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Description
Mathematical Modeling of Warfare and Combat PhenomenonThe primary goal of this book is to assist the student to develop the skills necessary to effectively employ the ideas of mathematics to solve military problems. At the simplest level I seek to promote an understanding of why mathematics is useful as a language for characterizing the interaction and relationships among quantifiable concepts, or in mathematical terms, variables. The text explores models of terrorism, attrition, search, detection,
The primary goal of this book is to assist the student to develop the skills necessary to effectively employ the ideas of mathematics to solve military problems. At the simplest level I seek to promote an understanding of why mathematics is useful as a language for characterizing the interaction and relationships among quantifiable concepts, or in mathematical terms, variables. The text explores models of terrorism, attrition, search, detection, missile defense, radar, and operational reliability
Throughout the text I emphasize the notion of added value and why it is the driving force behind military mathematical modeling. For a given mathematical model to be deemed a success something must be learned that was not obvious without the modeling procedure. Very often added value comes in the form of a prediction. In the absence of added value the modeling procedure becomes an exercise not unrelated to digging a ditch simply to fill it back up again.
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4.2 ★★★★★
Based on 2083 reviews
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Product Reviews
★★★★★ 5
Great Price, Great Quality, Save your money from other over priced Brands
I absolutely love this! Just as good as any of the more expensive brands! It has great cleaning abilities and is able to get in every corner and crevice. This quality is amazing and it has a mapping feature with a remote to set it up. Powerful suction, connects to the wifi easily and has a perfect spin rate so it doesn't miss a thing! My biggest issue is that I wasn't using it as much as I should! Make sure you set up a timer and it will take care of the rest!
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Reviewed in the United States on August 8, 2025
★★★★★ 4
Growing up with robots...
I'll spare you the obvious and only mention in passing that this is obviously a Roomba-wannabee. That aside, it turns out to be a pretty good R-wbee. Which is unsurprising since I combed through a couple of different comparison YouTube videos, both of which ranked this model near the top of their lists in the category of powerful vacuum robot on a budget.
This lil sucker is indeed quite effective. I only have a carpeted bedroom, so it doesn't wander much, but it easily traverses even the bulged or steeped edges of my old burber carpeting. Like any such device, if you're going to leave it unattended, you will need to clear away any cords or other small debris (anything up to about popcorn size will just get vacuumed). I empty mine every other time I use it, and it's rarely brimming over. The only problems I've encountered have always been some kind of cordage or wire or string getting wrapped around the spinning scrubber unit--easily corrected.
I'm very happy with the remote. I tend to use it mostly as a remote controlled vacuum device; ie, me lazily stalking behind it, using the remote to reverse it or to bring it back round for a second pass, til I'm satisfied. In addition to allowing N-S-E-W directions, you can also press and hold a direction button to make it speed up. You can also toggle between carpet and hardwood mode. The device charges pretty quickly and usually lets me get 2 to 3 large room sessions completed before displaying low battery.
I will note that my kitten was a mere 3 months old when I got this device and she has literally grown up with it. It long ago stopped frightening her and now she regards this device as a friend and playmate to such an extent that I had to move the charging dock from a floor corner to a low dresser drawer--because when I left it out in the open, my cat would always manage to depress the big GO button and send it off partially charged, destined to tangle up my charging cables and neckties. So if you plan on letting your cat grow up with this robot, take precautions.
I would definitely buy another one of these, and probably will. Recommended.
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Reviewed in the United States on May 29, 2023
★★★★★ 4
Jury is still out
Size: eufy L60 SES (renewed), Size: eufy L60 SES (renewed)
I really didn't want to purchase another Eufy product. I'm very mad at them because they're security doorbell cameras failing so readily (like a hardwired doorbell that stops working and gives me the input that there's no batteries even after we had it rewired.) And I caution everyone I am not a fan of their customer service anymore.
Years ago it used to be fantastic. It is rare today, when you send in a request for help that anyone fully reads what your expressing. You get scripted answers or links to technical information that you've already told them in previous communications you've tried.
Anyway... We have a dumber, earlier version of the Eufy vacuum cleaner that is about 5 years old --recently replaced the battery because I really love how well it draws up dirt and hair... Though the little chamber constantly gets jam-packed and the machine always gets stuck. I decided to move that one upstairs and get a smarter vac (only) and looked into several that could manage pet hair and that had good mapping and the ability to avoid scooping up toys etc.
What I like is the software's easy (much friendlier than Narwal!). I think the mapping was perfect right out of the gate.
Ease of splitting out larger areas into rooms is just wonderful.
