Thursday, March 24, 2016

15TB SSD from Samsung, 2,000,000 IOPS


Samsung’s monstrous 15TB SSD is now shipping | Ars Technica

"Samsung has announced that it is now shipping its PM1633a SSD...isn't just the biggest SSD around, it's straight-up the biggest drive around. At 15.36TB, it dwarfs other SSDs and surpasses the capacity even of the very latest magnetic spinning disks. Remarkably, it packs all this storage into a conventional 2.5-inch package."

Samsung unveils 2.5-inch 16TB SSD: The world’s largest hard drive | Ars Technica

"At the Flash Memory Summit, as reported by Golem.de, Samsung showed off a server with 48 of these new SSDs, with a total storage capacity of 768 terabytes and performance rated at 2,000,000 IOPS (input/output operations per second). By comparison, the consumer-grade SSD that you have in your PC is probably capable of around 10,000-90,000 IOPS, depending on the workload.
...
Today, an enterprise-grade 1TB SSD will cost you about £600 or $1,000; an enterprise-grade helium-filled 8TB hard drive from HGST costs about £400 or $700."



IOPS - Wikipedia, the free encyclopedia
7,200 rpm SATA drivesHDD~75-100 IOPS[2]SATA 3 Gbit/s
Samsung SSD 850 PROSSD100,000 read IOPS
90,000 write IOPS[19]
SATA 6 Gbit/s
Fusion-io ioDrive2SSDUp to 9,608,000 IOPS[48]PCIe
EMC DSSD D5FlashUp to 10 million IOPS [50]PCIe Out of Box, up to 48 clients with high availability.

ScottGu's Blog - Announcing the Biggest VM Sizes Available in the Cloud: New Azure GS-VM Series

Standard_GS5: 32 cores,  448 GB RAM,  80,000 IOPS, 2,000 MB/sec


==class: Learning How to Learn

Learning how to learn | Barbara Oakley | TEDxOaklandUniversity - YouTube

Learning How to Learn: Powerful mental tools to help you master tough subjects - University of California, San Diego | Coursera

"This course gives you easy access to the invaluable learning techniques used by experts in art, music, literature, math, science, sports, and many other disciplines. We’ll learn about the how the brain uses two very different learning modes and how it encapsulates (“chunks”) information. We’ll also cover illusions of learning, memory techniques, dealing with procrastination, and best practices shown by research to be most effective in helping you master tough subjects. Using these approaches, no matter what your skill levels in topics you would like to master, you can change your thinking and change your life."

The Most Popular Online Course Teaches You to Learn - The New York Times
"With 1,192,697 students enrolled since the course was created last year, “Learning How to Learn,” which is offered by the University of California through Coursera, an online learning company which has partnered with a number of universities, has narrowly edged out the more tightly focused course, “Machine Learning,” taught by Stanford University professor Andrew Ng, which currently has 1,122,031 students enrolled."


Dr. Barbara Oakley - University of California, San Diego | Coursera



... procrastination... studies have shown that if you look at something you
don't like, the pain centers of your brain actually activate
.
... 
And so in some sense, procrastination can actually be a little bit like an addiction.
You do it once, you do it twice-- it's not that big a deal.
You do it a lot of times, though, and it actually can be very, very detrimental for your life.

... the most effective way to help you deal with procrastination... Pomodoro Technique.
... recommends you set a timer for 25 minutes...and then you turn off everything else.
...And then you work with as careful a focused attention as you can for those 25 minutes.
... focusing on the task and the time, and not the pain of "I must complete this task," 
it somehow makes it so much easier to do... And then when you're done, you reward yourself.
And that reward is actually very important.. relax, and enjoy, and do something different.

...Because we know that some aspects of learning take place during this relaxed process"


home page: Barbara Oakley

book: BARBARA OAKLEY- A Mind For Numbers

10 Rules of Good and Bad Studying Updated By Barbara Oakley
  1. Use recall. After you read a page, look away and recall the main ideas
  2. Test yourself. On everything. All the time. 
  3. Chunk your problems. After you solve a problem, rehearse it.
  4. Space your repetition.
  5. Alternate different problem‐solving techniques during your practice
  6. Take breaks
  7. Use explanatory questioning and simple analogies.
  8. Focus. Turn off all interrupting
  9. Eat your frogs first. Do the hardest thing earliest in the day
  10. Make a mental contrast
book review: A Mind for Numbers | Brian Johnson


