Friday, 25 December 2015

Twitter’s Fiscal 2015: Up, Flat, And Down



Twitter did not have a lovely 2015. The world-famous social company saw its revenue rise, its usage flatten, and its share price fall.
The company failed to change the arc of its own narrative during the year: Strong financial performance, but continued failure to grow its user base, the latter of which the market appears to weight more strongly. It brought in a new CEO to turn things around, but so far it still hasn’t found a way to really do a better job of building its audience.
The result? Share price declines that have put Twitter near all-time lows as the year concludes.
Twitter Inc. (TWTR) Stock Price - 1 Year | FindTheCompany

The numbers speak for themselves. After its IPO, Twitter shot to more than $60 per share. The company then spent time in the $30 range, the $40 range, and the $50 range. This year, Twitter has seen its value fall further, bouncing around the low $20 range.
For employees who have options priced at a far higher levels, the declines are not theoretical. They are material. And there is a rot that can set in when it comes to falling share prices — the public equivalent of a down round, in some ways — as it becomes more difficult to hire, retain key talent, and keep morale up.
So, what’s happened this year? Let’s take a look.

Twitter’s financial performance

Key to Twitter’s success story — and it has been a success story — is its financial performance. The company has posted strong revenue growth, beaten expectations, and impressively monetized its user base. To its former critics that decried it as a fad, or financial impossibility, Twitter can drop the following revenue figures and saunter away:
  • First quarter, 2015: $436 million, up 74 percent, compared to the year-ago period.
  • Second quarter, 2015: $502 million, up 61 percent, compared to the year-ago period.
  • Third quarter, 2015: $569 million, up 58 percent, compared to the year-ago period.
If you were curious as to how to monetize social services, Twitter has blazed a trail worth studying. The company’s monetary performance is a credit to its management team.
However, there is a cap on Twitter’s future financial performance. While it has done yeoman’s work extracting more value from its existing user base, the firm is still dependent on user growth. That, in the long-term, is necessary to generate new revenue. The argument is simple: If Twitter can’t grow its cadre of active users, it cannot eventually further grow its revenue.
You can only squeeze a rag so hard, in other words.
And, where Twitter has been precisely brilliant regarding its improving top line, it has seen difficulty convincing the masses that using Twitter is what they should do.

Twitter’s stalling user growth

In the second quarter this year, new CEO Jack Dorsey pretty much summed up a significant challenge for the company in a single statement: “Our Q2 results show good progress in monetization, but we are not satisfied with our growth in audience.”
This statement serves as a microcosm for the company. Its financials looked good, but its number logged-in users did not grow as much as the company had hoped. The company’s monthly active user growth had essentially stalled — and for a company whose performance is dependent on its audience, that demonstrated a massive problem for investors.
Twitter MAU Over Time | SoftwareInsider
Still, that doesn’t mean Twitter’s total user base isn’t growing. There’s a whole swath of users that may simply be logged out — which is difficult to track, and something Twitter is working on. The company is also actively experimenting with new products in order to increase engagement among its users. But the best advertising targeting Twitter can do is on users that have built an interest graph, which involves signing up, logging in and following others to get a sense of what the user is looking for.
“One other thing to note, we also are monetizing logged-out users across the network,” COO Adam Bain said on the last earnings call. “This is the first time that we’ve been doing that. It’s going to come in handy as we also begin to run a pilot here in Q4 for on-Twitter logged-out monetization. So we’re going to take some of that learnings and apply it back on Twitter logged-out [advertising] products.”
But while Twitter’s financial performance continues to beat expectations, slowing logged-in audience growth serves as a limitation for the upside for the company. There are a couple of ways to increase its bottom line — it can improve its advertising products and come out with new ones, or acquire its way into new venues of advertising, for example. But in the end, if it’s going to really explode to new heights and impress investors, it needs to re-ignite its user growth as well.
In sum, while Twitter’s revenue has grown, and its user growth has stalled, its shares have fallen.
It’s up for you to decide if the investing classes are being too hard on Twitter. The firm still has a strong cash position, and is worth billions and billions of dollars. The proper question, perhaps, is how Twitter will manage to bolster its larger consumer appeal, without losing the interest of its key content creators.

In the end, Twitter is still a bit of a confusing company. It continues to improve and develop new advertising products, and bought its way into a brand-new kind of video format in the case of Periscope. That’s something that should impress investors, but Twitter’s finding that challenging — particularly because these kinds of bets are, in theory, long-term ones.
And for Twitter to be a long-term safe bet, it has to be firing on all cylinders, which includes finding ways to do a better job of building, measuring, and monetizing its audience.
A representative for Twitter directed us to the company’s 2015 Q3 earnings call when we requested comment.



