• Title/Summary/Keyword: Frequency restoration

Search Result 245, Processing Time 0.026 seconds

An Analysis on the Properties of the Domestic Laws Connected with Ecological Restoration Materials (생태복원재료 관련 국내 실정법의 속성 분석)

  • Shin, Ick-Soon
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.7 no.1
    • /
    • pp.85-96
    • /
    • 2004
  • The purpose of this study is to present the legal object in the related legislation taking the present condition of the domestic laws and the leading cases connected with ecological restoration materials and analyzing their properties according to the analytic standards which are legal class and ecological restoration material items, the present condition by the field of ecological restoration business, interrelationship between the law and the leading cases, comparison of the domestic laws with the foreign regulations. The results of this study are as follows; 1) Detailed enforcement regulation(36.5% of totals), enforcement regulation(32.4%) and law(31.1%) as legal class of the domestic legislation relating to ecological restoration materials are in the order of frequency that shows the little strong frequency at low-ranking class. By items, the number of legislation relating to planting material holds about majority, next to it, stone material, soil material and wood material are in the order of frequency. 2) By the field of ecological restoration business, legislation relating to administration forms the highest frequency(36.3% of totals), next to it, material properties(23.4%), plan design(13.0%) are in the order of frequency. 3) For the number of the leading cases by items of ecological restoration materials, those are, for the most part, them relating to planting material(93.8% of totals). The number of legislation relating to planting material forms the highest frequency at laws and the leading cases in common. 4) The domestic legislation connected with ecological restoration materials is mainly to be in legal class of the positive law, on the contrary, a foreign country has legislation widely consisted of laws, ordinances and other general regulations. Some foreign country legislated the topsoil conservation act, but not to domestic. The result of this study will be applied to legislature and court as reference materials, and to the public and public officer as a means of an understanding of ecological restoration materials.

Ventricle Image Restoration and Enhancement with Multi-thresholding and Multi-Filtering

  • Ryu, Kwang-Ryol;Jung, Eun-Suk
    • Journal of information and communication convergence engineering
    • /
    • v.7 no.2
    • /
    • pp.231-234
    • /
    • 2009
  • Speckle noise reduction for power Doppler ventricle coherent image for restoration and enhancement using Fast Wavelet Transform with multi-thresholding and multi-filtering on the each subbands is presented. Fast Wavelet Transform divides into low frequency component image to high frequency component image to be multi-resolved. Speckle noise is located on high frequency component in multi-resolution image mainly. A Doppler ventricle image is transformed and inversed with separated threshold function and filtering from low to high resolved images for restoration to utilize visualization for ventricle diagnosis. The experimental result shows that the proposed method has better performance in comparison with the conventional method.

Speckle Noise Reduction for 3D Power Doppler Ventricle Image Restoration Using Wavelet Packet Transform

  • Jung, Eun-sug;Ryu, Conan K.R.;Hur, Chang Wu;Sun, Mingui
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2009.05a
    • /
    • pp.156-159
    • /
    • 2009
  • Speckle noise reduction for 3D power doppler ventricle coherent image for restoration and enhancement using wavelet packet transform with separated thresholding is presented. Wavelet Packet Transform divide into low frequency component image to high frequency component image to be multi-resolved. speckle noise is located on high frequency component in multiresolution image mainly. A ventricle image is transformed and inversed with separated threshold function from low to high resolved images for restoration to be utilize visualization for ventricle diagnosis. The experimental result shows that the proposed method has better performance in comparison with the conventional method.

