• IE interfaces
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• v.9 no.3
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• pp.64-71
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• 1996

In the survivability and simplicity aspect, SONET Self-healing Ring(SHR) is one of the most important schemes for the high-speed telecommunication networks. Since the ring capacity requirement is defined by the largest STS-1 cross-section in the ring, load balancing is the key issue in the design of SONET SHR. Recently, most of the research on load balancing problem have been concentrated on the SONET single-ring case. However, in certain applications, multiple-ring configuration is necessary because of the geographical limitations or the need for extra bandwidth. In this paper, the load balancing problem for SONET dual-ring is considered by assuming symmetric inter-ring demands. We present a linear programming based formulation of the problem. Initial solution and improvement procedures are presented, which solves the routing and interconnection between the two rings for each demand. Computational experiments are performed on various size of networks with randomly generated demand sets. Results show that the proposed algorithm is excellent in both the solution quality and the computational time requirement. The average error bound of the solutions obtained is 0.26% of the optimum.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.1-5
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• 2010

In this paper, we proposed trench field ring for breakdown voltage of power devices. The proposed trench field ring was improved 10% efficiency comparing with conventional field ring. we analyzed five parameters of trench field ring for design of trench field ring and carried out 2-D devices simulation and process simulations. That is, we analyzed number of field ring, juction depth, distance of field rings, trench width, doping profield. The proposed trench field ring was better to more 1000 V.

• Structural Engineering and Mechanics
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• v.61 no.6
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• pp.701-709
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• 2017

Seismic dissipation devices can play a crucial role in mitigating earthquake damages, loss of life and post-event repair and downtime costs. This research investigates the use of ring springs with high-force-to-volume (HF2V) dissipaters to create damage-free, recentring connections and structures. HF2V devices are passive rate-dependent extrusion-based devices with high energy absorption characteristics. Ring springs are passive energy dissipation devices with high self-centring capability to reduce the residual displacements. Dynamic behaviour of a system with nonlinear structural stiffness and supplemental hybrid damping via HF2V devices and ring spring dampers is used to investigate the design space and potential. HF2V devices are modelled with design forces equal to 5% and 10% of seismic weight and ring springs are modelled with loading stiffness values of 20% and 40% of initial structural stiffness and respective unloading stiffness of 7% and 14% of structural stiffness (equivalent to 35% of their loading stiffness). Using a suite of 20 design level earthquake ground motions, nonlinear response spectra for 8 different configurations are generated. Results show up to 50% reduction in peak displacements and greater than 80% reduction in residual displacements of augmented structure compared to the baseline structure. These gains come at a cost of a significant rise in the base shear values up to 200% mainly as a result of the force contributed by the supplemental devices.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1488-1490
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• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch, The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply(HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.289-295
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• 1999

A new conceptual wave rolling ball reducer was proposed and investigated. The main components of the reducer were a eccentric input shaft and bearings, followers with balls, a flange, and a outer ring with waved groove. Followers moved along the holes of the flange according to the rotation of the shaft. And the balls installed in tips of followers were rolled with the waved groove of outer ring. When the shaft was rotated as one revolution and the outer ring was fixed, the flange was rotated as one wave. The kinematic analysis of the reducer carried out. The forces of each components were estimated, and the main design parameters were investigated. The design program using Visual C++ and Auto Lisp to determine the design parameters and to generate the drawing sheet.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.37-45
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• 2007

In this paper, we proposed a new customized e-Ring(Enterprise Ring Back Tone) system which could be represented each user and organization feature. The e-Ring system provided the ring back tone and additional services to reduce the waiting time when the client called an organization. This system was for an appropriate organization public relations instead of the meaningless ring back tone which was used usual call, also was maximized the service availability and work efficiency which was obtained from the automatic response and service suppling to users who had needs and questions.

• ETRI Journal
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• v.34 no.2
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• pp.199-209
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• 2012

In transport networks, a multi-ring architecture is very useful to facilitate network planning and to design and provide more resilient services for customers. Unlike traditional synchronous optical network multi-rings, the service resiliency of Ethernet-based multi-rings is significantly impacted by the ring hierarchy because a link or node failure in a certain level ring triggers filtering database flush actions in all higher level rings as well as in the ring with the failure, and consequently a large amount of duplicated data frames may be flooded. In this paper, we investigate how the ring hierarchy impacts the service resiliency of multi-ring networks. Based on extensive experiments on various single- and multiple-link failures, we suggest two effective inter-ring connection rules to minimize the transient traffic and to ensure more resilient multi-ring networks. In addition, we consider a flush optimization technique called e-ADV, and show that the combination of e-ADV and multi-ring structures satisfying our inter-ring connection rules results in a more attractive survivability performance.

• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.20-25
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• 2006

This paper deals with the design and aerodynamic analysis of a so-called 'ring-type' impulse turbine for wave energy conversion. Numerical analysis was performed using the CFD cock, FLUENT. The main idea of the proposed turbine rotor was to minimize the adverse effect of tip clearance of the turbine blade; the design was borrowed from a ducted propeller with connected ring tip for special purpose marine vehicles. Results show that the efficiency increases up to $10\%$, depending on flaw coefficient, with the higher flaw coefficient yielding better efficiency. Decrease of input coefficient CA was the main reason for higher efficiency. Performance of ring-type rotor at various design parameters, as well as flaw conditions, was investigated, and the advantages and the disadvantages of the present impulse turbine were also discussed.

• Journal of the Korean Institute of Gas
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• v.9 no.2 s.27
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• pp.16-21
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• 2005

Functions of the compression ring plate fixed at the concrete side wall are to connect and support the steel roof plate. It should be designed to endure stably all the loads such as weight of steel roof, inner pressure and concrete weight. Behavior of the compression ring during construction has been analyzed by the finite element method and real measured data. Additionally, on the basis of results from parametric study of design variables for the steel roof a more reasonable design method for the compression ring has been proposed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.6
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• pp.711-729
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• 2018

This paper reports on the experimental investigations on the failure modes of ring-stiffened cylinder models subjected to external hydrostatic pressure. Nine models were welded from general structural steel. The shells were initially formed by cold-rolling, and flat-bar ring frames were welded to the shell. The hydrostatic pressure tests were conducted by using water as the medium in pressure chambers. The details of the preparation and main test were briefly explained. The investigation identified the consequence of the structural failure modes, including: shell yielding, local shell buckling between ring stiffeners, overall buckling of the shell together with the stiffeners, and interactive buckling mode combining local and overall buckling. In addition, the ultimate strengths were predicted by using existing design codes. Non-linear numerical computations were also conducted by employing the actual imperfection coordinates. Finally, accuracy and reliability of the predictions of design formulae and numerical were substantiated with the test results.