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2012

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Nanotopographic Cell Culture Substrate: Polymer-Demixed Nanotextured Films Under Cell Culture Conditions, Jung Yul Lim, Christopher A. Siedlecki, Henry J. Donahue Jan 2012

Nanotopographic Cell Culture Substrate: Polymer-Demixed Nanotextured Films Under Cell Culture Conditions, Jung Yul Lim, Christopher A. Siedlecki, Henry J. Donahue

Department of Mechanical and Materials Engineering: Faculty Publications

Modulating physical cell culture environments via nanoscale substrate topographic modification has recently been of significant interest in regenerative medicine. Many studies have utilized a polymer-demixing technique to produce nanotextured films and showed that cellular adhesion, proliferation, and differentiation could be regulated by the shape and scale of the polymer-demixed nanotopographies. However, little attention has been paid to the topographic fidelity of the polymer-demixed films when exposed to cell culture conditions. In this brief article, two polymer-demixing systems were employed to assess topographic changes in polymer-demixed films after fibronectin (FN) extracellular matrix protein adsorption and after incubation in phosphate-buffered saline at …

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Usability Assessment Of Two Different Control Modes For The Master Console Of A Laparoscopic Surgical Robot, Xiaoli Zhang, Carl A. Nelson, Dmitry Oleynikov Jan 2012

Usability Assessment Of Two Different Control Modes For The Master Console Of A Laparoscopic Surgical Robot, Xiaoli Zhang, Carl A. Nelson, Dmitry Oleynikov

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this study is to evaluate potential interface control modes for a compact fourdegree- of-freedom (4-DOF) surgical robot. The goal is to improve robot usability by incorporating a sophisticated haptics-capable interface. Two control modes were developed using a commercially available haptic joystick: (1) a virtually point-constrained interface providing an analog for constrained laparoscopic motion (3-DOF rotation and 1-DOF translation), and (2) an unconstrained Cartesian input interface mapping more directly to the surgical tool tip motions. Subjects (n = 5) successfully performed tissue identification and manipulation tasks in an animal model in point-constrained and unconstrained control modes, respectively, with …

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Tool Sequence Trends In Minimally Invasive Surgery: Statistical Analysis And Implications For Predictive Control Of Multifunction Instruments, Carl A. Nelson, Evan Luxon, Dmitry Oleynikov Jan 2012

Tool Sequence Trends In Minimally Invasive Surgery: Statistical Analysis And Implications For Predictive Control Of Multifunction Instruments, Carl A. Nelson, Evan Luxon, Dmitry Oleynikov

Department of Mechanical and Materials Engineering: Faculty Publications

This paper presents an analysis of 67 minimally invasive surgical procedures covering 11 different procedure types to determine patterns of tool use. A new graph-theoretic approach was taken to organize and analyze the data. Through grouping surgeries by type, trends of common tool changes were identified. Using the concept of signal/noise ratio, these trends were found to be statistically strong. The tool-use trends were used to generate tool placement patterns for modular (multi-tool, cartridge-type) surgical tool systems, and the same 67 surgeries were numerically simulated to determine the optimality of these tool arrangements. The results indicate that aggregated tool-use data …

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The Impact Of Wire Stent Fabrication Technique On The Performance Of Stent Placement, Shijia Zhao, Xiangyi (Cheryl) Liu, Linxia Gu Jan 2012

The Impact Of Wire Stent Fabrication Technique On The Performance Of Stent Placement, Shijia Zhao, Xiangyi (Cheryl) Liu, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Braided wire stents demonstrate distinct characteristics compared to welded ones. In this study, both braided and welded wire stents with the same nominal dimensions were crimped inside a sheath and then deployed into a stenosed artery using finite element analysis. The braided wire stent was generated by overlapping wires to form crisscross shape. A welded wire stent was created by welding the intersection points of wires to avoid sliding between wires. The effect of fabrication technique on mechanical behavior of Nitinol wire stents was evaluated. The results showed that relative sliding between wires reduced the deformation of the braided stent, …

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Arterial Wall Mechanics And Clinical Implications After Coronary Stenting: Comparisons Of Three Stent Designs, Linxia Gu, Shijia Zhao, Stacey R. Froemming Jan 2012

