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Saturday, December 30, 2017

Algorithmic Trading with Quantopian, Random Stuff, and More

- latest in my series on financial trading:
- obviously, I've been looking at this field for a while. I've been look at Quantopian (and similar platoforms) in particular for a short while recently as well...
algorithmic trading online
alternative quantopia
- if you don't know the higher risk and volatility the more likely you can make (or lose) a lot of money in a short space of time. New asset categories such as Cryptocurrencies are interesting for this reason
selling algorithmic trading bots
I made a lot of passive income by coding trading bots for bitcoin.
- the reason why Quantopian (and similar) offerings are so interesting is that they effectively provide you with a trading platform, historical data, etc... You build algorithm and depending on whether your algorithm fits specific criteria they will fund you and provide you with a share of the profits. If you figure out what your final take may be it's not overly great even if you're chosen and your algorithm does well. Once you've 'figured things out you may actually be better off going out on your own?
- that said, there are huge problems with current platforms which basically crowd source algorithms? Key problem are investment strategies. Look at the strategies of some of these guys and they seem completely unrealistic? It feels like they have a theoretical basis in finance but not a practical grounding in trading at times? Everyone wants a way to not have to deal with broad based down turn but the way they're doing limits their exposure to the point whereby it's difficult to make a profit? Not possible? Naive thinking? Performance indicates they're very much struggling against 'tranditional quants'
Quantopian CIO departs as “crowdsourced” hedge fund’s performance disappoints
- most of the algorithms are simple. The problem isn't so much the code. It's the interface. Not enough space to see everything. A lot of jargon that is finance specific. Even if you have a background in finance there is still a lot of stuff that is highly specific to this particular field. Help varies depending on what platform you use 
quantopian algorithms sample
- learn from winners... The most interesting traders are the ones who can simply read the market over the long term as those who have the ability to 'manipulate markets'. These guys can beat beat markets over the long term. Look over most funds and most of them can not beat their own index a lot of the time for their own asset class
- correlations are critical especially in information sensitive market based mechanisms. Social media, machine learning/AI, etc... are core parts of these platforms (on top of what you create)... Often  Investment Banks, HFT, Hedge Funds, Arbs, Quants, etc... aren't pure in what they do and what assett classes they trade in...
google trends
- data varies and dependent on backtesting. Data can be both free or premium/paid. Data from social media feeds problematic because it can be false. Part of me wonders whether or machine learning, fuzzing could be better used in this particular area? We're effectively just looking for data correlations? A lot of platforms already have these capabilities built in
- some of them have 'sandbox' type environments that you often see on other trading platforms (using simulated environments. The 'real thing' is often much more difficult). It's very difficult to learn how to trade because emotion can get in the way (you need to bet a little. Even if it's only 'paper trades' it will help you understand markets. Having something on the line changes your perspective). Something that is often heard in professional gambling and trading is to 'play to the system'. As long as you play accordingly you can figure a way out. Remember you can not control the market unless you have sufficient capital or power and influence. You'll need an account to reach any 'sandbox' a lot of the time. No real chance to anonymously lurk on a lot of platforms...
- most common coding options are Python, Java, JavaScript, C++, Basic, etc... or a variation on any one of these
- quality of documentation and code samples needs to be updated on a lot of platforms. Code samples are sometimes wrong (we're talking basic stuff like syntax and compilation even. Maybe I got a few bad examples from a generally good batch though?)? You'll need to correct them yourself. Unlikely that you can just jump in and randomly change parameters to produce profitable algorithms. A lot have alternative channels. Use them
- get some time working for a Fintech if possible. That said their strategies and type of ones an individual with limited resources can pursue are radically different. Note that most finance firms can go through ups and downs. Even the supposed big names such as Goldman Sachs, HSBC, Optiver, Merill Lynch, UBS, etc... Note, many of these firms rely on their name and 'brand recognition'. Over the long term most of them give up on their perks and bonus structures because they are uneconomical?
- I wouldn't be surprised if Quantopian and similar platforms had backdoors with them. Why would you trade with them? Most people in 'finance' have 'an angle' of sort. Manipulators/speculators have a trade on the side (against their own clients at times), brokers take a cut or are front running/market making (HFT is basically the same as taking a commission if you're honest with yourself?), advisors take a cut/commission (and get a cut if they re-direct towards particular products), etc... Useful if you can't get finance, looking for experience in finance sector without having to get a job inside of the industry, etc... If an individual or group is making excess profits you should be asking the question, "what's the angle here?"
Optiver targets US but rules out purchase
- you can possibly manipulate markets from your bedroom but instances are rare. Put aside some cash if you do intend to do something like this. Most finance firms who knowingly engage in shady deals (such as money laundering) actually set aside some money in case something goes wrong. This money is then used to settle any cases that they need to dealt with with regulatory authorities
- if you haven't already figured out 'life isn't fair'. Modern capitalism and 'fairness' often have little to do with one another in spite of what regulators and governments say. Watch for major players within the markets, minor players who can come from no where, emerging markets, small/mid cap, for IPOs, new investments, bankruptcies, deliquincy rates, stress levels, insiders, drastic changes to supply and demand, new trade/commercial agreements and contracts, etc...
- be careful with regards to 'pump and dump' type strategies. The manipulators/speculators try to create bubble and have novice investors pile in so that they can pop the bubble whenever they want to and take their money. Forget about anyone being 'on your side'. Watch George Soros, Max Keiser, Mike Pento, Jim Rickards, etc... Despite what they say go enough background on them and you'll realise that they're on their own 'particular side'. Finance is a form of 'Hybrid Warfare', another way for competing for limited resources... If you just want to 'ride trades' on the way up you need to read markets and the way the 'manipulators/speculators' work in order to take advantage of their work...
- most trading strategies rely on the following: value (fundamentals good but is underpriced for some reason), growth (for some strange reason has an advantage over others and is gaining out of ordinary returns),  arbitrage (trade across markets based on moving average differentials), front-running (contrarian theory is a variation of front-running)
- capitalism is primarily about about lies, manipulation, and hyprocrisy now... Even investment is filled with it. Most trading platforms funnel you into products where they receive a 'kick back' of some sort. Despite what they say the US is 'classic economy'. It's composed of migrants, most of the reason why it became wealthy in comparison to others countries is due to slavery, colonialism, neo-colonialism, etc... The military industrial complex is 'core' to the US economy. Watch how closely GDP figures track their involvement in wars (GDP/growth rate goes up when they go to war, goes down when they're no involved in war. Hence, they're involved in conflicts all over the place?)
In an interview with the Washington Examiner on Tuesday, Paul said huge heaps of debt, inflation, and inequality could cause turmoil in the US.

