Posts about Engineering

I Just Finished Statistics for Experimenters and I Cannot Praise it Enough

Guest post by Michael Betancourt.

I just finished Box, Hunter, and Hunter (Statistics for Experimenters) and I cannot praise it enough. There were multiple passages where I literally giggled. In fact I may have been a bit too enthusiastic about tagging quotes beyond “all models are wrong but some are useful” that I can’t share them all.

photo of Statistics for Experimenters with many blue bookmarks shown

I wish someone had shared this with me when I was first learning statistics instead of the usual statistics textbooks that treat model development as an irrelevant detail. So many of the elements that make this book are extremely relevant to statistics today. Some examples:

  • The perspective of learning from data only through the lens of the statistical model. The emphasis on sequential modeling, using previous fits to direct better models, and sequential experiments, using past fits to direct better targeted experiments.
  • The fixation on checking model assumptions, especially with interpretable visual diagnostics that capture not only residuals but also meaningful scales of deviation. Proto visual predictive checks as I use them today.
  • The distinction between empirical models and mechanistic models, and the treatment of empirical linear models as Taylor expansions of mechanistic models with covariates as _deviations_ around some nominal value. Those who have taken my course know how important I think this is.
  • The emphasis that every model, even mechanistic models, are approximations and should be treated as such.
  • The reframing of frequentist statistical tests as measures of signal to noise ratios.
  • The importance of process drift and autocorrelation in data when experimental configurations are not or cannot be arbitrarily randomized.
  • The diversity of examples and exercises using real data from real applications with detailed contexts, including units everywhere.

Really the only reason why I wouldn’t recommend this as an absolute must read is that the focus on linear models and use of frequentist methods does limit the relevance of the text to contemporary Bayesian applications a bit.

Texts like these make me even more frustrated by the desire to frame movements like data science as revolutions that give people the justification to ignore the accumulated knowledge of applied statisticians.

Academic statistics has no doubt largely withdrawn into theory with increasingly smaller overlap with applications, but there is so much relevant wisdom in older applied statistics texts like these that doesn’t need to be rediscovered just reframed in a contemporary context.

Oh, I forgot perhaps the best part! BHH continuously emphasizes the importance of working with domain experts in the design and through the entire analysis with lots of anecdotal examples demonstrating how powerful that collaboration can be.

I felt so much less alone every time they talked about experimental designs not being implemented properly andthe subtle effects that can have in the data, and serious effects in the resulting inferences, if not taken into account.

Michael Betancourt, PhD, Applied Statistician – long story short, I am a once and future physicist currently masquerading as a statistician in order to expose the secrets of inference that statisticians have long kept from scientists. More seriously, my research focuses on the development of robust statistical workflows, computational tools, and pedagogical resources that bridge statistical theory and practice and enable scientists to make the most out of their data.
Twitter: @betanalpha
Website: betanalpha
Patreon: Michael Betancourt

Related: Statistics for Experimenters, Second EditionStatistics for Experimenters in SpanishStatistics for Experimenters ReviewCorrelation is Not Causation

Appropriate Technology: a Microscope and Centrifuge for Under $1

Malaria is estimated to have killed more than half the people that have ever lived. And it continues to kill millions. One big challenge is diagnosing malaria is difficult (those infected have flu like symptoms).

The video shows two great appropriate technology solutions to help diagnose malaria and save millions of lives. Manu Prakash from Stanford talks about 2 of his labs’ inventions the Foldscope and the Paperfuge. Combined these cost only 68 cents and they can be used to diagnose Malaria. Both of these are examples not only of simple, brilliant design, but of how engineering is used to make a positive dent in the world.

Read more about the Paperfuge: an ultra-low cost, hand-powered centrifuge inspired by the mechanics of a whirligig toy (open access paper).

This solution also shows the huge benefit people everywhere have gained when immigrants can take their skills and desires to institutions like Stanford to create solutions that greatly benefit the world. This powerful force has been creating huge benefits that we all have enjoyed for decades.

Related: Appropriate Technology and Focus on Improving Lives at MIT (2014)$1 Device To Give Throat Cancer Patients Their Voice Again (2016)Video showing malaria breaking into cell (2011)Engineering: Cellphone Microscope (2009)One Scientists 20 Year Effort to Defeat Dengue Fever (2012)

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Red-tailed hawk with squirrel

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Scientists and Engineers in Congress After the Recent Elections in the USA

The recent elections in the USA added to those serving in congress with STEM (science, technology, engineering and math) backgrounds.

USA Capital Building

US Capital Building in Washington DC by John Hunter.

Here is a list of elected representatives in the USA congress with science, technology, engineering and math backgrounds (after the 2018 election).