Interview: Learning How to Learn with Barbara Oakley - YouTube

Blast Away Procrastination with the Pomodoro Technique

"The Pomodoro Technique starts with a 25-minute interval of work...Once the 25 minutes is up, you take a 5-minute break. The break is meant to be away from the work entirely"
11


Explore the Brain and Mind - BrainFacts.org by Dr. Terrence Sejnowski

How the brain learns (many links)

Some notes from class:

Thinking modes 
"how brain works", "pinball machine analogy/metaphor".
  • Focused: 
    • familiar patterns, matching with known related 
    • blocking new patterns
  • Diffused
    • relaxed, neural resting, broad thinking, big picture perspective
    • when you need to find a new pattern
For learning, need to do a little work every day, to build "neuro-scaffold" for thinking
Brain is switching between modes, can't be in both at the same time.
Learning: creating and reinforcing synapses connections between neurons, changing structure of the brain. Sleep is essential for learning.

Chunking
  • "chunks": compact packages of information, that the mind can easily access
    it is enough to get main idea, "the chunk" 
  • "illusion of competence in learning" when just reading / viewing material without testing or recall
  • "overlearning": sometimes ineffective, spending too much time
  • "interleaving": intelligent switching between subjects
How to form a Chunk:
grasp bits o knowledge, skills, "mini chunks" that letter join to form larger chunks, more complex skills. Learning "bit by bit", starting from sample problems and workouts with solutions. It is important to focus on connections between the steps:
  1. Focus undivided attention on information trying to learn 
  2. Understand the basic idea; understanding is like a supper-glue holding memory together
    without understanding chunks are mostly useless, since they can't relate to other material
    Just understanding is not enough; need to review/test soon after learning to reinforce.
    Only doing something yourself creates neural patterns for mastery of a subject. 
  3. Gaining context, lean not just "how" but also "when" to use and not to use the chunk.
    Repeating and practicing in related and unrelated problems. 
    • bottom up learning (practice and repetition)
    • top down (big picture) learning
Avoid "illusions of competence"
Importance of recall, mini-testing, and making mistakes
  • re-reading is much less productive that recall (look away and see what you remembered) and practicing and testing. 
  • drawing concept maps is also found not to be as effective as recall and practice
    since basic chunks is not well established
  • retrieval process itself enhances deep learning, help in forming of chunks,
    building "neural hooks" 
  • 4 slots in working memory; chunks take less space
  • "you" need to practice, not to just recognize somebody else's solution 
  • highlighting and underlining must be minimized 
  • notes and words on margin and very useful 
  • testing is the best way to avoid illusion of competence 
  • mistakes are very valuable for learning, to repair thinking errors
  • useful to recall outside of the typical environment 
Bigger Picture
When you are interesting in something learning is easy. Why?
Neuro-modulators: chemicals that carry information about importance and value for the future
  • Acetylcholine: for focused learning, paying close attention,
    leading to new long term memory
  • Dopamine: controls motivation; reward learning; in basal ganglia;
    released when we receive unexpected reward; predicting future rewards;
    addictive drugs artificially increase dopamine activity, leading to craving and dependance
    lack of dopamine leads to rigidity, parkinson disease 
  • Seratonin: affects social life; alpha males have the most; prosaic drug increases it;
    lower level of seratonin leads to risk taking behavior; 
Motions are also strongly affecting learning;  "amygdala" part of the brain where motion and cognition are integrated; part of limbic system for processing memory and decision making, and regulating emotional reactions

Library of chunks
"Chunks" are pieces of information bound together through use and meaning;
essential for effective learning: a way to compress information;
experts in various fields develop a large "libraries" of chunks (neural patterns) for effective problem solving. It it necessary to practice with new "chunks" otherwise they faint and disappear.

Chunks are best developed by focused attention, understanding and practice.
"Recall" is very effective, remember the single point without looking at the page;
building "neuro-hooks" to better understand the material; help to recall in different places;
Minimize highlighting, that can fool you into illusion of learning.

"Transfer" is using chunks in understanding new concepts in a different similar domain.

