• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1552-1558
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• 2011

In this paper, a dual-loop Integer-N phase-delay locked loop(P DLL) architecture has been proposed using a low power consuming voltage controlled delay line(VCDL). The P DLL can have the LF of one small capacitance instead of the conventional second or third-order LF which occupies a large area. The proposed dual-loop P DLL can have a small gain VCDL by controlling the magnitude of capacitor and charge pump current on the loop of VCDL. The proposed dual-loop P DLL has been designed based on a 1.8V $0.18{\mu}m$ CMOS process and proved by Hspice simulation.

• The Journal of Korea Robotics Society
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• v.5 no.4
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• pp.309-317
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• 2010

This paper proposes an efficient measurement system for the velocity and direction of the wind using the dual rotor wind power generator in vessel. Conventional digital measurement system recognizes the direction and the velocity of the wind using the electric compass or synchronous motor and Vane probe method using hall sensors. But each system has its own short-comings: the synchronous motor has a larger measurement error than the magnetic compass and magnetic compass is weak for the external disturbances such as fluctuation of the vessel. To compensate these short-comings, this paper proposes a new compensation algorithm for the fluctuation errors according to the external interference and the unexpected movement of the vessel along the roll and pitch directions. The proposed system is implemented with the dual compasses and a synchronous motor. The proposed independent power generation system can be operated by itself and can raise the efficiency of the wind power generation systems of 30 ~ 400 W installed along the vertical and horizontal axes. The proposed system also realizes the efficient and reliable power production system by the MPPT algorithm for the real-time recognition of the wind direction and velocity. An advanced switching algorithm for the battery charging system has been also proposed. Effectiveness of the proposed algorithm has been verified through the real experiments and the results are demonstrated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1383-1388
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• 2013

Even though a dual lens stereoscopic camera allows for convenient stereoscopic photography, the necessity for the research comes up, since the dual lens stereoscopic camera can cause visual discomfort during zoom-in due to the fixed convergence point. We propose a method based on which a convergence point can be adjusted to prevent visual discomfort during zoom-in for a dual lens stereoscopic camera. First, the relational model is classified into nine kinds and defined, depending on locations of focus, object, and convergence point. And then, the method to minimize visual discomfort is suggested by adjusting convergence point on the given model. We also implement the suggested methods with anaglyph computer graphic and demonstrate the superiority of them.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.41-50
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• 2007

In this paper, a new Dual Round-Robin (DRR) based iterative SLIP (iSLIP) scheduling scheme, called DiSLIP is proposed for IP switching systems. By using DRR followed by iSLIP, DiSLIP can exploit desynchronization effect of DRR and high performance of iSLIP, while the drawbacks of two schemes are minimized. 'Through computer simulation, we verify the switch throughput and total waiting time of the proposed scheme under nonuniform and correlated self-similar traffic. Moreover, the proposed scheme can considerably reduce the complexity of parallel matching logics compared to iSLIP. From the result, we observe that the proposed scheme outperforms DRR on throughput as well as iSLIP schemes on complextiy.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.321-329
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• 2018

Classic braced walls use struts and wales to minimize ground movements induced by deep excavation. However, the installation of struts and wales is a time-consuming process and confines the work space. To secure a work space around the retaining structure, an anchoring system works in conjunction with a braced wall. However, anchoring cannot perform well when the shear strength of soil is low. In such a case, innovative retaining systems are required in excavation. This study proposes an innovative earth-retaining wall that uses in situ soil confined in dual sheet piles as a structural component. A numerical study was conducted to evaluate the stability of the proposed structure in cohesionless dry soil and establish a design chart. The displacement and factor of safety of the structural member were monitored and evaluated. According to the results, an increase in the clearance distance increases the depth of safe excavation. For a conservative design to secure the stability of the earth-retaining structure in cohesionless dry soil, the clearance distance should exceed 2 m, and the embedded depth should exceed 40% of the wall height. The results suggest that the proposed method can be used for 14 m of excavation without any internal support structure. The design chart can be used for the preliminary design of an earth-retaining structure using in situ soil with dual steel sheet piles in cohesionless dry soil.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.456-459
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• 2013

