scholarly journals Seismic Data Denoising Based on Sparse and Low-Rank Regularization

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 372 ◽  
Author(s):  
Shu Li ◽  
Xi Yang ◽  
Haonan Liu ◽  
Yuwei Cai ◽  
Zhenming Peng

Seismic denoising is a core task of seismic data processing. The quality of a denoising result directly affects data analysis, inversion, imaging and other applications. For the past ten years, there have mainly been two classes of methods for seismic denoising. One is based on the sparsity of seismic data. This kind of method can make use of the sparsity of seismic data in local area. The other is based on nonlocal self-similarity, and it can utilize the spatial information of seismic data. Sparsity and nonlocal self-similarity are important prior information. However, there is no seismic denoising method using both of them. To jointly use the sparsity and nonlocal self-similarity of seismic data, we propose a seismic denoising method using sparsity and low-rank regularization (called SD-SpaLR). Experimental results showed that the SD-SpaLR method has better performance than the conventional wavelet denoising and total variation denoising. This is because both the sparsity and the nonlocal self-similarity of seismic data are utilized in seismic denoising. This study is of significance for designing new seismic data analysis, processing and inversion methods.

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 40-41 ◽  
Author(s):  
Leon Thomsen

The topic of seismic anisotropy in exploration and exploitation has seen a great deal of progress in the past decade‐and‐a‐half. The principal reason for this is the increased (and increasing) quality of seismic data, of the processing done to it, and of the interpretation expected from it. No longer an academic subject of little practical interest, it is now often viewed as one of the crucial factors which, if not taken into account, severely hampers our effective use of the data. The following brief overview is not intended to be exhaustive, since any such attempt would surely be incomplete. However, it does provide a high‐level survey of the advances seen (at the end of this period) to be important by one who was closely involved, and it directly extrapolates this history to predict the future development of the topic.


2012 ◽  
Vol 27 ◽  
pp. 463-496 ◽  
Author(s):  
Max Diem ◽  
Miloš Miljković ◽  
Benjamin Bird ◽  
Tatyana Chernenko ◽  
Jen Schubert ◽  
...  

This paper summarizes the progress achieved over the past fifteen years in applying vibrational (Raman and IR) spectroscopy to problems of medical diagnostics and cellular biology. During this time, a number of research groups have verified the enormous information content of vibrational spectra; in fact, genomic, proteomic, and metabolomic information can be deduced by decoding the observed vibrational spectra. This decoding process is aided enormously by the availability of high-power computer workstations and advanced algorithms for data analysis. Furthermore, commercial instrumentation for the fast collection of both Raman and infrared microspectral data has rendered practical the collection of images based solely on spectral data. The progress in the field has been manifested by a steady increase in the number and quality of publications submitted by established and new research groups in vibrational biological and biomedical arenas.


Geophysics ◽  
2020 ◽  
pp. 1-60
Author(s):  
Ouyang Shao ◽  
Lingling Wang ◽  
Xiangyun Hu ◽  
Zhidan Long

Because there are many similar geological structures underground, seismic profiles have an abundance of self-repeating patterns. Thus, we can divide a seismic profile into groups of blocks with similar seismic structure. The matrix formed by stacking together similar blocks in each group should be of low rank. Hence, we can transfer the seismic denoising problem to a serial of low-rank matrix approximation (LRMA) problem. The LRMA-based model commonly adopts the nuclear norm as a convex substitute of the rank of a matrix. However, the nuclear norm minimization (NNM) shrinks the different rank components equally and may cause some biases in practice. Recently introduced truncated nuclear norm (TNN) has been proven to more accurately approximate the rank of a matrix, which is given by the sum of the set of smallest singular values. Based on this, we propose a novel denoising method using truncated nuclear norm minimization (TNNM). The objective function of this method consists of two terms, the F-norm data fidelity and a truncated nuclear norm regularization. We present an efficient two-step iterative algorithm to solve this objective function. Then, we apply the proposed TNNM algorithm to groups of blocks with similar seismic structure, and aggregate all resulting denoised blocks to get the denoised seismic data. We update the denoised results during each iteration to gradually attenuate the heavy noise. Numerical experiments demonstrate that, compared with FX-Decon, the curvelet, and the NNM-based methods, TNNM not only attenuates noise more effectively even when the SNR is as low as -10 dB and seismic data have complex structures, but also accurately preserves the seismic structures without inducing Gibbs artifacts.


