89 research outputs found
Improvement of PolSAR Decomposition Scattering Powers Using a Relative Decorrelation Measure
In this letter, a methodology is proposed to improve the scattering powers
obtained from model-based decomposition using Polarimetric Synthetic Aperture
Radar (PolSAR) data. The novelty of this approach lies in utilizing the
intrinsic information in the off-diagonal elements of the 33 coherency
matrix represented in the form of complex correlation
coefficients. Two complex correlation coefficients are computed between
co-polarization and cross-polarization components of the Pauli scattering
vector. The difference between modulus of complex correlation coefficients
corresponding to (i.e. the degree of polarization
(DOP) optimized coherency matrix), and (original) matrices is
obtained. Then a suitable scaling is performed using fractions \emph{i.e.,}
obtained
from the diagonal elements of the matrix.
Thereafter, these new quantities are used in modifying the Yamaguchi
4-component scattering powers obtained from . To
corroborate the fact that these quantities have physical relevance, a
quantitative analysis of these for the L-band AIRSAR San Francisco and the
L-band Kyoto images is illustrated. Finally, the scattering powers obtained
from the proposed methodology are compared with the corresponding powers
obtained from the Yamaguchi \emph{et. al.,} 4-component (Y4O) decomposition and
the Yamaguchi \emph{et. al.,} 4-component Rotated (Y4R) decomposition for the
same data sets. The proportion of negative power pixels is also computed. The
results show an improvement on all these attributes by using the proposed
methodology.Comment: Accepted for publication in Remote Sensing Letter
State level attribute compliance measure based efficient access restriction improved security in cloud environment
In this paper, Advanced Encryption Standard was modified to address the low diffusion rate at the early rounds by adding additional primitive operations such as exclusive OR and modulo arithmetic in the cipher round. Furthermore, byte substitution and round constant addition were appended to the key schedule algorithm. The modified AES was tested against the standard AES by means of avalanche effect and frequency test to measure the diffusion and confusion characteristics respectively. The results of the avalanche effect evaluation show that there was an average increase in diffusion of 61.98% in round 1, 14.79% in round 2 and 13.87% in round 3. Consequently, the results of the frequency test demonstrated an improvement in the randomness of the ciphertext since the average difference between the number of ones to zeros is reduced from 11.6 to 6.4 along with better-computed p-values. The results clearly show that the modified AES has improved diffusion and confusion properties and the ciphertext can still be successfully decrypted and recover back the original plaintext
High secure buffer based physical unclonable functions (PUF’s) for device authentication
Physical Unclonable Function (PUF) is fast growing technology which utilizes the statistical variability of the manufacture variations acts as a finger print to the each device. It can be widely used in security applications such as device authentication, key generation and Intellectual Property (IP) protection. Due to the simplicity and low cost arbiter delay based PUFs have been mostly used as a cryptographic key in Internet of Things (IoT) devices. As conventional arbiter PUFs are suffers from less uniqueness and reliability. This paper provides designing of new buffer based arbiter PUF. It has been demonstrated that experimental results of new buffer based arbiter PUF shows the considerable improvement in the uniqueness and reliability of the proposed design and the Monte-Carlo analysis applied for delay variability of the PUFs
Effect of thermal cycle loadings on mechanical properties and thermal conductivity of a porous lead-free solder joint
© 2011-2012 IEEE. This paper demonstrates to what extent the number of thermal cycles affects the mechanical properties as well as the thermal conductivity of a porous solder joint in an insulated-gate bipolar transistor discrete. The blind mode voids were used for a finite-element method (FEM) simulation to obtain the results close to the actual conditions. The FEM results indicate that the concentration of creep strain at the interface of the solder/chip is in its maximum value, and it slightly decreases along with the depth of the solder layer. FEM also reveals that the boundaries of voids act as critical regions for strain concentration. An upward in the number of thermal cycles also leads to the void growth and coalescence process. The enhancement of void volume from 0 to 15 cycles is about 4% volume of the solder layer. Moreover, scanning electron microscope micrographs approve the FEM results and show the void growth and the damage accumulation during thermal cycling. The thermal analyses indicate that the increase in thermal cycles (creep strain) leads to a significant rise in thermal impedance. This event can be due to the increase in the void volume of the solder layer leading to the decrease in the effective area of heat path
Effects of Cr microalloying on structural evolution, crystallization behavior and micromechanical properties of ZrCoAlCr bulk metallic glass
This paper deals with the role of minor addition of Cr on the atomic rearrangement and crystallization evolution in a Zr-based bulk metallic glass. For this purpose, Cr elements with 1-4% atomic percentage were added into the alloying composition. The X-ray diffraction results indicated that the trace element led to the increase in disordered structures in the glassy alloy and the decline in population of short and medium scale order
Effects of primary stored energy on relaxation behavior of high entropy bulk metallic glasses under compressive elastostatic loading
This paper aims to show the effects of primary stored energy in high entropy bulk metallic glasses (HE-BMGs) on their relaxation behavior after elastostatic loading process. For this purpose, three HE-BMGs with different chemical compositions and primary stored energy were fabricate
Breeding banana (Musa spp.) for drought tolerance: A review
Drought is a major abiotic stress affecting banana production worldwide, leading to yield losses of up to 65%. Consequently, numerous efforts to understand and mitigate drought effects that include developing tolerant crop varieties are ongoing in several banana breeding programmes. The breeding efforts, however, have been greatly slowed down by inherent banana problems (polyploidy and male or female sterility) and complexity of drought tolerance (reportedly controlled by several genes). This review summarizes the pertinent research findings on water requirements of banana for its proper growth and productivity, symptoms of drought‐sensitive varieties and field management strategies to cope with drought stress. The coping strategies deployed by resistant cultivars include high assimilation rates and water retention capacity as well as minor losses in leaf area and gaseous exchange. Reduced bunch weight, leaf chlorosis, wilting and strangled birth are underlined to be directly associated with drought susceptibility. Integration of conventional, molecular breeding and biotechnological tools as well as exploitation of the existing banana genetic diversity presents a huge opportunity for successful banana improvement
Decreased Prevalence of Lymphatic Filariasis among Diabetic Subjects Associated with a Diminished Pro-Inflammatory Cytokine Response (CURES 83)
Epidemiological studies have shown an inverse correlation between the incidence of lymphatic filariasis (LF) and the incidence of allergies and autoimmunity. However, the interrelationship between LF and type-2 diabetes is not known and hence, a cross sectional study to assess the baseline prevalence and the correlates of sero-positivity of LF among diabetic subjects was carried out (n = 1416) as part of the CURES study. There was a significant decrease in the prevalence of LF among diabetic subjects (both newly diagnosed [5.7%] and those under treatment [4.3%]) compared to pre-diabetic subjects [9.1%] (p = 0.0095) and non-diabetic subjects [10.4%] (p = 0.0463). A significant decrease in filarial antigen load (p = 0.04) was also seen among diabetic subjects. Serum cytokine levels of the pro-inflammatory cytokines—IL-6 and GM-CSF—were significantly lower in diabetic subjects who were LF positive, compared to those who were LF negative. There were, however, no significant differences in the levels of anti-inflammatory cytokines—IL-10, IL-13 and TGF-β—between the two groups. Although a direct causal link has yet to be shown, there appears to be a striking inverse relationship between the prevalence of LF and diabetes, which is reflected by a diminished pro-inflammatory cytokine response in Asian Indians with diabetes and concomitant LF
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