Secur(e/ity) Management: A Continuing Uphill Climb

With ever growing and evolving threats and cyber attacks, the management of enterprise security and the security of enterprise management systems are key to business—if not a nation’s—operations and survival. Secur(e/ity) management, the moniker for the intertwined topics of secure management and security management, has evolved trying to keep pace. The history of secur(e/ity) management is traced from its origins in the disjoint silos of telecommunications, internetworking and computer security to today’s recognition as necessary, interdisciplinary, interworking technologies and operations. An overview of threats and attacks upon managed and management systems shows that occurrences of ever more sophisticated, complex and harder to detect cyber misconduct are increasing as are the severity and costs of their consequences. Introduction of new technologies, expansion of the perimeters of an enterprise and trends in collaborative business partnerships compound the number of managed system targets of cyber compromise. Technical and marketplace trends in secur(e/ity) management reveal needs that must be bridged. Research attention should focus on developing axiomatic understanding of the natural laws of security, tools to realize vulnerability-free software, metrics for assessing the efficacy of secur(e/ity) management, tools for default-deny strategies so that signature-based security management can be retired, secur(e/ity) management approaches for virtualized and service-oriented environments, and approaches for composite, holistic, secur(e/ity) management.

Design of anti-backlash transmissions for precision position control systems

Position control system typical of machine tools and robots usually operate at relatively high torque and low speed. Although servo motors having these characteristics are now available, their cost, size, and weight generally exceed those of the traditional servo motor and gear reducer. Critical applications require transmissions with zero backlash and high stiffness, for which there are several solutions. This article reviews various anti-backlash techniques, discusses their subtleties and applications, develops models, and present design methodologies. Although presented in the context of geared transmissions, the ideas also apply to other machine elements and situations requiring precision and robustness. Two case studies, a robot revolute joint and a machine tool axis of rotation, help to reinforce the theory and raise practical issues.     

Preparation and characterization of electrospun polyurethane–polypyrrole nanofibers and films

Polyurethane (PU)–polypyrrole (PPy) composite films and nanofibers were successfully prepared for the purpose of combining the properties of PU and PPy. Pyrrole (Py) monomer was polymerized and dispersed uniformly throughout the PU matrix by means of oxidative polymerization with cerium(IV) [ceric ammonium nitrate Ce(IV)] in dimethylformamide. Films and nanofibers were prepared with this solution. The effects of the PPy content on the thermal, mechanical, dielectric, and morphological properties of the composites were investigated with differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR)–attenuated total reflection (ATR) spectroscopy, dielectric spectrometry, and scanning electron microscopy. The Young's modulus and glass-transition temperatures of the composites exhibited an increasing trend with increases in the initially added amount of Py. The electrical conductivities of the composite films and nanofibers increased. The crystallinity of the composites were followed with DSC, the mechanical properties were followed with DMA, and the spectroscopic results were followed with FTIR–ATR spectroscopy. In the composite films, a new absorption band located at about 1650 cm⁻¹ appeared, and its intensity improved with the addition of Py. The studied composites show potential for promising applications in advanced electronic devices. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Induction of CYP1A and DNA damage in the fathead minnow (Pimephales promelas) following exposure to biosolids