Name State BS Notes Link
Ralph Abraham Louisiana MD bio
Ami Bera California biological sciences MD bio
Tony Cárdenas California electrical engineering bio
Sen. Bill Cassidy Louisiana biochemistry MD bio
Sean Casten Illinois molecular biology and biochemistry MS biochemical engineering and engineering management, 2018* bio
Chris Collins New York mechanical engineering bio
Joe Cunningham South Carolina ocean engineering 2018* bio
Jeff Van Drew New Jersey D.D.S. (Dentist), 2018* bio
Bill Foster Illinois physics PhD physics bio
Brett Guthrie Virginia mathematical economics bio
Sen. Martin Heinrich New Mexico mechanical engineering bio
Kevin Hern Oklahoma electro-mechanical engineering 2018* bio
Chrissy Houlahan Pennsylvania engineering MS technology and policy, 2018* bio
Joe Kennedy III Massachusetts management science and engineering bio
Ted Lieu California computer science bio
Name State BS Notes Link
Dan Lipinski Illinois mechanical engineering engineering-economic systems (MS) bio
Elaine Luria Virginia physics masters in engineering management, 2018* bio
Jerry McNerney California mathematics PhD bio
Seth Moulton Massachusetts physics bio
Pete Olson Texas computer science (BA)
Sen. Jacky Rosen Nevada psychology associat’s degree in computing and information technology
Raul Ruiz California MD, 2018* bio
Brad Schneider Illinois industrial engineering bio
Kurt Schrader Oregon Dr. of Veterinary Medicine bio
Kim Schrier Washington astrophysics MD, 2018* bio
John M. Shimkus Illinois general engineering bio
Paul Tonko New York mechanical and industrial engineering bio
Lauren Underwood Illinois nursing MS in Nursing and Master of Public Health, 2018* bio
Steve Watkins Kansas engineering 2018* bio



Those with notes including “2018*” means they were newly elected to the congress in 2018.

Please send any information on possible additions to this list (see the continually updated list).

Related: Scientific Research Spending Cuts in the USA and Increases Overseas are Tempting Scientists to Leave the USA (2013)The Science Gap and the EconomyScientists and engineers in the USA Congress in 2008 (scroll down the page to see 2008) – Diplomacy and Science ResearchUnless We Take Decisive Action, Climate Change Will Ravage Our Planet (2009)Silicon Valley Shows the Power of Global Science and Technology Workforce

Protecting Cows with Lion Lights

It is wonderful to see what great things people accomplish to improve their lives using sensible, and fairly simple, engineering.

15 Year-Old Kenyan Prodigy, Richard Turere, Who Created “Lion Lights”

He fitted a series of flashing LED bulbs onto poles around the livestock enclosure, facing outward. The lights were wired to a box with switches and to an old car battery powered by a solar panel. They were designed to flicker on and off intermittently, thus tricking the lions into believing that someone was moving around carrying a flashlight.

The astonishing aspect of this is that Turere installed the whole system by himself, without receiving any training in electronics or engineering.

This is a great video which includes good examples of the value to experimenting, learning and adapting. Iteration is a critical skill when developing solutions. Try out prototypes and learn from what happens. Use that knowledge to develop new solutions or modify the existing solutions and experiment some more. Continue to iterate and improve.

This is another great example of people using their initiative, creativity and engineering talent to create appropriate technology solutions to create solutions that improve their lives. It is great to see how these efforts continue over time, this BBC article follows up on Richard Turere several years after his initial success:

What happened to the boy who chased away the lions?

The Lion Lights system is now in 750 homesteads in Richard’s community and beyond, with the innovator making small tweaks and improvements to each version.

Lion Lights 2.0 costs $200 (£150) to install. Half of the money usually comes from NGOs while the rest is provided by the herder.

This version has 16 different flashing light settings and Richard’s latest update is a homemade wind turbine for days when clouds limit the solar power potential.

But while his idea has travelled, support for Richard as a young innovator and the implementation of his own Lion Lights has stalled in recent years. He thinks Kenya could do more to help young innovators like himself.

“There are many young people in Kenya with brilliant ideas, better even than mine – they just need support,” he says.

They need someone to be there to tell them, “this idea is really nice., let’s develop it to help communities”.

The efforts of so many great young people to create solutions that make the world a better place are inspiring.

Related: Electric WindBeehive Fence Protects Farms from ElephantsAppropriate Technology and Focus on Improving Lives at MITUsing The Building of Robots to Engage Students in Learning

Using Horizontal Polarized Optics to Block Screens

Animated polarizer in front of a computer flat screen

Animated of a polarizer in front of a computer screen (via Wikipedia).


These interesting glasses block LCD/LED screens through horizontal polarized optics. I think this is more an interesting application of science that a useful product but maybe some people actually would like the product.

The video below looks at how IRL Glasses block most TVs (LCD/LED) and some computers (LCD/LED). IRL Glasses do not yet block smartphones or digital billboards (OLED).

Related: App to allow a user to use American Sign Language to interact with AlexaAutonomous Delivery Robots Launched in Europe and USA3D Printing at Home: Today, Challenges and OpportunitiesThe Engineer That Made Your Cat a Photographer

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Saving Lives with Appropriate Technology Health Care Solutions: Treating Infant Pneumonia

How a shampoo bottle is saving young lives, a doctor in Bangladesh has found a simple way to treat infant pneumonia

Last year 920,000 children under the age of five died of pneumonia, making it the leading killer of people in that age group. This figure is falling (in 2011 it was 1.2m), but it still represents 16% of all infant deaths. Such deaths are not, however, evenly distributed. In Bangladesh pneumonia causes 28% of infant mortality.

