• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.2
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• pp.193-204
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• 1998

Numerical analysis was performed with multicomponent transport properties and detailed reaction mechanisms for axisymmetric 2-D CH$_{4}$ jet diffusion flame. Calculations were carried out twice with the $C_{2}$-Thermal Mechanism including $C_{2}$ and thermal NO reactions and the $C_{2}$-Full Mechanism including prompt NO reactions in addition to the above $C_{2}$-Thermal NO mechanism. The results show that the flame structures such as flame temperature, major and minor species concentration are indifferent to respective mechanisms. The production path of Thermal NO is dominant comparing with that of Prompt NO in total NO production of pure CH$_{4}$ jet diffusion flame. This is because thermal NO mechanism mainly contributes to positive formation of NO in the whole flame region, but Prompt NO mechanism contributes to negative formation in the fuel rich region. In addition, 0$_{2}$ penetration near the nozzle outlet affects the flame structures, especially N0$_{2}$ formation characteristics.

• Journal of Korea Foundry Society
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• v.3 no.2
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• pp.100-105
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• 1983

The mechanism of coal-dust action on inhibiting burn-on of Sand to iron castings was taken in consideration by means of casting test and thermal decomposition test. To compare the ability of inhibiting sand burn-on, test castings were produced in green sand moulds added three different coal-rusts. And quantitative determination of lustrous carbon and volatiles production for coal-dust samples were performed.The lustrous carbon production was in good agreement with the casting test result. But total voltiles production was relatively inefficient on hibiting sand burn-on to test castings.The lustrous carbon theory can be given to explain the mechanism which coal-dust inhibits sand burn-on to iron castings.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.92-97
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• 2007

This study was carried out to minimize the lifting force and to design the slim sized frame of a height adjustment mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment as well as to achieve much slimmer frame for the pedestal. A tolerance analysis of 6 sigma was applied to achieve smooth lift at design stage not to change the tolerance specification of gap several times in a roller type of lifting mechanism at mass production stage. The specification of minimum gap and the target of production yield ratio were agreed with a quality team before tooling. A DFSS simulation on drawings had been done with reasonable tolerance and achievable standard deviation(${\sigma}$) several times until the target specification of gap and yield ratio was met. Once tolerance and deviation(${\sigma}$) were fixed tooling start was done successfully. A CAE method was applied to achieve a slim design. Design parameters were frozen when those parameters matched the reference strength data of standard model. Through those tolerance analysis and CAE simulation the number of tool modification was reduced and production yield ratio was raised up without arguing quality specification at production stage in the end.

• Journal of Korea Technology Innovation Society
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• v.6 no.1
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• pp.1-19
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• 2003

The mechanism of knowledge production in the basic science has been changed throughout the development process in Korea. During the 1970s, the focus resides in the support of individual scientists while it concentrated on the support of research organization, centered on center of excellence from the 1980s. The change in the sup-porting mechanism to basic science result in the transformation of knowledge production system in the university and impact on the behavior of individual scientists. This paper focuses on the co-evolution process between newly adopted supporting program for basic science and the knowledge production system via the case study of representative program of center of excellence supporting program in Korea.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1714-1721
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• 2004

This experimental study was designed to investigate the mechanism of Palmul-Tang(PMT) on the changes of cerebral hemodynamics in rats. The changes of cerebral hemodynamics in normal rats were as follows ; The PMT-induced increase in regional cerebral blood flow was significantly inhibited by pretreatment with indomethacin(1㎎/㎏, i.p.), an inhibitor of cyclooxygenase, and was inhibited by methylene blue(10㎍/㎏, i.p.), an inhibitor of guanylate cyclase. The PMT-induced dilation in pial arterial diameter was significantly inhibited by pretreatment with indomethacin and methylene blue. The PMT-induced increase in mean arterial blood pressure was significantly inhibited by pretreatment with indomethacin but was increased by methylene blue. This results were suggested that the mechanism of PMT was mediated by cyclooxygenase. The changes of cytokine production in cerebral ischemic rats were as follows ; In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion 1hr, sample group was decreased IL-1β and TNF-α production compared with control group, IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1hr, sample group was significantly decreased IL-1β production compared with control group and decreased TNF-α production compared with control group. IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, but IL-10 production of sample group was similar to that of control group. sample group was increased TNF-α and TGF-β production compared with control group. These results suggested that PMT had inhibitive effect on the brain damage by inhibiting IL-1β and TNF-α production, but by accelerating TGF-β production. The present author thought that PMT had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• Knowledge Management Research
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• v.11 no.4
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• pp.41-66
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• 2010

This research examines the effect of the relatedness and the gap between Resources and mechanisms on effectiveness of inter-organizational knowledge transfer. According to the literature, there has been a competing theory between two claims; one is that inter-organizational knowledge transfer will be more effective due to the reduction of the transaction cost as the relatedness increases. And the other is that the mutual complementarity of different organizational characteristics will increase synergy. In total, the relatedness and the gap of the Resource and mechanism makes the inverted U-shaped relationship with the inter-organizational knowledge transfer. As the result of empirical analysis about 109 Korean-based Joint Ventures entered country, it shows that the relatedness of parent company's production Resources, learning mechanisms, and coordination mechanisms made the inverted U-shaped relations with the inter-organizational knowledge transfer and the gap of production Resources and adjustment mechanism formed the same relationship. However, the U-shaped relationship has been established in the relatedness of market Resources, but the gap of market Resources and the learning mechanism was not statistically significant. Through this study, I can draw a best conclusion that the inter-organizational knowledge transfer will be more effective when the relatedness and the gap of management resources and mechanisms is in optimal level. However, when it comes to market Resources, it can be inferred that the result could be the opposite because the partner country's market environment would be different.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.441-446
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• 2001

