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Current Affairs Discourse

Blog about Current Affairs

Current Affairs Discourse

BCG Vaccine vs COVID-19 Immunity Hypothesis

There appears to be something to the theory that BCG (TB) vaccination provides immunity to COVID-19.

The clinical trial mentioned in the tweet above could take a long time. Since proving causation from a mere correlation is a giant leap.

However, if there is enough data to prove a strong R square for the regression between people with BCG vaccination and immunity to COVID-19 it might be enough to “prove” the causation via hypothesis test with reasonable degree of certainty.

Not too different from how most drugs are approved for specific purposes by the FDA.

Establishing causation conclusively by turning the problem on and off as is done in engineering problem solving, or should be I should say, is simply not possible in most medical issues.

Now there are situations where such conclusive proof is elusive even in the engineering world. The hypothesis test with 95% confidence level is quite adequate for most situations.

When it isn’t, it is still possible to fail safe the system via multiple redundant backup systems.

Like in an aircraft for example. However, even that can fail.

Case in point is Boeing 737 max MCAS fiasco.

Soon to be seen in the “full self drive” cars…

TALF Is Back!!

Is it 2008 Redux? This is about selling secuterized assets (loans) to the Fed. Term Asset Backed Securities Loan Facility (TALF)

What is the Other assets?

Basically zero percent loan backed by assets.

Will it be similar to 2008 or different? 2008 was about Collateralized Mortgage Bond Securities (CMBS) mostly and Colleteralized Debt Obligations (CDO).

I sure hope it is NOT Bitcoin and other block chain digital currencies this time around.

So what is it?

 

Proof Elon Musk is Following My Advise!

 

February 5, 2020: Evaluate Tennessee for Cybertruck Production

March 11, 2020: Not just Tennessee, but Nashville Tennessee

March 19, 2020: Ventilators require FDA certification unlike Cars and Rockets

March 21, 2020: Elon Musk Providing assistance to Medtronic. Is this a formal foray into healthcare space?

QED

 

Small Business Cash Flow Management during Coronavirus

Starting to see lot of posts from Small Business Owners about the severe contraction in cash flows due to the Cornonavirus shutdown.

Unlike large corporations that have a recourse via short term commercial paper to tide over cash flow constraints which is also being supported by The Fed now, Small Business do not have lot of options.

The fundamentals of cash flow management and Working Capital Gap reduction however are the same for all business. This might help.

 

Having said that, Small businesses do not have the leverage to negotiate with suppliers, lessors, banks etc. Customers are usually transactional and not in Long Term Contracts. So this poses unique challenges.

There are some levers that can be used. For VC funded startups, the VC might step in if they see viability. For the rest, usually the owner has to use personal resources.

However, before doing that it might help to optimize for the new reality.

How? contact@processisinc.com

 

WiFi6 Mesh Network for Gigabit Problem Solving

I have been trying to get the Gigabit internet service for a while now. It finally happened. Just in time for the entire family working and schooling from home due to the Corona virus induced COVID-19 seclusion!

The fiber service provider provides their own Modem in this case. Needed to get a new router since my old router is a Cable Modem/Router combo. Seemed like a good idea when I got the combo router just couple of years ago. Had to get a new router since the then five year old router was obsolete. Such is the travails of technology. The dreaded incompatibility of the hardware as software evolves.

Should have leased the router? Perhaps. I suspect a lifetime TCO analysis would probably indicate otherwise. Anyway, getting back to issue at hand, the new router evaluation brought to light, you guessed it, new technology! WiFi6 protocol.

Lo behold, I found a brand new router just out in the market. None of my devices are Wifi6 yet, but they will be eventually. Especially with IoT and the connected 21st century autonomous economy. So I went with it. It has been an interesting couple of weeks. Figured some things out during the course of troubleshooting with the service provider and the router vendor.

Needed to breakdown the problems into its individual components and formulate a hypothesis. Is it the back haul? The fiber install? The modem? The router hardware? The router software? Wifi congestion? Settings? Some combination of the above?

