scholarly journals Enhancing Scheduling Performance for a Wafer Fabrication Factory: The Biobjective Slack-Diversifying Nonlinear Fluctuation-Smoothing Rule

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Toly Chen ◽  
Yu Cheng Wang
Keyword(s):  
Standard Deviation ◽  
Wafer Fabrication ◽  
The Future ◽  
Simulated Case ◽  
Fluctuation Smoothing ◽  
Nonlinear Fluctuation

A biobjective slack-diversifying nonlinear fluctuation-smoothing rule (biSDNFS) is proposed in the present work to improve the scheduling performance of a wafer fabrication factory. This rule was derived from a one-factor bi-objective nonlinear fluctuation-smoothing rule (1f-biNFS) by dynamically maximizing the standard deviation of the slack, which has been shown to benefit scheduling performance by several previous studies. The efficacy of the biSDNFS was validated with a simulated case; evidence was found to support its effectiveness. We also suggested several directions in which it can be exploited in the future.

A Dynamically Optimized Fluctuation Smoothing Rule for Scheduling Jobs in a Wafer Fabrication Factory

2011 ◽  
Vol 7 (4) ◽  
pp. 47-64 ◽  
Author(s):  
Toly Chen
Keyword(s):  
Standard Deviation ◽  
Test Data ◽  
Cycle Time ◽  
Performance Metrics ◽  
The Other ◽  
Wafer Fabrication ◽  
Fluctuation Smoothing ◽  
Time Standard ◽  
Nonlinear Fluctuation ◽  
Better Than

This paper presents a dynamically optimized fluctuation smoothing rule to improve the performance of scheduling jobs in a wafer fabrication factory. The rule has been modified from the four-factor bi-criteria nonlinear fluctuation smoothing (4f-biNFS) rule, by dynamically adjusting factors. Some properties of the dynamically optimized fluctuation smoothing rule were also discussed theoretically. In addition, production simulation was also applied to generate some test data for evaluating the effectiveness of the proposed methodology. According to the experimental results, the proposed methodology was better than some existing approaches to reduce the average cycle time and cycle time standard deviation. The results also showed that it was possible to improve the performance of one without sacrificing the other performance metrics.

A Dynamically Optimized Fluctuation Smoothing Rule for Scheduling Jobs in a Wafer Fabrication Factory

2012 ◽  
pp. 265-284
Author(s):  
Toly Chen
Keyword(s):  
Standard Deviation ◽  
Test Data ◽  
Cycle Time ◽  
Performance Metrics ◽  
Experimental Results ◽  
The Other ◽  
Wafer Fabrication ◽  
Fluctuation Smoothing ◽  
Time Standard ◽  
Nonlinear Fluctuation

This paper presents a dynamically optimized fluctuation smoothing rule to improve the performance of scheduling jobs in a wafer fabrication factory. The rule has been modified from the four-factor bi-criteria nonlinear fluctuation smoothing (4f-biNFS) rule, by dynamically adjusting factors. Some properties of the dynamically optimized fluctuation smoothing rule were also discussed theoretically. In addition, production simulation was also applied to generate some test data for evaluating the effectiveness of the proposed methodology. According to the experimental results, the proposed methodology was better than some existing approaches to reduce the average cycle time and cycle time standard deviation. The results also showed that it was possible to improve the performance of one without sacrificing the other performance metrics.

A Fuzzy Fluctuation Smoothing Rule for Job Dispatching in a Wafer Fabrication Factory

2012 ◽  
Vol 2 (4) ◽  
pp. 47-63 ◽  
Author(s):  
Toly Chen
Keyword(s):  
Simulation Study ◽  
Cycle Time ◽  
Production System ◽  
Wafer Fabrication ◽  
Dispatching Rules ◽  
Cycle Times ◽  
Job Dispatching ◽  
Fluctuation Smoothing ◽  
Mean Cycle ◽  
Nonlinear Fluctuation

Job dispatching in a wafer fabrication factory is a difficult task, mainly due to the complexity of the production system and the uncertainty involved in the production activities. Recently, a number of advanced dispatching rules were proposed, which estimate the remaining cycle times of jobs. This predictive nature is conducive to the effectiveness of these rules. If the uncertainty in the remaining cycle time can be better considered, incorrect scheduling will possibly be reduced. The tailored nonlinear fluctuation smoothing rule for mean cycle time (TNFSMCT) is fuzzified in this study, by expressing the remaining cycle time with a fuzzy value. The effectiveness of the proposed methodology is illustrated with a simulation study.

