• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.86-97
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• 1994

An experimental investigation is reported on the wear mechanism of CBN cutting tools. The cutting experiments were conducted on a lathe equipped with a tool dynamometer for cutting force measurement. The investigation of wear mechanism was executed by observing the worn tools using tool microscope and scanning electron microscope. Results indicate that the flank wear occurs dominantly by abrasive wear mode and the crater wear by adhesive wear mode. The results also indicate that the width of flank wear is closely related with the passive component of cutting force.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.799-808
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• 2003

Existing security solutions such as Firewell and IDS (Intrusion Detection System) have a trouble in getting accurate detection rate about new attack and can not block interior attack. That is, existing securuty solutions have various shortcomings. Shortcomings of these security solutions can be supplemented with mechanism which guarantees an availability of systems. The mechanism which guarantees the survivability of node is various, we approachintrusion telerance using real time response mechanism. The monitoring code monitors related resources of system for survivability of vulnerable systm continuously. When realted resources exceed threshold, monitoring and response code is deployed to run. These mechanism guarantees the availability of system. We propose control mathod about resource monitoring. The monitoring code operates with this method. The response code may be resident in active node for availability or execute a job when a request is occurred. We suggest the node survivability mechanism that integrates the intrusion tolerance mechanism that complements the problems of existing security solutions. The mechanism takes asvantage of the automated service distribution supported by Active Network infrastructure instead of passive solutions. The mechanism takes advantage of the automated service distribution supported by Active Network infrastructure instead of passive system reconfiguration and patch.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1080-1084
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• 2011

Urban maglev should have such characteristics as not only environmentally friendliness and excellent driving capability but also curve negotiation performance because its routes have many sharp curves. Due to normal mechanism of urban maglev its relative displacements of secondary spring are bigger than conventional railway vehicle and the centering force of levitation magnet is smaller than wheel-on-rail system. These features of maglev affect the curving negotiation and so the additional steering device is to be required on Urban maglev to improve the running performance at sharp curve of less than about R50m. Some developed urban maglev had the passive steering device which consists of mechanical linkage or hydraulic cylinder and closed-route piping. But it has drawback as complexity of layout of understructure of vehicle and functional limitation of passive mechanism regarding transient curve. These demerits could be solved by using active steering system. But it has a weak point that an active device should have actuators and additional inverter or hydraulic power source. In this paper, the semi-active steering system for urban maglev is to be introduced.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.118-124
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• 2013

Mast cells is the key effector cells for IgE-mediated allergic responses. In this study, we investigated whether Rhus trichocarpa extract (RT) inhibited IgE-mediated allergic responses in mast cells and an allergic animal model. We further tried to find its mechanism of action in mast cells. We found that RT suppressed antigen-stimulated degranulation and production of TNF-${\alpha}$ and IL-4 in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. As the mechanism of action of RT, it inhibited the activation of spleen tyrosine kinase (Syk), a pivotal signaling molecule for activation of mast cells and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. RT also suppressed the activation of mitogen-activated protein (MAP) kinases and Akt. The current results demonstrated for the first time that RT has the anti-allergic effect through inhibiting degranulation and secretion of cytokines by suppression of Syk in antigen-stimulated mast cells. Therefore, RT might be useful for allergic diseases.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.59-67
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• 2012

In this paper, we designed an inter-operation architecture of 10G G-PON(Gigabit passive optical network) network and NGN(Next generation network) architecture. And, we proposed mechanism of dynamic GEM(G-PON encapsulation mode) Port-ID allocation. This is able to solve a problem of 10G G-PON inter-operation. The mechanism of dynamic GEM Port-ID allocation has OMCI(ONT management control and interface) mapping table for IP address and port number. That architecture is able to support per flow QoS(Quality of service) as well as QoS of NGN requirement. So that can improve the resource efficiency of QoS than the existing G-PON architecture.

