• Korean Journal of Child Studies
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• v.28 no.4
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• pp.245-264
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• 2007

This study analyzed physical knowledge displayed in the utterances of 10 Korean children 23 - 76 months of age. Utterances were blocked into four-month time periods, except the first two months and classified into 5 categories including properties of physical objects and materials, friction, buoyancy, gravity, and the motion of physical objects. All five types of physical expressions were found in the data of the earliest period the percent age of the properties and motion was higher than the percent of friction, buoyancy, and gravity. Data suggested two transitional points of change in physical knowledge : 2-year-old's descriptions were based only on perceptually salient physical features 3- to 4-year-olds described only end-state results while children older than 4 included systematic causality.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.149-152
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• 2005

In order to extend the life time of building and civil infra-structure, nowadays, patch type carbon sheets are widely used as repairing meterials. Repaired concrete columns and beams with carbon sheets gain their stiffness and strength, but they lose toughness and show brittle failure behaviors. Usually, the cracks of concrete structures are visible with naked eyes and the status of the structure in the life cycle is estimated with visible inspection. After repairing of the structure, crack visibility is blocked by repaired carbon sheets. Therefore, structural monitoring after repairing is indispensible and self diagnosis method with optical fiber sensor is very useful. In this paper, peel-out effects is detected with optical fiber sensors and the strain difference between main structure and repaired carbon sheets when they separate each other.

• Journal of the Korean Society of Marine Environment & Safety
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• v.8 no.2
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• pp.79-86
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• 2002

A heating cargo is solidified by several reasons during carriage. This study is to analyse a cargo accident which 811,202 US barrels of Nile Blend crude oil reamined solid In the tanks after discharge. There are some possibilities that low temperature of Beading cargo below cloud point and wax appearance temperature at loading time, heating interruption during voyage or discharging, and prohibition of crude oil washing during discharging might influence the cargo solidified. But we concluded that the defect of heating system would most affect the heating cargo solidified locally, and which blocked drain hole of bottom transverse and web frame and they obstruct flow of heating cargo in the tanks.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.177-181
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• 1995

The effects of histamine were investigated on the uterine smooth muscle motility in the pig. The results were summarized as fellows : 1. Histamine caused the contraction of the porcine uterine smooth muscle and the contractile responses increased between the concetration of histamine $10^{-8}$ and $10^{-5}$ M with a dose-dependent manner. 2. The contractile response Induced by histamine ($10^{-6}$ M) was completely blocked by pretrevatment with $H_1$-histaminergic receptor blocker, pyrilamine($10^{-6}$ M) 3. The contractile response induced by histamine($10^{-6}$ M) was increased by pretreatment with $H_2$-histaminergic receptor blocker, cimetidine($10^{-6}$ M) From these results, it was concluded that the effects of uterine smooth muscle by histamine were the contraction mediated by $H_1$-histaminergic receptor and the relaxation mediated by $H_2$-histaminergic receptor in pig.

• Journal of Korean Academy of Nursing
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• v.46 no.2
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• pp.215-225
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• 2016

Purpose: This study was performed to identify the meaning of life experience following suicide attempt among middle-aged men. Methods: A qualitative research design was adopted using van Manen's hermeneutic phenomenological approach. The participants were six middle-aged men who had attempted suicide at least one time. Data were collected in 2013 through in-depth interviews. Individual interviews were recorded; and literary, art works and phenomenological literature were searched to identify the meaning of the experience. Results: The five essential themes of the life experience of middle-aged men who attempted suicide were 'Bitter reality confronted again', 'Anger buried deep inside', 'Broken family, inescapable fetters', 'Blocked relationships, closed world' and 'A step towards a new life'. Conclusion: The meaning of lived experience found in this study provides deep insight into the experience following suicide attempt in middle-aged men and crucial information to give directions to appropriate support and nursing interventions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.533-539
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• 2011

