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bartkappenburg

2,970 karma · joined July 25, 2012

Inversive.nl
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bartkappenburg··on PHP 5.6 vs. PHP 7 Performance Comparison
OT: do they run on 5.6 or 7? ;-)
bartkappenburg··on Ask HN: Examples of great landing pages?
Or as good as https://github.com/jezen/is-thirteen
bartkappenburg··on How I Helped Potty-Train My Kid Using Twilio and an AWS IoT Button
Use a zwave (or equivalent) plug that can monitor loads and detect when the load is below a certain treshold. I have this for my dishwasher, dryer and washing machine. Works like a charm!

See for instance: https://philhawthorne.com/making-dumb-dishwashers-and-washin...

bartkappenburg··on I wrote a script that wins the majority of HQ Trivia games
Google Cloud Vision API does a really great job at OCR'ing your 'adversarial perturbations' example for HQ Trivia: https://imgur.com/a/f06JT
bartkappenburg··on Linkedin let their https certificate of all subdomains expire
It expired 13.00 CEST today: https://twitter.com/bartkappenburg/status/936213488388669440
bartkappenburg··on Car key 'relay' attack caught on CCTV
Wouldn't help: the latency to the relay box is at least as good as having the physical key nearby.
bartkappenburg··on Amazon’s Seattle campus is using a data center next door as a furnace
See Nerdalize[0]

From their site: Heat your home with cloud servers!

The CloudBox contains powerful servers, used by companies and researchers for their computations. The produced heat is used to heat up the water in your home. You get free hot water and save on your gas bill. And you contribute to an enormous reduction of CO2 emissions!

I think that’s a really nice concept!

[0] https://www.nerdalize.com/heating/

bartkappenburg··on Human sperm steer with second harmonics of the flagellar beat
If you're interested in the scripts (python!) and movies (xyz files for molecular representation) they used for analysis: https://zenodo.org/record/884626#.WgV1XFz81R4
bartkappenburg··on An Open Letter to Intel
From his CV:

One of the early users of MINIX was Linus Torvalds. He began modifying MINIX to add new features that he thought were needed. Over a period of time he had modified almost everything and launched it as a new operating system, Linux. It is fairly safe to say that had I not written MINIX there would have been no Linux.

bartkappenburg··on How Adversarial Attacks Work
I tried the example from the blog post (Stallone <-> Reeves) in Rekognition (AWS service) and it came out correct:

https://imgur.com/a/C0s05

bartkappenburg··on What works in e-commerce – A meta-analysis of online experiments [pdf]
Great research with lots of data and tangible results.

I'm missing 'authority' as way to improve conversion. Funny that they use it themselves in two ways: letting PWC check the results and, in a milder form, using a scientific way of communicating the results (LaTeX, article layout etc). The impact would have been less if it was just a blog post :-). I'm curious about results on authority, maybe someone from qubit can give us some insights on that?

At my company[0] we offer a solution to sites to implement these strategies through notifications/nudges. Having said that: we firmly believe in A/B testing but we believe even more in recognizing (we do that through machine learning) what technique works best on a personal level. This means that a site can have, for example, two strategies and that we apply none, either one or both on the visitor. That way you can reach higher uplifts.

[0] https://www.conversify.com

bartkappenburg··on A crashed advertisement reveals logs of a facial recognition system
I've tested it a few times and it's indecisive on my gender and age (depends if I'm smiling, angle etc etc).

Microsoft's service is much more consistent and accurate (I've tested the same images...): https://azure.microsoft.com/en-us/services/cognitive-service...

bartkappenburg··on Show HN: Tweeple Search – Find relevant audience and influencers on Twitter
Or: use the API from twitter (free up to 900 req/15 mins) and sort by followers: https://dev.twitter.com/rest/reference/get/users/search

What's the added value of Tweeple Search?

bartkappenburg··on Survivorship Bias
“Luck Is What Happens When Preparation Meets Opportunity"
bartkappenburg··on Introducing Increment
She joined stripe in Jan 2017 and left uber in dec 2016.
bartkappenburg··on Electron is flash for the desktop (2016)
I even got more used Slack memory than the article's writer: https://imgur.com/a/AQGYD
bartkappenburg··on Noiszy – A Chrome plugin that creates meaningless web tracking data
Someone already created that: http://suicidemachine.org/

The even got a cease and desist letter from FB.

bartkappenburg··on Show HN: Kite, copilot for programmers, available for Python
Just an honest (legal) concern:

Is stack overflow ok with having their answers inside an IDE? This decreases the number of pageviews on SO for each installed client. Is that something you guys checked?

