scholarly journals Methodology of Testing Foil Bearings in the Start-Stop Cycle in the Presence of a Working Medium - Stabilization of Temperature in the Test Chamber

2020 ◽  
Vol 24 (3) ◽  
pp. 63-72
Author(s):  
Bartosz Moczulak ◽  
Wojciech Miąskowski
Keyword(s):  
Temperature Increase ◽  
Test Chamber ◽  
Time Interval ◽  
Flexible Shell ◽  
Specific Time ◽  
Test Cycle ◽  
Sliding Bearings ◽  
Foil Bearings ◽  
Working Medium ◽  
Stop Test

AbstractThe article presents the methodology of testing sliding bearings with a flexible shell, focusing on the issue of temperature increase during experiments for a specific time interval of the START-STOP test cycle. Selected material pairs, used in previous studies, were used in the experiment. The stand used for tests in the start-stop cycle was developed under the project POIG.01.03.01-00-027 / 08-00 at the Faculty of Technical Sciences UWM in Olsztyn.

scholarly journals Methods of Research of Foil Bearings in START-STOP Cycle in the Presence of Working Medium

2019 ◽  
Vol 23 (4) ◽  
pp. 41-51
Author(s):  
Bartosz Moczulak ◽  
Wojciech Miąskowski
Keyword(s):  
Test Chamber ◽  
Test Cycle ◽  
Time Intervals ◽  
Sliding Bearings ◽  
Foil Bearings ◽  
Working Cycle ◽  
Automatic Mode ◽  
Working Medium ◽  
Stop Test ◽  
Selection Of

AbstractA method for testing sliding bearings with an elastic bearing liner was presented in the paper with a focus on the issue of selection of particular time intervals of the START-STOP test cycle. Then, results of the tests carried out according to the selected material combinations were presented. The working cycle of foil bearings tested on the test stand was performed in an automatic mode at the set number of sequences start-work-rundown-stop. Due to the highest use of sliding bearings during start and rundown of a machine, this type of tests is essential for selection of relevant sets of material for bearing elements. The article also presents the use of a thermo-visual camera for identification of additional thermal loads and manners of temperature stabilization in the test chamber.

scholarly journals Constructing Geographic Dictionary from Streaming Geotagged Tweets

2019 ◽  
Vol 8 (5) ◽  
pp. 216 ◽  
Author(s):  
Jeongwoo Lim ◽  
Naoko Nitta ◽  
Kazuaki Nakamura ◽  
Noboru Babaguchi
Keyword(s):  
Geographic Information ◽  
Time Interval ◽  
Specific Time ◽  
Time Intervals ◽  
Text Format ◽  
Short Text ◽  
Spatial Locality ◽  
Content Similarity ◽  
Types Of Information

Geographic information, such as place names with their latitude and longitude (lat/long), is useful to understand what belongs where. Traditionally, Gazetteers, which are constructed manually by experts, are used as dictionaries containing such geographic information. Recently, since people often post about their current experiences in a short text format to microblogs, their geotagged (tagged with lat/long information) posts are aggregated to automatically construct geographic dictionaries containing more diverse types of information, such as local products and events. Generally, the geotagged posts are collected within a certain time interval. Then, the spatial locality of every word used in the collected geotagged posts is examined to obtain the local words, representing places, events, etc., which are observed at specific locations by the users. However, focusing on a specific time interval limits the diversity and accuracy of the extracted local words. Further, bot accounts in microblogs can largely affect the spatial locality of the words used in their posts. In order to handle such problems, we propose an online method for continuously update the geographic dictionary by adaptively determining suitable time intervals for examining the spatial locality of each word. The proposed method further filters out the geotagged posts from bot accounts based on the content similarity among their posts to improve the quality of extracted local words. The constructed geographic dictionary is compared with different geographic dictionaries constructed by experts, crowdsourcing, and automatically by focusing on a specific time interval to evaluate its quality.