Even though a dual lens stereoscopic camera allows for convenient stereoscopic photography, the necessity for the research comes up, since the dual lens stereoscopic camera can cause visual discomfort during zoom-in due to the fixed convergence point. We propose a method based on which a convergence point can be adjusted to prevent visual discomfort during zoom-in for a dual lens stereoscopic camera. First, the relational model is classified into nine kinds and defined, depending on locations of focus, object, and convergence point. And then, the method to minimize visual discomfort is suggested by adjusting convergence point on the given model. We also implement the suggested methods with anaglyph computer graphic and demonstrate the superiority of them.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.702-708
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• 2002

In this paper, we design the dual frequency antenna that could easily determine two operation frequencies by its inverted-F antenna structure and spur line length. The spur line is applied to the inverted-F antenna, in order to dual operation characteristics in PCS and cellular frequencies. It has designed by using the IE3D commercial software based on the moment method. As the designed antenna is fabricated and measured, you can see the results such as the return loss, the input impedance, the radiation patterns, and the gain. The size of this antenna is 40 mm$\times$14 mm$\times$9.4 mm, it is compact enough to use as an intenna. Also, This antenna can be used with cellular and PCS phone of domestic market.

• The Journal of Advanced Prosthodontics
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• v.12 no.2
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• pp.61-66
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• 2020

PURPOSE. The aim of the present study was to determine the degree of conversion of light- and dual-cured resin cements used in the cementation of all-ceramic restorations under different thicknesses of translucent (T) and high-translucent (HT) polymer-infiltrated ceramic-network (PICN) material. MATERIALS AND METHODS. T and HT PICN blocks were prepared at 0.5, 1.0, 1.5, and 2.0 mm thicknesses (n=80). Resin cement samples were prepared with a diameter of 6 mm and a thickness of 100 ㎛. Light-cured resin cement was polymerized for 30 seconds, and dual-cure resin cement was polymerized for 20 seconds (n=180). Fourier transform infrared spectroscopy (FTIR) was used for degree of conversion measurements. The obtained data were analyzed with ANOVA and Tukey HSD, and independent t-test. RESULTS. As a result of FTIR analysis, the degree of conversion of the light-cured resin cement prepared under 1.5- and 2.0-mm-thick T and HT ceramics was found to be lower than that of the control group. Regarding the degree of conversion of the dual-cured resin cement group, there was no significant difference from the control group. CONCLUSION. Within the limitation of present study, it can be concluded that using of dual cure resin cement can be suggested for cementation of PICN material, especially for thicknesses of 1.5 mm and above.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.102-110
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• 2016

In this paper, a high-frequency dual mode control LLC resonant converter with wide input voltage range is proposed through zero voltage switching (ZVS) under the universal line input voltage and every load conditions. Conventional small power adapter driving should be satisfied with universal line input voltage because it has no power factor correction circuit regulation. The conventional LLC resonant converter for an adapter can reduce the size of transformer in terms of high-frequency driving and ZVS. However, this converter has a disadvantage in terms of design of resonant tank under various input voltages because the frequency modulation range is very wide to satisfy voltage conversion gain. Compared with the conventional one, the proposed LLC converter can be adapted to universal line input voltage and high-frequency driving because it is controlled by pulse width modulation and pulse frequency modulation with control voltage. The validity of the proposed LLC converter is proved through the 60 W prototype.

• Journal of the Korean Solar Energy Society
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• v.37 no.5
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• pp.27-37
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• 2017

In this study, an artificial solar simulator composed of a 2.5 kW Xe-Arc lamp and mirror reflector was used to carry out the solar thermal two step thermochemical water decomposition cycle which can produce high efficiency continuous hydrogen production. Through various operating conditions, the change of hydrogen production due to the possibility of a dual-zone reactor and heat recovery were experimentally analyzed. Based on the reaction temperature of Thermal-Reduction step and Water-Decomposition step at $1,400^{\circ}C$ and $1,000^{\circ}C$ respectively, the hydrogen production decreased by 23.2% under the power off condition, and as a result of experiments using heat recovery technology, the hydrogen production increased by 33.8%. Therefore, when a thermochemical two-step water decomposition cycle is conducted using a dual-zone reactor with heat recovery, it is expected that the cycle can be operated twice over a certain period of time and the hydrogen production amount is increased by at least 53.5% compared to a single reactor.