• Journal of electromagnetic engineering and science
• /
• v.8 no.4
• /
• pp.153-157
• /
• 2008

Most of malfunctions in electronic equipment or systems controlled by processors is occurred by the differential- and common-mode noises, and the electrical fast transient (EFT). The International Electrotechnical Commission (IEC) has prepared the dummy signal to test the immunity level of the equipment. For the countermeasure against the differential- and common-mode noises, and the EFT, we designed, fabricated, and tested a new electromagnetic compatibility (EMC) filter, which is composed of feed-through capacitors and ferrite beads with high permeability. As a result, the filter showed excellent differential- and common-mode noises filtering, and immunity improving characteristics over the frequency band from 30 MHz to 1.5 GHz and 1.8 GHz, respectively.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.2
• /
• pp.185-192
• /
• 2002

A novel GPS initial synchronization scheme with low hardware complexity is proposed. The proposed method has the decomposed differential matched filter, which consists of 25% multiplier and adder of the conventional matched filter. This paper presents the generalized mean acquisition time of initial synchronization scheme with multiple correlator. It is shown that the proposed method, in spite of its low hardware complexity, has the equal performance to the conventional method. The performance of the proposed method is verified through the simulation test by the GPS simulator. It is shown that the proposed method prevents the squaring loss of non-coherent integration.

• Journal of Power Electronics
• /
• v.19 no.5
• /
• pp.1289-1302
• /
• 2019

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

• Journal of Advanced Navigation Technology
• /
• v.17 no.2
• /
• pp.196-201
• /
• 2013

In this paper, a dual-mode balanced filter with symmetric coupled composite right/left-handed transmission line is introduced. Unlike the other symmetric structure, this configuration has the ability to operate under both common- and differential-mode excitation. These properties are achievable through providing physical short circuit by means of ground vias at the center of each unit-cell along the symmetry plane of the structure. Because the CRLH unit-cells are operated under both common- and differential-mode excitation, we implemented a balanced filter using these properties. To validity these features, a five-cell four port coupled CRLH-TL is simulated, fabricated and measured and the obtained performances agree with the simulation results under both common- and differential-mode excitation.

• International Journal of Aeronautical and Space Sciences
• /
• v.17 no.2
• /
• pp.222-231
• /
• 2016

This paper proposes a new method achieving computationally efficient attitude reference system for low cost strapdown sensors and microprocessor platform. The main idea in this method is to define and compare velocity differential vectors, geometrically computed from INS and GPS data with different update rate, for generating attitude error measurements which is further used for filter construction. A quaternion based Kalman filter configuration is applied for the attitude estimation with the adapted measurement model of differential vector comparison. Linearized model for Extended Kalman Filter and low pass filtered characteristics of measurement greatly extend the affordability of the proposed algorithm to the field of simple low cost embedded systems. For performance verification, experiment are done employing a practical low cost MEMS IMU and GPS receiver specification. Performance comparison with a high grade navigation system demonstrated good estimation result.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.8
• /
• pp.777-782
• /
• 2011

Neural network technique is widely employed in the fields of signal processing, control systems, pattern recognition, etc. Learning of neural networks is an important procedure to accomplish dynamic system modeling. This paper presents a novel learning approach for differential neural network models based on the Kalman-Bucy filter theory. We construct an augmented state vector including original neural state and parameter vectors and derive a state estimation rule avoiding gradient function terms which involve to the conventional neural learning methods such as a back-propagation approach. We carry out numerical simulation to evaluate the proposed learning approach in nonlinear system modeling. By comparing to the well-known back-propagation approach and Kalman-Bucy filtering, its superiority is additionally proved under stochastic system environments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.7
• /
• pp.1526-1531
• /
• 2009

This paper describes the design of a 5th order Elliptic CMOS Gm-C low-voltage filter for the RFID reader IC. The designed filter is composed of CMOS differential transconductors by parallel gain circuits to improve the gain of the conventional self-biased differential amplifier. The filter is designed to operate in low-voltage 1.8V to meet the specification of the RFID reader filter. The results of HSPICE simulation using 1.8V-0.18${\mu}m$CMOS processing parameter showed that the designed 5th order Elliptic low-pass filter satisfied the cutoff frequency of 1.35MHz given by the design specification.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.241-244
• /
• 1997

A dead reckoning navigation system is developed for autonomous mobile robot localization. The navigation system was implemented by novel sensor fusion using a Kalman filter. A differential encoder and the gyroscope error models are developed for the filter. An indirect Kalman filter scheme is adopted to reduce the computational burden and to enhance the navigation system reliability. The filter mutually compensates the encoder errors and the gyroscope errors. The experimental results show that the proposed mobile . robot navigation algorithm provides the reliable position and heading angle of the mobile robot without any help of the external positioning systems.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.5
• /
• pp.682-686
• /
• 2016

A fully differential RC calibrator for accurate cut-off frequency of a programmable channel selection filter is proposed. The proposed RC calibrator consists of an RC timer, clock generator, synchronous counter, digital comparator, and control block. To verify the proposed RC calibrator, a six-order Chebyshev programmable low-pass filter with adjustable 3 dB cut-off frequency, which is controlled by the proposed RC calibrator, was implemented in a $0.18-{\mu}m$ CMOS technology. The channel selection filter with the proposed RC calibrator draws 1.8 mA from a 1.8 V supply voltage and the measured 3 dB cut-off frequencies of the channel selection LPF is controlled accurately by the RC calibrator.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.11
• /
• pp.1185-1198
• /
• 1992

In this paper, the differential weighted algorithm proposed in order to improve th noise smoothing characteristics of conventional Median filter and FIR-Median Hybrid filter. Performance of some image restoration filter(median filter, FIR-Median Hybird filter, FIR-Median Hybrid filter to proposed differential weighted algorithm) are compared and evaluated on the noise smoothing characteristics and sharp edge conservation characteristics. Test and Real images used in this paper are Lenna and Urological images corrupted by impulse, gaussian, exponential and laplacian noise. Experimental results show that the FIR-Median Hybrid filter applied to the differential weighted algorithm are comparatively superior to others. But the filter orders have increased, the more time consumed to image processing. Hence if the adequate filtering by the type of image is selected. now after a great support will be take consideration into the various parts of application by computer science and of medical image processing.