scholarly journals Training Temporal Word Embeddings with a Compass

2019 ◽  
Vol 33 ◽  
pp. 6326-6334 ◽  
Author(s):  
Valerio Di Carlo ◽  
Federico Bianchi ◽  
Matteo Palmonari
Keyword(s):  
State Of The Art ◽  
Word Meaning ◽  
Time Interval ◽  
Word Embeddings ◽  
Specific Time ◽  
Training Process ◽  
Text Corpora ◽  
Corpus Size ◽  
Generate Vector ◽  
Vector Representations

Temporal word embeddings have been proposed to support the analysis of word meaning shifts during time and to study the evolution of languages. Different approaches have been proposed to generate vector representations of words that embed their meaning during a specific time interval. However, the training process used in these approaches is complex, may be inefficient or it may require large text corpora. As a consequence, these approaches may be difficult to apply in resource-scarce domains or by scientists with limited in-depth knowledge of embedding models. In this paper, we propose a new heuristic to train temporal word embeddings based on the Word2vec model. The heuristic consists in using atemporal vectors as a reference, i.e., as a compass, when training the representations specific to a given time interval. The use of the compass simplifies the training process and makes it more efficient. Experiments conducted using state-of-the-art datasets and methodologies suggest that our approach outperforms or equals comparable approaches while being more robust in terms of the required corpus size.

scholarly journals Local Aggregation Scheme for Data Collection in Periodic Sensor Network

2019 ◽  
Vol 9 (2) ◽  
pp. 3583-3588
Keyword(s):  
Sensor Node ◽  
Cluster Head ◽  
Temporal Correlation ◽  
Sensor Nodes ◽  
Time Interval ◽  
Specific Time ◽  
Aggregated Data ◽  
Redundant Data ◽  
Local Aggregation ◽  
Local Outlier

Data aggregation is an important technique for data collection & aggregation in WSN where sensor nodes sense the raw data and sends the aggregated data to the sink node. In a cluster based periodic network, sensor node senses the data on a specific time interval, performs local aggregation and send aggregated data to Cluster Head (CH). Various Local aggregation algorithms are used to remove redundant data at sensor nodes but local outlier detection problem is still unsolved. Therefore, a local aggregation algorithm has been proposed which uses the temporal correlation property of WSN to eliminate redundant and local outlier data which improves the data sent ratio and data quality. Sensor measurement is collected at different time interval of a sensor, exhibits temporal correlation because measurements varies with small or same difference (δ) and measurements are treated as similar measurements. In proposed local aggregation approach, each sensor node finds similar measurements of sensors with their frequency (number of occurrence) in a specific time interval (Temporal correlation). Set having higher frequency is selected and transmitted the average values of measurements that lie in the selected set to the cluster head. If sensors don’t detect any reading between intervals it simple send a message ‘data not found’ instead of sending empty set. In this way we delete redundant and local outliers. The experimental result shows that algorithm improves the data quality and data sent ratio by eliminating redundant data and local outliers

scholarly journals EFFICIENT MONITORING OF TIME SERIES DATA USING DYNAMIC ALERTING

2019 ◽  
Author(s):  
Girish L
Keyword(s):  
Time Series ◽  
Data Centers ◽  
Time Series Data ◽  
Series Data ◽  
Time Interval ◽  
Specific Time ◽  
Specific Data ◽  
Cloud Data ◽  
Data Collector ◽  
Cloud Data Centers

Network and Cloud Data Centers generate a lot of data every second, this data can be collected as a time series data. A time series is a sequence taken at successive equally spaced points in time, that means at a particular time interval to a specific time, the values of specific data that was taken is known as a data of a time series. This time series data can be collected using system metrics like CPU, Memory, and Disk utilization. The TICK Stack is an acronym for a platform of open source tools built to make collection, storage, graphing, and alerting on time series data incredibly easy. As a data collector, the authors are using both Telegraf and Collectd, for storing and analyzing data and the time series database InfluxDB. For plotting and visualizing, they use Chronograf along with Grafana. Kapacitor is used for alert refinement and once system metrics usage exceeds the specified threshold, the alert is generated and sends it to the system admin.