Solving problems techniques:
  • Sequential reasoning: step by step, focused mode
  • Holistic intuition: creative diffused mode; good for solving difficult concepts, new ideas;
    should be carefully verified by using focused mode; "intuitive" insights are not always correct. 
Law of Serendipity: "Lady Luck favors the one who tries"
after the first concept, the second and third concept comes more easily
Just pick one tiny thing to learn, and then another, and another. Just keep trying. 
  • Overlearning: Studying oven and over again is useful for "automaticity" that can be helpful, but is a waste in single learning session; repeating what you already know
    can lead to "illusion of competence" when you have only mastered "easy stuff";
    instead, deliberately focus on what you find more difficult: "deliberate practice"
    very useful: mini-test yourself frequently, to verify you are learning the material
  • Eistellung (German word for Mindset) initial idea, thought, may prevent a better idea or solution to be found; to avoid jump to focused mode use diffused mode, to "unlearn" older wrong ideas.
  • Choking: "jumping to water before learning how to swim"
  • Interleaving: mastering a new subject requires not only creating chunks but also select and use different chunks. The best way to jump between different situations that require mixing different strategies. Learn not only "how" but also "when" to use a technique. 
Procrastination
Good learning requires long term effort by spacing. Instant cramming does not build solid memory.
So postponing is a significant issue since it reduces available time to learn of effective pace.
Procrastination is similar to addiction, feels good on short term and can be devastating on long term.
Willpower is a limited resource, so that is not an effective method to deal with procrastination.
Good habits are the best strategy to deal with procrastination.
The advantage of habits is that they do not require conscious thinking, so they save energy.
Habits can be good or bad. They include 4 parts
  1. The Cue: a trigger
  2. The Routine: "zombie mode", habitual response to the cue
  3. The Reward: immediate feeling of pleasure
  4. The Belief: habits have power because you believe in them
It is perfectly normal to have a few negative feelings about learning session.
Solution: "focus on process, not on product":
i.e. spend 20 minutes working, put the best effort for a short period, "flow of work".
Note: this is common misunderstanding with pomodoro technique:
should focus not on "task" but "interval" of 25 minutes.
Process allows you to do unpleasant things that need to be done.

Habits
are useful since it is much easier to focus on process.
Building good habits by changing reaction to a cue.
  • Cues categories: location, time, how you feel, reactions
    Avoid damaging habits by preventing cues, distractions (just let them flow away)
  • Key for re-wiring routine is to have a plan, a new ritual. 
  • Reward could be substituted by sense of accomplishing something, even small, or some desired thing, to create sense of craving: expectation that help establish new habits.
    The better you become in something the more enjoyable it becomes.  
  • Belief that you can do it is the most important. Community can help. 
Effective learning: weekly list of key tasks => daily to-do task list evening before. 
That helps subconscious mind to figure out how to accomplish them.
Task list is freeing working memory. Keep journal on what works and what does not.
Important to plan stop time also.
"Eat your frog": do most difficult task first in the morning, at least one pomodoro.

Memory
Humans have outstanding "visual-spatial" (space-related) memory system,
for retaining general info about a place. That is result of evolution and environment.
("where things are and how they look")
Images connect directly to visual-spatial centers in brain, "neural hooks"
The funnier images the better, to be registered in temporary memory.
To store in long term memory need to: be memorable, and repeated.
Repeat sporadically over several days, i.e. by index cards, write by hand, on both sides.
Anki - powerful, intelligent flashcards

There are short term (working) and long term memory.
Brain part hippocampus is related to learning and memory of facts and events.
Process of storing to cortex is called "memory consolidation" could take many years.
Memories are not fixed, they keep changing all of the time.
On every recalling of memory it changes, by "reconsolidation" (during sleep).
By this process it is even possible to implant false memories.
Reinstated memory is in a new context, and could also be saved to long term.
As we learn new things our old memories also change.
Spaced repetition reinforces memory.

The function of memory reconsolidation as a function of time | Human Frontier Science Program

Besides neurons there are supporting "glial" cells: astrocyte (supply nutrients, repairs, learning)
Einstein had more astrocytes than average.

"Tricks" to enhance memory: create meaningful groups to simplify, i.e. acronyms,
or associating numbers with memorable events, or memorable sentences.
"Memory palace" technique: i.e. visually associate layout of known house to concepts to remember unrelated items. Improves with practice. Exercise in creativity, helps learning and understanding.

