u/mantra

It's whatever you want largely.

If you like latin and salsa, there is Brown Sugar

If you like ex-pat bars, there is Carnegies

If you like dance/house/rave, there is Luxy

If you like sports bar (esp, cricket, rugby, soccer), there is Brass Monkey

Etc., etc., etc.

One nice thing (for Americans): no Post-Prohibition-Era 2 a.m. closing - things close when they close and 2 a.m. is often just when things are getting started. Plus taxis are dirt cheap and abundant at all hours.

This violates so many laws it's crazy. It probably violates Title 9 itself ,the very reason they are supposedly doing this. The legal liability the university is putting itself into with this is stunning - anyone who feels sexually intimidated by this can trivially sue the university and its officials to high heaven for Title 9 violations by asking!!

Get out the popcorn, this will be fun to watch!

You can define a SNR based on channel width and signal strength. Typically RF amplifiers are spec'ed like this (strictly with Noise Figure but it's related to SNR).

More or less, yes.

This is what superheterodyning has always been about: down-converting to cheaper and/or more reliable and/or easier to implement circuit frequencies. It also enables you to tune very accurately, either by analog or digital control, with the same static RF and IF circuitry.

There once was an era when you would actually operate at the tuned RF frequency. Receivers for that were called "TRF" or Tuned Radio Frequency receivers. Last seen commonly in-the-wild in the 1920s!

The way you'd tune TRF receivers required changing the LC filter tuning of every amplifier in the receiver chain up to the detector/demodulator. Doing this at RF frequencies and managing to have all stages tuned the same is generally difficult to do. Back in the day, you had 3-5 tuning dials that all had to be set correctly to receive a station. Not really user friendly.

Then "the radio God" Edwin Armstrong invented superheterodyne. He also invented autodyne, regenerative and super regenerative, and frequency modulation (FM) radio technologies!

The other advantage of super heterodyning is you can achieve tuning by merely changing the local oscillator (LO) frequency but keeping the RF and IF circuits the same. This is exactly how the RTL-SDR works - when you tune, you are changing only the LO but keeping everything else the same.

The LO is tuned by using a "fractional-N phase-locked loop (pdf)" which allows you to tune thousands to millions of frequencies yet base your LO accuracy on a single frequency crystal oscillator (which can be made very accurate).

You couldn't tune the wide bands of frequencies like the RTL-SDR using a TRF architecture.

Sadly that may well be for the best.

Wishful thinking and "commitment to ideals" isn't going to change reality on the ground so rational adults normally drop back to "why are we even considering this course at all?"

This speaks volumes about the maturity of people in the political elite.

LEDs do have as much temperature dependence in their IV curve as any other diode does. I.e. Id = Is e^Vd/nKT where T is the temperature in ºK. Is is also temperature dependent: Is ~ A Eg / kT (same T). And then Eg (band gap) is also temperature dependent: Eg ~ Eg(0) - alpha T² / (T + beta), same T.

This temperature sensitivity is one of the special problems with LEDs in terms of lifetime - they tend to be very sensitive to heat and current regulation, failing far earlier than "expected" if you don't bias them correctly or well in order to limit both heat and current.

This why you 1) must minimally use a current limiting resistor per LED, 2) why even a current limiting resistor often isn't enough to assure long LED lifetime if ambient temperature changes a lot or broadly, hence the many switched power LED driver chips sold by pretty much every analog IC house (KCL works great for regulating many LEDs to the same current).

Having 3 LEDs on a resistor is a marginal design - OK for intermittent use but it's cutting too many corners for my taste as a designer. But it's probably typical of super-cheap Chinese LED strips.

The problem is "current hogging". If one diode is a bit "stronger" (and process variation guarantees one will be), more current will flow in that current divide leg, which will heat it more, which will increase the current more, etc. until it accelerates regular heat-activated damage to end-of-life failure. Then you have only two LEDs on the same resistor allowing high enough current for three but now only two - so they are each operating at 150% of designed current limit. Both are already overloaded compared to three and one will hog current which will increase the heat,... lather, rinse, repeat. Having 1 resistor per 1 LED is an easy fix for this.

