This Week I Learned - 2017 Week 38

The usual stuff or last week post.

Long weekend holidays. More rest and clean up.


Fluff in Scientific Writing by Celia M. Elliott (PDF). Right, I definitely write in a fluff way. Awareness is the first step to improve your own writing.


So you have a pair of passive speaker. What now? The next step is to get a DAC and an amplifier. Or you can get a Class-T amplifier with build-in USB DAC and headphone amplifier combo like Topping TP30-MARK2. The USB DAC let the amplifier serves as an external sound card so you can channel out the sound from your PC through the USB.

As I learned in the last week post, the quality of any amplifier is the whole sum of its electronic components, especially the amplifier chip and capacitors. Screenshot below illustrates the PCB board and its components. Unfortunately, the amplifier chip is Tripath TA2024, which push about 15 watts per channel, a bit lacking for bookshelf speakers.



SMSL SA-36A PRO, while it's a affordable and quality amplifier, has two different versions. To save cost, the manufacturer have switch the amplifier chip from Texas Instrument TPA3118D2DAP to STMicroelectronics TDA7492PE. The general consensus from the reviews and forum discussions recommended to get the TPA3118 version. Maybe the SMSL get a better pricing from STMicroelectornics or Texas Instrument cannot keep up with the demands. This also reminded me of certain manufacturer which produced quality and affordable first generation of said product to get good rave reviews and slowly replace with cheaper components for next generation.

Unfortunately, SMSL SA-50 is currently out of stock and I can't find it in the SMSL website. Maybe SMSL decided to phase it out from the market? What about SMSL SA-60? It's not shown in the official website as well.


Neurochome's LM3886 done right? The correct amplifier design compare to others like Circuit Basics or Electronics Lab. I believed Tom Christiansen's experiences at Texas Instrument allows him to design the most optimized audio amplifier using TI LM3886 amplifier chip.


YouTuber FFcossag channel is what I consider good review, teardown, and educational on a particular amplifier. Good example was how he evaluated through the specification of Breeze Audio TPA3116 as shown below. Even better, his videos are in public domain! While we need to absorb and digest large unknown information, his does provides a quantitative (objective) rather than qualitative (subjective) analysis of an amplifier. Sometimes, it sounds nice to the reviewer is a personal taste.



While we're on Breeze Audio. Be extra careful when you plug in the power supply. One reviewer, NFM popped and burned one of the capacitor while testing it. Luckily he was protected by the aluminum case. Be extra careful with all these low end amplifier, supply lower power to the amplifier or you switch the capacitors to a higher voltages type. It does raises quite a lot of safely concerns with all these low cost amplifiers (no quality control, cheap or cloned electronic components) from China.




FFcossag also provides another excellent objective review on popular Lepai LP-2020A+. See video below. While the amplifier is way under-power compare to what the manufacturer claimed in the spec sheet, it's still value for performance worthy amplifier. However, the same problem exists. You can't bloody get this amplifier in MY and have to try your luck sourcing it from China.



Similarly, he also trashed the Lvpin LP-838 and make the consumer aware of what are they getting of buying a cheap amplifier. To save cost, certain manufacturer will reuse or recycle certain components. Is it safe? Hard to tell but it certainly does not increases any confident (more on this later) in using the product. Be an informed buyer, buy from reputable dealer and brands.


Coursera - Writing in the Sciences - Week 2

Continue with week 2 study. Notes as follows.

2.1: Use the active voice
An active voice is a type of sentence that follows a format of subject-verb-object. Or it's the way we normally talk. Example as shown below.
She (agent) throws (verb) the ball (the recipient).

For passive voice, is the reverse which follows a format of object-verb-subject. Rewriting the above sentence as passive voice.
The ball (recipient) was thrown (verb) by her (agent).

Alternatively, we also can remove the agent. The sentence below does not tell us who throw the ball.
The ball (recipient) was thrown (verb).

Passive voice is useful when we're want to exclude the recipient. Good example is shown below where to evade any admission or person responsible.
Mistake was made.

How do we recognize a passive voice? Identify "to be" verbs in the sentence. "To be" verbs are weak and wordy and you can replace them with stronger verbs. List below shows the step-by-step guide to eliminate "to be" verbs.

(1) Identify
(2) Substitude
(3) Convert
(4) Change
(5) Combine

The restaurant’s parking lot (is) narrow.
(There are) not very many parking spaces and those (that are) available (are) too cramped.

Vs.
The restaurant (suffers) from a narrow parking lot with only a few cramped spaces.

To convert a passive voice to active voice, ask yourself this question. "Who does what to whom?"

Active voice have several advantages as listed below.

(1) Emphasis author responsibility.
Why passive voice is prevalent in scientific papers? Because first-person pronouns (I/We) usages should be kept to a minimum. In method section of your paper, you're encourage to use passive voice as what have been done is far more important that who done it. APA (The American Psychology Association) have different opinions on this. More on this in next module.

(2) Improves readability.
I like the example below because it shows we can skip first-person pronouns.

A strong correlation (was found) between use of the passive voice and other sins of writing.

Vs.
(We found) a strong correlation between use of the passive voice and other sins of writing.

Vs.
(Use of the passive voice) strongly correlated with other sins of writing.

(3) Reduces ambiguity.

