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does anyone know how to retrain Object Detection (coco-ssd) of TFJS for object 91?

So far I seen so many discussion on this topic and using different approaches to achieve this (https://github.com/tensorflow/models/issues/1809) but I want to know if anyone managed to successfully use Tensorflowjs to achieve this.
I know some also achieved this using transfer learning but it is not same as being able to add my own new class.

The short answer: No, not yet, though technically possible, I have not seen an implementation of this in the wild.
The longer answer - why:
Given that "transfer learning" essentially means reusing the existing knowledge in a trained model to help you then classify things of a similar nature without having to redo all the prior learning there are actually 2 ways to do that:
1) This is the easier route but may not be possible for some use cases: Use one of the high level layers of the frozen model that you have access to (eg the models that are released by TF.js are frozen models I believe - the ones on GitHub). This allows you to reuse some of its lower layers (or final output) which may already be good at picking out certain features that are useful for the use case you need eg object detection in a general sense, which you can then feed into your own unfrozen layers that sit on top of that output you are sampling from (which is where the new training would happen). This is faster as you are only updating weights etc for the new layers you have added, however because the original model is frozen, it means you would have to replicate in TF.js the layers you were bypassing to ensure you have the same resulting model architecture for COCO-SSD in this case if you wanted the architecture. This may not be trivial to do.
2) Retraining the original model - can think of tuning the original model - but this is only possible if you have access to the original unfrozen model and the data used to train that. This would take longer as you are essentially retraining the whole model on all the data + your new data. If you do not have the original unfrozen model, then the only way to do this would be to implement the said model in TF.js yourself using the layers / ops APIs as needed and then use that to train on your own data.
What?!
So an easier to visualize example of this is if we consider PoseNet - the one that estimates where human joints/skeletons are.
Now in this Posenet example imagine you wanted to make a new ML model that could detect when a person is in a certain position - eg waving a hand.
In this example you could use method 1 to simply take the output of existing posenet predictions for all the joints it has detected and feed that into a new layer - something simple like a multi layered perceptron - that could then very quickly learn from example data when a hand was in a waving position for example. In this case we are simply adding to the existing architecture to achieve a new result - gesture prediction vs the raw x-y point predictions for the joints themselves.
Now consider case 2 for PoseNet - you want to be able to recognise a new part of the body that it currently does not. For that to happen you would need to retrain the original model so that it could learn to predict that new body part as part of its output.
This is much harder as you would need to retrain the base model to do this, which means you need to have access to the unfrozen model to do that. If you didn't have access to the unfrozen model then you would have no choice but attempt to recreate PoseNet architecture entirely yourself and then train that with your own data. As you can see this 2nd use case is much harder and more involved to do.

Compare sound between source and microphone in JavaScript

I'm working about audio but I'm a newbie in this area. I would like to matching sound from microphone to my source audio(just only 1 sound) like Coke Ads from Shazam. Example Video (0.45 minute) However, I want to make it on website by JavaScript. Thank you.

Building something similar to the backend of Shazam is not an easy task. We need to:
Acquire audio from the user's microphone (easy)
Compare it to the source and identify a match (hmm... how do... )
How can we perform each step?
Aquire Audio
This one is a definite no biggy. We can use the Web Audio API for this. You can google around for good tutorials on how to use it. This link provides some good fundametal knowledge that you may want to understand when using it.
Compare Samples to Audio Source File
Clearly this piece is going to be an algorithmic challenge in a project like this. There are probably various ways to approach this part, and not enough time to describe them all here, but one feasible technique (which happens to be what Shazam actually uses), and which is also described in greater detail here, is to create and compare against a sort of fingerprint for smaller pieces of your source material, which you can generate using FFT analysis.
This works as follows:
Look at small sections of a sample no more than a few seconds long (note that this is done using a sliding window, not discrete partitioning) at a time
Calculate the Fourier Transform of the audio selection. This decomposes our selection into many signals of different frequencies. We can analyze the frequency domain of our sample to draw useful conclusions about what we are hearing.
Create a fingerprint for the selection by identifying critical values in the FFT, such as peak frequencies or magnitudes
If you want to be able to match multiple samples like Shazam does, you should maintain a dictionary of fingerprints, but since you only need to match one source material, you can just maintain them in a list. Since your keys are going to be an array of numerical values, I propose that another possible data structure to quickly query your dataset would be a k-d tree. I don't think Shazam uses one, but the more I think about it, the closer their system seems to an n-dimensional nearest neighbor search, if you can keep the amount of critical points consistent. For now though, just keep it simple, use a list.
Now we have a database of fingerprints primed and ready for use. We need to compare them against our microphone input now.
Sample our microphone input in small segments with a sliding window, the same way we did our sources.
For each segment, calculate the fingerprint, and see if it matches close to any from storage. You can look for a partial match here and there are lots of tweaks and optimizations you could try.
This is going to be a noisy and inaccurate signal so don't expect every segment to get a match. If lots of them are getting a match (you will have to figure out what lots means experimentally), then assume you have one. If there are relatively few matches, then figure you don't.
Conclusions
This is not going to be an super easy project to do well. The amount of tuning and optimization required will prove to be a challenge. Some microphones are inaccurate, and most environments have other sounds, and all of that will mess with your results, but it's also probably not as bad as it sounds. I mean, this is a system that from the outside seems unapproachably complex, and we just broke it down into some relatively simple steps.
Also as a final note, you mention Javascript several times in your post, and you may notice that I mentioned it zero times up until now in my answer, and that's because language of implementation is not an important factor. This system is complex enough that the hardest pieces to the puzzle are going to be the ones you solve on paper, so you don't need to think in terms of "how can I do X in Y", just figure out an algorithm for X, and the Y should come naturally.

