Does this type of Dual Voltage AC Drive exist?

Question:
The goal is to run a 3ph AC motor with either high or low voltage inputs.  The motor would be wired for a specified voltage and the controller drives a single output regardless of the line voltage.  I looked at VFDs but I can't seem to find a unit with a variable line input.  Does such a device exist?
Comment: The problem is that the internal DC bus voltage will be \$ \sqrt 2 V_{RMS} \$. Most drives have under and overvoltage protection - maybe ±15% of rated input and the drive will fault out. You might find one that will cope but beware of units not built by recognised industrial brands.
Comment: You can shop for a buck or boost or multi-tap transformer. It does not have to be the isolation type. Find one with a useful primary voltage but several output voltages. You could buy a 3-phase variac but they get expensive.
Comment: Just a common AC servo system.
Answer: It seems unlikely that you will find such a VFD, but it may be worthwhile to look carefully at the protection specifications and setting ranges if the UV and OV protections can be set by the user. The cost of the 400 V class models is sufficiently more than the cost of the 200 V class. That would make 400 V class products designed to accommodate 200 V class operation non-competitive in the market. Manufacturers are not going to offer products that are not competitive. Even if it costs little to make a 400 V VFD capable of operating in the lower range, manufacturers would not be likely to do it. However there may be a market for VFDs that can tolerate extreme voltage dips. So some manufacturers may have that capability that is not advertised as dual voltage capability.
Answer: This was done years ago with some brands of solid state soft starters. You could apply any voltage higher than the motor voltage and it would limit the output to the programmed lower level to match the motor. But soft starters are roughly 97% efficient, meaning you lose 3% of the power as heat, so they can't be enclosed without a lot of ventilation. Soft Starters are enclosed all the time of course, but because we use a bypass contactor, however using a bypass contactor then eliminates this possibility. So the product concept died about 20 years ago from lack of interest due to the inherent problems. Nobody has pursued it again most likely because transformers will always be cheaper.
I should note that soft starters are not "drives" in that they can't change the speed, just the voltage. With "drives" like VFDs, the problem described above makes the concept untenable; the DC bus voltage would be far too high and likely cause damage to a lower voltage motor.
Answer: To address another aspect:

Figure 1. A VFD internal diagram. The DC bus consists of the DC power-rails from the capacitor to the top and bottom of the transistor switches.
It should be clear from Figure 1 that the transistors will apply the full DC bus voltage to the motor. If running a 220 V motor, which would expect to see a phase to phase peak voltage of 220√2 maximum, on a 460 V supply it would see the DC bus voltage of 460√2 instead.
While the average voltage and current could be controlled in the VFD algorithm, the peak voltage could not. It is very unlikely that the winding insulation of a motor rated for 220 V could withstand that level of over-voltage.
Answer: there are dual rated drives but the output voltage is what the input voltage is. that means you would need to change the motor wiring according to the drive supply source negating the convenience of changing voltage input to a static motor.


How could I create a side chain of the eos mainnet?

Question: As EOSIO protocol says, the eos can support multiple chains, how can I setup a side chain and communicate with it, I've saw dan's paper, but, what's the technique way?
Answer: You can create your own sidechain with your own private EOS blockchain,for that you must have chain running on different chainId from Mainnet and you can select the block producer from 21 mainnet block producers or you can validate transaction by yourself however, should be able to perform cross chain communication one day so in theory, the side chain can communicate with the main chain.
will-eos-sidechains have the same block producers as the eos-main chain
Answer: oh, it's easy. Perhaps you find it hard cause you don't know that issue tokens is a process to create sidechains.
This's link could summarize for those steps.
https://congnghebitcoin.com/threads/common-steps-for-creating-eos-account-and-issue-token.1204/
Comment: Creating tokens and creating sidechains are two different things. This answer is wrong.
Comment: The answer is definitely wrong.
Comment: is it right? create a token is creating a sidechain?


Apple Magic Trackpad aftrer upgrade from Ubuntu 11.10 to Ubuntu 12.04 (64 Bit) - Multitouch not working!

Question: The title describes my problem. On Ubuntu 11.10 Multi-touch worked fine on my Apple Magic Trackpad. Now i have only "ONE-FINGER-Control". Scrolling is only possible on the right side of the pad with one finger. Three or four fingers are also not working any more (four fingers to to get the Dash or three fingers to move a window).
What could I do to get this working again?? (on 12.04)
Comment: no, i didn't install any driver on 11.10. I don't know what to re-install. I only did the pairing by "Using the Commandline" (from https://wiki.ubuntu.com/Multitouch/AppleMagicTrackpad) because there exists a bug: https://bugs.launchpad.net/ubuntu/+source/bluez/+bug/618838
Comment: Have you tried re-installing all of your drivers yet?
Answer: To get this working I had to install utouch:
<code>apt-get install utouch
</code>
For details, read:

https://wiki.ubuntu.com/Multitouch
https://wiki.ubuntu.com/Multitouch/Architecture
https://wiki.ubuntu.com/Multitouch/AppleMagicTrackpad
Comment: THX! It works now for 3 and 4 fingers. The only thing that does not work is two finger scrolling. On the mouse settings I can't set 2 finger scrolling, because my notebooks touchpad does not support 2 finger scrolling. So this option is disabled. Any ideas to get this separately (touchpad for notebook with sidescrolling and apple magic trackpad with 2 finger scrolling) working??
Comment: That ubuntu wiki page does not at this moment exist...
Answer: I was able to enable two-finger scroll by using the xinput command. xinput with no arguments shows all the input devices on the system. The Apple Trackpad was device 9 in my list; I used command xinput list-props 9 to see all the properties for the Apple Trackpad. I then disabled the edge scroll using the Mouse and Touchpad menu in System Settings, then enabled two-finger scrolling (282) using xinput.
xinput set-prop 9 282 1 1
The change is NOT reflected in the System Settings --> Mouse and Touchpad settings, but everything now works.


Sharepoint Online CORS to Provider Hosted Add-in

Question: I've got a really strange problem with Sharepoint Provider-hosted Add-in configuration, but only on production site.
I've got a frontend deployed to SiteAssets/home.js which is working fine, and the backend is on the Azure AppService.
On the site collection i've got the Application (_layouts/15/AppNewReg.aspx) created and the .app package from visual studio installed to global app catalog + added to the site.
When i'm calling the appService with ClientId from older deployment everything is working just fine, but when i generate a new ClientId, ClientSecret all i got from the appservice is a CORS ERROR.
I need to create exact configuration from scratch, and remove the previous, so i cannot just stick with the old "Frontend APP A"
+---------------------+----------------+----------------+
|                     | AppReg A       | AppReg  B      |
+---------------------+----------------+----------------+
| AppService Code OLD | OK             | CORS Error     |
| AppService Code NEW | 500 Error      | CORS Error     |
+---------------------+----------------+----------------+

There is a also a CORS error in the console

Access to XMLHttpRequest at 'https://xxx.sharepoint.com/sites/intra/layouts/15/AppRedirect.aspx?client_id=8c6c8d0f-28f7-4dfa-9ac0-b6bacc8be503&redirect_uri=https%3A%2F%2Fxxx.azurewebsites.net%2FFeedback%2FGetCountOfActiveTicketsForCurrentUser%3F%7BStandardTokens%7D%26IntraClient%3Df9e4fd3b-713c-47e0-8443-6c11b7abde84%26%3D1607450676287%26SPHasRedirectedToSharePoint%3D1' (redirected from 'https://xxx.azurewebsites.net/Feedback/GetCountOfActiveTicketsForCurrentUser?IntraClient=f9e4fd3b-713c-47e0-8443-6c11b7abde84&SPHostUrl=https%3A%2F%2Fxxx.sharepoint.com%2Fsites%2Fintra&_=1607450676287') from origin 'https://xxx.azurewebsites.net' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
xxx.azurewebsites.net/Scripts/jquery-3.1.1.js:9536
Answer: The solution found by comparing the tho HTTP Flows in the browser (using Teleriks Fiddler) was to enable cookies on the AppService O_O

<httpCookies sameSite="None" requireSSL="true"/>
<sessionState cookieSameSite="None" />


Are apps in SD card available after a factory reset?

Question: If I move some applications to a SD card and perform a factory reset, will they be available when I plug the card back again after the reset, even if the device's primary account changed?
Comment: I think apps moved to SD are encrypted?  Even with ext2SD or whatever you would still need to re-install the apps, at least.
Answer: To add to @Mattthew 's comment, even if you move the apps to SD card part of them always reside inside internal memory. Also the system needs to know what apps are installed, apps like Market need to know about them. So, no they won't work after factory reset.
For big games like from gameloft the extra data you downloaded from inside the game will work though. I don't know what will happen to this with the new Market policy of allowing upto 4GB files.


Melting point of solids from phonon dispersion

Question: Is there a way to predict the melting point of a solid from phonon dispersion curves, measured experimentally or via DFT?
Answer: There is a rule-of-thumb known as the "Lindemann criterion", which says that the melting point should occur when the root mean square thermal motion of a single atom is about 10% of the interatomic separation. This is not quantitatively accurate (10% is basically an arbitrary number) but a simple estimate which has a rough correlation to reality.
Using the dispersion relation one can estimate this thermal motion in the harmonic approximation, and thus make some very rough estimate of the melting temperature. Note that any calculation made using the dispersion relation must be approximate, since it only includes harmonic order in the potential, and thermal fluctuations in the lattice should be reasonably large for the system to melt (the entire idea of this criterion!)


Is Shiva a Yogi, who became Shiva by Yoga?