Arterial Wall Mechanics And Clinical Implications After Coronary Stenting: Comparisons Of Three Stent Designs, Linxia Gu, Shijia Zhao, Stacey R. Froemming

Department of Mechanical and Materials Engineering: Faculty Publications

The goal of this work is to quantitatively assess the relationship between the reported restenosis rates and stent induced arterial stress or strain parameters through finite element method. The impact of three stent designs (Palmaz–Schatz stent, Express stent, and Multilink Vision stent) on the arterial stress distributions were characterized. The influences of initial stent deployment location, stent-tissue friction, and plaque properties on the arterial stresses were also investigated. Higher arterial stresses were observed at the proximal end of the plaque. The Multilink–Vision stent induced lesser stress concentrations due to the high stiffness of the Cobalt Chromium material and thinner strut …

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Analysis Of A Monolithic, Two-Dimensional Array Of Quartz Crystal Microbalances Loaded By Mass Layers With Nonuniform Thickness, Nan Liu, J. S. Yang, Ji Wang Jan 2012

Analysis Of A Monolithic, Two-Dimensional Array Of Quartz Crystal Microbalances Loaded By Mass Layers With Nonuniform Thickness, Nan Liu, J. S. Yang, Ji Wang

Department of Mechanical and Materials Engineering: Faculty Publications

We study free thickness-shear vibrations of a monolithic, two-dimensional, and periodic array of quartz crystal microbalances loaded by mass layers with gradually varying thickness. A theoretical analysis is performed using Mindlin’s two-dimensional plate equation. It is shown that the problem is mathematically governed by Mathieu’s equation with a spatially varying coefficient. A periodic solution for resonant frequencies and modes is obtained and used to examine the effects of the mass layers. Results show that the vibration may be trapped or untrapped under the mass layers. The trapped modes decay differently in the two in-plane directions of the plate. The mode …

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Shear-Horizontal Vibration Modes Of An Oblate Elliptical Cylinder And Energy Trapping In Contoured Acoustic Wave Resonators, Huijing He, Jiashi Yang, John A. Kosinski Jan 2012

Shear-Horizontal Vibration Modes Of An Oblate Elliptical Cylinder And Energy Trapping In Contoured Acoustic Wave Resonators, Huijing He, Jiashi Yang, John A. Kosinski

Department of Mechanical and Materials Engineering: Faculty Publications

We study shear-horizontal free vibrations of an elastic cylinder with an oblate elliptical cross section and a traction-free surface. Exact vibration modes and frequencies are obtained. The results show the existence of thickness-shear and thickness-twist modes. The energy-trapping behavior of these modes is examined. Trapped modes are found wherein the vibration energy is largely confined to the central portion of the cross section and little vibration energy is found at the edges. It is also shown that face-shear modes are not allowed in such a cylinder. The results are useful for the understanding of the energy trapping phenomenon in contoured …

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The Formulation And Computation Of The Nonlocal J-Integral In Bond-Based Peridynamics, Wenke Hu, Youn Doh Ha, Florin Bobaru, Stewart A. Silling Jan 2012

The Formulation And Computation Of The Nonlocal J-Integral In Bond-Based Peridynamics, Wenke Hu, Youn Doh Ha, Florin Bobaru, Stewart A. Silling

Department of Mechanical and Materials Engineering: Faculty Publications

This work presents a rigorous derivation for the formulation of the J-integral in bond-based peridynamics using the crack infinitesimal virtual extension approach. We give a detailed description of an algorithm for computing this nonlocal version of the J-integral.We present convergence studies (m-convergence and δ-convergence) for two different geometries: a single edge-notch configuration and a double edge-notch sample.We compare the results with results based on the classical J-integral and obtained from FEM calculations that employ special elements near the crack tip.We identify the size of the nonlocal region for which the peridynamic J-integral value is near the classical FEM solutions.We discuss …

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Moisture Damage Characterization Of Warm-Mix Asphalt Mixtures Based On Laboratory-Field Evaluation, Yong-Rak Kim, Jun Zhang, Hoki Ban Jan 2012

Moisture Damage Characterization Of Warm-Mix Asphalt Mixtures Based On Laboratory-Field Evaluation, Yong-Rak Kim, Jun Zhang, Hoki Ban