finding relationships between a lot of variables

I'm going to keep this simple for the sake of the question but I will try to explain my issue as simple as possible.
I have a fairly large project I am working on with over 1000 variables. The user picks page's they want to fill out and in the order they choose. Each page has about 200 variables in it.
The average user has about 10 pages that they fill out.
Here is the tricky part I am trying to solve. There are a lot of variables on each page
that are related to other variables throughout the same page but, more imporantly, on other pages that the user may decide to use as well. There is not one particular page a user will definitely use, it just depends on their preference.
So relationships look something like
page1_address == page2_address == page3_address == page4_address == etc.
page1_total = page1_var1 + page1_var2;
page3_total = page1_total + page2_var1;
if (page6_var1 > 0) && (page6_var2 < 10)
then page3_super = "something important"
So sometimes the relationships are just based on whether they are the same. But sometimes I want to find relationships between variables that are a little bit more complicated. Obviously this only works if all the variables are present.
So my question is, is there a particular way that I should go about creating these
relational rules between variables?
What is the appropriate way of performing checks such as if a user filled out
page4 first and then I need to auto fill page1 with the relational variables such
as the address? What if I need to do a more complicated check but in the beginning not all the variables are present but now they are?
I'm not looking for a fool proof method, I know this is on a case by case basis. I am just looking for a direction to move towards. Any guidance would be appreciated.

You can represent your data as N-ary trees like here: N-ary trees. Or you can tyr Decision trees, may be they are more suitable for you: Decision trees. For Decision trees and data minig from them there are many great books and online courses and tutorials. You need to have at least basic experience with statistics.
Edit (from comments below):
Very good book is Data Mining with Decision Trees: Theory and Applications by Lior Rokach. Then you can try also Data Mining: Practical Machine Learning Tools and Techniques, Third Edition. If you want to do complex analysis of your data you need to study machine learning, statistics etc. But if you are not familiar with it, you must start somewhere and that is: Data structures and Statistics.

How to make a GOOD reporting Interface

I have a ton of associated data revolving around a school, students, teachers, classes, locations, etc etc
I am faced with a challenge put fourth by my client; they want to have reports on everything. This means they want the ability to cross reference data points every which way and i think i'm just short of writing a pretty query builder. :/
This stack question is aimed at soliciting opinions on how to structure a reporting interface beautifully.
Any suggestions, references, examples, jQ plugins etc would be amazing.
Thank you!

I find the Trac's query builder rather acceptable for what it is meant to do.
But most probably your clients don't want everything, they are just too lazy to think about what they want now. You could help them decide by analyzing the use cases together, and come up at least with a few kinds of queries with just a few parts customizable -- in the worst case -- or just a few canned queries they really need -- in the best.

You should probably schedule a meeting with your client to determine what they need to do. This does not mean having them speculate about how great it would be if your software could do everything, was ultra-flexible yet totally easy to use, etc... but sit down and find out what they are doing right now. I'm saying this because that "oh, I'd like to be able to cross-reference everything with everything else!" sounds a bit too familiar, and might end in an ugly case of inner-platform effect.
I've found that rapid paper prototyping with the client is a great way to explore possible ideas, as it shifts their attention away from "can you make this button yellow?" issues to The Big Picture, to let them make up their minds what they actually need. Plus, it's ridiculously inexpensive to do.
Apart from that, for inspiration, there are UI pattern languages that address handling potentially large amounts of interconnected data. What's great about these is that you will often be able to use these patterns to communicate ideas to your client, since a well-structured pattern language will guide a non-expert through domain-relevant design decisions in increasing detail.

