• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.1-7
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• 2006

3-dimensional(3-D) simulations of ideal double-gate bulk FinFET were performed extensively and the electrical characteristics. were analyzed. In 3-D device simulation, we changed gate length($L_g$), height($H_g$), and channel doping concentration($N_b$) to see the behaviors of the threshold voltage($V_{th}$), DIBL(drain induced barrier lowering), and SS(subthreshold swing) with source/drain junction depth($X_{jSDE}$). When the $H_g$ is changed from 30 nm to 45nm, the variation gives a little change in $V_{th}$(less than 20 mV). The DIBL and SS were degraded rapidly as the $X_{jSDE}$ is deeper than $H_g$ at low fin body doping($1{\times}10^{16}cm^{-3}{\sim}1{\times}10^{17}cm^{-3}$). By adopting local doping at ${\sim}10nm$ under the $H_g$, the degradation could be suppressed significantly. The local doping also alleviated $V_{th}$ lowering by the shallower $X_{jSDE}\;than\;H_g$ at low fin body doping.

• Journal of Nutrition and Health
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• v.42 no.4
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• pp.327-337
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• 2009

University students tend to have various dietary problems including undesirable dietary behaviors, inadequate intakes of nutrients and biased habits of liquid consumption. This study was conducted to find dietary behaviors (n = 357) by questionnaire survey and to examine dietary nutrient intakes (n = 60) and liquid consumption (n = 853) by food record method for 3-days among university students attended in K University of Chungnam province in Korea. Most subjects lived in the dormitory or self-boarding house, and they skipped breakfast most frequently and took breakfast most irregularly among three meals. Dietary mean intakes of energy, Ca, vitamin B2 and folate were lower than the KDRI (37-85%), and those of males were poorer than those of females. Ratios of energy intake among three meals and snacks were not distributed evenly, so the mean energy intake from snacks was higher and that from breakfast was lower than the ideal ratio, respectively. Daily mean consumption of liquid was 1,526.4 mL/d for males and 1,151.5 mL/d for females, and these intakes were more than the KDRI (1,300 mL/d for males and 1,100 mL/d for females). However, their sources of liquid consumption were not desirable because alcohol, soda, juice of fruit or vegetable and beverage mixed with fruit juice and/or vegetable juice were major sources of liquid as well as drinking water. These findings show that university students have poor dietary behaviors including frequent skipping of breakfast, irregularity of meals, inadequate intakes of nutrients and undesirable pattersirablliquid consumption including high portion of alcohol and soda as alliquid source, and these trends were stronger for males than for females. Therefore, we should endeavor to correct their meal problems id ated to dietary behaviors, nutrient intakes and liquid consumptions through nutrition education.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.146-154
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• 2020

With the advantages of biocatalytic method, enzymes have been excavated for the synthesis of chiral amino acids by the reductive amination of ketones, offering a promising way of producing pharmaceutical intermediates. In this work, a robust phenylalanine dehydrogenase (PheDH) with wide substrate spectrum and high catalytic efficiency was constructed through rational design and active-site-targeted, site-specific mutagenesis by using the parent enzyme from Bacillus halodurans. Active sites with bonding substrate and amino acid residues surrounding the substrate binding pocket, 49L-50G-51G, 74M,77K, 122G-123T-124D-125M, 275N, 305L and 308V of the PheDH, were identified. Noticeably, the new mutant PheDH (E113D-N276L) showed approximately 6.06-fold increment of k_cat/Km in the oxidative deamination and more than 1.58-fold in the reductive amination compared to that of the wide type. Meanwhile, the PheDHs exhibit high capacity of accepting benzylic and aliphatic ketone substrates. The broad specificity, high catalytic efficiency and selectivity, along with excellent thermal stability, render these broad-spectrum enzymes ideal targets for further development with potential diagnostic reagent and pharmaceutical compounds applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.30-39
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• 1997

In this paper, a new practical coherent detection scheme for biorthogonal signals, which uses multi-symbol observation interval, is proposed and its performances are analyzed and simulated. The technique jointly estimates both the demondulated data and the channel from received signal only while reducing computation complexity by an approximate maximum-likelihood sequence estimation rather than symbol-by-symbol detection as in previous noncoherent detection. The scheme achieves performance close to that of ideal coherent detection with perfect channel estimates when select the appropriate observation symbol interval N in the given symbol alphabet wize M. What is particularly interesting is that the requeired average signal-to-noise ratio per bit ${\gamma}_{b}$ can be reducedd by as much as 1.4dB and the capacity can be increase by as much as 38% when we use this system in the CDMA cellular reverse link.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.269-273
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• 2005