Method of loci - Wikipedia, the free encyclopedia
"memory palace or mind palace technique, it is a method of memory enhancement which uses visualization to organize and recall information"
How to Improve Your Memory with the Memory Palace Technique - YouTube

Renaissance Learning and Unlocking Your Potential
To become a better learner (based on brain scicence):
  • Exercise: new neurons are born every day, and used for learning;
    if not used for new experiences new neurons will die. 
  • "Practice makes perfect" but only when the brain is prepared;
    • "prefrontal cortex", maturing in early adulthood":
      social behavior, complex analysis, making decisions, planning
    • "visual cortex", maturing in childhood
Techniques:
  • learn using metaphor and analogy: the more visual the better; stories help;
    metaphors "glue an idea to the mind" by connecting to existing structures
  • work profitably with teammates
  • perform well on tests
Progress in learning: not linear; occasional "restructuring"; takes time to assimilate new knowledge
Using "chunks" to represent complex concepts in a simpler way.
People learn by trying to make sense of the information they perceive.
Once learned, concepts (libraries of chunks) become well trained intuition. 
Intelligence matters; larger memory helps, but it also makes it more difficult to be creative. 
"Deliberate practice" can help lift average brains to compare with "natural gifts"
"Imposter syndrome": feeling of inadequacy, common in people
Some parts of brain don't finish development at different times for different people. 
Teenage: wiring between intention and control area in brain is not completely formed. 
Practice, using brain, help strengthen and reinforce connections between brain regions.
We can make significant changes in the brain by changing how we think. 
"Perseverance": the virtue of the less brilliant, ability to admit errors. 
Learning on your own, finding fresh paths; most important: taking responsibility for own learning, unique path to mastery. Each material (book, video) is a partial version (2D) of full (3D) reality of the subject. 
Social environment: a challenge; the more you achieve, the more people feel threatened, criticize. 
Empathy is not universally beneficial; sometimes need to "tune some people out".
Not everyone is naturally compassionate,  some people don't want to help. 

Avoiding overconfidence; brain hemispheres:
  • Left ("interpret the world", try not to change): "focused mode", analytical;
    + rigidity, dogmatism, egocentricity
  • Right ("reality check", big picture): "diffused mode", creativity
    + step back and verify
Quote: "The first principle is that you must not fool yourself - and you are the easiest person to fool" - Richard Feynman, Nobel Prize winning physicist. 

One of best way to catch blindspots is to brainstorm, work and study with others.
While study groups can be very useful, if study sessions become socializing, all bets are off.

Testing is an extraordinary powerful learning experience, including mini-tests,
reinforcing recall, "concentrating the mind"
Testing is much more effective usage of time than just studying.

Test checklist by Richard Felder:
  • make a serious effort to understand the text
  • work with classmates on homework problems or check solutions with others
  • attempt to outline every homework problem solution
  • participate actively in homework group discussions
  • consult with the instructor
  • understand all homework problem solutions
  • ask in class for explanations of problem solutions unclear to you
  • use a study guide
  • outline lots of problem solutions quickly
  • go over study guide and quiz one another
  • attend a review session
  • reasonable night sleep before the test
Hard Start - Jump to Easy technique (for tests)
(usually wrong) idea: by the time you can tackle easy problem you will be confident in handling more difficult problems. This works for some people, but not for most people. 

Solution: start with hardest problems and quickly jump to easy ones. 
This way you initiate diffused mode for handling hard problems, avoid getting stuck. 

Efficient,  since it allows different parts of the brain to work simultaneously.


Helpful Hints for Tests
body "cortisol" chemical is reaction to stress, causing sweaty palms, racing hard, a knot of stomach.
Interpretation of stress makes all the difference: afraid (can't do it) => excited (do my best) 
Good technique: turn attention to your breathing from stomach, slow, relax,
counter "fight or flight" response that fuels anxiety. Practice breathing before the test.
Especially helpful: deliberately move to a deep breathing pattern.
  • Cover up the answers and try to recall answers on your own first
  • Try test in similar conditions as real test
  • Face your fears; have a "plan B" that can help subside the fear
  • Study hard, and then "let it go"
  • "Good worry": motivation and focus; "Bad worry": wastes energy
  • Day before the test have a quick look on material, don't push too hard. 
  • On the test, shift attention and then double-check answers from big picture perspective. 
  • Do checking in reverse order, to get fresh perspective
"Change your thoughts, change your life"
Enhancing neural structure by practicing thoughts that use those neurons.
Use whole brain, to double-check if answers make sense, avoid overconfidence.

Reading: Renaissance Learning and Unlocking Your Potential | Coursera

Richard Felder: Resources in Science and Engineering Education
Felder-Brent: Teaching and Learning STEM

The Secret to Good Writing: It's About Objects, Not Ideas - The Atlantic
Readable Writing | "Clear writing is a teachable style." –John G. Maguire