Dr Chisti says that, as well as saving lives, his device has cut the hospital’s spending on pneumonia treatment by nearly 90%. The materials needed to make his version of a bubble-CPAP ventilator cost a mere $1.25. The device also consumes much less oxygen than a conventional ventilator. In 2013 the hospital spent $30,000 on supplies of the gas. In 2017 it spent $6,000.

Efforts are underway to test this innovation and spread the adoption of this appropriate technology solution to other poor countries. It is wonderful to see engineering innovation making such important improvements in health care around the world.

Related: Appropriate Technology Health Care Solution Could Save 72,000 Lives a Year (low-tech visual exam cut the cervical cancer death rate)Drone Deliveries to Hospitals in Rwanda$1 Device To Give Throat Cancer Patients Their Voice AgainWristband Thermometer Can Save Many Babies’ Lives

Growing Citrus in the Snow

The system uses the constant ground temperature 2.5 meters (8 feet) below ground to heat a greenhouse. The underground-temperature on his farm is 11 degrees (52 degrees Fahrenheit). Other nearby areas range from 9 to 17 degrees (17 is near a hot spring).

Just circulating air through 64 meters (210 feet) of tubing buried 2.5 meters underground is enough to allow citrus and other plants to thrive. Selling at local farmer’s markets brings in a very high profit for farmers that can grow and sell locally.

Using the power of the sun to grow and the constant ground temperature to keep the air warm enough creates an opportunity to grow all year round. The same principles can be used to cool down indoor temperatures in very hot locations near the equator.

Due to the controlled environment growing organically is easy so that further increases the payoff for this type of farming.

The cost of the system can be as low as $25,000 if you have access to a backhoe to dig the trenches for the air pipes and can do much of the labor yourself. That is the cost of just the heating systems for a conventional greenhouse.

I really like this type of intersection of engineering and business (as well as environment and health benefits – providing healthy local food) that creates value to society by using our knowledge effectively.

Learn more at Citrus in the Snow. The Nebraska farmer (seen in the video) has been growing Citrus in Nebraska this way since 1992.

Related: Sustainable Ocean FarmingBeehive Fence Protects Farms from ElephantsFor Many Crops Ants Can Provide Pest Protection Superior or Equal to Chemicals at a Much Lower CostSmall Farm Robots

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Diagram of solar energy project using molton salt

molten salt solar system diagram

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Toyota’s Newest Humanoid Partner Robot

T-HR3 reflects Toyota’s broad-based exploration of how advanced technologies can help to meet people’s unique mobility needs. T-HR3 represents an evolution from previous generation instrument-playing humanoid robots, which were created to test the precise positioning of joints and pre-programmed movements, to a platform with capabilities that can safely assist humans in a variety of settings, such as the home, medical facilities, construction sites, disaster-stricken areas and even outer space.

“The Partner Robot team members are committed to using the technology in T-HR3 to develop friendly and helpful robots that coexist with humans and assist them in their daily lives. Looking ahead, the core technologies developed for this platform will help inform and advance future development of robots to provide ever-better mobility for all,” said Akifumi Tamaoki, General Manager, Partner Robot Division.

T-HR3 is controlled from a Master Maneuvering System that allows the entire body of the robot to be operated instinctively with wearable controls that map hand, arm and foot movements to the robot, and a head-mounted display that allows the user to see from the robot’s perspective. The system’s master arms give the operator full range of motion of the robot’s corresponding joints and the master foot allows the operator to walk in place in the chair to move the robot forward or laterally. The Self-interference Prevention Technology embedded in T-HR3 operates automatically to ensure the robot and user do not disrupt each other’s movements.

Onboard T-HR3 and the Master Maneuvering System, motors, reduction gears and torque sensors (collectively called Torque Servo Modules) are connected to each joint. These modules communicate the operator’s movements directly to T-HR3’s 29 body parts and the Master Maneuvering System’s 16 master control systems for a smooth, synchronized user experience.

Learn more on Toyota’s news site.

Related: Toyota Develops Thought-controlled Wheelchair (2009)Robots for Health Care from Toyota (2017)Toyota Human Support Robot (2012)Lexus Has Built a Working Hoverboard (2015)

Simple and Cheap Security Camera with 2 Way Audio and Backup to Cloud via Wifi

This is a cool product at a very reasonable price: $30.

The device offers a 1080p HD smart home camera with 14 days of free rolling cloud storage, wide-angle lens, two-way audio and the ability to send alerts to your phone. You setup the device to use a local wifi network and control it via a smartphone application.

I have long wanted such a product (they have been available for a few years but haven’t been cheap) and now they are available at a great price. The main drawback I see is that it requires a power connection (it doesn’t have a battery option). So setting it up as a doorbell is a bit of an issue (you have to get power to it somehow).

Order your camera. Learn more about the device from Wyzecam

Related: Camera Trap Images of Very Rare Wild CatsAnswer Your Doorbell with Your Smartphone Wherever You Are (and see video of who is at the door) (from 2015Video Cat CamCanon PowerShot SX60 HS Digital Camera

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