Top 10 Websites to Download Free eBooks

Digital Books or eBooks as they are popularly known have become a rage ever since the influx of eBook hand readers like Amazon Kindle, Apple iPad, Sony PRS eBook reader etc. Reading eBooks was never more fun. Here are some useful websites indexing hundreds and thousands of Free eBooks. Some are simple search engines, while others host free eBooks.
free-ebooks

Top 10 Websites to Download Free eBooks

1. Google Books – It is a web search engine by Google specially for Books. Google digitizes books from different sources and then make them available on its servers. Copyright oblige, some are only partially published. Google Books allows public-domain works and other out-of-copyright material to be downloaded in PDF format.

google-books
2. Mega PDF – Mega PDF indexes more than 379 million free downloadable eBooks in PDF format. From novels to biographies to technology books, you can find everything here.
megapdf
3. Pdfgeni – It lets you find and download books, novels, manuals, articles, document templates, reports, data sheets, and pretty much any information that is stored in PDF format.
pdfgeni
4. Project Gutenberg – Project Gutenberg is the place where you can download over 30,000 free ebooks to read on your PC, iPhone, Kindle, Sony Reader or other portable device. PG has the largest collection of public domain books. Lots of books from the world’s greatest fiction authors such as Shakespeare, Mark Twain, Dickens are present here.
5. NeoTake – Neotake is a new eBook search engine which has indexed several eBooks in various formats like ePUB, PDF, LRF, TXT, Mobipocket etc. It also has a mobile version of the site. More than 200,000 eBooks have been indexed currently.
6. Free-EBooks – Free-eBooks is an online source for free ebook downloads, ebook resources and ebook authors. Besides free ebooks, you also download free magazines or submit your own ebook. A bit of a downside is that you need to register before downloading your favorite eBooks.
7. ManyBooks – ManyBooks provides free ebooks for your PDA, iPod or eBook Reader. You can randomly browse for a ebook through the most popular titles, recommendations or recent reviews for visitors. There are more than 26,658 eBooks available here and they’re all free!
8. Search PDF eBooks – It’s another cool PDF eBooks search engine with millions of books in its database. Ignore the excessive ads and just enjoy the free ebooks!
search-pdf-books
9. ReadPrint – Free online books library for students, teachers, and the classic enthusiast. Thousands of stories, poems and novels listed down here.
10. KnowFree – It is a web portal where users are able to exchange freely e-books, video training and other materials for educational purposes and self-practice. It contains loads of free technology, engineering, web development and Business skills ebooks and in addition, there are lots of video tutorials available.

knowfree
So which one is your favorite? If you have any recommendation worth mentioning here, mention that in the comments section.


Thursday, 24 December 2015

How BB-8 Works

By now, there’s a pretty good chance that you’ve seen the new Star Wars movie — and for those who haven’t, don’t worry: no spoilers here. At long last, we’ve got a much-needed dose of Starfighters, Rebel Alliances, Lasers, and droids. BB-8, the adorable successor to R2-D2, has captured hearts and minds. As lovable as it is, and even with as much life as its creators managed to instill into it, in the end… it’s a super sophisticated prop. And now you’re wondering: how the heck does this thing work?
While JJ and Co. have kept the specifics of BB-8’s innards mostly under wraps, we can suss out the basics. Behind that trilling orange and white sphere, BB-8 is likely a set of wheels (propelling the sphere by spinning against its inner-wall) and a magnetic mast (to hold on to and control BB-8’s head). The sort of “wobbly” way BB-8 moves? It’s all inherent to the design — what might be considered a flaw if used anywhere else, here it helps to give BB-8 much of its character.
That explanation will leave a lot of you wanting for more. Want a more detailed breakdown than that? Read on, folks.
A lot of the analysis you see on the internet today has people treating BB-8 as two discrete operations, one each for the head and ball. However, one of the many patents filed by Disney and partner Sphero paints a different picture. This patent, for a “Magnetically coupled accessory for a self-propelled device,” explains how to get BB-8 to work without a separately controlled head. Combine this with Sphero’s Chief Scientist Adam Wilson telling Polygon.com that the head isn’t articulated independently, and you can start to paint a picture of what the internals look like.

