Inter-cell interference in multi-tier heterogeneous cellular networks: modeling and constraints

Telecommunication Systems - Interference is the main source of capacity limitation in wireless networks. In some medium access technologies in cellular networks, such as OFDMA, the allocation of...     

An Adaptable and Scalable Generator of Distributed Massive MIMO Baseband Processing Systems

Journal of Signal Processing Systems - This paper presents an algorithm-adaptable, scalable, and platform-portable generator for massive multiple-input multiple-output (MIMO) baseband processing...     

A Framework on the Performance Analysis of Cooperative Wireless Body Area Networks

Wireless body area networks (WBANs) are deal with wireless networks in the human body. We describe the performance analysis of dual-hop cooperative relaying systems employing amplify-and-forward (AF) technique in WBANs over independent and nonnecessary identically distributed Gamma fading channels. More specifically, we present closed-form derivations of the outage probabilities (OP), symbol error probabilities (SEP) and ergodic capacity (EC) for fixed gain and channel state information (CSI)-assisted relaying techniques at arbitrary signal-to-noise-ratios (SNRs). We also deduce novel expressions in the high SNR region. By doing so, we can quantify the performance of system by the diversity and coding gains. Using the derived expressions as a starting point and for the case of Exponential fading, we consider three practical optimization scenarios. They are optimal relay position with fixed power allocation, power allocation under the fixed location of the relay and joint optimization of power allocation and relay position under a transmit power constraint. The Monte Carlo simulations are used to validate the accuracy of our derivations, where it is demonstrated that the proposed adaptive allocation method significantly outperforms the fixed allocation method.

     

Determining Honesty of Accuser Nodes in Key Revocation Procedure for MANETs

Mobile Networks and Applications - Management of encryption keys is an essential task for establishing secure communication in a mobile ad hoc network (MANET). Any key management scheme must be...     

Microstructure and Optical Bandgap of Cobalt Selenide Nanofilms

Semiconductors - The purpose of this research is to explore the properties of CoSe nanostructured thin films on glass substrates prepared by a chemical solution deposition method. Special attention...     

Vicarious moral licensing: The influence of others' past moral actions on moral behavior.

This article investigates the effect of others' prior nonprejudiced behavior on an individual's subsequent behavior. Five studies supported the hypothesis that people are more willing to express prejudiced attitudes when their group members' past behavior has established nonprejudiced credentials. Study 1a showed that participants who were told that their group was more moral than similar other groups were more willing to describe a job as better suited for Whites than for African Americans. In Study 1b, when given information on group members' prior nondiscriminatory behavior (selecting a Hispanic applicant in a prior task), participants subsequently gave more discriminatory ratings to the Hispanic applicant for a position stereotypically suited for majority members (Whites). In Study 2, moral self-concept mediated the effect of others' prior nonprejudiced actions on a participant's subsequent prejudiced behavior such that others' past nonprejudiced actions enhanced the participant's moral self-concept, and this inflated moral self-concept subsequently drove the participant's prejudiced ratings of a Hispanic applicant. In Study 3, the moderating role of identification with the credentialing group was tested. Results showed that participants expressed more prejudiced attitudes toward a Hispanic applicant when they highly identified with the group members behaving in nonprejudiced manner. In Study 4, the credentialing task was dissociated from the participants' own judgmental task, and, in addition, identification with the credentialing group was manipulated rather than measured. Consistent with prior studies, the results showed that participants who first had the opportunity to view an in-group member's nonprejudiced hiring decision were more likely to reject an African American man for a job stereotypically suited for majority members. These studies suggest a vicarious moral licensing effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Performance Evaluation of ANN and ANFIS Models for Estimating Garlic Crop Evapotranspiration

Estimation of evapotranspiration (ET) is necessary in water resources management, farm irrigation scheduling, and environmental assessment. Hence, in practical hydrology, it is often necessary to reliably and consistently estimate evapotranspiration. In this study, two artificial intelligence (AI) techniques, including artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS), were used to compute garlic crop water requirements. Various architectures and input combinations of the models were compared for modeling garlic crop evapotranspiration. A case study in a semiarid region located in Hamedan Province in Iran was conducted with lysimeter measurements and weather daily data, including maximum temperature, minimum temperature, maximum relative humidity, minimum relative humidity, wind speed, and solar radiation during 2008–2009. Both ANN and ANFIS models produced reasonable results. The ANN, with 6-6-1 architecture, presented a superior ability to estimate garlic crop evapotranspiration. The estimates of the ANN and ANFIS models were compared with the garlic crop evapotranspiration (ETc) values measured by lysimeter and those of the crop coefficient approach. Based on these comparisons, it can be concluded that the ANN and ANFIS techniques are suitable for simulation of ETc.     

Exploring urban students’ constructions about school, work, race, and ethnicity.

This qualitative study is an exploration of 32 urban high school students’ narratives about the connection between school, work, and societal expectations of their future success related to their racial and ethnic background. The sample varied along 2 contextual dimensions: participation in a psychoeducational intervention (Tools for Tomorrow) and developmental status (i.e., half the sample were 9th-grade students and the other half were 12th-grade students). Using consensual qualitative research, the narratives revealed 3 major domains: future orientation; students’ perceptions of society’s expectations based on race and ethnicity; and students’ perception of the role of their race and ethnicity in future success. Results reveal that the majority of students endorse a connection between school and work, believe that society holds low expectations for them based on their racial and ethnic background, and cannot predict their future success based on their background. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An ultra low-voltage low power PSK backscatter modulator for passive UHF RFID tags compatible with C1 G2 EPC standard protocol

Reducing the power consumption of a passive radio frequency identification (RFID) tag is the key in many applications. As the modulator is usually the most power-hungry block in an RFID tag, this paper proposes a power-saving modulator. The proposed modulator uses phase shift keying (PSK) backscatter modulation which allows tag to communicate data from its memory to a reader by PSK modulation. The proposed modulator uses a MOSCAP as a variable impedance and is designed in a new one-inverter structure in compare to the conventional varactor-based modulators designed in two-inverter structure, as this modulator needs just a low voltage swing to drive its MOSCAP. Using MOSCAP as the variable capacitance leads to a low voltage design. Also, the fundamental equations required for determination of the capacitive impedance seen by the antenna is presented. This impedance is the master key in modulator design. The modulator has been designed, simulated and optimized in 0.18 μm CMOS technology. All possible simulation results are presented to approve its compatible operation with C1 G2 EPC global standard. The power consumption of less than 46 nW is achieved in all process corner cases at 0.8 V power supply.