Biosolids (treated sewage sludge) are increasingly disposed of on land. Thus particle-sorbed and dissolved constituents have the potential to enter nearby watersheds. Although organic contaminants are known to be present in biosolids these are not currently regulated and little data exist on their potential toxicity to aquatic organisms. We exposed Pimephales promelas to two concentrations of biosolids (0.5 and 2.5 g l(-1)) for 28-days (static-renewal) and characterized contaminants present and the extent of CYP1A and DNA damage induction at various time points. Many organic contaminants were detected in the biosolids, with polycyclic aromatic hydrocarbons (PAHs) being the dominant class. Substantial levels of polybrominated diphenyl ethers (PBDEs) and nonylphenols (NPs) were also present. Significant induction of hepatic CYP1A protein compared with controls (P<0.05) was observed in both low (0.5 g l(-1)) and high (2.5 g l(-1)) exposed fish from Day 7. CYP1A levels peaked at Day 21 with 21-fold and 8-fold inductions over controls in high and low dose fish respectively. Induction of DNA damage in hepatocytes (single strand breaks as measured using the COMET assay) was observed in both exposures compared with controls on Days 14 and 28 (P<0.05). A significant correlation was found between CYP1A induction and DNA damage (Pearson correlation index, P<0.05). It is plausible that activation of PAHs may be responsible for the induction of CYP1A and resulting increase in DNA damage. Our data show the potential for detrimental effects in the event of exposure of aquatic organisms to biosolids and the need for further investigations of possible impacts due to constituents not covered by current guidelines.     

Discrete system identification and self-tuning control of dissolved oxygen concentration in a stirred reactor

This work presents the applications of discrete-time system identification and generalized minimum variance (GMV) control of dissolved oxygen (DO) level in a batch bioreactor in which Saccharomyces cerevisiae is produced at aerobic condition. Air flow rate and mixing rate were varied to determine the maximum local liquid phase volumetric mass transfer coefficient (K _L a). Maximum K _L a value was determined at a mixing rate of 600 rpm and air flow rate of 3.4 Lmin⁻¹. For control purpose, manipulated variable was selected as air flow rate due to its effectiveness on the K _L a. To examine the dynamic behavior of the bioreactor, various input signals were utilized as a forcing function and three different model orders were tested. A second0order controlled auto regressive moving average (CARMA) model was used as the process model in the control algorithm and in the system identification step. It is concluded that the ternary input is more suitable than the other input types used in this work for system identification. Recursive least squares method (RLS) was used to determine the model parameters. GMV control results were compared with the traditional PID control results by using performance criteria of IAE and ITAE for different types of DO set point trajectories. DO concentration in the batch bioreactor was controlled more successfully with an adaptive controller structure of GMV than the PID controller with fixed parameters.     

Understanding cassava varietal preferences through pairwise ranking of gari-eba and fufu prepared by local farmer–processors

Within communities in Osun and Imo States of Nigeria, farmer–processors grew and processed a diverse set of improved and landrace cassava varieties into the locally popular foods, gari, eba and fufu. Local and 15 main varieties were grown in a ‘mother and baby trials’ design in each state. Mother trials with three replications were processed by farmer–processors renown in their community for their processing skills. Baby trials were managed and processed by other farmer–processors. The objective was to identify food quality criteria to inform demand-led breeding to benefit users, especially women, given their key roles in processing. Farmer–processors evaluated the overall quality of fresh roots and derived food products through pairwise comparisons. Improved varieties had higher fresh and dry root yield. Overall, landraces ranked first for quality of gari and eba, but several improved varieties were also appreciated for good quality. Landraces in Osun had higher gari yield and a higher swelling power compared to improved varieties. Colour (browning), bulk density, swelling power, solubility and water absorption capacity were the criteria most related to food product ranking by farmer–processors. Evaluation of varieties under farmer–processors’ conditions is crucial for providing guidance to breeders on critical selection criteria.     

Signs of resistance: technology re-membering

While it can be demonstrated historically that sophisticated craft processes predate systematic philosophy, we have yet to appreciate the significance of this fact for an approach to tectonics in architecture. If patterns of thought can, ultimately, be seen to arise out of patterns of action, it might be useful to consider the making process as a source of understanding about the physical world. This paper initially proposes an interdependence between this kind of knowledge and our sense of self- the idea that self-consciousness arises, ultimately, from our engagement with the external environment. By considering certain philosophers' work on the phenomenology of perception, as well as the influence of these ideas on the discussion of materiality in the fine arts, this paper suggests the possibility of a 'narrative tectonics', in describing the potential of our engagement with architecture.