  • PDF

Frequency Control of Battery Energy Storage System with a Deadband and Restoration Control in Microgrid (마이크로그리드에서의 데드 밴드와 회복 제어를 적용한 배터리 에너지저장시스템 주파수 제어)

  • Lee, Hak-Ju;Choi, Jin-Young;Choi, Jong-Chan;Won, Dong-Jun;Chae, Woo-Kyu;Park, Jung-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.61 no.11
    • /
    • pp.1584-1589
    • /
    • 2012
  • The grid-interconnected microgrid can be able to operate with and without the utility microgrid to supply electricity. when the microgrid operates in grid-connected mode, the frequency of the microgrid synchronizes with the system frequency. In this case, the frequency of the microgrid has small variation which is able to change the output of distributed generation with a droop controller. Thus, the small variation of frequency can make the distributed generation generate unnecessary electricity consistently. In this paper, we propose a frequency droop control with a dead band so as to prevent the distributed generations from generating unnecessary output while in grid-interconnected mode. In addition, a distributed generation can have a restoration control to restore the frequency changed by a droop control as a rated frequency. Also, we state the problem of restoration control with a dead band, and propose its solution when the microgrid operates in stand alone mode. We simulate the proposed droop control using PSCAD/EMTDC to verify the validity of the control.

The Comparison of Plants and Vegetation Transect in a Straight and a Restoration Section-A Case Study of Bulgwang Stream in Seoul, Korea- (직강화 하천구간과 자연형 하천복원구간의 식물상 및 출현빈도 비교-불광천을 사례로-)

  • 정진아;김혜주;이은희
    • Korean Journal of Environment and Ecology
    • /
    • v.18 no.1
    • /
    • pp.61-74
    • /
    • 2004
  • The study was to investigate and compare plants and frequency of appearing species of vegetation transect in a straight and a restoration Section of Bulgwang stream in Seoul. Some part of Bulgwang stream was restored as a closed-to-nature stream. This present study consists of two investigations, the first investigation being conducted on May and the second one on August -September 2003. Based on the analysis of the data collected from both investigations, this study classified and listed all of the plants appeared in a straight and a restoration section of the stream. The study used the Belt-transect method in order to examine and analyze discover the appearance frequency of the vegetaton transect per 200 meters. During the period of the first investigation and the second one, plants of 33 families, 73 classes, and 88 species appeared in the straight section, while plants of 36 families, 76 classes, and 90 species appeared in the restoration section. The Naturalized Index of the straight section was 22.7%, and that of the restoration section was 21.1%. As shown on the results indicating that the Urbanization Index of the straight section was 7.8%, and that of the restoration section was 7.4%, the Urbanization Index of the straight section was slightly higher than the restoration section. The results using belt-transect analysis method showed that in case of the straight section, the plants of the highest appearance frequency on the riverside were Persicaria hydropiper and Humulus japonicus. On the contrary, in the case of restoration section, the plants showing a higher appearance frequency on the riverside were identified as Salix gracilistyla, Persicaria hydropiper, Rumex crispus, and Humulus japonicus. In conclusion, there was no difference between the straight and the restoration section in the bank with regard to vegetation transect. However, a remarkable difference was found on the riverside for the Salix gracilistyla which was introduced in the restoration section.

Minimum Statistics-Based Noise Power Estimation for Parametric Image Restoration

  • Yoo, Yoonjong;Shin, Jeongho;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
    • /
    • v.3 no.2
    • /
    • pp.41-51
    • /
    • 2014
  • This paper describes a method to estimate the noise power using the minimum statistics approach, which was originally proposed for audio processing. The proposed minimum statistics-based method separates a noisy image into multiple frequency bands using the three-level discrete wavelet transform. By assuming that the output of the high-pass filter contains both signal detail and noise, the proposed algorithm extracts the region of pure noise from the high frequency band using an appropriate threshold. The region of pure noise, which is free from the signal detail part and the DC component, is well suited for minimum statistics condition, where the noise power can be extracted easily. The proposed algorithm reduces the computational load significantly through the use of a simple processing architecture without iteration with an estimation accuracy greater than 90% for strong noise at 0 to 40dB SNR of the input image. Furthermore, the well restored image can be obtained using the estimated noise power information in parametric image restoration algorithms, such as the classical parametric Wiener or ForWaRD image restoration filters. The experimental results show that the proposed algorithm can estimate the noise power accurately, and is particularly suitable for fast, low-cost image restoration or enhancement applications.

