• Computers and Concrete
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• v.12 no.4
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• pp.431-442
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• 2013

This study attempted to find a proper method applicable to simulating practical equifield lines of two-dimensional Accelerate Lithium Migration Technique (ALMT), and evaluate the feasibility of using the theoretical ion migration model of one-dimensional ALMT to predict the ion migration behavior of two-dimensional ALMT. The result showed that the electrolyte or carbon plate can be used as matrix to draw equifield line graph similar to that by using mortar as matrix. Using electrolyte electrode module for simulation has advantages of simple production, easy measurement, rapidness, and economy. The electrolyte module can be used to simulate the equifield line distribution diagram in practical two-dimensional electrode configuration firstly. Then, several equifield line zones were marked, and several subzones under one-dimensional ALMT were separated from various equifield line zones. The theoretical free content distribution of alkali in concrete under two-dimensional electric field effect could be obtained from duration analysis.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.3
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• pp.59-65
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• 2010

This paper proposes a modified heuristic mixed model assembly line (MMAL) balancing algorithm that provides consistent station assignments on a model by model basis as well as on a station by station. Basically, some of single model line balancing techniques are modified and incorporated to be fit into the MMAL. The proposed algorithm is based on N.T. Thomopoulos' [8] method and supplemented with several well proven single model line balancing techniques proposed in the literature until recently. Hoffman's precedence matrix [2] is used to indicate the ordering relations among tasks. Arcus' Rule IX [1] is applied to generate rapidly a fairly large number of feasible solutions. Consequently, this proposed algorithm reduces the fluctuations in operation times among the models as well as the stations and the balance delays. A numerical example shows that the proposed algorithm can provide a good feasible solution in a relatively short time and generate relatively better solutions comparing to other three existing methods.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.491-498
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• 2008

In this paper a decoupled control of a doubly-fed induction machine(DFIM) feed by a matrix converter is presented. It provides a robust regulation of the stator side active and reactive powers by the direct and quadratic components of the stator current vector, presented in a line-voltage-oriented reference frame. In this case, the stator windings are directly connected to the line grid, while the rotor windings are supplied by this later through a matrix converter controlled by a space vector modulation technique. The proposed solution is suitable for both energy generation and electrical drive applications with restricted speed variation range.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.55-67
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• 2012

Real-time image georeferencing is required to generate spatial information rapidly from the image sequences acquired by multi-sensor systems. To complement the performance of position/attitude sensors and process in real-time, we should employ on-line aerial triangulation based on a sequential estimation algorithm. In this study, we thus attempt to derive an efficient on-line aerial triangulation algorithm for real-time georeferencing of image sequences. We implemented on-line aerial triangulation using the existing Given transformation update algorithm, and a new inverse normal matrix update algorithm based on observation classification, respectively. To compare the performance of two algorithms in terms of the accuracy and processing time, we applied these algorithms to simulated airborne multi-sensory data. The experimental results indicate that the inverse normal matrix update algorithm shows 40 % higher accuracy in the estimated ground point coordinates and eight times faster processing speed comparing to the Given transformation update algorithm. Therefore, the inverse normal matrix update algorithm is more appropriate for the real-time image georeferencing.

• Smart Structures and Systems
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• v.25 no.2
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• pp.169-181
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• 2020

Sensor placement is a crucial aspect of bridge health monitoring (BHM) dedicated to accurately estimate and locate structural damages. In addressing this goal, a sensor placement framework based on the deflection influence line (DIL) analysis is here proposed, for the optimal design of damage detection-oriented BHM system. In order to improve damage detection accuracy, we explore the change of global stiffness matrix, damage coefficient matrix and DIL vector caused by structural damage, and thus develop a novel sensor placement framework based on the Fisher information matrix. Our approach seeks to determine the contribution of each sensing node to damage detection, and adopts a distance correction coefficient to eliminate the information redundancy among sensors. The proposed damage detection-oriented optimal sensor placement (OSP) method is verified by two examples: (1) a numerically simulated three-span continuous beam, and (2) the Pinghu bridge which has existing real damage conditions. These two examples verify the performance of the distance corrected damage sensitivity of influence line (DSIL) method in significantly higher contribution to damage detection and lower information redundancy, and demonstrate the proposed OSP framework can be potentially employed in BHM practices.