First, I can only support the other voices: work out with the clients what they actually need. A good argument is "I can do, but it will cost you X thousand dollars, every user will need Y hours of training, and you'll need a $100.000K/year developer to maintain it."
(Unfortunately, most clients at that point prefer to pick the guy who says "yes, can do cheaper!")
Only second, and only if the client says "yes we do need everything":
What works well is a list/grid view progressive filtering. Instead of buildign the SQL query, then running it, let the user directly work with the results: e.g. right clicking a cell, and selecting "limit to this value" could add a WHERE colN = <constant> constraint.
You can generate suggestions for columns from SELECT DISTINCT calls - if it returns less than, say, 20 values, you can offer checkboxes for a OR combination of possible values.
It would be interesting to discuss en elegant UI for the sea of remaining problems: OR'ed conditions across multiple columns, ordering by more than one column, grouping, ...

Handling combat effects in game development

I'm trying to nut out a highlevel tech spec for a game I'm tinkering with as a personal project. It's a turn based adventure game that's probably closest to Archon in terms of what I'm trying to do.
What I'm having trouble with is conceptualising the best way to develop a combat system that I can implement simply at first, but that will allow expansion and complexity to be added in the future.
Specifically I'm having trouble trying to figure out how to handle combat special effects, that is, bonuses or negatives that may be applied or removed by an actor, an item or an environment.
Do I have the actor handle all effects that are in play for/against them should the game itself check each weapon, armour, actor and location each time it tries to make a decisive roll.
Are effects handled in individual objects or is there an 'effect' object or a bit of both?
I may well have not explained myself at all well here, and I'm more than happy to try and expand the question if my request is simply too broad and airy. But my intial thinking is that smarter people than me have spent the time and effort in figuring things like this out and frankly I don't want to taint the conversation with the cul-de-sac of my own stupidity too early.
The language in question is javascript, although at this point I don't imagine it makes a great difference.

What you're calling 'special effects' used to be called 'modifiers' but nowadays go by the term popular in MMOs as 'buffs'. Handling these is as easy or as difficult as you want it to be, given that you get to choose how much versatility you want to be able to bestow at each stage.
Fundamentally though, each aspect of the system typically stores a list of the modifiers that apply to it, and you can query them on demand. Typically there are only a handful of modifiers that apply to any one player at any given time so it's not a problem - take the player's statistics and any modifiers imparted by skills/spells/whatever, add on any modifiers imparted by worn equipment, then add anything imparted by the weapon in question. If you come up with a standard interface here (eg. sumModifiersTo(attributeID)) that is used by actors, items, locations, etc., then implementing this can be quick and easy.
Typically the 'effect' objects would be contained within the entity they pertain to: actors have a list of effects, and the items they wear or use have their own list of effects. Where effects are explicitly activated and/or time-limited, it's up to you where you want to store them - eg. if you have magical potions or other consumables, their effects will need to be appended to the Actor rather than the (presumably destroyed) item.
Don't be tempted to try and have the effects modify actor attributes in-place, as you quickly find that it's easy for the attributes to 'drift' if you don't ensure all additions and removals are done following the correct protocol. It also makes it much harder to bypass certain modifiers later. eg. Imagine a magical shield that only protects against other magic - you can pass some sort of predicate to your modifier totalling function that disregards certain types of effect to do this.

Take a look at the book, Head First Design Patterns, by Elisabeth Freeman. Specifically, read up on the Decorator and Factory patterns and the method of programming to interfaces, not implementations. I found that book to be hugely effective in illustrating some of the complex concepts that may get you going on this.
Hope this helps to point you in the right direction.

At first blush I would say that the individual combatants (player and NPC) have a role in determining what their combat characteristics are (i.e. armor value, to-hit number, damage range, etc.) given all the modifiers that apply to that combatant. So then the combat system is not trying to figure out whether or not the character's class gives him/her an armor bonus, whether a magic weapon weighs in on the to hit, etc.
But I would expect the combat system itself to be outside of the individual combatants. That it would take information about an attacker and a desired type of attack and a target or set of targets and resolve that.
To me, that kind of model reflects how we actually ran combat in pencil and paper RPGs. The DM asked each player for the details of his or her character and then ran the combat using that information as the inputs. That it works in the real world suggests its a pretty flexible system.