• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.167-172
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• 1996

A Dual Mass Flywheel system is a evolution to the reduction of torsional vibration and impact noise occuring in powertrain when a vehicle is eit-her moving or idling. The name already explains what it is : The mass of the conventional single mass flywheel is divided. One section continues to belong to the mass moment of inertia of the engine-side. The ot-her section increass the mass moment of inertia of the transmission-side. The two masses are connected via a spring /damping system. This reduces the speed at which the dreaded resonance occurs to below idle speed. Since 1984 Dual Mass Flywheel has been de-veloped again and again. But the prosidures of de-velopment of D.M.F system didn't have had differe-nce from conventional clutch system's trial and err-or This paper presents the method for systematical design of D.M.F system with demensionless design variables of D.M.F system mass ratio between two flywheels λ. natual frequency rate of two flywheel s, ${\gamma}$and viscosity coefficient ζ. And experimental re-sults are used to prove these theoretical results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.134-141
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• 2005

Due to the complexity and stochastic nature of automated warehousing system, items are usually queued up at I/O point. We introduce a storage/retrieval policy : dual-command. We present quick approximations to queueing phenomena under these policies. It is assumed that the storage and retrieval arrival pattern follow the same poisson process. We also assumed that storage queue and retrieval queue being operated separately. The approximation attempts are performed under the proposed storage/retrieval policies after we derive S/R machine travel time distributions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2095-2110
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• 2015

This paper presents a design for a throughput-efficient online relay selection scheme for dual-hop multi-relay cooperative networks. Problems arise with these networks due to unpredictability of the relaying link quality and high time-consumption to probe the dual-hop link. In this paper, we firstly propose a novel probing and relaying protocol, which greatly reduces the overhead of the dual-hop link estimation by leveraging the wireless broadcasting nature of the network. We then formulate an opportunistic relay selection process for the online decision-making, which uses a tradeoff between obtaining more link information to establish better cooperative relaying and minimizing the time cost for dual-hop link estimation to achieve higher throughput. Dynamic programming is used to construct the throughput-optimal control policy for a typically heterogeneous Rayleigh fading environment, and determines which relay to probe and when to transmit the data. Additionally, we extend the main results to mixed Rayleigh/Rician link scenarios, i.e., where one side of the relaying link experiences Rayleigh fading while the other has Rician distribution. Numerical results validate the effectiveness and superiority of our proposed relaying scheme, e.g., it achieves at least 107% throughput gain compared with the state of the art solution.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.50-57
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• 2004

Two processors are generally used to drive the power circuits for controlling the dual motors independently. In this paper, we propose the new control scheme to drive dual inverters using only one controller with the aid of CAN network. The proposed system is very useful compared to conventional techniques especially in case of controlling the combined dual motors because the control algorithm can be implemented by the software program only without any additional processor or hardware interfacing. The proposed system is implemented and verified experimentally.

• BMB Reports
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• v.38 no.3
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• pp.334-342
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• 2005

Recently, the existence of T cells with dual T cell receptor (TCR) in the immune system is generally accepted, while it has been controversial whether signals through one TCR would affect the functions of the other. In this study T cells expressing two different TCR were obtained from cross-hybrids of LCMV and AND TCR transgenic mice specific for the gp33 and peptide fragment of PCC (fPCC), respectively. Peptide stimulation demonstrated that the dual TCR T cells functioned independently in an antigen-specific manner. To examine whether the tolerance targeted for the one TCR affects the responsiveness of the other, the cross-hybrids were treated with gp33. Although T cells from F1 mice were rendered anergenic to gp33, no functional changes to fPCC were observed in terms of cellular proliferation and IL-2 secretion, suggesting that the dual TCR T cells remained reactive to fPCC. We therefore propose that signaling through the TCR is receptor-specific and 'negative dominance' of one TCR by tolerance induction is not applicable in this dual TCR system.

• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.20-25
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• 2015

A circularly rotated array for a dual polarized applicator in a superficial hyperthermia system is proposed. The applicator has a wider effective treatment area due to the $180^{\circ}$ phase shift. The dual polarized circularly rotated array (DPCRA) suppresses overheating at the center of the array and helps evenly distribute the heat. This array provides a more effective treatment area than a lattice array when a $2{\times}2$ dual polarized array is fitted to the treatment area. The treatment area is 71.5% of the aperture, whereas the effective treatment areas of the $2{\times}2$ dual polarized lattice array (DPLA) and the single polarized array (SPA) are 57.2% and 38.6% of the same aperture, respectively. The measurement matches the simulation results without blood circulation effects. In a $2{\times}2$ array applicator, the proposed DPCRA has more heat uniformity than the DLA and the SPA.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.153-160
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• 1999

Dual-stage servo system for super-high density HDD has the chances of being composed of the coarse actuator(VCM) for track-seeking control and the fine actuator(microactuator) for-following control in near future. This paper presents the concept design of dual-stage servo system and the track-following control using an electrostatic microactuator for super-high density HDD. The electrostatic microactuator is designed and fabricated by MEMS(micro-electro-mechanical system) process. Both the nonlinear plant(voltage/displacement-to-electrostatic force) and the linear plant(electrostatic force-to-displacement) of the microactuator are established. Inverse function of the nonlinear plant is employed for a feedforward nonlinear compensator design. And feedforward control effect of this compensator is shown by time-domain experiments. A track-following feedback controller is designed using the feedback nonlinear compensator which is derived from the feedforward nonlinear compensator. The track-following control experiment is done to show the control efficiency of the proposed control system. And, excellent track-following control performance(2.21kHz servo-bandwidth, 7.51dB gain margin, $50.98^{\circ}$phase margin) is achieved by the proposed control system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.517-526
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• 2006

In order to achieve high capacity and reliable link quality in wireless communication, the significant efforts should be concentrated on mitigating interference between cells. To solve the interference problem, the newly introduced concept of a Distributed Wireless Communication System (DWCS) can provide the capability of joint control of the signals at multiple cells. This paper proposes a new concept of virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. The proposed system manages two kinds of virtual cell. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The proposed system constructs DVC by using antenna selection method. Also, for multi-user high-rate data transmission, the proposed system introduces multiple antenna technology to get a spatial and temporal diversity gam and exploits space-Time Trellis Codes known as STTC to increase a spectral efficiency.

• Honam Mathematical Journal
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• v.36 no.3
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• pp.543-553
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• 2014

The aim of this paper is to define hyperholomorphic functions with dual octonion variables on $\mathbb{C}^4{\times}\mathbb{C}^4$ in another way. Using condition of harmonicity, we research properties of functions of dual octonion variables in Clifford analysis.

• Honam Mathematical Journal
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• v.36 no.4
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• pp.921-932
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• 2014

The aim of this paper is to define hyperholomorphic functions with dual sedenion variables on $\mathcal{S}{\times}\mathcal{S}$, where $$\mathcal{S}{\sim_=}\mathbb{C}^8$$. By the condition of harmonicity, we research properties of hyperholomorphic functions of dual sedenion variables in Clifford analysis.