• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2475-2480
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• 2003

A control system design based on coupled nonlinear oscillators (CNOs) for a self-organized swarm system is presented. In this scheme, agents self-organize to flock and arrange group formations through attractive and repulsive forces among themselves using CNOs. Virtual agents are also used to create richer group formation patterns. The objective of the swarm control in this paper is to follow a moving target with a final group formation in the shortest possible time despite some obstacles. The simulation results have shown that the proposed scheme can effectively construct a self-organized multi-agent swarm system capable of group formation and group immigration despite the emergence of obstacles.

• International Journal of Control, Automation, and Systems
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• 제2권3호
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• pp.333-342
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• 2004

This paper presents a framework for the self-organization of swarm systems based on coupled nonlinear oscillators (CNOs). In this scheme, multiple agents in a swarm self-organize to flock and arrange themselves as a group using CNOs, which are able to keep a certain distance by the attractive and repulsive forces among different agents. A theoretical approach of flocking behavior by CNOs and a design guideline of CNO parameters are proposed. Finally, the formation scenario for cooperative multi-agent groups is investigated to demonstrate group behaviors such as aggregation, migration, homing and so on. The task for each group in this scenario is to perform a series of processes such as gathering into a whole group or splitting into two groups, and then to return to the base while avoiding collision with agents in different groups and maintaining the formation of each group.

• 대한후두음성언어의학회지
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• 제20권1호
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• pp.36-41
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• 2009

Background and Objectives: Topical administration of mitomycin-C (MMC) has been reported to reduce or delay scar formation in airway surgery. However, it is not infrequent to experience recurrent stenosis or adhesion of operative wound even after a meticulous MMC application during the laryngeal surgery. Therefore we aimed to evaluate the effectiveness of repeated postoperative MMC applications and the technical feasibility of MMC applications to the laryngeal wound at an outpatient clinic. Methods: We reviewed medical records of 13 consecutive patients who received office-based MMC applications after laryngeal airway surgery at Samsung Medical Center, Seoul, Korea. The patients were grouped into 3 categories according to the site of surgical wound and the purpose of MMC application; group I : supraglottic stenosis (n=5), group II : cordectomy and arytenoidectomy site granulation prevention (n=3), Group III : laryngeal web prevention (n=5). Outcomes in each group and adverse effects of repeated MMC applications were evaluated. Results: Office-based MMC application was successfully performed one to four times with a week interval for each patient. No significant complications were observed except slightly decreased mucosal wave in one female patient who received 4 times of MMC application at the anterior commissure of vocal fold. Repeated MMC applications at the outpatient clinic resulted in wide or acceptable supraglottic airway in group I, clean wound healing without granulation formation in group II, and negligible or no web formation at the anterior commissure in group III. Conclusion : Office-based topical administration of MMC to the larynx was technically feasible. Postoperative repeated MMC applications were effective to reduce recurrent stenosis or adhesion of supraglottic structures, to prevent granuloma formation after laser arytenoidectomy and glottic web formation after anterior commissure resection.

• 한국임상수의학회지
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• 제19권1호
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• pp.66-72
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• 2002

Korean safflower seed has been known to have healing effects on both bone fracture and osteoporosis. On the base of such a notice, this experiment was carried out to explore the effects of safflower seed on bone formation and bone repair. The toxicity test and the effect of Korean safflower seed were evaluated with 60 rats, 3-month old. Forty Sprague-Dawley rats composed of 20 male and 20 female were underwent unilateral tibial defect and then fastened with unilateral fixators. The operated rats were divided into two groups depending on the composition of diet, such as positive control group fed normal diet(C-OP group) and safflower seed group fed 30% of safflower seed diet and 70% of normal diet(S-OP group). Another 20 rats without operation were maintained, each 10 rats were fed either normal diet or 30% of safflower seed diet and 70% of normal diet, and observed the toxicity of safflower seed by measuring weight and urine parameters. Postoperative radiography were taken once in 2 weeks to evaluate callus formation for operated groups and blood collection via heart puncture were carried out once in 3 weeks for 3 groups. The concentration of Ca and Pi in serum were measured using both auto Kit and $^{31}$ P Nuclear Magnetic Resonance(NMR). At present study, no toxic effect was observed from both weight increment and urine index after feeding the safflower seed diet. The comparison of the radiography between C-OP and S-OP group were showed that the safflower seed diet appeared to stimulate the formation of callus in the rat. The ratio of Ca/P in serum was low in S-OP group compared to C-OP group with the auto Kit, but there were no significant differences between two groups (p < 0.05). In addition, the variations of Pi values in NMR examination were also confirmed based on the result of auto Kit. In conclusion, this study implied that safflower seed might influence to bone formation and shorten the periods of remedy by stimulating the calcification of bone

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.467-474
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• 2008

Purpose: To evaluate RBM surface implant which has its good character like that good initial stability, early bone formation. Material and Methods: In this study fixures have divided in 2 group: Machined(Group I), RBM(Group II). Total 10 fixtures were implanted on rabbit which sacrificed on week 2 and week 4 for the histological specimens. By these specimens polarized microscopic view, micro CT view, ISQ value were measured, compared and analysed by each group to figure out the evidence that clinical use of RBM implant. Result: ISQ value had no significance differences between 2 groups, However in each group 4, 8 weeks had higher ISQ value than 2 weeks. In polarized microscope, calcification level was following: Group II, Group I. In micro CT, formation of cancellous bone level was following: Group II, Group I. Conclusion: RBM implant was the most excellent on the early bone formation and good initial stability.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.215-221
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• 2017