The strongest justification for this kind of system is in watching BB-8 try to lean over. It doesn’t seem to be able to maintain a constant head angle while static. This strongly implies that the head isn’t articulated independently, and is consistent with the patent.
Let’s get things rolling
The head complicates things, so let’s just think about the body for now. An image from one of the patents is an extremely helpful illustration. To make things simple, let’s think about this problem in two dimensions, looking only at forward and backward motion. The same principles apply to keep this stable; all that’s happening when BB-8 turns is the internal assembly yawing to point in a different direction.
In a nutshell, what we’ve got is a sphere with wheeled mechanism inside it. The wheels are forced down against the wall of BB-8 in some way (either spring or gravity, it doesn’t matter a huge deal). Rotating the wheels shifts the center of the system’s mass, the bulk of which is in the wheel assembly, off of the vertical line that includes the center of the ball and the contact point with the ground. Leaning generates a moment. Do this right, and the ball moves in the direction that the wheels were shifted to. If we were to picture a mast mounted perpendicularly on top of the wheel base, the ball would move in a direction opposite to the mast.
patentgrab_wheelIMAGE: UNITED STATES PATENT APPLICATION
In broad strokes, this is similar to what it’s like to get a Zorb ball moving. Being the heaviest thing in the Zorb, moving forward changes your position relative to the ball’s center of mass. This, in the end, leads to rotation and forward motion. (We’re not going to go over the dynamics of this problem, but reach out if you really want to know).
zorbIMAGE: FLICKR/DAMIAN CUGLEY UNDER A CC BY-SA 2.0 LICENSE
A head for math
That mast we talked about earlier? That’s where BB-8’s head goes. Since it’s attached to the mast through the sphere, it makes sense that it would be attached magnetically, as the patent dictates. There are lots of ways to do this, but one that lets BB-8 bounce and still function like it does in the movie involves a set of attractive and repelling magnets. Repulsion probably keeps the head from contacting the ball, and magnetic attraction around the edges of the head keeps it from rolling off.
bb-8-3IMAGE: BRYCE DURBIN
Earlier, we went over how to get BB-8 to move if you wanted the mast (and therefore the head) to point in the direction opposite to motion. Through most of the movie, though, you see that BB-8’s head is tilted in the direction of motion. We also know that the head can’t move separately. So, how does this work?
giphy (1)
Again, BB-8’s floppy motion tells a lot. Notice how before BB-8 starts moving forward full tilt, there’s a brief period when it’s moving with the head almost rolling backward? Applying some dynamics to the problem helps explain what’s going on.
To clear things up, I don’t think that this is an inverted pendulum problem, even though it’s easy to draw some comparisons. However, let’s pull one concept out from the typical inverted pendulum problem that you go over in school. To get the inverted pendulum’s shaft pointed in the direction of motion, you first have to move the system backwards a little bit, let the shaft fall into place, and then reverse the direction of motion.
IMAGE: BRYCE DURBIN
Similarly, I suspect that the brief period of minimal motion when the base is moving but BB-8 as a whole isn’t is doing something similar. It’s likely that BB-8 gets into motion slowly (without a noticeable backward head shift). Then, by slowing the motors down, the head is allowed to roll forward. Once the head is pointing forward, you can resume the motors and get that nice full-tilt roll that’s shown in the movies.  Alternately, it’s possible that the motors drive the mast forward, letting the ball move backwards, and then the motors maintain constant angle as BB-8 moves forward. If the mast and wheel assembly have enough inertia relative to the rest of the system, you wouldn’t need more than a tiny initial motion before getting started.
All this is easier said than done, though. The control law and sensor suite running all this has to be incredibly sophisticated – making running BB-8 as much of a software problem as it is a hardware problem.
Calibration is Key
Since your entire operation depends on knowing the angle of offset from vertical (θ), your control system needs to be able to measure this to extreme accuracy. This is perhaps why we saw BB-8 needing to be calibrated when TechCrunch’s Lucas Matneyplayed around with a scale model toy earlier in the year. All this feeds into what you call a closed-loop control system, which maintains the angle (θ) of offset from the center at whatever value you set it as. This value is set by the software depending on how fast you want BB-8 to go.


All this being said, this system does mean the BB-8 comes with some handling restrictions. Really, it would have been simpler to just use the two-system method that other analysts predicted. I can see why the designers wouldn’t have done that, though – it’s just less cool.  A lot of this is in broad strokes based on what we can get from video and patent filings. It’s possible that I’m entirely wrong and BB-8 does something else.