Department of Mechanical and Materials Engineering: Faculty Publications

This study presents laboratory evaluation integrated with field performance to examine two widely used warm-mix asphalt (WMA) approaches—foaming and emulsion technology. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their counterpart hot-mix asphalt (HMA) mixtures were implemented in Antelope County, Nebraska. Field-mixed loose mixtures collected at the time of paving were transported to the laboratories to conduct various experimental evaluations of the individual mixtures. Among the laboratory tests, three (two conventional and one newly attempted) were performed to characterize moisture damage potential which is the primary focus of this study. From …

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Experimental Evaluation Of Anti-Stripping Additives In Bituminous Mixtures Through Multiple Scale Laboratory Test Results, Yong-Rak Kim, Ingryd Pinto, Seong-Wan Park Jan 2012

Experimental Evaluation Of Anti-Stripping Additives In Bituminous Mixtures Through Multiple Scale Laboratory Test Results, Yong-Rak Kim, Ingryd Pinto, Seong-Wan Park

Department of Mechanical and Materials Engineering: Faculty Publications

This paper presents performance changes and material characteristics associated with moisture dam-age due to anti-stripping additives in asphalt mixtures through various laboratory tests. Two additives (hydrated lime and fly ash) are investigated by adding them into two types of mixes where different asphalt binders and aggregates are used. Two widely used asphalt concrete mixture performance tests (the AASHTO T-283 and the asphalt pavement analyzer under water) and two mixture constituent tests (the boiling water test and the pull-off tensile strength test) are conducted to characterize the effects of anti-stripping additives on the binder-aggregate bonding potential in mixtures. Results from laboratory …

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Monitoring The Wall Mechanics During Stent Deployment In A Vessel, Brian Steinert, Shijia Zhao, Linxia Gu Jan 2012

Monitoring The Wall Mechanics During Stent Deployment In A Vessel, Brian Steinert, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Clinical trials have reported different restenosis rates for various stent designs . It is speculated that stentinduced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis . This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface. As a mesh stent is deployed …

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Novel Coherent Self-Heterodyne Receiver Based On Phase Modulation Detection, Tam N. Huynh, Lim Nguyen, Liam P. Barry Jan 2012

Novel Coherent Self-Heterodyne Receiver Based On Phase Modulation Detection, Tam N. Huynh, Lim Nguyen, Liam P. Barry

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

We propose a novel coherent self-heterodyne receiver structure based on phase modulation detection that potentially simplifies the frontend of a coherent optical receiver. The scheme has been demonstrated via simulations and experimentally for a 10 Gb/s DQPSK transmission system.

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Effects Of Phase Noise Of Monolithic Tunable Laser On Coherent Communication Systems, Tam N. Huynh, Frank Smyth, Lim Nguyen, Liam P. Barry Jan 2012

Effects Of Phase Noise Of Monolithic Tunable Laser On Coherent Communication Systems, Tam N. Huynh, Frank Smyth, Lim Nguyen, Liam P. Barry

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

We investigate the effects of different phase noise processes of SGDBR laser on coherent systems. The SGDBR device operated well with QPSK modulation at 5 Gbaud, while the performance of 16-QAM was significantly degraded due to excess noise. The white FM noise mainly defines the ultimate performance of coherent reception, but the low frequency excess noise can potentially degrade the performance of systems that employ 16-QAM format at 5 Gbaud.

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Redistricting Using Constrained Polygonal Clustering, Deepti Joshi, Leen-Kiat Soh, Ashok Samal Jan 2012

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 …

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Measuring Classroom Engagement By Comparing Instructor Expectations With Students’ Perceptions, Paul Savory, Amy Goodburn, Jody Koenig Kellas Jan 2012

Measuring Classroom Engagement By Comparing Instructor Expectations With Students’ Perceptions, Paul Savory, Amy Goodburn, Jody Koenig Kellas

Department of Communication Studies: Faculty Publications

Even instructors who can demonstrate student success in their courses can be challenged to document which practices are most effective in engaging student learning. National surveys designed to assess student engagement do not provide individual faculty with information that can help them assess their individual teaching efforts. This paper highlights a survey designed to help individual faculty members learn about their students and provides a comparison of instructors’ expectations with students’ perceptions. This paper illustrates the value of such a survey through an extended example of the insights that an instructor gained by using it in her course.

