properties of the discrete time fourier transform
Các phương pháp xử lý tín hiệu dùng bộ lọc, phương pháp Fourier Transform, STFT( Short Time Fourier Transform)
Ngày tải lên :
01/04/2013, 16:14
... Trong miền tần số: phương pháp Fourier Transform.
- Trong miền thời gian và tần số: STFT( Short Time Fourier Transform) .
2.4.1. Phương pháp Fourier:
2.4.1.1. Biến đổi Fourier:
Cho một hàm f(t) ... được một biến đổi Fourier cục bộ, chúng ta có thể định nghĩa một biến đổi
Fourier cửa sổ. Tín hiệu đầu vào được nhân với một hàm cửa sổ
W
(t - τ) và sau đó lấy
biến đổi Fourier của nó. Kết ... đổi Fourier của nó được định nghĩa:
() () ()
tfedtetfF
titj
,
ωω
ω ==
∫
∞
∞−
−
(2.14)
Biến đổi Fourier ngược là:
() ()
∫
∞
∞−
= ωω
π
ω
deFtf
tj
2
1
(2.15)
Giả sử rằng biến đổi Fourier...
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Tài liệu Psychometric properties of the quality of life scale Child Health and Illness Profile-Child Edition in a combined analysis of five atomoxetine trials pdf
Ngày tải lên :
12/02/2014, 19:20
... changes over time
impossible.
The objectives of the present combined analysis were to
evaluate the psychometric properties of the CHIP-CE at
baseline and over time and to assess the correlation
between ... to
use the sub-domains rather than the domains of the CHIP-
CE when evaluating ADHD patients. This is supported by
the factor analysis based on the sub-domains and the
correlation analysis of the ... and the core symptoms. The influ-
ence of the QoL of the parents or the parents’ diseases
(such as ADHD) could not be assessed because these data
were not obtained.
Conclusions
The strength of...
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Tài liệu Báo cáo khoa học: Toggle switches, pulses and oscillations are intrinsic properties of the Src activation/deactivation cycle doc
Ngày tải lên :
18/02/2014, 11:20
... presenting the pulse of Src activity in the plane
of the inactive and active fractions, s
i
and s
1
. If the
duration of the stimulus exceeds the critical value, the
trajectory in the (s
i
, ... 2009 The Authors Journal compilation ê 2009 FEBS
parameters and, for clarity of exposition, we present
the analysis of the Src cycle in terms of Eqns (6–8).
Intrinsic regulatory properties of the ... steady states of the Src cycle. When there are three
intersections, the steady state O
1
at the lower branch of
the Z-shaped curve (i.e. low Src activity) and the state
O
3
at the upper branch...
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Tài liệu Báo cáo khoa học: Properties of the recombinant glucose⁄galactose dehydrogenase from the extreme thermoacidophile, Picrophilus torridus ppt
Ngày tải lên :
19/02/2014, 16:20
... cleft, the
putative catalytic zinc being at the bottom of the cleft
and a lobe containing the structural zinc at the mouth
of the cleft and thus exposed to the solvent [8]. Grad-
ual depletion of the ... However, the addition of ZnCl
2
to the incubation
buffers showed a marked effect on the stability of the
enzyme at both high temperature and acidity. This
effect was the same across the range of ZnCl
2
concen-
trations ... Novagen.
Expression of Pt-gdh under the control of araB promoter
was induced for 4 h at 30 °C by the addition of 0.2% ara-
binose when the A
600
of the growing culture reached 0.5.
The cells from...
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Tài liệu Báo cáo Y học: Electrochemical, FT-IR and UV/VIS spectroscopic properties of the caa3 oxidase from T. thermophilus docx
Ngày tải lên :
21/02/2014, 15:20
... to the different environ-
ment of the heme centers. The difference signals observed at
442 nm and 603 nm can be assigned to the contributions of
the hemes a and a
3
, with the position of the ... modes on the basis of the data
presented here, in spite of the fact that bands in the
difference spectra are observed in the region where the
modes were attributed.