Fuzzy-neural-network-based fluctuation smoothing rule for reducing the cycle times of jobs with various priorities in a wafer fabrication plant: A simulation study

2009 ◽  
Vol 223 (8) ◽  
pp. 1033-1043 ◽  
Author(s):  
T Chen
Keyword(s):  
Neural Network ◽  
Cycle Time ◽  
Fuzzy Neural Network ◽  
Optimal Solution ◽  
Wafer Fabrication ◽  
Estimation Accuracy ◽  
Cycle Times ◽  
Fuzzy Neural ◽  
The Difference ◽  
Fluctuation Smoothing

This paper presents a fuzzy-neural-network-based fluctuation smoothing rule to further improve the performance of scheduling jobs with various priorities in a wafer fabrication plant. The fuzzy system is modified from the well-known fluctuation smoothing policy for a mean cycle time (FSMCT) rule with three innovative treatments. First, the remaining cycle time of a job is estimated by applying an existing fuzzy-neural-network-based approach to improve the estimation accuracy. Second, the components of the FSMCT rule are normalized to balance their importance. Finally, the division operator is applied instead of the traditional subtraction operator in order to magnify the difference in the slack and to enhance the responsiveness of the FSMCT rule. To evaluate the effectiveness of the proposed methodology, production simulation is applied to generate some test data. According to the experimental results, the proposed methodology outperforms six existing approaches in the reduction of the average cycle times. In addition, the new rule is shown to be a Pareto optimal solution for scheduling jobs in a semiconductor manufacturing plant.

Surfers' awareness of the preventability of ‘surfer's ear’ and use of water precautions

2011 ◽  
Vol 125 (6) ◽  
pp. 551-553 ◽  
Author(s):  
V M Reddy ◽  
T Abdelrahman ◽  
A Lau ◽  
P M Flanagan
Keyword(s):  
Standard Deviation ◽  
External Auditory Canal ◽  
The Future ◽  
And Gender

AbstractObjective:To establish surfers' knowledge of the preventability of external auditory canal exostoses (‘surfer's ear’), and their use of water precautions.Method:Survey of surfers conducted between December 2009 and March 2010 at beaches in Cornwall, UK.Results:Ninety-two surfers were included (78 males and 14 females, mean age 27 years, standard deviation 7.9 years). Participants were grouped according to their awareness of the preventability of surfer's ear (55 aware, 37 unaware). These groups were comparable in age, surfing history and gender mix (p > 0.05). Surfers aware of the preventability of exostoses (66 per cent) were more likely to use water precautions than those who were not (38 per cent) (p < 0.01). Two surfers used water precautions regularly and 48 used them occasionally. Sixty-one of the 76 surfers who did not use water precautions (ear plugs) suggested they would consider doing so in the future.Conclusion:Awareness of the preventability of surfer's ear was associated with greater use of water precautions. Further research should explore reasons for the low uptake of such precautions. Most surfers not already using ear plugs would consider doing so in the future.

scholarly journals A Novel Fuzzy-Neural Slack-Diversifying Rule Based on Soft Computing Applications for Job Dispatching in a Wafer Fabrication Factory

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Toly Chen ◽  
Richard Romanowski
Keyword(s):  
Soft Computing ◽  
Cycle Time ◽  
Fuzzy Classification ◽  
Wafer Fabrication ◽  
Estimation Accuracy ◽  
Soft Computing Techniques ◽  
Fuzzy Neural ◽  
Job Dispatching ◽  
Neural Network Prediction ◽  
Fluctuation Smoothing

