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An EHS student and KDOT official interact demonstrate the Airspace Awareness Tool.
Here's a conundrum being faced in the state of Kansas: harnessing the state's great potential for wind energy while also safely advocating for aircraft traffic servicing the state's 138 airports and abiding by the siting guidelines for industrial wind turbines.

The state of Kansas approved a landmark piece of legislation in 2009, the Kansas Net-Metering and Easy Connection Act, which not only allowed for citizens to connect their energy generators to the grid but also standardized a 1-to-1 buyback policy (they would earn credits from their utility provider at the same rate that they would purchase energy from the same provider).

Here's where the math comes into play: industrial wind turbine installations are subjected to a battery of governances before the FAA (Federal Aviation Administration) gets their chance to have a say. Wind farm developers would then submit their site proposal through the FAA's Obstruction Evaluation process. Affected projects would include:
  • Any construction or alteration exceeding 200 feet above ground level (which requires a lighted beacon to make it visible to aircraft, common on water towers in my area)
  • When requested by the FAA (and sometimes as an anticipated last step in the developer's proposal process, which can negate a substantial amount of work, just to have to start from square one because the project might interfere with safe air travel)
  • Any construction or alteration located on a public use airport or heliport regardless of height or location
  • those located within 20,000; 10,000; or 5,000 feet or public use or military airports at varying height levels depending upon proximity to those airports (THIS is where the lesson focuses, on how to visualize these criteria before the FAA comes a-callin')
These criteria hardly lay out like a list of constraints for linear programming or a system of inequalities, but the logic involved definitely could be used in the same breath as one another. 

Try some of the requirements in the applicable city ordinance in trying to obtain a wind turbine on our high school campus, as part of the Kansas Wind for Schools program:
  • Blade-tip clearance, at its lowest point, shall have a ground clearance of not less than 25 feet tall
  • Overall height of 60 feet or less to fit Micro-WECS (Wind Energy Conversion Systems) class of devices
  • Minimum setback (measured from the closest adjacent lot line or parcel line or above ground public utility) of 110% of the device's overall height [Example: a 50-foot tall turbine would need to have a 55-foot radius clear of it to the nearest property line or easement]
  • No buildings within 110% of the device's height where the turbine's collapse could potentially damage another building of the property owner's
  • Ensuring that the noise emitted from the wind turbine shall not exceed 50 dbA within 100 feet of the nearest property line, except during short-term events such as utility outages and severe windstorms. [NOTE: The math involved with decibels is a great application to logarithms and how exponential behavior applies to the height-noise relationship in this case]

Do the phrases "not less than", "within", "n feet or less" start looking like the real-world examples we would hope to incorporate when teaching systems of inequalities? This gives students not simply an opportunity to see that our turbine site is a solution to the system of inequalities, but can drive some curiosity as to where else a turbine might be positioned and still satisfy all these criteria.

Check the brief video tutorial below on how to use the Airspace Analysis Tool (link to actual site included HERE), a product of the Kansas Department of Transportation Division of Aviation in conjunction with Burns & McDonnell Engineering (Please note links on the User Agreement page that help out with loading the Google Earth Plug-In necessary to use the site. From past experience, this has not been as successful using Safari as it has on Chrome, Fireforx, and Internet Explorer).


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A screenshot from the Airspace Analysis Tool, near Lawrence, Kansas.
Now, the fun, behind-the-scenes news about all this: KDOT actually unveiled their Airspace Analysis Tool IN MY CLASSROOM at a press conference hosted on a teacher inservice day (i.e. supposedly no classes in session). Here's the news story from the Lawrence-Journal-World.

Their personnel said it would be nice if we could have some students available to play around with the project and give their candid feedback. To their chagrin, I almost needed to bring in more chairs! Thank goodness some of the media on hand chose to stand and work behind their tripods and cameras, to catch the multiple perspectives of KDOT staff and students interacting. 

Students were anxious to see their project because it touched on a topic they had some curiosity about, and liked the potential to see some engineers in action. To show up at 8 a.m. ON THEIR DAY OFF was a remarkable thing for them to do and made another tally mark in the column for times I've loved my job.

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Situation hopefully made safer by the KAAT. Click image for image source link.
While students had an opportunity to try out and manipulate the tool during our press conference, they investigated the maps with relative ease because of their awareness of the familiar interface, Google Earth (even mentioned on the Google Earth blog after its release for an innovative use of their software). When the folks with Burns & McDonnell and KDOT asked for feedback on the beta version they released, our students swung for the fences and suggested another visual aspect: avatars. So now, the KAAT includes superimposed images of the device proposed at a location, as well as for existing structures on file. For those in the aviation industry, as well as in the land development and construction industries, this has been a welcome addition. As mobile devices become ever-present around us, this interface very well could find its way being incorporated into the cockpits of aircraft to help with flight instruction feedback in real time.

Since its release, the Kansas Airspace Analysis Tool (KAAT) has garnered national attention for its innovative ideas and interface, not simply for helping wind energy developers but also companies and communities who are looking to install water towers or cell/communications towers.

Here is part of one announcement I was able to retrieve (and HERE is a copy of their online newsletter announcing the recognitions), touting the acclaim that the KAAT has received:

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Some of the awards received presented to the KAAT project.
  • For the first time in the history of the National Association of State Aviation Officials’ Awards, a single state received both the State Most Innovative Program Award and the NASAO Center Outreach and Education Award for two separate programs.  The State Most Innovative Program Award was presented to the State of Kansas for the Kansas Airspace Awareness Program - Aeris Vigilis (Airspace Guardian).  The NASAO Center Outreach and Education Award was presented to the State of Kansas for its “Ops for Cops” program.  The program partnered KDOT, the Transportation Security Administration, Drug Enforcement Administration and airport managers to provide tactical and legal information for law enforcement officials called to airports.  Kansas also received a national best practice recognition for its continuing legal education program in partnership with the Kansas Commission on Aerospace Education.
  • The KDOT Aviation team received word that the Kansas Airspace Awareness Tool, a major component of the Airspace Awareness Program, will receive the American Association of State Highway and Transportation Officials (AASHTO) President’s Award for Aviation in November.  The Tool was recognized in April by the American Council of Engineering Companies with an Engineering Honors Award.


