Science and Technology Studies Commons^™

Myth Or Fact: Is Open Source Software More Secure Than Closed Source Software?, Daniel Saffioti, Gene Awyzio, Robert B. K. Brown

Associate Professor Daniel F. Saffioti

This paper examines one aspect of quality that organizations look for when selecting software, namely security. Studies over time have indicated that security; scalability, interoperability and flexibility are important however the major issue has always been support. This has led to the sometimes inflexible concept of Standard Operating Environments (SOEs) within organisations. Whilst SOEs provide many benefits to an organisation they can leave them vulnerable to several large security risks. CERT statistics show that security incidents have increased six fold since 2000 [1]. This paper will examine trends in both open and closed software development for a number of platforms …

Engineering Standards In Highway Design Litigation, Michael Lewyn

Michael E Lewyn

Effect Of Suction History On The Small Strain Response Of A Dynamically Compacted Soil, Ana Heitor, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Ana Heitor

The small strain behaviour is a key indicator for assessing the performance of compacted fills. Compaction conditions i.e. initial moisture content and applied energy, govern compaction effectiveness and, thus, the structure and matric suction of compacted soil. During their service life, most earth structures experience changes in hydraulic behaviour owing to climatic changes. While the results of previous research studies indicate that the effect of changes in suction on the dynamic response is significant, only limited research has been engaged in the assessment of the effect of post-compacted changes in suction induced by periods of intensive precipitation (i.e. wetting) and …

Greenland Ice Sheet Mass Balance Reconstruction. Part I: Net Snow Accumulation (1600-2009), Jason E. Box, Noel Cressie, David H. Bromwich, Ji-Hoon Jung, Michiel Van Den Broeke, J H. Van Angelen, Richard R. Forster, Clement Miege, Ellen Mosley-Thompson, Bo Vinther, Joseph R. Mcconnell

Professor Noel Cressie

Ice core data are combined with RACMO2 regional climate model (RCM) output (1958-2010) to develop a reconstruction of the Greenland ice sheet net snow accumulation rate (Ât(G)) spanning years 1600-2009. Regression parameters from RCM output regressed on 86 ice cores are used with available cores in a given year resulting in the reconstructed values. Each core site’s residual variance is used to inversely weight the cores’ respective contributions. The interannual amplitude of the reconstructed accumulation rate is damped by the regressions and is thus calibrated to match that of the RCM data. Uncertainty and significance of changes is measured using …

Figures Of Merit For Simultaneous Inference And Comparisons In Simulation Experiments, Noel A. Cressie, Sandy Burden

Professor Noel Cressie

2015 John Wiley & Sons, Ltd. This article considers the traditional figures of merit, namely, bias and mean squared (prediction) error, which are typically used to evaluate simulation experiments. We propose functions of them that account for different variables' units; these alternative figures of merit are closely tied to simultaneous multivariate inference on an unknown parameter vector or unknown state vector. Their usefulness is illustrated in a simulation experiment, where the goal is to determine the statistical properties associated with prediction of a multivariate state.

Bayesian Learning And Predictability In A Stochastic Nonlinear Dynamical Model, John Parslow, Noel Cressie, Edward P. Campbell, Emlyn Jones, Lawrence Murray

Professor Noel Cressie

Bayesian inference methods are applied within a Bayesian hierarchical modelling framework to the problems of joint state and parameter estimation, and of state forecasting. We explore and demonstrate the ideas in the context of a simple nonlinear marine biogeochemical model. A novel approach is proposed to the formulation of the stochastic process model, in which ecophysiological properties of plankton communities are represented by autoregressive stochastic processes. This approach captures the effects of changes in plankton communities over time, and it allows the incorporation of literature metadata on individual species into prior distributions for process model parameters. The approach is applied …

Comment On Article By Ferreira And Gamerman, Noel A. Cressie, Raymond L. Chambers

Professor Noel Cressie

A utility-function approach to optimal spatial sampling design is a powerful way to quantify what "optimality" means. The emphasis then should be to capture all possible contributions to utility, including scientific impact and the cost of sampling. The resulting sampling plan should contain a component of designed randomness that would allow for a non-parametric design-based analysis if model-based assumptions were in doubt.

The Digital Dionysus: Nietzsche & The Network-Centric Condition

Dan Mellamphy

No abstract provided.