“We’re on the verge of something like what happened in ‘89 when the Soviet system just collapsed,” he said. “I’m just hoping our system comes apart as gracefully as the Soviet system."
- socio-economic systems regulated methods of taking advantage of one another. Not much different animals. Regardless humans created the system that they deserve?
- modern economics is mostly 'mumbo jumbo'. At the end of the day it's all about the following. Buy low, sell high... The rest of it is just 'noise'. If you can't compete directly use 'grey areas'. Work around, up, over, and around the laws and regulations, etc... Even 'hedging theory' is gibberish/garbage. Most 'hedge funds' fail and can't compete even with market indexes over the short term. Moreover, if the past could predict the future then everyone would converge on a single theory but it would come at the cost of inflation or be a race to the finish line as we've seen in the HFT world. A single or small number of winners would take most of the spoils. 'Hedging theory' is based on the notion of a self-fulfilling prophecy. The more people embrace it/fall for it the more likely the future repeats the past as hedging theory predicts. It's almost laughable the way it works
- few if any countries are genuinely 'exceptional'. History tells us that most people are fairly similar. Most people and countries use 'shenanigans' of some type or form. They don't want to know about the shenanigans because they lose 'competitive advantage'. Watching those who can 'move and shake' things is the most interesting aspect of the whole equation. Technically, this is a geo-political game. Quants always neglect to factor in how human behaviour and psychology plays a role in finance and how big of a role it actually plays. Crypto is interesting because it upends the US/Western financial system which they created and built for their own advantage. To a certain extent those who 'embrace hyprocrisy' are lucky. It's allowed them to more easily move around in 'certain circles'?
- verify every single piece of information that you use in trading (whether automated or not) but remember it's not about what's true, it's about what people believe because that is what ultimately governs investment decisions (remember 'Big Short' movie). Most 'relevant movement' comes from unknown data or data that people want to be under wraps