2019 ◽  
Vol 11 (24) ◽  
pp. 2897 ◽  
Author(s):  
Yuhui Zheng ◽  
Feiyang Wu ◽  
Hiuk Jae Shim ◽  
Le Sun

Hyperspectral unmixing is a key preprocessing technique for hyperspectral image analysis. To further improve the unmixing performance, in this paper, a nonlocal low-rank prior associated with spatial smoothness and spectral collaborative sparsity are integrated together for unmixing the hyperspectral data. The proposed method is based on a fact that hyperspectral images have self-similarity in nonlocal sense and smoothness in local sense. To explore the spatial self-similarity, nonlocal cubic patches are grouped together to compose a low-rank matrix. Then, based on the linear mixed model framework, the nuclear norm is constrained to the abundance matrix of these similar patches to enforce low-rank property. In addition, the local spatial information and spectral characteristic are also taken into account by introducing TV regularization and collaborative sparse terms, respectively. Finally, the results of the experiments on two simulated data sets and two real data sets show that the proposed algorithm produces better performance than other state-of-the-art algorithms.


2013 ◽  
Vol 373-375 ◽  
pp. 569-573
Author(s):  
Rui Yang ◽  
Guang Xun Chen ◽  
Pan Ke Qin ◽  
Neng You Wu ◽  
Jia Shun Yu

In order to improve the resolution and accuracy of the inversion, this paper proposed a new inversion method. By introducing constraint sparse spike inversion, the new method can fully take the advantages of high vertical resolution of logging data and the preferable transverse continuity of the seismic data to improve the resolution of the profiles and the quality of imaging and inversion in specific areas. Experimental results showed that this solution can deduce more precise and reasonable inversion result than other inversion solution. Constraint sparse spike inversion can generate reflection coefficients with broad frequency band and solve the marking problems preferably, thereby makes the impedance model obtained from the inversion even close to the actual situation underground.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


2018 ◽  
Vol 5 (2) ◽  
pp. 102
Author(s):  
Enike Dwi Kusumawati ◽  
Selvinus Lawu Woli ◽  
Aju Tjatur Nugroho Krisnaningsih ◽  
Waluyo Edi Susanto ◽  
Syam Rahadi

