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.

Accurate WiFi Based Localization for Smartphones Using Peer Assistance

Abstract: Highly accurate indoor localization of smartphones is critical to enable novel location based features for users and businesses. In this paper, we first conduct an empirical investigation of the suitability of WiFi localization for this purpose. We find that although reasonable accuracy can be achieved, significant errors (e.g., 6 8m) always exist. The root cause is the existence of distinct locations with similar signatures, which is a fundamental limit of pure WiFi-based methods. Inspired by high densities of smartphones in public spaces, we propose a peer assisted localization approach to eliminate such large errors. It obtains accurate acoustic ranging estimates among peer phones, then maps their locations jointly against WiFi signature map subjecting to ranging constraints. We devise techniques for fast acoustic ranging among multiple phones and build a prototype. Experiments show that it can reduce the maximum and 80-percentile errors to as small as 2m and 1m, in time no longer than the original WiFi scanning, with negligible impact on battery lifetime.

CIO reporting structure, strategic positioning, and firm performance

Abstract: Almost 30 years after the introduction of the CIO position, the ideal CIO reporting structure (whether the CIO should report to the CEO or the CFO) is yet to be identified. There is an intuitive assumption among some proponents of IT that the CIO should always report to the CEO to promote the importance of IT and the CIO's clout in the firm, while some adversaries of IT call for a CIO-CFO reporting structure to keep a tab on IT spending. However, we challenge these two ad hoc prescriptions by arguing that neither CIO reporting structure is necessarily optimal, and that the CIO reporting structure should not be used to gauge the strategic role of IT in the firm. First, extending the strategy-structure paradigm, we propose that a firm's strategic positioning (differentiation or cost leadership) should be a primary determinant of its CIO reporting structure. We hypothesize that differentiators are more likely to have their CIO report to the CEO in order to pursue IT initiatives that help the firm's differentiation strategy. We also hypothesize that cost leaders are more likely to have their CIO report to the CFO to lead IT initiatives to facilitate the firm's cost leadership strategy. Second, extending the alignment if it view, we propose that firms that align their CIO reporting structure with their strategic positioning (specifically, differentiation with a CIO-CEO reporting structure and cost leadership with a CIO-CFO reporting structure) will have superior future performance. Longitudinal data from two periods (1990-1993 and 2006) support the proposed hypotheses, validating the relationship between a firm's strategic positioning and its CIO reporting structure, and also the positive impact of their alignment on firm performance. These results challenge the ad hoc prescriptions about the CIO reporting structure, demonstrating that a CIO-CEO reporting structure is only superior for differentiators and a CIO-CFO reporting structure is superior only for cost leaders. The CIO reporting structure must, therefore, be designed to align with the firm's strategic positioning, independent of whether IT plays a key strategic role in the firm.

Transmit Subaperturing for MIMO Radars With Co-Located Antennas

Abstract: We present a transmit subaperturing (TS) approach for multiple-input multiple-output (MIMO) radars with co-located antennas. The proposed scheme divides the transmit array elements into multiple groups, each group forms a directional beam and modulates a distinct waveform, and all beams are steerable and point to the same direction. The resulting system is referred to as a TS-MIMO radar. A TS-MIMO radar is a tunable system that offers a continuum of operating modes from the phased-array radar, which achieves the maximum directional gain but the least interference rejection ability, to the omnidirectional transmission based MIMO radar, which can handle the largest number of interference sources but offers no directional gain. Tuning of the TS-MIMO system can be easily made by changing the configuration of the transmit subapertures, which provides a direct tradeoff between the directional gain and interference rejection power of the system. The performance of the TS-MIMO radar is examined in terms of the output signal-to-interference-plus-noise ratio (SINR) of an adaptive beamformer in an interference and training limited environment, where we show analytically how the output SINR is affected by several key design parameters, including the size/number of the subapertures and the number of training signals. Our results are verified by computer simulation and comparisons are made among various operating modes of the proposed TS-MIMO system.