• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.24.4-24.4
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• 2011

Frozen orbit concept is very useful in designing particular mission orbits including the Sun-synchronous and minimum altitude variation orbits. In this work, variety of frozen and Sun-synchronous orbit conditions around the Moon is investigated and analyzed. The first two zonal harmonics of the Moon, J2 and J3, are considered to determine mean orbital elements to be a frozen orbit. To check the long-term behavior of a frozen orbit, formerly developed YonSei Precise Lunar Orbit Propagator (YSPLOP) is used. First, frozen orbit solutions without conditions to be the Sun-synchronous orbit is investigated. Various mean semi-major axes having between ranges from 1,788 km to 1,938 km with inclinations from 30 deg to 150 deg are considered. It is found that a polar orbit (90 deg of inclination) having 100 km of altitude requires the orbital eccentricity of about 0.01975 for a frozen orbit. Also, mean apolune and perilune altitudes for this case is about 136.301 km and 63.694 km, respectively. Second, frozen orbit solutions with additional condition to be the Sun-synchronous orbit is investigated. It is discovered that orbital inclinations are increased from 138.223 deg to 171.553 deg when mean altitude ranged from 50 km to 200 km. For the most usual mission altitude at the Moon (100 km), the Sun-synchronous orbit condition is satisfied with the eccentricity of 0.01124 and 145.235 deg of inclination. For this case, mean apolune and perilune altitudes are found to be about 120.677 km and 79.323 km, respectively. The results analyzed in this work could be useful to design a preliminary mapping orbit as well as to estimate basic on-board payloads' system requirements, for a future Korea's lunar orbiter mission. Other detailed perturbative effects should be considered in the further study, to analyze more accurate frozen orbit conditions at the Moon.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.18-22
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• 2002

This study was carried to investigate efficient pot diameter and substrate weight in pot cultivation of Pleurotus ostreatus. Cultivating substrate was pine sawdust+beet pulp+cotten seed flour (50 : 30 : 20, v/v). Ranges of pot diameter and substrate weight were $10{\sim}20\;cm\;and\;600{\sim}2,500\;g/pot$, respectively. Smaller pot diameter resulted in longer pot length according to increasing substrate weight, so mycelial growth period and total cultivation period was retarded. Wider pot diameter resulted in a little lower biological efficiency in the same substrate weight. Heavier substrate weight was brought higher yield but lower biological efficiency. Average yield according to pot diameter was decreased at wider than 14 cm during second flush. And average biological efficiency according to substrate weight was lower than 100% at heavier than 1,200 g/pot during second flush. So suitable pot diameter and substrate weight in pot cultivation of Pleurotus ostreatus were estimated $10{\sim}14\;cm\;and\;800{\sim}1,200\;g$, respectively.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.321-330
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• 2006

The pathogenic mechanism of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK) by Acanthamoeba has yet to be clarified. Pretense has been recognized to play an important role in the pathogenesis of GAE and AK. In the present study, we have compared specific activity and cytopathic effects (CPE) of purified 33 kDa serine proteinases from Acanthamoeba strains with different degree of virulence (A. healyi OC-3A, A. lugdunensis KA/E2, and A. castelianii Neff). Trophozoites of the 3 strains revealed different degrees of CPE on human corneal epithelial (HCE) cells. The effect was remarkably reduced by adding phenylmethylsulfonylfluoride (PMSF), a serine proteinase inhibitor. This result indicated that PMSF-susceptible proteinase is the main component causing cytopathy to HCE cells by Acanthamoeba. The purified 33 kDa serine proteinase showed strong activity toward HCE cells and extracellular matrix proteins. The purified proteinase from OC-3A, the most virulent strain, demonstrated the highest enzyme activity compared to KA/E2, an ocular isolate, and Neff, a soil isolate. Polyclonal antibodies against the purified 33 kDa serine proteinase inhibit almost completely the proteolytic activity of culture supernatant of Acanthamoeba. In line with these results, the 33 kDa serine proteinase is suggested to play an important role in pathogenesis and to be the main component of virulence factor of Acanthamoeba.

• Textile Coloration and Finishing
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• v.20 no.3
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• pp.31-38
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• 2008

Regenerated composite fibers were prepared from solution of styela clava tunics(SC) and poly vinyl alchol(PVA) using N-methylmorpholine-N-oxide(NMMO)/water(87/13)(wt%/wt%) as a solvent by dry jet-wet spinning. Structure and physical properties of regenerated composite fibers were investigated through birefrngence, x-ray diffratograms, tenacity, fibrillation and SEM. Optimal blend ratio of SC/PVA for mechanical properties of composite fibers was 70/30 and total weight was 4wt% concentrations in NMMO/$H_2O$ solvent system. Crystallinity index of composite fibers were decreased as the PVA contents increased. Fibrillation of $10{\sim}20wt%$ PVA blended fibers were occurred less than pure SC fiber. Shape of composite fibers were a circle cross section within 10wt% PVA content. But the cross section of fibers were changed as crushed flat with the PVA contents increased.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.272-276
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• 2005

To accept basic data of utilizing of cheongtae as a raw material of new food and industrial products, major chemical components were investigated. As a results of mineral analysis, the content of P (310.52mg/100 g) was much higher. than those of K (48.65 mg/100 g), Ca (40.93 mg/100 g), Mg (27.87 mg/100 g), Na(14.36 mg/100 g), Fe (6.31 mg/100 g), Zn (4.40 mg/100 g) and Cu(1.27 mg/100 g). The main components of free sugar in cheongtae were sucrose and glucose. The main fatty acids of total lipid were linoleic acid and oleic acid, which comprised over 75$\%$ of total fatty acids. The daidzein and genistein levels in cheongae were 40.95 mg/100g, 38.02 mg/100 g, respectively.