2.2: Is it really OK to use "We" and "I"
Is using personal pronouns like I/We in scientific writing acceptable? Based on her explanation, it's okay to do so although some said not using personal pronouns make your writing more objective.

However, different journal have different opinions on using personal pronouns. Check the publication style guides you are submitting to and follow its guidelines. For example, the style guide of Science Magazine recommends:

Use active voice when suitable, particularly when necessary for correct syntax 
(e.g., "To address this possibility, we constructed a λZap library . . .," 
not "To address this possibility, a λZap library was constructed . . .").

Note to self. Do search and read up these style guides. Start with the The Element of Style that you've bought few months back.

2.3: Active voice practice
Some practices on converting paragraphs from passive voice to active voice. Pretty much quite straight forward. One of the key or first step is to recognize passive voice is to find these keywords : be, is, are, a, was, were, has been, have been, will be, and being.

2.4: Write with verbs

We must follow three rules.

(1) Use strong verbs.
When you have limited vocabulary, your writing is boring. One way is to expand your vocabulary. But how? Read a lot, really a lot. I like this approach of treating every read is a write to expand your vocabulary. The example shown in the lecture exemplified this point. Pay attention to the verb. Compare the verbs. See how using strong verbs change the tone of the sentence.

Note to self: Expand your vocabulary. Read and write more.

Before:
"Loud music (came) from speakers embedded in the walls, and 
the entire arena (moved) as the hungry crowd (got) to its feet."

After:

"Loud music (exploded) from speakers embedded in the walls, and 
the entire arena (shook) as the hungry crowd (leaped) to its feet."

One good way is to identify and underline all the "to be" verbs like is, are, was, were, has, been, am, and others and replace with with stronger and more vivid verbs. Example of boring usage of "to be" verbs as shown.
"She is an excellent scientist. Her research is top notch. Her experimental
technique is also beyond compare."

(2) Avoid turning verbs into nouns.
Again, another example where I always use in my writing. Using nouns instead of verbs. Why using now is not recommended? It lack the impact of using a verb and may lead to ambiguity.

Let's start with the example given.

Before:
"During DNA damage, (recognition) of protein one by protein two results in (recruitment) 
of protein three and (repression) of cell proliferation genes."

After:
"During DNA damage, protein one (recruits) protein two and protein three, which together 
(repress) cell proliferation genes."

(3) Don't bury the main verb.
Another good example here where the subject and the main verb (predicate) close together.

Before:
"(One study of 930 adults with multiple sclerosis (MS) receiving care and one of two 
managed care settings or in a fee-for-service setting) (subject) (found that) (predicate) only 
two-thirds of those needing to contact a neurologist for an MS-related problem in the prior 6 
months had done so."

After:
"One study (found that), of 930 adults with multiple sclerosis (MS) who were receiving 
care in one of two managed care settings or in a fee for service setting, only two-thirds of those 
needing to contact a neurologist for an MS-related problem in the prior six months had done so."

2.5: Practice examples
A few rules while going through these examples.

(1) Don't use long subject
(2) Don't use buried, boring predicate and passive verb.
(3) Don't turn verb into noun.
(4) Don't use negatives words
(5) Don't use "hedge" words.
(6) Don't use "fluff" words. For example, very, important, and others.

Before:
(The (fear)(3) expressed by some teachers that students would (not learn)(4) statistics 
well if they were permitted to use canned computer programs)(1) (has (not been)(4) realized)(2). 
(A careful (monitoring)(3) of achievement levels before and after the introduction of computers 
in the teaching of our course)(1) (revealed)(2) no (appreciable)(5) change in students' performances"

After:
"Many teachers feared that the use of canned computer programs would prevent 
students from learning statistics. We monitored student achievement levels before and 
after the introduction of computers in our course and found no detriments in performance."

The whole exercise makes me want to pick any scientific papers out there and identify and issues and rewrite it. As I love to read papers, this should be quite an interesting writing exercise.

2.6: A few grammar tips
And I thought I was aware of these grammar rules.

(1) Data is plural.

(2) Affect and effect.
Yes, the RAVEN (Remember Affect Verb Effect Noun) rule is not entirely correct. We can use the word affect as a noun and the word effect as a verb.

(3) Compare to and compare with.
Compare to is used to compare similarities with different things.
Compare with is used to compare differences with similar things.

Examples:
The bike that is broken is in the garage. (one bike out of many bikes)
The bike, which is broken, is in the garage. (regarding one particular bike)

(4) That and which.
That is a restrictive pronoun.
Which is a nonrestrictive pronoun. Meaning that the word is optional and if you remove it, does not change the meaning of the sentence. Also, there is a comma, before the word.

Learning Objectives
(1) Distinguish between active and passive verbs.
When to use passive voice? When you're asking a questions!

(2) Practice writing with strong, active verbs.
As I was going through the week 2 course, I tends to write more in active voice rather than passive voice these days. Surprising to find that I use more passive voice than ever in my writing. While changes is inevitable, I still struggle to adapt to the new writing and constantly needs to remind myself to write in active voice.

(3) Fix sentences where the subject and predicate are too far apart.
Definitely something new for me and I don't even realize that.

(4) Correct specific grammar mistakes.
I can't remember what I've learned here.