The Main Regularities of Ignition and Combustion of Coal-Water Fuels Produced from Brown, Flame and Gas Coals

2018 ◽  
Vol 37 ◽  
pp. 141-157 ◽  
Author(s):  
Valeriya Pinchuk
Keyword(s):  
Maximum Temperature ◽  
Time Interval ◽  
Power Type ◽  
Time Duration ◽  
Medium Temperature ◽  
Working Medium ◽  
Temperature Dependences ◽  
Ignition And Combustion ◽  
Coal Grade ◽  
Combustion Processes

An experimental investigation was carried out of coal-water fuel (CWF) drops ignition and combustion. CWF examples were produced by using of coal of different metamorphic stages, including brown coal, flame coal, and gas coal. The processes of combustion and ignition of CWF took place in the air. Time-temperature dependences of ignition and combustion processes were obtained; basic stages of CWF combustion were established and investigated; combustion completeness was defined and ash residue structure and properties were investigated during the experimental research. Influence of the working medium temperature on the time duration of each burning stage was defined. Generalization of results was carried out. It is shown, that duration of the volatiles combustion stage doesn’t depend on the medium temperature and stay constant for each of coal grade. Time interval before CWF ignition can be described with power-type dependence, which is identical for all metamorphic stages of coal. The maximum temperature of CWF combustion grows linearly in respect to the medium temperature in the oven.

Access to care and patient satisfaction for surgically-treated breast cancer

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 17010-17010
Author(s):  
G. A. Porter ◽  
J. M. Murdoch ◽  
K. M. Inglis ◽  
P. J. Veugelers
Keyword(s):  
Breast Cancer ◽  
Patient Satisfaction ◽  
Short Interval ◽  
Time Interval ◽  
Specific Time ◽  
Time Intervals ◽  
Satisfaction Questionnaire ◽  
Younger Women ◽  
Natural Logarithm ◽  
Abnormal Mammogram

17010 Background: Although recent studies have described timeliness of breast cancer (BC) care and its impact on outcomes, there is little data on patient perception of timeliness. This study examined the association between clinicodemographic factors, timeliness and patient satisfaction for surgically-treated BC patients across defined intervals of diagnosis (Dx) and treatment. Methods: All patients undergoing surgery for primary BC within a single Health District over 24 months were enrolled in a prospective consecutive cohort study. A comprehensive, standardized method of ascertaining specific time intervals, including a patient interview, was used to quantify the timeliness of presentation, Dx and treatment. A validated satisfaction questionnaire was applied to patients 2 weeks after surgery, and following chemotherapy. Multiple linear regression, using the natural logarithm of the time interval as the dependant variable, was performed to examine the association of factors and satisfaction with specific time intervals. Results: Among the 519 patients in the study, 317 (61%) were screen-detected and 202 (39%) presented symptomatically. Complete satisfaction questionnaire responses were obtained in 348 (67%). The median time intervals in days (interquartile range) were: abnormal screen to Dx - 33 (21–48); symptoms to Dx 44 (23–97); Dx to surgery - 31 (22–43); surgery to adjuvant chemotherapy 63 (49–73). On multivariate analysis, the interval from presentation (either abnormal mammogram or symptoms) to Dx was 33% longer for screen-detected patients (p<0.0001) and 38% longer for patients where more than one diagnostic test was performed (p=0.009). Moderate correlation was identified between patient satisfaction and both the intervals from presentation to Dx (r2=0.212;p<0.0001) and from Dx to surgery (r2=0.262;p<0.0001). Controlling for the length of these intervals, younger women (p=0.01) and those with a Dx made via screening (p=0.004) had significantly lower satisfaction scores. Conclusions: The timeliness of care for BC involves several defined components; variations in the relatively short interval from Dx to surgery appeared to have most impact on patient satisfaction. Younger women and those diagnosed via screening were less satisfied with their access to timely care. No significant financial relationships to disclose.

scholarly journals Dynamic Reliability Evaluation of Linear Consecutive k-out-of-n0: F System With Multi-State Components