Question: Who is Shiva ? Was he a normal human like us who became a Yogi just by Sadhana?
Comment: Shiva is used as different things in different contexts. For example in Kashmir Shivaism, Bhairava (or Shiva) is used to refer to self. It could be a deity who grants liberation in dualistic schools to enlightened beings to self and also in non-dual schools.
Answer:
"He is Yoga and the Abode/Lord of Yoga" ~ Drona Parva 203

So he became Adi Yogi, the first yogi who is one with creation.
He is the one who brought forth the Seven Sages (saptarśi) as the Seven Gems RV6.74.1
Since He had no name and came from the North (Mūjavant), and dwelled in mountains, they called him Girisha. And they called his abode in the mountains as Kailash RVB33 as this is where all the Devas dwell being delighted in his presence.
As he was the foremost, they placed him on Dakshina and so called him Dakshina MurthiSU4.21.
Since he married the daughter of the mountain, as Kenopanishad says "Uma daughter of Himavat" they called him Umapathi TA10.22.40.22 .
All beings (bhootas) flocked around him, including pious, nefarious, and animals, especially snakes as they have unique chemistry with those in a meditative state, so they called him Paśūpati/Satpati/Bhootapati TS4.5.2, RV2.33.12, AV11.2.1 so as an overlord of all beings they called him Isha. Those who were brave and courageous took a step towards him and so He became the leader of the brave RV10.92.9.
He was independent and sovereign they called Svatantra, Svadhanva, and Svatava RV1.166.2 (Sva = sovereign).
Since he was the supreme overload/authority they called him Isha. So together he was titled Isha + Sva = Ishvar.
In him, they saw Mahat = the great principle, so they called him Maha + Isha + Svara = Mahesvara. In him they saw Vishvam, they called him Vishveswara. In him, they saw everything (Sarva) so they called him Sarveshwara CKA2.100. They saw the highest Divinity in him so they called him Mahadeva SB6.3.
They realized he was foremost and pure so they called him Sriṣṭhaḥ.
Let's start with what Yoga Sutras have to say:

"The attainment of Dhyāna Avasta shows that the mind is getting ready
for the last stage and the real practice of Yoga. Unless and until
this condition is fulfilled the practice of Samādhi cannot be begun
and the real secret of Yoga will remain hidden…. When the state of
Dhyāna has been well established and the mind can hold the object of
meditation without any distractions it is possible to know the object
much more intimately than in ordinary thinking. How does the mind
interfere with the realization of the very essence of the object? By
interposing consciousness of itself between the reality hidden behind
the object and the consciousness of the Yogi. It is this
self-consciousness or subjectivity, pure and simple, which serves as a
veil to keep it separated from the object and to hide the reality he
(sadaka) is seeking…. Patanjali calls this disappearance of the mind's
awareness of itself is Svarūpa Sunyam iva. When self-awareness has
disappeared, what is left in the mind? Only the object of meditation
can remain this is the meaning of the phrase Arthamatra-Nirbhasam… In
this Samādhi state there is complete freedom both from distractions
and self-awareness and the object alone remains in the field of
consciousness… A person that comes out of true Samādhi brings with him
the transcendent knowledge, wisdom, peace, and strength of the inner
life."
Patanjali Yoga Sutra Vibhuti Pada 1-5 by I.K Taimni

So Kailash in our mind is in the state of "ordinary thinking", and the true Kailash has to be known intimately via Yoga Samādhi. Only those Yogis/Rśis whose Veil covering their consciousness is removed the true Svarūpa Śūnyam is witnessed, this is called Darshana, where one's own consciousness is its own Witness called Sakṣhi. And these Yogis are the ones who have given us the transcendental knowledge of States beyond the mind's ordinary thinking. This state is where one can witness that Śiva with his Śakti seated beside him (together they are Śivā). And this state is not external but is the indweller of all and that indweller is Rudra. Itihasas for this very reason is the best literature that summarizes many aspects of Vedas in conjunction with various historical events. The following is from Mahabharata Itihasa Udyoga Parva belonging to the core Jaya section, wherein Garuda explains the significance of various locations/directions to the learned sage Rśi Gālava son of Brahmārśi Viśvāmitra and he beautifully summarizes it:

Gadura said: 'O Brahmanas, since this quarter saveth from sin (pápa),
and since one attaineth to salvation (Mukti) here, it is for this
saving (Uttarana) power that it is called the North (Uttara). And, O
Gālava, because the abode of all the treasures of the north stretches
in a line towards the cast and the west, therefore is the North
sometimes called the central region (madhyama). And, O bull among the
twice-born, in this region that is superior to all, none can live that
is unamiable, or of unbridled passions, or unrighteous. Hither, in the
asylum, known by the name of Vadari, eternally dwells Krishna who is
Nārāyaṇa's self, and Viṣṇu that most exalted of all male beings, and
Brahmā (the Creator). Hither, on the breast of Himavat always dwelleth
Maheswara endued with the effulgence of the fire that blazeth up at
the end of the Yuga. As Purusha, he sporteth here with Prakriti (the
universal mother). Except for Nara and Narayana, he is incapable of
being seen by the diverse classes of Munis, the gods with Vasava at
their head, the Gandharvas, the Yakshas, and the Siddhas. Though
invested with Maya, him the eternal Viṣṇu alone, of a thousand heads
and thousand legs, can behold. It was in this region that Chandramas
(the moon) was installed into the sovereignty of the entire regenerate
order. It was in this region, O foremost of all acquainted with
Brahmā, that Mahadeva first received her on his head, afterward let
(the sacred stream) Ganga fall from the heavens to the world of men.
It was here that the Goddess (Uma) underwent her ascetic austerities
from her desire of obtaining Maheswara (as her Lord). It was in this
region that Kama, the wrath (of Siva), Himavat, and Uma, all together
shone brilliantly. It was here, on the breast of Kailasa, O Gālava,
that Kuvera (Kubera) was installed on the sovereignty of the
Rakshasas, the Yakshas, and the Gandharvas. It is in this region that
(Kuvera' s gardens called) Chaitraratha lie, and it is here that the
asylum of (the Munis called the) Vaikhanasas is situated. It is here,
O bull among the twice-born, that (the celestial stream called)
Mandakini, and the mountain Mandra are to be seen. It is here that the
gardens called Saugandhi-kanaka are always guarded by the Rakshasas.
Here are many plains covered with grassy verdure, as also the plantain
forest and those celestial trees called the Sautanakas. It is in this
region, O Gālava, that the Siddhas, with souls ever under control and
always sporting at will, have their fit abodes, abounding with every
object of enjoyment. It is here that the seven Rishis with Arundhati
may be seen. It is here that the constellation Swati is to be seen,
and it is here that it first rises to the view. It is in this region
that the Grandsire Brahmā dwelleth in the vicinity of Yajna (sacrifice
embodied). It is in this quarter that the sun, the moon, and the other
luminaries are seen to revolve regularly. It is in this region, O
foremost of Brahmanas, that those illustrious and truth-speaking Munis
called by the name of Dharma, guard the source of the Ganges. The
origin and physical features and ascetic penances of these Munis are
not known to all. The thousand dishes they use for serving the food
offered in hospitality and the edibles also they create at will, are
all a mystery. The man, O Gālava, that passeth beyond the point
guarded by these Munis, is certain, O foremost of Brahmanas, to meet
with destruction. None else, O bull among Brahmanas, save the divine
Narayana, and the eternal Nara called also Viṣṇu, succeeded in passing
beyond the point so guarded. It is in this region that the mountains
of Kailasa lie, the abode of Ailavila (Kuvera). It was here that the
ten Apsaras known by the name of Vidyutprabha had their origin. In
covering, O Brahmana, the three worlds with three steps in the
sacri1fice of Va!i (the Asura king), Viṣṇu had covered this whole
northern region; and, accordingly, there is a spot here called
Viṣṇupada. And it is so called after the footprint of Viṣṇu caused on
that occasion. Here, in this quarter, at a place called Usiravija, by
the side of the golden lake, king Marutta performed, O foremost of
Brahmanas, a sacrifice. It is here that the brilliant and shining gold
mines of Himavat exhibit themselves to the illustrious and regenerated
Rishi Jimuta. And Jimuta gave away the whole of that wealth to the
Brahmanas. And having given it away, that great Rishi solicited them
to call it after his own name. And hence that wealth is known by the
name of the Jaimuta gold. Here, in this region, O bull among Bharatas,
the Regents of the worlds, O Gālava, every morning and evening,
proclaim. 'What business of what person shall we do? It is for these,
O foremost of Brahmanas, and other incidents, that the Northern region
is superior to all quarters. And because this region is superior
(Uttara) to all, therefore, it is called the north (Uttara). The four
regions have thus, O sire, been, one after another described to thee
in detail. Towards which quarter then dost thou desire to go? I am
ready, O foremost of Brahmanas, to show thee all the quarters of the
earth !' '
Mahabharata Itihasa Udyoga Parva 111, Jaya section

Samvarta said, "There is a peak named Munjaban on the summits of the
Himalayan mountains, where the adorable Lord of Uma (Mahadeva) is
constantly engaged in austere devotional exercises. There the mighty
and worshipful god of great puissance, accompanied by his consort Uma,
and armed with his trident, and surrounded by wild goblins of many
sorts, pursuing his random wish or fancy, constantly resides in the
shade of giant forest trees, or in the caves, or on the rugged peaks
of the great mountain. And there the Rudras, the Saddhyas, the
Viśvedevas, the Vasus, Yama, Varuna, and Kuvera with all his
attendants, and the spirits and goblins, and the two Agwins, the
Gandharvas, the Apsarasas, the Yakshas, as also the celestial sages,
the Sun-gods, as well as the gods presiding over the winds, and evil
spirits of all sorts, worship the high-souled lord of Uma, possessed
of diverse characteristics.' And there, O king, the adorable god,
sports with the wild and playful followers of Kuvera, possessed of
weird and ghastly appearances.^ Glowing with its own splendor, that
mountain looks resplendent as the morning sun.^ And no creature with
his natural eyes made of flesh, can ever ascertain its shape or
configuration, and neither heat nor cold prevails there, nor doth the
sun shine or the winds blow.^ And, O king neither doth senility, nor
hunger, nor thirst, nor death nor fear afflict anyone at that place.^°
And O foremost of conquerors, on all sides of that mountain, there
exist mines of gold, resplendent as the rays of the sun. And, O king,
the attendants of Kuvera, desirous of doing good to him, protect these
mines of gold from intruders, with uplifted arm.
Mahabharata Itihasa Aśhwamedhika Parva 7, Non-Jaya section

Vedas describes Rudra as being the indweller of all and the heart of all Devas RV 7.46, TS 4.5, SUpa 3.7/3.2, Brūpa. All possibilities and celestial dimensions that come into being is that Rudra TA 10.24.42. When all possibilities arise in Him, how can He be fit on something or dwell in a specific geographic location?

