Analysis of wideband phased array beamforming at millimeter wave frequencies

Abstract. Industries are undergoing an information and communication technology-driven transformation as the world becomes increasingly digitally and globally linked. 5G technology provides a common basis for providing the multiple vertical sectors with a more cost-effective, open, and wide ecosystem solutions. Due to the generally large attainable bandwidths, high frequency technologies have emerged as a promising solution for future wireless communications and attracted great interest in the literature. The millimeter wave (mmWave), i.e., the frequency range 30–300 GHz, would enable the exploitation of tens of gigahertz transmission bands, resulting in a massive channel capacities of even over one Tbps. However, one of the most challenging issues in high-frequency communication connections is the significant channel losses that require highly directional antennas and, in most cases, line-of-sight link between the transmitter and receiver. In this thesis, we study the beamforming design for wideband systems with different bandwidths. The simulation results show that with a larger bandwidth, the power loss increases with the beamforming angle. The loss of power behavior due to beam squinting effect is quite similar over different distances

Reproductive and developmental toxicity testing: Examination of the extended one-generation reproductive toxicity study guideline

AbstractAn important aspect of safety assessment of chemicals (industrial and agricultural chemicals and pharmaceuticals) is determining their potential reproductive and developmental toxicity. A number of guidelines have outlined a series of separate reproductive and developmental toxicity studies from fertilization through adulthood and in some cases to second generation. The Extended One-Generation Reproductive Toxicity Study (EOGRTS) is the most recent and comprehensive guideline in this series. EOGRTS design makes toxicity testing progressive, comprehensive, and efficient by assessing key endpoints across multiple life-stages at relevant doses using a minimum number of animals, combining studies/evaluations and proposing tiered-testing approaches based on outcomes. EOGRTS determines toxicity during preconception, development of embryo/fetus and newborn, adolescence, and adults, with specific emphasis on the nervous, immunological, and endocrine systems, EOGRTS also assesses maternal and paternal toxicity. However, EOGRTS guideline is complex, criteria for selecting doses is unclear, and monitoring systemic dose during the course of the study for better interpretation and human relevance is not clear. This paper discusses potential simplification of EOGRTS, suggests procedures for relevant dose selection and monitors systemic dose at multiple life-stages for better interpretation of data and human relevance

The Use of ICT in Education: Focus on Nigeria

The use of ICT in educational settings is a catalyst for change. The paper has sought to explore the role of ICT in education as we progress into the 21st century. The first phase focuses on the conceptual framework of the use of ICT in education. In this model the dependent variable is education and its sub variables are educational level of teachers and students which is directly affected by the independent variables which are the use of ICTs, ICT infrastructure and staff development. The second phase is the pilot study to answer two major questions: (i) Is ICT mandatory or voluntary at your institutions? (ii) What are the greatest barriers to using ICT to you as an academician? The results show that majority of the academic staff (86%) responded that ICT is mandatory. However, the survey revealed that most of the part-time lecturers ticked the use of ICT as voluntary. Some of these part-time lecturers in the cadre of professors, responded to Q32 as (do not fit my program). Actually in their dispensation, lecturing was done using the chalk board only. The research confirms that two major barriers affect the use of ICT; they are lack of time to use ICT the systems and training opportunities. Respondents on these are 38% and 32% respectively. Based on these findings, the paper recommended that, all employed teachers in Federal, State and Private institutions should undertake mandatory training and retraining on ICT programmers. The government should develop ICT policies and guidelines for the application of ICT in education

Behavior and properties of tin slag polyester polymer concrete confined with frp composites under compression

Polymer concrete (PC) has acquired niche in construction industry due to superior mechanical properties, recyclability and adoption of variety of aggregates. This workpresents compressive behavior and properties of one such novel PC i.e. tin slag/polyester polymer concrete. Comparable siliceous content of tin slag was considered promising to provide better mechanical strength as in natural aggregates. Cylindrical short column specimens were fabricated to be tested under quasi-isostatic loading rate of 1 mm/min. Three different aggregate sizes in gap-graded configuration were tested to assess influence on mechanical properties. In addition, specimens were confined with GFRP and CFRP to determine and compare mechanical behavior with Portland Cement Concrete (PCC). Coarsest size (4+2 mm) aggregate offered the highest strength of 37.71 MPa for unconfined sample. This performance of coarsest size persisted in confined condition with compressive strength increment of 69.68 MPa (84.7%) and 98.36 MPa (160.8%) for one and two layers GFRP; 86 MPa (128.05%) and 125.07 MPa (231.66)% for one and two-layer CFRP, respectively. It was concluded that both increment in aggregate size and number of layers improved the compressive strength

Creatr, a genergtic graphical distributed debugger with language support for application interfacing

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 84-86).by Shakil A. Chunawala.M.S

Traceability for Model Driven, Software Product Line Engineering

Traceability is an important challenge for software organizations. This is true for traditional software development and even more so in new approaches that introduce more variety of artefacts such as Model Driven development or Software Product Lines. In this paper we look at some aspect of the interaction of Traceability, Model Driven development and Software Product Line

Immunosuppression for liver transplantation in HCV-infected patients: Mechanism-based principles

We retrospectively analyzed 42 hepatitis C virus (HCV)-infected patients who underwent cadaveric liver transplantation under two strategies of immunosuppression: (1) daily tacrolimus (TAC) throughout and an initial cycle of high-dose prednisone (PRED) with subsequent gradual steroid weaning, or (2) intraoperative antithymocyte globulin (ATG) and daily TAC that was later space weaned. After 36 ± 4 months, patient and graft survival in the first group was 18/19 (94.7%) with no examples of clinically serious HCV recurrence. In the second group, the three-year patient survival was 12/23 (52%), and graft survival was 9/23 (39%); accelerated recurrent hepatitis was the principal cause of the poor results. The data were interpreted in the context of a recently proposed immunologic paradigm that is equally applicable to transplantation and viral immunity. In the framework of this paradigm, the disparate hepatitis outcomes reflected different equilibria reached under the two immunosuppression regimens between the relative kinetics of viral distribution (systemically and in the liver) and the slowly recovering HCV-specific T-cell response. As a corollary, the aims of treatment of the HCV-infected liver recipients should be to predict, monitor, and equilibrate beneficial balances between virus distribution and the absence of an immunopathologic antiviral T-cell response. In this view, favorable equilibria were accomplished in the nonweaned group of patients but not in the weaned group. In conclusion, since the anti-HCV response is unleashed when immunosuppression is weaned, treatment protocols that minimize disease recurrence in HCV-infected allograft recipients must balance the desire to reduce immunosuppression or induce allotolerance with the need to prevent antiviral immunopathology. Copyright © 2005 by the American Association for the Study of Liver Diseases

Factors Affecting Weld Line Movement in Tailor Welded Blank

Tailor Welded Blanks (TWB) are utilized in automotive industries widely because of their advantage of weight and cost reduction and maintaining required strength and structural integrity. TWB consist of two or more sheet having dissimilar or similar material and thickness; welded together to form a single sheet before forming it to desired shape. Forming of the tailor welded blank is affected by ratio of thickness of blanks, ratio of their strength, etc. mainly due to in-homogeneity of material. In the present work the relative effect of these parameters on weld line movement is studied during deep drawing of TWB using FE simulation using HYPERWORKS. The simulation is validated with results from the literature. Simulations were than performed based on Taguchi orthogonal array followed by the ANOVA analysis to determine the significance of these parameters on forming of TWB