The problem of heat on other things (e.g. fire hazard) is generally no worse than an incandescent since the same lumens requires far more heat with those than an LED, i.e. LEDs are more efficient and produce less heat for the same amount of light.

This as long as you follow electrical codes sufficient for incandescents, you should be fine (also assuming the LED light isn't some home brew mess). If it is home-brew, look into heat sinking typically used for LED lamps if there's a lot of heat.

Basically measure the steady-state temperature explicitly to know how much. Temperatures below 60C-80C are probably nothing to worry about as nothing much kindles that low. Above that temperature the LEDs will die quickly anyway.

I'd remediate with resistors-per-LED first or by buying a better quality LED strip. Thermistors seem like a lot of trouble and could "break" functional or fail to make a difference at all, if you don't design them in carefully enough.

This.

But too many app developers (or maybe their marketing folks) don't stick to the core purpose and glue on "revenue generation" usage of things like Location, which I find morally and customer/brand dubious.

Call me "old school" but if Location isn't part of the primary app purpose you shouldn't be doing Location at all in your Capabilities (which is what triggers the prompts).

If you need metrics, and it's not core functionality, there are other ways than Location. If you need money, price correctly and bake that into your development plans. Even if it is core functionality, design your app so it can live without Location as much as possible. Sometimes location data isn't available, so then what? What's the back-up plan? The app becomes totally useless? That's fail. Unless it's core, most apps don't really need Location or could creatively work around missing it.

Sorry about the rant. I like your take on it.

I had the same thought. Probably just for completeness (often goes with height, medically) and efficiency (the code already handles all the other values as time-series).

3 or 4 examples downloaded given are in public domain.

On top of that this is pretty much the same as RIAA+File-sharing: a seller created black market created by seller pricing far above the market value.

Market value isn't dictated by the seller: economic transactions are negotiations and laws are always trumped by economic realities and needs of the market. Try bidding the books' price instead and you'll see what its real value/price is. It won't be the list price students are currently being forced to pay (if they buy it "legally").

On top of this, writing textbooks is a thankless and unprofitable proposition. 99% of professors who write them make little or no money. My graduate advisor in school wrote 3 now-standard textbooks but he never made more than a few $K in royalties. That's not a reason or justification for mispricing - better would be to eliminate the publishing middle-man and self-publish or coop publish under an appropriate license online. That is the future. And it's not even that hard.

It's OK - it's GFI

Absolutely agree - these are major red flags for ANY STEM grad lab/PI. Avoid! And don't let others fall into the trap - it only perpetuates the existence of such labs/PIs. Darwin them academically and financially.

Start with farm use of antibiotic first!! That's where the problem comes from first. Hospitals are merely petri dishes of people with weakened health the amplify what is coming in from farms. (There was a recent link to pig farms and how some workers are Typhoid Marys for exactly the MSRA and other resistant bacteria and they carry for weeks to months).

Even the small ones are extravagant in their selection of pens, pencils and paper. Most neighborhoods have them because it's where school kids get their school supplies.

Just semantic sugar - still properties underneath.

Frankly there isn't much you could train Iranians about that they don't already know.

Sounds like a plan.

Of course, it's not like even different areas of physics don't use different symbologies anyway. It makes condensed matter physics papers Greek to astrophysicists, et al. I've found you often don't get a choice - you adapt and learn a subfields oddments and nomenclature as a matter of course.

Try the link. Go ahead. I've got my popcorn out.

A 4-port s-parameter device just a 4x4 matrix problem. All the matrix math you'd use with 2-port with a 2x2 matrix applies directly except N=4 instead of N=2. Think in matrix math and you're (mostly) done. Above N=2 this is sometimes called a "scatter matrix" instead of s-parameters but it's the same thing.

