• The Journal of Korea Robotics Society
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• v.8 no.2
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• pp.92-103
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• 2013

Humanoid robot is the most intimate robot platform suitable for human interaction and services. Biped walking is its basic locomotion method, which is performed with combination of joint actuator's rotations in the lower extremity. The present work employs humanoid robot simulator and numerical optimization method to generate optimal joint trajectories for biped walking. The simulator is developed with Matlab based on the robot structure constructed with the Denavit-Hartenberg (DH) convention. Particle swarm optimization method minimizes the cost function for biped walking associated with performance index such as altitude trajectory of clearance foot and stability index concerning zero moment point (ZMP) trajectory. In this paper, instead of checking whether ZMP's position is inside the stable region or not, reference ZMP trajectory is approximately configured with feature points by which piece-wise linear trajectory can be drawn, and difference of reference ZMP and actual one at each sampling time is added to the cost function. The optimized joint trajectories realize three phases of stable gait including initial, periodic, and final steps. For validation of the proposed approach, a small-sized humanoid robot named DARwIn-OP is commanded to walk with the optimized joint trajectories, and the walking result is successful.

• Journal of Plant Biology
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• v.25 no.1
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• pp.37-53
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• 1982

Pollen analysis from lake districts, Youngnangho, Wolhamji and Bangeojin, revealed vegetational patterns in Korea. The pollen stratigraphy was divided into five zones, zone L, I, II, IIIa and IIIb for the past 15,000 years. During zone L (earlier than 10,500 yr BP), late-glacial period, Youngnangho was vegetated with a coniferous forest dominated by spruce, larch, haploxylon pine and fir with considerable amount of herbs. Zone I(10,500~7500 yr BP) was predominantly herbaceous vegetationj with significant amount of oak and diploxylon pine. It suggests that the overall environment became milder and drier than late-glacial period. Zone II(7,500~4,000 yr BP), hypsithermal period, showed significant warming condition, indicated by high pollen concentrations of oak, diploxylon pine and hornbeam, and by more diverse flora of deciduous broad-leaved trees than before. Herbs were not an important part of vegetation. Zone III$^a$(4,000~1,500 yr BP) had pine and oak as main elements. Birch increased slightly while hornbeam decreased in this time. It indicates cooling condition. Zone III$^b$(1,5000-present) which can be called pine period showed obvious human interference. Following forest clearance, agriculture was intensified. The beginning of logging and agriculture was discernible by a sudden decline of arboreal species and by considerable amount of rice, buckwheat, sorrel and plantain. Numerous charcoal fragments were observed in zone I and zone III$^b$.

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1164-1169
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• 2005

Brain microglia are phagocytic cells that are the major inflammatory response cells of the central nervous system and widely held to play important pathophysiologic roles in Alzheimer's disease (AD) in both potentially neurotoxic responses and potentially beneficial phagocytic responses. In the study, we examined whether ginsonoside Rg3, a by-product of red ginseng, enhances the microglial phagocytosis of $A{\beta}$. We found that Rg3 promoted $A{\beta}$ uptake, internalization, and digestion. Increased maximal $A{\beta}$ uptake was observed at 4 and 8 h after Rg3 pretreatment (25 ${\mu}g/mL$), and the internalized $A{\beta}$ was almost completely digested from cells within 36 h when pretreated with Rg3 comparing with single non-Rg3-treated groups. The expression of MSRA (type A MSR) was also up-regulated by Rg3 treatment in a dose- and time-dependent manner which was coincidently identified in western blots for MSRA proteins in cytosol. These results indicate that microglial phagocytosis of $A{\beta}$ may be enhanced by Rg3 and the effect of Rg3 on promoting clearance of $A{\beta}$ may be related to the MSRA-associated action of Rg3. Thus, stimulation of the MSRA might contribute to the therapeutic potentials of Rg3 in microglial phagocytosis and digestion in the treatment of AD.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.181-186
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• 1998

This study was attempted to investigate the pharmacokinetics of cyclosporine (10mg/kg, oral) in rabbits with $CCI_4$ and bile duct ligation-induced hepatic disorder. The area under the curve (AUC) of blood cyclosporine concentration versus time was significantly increased ($CCI_4$-induced hepatic disorder. Elimination rate constant (Kel) was significantly decreased (p<0.05, p<0.01) in rabbits with $CCI_4$ and bile duct ligation-induced hepatic disorder. Volume of distribution (Vdss) and total body clearance (CLtot) were significantly decreased (p<0.01) in rabbits with $CCI_4$-induced hepatic disorder. But Vdss was significantly increased (p4-induced hepatic disorder were 874ng/ml and 2.71 hr, respectively. Cmax and Tmax values in rabbits with bile duct ligation were 105ng/ml and 2.834 hr, respectively. From results of this experiment. It is desirable to do therapeutic drug monitoring of cyclosporine for effective treatment when the cyclosporine is administered to patients with liver disorder m clinical practice.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.428-433
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• 1994

