نتایج جستجو برای: frequency and spatial domain

تعداد نتایج: 16961384  

2008
G. D. Lodwick S. H. Paine

Various spatial filtering techniques have been developed to process digital Landsat data. This research aimed to filter the same digital data within the frequency domain, and involved the use of the Butterworth lowpass and highpass filters. The lowpass filter is used primarily for the reduction of noise whereas the highpass filter is used primarily for edge enhancement. The analysis of these tw...

2014
Richika Mahajan B. V. Kranthi

An Improved Image Steganography Technique Using Discrete Wavelet Transform Richika Mahajan, B.V. Kranthi Electronics and Communication Engineering Lovely Professional University Jalandhar, Punjab, India _________________________________________________________________________________________ Abstract: This paper proposes a new method for hiding a data in frequency domain. In this a spatial doma...

2009

Frequency domain filtering modifies the brightness values of the pixels in the image depending on their periodic patterns and on the spatial distributions of brightness variations in the image. The high pass filters tend to preserve the sharp brightness variation patterns and to remove the smooth variations in the image (along with the DC component, i.e. with the average brightness which is set...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2012
amir heidari mansour shirvani

in this contribution, linearized dynamic model of cumulative mass fraction (cmf) of potassium nitrate-water seeded continues mixed suspension mixed product removal (cmsmpr) crystallizer is approximated by a simplified model in frequency domain. frequency domain model simplification is performed heuristically using the frequency response of the derived linearized models data. however, the cmf fr...

Journal: :فیزیک زمین و فضا 0
محبوبه رضایی فرح آبادی دانشجوی کارشناسی ارشد ژئوفیزیک، گروه ژئوفیزیک، دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران، ایران محمد علی ریاحی دانشیار، گروه فیزیک زمین، مؤسسة ژئوفیزیک دانشگاه تهران، ایران میرستار مشین چی استادیار، گروه ژئوفیزیک، دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران، ایران

one of the common problems in reflective seismic records is the existence of coherent linear and random noises which cause covering of the most important parts of reflective signals; therefore, it is necessary to attenuate them by processing methods. several processing techniques have been devised for attenuation of coherent linear noises and linear radon or ?-? transform is a powerful techniqu...

2007
Marios Savvides Ramamurthy Bhagavatula Yung-hui Li Ramzi Abiantun

In the always expanding field of biometrics the choice of which biometric modality or modalities to use, is a difficult one. While a particular biometric modality might offer superior discriminative properties (or be more stable over a longer period of time) when compared to another modality, the ease of its acquisition might be quite difficult in comparison. As such, the use of the human face ...

Journal: :روش های عددی در مهندسی (استقلال) 0
محمدرضا بهبهانی فرد m. r. behbahanifard محمدمهدی سعادتپور m.m. saadatpour

a frequency domain dynamic analysis is needed to obtain the response of structures constructed on a system of base isolators on flexible soil when subjected to earthquake ground motion. in such systems, the lateral stiffness of the base isolators is so small, compared to the structural stiffness, that in an earthquake attack the fundamental vibration mode dominates the response. with this in mi...

Journal: :journal of mining and environment 2011
a. r. arab-amiri a. moradzadeh n. fathianpour b. siemon

helicopter-borne frequency-domain electromagnetic (hem) surveys are used extensively for mineral and groundwater exploration and a number of environmental investigations. to have a meaningful interpretation of the measured multi- frequency hem data, in addition to the resistivity maps which are provided in each frequency or for some particular depth levels, it is a necessity to have a suit...

Journal: :int. journal of mining & geo-engineering 2014
abolfazl asadian ali moradzadeh alireza arab-amiri ali nejati kalateh davood rajabi

the helicopter-borne electromagnetic (hem) frequency-domain exploration method is an airborne electromagnetic (aem) technique that is widely used for vast and rough areas for resistivity imaging. the vast amount of digitized data flowing from the hem method requires an efficient and accurate inversion algorithm. generally, the inverse modelling of hem data in the first step requires a precise a...

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