Dam collapse in Laos devastates several villages (July 2018)

Last Monday (July 23, 2018), one hydropower dam in Laos collapsed, causing a massive flood that destroyed several towns and several deaths (the number is still unknown). The flood destroyed town located as far as more than 70 km downstream. 

The dam was still under construction when it collapsed. The dam was part of the Xe-Pian Xe-Namnoy hydropower project being constructed by Laotian and Thai and South Korean firms. The collapsed dam was not a main dam; it was a dam designed to help divert water around a local reservoir. The dam was 8 m wide, 770 m long and 16 m high.

Image. Flood due to dam collapse in Laos (Source: scmp)

Laos dam collapse time frame (July 22 - July 24, 2018)

• Sunday 21:00 local time (14:00 GMT) - The dam is found to be partially damaged. The authorities are alerted and villagers near the dam start to be evacuated. A team is sent to repair the dam - but is hampered by heavy rain, which has also damaged many roads.
• Monday 03:00 - Water is discharged from one of the main dams (Xe-Namnoy dam) to try to lower water levels in the subsidiary dam.
• Monday 12:00 - The state government orders villagers downstream to evacuate after learning that there could be further damage to the dam.
• Monday 18:00 - More damage is confirmed at the dam.
• By Tuesday 01:30, a village near the subsidiary dam is flooded, and by 09:30 seven villages are flooded.

Image. Dam collapse and areas affected (Source: bbc)

The difference Windows vs Mac. Should I buy windows or Mac?

 A Windows Microsoft PC or Mac? This is a common question among computer users. The best answer is: It depends on your needs. In order to understand this question and its answer, it is important to understand how a computer works. To make it easy, we can describe a computer as 4 components:

• The interface is where the user interacts, is what the users sees and where the user works. In other words, is the screen with the windows and commands.
• The software or apps. This component process the user's instructions and tells the computer what to do. 
• The operating system receives the instruction from the software and re-sends it to the specific hardware. Actually, it translates the instruction to the language of the hardware and delivers the translated instruction so that the hardware will understand the instruction. We can say that it contains the drivers for each component (the word drivers is not the right one, but I will use it in this post because it is easier to understand).
• The hardware performs all the tasks. It performs the computations, it prints, it scans, it does everything.

Image 1. Components of a computer

Usually the question PC Microsoft vs Mac refers to the operating system.

The difference between Windows and Mac

A Mac computer is only compatible with Mac components (only Mac hardware). If you have a Mac you can only install Mac hardware. When Mac makes a given hardware it also makes the specific drivers for that hardware. 

On the other hand, Microsoft goes for compatibility. That means that you can add any hardware (from any brand) to a Windows Microsoft PC, but you also have to install the drivers that come with the hardware.

One simple example is the use of a printer. If the user has a Mac a want to buy a printer, he must buy a printer Mac. On the other hand, if the user has a Microsoft PC, he can buy any printer he wants. 

Advantages and disadvantages

Both Operating Systems have their own advantages and disadvantages depending on your needs.

Price. One clear difference is that Mac is much more expensive because Mac hardware is designed specifically for Mac. On the other hand, Microsoft PC accepts any brand; thus, brands that focus on one given hardware can produce hardware at lower cost. Besides, the user can choose between different options (Point for Windows).

Availability. This is another disadvantage for Mac and one of the main reasons why I do not use Mac. When a given software or hardware is released, it is immediately available for Windows Microsoft PC. On the other hand, Mac requires a specific version, then they (Mac) test it, and after some months they release it. Actually this lack of compatibility is an important limitation for Mac because Microsoft PC is the most used operating system. Therefore, sometime data processed in a Mac cannot be shared or delivered (Point for Windows).

Open source compatibility. This is a result of the previous point. This is another reason why I do not use Mac, because this may become a serious limitation especially when you work with open source or when you make your own code (Point for Windows).

Security. Since Mac produces and controls the software and hardware allowed to be used with a Mac, there is low probability to be attacked by a computer virus or to have malfunction due to bugs. Applications that may contain hidden doors to viruses usually are not allowed to be installed on a Mac and Mac drivers usually contain less bugs because they are tested before being released. I believe this one is the only advantage of a Mac (Point for Mac).