A furocoumarin derivative, psoralen (7H-furo[3,2-g][1]benzopyran-7-one), was isolated from the n-hexane fraction of Heracleum moellendorffii Hance. We examined the effects of psor-alen on a human Kv1.5 potassium channel (hKv1.5) cloned from human heart and stably expressed in Uk- cells. We found that psoralen inhibited the hKv1.5 current in a concentration-, use- and voltage-dependent manner with an IC$_{50}$ value of 180 $\pm$ 21 nM at +60 mV. Psoralen accelerated the inactivation kinetics of the hKv1.5 channel, and it slowed the deactivation kinetics of the hKv1.5 current resulting in a tail crossover phenomenon. These results indicate that psoralen acts on the hKv1.5 channel as an open channel blocker. Furthermore, psoralen prolonged the action potential duration of rat atrial muscles in a dose-dependent manner. Taken together, the present results strongly suggest that psoralen may be an ideal antiarrhythmic drug for atrial fibrillation.

• Journal of the Korean Chemical Society
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• v.41 no.6
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• pp.284-291
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• 1997

The critical micelle concentrations($CMC^*$) of a cationic surfactant cetylpyridinium chloride (CPC) and a nonionic surfactant triton X-100(TX-100) in aqueous solutions of n-alcohols(methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol) were determined by UV spectroscopic method at 25$^{\circ}C$. The various thermodynamic values in 0.1 M n-alcohols were calculated by means of the equation derived from the pseudo-phase separation model and compared with the values in the absence of n-alcohols. The results were a good agreement with the nonideal mixed micelle model, and they showed negative deviation from the ideal behavior.

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.199-209
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• 2005

An ideal space is ${\cal{I}}-resolvable$ if it has two disjoint ${\cal{I}}-dense$ subsets. We answer the question: If X is ${\cal{I}}-resolvable$, then is X (${\cal{I}}\;{\cup}\;{\cal{N}$)-resolvable?, posed by Dontchev, Ganster and Rose. We give three generalizations of the well known Banach Category Theorem and deduce the Banach category Theorem as a corollary. Characterizations of completely codense ideals and ${\cal{I}-locally$ closed sets are given and their properties are discussed.

• Carbon letters
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• v.13 no.2
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• pp.61-72
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• 2012

Dye removal from waste water via adsorption by activated carbons (ACs) developed from agricultural wastes represents an ideal alternative to other expensive treatment options. Physical and chemical ACs were prepared from rice husks. The textural properties of the ACs were characterized by Brunauer-Emmett-Teller-$N_2$ adsorption and scanning electron microscopy. The chemistry of the carbon surface was investigated by Fourier transform infrared spectroscopy, base and acid neutralization capacities, pH of the active carbon slurry, and $pH_{pzc}$. The adsorption capacities of the ACs for the basic dye (methylene blue) and acid dye (acid green 25) were determined using parameters such as contact time, pH, and temperature. NaOH-ACs showed the highest surface area and total pore volume, whereas steam-ACs showed the lowest ones.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1337-1339
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• 1998

The trench termination scheme is introduced for high voltage devices. The curvature of the depletion region at field limiting ring is critical factor to determine the breakdown voltage. The smooth curvature of the depletion junction alleviate the electric field crowding effect around this region. In the trench field limiting ring, the radius of the depletion region is smaller than conventional field limiting ring, but the distance between every trench is spaced small enough to punchthrough before initiation of local breakdown. The trench field limiting ring on silicon can ne formed by RIE followed by oxidation on side wall surface of the trench, and polysilicon filling. The combined termination of this trench floating field ring and field plate have been designed and analyzed. The breakdown simulation by 2-dimensional TCAD shows that the cylindrical junction breakdown voltage for substrate doping might be 99 percent of the ideal breakdwon voltage for substrate doping concentration of $3\times10^{14}cm^{-3}$ with about $100{\mu}m$ of lateral termination width.

• Structural Engineering and Mechanics
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• v.42 no.3
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• pp.313-334
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• 2012

This paper examines the problem of a penny-shaped crack in a thermoporoelastic body. On the basis of the recently developed general solutions for thermoporoelasticity, appropriate potentials are suggested and the governing equations are solved in view of the similarity to those for pure elasticity. Exact and closed form fundamental solutions are expressed in terms of elementary functions. The singularity behavior is then discussed. The present solutions are compared with those in literature and an excellent agreement is achieved. Numerical calculations are performed to show the influence of the material parameters upon the distribution of the thermoporoelastic field. Due to its ideal property, the present solution is a natural benchmark to various numerical codes and simplified analyses.