On global interconnectivity, the activation of real-time and worldwide contents will permeate and impact all aspects of day-to-day life well throughout this century. In managing contents and models, we too will see the impact of this rapidly changing environment. The real time availability of contents pertaining to a companys supply chain through means of the Internet and mobile networks(e.g., the IMT-2000) will necessitate a change in decision-making processes for effective management of contents and models. To increase the availability of many contents and models, a management system should have adaptive function in proving adequate content and model for companies. In the respect of management of contents and models, this paper discusses a production mechanism of meta-knowledge for effectively managing contents and models. Through two experimental analyses with the production mechanism, it is proven that the system enabling adaptive contents and models provision goes beyond existing ones in view of efficiency of management of contents and models in the wire and wireless networks.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.146-153
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• 2007

The detailed chemistry with reaction mechanism of GRI 2.11, which consists of 49 species and 279 elementary reactions, have been numerically conducted to investigate the flame structure and NO emission characteristics in a non-premixed counterflow flame of blended fuel of $H_2/CO_2/Ar$. The combination of $H_2,\;CO_2$, and Ar as fuel is selected to clearly display the contribution of hydrocarbon products to flame structure and NO emission characteristics due to the breakdown of $CO_2$. Radiative heat loss term is involved to correctly describe the flame dynamics especially at low strain rates. All mechanisms including thermal, $NO_2,\;N_2O$, and Fenimore are also taken into account to separately evaluate the effects of $CO_2$ addition on NO emission characteristics. The increase of added $CO_2$ quantity causes flame temperature to fall since at high strain rates diluent effect is prevailing and at low strain rates the breakdown of $CO_2$ produces relatively populous hydrocarbon products and thus the existence of hydrocarbon products inhibits chain branching. It is also found that the ratio of the contribution by Fenimore mechanism to that by thermal mechanism in the total mole production rate becomes much larger with increase in the $CO_2$ quantity and strain rate, even though the absolute quantity of NO production is deceased. Consequently, as strain rate and $CO_2$ quantity increase, NO production by Fenimore mechanism is remarkably augmented.

• Journal of Haehwa Medicine
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• v.25 no.1
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• pp.71-86
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• 2016

Objective : Hongyi (Formica yessensis) is the dried insect of fomicidae. In previous studies, it appeared possibilities on anti-thrombosis, preventing atherosclerosis, treating rheumatoid disease, and inhibiting hela cell. In this study, we investigated anti-inflammatory effects and mechanism of Hongyi. Methods : Hongyi A was extracted by water and made dried powder. Hongyi B was extracted by ethanol and made dried powder. We measured Nitric Oxide (NO) production on the mouse macrophages (RAW 264.7), mouse vascular endothelial cell (MOVAS) and human vascular endothelial cell (HUVEC) for anti-inflammatory effect. In addition, we conducted reverse transcription reaction (RT-PCR) for investigating the mechanism. Results : In RAW 264.7 macrophages stimulated by LPS, Hongyi A ($100{\mu}g/m{\ell}$) decreased NO production compared with LPS $2{\mu}g/ml$ control group with statistical significance (p<0.05). Hongyi A (50, $100{\mu}g/m{\ell}$) also decreased NO production compared with LPS $4{\mu}g/ml$ control group with statistical significance (p<0.01). Hongyi B (50, $100{\mu}g/m{\ell}$) decreased NO production compared with LPS $2{\mu}g/ml$ control group with statistical significance (p<0.01). Hongyi B (10, 50, $100{\mu}g/m{\ell}$) also decreased NO production compared with LPS $4{\mu}g/ml$ control group with statistical significance (p<0.01, p<0.001, p<0.001). In the MOVAS, Hongyi A and B increased NO production compared with control group. In the HUVEC, Hongyi B increased NO production compared with control group. The expression of NF-${\kappa}B$ in 12-hours MOVAS culture was decreased by Hongyi A and B (10, $50{\mu}g/ml$) compared with control group, but expression of $I{\kappa}B$ was increased. In the 24-hours MOVAS culture, expression of $I{\kappa}B$ was significantly increased. The expression of NF-${\kappa}B$ in 12-hours HUVEC culture was decreased by Hongyi A and B compared with control group, but expression of $I{\kappa}B$ was increased. Hongyi B also increased eNOS mRNA gene expression. Conclusions : Hongyi A and B showed anti-inflammatory effect in mouse macrophages with the activation of vascular endothelial cell through NO production in MOVAS and HUVEC repectively. Honyi B showed superior effect than Hongyi A, but additonal mechanism study should be conducted.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.211-214
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• 2012

A short reaction mechanism was developed in order to predict the flame phenomena in premixed Dimethyl Ether-Air flame with the methods of SEM-CM(Simulation Error Minimization Connectivity Method), sensitivity analysis, and the rate of production analysis. It consisted of 31 species including nitrogen as inert gas and 177 elementary reactions. The flame structures obtained using a detailed reaction mechanism and the short reaction mechanism were compared with various equivalence ratios and pressure, and the results were in good agreement. Therefore, the short reaction mechanism would be used to aim at studying the development of a reduced reaction mechanism.