Physical Sciences and Mathematics Commons^™

Connecting Soil To The Cloud: A Wireless Underground Sensor Network Testbed, John Tooker, Xin Dong, Mehmet C. Vuran, Suat Irmak

CSE Conference and Workshop Papers

In this demo, a novel underground communication system and an online underground sensor network testbed is demonstrated. The underground communication system, developed in the Cyber-physical Networking (CPN) Laboratory at the University of Nebraska-Lincoln, includes an underground antenna that is tailored to mitigate the adverse effects of soil on underground communication. An online connection is established with the CPN underground sensor network testbed that is located at Clay Center, Nebraska. The underground sensor network testbed consists of a network of underground communication systems equipped with soil moisture sensors and a mobile data harvesting unit equipped with cellular communication capabilities. Real-time soil …

An Efficient Water-Filling Algorithm For Power Allocation In Ofdm-Based Cognitive Radio Systems, Qilin Qi, Yaoqing Lamar Yang

CSE Conference and Workshop Papers

In this paper, we present a new water-filling algorithm for power allocation in Orthogonal Frequency Division Multiplexing (OFDM) – based cognitive radio systems. The conventional water-filling algorithm cannot be directly employed for power allocation in a cognitive radio system, because there are more power constraints in the cognitive radio power allocation problem than in the classic OFDM system. In this paper, a novel algorithm based on iterative water-filling is presented to overcome such limitations. However, the computational complexity in iterative water-filling is very high. Thus, we explore features of the water-filling algorithm and propose a low-complexity algorithm using power-increment or …

Sensing Through The Continent: Towards Monitoring Migratory Birds Using Cellular Sensor Networks, David Anthony, William P. Bennett, Mehmet C. Vuran, Matthew B. Dwyer, Sebastian Elbaum, Anne Lacy, Mike Engels, Walter Wehtje

CSE Conference and Workshop Papers

This paper presents CraneTracker, a novel sensor platform for monitoring migratory birds. The platform is designed to monitor Whooping Cranes, an endangered species that conducts an annual migration of 4, 000 km between southern Texas and north-central Canada. CraneTracker includes a rich set of sensors, a multi-modal radio, and power control circuitry for sustainable, continental-scale information delivery during migration. The need for large-scale connectivity motivates the use of cellular technology in low-cost sensor platforms augmented by a low-power transceiver for ad-hoc connectivity. This platform leads to a new class of cellular sensor networks (CSNs) for time-critical and mobile sensing applications. …

A Performance Comparison Of Mobile Wimax Spectrums: 2.5 Ghz Vs. 3.65 Ghz, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif

CSE Conference and Workshop Papers

Mobile WiMAX is a popular broadband solution with diverse applications. In the United States, the Federal Communications Commission (FCC) currently issues licenses for Mobile WiMAX in several frequency bands, of which 2.5 GHz and 3.65 GHz are the most prevalent. A significant amount of research has been conducted in the domain of 2.5 GHz due to its widespread commercial use. However, no such work – academic or industrial – has been reported for 3.65 GHz, in spite of it being a more favorable option for many applications, particularly because of its licensing requirements. In this paper, we present a comprehensive …

An Approach To The Virtual Flora Of Mongolia – From A Data Repository To An Expert System, Http://Greif.Uni-Greifswald.De/Floragreif/, Jörg Hartleib, Martin Schnittler, Sabrina Rilke, Anne Zemmrich, Bernd Bobertz, Ulrike Najmi, Reinhard Zölitz, Susanne Starke

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

FloraGREIF is an internet accessible information system providing taxonomic, phytogeographic and ecological information on Mongolia’s flora in terms of descriptions, high-resolution plant images and an interactive WebGIS application. Organised along an updated checklist of the approx. 3000 Mongolian vascular plants that serves as a taxonomic backbone, information is split into the taxon level, referring to plant species, and the record level, referring to record or a collected plant specimen. At the latter level, images of living plants, scans of herbarium sheets, habitat photos and further notes can be found. Both data levels are linked by the name of the respective …

Amplifying Tests To Validate Exception Handling Code, Pingyu Zhang, Sebastian Elbaum

CSE Conference and Workshop Papers

Validating code handling exceptional behavior is difficult, particularly when dealing with external resources that may be noisy and unreliable, as it requires: 1) the systematic exploration of the space of exceptions that may be thrown by the external resources, and 2) the setup of the context to trigger specific patterns of exceptions. In this work we present an approach that addresses those difficulties by performing an exhaustive amplification of the space of exceptional behavior associated with an external resource that is exercised by a test suite. Each amplification attempts to expose a program exception handling construct to new behavior by …