The vibrational modes of bound ... particular problem of the assignment in the difference
spectra is the superposition of signals from different
constituents of the oxidase, which can lead to the possibility
of multi component...
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Tài liệu Báo cáo Y học: Short peptides are not reliable models of thermodynamic and kinetic properties of the N-terminal metal binding site in serum albumin doc
Ngày tải lên :
22/02/2014, 04:20
... solution by
the rest of the protein. There is no correlation between the
complex stability and the rate of its formation.
The Ni(II) for Cu(II) exchange rates f or peptides are o f
the order of 10
)6
s
)1
in ... albumins. On the other hand, the direct
thermodynamic and kinetic characterization of Ni(II)
binding at site I in HSA and BSA was obtained. These
data can be very useful in further studies of the toxicolo-
gically ... values of
*K, the equilibrium constant of the actual complex
formation reaction:
M ỵ H
n
L ẳ MH
j
L ỵnỵjịH
ỵ
This constant represents the overall ability of ligand L to
form a given complex.
The other...
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Tài liệu MECHANICAL PROPERTIES OF THE HEART AND ITS INTERACTION WITH THE VASCULAR SYSTEM ppt
Ngày tải lên :
22/02/2014, 09:20
... characterize the time course of change in ventricular mechanical properties by
plotting the time course of change in the slope of the instantaneous PVR. Above, we referred to
the slope of the ESPVR ... interaction between the ongoing contraction process of the
cardiac muscles and the properties of the arterial system and is beyond the scope of this lecture.
As the contraction process of the cardiac ... contraction there is a period of time during which the mechanical
properties of the heart are characterized by the EDPVR;
knowledge of the EDPVR allows one to specify, for the end of
diastole,...
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Báo cáo khoa học: Structure analysis of the flavoredoxin from Desulfovibrio vulgaris Miyazaki F reveals key residues that discriminate the functions and properties of the flavin reductase family pdf
Ngày tải lên :
07/03/2014, 02:20
... reverse-phase HPLC on a C
8
column,
and the retention time of the obtained prosthetic group
was compared with those of flavin derivatives. The
retention time of the prosthetic group bound to recom-
binant ... of the structure of NADP
+
-bound FeR
revealed that the nicotinamide moiety of NADP
+
faces the re-side of the isoalloxazine ring, and that the
2Â-P-AMP moiety is held in the groove between the ... direction along the b10 of the other mono-
mer, forming an anti-parallel intermolecular b sheet
(Fig. 2A). The subsequent residues of the loop (Ala7–
Pro13) turn into the interior of the dimer interface,
and...
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Báo cáo khoa học: Effect of oculopharyngeal muscular dystrophy-associated extension of seven alanines on the fibrillation properties of the N-terminal domain of PABPN1 pot
Ngày tải lên :
07/03/2014, 11:20
... alanines are likely. The
manner in which the number of alanines determines
the atomic structure of the fibril and the b-strand
arrangements remains to be determined.
Yet, knowledge of the structure and ... using the nanoscope analysis software.
Chemical stability of fibrils
The chemical stability of fibrils was tested after the fibrilla-
tion process was completed (no further rise of ANS sig-
nals). The ... consisting primar-
ily of PABPN1. Poly l-alanine-dependent fibril formation was studied using
the recombinant N-terminal domain of PABPN1. In the case of the protein
fragment with the expanded poly...
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Báo cáo khóa học: Structural properties of the protein SV-IV potx
Ngày tải lên :
07/03/2014, 14:20
... identified by the mass
increase of 42 mass units. The relative level of acetylation of
a peptide was estimated on the basis of the intensity ratio of
the native and acetylated species. From the data ... a-helix in the whole protein, and the 1–70
region is poorly structured.
SDS increases the a-helix content of proteins revealing
the helical potential. The a-helix content of the monomeric
form of SV-IV ... Lys80,
showed partial acetylation at one of the three residues,
because the signal of the triacetylated species was less
intense than that of the diacetylated species. The MS/MS
Fig. 2. Secondary-structure...
