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.

New development of ultra-high-performance concrete (UHPC)

Abstract: Ultra-high-performance concrete (UHPC) is a type of cement-based composite for new construction and/or restoration of existing structures to extend service life. UHPC features superior workability, mechanical properties, and durability compared with conventional concrete. However, some challenges limit the wider application of UHPC, such as low workability for large-volume production, high autogenous shrinkage, insufficient flexural/tensile properties, and unpredictable durability after concrete cracking. Therefore, this paper reviews the state-of-the-art technologies for developing UHPC mixtures with improved properties. This review covers the following aspects: (1) the existing design methodologies; (2) the typical ingredients (e.g., binders, aggregates, chemical admixtures, and fibers) for preparation of UHPC and the underlying working principals; (3) the technologies for improving and controlling key properties (e.g., workability, autogenous shrinkage, compressive performance, tensile/flexural properties, and durability); and (4) the representative successful applications. This review is expected to advance the fundamental knowledge of UHPC and promote further research and applications of UHPC.

An examination of the effects of an upward feedback program over time

Abstract: Despite the growing popularity of upward feedback programs, there has been very little research on the effects of upward feedback on changes in managerial performance over time. We examined the effects of implementing an upward feedback program in which subordinates' ratings were collected for 238 first-through fifth-level managers in a large corporation at two points in time about 6 months apart. Research questions drawn from goal-setting, control, and social cognition theories guided our investigation of the effects of (a) receiving feedback, (b) completing self-ratings, (c) managers' initial level of performance, and (d) subordinate's familiarity with the manager on changes over time in the level of ratings and reported opportunity to observe managerial behaviors. Ratings were provided on a 33-item behavioral observation scale that focused on areas such as the manager's commitment to quality, communications, support of subordinates (encouraging participation, coaching), and fairness. Based on subordinates' ratings, managers whose initial level of performance was moderate or low improved over the 6-month period, and this improvement could not be attributed solely to regression to the mean. Also, both managers and their subordinates became more likely over time to indicate that the managers had an opportunity to demonstrate behaviors measured by the upward feedback instrument.

The relative importance of project success dimensions

Abstract: Traditionally, the success of a project is assessed using internal measures such as technical and operational goals, and meeting schedule and budget. More recently, it has been recognized that several other measures should be used to define project success. These measures reflect external effectiveness: the project's impact on its customers, and on the developing organization itself. In our study of 110 defense projects performed by Israeli industry, we used a multidimensional approach to measure the success of defense projects. Based on previous studies, we defined four dimensions of success: meeting design goals; benefits to the customer; benefits to the developing organization; and benefits to the defense and national infrastructure. For each project, we asked three different stakeholders (the customer, the developing organization, and the coordinating office within the Ministry of Defense) for their views on the relative importance of these dimensions of success. Analysis of the data revealed that the dimension benefits to the customer is by far the most important success dimension. The second in importance is meeting design goals. The other two dimensions are relatively unimportant.

Approaching the Intrinsic Photoluminescence Linewidth in Transition Metal Dichalcogenide Monolayers

Abstract: Excitonic states in monolayer transition metal dichalcogenides (TMDCs) have been the subject of extensive recent interest. Their intrinsic properties can, however, be obscured due to the influence of inhomogeneity in the external environment. Here we report methods for fabricating high quality TMDC monolayers with narrow photoluminescence (PL) linewidth approaching the intrinsic limit. We find that encapsulation in hexagonal boron nitride (h-BN) sharply reduces the PL linewidth, and that passivation of the oxide substrate by an alkyl monolayer further decreases the linewidth and also minimizes the charged exciton (trion) peak. The combination of these sample preparation methods results in much reduced spatial variation in the PL emission, with a full-width-at-half-maximum as low as 1.7 meV. Analysis of the PL line shape yields a homogeneous width of 1.43$\pm$0.08 meV and inhomogeneous broadening of 1.1$\pm$0.3 meV.