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排序方式: 共有5185条查询结果,搜索用时 31 毫秒
61.
Badal Soni Saswati Debnath Pradip K. Das 《International Journal of Speech Technology》2016,19(3):525-536
An important task of speaker verification is to generate speaker specific models and match an input speaker’s utterance with these models. This paper focuses on comparing the performance of text dependent speaker verification system using Mel Frequency Cepstral Coefficients feature and different Vector Quantization (VQ) based speaker modelling techniques to generate the speaker specific models. Speaker-specific information is mainly represented by spectral features and using these features we have developed the model which serves as an important entity for determining the claimed identity of the speaker. In the modelling part, we used Linde, Buzo, Gray (LBG) VQ, proposed adaptive LBG VQ and Fuzzy C Means (FCM) VQ for generating speaker specific model. The experimental results that are performed on microphonic database shows that accuracy significantly depends on the size of the codebook in all VQ techniques, and on FCM VQ accuracy also depend on the value of learning parameter of the objective function. Experiment results shows that how the accuracy of speaker verification system is depend on different representations of the codebook, different size of codebook in VQ modelling techniques and learning parameter in FCM VQ. 相似文献
62.
Ashwin S. Dhabale Rutuja Dive Mohan V. Aware Shantanu Das 《Asian journal of control》2015,17(6):2143-2152
In this paper a new algorithm is presented to calculate the poles and zeros to approximate a fractional order (FO) differintegral (s±α,α∈(0,1)) by a rational function on a finite frequency band ω∈(ωl,ωh). The constant phase property of the FO differintegral is the basis for development of the algorithm. Interlacing of real poles and zeros is used to achieve the constant phase. The calculations are done using the asymptotic Bode phase plot. A brief investigation is made to get a good approximation for the Bode phase plot. Two design parameters are introduced to keep the average phase close to the desired phase angle and to keep the error within the allowed bounds. A study is done to empirically understand the relationship between the error and the design parameters. The results thus obtained help in the further calculations. The algorithm is computationally simple and inexpensive, and gives a fairly good approximation of fractance frequency response on the specified frequency band. 相似文献
63.
Optimizing Safe Yield Policy Implementation 总被引:1,自引:1,他引:0
The presented method enhances groundwater-mandated safe yield management. It is useful for settings that prevent sustained
yield or integrated management. To protect hydraulically connected surface water rights, the Utah government’s Cache Valley
groundwater management plan proposes that total pumping increase not exceed 84,431 m3/day. To determine how best to spatially distribute additional allowable pumping, stakeholders quantified limits defining
acceptable impacts on selected water resource indicators. A new simulation–optimization (S–O) algorithm used these limits
while computing optimal spatially distributed perennial yield or safe yield groundwater pumping extraction strategies. The
limits prevent unacceptable decreases in: head and net flow between aquifer and surface waters (rivers, surface/subsurface
drains, springs, lakes). The optimization objective function maximizes weighted pumping to provide water for 18 growing municipalities.
For 16 perennial yield scenarios, computed optimal pumping increases differ in protectiveness toward senior water rights,
and range from 16% to 103% of the state plan-proposed increase. Implementing a protective strategy would achieve 90% of the
storage changes needed to reach equilibrium within 23 years. Indicator potentiometric heads would reach equilibrium within
10–40 years. At equilibrium, an optimal Cache Valley perennial yield strategy acceptably minimizes net annual non-pumping
discharges. By comparison, multi-period 20-year transient groundwater mining optimizations allow more pumping in early years.
Pumping then must decline to satisfy seepage and head constraints through year 20. Adverse seepage impact would increase for
years thereafter. For situations governed by safe or perennial yield policy, equilibrium-based (steady-state) optimization
is very useful. It effectively develops optimal perennial yield strategies. 相似文献
64.
Probir Saha Debashis Tarafdar Surjya K. Pal Partha Saha Ashok K. Srivastava Karabi Das 《Applied Soft Computing》2013,13(4):2065-2074
This paper proposed a Neuro-Genetic technique to optimize the multi-response of wire electro-discharge machining (WEDM) process. The technique was developed through hybridization of a radial basis function network (RBFN) and non-dominated sorting genetic algorithm (NSGA-II). The machining was done on 5 vol% titanium carbide (TiC) reinforced austenitic manganese steel metal matrix composite (MMC). The proposed Neuro-Genetic technique was found to be potential in finding several optimal input machining conditions which can satisfy wide requirements of a process engineer and help in efficient utilization of WEDM in industry. 相似文献
65.
66.