Rudra is the pure, spontaneous self-experience which is the one
consciousness that dwells in all substances. It is the seed of all
seeds, He is Prana, He is Atman, it is the essence of this world
appearance, it is the greatest of actions. It is the cause of all
causes and it is the essence in all beings, though in fact it does not
cause anything nor is it the concept of being, and therefore cannot be
conceived. It is the awareness in all that is sentient, it knows
itself as its own object, it is its own supreme object and it is aware
of infinite diversity within itself. This infinite consciousness can
be compared to the ultimate subatomic particle which yet hides within
its heart the greatest of mountains. It encompasses the span of
countless epochs, but it does not let go of a moment of time. It is
subtler than the tip of a single strand of hair, yet it pervades the
entire universe. No one has seen its limits or boundaries.
Yoga Vaśiṣṭham 6.1.36 Swami Venkateshananda

Rśi Kasyapa said, 'Rudra exists in the hearts of men. He destroys the
bodies themselves in which he dwells as also the bodies of others.
Rudra has been said to be like atmospheric visitations and his form is
like that of the wind-gods.  Mahabharata Itihasam, Shanti Parva,
Pratap Chandra Roy

All that is (विश्वं) and all beings (भूतं) and all celestials dimensions (भुवनं)
and all the wonders (चित्रं) all possibilities and diversities (बहुधा)
all that is born/all happening/ all existence (जातं) all that has come
into being (जायमानं) is that (यत् =is that Rudra) | Entirety is
controlled (सर्वोह्येष) Rudra's delight (रुद्रस्सन्महो) to him we
surrender/salutations (नमो) so it be, said/concluded (अस्तु)
Taittirīya Āraṇyaka 10.24.42

Source: 1. Who is Shankara
2. What is Kailash and where is it located


Can any one who tests game can test software?

Question: One who test games, can they test software too? or they need any special requirements for software testing?
Comment: A game is a piece of software. A "game tester" therefore tests software. A professional "game tester" should of course be able to test other software than games. So why do you ask?
Comment: The question worded this way ask more for opinions than for knwoledge. I would rather ask what makes testing games different from testing other software.
Answer: I'm going to start with my standard response: it depends.
I'm assuming you're talking about computer games and not board or other kinds of games, but the computer game industry has something of a reputation for using a lot of unskilled testers. That reputation comes from the fact that the large game development companies can call on gamers who think it would be cool to get their hands on the new hot game before anyone else (and some of them would do it free). That pool burns out fast but gets cycled quickly, too. Someone whose only games testing experience is from this group is going to be out of their depth in most commercial applications testing.
On the flip side, the skilled testers in the game industry would have no difficulty moving to commercial applications. They'd need to become familiar with the application domain but beyond that, there wouldn't be a problem.
Comment: On a slight flipside to this, I often find that a good games tester exhibits skills that you would want in any industry, and often prove to be excellent within the software industry because of it. After starting in the games industry and hiring those from it into software, I consider these traits high on my hiring list... and I can easily spot someone without them.
Comment: Absolutely @DiscoMcDisco - skilled testers are skilled testers whatever segment of the software industry they're in.
Answer: Tester role requires some degree  of creativity, ability to spot the things and learn-ability.
Those who are testing games do have these qualities. Question comes to understanding and adapting  tools and process used in software testing.
I guess it is matter of adapting and learning  tools and processs for person who is in game testing.
Answer: Game is software actually. Testing process is still same in common for any software product for selected workflow. Game testing has own features but it still software testing as far as I know. Each software product requires some special knowledge which you can get during work.  So, answer on your question is YES, test engineer who understand development life-cycle, testing process would not get any hard problems in software testing.


App Store update not working in Mac after upgrading to Sierra

Question: I have recently upgraded my Mac to Sierra. After upgrading AppStore update not working. It shows I have to update for apps Keynote, Pages, Numbers and GarageBand. But while I want to update those individually or all at once every time AppStore ask for the password. If I put correct password it ask the password again and again. If I put incorrect password it shows that password is incorrect.
Answer: Here's some things to try:

Close and reopen App Store
Reenter iCloud credentials in System Preferences
Turn Mac off and back on

If none of those work, it might be an issue with Apple's servers, in which case you'll have to wait it out.


Why did the Rosen corporation want to discredit the Voight-Kampff test?

Question: In Philip K. Dick's Do Androids Dream of Electric Sheep?, why did the Rosen corporation want to discredit the Voight-Kampff test? If the new Nexus 6 types were to be so good and human-like that they pass the empathy test, then wouldn't the pressure be on the Rosen corporation to stop the Nexus 6 production? I would imagine that the company would be glad if they failed the test so that escaped androids can still be easily detected and retired. Were they trying to show how good their Nexus 6 are?
Comment: The VK test may not be a definite yes/no thing. There's a score - over this score you're a replicant, under that score you're human. Neither ever scores close to the borderline. But if the Nexus 6 can get scores close enough to human values that there is doubt, then discrediting the VK test (even a bit) means it can't be used reliably, which helps the corporation.
Answer: I believe that it was a way to get a hold on Bryant.
They made him make a mess of the test and then used that to get him to be cooperative.


Arguments passed to the services giving dependency non-existence service error in shopware 6

Question: I have to use HttpClientInterface at my service page. So I defined as following:
use Symfony\Contracts\HttpClient\HttpClientInterface;

public function __construct(HttpClientInterface $httpClient)
    {
        $this->httpClient = $httpClient;
    }

In my services.xml file I have also trying passing the argument and also set autowiring

<service id="SwagMasterBundle\Service\ProductManager" autowire="true" autoconfigure="true">
    <argument id="Symfony\Contracts\HttpClient\HttpClientInterface" type="service" key="$httpClient"></argument>
</service>

But I am getting error:
The service "SwagMasterBundle\Service\ProductManager" has a dependency on a non-existent service "Symfony\Contracts\HttpClient\HttpClientInterface".
Can anybody help me what I have done wrong here ?
Thank You.
Answer: You can't expect an interface, since an interface needs to be implemented from a concrete class. So, in your case you need an concrete object - Symfony services are simple objects.
Please refer to object orientated programming basics first.
Edit: Also autowiring and defining the given services doesn't make sense. Let the framework determine the needed object or do it yourself, but chose one option, not both at a time.
Comment: ok but how can I use httpClient in Shopware 6. I used same way in symfony project.


WPF: Show UserControl before all bound properties are loaded

Question: I have one UserControl which has a ListView showing a list of Client objects. Double clicking one of the rows plays an animation and transitions to another UserControl which shows the list of accounts for that client.
The second user control is bound to the Accounts property on the Client object. The list of accounts is loaded the first time the property is accessed. This all works great if the list of accounts is small. If the list of accounts is large, there is a very noticeable delay between double clicking and the list of accounts appearing. And the animation doesn't play at all.
I understand what's going on here, but I'm not sure of the best way to fix it. How would I make it so that the animation still plays and the second user control is shown, but the list of accounts appears as they're loaded? I understand I'm going to need to load the list view asynchronously, and I have no problem using a BackgroundWorker for this, but I'm not sure where this loading would happen.
The list of accounts is an ObservableCollection, and the Client object implements INotifyPropertyChanged, however doesn't call PropertyChanged for the accounts property because it doesn't have a setter.
Answer: I think you need to look at the Virtualized controls in WPF - these only display the contents required not the whole list and are therefore a lot faster than the standard ListView.
Answer: You can try and set IsAsync=true on the binding, for example: {Binding Path=Accouns, IsAsync=true}


Spanning text across facing pages in Indesign

Question: I have a document with 8.5x11 facing pages that will be printed on 11x17 paper. Can I span a headline across the facing pages without running into a problem with text being cut off? Or would it be better to create the document as 11x17 instead?
Comment: Why wouldn't you just use an 11x17 document if that's your intent?
Answer: Depending on the thickness if your document (how many pages?), you might lose some of the middle in the gutter but otherwise you'll be fine.
How many pages? Where will this spread be in your document (centrefold? Somewhere else?)
Answer: It will not matter if you span your text over facing pages, or if you are using a single page. What matters is how you output, or finish the product.
If you are making a folder with more than 4 pages, you should start thinking about the risk of text being cut of. Generally there is a good rule to not place any letters in the fold. You might also want to increase the kerning slightly between the two letters at each side of the fold, to give some extra space. Also keep low width letters (i, I, l, j) away from the fold, as there is a risk of misalignment resulting in a small width letter disappearing completely.
As a rule I will recommend that you always use facing pages rather than single sheets for folders. This might save you from extra work later in the project.
Answer: Any text that falls outside of the printer's printable area (typically .25-.375) will get cut off.
There are a couple of ways you can resolve your issue.
Probably the easiest way around you issues is to check the "Spreads" button in the "General" tab of the print dialog box. This will print the facing pages together on your 11x17 page.
Alternately, you can change your page dimension to 17" x 11" and double your L/R margin in the center of the page to account for the gutter. Then print normally on your 11x17 paper.


Naming a book in a language different from where it would be published: is it good?

