Can a Habit Formation Model really explain the forward premium anomaly?

Verdelhan (2009) shows that if one is to explain the foreign exchange forwardpremium behavior using Campbell and Cochrane (1999)'s habit formation modelone must specify it in such a way to generate pro-cyclical short term risk free rates.At the calibration procedure, we show that this is only possible in Campbell andCochrane's framework under implausible parameters speci cations given that theprice-consumption ratio diverges in almost all parameters sets. We, then, adoptVerdelhan's shortcut of xing the sensivity function (st) at its steady state level toattain a nite value for the price-consumption ratio and release it in the simulationstage to ensure pro-cyclical risk free rates. Beyond the potential inconsistenciesthat such procedure may generate, as suggested by Wachter (2006), with pro-cyclical risk free rates the model generates a downward sloped real yield curve,which is at odds with the data.

McKee Minute November 2015

The November 2015 McKee Minute features several books on The History & Mystery of Time, including The Little Book of Time by Klaus Mainzer and Splitting the Second by Tony Jones. Featured films include The Adventures of Huck Finn and The Life and Work of Mark Twain. Featured Adventist periodicals include Adventist Frontiers and Journal of Adventist Education. This month\u27s spotlight is on chemistry

Blessing or Curse: Impact of Algorithmic Trading Bots Invasion of the Cryptocurrency Market

In this paper, we investigate the impact of the absence of trading bots on human traders’ investment returns. Using comprehensive data set obtained from a large cryptocurrency exchange platform, we find that trading bots play a market-making role, and they boost human traders’ investment returns. We use the natural experiment setting that transforms a heterogenous market co-created with trading bots and human traders into a human-only financial market for empirical design. This paper extends the traditional investment decision under uncertainty by considering human attitudes toward algorithms while providing significant contributions to policymakers and regulators by providing empirical evidence on trading bots

The role of the patellar tendon angle and patellar flexion angle in the interpretation of sagittal plane kinematics of the knee after knee arthroplasty: A modelling analysis

BACKGROUND: Many different measures have been used to describe knee kinematics. This study investigated the changes of two measures, the patellar tendon angle and the patellar flexion angle, in response to variations in the geometry of the knee due to surgical technique or implant design. METHODS: A mathematical model was developed to calculate the equilibrium position of the extensor mechanism for a particular tibiofemoral position. Calculating the position of the extensor mechanism allowed for the determination of the patellar tendon angle and patellar flexion angle relationships to the knee flexion angle. The model was used to investigate the effect of anterior-posterior position of the femur, change in joint line, patellar thickness (overstuffing, understuffing), and patellar tendon length; these parameters were varied to determine the effect on the patellar tendon angle/knee flexion angle and patellar flexion angle/knee flexion angle relationships. RESULTS: The patellar tendon angle was a good indicator of anterior-posterior femoral position and change in patellar thickness, and the patellar flexion angle a good indicator of change in joint line, and patellar tendon length. CONCLUSIONS: The patellar tendon angle/knee flexion angle relationship was found to be an effective means of identifying abnormal kinematics post-knee arthroplasty. However, the use of both the patellar tendon angle and patellar flexion angle together provided a more informative overview of the sagittal plane kinematics of the knee

Three-dimensional ultrasonic colloidal crystals

Colloidal assembly represents a powerful method for the fabrication of functional materials. In this article, we describe how acoustic radiation forces can guide the assembly of colloidal particles into structures that serve as microscopic elements in novel acoustic metadevices or act as phononic crystals. Using a simple three-dimensional orthogonal system, we show that a diversity of colloidal structures with orthorhombic symmetry can be assembled with megahertz-frequency (MHz) standing pressure waves. These structures allow rapid tuning of acoustic properties and provide a new platform for dynamic metamaterial applications.Comment: 23 pages (including 12 figures

The Biocentric Design Model: How Features of Living Things Go Beyond Irreducible Complexity and Specified Complexity, and How Creation Science Could Foment New Discoveries in Biology

This paper highlights features of living organisms that go beyond that of machines on the one hand and computational devices on the other. These features exceed those of human crafted artifacts, as well as demonstrate insight and creativity in their creation. It will be demonstrated that they cannot arise from natural processes but are the result of mind and intelligence. It is hoped that the biocentric design attributes described here would augment irreducible complexity and specified complexity as evidence of design in living organisms. The issues addressed are of particular relevance in the light of recent discoveries in epigenomics and metagenomics, as well as developments in the new disciplines of systems biology and synthetic biology. Just as these disciplines focuses on designing biological systems, so too biology is no less than the science of how living organisms are designed. This paradigm shift could lead to the discovery of universal laws and scientific explanations of how living organisms are designed, superseding historical narratives in evolutionary biology

Contact Mechanics of Fish Scale Inspired Exoskeletal Components on a Nonlinear Elastic Substrate

The contact mechanics of structures with exoskeletal components deviate significantly from classical Hertzian and non-linear models. In the case of fish scale inspired samples under blunt indentation loading these factors are inherently tied to both the size of the indenter and the scales\u27 distribution and orientation. Control of these geometric parameters provides a pathway to tailor the properties of surfaces for better grip, damage mitigation and controlled deformation. This study explores the response of a substrate with stiff scales protruding from its surface, which is comprised of a soft elastomeric material with properties typical of those in soft robotics applications. It is found that the exoskeletal components amplify the nonlinearly of the system by artificially increasing the effective Hertzian contact area, which alters the contact stiffness and breaks the symmetry of the load across the surface. These effects are quantified using a combination of numerical modeling, finite element (FE) computation and experimental 3D Digital Image Correlation (DIC). While previous works have focused on biological fish scales, fully embedded scale composites and perforation studies, this study investigates and develops a numerical model to quantify the contact behavior of nonlinear elastic substates with exoskeletal scale structures

MetaMesh: A hierarchical computational model for design and fabrication of biomimetic armored surfaces

Many exoskeletons exhibit multifunctional performance by combining protection from rigid ceramic components with flexibility through articulated interfaces. Structure-to-function relationships of these natural bioarmors have been studied extensively, and initial development of structural (load-bearing) bioinspired armor materials, most often nacre-mimetic laminated composites, has been conducted. However, the translation of segmented and articulated armor to bioinspired surfaces and applications requires new computational constructs. We propose a novel hierarchical computational model, MetaMesh, that adapts a segmented fish scale armor system to fit complex “host surfaces”. We define a “host” surface as the overall geometrical form on top of which the scale units are computed. MetaMesh operates in three levels of resolution: (i) locally—to construct unit geometries based on shape parameters of scales as identified and characterized in the Polypterus senegalus exoskeleton, (ii) regionally—to encode articulated connection guides that adapt units with their neighbors according to directional schema in the mesh, and (iii) globally—to generatively extend the unit assembly over arbitrarily curved surfaces through global mesh optimization using a functional coefficient gradient. Simulation results provide the basis for further physiological and kinetic development. This study provides a methodology for the generation of biomimetic protective surfaces using segmented, articulated components that maintain mobility alongside full body coverage.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract No. W911NF-13-D-0001)United States. Army Research Office (Institute for Collaborative Biotechnologies (ICB), contract no. W911NF-09-D-0001)United States. Department of Defense (National Security Science and Engineering Faculty Fellowship Program (Grant No. N00244-09-1-0064)