The methabolism and phamacokinetics of a mixed disulfide S-(N, N-diethyldithiocarbamoyl)-N-acetyl-L-cysteine (AC-DDTC) were studied in rats. Two metabolites of AC-DDTC following iv and po administration were indentified in plasma and liver by HPLC and GC, namely N, N-diethyldithiocarbamate (DDTC) and the methyl ester of DDTC (Me-DDTC). AC-DDTC was very unstable in vivo and could not be detected neither in plasma nor in urine. Pharmacokinetic parameters of DDTC following intravenous administration of AC-DDTC (20 mg/kg) were calculated. DDTC has a low affinity to rat tissue and the body clearance was $9.0{\pm}3.4mkl/mim/kg$. The mean residence time (MRT) was $11.5{\pm}16.3 min$. After oral administration of 20 mg/kg AC-DDTC, maximal plasma concenttion ($C_{max}$) was $3.8{\pm}0.2 nmol/ml$ and the bioavailability was 7.04%. $C_{max}$ for DDTC at a dose of 120 mg/kg. AC-DDTC was $40.1{\pm}2.2 nmol/ml$. ART was $47.1{\pm}2.8min$.at a dose of 20 mg/kg and $110.5{\pm}6.0 min$ at 120 mg/kg.

• Korean Journal of Clinical Pharmacy
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• v.9 no.2
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• pp.88-91
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• 1999

The purpose of this study was to compare the pkarmacokinetic parameters of vancomycin using a 2-compartment model in 8 Korean healthy volunteers and 8 lymphoma patients. Vancomycin (1.0 g) was administered by IV infusion over 60 minutes. The $\beta-phase$ rate constant $(\beta)$, apparent volume of distribution at steady srate $(V_{ss})$, total body clearance (CL) and area under the plasma level-time curve (AUC) of vancomycin in healthy volunteers were $0.15\pm0.02\;hr^{-1},\;33.8\pm4.12\;L/kg,\;5.36\pm0.61\;L/hr\;and\;185.8\pm20.5\;{\mu}g/ml{\cdot}hr$, respectively. The corresponding values in lymphoma patients ere $0.09\pm0.02\;hr^{-1},\;38.2\pm5.11\;L/kg,\;4.58\pm0.52\;L/hr\;and\;218.3\pm22.9\;{\mu}g/ml{\cdot}hr$. There were significant differences (p<0.05) in ${\beta}$ and CL between healthy volunteers and lymphoma patients.

• Journal of Hydrogen and New Energy
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• v.21 no.3
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• pp.167-183
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• 2010

This paper analyzes the backgrounds of the standards for protection against electric shock in Global Technical Regulations (GTR) of Fuel Cell Vehicle (FCV). Targets on research were high voltage criteria, safety current, isolation and grounding resistance, time limitation, energy, adequate clearance, and test procedure. Based on human impedance and effect of current in IEC 60479-1, safety of human was examined. Then, isolation and grounding circuit model of FCV were analyzed theoretically. The results give several suggestions: touch voltage less than 25V, AC energy less than 0.0813J, separation considering middle finger length, grounding resistance less than $0.2\Omega$, maximum AC ground voltage of 1V (rms), and isolation resistance between earth and electrical chassis. In MATLAB/Simulink environment, error characteristics of isolation resistance measurement procedure using internal DC sources were analyzed under variations of internal resistance of voltmeter and isolation resistance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.119-126
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• 2014

Micro-holes of conductive ceramic are required in micro structures. Micro-electrical discharge machining (Micro-EDM) is an effective machining method since EDM is as process for shaping hard metals and complex-shaped holes by spark erosion in all kinds of electro-conductive materials. However, as the depth of micro hole increases, the machining condition becomes more unstable due to inefficient removal of debris between the electrode and the workpiece. In this paper, micro-EDM was performed to evaluate machining characteristic such as electrode wear, machining time, taper angle, radial clearance with varying voltage and ultrasonic vibration on 10 vol.% Carbon-nanotube reinforced conductive $Al_2O_3$ composite fabricated by spark plasma sintering in previous research.

• International Commerce and Information Review
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• v.14 no.2
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• pp.473-495
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• 2012

e-Trade should be activated for cost saving and efficient management of trade as it provides bases to actively respond to changes in markets through quick clearance of export and import. It also has tangible and intangible effects in providing services to customers through real-time sharing of information and can help enhance external competition and images through cost saving and efficient management of traders. Therefore, the study suggests that e-trade platforms to construct global trade systems should be executed to maximize economic ripple effects in terms of trade documents and cost, and paradigms of the past trade should be changed into new systems and presents future countermeasures to enhance its ripple effects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.450-455
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• 2008

A Single Nucleotide Polymorphism (SNP) is a small genetic change or variation that can occur within a DNA sequence. It's the difference of one base at specific base pair position. SNP variation occurs when a single nucleotide, such as an A, replaces one of the other three nucleotide letters-C, G, or T. On average, SNP occur in the human population more than 1 percent of the time. They occur once in every 300 nucleotides on average, which means there are roughly 10 million SNPs in the human genome. Because SNPs occur frequently throughout the genome and tend to be relatively stable genetically, they serve as excellent biological markers. They can help scientists locate genes that are associated with disease such as heart disease, cancer, diabetes. They can also be used to track the inheritance of disease genes within families. SNPs may also be associated with absorbance and clearance of therapeutic agents. In the future, the most appropriate drug for an individual could be determined in advance of treatment by analyzing a patient's SNP profile. This pharmacogenetic strategy heralds an era in which the choice of drugs for a particular patient will be based on evidence rather than trial and error (so called "personalized medicine").