Covariance matrix transformation method in all-earth integrated navigation considering coordinate frame conversion

In the exploration of polar region, navigation is one of the most important issues to be resolved. To avoid the limitations of single navigation coordinate frame, the navigation systems usually use different navigation coordinate frames in polar and nonpolar region, such as the north-oriented geographic frame and the grid frame. However, the error states and covariance matrix are related with the definition of navigation coordinate frame, since the coordinate frame conversion will cause the integrated navigation Kalman filter overshoot and error discontinuity. To solve this problem, the transformation relationship of error states defined in different frames is deduced, whereby the covariance matrix transformation relationship is also analyzed. On this basis, covariance transformation-based the open-loop and the closed-loop Kalman filter integrated navigation algorithms are proposed. The effectiveness of algorithms is verified by flight tests with rotational strapdown inertial navigation system (RSINS)/global navigation satellite system (GNSS) integrated navigation system.

The “case to theory transformation method” for initiating is theory: the process and an illustration using is integration following mergers and acquisitions

PurposeThis to show how critical success factors (CSFs) from practitioner-oriented research can be tested and used to generate new theory.Design/methodology/approachThis paper uses an extended example regarding the integration of IT departments following organizational mergers and acquisitions to illustrate in proof of concept that such practitioner-oriented research can generate new substantive theory and be used to begin a cycle of representation-testing leading to enhancing domain knowledge. The method used consists of the identification of an exemplary practitioner-oriented research article, restatement of CSFs into testable propositions, gathering data through interviews with phenomenon participants, analyzing and interpreting data relative to these CSFs, then presenting the results pertaining to these CSFs and observations from examining them holistically.FindingsNo CSFs were affirmed in all cases, neither were they rejected in all cases. The pattern of answers reveals a significant difference between factors representing general management best practices and technical practices. The higher frequency among management factors shows a relative universality to these items, whereas the technical issues are noted less frequently as they each apply to smaller subsets of all post mergers and acquisitions integrations but remain critical when they do apply. This set of responses suggests that the frequency of responses does not indicate the importance of any given factor across settings.Research limitations/implicationsThis study suggests (1) CSFs, while generally helpful, can also be misleading when applied such that, where of potential importance, they can be brought into a theorizing mode for refinement and extraction of additional knowledge; (2) that CSFs can be sorted into those tending toward general management principles that apply most frequently in contrast to those of critical importance but applicable across fewer situations; and (3) that as a proof of concept the case to theory transformation method can work to introduce heuristic knowledge into a process-initiating theorizing, raising prospects for subsequent continued improvement.Practical implicationsAssuming robust reporting of CSFs in well-conducted cases, this study knows that at least in one setting these factors were important in achieving particular results. However, this study does not know, without subsequent testing and theorizing, whether the factor applies across circumstances and whether it requires particular handling (e.g. timing may be critical but relies on varied conditions to indicate when actions need be taken). By theorizing based upon CSFs for important IS phenomena, the authors create a bridge between knowledge as used in practice and the scientific tools for increasing its value over time.Originality/valueAlthough the authors know of case and multiple case studies surfacing best practices in post mergers and acquisitions integrations, they know of no broad studies across numerous organizations; they also know of no studies demonstrating the relationship of management and technical CSFs in an IS phenomenon. Further, although there are other techniques advocated for theory initiation and building, the authors know of none that transforms heuristic or anecdotal knowledge for subsequent theorizing and continual improvement at a more detailed level than mid-range theory.

Off-centered stagnation point flow of an experimental-based hybrid nanofluid impinging to a spinning disk with low to high non-alignments

Purpose The purpose of this study is to model and solve numerically the three-dimensional off-centered stagnation point flow and heat transfer of magnesium oxide–silver/water hybrid nanofluid impinging to a spinning disk. Design/methodology/approach The applied effective thermophysical properties of hybrid nanofluid including thermal conductivity and dynamics viscosity are according to the reported experimental relations that would be expanded by a mass-based algorithm. The single phase formulations coupled with experimental-based hybrid nanofluid model is implemented to derive the governing partial differential equations which are then transferred to a set of dimensionless ordinary differential equations (ODEs) with the use of the similarity transformation method. Afterward, the reduced ODEs are solved numerically by bvp4c function from MATLAB that is a trustworthy and efficient code according to three-stage Lobatto IIIa formula. Findings The effect of spinning parameter and nanoparticles masses (mMgO, mAg) on the hydrodynamics and thermal boundary layers behavior and also the quantities of engineering interest are presented in tabular and graphical forms. The recent work demonstrates that the analysis of flow and heat transfer becomes more complicated when there is a non-alignment between the impinging flow and the disk axes. From computational results demonstrate that, the radial and azimuthal velocities are, respectively, the increasing and decreasing functions of the disk spinning parameter. Further, for the greater values of the spinning parameter, an overshoot of the radial velocity owing to the centrifugal forces of the spinning disk is observed. Besides, the quantities of engineering interest gently enhance with first and second nanoparticle masses, while comparing their absolute values illustrates the fact that the effect of second nanoparticle mass (mAg) is greater. Further, it is inferred that the second nanoparticle’s mass enhancement results in the amplification of the heat transfer; although, the high skin friction and the relevant shear stress should be controlled. Originality/value The combination of experimental thermophysical properties with theoretical modeling of the problem can be the novelty of the present work. It is evident that the experimental relations of effective thermophysical properties can be trustable and flexible in the theoretical/mathematical modeling of hybrid nanofluids flows. Besides, to the best of the authors’ knowledge, no one has ever attempted to study the present problem through a mass-based model for hybrid nanofluid.