All said and done, the performance of the network is a lot better than it was before I got the gigabit service. However, it could be better.

Still work in progress…

21st Century Entrepreneurship! It is not about mobile apps…

The recent upheaval in the 2019 IPOs might just be a good indication of peak mobile and peak mobile apps.

 

WeWork just shelved its IPO! Most of the the other 2019 IPOs are trading well below the IPO valuations and may have a long way to go before reasonable valuation if any.

 

Moving forward, the opportunity of a lifetime might be in the autonomous space (not limited to automotive) where AI and 5G enabled edge computing via IoT is the key enabler and safety & security is paramount.

 

These are interesting times indeed for early stage startup scene…

 

We are at the cusp of yet another episode of Roaring 20s. 100 years since the last one.

Here is why: https://www.slideshare.net/ShakerCherukuri/roaring-20s-again

Stay tuned for more…

Boeing 737 Max 8 adding New Flight Control System Module?

This is a big deal! Agree.

https://twitter.com/processisinc/status/1157459811514142720?s=21

However what is the new problem discovered?

https://twitter.com/processisinc/status/1155102744216264704?s=21

So looks like the software only fix was deemed to be ludicrous as I suspected.

 

The erroneous streams of data are now deem to be due to cosmic rays bombarding the microprocessor cells?

 

This was replicated in a lab? How? Using cosmic rays?

 

Was the problem tuned on and off?

 

The fix will now be a third control module that evaluates the two Flight control systems outputs and decide what makes sense? During erroneous streams of data caused by cosmic rays bombardment on the microprocessor cells?

 

How exactly is all this going to be validated?

 

To be continued…

Flight Control Systems and Systems Integration issues on Boeing 737 Max 8?


Update 7

The offset was 60 degrees between the two AOA sensors in the case of Ethiopian Air after an incident during take off? Bird strike?

Plus the following…

 

Cutting out the power to MCAS motors did not fix the steep dive? What does that mean?

The Integration issues:

https://twitter.com/ProcessISInc/status/1113051884225486848

Flight control systems issue: Major upgrade in the works. Plus AOA sensor input to MCAS is not the same on all aircrafts?

This is Epic systems design and implementation failure possibly?

Boeing 737 Max 8 MCAS – Is the proposed Fix good enough?

Swiss cheese. You hear that a lot in systems design and engineering.

It is often not possible to fail safe a system with 100% certainty.

Especially true when there is an unforeseen and/or unintended consequence and a fix is proposed to a problem.

Root cause may not be known with certainty, however, a fix could be put in place as a short term remedy to alleviate the cascade catastrophic failure.

Swiss cheese.

If you stack up a few of them, then the likelihood of a through and through hole is quite low.

In fact, the entire aircraft systems design is based on this principle. With several redundancies and backup and backups for backups.

Engines being the most obvious example. There is computers, sensors etc that also have redundancies. Which is why the 737 Max and other Aircrafts cost $100Million.

So why then was this Autonmous MCAS System basing it’s entire activation on a single sensor input?

The proposed fix:

It appears that Ethiopian Air AOA sensor offset was also 20 degrees!!

What does that imply? MCAS won’t activate with 20 degree offset with the above fix.

However, it doesn’t fix the root of the issue. What is causing this offset?

Could there be a deeper issue here which could be impacting other systems as well?

Could this be more than the unintended consequences of the MCAS algorithm discussed here:

MCAS Algorithm & The Unintended Consequences – Boeing 737 Max

 

To be continued…thoughts in progress.

MCAS Algorithm & The Unintended Consequences – Boeing 737 Max

An Exclusive by Seattle times reporter Dominic Gates has detailed some of the lapses in the design of the Boing 737Max8 MCAS control algorithm.

It raises several questions about flaws in the design, design process and safety reviews.

My hypothesis published soon after Lion Air JT610 crash is along the similar lines.