Question: The book is being written in Portuguese, would it be bad if the name is in English?
The name is just "The Awakening". I prefer the title in English because it sounds better than in Portuguese ("O Despertar"), which sounds a bit like a generic fiction. But would it be good? Because "awakening" is a word of significant size, and have "W" and "K", and "ening".
Comment: You know the Portuguese/Brazilian market: is it common to have books with English titles, although the rest is translated? My *feeling* is that it is a cultural thing.
Comment: Unfortunately, no. There are very rare cases of productions in English which the title is left untranslated, like Minority Report, Game of Thrones, and some others.
Answer: I cannot speak for Portugal, but in Germany, "American" (that is, US American) movies, music and books are considered to be great by default. In media, "American" is a label that signals great entertainment to German consumers, and the most popular films, tv series, books and musical recordings are "Made in America". On top of that, English is considered a "cool" language, everyone learns it in school, it is the language of the music we listen to as teens, and it is the lingua franca of the internet. In Germany, many advertisings for "cool" products feature English slogans, and many products have English or English sounding names.
As for media, while movies are generally dubbed and books translated, American movies usually retain their original titles, even if those titles invovle puns or other features that are difficult for the average German to understand. Books, on the other hand, often receive a new German title, which may or may not be a translation of the English title. But recently many books from the Young Adult category have been published in a German translations with the original (Americal) English title. An example is James Dashner's Maze Runner trilogy:

This may be a phase only, but it stands in the context of the general appreciation of American media and the English language that I tried to briefly describe above, and in fact there are books outside of YA that are published with their original English title, like Oliver Sacks Awakenings:

So, in Germany, a book with an English title would certainly work, especially if it was aimed at a younger audience, no matter if it was originally written in German or any other language.
On the other hand, "the awakening" can be easily translated into German as "das Erwachen", which has a nice sound and feel to it, and I don't think that any publisher would decide on the English title in that case. They would only use the English title, if it sounded better than the German translation.
Maybe this will give you some ideas about your own language and country, which I am not familiar with.
Answer: If the target audience understand the meaning of the tittle, then its fine. I'm an English only speaker, but if a book was titled 'El Diablo' that would be fine because I am familiar with those two specific spanish words. Also I would probably assume that the book was set in a Spanish speaking country or has something to do with spanish speaking people.
Would an English tittle imply that the story had something to do with an English speaking culture? Is that good or bad for your specific book?
When seen in book shops, would the customer falsely assume that the book was in English and not look at if if they can't read English? Maybe you could have a Portuguese quoat on the cover as well.
Answer: I recently finished reading a novel in translation to English from Russian.  The title was in Latin (in the original edition, the title was transliterated to Russian, but the English edition was in English transliteration.).
In this case, the authors (a duo) used a Latin phrase because it had meaning within the book.  None of the characters spoke Latin (or anything else but Russian) but Latin is commonly used in literature (and movies too) for its nifty phrasing.  These characters used a few Latin phrases in their work, including the one used for the title.
If English has cache in your country, or if you're publishing in an English-speaking country, or if your characters use English terms, including the title, then what you're proposing may work well.
But, if your only reason for changing the language of the title is because you think it sounds prettier, don't.  If it's not common in your country, it may come off as pretentious.  You'll turn readers off who don't know English too.
Another issue is there are already similarly named titles in English.  Over 12,000 listings in Goodreads with the word "Awakening" in the title (may not be an accurate count, but it's still gonna be big).  On a quick browse of the first two pages of the search, there are 5 titles that are simply "The Awakening."  Including the famous novel by Kate Chopin.
If the sound of the title is your focus, choose another phrase in Portuguese.


When will you upgrade your app to Rails 3?

Question: Now that the Rails 3 beta is here, let's take a little straw poll.
Please tell us briefly what your application does and when you will upgrade it to Rails 3. Or, if you're not planning on upgrading any time soon, tell us what's stopping you.
Answer: Honestly? When developers wake up and start work on Rails 3/Ruby 1.9 in their gems and plugins. They know it's been coming for several months now, and most haven't even bothered to upgrade. One in particular that I'd like to point out is authlogic, one of the most used authentication plugins out there. It still doesn't work for Rails 3.
Whoops!
Answer: I'm not planning to. I'm sure I'm in a very small minority, but my big application is still running 1.2.6. Each time I consider making the effort to upgrade it seems Rails changes again.
It does what I want it to do, makes good money, and despite feeling more and more left out in the cold I just don't have a sufficiently compelling reason to update it.
Comment: You're crazy. How dare you make money off of a stable application?
Answer: I'm not going to upgrade any apps to rails 3.
However, I just decided that all new projects will be rails3 going forward.  The lack of plugin support isn't a big issue as I see it as an opportunity to decouple my apps from plugins so that I can swap them in and out as I please later.
I also suspect that the big plugins will upgrade very quickly as they won't want to be left in the dust.
Keep track of plugin status here.
Answer: All my Rails apps are currently running under Rails 2.3.5 and every app has a LOC of 80% or greater. This has always been a key requirement for every product I create for myself or I manage at work.
Usually, upgrading to a minor/bugfix release is just a matter of a few minutes.
Change GEM version, upgrade requirements, run tests, fix issues and commit.
Rails 3.0 is a major rewrite and the biggest problem is represented by plugin compatibility.
Plugins are not under my direct control. This is the same reason why I had hard time trying to upgrade to Ruby 1.9.1.
However, I'm already playing with Rails 3. I want to learn the most important changes of Rails 3 as soon as possible in order to start moving the existing apps to the right directions. Moreover, as a plugin author, it's important to me to start working with Rails 3 in order to make my plugins compatible.
Yesterday I start with my most simple app. Well, at least this is what I was used to think about it. Anyway, it is the app with the lower number of external dependencies (less than 3 Gems) and it took about 1 hour to upgrade and 3 hour to figure out why Rails was failing to load my routes. It turned out, the Rails Metal component was fighting with the new Rails 3 stack.
There are some minor issues I have to figure out, but I can say I successfully migrated my first app to Rails 3.
I'm planning to migrate all my Rails apps to Rails 3 as soon as possible, once Rails 3 stable will be available. Or at least, as soon as I can figure out whether the dependencies actually work with Rails 3. Fortunately, a project has been started at http://railsplugins.org/ with the intent of listing all compatible/incompatible Rails plugins.
My remote environment is already compatible with Rails 3, I'm using Passenger with Ruby Enterprise Edition (1.8.7). The only blocking issue are plugins.
I guess it would take at least one month before having the major part of my Rails app ready for Rails 3 thought I won't probably start the upgrade until Rails 3 stable is out or I really need the new version for some blocking feature (ex. subdomain-based routing).
Answer: I've been keeping my apps on the edge of 2.3, but since there's a lot of fundamental changes to Rails in 3, I'll probably install the beta, work on converting them over and hope to be ready by the time it's released as stable.
I'm also glad there's a lot of lead time before RailsConf so I can really get familiar with the new features of Rails 3 and won't feel lost/overwhelmed there.
Answer: I don't think I'll upgrade any of my applications. It would be a large amount of work compared to what I'd gain from it. Also in some cases the plugins/gems I used in my app are not compatible with Rails 3 so upgrading would be impossible or would require to fork the gems... too time consuming.
If I had to update, I'd probably wait a bit more for all the gems/plugins to be updated to Rails 3. Of course any new application I'll develop will be done using Rails 3.
Answer: After trying out the beta and it not wanting to work with any commands, I have decided to wait until a new beta.
The ticket has already been opened for the issue.
Answer: I'll answer my own question.
I'm not sure how many betas there are going to be for Rails 3, but I'm going to hold off converting my blog application until the next beta or the final release. I think it's going to be quite a time-consuming process because I have a lot of view helpers that build markup, a lot of named scopes and some quite complicated routing.
I want to add page caching first before tackling Rails 3!
Answer: After realising that I probably spend more time in Zend Framework and Doctrine getting code to work (fixing framework bugs, annoying language workarounds, and just plain pain), than actually coding features I decided that it's finally time to give RoR a go. Especially as RoR3 is now out with a bunch of documentation.
5 hours through and it's looking really promising. 1 hour of it was debugging though, some documentation on a plugin was not up to speed,  but alas I'm there.
It's interesting, and does seem to be in a better direction. More time to code on features, and less time coding to debug.
So the app I'm converting is my premium CMS that is deployed in over 20 websites now, and powers my own balupton.com - so will be interesting, as the CMS is already a complete featured cms.
Comment: Yours is the first site where I've had to actually reduce the font size so I could read it "better" :)


loading a graph with till Depth N in main memory in java

Question: How to load a entire graph rooted at vertex V in java ?
I have a veertex V which is root node.Now this is connected to Some other vertex which intern is connected to more vertices and so on.
I want to load entire graph till depth N.
Is possible?
public class GraphLoader{

   public void loadGraph(RootID id){
      //load here
      //What will be return type ??Vertex??I mean class of rootNode?
   }

}

1)How can i to it using native libs?

2)How can i do it using ThinkerPop bluprientAPI

I am not in favour of get a vertex from vertex then geting next then next.This will take long time.
My graph is of depth around 100 and number of nodes may be many
Answer: About (1) lok at OrientDB Java Traverse.


Using 'the' before a language

Question: Is it right to use 'the' before a language like 'the Japanese', 'the Hindi', etc.?
Comment: too late in my time zone to do the research to write an answer, but I've never read "translating from the English we find that....." or "translating from the German we find that" but I have read "translating from the [obscure or now-little-spoken language] we find that..." for languages such as Inuktitut or even [classical] Greek.   I think this probably was a habit of academics which has now fallen out of favor.   Advice:  don't use the "the" before a language unless you are writing for a publication which does.
Comment: We normally say 'I speak Japanese' 'He is a teacher of Hindi',. As others have indicated, sometimes we use 'the' when referring to a particular text in a foreign language - 'I have read _The Three Musketeers_ in the original French'.
Comment: As the linked answer already explains but no one mentioned here yet, it isn't wrong but it changes the meaning. The Japanese are a people, whether reckoned by ethnicity or nationality. Japanese is a language. Anime is generally translated from Japanese to English for the American market. Documents are translated from the Japanese, which refers by ellipsis/metonymy to "the original Japanese text".
Answer: Only if qualified with "language" or for this to be implicitely inferable. Otherwise the meaning is obscure (japanese people/language/?)

Using 'the' before a language


Merge the tags [javascript], [javascript-events] and [javascript-library]

Question: Can these tags be merged?
javascript javascript-library javascript-events
Comment: See also: http://meta.stackexchange.com/questions/33023/on-the-tagging-of-events-and-event-handling
Answer: No, they're not the same.
But I agree that we should get rid of javascript-events in favor of events, and javascript-libraries should be thrown into the pit.
Answer: Why merge javascript and javascript-events? It looks like the latter is about a pretty well-defined subset of the more general javascript.
Personally I think javascript-events has some valid uses.
javascript-library seems to be used a bit less consistently. I see it used mostly on two kinds of questions:

questions about a specific JavaScript library. In this case it's not useful, as they usually have the concrete library tag as well (and should have it if they don't).
questions about finding a JavaScript library for some specific use case (or worse: "which of those is better?").