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Applications Of Cognitive Radio Networks, Jordi Perez-Romero, Linda Doyle, Mehmet C. Vuran Jan 2012

Applications Of Cognitive Radio Networks, Jordi Perez-Romero, Linda Doyle, Mehmet C. Vuran

School of Computing: Faculty Publications

The term cognitive radio (CR), originally coined in the late 1990s, envisaged a radio that is aware of its operational environment so that it can dynamically and autonomously adjust its radio-operating parameters to accordingly adapt to the different situations. Cognition is achieved through the so-called cognitive cycle, consisting of the observation of the environment, the orientation and planning that leads to making appropriate decisions in accordance with specific operation goals, and finally, the execution of these decisions (e.g., access to the appropriate channel). Decisions can be reinforced by learning procedures based on the past observations and the corresponding results of …

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Real-Time Scheduling In Mapreduce Clusters, Chen He, Ying Lu, David Swanson Jan 2012

Real-Time Scheduling In Mapreduce Clusters, Chen He, Ying Lu, David Swanson

School of Computing: Technical Reports

MapReduce has been widely used as a Big Data processing platform. As it gets popular, its scheduling becomes increasingly important. In particular, since many MapReduce applications require real-time data processing, scheduling real-time applications in MapReduce environments has become a significant problem. In this paper, we create a novel real-time scheduler for MapReduce, which overcomes the deficiencies of an existing scheduler. It avoids accepting jobs that will lead to deadline misses and improves the cluster utilization. We implement our scheduler in Hadoop system and experimental results show that our scheduler provides deadline guarantees for accepted jobs and achieves good cluster utilization.

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Finding The Boundary Of Use To Improve Repair Mechanisms For Supervised Learning Systems, L. Dee Miller, Leen-Kiat Soh Jan 2012

Finding The Boundary Of Use To Improve Repair Mechanisms For Supervised Learning Systems, L. Dee Miller, Leen-Kiat Soh

School of Computing: Technical Reports

Numerous “repair” mechanisms have been developed to improve the training data for super-vised learning (SL) systems including feature selection, noise correction, and active learning. These repair mechanisms myopically repair in-stances as long the estimated system performance continues to improve. Such general re-pair can lead to unnecessary repairs and overfitting from repair which can lower system performance on new instances. We propose a Boundary of Use (BoU) meta-reasoning framework to decide which instances should be repaired. This framework uses a semi-supervised clustering approach to partition the training instances into regions where the SL system does well without re-pair, regions where it …

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Roles In A Networked Software Development Ecosystem: A Case Study In Github, Patrick Wagstrom, Corey Jergensen, Anita Sarma Jan 2012

Roles In A Networked Software Development Ecosystem: A Case Study In Github, Patrick Wagstrom, Corey Jergensen, Anita Sarma

School of Computing: Technical Reports

Open source software development has evolved beyond single projects into complex networked ecosystems of projects that share portions of their code, social norms, and developer communities. This networked nature allows developers moving into a new project to easily leverage knowledge about process and social norms along with reputation gained in related projects. In this paper we examine a subset of the communities found in GitHub, a large software development community that focuses on “social coding”. We identify a variety of roles in the ecosystem that go beyond the previous user/developer dichotomy and find that these roles often persist across sub-communities …

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Algorithms For The Minimal Network Of A Csp And A Classifier For Choosing Between Them, Shant K. Karakashian, Robert J. Woodward, Berthe Y. Choueiry, Stephen Scott Jan 2012

Algorithms For The Minimal Network Of A Csp And A Classifier For Choosing Between Them, Shant K. Karakashian, Robert J. Woodward, Berthe Y. Choueiry, Stephen Scott

School of Computing: Technical Reports

The minimal constraint network of a constraint satisfaction problem (CSP) is a compiled version of the problem where every tuple in a constraint’s relation appears in at least one solution to the CSP. Recently, Gottlob argued that, when a CSP has this property, a number of NP-hard queries can be answered in polynomial time, but he also showed that deciding whether or not a given network is minimal is NP-complete [Gottlob, 2011]. We propose two search-based algorithms for computing the minimal network of a CSP. We investigate the performance of the two algorithms and propose a classifier to select the …