ABSTRAKPenelitian ini dilakukan untuk mengetahui motilitas dan viabilitas spermatozoa ayam kampung pada suhu 5oC menggunakan pengencer dan lama simpan yang berbeda. Metode yang digunakan dalam penelitian ini adalah penelitian laboratorium menggunakan Rancangan Acak Lengkap (RAL) Faktorial dengan pengencer ringer lactat solution, air kelapa dan tanpa pengencer serta lama simpan 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, masing-masing diulang 10 kali. Variabel yang diamati yaitu motilitas dan viabilitas spermatozoa. Analisa data yang digunakan adalah analisis varian. Hasil analisis data menunjukkan bahwa motilitas dan viabilitas spermatozoa menggunakan pengencer ringer lactat solution lebih tinggi (P<0,01) serta dapat bertahan sampai lama simpan 24 jam dibandingkan air kelapa dan tanpa pengencer. Adapun nilai motilitas ringer lactat solution, air kelapa dan tanpa pengencer pada lama simpan 24 jam masing-masing sebesar 43,5±17,17%; 8±4,83%; 6,5±2,4%, sedangkan nilai viabilitasnya sebesar 83,2±7,25%; 64,6±3,20%; dan 63,1±2,33%. Kesimpulan dari hasil penelitian ini adalah ringer lactat solution lebih baik dibandingkan air kelapa dan tanpa pengencer dalam mempertahankan kualitas semen ayam kampung pada suhu simpan 5oC sampai lama simpan 24 jam.Kata Kunci : air kelapa, ayam kampung, motilitas, spermatozoa, viabilitas  ABSTRACTThis study was conducted to determine the motility and viability of spermatozoa of Native chickens at 5oC using different diluents and time storage. The method used in this study was laboratory research using Factorial Completely Randomized Design with ringer lactate solution, coconut water and without diluent at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 hours of time storage each repeated 10 times. The variables observed were motility and viability of sperm. Data analysis used is variance analysis. The results of data analysis showed that the motility and viability of spermatozoa using ringer lactate solution diluents was higher (P <0.05) than coconut water and without diluents. The motility values of ringer lactat solution, coconut water and without diluents were 43,5±17,17%; 8±4,83%; 6,5±2,4% respectively, while the viability values were 83,2±7,25%; 64,6±3,20% and 63,1±2,33%. The conclusion of this study is that ringer lactat solution is better than coconut water an without diluents in maintaining the quality of Native chicken semen at a storage temperature of 5oC until 24 hours.Keywords: coconut water, motility, native chicken, sperm, viability


2020 ◽  
Vol 7 (2) ◽  
pp. 119
Author(s):  
Lukman Affandhy ◽  
Muchamad Luthfi ◽  
Dian Ratnawati ◽  
Frediansyah Firdaus

ABSTRAK  Penelitian bertujuan untuk mengetahui pengaruh pemberian bubuk daun Moringa oleifera (MO) terhadap kuantitas dan kualitas semen sapi peranakan ongole (PO). Metode penelitian menggunakan percobaan lapang dengan rancangan acak lengkap dengan tiga perlakuan pemberian MO sebesar 0 kg/ekor/hari (P1); 0,05 kg/ekor/hari (P2) dan 0,1 kg/ekor/hari (P3). Analsis data menggunakan one way analysis of variance. Masing-masing perlakuan terdiri atas empat ekor dengan tiga periode pengamatan sebagai ulangan, yaitu periode pertama dan ketiga tanpa MO, dan periode kedua diberikan MO pada P2 dan P3. Hasil penelitian menunjukan bahwa volume dan pH semen perlakuan P1, P2 dan P3 tidak berbeda semua periode pengamatan. Motilitas massa spermatozoa P2 dan P3 periode kedua dan ketiga menunjukan nilai +++ berbeda nyata (P<0,05) dibandingkan dengan P1 (++); motilitas individu  perlakuan P1 menunjukkan nilai terendah 60,56±2,94 % (P<0,05) dibandingkan P2 dan P3 pada periode kedua dan ketiga (75,50±2,29 dan 72,50±2,34%). Konsentrasi spermatozoa P2 dan P3 periode kedua dan ketiga menunjukkan rata-rata  >1.350 juta/ml berbeda nyata (P<0,05) daripada P1 (876±152juta/ml), sedangkan total spermatozoa motil menunjukkan nilai tertinggi 5.647±829 juta/ml pada P3 periode kedua.Viabilitas spermatozoa P2 dan P3 menunjukkan nilai >88-89 % beda nyata (P<0,05) daripada P1 (<84 %) pada periode kedua dan ketiga, sedangkan nilai abnormalitas spermatozoa yang terbaik adalah P2 sebesar 4,30% pada periode kedua dan P3 sebesar 5,33% pada periode ketiga. Disimpulkan pemberian bubuk daun MO dengan dosis 0,1 kg/ekor/hari dapat memperbaiki kuantitas dan kualitas semen (viabilitas dan total spermatozoa motil) sapi pejantan PO.Kata kunci:  kuantitas dan kualitas semen, Moringa oleifera, sapi pejantan ABSTRACTThe research aimed to determine the effect of Moringa oleifera (MO) leaf powder on the quantity and quality of semen of ongole crossbreed. The research method used was a field experiment with a completely randomized design with three treatments giving MO of 0 kg/head/day (P1); 0.05 kg/head/day (P2) and 0.1 kg/head/day (P3). Each treatment consisted of four heads with three periods of observation as replications, namely the first and third periods without MO, and the second period was given MO on P2 and P3. Data analysis used a one-way analysis of variance. The results showed that the volume and pH of semen treated P1, P2, and P3 didn’t different in all observation periods. The second and third period spermatozoa mass motility of P2 and P3 showed that the value of +++ was significantly different (P<0.05) compared to P1 (++); Individual motility of P1 treatment showed the lowest value 60,56±2,94 % (P<0.05) compared to P2 and P3 in the second and third periods (75,50±2,29 and 72,50±2,34%). The second and third periods of P2 and P3 spermatozoa concentrations showed an average of >1,350 million/cc significantly different (P<0.05) than P1 (876±152 million/cc), while the total motile spermatozoa showed the highest value of 5,647±829 million/cc in the second period P3. The spermatozoa viability of P2 and P3 showed values >88-89% significantly different (P<0.05) than P1 (<84%) in the second and third periods, while the best spermatozoa abnormalities were P2 at 4.30% in the second period and P3 at 5.33% in the third period. It was concluded that the giving of MO leaf powder at a dose of 0,1 kg/head/day could improve the quantity and quality of semen (viability and total motile spermatozoa) of Ongole Crossbreed bulls. Keywords: bulls, Moringa oleifera, quantity and quality of semen


2012 ◽  
Vol 9 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Gina G Mentzer ◽  
Alex J Auseon

Heart failure (HF) affects more than 5 million people and has an increasing incidence and cost burden. Patients note symptoms of dyspnea and fatigue that result in a decreased quality of life, which has not drastically improved over the past decades despite advances in therapies. The assessment of exercise capacity can provide information regarding patient diagnosis and prognosis, while doubling as a potential future therapy. clinically, there is acceptance that exercise is safe in hf and can have a positive impact on morbidity and quality of life, although evidence for improvement in mortality is still lacking. specific prescriptions for exercise training have not been developed because many variables and confounding factors have prevented research trials from demonstrating an ideal regimen. Physicians are becoming more aware of the indices and goals for hf patients in exercise testing and therapy to provide comprehensive cardiac care. it is further postulated that a combination of exercise training and pharmacologic therapy may eventually provide the most benefits to those suffering from hf.


2018 ◽  
Vol 1 (2) ◽  
pp. 1
Author(s):  
Andi Asadul Islam

Neurosurgery is among the newest of surgical disciplines, appearing in its modern incarnation at the dawn of twentieth century with the work of Harvey Cushing and contemporaries. Neurosurgical ethics involves challenges of manipulating anatomical locus of human identity and concerns of surgeons and patients who find themselves bound together in that venture.In recent years, neurosurgery ethics has taken on greater relevance as changes in society and technology have brought novel questions into sharp focus. Change of expanded armamentarium of techniques for interfacing with the human brain and spine— demand that we use philosophical reasoning to assess merits of technical innovations.Bioethics can be defined as systematic study of moral challenges in medicine, including moral vision, decisions, conduct, and policies related to medicine. Every surgeon should still take the Hippocratic Oath seriously and consider it a basic guide to follow good medical ethics in medical practice. It is simple and embodies three of the four modern bioethics principles – Respecting autonomy, beneficence, nonmaleficence, and justice.Spinal cord injury (SCI) is a devastating condition often affecting young and healthy individuals around the world. Currently, scientists are pressured on many fronts to develop an all-encompassing “cure” for paralysis. While scientific understanding of central nervous system (CNS) regeneration has advanced greatly in the past years, there are still many unknowns with regard to inducing successful regeneration. A more realistic approach is required if we are interested in improving the quality of life of a large proportion of the paralyzed population in a more expedient time frame.


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