Aeronautics Education, Research, And Industry Alliance (Aerial) Progress Report And Proposal, Brent D. Bowen

Brent Bowen

UNOAI Report 04-2

The Aeronautics Education, Research, and Industry Alliance (AERIAL), which began as a comprehensive, mufti-faceted NASA EPSCoR 2000 initiative, has contributed substantially to the strategic research and technology priorities of NASA, while intensifying Nebraska's rapidly growing aeronautics research and development endeavors. AERIAL has enabled Nebraska researchers to: (a) continue strengthening their collaborative relationships with NASA Field Centers, Codes, and Enterprises; Co) increase the capacity of higher education throughout Nebraska to invigorate and expand aeronautics research; and (c) expedite the development of aeronautics-related research infrastructure and industry in the state. Nebraska has placed emphasis on successfully securing additional funds …

Aeronautics Education, Research, And Industry Alliance (Aerial) Progress Report And Proposal, Brent D. Bowen

Brent Bowen

UNOAI Report 04-2 The Aeronautics Education, Research, and Industry Alliance (AERIAL), which began as a comprehensive, mufti-faceted NASA EPSCoR 2000 initiative, has contributed substantially to the strategic research and technology priorities of NASA, while intensifying Nebraska's rapidly growing aeronautics research and development endeavors. AERIAL has enabled Nebraska researchers to: (a) continue strengthening their collaborative relationships with NASA Field Centers, Codes, and Enterprises; Co) increase the capacity of higher education throughout Nebraska to invigorate and expand aeronautics research; and (c) expedite the development of aeronautics-related research infrastructure and industry in the state. Nebraska has placed emphasis on successfully securing additional funds …

Exploring Bridge-Engine Control Room Collaborative Team Communication, Aditi Kataria, Eric Holder, Gesa Praetorius, Michael Baldauf, Jens-Uwe Schröder-Hinrichs

Michael Baldauf

The EC funded CyClaDes research project is designed to promote the increased impact of the human element in shipping across the design and operational lifecycle of ships. It addresses the design and operation of ships and ship systems. One of the CyClaDes’ tasks is to create a crew‐centered design case‐study examination of the information that is shared between the Bridge and Engine Control Room (ECR) that helps the crew coordinate to ensure understanding and complete interconnected tasks. This information can be provided in various ways, including communication devices or obtained from a common database, display, or even the ship environment …

Stochastic Modeling And Optimization Of Multi-Plant Capacity Planning Problem, Anoop Verma, Nagesh Shukla, S.K Tyagi, Nishikant Mishra

Nagesh Shukla

n this paper the problem of capacity planning under risk from demand and price/cost uncertainty of the finished products is addressed. The deterministic model is extended into a two-stage stochastic model with fixed recourse by means of various expected levels of demand as random. A recourse penalty is also included in the objective for both shortage and surplus in the finished products. The model is analyzed to quantify the risk using Markowitz mean-variance model.

Tour-Based Travel Mode Choice Estimation Based On Data Mining And Fuzzy Techniques, Nagesh Shukla, Jun Ma, Rohan Wickramasuriya, Nam N. Huynh, Pascal Perez

Nagesh Shukla

No abstract provided.

Summability For Nonunital Spectral Triples, Adam C. Rennie

Associate Professor Adam Rennie

This paper examines the issue of summability for spectral triples for the class of nonunital algebras. For the case of (p, -) summability, we prove that the Dixmier trace can be used to define a (semifinite) trace on the algebra of the spectral triple. We show this trace is well-behaved, and provide a criteria for measurability of an operator in terms of zeta functions. We also show that all our hypotheses are satisfied by spectral triples arising from eodesically complete Riemannian manifolds. In addition, we indicate how the Local Index Theorem of Connes-Moscovici extends to our nonunital setting.

Smoothness And Locality For Nonunital Spectral Triples, Adam C. Rennie

Associate Professor Adam Rennie

To deal with technical issues in noncommuntative geometry for nonunital algebras, we introduce a useful class of algebras and their modules. Thes algebras and modules allo us to extend all of the smoothness results for spectral triples to the nonunital case. In addition, we show that smooth spectral tiples are closed under the C- functional calculus of self-adjoint elements. In the final section we show that our algebras allow the formulation of Poincare Duality and that the algebras of smooth spectral triples are H-unital.

