Become a fan of Slashdot on Facebook


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:There is nothing to support that claim. (Score 0) 99

You are missing the point. Even if they do not care about traffic signals you are practically just as unlikely to get his as if they were. (I agree it is a psychological difference, but that is all there is)

Cyclists and pedestrians have less speed and more awareness of their physical size so they are able to negotiate through an intersection efficiently without traffic lights and without getting in each others way.

Comment Re:Electrical engineers write sucky code (Score 1) 78

Actually it looks like a manufacturing managers decision. Somone writes code that depend on that manufacturing needs to inject and track unique keys for each device. Manufacturing sees this and realizes they actually need to earn their keep and set up infrastructure to support product requirements, instantly balks, and force through a security hole they neither understand or care about.

Comment Re:Doesn't solve the problem (Score 1) 136

Have you ever tried to ride with a good set of studded bicycle tires? Spinning or breaking traction really is no problem as they grip every bit as good as a studded car tire (Directly related to tire pressure), but are subject to much less sideways loading due to significantly less speed and mass.

Regarding lights, you obviously need to get a light to see by, not just a marker. Such lights are readily available and not at all a speciality item any more. (more often the problem lies in the opposite end: That lights are too powerful without enough thought to the light distribution, but light solving these issues are also easily available)

Bikes are not unstable at low speeds. It is hard to balance with NO speed (But you can just put a foot down), as long as you have any speed at all stability is good. Braking power is as good as your traction, which is very good with good studded tires. Compared to cars bikes have comparable contact area in relation to mass (Pretty much given by tire pressure)

I ride safely throughout winter and here we have ice and snow for 4-5 months every year with temperatures as low as -25C

Comment Re:Just moves a choke point (Score 3, Informative) 395

Mangled my own text. Sorry.

Generally fast chargers will not be in constant use. Hence it is acceptable to build a battery pack in the charging station, which can charge at a more reasonable speed off the grid and be capable of delivering high current at a presumably much much less than 100% duty cycle.

This was done here:

(Apparantly slashdot chokes on the much much less than sign)

Comment Re:Just moves a choke point (Score 2) 395

Generally fast chargers will not be in constant use. Hence it is acceptable to build a battery pack in the charging station, which can charge at a more reasonable speed off the grid and be capable of delivering high current at a presumably

Keep in mind most EV charging can be done overnight at household outlets, only a few very long journeys will need topping up during the day, so it is reasonable that the number of fast charging outlets will be much less than current gas pumps even when EVs reach near complete market penetration, thus the number of installations will be small enough that costs will not be onerous.

Comment Fun project but... (Score 1) 46

why so much complexity to decode a standardized protocol.

Just to be clear. This is no security breach this is just a very complicated way to set up a demodulator. All that happens is that this guy pulls out the bits from the on-air datastream. Any reasonably configurable 2.4GHz band RF device capable of 1Mbit GFSK would be able to do this.

BLE uses AES to encrypt the channel, so to compromise security you need to extract the key. You either need to compromise the initial key exchange, or you need to perform a successful side channel attack. Both options are certanly viable technically. However in practice. BLE devices pair once at the start of their life and never again limiting the practical scope of a key extractioppn by key exchange comprtomise. Side channel attacks require physical access and as BLE devices tend to be in physical control of their user this is also a bit challenging.

Comment Left as an excersise for the reader... (Score 1) 365

As a first pass you can estimate adders as 10 gates pr. bit, state as 20 gates pr. bit and multipliers as 10x bits squared (Unless it is by a power of two in which case it is free) If you need to to division in your algorithm you should redesign it. If you use floating point, everything gets huge (Try not to use floating point, remember in hardware you do not need to deal with arbitrary word size restrictions, just scale word sizes to suit the requirements)

Now, figuring out exactly what resources you need, this is where you will get into trouble. Normally you will reuse some (lots) of your arithmetic, but exactly how much depend on what performance/power/gate count target you need to hit. More reuse means less gates but faster clocks (Which can drive you to more gates if you get into trouble on timing closure). The extreme case is software which just reuse a very limited set of ALUs, the other extreme is an unrolled design where algorithmic operation have dedicated hardware, so one iteration takes one clock.

Depending on performance targets the same algorithm can have a factor 1000 difference in gate count.

Comment High Frontier (Score 1) 87

Try High Frontier by Phil Eklund ( A game about industrializing space made by an actual rocket scientist.

The board is beautiful with spaces representing stable orbits and movements represented by delta-v needed to change orbits.

Rocket stacks are built by reasonably realistic technologies and fueling and mass adhere to the Tsiolkovsky rocket equation (Placed in an elegant table array for simple use)

Comment Re:Always wondered.... (Score 2) 348

Some legislatures assert that the person whose name is associated with the cars license is ultimately responsible for illegal operation of the vehicle. Such legislatures usually cancel the fine if you have reported the car stolen or will reassign it if you provide information on who actually drove the car.

Comment What about capacity (Score 1) 333

The largest issue I have with the hyperloop proposal is its rather pitiful capacity. At the highest rate proposed, with once cart every 30 seconds it still only transpoprts ~3600 PAX/hr, which is about on par with a 3 lane highway and that is before mixing in the car carriers.

Bog standard high-speed train lines do 30000 PAX/hr routinely, and while the hyperloop carts might be able to scale some, based on how they do the air bearing and that I think linked carts likely will not work, I doubt they can scale much other than by building multiple tubes (which adds upp the most expensive component in the system)

The biggest value add by public transport is to be able to free up the excessive area consumption an automobile based society incurs, but to do this the public transport in question better beat the automobile in land use with a wide margin.

Looking at speed alone is a bit of a red herring. faced with increased transport speeds people have always responded by traveling further which just escalates the problem of increased land use and increased energy use for transport. Throughput pr. unit land is likely a better metric for sustainable travel solutions than raw speed.

Slashdot Top Deals

Earth is a beta site.