Use of Collaborative Technologies and Knowledge Sharing in Co-located and Distributed Teams: Towards the 24-Hour Knowledge Factory

The relocation of knowledge work to emerging countries is leading to an increasing use of Globally Distributed Teams (GDT) engaged in complex tasks. In the present study, we investigate a particular type of GDT working ‘around the clock’: the 24 hours knowledge factory (Gupta, 2008). Adopting the productivity perspective on knowledge sharing (Haas and Hansen, 2005, 2007), we develop 11 hypotheses to compare technology use, knowledge sharing processes, and performance of a 24 hours knowledge factory with a co-located team. We conducted a quasi-experiment in IBM and collected both quantitative and qualitative data, over a period of 12 months, on a GDT and a co-located team. Both teams were composed of the same number of professionals, provided with the same technologies, engaged in similar tasks, and given similar deadlines. We found that they differed in their use of technologies and in knowledge sharing processes, but not in efficiency and quality of outcomes. We show how the co-located team and the GDT enacted a knowledge codification strategy and a personalization strategy respectively; in each case, they grafted elements of the other strategy in order to attain both knowledge re-use and creativity. We conclude by discussing theoretical contributions to knowledge sharing and GDT literatures, and by highlighting managerial implications to those organizations interested in developing a fully functional 24 hour knowledge factory

Human Mars Entry, Descent, and Landing Architecture Study: Phase 3 Summary

Over the past four years, NASA has directed the Entry, Descent and Landing Architecture Study (EDLAS) to evaluate candidate technologies to deliver human-scale vehicles (carrying 20t payloads) to the surface of Mars. The study focused on two vehicles in Phase 3 (during 2018 and 2019), one low and one mid lift-to-drag (L/D) vehicle. This paper summarizes updates to the structural and aeroshell outer mold line design for the mid-L/D Mars entry lander vehicle that occurred during EDLAS Phase 3. The design efforts used parametric optimization to arrive at a solution for total vehicle primary and secondary structure mass, and vehicle center-of-gravity location. Additionally, the end of Phase 2 provided an updated surface payload manifest that required three 22 t landers. This paper also summarizes the results of the packaging feasibility study of the updated payload configurations for those three reference missions. The study verified an arrangement of the payload elements within the mid-L/D vehicle that satisfied the center of gravity location limitations for flight

Design of Self-tuning PID Controller Parameters Using Fuzzy Logic Controller for Quad-rotor Helicopter

This paper presents the design of a Fuzzy PID controller (FPID) based on fuzzy logic with a PID structure with many valued logic and reasoning. The self-turning Fuzzy PID control take in an error and the rate of change of error of the altitude and attitude of the quadrotor as the input to the fuzzy controller and use the fuzzy rules to adjust the PID parameter automatically. Simulations have been conducted to observe the differences in controlling the quadrotor in flight using the new FPID controller instead of using PID controller. The effectiveness of the developed FPID is verified using the dSPACE platform whereby the Simulink model of the controller is converted to a real time system to generate the control signals for the control of quad rotor helicopter

Cell-cell communication enhances the capacity of cell ensembles to sense shallow gradients during morphogenesis

Collective cell responses to exogenous cues depend on cell-cell interactions. In principle, these can result in enhanced sensitivity to weak and noisy stimuli. However, this has not yet been shown experimentally, and, little is known about how multicellular signal processing modulates single cell sensitivity to extracellular signaling inputs, including those guiding complex changes in the tissue form and function. Here we explored if cell-cell communication can enhance the ability of cell ensembles to sense and respond to weak gradients of chemotactic cues. Using a combination of experiments with mammary epithelial cells and mathematical modeling, we find that multicellular sensing enables detection of and response to shallow Epidermal Growth Factor (EGF) gradients that are undetectable by single cells. However, the advantage of this type of gradient sensing is limited by the noisiness of the signaling relay, necessary to integrate spatially distributed ligand concentration information. We calculate the fundamental sensory limits imposed by this communication noise and combine them with the experimental data to estimate the effective size of multicellular sensory groups involved in gradient sensing. Functional experiments strongly implicated intercellular communication through gap junctions and calcium release from intracellular stores as mediators of collective gradient sensing. The resulting integrative analysis provides a framework for understanding the advantages and limitations of sensory information processing by relays of chemically coupled cells.Comment: paper + supporting information, total 35 pages, 15 figure