Setting up a 485 network

Question: I have a problem where my 485 transceiver just get damaged at field, when it's at laboratory everything runs fine, now reading about it I saw that 485 requires a 120Ohm impedance on both ends and bias resistor, what I used was 120Ohm on each drop and 4k7 pull-up on A, 4k7 pull-down on B on every drop. We use 2 transceiver MAX485 and Texas' SN75176, both are getting damaged, when I change transceiver, the communication doesn't happen.
I need some advices about resistors, good quality transceivers, etc.
Edit:
We use a 4 pin connection, 5V, GND, A,B, while 5V isn't connected. There's a common gnd between them. Also, for protection we use two 5,6V Zener at A and B, but normally on web searchs I see they using TVS.
Schematic
The BUS is a PCB that only carries A,B,GND and 5V, there's a connector at the end and it's not connected, only connected when I want to probe what is being transmitted.
My power supply is a 5V/3A flyback SMPS. The field condition is a aluminium "crate" which my PCBs are in, sometimes we use a PC too. It's stay at sun and rain 24/7.
Comment: Please show the relevant schematic.
Comment: What are your field conditions?   What are your power supplies?
Answer: Use TVS diode and make sure the capacitance is low, you didn't put any part numbers on those zeners so there is no way to check the leakage and capacitance.
The next problem is you don't need the pullups and pulldowns on each device, only on one end. The rest only need a 120ohm resistor. The cable also needs to be matched to 120ohm.
You might have a voltage drop between devices and with the pull ups and/or pulldowns you are getting too much current for a given transmitter.

Intefacebus.com has a good schematic for reference on how to terminate the buses.
Comment: At this point, don't worry about matching the cable impedance, 100 ohms is "close enough."  Getting "damaged" is not descriptive enough.  Id the whole chip burnt? Are the IO pins melted?  Does the "damage" magically disappears at the lab, or is it  because the chips are replaced?
Comment: Sorry for that, the Zeners are 1N5339, now about the resistors, why 620 ohm both?  The extra current brought by the pull-up/down on each line could damage my devices? How should I put the TVS diodes? About cables, Twisted pair normally have 100 Ohm impedance, should I insert a 20ohm at the end, or just a 120 ohm at both points of cable?
Comment: You don't need 620, you size the pull ups and pull downs for how many devices you have. The pull ups and pull downs could be creating to much a load for the driver to handle. Read the link for how to size the bus.
Comment: Thanks for the edit, I was searching the website thoroughly, I'll read the link now.
Comment: https://meta.stackexchange.com/questions/126180/is-it-acceptable-to-write-a-thank-you-in-a-comment
Comment: Sorry, my above comment mas meant for Marlon.
Answer: I do not understand what you mean by "damaged."  Assuming that you mean they don't work, I would say that the problem is that in the field, the line is not properly terminated (missing the 120 ohm resistor). If the communication does not work, this in itself would not be the cause of the damage (overheating?) of the chips.  You need to verify that the current load on the output pins is not greater than they can safely source (this would be a design problem)!
Comment: About this and your other answer, for what they say to me, the chips just "start working", or "MAX doesn't work with SN75176". They just replace all the chips and then, everything start working again, I'm getting chance to put my hands on it now, the first problem I had everyone claimed the chips were damaged, couldn't communicate with each other it was just other thing fault. So I appreciate everyone answers and as soon as I get more problems in my hand to study I'll update this post.

Setting up a 485 network


How to count magnetic repulsion

Question: I have two equal flat round magnets. I know amount of force $F$ which attracts iron objects to one of them and geometric characteristics of magnets. I want to fix first of magnet and some additional mass in the air by second magnet. To do so, I am going to orient magnets so that second magnet repulse first and additional mass. But I need to establish dependence between distance between magnets and value of additional mass this construction can held. How to gain this dependence?
Comment: Possible duplicate: http://physics.stackexchange.com/q/17309/2451 and links therein.
Answer: To a good approximation, normal magnets can be treated as dipole magnets, in which case the force between them can be found in this wikipedia article. To avoid link-only answers, here it is:
$$\mathbf{F} = \dfrac{3 \mu_0}{4 \pi r^5}\left[(\mathbf{m}_1\cdot\mathbf{r})\mathbf{m}_2 + (\mathbf{m}_2\cdot\mathbf{r})\mathbf{m}_1 + (\mathbf{m}_1\cdot\mathbf{m}_2)\mathbf{r} - \dfrac{5(\mathbf{m}_1\cdot\mathbf{r})(\mathbf{m}_2\cdot\mathbf{r})}{r^2}\mathbf{r}\right].$$
However, be warned that while equilibrium levitation is possible using magnets, stable equilibria are impossible due to Earnshaw's theorem. Magnetic levitation is indeed possible but you need fancier schemes than just two magnets. The wikipedia article on it is a good starting point.
Comment: How can i find $m_1$, $m_2$ and $\mu_0$?

I'm planning to use some strings to establish equilibrium.
Comment: $\mu_0$ is the magnetic permeability of free space. $\mathbf{m}_i$ are the magnetic dipole moment vectors of the two magnets; once you know their direction (e.g. using an iron-filing experiment) you only need the product $m_1m_2$ of their magnitudes and that you can find with a single force reading.
Comment: However, please consider the stability of the equilibrium you are trying to build. If strings are involved, why not just hang the magnets? The equilibrium obtained using simple magnets is as stable as an up-ended pendulum. Do read the WP link!

How to count magnetic repulsion


Feasibility Study Format on SDLC

Question: Is there a specific format for a feasibility study in SDLC? If so, do you know any sources where I can find more information about this? or can you show me at least an outline of what it should contain?
Comment: By SDLC to you mean Software Development Life Cycle? If so what kind of study are you talking about. More information may help get this discussion started. (From @Carlosfocker).
Comment: Do you mean whether you should adopt a life cycle (you have one whether it's formal or not) or something else? Not really sure what you are after here.
Answer: Check out the creative commons OpenSDLC http://openSDLC.org it has great sections on strategic planning as part of the early release gates.

SDLC IT Strategic Planning This document provides an overview of the iterative strategic planning process of IT. Information Technology Strategic planning in an continuous process managed through a project management methodology. Major changes in the business environment (internal and/or external) will lead to a re-assessment of the IT Strategy to ensure it is fully aligned with the business strategy for the company...
Answer: I would have thought a feasibility study is part of your project management. Once that is completed you would start on your SDLC with analysis, design..etc. Or you may include pm in your SDLC according to company practice.
further to an answer, a feasibility study might include all project related costs, user acceptance, affects on company image, your ability to complete the project, time related risks etc..
Answer: I would tend to regard a feasibility study as a project in it's own right, separate to the project it may trigger if the feasibility study is successful.
So ultimately I'd start it exactly as I'd start any other project - outline what a successful outcome looks like so you know where you're heading, break it down into tasks, outline the quality metrics (potentially fairly low though you might want test input to validate the programmers findings).
Once you've got that you can select your SDLC - either waterfall or agile would work - and plan as appropriate.
But the key thing with a feasibility study is to be clear what your goals are (that is we wish to prove concept X and concept Y can be achieved within timescale X) and make sure you've got the mechanisms in place to measure them so you know when you've either succeeded or failed.
And remember, finding something isn't feasible is a valid outcome from a study and not a failure on the part of the team involved - if everything that came out of them was found to be feasible then you'd have to ask questions why they were necessary.

Feasibility Study Format on SDLC


Can't post on a protected question with 101 reputation

Question: I'm trying to post an answer to this question. I have 101 reputation (with the bonus for being trusted on other SO sites), but it is still telling me that I can't answer it because it's protected, requiring 10 rep. I clearly have 10 rep.
Answer: Protected questions don't factor in the +100 reputation from the association bonus. In order to answer protected questions, you need to have earned at least +10 reputation elsewhere on this site specifically, via questions, answers, edits, et cetera.
For more information, see this question on Meta SE. (This question talks about rewording "protection" for clarity.)
Comment: I looked into this the other day, because I noticed someone unable to answer, and it bothered me.  I found this, as well which places it out of the realm of meta questions and into the actual site help page portions: http://puzzling.stackexchange.com/help/privileges/new-user


Side lobe reduction

Question: How can side-lobes be reduced in an Level-1 SAR image in Spatial Domain?The input here in this problem is an complex SAR image?which parameters(like amplitude) of SAR image should be considered mainly while removing side lobes at image level?
Comment: Your question makes no sense: "how can I do signal processing without doing signal processing".
Comment: The input I have is an Image,should I convert it to any domain before removing side lobes because Im quiet new to signal processing
Comment: that is quite different from what you asked in the question? Could you **edit** your question and ask with way more background on what 1. you're currently doing,  what you're trying to achieve, 3. the specific hurdle you're facing right now. Right now, your question is simply inanswerable!
Comment: There are techniques to reducing sidelobes in most applications (I can't speak to yours in particular) but they come at the cost of additional main lobe width. Is that something your application can afford to sacrifice?
Comment: @AnalogEE ..Yes to a certain extent.All I have is an complex SAR image as an input,I need to remove the strong scatters which happen to be side lobes.Many scientific papers related to side-lobe reduction give information on reducing them at signal level..How can those be applied at image level..or is there any techniques or ideas you would like to suggest?
Comment: @Marcus Müller,I have edited the question, Im not getting proper results when I simply try to remove as side lobe using python opencv etc,should any signal level information be used in this regards?
Answer: If you want to reduce sidelobes and are willing to accept lobe width increase, I'd suggest a Taylor window. Applying it to an image instead of a time-domain signal should not be an issue, so long as it is spatial sidelobes, not temporal ones, that you wish to suppress. Images are just spatial signals, so you can apply this filter in the X and Y dimension of the image I think (may require decomposition of some kind so you don't end up filtering twice).
https://www.mathworks.com/help/signal/ref/taylorwin.html

Side lobe reduction


Oracle Global Temporary Table / PHP interaction question

Question: I've never used the Global Temporary Tables however I have some questions how they will work in a php environment.
How is data shared: Assuming persistent connections to oracle through php using oci8.  Is the data tied to a database id? is it done based on the Apache httpd demons?  Or is each individual request unique?
When is the data for the session cleared from the global temporary table? I'm assuming (or rather hoping) that its done when the php script exits.  Alternatively if not I'm assuming I'll need to remove it before script exit.
Answer: The global temporary table is simply the logical definition of a table structure (Name, column names, column data types etc). When a session references it by inserting data, a data segment is created in a temporary tablespace to hold only that session's data. Different sessions can therefore reference the same logical table definition because they each have their own dedicated data segment which can be purged easily on commit or when the session disconnects without affecting other sessions.
The purging of the data in the GTT can either be on commit or when the session ends, depending on the option with which it was created. In either case you do not have to attend to the purging yourself before disconnecting.
A useful alternative to the GTT is the subquery factoring clause ("WITH"), in which you can create multiple relations that can reference those previously declared in that SQL statement. These can be materialised as a data segment in a temporary tablespace either automatically by Oracle when they exceed a certain memory usage, or manually by using the MATERIALIZE optimizer hint.
Answer: If I remember correct, the data in global temporary tables is available only from one active session and only for this active session (I mean session = connection). So you can see only data which was inserted before in active session. Therefore I belive, this data is cleared after closing session. No matter which language are you using.
At least I think so. :D
As is it written here:
http://www.oracle-base.com/articles/8i/TemporaryTables.php
The data in a global temporary table is private, such that data inserted by a session can only be accessed by that session.
Data in temporary tables is automatically delete at the end of the database session, even if it ends abnormally.
Sorry for my bad english.


