Note from the nursery

Question: My 2.5 years old daughter don't follow the instructions at the nursery sometimes does that considered lack of focus?
When the nanny ask them to stand in a line to go to lunch sometimes my daughter stay standing and the nanny has to go back for her.
Although she's very smart she can count to 10 since 18 months she can tell the colors, shapes,and she memories sentences from the stories I read to her and she's emotionally healthy she express her feelings and recognize others feelings. Is that thing about the lunch line considered as a lack of focus? Thank you.
Comment: Can you be more precise in what way your daughter doesn't follow the instructions? Also, how elaborate are the instructions? For example, does she get a single instruction like "put your toys away, come stand in line and follow me to lunch" and your daughter gets distracted halfway through and forgets to move with the line?
Comment: The nanny ask all the children to stand in line so they go to have lunch,my daughter wouldn't follow them sometimes. It happened twice.
Comment: Twice for a three-year-old, and no other signs of trouble?  That seems like a "background noise" level of misbehavior for that age.  I wonder why the teachers are bringing that up--are you able to talk to them and find out if there are other signs of trouble that they are not mentioned in the note?
Comment: Many thanks for your answer, yes I talked to them and I asked them for other signs if there's any and they didn't mention anything else! I was surprised and I told them that we should follow up with each other and that we should speak next week and now I'm doing my research about this because I'm familiar with the children development and I read all the time to be a better parent my husband as well.My daughter count to 10 since 18 months she have a big vocabulary in Arabic and English she express her feelings very well she notices small details in the stories I read to her so I was upset
Comment: I want to speak to them next week after I finish my readings about this to be fair to my daughter and to understand why her teacher think that! My daughter know the shapes, colors, she's very good in music, she know animals with their voices, she know the solar system with an information about each planet.and much more I'm not kidding I was really upset and sad and I felt like they were unfair with her and I asked them not to discuss this in front of her, please I need your opinion all,my daughter is smart and normal I believe in her very much. Can you give me your feedback please.Many thanks
Answer: I have a hard time believing that a reasonable and reasonably trained teacher would call out your daughter's behavior as a lack of focus.
No 2.5yo has good focus, and the teacher should know that, because it's called childhood development.  All 2.5yo's should be expected to not notice things, forget things, bounce from one activity to another, and at times zone out and not respond to an adult's request, because this is what 2.5yo's do.
None of those behaviors are a result of a 2.5yo child trying to cause a problem.  Your daughter is simply being 2.5yo.
When my daughter had issues at daycare, the only way I was able to fully understand the situation was to visit the daycare and observe my daughter and how her teachers were interacting with her.
My daughter's daycare had a window from the hall into the classroom so I could watch without being in the room.   If you have to be in the room, a good way to observe is to pretend you're doing something on your phone, so that your daughter doesn't see you watching her.
My daughter needed extra supervision, and when I observed at my daughter's daycare it was clear that the teachers didn't understand the level of supervision that she needed, and I ended up pulling her out of daycare.
My daughter's teachers weren't bad, but uninformed, and not able to provide proper care for my daughter.
I would suggest that in addition to talking to the teachers, you visit your daughter's daycare to fully understand the situation.
Comment: Many thanks for your answer,yes I think I'll do this.

Note from the nursery


Moving an existing site to Mongo DB

Question: How hard is it to move a live site to mongoDB when its traffic hits high? Is it easy to built a Drupal site on it? How is the learning curve for a developer who is quite comfortable with Drupal7 and php.
Comment: See this nice article http://drupalconnect.com/blog/converting-existing-drupal-site-mongodb
Answer: I assume you're going to use the mongoDB module. This doesn't move the ENTIRE database over, just parts of it, like cache, blocks, watchdog, etc.
This works well because mongo, or any "document" oriented database is not great at relations. So you can move the data that is not very relational into mongoDB easily.
Mongo itself is cake. Easy to install, easy to understand. It's simply "JSON" data. If you don't know JSON, read up on it now. Already, many parts of Drupal's data are stored as JSON inside text fields in a regular SQL database such as MySQL.
I'd re-iterate that you probably don't want to move EVERYTHING over, like the nodes, taxonomy, etc. Those things are highly relational. Also, the mongoDB module doesn't support those for that reason.
Installation of the module is pretty straight forward and happens in settings.php. See the mongo module readme file for more info.
Comment: I've never used it, so I can't tell you for sure, but in theory it should work with ZERO problems on things like cache. They're simply rebuilt. Where data is more permanent, such as "Blocks", I'd assume you'd need to import the data into mongo somehow. The module might do this for you, I'm not sure. I think you'll probably just have to give it a go.
Comment: If you're looking for performance and your users are NOT authenticated then this should be pretty easy to acheive with Varnish. At least from the drupal side. You'll also want to make sure you have CDN for a media site. I'm sure you know this but I've run a few large drupal sites and the bottleneck was usually the CDN, not Drupal (for non-authenticated users, that is).
Comment: Will there be any serious changes you will have to do to your site? Or does the module automatically start using mongodb for your cache, block etc?
Comment: Sure. I will do that. I am going to work on a really huge media portal for a television channel with at least 50k hits per day. I believe I should think of this more seriously.
Answer: Fields on a live site can be migrated with drush to mongodb as per chx's post here https://drupal.org/node/1653202

Moving an existing site to Mongo DB


What's the color of the sahasrara chakra?

Question: In some sources, I read that the Sahasrara chakra is white, in others violet, and in others purple.
What is its color, and what's the meaning of the color?
Answer: Sahasrara Chakra is all coloured.

"mUlAdhArAdiShaTchakra.n shaktisthAnamudIritam.h | kaNThAdupari mUrdhAnta.n shAMbhava.n sthAnamuchyate |" (Varaha Upanishad 5:53).
"The six Chakras beginning with Muladhara are said to be the seat of Sakti (Goddess). From the neck to the top of the head is said to be the seat of Sambhu (Shiva)".

Through Pranayama, Kundalini uncoils herself in the Mooldhara Chakra and rises up in Sushuma Naadi (One of the nerves which passes through heart) with the help of Breath (Prana/wind) and Body heat produced during Yoga (Agni). At 1st, she pierces Brahma Granthi (Knot) near navel. Then Vishnu Knot near hear and after that Rudra Granthi near Throat and Reaches Sahasrara Chakra where Parama Shiva is residing. Thus, Shakti meets with Shiva in Sahasrara and the yogi gets liberation.
Yoga Kundalini Upanishad.:

ज्वलनाघातपवनाघातोरून्निद्रितोऽहिराट् । ब्रह्मग्रन्थिं ततो भित्त्वा विष्णुग्रन्थिं भिनत्त्यतः॥८५॥
रुद्रग्रन्थिं च भित्त्वैव कमलानि भिनत्ति षट् । सहस्रकमले शक्तिः शिवेन सह मोदते॥८६॥
सैवावस्था परा ज्ञेया सैव निर्वृतिकारिणी॥८७॥
1.85-87. From the blowing of Vayu and Agni, the chief (Kundalini) pierces open the Brahmagranthi and then Vishnugranthi. Then it pierces
Rudragranthi, after that, (all) the six lotuses (or plexuses). Then Sakti is happy with Shiva in Sahasrara Kamala (1000 lotuses seat or pineal gland). This should be known as the highest Avastha (state) and it alone is the giver of final beatitude (Moksha).

"prakR^ityashhTakaruupa.n cha sthaana.n gachchhati kuNDalii | kroDiikR^itya shiva.n yaati kroDiikR^itya viliiyate |" (YogaKundalini Upanishad 1:74).
"Kundalini assumes the eight forms of Prakriti (matter) and attains Shiva by encircling him and dissolves itself in Shiva".

Sahasrara Chakra is also called the city of Brahman.:

"taM chedbrUyuryadidamasminbrahmapure daharaM puNDarIkaM veshma daharo.asminnantarAkAshaH kiM tadatra vidyate yadanveShTavyaM yadvAva vijij~nAsitavyamiti sa brUyAt.h | (Chandogya Upanishad VIII-I-2).
yAvAnvA ayamAkAshastAvAneSho.antarhR^idaya akAsha ubhe asmindyAvApR^ithivI antareva samAhiteubhAvagnishcha vAyushcha sUryAchandramasAvubhau vidyunnakShatrANi yachchAsyehAsti yachcha nAsti sarvaM tadasminsamAhitamiti |" (Chandogya Upanishad VIII-I-3).
"If the disciples should say to him, 'In this city of Brahman in which is a small mansion in the shape of a lotus and in the small inner Akasa within – what is it that lies there which should be sought, which one should desire to understand ?' – He should say in reply, 'As large indeed as is this Akasa, so large is that Akasa in the heart. Within it, indeed, are contained both heaven and earth, both fire and air, both the sun and the moon, lightning and the stars. Whatever there is of him in this world and whatever is not, all that is contained within it'".

The colour of the Knots and the Sahasrara are as follows.:

प्रथमा रक्तपीता महद्ब्रह्म दैवत्या । द्वितीया विद्युमती कृष्णा विष्णुदैवत्या । तृतीया शुभाशुभा शुक्ला रुद्रदैवत्या । यावासानेऽस्य चतुर्थ्यर्धमात्रा सा विद्युमती सर्ववर्णा पुरुषदैवत्या ।
The first is the red Lord Brahma ( creative aspect ) , the second the black Lord Vishnu ( the administrative aspect ), the third the holy white Lord Rudra ( destructive aspect ) , and the fourth which is like lightning is the all-coloured (have all aspects) Purushothama (Shiva). (AtharvaShikha Upanishad 1.7).

Maitreya Upanishad also confirms this.:

सर्वदा समरूपोऽस्मि शान्तोऽस्मि पुरुषोत्तमः ।
III-24. "I (Shiva) am always equanimous, I (Shiva) am quiescence, the greatest being (Purushottama);"

And Also,
Rig-Veda Khilla Part, Shiva Sankalpa Shuktam.:

यो वै वेद महादेवं परमं पुरुषोत्तमम् । यः सर्व यस्य चित्सर्व तन्मे मनः शिवसंकल्पमस्तु ।। 21 ।।
21. The one who knows the great God (Maha Deva), Om the highest of Persons (Param Purushottoma) of the vedas, Om the Supreme Self, may such my mind be of beautiful and divine resolves, be always remain filled with Auspicious Shiva-thoughts.