Finding Suitable Programs: Semantic Search With Incomplete And Lightweight Specifications, Kathryn T. Stolee

CSE Conference and Workshop Papers

Finding suitable code for reuse is a common task for programmers. Two general approaches dominate the code search literature: syntactic and semantic. While queries for syntactic search are easy to compose, the results are often vague or irrelevant. On the other hand, a semantic search may return relevant results, but current techniques require developers to write specifications by hand, are costly as potentially matching code need to be executed to verify congruence with the specifications, or only return exact matches. In this work, we propose an approach for semantic search in which programmers specify lightweight, incomplete specifications and an SMT …

Space-Efficient Algorithms For Reachability In Surface-Embedded Graphs, Derrick Stolee, N. V. Vinodchandran

CSE Conference and Workshop Papers

This work presents a log-space reduction which compresses an n-vertex directed acyclic graph with m(n) sources embedded on a surface of genus g(n), to a graph with O(m(n) + g(n)) vertices while preserving reachability between a given pair of vertices. Applying existing algorithms to this reduced graph yields new deterministic algorithms with improved space bounds as well as improved simultaneous time space bounds for the reachability problem over a large class of directed acyclic graphs. Specifically, it significantly extends the class of surface-embedded graphs with log-space reachability algorithms: from planar graphs with O(log n) sources, to graphs with …

Mobile Data Harvesting In Wireless Underground Sensor Networks, John Tooker, Mehmet C. Vuran

CSE Conference and Workshop Papers

Wireless Underground Sensor Networks (WUSNs) allow for continuous field monitoring without interfering with aboveground activities, such as plowing or football games. Due to the increased path loss in soil, it is challenging to ensure that a large-scale underground network is connected while still being cost effective in terms of deployment and maintenance.

In this paper, a practical WUSN architecture is developed, consisting of mobile nodes that harvest data from stationary underground nodes. To this end, the impacts of packet size and error control schemes on network performance are investigated through field experiments. By developing a better understanding of the wireless …

Redistricting Using Constrained Polygonal Clustering, Deepti Joshi, Leen-Kiat Soh, Ashok Samal

School of Computing: Faculty Publications

Redistricting is the process of dividing a geographic area consisting of spatial units—often represented as spatial polygons—into smaller districts that satisfy some properties. It can therefore be formulated as a set partitioning problem where the objective is to cluster the set of spatial polygons into groups such that a value function is maximized [1]. Widely used algorithms developed for point-based data sets are not readily applicable because polygons introduce the concepts of spatial contiguity and other topological properties that cannot be captured by representing polygons as points. Furthermore, when clustering polygons, constraints such as spatial contiguity and unit distributedness should …

Exploring The Design Space Of Multichannel Peer-To-Peer Live Video Streaming Systems, Miao Wang, Lisong Xu, Byrav Ramamurthy

School of Computing: Faculty Publications

Most of the commercial peer-to-peer (P2P) video streaming deployments support hundreds of channels and are referred to as multichannel systems. Recent research studies have proposed specific protocols to improve the streaming quality for all channels by enabling cross-channel cooperation among multiple channels. In this paper, we focus on the following fundamental problems in designing cooperating multichannel systems: 1) what are the general characteristics of existing and potential designs? and 2) under what circumstances should a particular design be used to achieve the desired streaming quality with the lowest implementation complexity? To answer the first question, we propose simple models based …

Features For Non-Targeted Cross-Sample Analysis With Comprehensive Two-Dimensional Chromatography, Stephen E. Reichenbach, Xue Tian, Chiara Cordero, Qingping Tao

School of Computing: Faculty Publications

This review surveys different approaches for generating features from comprehensive two-dimensional chromatography for non-targeted cross-sample analysis. The goal of non-targeted cross-sample analysis is to discover relevant chemical characteristics (such as compositional similarities or differences) from multiple samples. In non-targeted analysis, the relevant characteristics are unknown, so individual features for all chemical constituents should be analyzed, not just those for targeted or selected analytes. Cross-sample analysis requires matching the corresponding features that characterize each constituent across multiple samples so that relevant characteristics or patterns can be recognized. Non-targeted, cross-sample analysis requires generating and matching all features across all samples. Applications of …