32 research outputs found
Multiple Objective D-Optimal Sensor Management for Group Target Tracking
A group target is moving in an area well covered by a network of passive sensor nods with known positions. Additionally, there are a number of mobile robots with active sensors. In order to obtain a robust estimate of the position of the target and decrease the amount of energy spent on active sensing and communications by the sensor network and the mobile robots a sensor management system optimises the spatial configuration of the mobile robots over time. A tracking algorithm predicts the position of the target over multiple steps. An estimate for the tracking accuracy for each possible sensor action is calculated based on a function of the expected resulting posterior inverse covariance (information) matrix given the position of the nodes of the sensor networks and the feasible position of the mobile robots in future time instants. We propose a novel approach for active sensor management that combines the Rao-Blackwellised particle filter/predictor and multi-objective D-optimal optimisation. The designed decentralised Rao-Blackwellised particle filter (RBPF) is composed of two parts: a decentralised Information or Kalman filter and a particle filter (PF). The sensor management framework that is based on the generalised D-optimal optimisation with slack variables is proposed
Synthesis, X-ray diffraction and optical band gap study of nanoparticles of NiFe<sub>2</sub>O<sub>4</sub>
774-776Nanoparticles of
NiFe2O4 have been synthesized by chemical
co-precipitation method. X-ray diffraction pattern confirms the formation of
single-phase cubic spinel structure and the lattice constant is 8.2 Å. The
energy band gap measurements of nanoparticles of Ni ferrite in pellet form have
been carried out by reflection spectra using double beam spectrophotometer. A
pellet of nanoparticle ferrite was made under a load of 10 tons. From the
analysis of reflection spectra, nanocrystalline Ni ferrite have been found to
have energy band gap of 2.5 eV at room temperature
Superparamagnetic behaviour of nano-particles of Ni-Cu ferrite
169-172The nano-particles of Ni0.8Cu0.2Fe2O4
with a log-normal size distribution of the median diameter of 9 nm and
standard deviation of 0.60 have been synthesized by the chemical
co-precipitation method followed by annealing at 500°C. The cubic spinel structure in single phase has been confirmed by
X-ray diffraction. Reduction in saturation magnetization has been explained on
the basis that the magnetic moments in the surface layers, outside the core are
in a state of frozen disorder. The dc magnetization
is measured which show that the nano-particle sample is super-paramagnetic
above the blocking temperature of 250 K. Secondly, the departure of fc curve from the zfc curve is suggestive of temporal relaxation
Mössbauer study of nanoparticles of Co₀․₄Zn₀․₆Fe₂O₄
826-829Two samples of nanoparticles of Co₀․₄Zn₀․₆Fe₂O₄ with the average particle sizes of 6 nm and 15 nm have been synthesized by chemical co-precipitation method and followed by heat treatment at 600ºC. The cubic spinel structure in single phase has been confirmed by X-ray diffraction. The lattice parameters are 8.39 Å and 8.41 Å, respectively. ⁵⁷Fe Mössbauer spectra were recorded at 300 K and 80 K. Both samples are resolved in two patterns corresponding to two crystalline sites. The Mössbauer spectra and hysteresis curves for the two samples recorded at 300 K show superparamagnetic behaviour. The analysis of Mössbauer spectra reveal that the intensity of Fe³⁺ ions on both sites is nearly the same which indicate that the Zn²⁺ occupies the octahedral site in these samples
<span style="font-size:22.0pt;mso-bidi-font-size:15.0pt; line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">Magnetic behaviour of (Fe<sub><span style="font-size:15.5pt;mso-bidi-font-size: 8.5pt;line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">0.90 </span></sub><span style="font-size:22.0pt;mso-bidi-font-size:15.0pt; line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">Mn<sub>x</sub> Co<sub><span style="font-size:15.5pt;mso-bidi-font-size:8.5pt; line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA;mso-bidi-font-weight:bold">0.1-x</span></sub><span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;line-height:115%;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font: minor-fareast;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: AR-SA;mso-bidi-font-weight:bold">)<sub>2 </sub><span style="font-size: 22.0pt;mso-bidi-font-size:15.0pt;line-height:115%;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold">P</span></span></span></span>
488-490<span style="font-size:
15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""=""> <span style="font-size:22.0pt;
mso-bidi-font-size:15.0pt;font-family:" times="" new="" roman","serif";mso-bidi-font-weight:="" bold"="">Fe<span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;
font-family:" times="" new="" roman","serif";mso-bidi-font-weight:bold"="">0.90 Mnx Co<span style="font-size:
15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif";="" mso-bidi-font-weight:bold"="">0.1-x<span style="font-size:15.5pt;
mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif";mso-bidi-font-weight:="" bold"="">)2<span style="font-size:22.0pt;mso-bidi-font-size:
15.0pt;font-family:" times="" new="" roman","serif";mso-bidi-font-weight:bold"="">P
with
x=0.03 , 0.05 and 0.07 (hereafter referred to as FMC37, FMC55 and FMC73,
respectively) crystallize in Fe2P like hexagonal symmetry. DC
magnetization measurements have been made on these alloy systems in external fields
up to 8.5 kOe a<span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;
font-family:HiddenHorzOCR;mso-hansi-font-family:" times="" new="" roman";mso-bidi-font-family:="" hiddenhorzocr"="">nd <span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;
font-family:" times="" new="" roman","serif""="">in the temperature range 85-400K. The
alloys are ferromagnetic with Tc~325K for FMC37, ~250K for FMC55 and
~220K for FMC73. While FMC37 shows a clear paramagnetic to ferromagnetic
transition, in FMC55 and FMC73, the transition anomaly is field-dependent and
gets suppressed by rather low fields. In these two systems, FM order keeps
evolving with cooling below these Curie points and at still lower temperatures
negative exchange gains in strength, giving rise to disordered magnetic state,
which shows long time magnetic relaxation. Below 85 K, there could be another
modification in magnetic states of the two systems with positive exchange
interaction regaining in strength.
