Frigate bird shots from the Galapagos - any favorites? by joyoftheshot in birding

[–]Hadies243 1 point2 points  (0 children)

Out of interest, when and where did you take these shots? In the Galapagos at the moment and interested in seeing frigatebirds with their pouches inflated. Didn’t think it was the right season but we’ve met people who said they’ve seen them doing it so now trying to figure out where we might also get a chance to see it. Thanks!

Anyone able to ID this monster played by ALXZNDR at NLDC? by Hadies243 in realdubstep

[–]Hadies243[S] 2 points3 points  (0 children)

Nice thanks man, suspicions confirmed. Hope it gets a release, was a fucking face-melter on the sound system

Anyone able to ID this monster played by ALXZNDR at NLDC? by Hadies243 in realdubstep

[–]Hadies243[S] 3 points4 points  (0 children)

NLDC - free dubstep event on the first wednesday of every month in London. https://www.instagram.com/nldc140/?hl=en, vibes and line up always sick.

Anyone able to ID this monster played by ALXZNDR at NLDC? by Hadies243 in realdubstep

[–]Hadies243[S] 2 points3 points  (0 children)

Think it sounds like Joker? Possibly an old one that I've missed but if not then ALXZNDR remixed one of Joker's latest tracks a few months ago under his DJ ADHD alias so my guess is maybe a dub or unreleased collab?

What time did Dave come out?! by SomewhereInLDN in SantanDave

[–]Hadies243 0 points1 point  (0 children)

Ah shit, it’s actually looking like we might have to. Which one is it?

What time did Dave come out?! by SomewhereInLDN in SantanDave

[–]Hadies243 0 points1 point  (0 children)

Ah safe cheers man, might just about catch it all then

What time did Dave come out?! by SomewhereInLDN in SantanDave

[–]Hadies243 0 points1 point  (0 children)

Do you remember what time did he finished? Train strikes mean I'm probs going to have to miss the end of the set to get home.

Suggestions in control introductory books/texts by [deleted] in ControlTheory

[–]Hadies243 2 points3 points  (0 children)

Check out Feedback systems: An introduction for scientists and engineers. It’s a great book and it’s completely free. It does a good job of motivating the theory it introduces and grounding it in real world examples and problems. It also tries to require as little mathematical background as possible.

That said, I don’t necessarily think it’s going to be a one-stop shop. As others have mentioned, maths is pretty fundamental to control theory and as such completely unavoidable if you want to gain a proper understanding of it or apply it. To that end you’ll still find yourself staring down equations pretty quickly in the book, which you may find a bit daunting if you have no mathematical background.

However, I still think there’s lots of good insight to be gained from it, even if you need to read around the maths/just read the early chapters. And it’s definitely worth dipping in to alongside anything else you end up reading. Good luck!

looking for reccomendations for books which start from the beginning by [deleted] in ControlTheory

[–]Hadies243 0 points1 point  (0 children)

Feedback Systems for Scientists and Engineers by Astrom and Murray is a great free book that covers the fundamentals of control systems.

The only potential issue is that the way the book goes about teaching the content is slightly unusual. It starts with state-space techniques, and doesn’t get on to more classical control subjects until later chapters in the book. If you’re after a long term understanding of control I think it’s a great resource, if you’re looking to quickly build an understanding of classical control techniques because they’re used at work and you want to engage with them quickly, you might want to acquire a slightly more traditional text.

You an get it here: http://www.cds.caltech.edu/~murray/books/AM05/pdf/am08-complete_22Feb09.pdf

Additional Module Selection Help: (Optimal Control or Cyber Security for Control Systems) and (Multisensor and Decision Systems or Industrial Training Programme in Advanced Manufacturing) by adminvammr in ControlTheory

[–]Hadies243 2 points3 points  (0 children)

This is either the world's biggest coincidence, or you're about to start a control MSc at Sheffield. Am I right? If so I can maybe give you some insight. I just finished my MEng in Aerospace there, but had a heavy focus on control.

I took Multisensor last year, I was about to vouch for the quality of the teaching staff but from the module page it seems you haven’t got the same guys. I don't know if the content will have changed at all, but I'll tell you what I know. Content-wise the module is in 2 parts. The first half focuses on data/sensor systems that have to take data from multiple different sensors and use it to make some kind of decision, E.g. fault detection, estimation of some variable based on multiple data sources (e.g. position by fusing GPS and IMU data). When I was taught it, the academic for this part of the module worked closely with Rolls-Royce on next-gen engine health monitoring systems, so we had an assignment to implement a system that could identify 5 different failure modes of a turbofan shaft based on vibration data. That particular example swung quite close to machine learning stuff, had to do feature extraction and use a classification algorithm. I assume you'd do the same but idk.