Inconsistent times in inbox dropdown

Question:

Why does it say one day in one of them, but 24 hours in another?
Answer: One day is the equivalent of 24 hours. A minute probably ticked by before the next notification so it's no longer 1 day. So they round it to a more "reasonable" hour, hence 23 hours. But the actual time is still closer to 24 hours, but they don't want to push 2 notifications on the same hour because reminding the user twice at a time won't help.
From StackOverflow page on Bounties:

If you do not award your bounty within 7 days (plus the grace period), the highest voted answer created after the bounty started with a minimum score of 2 will be awarded half the bounty amount. If two or more eligible answers have the same score (i.e., their scores are tied), the oldest answer is awarded the bounty. If there's no answer meeting those criteria, the bounty is not awarded to anyone.
If the bounty was started by the question owner, and the question owner accepts an answer posted during the bounty period, and the bounty expires without an explicit award then we assume the bounty owner liked the answer they accepted and award it the full bounty amount at the time of bounty expiration.

https://stackoverflow.com/help/bounty

Also, a special note from Shadow Wizard:

"expiring in one day" and "expiring soon" are two different events, with different code for each.
Comment: No, it's on two separate days. One says the bounty will expire (one day). One says the bounty has expired, but will be awarded (24).
Comment: I'm pretty sure that both notifications clearly state "Bounty expiring..." not "Bounty has expired". After a bounty has been placed, it will expire within a certain time. Since the bounty is on your own question, it can be auto-rewarded.
Comment: It's not my own question. They are 2 different things, aren't they? One says that it will end, which is different to the end if the grace period...
Comment: The top one says when the bounty will expire (the time the bounty will exist for). The other says when it will be auto-rewarded because it meets the criteria for an auto-reward (see the block quote in my answer for details).
Comment: I know what they are for. Why are they using different units?
Comment: No update on why they are?
Comment: Sorry, I haven't been able to find legitimate reasons on the unit difference.
Comment: @Tim I just picked up from Shadow Wizard that: "expiring in one day" and "expiring soon" are two different events, with different code for each.

Inconsistent times in inbox dropdown


How can I time SQL-queries using psql?