"Shri Lalita SahashraNama Stotram.:*

सहस्रदल-पद्मस्था सर्व-वर्णोप-शोभिता ।
सर्वायुधधरा शुक्ल-संस्थिता सर्वतोमुखी ॥ १०९॥
She (Lalita Tripura Sundari) is situated on a thousand-petalled lotus and is adorned with all kinds of colours.
She is armed with all kinds of weapons and is seated on a white robe and faces all directions. ।। 109 ।।

Conclusion.: So, Sahasrara Chakra is of All-Coloured and it's meaning is that, it (The city of Brahman) is the essence of the whole universe.
I hope this clarifies all your queries. Prd..


How much was the final Sandpiper settlement?

Question: How much was the final sandpiper settlement amount?
I think it was around 20 million. I ask because Saul was hoping for his cut of around 20 percent.
Comment: Just a note; Saul's cut was 20% of the counsel fee; i.e. the segment of the settlement apportioned to the lawyers, not the actual plaintiffs.
Comment: And as noted in the answer below (and the attached video), the counsel fee was 1/3 of the total settlement.  So overall Jimmy stood to personally gain 1/15 of the total settlement amount;  if the final settlement totaled $20 million then his share would have been $1.33 million.
Answer: In Act II of 'Plan and Execution' (S06E07), "Cliff announces through the conference call that a settlement agreement has been reached".
This settlement is the "original settlement offer ([.. which would have been] reduced by a million dollars a day if it's not accepted immediately)", and the agreement takes place as Kim and Jimmy's—now successful—plan to force the settlement has its worst and most visible effects on Howard.
It is uncertain but likely that this original offer is the $20M that Chuck demanded from Sandpiper.

She shows Jimmy a settlement offer presented to her by Erin Brill, his former co-worker at Davis & Main. Taken aback by the figure, Jimmy calculates that he stands to make $1.16 million from his 20% share of the settlement. source

This is from the initially calculated $17.4M settlement (you can watch Jimmy make the calculations here).


Does RDC catch the dynamic IP when using FQDN name?

Question: I have connected to my remote server using the FQDN machine name: server1.mydomain.com, one day later I cannot any more connect using server1.mydomain.com but I am still able to connect using the dynamic public IP address. Is there something to configure to make RDP follow dynamic dns?
Comment: The server doesn't know anything about what dynamic ip address is being used to NAT/forward incoming RDP sessions to it. The server only knows about the ip address that's assigned directly to it's NIC and it only knows about what port it's listening on for incoming RDP sessions. Everything else is external to the server. This is a DNS or router or firewall problem.
Comment: When it doesn't work, have you tried pinging the fqdn? Or doing nslookup? Or clearing your dns cache?
Comment: @longneck, It just worked now. Before, I succeded pinging the fqdn and resolves the latest IP, but have never tried clearing dns cache. Clearing dns cache is something new for me...
Comment: @joeqwerty, since it makes some delay to work, do I have to enable dns role to configure something there ?
Comment: You're using the public FQDN to connect to the server from the outside, right?
Comment: Yes, I am using the public FQDN to connect to the server from the outside. and domain name dns is hosted at registrar. I have no dns role configured on my server.
Answer: This has nothing to do with your server needing to follow dynamic DNS or having the DNS role installed.
When the IP address changes, it takes time for your computer to realize the address has changed because it caches the results of DNS queries. You can clear this cache by running ipconfig /flushdns from an elevated command prompt.
Also, DNS servers between you and your dynamic DNS provider can cache their responses. Your dynamic DNS provider can set the length of time that downstream DNS servers are supposed to cache DNS entries, but not everyone obeys those values. Therefore, you could be at the mercy of their cache configuration.
Comment: Sorry for the delay to give a new feed back, I had to wait to verify what happens when the public IP address changes, As the client updater software recommanded by my dns supplier has no logs, I could not know what realy happens when IP changes. and since this is my first time using a dns client updater, I could not know how this kind of tools works on the local machine, Finaly, I just discovered that the client software runs dns updates only if it is open.
Comment: So I launched a new google for a dns client software that could run as a Windows service, then fall on this: [http://freedns.afraid.org/scripts/freedns.clients.php](http://freedns.afraid.org/scripts/freedns.clients.php)


Corn tortillas from Hominy(nixtamalizing corn) vs store bought masa harina?

Question: Does anyone know the difference between corn tortillas made from masa harina from brands like Maseca and corn tortillas vs made from homemade hominy or store-bought hominy (canned or dried)?
Answer: Masa is made by nixtamalizing dried corn.  Hominy is also the result of nixtamalization, but to make hominy one cooks the corn in alkali water further than one would cook it in order to make masa for tortillas; that is; until the kernel is fully hydrated. Hominy is not used to make tortillas.
Nixtamal for tortillas is partially cooked, then left to soak, then ground. Generally speaking, nixtamalizing dried corn, soaking, grinding, then making tortillas is an over-night process.
Masa Harina begins with the same process, but the masa is dehydrated.  This is for convenience.  So that one simply needs to add water, then proceed to tortilla making. So, rather than hours, one can have tortillas in minutes.
Other than the convenience/process differences, tortillas made from freshly nixtamalized corn simply taste better.
Comment: I've actually made tamales from ground hominy, with quite good results compared to masa meal. But I guess the hydration would be too high for tortillas.
Comment: I saw some recipes that use ground hominy then add masa harina to bring the hydration to right level.


Is there a way to differentiate Kanji and Hanzi?

Question: eg 後樂園 is completely kanji but I thought it was a place in Taiwan until I looked it up and it was in Japan. Also what about reading it in the Chinese reading (hou le yuan) instead of the actual Japanese reading (korakuen)? I'm confused on cultural notes such as these
Comment: No. They're different name for the same thing
Answer: You can only differentiate Kanji and Hanzi by looking into the context. Most Japanese Kanji look exactly like Chinese Hanzi because they were copied from  Hanzi.
There are few unique Kanji that's coined by Japanese and not in use in Chinese. Those are called Kokuji. Kokuji are inspired by Hanzi, but not copied from, they can be easily identified as Japanese
Also, some Japanese characters are simplified different from the Mainland China's simplied Hanzi, but the non-simplified Kanji all look the same as traditional Chinese
Answer: Kanji are almost exactly the same as the Chinese Traditional Characters... Know your history. There are a few differences though in a very short amount of characters which even in traditional Chinese seem different from the ones in Japanese, as Japanese went through its own simplifying process.
To know if its Kanji or Hanzi you will have to see the context. Yet, proper names such as this one you mentioned tend to be written with the same characters.
Answer: The best way to differentiate Kanji and Hanzi and to master either one.
If you know more about the logic of either one, you can easily tell if it's Kanji and Hanzi.
後樂園 can be confusing but actually a single character後 as an adjective to describe 樂園 is a Japanese-style word
another example can be 介紹 and 紹介
same characters with different order implies different languages


What are the uses of rice hulls?

Question: I see a lot of rice hulls that are burned after harvest seasons. Is there a good use for it in my garden or it is best suited for large scale farming like rice and corn? Is there a good use for its ashes?
Comment: I used to purchase rice hulls 3-4$ per lb. for brewing. they make up a nice filter in an all grain mash tun.
Answer: Rice hulls would make a decent mulch:

Rice hulls are very lightweight and in order to be used satisfactorily as a mulch, a thin layer of dirt must be spread over them, then gently but thoroughly moistened. This way they will hold their position the rest of the season controlling weeds and conserving moisture.

The ash is high in silica, and the hulls themselves are fairly nutrient-poor to begin with; I'm not sure it would be much benefit for your garden.
If you can get your hands on the unburned hulls, I'd use them for mulch as described above. Wikipedia also says they also make good insulation, so if you have a greenhouse or other situation that would benefit from this insulation you could use it there.
Comment: I already got myself a truck load of it and I'll be using it tomorrow in some of my vegetables as mulch, and I'll also mix some of it to clay-like soil around my avocado tree.

What are the uses of rice hulls?


Image resolution issue while scaling image

Question: In my iPhone app i have to do image editing. User can add caption on image and then save that image with caption and share that image. First when we choose picture from gallery i have used below method to scale image for my image view:
<code> UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, 0.0f);
float hfactor = img.size.width / screenRect.size.width;
float vfactor = img.size.height / screenRect.size.height;

float factor = MAX(hfactor, vfactor);

float newWidth = img.size.width / factor;
float newHeight = img.size.height / factor;

float leftOffset = (screenRect.size.width - newWidth) / 2;
float topOffset = (screenRect.size.height - newHeight) / 2;

if (leftOffset>0) {
    mainImgView.frame=CGRectMake(leftOffset+10, screenRect.origin.y, newWidth, newHeight);
}
else if(topOffset>0)
{
    mainImgView.frame=CGRectMake(screenRect.origin.x, topOffset+10, newWidth, newHeight);
}

CGRect newRect = CGRectMake(0, 0, screenRect.size.width, screenRect.size.height);

[img drawInRect:newRect blendMode:kCGBlendModePlusDarker alpha:1];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

return newImage;
</code>
}
For saving the image with caption i have taken screenshot of view on which both image view and caption label are taken using below code:
<code> UIGraphicsBeginImageContextWithOptions(mainImgView.frame.size,NO,0.0f);
 [mainImgView.layer renderInContext:UIGraphicsGetCurrentContext()];
 UIImage *newImage=[[UIImage alloc]init];
 newImage=UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
</code>
But by taking screen short , image that get saved has very low resolution and get pixelated when we zoom that image. Is there any way to save image with actual resolution, so that both picture and caption are saved as image?
Answer: Probably the reason is in scaleFactor for retina display.Note that in retina devices images have to be twice larger than container's size, that holds it.
Try this:
<code>     UIGraphicsBeginImageContextWithOptions(mainImgView.frame.size,NO, [UIScreen     mainScreen].scale);
</code>


What's the adjectival form of "sauce" as "salty" is to "salt"?

