Search results for "access"
showing 10 items of 1232 documents
Spectral Slicing of a Supercontinuum Source for WDM/DS-OCDMA Application
2008
WDM and optical CDMA are leading contenders to easily upgrade access network performances in terms of multiple access technique. Both methods can be used at once, using a single multiwavelength optical source. We show, numerically and experimentally, that spectral slicing of a 10-GHz pulse train broadened to a supercontinuum yields pulses suitable for use in a direct sequence optical CDMA system. Simulations with optical CDMA encoders and decoders based on superstructured fiber Bragg gratings indicate good performance can be expected.
Energy efficient resource allocation for secure OFDMA relay systems with eavesdropper
2016
In this paper, we address the energy efficient resource allocation problem for a secure orthogonal frequency division multiple access (OFDMA) relay system. In particular, we consider there is a eavesdropper near the base station (BS) which tries to overtake the information sent by BS. We formulate the joint optimization problem with the objective to optimize the energy efficiency of the considered system by considering subcarrier pairing, secret data rate and power allocation. In addition, the system can assign different priority to different users such that the security of information transmission can be guaranteed. The proposed iterative algorithm not only maximizes the system energy effi…
Joint Spectral and Energy Efficiency Optimization for Downlink NOMA Networks
2020
Non-orthogonal multiple access (NOMA) holds the promise to be a key enabler of 5G communication. However, the existing design of NOMA systems must be optimized to achieve maximum rate while using minimum transmit power. To do so, this paper provides a novel technique based on multi-objective optimization to efficiently allocate resources in the multi-user NOMA systems supporting downlink transmission. Specifically, our unique optimization technique jointly improves spectrum and energy efficiency while satisfying the constraints on users quality of services (QoS) requirements, transmit power budget and successive interference cancellation. We first formulate a joint problem for spectrum and …
The taint of torture and the brazilian legal system
2019
In Brazil, the practice of torture intertwines deeply with its own history. The literature on the subject has had a greater intensification on its registers during the Dictatorial Regime (1964 to 1985). In spite of the Brazilian Constitution of 1988, Brazil only makes efforts to investigate the crimes of torture of this period to comply with the provisions of the United Nations in 2011. Within this scenario, the NationalTruth Commission (Law 12.528, of November 2011) was created with the purpose of clarifying the facts and circumstances of cases concerning human rights violations, as well as the Law on Access to Information (Law 12.527 of November 2011), which have regulated the constitutio…
Determinants of interest margins in Spanish credit institutions before and after the 2008 financial crash
2017
As interest margins of credit institutions affect economic performance of countries, finding out which are the main determinants of their evolution is a research task of great interest at current times. This is the purpose of the present paper as regards to the Spanish case over the period 2004-2012. Based on the econometric contributions by Ho and Saunders (1981) and some of its extensions, the authors develop a model that includes as explanatory variables the factors usually examined in the literature and other singular variables that might be relevant. Particularly, the rate of leverage, the quality of their assets measured according to their risk, and the profit obtained from the sellin…
An entrepreneur's social capital and performance: the role of access to information in the Argentinean case
2012
Purpose - The aim of this paper is to analyze the impact of an entrepreneur's social capital on their access to information, and how such access improves the performance of their entrepreneurial project. Design/methodology/approach - A structural equations model (SEM) is estimated and validated from a database including information from 282 Argentinean entrepreneurs who answered a questionnaire specifically designed for this research. The analysis of this model allowed the impact of dependent latent variables on the performance of the start-up to be determined. Findings - The performance of an entrepreneurial project depends on an entrepreneur's access to finance, markets and information. S…
Effect of partner–agent model practice on microinsurance client value: Insight from microfinance institutions in Tanzania
2018
In absence of formal microinsurance to protect low-income people against natural and man-made disasters, the partnership between insurance companies and microfinance institutions (MFIs), also known as the Partner–Agent Model (PAM), is gaining global recognition from governments, practitioners, and donors for its potential role to deliver microinsurance. Although the model is still nascent in Tanzania, it has significantly increased microinsurance outreach. However, while the microinsurance landscape has been extensively studied, the effect of PAM practice on mandatory microinsurance client value has not received much attention. Therefore, this study examines how the PAM practice affects mic…
Blind source separation based interference suppression schemes for OFDM and DS-CDMA
2015
In statistical wireless signal processing, extraction of unobserved signals from observed mixtures can be achieved using Blind Source Separation (BSS) algorithms. Orthogonal Frequency Division Multiplexing (OFDM) and Direct Sequence-Code Division Multiple Access (DS-CDMA) can be pronounced as the well established predominant air interface communication techniques. Consequences of an effort taken and counteractive solutions to diminish the undesirable influences encountered within the wireless air interface of those techniques with aid of BSS schemes are disclosed. Filter coefficients for the receiver are ascertained with the support of a set of energy functions and the iterative fixed point…
On the role of the upper part of words in lexical access: evidence with masked priming.
2012
More than 100 years ago, Huey (1908) indicated that the upper part of words was more relevant for perception than the lower part. Here we examined whether mutilated words, in their upper/lower portions (e.g., , , , ), can automatically access their word units in the mental lexicon. To that end, we conducted four masked repetition priming experiments with the lexical decision task. Results showed that mutilated primes produced a sizeable masked repetition priming effect. Furthermore, the magnitude of the masked repetition priming effect was greater when the upper part of the primes was preserved than when the lower portion was preserved –this was the case not only when the mutilated words we…
Neue Aspekte der elektrischen Defibrillation
1998
In allen internationalen Empfehlungen stellt die schnellstmogliche Defibrillation die Masnahme der Wahl bei Kammerflimmern (VF) und pulsloser ventrikularer Tachykardie (VT) dar. Der Defibrillation kommt eine Schlusselrolle bei der Bekampfung des plotzlichen Herztodes zu. Technische Neuerungen: Entwicklungen auf technischem Gebiet haben einerseits eine weitere Miniaturisierung und Vereinfachung der Gerate, andererseits eine Anpassung der Energiemenge an die individuellen Patientenbedingungen zum Ziel. Implantierbare Kardioverter-Defibrillatoren (ICD) und automatisierte externe Defibrillatoren (AED) basieren auf der gleichen Technologie, einer gerateinternen Analyse des EKG-Signals mit nachfo…