The Resolvent Cocycle In Twisted Cyclic Cohomology And A Local Index Formula For The Podle's Sphere, Adam Rennie, Roger Senior

Associate Professor Adam Rennie

We continue the investigation of twisted homology theories in the context of dimension drop phenomena. This work unifies previous equivariant index calculations in twisted cyclic cohomology. We do this by proving the existence of the resolvent cocycle, a finitely summable analogue of the JLO cocycle, under weaker smoothness hypotheses and in the more general setting of 'modular' spectral triples. As an application we show that using our twisted resolvent cocycle, we can obtain a local index formula for the Podles sphere. The resulting twisted cyclic cocycle has non-vanishing Hochschild class which is in dimension 2.

The K-Theory Of Heegaard Quantum Lens Spaces, Piotr M. Hajac, Adam Rennie, Bartosz Zielinski

Associate Professor Adam Rennie

Representing Z/NZ as roots of unity, we restrict a natural U(1)-action on the Heegaard quantum sphere to Z/NZ, and call the quotient spaces Heegaard quantum lens spaces. Then we use this representation of Z/NZ to construct an associated complex loine bundle. This paper proves the stable non-triviality of these line bundles over any of the quantum lens spaces we consider. We use the pullback structure of the C*-algebra of the lens space to compute its K-theory via the Mayer-Vietoris sequence, and an explicit form of the Bass connecting homomorphism to prove the stable non-triviality of the bundles. On the algebraic …

The Fate Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters And Pesticides During Mbr Treatment, Kaushalya C. Wijekoon, Faisal I. Hai, Jinguo Kang, William E. Price, Wenshan Guo, Hao H. Ngo, Long D. Nghiem

Faisal I Hai

This study examined the relationship between molecular properties and the fate of trace organic contaminants (TrOCs) in the aqueous and solid phases during wastewater treatment by MBR. A set of 29 TrOCs was selected to represent pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides that occur ubiquitously in municipal wastewater. Both adsorption and biodegradation/transformation were found responsible for the removal of TrOCs by MBR treatment. A connection between biodegradation and molecular structure could be observed while adsorption was the dominant removal mechanism for the hydrophobic (logD > 3.2) compounds. Highly hydrophobic (logD > 3.2) but readily biodegradable compounds did not accumulate in sludge. …

Effects Of Salinity Build-Up On Biomass Characteristics And Trace Organic Chemical Removal: Implications On The Development Of High Retention Membrane Bioreactors, Wenhai Luo, Faisal I. Hai, Jinguo Kang, William E. Price, Wenshan Guo, Hao H. Ngo, Kazuo Yamamoto, Long D. Nghiem

Faisal I Hai

This study investigated the impact of salinity build-up on the performance of membrane bioreactor (MBR), specifically in terms of the removal and fate of trace organic chemicals (TrOCs), nutrient removal, and biomass characteristics. Stepwise increase of the influent salinity, simulating salinity build-up in high retention MBRs, adversely affected the metabolic activity in the bioreactor, thereby reducing organic and nutrient removal. The removal of hydrophilic TrOCs by MBR decreased due to salinity build-up. By contrast, with the exception of 17α-ethynylestradiol, the removal of all hydrophobic TrOCs was not affected at high salinity. Moreover, salinity build-up had negligible impact on the residual …

Continuous Biotransformation Of Bisphenol A And Diclofenac By Laccase In An Enzymatic Membrane Reactor, Ngoc Luong Nguyen, Faisal I. Hai, William Price, Frederic Leusch, Felicity Roddick, Ewan J. Mcadam, Saleh Faraj Magram, Long D. Nghiem

Faisal I Hai

A novel enzymatic membrane reactor (EMR) was explored for continuous removal of two trace organic contaminatnts (TrOCs) ubiquitously detected in wastewater - namely bisphenol A (BPA and diclofnac (DCF) - by a commercially available laccase from aspergillus oryzae.

