• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.140-142
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• 2006

Because ochratoxin A recovery level of Makgeolli is lower (<50%) than those of other commodities such as rice, barley, and beer, Makgeolli was evaluated to improve the recovery and enable routine analysis. Use of 3% sodium bicarbonate instead of phosphate-buffered saline as homogenizing solution provided good recovery of ochratoxin A (>80%) spiked in Makgeolli at level of 1 ppb. To determine if this analytical method is reliable for ochratoxin A detection in Makgeolli, survey was conducted for ochratoxin A in 30 sterile Makgeolli samples retailed in Korea. Only two wheat-based Makgeolli samples contained detectable level of ochratoxin A (0.8 and 2.1 ppb) as confirmed by HPLC- electrospray ionization- mass spectrometry. Extraction of sample with 3% sodium bicarbonate for 3 min, followed by cleanup of extracts with immunoaffinity columns, and HPLC with fluorescence detection provided dependable detection of ochratoxin A in Makgeolli samples.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.317-323
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• 2024

According to the section A-VI/3 of the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW), Water-based firefighting training center is mandatory to obtain onboard certificates. This space, being similar to fire situations on ships requires that safety measures be quantified to ensure occupant safety and establish operational standards. For fire safety evaluation, cases were designed based on the presence or absence of smoke control equipment using Pyrosim based on Fire Dynamics Simulation (FDS). Vector analysis was performed to evaluate flow of smoke and heat. Available safe escape time / required safe escpae time (ASET/RSET) analysis was conducted to evaluate safety by comparing the interpreted numerical results through Pathfinder. During safety evaluation of the current operational condition, the appropriateness of the function of each smoke control equipment was numerically and visually indicated. The emergency situation with dust collector stopped was expressed by each evacuation time and safety margin of 111.2 seconds, suggesting that be used as a standard of evacuation time.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.980-985
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• 2004

This paper shows a performance analysis for conical type sealless cylinders and rod bearings. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the performance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a sealless cylinder are presented. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively. Leakage flow test is conducted to evaluate performance of piston and rod bearing in sealless cylinder.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1244-1249
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• 2008

This paper shows a perfonnance analysis for pneumatic servo cylinder. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the perfonnance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a servo cylinder are presented. A prototype of servo cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.29-32
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• 2004

Fully depleted Silicon-on-Insulator (FD-SOI) devices lead to better electrical characteristics than bulk CMOS devices. However, the presence of a thin top silicon layer and a buried SiO2 layer causes self-heating due to the low thermal conductivity of the buried oxide. The electrical characteristics of FDSOI devices strongly depend on the path of heat dissipation. In this paper, we present a new three-dimensional (3-D) analysis technique for the self-heating effect of the finger-type and bar-type transistors. The 3-D analysis results show that the drain current of the finger-type transistor is 14.7% smaller than that of the bar-type transistor due to the 3-D self-heating effect. We have learned that the rate of current degradation increases significantly when the width of a transistor is smaller that a critical value in a finger-type layout. The current degradation fro the 3-D structures of the finger-type and bar-type transistors is investigated and the design issues are also discussed.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.532-539
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• 2012

Electron spin resonance (ESR) spectroscopy of gamma-irradiated fresh broccoli and kimchi cabbage was conducted to identify their irradiation history. Different pretreatments, such as freeze-drying (FD), oven-drying (OD), alcoholic-drying (ALD), and water-washing and alcoholic-drying (WAD) were used to lower the moisture contents of the samples prior to ESR analysis. The non-irradiated samples exhibited a single central signal ($g_0$=2.0007) with clear effect of $Mn^{2+}$, especially in kimchi cabbage. Upon irradiation, there was an increase in the intensity of the central signal, and two side peaks, mutually spaced at 6 mT, were also observed. These side peaks with $g_1$ (left)=2.023 and $g_2$ (right)=1.985 were attributed to radiation-induced cellulose radicals. Leaf and stem in broccoli, and root and stem in kimchi cabbage provided good ESR signal responses upon irradiation. The signal noise was reduced in case of ALD and WAD pretreatments, particularly due to $Mn^{2+}$ signals. The ALD treatment was found most feasible to detect the improved ESR spectra in the irradiated samples.

