• Korea Science and Art Forum
• /
• v.25
• /
• pp.379-388
• /
• 2016

There are some studies to get rid of slice patterns in coronal and sagittal images by FFT(Fast Fourier Transform) and Notch filter. However, the use of a notch filter is the ringing effect according to the rapid frequency change occurs in common. Therefore, this study will be to evaluate the shape and effect of the notch filter. In addition, it is proposed a new notch filter design. Results of the study are as follows. First, Emission-Notch filter was relatively naturally correcting the cutting pattern. Second, Emission-Notch filter to use as Ringing effect is reduced relatively. The next through these findings and further research progress more completely removed the Ringing effect, and expects to reproduce the data close to the actual human body information.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.10 no.5
• /
• pp.250-257
• /
• 1985

High order filters are usually realized by cascading second order stages. In this paper, a simple method of pole-zero pairing in the high order band-pass and band-reject filter realization of the elliptic functions is proposed for the enhancement of overall dynamic range. Futrhermore, the optimum sequence of the various biquads of high-pass notch, low-pass notch and symmetrical notch etc., is developed for the elliptic band-pass and band-reject filters.

• The Journal of the Korea Contents Association
• /
• v.11 no.5
• /
• pp.15-24
• /
• 2011

Recently various anatomic researches by using serially sectioned images in VK(Visible Korean) project are in progress. In that sense, it is very important and necessary to represent images which keep information of the original anatomic images. In this regard, there are some studies to get rid of slice patterns in coronal and sagittal images. However, according to the rapid spatial frequency changes, the ringing effect occurred in common. In addition, because of merge with the original images which have splice patterns, those patterns appeared again. Therefore, in this study we found effective color space to apply to FFT(Fast Fourier Transform) and notch filter in getting rid of the slice patterns. To verify this, we used RGB, LAB, CMYK, HSV and HSL color space. Secondly we got rid of and alleviated the ringing effect by improving notch filter. To verify this, we compared proposed method with previous study on the basis of original images by visual method and objective values. These result images are expected to contribute to anatomy research in relation to VK project.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.3
• /
• pp.71-78
• /
• 2009

In this study, estimation of heart rate from measured PPG signal is proposed. PPG signal is to be measured blood flow in a blood vessel effected by systole and diastole. PPG sianl has single frequency so that PPG frequency can be tracked by 2nd IIR adaptive notch filter. PPG frequency is obtained continually from updating filter coefficient throughout adaptive algorithm and then the heart rate of human is approximately estimated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.9 s.100
• /
• pp.941-948
• /
• 2005

In this paper, we have proposed a Ultra-Wideband slot notch antenna by using a semi-circular extension. The proposed antenna cover the entire UWB band(3.1${\~}$10.6 GHz) and notch out the IEEE 802.1la frequency band(5.15${\~}$5.825 GHz) by inserting a $\lambda$/4 length slot into the patch. A prototype antenna was fabricated on FR-4( ${\epsilon}_r$ =4.4, substrate thickness=0.8 mm) and measured for VSWR characteristics. The measured notched frequency variations versus frequency for different slot length. The path loss and group delay were measured. The proposed antenna also show a good gain flatness(1.9 dBi) except the IEEE 802.1la frequency band.