Question: Saucy has a totally different meaning. When I describe food having too much sauce, I would like to use an adjective, however salty is not really applicable here.
Comment: "Drowning"?....
Comment: @RegDwight, thanks for correcting the tags, however originally I said "however salty is not really applicable here". By that I meant it's salty because of too much sauce and not just too much salt.
Comment: Ah. I wasn't sure, actually (hence the question mark in my edit summary). Thanks for the clarification, reverting that part.
Comment: what about "swimming in sauce" ? :)
Comment: Really? Meat, meaty. Heat, heaty. Grub, grubby. Fire, fiery. Hmmm ... sauce, xxxy?
Comment: Isn't **that** the primary meaning of *saucy* anyway? (Seen this post just now.)
Answer: I'm not sure what the objection to using saucy is all about. Merriam-Webster says:

saucy adj
  1: served with or having the consistency of sauce
  2a : impertinently bold and impudent
  b : amusingly forward and flippant : irrepressible
  3: smart, trim <a saucy little hat>

The very first definition is exactly the meaning you are looking for. Sure, the word has other meanings, but most words have multiple meanings. If your food is too saucy, then just say so.
Comment: Maybe dictionary.com is not the best source for research. I looked it up and only found two meanings: 1. impertinent; insolent: a saucy remark; a saucy child. 2.
pert; boldly smart: a saucy little hat for Easter.
Comment: The "objection" is that in BrE, meanings 2a and 2b are so dominant, and meaning 1 is so infrequently used, that the use of the word "saucy" (in the context of food) may sound a bit "off" to British ears.
Answer: How about "over-sauced"?
While the suggestion "swimming in sauce" as suggested by nico is the probably the most idiomatic option, it's colloquial and might not be the best choice if you were speaking, say, formally in a kitchen or in a restaurant review.
As mentioned above also, "saucy" is an old term meaning "pert" or "impudent." Yet, the primary definition offered by Merriam-Websters is "served with or having the consistency of sauce." So given these prior meanings, whatever solution devised will be a nonce coinage.
Comment: Are you sure? In a professional context "over-sauced" would be immediately understood, whereas "saucy" would be ambiguous.
Comment: Hrm -- unfortunate echoes of 'over-sexed,' especially when we've got 'saucy' in the verbal pot already.
Comment: You are probably right that in a kitchen this would be obvious and quickly understood.   I'm less sure about a print review -- if it were me, I'd look for another phrase, but I think many writers could make the intent clear from style and context.  So, I'm not a fan of 'over-sauced', and I think some would agree with me, but this may be the best one-word solution, and possibly the most appropriate one.  (I also didn't mean to imply that I thought 'saucy' was workable.)
Answer: There isn't a word for that specifically.  However, in some cases you might describe something as "runny" if it has too much liquid and isn't solid enough.
If you are just looking for a contraction of "was made with too much sauce", you could describe it as "over sauced" although this is not an everyday phrase (we are simply using the prefix "over" as it can be used with any verb) and may sound a bit pretentious.
From a practical point of view, within the context of food, you will be understood if you just say "too saucy", although it's not dictionary-correct.
Comment: Oh, we can overload, it's just the risk of being amusingly  misunderstood rises in some cases, like this one.
Comment: That's too sad! Why can't we just overload a word like "saucy"? Runny doesn't help me here if the kind of sauce I'm talking about is sort of sticky.
Answer: The food can be described as overflowing with sauce. If instead you say the food is saucy,
well i'd guess it would be chocolate and strawberries :D
Answer: If you insist on a single word, you may try "overcondimented".
But "drenched in sauce" sounds better.
Answer: If I were served a dish with a sauce that had far too much sauce, I would call it "soupy". As in, there's so much sauce that it may as well be a soup.
http://www.learnersdictionary.com/definition/soupy


power and sample size estimation

Question: For a one-sided test:
$$H_0: \mu_1 \leq \mu_2 \ H_1: \mu_1 >\mu2$$
$$\alpha=0.025,\beta=0.1$$
How to calculate the sample size needed? Is this information enough to calculate the sample size?
Comment: No, it's not. You need an effect size.
Answer: Suppose that this is a one-sided, one-sample t test.
You want to detect whether $\mu_2 - \mu_1 = \Delta = 2$ or more and you estimate that the population standard deviation is $\sigma = 10.$ You are working at level 2.5% and want power
90% $(\beta = 0.1).$
Minitab, R, and many other statistical programs (and some on-line sites) have 'power and sample size' procedures that
allow you to find the sample size implied by the constraints
mentioned above. (These program implement a formula that uses the
non-central t distribution.)
It turns out that the quantity $\Delta/\sigma$ is used in the formula, so if all else
remains the same, $\Delta =1, \sigma = 5$ would lead to
the same sample size: $n=199$ in the current problem.
Here is a relevant printout from Minitab:
Power and Sample Size

1-Sample t Test

Testing mean = null (versus > null)
Calculating power for mean = null + difference
α = 0.025  Assumed standard deviation = 10

            Sample  Target
Difference    Size   Power  Actual Power
         2     199     0.8      0.801690

We can use simulation of $100\,000$ experiments in R
to verify that $n = 199, \Delta = 2, \sigma = 10, \alpha=0.025,$ lead to a simulated power of about 80%.
set.seed(2022)
pv = replicate(10^5,
      t.test(rnorm(199,100,10), mu=98, alt="g")$p.val)
mean(pv <= 0.025)
[1] 0.8031  # aprx power 80%

Changing $\Delta$ and $\sigma$ as mentioned above.
set.seed(522)
pv = replicate(10^5,
      t.test(rnorm(199,100,5), mu=99, alt="g")$p.val)
mean(pv <= 0.025)
[1] 0.80179

power and sample size estimation


different prime factor

Question: Let $k$ be an positive integer and $m$ is the odd positive integer. Prove that there exist a natural number $n$ such that $ m^n + n^m $ have at least $k$ different prime factor
Comment: Without any constraints on $k$, I don't see how you'd solve this other than saying that clearly, $m^n + n^m$ is either prime or has a bunch of prime factors.
Comment: Actually i just got this problem from a teacher i cant explain more since i havent solved it too
Answer: Let $p$ be a prime not dividing $m$. Then $m^n\equiv 1\pmod p$ whenever $n\equiv 0\pmod{p-1}$. If additionally $n\equiv -1\pmod p$ then (here we use that $m$ is odd)
$$ m^n+n^m\equiv 1+(-1)^m\equiv 1-1\equiv 0\pmod p.$$
As said, this holds whenever $n\equiv 0\pmod{p-1}$ and $n\equiv -1\pmod p$. To solve the problem at hand, pick $k$ distinct primes $p_1,\ldots,p_k$ such that these congruences can be fulfilled concurrently. It suffices to ensure that $p_i>m$ (so definitely $p_i\nmid m$) and $p_i\nmid p_j-1$ for all $i,j$. This can be done recursively: Given suitable primes $\max(m,3)<p_1< \ldots< p_{k-1}$ pick $p_k>p_{k-1}$ such that $p_k\equiv 2\pmod {p_1\cdots p_{k-1}}$, which is possible by Dirichlet.

different prime factor


Generation starship with kids raised by robots

Question: There's a book I remember reading sometime around 1981 or 1982 about a colony/generation starship where kids were raised by robots who gave them something in their food that kept the kids from maturing until they reached their destination... or something like that.  Unfortunately, I don't remember much more about the plot, except that it was definately a "coming of age" book.
Comment: Not the story you're looking for, but there was a book called [Flight of the Dragonfly](http://www.amazon.com/Flight-Dragonfly-Robert-L-Forward/dp/0671499440/) which had a longevity drug which reduced adults to child like state and they were attended to by a robot/AI for the duration of their voyage.
Comment: possibly the same as https://scifi.stackexchange.com/questions/242583/book-about-ai-called-angels-who-look-after-a-child-left-alone-on-a-spaceship (which is newer but has an accepted answer)
Answer: This is probably Earthsearch by James Follett.

Three crew-generations previously, the starship Challenger - a vast ten-mile-long survey vessel – was launched from Earth on an interstellar mission to search the universe for an Earth-type planet to colonise. This has been unsuccessful, and the ship's once enormous crew-count has now been reduced to four. Telson (the ship's Commander), Sharna (Science officer), Darv and Astra are the third-generation crew- the only survivors of the disastrous Great Meteoroid Strike which seriously damaged the ship two decades previously, killing the entire second-generation crew and rendering large areas of the ship "uncontrolled" and inaccessible to its electronic systems.
From infancy, the four third-generation crew members (now in their early twenties) have been raised by robots and by the Angels – mysterious unseen beings who run the ship and who only manifest as disembodied voices. Darv, the most sceptical and enquiring of the crew members, suspects that the Angels are merely computers; but the others consider them as "Guardian Angels" and work entirely under their guidance.
With no suitably colonisable planet found after over a hundred years of searching, a crew-vote is taken and the Challenger sets a course for the return to Earth. Darv and Astra, while exploring one of the uncontrolled zones, find a survey recording of an Earth-type planet called Paradise. (In the accompanying novelisation, Darv is alone when he makes the discovery.) As is standard procedure, the crew enter suspended animation in order to prevent ageing and possible death during the many years of journey time.
Unrevealed to the crew, the Angels (who are the ship's control computers; their name being an acronym of ANcillary Guardian of Environment and Life ) have their own agenda. They desire absolute control and mastery over any colony resulting from the mission. To this end, they covertly engineered the apparent accident which killed the second-generation crew (who would otherwise have ended the mission before the Angels wanted it to end) and have kept the third-generation crew sexually immature and innocent via drugs and disinformation in order to keep them more tractable. However, their machinations have begun to backfire already. Their requirement of a minimum human crew of four to man the Challenger's control room requires the Angels to work mainly via suggestion and manipulation. Also, the Great Meteoroid Strike damaged the ship and their control over it more than was planned, including damage to their own memory banks, which in turn deprived them of vital information about the Theory of Relativity. Concerned that the discovery of the Paradise recording may convince the crew members to change their plans, the Angels suppress Darv's and Astra's memories of the survey recording by hypnotic manipulation, in Darv's case by using violent, nightmare-inducing imagery.

