• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.165-168
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• 2001

This Paper presents the design method and performance characteristics of a dual band balun. The design method for dual balun is based on the lumped element eqiuvalent circuit of quater-wave transformaer. By employing the proposed configuration and the derived formulas, dual band balun are designed and simulated and manufactured. The proposed design method and equivalent circuit can make it easy to adapt to designing of ceramic multi-layer chip type dual band balun. The dual band will find applications in wireless communication circuits.

• Journal of Ocean Engineering and Technology
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• v.30 no.2
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• pp.125-133
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• 2016

In this paper, we propose a vertical axis water turbine with dual blades. A parametric study was conducted using numerical analyses. First, a two-dimensional finite-volume analysis with a commercial code was used to find the pitch angle of the main blade under different tip speed ratio conditions. Second, we developed a potential-based panel method to find the best configuration of the inner blades. Experimental tests were conducted at the circulating water channel of Chungnam National University. Various configurations of the dual blades were considered, and their performances were comparatively investigated. The results showed that the turbine with movable dual blades produces a constant torque and tip speed ratio at various flow rates.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.386-387
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• 2012

This experimental study is the supersonic combustion of dual combustors in dual combustion ramjet engine. Through the preliminary performance analysis of DCR, the configuration of dual combustors was determined and constructed, supersonic experiments were accomplished.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.935-940
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• 2005

In this paper, dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor bearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation method effectively attenuates the rotor vibration all over the operating range of rotational speed.

• Proceedings of the KIEE Conference
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• summer
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• pp.572-574
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• 2004

The configuration of Distribution Automatic System(BAS) is dual servers and raid 5(redundant arrays of inexpensive disks) clustering dual HDD. The DAS has the distributed object-oriented architecture using middleware software(BASEstar), so the number of client nodes has no limitation. Because the DAS is scalable, it can be configured using various application programs and be upgraded easily. The DAS has competitive to export because there are system development and accumulation of technology that coincide in International Standard, using common 05 and DB. This paper describes the structure of DAS hardware and software separately and proposes to improve program to share real time DB efficiently at each node.

• Clinics in Shoulder and Elbow
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• v.18 no.2
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• pp.105-112
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• 2015

In orthopedic trauma surgery, treatment of intraarticular distal humerus fractures is a challenge. With development of implants and biomechanical studies, surgical strategies with recommendations including preoperative computed tomography images, proper approaches and open reduction and internal fixation with dual plates have emerged. In addition, as an effort to provide stable fixation to permit early elbow motion, different methods of internal fixation, particularly plate configuration, have evolved. Using dual plates, either oriented parallel to each other or orthogonal, stable fixation has been achieved and satisfactory clinical outcomes have been reported. With rationales and advantages/disadvantages of each plate configuration, both techniques are selected according to surgeons' preference, and, in specific cases, one could be preferred over another. The key to successful fixation by either technique is obtaining anatomical reduction with restoration of two stable columns of the distal humerus.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.9 s.102
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• pp.1045-1052
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• 2005

Tn this paper. dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor hearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation scheme effectively attenuates the rotor vibration all over the operating range of rotational speed.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.12-17
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• 2003

We develop Mueller-matrix spectroscopic ellipsometry based on dual compensator configuration. This technique is very powerful for measuring surface anisotropy in nano-scale, especially when materials show depolarization. Dual-rotating compensator configuration is adopted with the rotational ratio of 5:3 originally developed by Collins et al [1]. The instrument can provide 250-point spectra over the wavelength range from 230 nm to 820 nm in one irradiance waveform with minimum acquisition time of $Tc{\approx}10 s$. In this work, the results obtained in transmission modes are presented for the initial attempt. We present calibration procedures to diagnose the system from the utilize data collected in transmission mode without sample. We expect that the instrument will have important applications in thin films and surfaces that have anisotropy and inhomogeneity.

• Steel and Composite Structures
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• v.19 no.2
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• pp.467-484
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• 2015

Seismic performances of dual steel moment-resisting frames with mixed use of rigid and semi-rigid connections were investigated to control of the base shear, story drifts and the ductility demand of the elements. To this end, nonlinear seismic responses of three groups of frames with three, eight and fifteen story were evaluated. These frames with rigid, semi-rigid and combined configuration of rigid and semi-rigid connections were analyzed under five earthquake records and their responses were compared in ultimate limit state of rigid frame. This study showed that in all frames, it could be found a state of semi-rigidity and connections configuration which behaved better than rigid frame, with consideration of the base shear and story drifts criterion. Finally, some criteria were suggested to locate the best place of the semi-rigid connections for improvement of the seismic performance of steel moment-resisting frames.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.149-152
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• 2012

The laboratory experiments have been conducted to investigate the effects of air preheated temperature on the emission characteristics by a model gas turbine burner with a hybrid/dual swirl jet flames configuration. The concentration of NOx and CO emissions, and flue gas temperature at combustor exit were measured with varying the equivalence ratio for different air preheated temperatures of 300, 400, 500K at atmospheric pressure. It was overall shown that the NOx and CO emissions, and flue gas temperature were decreased according to the decreasing of equivalence ratio due to the effects of lean premixed combustion regardless of the air preheated temperature. Experimental results of a lean premixed flames configuration indicated that the NOx emission was increased with higher inlet air temperature and air flow rate, which is attributed to the increasing of flue gas temperature and heat release related to the thermal NOx mechanism. But the CO emission was shown the opposite tendency, that is, the CO emission was decreased with increasing of inlet air temperature and flow rate.