Prediction of the braid pattern on arbitrary-shaped mandrels using the minimum path condition

2014 ◽  
Vol 91 ◽  
pp. 30-37 ◽  
Author(s):  
Won-Jin Na ◽  
Hyun Chul Ahn ◽  
Seung-Yeol Jeon ◽  
Joon Seok Lee ◽  
Hyun-Min Kang ◽  
...  
Keyword(s):  
Author(s):  
Francisco Arcas-Tunez ◽  
Fernando Terroso-Saenz

The development of Road Information Acquisition Systems (RIASs) based on the Mobile Crowdsensing (MCS) paradigm has been widely studied for the last years. In that sense, most of the existing MCS-based RIASs focus on urban road networks and assume a car-based scenario. However, there exist a scarcity of approaches that pay attention to rural and country road networks. In that sense, forest paths are used for a wide range of recreational and sport activities by many different people and they can be also affected by different problems or obstacles blocking them. As a result, this work introduces SAMARITAN, a framework for rural-road network monitoring based on MCS. SAMARITAN analyzes the spatio-temporal trajectories from cyclists extracted from the fitness application Strava so as to uncover potential obstacles in a target road network. The framework has been evaluated in a real-world network of forest paths in the city of Cieza (Spain) showing quite promising results.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 411-411
Author(s):  
Julia Sheffler ◽  
Melissa Meynadasy ◽  
Dimitris Kiosses ◽  
Natalie Sachs-Ericsson

Abstract Emotion regulation (ER) difficulties in older adults are associated with increased depression and decreased resiliency to stressful life events. In general, maladaptive ER is a transdiagnostic risk factor for a range of psychological and physical problems across the lifespan. Thus, interventions targeting ER may be valuable in reducing risk for a range of late-life pathologies. The present study evaluated and adapted an existing ER-focused treatment (i.e., Problem Adaptation Therapy (PATH)) for community older adults. We completed a small clinical pilot study to assess the feasibility of the adapted protocol and initial signals of effect of the intervention on ER, depression, and resiliency. Participants were recruited using an online survey, which was used to then identify participants scoring in the highest and lowest quartiles for ER. Individuals in the lowest ER quartile (N=27) were randomly assigned to the PATH condition or a physical health education (PHET) control condition. Of the 27 participants in the low ER group, four participants (3 PATH, 1 PHET) dropped out of the intervention. A paired samples t-tests revealed significant decreases in depressive symptoms, significant increases in self-reported ER skill, and improvements in resiliency (all ps<.05) for the PATH condition. For the PHET condition, only significant increases in self-reported ER skill (t(12) = -2.68, p = .020) were observed. In sum, the intervention protocol proved feasibility and demonstrated initial signals of effect in the expected directions. Future studies will examine mechanisms of action and the efficacy of the adapted PATH protocol.


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2853 ◽  
Author(s):  
Nikola Jovalekic ◽  
Vujo Drndarevic ◽  
Ermanno Pietrosemoli ◽  
Iain Zennaro

Low Power Wide Area Networks (LPWANs) are gaining attention in both academia and industry by offering the possibility of connecting a large number of nodes over extended distances. LoRa is one of the technologies used as a physical layer in such networks. This paper investigates the LoRa links over seawater in two typical scenarios: clear Line-of-Sight (LOS) and obstructed path in two different Industrial, Scientific and Medical (ISM) radio bands: 868 MHz and 434 MHz. We used three different LoRa devices in the experiments: the Own Developed LoRa Transceiver (ODT) and two commercial transceivers. Firstly we investigated transceivers’ Receive Signal Strength Indicator (RSSI) and Signal-to-Noise (SNR) measurement chain linearity and provided correction factors for RSSI to correlate it with actual signal levels received at transceivers’ inputs. Next, we carried out field experiments for three different LoRa Spreading Factors, S F ∈ [ 7 , 10 , 12 ] , within a bandwidth of B W = 125 kHz and Coding Rate C R = 4 / 6 . The experiments showed that LoRa links are fully feasible over seawater at distances at least 22 km long, using only low-cost off-the-shelf rubber duck antennas in LOS path condition in both ISM bands. In addition, we showed that LoRa links can be established over 28 km obstructed LOS oversea path in ISM 434 MHz band, but using costly, higher gain antennas. Furthermore, the laboratory experiments revealed that RSSI is linear in a wide range, up to - 50 dBm, whereas the SNR measurement chain goes into saturation for Received Signal Strength (RSS) values higher than - 100 dBm. These findings enabled accurate interpretation of the results obtained in field experiments.


2021 ◽  
Vol 11 (22) ◽  
pp. 10616
Author(s):  
Jingtian Xu ◽  
Man Yang ◽  
Shugang Li

The hardware reliability of a gas monitoring system was investigated using the fuzzy fault tree analysis method. A fault tree was developed considering the hardware failure of the gas monitoring system as a top event. Two minimum path sets were achieved through qualitative analysis using the ascending method. The concept of fuzzy number of the fuzzy set theory was applied to describe the probability of basic event occurrence in the fault tree, and the fuzzy failure probabilities of the middle and top events were calculated using fuzzy AND and OR operators. The results show that the proposed fuzzy fault tree is an effective method of reliability analysis for gas monitoring systems. Results of calculations using this method are more reasonable than those obtained with the conventional fault tree method.


2016 ◽  
Vol 2 (1) ◽  
pp. 20
Author(s):  
Lili Yan

<p><em>With the increase of development the well integ</em><em>c</em><em>rity</em><em> </em><em>problem are becoming more and more serious. This article uses the </em><em>F</em><em>ault </em><em>T</em><em>ree </em><em>A</em><em>nalysis (FTA) method for many factors, such as completion, production and operation process, pressure annulus, the cementing quality, the wellhead system and leakage of pipe string.</em><em> </em><em>Many wellbore risk factors to conduct a comprehensive analysis and evaluation. Through the qualitative analysis of wellbore integrity failure risk, determining the level of risk factors and establishing the damage analysis model of the wellbore. According to the selected blocks in Shengli Oilfield example analysis of single wells find out the minimum cut sets, the minimum path sets and structure importance. The results showed that the selected block probability of top event is calculated and it’s 0.9961, and the actual selection conforms to statistics prove that the proposed based on the FTA wellbore damage risk analysis method is feasible, and through quantitative analysis and calculation of basic events of different important degree of parameters.</em></p><p><em>According to these risk factors for prevention of failure risk control measures are put forward, which provides reference for predict wellbore integrity to ensure the safety of oil and gas production run smoothly.</em></p>


Networks ◽  
2005 ◽  
Vol 46 (3) ◽  
pp. 119-123
Author(s):  
Petra M. Gleiss ◽  
Josef Leydold ◽  
Peter F. Stadler
Keyword(s):  

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