Off-diagonal s-parameters are easier to grok. These are "transfer function parameters" in the same sense as y(jω) = H(jω) x(jω) in linear systems where H is a transfer function. The only trick is s-parameters are power transfer/reflection parameters so the incident input must be power and the resultant transferred/reflected output is power.

So Pi = Vi²/Zo. Then Pj = Sji Pi. And then convert back with Vj = sqrt(Pj Zo). This works to 1st order and is exact if you have perfect input and output match to the 4-port.

On-diagonal terms are equal to 𝚪 or "gamma" or the complex reflection coefficient for that port: s11 = 𝚪11. The relation to reflection coefficient is ρ = |𝚪|. These are "impedance parameters", that is, they indicate the effective load or Thevenin impedance into or out of the port.

Again this is strictly a power mismatch when it comes to measured s-parameters. With these you have mismatch terms that enter into the signal flow analysis as mismatch loss for transfer calculations of 2nd or higher orders.

If you are going to load impedances different from the characteristic impedance, you MUST calculate everything in power and convert back to voltage from power. Power is the only truth in microwave measurements. Voltage can be anything.

These mismatch terms arise if you have "sufficient" mismatch on i or j ports or if you have mismatch on other cross terms to i or j - this is where "Signal Flow Graphs" comes in to account for these. Some good links for signal flow graphs IMO:

http://whites.sdsmt.edu/classes/ee481/notes/481Lecture21.pdf

http://www.ittc.ku.edu/~jstiles/723/handouts/section_4_5_Signal_Flow_Graphs_package.pdf

Iterative gain/reflections arises because you have reflections created by mismatch that bounce back and forth hitting both gain and mismatch again.

This is what signal flow accounts for (usually up to the 2nd reflection back through - after that the signal level is usually assumed to be "sufficiently small" to ignore because reverse parameters tend to be small gain - of course there are cases where that wouldn't be true also). Again, if you have decent matches, you can ignore these to 1st order.

If you are dealing with port load impedances significantly different from the primary characteristic impedance, you will have to deal with signal flow and mismatch losses. s-parameters measured data and VNAs are pretty much only referenced in 50 ohms or 75 ohms. VNAs become more inaccurate the farther you get from their characteristic impedance.

Edit: some words

Given that the Spanish Flu made it all the way to the most remote Aleutian Islands and Northwest Territories of Canada and killed plenty, there's probably is no place on Earth you can run to actually escape.

You'd need to use a micro/nano power switcher akin to a Joule thief. Certain commercial switcher ICs targeting micro power for "energy harvesting"

http://www.ti.com/lsds/ti/apps/alternative_energy/harvesting/overview.page?DCMP=MSP430_Energy&HQS=energyharvesting

http://www.linear.com/product/LTC3588-1

http://www.maximintegrated.com/en/products/power/battery-management/MAX17710.html

"Outside the box", in practice, simply means asking the question, both in good times and bad times, "Is there another way we could be doing this?" Where this is anything you are doing for the business. That's all.

It could be product design. It could be selling. It could be marketing. It could be operations. It could supply chains and vendors. Anything.

The obviousness of this is more plain when you are hitting your head against the wall when you are up against the wall and nothing is working with things looking bleak. But that's also the moment when you start wondering: "Why didn't we ask this question 12 months ago before the SHTF?". Hence you should ask it when everything is going well also.

Basically it's saying you can't obsess about just one metric. People do do that. It's easier but it wrong because business and its markets aren't one-dimensional like that.

Singular focus can drive you into a rut and you'll miss important stuff if you just focus on one thing - this is the road to perdition that "profit maximization" can get you into, for example. You can technically maximize profit on paper in most companies by eliminating all costs - technically until the revenue disappears you are "maximized".

Total is ALWAYS better than partial for any language. If "best" learning is the sole criteria, there is no question.

What enters the picture to temperate that is economic and situational constraints. That is the proper trade-off to focus on.

I won't mention the toxics involved - presumably you already know but don't care...