The on-screen guidance as you're using this software is mostly excellent.
I really like how you can choose a setting that the vacuum will go to recharge and re-start itself back into motion to finish the job that wasn't finished when it went kaput.
I like that you can choose the frequency of having the vacuum empty into the charging station.
These two features that I just mentioned are a little bit hidden under settings. I think tabs would be nice for some pictures like this.
I don't like that it only has one rotating brush. The older Eufy has two and I think it's a much better design to sweep things into the suction range.
I like the quiet of this vacuum. The older version was quiet and this one is quieter yet.
As a matter of fact it worries me because the difference in suction sound makes it seem as though it really isn't changing at all.
I am not so sure the suction is as effective as It's been bragged about in its right up and in other reviews... it's actually gone over places on my carpet and it really didn't pull up all the fur. (That is in the video)
I have also watched it go over small pieces of cardboard from a scratching post and it didn't pick it up... Again if the brush was there on that side it would have been pushed into the suction path better.
I am not a fan of how it seems to not know how to avoid things. When setting up and getting ready to map your home with the LIDAR, the guidance is to take everything off the floor that is possible. Of course I put things back down like the tall cat toy that that has absolute presence, no different than a small cat --and the vacuum just runs right into it and starts pushing it...Our cat food bowls and water bowls just get pushed around. And the vacuum simply runs right into any toy and doesn't bother going around any of it so I would be sure you DO NOT BUY THIS IF YOU HAVE A CAT OR DOG THAT LEAVES MESSES ON THE FLOOR!
Also on some things that were not picked up like the kitchen table, I don't get how come this vacuum just runs into it with full speed. Also it is very weird that it has a real problem transitioning to rugs. I have a leather throw rug that stays in place with people and animals going across it. But this machine's able to nose it up into the air and then get tangled in it. It means that when I have my schedule in place I have to roll up this carpet and my toilet carpets. As you can guess it's annoying.
I also found it odd that when I'm trying to have it avoid going over something I will stand in place and despite the fact that it is vacuuming according to a grid it actually came back and circled and bumped into my feet five times before it finally gave up. What if that was an animal that was standing there? Would it bump into it also?
There are reviews on here that are so much more detailed. All I can say is I tried a Roomba (returned it to store) and I tried the Narwal (The mapping was awful and I returned that one also.)
I'm simply not wanting to return another vacuum. I do want to note that I purchased this one and accidentally ordered a 'used' model which means somebody else returned it. I have a feeling it has to do with this weird occasional click click click sound that makes it sound as though something is stuck in the rollers or something to that effect.
Now that I finished muddling through this review I do know that this week I'll be getting in touch with Eufy. I can't help but wonder is this really the way this thing is supposed to be working.
Oh, I did get the setup with the vacuum bag tower. As others have said it is extremely loud. The feature that reportedly cuts cat hair also has some volume to it, but for all its noise I don't think it really cuts but maybe 50% of the hair. I still have to manually clean the roll brush frequently. See photo.
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Reviewed in the United States on November 11, 2024
★★★★★ 5
Better than my new fancy robo
Great suction power. Doesn't get stuck often. I've had this vacuum for 5 years and it still works great. We got an AirRobo with a mop feature and demoted the Eufy to the basement. But, the eufy works way better and I frequently bring it upstairs to pre-clean before the AirRobo.
Love this vacuum! Do you have a version with a mop?
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Reviewed in the United States on January 27, 2026
★★★★★ 5
The best little helper!
Size: eufy L60 SES (renewed)
I've never owned a robot vacuum prior to this, and was somewhat curious on how it would work, and what it would really do in my small home. I got the L60 refurbished unit, and it came in a brand new box and it looked brand new when I removed it from the packaging. I charged it up, setup the app and connected it to Wi-Fi, ran a cycle and it was all so easy. It mapped my home and it is was off! It does an absolutely fantastic job. I run it daily and can notice just how much cleaner my hardwood floors are.
We have a cat who is intrigued by it, but it does a fantastic job of cleaning up the litter that is tracked from his litter box. That alone is a lifesaver. I will run it in the morning and at night in cats area to keep the hair and litter completely cleaned up.
So far I've only had a few small issues where it got stuck, twice from items left out, and once from a dirty sensor. You really need to make sure you have things put away and have the areas picked up, especially of cat toys and shoe laces, and once in a while wipe the sensors off if they get really dusty.
I highly recommend this, it truly has been a huge help just in daily pickup and keeping the house clean. Its absolutely worth the money.
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Reviewed in the United States on February 25, 2026