• Journal of the Korean Electrochemical Society
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• v.7 no.4
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• pp.179-182
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• 2004

The aim of this study is to investigate the initiation and propagation of crevice corrosion for ferritic stainless steel in artificial crevice based on micro capillary tube method. The 430 stainless steel in artificial crevice is potentiostatically polarized in different sodium chloride solutions. Potentiodynamic and potentiostatic polarization data were measured in situ. The potentials in the crevice were measured by depth profile using the 0.04 mm diameter micro capillary tube inserted in the crevice. The potentials in the crevice ranged from -220 mV to -360 mV vs SCE from opening to bottom of crevice, which are lower than the external surface potential, -200 mV vs SCE. Such a potential drop induced the change of the metal surface state from passive to active. The surface of metal is located in passive state in -200 mV but the inner surface keeps active state below -220 mV, Thus these results show that the It drop mechanism in the crevice was more objective for evaluation and the method was easier to reproduce. Therefore the potential drop is one of the reasons for crevice corrosion by measuring the potentials in narrow crevice with a new micro measuring system.

• YAKHAK HOEJI
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• v.56 no.1
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• pp.26-34
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• 2012

Mast cells play an important role in early and late phase allergic reactions through allergen and IgE-dependent release of histamine, proteases, prostaglandins, and several multifunctional cytokines. In this study, we investigated whether Cudrania tricuspidata extract (CTE) suppresses IgE-mediated allergic responses in mast cells, an allergic animal model, and its mechanism of action in mast cells. We found that CTE inhibited IgE-mediated degranulation and cytokine production in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as passive cutaneous anaphylaxis (PCA) in mice. With regard to its mechanism of action, CTE suppressed the activating phosphorylation of spleen tyrosine kinase (Syk), a key enzyme in mast cell signaling processes and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. CTE also suppressed the activating phosphorylation of mitogen-activated protein (MAP) kinases and Akt. The present results strongly suggest that the anti-allergic activity of CTE is mediated through inhibiting degranulation and allergic cytokine secretion by inhibition of Syk kinase in mast cells. Therefore, CTE may be useful for the treatment of allergic diseases.

• Steel and Composite Structures
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• v.30 no.4
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• pp.383-392
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• 2019

Passive steel dampers have shown favorable performance in last earthquakes, numerical and experimental studies. Although steel dampers are more affordable than other types of damper, they are not economically justified for ordinary buildings. Therefore, in this paper, an innovative steel damper with shear yielding mechanism is introduced, which is easy to fabricate also can be easily replaced after sever earthquakes. The main goal of implementing such a mechanism is to control the possible damage in the damper and to ensure the elastic behavior of other structural components. The numerical results indicate an enhancement of the hysteretic behavior of the concentrically braced frames utilizing the proposed damper. The proposed damper change brittle behavior of brace due to buckling to ductile behavior due to shear yielding in proposed damper. The necessary relations for the design of this damper have been presented. In addition, a model has been presented to estimate load-displacement of the damper without needing to finite element modeling.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.317-324
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• 2020

Mast cells play a key role in IgE-mediated allergic response. We investigated whether Swertia pseudochinensis Hara extract (SPE) inhibits IgE-mediated allergic response in mast cells and an allergic animal model. Additionally, we explored SPE's mechanism of action in mast cells. Our results showed that SPE inhibited both antigen-stimulated degranulation and the production of TNF-α and IL-4 in bone marrow-derived mast cells (BMMCs) and rat basophilic leukemia (RBL)-2H3 cells. SPE also suppressed allergic response in IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. As for the mechanism of action of SPE in mast cells, it inhibited the activation of Syk kinase, a critical signaling protein in the FcεRI-mediated signaling pathway, and also the activation of LAT, a downstream adaptor protein of Syk. We further observed the reduced activation of mitogen-activated protein (MAP) kinases (P38, ERK1/2, and JNK) and Akt in mast cells. Our results described for the first time that SPE has an anti-allergic effect by suppressing mast cells through the inhibition of Syk kinase. Therefore, SPE may be useful for the treatment of type I allergic diseases.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.345-356
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• 2023

Target signal of passive sonar shows narrow band harmonic characteristic with a variation in intensity within a few seconds and long term frequency variation due to the Lloyd's mirror effect. We propose a signal classification algorithm based on Gated Recurrent Unit (GRU) that learns local and global time series features. The algorithm proposed implements a multi layer network using GRU and extracts local and global time series features via dilated connections. We learns attention mechanism to weight time series features and classify passive sonar signals. In experiments using public underwater acoustic data, the proposed network showed superior classification accuracy of 96.50 %. This result is 4.17 % higher classification accuracy compared to existing skip connected GRU network.