Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror

Comment: Diodes (Score 1) 553

by Lonewolf666 (#49797329) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

Even with switching power supplies, 12v is not optimal because of the losses in the diodes. Even Schottky diodes have a voltage drop of 0.3v or so.

I think it would be a good idea to standardize on something in the 40-50 volt range for the DC grid in the house, with some leeway for adjusting the actual charging voltage to what is convenient for the battery.
A 42-volt electrical system (http://en.wikipedia.org/wiki/42-volt_electrical_system#Choice_of_voltage) comes to mind. Even if it did not really take off the first time around.

Comment: Interesting callousness towards those maintaining (Score 1) 93

by sethstorm (#49793511) Attached to: Cloud Boom Drives Sales Boom For Physical Servers

The promise of the cloud is that your storage and computing problems will be abstracted away from messy physical objects that you need to maintain, taken care of far way by other people that are not well treated for their work.

At least the first mainframe era had some respect for the people involved in the infrastructure. These days, globalization has killed it in favor of mistreatment and abstraction of the workforce.

Comment: Re: Dry Heat: it is about acclimation. (Score 1) 154

by WindBourne (#49789171) Attached to: Heat Wave Kills More Than 1,100 In India
30% is low. Back in the 70s in I'll, I would work in temps of 105 with 60-90% humidity. That was humid. And yes, it sux.
In addition, in the winter, it hit -40f. Most of the time, we would have -30 through -35 for 2-3 weeks at a time.
But I was acclimated to it.

After 3 years of moving to Colorado, I went to visit a friend in IL, in the middle of winter when temps were -20 to -25f. I wore the same clothes that I used to ( good down jacket, etc.). AND like always, never a hat. I walked for 20 mins in that and nearly lost my ears for that. Ears were black and it was touch/go if they were to be removed.
The body can handle extremes, but it needs to acclimate to it. without that , it is a killer.

Comment: Re:Answer (Score 2) 333

by Jeremi (#49788345) Attached to: How Much C++ Should You Know For an Entry-Level C++ Job?

I have yet to encounter a non-contrived example where multiple interitance is a plausible solution to a problem.

Okay, I'll give it a shot, then... here's where I find multiple inheritance not just plausible, but preferable.

I have a publish/subscribe model including an abstract-base-class/interface (call it IDataSubscriber) that can be subclassed by any object that wishes to be notified about e.g. data updates coming in from the network.

There are a number of common-case standard responses (implemented as concrete IDataSubscriber methods) to those data updates that are useful for many situations, and I don't want to have to have to rewrite them separately for every subclass, so I make a concrete or almost-concrete subclass (e.g. StandardDataSubscriber) that contains this common logic.

Finally, in my client code (based on Qt) I have a number of GUI widgets based on QWidget or QPushButton or whatever. I want these widgets to react to published data in the standard way, so I often end up with this:

class MyButton : public QPushButton, public StandardDataSubscriber {...}

... and it handles my needs nicely. It's also possible to do the same thing with "just" single inheritance and interfaces as well, or with Qt's signals-and-slots, but AFAICT do to it that way you end up having to do lots of manual method-call-forwarding through proxy objects (or, alternatively, lots of manual signal/slot connecting), which is less efficient, harder to read/understand, and more error-prone.

"I'm growing older, but not up." -- Jimmy Buffett

Working...