## woey

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woey replied to the topic Simple Linear Regression Analysis in the forum General 17 years, 5 months ago

Thanks for all the work. I tried to do a polynomial regression, and got a pretty good y and x relationship. The R^2 is 0.998. I would like to use powerfit, however I have no idea how good the powerfit in relating y and x.

woey replied to the topic Simple Linear Regression Analysis in the forum General 17 years, 5 months ago

What I want to achieve is to establish a specification for a medical device that my company is making. Given a acceptable pressure value to average patient population, I need to find out the best fit flowrate value. From the flowrate, I can find out the relationship between volume and time. Thanks everyone for the inputs.

woey replied to the topic Tolerance Stack-up Analysis in the forum General 17 years, 7 months ago

Gabriel: Nice presentation. I like your approach to the problem. However I have a dumb question-Why the max shift of the average from the target value (40) is 0.25mm?

Thanks!woey replied to the topic Sealed Pouch Strength-When to Fail? in the forum General 17 years, 11 months ago

here is the detailed information of the heat sealing validation: The contents of the pouch consists of three different components, and they are relatively light. Hence, I would not consider the long term weight impact of those components on the sealed area. What I am considering is the impact of time and enviromental factors that make the sealed…[Read more]

woey replied to the topic Sealed Pouch Strength-When to Fail? in the forum General 17 years, 11 months ago

Ron: Thanks for your prompy reply. Do you know of any goood website that I can get those information? I don’t have extensive background on reliability. Thanks!P/S: When I perform Weibull Analysis, what kind of data do I need?

woey replied to the topic T-Test for Attribute Data in the forum General 18 years, 2 months ago

Robert Butler:

I am a moron on t-test in fact. Can you please tell me in more detail what do you mean by ” If you have say 15 tubes measured before and after annealing you would take the differences between the measurements and sum them. The null hypothesis between non-annealed and annealed is that the signs on the differences are equally…[Read more]woey replied to the topic Established Control Limits in the forum General 18 years, 5 months ago

Jim: how many subgroup of data that I need so that I can use the UCL/LCL on the charts? The reason I ask because I need to establish UCL/LCL for a process on the production floor for in-process inspection. I want to be able to justify using UCL/LCL on the charts. Do I need to use different set-up at the machine, then collect more data, and create…[Read more]

woey replied to the topic Weibull Analysis in the forum General 18 years, 7 months ago

Erik, Thank you for your prompt and detail reply. I appreciate that. Actually my question is more complicated than that. Can I have your e-mail so that I can send an e-mail to you describe more detail, and hope you can help me. Thanks!

woey replied to the topic OC Curve and Sampling Plan in the forum General 18 years, 7 months ago

tom,

thanks for your response.

does it means we always use hypergeometric distribution when dealing with oc? why we use that distribution then? thanks!

woeywoey replied to the topic measureable quality in the forum General 18 years, 7 months ago

rus,

what is COPQ?woey replied to the topic measureable quality in the forum General 18 years, 7 months ago

Ken,

seem like you always respond to my posting real quick. thanks!

well, back to your response to my posting, if the $$$ is the best way of measuring, then how do you trace cost accurately? Use activity based costing? woeywoey started the topic First Article Inspection Sample Size in the forum General 18 years, 8 months ago

Is anyone knows a statistically significant sample size for First Article Inspection? Why some people calculate Ppk (instead of Cpk) when they analyze measurement for First Article Inspection? Let me know, and I appreciate your kind help.

woey replied to the topic Gage capability study – destruct test in the forum General 18 years, 8 months ago

Ben,

Try Nested Gage R&R Study. Minitab 13 has the capability to do this.woey replied to the topic Ppk Calculation in the forum General 18 years, 9 months ago

use the same formula as Cpk, but use different standard deviation.