Drone battle: Parrot ANAFI vs DJI Mavic

Last month (June 2018), Parrot announced the release of its new drone ANAFI. ANAFI is a small and foldable drone in the same concept as the DJI Mavic and is planned to be a direct competitor for the DJI Mavic. ANAFI is already on sale (since July 2018), and some drone enthusiasts are curious about its capabilities and the comparison ANAFI vs Mavic. 5 points were considered.

• Camera
• Portability
• Flight ttime
• Price
• Additional features

Camera

After commenting in several photography forums, we can conclude that ANAFI is better than Mavic for the following reasons:

Although both drones sport a Sony CMOS camera sensor for photo and video, while Anafi employs a superior 1/2.4” sensor that shoots 21MP (5,344 x 4,016) (Mavic Air uses a 1/2.3” sensor capable of 12MP 4,056 x 3,040). 

Comparing lenses, the ANAFI has a superior aperture (F2.4 vs F2.8) and can hit faster shutter speeds (1/10000s vs 1/8000s). This may be an important advantage for surveying applications because it would allow for higher resolution images and higher elevation flights; thus, higher elevation flight means more area covered in less flying time. 

Besides, Parrot implemented a dynamic new lossless digital zoom. This allows you magnify up to 2.8x without a reduction in image or video quality, making it easier to get details without having to get so close.

Yet another camera advantage is that ANAFI's camera is not embedded in the frame. ANAFI's camera sits by itself allowing 180 degrees of vertical movement.

ANAFI also has an advantage in video because it allows filming in 4K Cinema mode (4,096 x 2,160), which would be a great advantage in filming. Nevertheless, there is one video filming capability in favor of Mavic. Mavic films 120 FPS compared to the 24 FPS of ANAFI.

Image. ANAFI 360 degree camera

Portability

In this point I would call it a draw. Although Mavic is shorter, it is a little wider. This led to some confusion arguing that ANAFI is smaller. However, comparing the total size of ANAFI (244mm * 66mm * 63.5mm) with the total size of Mavic (168mm * 83mm *49mm), we see that Mavic is much smaller (Mavic = 683256 mm3; ANAFI = 1022604 mm3). This appears to be point for Mavic. However, ANAFI's 320 g are much lighter than Mavic's 430 g. Therefore, we call this point a 1-1 draw.

Image. Folding ANAFI

Flight time

This may also be considered a draw. ANAFI allows for 25 min flight. Although this is longer time than the Mavi Air, it is quite shorter that the Mavic Pro 27 min (point for Mavic). However, the tests showed that ANAFI has better stability. ANAFI resists winds up to 68 km/h, while Mavic (and any DJI drone) is limited to winds up to 55 km/h (point for ANAFI). Thus, this point is also a draw.

Price

This one is a point for ANAFI. ANAFI costs only 699 $ in Amazon, which is almost half the price of Mavic Pro (1300 $). Moreover, ANAFI is even cheaper than Mavic Air's 800 $.  

Additional features

Several blogs argue that obstacle avoidance would be an advantage of Mavic. However, I do not believe so because of 2 reasons:

• Flight planning. As a drone user, you should always plan your flight (actually I would change the should for MUST plan the flight). Flying without flight plan is like traveling without a destination. Thus, potential obstacles can be avoided prior the flight.
• Flight regulations. Flight regulations forbid to flight drones over crowded areas. Thus, you should not be worried about crashing into a home or a person because you are not supposed to fly over houses or persons.

As we are talking about regulations, I would like to mention that several NATO countries (North Atlantic Treaty Organization) issued concerns (and in some cases bans) over DJI products. This would be a point for ANAFI (French industry). Thus, let's call it a draw.

An additional feature that may result in a point for Mavic, is that third party applications have not included updates to control ANAFI yet. Nevertheless, they already answered that upgrades including ANAFI compatibility will be issued soon.

Final result

As we can see in the following table, ANAFI wins 2-0. We can make an analogy with the current world cup, and we can consider each feature as a game. Thus, after 5 games we have 3 draws and 2 ANAFI victories

ANAFI overcomes Mavic in the features that made Mavic so popular. ANAFI is lighter, has longer flying time, better camera and is cheaper.

Image. Comparisson ANAFI vs Mavic