Development Of A Predictive Framework To Assess The Removal Of Trace Organic Chemicals By Anaerobic Membrane Bioreactor, Kaushalya C. Wijekoon, James Mcdonald, Stuart J. Khan, Faisal I. Hai, William E. Price, Long D. Nghiem

Faisal I Hai

This study aims to develop a predictive framework to assess the removal and fate of trace organic chemicals (TrOCs) during wastewater treatment by anaerobic membrane bioreactor (AnMBR). The fate of 27 TrOCs in both the liquid and sludge phases during AnMBR treatment was systematically investigated. The results demonstrate a relationship between hydrophobicity and specific molecular features of TrOCs and their removal efficiency. These molecular features include the presence of electron withdrawing groups (EWGs) or donating groups (EDGs), especially those containing nitrogen and sulphur. All seven hydrophobic contaminants were well removed (>70%) by AnMBR treatment. Most hydrophilic TrOCs containing EDGs …

Enhancement Of Removal Of Trace Organic Contaminants By Powdered Activated Carbon Dosing Into Membrane Bioreactors, Ngoc Luong Nguyen, Faisal Ibney Hai, Long Nghiem, Jinguo Kang, William Price, Chul Park, Kazuo Yamamoto

Faisal I Hai

This study compared the removal efficiency of 22 widespread trace organic contaminants by a laboratory-scale membrane bioreactor (MBR) with and without direct addition of powdered activated carbon (PAC) into the activated sludge reactor over a period of 312 days. The removal of hydrophilic and biologically persistent trace organic contaminants was immediately improved to above 95% after the addition of PAC into MBR. However, a compound-specific gradual decrease in removal underscored the requirement for the addition of fresh PAC. Adsorption onto PAC-added sludge appeared to play a significant role in the relatively more effective aqueous phase removal of a few resistant …

Introduction - A Review Of Membrane Reactors, Fausto Gallucci, Angelo Basile, Faisal Ibney Hai

Faisal I Hai

In the last decades, membrane catalysis has been studied by several research and the significant progress in this field is summarized in several review articles (Armor 1998, Lin 2001, Lu 2007, Mcleary 2006, Sanchez 2002, Saracco 1994, Shu 1991). Considering a IUPAC definition (Koros 1996), a membrane reactor (MR) is a device for simultaneously performing a reaction (steam reforming, dry reforming, autothermal reforming, etc.) and a membrane-based separation in the same physical device. Therefore, the membrane not only plays the role of a separator, but also takes place in the reaction itself. The term Membrane Bioreactor (MBR), on the other …

Removal Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters, Industrial Chemicals And Pesticides By Trametes Versicolor: Role Of Biosorption And Biodegradation, Luong Nguyen, Faisal Ibney Hai, Shufan Yang, Jinguo Kang, Frederic Leusch, Felicity Roddick, William E. Price, Long D. Nghiem

Faisal I Hai

This study reports the removal of 30 diverse trace organic contaminants (TrOC) by live (biosorption þ biodegradation), intracellular enzyme-inhibited and chemically inactivated (biosorption only) whole-cell preparations and the fungal extracellular enzyme extract (predominantly laccase) from Trametes versicolor (ATCC 7731). Because phenolic substrates are amenable to degradation by laccase, all 14 phenolic TrOC were readily biodegraded. On the other hand, only eight of the 16 non-phenolic TrOC were readily biodegraded while the removal of hydrophilic TrOC (log D < 3) was negligible. With the exception of diclofenac, no non-phenolic TrOC were degraded by the extracellular enzyme extract. The whole-cell culture showed considerably …

Selection Of Forward Osmosis Draw Solutes For Subsequent Integration With Anaerobic Treatment To Facilitate Resource Recovery From Wastewater, Ashley J. Ansari, Faisal I. Hai, Wenshan Guo, Hao H. Ngo, William E. Price, Long D. Nghiem

Faisal I Hai

Forward osmosis (FO) can be used to extract clean water and pre-concentrate municipal wastewater to make it amenable to anaerobic treatment. A protocol was developed to assess the suitability of FO draw solutes for pre-concentrating wastewater for potential integration with anaerobic treatment to facilitate resource recovery from wastewater. Draw solutes were evaluated in terms of their ability to induce osmotic pressure, water flux, and reverse solute flux. The compatibility of each draw solute with subsequent anaerobic treatment was assessed by biomethane potential analysis. The effect of each draw solute (at concentrations corresponding to the reverse solute flux at ten-fold pre-concentration …

Sludge Cycling Between Aerobic, Anoxic And Anaerobic Regimes To Reduce Sludge Production During Wastewater Treatment: Performance, Mechanisms, And Implications, Galilee Semblante, Faisal Ibney Hai, Huu H. Ngo, Wenshan Guo, Sheng-Jie You, William Price, Long Nghiem