• Archives of Plastic Surgery
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• v.42 no.6
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• pp.686-694
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• 2015

Background Rosa damascena, a type of herb, has been used for wound healing in Eastern folk medicine. The goal of this study was to evaluate the effectiveness of rose placenta from R. damascena in a full-thickness wound model in mice. Methods Sixty six-week-old C57BL/6N mice were used. Full-thickness wounds were made with an 8-mm diameter punch. Two wounds were made on each side of the back, and wounds were assigned randomly to the control and experimental groups. Rose placenta ($250{\mu}g$) was injected in the experimental group, and normal saline was injected in the control group. Wound sizes were measured with digital photography, and specimens were harvested. Immunohistochemical staining was performed to assess the expression of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), and CD31. Vessel density was measured. Quantitative analysis using an enzyme-linked immunosorbent assay (ELISA) for EGF was performed. All evaluations were performed on postoperative days 0, 2, 4, 7, and 10. Statistical analyses were performed using the paired t-test. Results On days 4, 7, and 10, the wounds treated with rose placenta were significantly smaller. On day 2, VEGF and EGF expression increased in the experimental group. On days 7 and 10, TGF-${\beta}1$ expression decreased in the experimental group. On day 10, vessel density increased in the experimental group. The increase in EGF on day 2 was confirmed with ELISA. Conclusions Rose placenta was found to be associated with improved wound healing in a mouse full-thickness wound model via increased EGF release. Rose placenta may potentially be a novel drug candidate for enhancing wound healing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5393-5399
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• 2014

To examine the effects of a mycosporine-like amino acids (MAAs) mixture from microalgae, Chlamydomonas sp, on the anti-wrinkle activities, the expression levels of genes that are associated with skin aging, including type I procollagen, elastin and involucrin, were analyzed. Asterina 330+palythine (A+P) and shinorine+palythine (S+P) mixtures were purified from Chlamydomonas sp using the following steps: 80% methanolic extraction, column purification, and HPLC analysis. As a result of the MTT assay, A+P and S+P did not induce cellular cytotoxicity with up to 0.1 mg/mL of both MAAs. In addition, the treatment of UV-exposed fibroblasts with A+P (0.05 mg/mL) and S+P (0.01 mg/mL) increased the levels of the PCOLCE mRNAs by 2.7 and 3.6 fold compared to the control group, respectively, The levels of elastin gene expression were elevated 5.59 and 3.1 fold in the A+P and S+P treated (0.01 mg/mL) cells, respectively. In particular, at a concentration of 0.01 mg /mL, the A+P and S+P expression levels of Involucrin mRNAs were increased 3.5 and 2.5 fold in the UV-exposed cells compared to the control, respectively. In conclusion, the MAAs derived from Chlamydomonas sp can be utilized as functional cosmetic materials with anti-wrinkle effects on the skin.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.211-216
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• 2013

The IVA(Independent Vector Analysis) is a well-known FD-ICA method used to solve the frequency permutation problem. It generally works quite well for blind source separation problems, but still needs some improvements in the frequency bin permutation problem. This paper proposes a post-processing method which can improve the source separation performance with the IVA by fixing the remaining frequency permutation problem. The proposed method makes use of the correlation coefficient of power ratio between frequency bins for separated signals with the IVA-based 2-channel source separation. Experimental results verified that the proposed method could fix the remaining frequency permutation problem in the IVA and improve the speech quality of the separated signals.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.200-203
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• 2008

Water mist fire suppression system utilizes the fire suppression features such as cooling of fire source, dilution of ambient oxygen, and shielding of radiation heat with the evaporation of microscopic water droplets. The momentum of water mist is relatively low and the infiltration of water mist to the fire source is not effective. In addition to lower penetration force, the evaporated water vapor is liable to decline to limited portion of fire source due to its light weight and sparse density. On the other hand, the cycling water mist system is expected to improve the penetration force of water mist as well as the dilution coverage capability with the stratified spray characteristics. At this paper we present the analyzed fire suppression capability of intermittent water spray pattern by use of FDS which is computational fire dynamics fire model. We expect this analysis shall be supportive to the development of the prototype of water mist nozzle.