• Title, Summary, Keyword: {\alpha}-entropy$

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NEW CLASSIFICATION TECHNIQUES FOR POLARIMETRIC SAR IMAGES AND ASSOCIATED THREE-COMPONENT DECOMPOSITION TECHNIQUE

  • Oh, Yi-Sok;Chang, Geba;Lee, Kyung-Yup
    • Proceedings of the KSRS Conference
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    • pp.29-32
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    • 2008
  • In this paper, we propose one unsupervised classification technique using the degree of polarization (DoP) and the co-polarized phase-difference (CPD) statistics, instead of the entropy and alpha. It is shown that the DoP is closely related to the entropy, and the CPD to the alpha. The DoP explains the feature how much the effect of multiple reflections is contained. Hence, the DoP could be used as an important factor for classifying classes. The CPD can also be computed from the measured Mueller matrix elements. For the smooth surface scattering, the CPD is about $0^{\circ}$, and for dihedral-type scattering, the CPD is about $180^{\circ}$. A DoP-CPD diagram with appropriate boundaries between six different classes is developed based on the SAR image. The classification results are compared with the existing Entropy-alpha diagram as well as the IPL-AirSAR polarimetric data. The technique may have capability to classify an SAR image into six major classes; a bare surface, a village, a crown-layer short vegetation canopy, a trunk-layer short vegetation canopy, a crown-layer forest, and a trunk-dominated forest. Based on the DoP and CPD analysis, a simple three-component decomposition technique was also proposed.

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Entropy Generation Minimization in MHD Boundary Layer Flow over a Slendering Stretching Sheet in the Presence of Frictional and Joule Heating

  • Afridi, Muhammad Idrees;Qasim, Muhammad;Khan, Ilyas
    • Journal of the Korean Physical Society
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    • v.73 no.9
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    • pp.1303-1309
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    • 2018
  • In the present paper, we study the entropy analysis of boundary layer flow over a slender stretching sheet under the action of a non uniform magnetic field that is acting perpendicular to the flow direction. The effects of viscous dissipation and Joule heating are included in the energy equation. Using similarity transformation technique the momentum and thermal boundary layer equations to a system of nonlinear differential equations. Numerical solutions are obtained using the shooting and fourth-order Runge-Kutta method. The expressions for the entropy generation number and Bejan number are also obtained using a suggested similarity transformation. The main objective of this article is to investigate the effects of different governing parameters such as the magnetic parameter ($M^2$), Prandtl number (Pr), Eckert number (Ec), velocity index parameter (m), wall thickness parameter (${\alpha}$), temperature difference parameter (${\Omega}$), entropy generation number (Ns) and Bejan number (Be). All these effects are portrayed graphically and discussed in detail. The analysis reveals that entropy generation reduces with decreasing wall thickness parameter and increasing temperature difference between the stretching sheet and the fluid outside the boundary layer. The viscous and magnetic irreversibilities are dominant in the vicinity of the stretching surface.

INTERGALACTIC MEDIUM IN THE ACDM UNIVERSE FROM COSMOLOGICAL SIMULATIONS

  • FENG LONG-LONG;HE PING;FANG LIZHI;SHU CHI-WANG;ZHANG MENG-PING
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.129-133
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    • 2005
  • The temperature (T) and entropy (S) fields of baryonic gas, or intergalactic medium (IGM), in the ACDM cosmology are analyzed using simulation samples produced by a hybrid cosmological hydrodynamic/N-body code based on the weighted essentially non-oscillatory scheme. We demonstrate that, in the nonlinear regime, the dynamical similarity between the IGM and dark matter will be broken in the presence of strong shocks in the IGM. The heating and entropy production by the shocks breaks the IGM into multiple phases. The multiphase and non-Gaussianity of the IGM field would be helpful to account for the high-temperature and high-entropy gas observed in groups and clusters with low-temperature IGM observed by Ly$\alpha$ forest lines and the intermittency observed by the spikes of quasi-stellar object's absorption spectrum.

A NOTE ON THE RETURN TIME OF STURMIAN SEQUENCES

  • Kim, Dong Han
    • Korean Journal of Mathematics
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    • v.16 no.3
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    • pp.301-307
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    • 2008
  • Let $R_n$ be the the first return time to its initial n-word. Then the Ornstein-Weiss first return time theorem implies that log$R_n$ divided by n converges to entropy. We consider the convergence of log$R_n$ for Sturmian sequences which has the lowest complexity. In this case, we normalize the logarithm of the first return time by log n. We show that for any numbers $1{\leq}{\alpha},\;{\beta}{\leq}{\infty}$, there is a Sturmian sequence of which limsup is ${\alpha}$ and liminf is $1/{\beta}$.

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SOME INEQUALITIES FOR THE $CSISZ{\acute{A}}R\;{\Phi}-DIVERGENCE$

  • Dragomir, S.S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.7 no.1
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    • pp.63-77
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    • 2003
  • Some inequalities for the $Csisz{\acute{a}}r\;{\Phi}-divergence$ and applications for the Kullback-Leibler, $R{\acute{e}}nyi$, Hellinger and Bhattacharyya distances in Information Theory are given.

