M-Channel compactly supported biorthogonal cosine-modulated wavelet bases

In this correspondence, we generalize the theory of compactly supported biorthogonal two-channel wavelet bases to M -channel. A sufficient condition for the M-channel perfect reconstruction filter banks to construct M-channel biorthogonal bases of compactly supported wavelets is derived. It is shown that the construction of biorthogonal Af-channel wavelet bases is equivalent to the design of a Af-channel perfect reconstruction filter bank with some added regularity conditions. A family of M-channel biorthogonal wavelet bases based on the cosinemodulated filter bank (CMFB) is proposed. It has the advantages of simple design procedure, efficient implementation, and good filter quality. A new method for imposing the regularity on the CMFB's is also introduced, and several design examples are given. ©1998 IEEE.published_or_final_versio

M-channel cosine-modulated wavelet bases

The 13th International Conference on Digital Signal Processing, Santorini, Greece, 2-4 July 1997In this paper, we propose a new M-channel wavelet bases called the cosine-modulated wavelets. We first generalize the theory of two-channel biorthogonal compactly supported wavelet bases to the M-channel case. A sufficient condition for the M-channel perfect reconstruction filter banks to construct M-channel compactly supported wavelet bases is given. By using this condition, a family of orthogonal and biorthogonal M-channel cosine-modulated wavelet bases is constructed by iterations of cosine-modulated filter banks (CMFB). The advantages of the approach are their simple design procedure, efficient implementation and good filter quality. A method for imposing the regularity on the cosine-modulated filter banks is also introduced and design example is given.published_or_final_versio

Theory and design of arbitrary-length biorthogonal cosine-modulated filter banks

IEEE International Symposium on Circuits and Systems, Hong Kong, China, 9-12 June 1997The design and generalization of Perfect-reconstruction (PR) cosine-modulated filter banks (CMFB) have been studied extensively due to its low design and implementation complexity. In this paper, the theory and design of arbitrary-length biorthogonal CMFB is considered. This is a generalization of the method used in [5] for designing arbitrary length orthogonal CMFB and has the advantage of simple design procedure. We also propose a systematic design method so that biorthogonal CMFB with longer length can be obtained.published_or_final_versio

Ultrafine particle transport and deposition in the upper airways of a CT-based realistic lung

© 2018 Australasian Fluid Mechanics Society. All rights reserved. The understanding of the toxic pollutant particles transport and deposition is important for dosimetry and respiratory health effects analysis. The studies over the last few decades for ultrafine particle transport and deposition improves the understanding of the drug-aerosol impacts in the extrathoracic airways. A limited number of studies has also considered upper airways and almost all of those studies used the non-realistic smooth surface for upper airway model. However, the smooth surface anatomical model is far from the realistic lung and it is important to consider realistic lung model for better prediction of ultrafine particle deposition. This study aims to simulate the ultrafine particle transport and deposition in the upper airways of a highly asymmetric CT-based model. The anatomically explicit digital airway model is generated from the high-resolution CT data of a healthy adult. Unstructured tetrahedral mesh throughout the geometry and fine inflation layer mesh near the wall is generated. Euler-Lagrange (E-L) approach and ANSYS Fluent solver (18.2) are used to investigate the ultrafine particle transport and deposition. A wide range of diameter (1 ≤ nm ≤ 1000) and different flow rates are considered for the ultrafine particle simulation. Pressure drop is calculated for right and left lobes which might be helpful for the therapeutic purpose of the asthma patient. The numerical study shows that the deposition efficiency in the right lung and the left lung is different for dissimilar flow rates, which could help the health risk assessment of the respiratory diseases and eventually could help the targeted drug delivery system

Ultrafine particle transport and deposition in the upper airways of a CT-based realistic lung

© 2018 Australasian Fluid Mechanics Society. All rights reserved. The understanding of the toxic pollutant particles transport and deposition is important for dosimetry and respiratory health effects analysis. The studies over the last few decades for ultrafine particle transport and deposition improves the understanding of the drug-aerosol impacts in the extrathoracic airways. A limited number of studies has also considered upper airways and almost all of those studies used the non-realistic smooth surface for upper airway model. However, the smooth surface anatomical model is far from the realistic lung and it is important to consider realistic lung model for better prediction of ultrafine particle deposition. This study aims to simulate the ultrafine particle transport and deposition in the upper airways of a highly asymmetric CT-based model. The anatomically explicit digital airway model is generated from the high-resolution CT data of a healthy adult. Unstructured tetrahedral mesh throughout the geometry and fine inflation layer mesh near the wall is generated. Euler-Lagrange (E-L) approach and ANSYS Fluent solver (18.2) are used to investigate the ultrafine particle transport and deposition. A wide range of diameter (1 ≤ nm ≤ 1000) and different flow rates are considered for the ultrafine particle simulation. Pressure drop is calculated for right and left lobes which might be helpful for the therapeutic purpose of the asthma patient. The numerical study shows that the deposition efficiency in the right lung and the left lung is different for dissimilar flow rates, which could help the health risk assessment of the respiratory diseases and eventually could help the targeted drug delivery system

