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P packet Flooding Attack Network Bandwidth Denial of Service (DoS) Packet-Dropping AttackBog'liq gu2011 AQLLI SHAHAR, TEST, 1-мактаб тўгарак жадвал, BUYRUQ. YASIN BREND, TAQRIZ YANGI, 2, Tarjima SPLINES, DIFFERENTIAL EQUATIONS, AND OPTIMAL, (11-ozbetinshe K.U.A)Q.Zafar, APPLIKATSIYADA QIRQISHNI HAR HIL USULLARINI BAJARISH, EDUCATION SYSTEM OF UZBEKISTON, O’zbekistonning va jahon hamjamiyati, OCHILOVA NIGORANING, 7 yosh inqirozi uning sabablari va alomatlari, TEXNIKA MADANIYATI, AAACompetitive Code
Competitive code is an effective method for the extraction
and representation of palm line orientation information.
The D Gabor function is adopted for filtering the palm-
print images. Furthermore, since palm lines are negative,
only the negative real part of the D Gabor function shown
as follows:
ψ
(x, y, x
, y
, ω, θ, κ
)=
−ω
√
πκ
e
−
ω
κ
(x
′
+y
′
)
(cos(ωx
′
) − e
−
κ
),
()
is used, where x
′
= (x − x
) cos θ + (y − y
) sin θ, y
′
=
−(x − x
) sin θ + (y − y
) cos θ, (x
, y
) is the center of
the function, ω is the radial frequency in radians per unit
length and θ is the orientation of the Gabor functions in
radians. The κ is defined by κ
=
√
ln
(
δ
+
δ
−
), where δ is
the half-amplitude bandwidth of the frequency response.
When σ and δ are fixed, ω can be derived from ω
= κ/σ.
Let I
(x, y) denote the preprocessed image, ψ(x, y, θ) is the
filter with orientation θ, the competitive rule is defined as:
j
= arg min
θ
{I(x, y)∗ ψ(x, y, θ)} ,
()
where j is the winning index, and
∗ denotes the convolu-
tion operator. In the competitive coding scheme, six fil-
ters with orientations θ
p
= pπ/, p = {, , . . . , } are
selected for the competition. The procedure of the feature
extraction and representation is illustrated in
Fig.
.
After feature extraction, the distance of two palmprints
is measured by the summation of angular distance of all
sampling points. The winning index is represented by bits
to efficiently calculate this angular distance, as illustrated
in
Tables
and
. With this bitwise representation, the
angular distance of two competitive codes can be efficiently
computed with Boolean XOR operators.
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