University of Nebraska–Lincoln

About: University of Nebraska–Lincoln is a education organization based out in Lincoln, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 28059 authors who have published 61544 publications receiving 2139104 citations. The organization is also known as: Nebraska & UNL.

Discrimination, historical loss and enculturation: culturally specific risk and resiliency factors for alcohol abuse among American Indians.

Abstract: Objective: This report investigates the effects of discrimination, historical loss and enculturation on meeting diagnostic criteria for 12-month alcohol abuse among American Indians who share a common culture in the upper Midwest. We introduce an empirical measure of historical loss and hypothesize that historical loss will mediate the effects of discrimination on meeting 12-month diagnostic criteria for alcohol abuse. We also hypothesize that enculturation will be negatively associated with 12-month alcohol abuse and mediate or moderate the effects of discrimination. Method: A sample of 452 (351 women) American-Indian parents/caretakers (mean age: women = 39 years, men = 42 years) of children ages 10 to 12 years participated in diagnostic interviews for lifetime and 12-month alcohol abuse. The subjects' perceptions of discrimination, historical loss and enculturation were also measured. Structural equation modeling was used to evaluate direct and potential mediating effects of latent constructs of encult...

DRAND: Distributed Randomized TDMA Scheduling for Wireless Ad Hoc Networks

Abstract: This paper presents a distributed implementation of RAND, a randomized time slot scheduling algorithm, called DRAND. DRAND runs in O(delta) time and message complexity where delta is the maximum size of a two-hop neighborhood in a wireless network while message complexity remains O(delta), assuming that message delays can be bounded by an unknown constant. DRAND is the first fully distributed version of RAND. The algorithm is suitable for a wireless network where most nodes do not move, such as wireless mesh networks and wireless sensor networks. We implement the algorithm in TinyOS and demonstrate its performance in a real testbed of Mica2 nodes. The algorithm does not require any time synchronization and is shown to be effective in adapting to local topology changes without incurring global overhead in the scheduling. Because of these features, it can also be used even for other scheduling problems such as frequency or code scheduling (for FDMA or CDMA) or local identifier assignment for wireless networks where time synchronization is not enforced. We further evaluate the effect of the time-varying nature of wireless links on the conflict-free property of DRAND-assigned time slots. This experiment is conducted on a 55-node testbed consisting of the more recent MicaZ sensor nodes.

A Survey on Inter-Cell Interference Coordination Techniques in OFDMA-Based Cellular Networks

Abstract: Orthogonal Frequency Division Multiplexing Access (OFDMA) has been increasingly deployed in various emerging and evolving cellular systems to reduce interference and improve overall system performance. However, in these systems Inter-Cell Interference (ICI) still poses a real challenge that limits the system performance, especially for users located at the cell edge. Inter-cell interference coordination (ICIC) has been investigated as an approach to alleviate the impact of interference and improve performance in OFDMA-based systems. A common ICIC technique is interference avoidance in which the allocation of the various system resources (e.g., time, frequency, and power) to users is controlled to ensure that the ICI remains within acceptable limits. This paper surveys the various ICIC avoidance schemes in the downlink of OFDMA-based cellular networks. In particular, the paper introduces new parameterized classifications and makes use of these classifications to categorize and review various static (frequency reuse-based) and dynamic (cell coordination-based) ICIC schemes.