I know it as a radio drama, but it was published as a book too.
Comment: My first thought was "Earthsearch" too. I think the book is out of print but the original radio series is available from Audible.
Answer: It's a bit of a long shot, but Earthseed by Pamela Sargent was published in 1983, and is about a colony ship where the kids were basically raised by robots controlled by the Ship (who acted as mother/father to them). It's definitely a "coming of age" book, but there's nothing in it about something in the food keeping the kids from maturing. Most of the book is spent in "The Hollow", a large expanse of wilderness that the kids have to survive in.
Answer: It's "Voyage from Yesteryear" by James Hogan

The story opens early in the 21st century, as an automated space probe is being prepared for a mission to explore habitable exoplanets in the Alpha Centauri system. However, Earth appears destined for a global war which the probe designers fear that humanity may not survive. It appears that the only chance for the human species is to reestablish itself far away from the conflict but there is no time left for a manned expedition to escape Earth. The team, led by Henry B. Congreve, change their mission priority and quickly modify the design to carry several hundred sets of electronically coded human genetic data. Also included in this mission of embryo space colonization is a databank of human knowledge, robots to convert the data into genetic material, care for the children and construct habitats when the destination is reached and a number of artificial wombs. The probe's designers name it the Kuan-Yin after the bodhisattva of childbirth and compassion.
Comment: There are generation ships, but I can't find anything about drugs to retard maturation.


Magento 1.8 Allow Same Email for 2 or More Customer Accounts

Question: I´m using magento as POS for travel services, so the user only fills in the customer create account and my sale people finish the sale from backend.
Since sometimes we have a family traveling together but all contracts (for legal purposes) are individual, however most times one person is responsible for filling in the form (I´m using create account page for that) and paying, I have the same email for 2 or more customers.
And here is the problem, since magento does not allow to create 2 accounts with same email.
Does anyone have an idea on how to allow it to create different accounts with same email address?
(remember, I don´t allow customers to login to the system so it´s not a problem future password retrieve or login attempts).
Comment: Why do you need to create accounts? Magento offers guest orders. Since you are not using any other functionality of customer account other that email and name you could simply just make guest orders which have all those informations and only build a module that would scan orders for new emails and present them in customer-like fashion without actual customer accounts (if you need such listing).
Comment: This is because the POS system requires that the customer is registered so my sale people can finish the booking (checkout cart). And also, people need to confirm that their info is correct, than the sales person get the client info and proceed to checkout. So that´s why I can not use guest checkout (the customer is not the one that checkouts and the sales person can not input guest data).
Answer: Changing Magento behaviour would be too complex.
I suggest that you create a custom entity (EAV if needed to). Following the guide here: http://inchoo.net/magento/creating-an-eav-based-models-in-magento/.
For example you can call the entity Traveller. Then in the frontend you create a form for customer to fill up their detail along with their booking preference.
Once you have that information in the backend you can create a guest order using the detail in the traveller table.
Comment: I´m not sure I understood this William, you are suggesting to create another table, another form and instead of geting data for customer table get from this customized one? Is that it?


How to switch between cameras?

Question: I just started with the BGE and am making a 2D mario-type scroller game. The level is long enough to require two cameras, so I made an invisible plane which on collision switches to the sexing camera. However, I also want to go back to the first camera. How do I switch back?
Comment: @ShadyPuck Regarding edits, just worth noting that edits should be *substantial*, see: http://meta.blender.stackexchange.com/a/242/241
Comment: I have seen it. Most edits that I do _are_ substantial. @RayMairlot
Answer: Stateless solution
I suggest to do the exact same thing.
So you get:

logic to switch from A to B
logic to switch from B to A

Ensure to avoid triggering both at the same time. e.g. have a according difference between the collision objects.
Answer: Go to the game logic editor and under actuator select scene then select set camera where it says restart. Then choose which which camera you want. Make sure to set the sensor for ever you need.
Answer: you could try to incorporate a property to go along with the plane. For example when your character hits the plane and the property is 0 set camera to camera1 then when character hits plane and property is 1 set camera to camera0
link to download blend
click
Comment: I did that but if I add 2 planes side by side I'll get no where because as soon as I collide with the other it will bring me back to camera one.     I apologise if I'm misunderstanding you.
Comment: @Ayush look at the blend file in the link
Comment: This is a state-full solution. Beside the event you measure what state you currently have. Usually you would check what camera is active. As this is not possible without Python you can use a proxy (the property). It is important to keep the property and the active camera in sync. This means when you switch to camera A, the property always switches to 1. When you switch to camera B the property always switches to 0. Ensure to disable [True Level Triggering] at the collision sensors. Otherwise the cameras will constantly toggle.
Answer: Python solution
Since this a general question about changing the camera in the BGE, I'd like to throw in a method using Python. The following screenshot shows an example where the camera is switched when the spacebar is pressed. It involves:

two cameras (cObserver and cFollow)
an object (LOGIC) carrying the script (nextCam)
a script containing the camera list and simple logic

Think of a racing game with several cockpit-, follow- or even spectatorviews with keyframed camerashakes.
I personally prefer this method when the number of cameras increases, since it's easier to maintain than logic bricks. Additionally you can run additional logic depending on the active view, like changing the zoom level of the active cam with KX_Camera.lens.

How to switch between cameras?


Workflow Rule Runs Twice

Question: The scenario is, there is a field called 'Expected closing Date' on the opportunity object. When the opportunity owner changes the expected closing date it should go for the approval of his manager. For this, I have written a workflow rule for storing the expected closing date before changing it because when the approver rejects the proposal then it should update for its original date, I have done it in rejection action of approval process(approval process fired by process builder) but it causes the workflow run again. I have set the flag true also in rejection but the user can change the date multiple times.
How I can avoid the recursiveness of the workflow rule in this scenario? Any help will be appreciated!
Answer: There is one checkbox called "Re-evaluate Workflow Rules after Field Change" available under field update. Uncheck that checkbox so it won't fire the workflow if the date is changed via approval process rejection action.
Comment: Thank you very much, Kalpana! you solved my problem.
Comment: Any other reasons why this might happen? I'm seeing the same thing, but my process is already not recursive

Workflow Rule Runs Twice


Complex Numbers in Fractal Algorithms

Question: I am a high school freshman who is undertaking a small development project on fractals.  I do not want to get too in depth, but I would love to blow my math teacher's socks off.  Having looked through various Wikipedia articles, I struggle to figure out how complex numbers play a role in fractal algorithms.  Can anybody help me understand what exactly complex numbers do in the formation of fractals?
Comment: I'm not sure I understand correctly, but there are some fractals (such as the Mandelbrot sets http://en.wikipedia.org/wiki/Mandelbrot_set) whose definition is easily formulated with complex numbers. I think they play a role because complex numbers can be used to do planar geometry.
Comment: In the case of the Mandelbrot fractal for example, the fractal literally is a subset of the complex numbers. I imagine the answer to what they "do" in the formation is that the formation of these kinds of fractals (pick which ones you want to look at) involve iterating an algebraic operation in the field of complex numbers and then performing some kind of check. (See JC's WP link above for more information.)
Comment: Im no expert, but from what I see in the WP article, a Mandelbrot set would be quite hard for a high-schooler (who hasn't "officially" passed Geometry, but I have dabbled with derivatives ^^) to iterate...
Answer: To work with the complex plane born with the work of Fatou and Julia about rational functions, then the basic theory is on this numbers, specialy in the Riemann Sphere, but they cannot see this objets because they didn´t have computer.
If we only consider the Real numbers for the iteration, f^n(x)=f(f(f(...f(x)))) n times, which is the principal idea behind fractals is relative simple, for example, for the function $x^2$ the points $x<|1|$ tend to $0$ lets paint in red, $x>|1|$ tends to infinity lets paint in blue and when $x=1$ 1 is a fixed point lets paint in black, the real line is painted in three colors and the fractal is not enough pretty.

Now the natural way to generalize this is take a plane and associate to this the complex numbers then for the iterations we have points in the plane.
The next step is take a region of the plane, for example, $[-2,2]\times[-2,2]$ and take a division of $100\times 100$ points, then we have 10000 pixels. Then we can associate complex numbers and pixels, like the functions work well with complex numbers we can proced to iterate. With the same argument for $z^2$ we have the next picture:

But if we take another function like $z^2+1$ we have:

The color are simple because black indicates points with simple behavior and green the Julia or fractal Points.

Complex Numbers in Fractal Algorithms


Can't access shares after installing SP1 for Server 2008

Question: Just finished installing SP1 for Server 2008 R2, all went fine other than i can't access any shares using a UNC. When using \server from clients or on the server i get the following message;
Windows cannot access \\ntserver

Check the spelling of the name. Otherwise, there might be a problem with your network. To try to identify and resolve network problems, click Diagnose.

Error Code: 0x80070002
The System cannot find the file specified.

I've also tried with the FQDN and the ip and i get the same message. I've disabled the firewalls on the server and client and still have the issue.
EDIT: also found these in the event logs, unsure if they are related;
The WinRM service failed to create the following SPNs: WSMAN/NTSERVER.school.local; WSMAN/NTSERVER.

Additional Data
 The error received was 8344: %%8344.
User Action
 The SPNs can be created by an administrator using setspn.exe utility.
The winlogon notification subscriber <GPClient> took 97 second(s) to handle the notification event (CreateSession).

I'm lost at what to try now!
Answer: Have a look at this page

Open Regedit "HKEY LOCAL_MACHINE\SYSTEM \CurrentControISet\Control\NetworkProvider\Order"
The "ProviderOrder" Key has just one value for the "hgfs"
Validated with another server having the same configuration  the Key above and the information found were different:
The Key "ProvideOrder" contains: "vmhgfs,hgfs,RDPNP,LanmanWorkstation"
Copied the value from this server to Issued Server.
Comment: Already tried that one and i'm still having the same issue. thanks


honda 2002 turns over but will not start (freespins)

Question: i have a 2002 honda civic that will not start it turns over but will not crank.
it just died when we pulled out of drive and wouldnt start.Just freespins we replaced fuel pump still wont start?
Comment: Welcome to the site. Was there a reason you decided to replace the fuel pump?
Comment: Besides the fuel pump, what else have you checked? Have you had the codes read? First thing which comes to my mind is a cam/crank position sensor, but really, you need to have an idea of what is happening before you throw parts at it. Get us the codes (if there are any) and we can go from there.
Comment: no the codes havent been read .it is at my work and i dont know who knows how to get the codes?i cant drive it anywhere to be checked .He replaced the fuel pump and still doesnt seem to have any fuel under the hood  injectors dry?
Answer: just fyi it was my timing belt that broke .we took the bonnet off and while turning over the engine the valves nor anything is moving at all ,but thanks for the imput from all .
Comment: Well, at least you figured out what's going on. Sorry for the issues! We appreciate you coming back and letting us know.


