Search results for "Wear"

Wearable wireless photoplethysmography sensors

2008

Wearable health monitoring sensors may support early detection of abnormal conditions and prevention of their consequences. Recent designs of three wireless photoplethysmography monitoring devices embedded in hat, glove and sock, and connected to PC or mobile phone by means of the Bluetooth technology, are described. First results of distant monitoring of heart rate and pulse wave transit time using the newly developed devices are presented.

Real time assessment of hand-arm vibration system based on capacitive MEMS accelerometers

2012

Vibrations are a well known potential cause of health diseases and therefore constitute a main concern for the safety of workers in a large number of activities. In order to prevent health hazards, national and international institutions have issued laws and directives which establish recommended limits to the workers' exposure to vibrations during operations. Consequently, if the amount of adsorbed vibration exceeds the allowable daily limits the worker has to stop his job. Recent wireless sensing and communicating technologies can effectively be employed for such purpose, allowing to develop monitoring customized devices at affordable cost which could be easily employed during the workers…

Feasibility of Body-centric Systems by Using passive textile RFID tags

2012

Recent progresses in the design of wearable RFID-tag antennas stimulate the idea of passive body-centric systems, wherein the required power to drive the wearable tags is directly scavenged from the interrogation signal emitted by the reader unit. While active body-centric links have been extensively investigated, the feasibility of passive systems is still questionable, due to the poor sensitivity of the tags and due to the modest reading distances. This paper describes a systematic measurement campaign involving low-profile wearable textile tags in the UHF RFID band. It was demonstrated that both on-body and off-body links are affordable, with a power budget fully compliant with the avail…

Methods to Use Big Wearable Heart Rate Data for Estimation of Physical Activity in Population Level

2015

Technologies for wearable health monitoring are becoming increasingly popular and affordable. As a result, large-scale health databases from a large number of individuals are becoming available. However, analysis of these databases requires special methodology to transform available parameters into more generic ones and to manage such non-balanced data characteristics as biases and sampling issues. In this paper, we introduce a methodology for studying physical activity from big wearable heart rate (HR) data on about 5 000 working-age individuals, each measured only for a few days. Physical activity was assessed by oxygen consumption (VO2) calculated from measured HR data using a neural net…

Prediction of Tool Wear in Machining

2007

On the effectiveness of Finite Element simulation of orthogonal cutting with particular reference to temperature prediction

2007

Abstract Finite Element simulation of orthogonal cutting is nowadays assuming a large relevance; in fact a very large number of papers may be found out in technical literature on this topic. In recent years, numerical simulation was performed to investigate various phenomena such as chip segmentation, force prediction and tool wear. On the other hand, some drawbacks have to be highlighted; due to the geometrical and computational complexity of the updated-Lagrangian formulation mostly used in FE codes, a cutting time of only a few milliseconds can be effectively simulated. Therefore, steady-state thermal conditions are not reached and the simulation of the thermal phenomenon may be ineffect…

Wear modelling in mild steel orthogonal cutting when using uncoated carbide tools

2007

Abstract Wear prediction in machining has been recently studied by FEM although the use of numerical methods for such applications is still a very challenging research issue. In fact, wear phenomenon involves many aspects related to process mechanics which require a very accurate modelling. In other words, only a very punctual code set-up can help the researchers in order to obtain consistent results in FE analysis. The high relative velocity between chip and tool requires effective material models as well as friction modelling at the interface. Moreover the prediction of temperature distribution is another critical task; in the paper some different procedures are discussed. Subsequently a …

Dietary behaviour and competition for vegetal resources in two Early Miocene pecoran ruminants from Central Spain

2012

ABSTRACT Dietary behaviour and competition for resources are investigated for the small-sized ruminants Andegameryx Ginsburg, 1971 and Procervulus Gaudry, 1877 representatives of two largely distinct states of diversification of pecorans. Results obtained from dental microwear and mesowear methodologies are concordant with a mixed feeder strategy for the taxa from the Early Miocene environments of the Iberian Chain (Central Spain). Further, the Spanish taxa investigated had less abrasive diets than their relatives from others similarly aged localities in Europe. This fact raises an important evolutionary uncertainty concerning the traditional characterization of first pecorans as specialize…

Repeatability and reliability of the footwear assessment tool in Spanish patients: A transcultural adaptation

2023

[Abstract] Background: The footwear assessment tool was designed to advise an appropriate footwear for each situation and patient. Footwear alterations structures can influence in musculoskeletal disorders, developing foot ulcers, increase the peak plantar pressure, bacterial growth, low back pain. Methods: To validate the study 101 subjects were recruited. The study was tested by two expert podiatrists using the tool for the assessment of footwear characteristics that is composed by five domains, fit, general features, general structure, motion control properties and cushioning system. Each domain analyzes different shoe items. Results: An excellent agreement between the test-retest. A sui…

Tool Wear and Damage

2008

This chapter provides comprehensive knowledge regarding tool wear mechanisms and characterizes their physical fundamentals. Adhesion, abrasion, diffusion and oxidation are selected as predominant mechanisms controlling tool wear, depending on the mechanical and thermal conditions at the rake and flank faces. The analytical models describing the wear rate and volumetric material loss for different wear mechanisms are provided. The tool wear indicators related to crater, flank and notch wear specified in ISO 3685 are presented for both flat-faced and grooved tools. Tool life is defined and corresponding models, including the influence of cutting speed, feed and the depth of cut, are derived. …