Random Stuff:
- as usual thanks to all of the individuals and groups who purchase and use my goods and services
- latest in science and technology
- latest in finance and politics
- latest in defense and intelligence
Spain commits to boosting military spending by 80% up to 2024
- latest in animal news
- latest in music and entertainment

Random Quotes:
- "The aeroplane is the nearest thing to animate life that man has created. In the air a machine ceases indeed to be a mere piece of mechanism; it becomes animate and is capable not only of primary guidance and control, but actually of expressing a pilot's temperament."
-- Sir Ross Smith, K.B.E.
National Geographic Magazine
March 1921. 
- The E-2D’s Lockheed Martin AN/APY-9 UHF-band radar is the central feature of the Advanced Hawkeye. Both friend and foe alike have touted UHF radars as an effective countermeasure to stealth technology. One early public example of that is a paper prepared by Arend Westra that appeared in the National Defense University’s Joint Forces Quarterly academic journal in the fourth-quarter issue of 2009. “It is the physics of longer wavelength and resonance that enables VHF and UHF radar to detect stealth aircraft,” Westra wrote in his article, titled “Radar vs. Stealth.”

UHF-band radars operate at frequencies between 300MHz and 1GHz, which results in wavelengths that are between ten centimeters and one meter long. Typically, due to the physical characteristics of fighter-sized stealth aircraft, they must be optimized to defeat higher frequencies in the Ka, Ku, X, C and parts of the S-bands.

There is a resonance effect that occurs when a feature on an aircraft—such as a tail-fin tip—is less than eight times the size of a particular frequency wavelength. That omnidirectional resonance effect produces a “step change” in an aircraft’s radar cross-section. Effectively, what that means is that small stealth aircraft that do not have the size or weight allowances for two feet or more of radar absorbent material coatings on every surface are forced to make trades as to which frequency bands they are optimized for.

That would include aircraft like the Chengdu J-20, Shenyang J-31, Sukhoi Su-57 PAK-FA and, indeed, the United States’ own Lockheed Martin F-22 Raptor and tri-service F-35 Joint Strike Fighter. Only very large stealth aircraft without protruding empennage surfaces—like the Northrop Grumman B-2 Spirit or the forthcoming Long Range Strike Bomber—can meet the requirement for geometrical optics regime scattering. Effectively, that means the E-2D’s AN/APY-9 radar can see stealth aircraft like the J-20 or J-31.
- The drones tested don’t have a power motor, instead they glide through the air towards their destinations. They also don’t possess onboard cameras. The drones launched using an electromagnetic pulse that caused them to accelerate them from 0-100kph within an arm’s length.

“It shot out like a bullet,” Yang Yanchu, one of the project's lead scientists, told the publication. The drones then glided towards their targets, which were more than 100km (60 miles) away, adjusting course and altitude automatically.

Furthermore, due to their small size, only a minimal trace of their presence was detected on radar – a major plus for a spy-drone. “The goal of our research is to launch hundreds of these drones in one shot, like letting loose a bee or ant colony,” Yang added.

While current near-space drones, such as the American made MQ-9 Reaper and China’s Caihong 5, cost millions of dollars to produce and can reach altitudes of only about 10km (6 miles), these new prototypes would cost “as little as a few hundred yuan.” They are small enough to fit inside a shoebox and weigh about as much as a football.
- Students attending Britain’s top public schools are 94 times more likely to join the highest ranks of society. That’s according to an analysis of Who’s Who by the London School of Economics (LSE).

The study analyzed how pupils from Britain’s nine top, fee-charging schools made it onto the country’s league of most influential people. It found that those attending Clarendon schools – including Eton, Westminster, Harrow and St Paul’s – account for just 0.15 percent of British pupils but 10 percent of Britain’s crème de la crème.
- Australia's system of political finance law is broken, open to exploitation and soft-corruption, a Senate inquiry has heard. 

"You can get a politician for $2000 a year, a party for $100,000 a year and policy for $200,000 a year," Monash University academic Charles Livingstone said in Melbourne on Thursday.  

Friday, December 29, 2017

Android App Inventor Setup Issues, Random Stuff, and More

- I've obviously been around at alternative Android development platforms for a while and have a number of posts on this area. This is a continuation of such research:
- as I said previously there aren't that many that are 'completely and genuinely free' anymore. Closest I could get to were variants/modifications of App Inventor... There are also some interesting libraries that offer cross platform development as well such as Rubymotion, Basic4Android, Kivy, Renpy, etc... Look deeper and you'll realise that once again toolchain setup let alone long term usage may be very problematic (see below and in my other posts for further details)?
easy android development
xamarin free alternative
how to create an android app without coding
- for those who don't know the total number of offline options are actually diminishing over time. Many have migrated towards 'Cloud' style operations...
how to create an android app offline
android app maker offline
open source version basic4android
- pricing models for a lot of platforms online vary drastically. Normally, prices converge over time though. It could simply be that they haven't reached that point yet?
- compilation and build progress varies drastically. Toolchain setup can be incredibly frustrating if you've ever had to deal with this... Frameworks flexibility and capability enormously problematic
- App Inventor is the best known and most online stores have a variation of it in some way?
app inventor
- there are versions of the software for all platforms basically. 'Classic' version still available online
- documentation is somewhat of a problem... It's up and down in terms of quality
- following code will get you the book in question...
for i in $(lynx -dump "http://www.appinventor.org/book2" | grep "bookChapters" | sed -r 's/^.* h/h/g')
  wget -c "$i"
app inventor pdf documentation
- I had a very frustrating problem during installation/setup with no mentions of any solutions being metioned online? Errors regarding 'Java, svchost.exe' and 'android app inventor "error 404: not found" index.html', 'appinventor 404 720 error', 'address already in use ai2u 8888', 'App Inventor Offline version causes error 404'. Tried safe mode, shutting down services, switching browsers, termininating various processes, etc... Strange thing was that there was so little useful logging/diagnostic messages? If you've worked for any software vendor then you sort of realise what the problem is. The company makes the assumption that they've covered all bases or that their software is self explanatory. Yes, I had conflicts. I somehow also made the assumption that the login URL via browser (it doesn't work with Internet Explorer apparently, you'll need to resort to Firefox, Chrome, Opera, etc...) in offline version was localhost:8004 as opposed to localhost:8888 since that was the window that is last left open (and maximised). Only when I looked through all windows that I saw the flaw... See next for more details
App Inventor Offline version causes error 404
I can't connect without any method(WIFI, USB, Emulator)
App Inventor 2 on Ubuntu 14.04 (64bit) runs, but connecting gives 404 error
- did some troubleshooting. Logging/diagnostics isn't that great. Apparently, under some circumstances things don't redirect the way they're supposed to? None of my browsers were re-directing properly in spite of me online instructions telling me to go to localhost:8888 which led to a page which was asking for a username and password combination (I thought I actually had to setup a mail server to receive the new account setup mechanism at one point). Had to read through code of login.jsp to find proper URL which is Multiple times now, I've found 'genuine bugs' in Google software (whether online or offline. Direct connection or strong association), documentation has tended to be sub-standard/outdated, they often try to 'cover bugs up' (never acknowledge. Fix things under the table especially if a new release is what causes the issue), etc... Can be frustrating dealing with them at times (depends on who you end up with at times. A lot of their work seems to be 'outsourced' even in areas you wouldn't expect?)?
default login is
username is test@example.com
Hit 'Log In' button and you're in
app inventor debian setup
nohup /home/moxalt/App-Inventor/appengine-java-sdk-1.9.27/bin/dev_appserver.sh –port=8888 –address= /home/moxalt/App-Inventor/appinventor-sources/appinventor/appengine/build/war/ > serverlog.out &
cd /home/moxalt/App-Inventor/appinventor-sources/appinventor/buildserver
nohup ant RunLocalBuildServer > ../../buildserver-log.out & 
App Inventor Install on Windows not working
saved aia from website to computer
App Inventor Offline version causes error 404
Setup a Local Only Email Server (Windows Only)
- there are sample projects online but to be honest I think you're best bet is to just play around a bit...
sample projects appinventor
appinventor templates
ppinventor aia templates
app inventor template library
download app inventor project files
- if you're switching from App Inventor Classic to App Inventor 2 then there are conversion utilities online... There are no guarantees of perfect conversion though...
AI1 to AI2 Converter (Version 1.2)
- this apparently converts App Inventor code into native Java code. Haven't tried it yet...
- I've been wondering whether it's possible to build a cryptocurrency via App Inventor. Technically, you can't directly but by using a Java Bridge you should be able to...
cryptocurrency app inventor
Explore Digital Wallet, App Development, and more!
cryptocurrency java implementation
- use the following code to more easily get at the code in question (as opposed to manually downloading each file. Most download managers are 'too simple' to deal with this...)
for i in $(lynx -dump "https://sourceforge.net/projects/puravidaapps/files/" | grep -ie "\.aia" -ie "\.aix" -ie "\.md" | grep "https" | grep "download" | sed -r 's/ [0-9]+\. h/h/'); do wget  --content-disposition "$i"; done
for i in $(lynx -dump "http://www.appinventor.org/starterApps" | grep "\.aia" | grep starterApps | sed -r 's/  [0-9]+\. h/h/'); do wget -c "$i"; done
for i in $(lynx -dump "https://sourceforge.net/projects/released/files/AppyBuilder/" | grep "https://sourceforge.net/projects/released/files/" | grep "download" | grep -e aix -e apk -e mp4 -e aia -e csv | sed -r 's/^.*http/http/'); do wget -c --content-disposition "$i"; done
for i in $(lynx -dump "https://sourceforge.net/projects/released/files/?source=directory" | grep "https://sourceforge.net/projects/released/files/" | grep "download" | grep -e aix -e apk -e mp4 -e aia -e csv | sed -r 's/^.*http/http/'); do  wget -c --content-disposition "$i"; done
- App Inventor itself sort of limits you in terms of the complexity of the type of applications that you can ultimately pursue. That said for most user land applications this shouldn't be a problem?
most complex app inventor application

Random Stuff:
- as usual thanks to all of the individuals and groups who purchase and use my goods and services
- latest in science and technology
- latest in finance and politics
- the nature of defense and intelligence is hilarious at times. We shall watch you while you build up the military strength to crush us? That will change your mind so there! LOL
- latest in defense and intelligence
- latest in animal news
- latest in music and entertainment

Random Quotes:
- "Opportunities exist in the areas most people complain," he added.

"We have to make sure that everybody is connected."
- “Moscow has been offering to sell arms to us since the mid-1990s and they are willing to barter guns for bananas,” he said, adding that Russia was selling fighters, helicopters and submarines to the Philippines. 
- In a video released by the North Korean government website Uriminzokkiri in July, Jeon Hye-sung said she was told to “slander and speak ill” of North Korea, criticising the Kim Jong-un regime against her will on South Korean television.

“I viciously slandered and spoke ill of the DPRK as I was told to,” Jeon said.

She went by the name Lim Ji-Jihyun in South Korea, but claims in the video that was an alias.

“I went to the South, led by fantasy that I could eat well and make a lot of money.

“But in the country where everything is judged by money, I was haunted by physical and psychological pain although I worked my butt off at bars and other places,” she said.

“Now I’m in the motherland, staying with my parents in Anju, South Pyongan Province.”

However that video came amid reports she was kidnapped and forced to return to the totalitarian state.
- “We cannot solve this problem only through prayers,” he said at the time. “I am a Buddhist and I believe in praying. But humans have created this problem, and now we are asking God to solve it. It is illogical. God would say, solve it yourself because you created it in the first place.”

He cited the excessive violence of the 20th century, expressing concern it was spilling over into the 21st. “The twentieth century was a violent one, and more than 200 million people died due to wars and other conflicts. We now see a spillover of the previous century’s bloodshed in this century.”

“If we emphasize more on nonviolence and harmony, we can herald a new beginning,” he also said, cautioning against failing to work toward this ideal:

“Unless we make serious attempts to achieve peace, we will continue to see a replay of the mayhem humanity experienced in the 20th century.” 
- Glyphosate is the world's most widely used herbicide. In Germany alone, farmers treat about 40 percent of arable land with it.

The herbicide, marketed by Monsanto under the brand name RoundUp, is a powerful tool in modern agriculture — it's very effective in killing weeds, thus saving farmers a lot of time.

Before sowing, farmers spray glyphosate on their fields to kill unwanted vegetation. Plants absorb the poison via their stems and leaves, and then die.

Especially controversial is when farmers apply the herbicide in preparation for harvesting. This kills all weeds, allowing only the crops to survive. This makes the harvesting process simpler.