Graphical Layout Scroll Problem in Eclipse Android Development

Question: I am trying to develop an android application. I've put a scroll view as main container using graphical layout in eclipse. After that, I had put some UI elements, like buttons. When the total height of elements become more than viewable area, it can be seen using scroll view as expected. There is no problem until this point. The problem is the elements that are not fit viewable are of the screen can not be seen using graphical container of the eclipse interface. There is no problem with the source code, as it runs expectedly. Is there any option in the Eclipse gui to see the UI elements that are not fit the viewport?
Comment: The question is quite unclear like this. Please add your XML code, that might help a bit.
Comment: I tried to make it clear, since English is not my native language, it becomes a little hard for me to easily explain my problem. Thanks for your understanding.
Answer: I know what you're talking about. When you're viewing the xml file on the Eclipse Graphical layout you can only see the elements that fit on the screen. You can't scroll down to see the entire UI.
I use Eclipse at home and work. I'm using Eclipse Helios Service Release 1, on both systems. For some reason at home, when I'm on the graphical layout, there's a button on the upper right of the graphical viewer that says something like 'Remove Clipping'. (I'm at work now. So can't look to see exactly what it says).
When I click that button, I can now scroll down to see the entire UI. However, on my copy of Eclipse at work that same button isn't displayed. I've tried to figure out what the difference is between the setup on the two copies of Eclipse. But so far haven't been able to figure it out. Note, I've tried viewing the same exact xml file, within the same project, on both copies of Eclipse.
The problem seems to only occur when you're using a scrollview and all the ui elements won't fit on the graphical layout screen within Eclipse.
Answer: I have the same problem. I've been unable to troubleshoot, so I've resorted to using my physical device instead. I try to get the bulk of work done within the the Eclipse GUI... then nudge and polish with my device. Its a PITA to be sure, uploading what seems like a million times only to move one element a tiny bit more.
Best practices recommend developing on a device. Further, the Layout-tools && scrollView basically make it mandatory to really know what is going on. I can't seem to form this into a coherent search argument as my Google-fu has let me down on this one.
BTW - I'm using the shiny new r10 ADT plugin and I've been struggling with this for about 6 months.
Another workaround: You can use a smaller-ish tablet port in the GUI to get a really rough idea of what you are working with.
Answer: If your target layout is for a phone or smaller device, simply switch the preview to a larger  screen size configuration.
In the upper left corner, under where it says 'Editing config: ~default', The list provides you with a number of screen sizes to target.  Pick the 10.1 in version, and it will scale the preview, and will then allow you to see and work with all of the views that have scrolled off the screen.
Cheers-
Answer: I think this is an old topic but I was having the same issue. I have 2 apps made from outsourcing. when I opened each in eclipse one would show the full contents of the scrollview and one was clipped off. After numerous google searches nothing came up as a solution. I just happen to look and saw the app that is clipped was android version 1.6 and the app that shows everything like i wanted it to so I can use the graphical layout for a scrollview was android verion 2.1.
So i changed the one app to version 2.1 and it fixed it. noone seemed to address that. so for me the fix was make sure the android version you are building for is 2.1. you can always change it back to 1.6 compatable after you are done designing.
Hope this helps
Answer: The best way i could figure out is to give negetive top margin to the root layout that will make the rest of the content visible. This is only for dev purpose and should be removed when completed


What Magnum Opus upgrades can I skip?

Question: Each category of Magnum Opus (car) upgrades is different in that some categories require sequential updates and others don't. I'd prefer to save the scrap by skipping upgrades where possible (upgrading right to the final version), but it's hard to tell which I can skip from the requirements alone. (Some items list "Additional Requirements", such as completing a mission, but still end up requiring the previous upgrade when the prerequisite is removed. So in those cases, I could have upgraded sooner.)
Comment: It's worth noting that the final upgrades are not necessarily *the best* by every measure. Progressive bumper upgrades add armor but also add more weight. Upgrade tiers are more of a scale you can use to balance your car's performance the way you like
Comment: @GnomeSlice is right. You are probably not going to want the highest tier of every item equipped all the time.
Answer: "Cannot skip" below indicates that the upgrades must be purchased sequentially, regardless of the other unlock conditions (so might as well invest as soon as you see fit).

Ramming grill – CAN skip
Armor – cannot skip
Engine – cannot skip, except to V8 class
Exhaust – CAN skip
Tires – CAN skip
Suspension – CAN skip
Boost – cannot skip
Rims – CAN skip
Boarder spikes – CAN skip
Sniper rifle – cannot skip
Harpoon – cannot skip
Thunderpoon – cannot skip
Side burners – cannot skip
Repair speed – cannot skip
Car body, Body color, Decals, Hood ornament – N/A

Keep in mind that if you are looking to build all 16 Archangel vehicles, you'll likely need to purchase those in-between updates anyway. Also, all of Max's clothes upgrades can be skipped. As noted in the comments, the "final" upgrade might not be the "best" according to its description, but I've yet to read a report that suggests a noticeable perk from using anything but the last upgrade.
Comment: I think the clothes upgrades are just extra information at this point, since the question is technically about the car, not Max. Additionally, the sniper cannot be skipped, if I remember correctly. It's needed as part of a mission.
Comment: It's information I would have wanted to know

What Magnum Opus upgrades can I skip?


Pieces Differ in Color/Shape from Diagrams and are Missing Lego Writing

Question: Ferrari 488 GTE (42125) is my first Lego technic set and I've noticed that some pieces differ in the shade of the red/maybe even the type of plastic and also don't match the diagrams and pictures from other folks' assemblies posted on the Lego.com. Is this a counterfeit concern and, overall, does this happen a lot with Lego technic as it does seem to be damaging the look?
Comment: The color variation is relatively normal, color matching is difficult to begin with, but especially so with injection-molded parts. FWIW, the variance seen in your photo is not too horrible as far as LEGO parts go, and you may have some success hiding it in this case by using lighting with a lower color temperature (for example, low-wattage incandescent lamps instead of LEDs or CFLs) simply because of how that affects perception of reds and oranges.
Answer: According to Bricklink, the 42125 should contain 4 pieces of Technic, Axle and Pin Connector Perpendicular Double Split, which looks like the one the instructions show:

However, it has a mold variant* called Technic, Axle and Pin Connector Perpendicular Double Split, Reinforced Sides, which looks like the one you have:

Based on this, I'd say your set is probably authentic, just got parts from a different manufacturing batch due to mold transition or surplus pieces.
The occasional color variance between pieces in the same official set that are supposed to be the same hue is known for a long time, that doesn't indicate a counterfeit item.
If you want to be sure, you can consider how you have acquired this particular set: on one end of the spectrum, buying directly from LEGO.com 100% nets you an authentic one. On the other end, buying for a tenth of the official price from a noname pop-up webshop will almost guaranteed to be a knockoff. Other retailers and private sales occupy some position between these two.
You can also look for LEGO markings, which should be present on most pieces. If your set was new and sealed in a box, and you've found LEGO marked pieces, you can rest assured it is an original one.
Or you can contact LEGO directly to ask if that mold variant has ever been put into an official set of this model.
*Edit: a mold variant is a piece that has largely the same functionality, maybe with minor changes in possibilities or strength. See this article for several examples.
Comment: It would probably be worth briefly explaining what a "mold variant" is. It might well be self-explanatory for many readers, but just in case…
Comment: Yeah, the mark definitely has me wondering if they could have injected from the other side which would normally be at least semi-concealed by the axle running through the part.
Comment: What really bothers me is how visible the dot left from the manufacturing process is… Right on top and the original piece seemed flawless at the angle
Comment: It is also probably worth mentioning that while many color variations are definitely well known, a visible spot like that is usually considered a production flaw and is worth [reporting as a "broken" part.](https://www.lego.com/en-us/service/replacementparts)
Comment: @NathanStohlmann If, by "spot" you mean the white dots on the circled parts - those are known artifacts of the injection molding process and not grounds for part replacement. But if you mean "visible spot" as in "location of the part in the finished model that can be seen", then yes, you're right.


How thick (or thin) is the die/wafer inside an IC?

Question: There are packages as thin as 0.3 mm (maybe even less), so I was wondering how thin the actual die/wafer inside them are. I guess the package top and bottom will also need a certain thickness to be useful, so how much is left for the die?
Comment: I guess it was down voted because it was a bit vague, but who knows, I knocked it up for you. I also suggested an edit to make it a bit more readable.
Comment: Downvoter, can you tell why?
Comment: @FedericoRusso: This is Stack Exchange website. Where downvotes depends on the mode by some people.
Comment: @FedericoRusso: one reason for a downvote is that there is no hint in your question that you did some research for yourself. "*... so I was wondering ...*" sounds as though you though of this and decided to ask someone to write an answer for you to save you the bother of looking it up. Your high rep probably works against you in this case as you would understand well how the site works.
Answer: Very thin, ~700µm (0.7mm) is close to the upper limit. Around 100µm (0.1mm) is about as thin as they get. However the size varies a lot, depending on multiple things, like the package it's made for, quality, price, and the overall size of the wafer.
Update After further research, I found that for certain applications, the wafer may be as thin as 50µm.

guess the package top and bottom will also need a certain thickness to
  be useful, so how much is left for the die?

An incredibly small amount, take a look at this picture and the others at the bottom.
Yamaha YMF262 audio IC decapsulated

It varies with the size of the wafer, according to wiki,

2-inch (51 mm). Thickness 275 µm.
3-inch (76 mm). Thickness 375 µm.
4-inch (100 mm). Thickness 525 µm.
5-inch (130 mm) or 125 mm (4.9 inch). Thickness 625 µm.
150 mm (5.9 inch, usually referred to as "6 inch"). Thickness 675 µm.
200 mm (7.9 inch, usually referred to as "8 inch"). Thickness 725 µm.
300 mm (11.8 inch, usually referred to as "12 inch"). Thickness 775 µm.
450 mm (17.7 inch, usually referred to as "18 inch"). Thickness 925 µm.

