Stevens Institute of Technology

About: Stevens Institute of Technology is a education organization based out in Hoboken, New Jersey, United States. It is known for research contribution in the topics: Computer science & Cognitive radio. The organization has 5440 authors who have published 12684 publications receiving 296875 citations. The organization is also known as: Stevens & Stevens Tech.

Cooperative relay techniques for cognitive radio systems: Spectrum sensing and secondary user transmissions

Abstract: Cognitive radio is a promising technology that enables an unlicensed user (also known as a cognitive user) to identify the white space of a licensed spectrum band (called a spectrum hole) and utilize the detected spectrum hole for its data transmissions. To design a reliable and efficient cognitive radio system, there are two fundamental issues: to devise an accurate and robust spectrum sensing algorithm to detect spectrum holes as accurately as possible; and to design a secondary user transmission mechanism for the cognitive user to utilize the detected spectrum holes as efficiently as possible. This article investigates and shows that cooperative relay technology can significantly benefit the abovementioned two issues, spectrum sensing and secondary transmissions. We summarize existing research about the application of cooperative relays for spectrum sensing (referred to as the cooperative sensing) and address the related potential challenges. We discuss the use of cooperative relays for the secondary transmissions with a primary user's quality-of-service (QoS) constraint, for which a diversity-multiplexing trade-off is developed. In addition, this article shows a trade-off design of cognitive transmissions with cooperative relays by jointly considering the spectrum sensing and secondary transmissions in cognitive radio networks.

Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus.

Abstract: Aims: The focus of this study was to evaluate the potential use of the predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to control the pathogens associated with human infection. Methods and Results: By coculturing B. bacteriovorus 109J and M. aeruginosavorus ARL-13 with selected pathogens, we have demonstrated that predatory bacteria are able to attack bacteria from the genus Acinetobacter, Aeromonas, Bordetella, Burkholderia, Citrobacter, Enterobacter, Escherichia, Klebsiella, Listonella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio and Yersinia. Predation was measured in single and multispecies microbial cultures as well as on monolayer and multilayer preformed biofilms. Additional experiments aimed at assessing the optimal predation characteristics of M. aeruginosavorus demonstrated that the predator is able to prey at temperatures of 25–37°C but is unable to prey under oxygen-limiting conditions. In addition, an increase in M. aeruginosavorus ARL-13 prey range was also observed. Conclusions: Bdellovibrio bacteriovorus and M. aeruginosavorus have an ability to prey and reduce many of the multidrug-resistant pathogens associated with human infection. Significance and Impact of the Study: Infectious complications caused by micro-organisms that have become resistant to drug therapy are an increasing problem in medicine, with more infections becoming difficult to treat using traditional antimicrobial agents. The work presented here highlights the potential use of predatory bacteria as a biological-based agent for eradicating multidrug-resistant bacteria, with the hope of paving the way for future studies in animal models.

Siberian wetlands: Where a sink is a source

Abstract: [1] A greenhouse gas inventory can for some ecosystems be based solely on the net CO2 exchange with the atmosphere and the export of dissolved organic carbon. In contrast, the global warming effect may be more complex in ecosystems where other greenhouse gases such as CH4 or N2O have significant exchanges with the atmosphere. Through micrometeorological landscape- scale measurements from the largest wetlands on Earth in West Siberia we show that CH4 has a stronger effect than CO2 on the greenhouse gas budget in terms of radiative forcing on the atmosphere. Direct measurements of the CO2 and CH4 exchange during the summer of 1999 show that these wetland ecosystems, on average, acted as net sinks of carbon of 0.5 g C m(-2) day(-1) but large net sources of CH4. Given the high Global Warming Potential of CH4, the Siberian wetlands are an important source of radiative forcing, even in comparison to anthropogenic emissions. (Less)

Key Issues for IT Executives 2009: Difficult Economy’s Impact on IT

Abstract: The global financial crisis has brought exacting times for organizations around the world. Faced with sharp decreases in revenue, companies have experienced IT budget and salary reductions, projects and purchases put on hold, and hiring freezes. While many IT organizations have been collaborating with their business partners to leverage IT to help reduce costs and improve productivity across the business, most are anticipating an economic turnaround, albeit not with much optimism, for a better 2010. When this survey was conducted, in June 2009, initial signs of the recession’s end had begun to appear, although companies were, and remain, cautious about future initiatives. Since its inception in 1980, the Society for Information Management (SIM) survey has helped IT leaders around the globe understand important issues and trends. This article presents the major findings based on survey responses from 243 U.S. organizations. The top five management concerns in 2009 were: 1. Business productivity and cost reduction; 2. IT and business alignment; 3. Business agility and speed to market; 4. Business process re-engineering; 5. IT cost reduction.This is the fourth in a series of MISQE-published reports based on the SIM membership survey facilitated by the lead author. As in previous surveys, this article also presents findings on key application and technology development, and on various aspects of the IT organization. This year, the survey included additional results from European (27) and Chinese (174) organizations, giving the survey a more global perspective. The respective similarities and differences between the U.S. and these other two regions are highlighted throughout this article.

Innovation Strategies Under Uncertainty: A Contingency Approach for New Product Development

Abstract: Innovation is especially critical, yet risky, in dynamic, uncertain markets where the product or service employs new and uncertain technologies. Under these conditions, the new product professional should rely on a variety of tools and techniques to assist him or her to innovate more effectively with a greater probability of succeeding. The new product development literature offers several tools to help. These tools are based on one of six innovation strategies: process, speed, learning, market, technology, and quantitative. However, it is not clear which strategy should be used and when. This article examines these dominant innovation strategies and evaluates their applicability in the environment of emerging markets with emerging technologies. We have found that for the more extreme forms of innovation, a learning-based strategy will improve the chances of success.