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Báo cáo khoa học: Spectroscopic and kinetic properties of the horseradish peroxidase mutant T171S Evidence for selective effects on the reduced state of the enzyme potx
Ngày tải lên :
07/03/2014, 21:20
... the ferrous state of the mutant may contribute to an
increase in the disorder and hence entropy of the
reduced state of the mutant compared to that of the
wild-type protein.
In contrast to the ... disposition of the
proximal His and Asp residues, affecting the imidazo-
late character of the His, but also by the formation of
a LS species. The latter indicating the probable bind-
ing of His42 to the ... impact
on the properties of His170. The strength of the hydro-
gen bond between the proximal His and Asp residues,
and thus the imidazolate character of the His is expec-
ted to modulate not only the...
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Báo cáo Y học: Properties of the Na+/H+ exchanger protein Detergent-resistant aggregation and membrane microdistribution potx
Ngày tải lên :
08/03/2014, 16:20
... [1,4]. The protein is known to exist as a dimer and
the NHE1 isoform specifically dimerizes to itself and not to
other isoforms of the Na
+
/H
+
exchanger [5].
Although the NHE1 isoform of the Na
+
/H
+
exchanger
is ... concentrations of the fractions, together with
the relative amount of Na
+
/H
+
exchanger present in the
supernatant and the pellet [19], it was found that over 80%
of the Na
+
/H
+
exchanger remained in the ... that could
either alter the distribution of the Na
+
/H
+
exchanger or the
constituency of the lipid rafts, we used an established
detergent-free lipid raft isolation procedure for some of our
studies...
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Báo cáo Y học: Electrostatic properties of the structure of the docking and dimerization domain of protein kinase A IIa doc
Ngày tải lên :
08/03/2014, 22:20
... the site of
interaction with AKAP proteins [5,6]. The symmetry axis of
the dimer is along the y-axis shown in the Figure. Figure 4B
shows the van der Waals model of the top face of the best
structure ... A further rotation of the orientation of RIIa
D/D of Fig. 4B by 180° about the x-axis shows the bottom
face of RIIa D/D (Fig. 4C). There is some hydrophobic
character in the bottom face of RIIa ... bar at the C-terminus of each
helix corresponds to the variable helical range within the ensemble of
the 24 structures. There is no variation at amino terminus of each helix.
The sequence of ionizable...
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Báo cáo khoa học: Biochemical properties of the human guanylate binding protein 5 and a tumor-specific truncated splice variant Mark Wehner and Christian Herrmann doc
Ngày tải lên :
15/03/2014, 10:20
... con-
served in the primary structure of the GTPase domain
of hGBP5, so the formation of GMP must be impaired
in an as yet unknown manner. Sequence alignments of
the large GTP-binding domains of hGBP1, ... for the lack of GMP formation
(see Fig. S2). The similar hydrolytic activities of the
a ⁄ b and C-terminally truncated forms of hGBP5 are in
contrast to that of the analogous deletion mutant of
hGBP1 ... account). The size of the protein complex is only
slightly increased when nucleotide-free or in the
presence of GTP. As with hGBP5ta, the complex is
increased to the size of a tetramer after binding of
GppNHp,...
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Báo cáo khóa học: Functional properties of the protein disulfide oxidoreductase from the archaeon Pyrococcus furiosus A member of a novel protein family related to protein disulfide-isomerase doc
Ngày tải lên :
16/03/2014, 16:20
... of the PDI [42], and t hat this site is far away from
the redox active sites in the sequ ence. Furthermore, the
measurements of the rates of PDI-catalysed refolding of
scrambled RNase A, in the ... (225 m
M
)9:1
(25 m
M
). At the end of the incubation, 40 lL of the mixture
was added to each of the five solutions; these were then left
to react on ice for 5 min. The reaction mixtures w ere
analysed ... of the active site in the
N-unit. As regards the oxidative activity, the two units also
display differences in their functional properties, with the
site at the C-termus always predominant, the...
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