Modifying the Yamaguchi Four-Component Decomposition Scattering Powers Using a Stochastic Distance

Model-based decompositions have gained considerable attention after the initial work of Freeman and Durden. This decomposition which assumes the target to be reflection symmetric was later relaxed in the Yamaguchi et al. decomposition with the addition of the helix parameter. Since then many decomposition have been proposed where either the scattering model was modified to fit the data or the coherency matrix representing the second order statistics of the full polarimetric data is rotated to fit the scattering model. In this paper we propose to modify the Yamaguchi four-component decomposition (Y4O) scattering powers using the concept of statistical information theory for matrices. In order to achieve this modification we propose a method to estimate the polarization orientation angle (OA) from full-polarimetric SAR images using the Hellinger distance. In this method, the OA is estimated by maximizing the Hellinger distance between the un-rotated and the rotated $T_{33}$ and the $T_{22}$ components of the coherency matrix $\mathbf{[T]}$. Then, the powers of the Yamaguchi four-component model-based decomposition (Y4O) are modified using the maximum relative stochastic distance between the $T_{33}$ and the $T_{22}$ components of the coherency matrix at the estimated OA. The results show that the overall double-bounce powers over rotated urban areas have significantly improved with the reduction of volume powers. The percentage of pixels with negative powers have also decreased from the Y4O decomposition. The proposed method is both qualitatively and quantitatively compared with the results obtained from the Y4O and the Y4R decompositions for a Radarsat-2 C-band San-Francisco dataset and an UAVSAR L-band Hayward dataset.Comment: Accepted for publication in IEEE J-STARS (IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

Comparison of selected startup ecosystems in Germany and in the USA Explorative analysis of the startup environments

The startup ecosystems in Germany and in the US aredifferent in several dimensions and they have a huge impact onthe success of startups. In this study the factors that affects thestartup ecosystems are compared. It is analyzed what startupsconsider as critical to their success and how this varies based onthe location of the startups. Using the developed scoringmechanism, the study compares the relative scores of varioussuccess factors between the German and American startups toidentify areas for improvement. The findings suggest thatGermany is successful in implementing co-working spaces andincubators but it lacks on accelerator programs. Further, it needsto develop a better support system for their startups while theGerman startups themselves need to focus on building a strongerinternal team in order to boost the startup ecosystem

Gabriel Trujillo Muñoz: Escritor, editor y estudioso de la ciencia ficción mexicana

This article provides a panoramic overview of Gabriel Trujillo Muñoz's most relevant works

Transdermal Delivery of Functional Collagen \u3cem\u3eVia\u3c/em\u3e Polyvinylpyrrolidone Microneedles

Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcine and human skin, and their effectiveness was examined using fluorescence microscopy. The results illustrate that this microneedle delivery system is effective in delivering collagen I into the epidermis and dermis of porcine and human skin. Since the technique presented in this paper is quick, safe, effective and easy, it can be considered as a new collagen delivery method for cosmetic and therapeutic applications

Quasi-one dimensional electrical conductivity and thermoelectric power studies on a discotic liquid crystal

We have studied the electrical conductivity of well aligned samples of hexahexylthiotriphenylene (HHTT) in the pure as well as doped states. The dopant used was a small concentration (0.62 mole %) of the electron acceptor trinitrofluorenone (TNF). In the columnar phases, doping causes the AC(1 kHz) conductivity along the columnar axis (σ ||) to increase by a factor of 107 or more relative to that in undoped samples; σ || attains a value of 10-2S/m, which was the maximum measurable limit of our experimental set up. On the other hand, in the isotropic phase doping makes hardly any difference to the conductivity. The frequency dependence of the conductivity has been investigated. The DC conductivity of doped samples exhibits an enormous anisotropy, σ ||/σ⊥ ≥ 1010, which is 7 orders higher than that reported for any liquid crystalline system, and, to our knowledge, the largest observed in an organic conductor. We also report the first thermoelectric power studies on these 'molecular wires'. The sign of the thermoelectric power is in conformity with the expected nature of the charge carriers, namely, holes

Hatchery Production of Shrimp Seeds

T he pioneering efforts of Hudinaga in the successful spawning of Penaeus japonicus under controlled conditions and their subsequent rearing upto the juvenile stage have paved way for the large scale hatchery production of seed of penaeid prawns for aquaculture. There are two basic hatchery techniques for mass rearing of larvae of penaeid prawns - Japanese techniques and Galveston technique. These techniques have been appropriately modified to suit different geographical and climatic conditions and different species of prawns used for aquaculture. Thus m any gradations between these two techniques have been noticed in different parts of the world. Som etim es combinations o f these two techniques have also been used

Shrimps

Among edible crustaceans (shelled organism s) shrimp is considered as a highly valuable commodity. The great economic use of this resource for domestic and export purposes has led to over exploitation of most of the major shrimp stocks of the world. According to World Fishery Statistics, the global shrimp production, showing a rather slow annual growth rate of 4.5 to 10% during 1981-87 period, has been stagnating at about 2.5 million tonnes per year during 1988-90 period. The Indian ocean accounts for an average of about 3.6 lakh tonnes (17%) annually, of which nearly 65% com es from the Eastern region. While the fishery of this region showed an upward trend during the past few years mainly due to increased landings in Indonesia, Bangladesh and East coast of India, the fishery of Western Indian Ocean remained more or less steady at about 2.3 lakh tonnes. From the present level of shrimp production against the effort input it is universally believed that further increase in production of this resource from the conventional shrimp grounds is not possible to any appreciable extent. This being the case, development of deep-sea shrimping and aquaculture of shrimp has been given considerable stress as alternate means of augmenting production through out the world

The big picture:the future role of gas

There are a plethora of drivers of change in energy systems until 2015. The role of social and political actors is likely to be more noticeable. In Europe, locally, high-impact ideas like green consumerism and limited acceptance of energy systems that result in trade-offs will be important. Nationally, the empowerment of individuals and communities and the politicization of energy-related issues will be drivers of change. Internationally, energy issues will become more important in the foreign and security policies of state and non-state actors

Maximum Power Point Tracking for Cascaded PV-Converter Modules Using Two-Stage Particle Swarm Optimization

The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods