• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2664-2669
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• 2011

We proposed a new method to improve the resolution of far object image in curving effective integral imaging system. Basically, the curving effective integral imaging(CEII) system can improve the resolution of the reconstructed images with an increased sampling rate of elemental images. However, in the case when an object located far from the lenslet array is picked up, the low resolution of the reconstructed images of the far object has been a primary problem because the sampling rate is very low. In order to solve this drawback, by using the direct pixel mapping(DPM) method the EIA picked up from a far object is transformed into a new EIA that virtually looks like the EIA picked up from the object originally located close to the lenslet array. From this new EIA, highly resolution-enhanced images of far object could be reconstructed in the CEII system. To show the feasibility of the proposed method, simulation results are compared with the conventional method.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.304-305
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• 2004

• Journal of Power Electronics
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• v.12 no.6
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• pp.895-903
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• 2012

This paper presents a fast switching direct torque control (FS-DTC) using only a single DC-link current sensor. In FS-DTC, six new active voltage complex space vectors (CSVs) are synthesized by the conventional active voltage space vectors (SVs). The corresponding sectors are rotated in the anticlockwise direction by 30 degrees. A selection table is defined to select the CSVs. Based on the "Different Phase Mode", the output sequence of the selected CSV is optimized. Accordingly, a reconstruction method is proposed to acquire the phase currents. The core of the FS-DTC is that all of the three phase currents can be reliably reconstructed during every two sampling periods, which is the result of the fast switching between different phases. The errors between the reconstructed and actual currents are strictly limited in one sampling period. The FS-DTC has the advantages of the standard DTC scheme such as simple structure, quick torque response and robustness. As can be seen in the analysis, the FS-DTC can be thought of as an equivalent standard DTC scheme with 86.6% of the maximum speed, 173.2% of the torque ripple, and 115% of the response time of the torque. Based on a dSPACE DS1103 controller, the FS-DTC is implemented in an induction machine drive system. The results verify the effectiveness of the FS-DTC.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.194-202
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• 2008

This paper describes a new method for indoor environment mapping and localization with stereo camera. For environmental modeling, we directly use the depth and color information in image pixels as visual features. Furthermore, only the depth and color information at horizontal centerline in image is used, where optical axis passes through. The usefulness of this method is that we can easily build a measure between modeling and sensing data only on the horizontal centerline. That is because vertical working volume between model and sensing data can be changed according to robot motion. Therefore, we can build a map about indoor environment as compact and efficient representation. Also, based on such nodes and sensing data, we suggest a method for estimating mobile robot positioning with random sampling stochastic algorithm. With basic real experiments, we show that the proposed method can be an effective visual navigation algorithm.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.82-87
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• 2000

The direct simulation Monte Carlo (DSMC) method is applied to investigate the flow field of a disk-type drag pump. The pumping channels are cut on both sides of a rotating disk. The rotor has 10 Archimedes' spiral blades. In the present DSMC method, the variable hard sphere model is used as a molecular model, and the no time counter method is employed as a collision sampling technique. For simulation of diatomic gas flows, the Larsen-Borgnakke phenomenological model is adopted to redistribute the translational and internal energies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.776-779
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• 2008

It is expect that Microarray technique be direct classification and diagnosis of Genetic data have abnomal data value because DNA technique. It is necessary that many noses that is abnomal data in sampling genetic data. So in this paper reported sampling method in exiting study then suggests new data classific system and modeling method using EP by Matlab about three dataset.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.408-413
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• 2011

In this paper, a real-coefficient approach to Adaptive Frequency Sampling (AFS) technique is developed for efficient equivalent circuit modeling of RF components. This proposed method is advantageous than the vector fitting technique and the conventional AFS method in terms of fewer samples leading to a lower order of a rational function on a given data and to a direct conversion to an equivalent circuit for PSPICE(Personal Simulation Program with Integrated Circuit Emphsis) simulation, respectively. To validate the proposed method, the distributed equivalent circuit of a presented multi-layered RF low-pass filter is obtained using the proposed real-coefficient AFS, and then comparisons with EM simulation and circuit simulation for the device under consideration are achieved.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.643-648
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• 2001

The direct simulation Monte Carlo(DSMC) method is applied to investigate steady and unsteady flow fields of a single-stage disk-type drag pump. Two different kinds of pumps are considered: the first one is a rotor-rotor combination, and the second one is a rotor-stator combination. The pumping channels are cut on a rotor and stator. The rotor and stator have 10 Archimedes' spiral blades, respectively. In the present DSMC method, the variable hard sphere model is used as a molecular model, and the no time counter method is employed as a collision sampling technique. For simulation of diatomic gas flows, the Borgnakke-Larsen phenomenological model is adopted to redistribute the translational and internal energies. The DSMC results are in good agreement with the experimental data.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.1
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• pp.8-16
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• 1986

For digital process control, a low order discrete time modeling method is suggested and a direct digital control algorithm has been developed. The modeling method maintains process order of 3, while the sampling rate is doubled for fast response. With easy calculation it is possible to compute the model parameters and the controller gains. Controller tuning is possible on the spot. Simulation results show that this method has better performance than the deadbeat control agorithm.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.533-536
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• 1999

We consider digital implementation problems of continuous-time controllers. In general, digital controllers use fixed point representation of number and of finite word length(FWL). Under these conditions, this paper investigates the closed-loop stability caused by three design constraints; (i) finite precision representation of the controller parameters, (ii) realization forms such as direct form, cascade form, and parallel form, and (iii) sampling time. We calculate the coefficient stability margins of both predesigned controllers and controller to be implemented. This method can be applied to determine the word length, realization structure, and sampling time so that remains the stability.