Critical Density for Coverage and Connectivity in Three-Dimensional Wireless Sensor Networks Using Continuum Percolation 总被引:3,自引:0,他引:3
Although most of the studies on coverage and connectivity in wireless sensor networks (WSNs) considered two-dimensional (2D) settings, such networks can in reality be accurately modeled in a three-dimensional (3D) space. The concepts of continuum percolation theory best fit the problem of connectivity in WSNs to find out whether the network provides long-distance multihop communication. In this paper, we focus on percolation in coverage and connectivity in 3D WSNs. We say that the network exhibits a coverage percolation (respectively, connectivity percolation) when a giant covered region (respectively, giant connected component) almost surely spans the entire network for the first time. Because of the dependency between coverage and connectivity, the problem is not only a continuum percolation problem but also an integrated continuum percolation problem. Thus, we propose an integrated-concentric-sphere model to address coverage and connectivity in 3D WSNs in an integrated way. First, we compute the critical density lambdaC con above which coverage percolation in 3D WSNs will almost surely occur. Second, we compute the critical density lambdac con above which connectivity percolation in 3D WSNs will almost surely occur. Third, we compute the critical density lambdac cov-con above which both coverage and connectivity percolation in 3D WSNs will almost surely occur. For each of these three problems, we also compute their corresponding critical network degree. Our results can be helpful in the design of energy-efficient topology control protocols for 3D WSNs in terms of coverage and connectivity. 相似文献
67.
Regression models for six muscles, the left and right iliocostalis, the left and right erector spinae, and the left and right external oblique, were developed for asymmetry and height effects for floor and knuckle lifts. The models were based on participant anthropometric and other measures. Stepwise regression was performed for developing the prediction models. The models developed were discrete in terms of specific height and asymmetry. © 2009 Wiley Periodicals, Inc. 相似文献
68.
KP Dingemans MA van den Bergh Weerman RF Keep PK Das 《Canadian Metallurgical Quarterly》1994,57(3):433-439
We have previously reported that an invasive morphotype can be evoked in a rat colon carcinoma by transplanting it into pre-induced subcutaneous granulation tissue. We have now studied the interaction of the same tumor with liver tissue, which is extremely poor in connective tissue in comparison with the subcutaneous site. Tumor cells were injected into the portal system and the resulting experimental liver metastases were examined by electron microscopy and immunohistochemistry. Early metastases consisted of well-differentiated acini, fully surrounded by connective tissue that was derived from the periportal stroma. In a later stage, this connective tissue was overgrown by tumor cells and, almost immediately, acinar differentiation was lost. Most metastases eventually reached the liver capsule, which reacted by forming a layer of granulation tissue. Only in this layer, we observed invasion by thin tumor cell strands, which were often intimately associated with fibroblasts or with blood capillaries. The tumor cells remained smooth and rounded during this process. After fully penetrating the granulation tissue, the tumor cell strands reached the liver surface, where they formed poorly structured papillary masses that were nearly devoid of stroma. Our observations indicate that, even in a relatively homogeneous organ like the liver, the tumor-host interaction is highly complex and dynamic. They also confirm the notion that granulation tissue stimulates tumor invasiveness. Finally, they show that tumor cells can actively invade host tissues without exhibiting a "fibroblastic" morphology. 相似文献
69.
For studying flow problems involved with complex physics it is now common to use numerical field methods for solving Navier-Stokes or Euler equations. However, for a large class of fluid mechanics problems, which can be dealt with linearized potential equations, the boundary element method proves to be quite useful, especially for its easy application and relatively less computational effort compared to the field methods. The boundary element method has undergone some significant advancements in the last decade with respect to the study of steady and unsteady flow problems concerning wing aerodynamics in compressible medium, flow fields of propellers and rotors and acoustical disturbance propagation from moving bodies. In this paper a few recent contributions which evolved in the DLR as research projects and as doctoral and diploma thesis of the Technical University Braunschweig are concisely described.List of symbols
a
Sound velocity
-
b
Span of a wing
-
c
p
Coefficient of static pressure
-
c
dp
Coefficient of profile drag
-
c
1, c
d, cm
Coefficient of lift, drag and moment per unit span width
-
c
L, cD, cM
Total lift, drag and moment-coefficients
-
c
T, cP
Thrust and power-coefficient of a propeller
-
d
Distance
- D
Doublet strength
-
e
Specific heat energy
-
E
Total energy in a moving medium element
-
f
Frequency
-
F
Field point
-
g
Gravitational acceleration
-
h
Radial distance in cylinder coordinates
-
I
1, I
2
Inducing functions
-
i, j, k
Unit vectors in cartesian coordinates
-
k
Wave number [/a
]
-
l
Local wing-chord
-
l
0, l
v
Length of singularity element at t
oand t
v
-
m
Notation for Fourier-component
-
M, M
*
Mach number based on local and critical sound speed
-
n
Number of rotation per second
- n
Unit normal vector to a surface 相似文献
70.
The present work has been carried out to develop a performance evaluation framework of distribution network design in public health with specific reference to essential medicines based on six different types of public health distribution networks (PHDNs) prevalent across six Indian states. We evaluated the performance of PHDNs on the criteria of cost and service and also on the sub-criteria of cost and service by following the analytic hierarchy process. We utilized the pairwise comparison method in determining the relative importance of criteria and sub-criteria by seeking responses from several experts and subsequently evaluated the PHDNs on all sub-criteria in a 7-point Likert scale by seeking views from the same experts. Finally, we developed the “cost–service matrix,” in which cost and service have been depicted in the horizontal and vertical axes, respectively. We demonstrated the performance of six PHDNs in this matrix in terms of cost and service by plotting scores obtained by them on cost and service, respectively. The findings of the study provide rich insights to the policy planners of public health. 相似文献