THE INTERNATIONAL SOCIETY for Clinical Densitometry (ISCD) periodically convenes a Position Development Conference (PDC) for the purpose of making recommendations on quality control, acquisition, analysis, interpretation, and reporting of bone densitometry. Questions regarding relevant topics are assigned to subcommittees for a comprehensive medical literature review and presentation of a repor...

A kernel method has been developed to model finite degree, finite memory length and infinite degree, finite memory length Volterra series using polynomial and exponential kernels, respectively. Here, the kernel method is extended to identify NARX (Nonlinear AutoRegressive with eXogenous inputs) models. To verify its effectiveness, the proposed approach is used in modeling friction dynamics, whi...

Purpose The purpose of this study is to assess the application of knowledge management (KM) models in managing and integrating indigenous and exogenous knowledge for improved farming activities in Tanzania, by examining the management of indigenous knowledge (IK), access and use of exogenous knowledge, the relevancy of policies, legal framework, information and communication technologies (ICTs)...

Although diverse, theories of visual attention generally share the notion that attention is controlled by some combination of three distinct strategies: (1) exogenous cuing from locally contrasting primitive visual features, such as abrupt onsets or color singletons (e.g., L. Itti, C. Koch, & E. Neiber, 1998), (2) endogenous gain modulation of exogenous activations, used to guide attention to t...

People find their way through cluttered environments with ease and without injury. How do they do it? Two approaches to wayfinding are considered: Differential motion parallax (DMP) is a retinal motion invariant of near and far objects moving against fixation; the information in optical flow (IOF) is a radial pattern of vectors, relying on decomposition of retinal flow. Evidence is presented th...

Although diverse, theories of visual attention generally share the notion that attention is controlled by some combination of three distinct strategies: (1) exogenous cueing from locallycontrasting primitive visual features, such as abrupt onsets or color singletons (e.g., Itti et al., 1998); (2) endogenous gain modulation of exogenous activations, used to guide attention to task relevant featu...

The entry of baby boomers into the labor force in late 1960s and 1970s slowed growth for physical human capital per worker because young workers have little both. Thus, boom could contributed to productivity slowdown. I build calibrate a model à la Huggett et al. (2011) with exogenous population growth, life expectancy, retirement TFP evaluate this theory. alone accounts 53% slowdown period 196...

This paper assumes that output depends on a large number of variables, but that economic theory has only revealed a subset of these variables. The variables that determine output include exogenous shocks, as well as endogenous variables that depend on both the exogenous variables and agents’ expectations. This paper examines a policy maker’s attempts to forecast output under two different types...

Human actions are guided either by endogenous action plans or by external stimuli in the environment. These two types of action control seem to be mediated by neurophysiologically and functionally distinct systems that interfere if an endogenously planned action suddenly has to be performed in response to an exogenous stimulus. In this case, the endogenous representation has to be deactivated f...

Salicylic acid (SA) is considered to be plant signal molecule that plays a key role in plant growth, development, and defense responses. The physiological mechanism of exogenous SA to affect the senescence of cut lisianthus flowers during vase life was investigated. Fresh cut lisianthus flowers were treated with distilled water (control), 0.5, 1 and 2 mM SA and then held at 25◦C up to 12 days. ...