This study proposes a slack-diversifying fuzzy-neural rule to improve job dispatching in a wafer fabrication factory. Several soft computing techniques, including fuzzy classification and artificial neural network prediction, have been applied in the proposed methodology. A highly effective fuzzy-neural approach is applied to estimate the remaining cycle time of a job. This research presents empirical evidence of the relationship between the estimation accuracy and the scheduling performance. Because dynamic maximization of the standard deviation of schedule slack has been shown to improve performance, this work applies such maximization to a slack-diversifying fuzzy-neural rule derived from a two-factor tailored nonlinear fluctuation smoothing rule for mean cycle time (2f-TNFSMCT). The effectiveness of the proposed rule was checked with a simulated case, which provided evidence of the rule’s effectiveness. The findings in this research point to several directions that can be exploited in the future.

scholarly journals THE RELATIONSHIP BETWEEN VOLUNTEERS SATISFACTION AND INTENTION TO CONTINUE VOLUNTEERING IN COMMUNITY RUNNING EVENTS

2021 ◽  
Vol 17 (1) ◽  
pp. 11
Author(s):  
Azlina Zid ◽  
Adlin Hani Mazlan Hanafi ◽  
Siti Aishah Wahab ◽  
Nurul Ain Muhammad Rafiai ◽  
Maizan Mohd Nor ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Significant Relationship ◽  
Pearson Correlation ◽  
Inferential Statistics ◽  
Volunteer Satisfaction ◽  
The Future ◽  
Future Events ◽  
Intention To Continue ◽  
The Relationship

This purpose of this study is to identify the relationship between volunteers’ satisfaction and intention to continue volunteering as a volunteer in the future. There were 133 volunteers from MY10K Night run involved in this community-running event. Volunteer’ satisfaction and intention to continue volunteering questionnaires were used in this study. The data was analysed using descriptive and inferential statistics to identify the percentage, mean, standard deviation and pearson correlation. The study findings showed that there was a significant relationship between the volunteers’ satisfaction and the intention to continue volunteering (r=0.37, p<0.01). The nature of work (m=4.10) was the highest factor of volunteers’ satisfaction to remain as volunteers in future events and followed by appreciation (m=4.01). Whereas supervision and communication (m=3.96) were found to be least volunteers’ satisfaction to remain as volunteers. Identifying these factors of volunteering, as well as the relations between them, can be beneficial for the management of volunteers to retain the experienced volunteers and to ensure the continuation of the event in the future.

scholarly journals Determining a One-Tailed Upper Limit for Future Sample Relative Reproducibility Standard Deviations

2006 ◽  
Vol 89 (3) ◽  
pp. 797-803
Author(s):  
Foster D McClure ◽  
Jung K Lee
Keyword(s):  
Standard Deviation ◽  
Linear Combination ◽  
Square Root ◽  
Sample Mean ◽  
Upper Limit ◽  
Reproducibility Standard Deviation ◽  
The Future ◽  
Standard Deviations ◽  
Future Sample

Abstract A formula was developed to determine a one-tailed 100p% upper limit for future sample percent relative reproducibility standard deviations &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq1.gif"/&gt; &lt;/inline-formula&gt; , where sR is the sample reproducibility standard deviation, which is the square root of a linear combination of the sample repeatability variance ( &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq2.gif"/&gt; &lt;/inline-formula&gt; ) plus the sample laboratory-to-laboratory variance ( &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq3.gif"/&gt; &lt;/inline-formula&gt; ), i.e., &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq4.gif"/&gt; &lt;/inline-formula&gt; , and y is the sample mean. The future RSDR, % is expected to arise from a population of potential RSDR, % values whose true mean is &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq5.gif"/&gt; &lt;/inline-formula&gt; , where R and are the population reproducibility standard deviation and mean, respectively.

Sign in / Sign up

Export Citation Format

Share Document