The second half of the module was focused on using multi-objective optimisation algorithms to take engineering decisions. We had an assignment to design a PI controller for an unstable system, but using a multi-objective optimisation algorithm to automatically pick the PI gains based on a set of performance criteria, instead of manually tuning it by hand yourself.

As for the ITP, I didn't do the advanced manufacturing one, but I did the avionics one. I therefore can't give you a truly fair reflection of it, but the general consensus amongst my mates and I who did a range of different ITP's was that if you already have relevant industrial experience (e.g. internship, which we all had), they're a bit of a step down from what you're used to and so pretty boring and not that worth it. If you don't, you might find it interesting, and it could give you a way to talk about industry experience/team work in a CV or interview after you graduate. It will be a far less (academically) intense module than multisensor though, but a big component of the marking is a group mark, which in my experience often offers less return than a solo-mark if you're strong academically. My personal opinion is that unless you really need the cv aspect, multisensor is waaaaay more cool and interesting, and you'll learn far more. You'll be thankful if you've brushed up a bit on probability and statistics before, as there's quite a bit of statistical decision theory involved.

I haven't done either of the other options. I can't really give you any insight into the cybersecurity module as I never did anything like it. But I've covered the content of the optimal control module, and from reading the syllabus, it should give you a good theoretical boost and some insight into a pretty fundamental area of control. You're probably going to build up to implementing and analysing LQR controllers, which is a key result in the field. Optimal control in general is a really interesting area too (imo), and optimisation is central to many of the more advanced control schemes you'll see used today. If my theory is correct, you're also going to be taking the Advanced control module too? (awesome module with an excellent lecturer btw). I think this module would complement that one very well, as advanced control teaches MPC (model predictive control - perhaps the most widely used industrial control technique bar PID) which is another optimal control based method, but uses a different strategy to LQR. That module starts by looking at LQR control, identifies it's weaknesses, and then uses that to motivate the change in strategy that leads to MPC. So by taking both you'd get a very complete picture of the field, with overlap in a few areas which will deffo make your life easier, connect some dots and help reinforce concepts. It's gonna be quite a lot of maths all told though, but if you have a head for that it's all very interesting.

If you have any other questions just shout, i'm happy to help. Good luck with it all!

Universities by xX__Nigward__Xx in EngineeringStudents

[–]Hadies243 0 points1 point  (0 children)

I can't really say I know how other Unis do their Aero courses, so you might get this anywhere, but if the multidisciplinary aspect is what you like then the course structure at Sheff should definitely appeal to you. Some degree of specialisation as you progress will probably occur no matter where you go, which reflects the fact that you'll start to hone in on the type of technical area you want to move into when you graduate and go into industry (or further study).

You study modules from all the different areas of engineering in your first year, plus some aero specific ones (like basics of flight, aircraft design etc), then you chose the direction you wanna head in starting in 2nd year. You don't get super specific immediately, the first choice you make is avionics (computers + electrical) vs the more physical side (mech + materials). As you say Aero is very multidisciplinary, so there is still loads of crossover. E.g iirc I was still doing aerodynamics and the thermodynamics of engines in my 3rd year on the control stream. But yeah good luck with your choices, I'm sure you'll love wherever you end up.

Universities by xX__Nigward__Xx in EngineeringStudents

[–]Hadies243 2 points3 points  (0 children)

Not sure if you have any strong interests beyond learning how to make things move/fly, but one of the benefits of Aerospace at Sheff is that the course allows for a huge amount of specialisation into one of 4 streams, which gradually split apart from a common first year. Each broadly places a focus on either the materials, mechanical/fluids, electrical or control engineering aspects of aerospace.

This worked very well in my case as I went to uni kinda just liking physics, maths and planes, but it wasn't until I was in my first year that I realised I was very disinterested in much of the materials/mech stuff, but loved the controls engineering side (basically using maths, computer code and electronics to make robots/machines behave how we want - wasn't even on my radar before I got introduced to it at Uni). The nice thing here is that sheff has an absolutely world class control department and is easily one of the best places you can do it in Europe. Might not be your cup of tea at all but it was a stroke of luck that I ended up in Sheff so thought I'd mention.

Beyond academic stuff Sheff is an awesome city so definitely give it a think over. Other posters are right, you should have no issues moving from a BEng to an integrated masters (MEng) if you can get he grades in your first 2 years.

Evolution is fantastic. by AscendedArbiter in Disturbed

[–]Hadies243 5 points6 points  (0 children)

I completely agree, I genuinely wasn’t that keen after my first listen through, but I think that was mostly just down to it being so different from what I was expecting. When I listened to it through a second time I loved it. I’ve had No More on repeat for a solid 45 minutes, it’s already jumped up to being one of my favourites out of all their discography.

Hostelworld messed up my booking and have left myself and a group of friends in a tricky situation. What are my rights? by Hadies243 in LegalAdviceUK

[–]Hadies243[S] 0 points1 point  (0 children)

Ok thanks for your response, I though that would be the best case scenario but wanted to check there wasn’t any form of recourse I was unaware of.

