Cyperus limiticola, a new name for a Madagascan Cyperus (Cyperaceae)

A

Modeling reinforcement structures in textile aimed at biomechanical purposes

While sporting, muscles, tendons and the body in general come under extreme loads which may lead to wrong movements and injuries which impact the performance or lead to mandatory rest. As athletes often wear compression garments, we investigate how reinforcement structures such as elastic bands, yarns or fabric strips with a given pretension, or rigid structures can be added to compression garments to prevent incorrect sport movements. This paper discusses how an existing simulation tool (DySiFil) can be adapted to be able to extract supportive forces and pressures and validates the findings for the case of overextension of the fingers and the thumb

Two new species of Cyperus (Cyperaceae) from the Zambezian region of Africa

Cyperus absconditicoronatus Banters, Reynders & Goetgh. and C. unispicatus Banters, Reynders & Goetgh., two new species of Cyperus L. (Cyperaceae) from Angola and Zambia, are recognized. Cyperus absconditicoronatus is a tall species (55-100 cm) characterized by a scaled rhizome, a single terminal capitulum, a ciliated spikelet bract, and deciduous spikelets. Cyperus unispicatus can be recognized by a swollen and fibrous stem base growing from slender rhizomes, a single terminal spike, and short involucral bracts. The taxa are described and illustrated, and differences with the closest resembling species are discussed

Dilational Viscosity of Langmuir monolayers

The dilational viscosity $\epsilon'$ of Langmuir monolayer is considered in a theoretical model taking into account an orientational effect of the dilational wave on surface molecules. This orientational order is described by the surface order parameter Q; the orientational part of the free surface energy is given by Landau's expansion in powers of Q. The magnitude of surface viscosity, driven by the surface tension derivative $\partial\gamma/\partial Q$, is in good accord with the experimentally observed $\epsilon'$. The sign of $\epsilon'$ is positive that indicates that increased in-plane ordering increases the surface tension.Comment: 11 pages, 2 Postscript figures, submitted to Physica A (September 1998

A fossil Chimaeroid from the Gronsveld Member (Late Maastrichtian , Late Cretaceous)of northeast Belgium

The associated fragments of a single male individual of a large chimaeroid fish are described from the Gronsveld Member (LateMaastrichtian, LateCretaceous) of Romontbos Quarry in northeast Belgium. The material includes a complete dorsal fin spine, tooth plate fragments and frontal clasper denticles. The arrangement of the tritors on the tooth plates indicates that the specimen belongs to Edaphodon sp., having closest similarity with E.agassizi and E.ubaghsi. Chimaeroid frontal clasper denticles are figured and described in detail for the first time, with the development of an appropriate terminology. Clasper denticles are arranged in a closely fitting revetment of longitudinal and diagonal rows, with a consistent pattern of base overlap. Edaphodon clasper denticles differ from those of extant chimaeroids in various features of the base. Clasper denticle morphology is a potentially useful taxonomic tool at the suprafamilial level. Attachment of posterolateral denticles to the dorsal fin spine was secondary, and proceeded in an apical direction. Anterior dorsal fin spine denticles are primary features of spine development in Edaphodon. Bloodvessel tracery is described from the lateral walls of the spine. Dorsal fin spine morphology appears to be taxonomically useful at the generic level

Scale Dependence of Overconfidence in Stock Market Volatility Forecasts

In this study, we analyze whether volatility forecasts (judgmental confidence intervals) are influenced by the specific elicitation mode (i.e. whether forecasters have to state future price levels or directly future returns as upper and lower bounds). We present questionnaire responses of about 250 students from two German universities. Participants were asked to state median forecasts as well as confidence intervals for seven stock market time series. Using a between subject design, one half of the subjects was asked to state future price levels, the other group was directly asked for returns. Consistent with prior research we find that subjects underestimate the volatility of stock returns, indicating overconfidence. As a new insight, we find that the strength of the overconfidence effect in stock market forecasts is highly significantly affected by the fact whether subjects provide price or return forecasts. Volatility estimates are lower (and the overconfidence bias is thus stronger) when subjects are asked for returns compared to price forecasts

Modal analysis and experimental research into improved centering-leveling devices

Centering–leveling devices are often used together with rotary tables to improve measuring process in various fields of metrology. The most important factor of measurement quality – accuracy – is affected by numerous external and internal factors. To ensure the optimum quality of measurements, several factors have to be well known and thus taken into account in the final measurement to minimize their influence. Analysis of structural dynamics provides data on sensitivity as well as an appropriate method to verify the analytical model. The paper deals with an analysis of structural dynamics of a plain structure centering–leveling device by performing appropriate modal analysis. The experimental setup for vibration monitoring and measurement principle underpinning the work is described in the paper. Measurement results of table dynamics as well as a comparison of theoretical and experimental modal shapes are discussed

Real-time performance monitoring of tuned mass damper system for a 183 m reinforced concrete chimney

A 183 m reinforced concrete chimney for a coal-fired power station was instrumented in the latter part of its life during the construction of a replacement chimney. Because of concerns about large-amplitude response induced by interference effects from the new chimney in the prevailing upwind direction, a response monitoring system was installed, quickly followed by a tuned mass damper (TMD) system. As well as providing live display of the chimney response, the monitoring system was also used to check the functioning of the TMD. The monitoring system featured a direct implementation of the stochastic subspace identification procedure in the 'virtual instrument' controlling the system, so that modal damping values for the system were displayed automatically, in real-time. The system thus provided an immediate visual indication of increased damping levels during strong winds, showing the correct functioning of the TMD. The paper describes the chimney, the monitoring system and its installation, the data processing and system identification procedure, together with performance data before, during and after installation of the TMD. (C) 2009 Elsevier Ltd. All rights reserved

Estimation methods for computing a branch’s total value added from incomplete annual accounting data. National Bank of Belgium, Working Paper No. 371

Timely monitoring of the economic performance of a particular sector is generally hindered by the fact that not all companies have deposited their annual accounts by the time that an evaluation is made. In view of this, we develop several imputation strategies that each enable predicting a company’s value added based on available information from past and current years for those companies where the value added was not timely reported. For each proposed strategy we discuss the assumptions which must be fulfilled for unbiased estimation and calculate the estimation uncertainty. In particular, the proposed imputation procedures all rely on an assumption of missing at random, namely that the values added in companies that did not yet deposit their annual accounts are similar (in some way) to those in companies with the same characteristics (e.g. the same historical data) that did deposit their accounts by the evaluation date. We show how to retrospectively assess the validity of this assumption, and how to adjust the imputation procedure in case the assumption fails. The importance of the availability of the uncertainty margins should not be underestimated because they will result in faster and higher quality publications. Finally we retrospectively apply each strategy to data from the Belgian Port sector and compare their performance at several evaluation dates. All the proposed methods show good results on these data. The method using (ordinary least squares) regression is preferred because it is very flexible in the use of auxiliary variables, requires weaker assumptions, has smaller estimation uncertainty and is easily automatable