Basically they take a slice of silicon that's about .6mm thick (on average,) grind it, smooth it, etch it, then grind the back side.
Here's a good video to watch, How Silicon Wafers are Made. And to see how a chip is decapsulated, watch Chris Tarnovsky's video How to Reverse-Engineer a Satellite TV Smart Card.
If your interested in decapsulating chips, and close up images and probing of the die, FlyLogic's blog has some awesome posts, and great pictures!
And a few pictures of decapsulated chips,

The following 2 images are of a ADXL345 3mm × 5mm × 1mm LGA package. The first is a side X-ray. The X-ray clearly shows the presence of a separate ASIC die and MEMS die, with a hermetic cap. The internal structure of the device is more clearly seen in the SEM micrograph of the decapsulated device, in the second image.
Comment: the last pictures are really cool.  I am having a hard time understanding what all of those au bond wires are doing stuck what looks like directly to the porous substrate ... just to hold it in place?  how does this thing communicate to the outside world?
Comment: @jbord39 It may be that the parts are not yet encapsulated but those connections may be the contacts on the actual chip when it is. Looking at the schematic, page 35 of 40, it matches the pinout http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf
Answer: Prime wafers (which is a specification) nominally 720μ, additional processing for metal layers may add as much as 7μ.  There is some variation in thickness.  Some devices are thinned through a process known as back-grinding but that thickness is usually only taken to 300μ total thickness.  This is used in cases where thickness matters, like in image sensor modules (which only use the die - the die are not packaged) or in the case of stacked die where one die is placed on top of another, like the combination of Flash memory and DRAM, used in mobile handsets.
Comment: Thanks for mentioning backgrinding. It is an important process to consider when answering this question. I just went down this search to find out approximate die thicknesses in ICs and almost stopped when I found the beginning wafer thickness as shown in the accepted answer. End thickness can be much different due to backgrinding.


How to reconstruct RAID-1 in Ubuntu?

Question: There was RAID-1 device created of two partitions of the similar size on two disks. Disks are not of the same size and there are other (non-RAID) partitions.
During clean install of 13.04, I haven't touched those two partition (left them unformatted and assigned to anything) and now have newly installed system with old (non-RAID) partition regularly accessible. And I have those two partition which were part of RAID-1 device and they are unreadable.
I would like to create RAID-1 using those two partitions. Is it possible to do it, get functional RAID-1 and gain back access to data stored there?
Answer: Install the mdadm package and the array should show up as /dev/md127 and you should be able to open it in the gui.

How to reconstruct RAID-1 in Ubuntu?


How many days of inactivity before Bitizens leave?

Question: Given the lack of end-game content, I'm starting to play less. I have heard that Bitizens may leave your Death Star automatically if you do not play for a certain number of days, which would screw up some of my 3-star businesses. Is this true, does this happen after a certain number of days of not playing and, if so, how many days?
Comment: Is that true?  Where did you read about it?
Comment: I remember seeing people discuss it in some comments on those other "Tips for Tiny Death Star" sites or posts, but I can't find it now.  Seems really crummy to get punished for not playing, especially if you spent a lot of time building it up. Guess the first step is to determine if this has happened to anyone. I'll update the question if I find the source again.
Answer: I just tested this on my iPhone and I do not think this is true.   I know the game has some anti-cheating features in it, but I set my phone to airplane mode, launched the game, closed the game, changed the time on my phone from today (1/20/2014) to a future date (2/15/15) and then relaunched the game.  I was awarded coins for all of the products that have sold in the simulated 391 days, but I did not lose any bitizens for the simulated inactivity.
This would make me believe that there is no penalty for being inactive.
Comment: This seems as good a test as any, although I've always wondered if they wait till you jump back before the "accident" happens. Going to consider this answered then. Also, condolences to you and the family of Tycho Piett - hope he wasn't doing his dream job. :)
Comment: *sets it back to normal* .... [annnnnnddddd airlock accident](http://i.imgur.com/v0HW6xU.png) :(


2 Legends in Leaflet

Question: In Leaflet I want to add a legend when I turn on an overlay, then when I turn off that overlay I want the legend to disappear and when I turn on a second overlay I want a second legend to appear. I have 2 png legends that I am using. I'm using 'overlayadd' & 'overlayremove' but can't get it working
Comment: What software are you using on your project?
Comment: I am using QGIS
Answer: Perhaps use DOM methods to replace the contents of the div. http://leafletjs.com/examples/choropleth.html look at the info.update function which sets the innerHTML.

2 Legends in Leaflet


Ubuntu host/client server for backups?

Question: I'm wanting to use an Ubuntu Server to host a backup service of some kind to back up customer files that are located on Windows computers at an off-site location. Any recommendations would be greatly appreciated on how this could be done.
Answer: You can use rsync for that. There is a Windows version of rsync called cwRsync. It is based on cygwin.
You can install cwRsync on your Windows boxes and then rsync the data to your Ubuntu machine. I've used rsync for that when I migrated a server from Linux to Windows and had to copy a few GB of data from one machine to the other.
Here is an example how to do it.
If you create a batch file for the backup, you can then run it automatically using Event Scheduler in Windows.
Answer: You could use a simple rsync (cwRsync as mentioned by NZB) to sync the client data to your server.
On top of that I would let the server make daily snapshots of the synced data. If your client messes up the data, your live rsync copy is probably also screwed up. In this case you want to recover the data from the latest snapshot.
Read this for inspiration on how to do that using hard links. I would not use archives, because you will typically end up using a lot more disc space.

Ubuntu host/client server for backups?


How to reject call on HTC desire Z?

Question: Is it possible to reject call somehow when screen is locked as the same moment I unlock the screen, I acctualy accept the call?
Comment: Actually I solved it with removing screen lock option completely using application "No lock". Thanks
Answer: Just to answer this question in case future users have it.
I believe in HTC Sense when a call comes in and the screen lock is there it should say slide up to reject the call and down to answer.

How to reject call on HTC desire Z?


Gear Design - Teeth Fit

Question: I am working on designing a set of gears for 3D printing. I have not done any gear design before - how should I improve the design to prevent gear slipping?
Comment: By "gear slippage" are you referring to excessive backlash or teeth slipping from one tooth to the next??
Comment: Your question is too broad, be more specific.
Comment: Primarily teeth slipping, though I would like to minimize backlash if possible.
Answer: Teeth on gears generally will not slip if your pitch and tooth profiles match properly, since the teeth would have to break off to slip. Minimizing backlash can be done by tight tolerance control.
Looking at the images you have it appears as though you've designed the teeth more freeform and by eye, rather than calculating the profiles (I could be wrong though). If you're working through CAD to completely design the gears, you can write a macro that will generate profiles based on any tooth profile.
The general process for this is create your drive gear however you like. Then create an idler gear with no tooth profile at all overlapping the drive gear. Subtract the interferance between the two parts from the idler, then rotate each based on your prescribed gear ratio. (how much you rotate each will depend on how accurate you need you profile to be). Repeat until you've completed one full rotation of whichever gear you're trying to make.
- basic youtube video of how it works here https://www.youtube.com/watch?v=9MycFQKnZkA
Or you can go the pure math method of designing the gear tooth profile completely through mathematics. Which is much more complicated.
Easier still, use off the shelf gears!
Comment: It's very cool to see that someone has inserted a link from a channel that I've been tracking for a long time.
Comment: Am i also right to comment that the teeth will slip if it has parabolic/curved profile? Is the contact between the gears significantly reduced due to its shape?
Comment: @JemEripol I'm not totally sure what you mean by parabolic/curved profile.  Depending on the size of the gear and pitch circle a true parabolic curve may or may not give you constant contact between teeth. But if the pitch circles between two mating gears intersect at the point of contact your gears won't slip unless you break a tooth off or the axis of the gears moves.
Comment: I'm not sure if I answered your question or not. To be clear though, teeth on gears don't slip if the gears are made properly. That's one of the primary reasons to use them over a belt-pulley system. For teeth to slip the teeth would have to break off, be sized incorrectly to allow them to flex out of the way under loading (EXTREMELY mis sized gears) or, the two axes have enough play in them the the teeth no longer touch, or the tooth profiles don't mesh properly. All of those are easy to tell just by looking at the gears.
Answer: In gear design, the most used tooth profile is the involute profile. I am not sure what do you mean by avoiding slipping(Velocity of sliding) because for two gears to move, there will definitely be slip as they have to maintain the contact while they transmit motion(except at the pitch point).
Since you are using a 3D printer, please use the cycloidal profile as a tooth profile which rolls without slipping. The reason people don't use it is the difficulty in mass manufacturing.(Although they are used in clocks and watches)

Gear Design - Teeth Fit


Invoking a EJB from PHP

Question: Is there any easy way to invoke a RMI method on a EJB from PHP? We have a java app and a PHP app that sometimes needs to talk to it. What we do now is have a java binary that PHP invokes when it needs to do something, but I would love to know if there is a way to do this directly from PHP?
Answer: maybe this helps you out. i'm facing the same problem at the moment and finally i decidet to do all i need via SOAP, using a java-webservise as server and the soap-client in php.
Answer: There are a couple of options to tightly (or loosely) integrate PHP and Java. There are 2 PHP-Java bridge solutions out there. One open source, the other by Zend.
http://php-java-bridge.sourceforge.net/pjb/
Alternatively, there is a product called Quercus which actually runs your PHP code in Java. You can then call anything that java can from inside PHP as if it was a native function. Quercus doesn't support ALL PHP functions and commands, but you can run WordPress under without changes.
http://www.caucho.com/resin-3.0/quercus/

Invoking a EJB from PHP


How do I insert a row into numbers, in just one column

Question: How do I insert a row in one column only. By moving the current data down and inserting a row above it. I don't want to insert a row across the entire spreadsheet - just that column.
Answer: From Numbers help:

Move rows and columns within a table Select one or more rows or
  columns.
Do any of the following:
Move rows: After selecting the rows, click and hold the row numbers
  until the rows appear to rise off the table, then drag them above or
  below another row.
Move columns: After selecting the columns, click and hold the column
  letters until the columns appear to rise off the table, then drag them
  to the right or left of another column.
Tip: If you drag rows or columns outside of an existing table, you
  create a new table with them.

This has plagued me for ages and I took to forums to unsuccessfully find the answer, till I finally used the help function found in Numbers.
Answer: In excel it is no brainier, just use copy and Insert and it will asks you to move that row up or down.
In Numbers I found this answer here.