Long-term health outcomes of allogeneic hematopoietic stem cell transplantation

BackgroundFifty years of hematopoietic cell transplantation (HCT) has ushered in an exciting era of cellular therapy and has led to enormous progress in improving the outcomes of patients with both malignant and non-malignant hematologic disease. As the survival of transplanted patients has increased, so has the recognition of long-term complications related to this therapy.PurposeThe goal of this review is to highlight some of the most common long-term complications of HCT.Data sourcesTo this end, we have conducted a review of the published literature on the long-term complications of HCT encompassing the past 50 years.Study selectionWe have endeavored to include long-term complications reported in research articles, case series and case reports, reviews, and abstracts. We have focused primarily on adult allogeneic HCT, but have included some data from studies of pediatric allogeneic HCT as well. We have also prioritized the literature published in the last 15 years.Data extractionKey data supporting the onset and prevalence of the most common long-term complications was extracted.LimitationsWhile the list of long-term complications extracted and reported was comprehensive, it was not exhaustive.ConclusionsWe have endeavored to highlight some of the most common long-term complications of HCT, the recognition and management of which constitutes an important part of HCT survivorship care

A hardware implementation of 6dof quadcopter matlab/simulink controller algorithm to an autopilot

This paper presents a hardware implementation of Control algorithm for 6DOF Quadcopter developed on MATLAB/SIMULINK to an autopilot Microcontroller (PIXHAWK) using MATLAB/SIMULINK Embedded Coder. After the validation of the SIMULINK model controller results through the software simulation, the designed controller is converted into C\C++ and uploaded into the Pixhawk autopilot by creating SIMULINK application in the autopilot firmware. This paper presents a rapid and real test solution for quadcopter control system using Pixhawk autopilot which will provide further real adjustment for the control parameters. This feature is used in this research is to deploy the SIMULINK codes into the Pixhawk autopilot board through the Embedded Coder Tool.N/

Surface Instability in Windblown Sand

We investigate the formation of ripples on the surface of windblown sand based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71, 197 (1993)], which contains the processes of saltation and grain relaxation. We carry out a nonlinear analysis to determine the propagation speed of the restabilized ripple patterns, and the amplitudes and phases of their first, second, and third harmonics. The agreement between the theory and our numerical simulations is excellent near the onset of instability. We also determine the Eckhaus boundary, outside which the steady ripple patterns are unstable.Comment: 23 pages, 8 figure

Morpho-metric study of the facial nerve in the Andaman and Nicobar islands population: A Cadaveric study

Background: Facial nerve (FN) is the seventh cranial nerve. It is the only cranial nerve which has a long course in a bony canal. From the brain stem, to its terminal branches, it changes its direction 5 times, to innervate, muscles of the second pharyngeal arch. Hence, it is morphometric study and has great clinical importance. Aims and Objectives: This study was conducted to ascertain the variations of the length of facial Never at different parts of the crania so that this study could be helpful for neurosurgeon, radiologist, and clinician, to deal with various diseases of FN. Materials and Methods: Thirty-five (35) male cadaveric temporal bones, were taken out, by removing soft parts attached to it. The FN was exposed. The length of the FN was measured, by digital vernier calliper, in different regions, of the temporal bone. Results: 7.90 (SD±1.24) in petrous part, 3.7 (SD±0.40) in labyrinthine part, 12.13 (SD±0.36) in tympanic, 12.24 (SD±1.86) mastoid part, 15.76 (SD±0.54) length of nerve to stapedius, and 19.06 (SD±0.66) length of branches of chorda-tympani. Conclusion: The present cadaveric study has clinical importance, for the ENT surgeon, neurosurgeon, neurophysician, and the radiologist

Effects of normobaric hypoxia on oxygen saturation variability

Background: The study is the first to evaluate the effects of graded normobaric hypoxia on SpO2 variability in healthy individuals. / Materials and Methods: Twelve healthy males (mean [standard deviation] age 22 [4] years) were exposed to four simulated environments (fraction of inspired oxygen [FIO2]: 0.12, 0.145, 0.17, and 0.21) for 45 minutes, in a balanced crossover design. / Results: Sample entropy, a tool that quantifies the irregularity of pulse oximetry fluctuations, was used as a measure of SpO2 variability. SpO2 entropy increased as the FIO2 decreased, and there was a strong significant negative correlation between mean SpO2 and its entropy during hypoxic exposure (r = −0.841 to −0.896, p < 0.001). In addition, SpO2 sample entropy, but not mean SpO2, was correlated (r = 0.630–0.760, p < 0.05) with dyspnea in FIO2 0.17, 0.145, and 0.12 and importantly, SpO2 sample entropy at FIO2 0.17 was correlated with dyspnea at FIO2 0.145 (r = 0.811, p < 0.01). / Conclusions: These findings suggest that SpO2 variability analysis may have the potential to be used in a clinical setting as a noninvasive measure to identify the negative sequelae of hypoxemia