• The Korean Journal of Pain
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• v.4 no.2
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• pp.152-156
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• 1991

Cervical radiculopathy has been recognized as a common cause of neck, shoulder, and arm pain. It was conventionally treated with rest, traction, cervical collars, manipulation, transcutaneous electrical nerve stimulation, and nonsteroidal anti-inflammatory drugs with varying results. Surgery has not always been successful so the idea of epidural steroid injection was developed as in the case of lumbar epidural injections, for the treatment of low back pain and sciatica. Thirty one patients with evidence of cervical radiculopathy were treated with injections of triamcinolone acetate into the cervical epidural space. The effect of the steroid injection could be evaluated in twenty one patients who received epidural injections more than twice. No improvement was seen in 6 patients and 15 patients showed good to excellent pain relief for a week to over 6 months. Epidural steroid injection seems to have a positive role in the treatment of cervical radiculopathy.

• The Journal of Internal Korean Medicine
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• v.26 no.3
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• pp.521-532
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• 2005

Objectives & Methods : In order to evaluate the in vitro synergic effects or Eunkyo-san which is a traditional poly-herbal formula that has been used in the treatment of respiratory diseases in oriental medicine, and quinolone antibiotics, rufloxacin (RUFX) and iprofloxacin(CPFX), experimentation was designed to determine minimal inhibitory concentration(MIC), $MIC_{50}\;and\;MIC_{90}$ of single use of quinolones and concomitant treatment with Eunkyo-san against 5 strains of aerobic gram negative bacteria, Escherichia coli, Klebsiella peumoniae, Hemophilus influenzae, Citrobacter freundii and Pseudomonas aeruginosae. Result : In the case of aerobic gram negative bacteria, the MIC, $MIC_{50}\;and\;MIC_{90}$ against Klebsiella peumoniae and Citrobacter freundii significantly decreased in concomitant-treated groups with Eunkyo-san compared to those of single-treated groups of RUFX and CPFX, respectively. However, no significant changes were demonstrated against Echerichia coli, Hemophilus influenzae and Pseudomonas aeruginosae. Conclusion : According to these results, concomitant use of Eunkyo-san against some strains of aerobic gram-negative bacteria dramatically increases in vitro antibacterial activity of RUFX and CPFX, and the increase and selectivity of antibacterial activities against these strains is attributable to Eunkyo-san, and not RUFX or CPFX activity.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.64-69
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• 2012

Laser welding was carried out on austenitic 304 (STS 304) and 22 APU stainless steels. In this case, the differences between the corrosion characteristics of the welding zones of the two stainless steels were investigated using electrochemical methods. The Vickers hardness values of the weld metal (WM) zones in both cases, the STS 304 and 22 APU stainless steels, showed relatively higher values than those of other welding zones. The corrosion current densities of the heat affected zone (HAZ) of the 22 APU and the base metal (BM) zone of the STS 304 exhibited the highest values compared to the other welding zones. It is generally accepted that when STS 304 stainless steel is welded using a general welding method, intergranular corrosion is often observed at the grain boundary because of its chromium depletion area. However, when laser welding was performed on both the STS 304 and 22 APU stainless steels, no intergranular corrosion was observed at any of the welding zones. Consequently, it is considered that the intergranular corrosion of stainless steel can be controlled with the application of laser welding.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.248-254
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• 2002

Single cell gel electrophoresis assay was carried out to evaluate DNA damage in T-and B-lymphocytes from rats exposed to benzene and the correlation between DNA damage and the level of t,t-muconic acids, which are urinary benzene metabolites, was investigated. In control rats, the mean values of Olive tail moments in T-and B-lymphocytes were 1.507$\pm$0.187 and 1.579$\pm$0.206 respectively. DNA damages of T-lymphocytes in rats exposed for 4 weeks showed the highest Olive tail moments at each benzene concentration examined (2.72-4.351). However this DNA damage was decreased after 6 weeks of exposure (1.74-2.09). DNA damages of B-lymphocytes did not show such differences with exposure time or benzene concentration (1.49-2.07) except at 200 ppm at 4 weeks. T-lymphocytes show significantly more damages than B-lymphocyte upon acute exposure to benzene.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1191-1200
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• 2009

The replicas in the Grid database is utilized for a lot of application services. And for deferent services or for deferent information depends on location, the access frequency of each replica is dissimilar. When one replica is stored in many nodes, each replicas applies the week-consistency in the grid computing environment. Especially, when a node work load or operation capacity is varied from others, the replica management would cost expansive. Therefore, this paper proposed the Update Method based on Dynamic Access-Frequency Tree. The dynamic access-frequency tree is pre-constructed by grouping nodes based on each nodes access frequency to manage the replica efficiently and avoid unbalance replica tree. The performance evaluation shows the proposed methods support more quick update than current methods.