Numbers and Excel are built on different frameworks in the sense that
  an Excel table/spreadsheet is virtually boundless and Numbers tables
  are finite and generally only as large as the data requires. Pushing
  some cells out of the way to make room for others has greater
  implications in Numbers, and it is left to the user to make room by
  moving the cells manually. I once counted mouse clicks to achieve the
  insertion in Numbers vs. Excel and the difference was small to none.
  Yes, Excel will move cells for you, but not until you tell it which
  way to move them. With Numbers you just do it yourself.
There's a nifty command pair in Numbers that helps with the job. It is
  +Mark for Move+ and Move.
Select the cells to be moved, Edit > Mark for Move, click to select
  the cell where you want the upper left cell of the range to move to
  and then Edit > Move.
Comment: Gone in the current version. :(
Comment: Not an answer but, This has rendered Numbers useless to me as I often add internal rows in spreadsheets and need o move existing rows up or down without affecting other columns.


Can you get burn cards anyway other than challenges?

Question: Are you limited to only receiving burn cards as challenge rewards, or is there someway to get them for just scoring? What happens when you run out of challenges?
Answer: You get burn cards everytime when:

every 5 levels you get a pack of rares
after every match you get one

you also receive cards randomly as you do pretty much anything in the game:

kill grunts
kill spectres
kill titans
kill pilots
escape
destroy drop ship
cancel other player's cards

You will see "burn card earned [task]" (example "burn card earned grunt" for killing some grunts) in red/orange in your xp feed when you collect a new card.
The cards you get from challenges are more related to the challenge itself (Gun challenges will give you amped versions of that gun), while gameplay cards are completely random.
Answer: Yes, various actions (killing stuff, not noticed any for peaceful play) in game may randomly award you a burn card. Completing challenges is not the only way to acquire them, and from what I've played so far it isn't even the biggest provider of them.
Comment: Actually, come to think about it, I think you can get them for evacs.


TimeOut excpetion on websocket using Nethereum

Question: I'm working on a frontrunning bot using Nethereum. the problem I'm facing is the following, once I get all the pending transaction hashes through the websocket, I pass the hash trhough EthGetTransactionByHash to get its details and two scenarios happen:
if I declare one web3 or websocketclient instance and use it for all the EthGetTransactionbyHash requests, I end up very quickly getting the details too late(transaction already validated). On the other hand, If I create one instance of web3 or websocketclient per EthGetTransactionbyHash request, it becomes very fast, which is nice, but after few seconds it starts generating Nethereum.JsonRpc.Client.RpcClientTimeoutException: Rpc timeout after 20000 milliseconds ---> System.Threading.Tasks.TaskCanceledException. AND Nethereum.JsonRpc.Client.RpcClientUnknownException: Error occurred when trying to web socket requests(s): eth_getTransactionByHash ---> System.OperationCanceledException: the operation was cancelled).
so far, I haven't made any major coding, it's just the websocket and streaming tutorial https://docs.nethereum.com/en/latest/nethereum-subscriptions-streaming/ plus eth_getTransactionByHash for each hash detected, nothing more
Answer: I found the solution, what I have done, I created a concurentQueue that I populated with 100 web3geth variables (it only works with web3geth and the RPC URL, don't ask me why :-p  ). then I use each entry for one request via dequeue, once it is dequeued and used, I enqueue it again so concurentqueue remains populated without having to create any new variables. I tested the app for 5 minutes and it didn't raise the exception once. so you can keep it in mind for future reference if someone else asks. PS the ethgettransactionbyHash also needs to be launched in a new thread.


Sprite Animation in Pygame Zero

Question: How do I use a sprite sheet in pygame zero?
The height of the images are 32, width is 25
Comment: Have you looked up guides for using spritesheet animations in Pygame, and tried using them in Zero? Where did you encounter a specific obstacle or incompatibility when doing this?
Comment: @DMGregory All pygame sprite tutorials use py. or some variation of that, pygame zero is simple, no code is necesarry to make a window in pygame zero, it could be a 100% blank file, and it accepts it.
Answer: As you've probably discovered, Pygame Zero doesn't have direct support for spritesheets. If you want to programmatically extract the desired sprites from the sheet at run time you'll need to use python code to do that. There's  spritesheet code on the Pygame wiki.
Alternatively, you can use some other app to extract the sprites to individuals files for Pygame Zero to use. A web search for "spritesheet extractor" brings up a number of online options. You could also use most any image editing capable software (Photoshop, Gimp, Krite, Paint.net, etc) to manually extract the desired sprites.

Sprite Animation in Pygame Zero


Can we get rid of automatic conversion to CW?

Question: Here is a recent example. Can we get rid of automatic conversion of questions to CW?
https://cstheory.stackexchange.com/questions/19222/constant-factor-approximation-of-hypergraph-maxdicut
Comment: @Suresh, I don't know. I have avoided doing it so far and would prefer if this is fixed in place of us unCWing posts. Since the CWization questions is now a mod only action it seems strange that they have kept this relic feature.
Comment: Hmm. this is a weird case when the same user did a frantic series of updates triggering the CW mechanism.
Comment: @Suresh, yes, it is. ps: see also http://meta.mathoverflow.net/questions/871/
Comment: so we can (and should) remove CW status from that question ?
Comment: Is there a typo in the linked question?  Clicking on it takes me to a "page not found" error".
Comment: @D.W. the link is correct. Its author has deleted the question.
Comment: Ahh, gotcha.  Thanks.  Do you think we lost that content because the author was frustrated over the auto-CW conversion, or do you think the deletion was unrelated?  (I realize there's probably no way to know.  Please feel free to ignore my curiousity if it's inappropriate.)
Comment: As Kaveh points out, CW is now a mod-only feature, so auto-conversion makes no sense anymore.  Moreover, I think editing a post to bump it to the top of the activity page is likely to make people want to remove their upvotes in irritation, and the updates will allow them to do so.
Comment: For another example, this question http://cstheory.stackexchange.com/questions/19626/questions-about-special-types-of-partial-assignments was made CW after a series of updates.
Answer: TL;DR: This is an excellent suggestion -- one that I think there is sadly no chance of being implemented, alas.  The only way to fix this is to rely upon our moderators to un-CW such questions (you'll have to flag it for their attention).  I'd certainly hope our moderators would be glad to do that.

In more detail: I agree with you.  I too would like to see automatic conversion to community wiki disabled.  I think it's a lousy feature; it disincentives improvements to questions and answers.
Unfortunately it has been suggested previously on Meta.Stackoverflow many times over the past 4 years, and it looks very unlikely that it will be changed:

SO is too eager to turn my edited answers into Community Wiki
Community Wiki punishes users for improving their posts
Should authors be encouraged to maintain their answers?
What is the reason behind auto convertion to Community Wiki after 5-10 edits?
Why does repeated editing by same user lead to community wiki?
Is there any point forcing a post to Community Wiki after 6 owner edits?
Don't auto community wiki answers to questions made CW through too many edits
Give some kind of warning before Community Wiki takes effect?
Add warning if your edit will make the post Community Wiki
Avoid conversion to CW at 10 edits: allow user option to not have post pushed to top of home page

Apparently, the rationale given for the existing auto-CW-conversion behavior is that the site designers were worried that people would continually edit their question to bump it to the front page of the site.  I personally don't think the current behavior is the best solution to that problem, but whatever: it's clear that the site developers have a different view, that they have thought about this, they do have reasons for the current behavior, and ultimately, this is unlikely to change (at least, not in the foreseeable future).
For now, no changes seem likely to come our way.
Instead, the standard workaround seems to be: if you notice that a question/answer was auto-converted to CW inappropriately, flag it for a moderator (flag as "needs moderator attention"), and ask the moderator to please reverse the community wiki status.  Moderators have that ability.  Apparently, many moderators have stated that they do routinely grant these requests (absent concrete reasons not to), and it is considered legitimate to ask the moderators to do so.  See, e.g.,

https://meta.stackexchange.com/a/179756/160917
What criteria are taken into account when deciding to undo Community Wiki status on answers?
https://meta.stackexchange.com/a/192438/160917
https://meta.stackexchange.com/a/83373/160917
https://meta.stackexchange.com/a/179825/160917

Unfortunately, you'll still lose any rep that was accumulated between when the answer was auto-converted to CW and when the moderator reverts the CW status.

My proposal: Our moderators should routinely and gladly grant such flag requests, as long as there has not been any signs of abuse.  We should be grateful to anyone who takes the time to improve their questions or answers, as long as they're not abusing the feature to try to bump their question/answer to the front page.  I don't think our moderators should refuse to grant such flags (e.g., on the basis that they're going to wait for this behavior to be changed -- as it's pretty clear this behavior is not going to be changed any time soon).  That just penalizes people who put extra time and energy into improving their questions/answers.
Comment: Your rationale is only partially correct. The premise was that if enough people are constantly editing and adding to a post, that shared collaboration becomes a "wiki" owned by the community. The most common use case when *one* user is constantly updating their post, is when they are maintaining a summary answer from a lot of contributions below. I'm not fond of the feature itself, but the automation works the majority of the time. But when it doesn't, it's a simple matter for a Moderator♦ to correct and inadvertent changeover like that. That's why we call them "exception handlers."
Comment: @RobertCartaino, yeah, I've seen that argument before.  Just one comment.  You write that, when an author's repeated updates triggers auto-conversion to CW, the most common cause is that the author is maintaining a summary answer based upon contributions from others in the comments.  Well, that's not my personal experience (though others' experience may vary).  Anyway, I agree the solution is to ask a Moderator to un-CW affected posts.  I hope your note will encourage the moderators to be open to do so, where appropriate.


What makes Oracle Database Enterprise Edition worth the money?

