Barriers in spatial interactions and communications

Barriers are defined as discontinuities in the broadly defined marginal costs of communication, usually leading to a discontinuity in interaction. This paper addresses conceptual issues about barriers to communication. Several typologies of barriers are given. For example, according to the degree of permeability, barriers may discourage interaction, or may even be entirely impermeable, but examples may also be given of barriers which stimulate communication in one or both directions. Another typology of barriers addresses reasons of existence, including natural barriers, barriers created for protection purposes, barriers created for reasons of convenience, etc. The paper concludes with a number of suggestions for further research on communication barriers.     

Design methodology of refractive index engineering by implantation of high-energy particles in electro-optic materials

Slab waveguides were constructed in K(1-x)Li(x)Ta(1-y)Nb(y)O(3) crystals by the implantation of (12)C(+4) ions at 30 MeV and (16)O(+5) ions at 30 and 40 MeV. The waveguides were characterized by a prism coupler setup. A refractive index drop of 10.9% was observed in a layer formed by the implantation of (16)O(+5) ions at 30 MeV. The carbon-implanted waveguides were found to be thermally stable after annealing at 450 degrees C. A semiempirical formula for predicting the change in the refractive index given the parameters of the implantation process was developed. It is argued that the combination of the basic implantation process with the semiempirical formula can be developed to become a generic method for constructing complex electro-optic circuits with a wave-guided architecture.     

Visual Homing: Surfing on the Epipoles

We introduce a novel method for visual homing. Using this method a robot can be sent to desired positions and orientations in 3D space specified by single images taken from these positions. Our method is based on recovering the epipolar geometry relating the current image taken by the robot and the target image. Using the epipolar geometry, most of the parameters which specify the differences in position and orientation of the camera between the two images are recovered. However, since not all of the parameters can be recovered from two images, we have developed specific methods to bypass these missing parameters and resolve the ambiguities that exist. We present two homing algorithms for two standard projection models, weak and full perspective.Our method determines the path of the robot on-line, the starting position of the robot is relatively not constrained, and a 3D model of the environment is not required. The method is almost entirely memoryless, in the sense that at every step the path to the target position is determined independently of the previous path taken by the robot. Because of this property the robot may be able, while moving toward the target, to perform auxiliary tasks or to avoid obstacles, without this impairing its ability to eventually reach the target position. We have performed simulations and real experiments which demonstrate the robustness of the method and that the algorithms always converge to the target pose.     

Modulations in structural and ferroelectric properties due to tensile strain in BiFeO3 films on MgAl2O4 substrates induced by thermal-expansion

The effect of tensile strain on structural and ferroelectric properties of BiFeO₃ epitaxial films was investigated. The films grown by pulsed laser deposition on MgAl₂O₄ (0 0 1) substrates revealed monoclinic structure deviated from the bulk rhombohedral structure due to a tensile strain along the in-plane direction. The strain is induced by the difference in thermal expansion coefficients between the film and the substrate. A Poisson ratio is calculated from the in-plain and out-of-plain lattice constants at different temperatures measured by reciprocal space maps of X-ray diffraction. The small Poisson ratio compared to the bulk suggests a weaker elastic response at high temperature. The ferroelectric polarization of the tensile-strained film along the (0 0 1) is also decreased from the bulk value.     

Regulatory framework and business models for charging plug-in electric vehicles: Infrastructure,agents, and commercial relationships

Electric vehicles (EVs) present efficiency and environmental advantages over conventional transportation. It is expected that in the next decade this technology will progressively penetrate the market. The integration of plug-in electric vehicles in electric power systems poses new challenges in terms of regulation and business models. This paper proposes a conceptual regulatory framework for charging EVs. Two new electricity market agents, the EV charging manager and the EV aggregator, in charge of developing charging infrastructure and providing charging services are introduced. According to that, several charging modes such as EV home charging, public charging on streets, and dedicated charging stations are formulated. Involved market agents and their commercial relationships are analysed in detail. The paper elaborates the opportunities to formulate more sophisticated business models for vehicle-to-grid applications under which the storage capability of EV batteries is used for providing peak power or frequency regulation to support the power system operation. Finally penetration phase dependent policy and regulatory recommendations are given concerning time-of-use pricing, smart meter deployment, stable and simple regulation for reselling energy on private property, roll-out of public charging infrastructure as well as reviewing of grid codes and operational system procedures for interactions between network operators and vehicle aggregators.     

The Quality of Domestic Legal Institutions and Export Performance

• Does the quality of domestic legal institutions matter for export performance? How does differential access to protections and privileges offered by informal institutions moderate the relationship between the quality of formal legal institutions and export performance? To answer these questions, we develop a theoretical framework drawing on insights from trade theory and institutional theory.
• We propose that higher-quality legal systems in an exporter’s location are associated with higher export performance, particularly when trade partners face higher levels of external and internal uncertainty. We further propose that firms that have less access to local informal institutions to reduce transaction costs and opportunism benefit more from better-developed legal institutions.
• Using information for more than 198,000 firms and legal quality information for 120 cities in China, we find strong support for our predictions. We discuss our contributions to the literature on institutions and export.

     

Internalized homophobia and relationship quality among lesbians, gay men, and bisexuals.

The authors examined the associations between internalized homophobia, outness, community connectedness, depressive symptoms, and relationship quality among a diverse community sample of 396 lesbian, gay, and bisexual (LGB) individuals. Structural equation models showed that internalized homophobia was associated with greater relationship problems both generally and among coupled participants independent of outness and community connectedness. Depressive symptoms mediated the association between internalized homophobia and relationship problems. This study improves present understandings of the association between internalized homophobia and relationship quality by distinguishing between the effects of the core construct of internalized homophobia and its correlates and outcomes. The findings are useful for counselors interested in interventions and treatment approaches to help LGB individuals cope with internalized homophobia and relationship problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conductivity Measurement Using Four Linear Electrodes Embedded Inside a Rectangular Sample

Using solid materials prepared by melting or sintering allows inert metal electrodes to be embedded inside the solid. The I–V relations for four linear electrodes embedded inside a rectangular sample are evaluated. Two cases are considered: (a) a sample with uniform electronic (electron/hole) conductivity and (b) the electron/hole partial current in a sample that is a mixed ionic-electronic conductor with a nonuniform electron/hole distribution. Equations are derived which allow the determination of the conductivity from four-electrode measurements if a pure electronic conductor is considered or if a mixed ionic-electronic conductor is considered with the ionic current being blocked.     

The interconnections between socio-spatial factors and labour market integration among Arabs in Israel

The current study investigated labour market integration of Arabs in Israel using Schnell et al.'s ( 2015 ) global segregation/integration index (GSI) that assesses minorities’ socio-spatial integration in multi-ethnic contexts. The merit of this approach lies in being multifaceted and systematically incorporating socio-spatial spheres. The study also conducted structured interviews with the respondents (n = 142), and employed GPS loggers to track their weekly movements. GSI socio-spatial indicators emerged significantly associated with integration in the labour market, with movement in space being the prominent. The study signifies the socio-spatial approach's application to the study of minorities’ labour market integration in metropolitan areas.