Question: I would like to benchmark some SQL-queries agains my PostgreSQL database. Is there any way I can time SQL-queries using psql?
Comment: For more details on benchmarking PostgreSQL queries: http://dba.stackexchange.com/q/42012/9622
Answer: Just turn on timing by entering:
\timing
Comment: Or do `psql -c '\timing' -c 'select 1'`
Comment: Add `\timing` to `~/.psqlrc` if you want it enabled each time you start the client.
Comment: From out bash, the "-c" option of `psql` does not allow this setting. You can do this with something like:

```psql  --o /dev/null <> ~/.psqlrc`
Answer: Timing can be turned on with \timing at the psql prompt (as Caleb already said).
If you are on 8.4 or above, you can add an optional on/off argument to \timing, which can be helpful if you want to be able to set timing on in .psqlrc - you can then set \timing on explicitly in a script where plain \timing would otherwise toggle it off
Answer: The time that \timing returns also includes the network latency, if you're connecting to a remote server.
When you don't want that and don't need the query output too, better use EXPLAIN ANALYZE,  which outputs the query plan with the planner estimates plus the actual execution times.
for example, EXPLAIN ANALYZE SELECT foo from bar ;
Comment: Using `explain analyze` yields times that are approximately double what I see when using `\timing`, which is the opposite of what I would expect based on the comments here regarding network latency. I suspect that there is overhead in the normal execution of `analyze` that adds to the query time. Based on the docs, I think that `EXPLAIN (ANALYZE, TIMING OFF) SELECT foo FROM bar` will give you more useful timing information. See https://www.postgresql.org/docs/9.6/static/sql-explain.html for details.
Comment: ... the only issue being that you don't receive the normal query output.

How can I time SQL-queries using psql?


Can I use an Arduino Uno to support an RFID reader, Zigbee module and a touch screen at the same time?

Question: I'm almost a beginner to microcontrollers and have done a few simple projects, but this time I have to use an Arduino Uno (powered by a battery) to support an RFID reader (RC522), a Zigbee module and a touch screen altogether. Apparently there are too few pins to support all the modules. What is the easiest way to implement such a system?
Comment: use an i2c or spi screen. try to match that protocol with your other modules. with all i2c modules, you can connect all three with only 2 pins. With all SPI, you still only need 5 or 6 pins.
Answer: Also I don't know what the RFID, zigbee and touch screen uses (generic GPIO pins, I2C, SPI, something else)?
You always can combine multiple inputs/outputs using a multiplexer (i.e. 74HC165, 74HC595), although it will mean extra software and less performance.
About the touch screen, that might be problematic regarding performance and memory usage, since the Uno has only a few KB and even the more expensive Arduino's do not have that much memory you might need.


Whirlpool washing machine has a small leak from bottom

Question: I have replaced the seal below the pump and the drain hose and I have a leak only on normal when it's operating in spin cycle. It's a small leak on the front bottom counter weight. Can anyone help? I have checked and the seal below is on very well. I thought this was the problem from the beginning, but I guess not!!!
Answer: Since this is only on spin, when water is being drained, check out the whole length of the drain hose while the machine is on spin and draining... the drip could be from where it enters the waste pipe, from the hose itself, or from the connection under the tub.
Also, search online specifying the washer make and model, as well as "drain leak", as it might be a well-known issue.


How many XBox 360 controllers can you use on PC?

Question: My friends and are going to meet up soon and I am thinking of getting Castle Crashers on steam. We already have enough controllers for 4 player, but I am wondering if we will be able to all use them. Assuming there are enough USB ports for a wired connection, can Steam, Windows, and Castle Crashers handle that many wired controllers?
Comment: XInput (Windows standard for controllers) allows for 4 controllers at once, so If you're all using Xbox 360 (or compatible) controllers, you should be good.
Comment: @RedRiderX Thanks! Is XInput already on Windows 10, and can the standard wireless controllers be played wired?
Comment: Hmm wireless controllers are a bit of a different situation, see here for more info: http://gaming.stackexchange.com/q/372/12937
Answer: Windows and Steam do support 4 Controllers (regardless if they are wired or not).
Doubtful, however, is if Castle Crashers does.
In the Steam dicussions to the game ( e.g. here) there are both people who have success with playing with mutliple controllers and people who failed in trying this.
The player from the above link apparently got it to work by plugging in the controllers after having gone to the character selection.
Another alternative is to install an additional software such as xpadder. xpadder allows the mapping of keyboard keys and mouse buttons to your controller. This would work with a high chance when Castle Crashes supports a 4man multiplayer anyway. xpadder is not freely purchaseable, but alternativeto.net delivers a lot of results for xpadder. Such programs also allow you to play games that are normally not playable with controller at all.
Comment: Your link specifically talks about mixing gamepads and keyboards as controllers, which doesn't really have a bearing on how many gamepads a game supports


Real IP phone in GNS3 Problem

Question: I am trying to link this configuration to a real SPA 303 IP phone but I do not know where to begin with this. I have the physical IP Phone, but I want to run it through the simulated environment that I have set up for the purpose of simulating voip issues. I've searched all over the internet and have found nothing pertaining to that goal. Please provide any thoughts you have on this.
Comment: What is the error or with which device are you facing problems? I can tell you a few things about phone configuration, but not if it's about firewall.
Comment: It is about the phone configuration. I cannot for the life of me figure out how to run my external device (SPA 303 IP phone) to the simulated environment in my GNS3 file
Comment: Please stop adding remarks to the subject which have nothing to do with the actual question. Please read http://networkengineering.stackexchange.com/help/no-one-answers instead.
Answer: I've posted about this on my blog a few times. The short of it is that you bind your PC's network card to a cloud object in GNS3. This connects your virtual (GNS3) network to your physical network. If your PC is connected to a switch, everything on that switch will have connectivity to the virtual network and vice versa.
If you're still having connectivity issues, switch off your PC's firewall and try again.
Comment: I might be looking in all the wrong places in your blog, but I did not see anything about putting a real IP phone into the GNS3 network. If you have it and want to direct me to the appropriate article that would be much appreciated. Thanks
Comment: The blog post I linked to is a demonstration of what you can achieve by joining virtual and physical lab equipment, while my suggestion to use GNS3's cloud object was an explanation on how to do it. If you'd like a step by step guide, check out this site I put together - http://www.ultimateciscolab.info

Real IP phone in GNS3 Problem


C99 not default C- version for GCC?

Question: Why does not GCC compile the C99 by default? I mean why is it necessary to add --std=c99 flag
everytime a code in C99 is written?
Answer: Edit: As of GCC 5, -std=gnu11 is the default. See Porting to GCC 5.

See C Dialect Options, gnu89 is the default.

`gnu89'
GNU dialect of ISO C90 (including some
  C99 features). This is the default for
  C code.

As @tsv mentioned, ISO C99 is not fully supported yet:

`c99'
  `c9x'
  `iso9899:1999'
  `iso9899:199x'
ISO C99. Note that this standard is not yet fully supported; see http://gcc.gnu.org/c99status.html for more information. The names `c9x' and `iso9899:199x' are deprecated.

And also:

`gnu99'
  `gnu9x'
GNU dialect of ISO C99. When ISO C99 is fully implemented in GCC, this will become the default. The name `gnu9x' is deprecated.
Comment: gcc5 will use gnu11 as default version.
Answer: Perhaps because it still isn't fully implemented - see C99 status.
It also could be argued C99 features haven't been widely adopted, although that's something of a circular argument.
Answer: Use the command c99 to compile C programs.
The current POSIX standard specifies the command c99, so it should be available in most Unix-like systems.
Answer: The reason is that default configurations of gcc take a really long time to be changed, since every time a default configuration is changed, it can potentially break the compilation of valid programs (in this case valid c89 programs which are invalid in c99). Starting with gcc 5.0, the default C standard used by gcc will be gnu11, which is c11 with gnu extensions (see here):

The default mode for C is now -std=gnu11 instead of -std=gnu89.

C99 not default C- version for GCC?


How can I teleport one player to a random other player using a potion as the trigger?

Question: I am making a Minecraft map. I want to make it that when someone uses a certain potion, that same person teleports to a random user on the map.
I can't use the @p thing because the other players might teleport instead.  I know to use the /effect code on command blocks and some other commands.
Comment: I've been working on this for probably an hour now. Maybe longer, I've lost track. I've solved the issue of specifying the first player using `@p[c=n]`, the problem I'm running into now is the "random other player" part, since `/tp Unionhawk Unionhawk` is valid.
Comment: I'm trying it using experience as an identifier, however, it is only possible to identify players who are *inside* a certain level range, and cannot identify players who are *not* a specified level, except at level 0.
Answer: This was a very interesting challenge for me to work out. There are many parts to this problem, which are a lot harder to accomplish than one might think. There's identifying the player with the status effect, and identifying a set of random players who are not them (since /tp Unionhawk Unionhawk is a valid result of /tp @p @r, and does nothing).
But, finally, here is my setup, which works for a bounded number of players on a server. Some of its flaws include only allowing one game to be played on a given server, and using experience level to identify players. As such, /gamerule doMobLoot false must be used, and /gamerule commandBlockOutput false is strongly advised.

So there's quite a lot of things going on here, as you can see. But this is all accomplished using 4 commands and a hopper clock.
The Group 1 command blocks are there to detect when a player has the specified potion effect, remove it, and proceed to the matching Group 2 command block. I used /effect @p[c=n] 4 0 for that one, which removes the mining fatigue effect from player n on the server (going down the list of players on the server). When that command evaluates, the Group 2 command blocks give that player one level of experience using /xp 1L @p[c=n].
From there, the next time the hopper clock pulses, the "Group" 3 (you only need one) command block teleports a player with 1 level or more to a random player without any levels using /tp @p[lm=1] @r[l=0]. When this command evaluates, the "Group" 4 command block clears the experience level of all players using /xp -9999L @a.
Answer: All you have to do is (no potions) do /give [your username] 137 1, that gets you a command block. Put this in the command block: /tp @p -522 9 -434
Comment: This does not answer the question asked.


IIS6: When an app pool is recycled, is Session_End called?

Question: I need to know because I have to explicitly close some remote resources that are tied to the user's session.
Answer: I must disagree with Darin. I call a function in Session_End to record the end of the session. I have not tested this explicitly, but I looked in my logs for the last few times that the app pool recycled. The function got called and the end of the active sessions got logged.
This occurred both when the app pool recycled on a schedule, and when it recycled because I deployed some new dlls.
Comment: Agreed, just tested and it fired :-)
Answer: If I recall correctly (been a while since I read the docs) having active sessions will delay the normal App pool recycling timer (which fires when the resources should be freed) because the server banks on active sessions meaning that there is continued need. Once the sessions expire (and fire the session_end event) the app recycle timer starts over and counts down, eventually firing before the thread pool releases its own resources and terminates the app.
That is under normal circumstances, it should be noted that the session_end event is not guaranteed to fire (there use to be very specific scenarios where it would not), I think now this is mostly related to crashed instances of IIS or App Pool recycles for OOM or errors. It use to be unless you were using just one of the session types (state server I believe) it would not reliably fire. This may be different now.
If you need to guarantee that resources are freed, I am not sure session_end is the appropriate place to do it. Can you elevate it to the App Cache or HTTP Cache and use session unique keys with periodic cleanup events? That might be more reliable (more code) but more reliable.
It has been my general experience that session_end fires fairly reliably, but I have seen it fail under substantial load (100s of hits a second) and I know when you start talking about server farms it gets vastly more complicated as well.
Comment: I'm only talking about 20-30 users max, but the cost of leaving the connection open is very high and I don't trust the remote server to close it.
Answer: Note too that Session_End is only called if you use the Inproc session mode.  For other modes (including SQL session state mode) this event is never raised.


Keep android application open

Question: On the Android Market there is an app called Sleep Timer, and it is a type of alarm clock that brings runs the alarm even though you locked your phone while on facebook.  I made a type of app that detects movement however it only works if the phone is left on that app... How can I make it work when the app wasn't left upfront, but is still running in the background?
Answer: You should take a look at Android Services, which provide the functionality you seek. Basically they enable you to create components that run in the background even when the user switch away from your application.
You can find a very good introduction to them here: http://developer.android.com/guide/components/services.html

Keep android application open


How to use pentatonic scale(s) for bass lines

Question: In creating bass lines using pentatonic scale, do you use the pentatonic scale of the key you are in or of the chord you are playing?
Comment: Thanks! I just started learning the pentatonic scale and the different shapes across the fretboard. I was just confused because some say use the pentatonic scale of the key, and some say use the scale of the chord. So I guess it's a preference thing?
Comment: @exnihilo - the answer is indeed, like some others  here, both, either, neither. But for OP's sake, an  explanation of why what works or not should be part of an answer. Just saying either, neither, both doesn't really help anyone.
Comment: @exnihilo - they did come across, and I was hoping you'd include them in an answer!
Comment: Do you have any particular bass players you like?  We might be able to identify some songs where their bass lines are [predominantly] pentatonic.
Comment: i rarely use it, its actually much simpler to stick to diatonic scales which allow you more freedom in note choice than shackling yourself to five notes, of which some will sound right, and some a bit wrong.
Answer: Pentatonic scales are fun to play and very commonly used for improvising and also creating melodies and lines for all instruments including bass.
When you say bass lines I assume you are talking about lines that make up the bass part of a song and not just playing lines from the perspective of improvising and soloing. If you are thinking of soloing then it is fairly typical to play a single pentatonic scale over a chord progression since you are not concerned with playing a stable supporting bass line at that point.