Sulfuretin is one of the main flavonoids produced by Rhusverniciflua. Sulfuretin has been shown to exhibit many pharmacological activities including anti-oxidant, anti-obesity, anti-inflammatory and anti-mutagenic activities. However, the anti-skin photoaging effects of sulfuretin has not yet been reported. In the present study, we investigated the inhibitory effect of sulfuretin on the expression levels of MMP-1 and -3 in the human dermal fibroblast cells. Western blot analysis and real-time PCR revealed sulfuretin inhibited UVB-induced MMP-1 and -3 expressions in a dose-dependent manner. UVB-induced MAPK/NF-${\kappa}B$/p50 activation and MMP expression were completely blocked by pretreatment of sulfuretin. Taken together, sulfuretin could prevent UVB-induced MMP expressions through inhibition of MAPK/NF-${\kappa}B$/p50 activation.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.150-154
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• 2008

Butein is a one of polyphenolic compound widely available in numerous plants. It has broad biological activities including antioxidant and anti-inflammatory activities, which contributed to its protective effects against cancer. Evidences that butein influence proliferation of tumor cells make it important to determine how butein affects cell death of various cancers. In this study, we show that butein, a phenolic compound, induces apoptosis in human T lymphoma jurkat cells. We found that treatment of cells with butein increased apoptosis in a dose- and time- dependent manner as determined by staining cells with Annexin V and 7AAD. There was no significant apoptotic cell death when normal lymphocytes and monocytes from healthy donor were treated with butein. We also found caspase-3 activity was increased during butein-induced apoptosis. The buteininduced apoptotic cell death was blocked by the treatment of cells with caspase-3 inhibitor. These results indicate that butein has the potential to provide an effective strategy against cancer with the advantage of being widely avalible.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.267-273
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• 2004

Maturation of oocytes is maintained by complex procedures along with follicular genesis and is a critical step for embryonic development. Purine known as an oocyte maturation regulator is present in follicular fluid. In this study, the roles of guanosine as a strong inhibitor of GVBD and a modulator of cyclic GMP concentration in ooyctes were revealed. Denuded immature oocytes were treated with guanosine, and the maturation rates and cGMP concentration of oocytes were measured. GVBD was blocked in a concentration dependent manner by guanosine, but this effect was reversible. However, GVBD was lagged yet not significant by adenosine. Both guanosine and adenosine modified cGMP concentration in oocytes. The characteristic of the guanosine-treated oocyte was significantly higher cGMP compared with the adenosine-treated oocyes at initial time of the maturation. Based these results, guanosine may be a strong and reversible GVBD inhibitor. Although the precise mechanism of guanosine presently is unclear, the results suggest that guanosine may lead the accumulation of cGMP in oocyte cytoplasm, which in turn suppresses GVBD.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5437-5454
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• 2016

A Wireless Sensor Network (WSN) is composed of several sensor nodes which are severely restricted to energy and memory. Energy is the lifeblood of sensors and thus energy conservation is a critical necessity of WSN. This paper proposes a clustering algorithm namely Energy Efficient Trustworthy Clustering algorithm (EETCA), which focuses on three phases such as chief node election, chief node recycling process and bi-level trust computation. The chief node election is achieved by Dempster-Shafer theory based on trust. In the second phase, the selected chief node is recycled with respect to the current available energy. The final phase is concerned with the computation of bi-level trust, which is triggered for every time interval. This is to check the trustworthiness of the participating nodes. The nodes below the fixed trust threshold are blocked, so as to ensure trustworthiness. The system consumes lesser energy, as all the nodes behave normally and unwanted energy consumption is completely weeded out. The experimental results of EETCA are satisfactory in terms of reduced energy consumption and prolonged lifetime of the network.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.399-404
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• 2004

Recently GPS has been playing an increasingly important role in geodesy and positioning, for example, car navigation system, surveying, ITS(intelligent transport systems), LBS(Location Based Service) and so on. For telematics application, reception conditions of GPS signal are important. In some situation, such as in areas between buildings, metropolitan areas or areas with large skyscraper complexes, there are situations whereby the satellite signal is seriously restricted by various obstacles. Before the signal arrives at the receiver, it may be blocked, reflected, delayed, attenuated or scattered by terrestrial obstacles such as buildings. In this paper, we present satellite imagery data for telematics application. Therefore, for propriety of this studies, we made a GPS satellite visibility experiments in Bun-Dang on same time. This paper describes an approach to calculate building level using 0.6m, 1m, 6.6m resampling aerial polo imagery in stead of the satellite imagery and make a comparative study of accuracy. This paper tests the simulation of GPS signal using the building level.