bartkappenburg··on Uber is being sued for hundred of millions dollars for allegedly avoiding UK VAT
Changed the title to better reflect the article
bartkappenburg··on Cloudflare Reverse Proxies Are Dumping Uninitialized Memory
From a cloudflare employee:

"We were working to disclose the bug as quickly as possible, but wanted to clean up search engine caches before it became public because we felt we had a duty of care to ensure that this private information was removed from public view. We were comfortable that we had time as Google Project Zero initially gave us a 90 day disclosure window (as can still be seen in their incident tracker), however after a couple of days, they informed us that they felt that 7 days was more appropriate. Google Project Zero ended up disclosing this information after only 6 days."

bartkappenburg··on Cat-proofing a cat feeding machine
That last ditch effort is called an extinction burst [0]

https://en.m.wikipedia.org/wiki/Extinction_(psychology)#Exti...

bartkappenburg··on Quick, Draw
It reminds me of what google did to improve their search for images: https://crowdsource.google.com/imagelabeler/category

The things you draw here is new input for their model.

bartkappenburg··on How Steve Jobs Became a Billionaire
I have the same 'issue' with other professions. Before the tech-industry was big, you had the occasional CEO saying: "I started in the mailroom!", implying that you too can be a CEO one day. That's reversed reasoning gone wrong: the chance that a CEO worked in the mailroom is a million times bigger than that a mailroom employee is bound to be a CEO.

Same holds for famous artists: talk to their parents and they probably say that he/she was always singing with a fake microphone in front of a mirror. 90% of the kids do that...

bartkappenburg··on Facebook is imposing American censorship on the rest of the world
Not sure how the 'flag' system works but based on the two examples (famous news photo and famous work of art), you could easily circumvent wrong flagging (wrong = deleting famous and important photos) by generating a 'similar photo search' in the system and giving context. That would help the over-ambitious flagger to recognize this.
bartkappenburg··on What is the Nash Equilibrium and why does it matter?
Quite disappointing that the article 'explains' the Nash equilibrium (NE) without going into details of how a NE is reached.

During my econometrics study this explanation helped me to explain it to others without going in to the mathematical details:

- Person A needs to decide what the best strategy is for all strategies of B (circle, on paper, the outcomes for A)

- Person B has to do the same (circle as well)

NE => look for 'box' (ie. outcome) that has two circles (there could be more!)

This leads to (confess, confess).

bartkappenburg··on How Teletext and Ceefax are coming back from the dead
That's not weird at all.

It's lightweight (and thus fast!) and curated by a reliable news source.

It gives, at any given moment, the 10 most important news items. Try that on a news site.

I use it more than a dozen times a day...

bartkappenburg··on Moving 12 years of email from GMail to FastMail
You would still have some meta-data :-)
bartkappenburg··on Moving 12 years of email from GMail to FastMail
"I do have FastMail’s Android app on my telephone. The app is a Cordova / PhoneGap / CrossWalk style unit with real-time email push and notification via Google Cloud Messaging (this is a relatively energy-efficient way for android phones to get push notification and is natively supported by FastMail)."

Migrating away from GMail for privacy reasons and he still ends up with Google for functionality...

bartkappenburg··on Emailing SaaS companies to test support time
We implemented a 'smart' contact form. I basically was a decision tree based on our FAQ (updating our FAQ also updated our contact form). People had to choose the subject and some follow up questions wit radiobuttons. At the end (just 2 or 3 clicks) we showed them the answer from the FAQ. It that didn't answer their question they could fill in their question.

5^3 (5 choices and max 3 clicks) makes 125 possibilities and will cover most questions (if not all).

It made the support questions drop with 90% with the same customer satisfaction if not more.

TL;DR: People don't read FAQs, make them pick the correct subject for contacting you while showing answers to common questions. It will decrease support questions with 90% (n=1 though).

bartkappenburg··on A Simple Content-Based Recommendation Engine in Python
TF-IDF uses no click/buys data whatsoever. It's purely based on characteristics of the product (description, name, brand etc etc).

Regarding the example picture I gave: that's the difference between substitutes and complementary products. The example gives alternatives (other straws...). We're building a way to have recommendations on these two types.

Why TF-IDF works better vs buys? A set of bought products holds no to little similarities between those products, it's better to use it for complementary products.

Why TF-IDF works better vs clicks? Click paths on sites are more random than you think. Combining click data with TF-IDF makes more sense.

As said: TF-IDF as a first filter and using CF as sorting could be the most optimal for substitute products. Complementary products should rely more on CF.

A problem with clicks/buys only is that new products tend to get overlooked, you can fix that by mixing in TF-IDF.

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