Here we present the tools developed in the context of MiniChallenge 2 of the VAST Challenge 2021, as well as higher-resolution images of what is presented in the challenge submission.

Getting things to work

To get the tools to work, you will have to activate Cross-Origin Resource Sharing (CORS) and allow your browser to show mixed content from http and https sources.

The instructions below are for the Google Chrome browser.

Activate CORS

Install the CORS Unblock extension from the Chrome Web Store.

Allow mixed content

For each of the URLs mentioned below, add the URL in the “Allowed to show insecure content” section of the Chrome Preferences: Preferences => Privacy and security => Site settings => Additional content settings => Insecure content


Higher-resolution versions of submitted images

  • Figure 1. The number of transactions per location fig1
  • Figure 2. Transactions over time. Locations were grouped manually fig2
  • Figure 3. The credit-to-loyalty card matching process fig3
  • Figure 4. Credit-to-loyalty card price vector correlations fig4
  • Figure 5. Relations between credit and loyalty cards fig5
  • Figure 6. Price differences between credit and loyalty card transactions. Darker colors indicate more transactions fig6
  • Figure 7. L6267 is used by both 6899 and 6691. On Saturday 11, there is a 10-minute gap between transactions at different locations fig7
  • Figure 8. L3288 is used by 1286 and 9241. 1286 uses L3288 for lunches of around 50 Kr fig8
  • Figure 9. Estimated transaction times fig9
  • Figure 10. Stops of car 5 (colored bars) with transactions of credit cards 6691 and 6899. Transactions centered on a stop match in location and time. Transactions above the stops could not be matched to the stop. Tooltips provide details and give access to the (un)match button. The match all button accepts all shown possible matches fig10
  • Figure 11. Stops of cars 22 and 28 with transactions of 1286 and 9241. The pink stop indicates a period of missing GPS signal. Places visited together are annotated fig11
  • Figure 12. An example of incorrect Kronos Mart transaction time fig12
  • Figure 13. Decision tree for GPS classification fig13
  • Figure 14. Begin and end GPS positions of non-moving periods. Red lines indicate missing periods. Black arrows indicate the offset of car 28 fig14
  • Figure 15. Timeline of GPS activity for cars 1, 9, 28 and 107. Red indicates missing periods, black spikes indicate movement fig15
  • Figure 16 (animated gif). Filling in periods of missing GPS data (animated gif). Transaction times could be used to estimate the deprature time in the missing period fig16
  • Figure 17. Points of Interest, coloured by type and sized by the number of distinct visiting cars fig17
  • Figure 18. The car-to-credit card matching process fig18
  • Figure 19. Car-to-credit card matches
  • Figure 20. Matched credit cards of car 29 fig20
  • Figure 21. Surprise party of Lars Azada (2). Circles are an Upset visualization indicating which cars were present, color indicates households, black for 1-person households fig21
  • Figure 22. Nightly guard-duty pattern of perimeter control personnel at executives’ homes fig22
  • Figure 23. Elsa Orilla (7) and Brand Tempestad (33) regularly meet around lunch time for 2 hours at the Chostus Hotel fig23
  • Figure 24. Hennie Osvaldo (21) regularly visits the household of Lidelse Dedos (14) and Birgitta Frentet (18) on Wednesday nights and Sundays fig24
  • Figure 25. Nils Calixto (1) and Isak Baza (5) are regulars at Ouzeri Elian fig25
  • Figure 26. Price-distributions per location fig26
  • Figure 27. Activity of car 101 on Thursday 16 (animated gif). Repeated route: Stewart and Sons -> Nationwide Refinery -> Office -> Airport fig27
  • Figure 28. Activity of car 104 on Thursday 16 (animated gif). Repeated route: Office -> Airport fig28
  • Figure 29. Activity of car 105 on Thursday 16 (animated gif). Repeating route: Office -> Carlyle Chemical Inc. -> Office -> Katerina’s Café fig29
  • Figure 30. Activity of car 106 on Thursday 16 (animated gif). Repeating route: Scrapyard -> Stewart and Sons Fabrication -> Office -> Airport fig30
  • Figure 31. Nils Calixto (1) goes to the office at night on multiple occasions fig31
  • Figure 32. Ingrid Barranco (4), Ada Campo-Corrente (10), and Willem Vasco-Pais (35) play golf together. One week later Orhan Strum (32) and Sten Sanjorge Jr. (31) are also present fig32
  • Figure 33. CEO Sten Sanjorge Jr. (31) eats with security personnel at Guy’s Gyros on Sunday 19 fig33
  • Figure 34. Ada Campo-Corrente (10), Orhan Strum (32), and Willem Vaco-Pais (35) eat with engineering personnel at Hippokampos fig34