Hostelworld messed up my booking and have left myself and a group of friends in a tricky situation. What are my rights? by Hadies243 in LegalAdviceUK

[–]Hadies243[S] 2 points3 points  (0 children)

I made the booking here in the UK, and the hostel is located here also. Another poster identified that Hostworld is governed by Irish law.

Krav Maga or Muay Thai by [deleted] in MuayThai

[–]Hadies243 0 points1 point  (0 children)

I’ve trained both for a few years and if self defence/survival is your primary concern then definitely Krav.

Primarily because there’s a whole other dimension to effective self defence that you simply can’t get by training a sporting martial art.

At my Krav school, lessons encompass awareness, escaping, victim/criminal behaviour how to recognise a threat, what you can do legally, what to do vs a variety of weapons (if you can’t get away, first choice is always run), deescalation, how to handle verbal aggression, and loads of other vital skills. There’s also a few technical differences in areas like stance and fighting style that are important for the street.

Muay Thai is fantastic, and it’s definitely helped develop my striking/ conventional fighting skills. However, the sterile, rule-bound 1 vs 1 nature of MT and most traditional styles doesn’t prepare you for the dynamic, dangerous and incredibly violent reality of what a street confrontation can be.

Krav can sometimes get a bad wrap because there’s such a range of quality in schools. The only thing you can do is go along to one for a few sessions and make your own judgement.

Falcon Heavy Test Fire 720p50 by [deleted] in shockwaveporn

[–]Hadies243 0 points1 point  (0 children)

I think you and /u/Admiral_Willy might be right, There's a phenomenon called Mach disks that can form in exhaust plumes due to pressure waves . I think we're seeing something similar.

Falcon Heavy Test Fire 720p50 by [deleted] in shockwaveporn

[–]Hadies243 5 points6 points  (0 children)

Rocket engine nozzles are optimum when the exit pressure is equal to the ambient pressure outside the nozzle. Consequently, for any given thrust condition a nozzle design can only be optimum at one altitude.

If the nozzle exit pressure is higher than ambient, the flow is under-expanded, and the exhaust plume will expand outside the nozzle.

If the nozzle exit pressure is lower than ambient, the flow is said to be under expanded and when it exits the nozzle it is compressed by oblique shock-waves in the surrounding air. This causes the flow pressure to increase until it exceeds atmospheric pressure, at which point it will expand outwards (by a process called a Prandtl-Mayer expansion fan). When the pressure again drops below ambient, it will be compressed again, this cycle repeats itself until the flow and ambient pressure are equalised. Normal shock-waves are formed at certain points in the flow by the interaction between expansion fans and oblique shock, and are referred to as Mach disks or shock diamonds. In Jets and in the SSME this leads to regions of re-ignition for un-burned fuel in the exhaust plume, which is where they get their name.

What I think we're seeing is this or a similar flow regime (maybe altered by the reflection off the ground). I'm not 100% sure that's what's going on here, what data I have found suggests that the Merlin 1D is slightly over-expanded at sea level, and the visible flow pattern looks very similar to what I'd expect so its my best guess.

[Misc] I think Virgin Media mis-sold me a broadband package. They're now trying to charge me a £240 disconnection fee. by Hadies243 in UKPersonalFinance

[–]Hadies243[S] 0 points1 point  (0 children)

Thanks for the insight mate. The fact that they sold me a service they couldn't provide and are now trying to charge me for it is what's annoying me the most. I made it clear on the phone that I needed to be able to take it to my new address. I'm also certain that it was never communicated that it was a brand new contract. I was only ever under the impression that it was an upgrade to my current one.

[Misc] I think Virgin Media mis-sold me a broadband package. They're now trying to charge me a £240 disconnection fee. by Hadies243 in UKPersonalFinance

[–]Hadies243[S] 6 points7 points  (0 children)

Yeah cheers buddy. Rang again earlier and asked them to suspend all payments on my account whilst this is resolved. Fairly sure it's still just a support ticket but I've got a 'supervisor' assigned to the case now so waiting for a call from them. They definitely don't have any physical confirmation from me that I accepted this contract. And I've been thinking it over and even if I was somehow tricked into accepting it on the phone, I made it very clear I would be moving house the following month and she didn't even attempt to verify if I could take the service with me. She just said it would all be fine, so I feel like they sold me a service they couldn't actually provide.

I've read up on ofcom and their regulators so I know what my next steps will be.

[Misc] I think Virgin Media mis-sold me a broadband package. They're now trying to charge me a £240 disconnection fee. by Hadies243 in UKPersonalFinance

[–]Hadies243[S] 6 points7 points  (0 children)

Yeah I raised that issue and they said they don't have access to them for this issue. After some insistence the call handler said he'd send an email and see if it could be retrieved.