Faisal I Hai

Alternate cycling of sludge in aerobic, anoxic, and anaerobic regimes is a promising strategy that can reduce the sludge yield of conventional activated sludge (CAS) by up to 50% with potentially lower capital and operating cost than physical- and/or chemical-based sludge minimisation techniques. The mechanisms responsible for reducing sludge yield include alterations to cellular metabolism and feeding behaviour (metabolic uncoupling, feasting/fasting, and endogenous decay), biological floc destruction, and predation on bacteria by higher organisms. Though discrepancies across various studies are recognisable, it is apparent that sludge retention time, oxygen-reduction potential of the anaerobic tank, temperature, sludge return ratio and loading …

The Effects Of Mediator And Granular Activated Carbon Addition On Degradation Of Trace Organic Contaminants By An Enzymatic Membrane Reactor, Luong N. Nguyen, Faisal I. Hai, William E. Price, Frederic Leusch, Felicity Roddick, Hao H. Ngo, Wenshan Guo, Saleh Faraj Magram, Long D. Nghiem

Faisal I Hai

The removal of four recalcitrant trace organic contaminants (TrOCs), namely carbamazepine, diclofenac, sulfamethoxazole and atrazine by laccase in an enzymatic membrane reactor (EMR) was studied. Laccases are not effective for degrading non-phenolic compounds; nevertheless, 22-55% removal of these four TrOCs was achieved by the laccase EMR. Addition of the redox-mediator syringaldehyde (SA) to the EMR resulted in a notable dose-dependent improvement (15-45%) of TrOC removal affected by inherent TrOC properties and loading rates. However, SA addition resulted in a concomitant increase in the toxicity of the treated effluent. A further 14-25% improvement in aqueous phase removal of the TrOCs was …

Removal Of Emerging Trace Organic Contaminants By Mbr-Based Hybrid Treatment Processes, Luong Nguyen, Faisal Ibney Hai, Jinguo Kang, William E. Price, Long D. Nghiem

Faisal I Hai

The aim of this study was to demonstrate the complementarity of combining membrane bioreactor (MBR) treatment with UV oxidation or high pressure membrane filtration processes such as nanofiltration (NF) or reverse osmosis (RO) for the removal of trace organic contaminants (TrOC). The results suggest that the removal mechanisms of TrOC by either UV oxidation or NF/RO membrane filtration differ significantly from those of an MBR system. Thus, they can complement MBR treatment very well to significantly improve the removal of TrOC. MBR treatment can effectively remove hydrophobic and readily biodegradable hydrophilic TrOC. The remaining hydrophilic and biologically persistent TrOC were …

Removal And Fate Of Micropollutants In A Sponge-Based Moving Bed Bioreactor, Yunlong Luo, Wenshan Guo, Huu H. Ngo, Long Nghiem, Faisal Ibney Hai, Jinguo Kang, Siqing Xia, Zhiqiang Zhang, William Price

Faisal I Hai

This study investigated the removal of micropollutants using polyurethane sponge as attached-growth carrier. Batch experiments demonstrated that micropollutants could adsorb to non-acclimatized sponge cubes to varying extents. Acclimatized sponge showed significantly enhanced removal of some less hydrophobic compounds (logD < 2.5), such as ibuprofen, acetaminophen, naproxen, and estriol, as compared with non-acclimatized sponge. The results for bench-scale sponge-based moving bed bioreactor (MBBR) system elucidated compound-specific variation in removal, ranging from 25.9% (carbamazepine) to 96.8% (b-Estradiol 17-acetate) on average. In the MBBR system, biodegradation served as a major removal pathway for most compounds. However, sorption to sludge phase was also a notable …

Effects Of Iron Salt Addition On Biosolids Reduction By Oxic-Settling-Anoxic (Osa) Process, Galilee U. Semblante, Faisal I. Hai, Heriberto Bustamante, Nelly Guevara, William E. Price, Long D. Nghiem

Faisal I Hai

The oxic-settling anoxic (OSA) process interchanges activated sludge between alternating redox conditions (e.g., aerobic and anoxic) to reduce biosolids production. Iron salts addition to wastewater is performed to remove phosphorous, but this study demonstrated that it may impair OSA performance. Batch test results showed that the addition of iron salt (as Fe2+) decreased the volatile solids reduction of an intermittently aerated batch reactor (i.e., aerobic/anoxic), probably because iron reduced the destruction of extracellular polymeric substances (EPS) that serve as the structural framework of sludge flocs. The effect of different FeCl2 dosages (0, 15, and 30 mg l−1) on the sludge …