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On The Benefits Of Providing Versioning Support For End-Users: An Empirical Study, Sandeep Kaur Kuttal, Anita Sarma, Gregg Rothermel Jan 2012

On The Benefits Of Providing Versioning Support For End-Users: An Empirical Study, Sandeep Kaur Kuttal, Anita Sarma, Gregg Rothermel

School of Computing: Technical Reports

End users with little formal programming background are creating software in many different forms, including spreadsheets, web macros, and web mashups. Web mashups are particularly popular because they are relatively easy to create, and because many programming environments that support their creation are available. These programming environments, however, provide no support for tracking versions or provenance of mashups. We believe that versioning support can help end users create, understand, and debug mashups. To investigate this belief, we have added versioning support to a popular wire-oriented mashup environment, Yahoo! Pipes. Our enhanced environment, which we call “Pipes Plumber”, automatically retains versions …

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Automated Generation Of Context-Aware Tests, Zhimin Wang, Sebastian Elbaum, David Rosenblum Jan 2012

Automated Generation Of Context-Aware Tests, Zhimin Wang, Sebastian Elbaum, David Rosenblum

School of Computing: Technical Reports

The incorporation of context-awareness capabilities into pervasive applications allows them to leverage contextual information to provide additional services while maintaining an acceptable quality of service. These added capabilities, however, introduce a distinct input space that can affect the behavior of these applications at any point during their execution, making their validation quite challenging. In this paper, we introduce an approach to improve the test suite of a context-aware application by identifying context-aware program points where context changes may affect the application’s behavior, and by systematically manipulating the context data fed into the application to increase its exposure to potentially valuable …

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Experiments On Video Streaming Over Computer Networks, Steven Becker Jan 2012

Experiments On Video Streaming Over Computer Networks, Steven Becker

School of Computing: Technical Reports

Video traffic (including streaming video service) is dominating the Internet traffic today. Video can be streamed using a dedicated server, a content delivery network (CDN), or peer-to-peer (P2P) overlays across a network. Video can be transmitted in multiple formats and at different resolutions. Video is also being distributed to a variety of devices (fixed and mobile).

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An Efficient Water-Filling Algorithm For Power Allocation In Ofdm-Based Cognitive Radio Systems, Qilin Qi, Yaoqing Lamar Yang Jan 2012

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

School of Computing: 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 …

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A Performance Comparison Of Mobile Wimax Spectrums: 2.5 Ghz Vs. 3.65 Ghz, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif Jan 2012

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

School of Computing: 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 …

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Hyscaleii: A High Performance Hybrid Optical Network Architecture For Data Centers, Shivashis Saha, Jitender S. Deogun, Lisong Xu Jan 2012

Hyscaleii: A High Performance Hybrid Optical Network Architecture For Data Centers, Shivashis Saha, Jitender S. Deogun, Lisong Xu

School of Computing: Conference and Workshop Papers

Tremendous growth in data-intensive cloud applications have resulted in an increased demand for highly scalable data center network (DCN) architectures with high throughput and low network complexity. In this paper, we propose HyScaleII to improve the performance of HyScale [17]. HyScaleII is a switchcentric high performance hybrid optical network based DCN architecture that has most of the desirable properties of a data center, e.g. high scalability, low diameter, high bisection width, fault-tolerance, and low network complexity. We also present an efficient and simple routing scheme called HySII routing, which exploits the structural properties of HyScaleII. In our experiments, HyScaleII …

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Space-Efficient Algorithms For Reachability In Surface-Embedded Graphs, Derrick Stolee, N. V. Vinodchandran Jan 2012

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

School of Computing: 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 …

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Finding Suitable Programs: Semantic Search With Incomplete And Lightweight Specifications, Kathryn T. Stolee Jan 2012

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

School of Computing: 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 …

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Connecting Soil To The Cloud: A Wireless Underground Sensor Network Testbed, John Tooker, Xin Dong, Mehmet C. Vuran, Suat Irmak Jan 2012

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

School of Computing: 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 …

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Amplifying Tests To Validate Exception Handling Code, Pingyu Zhang, Sebastian Elbaum Jan 2012

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

School of Computing: 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 …

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