2018 ◽  
Vol 22 ◽  
pp. 01057
Author(s):  
Gökhan GÖKDERE ◽  
Mehmet GÜRCAN
Keyword(s):  
Operating Performance ◽  
Reliability Evaluation ◽  
Technical System ◽  
Time Interval ◽  
Specific Time ◽  
Time Intervals ◽  
Engineering Applications ◽  
Dynamic Reliability ◽  
Reliability Calculation ◽  
The Status

In engineering applications, analyzing a technical system vary according to the operating principles of the system. In some situations, the status of the system is a function of stresses which act on the system and cause degradation. In order to efficiently analysis the reliability of a system which operates under stress, assigning the various states to the components depending on their operating performance is very important. In this paper, we have investigated the linear consecutive k-out-of-n: F system and assigned multiple states to its components. Due to the reason, the operating performance of the components can easily be controlled. Apart from that the reliability of the system depending on the states of its components can be calculated at any time interval. In the numerical example, the states of the components and the reliability calculation of the system at specific time intervals are shown clearly.

Optimal mission duration for systems subject to shocks and internal failures

2017 ◽  
Vol 232 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Maxim Finkelstein ◽  
Gregory Levitin
Keyword(s):  
Failure Probability ◽  
Premature Termination ◽  
Cost Effective ◽  
Optimal Time ◽  
Time Interval ◽  
System Failure ◽  
Repairable Systems ◽  
Specific Time ◽  
Mission Time ◽  
Mission Duration

At many instances, it is more cost-effective to terminate operation of a system than to wait for its failure or completion of a mission. Usually, completion of a mission (contract) results in an additional reward, whereas premature termination results in a penalty. However, the system failure during the mission can incur considerable expenses. As the failure probability increases with the mission time, this can make the mission completion too risky and not beneficial. This article analyzes the optimal mission duration for non-repairable systems subject to shocks and internal failures. Under certain assumptions, an optimal time of mission termination is obtained. It is shown that, if for some reason, the termination is not technically possible at this optimal time, the mission should be terminated within a specific time interval and, if this is not possible, it should not be terminated beyond this interval. Illustrative examples are presented.

scholarly journals The Effect of Biomass Pellet Length, Test Conditions and Torrefaction on Mechanical Durability Characteristics According to ISO Standard 17831-1

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 3000 ◽  
Author(s):  
Hamid Gilvari ◽  
Wiebren De Jong ◽  
Dingena L. Schott
Keyword(s):  
Length Distribution ◽  
Mechanical Degradation ◽  
Time Interval ◽  
Specific Time ◽  
Time Intervals ◽  
Durability Test ◽  
Iso Standard ◽  
Test Conditions ◽  
Mechanical Durability ◽  
Biomass Pellet

With the recent increase in biomass pellet consumption, the mechanical degradation of pellets during transport and handling has become more important. ISO standard 17831-1 is an accepted global standard that is commonly used amongst researchers and industries to determine the mechanical durability of pellets. However, the measured mechanical durability sometimes fails to match the certificate accompanying the shipment. In such cases, pellet length specifications are suspected to play a role. This paper studies the effect of pellet length on mechanical durability for various types of commercially produced biomass pellets. In addition, the effect of test conditions and torrefaction on the mechanical durability of biomass pellets has been investigated. To study the effect of pellet length, pellets were classified into three groups: shorter than 15 mm, 15 to 30 mm, and longer than 30 mm, and their length distributions were measured using an in-house image processing tool. Then, the mechanical durability of pellets was measured using ISO standard 17831-1. The mechanical durability results were compared to random-sized pellet samples. To study the effect of test conditions, the mechanical durability test was operated at different time intervals to elucidate the effect of tumbling at different conditions. The results show that the mechanical durability depends highly on the length distribution of the pellets, with a difference between categories of up to 13%. It was also observed that the mechanical durability remains relatively constant after a specific time interval. Based on the results, we highly recommend modifying the current ISO standard to account for the pellet length distribution (PLD).

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