Dynamic Research Design: Iteration in Field-Based Inquiry

This article examines how “iteration”—the dynamic updating of a research design in the course of conducting a study—contributes to making fieldwork a powerful form of inquiry. Considering epistemic disagreement on the utility and acceptability of iteration and drawing on published work, our own experiences, and an original survey and interviews, we contend that iteration is a core aspect of field-based inquiry because such work often examines areas for which theory or empirical knowledge is underdeveloped and requires reacting as the research environment evolves. We demonstrate why iteration is challenging, consider the analytic risks it poses, and offer a framework to help scholars iterate in analytically productive ways. We conclude by outlining the implications for the discipline of embracing and being transparent about iteration.

Comparison of dynamic updating strategies for clinical prediction models

Background Prediction models inform many medical decisions, but their performance often deteriorates over time. Several discrete-time update strategies have been proposed in the literature, including model recalibration and revision. However, these strategies have not been compared in the dynamic updating setting. Methods We used post-lung transplant survival data during 2010-2015 and compared the Brier Score (BS), discrimination, and calibration of the following update strategies: (1) never update, (2) update using the closed testing procedure proposed in the literature, (3) always recalibrate the intercept, (4) always recalibrate the intercept and slope, and (5) always refit/revise the model. In each case, we explored update intervals of every 1, 2, 4, and 8 quarters. We also examined how the performance of the update strategies changed as the amount of old data included in the update (i.e., sliding window length) increased. Results All methods of updating the model led to meaningful improvement in BS relative to never updating. More frequent updating yielded better BS, discrimination, and calibration, regardless of update strategy. Recalibration strategies led to more consistent improvements and less variability over time compared to the other updating strategies. Using longer sliding windows did not substantially impact the recalibration strategies, but did improve the discrimination and calibration of the closed testing procedure and model revision strategies. Conclusions Model updating leads to improved BS, with more frequent updating performing better than less frequent updating. Model recalibration strategies appeared to be the least sensitive to the update interval and sliding window length.

Local Dynamic Updating Method of Orebody Model Based on Mesh Reconstruction and Mesh Deformation

In this paper, to update the orebody model based on the given interpreted geological information, we present a local dynamic updating method of the orebody model that allows the interactive construction of the constraint deformation conditions and the dynamic updating of the mesh model. The rules for constructing deformation constraints based on the control polylines are discussed. Because only part of the model is updated, the updated mesh is effective and the overall quality is satisfactory. Our main contribution is that we propose a local dynamic updating method for the orebody model based on mesh reconstruction and mesh deformation. This method can automatically update a given 3D orebody model based on a set of unordered geological interpretation lines. Moreover, we implement a deformation neighborhood region search method based on the specified ring radius and a local constrained mesh deformation algorithm for the orebody model. Finally, we test the method and show the model update results with real geological datasets, which proves that this method is effective for the local updating of orebody models.

A Novel Architectural Model for Dynamic Updating and Verification of Data Storage in Cloud Environment

Cloud computing is a quickly emerging computing model in the IT industry. Due to the rapid increase in technology, many clients want to store multiple copies of the same data in multiple data centers. Clients are outsourcing the data to cloud service providers and enjoying the high quality of service. Cloud service providers (CSP) are going to charge extra amounts for storing multiple copies; CSP must provide the firm guarantee for storing multiple copies. This paper proposes a new system model for storing and verifying multiple copies; this model deals with identifying tarnished copies which are transparent for the clients. Also, it deals with dynamic data control in the cloud with optimal results.

The capacity and cognitive processing of vibrotactile working memory for frequency

A hallmark of working memory (WM) is its limited capacity. While visual and verbal domains of WM are able to store multiple items, the capacity of parametric vibrotactile WM (vtWM) has not yet been established for supra-threshold, one-dimensional sensory vibrotactile frequencies. The present study extends the standard delayed match-to-sample vibrotactile discrimination task to determine the capacity of the vtWM and its cognitive mechanism. Here, by presenting subjects with 2 to 6 vibratory frequencies sequentially in each trial, the present study demonstrates that it is possible to retain about only two vibrotactile frequencies information in vtWM. The results also showed that the capacity of vtWM does not depend on whether sequentially presented vibrotactile frequencies are delivered to the same or to different fingers. At the same time, the rate of correct report depends on sequence length and when in the sequence the stimuli are presented, suggesting the dynamic updating of vtWM similar to that of visual WM.

Towards User-Oriented Recommendations for Local Therapy of Leg and Foot Ulcers—An Update of a S3-German Guideline

Background: The German S3- guideline on local therapy of leg ulcers and diabetic foot ulcers is in the process of being updated. Major goals are to improve the guidelines’ applicability and to take steps towards a living guideline according to current methodological standards. The aim of this article is to describe the main measures to achieve these goals. Methods: The context of the guideline in the field of local wound care and the stakeholder requirements are briefly described. Based on a derived framework, the project team adjusted the methods for the guideline. Results: Main adjustments are more specific inclusion criteria, online consensus meetings and the use of an authoring and publication platform to provide information in a multi-layered format. A new set of practice-oriented key questions were defined by the guideline panel to foster the formulation of action-oriented recommendations. Conclusions: The set of new key questions addressing practical problems and patients’ preferences as well as the adjustments made to improve not only the guidelines’ applicability, but also the feasibility of the further dynamic updating processes in the sense of a living guideline, should be steps in the right direction.