• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.106-113
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• 2014

Recently, to reduce test cost by efficiently compressing test patterns for SOCs(System-on-a-chip), different compression techniques have been proposed including the FDR(Frequency-directed run-length) algorithm. FDR is extended to EFDR(Extended-FDR), SAFDR(Shifted-Alternate-FDR) and VPDFDR(Variable Prefix Dual-FDR) to improve the compression ratio. In this paper, a frequency-ordered modification is proposed to further augment the compression ratios of FDR, EFDR, SAFRD and VPDFDR. The compression ratio can be maximized by using frequency-ordered method and consequently the overall manufacturing test cost and time can be reduced significantly.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.717-729
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• 2015

This study explains the differences in household work sharing and perceptions of equitable and unequitable household work sharing in dual-earner households by gender. The study also examines the effects of household work sharing and perceptions of equitable and unequitable household work sharing in dual-earner households. The sample consisted of 270 males and 349 females in their twenties to fifties in dual-earner households. Data analysis methods included frequency analysis, t-test, and multiple regression analysis methods. First, there were significant differences in household work sharing by gender. Second, there were significant differences in perceptions of equitable and unequitable household work sharing between males and females. Third, there were significant differences in perceptions of equitable and unequitable household work sharing in dual-earner households. These results verify differences in perceptions of equitable and unequitable household work sharing by gender in dual-earner households and demonstrate differential effects of factors influencing perceptions of equitable and unequitable household work sharing in dual-earner households.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.5
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• pp.31-35
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• 2011

In this paper, the miniaturized FM transmitter with dual-frequency is developed, and tested in the field. In this system two frequencies 88.1 MHz and 88.3 MHz is used. The transmitter is designed with 2.6 cm^3 system size, horizontal, vertical, height respectively. The operating voltage is 3.7 V and used the built-in storage battery in order to minimize. The system can use continuously during 7 hour with once charging. The channel separation ability is 40 dB. Consequently, this system is used conveniently with short distance information transmitter system at the industry field.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.37-44
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• 2020

In this paper, we proposed a compact printed monopole antenna with an inverted L-shaped slot for dual-band operations. Two operating frequency bands are achieved with the use of an inverted L-shaped slot etched on the radiating strip for bandwidth enhancement and a defected ground structure for return loss improvement in the higher frequency band. The measured results showthat the proposed antenna has impedance bandwidths (S₁₁< -10 dB) of 270 MHz (1.81-2.08 GHz) and 340 MHz (2.36-2.70 GHz), covering the required bandwidths for PCS (1850.5-1989.5 MHz), CDMA 2000 (1850-1990 MHz), TD-SCDMA (1880-2025 MHz) and 2.4 GHz WLAN (2400-2484 MHz). The measured return loss of the proposed antenna has a good value of approximately 27.2 dB at 2.4 GHz WLAN. The antenna's peak gains also have a high value of 1.92 dBi at 2 GHz and 2.12 dBi at 2.45 GHz. The proposed antenna shows omnidirectional radiation patterns over the entire frequency range of interest.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.912-918
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• 2003

In this paper, we designed and implemented the dual band monopole antenna for cellular CDMA(Code Division Multiple Access) and IMT-2000(International Mobile Telecommunication 2000) repeater. The antenna was designed by using 3D simulations program, HFSS(High Frequency Structure Simulator). Electrical characteristics were measured by using HP 8720C network analyzer and measured maximum S$\_$11/ was -10.9 dB for all frequency bands of interests in Cellular CDMA and IMT-2000. Simulation results for antenna gain at 859 MHz and 2027.5 MHz were 2.38 dBi and 4.02 dBi respectively with omni directional radiation pattern. The size of implemented antenna is compact and the antenna can be produced in low cost enough for commercialization.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1596-1600
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• 2000

We propose a novel adaptive feed forward controller (AFC) design method for rejecting the effect of micro actuator resonance in the design of dual-stage actuator servo systems for disk drives. Microactuator's resonance is one of important issues in dual-stage actuator servo, which varies up to ${\pm}10%$ per product and even during operation. We derive an adaptive algorithm for the proposed AFC design, which turns out to be identical to the delayed-x LMS algorithm which is a special form of the filtered-x LMS algorithm. In the algorithm, coefficients of the AFC are adapted by the residuals of constrained structure defined in such a way that the coefficients become time invariant. Contrary to the conventional AFC, it considers the phase delay of closed-loop transfer function at resonance frequency for system stability. We also apply an adaptive algorithm with frequency tracking capability. The frequency tracking algorithm is induced by the orthogonality of AFC coefficients. Computer simulations are carried out to demonstrate effect of the proposed AFCs.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.489-492
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• 2006

We demonstrate a beat frequency-Switchable dual-mode external cavity laser hybrid integrated on planar lightwave circuit with an FP-LD and a sampled grating as external reflector. The dual-mode external avity laser was able to switch its beat frequency from 132GHz to 406GHz by changing LD current from 50mA to 55mA.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.84-90
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• 2011

In this paper, a dual-band pseudo-combline narrow bandpass filter is proposed. The proposed bandpass filter adopts the open resonant stubs and the proposed bandpass filter can be used for ITS(Intelligent Transport System) and X-band satellite systems application. The proposed bandpass filter has the insertion and return losses of 1.72 dB and 15.5 dB at the bandwidth of 3.6 % and center frequency of 5.8 GHz, respectively. Also, the second operating frequency band for insertion and return losses are 1.92 dB and 16.3 dB at the bandwidth of 3% and center frequency of 8.5 GHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.107-116
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• 2001

In this thesis, characteristics of compact PIFA are analyzed for operation in dual frequencies (dual-PIFA) as variety of parameters. The antenna is composed of two patches. These are operated in high frequency and low frequency. The dimension of experiential antenna is fixed for attaching at the handset. The variable parameters are dimension of small patch, length of shorting strip and dimension of folded conductor plate, the frequencies are 900 MHz and 1800 MHz. The compact antenna is implemented with 2-layer type, electric field intensities and radiation patterns are simulated. In order to analyze characteristics of a performance as variety of parameters, FDTD method is used.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.337-338
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• 2016

This paper introduces a novel dual Full-Bridge LLC(FBLLC)resonant converter for CC/CV Charge of the Battery for Electric Vehicles. One full-bridge LLC resonant converter operates with a fixed-resonant network and the other operates with a variable-resonant network for CC and CV mode operations. The proposed converter can achieve ZVS for all the primary switches and exhibits a highefficiency characteristics like aconventional single FBLLC resonant converter. In addition, the variable-resonant network helps minimize the switching-frequency variation. The dual structure makes the proposed converter possible to achieve ZVS and nearly ZCS for all the primary switches in CC mode operation. Since the proposed converter can operate at a fixed frequency in CV mode, it can minimize the circulating current and achieve nearly ZCS. A 6.6 kW prototype converter is implemented to verify the validity of proposed converter and the maximum efficiency of 98.3% was achieved.