• Journal of Power Electronics
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• v.18 no.1
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• pp.81-91
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• 2018

This paper proposes a double line voltage synthesis (DLVS) strategy for three-to-five phase direct matrix converters. In the proposed strategy, the input and expected output voltages are divided into 6 segments and 10 segments, respectively. In addition, in order to obtain the maximum voltage transfer ratio (VTR), the input line voltages and "source key" should be selected reasonably according to different combinations of input and output segments. Then, the corresponding duty ratios are calculated to determine the switch sequences in different segment combinations. The output voltages and currents are still sinusoidal and symmetrical with little lower order harmonics under unbalanced or distorted input voltages by using this strategy. In addition, the common mode voltage (CMV) can be suppressed by rearranging some of the switching states. This strategy is analyzed and studied by a simulation model established in MATLAB/Simulink and an experimental platform, which is controlled by a DSP and FPGA. Simulation and experimental results verify the feasibility and validity of the proposed DLVS strategy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.598-604
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• 2011

A method of miniaturizing branch line coupler with connected coupled lines is presented. The quarter-wavelength transmission lines in the typical microstrip branch line coupler are replaced with the connected coupled lines with same characteristics of ones for compact size. The connected coupled line is analyzed by T-equivalent circuit and Z parameters based on the even-odd mode analysis. The proposed branch line couplers with connected coupled line are designed and fabricated on FR4 substrate at 2.4 GHz. The measured results show good agreement with theoretical prediction. And the experimental results show that the size of coupler is 37 precent smaller than conventional coupler. This minimized coupler is suitable for Butler Matrix as feeder for mobile communication beam forming antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.137-144
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• 2013

A delay-locked loop (DLL) that generates a 32-phase clock with the operating frequency of 125 MHz is introduced. The proposed DLL uses a delay line of $4{\times}8$ matrix architecture to improve a differential non-linearity (DNL) of the delay line. Furthermore, a integral non-linearity (INL) of the proposed DLL is improved by calibrating phases of clocks that is supplied to four points of an input stage of the $4{\times}8$ matrix delay line. The proposed DLL is fabricated by using $0.11-{\mu}m$ CMOS process with a 1.2 V supply. The measured operating frequency range of the implemented DLL is 40 MHz to 280 MHz. At the operating frequency of 125MHz, the measurement results shows that the DNL and INL are +0.14/-0.496 LSB and +0.46/-0.404 LSB, respectively. The measured peak-to-peak jitter of the output clock is 30 ps when the peak-to-peak jitter of the input clock is 12.9 ps. The area and power consumption of the implemented DLL are $480{\times}550{\mu}m^2$ and 9.6 mW, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.802-805
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• 2007

A hardware architecture is presented of a wavelet based multiple line addressing driving scheme for passive matrix displays using the FPGA (Field Programmable Gate Arrays), which will be integrated in the scalable video coding $architecture^{[1]}$. The incoming compressed video data stream will then directly be transformed to the required column voltages by the hardware architecture without the need of employing the video decompression.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1321-1324
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• 2004

Unbalanced systems, such as distribution systems, have difficulties in fault locations due to single-phase laterals and loads. In this paper, a novel fault location algorithm is suggested for a line to line faults using inverse theorem of matrix on electric power lines. The fault location for balanced systems has been studied using the current distribution factor, by a conventional symmetrical transformation, but that for unbalanced systems has not been investigated due to their high complexity The proposed algorithms overcome the limit of the conventional algorithm using the conventional symmetrical transformation, which requires the balanced system and are applicable to any electric power system but are particularly useful for unbalanced distribution systems. The simulation results oriented by the real distribution system are presented to show its effectiveness and accuracy.