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Effects of Emulsifier on the Thermal Behaviour in Palm Oil (유화제의 첨가가 팜유의 열 특성에 미치는 영향)

  • Chang, Young-Sang;Yi, Young-Soo;Kang, Woo-Suk;Shin, Zae-Ik
    • Korean Journal of Food Science and Technology
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    • v.21 no.6
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    • pp.857-862
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    • 1989
  • Palm oil was crystallized and melted in the differential scanning calorimeter (DSC) in the presence and the absence of sucrose fatty acid ester (SE) at the different scanning rate. In the presence of SE, the crystallization temperature of palm oil was lowered, because SE inhibited the formation of mother crystal at the initial cooling stage The melting curves of SE added palm oil changed irregularly in the ${\alpha}-form$ transition and fusion entropy. It was that the presence of SE affected the molecular diffusion in palm oil.

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The Study on Volumetric Transition Polymer Gel (체적상전이고분자 겔에 관한 연구)

  • 김정곤
    • Journal of the Korean Printing Society
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    • v.14 no.1
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    • pp.47-54
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    • 1996
  • Deuterium NMR studies have been carried out for two kinds of main- chain dimer liquid crystals $\alpha$.$\omega$-bis[(4,4`-cyanobipheny0oxy] alkane (CBA-n, n=9,100.The H-NMR spectra were recorded on a JEOP JNM-GSX-500 spectrometer by using deuterium labelled CBA-n at various temperatures. The RIS analysis of the NMR spectra was performed so as to elucidate the conformational characteristics of the spacer in the nematic phase. Following the previous treatment, the single-ordering-matrix model was adopted, in which the molecular axis was defined parallel to the line connecting the centers of the terminal mesogenic cores. Conformer fractions of the spacer were estimated by simulation so as to reproduce the observed NMR profile. The conformational entropy changes at both CN and NI interphases were estimated on the basis of the nematic conformations taken from the conformation map as well as those derived from the simulation. In these calculations the spacer was assumed th by in the all-trans conformation and in the random coil stats in the crystal and isotropic phases respectively. The esimated conformational entropy change values were then compared with the corresponding constant-volume entropies obtained from PVT measurements. The correspondence between both entropy values was found to be quite good in consideration of the uncertainties involved in both experiment and calculations.

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Characterization of New Two Parametric Generalized Useful Information Measure

  • Bhat, Ashiq Hussain;Baig, M. A. K.
    • Journal of Information Science Theory and Practice
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    • v.4 no.4
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    • pp.64-74
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    • 2016
  • In this paper we define a two parametric new generalized useful average code-word length $L_{\alpha}^{\beta}$(P;U) and its relationship with two parametric new generalized useful information measure $H_{\alpha}^{\beta}$(P;U) has been discussed. The lower and upper bound of $L_{\alpha}^{\beta}$(P;U), in terms of $H_{\alpha}^{\beta}$(P;U) are derived for a discrete noiseless channel. The measures defined in this communication are not only new but some well known measures are the particular cases of our proposed measures that already exist in the literature of useful information theory. The noiseless coding theorems for discrete channel proved in this paper are verified by considering Huffman and Shannon-Fano coding schemes on taking empirical data. Also we study the monotonic behavior of $H_{\alpha}^{\beta}$(P;U) with respect to parameters ${\alpha}$ and ${\beta}$. The important properties of $H_{{\alpha}}^{{\beta}}$(P;U) have also been studied.

Polarimetric Scattering of Sea Ice and Snow Using L-band Quad-polarized PALSAR Data in Kongsfjorden, Svalbard (북극 스발바드 콩스피오르덴 해역에서 L 밴드 PALSAR 데이터를 이용한 눈과 부빙에 의한 다중편파 산란특성 해석)

  • Jung, Jung-Soo;Yang, Chan-Su;Ouchi, Kazuo;Nakamura, Kuzaki
    • Ocean and Polar Research
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    • v.33 no.1
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    • pp.1-11
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    • 2011
  • This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

Detection of Icebergs Using Full-Polarimetric RADARSAT-2 SAR Data in West Antarctica (고해상도 다중편파 RADARSAT-2 SAR자료를 이용한 서남극해의 빙산 탐지)

  • Kim, Jin-Woo;Kim, Duk-jin;Kim, Seung-Hee;Hwang, Byong-Jun;Yackel, John
    • Korean Journal of Remote Sensing
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    • v.28 no.1
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    • pp.21-28
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    • 2012
  • In this study, detection of icebergs that have various scattering characteristics around Wilkinson glacier in West Antarctica is investigated using C-band fully-polarimetric RADARSAT-2 SAR data. Various polarimetric analyses including Freeman-Durden decomposition, H/A/$\bar{\alpha}$ decomposition, entropy (H) and anisotropy (A) method, and Wishart unsupervised classification, were applied for the RADARSAT-2 data used in this study. The polarimetric decomposition methods were successfully classified most of the iceberg, yet some iceberg with similar intensity of volume and surface scattering as sea ice were indistinguishable. Unsupervised classification with a combination of the polarimetric parameter, [1-H][1-A], gave a possibility to distinguish those unclassified iceberg.