence band states of ${\Gamma}_4(z),\;{\Gamma}_5(x),\;and\;{\Gamma}_5(y)$ to the exciton below the conduction band state of ${\Gamma}_1(s)$, respectively. The 0.122 eV crystal field splitting and the 0.017 eV spin orbit splitting were obtained. Thus, the temperature dependence of the optical band gap obtained from the PC measurement was well described by $E_g$(T)=2.7116eV - $(7.65{\times}10^{-4}\;eV/K)T^2$/(425+T). But, the behavior of the PC was different from that generally observed in other semiconductors. The PC intensities decreased with decreasing temperature. This phenomenon had ever been reported at a PC experiment on the bulk crystals grown by the Bridgman method. From the relation of log $J_{ph}$ vs 1/T, where $J_{ph}$ is the PC density, two dominant levels were observed, one at high temperatures and the other at low temperatures. Consequently, the trapping centers due to native defects in the $CdIn_2S_4$ film were suggested to be the causes of the decrease in the PC signal with decreasing temperature.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.245-252
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• 1998

The chitosanolytic capabilities of cellulases, glucosidases, proteases and commercial enzymes were evaluated, and effective chitosanolytic cellulases from T. viride, T. reesei and Celluclast, a commercial enzyme from T. reesei were characterized. The reaction of cellulase from T. viride, T. reesei and Celluclast was optimal at pH 5. 0 and $45{\sim}55^{\circ}C$. Max. chitosanolytic activities of cellulases from both T. viride and T. reesei were observed at the enzyme/chitosan ratio=0.1 and chitosan concentration=3.0%. For the possible application of commercial Celluclast to chitosan oligosaccharides production, 3%(w/v) chitosan was reacted with 1%(v/v) Celluclast at pH 5.0 and $55^{\circ}C$. The apparent viscosity decreased by 98% within 30 minutes reaction and Max. contents of 50% EtOH solubles were 70% at 15 hrs reaction. Total reducing sugars were also increased with reaction time and maintained approx. 13.5% after 2hrs reaction. In 15 hrs treated chitosan hydrolyzates, various kinds of chitosan oligosaccharides were produced and contents of chitosan hexamer, known for its antitumor activities, were about 8.0%, about 4 times higher values compared with acid hydrolysis method. The results suggested that chitosan oligosaccharides could be produced with low-cost cellulases from T. reesei.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.27-34
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• 1987

To verify the direct effects of the thyroid hormone ($T_3$) on the rabbit heart, $T_3$-Tyrode solution in vitro was perfused on the normal atrial muscles and enzymatically isolated ventricular myocytes of the rabbit. All the experimental procedures were conducted at $35^{\circ}C$ and the same procedures were repeated after Ca. 120 minutes from the beginning of $T_3$-Tyrode perfusion. Compared to the state between the normal Tyrode solution and $T_3$-Tyrode solution, results were observed on the same cells by electrophysiological methods (conventional intracellular recording and whole cell patch clamping) as soon as possible. The results obtained were as follows : 1. Action potential duration (APD) on the left atrial muscle was reduced under the perfusion of $T_3$-Tyrode. 2. Absolute refractory Period was shortened by $T_3$-Tryrode perfusion. (117 msec./114 msec., 90 msec./78 msec.) 3. Maximal Ca currents ($i_{Ca}$) were decreased in single: ventricular myocytes under the $T_3$-Tyrode (2.98 nA) than under the normal Tyrode (6.65 nA) 4. On I-V relation, reversal potential was shifted to lower membrane potential and membrane potential showing maximal $i_{Ca}$was lowered from +10mV to -20mV by $T_3$ effect. 5. Above results were likely to explain that tachycardia in the hyperthyroid state was caused in part by the reduced repolarization phase and the reduced refractory period due to the decrease of the Ca current.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.155-167
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• 2007

A graph G is called to be a 2-degree integral subgraph of a q-tree if it is obtained by deleting an edge e from an integral subgraph that is contained in exactly q - 1 triangles. An added-vertex q-tree G with n vertices is obtained by taking two vertices u, v (u, v are not adjacent) in a q-trees T with n - 1 vertices such that their intersection of neighborhoods of u, v forms a complete graph $K_{q}$, and adding a new vertex x, new edges xu, xv, $xv_{1},\;xv_{2},\;{\cdots},\;xv_{q-4}$, where $\{v_{1},\;v_{2},\;{\cdots},\;v_{q-4}\}\;{\subseteq}\;K_{q}$. In this paper we prove that a graph G with minimum degree not equal to q - 3 and chromatic polynomial $$P(G;{\lambda})\;=\;{\lambda}({\lambda}-1)\;{\cdots}\;({\lambda}-q+2)({\lambda}-q+1)^{3}({\lambda}-q)^{n-q-2}$$ with $n\;{\geq}\;q+2$ has and only has 2-degree integral subgraph of q-tree with n vertices and added-vertex q-tree with n vertices.

• Journal of Chest Surgery
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• v.15 no.3
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• pp.346-354
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• 1982

A Complete transposition of the great arteries combined with V.S.D, A.S.D, dextrocardia, and P.S is a rare congenital anomaly. The patient was a 10 year-old female whose complaints were frequent URI, exertional dyspnea, and cyanosis at rest since birth. Cheat X-ray films showed Dextrocardia ; situs inversus, moderate cardiomegaly, and Characteristic egg-shape heart shadow. E.K.G, Echocardiography, Cardiac Catheterization, and Angio-Cardiography were performed. Open heart Surgery was done under diagnosis of d-TGA, Dextrocardia, V.S.D, A.S.D, and P.S. At the time of Operation, Dextroeardia, T.G.A, Secndum type A.S.D, A.S.D, and P.S. At the time of Operation, Dextroeardia, T.G.A, Secndum type A.S.D. ($2.0{\times}2.0cm$. in diameter), V.S.D. type II ($1.5cm{\times}1.5cm$ in diameter), and pulmonary valvular stenosis were noted. Mustard operation using pericardial Baffle in the atrium for T.G.A. was perforsned. Teflon patch graft for closure of V.S.D. through tricuspid orifice and pulmonary Valvulotomy through pulmonary arteriotomy were performed. The post-op, low cardiac output Syndrome and dysrhythmicawere developed till Postoperative day #7, so that was controlled by inotropic and antiarrhythmic agents. After that, patient's conditions were Uneventful.