The electroless plating process largely consists of substrate cleaning, seed formation (activator formation), and electroless plating. The most widely used activator in the seed formation step is Pd, and Sn ions are used to facilitate the formation of this Pd seed layer. This is problematic because the Sn ions interfere with the reduction of Cu ions during electroless plating; thus, the Sn ions must be removed by a hydrochloric acid cleaning process. This method is also expensive due to the use of Pd. In this study, Cu electroless plating was performed by forming a seed layer using a silver nanosol instead of Pd and Sn. The effects of the Ag nanosol concentration in the pretreatment solution and the pretreatment time on the thickness and surface morphology of the Cu layer were investigated. The degrees of adhesion to the substrate were similar for the electroless-plated Cu layers formed by conventional Pd activation and those formed by the Ag nanosol.

• 생약학회지
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• 제43권4호
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• pp.345-351
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• 2012

In this study, 49 Korean herbal medicines have been investigated with an in vitro evaluation system using glycation end products (AGEs) formation inhibitory activity. Of these, 18 herbal medicines ($IC_{50}$ < $50{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Of these, five herbal medicines ($IC_{50}$ < $50{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Particularly, Mallotus japonicus (twigs and leaves), Rhus javanica (twigs and leaves), Boehmeria nivea (whole plants), Quercus acuta (stems), and Eurya japonica (stems) showed more potent inhibitory activity (approximately 9-37 fold) than the positive control aminoguanidine ($IC_{50}=76.47{\mu}g/ml$).

• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.158-162
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• 1995

The effect of carbon and nitrogen sources on the production of novel aminopeptidase M inhibitors MR-387A and B by Streptomyces sp. SL-387 has been studied. High D-glucose and ammonia concentrations (5$\%$ and 1$\%$, respectively) exerted a negative influence on the inhibitor formation. The suppressive effect of glucose on the inhibitor formation is probably caused by an effect of medium pH rather than that of cyclic AMP. To establish the optimum conditions for inhibitor overproduction, various nitrogen sources and ammonium ion-trapping agents were examined. The use of ammonia slow-releasing nitrogen sources such as soybean meal and fish meal, or ammonium ion-trapping agents such as kaoline, celite, and natural zeolite achieved the enhancement of inhibitor production. These results also indicate that inhibitor formation is affected by ammonium ion repression.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.27-39
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• 2000

To evaluate the effects of Dexamethasone(Dex), Platelet derived growth factor-BB(PDGF) and combination of Dex and PDGF(DP) on the growth and differentiation of MC3T3-E1 cells, Dex($10^{-7}\;M$) and PDGF(10 ng/ml) in experimental group were added to the cells at the days 5, 10, 15, 20, 25 and examined for cell proliferation activities, DNA synthesis activities, ALP activities and bone nodule formation. The results were as follows : 1. In Dex group, cell proliferation, DNA synthesis and ALP activities were lower until 15 days when compared to the control group. Bone nodules formation were shown at 10 days. 2. In PDGF group, cell proliferation and DNA synthesis activities were higher until 15 days and ALP activities were lower when compared to the control and Dex groups. Bone nodules formation were shown at 20 days. 3. In DP group, cell proliferation and DNA synthesis activities of PDGF were suppressed by Dex and synergistic effects of combination of Dex and PDGF on ALP activities were shown at days 5 when compared to control and Dex groups. Bone nodules formation activities of Dex were suppressed by PDGF.

• 한국수정란이식학회지
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• 제31권3호
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• pp.153-159
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• 2016

(-)-Epicatechin gallate (ECG) is a polyphenol compound of green tea exhibiting biological activities, such as antioxidant and anticancer effects. To examine the effect of ECG on porcine oocytes during in vitro maturation (IVM), oocytes were treated with 0-, 5-, 15-, and $25{\mu}M$ ECG. After maturation, we investigated nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels and subsequent embryonic development after parthenogenetic activation (PA) and in vitro fertilization (IVF). After 42 hours of IVM, the $5{\mu}M$ group exhibited significantly increased (p< 0.05) nuclear maturation (89.8%) compared with the control group (86.1%). However, the $25{\mu}M$ group observed significantly decreased (p< 0.05) nuclear maturation (83.5%). In intracellular maturation assessment the 5-, 15-, and $25{\mu}M$ groups had significantly increased (p< 0.05) GSH levels and decreased ROS levels compared with the controls. The 5- and $15{\mu}M$ group showed significantly increased (p< 0.05) embryo formation rates and total cell number of blastocysts after PA (18% and 68.9, 15% and 85.1 vs. 12% and 59.5, respectively) compared with controls. Although the $25{\mu}M$ group observed significantly lower blastocyst formation rates after PA (27.6% vs. 23.2%) than control group, the $5{\mu}M$ group showed significantly increased blastocyst formation rates after PA (37.2% vs. 23.2%) compared to the control group. Furthermore, the $5{\mu}M$ group measured significantly increased blastocyst formation rates (20.7% vs. 8.6%) and total cell number after IVF ($88.3{\pm}1.5$ vs. $58.0{\pm}3.6$) compared to the control group. The treatment of $5{\mu}M$ ECG during IVM affectively improved the porcine embryonic developmental competence by regulating intracellular oxidative stress during IVM.