</span
Coastal Risk Assessment Framework: Comparison of modelled fluvial and marine inundation impacts, Bocca di Magra, Ligurian coast, Italy
The identification and classification of critical coastal areas is becoming more and more important from a coastal management point of view, especially considering future climate change. The standardized assessment of multiple hazards and their potential impacts is crucial, in terms of risk management, for those coastal areas where both marine and fluvial hazards can occur. Nevertheless, in Bocca di Magra (Liguria Region, Italy), where both coastal and fluvial flooding can occur, up until now the potential impacts from marine flooding have not been thought to be of importance; only the impact of fluvial flooding has been systematically analysed. Now, however, the Liguria Regional stakeholders have become interested in understanding the potential impact of marine inundations compared to fluvial inundations, applying the CRAF (Coastal Risk Assessment Framework) methodology developed inside the RISC-KIT project. The hazard modelling of coastal and fluvial inundations was used, together with exposure data, to evaluate the direct and systemic impacts generated by both flooding mechanisms separately. An End-User-driven Multi-Criteria Analysis was implemented to compare coastal and fluvial impacts on the same area. For an event with a 1 in 200 year return period, the CRAF predicts that fluvial inundation generates higher impacts, in comparison to the marine one. Even though the impacts in the coastal area are less, the impacted exposed elements are different from those impacted by fluvial inundation and none of them can be excluded from the analysis. This work highlights the need for regional managers to develop combined coastal-fluvial flooding assessments; such actions should be seen as a priority for flood disaster risk management in locations affected by both marine flooding and riverine flash flooding
The Problems of Informational Provision of Arts Teachers' Training
В статье проанализированы проблемы повышения эффективности учебного процессасредствами информационных технологий. Обоснована необходимость создания электронной среды и введения электронных словарей и учебников в повседневную практику высших учебных заведений. Предложены рекомендации по составлению электронных словарей для будущих учителейхудожественных дисциплин.The problems of enhancing the teaching process efficiency by means of modern informational technologies are analyzed. The necessity of creating the electronic environment and incorporating the electronic dictionaries and electronic textbooks into the daily practice of higher educational institutions is emphasized. Some recommendations to composing the electronic dictionaries for prospective teachers are offered
Retraction Note to: Synthesis, Structural and Magnetic Properties of Polypyrrole Coated Ni0.2Ca0.8Fe2O4 Nanocomposite
Magnetic study of nanoparticles of Mg<sub>0.95</sub>Mn<sub>0.05</sub>Fe<sub>2</sub>O<sub>4</sub> spinel ferrite
771-773Magnetization of nanoparticles of Mg-Mn ferrite, synthesized using high energy ball milling has been studied. X-ray diffraction pattern of the particles milled for 6 h confirmed the single-phase cubic spinel structure
with a lattice parameter of 8.47 Å.
Langevin function fitting on M-H data at 300K gives a log-normal
particle size distribution with median diameter of 6.4 nm and standard
deviation 0.7. The isothermal dc
magnetization studies have been performed using SQUID and vibrating sample
magnetometer in the temperature range 5-300 K. These measurements show that the
sample is superparamagnetic above the blocking temperature TB ~ 246 K. The
reduction in saturation magnetization in the case of nanoparticles has been
explained on the basis that the magnetic moments in the surface layers outside
the core are in a state of frozen disorder