Approximation Strategies for Incomplete MaxSAT

Incomplete MaxSAT solving aims to quickly find a solution that attempts to minimize the sum of the weights of the unsati sfied soft clauses without providing any optimality guarantees. In th is paper, we propose two approximation strategies for improving incomp lete MaxSAT solving. In one of the strategies, we cluster the weights and approximate them with a representative weight. In another strategy, we b reak up the problem of minimizing the sum of weights of unsatisfiable clauses into multiple minimization subproblems. Experimental res ults show that approximation strategies can be used to find better solution s than the best incomplete solvers in the MaxSAT Evaluation 2017

Environmental Modeling and Exposure Assessment of Sediment-Associated Pyrethroids in an Agricultural Watershed

Synthetic pyrethroid insecticides have generated public concerns due to their increasing use and potential effects on aquatic ecosystems. A modeling system was developed in this study for simulating the transport processes and associated sediment toxicity of pyrethroids at coupled field/watershed scales. The model was tested in the Orestimba Creek watershed, an agriculturally intensive area in California' Central Valley. Model predictions were satisfactory when compared with measured suspended solid concentration (R2 = 0.536), pyrethroid toxic unit (0.576), and cumulative mortality of Hyalella azteca (0.570). The results indicated that sediment toxicity in the study area was strongly related to the concentration of pyrethroids in bed sediment. Bifenthrin was identified as the dominant contributor to the sediment toxicity in recent years, accounting for 50–85% of predicted toxicity units. In addition, more than 90% of the variation on the annual maximum toxic unit of pyrethroids was attributed to precipitation and prior application of bifenthrin in the late irrigation season. As one of the first studies simulating the dynamics and spatial variability of pyrethroids in fields and instreams, the modeling results provided useful information on new policies to be considered with respect to pyrethroid regulation. This study suggested two potential measures to efficiently reduce sediment toxicity by pyrethroids in the study area: [1] limiting bifenthrin use immediately before rainfall season; and [2] implementing conservation practices to retain soil on cropland

Dietary melatonin attenuates age-related changes in morphology and in levels of key proteins in globus pallidus of mouse brain.

The ability of melatonin treatment of aged animals to partially restore the pattern of gene expression characterizing the younger animal has been frequently reported. The current study examines the effect of melatonin upon age-related changes of some key proteins relevant to the aging process. Male B6C3F1 mice, aged 5.5 months and 23.4 months were used as a model for aging and half of each group received a diet supplemented with 40-ppm (w/w) melatonin for 9.3 weeks. Protein components of the globus pallidus were studied including glial fibrillary acidic protein (GFAP), NF-κB, protein disulfide isomerase (PDI), and Nissl staining. Some age-related changes were in an upward direction (GFAP and NF-κB), while others were depressed with age (PDI and intensity of Nissl staining). However, in either case, melatonin treatment of aged mice generally altered these parameters so that they came to more closely resemble the levels found in younger animals. The extent of this reversal to a more youthful profile, ranged from complete (for NF-κB) to very minor (for Nissl staining and PDI). Overall, these findings are in accord with prior data on the effect of melatonin on cortical gene expression and confirm the value of melatonin as a means of retarding events associated with senescence

Use-Exposure Relationships of Pesticides for Aquatic Risk Assessment

Field-scale environmental models have been widely used in aquatic exposure assessments of pesticides. Those models usually require a large set of input parameters and separate simulations for each pesticide in evaluation. In this study, a simple use-exposure relationship is developed based on regression analysis of stochastic simulation results generated from the Pesticide Root-Zone Model (PRZM). The developed mathematical relationship estimates edge-of-field peak concentrations of pesticides from aerobic soil metabolism half-life (AERO), organic carbon-normalized soil sorption coefficient (KOC), and application rate (RATE). In a case study of California crop scenarios, the relationships explained 90–95% of the variances in the peak concentrations of dissolved pesticides as predicted by PRZM simulations for a 30-year period. KOC was identified as the governing parameter in determining the relative magnitudes of pesticide exposures in a given crop scenario. The results of model application also indicated that the effects of chemical fate processes such as partitioning and degradation on pesticide exposure were similar among crop scenarios, while the cross-scenario variations were mainly associated with the landscape characteristics, such as organic carbon contents and curve numbers. With a minimum set of input data, the use-exposure relationships proposed in this study could be used in screening procedures for potential water quality impacts from the off-site movement of pesticides