• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.154-157
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• 1999

Photonic Slot Routing(PSR) is a promising approach to solve the fundamental scalability problem of all-optical packet switched WDM networks. In photonic slot routing, packets destined for the same subnetwork are aggregated to form a photonic slot which is jointly routed as a single unit of information through the network. The relative location of the nodes from bridge may cause to fairness problem in the unidirectional WDM ring network based on PSR. As photonic slots from different subnetworks can originate contentions at the bridge, packets may be dropped and retransmitted. Thus we evaluated the performance of PSR based WDM ring network in the point of fairness for each node and slot contentions at the bridge. Simulation results show that the PSR based WDM ring requires a slot access mechanism to guarantee the transmission fairness and efficient switch architecture to resolve slot contention at the bridge.

• Journal of the Korean Wood Science and Technology
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• v.22 no.1
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• pp.80-84
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• 1994

The orientation of bezene ring in latex film was investigated with raman spectroscopy. The benzene ring of anionic latex ran parallel with the film surface of latex, whereas that of amphoteric latex did not. Consequently, it showed the possibility of interactions or interrelations between the orientation of benzene ring and ink, contact angle, printability and so on.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1169-1176
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• 2002

Analytical model of beat response is derived on a slightly asymmetric ring and is veryfied by experiment. The asymmetric ring is a simplified model used to explain the beat property of a Korean bell. The asymmetric ring has mode pair having slight frequency difference in each radial mode. Each mode pair produces beat phenomenon by the interaction of the two close frequency components. Based on the analytical model, beat maps are first proposed and characteristics of beat on the circumference are detaily explained.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.394-398
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• 2012

Based on the theory of a bipolar fuzzy set, the notion of a bipolar fuzzy subring/ideal of a Near ring is introduced and related properties are investigated. Characterizations of a bipolar fuzzy subnear ring and a bipolar fuzzy ideal in near ring are established. Relations between a bipolar fuzzy ideal and a level cut are discussed. Using bipolar fuzzy ideals, we discuss characterizations of Noetherian Near ring.

• Journal of electromagnetic engineering and science
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• v.3 no.2
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• pp.104-110
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• 2003

A ring filter is proposed as a wide-banded filter. It consists of a ring and two short stubs, which are connected at 90$^{\circ}$ and 270$^{\circ}$ points of the ring. Since the termination impedance at 90$^{\circ}$ and 270$^{\circ}$ points of the ring and the characteristic impedance of the short stub have an effect on designing of it, the relation between them and bandwidths has been studied. Based on the study, two types of small-sized wideband CVT(constant VSWR-type impedance transformer)- and CCT(constant conductance-type impedance transformer)-ring filters are introduced, designed, simulated and one of two, a CCT -ring filter, is tested. The circumference of the ring can be reduced theoretically up to 60$^{\circ}$ and two of many cases having about 300$^{\circ}$ circumferences are simulated. The simulated results show more than 100 % fractional bandwidth, which can be obtained with more than 5 stages in conventional filter-design techniques. To test the designed CCT-ring filter, it has been fabricated in microstrip technology and the measured results show good agreement with the simulated ones, having more than 100 % fractional bandwidth.

• Journal of the Korean Mathematical Society
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• v.42 no.3
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• pp.457-470
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• 2005

Yu showed that every right (left) primitive factor ring of weakly right (left) duo rings is a division ring. It is not difficult to show that each weakly right (left) duo ring is abelian and has the classical right (left) quotient ring. In this note we first provide a left duo ring (but not weakly right duo) in spite of it being left Noetherian and local. Thus we observe conditions under which weakly one-sided duo rings may be two-sided. We prove that a weakly one-sided duo ring R is weakly duo under each of the following conditions: (1) R is semilocal with nil Jacobson radical; (2) R is locally finite. Based on the preceding case (1) we study a kind of composition length of a right or left Artinian weakly duo ring R, obtaining that i(R) is finite and $\alpha^{i(R)}R\;=\;R\alpha^{i(R)\;=\;R\alpha^{i(R)}R\;for\;all\;\alpha\;{\in}\;R$, where i(R) is the index (of nilpotency) of R. Note that one-sided Artinian rings and locally finite rings are strongly $\pi-regular$. Thus we also observe connections between strongly $\pi-regular$ weakly right duo rings and related rings, constructing available examples.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.357-360
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• 2007

The profile ring rolling process of Ti-6Al-4V alloy was designed by finite element(FE) simulation and experimental analysis. The design includes geometry design and optimization of process variables. The geometry design such as initial billet and blank sizes, and final rolled ring shape was carried out with the calculation method based on the uniform deformation concept between the wall thickness and ring height. FEM simulation was used to calculate the state variables such as strain, strain rate and temperature and to predict the formation of forming defects during ring rolling process. Finally, the mechanical properties of profiled Ti-6Al-4V alloy ring product were analyzed with the evolution of microstructures during the ring rolling process.

• Journal of the Korean Mathematical Society
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• v.50 no.5
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• pp.959-972
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• 2013

Rege-Chhawchharia, and Nielsen introduced the concept of right McCoy ring, based on the McCoy's theorem in 1942 for the annihilators in polynomial rings over commutative rings. In the present note we concentrate on a natural generalization of a right McCoy ring that is called a right nilpotent coefficient McCoy ring (simply, a right NC-McCoy ring). The structure and several kinds of extensions of right NC-McCoy rings are investigated, and the structure of minimal right NC-McCoy rings is also examined.

• KSTLE International Journal
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• v.2 no.1
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• pp.40-45
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• 2001

The paper deals with a non-linear finite element analysis of the thermomechanical distortions of an elastomeric O-ring seal including a temperature gradient. Axial compression of O-ring seals, as well as the influence of the temperature gradients and various O-ring seal models, are investigated based on the axisymmetric analysis. The highest temperature occurs near the interface of the O-ring between the dovetail groove bottom and the O-ring seal. The calculated FEM results indicate that the composite O-ring with the diametral ratio, 0.8 shows very stable and recommendable compared with other seal models far elevated temperatures and corrosive environments.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.533-540
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• 2002

Tubular joints having a large diameter are reinforced using internal ring stiffener in order to increase the load carrying capacity. In this study, the static strengths of Internally ring-stiffened tubular T-joints subjected to compressive brace loading are assessed. Nonlinear finite element analyses are used to compute the behavior of unstiffened and ring-stiffened T-joints. From the numerical results, Internal ring stiffener is found to efficient in improving the ultimate capacity, and reinforcement effect are calculated. The influence of geometric parameters for members and ring is evaluated. Based on the FE results, regression analysis is performed considering practical sizes of ring stiffener, finally strength estimation formulae for ring-stiffened T-joints are proposed.