Lion Air Flight 610 Boeing 737 MAX 8

I will try to answer some of the questions raised in the Seattle Times article and also in my previous blogs about this issue since we now have more information.

 

  1.  Why was the MCAS algorithm put in place?

The algorithm was required to get FAA airworthiness certification for Boeing 737Max due to possibility of high speed stall. This situation was determined to be possible by the nature of the design of the aircraft with bigger engines and different mounting locations. Possibly via CFD analysis etc.

Possible. But how likely was it?

2. So what went wrong?

Sensors. Angle of Attack (AOA) sensors to be precise. It appears that either one or perhaps both of the AOA sensors were compromised. The MCAS is an algorithm. It needs input from the sensors to act. If the data is flawed, it will act in unintended operating envelopes. Unless of course, it is designed to account for that. Which it wasn’t perhaps?

3. Why was the sensor data flawed?

There could be several reasons for this. Let us see what is believed to have happened In the case of Air France flight 447 crash in 2009.

In that case (Airbus Air France Flight 447) it was determined that the Pitot Tubes (Speed sensors) were flash frozen due to super cooled condensation in the air. This caused the aircraft to stall. To bring it out of stall, the pilots needed to pitch the nose down. However, the stall alarm algorithm had a design flaw. It would come on when nose was pitched down and turn off when nose was pitched up since in the up condition with zero speed it assumed the aircraft was on the ground. So the pilots got confused.

In this case (Boing 737Max), the Lion Air FDR showed that there was an offset between the two AOA sensors. Lion Air Aircrafts do not have the optional AOA sensors mismatch light. However, the previous flights of the same aircraft had encountered similar flight control problems and it appears the maintenance crew determined that the sensor(s) were bad and replaced them.

The optional light just alerts the pilot to possible issue. Doesn’t impact the operation of the MCAS algorithm.

4. So if the sensors were replaced, then how come they went bad again?

Now it is possible that the new sensors were also bad. How likely is that? So possibly there is something else going on. A system issue (raised in my Lion Air Post above).

5. So how come just one bad sensor out of the two caused MCAS to trim down?

That is the big question. My initial thoughts on this was that MCAS was simply selecting the worst case/input. It appears that is not the case. It is only getting only one input? If this true, then why have two sensors?

My guess is that there is some pre selection of the signal via signal conditionining ASIC or ECU before feeding the input to MCAS algorithm ECU. The two ECU’s might not be the same – the signal selection and MCAS algorithm ECU. There could be several reasons for this.

Would be interesting to know the ECU vintages and commonality with prior and/or other 737 models. This could be the smoking gun in my opinion.

6. Why doesn’t MCAS look at other inputs and conditions and determine validity of the sensor signal before acting on it?

Good question. It should. Should have been flagged in safety reviews. Seattle Times article has good info on this.

7. What about how far it can trim and how much?

This is an  aeronautical engineering question. Outside my scope of expertise. Seattle Times Dominic Gates articles covers this well. I will add this though:

The trim limits and activation thresholds should have been engineering calibrations in the algorithm. It would have made it possible to “tune it” for each aircraft  variations.

 

The FAA CANIC (Continued Airworthiness Notification to International Community) published does seem to (?) address all three issues (5,6,7). See my Ethiopian Airlines post on this.

Ethiopian Airlines ET 302 Boeing 737 Max 8

8. So if the fixes are in the works, we should be good right?

No. It isn’t just about this MCAS feature anymore. The whole design and development of this aircraft and possible all aircrafts at Boeing is suspect now. It is imperative that it be investigated properly. In the works maybe?

Who is really incharge of the Boeing 737 Max investigation?

Update/Additions 1

Just came across this. Even Airbus Aircrafts have anti stall systems which get triggered falsely due to bad AOA sensors!!

Update 2.

Interesting twitter conversation with Peter Lemme (interviewed for the Seattle Times article above) back in November.

Note: Will update as needed.