Weakly supervised semantic segmentation by iteratively refining optimal segmentation with deep cues guidance

Neural Computing and Applications - Weakly supervised semantic segmentation under image-level label supervision has undergone impressive improvements over the past years. These approaches can...     

Measurements and Analysis of Fingerprinting Structures for WLAN Localization Systems

Channel‐based radio‐frequency fingerprinting such as a channel impulse response (CIR), channel transfer function (CTF), and frequency coherence function (FCF) have been recently proposed to improve the accuracy at the physical layer; however, their empirical performance, advantages, and limitations have not been well reported. This paper provides a comprehensive empirical performance evaluation of RF location fingerprinting, focusing on a comparison of received‐signal strength, CIR‐, CTF‐, and FCF‐based fingerprinting using the weighted k‐nearest neighbor pattern recognition technique. Frequency domain channel measurements in the IEEE 802.11 band taken on a university campus were used to evaluate the accuracy of the fingerprinting types and their robustness to human‐induced motion perturbations of the channel. The localization performance was analyzed, and the results are described using the spatial and temporal radio propagation characteristics. In particular, we introduce the coherence region to explain the spatial properties and investigate the impact of the Doppler spread in time‐varying channels on the time coherence of RF fingerprint structures.     

The development of forced convection heat transfer near a forward stagnation point with Newtonian heating

A mathematical model for the unsteady forced convection boundary-layer flow near a forward stagnation point is considered when there is Newtonian heating on the surface whereby the heat transfer is proportional to the local surface temperature. In a previous paper (Salleh et al. J Eng Math 69:101–110, 2011), a critical value γ _c, dependent on the Prandtl number σ, of the heat transfer coefficient γ was identified, with solutions for the corresponding steady problem possible only for γ < γ _c. The unsteady problem considered here shows that these steady states are attained at large times when γ < γ _c. For γ > γ _c, the solution still continues to large time, now growing exponentially with time. This rate of growth is determined by an eigenvalue problem which we solve numerically for general values of γ and σ and asymptotically for large γ and both large and small σ.     

Measurement and Explanation of DC/RF Power Loci of an Active Patch Antenna

A case study of an active transmitting patch antenna revealed a characteristic loop locus of DC power versus RF output power as drive frequency was varied, with an operational bandwidth substantially smaller than the impedance bandwidth of the radiator. An approximate simulation technique, based on separation of the output capacitance of the power transistor, yielded easily visualized plots of power dependence on internal load impedance, and a simple interpretation of the experimental results in terms of a near‐resonance condition between the output capacitance and output packaging inductance.     

Multiobjective electric distribution system expansion planning using hybrid energy hub concept

This paper presents a novel approach for optimal electric distribution system expansion planning (OEDSEP) using a hybrid energy hub concept. The proposed method uses an energy hub model to explore the impacts of energy carrier systems on OEDSEP procedure. This algorithm decomposes the OEDSEP problem into three subproblems to achieve an optimal expansion planning of a system in which the investment and operational costs are minimized, while the reliability of the system is maximized. The algorithm was successfully tested in the present research for an urban distribution system.     

MHD flow and heat transfer over stretching/shrinking sheets with external magnetic field,viscous dissipation and Joule effects

The present article considers the steady magnetohydrodynamic (MHD) laminar boundary layer flow of a viscous and incompressible electrically conducting fluid near the stagnation point on a horizontal stretching or shrinking surface, with variable surface temperature and a constant magnetic field applied normal to the surface of the sheet. The governing system of partial differential equations is first transformed into a system of ordinary differential equations by introducing an appropriate similarity transformation, which is then solved numerically using a finite‐difference scheme known as the Keller‐box method. The effects of the governing parameters on the skin friction coefficient, the local Nusselt number as well as the velocity and temperature profiles are determined and discussed. Results indicate that for the stretching sheet, solution exists and is unique for all values of the stretching/shrinking parameter $\lambda $ , while for the shrinking sheet, solutions only exist up to some critical values $\lambda = \lambda _{{\rm c}} $ , and these solutions may be unique, dual and sometimes triple. © 2011 Canadian Society for Chemical Engineering     

Impact of income strategies on food security in rural Mayan communities in northern Campeche

This paper examines the effect of income strategies on sufficiency of caloric intake in Mayan domestic groups (DG) of Campeche, Mexico. The analysis was based on the sustainable livelihoods approach. Information was obtained through a survey of households (N = 237) in four communities. The results reveal that all of the DG have diversified income strategies with clearly defined orientations. The caloric sufficiency index (CSI) is different (p < 0.05) among conglomerates (C) of DG and increases with the increase of the proportion of agricultural income in relation to total income. The wage labor strategy (37.6%) corresponding to C1 of DG (CSI-C = 0.69) and the agriculture-wage labor strategy (42.6%; CSI-C2 = 0.87) do not cover energy requirements of the DG. Only the agricultural strategy satisfies caloric intake needs (CSI-C3 = 1.09; CSI-C4 = 1.30) of the DG (19.8%). These results are associated with the heterogeneity of resources of the DG's, particularly, with the quality and extent of land, presence of producer organizations, and current rural policies. Implementation of differentiated local policies, interinstitutional coordination, and community participation could contribute to improving effectiveness of policies aimed at eradicating food insecurity.     

Evaluating fire blocking performance of barrier fabrics

A series of evaluations were performed on different types of barrier fabrics (BFs) used in soft furnishings. Fundamental properties that influence the heat transfer characteristics of barrier material as it relates to thermal protection of cushioning components in upholstered products are discussed. This is important to enable a priori selection of BFs such that a final upholstered product complies with flammability regulations. Heat transfer measurements are used to determine effectiveness of materials to be used as barrier materials. A new bench‐scale composite test method is also described to assess qualitative fire blocking performance of BFs. When tested for heat transfer characteristics, the area density and thickness of BFs show strong influence. However, when tested as a composite in a mock‐up assembly, the BFs considered in this study showed a clear distinction between active and passive BFs. In the case of chemically active BFs, the construction parameters and material properties such as thickness, air permeability, and heat transfer were of little significance. In the case of passive BFs, however, these parameters became decisive. Results from this study suggest that if the BF is not an active fire barrier, then the amount of heat transferred through BF is critical. Copyright © 2013 John Wiley & Sons, Ltd.     

Spectroscopic study of Alizarin Red S binding with cetyltrimethylammonium bromide at low concentrations

The anthraquinoid dye, Alizarin Red S, forms an anionic moiety in aqueous solution. The complex formation of this dye was studied with the cationic surfactant, cetyltrimethylammonium bromide, in an aqueous environment at low surfactant concentrations. The complex was studied with the help of ultraviolet–visible spectroscopy. A method of continuous variation was applied to confirm the complex formation and showed that a 1:1 complex was evident from the experimental results. The equilibrium constant for the formation of the complex was determined at various temperatures. Different thermodynamic parameters, free energy of binding, enthalpy of binding and entropy of binding were calculated.