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: Cognitive radio & Wireless network. The organization has 5440 authors who have published 12684 publications receiving 296875 citations. The organization is also known as: Stevens & Stevens Tech.

New Product Development in Turbulent Environments: Impact of Improvisation and Unlearning on New Product Performance

Abstract: Team learning is vital for organizations in order to compete in fast-paced environments. However, the ways learning can be effective in such environments warrents research, especially for teams developing new products under rapidly changing technological and market conditions. Interestingly, recent new product development (NPD) literature demonstrates the essential role of improvisation (i.e., planning and executing any action simultaneously) and unlearning (i.e., changes in team beliefs and project routines) for effective learning and performing under turbulent conditions. However, the combined effect of team improvisation and unlearning on new product success (NPS) has largely been ignored. This paper investigates the nomological relations among team improvisation and unlearning, new product success, and environmental turbulence, and contributes to the literature on NPD team learning, and on team flexibility under turbulent conditions. By examining 197 new product-development projects, we found that (1) environmental turbulence positively affects team unlearning, (2) team unlearning concurrently stimulates team improvisation, (3) team improvisation positively impacts new product success by utilizing/implementing new knowledge acquired by unlearning and improvisation. We further discuss the theoretical and managerial implications of our conclusions.

An Analytical Model for Primary User Emulation Attacks in Cognitive Radio Networks

Abstract: In this paper, we study the denial-of-service (DoS) attack on secondary users in a cognitive radio network by primary user emulation (PUE). Most approaches in the literature on primary user emulation attacks (PUEA) discuss mechanisms to deal with the attacks but not analytical models. Simulation studies and results from test beds have been presented but no analytical model relating the various parameters that could cause a PUE attack has been proposed and studied. We propose an analytical approach based on Fenton's approximation and Markov inequality and obtain a lower bound on the probability of a successful PUEA on a secondary user by a set of co-operating malicious users. We consider a fading wireless environment and discuss the various parameters that can affect the feasibility of a PUEA. We show that the probability of a successful PUEA increases with the distance between the primary transmitter and secondary users. This is the first analytical treatment to study the feasibility of a PUEA.

Stack-based access control and secure information flow

Abstract: Access control mechanisms are often used with the intent of enforcing confidentiality and integrity policies, but few rigorous connections have been made between information flow and runtime access control. The Java virtual machine and the .NET runtime system provide a dynamic access control mechanism in which permissions are granted to program units and a runtime mechanism checks permissions of code in the calling chain. We investigate a design pattern by which this mechanism can be used to achieve confidentiality and integrity goals: a single interface serves callers of more than one security level and dynamic access control prevents release of high information to low callers. Programs fitting this pattern would be rejected by previous flow analyses. We give a static analysis that admits them, using permission-dependent security types. The analysis is given for a class-based object-oriented language with features including inheritance, dynamic binding, dynamically allocated mutable objects, type casts and recursive types. The analysis is shown to ensure a noninterference property formalizing confidentiality and integrity.

Diamagnetic susceptibility at the transition to the superconducting state.

Abstract: Fluctuating Cooper pairs contribute to the diamagnetic susceptibility in a superconductor above the critical temperature. The effect is the greatest in a clean metal where the extra susceptibility is about ${10}^{\ensuremath{-}7}\ifmmode\times\else\texttimes\fi{}{[\frac{{T}_{c}}{(T\ensuremath{-}{T}_{c})}]}^{\frac{1}{2}}$ in a bulk sample.

Hollow fiber solvent extraction removal of toxic heavy metals from aqueous waste streams

Abstract: This study is concerned with the applications of the immobilized interface-based techniques to reversible chemical complexation-based solvent extraction of toxic heavy metals from industrial wastewaters using microporous hydrophobic hollow fiber (MHF) modules. Toxic heavy metals studied were copper and chromium(VI). Each metal was individually removed in separate once-through experiments from a synthetic wastewater by organic extractants flowing in the shell-side countercurrent to wastewater flowing in the fiber bore. The organic extractant used for copper extraction was 5-20 % v/v LIX 84 diluted in n-heptane, and that for chromium extraction was 30 % v/v TOA (tri-n-octylamine) diluted in xylene. A mathematical model was developed to predict the extent of copper extraction from the aqueous synthetic wastewater by the MHF module. The equilibrium constant for copper was determined to be 1.7 from experimental partitioning data. The experimental data on copper extraction in the MHF module are described well by the model if the forward interfacial chemical reaction rate constant is 9.0 X 10[sup [minus]6] cm/s.