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Icesense proof of concept: Calibrating an instrumented figure skating blade to measure on-ice forces
No full text© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Competitive figure skaters often suffer from overuse injuries, which may be due to the high impact forces endured during jump repetitions performed in practice and competition. However, to date, forces during on-ice figure skating have not been quantified due to technological limitations. The purpose of this study was to determine the optimal calibration procedure for a previously developed instrumented figure skating blade (IceSense). Initial calibration was performed by collecting data from the blade while 11 skaters performed off-ice jumps, landing on a force plate in the lab. However, mean peak force measurements from the blade were greater than the desired error threshold of ±10%. Therefore, we designed a series of controlled experiments which included measuring forces from a load cell rigidly attached to the top of the blade concurrently with strain data from the strain gauges on the blade. Forces were applied to the blade by adding weight to a drop tower or by manually applying force in a quasi-static manner. Both methods showed similar accuracy, though using the drop tower allowed precise standardization. Therefore, calibration was performed using the weighted drop method. This calibration was applied to strain gauge data from out-of-sample drop trials, resulting in acceptable estimates of peak force (less than 10% error). Using this calibration, we collected data on one figure skater and present results from an exemplar on-ice double flip jump. Using the IceSense device to quantify on-ice forces in a research setting may help inform training, technique, and equipment design
The journey from customer participation in service failure to co-creation in service recovery
No full text© 2020 Elsevier Ltd Customer participation is growing into a widespread phenomenon in the service context. Despite the inherent significance of customer expectations to service failures in the high-participation service context, scant research exists on studying the links among customer participation, customer expectation of service recovery, and service outcomes (e.g., word-of-mouth or WOM). Even more pressing is the lack of research on the type of service recovery that can countervail the inflated customer expectation of service recovery and restore service outcomes. This research demonstrates that high contribution of customers in the beginning of service provision procedure leads to high recovery expectations and low satisfaction. The results also support that co-created service recovery (CCS-R), as contrasted to firm and customer recoveries, has a greater positive effect on satisfaction. Further, the contrasting impacts of each service recovery type on positive and negative WOM are presented. An experiment was conducted using service failure and recovery scenarios. Regression analysis was used to test the hypotheses. The current research has some important implications for scholars and managers who wish to effectively recover failed high-participation service encounters
Polycentric to monocentric governance: Power dynamics in Lake Victoria\u27s fisheries
No full text© 2020 ERP Environment and John Wiley & Sons Ltd In theory, polycentric governance arrangements are better able to respond to complex, uncertain, and multiscale challenges. Research on polycentric governance challenges these normative assumptions to find that the functionality of polycentric systems is constrained because different kinds of power influence not only the emergence and design of polycentric systems, but also decisions about policy choices and outcomes. This study uses a polycentric power typology to provide insights into the power dynamics underpinning the polycentric fisheries system of Lake Victoria through qualitative case study methods. The study reveals that power by design creates a polycentric structure that could potentially provide opportunities for power-sharing between higher and lower decision centers. However, pragmatic and framing power erode power away from lower-level authorities by either taking over or dismantling lower-level decision centers and institutions. Without a genuine intent to share power among decision centers, cross-level linkages are deliberately nonfunctional or have high transaction costs, creating and intensifying conflicts and competitions between the state and local governments. In the absence of functional cross-linkages, information-sharing, accountability, and conflict-resolution mechanisms are hampered as is the inclusion of lower-level actors in management. Higher-level actors justify taking over functions of lower-level actors by deploying frames of the lower-level\u27s “lack of capacity.” In combination, these factors concentrate power at the center, resulting in maladaptive outcomes in Lake Victoria\u27s fisheries. The findings suggest that improving understanding of contextual conditions that are more suited to polycentric governance is important for refining theory and improving governance
Global Hybrid Multiconfiguration Pair-Density Functional Theory
No full textCopyright © 2020 American Chemical Society. A global hybrid extension of multiconfiguration pair-density functional theory (MC-PDFT) is developed. Using a linear decomposition of the electron-electron repulsion term, a fraction λ of the nonlocal exchange interaction, obtained from variational two-electron reduced-density matrix (v2RDM)-driven complete active-space self-consistent field (CASSCF) theory, is combined with its local counterpart, obtained from an on-top pair-density functional. The resulting scheme (called λ-MC-PDFT) inherits the benefits of MC-PDFT (e.g., its simplicity and the resolution of the symmetry dilemma) and, when combined with the v2RDM approach to CASSCF, requires only polynomially scaling computational effort. As a result, λ-MC-PDFT can efficiently describe static and dynamical correlation effects in strongly correlated systems. The efficacy of the approach is assessed for several challenging multiconfigurational problems, including the dissociation of molecular nitrogen, the double dissociation of a water molecule, and the 1,3-dipolar cycloadditions of ozone to ethylene and ozone to acetylene in the O3ADD6 benchmark set
Validity of Visual Assessment of Sit to Stand after Hip Fracture
No full text© 2020 Journal of Geriatric Physical Therapy. All rights reserved. Background and Purpose: When treating older adults post-hip fracture, physical therapists routinely assess the sit-to-stand (STS) task using observational analysis. Studies have demonstrated that significant movement asymmetries in ground reaction force production of the fractured lower limb persist during STS, even though individuals may rise independently. To date, the validity of therapist judgments of lower limb force during STS has not been addressed. The purpose of this observational cohort study was to determine the accuracy of physical therapists\u27 observational assessments of STS for detecting the involved limb and its ground reaction force contribution in older adults post-hip fracture. Methods: Eighteen home health physical therapists assessed 10 videotapes of older adults post-hip fracture rising from sitting and judged the side of involvement and the amount of ground reaction force generated by the fractured lower limb. Each videotape was synchronized with its respective force data. A wide spectrum of asymmetry in rising was represented in the test videos. Before making these judgments, the therapists viewed a separate set of training videos and received instructions in the use of specific visual cues to assist with subsequent judgments. Results and Discussion: Therapists judged the involved side correctly 74% of the time. Mean accuracy in judging ground reaction force output was 39% across all therapists. Force symmetry did not significantly influence accuracy of force judgments. Inaccurate judgments of force may limit therapeutic intensity and minimize the potential for developing motor strategies that favor force production of the involved limb. Augmenting observational analysis of STS with quantitative data could assist in optimizing restorative function. Conclusion: Judgments of lower limb ground reaction force output during STS based on observation alone are not valid and may need to be supplemented with quantitative data