If you are thinking of creating a bass part a different approach is required. First of all there are not enough notes in the pentatonic scale to cover the roots of the seven diatonic chords that exist in a major or minor key, not to mention non-diatonic chords. For example if you were in the key of C and had to play an F chord you would be out of luck with a C pentatonic scale. Another issue is bass lines are the harmonic foundation and rely heavily on chord tones, especially thirds and fifths. Once again a single pentatonic will leave you high and dry. For this reason a single pentatonic scale does not work for creating a bass line over a progression
If you want to use pentatonic scales for creating bass lines the best approach is to use the major or minor pentatonic scale that goes with whatever chord you are playing at that moment. Both major and minor pentatonic scales have the root, third and fifth plus two other useful notes. This will allow you to create coherent motif based baselines over chord changes. It is not foolproof, you have to examine the context and use your ears to see if it works in different situations but you can do quite a bit with this approach.
I would also like to point out that using pentatonic scales to create bass lines is only one of many different approaches you can take and is not really the best approach to creating good bass lines.
Answer: Mission Briefing
ROLE: Bass player
PRIMARY OBJECTIVE: Support the RHYTHM and the HARMONY of the SONG.
Any questions?
Q: Do I use the pentatonic scale of the key or the chord?
A: Whatever you do, do not jeopardize the PRIMARY OBJECTIVE of your mission.

Let's compare the use of pentatonic scales for guitarists vs bass players.
Why do guitarists use pentatonic scales?
Guitarists use (major and minor) pentatonic scales in guitar solos mainly for the following reasons:

Reason 1: beginner safety. Playing pentatonics "of the key" is a safe shortcut to soloing not-blatantly-wrong notes without knowing what you're doing and what's happening with chord changes. The major and minor pentatonic scales are harmonically slightly ambiguous, because they lack the two harmonically strong and polarizing notes (out of the seven diatonic notes), and so it's more likely that a randomly selected note will not sound horribly wrong. Randomly played pentatonic scale notes sound like staying relatively close to "home" position.
Reason 2: bluesiness. The pentatonic scales can sound bluesy, even without using so-called blue notes.
Reason 3: outside playing. In jazz style solos, pentatonic scales can be used for their "home position" characteristics - not to enforce the original home key but to bring flavors form other keys. One way to bring an "outside" playing feeling it to use pentatonic scales from different keys. As an example that's often used in blues/soul styles is to play pentatonics from the key three semitones higher. For example in C major, you would layer C minor (Eb major) pentatonics, creating a bluesy modal mixing sound.

Why would a bass player use pentatonic scales?
Why would a bass player use pentatonic scales, when not playing a bass solo??? When playing accompaniment, they're not supposed to be doing basically any of the stuff that guitarists try to do in their solos.
A single bass note can have a relatively large impact on the total harmony of the band, compared to any single note that a guitarist might play in a solo. Particularly in the rhythmically strong beats of the comping pattern (whatever the meter and pattern might be), the bass player can change the whole overall chord to something completely different by playing one single note. If the rest of the band plays an F chord and the bass player plays a G, the overall chord just became essentially a dominant chord heading to C. But if the bassist plays a D, the overall chord became a Dm7.
If you play pentatonic bass lines that do not highlight the chord tones on the strong beats of your rhythm pattern, then you're not supporting the written chords. It may still sound good, you're just changing the whole chord progression to something else.
However, the bluesy-sound reason for using pentatonics might apply for in-between filling or passing notes, as long as your strong-beat notes support the harmony.
There are many styles of writing bass lines, but they all have one thing in common: the bass line has to support the intended harmony progression. Pentatonic scales only have five notes, so one pentatonic scale per key only covers a small part of the potential chords you might have to support. The other way, pentatonic scale per chord, isn't much better either. As an easy example, if you're supposed to support a diminished seventh chord - trying to overlay a minor or major pentatonic scale with the chord's root note is going to spoil the chord.
To sum this up, I'd simplify all this into: at least in the beginning of your bass player journey, forget about pentatonic scales. It's much more important to know and to practice the basic diatonic seven-note scale of the key and to know all chord tones. After you can play chord tones, you can start adding some walking or approach notes in your bass lines from the basic diatonic scale of the key, or even chromatic approach notes. Or play alternating bass, i.e. alternate between the root and its fifth, like C and G for a C major or C minor chord. This is bread-and-butter stuff for bass players.
If you feel that you absolutely must overlay pentatonics (of the key, or rooted on the chord's root) on a chord, you still have to know all of the intended chord's chord tones, to understand if and how the pentatonic notes might fit in there. The total end-result will be non-pentatonic anyway.
Answer: This very question was asked by a student in one of my lessons last week.(A guitarist becoming bassist).
First to establish is which pentatonic scale we're talking about. There are two - major and minor.
The minor pent. doesn't work well, as there are notes which clash with the underlying chord - mainly the 3rd. In pent. min., it's ♭3 which doesn't blend well with the M3 in the chord itself. That m3 works fine when used for soloing in Blues - although it often gets that stretch up to (or near) the M3 anyway, but doesn't have the same effect when played on bass.
The major pent. does work well, as it contains all three notes that occur in the underlying chord - 1, 3 and 5. And the main job of a bassist - in the majority of pieces - is to outline the chord played.
Having said all that, and pointed out the differences between maj. and min. pents., it will be, as often the case, genre specific. Thus, the ♭7 from min. pent. will fit when the chord changes from I to IV, say, and the M6 from maj. pent. will work when I is followed by another I.
Consider also, as most seasoned players do, of mixing the two! Think of the bassline 1 3 5 6 ♭7 6 5 3 , over two bars - quite a well known pattern that blends the two!
EDIT: to more specifically answer the question(s), only using the notes of the pentatonic scale from the key won't work particularly well. Changing to use the pent. notes from the current chord will work beetter - but bear in mind what I've said earlier.
Comment: I like to simplify things and only talk about one pentatonic scale per key signature. The A minor pentatonic is your go-to pentatonic pattern for both C major and A minor keys. This also suggests looking at relative major and minor keys as being the same thing in many ways, and I like to simplify scale degree numbering by standardizing on the major key's tonic being I, and minor key tonic being a vi. This reduces the amount of things to memorize a lot, IMO, and makes things easier to talk about, when one (unnecessary) layer of complication is removed.
Comment: I find the neutral/suspended pentatonic (1 2 4 5 ♭7) to be useful in some settings as well.  The other two modes (1 ♭3 4 ♭6 ♭7 and 1 2 4 5 6) not as much.
Comment: *The minor pent. doesn't work well, as there are notes which clash with the underlying chord - mainly the 3rd. In pent. min., it's ♭3 which doesn't blend well with the M3 in the chord itself.* - I don't get where the assumption that 'the chord' has an M3 comes from? I'm sure there's a whole bunch of classic basslines that can be seen as minor pentatonic.
Answer: You could use a five tone pattern and move it over a chord progression, something like this...

But, you should also consider that can be viewed as just some passing tones between a simple arpeggiation of the chords, like this...

Also, when you consider all the tones that are used after moving the five tone pattern over the I IV V chords, you end up playing all the tones of the major scale...

In that example, I think it's questionable to call those "pentatonic" when the end result is not at all pentatonic. The resemblance of the five tone pattern to a pentatonic scale is more coincidence. IMO pentatonic ought to be used to describe music, at least melodies, that are truly limited to just a five note scale, and that is not the same as isolated measures of five tones.

...do you use the pentatonic scale of the key you are in...

Of course you can do anything you want, but the typical role of the bass is to establish the harmonic foundation. Usually the bass works around chord roots or chord tones. If you used only a pentatonic scale in the bass, while playing some progression like I IV V7/V V, you will potentially have places where the bass isn't matching the chords, or certain chord roots are not available in the pentatonic scale. FWIW, you can get a pentatonic scale to match some chord tones even in a progression with lots of secondary chords, but doing that in the bass means playing a lot of inverted harmony instead of chord roots. That may or may not work for all kinds of different reasons.
Two theory terms that come to mind are ostinato and pedal point both of which can occur in the bass. Look up those terms. The basic idea is the bass would repeat a pattern or hold a tone while the other instruments play chord changes. The separate parts often start together, move apart from each other harmonically and create dissonance, then return to match each other. This is one way you might get a pentatonic pattern in the bass to work with chord progressions that "don't fit" the pentatonic scale.


How do I create Fortify Alchemy enchantments up to 29%?

Question: I was making a set of Fortify Alchemy to 29% to be able to create stronger enchantments. For some reason my Fortify Alchemy gear only goes to a maximum of 23% and I've read/seen people creating enchantments with a 29% bonus.
I have 100 Alchemy skill and 100 Enchantment skill with all the necessary perks.
I was trying to do this: http://elderscrolls.wikia.com/wiki/Enchanting_(Skyrim)#Exploit
Comment: I have the same problem, with all the perks and all lvl 100 skills needed my first potion gives only 27% fortify enchanting - the gears 20% fortify alchemy - the second gear 22% and the next potion 28% fortify enchanting - now the number does not increase - gear 22% and potion 28%.
Answer: You can raise your Enchantment skill above 100, by using potions that increase your Enchantment skill.
To get the maximum possible enchantments you need to raise your Alchemy skill to the highest level. You can create Fortify Alchemy enchantments that will increase the effect of your potions considerably.
So you should first create a set of Apparel that gives you the highest possible bonus you can currently achieve to Alchemy. Use that set to create a batch of Fortify Enchanting potions. Now your enchantments should be stronger when you use the potions just before enchanting your gear.
You will have to do a few rounds of enchanting and creating potions if you're after the maximally possible effect. So, use your enchanted alchemy gear to create an enchanting potion. Then use that potion to create better Fortify Alchemy gear. Now you can use that improved gear to create a better enchanting potion, repeat until no more improvement is visible.
There are diminishing returns, so you won't be able to increase your stats infinitely.
Comment: the problem is my enchants are coming lower than it should, with the first use of fortify ench potion the gear of fort alch should be 26%, i can only get 21% on those
Comment: @shandow do you have the appropriate enchanting perks? 100% better enchantments, and +25% on fortify skill perks?
Comment: i have enchanter 5/5, insightful enchanter, curpus enchanter and extra effect.
Comment: Are you possible to get this effect without having 5/5 enchanting? What if you just make more potion rounds? Like instead of 3 alchemy clothing, you make even more?
Comment: no its not possible to get the max effect without investing all the perks
Answer: The trick is to do multiple loops of Fortify Alchemy/Enchanting
You will need some cheap clothing for this.
Important is to have 100 Alchemy, 100 Enchanting, and (optional) 100 Smithing.
You will need at least the following Perks:

Alchemist 5/5 (Alchemy)
Enchanter 5/5 (Enchanting)
Insightful Enchanter (Enchanting)
(Optional) Extra Effect (Enchanting)
(Optional) Armor of your choice (Smithing)

Create a 4 pieces of Fortify Alchemy Equipment (hat, gloves, necklace, ring)
With the clothing on, create some (4) Fortify Enchanting Potions
Create a new, stronger set of Fortify Alchemy Clothing by drinking those potions.
With the Stronger Set, Create some new Fortify Enchanting Potions (they're stronger as the previous ones.)
Now you'll create your Final set of Fortify Achemy Equipment (hat, gloves, necklace, ring) under influence of those stronger potions.
You now can use this Fortify Achemy set to create as many Fortify Enchanting Potions as you need to improve your other stuff.
(Optional) Create some Fortify Smithing Potions, and some (4) Fortify Enchanting Potions (obviously, while wearing your Final set of Fortify Alchemy Equipment)
(Optional) Create a set of Fortify Smithing Equipment (armour, gloves, necklace, ring)
(Optional) Improving weapons while under the influence of those Fortify Smithing Potions while wearing Fortify Smithing Equipment allows you to create the strongest weapons in the game.
Comment: The fastest way to level up Alchemy is to make potions that have the most value, for example Invisibility potions. When playing the game and leveling your toon, you pick up all ingredients you come across everywhere and store them some place until the day you make potions. Then just create tons of pots with high value wearing a full +alchemy gear set. Similarly for blacksmithing you can improve e.g. glass or ebony gear that you have improved perk in while wearing +blacksmith gear. Blacksmithing will level up very fast then.
Comment: In the beginning btw you can pick up all leather gear too and improve those to level blacksmithing faster in the start - although later you will have to do it for higher quality gear.
Answer: Wear a falmer helmet and a circlet at the same time. This gives you five slots for fortify alchemy instead of four. I believe it maxes out being able to make potions that give +37% Enchanting for 30 Seconds. That's when you're wearing five +29% bonuses to alchemy and make the potion. I do not think you can go higher, correct me if I'm wrong.
Comment: The Smart guy here is the one who just told me about wearing the falmer helment and a circlet at the same time (thanks, couldnt get past 29%). everything else is commen sense mathmatically speaking. if u want to be a beast u want smithing, enchanting, and alchemy. use those bad boys and u will rule on master difficulty (assuming u got heavy armor and a very high magicka resistance). spend points in sneak if u want tha one hitter quitter. FYI: dagger perk is useless sword surpasses it in the end.
Answer: The glitch that may be causing the problem concerns equipping the fortify alchemy equipment.
If you have 100 in alchemy and 100 in enchanting, 5/5, and the perks, then you should be able to begin with creating 25% fortify alchemy gear. If you can't, then check your magical effects before beginning. If they all are not in effect, try unequipping and re-equipping your fortify alchemy gear. There appears to be a glitch and sometimes the effects are not properly activated. The unequipping and re-equipping of the gear seems to correct the problem.
Answer: It's a bug. Generally, 100 enchantment with 5/5 first perk and improved fortifies should give +25% alchemy with a grand soul without any potions. If in your version it only gives 21-23, you need to update your game.