Question: Oracle Database Enterprise edition costs $47 000 per processor. I wonder what features make it worth this money?
Comment: Compared with what ? Against a person's annual salary it isn't that much, and a typical equation is, if we pay for *function/product x* what are the savings against the cost of Full Time Employees (FTE)
Answer: My personal opinion (and do feel free to mark it down if you don't agree) is that the people at Oracle aren't that dumb. They know their marketplace and segment there offerings to match. So they price it based on what they believe the customer is willing to pay for the features available.
From the customer perspective i'm sure Oracle's clients do look at the feature set and services they offer. Then if the ROI proposition is sound and the features are required then thats what will be paid.
Having said that the $47,000 is the list price and depending on the company size and influence with Oracle this can be reduced when negotiating contracts.
Comment: Joining the dots between your answer and Kevin's, one reason for the large list price is that it is used as the basis for the 22% annual maintenance/support fee.
Answer: The reality is that it is not worth that price and almost nobody pays it. All of the DB vendors have large list prices except for MS. Talk to a sales rep. from each. Have them come in and do their pitch and they each submit a proposal based upon your needs. If there is one brand you want more than the others, bring them back in and tell them how you really thought their product was the best fit for your needs, but there is no way you can justify a 10x price difference, they need to drastically sharpen their pencil and give you a much better bid to win your service. Most of the time, if you time it near quarter or year end properly, these vendors will not lose the sale based upon price.
Your next challenge will be the maintenance / service contract. They will try to base it on a percentage of list, and you will need to get it based on that same % of their price on the bid.
Comment: That's not true.  Almost everyone uses the enterprise edition.  Almost no one uses the strip down version because they could get the same features from one of the open source databases.
Answer: The features that make it worth the money are the ones you can't live without ;-)
Have a look at Burleson's blog for a list of features in EE that aren't in SE.
From Orafaq.com:

Standard Edition is designed for smaller businesses and enterprises. It offers a subset of the features/ functionality implemented in Enterprise Edition. Database options like Data Guard, Partitioning, Spatial, etc. is not available with Standard Edition (from 10g one can use RAC with Standard Edition). Standard Edition can only be licensed on servers with a maximum capacity of four processors.
Answer: Looking at the most recent list, I think the biggest thing right now is streams capture.  That's a key part to geographically distributing data.  Of course the CPU limit means it's only useful to for small to medium businesses but 4 CPUs on Oracle gets you a ton of capacity that will likely be more than your I/O subsystem can use.


The principle in 'Trompe' is applied to airplanes?

Question: 'Trompe' (see Wikipedia) is a water-powered air compressor, commonly used before the advent of the electric-powered compressor. A trompe is somewhat like an airlift pump working in reverse, used to provide compressed air for bloomery furnaces in Catalonia and USA. By sending a fast water flow through a duct, a pull effect on air is obtained.
I wonder if a pure Turborreactor working inside a larger Duct, with no Low Pressure Fan, would have same efficiency, with less parts, as a high Bypass Ratio Turbofan. Operation inside duct, or even inside fuselage, would result in reduction of sound and thermal prints. Salut +
Comment: Hint: compare weight of a trompe to that of a conventional pump to produce the same volume and pressure of air.
Answer: You are basically describing an ejector pump. This would not be very efficient, I'm afraid (I'll try to dig up some comparative figures).
The arrangement in this case would be a jet engine used to accelerate an amount of air inside a duct. With a long enough duct, the end result would be a single airmass exiting at (somewhat) uniform speed. Unfortunately, because energy must be conserved, the kinetic energy of the air exiting the apparatus would not even match the kinetic energy of the air exiting the jet engine, because of turbulence, skin friction of the duct etc.
Comment: The Dyson fans use this principle, there is a discussion about it here in Aviation Stack Exchange. Blessings +
Comment: My doubt came from the fact that behavior of a high speed hot jet differs from that of a large fan moving higher mass at lower speeds, and that the Trompe is somehow similar to the Dyson home fans, cited elsewhere in this site, that seem having good efficiency with low energy use. If same amount of air can be moved with a low speed fan and with the Trompe arrangement, reaching an overall efficiency close to a high bypass ratio Turbofan, you save a lot of weight and parts susceptible of failures, besides 'Stealthyness'. Was this ever tested? Thanks. Salut +


Why few languages do not have any written form?

Question: There are many languages available in the world which have no written form like shanghainese , Hakka etc .
My question is, why a language do not have any written form ? What's the root cause of it ?
Comment: Also, Shanghainese and Hakka both have written forms. Those written forms are based on the same characters used to write Mandarin and nearly all other Chinese languages, but they are particular to Wu and Hakka. For one thing, special characters are used for words which have no equivalents in other languages (e.g., 覅 _vyo_ 'don't' in Shanghainese); but more importantly, the characters represent the morphemes and phonemes of these languages, and their order follows local syntax.
Comment: The most typical reason is that nobody cares,
Comment: There are far too many possible reasons for such a broad question to be practically answerable. For one thing, you need to adequately define what constitutes a 'language' (a task the linguistic community has so far not managed) – not being considered a language is a common reason. Politics play a role, history and cultural encounters play a role, social stratification and diglossia play a role… there are myriad combinations of factors that lead to a specific form of speech having or not having a written equivalent.
Comment: There is also a world-wide organization, the Summer Institute of Linguistics, which has as its purpose the documentation of indigenous languages and translation of Christian scriptures into them. They have done a **vast** amount for literacy in all languages. Most of the grammars of very small languages come from SIL, for instance; plus they do the Ethnologue.
Answer: Writing is a technology, developed by human ingenuity within the last 5000 years. Most humans who have ever lived have had no access to that technology; and the global level of literacy reached 50% well under a century ago.
Why would you expect every language to be written?
Also, in many parts of the world, most people routinely speak several languags, and usually one or more of them have higher status, and are used to communicate with authorities. These higher status languages are almost certainly written now (though they would not necessarily have been two hundred years ago); but the other languages spoken may not be, especially if they are local. Sometimes it is even regional or national policy to prevent literacy in minority langauges.
Answer: Your title question asserts that there are few languages with no written form, and the body asserts that many languages have no written form. I'm guessing that you the titular assumption doesn't express your intent, but it is the more accurate statement. Most languages have a written form of some sort. However, most languages do not have a well-established, standardized written form. For example, there is substantial chaos in the writing of the Bantu language Logoori – no fixed, official orthography. Nevertheless, it is written, when people write in Logoori (which is not very often). Likewise the Kalenjin languages can be written, but there are multiple spelling schemes for the language, and not a single monolithic set of writing conventions. These languages are easily writable in a conventional fashion, and are so written, but the orthographic conventions are "fluid". The first question that ought to be answered is, what standard should be assumed in assessing whether a language "has a written form"?
One language that has no written form is Sentinelese. The reason why there is no written language is that it's illegal to visit their island and the evidence of arrows being shot at planes indicates that the inhabitants don't want an outsider invasion. Such isolated communities with no schools and no literacy at all are extremely rare in the modern world. Another possible example is Quinault, a Salishan language on the coast of Washington – the Quinault rejected linguists and anthropologists probing their culture, and it is possible that no written form was developed (maybe Jlawler knows more about that). On the other hand, Lushootseed has a written form, a standardized non-IPA Americanist phonetic transcription, which I thought only a linguist would love but it has been firmly embraced by the people (no doubt because Taqʷšəblu spent decades promulgating the language). In other words, (a) someone has to suggest a way of writing a language and (b) the people who speak the language have to accept that suggestion.
Languages which are so big that they are national languages enjoy the prestige of governmental support and potentially standardizing legislation. Hence in Norway, Bokmål and Nynorsk are two standardized ways of writing Norwegian. Local dialects like Northern Norwegian or Valdrismål are writable, but there isn't the same standardizing force dictating that there be just one way to write.
Since the vast majority of languages in the world are small local languages with limited resources or economic appeal, and most people speak one of a few major, standardized languages, systematic writing systems for most languages are not crucial. People can manage with a certain degree of variability in how they write the local language, if they do need / want to write the local language.
Comment: Do we actually know that Sentinelese has no written form? Given their environment, populace and way of life, it's not particularly likely the Sentinelese have invented writing, but we don't actually know for sure, do we?
Comment: NW Americanists know that the Quinault don't want their language and culture examined by outsiders, and we don't, by and large. But there's a lot on the surrounding languages and cultures, all of which have orthographies and resemble one another. There was a similar problem with the Hope when Ken Hill was working on his dictionary; for that reason it was published only within the tribe and is now out of print. But Hopi speakers can use it, and there's an orthography.
Comment: FWIW, the title is just incorrect English. OP's native language perhaps lacks articles, but it's clear when the indefinite is added before "few."


Finding The Goblin Tinkerer in Terraria Xbox360

Question: I know other People already asked this question, but I just cant't find the Goblin Tinkerer. I am really close to defeating Skeletron, but many are telling me he is not in the Dungeon. Help!?
Comment: By the way, he can spawn in any underground area, including the dungeon itself.
Answer: The goblin can show up randomly in caves , as it is not necessary to kill* Skeletron Martar it then appears .
Comment: He can only show up after defeating the goblin army at least once. That's the only requirement.
Answer: You need to be on hard mode.Defeat the goblin army and then you can randomly find him underground in the places you've already explored.
But you can't see his icon on the map until you see him on your screen while exploring.
    Hope I helped.
Comment: Hardmode ? No way. You must have confused him with the Wizard NPC, as he spawns randomly in caves when hardmode is activated.
Comment: Oh,I thought he only spawned in Hardmode because I always find him in hardmode.
Comment: Well, it's all a matter of luck, so it could have happened for the unlucky ones to go in hardmode before finding him :)
Answer: You do not need to defeat Skeletron, or in fact any other bosses for the Tinkerer to spawn.
You must complete the Goblin Army event at least once in that world. For the event to trigger (from the Terraria wiki):

You must have at least one person in the game with at least 200 current life.
You must have smashed at least one Shadow Orb or Crimson Heart.

Once these conditions are met, the Goblin Army has a 1/3 chance of happening each day. Alternatively, you can craft a Goblin Battle Standard using Wood and Tattered Cloth at a Loom, and use this item to trigger the Goblin Army. Tattered Cloth can be obtained by defeating Goblin Scouts in the outer 2/3 of the world (ie. closer to the Oceans, far from the spawn point).
After completing the Goblin Army event, the Goblin Tinkerer can be found randomly tied up underground. Keep a close eye when adventuring and he should be fairly easy to spot. Also, if he spawns underground and the player walks too far away he can respawn at another location. Speak to him and release him, and he will move into the next available house.
Comment: Great answer. We tend to prefer you reword a copy paste from the internet, though. Especially if you fail to reference your source
Comment: How did I fail to reference the source? The source is literally linked in the same sentence.
Comment: Edited the answer to add a source. Was that why I had a downvote?
Answer: You can find him anywhere underground, possibly even the dungeon. So I suggest looking underground. If he's not there, he is in the dungeon.
Comment: Note: I found him next to d.a