Without glyphosate, farmers would need to manually till their land to remove weeds. That would catapult them back into agricultural methods of the 1970s and 1980s, said Michael Lohse, a spokesman of the German Farming Association.

"Glyphosate enabled the revolutionary step to non-plough tillage — which saves time, protects the groundwater and avoids soil erosion," Lohse told DW. "A ban would mean a competitive disadvantage for European farmers compared to farmers in, let's say, South America who are still allowed to use it."

Yet, the German Farming Association is aware of fears that glyphosate may cause cancer, and says it's also in the farmers' interest to clarify possible health threats.

A 2015 study from the World Health Organization's (WHO) International Agency for Research on Cancer found that glyphosate was "probably carcinogenic." But the next year, the European Food Safety Authority and the European Chemicals Agency said the substance was not likely to cause cancer in humans. 

The studies used two different approaches, and their results — and sources — continue to be debated.

But right now, Lohse doesn't see any alternative. "There's no other herbicide that is as effective as glyphosate. Farmers would need to use a mix of other herbicides — and who knows whether that would be any better," he added.
- GEN was founded by Sherrie Caltagirone, who told iTWire the threat intelligence and security community is a small one. Caltagirone knew Monzy Merza, Splunk's director of Cyber Research and Chief Security Evangelist, who was working with Splunk Pledge's Corey Marshall to identify the right partner for Splunk's non-profit commitment. "Not just a partner, but the right partner," Caltagirone says, "someone doing something tangible."

Thus, GEN signed up with Splunk Pledge for education credits, expertise and licensing. "We hit the ground running," Caltagirone says. "We brainstormed, flew out to Seattle and put the plan together."

GEN describes itself as the global clearing house for trafficking intelligence, and its mission as facilitating communication and technology-sharing initiatives between anti-trafficking organisations.

Specifically, GEN collects data from the open Web, the deep and dark Webs, and anywhere it thinks trafficking is happening in all its many forms. The organisation looks to find patterns in the data - perhaps the same phone number appearing at the same time in different places, or maybe where a dark web screen name is used on public Internet social sites. All of this effort works towards GEN's mission – to identify and rescue every victim, to identify and stop every trafficker.
- American security firm McAfee has said it will no longer allow source code reviews by foreign governments, becoming the second US security firm to make such an announcement this month.

Reuters reported that the McAfee move came as experts warned that the practice could be used by other countries to carry out attacks. Symantec made a similar announcement in the second week of October.

In June, a report said that McAfee was among several Western companies that had allowed Russia to inspect its source code as it strove to improve sales in the country.

Earlier this month, as iTWire reported, HPE was revealed to have allowed the inspection of the source code for ArcSight — which is now owned by British mainframe company Micro Focus — because it wanted to sell the product in Russia.

Prior to that, Microsoft, had to allow China to inspect the source code of Windows, a process that took two years, before it was allowed to craft a product — Windows 10 China Government Edition — that could be sold to the Chinese public sector.

Reuters quoted a McAfee spokesperson as saying: “The new McAfee has defined all its own new processes, reflecting business, competitive and threat landscapes unique to our space. This decision is a result of this transition effort.”

McAfee stopped the practice of allowing source code reviews after it was spun off recently as an independent entity, after being an integral part of Intel.

Russian security firm Kaspersky Lab has been under the gun in the US, with its products banned from being used by the public sector despite offering its source code for inspection by independent third parties.
"I get the most joy by looking outside every day and seeing God's creation, maybe a little bit from his perspective," Bresnik said, adding that the visible thinness of the planet's atmosphere showed how fragile life on Earth is.

Nespoli - on his third trip into space - said that despite the bird's eye view of Earth he remained perplexed. "Our aim here is to spread knowledge, (but) the more we learn, the more we realize we do not know."

"I would like people like you, theologians, philosophers, poets, writers, to come to space to explore what it means to be a human in space," Nespoli went on.

Francis nodded and smiled in response, after a 30-second delay.

Far from wars, famines, pollution or human folly, Nespoli said: "The future of humanity looks better from up here." He added that he was ill-equipped to reflect on the destiny of humanity.

He then thanked the pope for "making us think about things that are bigger than us."

Automated Audiobook Maker Script, Random Stuff, and More

- wanted to find a way to automated building of audiobooks. Built the following: https://sites.google.com/site/dtbnguyen/audiobook_maker-...