Since the unveiling of the Kansas Airspace Analysis Tool at our school, student have made contact with some of the personnel on hand for this event and gained insight into numerous STEM-related paths that could potentially open other doors for them later. 

My favorite experience from all of this comes from a comment a student shared with me a few weeks later:
   "Mr. Keltner, you know those algebra problems with the 'a plane flies with the wind between towns in 2 hours but the return flight takes 3 hours because it's going into the wind?' Well, Mr. Young from KDOT took me up in a plane and let me try the controls for a bit and I looked at my clock and could SEE that problem playing out along our trip as it was happening!"

So, I hope you enjoy this potential class project you can utilize. Granted, it is for the state of Kansas, but I think the technology and the ease of integration into class speaks well for student engagement and enjoyment. I know my students have enjoyed it and have bragged to me about being able to put a 2,000-foot tower in their back yard. I guess that goes to show you, the sky is the limit. Only in this case, they can actually SEE it.

--Keltner--

One last shout out to the folks at Burns & McDonnell and the Kansas Department of Transportation Division of Aviation, namely Director of Aviation Edward Young who gave our students a wonderful opportunity when he selected our school for the unveiling of his project. Thank you for allowing us to be a part of this project.

 
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In the spirit of Black Friday, let's see if we can save some green.
   Whether you are guilty of joining the Black Friday "festivities" or not, this lesson contains something for you to be aware of in your shopping with coupons.

   If you have multiple coupons, of different discount types (amount discount vs. percent discount, that is), then there is a particular way to apply these savings that will earn more savings than the other.


Long story short: 
Apply the percent discount before applying the amount discount for more savings.

   The concept relies on the concept of composition of functions, commonly written in the form f(g(x)). These are functions that evaluate in one functions and then another, in a particular order. The topic puts emphasis on evaluating with the order of operations as well as other properties like the commutative property and associative property, both of which are staples in algebraic concepts.

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Remember, always use the percent discount FIRST when given the opportunity.
   Teaching this lesson in class works well, mainly due to the fact students get so wrapped up in seeing whether they know how to reap the biggest reduction on their purchases in the future.

   To help solidify their learning, or ward off skeptics on the topic, we try a couple examples: a $50 purchase and a $100 purchase, for ease of computation.  Follow along:

   For a $50 purchase:
  • $10 discount applied first: $50 - $10 discount = $40, then $40 - (0.2)*$40 = $32 final price
  • 20% discount applied first: $50 - (0.2)*$50 = $40, then $40 - $10 = $30 final price
   For a $100 purchase:
  • $10 discount applied first: $100 - $10 discount = $90, then $90 - (0.2)*$90 = $72 final price
  • 20% discount applied first: $100 - (0.2)*$100 = $80, then $80 - $70 = $70 final price

   It is no strong coincidence that there is a two-dollar difference between these scenarios. This is the critical piece of what I'm trying to convey with this post (oh, and it's a fun math lesson to teach). 

   In using the dollar-discount first, the consumer or retailer is causing the percent-discount to be applied to a smaller value, therefore not letting it stretch as far as it could otherwise. It is, in essence, as if you are also taking the percent OFF of the dollar discount you wish to use (note the examples above, where there is a $2 difference and $2 is 20% of $10).

   In applying the percent discount first, your percent covers the larger original purchase price and stretches further. This is the gist of why the percent coupon should be applied first, when you have the opportunity.  NOTE: Some retailers have a point-of-sale system which is programmed to use the dollar discount first, no matter when you had a coupon to the cashier, so you might be forced to play their game and sacrifice part of your savings. I will not name names, but have had a couple of disappointed students bring in receipts and show me how much MORE they could have saved if the register didn't force the order of discounts applied.

   I'm making a bunch of links in this sentence if you would like either the TI-Nspire file I have shown up above in the slideshow, or the original presentation and handout I did for this topic to earn T^3 Instructor status a few summers ago. (Don't have a TI-Nspire? Try running the TI-Nspire file through the TI-Nspire Document Player without a need for download of software.)

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A 101qs.com entry I posted in May, 2012. This was a head-scratcher but good example.
   I managed to take a trip to an outlet mall, where I saw a curious sale display, pictured at left. To use the word "PLUS" in this instance seemed additionally confusing (yes, pun intended there), and caught the ire of Dan Meyer on his blog shortly after I'd posted the photo to 101qs.com.

   This, and other sale opportunities like it have been a common cause of commotion in class among my students who have heard me teach this lesson. They are able to bring up new shopping adventures they have had, where they might have corrected the way a cashier had rang something up, or a discount was applied more favorably than they expected, or the discount merely balanced out the sales tax they would have paid anyway.  Regardless, the lesson sticks.

   Applying similar, consecutive discounts have proven to be a decent introduction to exponential growth, since students are aware that "50% off, then another 50% off does not make the item FREE."  For those students who are very shopping-savvy, these applications hit home for them much more quickly than any compound interest problem ever could.

   Speaking of interest, I hope this sparked some of yours. Have a good day and enjoy the holiday season, saving all the while!

--Keltner--