Experimental realization of an imaging system using wavefront coding in mobile phone camera (휴대폰용 카메라 모듈에서 파면코딩을 통한 이미지 시스템 실험구현)

  • Kim, Jong-Pil;Lee, Sang-Hyuck;Park, No-Cheol;Park, Young-Pil;Park, Kyoung-Su
    • Transactions of the Society of Information Storage Systems
    • /
    • v.5 no.1
    • /
    • pp.36-40
    • /
    • 2009
  • We describe the experimental realization of image system using wavefront coding in 3-Mega pixel mobile phone camera. We designed aspheric lens to extend the depth of field (DOF) using wavefront coding. In addition, through the aspheric lens and lens barrel manufacturing, we obtained a raw image from a camera module. In our method, the acquired images are restored in the spatial frequency domain using the proposed filter and the spatial frequency response (SFR) is calculated. The proposed filters are composed of image denoising filter using low band pass filter in frequency domain and restoration filter for image restoration. Finally, we achieve an enhanced image by super-resolution image processing. Visual examples are given to demonstrate the performance of the proposed filter.

  • PDF

A Study on the Still Image Compression using the Low Pass Filter (로우 패스 필터를 이용한 정지 영상 압축에 관한 연구)

  • 김성종;신인철
    • Proceedings of the Korea Society for Industrial Systems Conference
    • /
    • 1997.11a
    • /
    • pp.91-101
    • /
    • 1997
  • The demand for handling images in digital form has increased dramatically in recent years. Digital image compression is required to store and transmit mass information in different from general information. JPEG(Joint Photographic Experts Group) committee founded by CCITT and ISO is define the still-image standard compression/restoration algorithm. JPEG is proposed the standard of grayscale and color still-image compression/restoration. In the image quality, JPEG is applicable to the various applications in which compression is able to from 1/10 to 1/50 without the visible obstacle. In this paper, we proposed that the proposed method enhance the compression ratio which is reducing the higher frequency in order to increasing the spatial redundancy in the image. The proposed method is using the low pass filter in order to reducing the higher frequency. The low-pass filters are using the median filter and convolution filter in the spatial domain, FFT filter in the frequency domain. We acquired the additive compression ratio reducing the higher frequency using the low-pass filter.

  • PDF

Effect of Inverse Filter in Image Restoration Using Hunt's Method (Hunt 방법을 이용한 Image Restoration에 있어서의 인버스 필터 효과)

  • Lee, Seong-Chun;Gang, Cheol-Ho;Lee, Jeong-Han
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.21 no.2
    • /
    • pp.54-60
    • /
    • 1984
  • In this paper, the modified Hunt's constrained least squares estimation method for image restoration is studied with the parameter ${\alpha}$ which represents the effect of inverse filter, And it is akown that high frequency components in the restored image obtained by the proposed method are emphasized by optimizing the constraining factor ${\gamma}$, depending upon ${\alpha}$.

  • PDF

Estimation of Design Discharge Considering Nonstationarity for River Restoration in the Mokgamcheon (목감천 복원설계를 위한 비정상성을 고려한 설계홍수량의 산정)

  • Lee, Kil Seong;Oh, Jin-Ho;Park, Kidoo;Sung, Jang-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.4
    • /
    • pp.1361-1375
    • /
    • 2013
  • The design flow considering nonstationarity is estimated to determine the design flood related to hydraulic structure quantitatively based on the design process for stream restoration in the Mokgamcheon watershed proposed by Lee et al. (2011). The purpose of this research is to suggest new ways that the design flood was calculated considering nonstationarity at the Mokgamcheon watershed. Storm-unit hydrograph method to calculate design flood and direct frequency analysis were applied and nonstationarity was considered for the frequency analysis through extRemes toolkit developed at NCAR (National Center for Atmospheric Research). Although the method of direct flood frequency analysis due to dealing with flowrates directly has a more reliable than strom-unit hydrograph method, as a result, the method of direct flood frequency analysis underestimated the design flood than strom-unit hydrograph method due to the characteristics of the flow data. Therefore, the flood of storm-unit hydrograph method (100 years frequency) was determined as the design flood in the Mokgamcheon watershed.