• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.414-430
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• 1996

In this paper, a new kinematic structure of a parallel manipulator with six Cartesian degrees of freedom is proposed. It consists of a platform which is connected to a fixed base by means of 3-PPSP(parameters P, S denote the prismatic, spherical joints) subchains. Each subchain has a link which is concected to a passive prismatic joint at the one end and a passive spherical joint at the other. The spherical joint is then attached to perpendicularly arranged prismatic actuators which are fixed at the base. The spherical joint is then attached to perpendicularly arranged prismatic actuators which are fixed at the base. This arrangement provides a basis to control all six Cartesian degrees of motion of the platform in space. Due to its efficient architecture, the colsed-form solutions of the inverse and forward kinematics can be obtained. As a consequence, this new kinematic structure can be servo controlled using simple inverse kinematics becaese forward kinematics allows for measuring the platform's position and orientation in Cartesian space. Furthermore, the proposed structure provides an effective functional workspace. Series of simulations are performed to verify the results of the kinematics analyses.

• Journal of Powder Materials
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• v.26 no.6
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• pp.515-527
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• 2019

High-entropy alloys (HEAs) are generally defined as solid solutions containing at least 5 constituent elements with concentrations between 5 and 35 atomic percent without the formation of intermetallic compounds. Currently, HEAs receive great attention as promising candidate materials for extreme environments due to their potentially desirable properties that result from their unique structural properties. In this review paper, we aim to introduce HEAs and explain their properties and related research by classifying them into three main categories, namely, mechanical properties, thermal properties, and electrochemical properties. Due to the high demand for structural materials in extreme environments, the mechanical properties of HEAs including strength, hardness, ductility, fatigue, and wear resistance are mainly described. Thermal and electrochemical properties, essential for the application of these alloys as structural materials, are also described.

• Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.186-191
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• 2011

An agar-degrading enzyme-producing strain was isolated from seawater. The isolate was identified as Microbulbifer sp. SD-1 by 16S rRNA sequencing analysis. The optimal pH and temperature for growth were 6.0 and $30^{\circ}C$, respectively, and growth was possible at pH 9.0 and $60^{\circ}C$. The isolate required 5% NaCl for optimal growth and showed 45% growth activity without NaCl. Agar concentrations of 0-0.4% in the medium did not affect growth. Thin-layer chromatography analysis revealed that this strain could degrade agar into a monosaccharide and oligosaccharide, which may have industrial applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.91-92
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• 2018

As we begin to develop into an aging society, a lot of safety issues are emerging recently. Also, laws and products related to the safety and welfare of the elderly are being released. Therefore, this paper investigated the safety of the elderly. In this paper, we propose a system that can detect motion such as falling or slipping of elderly people by using gyro sensor and accelerometer to solve these factors.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.24 no.1
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• pp.36-44
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• 2011

Objective : Propolis (PP) has been used in oriental medicine. PP has various biological activities. However, its immunoregulatory and anti-inflammatory activities have not been well studied. In this study, I investigated these activities of PP by using ovalbumin-induced allergic asthma in mice. Methods : To examine the effect of PP on allergic asthma, mice were sensitized with $100{\mu}g$ of OVA and 1mg of aluminum potasssium sulfate (Alum; Sigma) intraperitoneally on day 0 and 7. On day 14, mice were challenged on consecutive 3 days with 5% OVA and AHR was assessed 24 hours after the last challenge. To examine severity of AHR, I examined the population of eosinophiles and T cells in spleen and lung and cytokine production in T cells. Futhermore, I examined histological changes during the OVA-induced allergic asthma. Results and Conclusion : PP reduced the population of eosinophil and CD4+ T cells on the OVA-induced AHR mice model. PP also inhibited IL-4 production but increased INF-g production in T cells. These results suggest that PP may be beneficial material for allergic asthma.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.241-252
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• 2016

Cellulose acetate is one of well-known industrial materials which have various commercial uses. We treated the lignocellulosic biomass using two-step (steam explosion-chemical) reaction followed by acetylation to get the cellulose acetate in this study. The two-step treatment was done to improve the yields of acetylation of the substrates. The yields of the cellulose acetate were about 88.4, 88.1, and 151.7% in barley straw, rice straw, and oak tree, respectively. Also the degree of substitution (DS) of the acetates was 2.1 to 2.5 in the biomass. We found that the biomass were valuable cellulosic sources, including their derivatives, in this study. This means that the biomass can be converted into the high-valued cellulosic stuff.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.106-111
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• 1989

A new EMG signal processing algorithm for SMUAP pattern classification is proposed. It checks the combination and regularity of ISI using a spike counter as a decision making routine, and performs SMUAP waveform alignment in frequency domain and selects spikes through FIR filtering. As a result, with the EMG signals recorded during 5 seconds at 10-50% MVC force level, the SMUAP ranged from five to nine units were classified and identification rate is greater than 55 percent using a concentric needle electrode. In the IBM PC/AT the processing time typically required 2 minutes.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.536-545
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• 2006

In this study the behavior of piles with an extended head is invested experimentally using reduced-scale model tests. Special attention is given to verifying the increase of end bearing capacity of piles with spreading head. Model piles and extended head plates made of steel pipe were used in this study. Bearing capacity of piles is regarded as only end bearing capacity. The study analyzed the tendency of single and group pile of bearing capacity compared with the existing PHC pile, and examined optimum effect of extended head.

• Journal of Korean Critical Care Nursing
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• v.4 no.1
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• pp.11-24
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• 2011

Purpose: The purpose of this study was to grasp the subjectivity of the nurses toward DNR (Do not resuscitation) order. Methods: Q methodology was employed to explore the nurses' subjectivity. Q population consisted of 292 statements that were obtained through individual in-depth interviews targeting 30 employees(nurses, doctors, staff members) and literature review. Finally, 30 nurses classified 34 statements using a 9 point scale. Results: The current survey that probed into the subjectivity of the nurses relative to DNR order abstracted four categories. The first type (restrictive acceptance type) perceived the determinants of DNR as the patient's hopeless state. The second type (evidence-based type) emphasized the decision based on the guideline. The third type (medical personnel-centered type) showed the characteristic that depends passively on the professional judgement. The fourth type (rationalistic type) emphasized rational characteristic that DNR decision needs to be made by considering several situations such as economic and psychological burden of family and the quality of life. Conclusion: These types of nurse's perception need to be considered in the nurses' continuing educational program in order to confront affirmatively and positively with ethical dilemma.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.317-320
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• 2006

Octadeca-9,12-dienyl-3,4,5-hydroxybenzoate (GA-LA) was chemically synthesized from gallic acid and linoleic acid ester, and its biological functions were tested. Radical-scavenging activity of GA-LA was comparable to those of gallic and ascorbic acids at 0.24 mM, and tyrosinase inhibition effect was higher than that of ascorbic acid. Gallic and linoleic acids did not show any tyrosinase activity. Results of cyclooxygenase (COX) inhibition effect indicate GA-LA has higher selectivity in COX-1 inhibition. GA-LA from gallic and linoleic acids could be used as functional reagent for antioxidative, skin-whitening, and anti-inflammatory effects in food, pharmaceutrical, and cosmetic industries.