On the Observed Robustness of Disturbance-Observers; A Technical Explanation and Simulation Validation

This paper examines the ability of a real-time "disturbance-observer" to adapt-to and closely estimate the time-behavior of a disturbance-input w(t) (and of it's state-vector z(t)) even when the actual w(t) time-behavior deviates from the observer's "internal-copy" of the nominal/predicted w(t)-behavior. By means of technical explanations and confirming simulation studies of numerical examples, the disturbance-observer's adaptive ability is explained in terms-of the underlying spline-model used to derive the disturbance state-model and the intrinsic dynamic characteristics of a state-observer

Dynamics of Formal Political Structure: An Event-History Analysis

The authors apply event history analysis to records on 90 countries from 1950-1975 to test hypotheses consistent with world systems and modernization hypotheses. The hypotheses predict factors associated with political change from/to one-party and multi-party governments. Modernization hypotheses predict that changes making a society more modern (that is, more like European societies) increase the chances for multi-party democratic governments. World systems hypotheses predict that governments are more affected by a country’s place in the world economic system than by internal changes. Results here show small effects of modernizing on government form, and event history methods show a complex relationship between GNP per capita and form of government

Static Controls Performance Tool for Lunar Landers

This document presents a static analysis tool used to evaluate the controllability of Lunar landers. This was created as part of the NASA Lunar Cargo Transportation and Landing by Soft Touchdown (Lunar CATALYST) program. This tool is capable of accepting typical design information such as location and direction of thrusters, maximum thruster forces, gravity vectors, and center of mass locations. The tool evaluates how far the center of gravity can move from its starting position while still maintaining control. This type of analysis is intended to support results produced by time domain simulations. The code created for this project was implemented in Python, and it was designed to be integrated into systems level optimization tools to yield first-cut results on optimal thruster placement

Alternative Estimation Procedures for Event-History Analysis: A Monte Carlo Study

The authors compare alternative procedures for estimating parameters of event-history models: ordinary least squares, Kaplan-Meier least squares, maximum likelihood, and partial likelihood. They report results of simulations comparing maximum likelihood and partial likelihood estimators for small samples in terms of several potential sources of error. A related paper is Tuma, Hannan, and Groeneveld (1979)

An approach to measuring and encouraging research translation and research impact

Background: Research translation, particularly in the biomedical area, is often discussed but there are few methods that are routinely used to measure it or its impact. Of the impact measurement methods that are used, most aim to provide accountability - to measure and explain what was generated as a consequence of funding research. This case study reports on the development of a novel, conceptual framework that goes beyond measurement. The Framework To Assess the Impact from Translational health research, or FAIT, is a platform designed to prospectively measure and encourage research translation and research impact. A key assumption underpinning FAIT is that research translation is a prerequisite for research impact. Methods: The research impact literature was mined to understand the range of existing frameworks and techniques employed to measure and encourage research translation and research impact. This review provided insights for the development of a FAIT prototype. A Steering Committee oversaw the project and provided the feedback that was used to refine FAIT. Results: The outcome of the case study was the conceptual framework, FAIT, which is based on a modified program logic model and a hybrid of three proven methodologies for measuring research impact, namely a modified Payback method, social return on investment, and case studies or narratives of the process by which research translates and generates impact. Conclusion: As funders increasingly seek to understand the return on their research investments, the routine measurement of research translation and research impact is likely to become mandatory rather than optional. Measurement of research impact on its own is insufficient. There should also be a mechanism attached to measurement that encourages research translation and impact - FAIT was designed for this tas

CaMKK2 as an emerging treatment target for bipolar disorder

Current pharmacological treatments for bipolar disorder are inadequate and based on serendipitously discovered drugs often with limited efficacy, burdensome side-effects, and unclear mechanisms of action. Advances in drug development for the treatment of bipolar disorder remain incremental and have come largely from repurposing drugs used for other psychiatric conditions, a strategy that has failed to find truly revolutionary therapies, as it does not target the mood instability that characterises the condition. The lack of therapeutic innovation in the bipolar disorder field is largely due to a poor understanding of the underlying disease mechanisms and the consequent absence of validated drug targets. A compelling new treatment target is the Ca2+-calmodulin dependent protein kinase kinase-2 (CaMKK2) enzyme. CaMKK2 is highly enriched in brain neurons and regulates energy metabolism and neuronal processes that underpin higher order functions such as long-term memory, mood, and other affective functions. Loss-of-function polymorphisms and a rare missense mutation in human CAMKK2 are associated with bipolar disorder, and genetic deletion of Camkk2 in mice causes bipolar-like behaviours similar to those in patients. Furthermore, these behaviours are ameliorated by lithium, which increases CaMKK2 activity. In this review, we discuss multiple convergent lines of evidence that support targeting of CaMKK2 as a new treatment strategy for bipolar disorder

Spillback Effects of Expansion When Product-Types and Firm-Types Differ

Contrary to perspectives that credit firms with only limited abilities to undertake significant change successfully, recent research has demonstrated that firms often improve their performance after undertaking major expansion to their operations. In this paper, we build on a study by Mitchell and Singh (1993) to test for differences in expansion effects, depending on whether the new goods substitute for old products and whether the firm is a generalist or specialist participant in the industry. The analysis helps us understand when a business can undertake major change successfully. The results have implications for ecological and other definitions of the core of a business and highlight the necessity for firms to undertake changes even at considerable risk to their existing operations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68398/2/10.1177_014920639502100105.pd