After how many shots is a camera considered old?
How many actuations are "too many actuations"?
Vertical spacing for two consecutive figure environments Perform feature normalization before or within model validation? A common good practice in Machine Learning is to do feature normalization or data standardization of the predictor variables, that's it, center the data substracting the mean and normalize it dividing by the variance (or standard deviation too). For self containment and to my understanding we do this to achieve two main things:   Avoid extra small model weights for the purpose of numerical stability. Ensure quick convergence of optimization algorithms like e.g. Conjugate Gradient so that the large magnitude of one predictor dimension w.r.t. the others doesn't lead to slow convergence.   We usually split the data into training, validation and testing sets. In the literature we usually see that to do feature normalization they take the mean and variance (or standard deviation) over the whole set of predictor variables. The big flaw I see here is that if you do that, you are in fact introducing future information into the training predictor variables namely the future information contained in the mean and variance.  Therefore, I do feature normalization over the training data and save the mean and variance. Then I apply feature normalization to the predictor variables of the validation and test data sets using the training mean and variances. Are there any fundamental flaws with this? can anyone recommend a better alternative? Which browsers are officially supported, and what else do I need? Which browsers are officially supported by Stack Exchange?  Also, what else is needed in order to use every feature of the site? Add asterisk after labels in enumerate I would like to add an asterisk after certain labels in the enumerate environment. So for example  \documentclass{article} \begin{document}  \begin{enumerate}     \item Kuttel     \item* Daddeldu \end{enumerate}  \end{document}   but without the space between 2. und *. In Minecraft, I know you can breed animals. In fact, in recent updates it's required for the player who just can't start their mornings without bacon and eggs!  I've tried pulling two pigs together in a single pen, but all they do is snort at me. And the chickens? Well, there's plenty of eggs, but no hatching.  How do I get them to make more bacon and eggs? What is a deterministic method for evaluating a sensible buffer pool size? I'm trying to come up with a sane way to understand if the max server memory (mb) setting is appropriate (either should be lower, or higher, or stay the way it is).  I am aware that max server memory (mb) should always be low enough to leave room for the operating system itself, etc.    The environment I'm looking at has several hundred servers; I need a reliable formula I can use to determine if the present size of the buffer pool is appropriate since RAM is costed per GB allocated to each server.  The entire environment is virtualized, and "physical" RAM allocated to a VM can easily be changed up or down.  I have a particular SQL Server Instance I'm looking at now with a PLE of 1,100,052 seconds, which equates to 12.7 days (the amount of time the server has been up).  The server has a max server memory setting of 2560MB (2.5GB), of which only 1380MB (1.3GB) is actually committed.    I've read several items including one by Jonathan Keheyias () and another by Paul Randal (), and several others.  Jonathan advocates monitoring for a PLE below 300 per 4GB of buffer pool as being too low.  For the SQL Server Instance above, 300 * (2.5 / 4) = 187 results in a really really low target PLE below 300.  This instance has 290GB of SQL Server data (not including log files), and is only used for integration testing.  Assuming the last 12 days is representative of typical usage for this server, I'd say the max server memory (mb) setting could be lowered.  At the other end of the scale, I have another integration-test server with a PLE of 294, that has a max server memory (mb) setting of only 1GB.  This server has only 224MB of SQL Server data not including logs, and is running some BizFlow databases.  This server might benefit from a higher max server memory (mb) setting.  I'm thinking a good starting place for targets that might be assigned too much memory could include looking at:  SELECT      RamMB = physical_memory_in_bytes / 1048576     , BufferPoolCommittedMB = bpool_committed * 8192E0 / 1048576     , BufferPoolCommitTargetMB = bpool_commit_target * 8192E0 / 1048576     , PercentOfDesiredSizeMB = CONVERT(INT,(CONVERT(DECIMAL(18,2),bpool_committed)                              / bpool_commit_target) * 100) FROM sys.dm_os_sys_info;   If BufferPoolCommitTargetMB / BufferPoolCommittedMB is greater than 1, the server is not using the entire buffer pool.  If the machine in question also has a PLE of greater than "x" then it might be a good candidate for a decrease in max server memory (mb).  Since the Buffer Manager:Lazy writes/sec performance counter tracks the number of times SQLOS has written pages out to disk between checkpoints due to memory pressure, this might be another good thing to look at.  DECLARE @WaitTime DATETIME; SET @WaitTime = '00:00:15'; DECLARE @NumSeconds INT; SET @NumSeconds = DATEDIFF(SECOND, 0, @WaitTime); DECLARE @LazyWrites1 BIGINT; DECLARE @LazyWrites2 BIGINT;  SELECT @LazyWrites1 = cntr_value  FROM sys.dm_os_performance_counters dopc WHERE (         dopc.counter_name LIKE 'Lazy writes/sec%' COLLATE SQL_Latin1_General_CP1_CI_AS     )     AND dopc.object_name = 'MSSQL$' + CONVERT(VARCHAR(255),                SERVERPROPERTY('InstanceName')) + ':Buffer Manager';  WAITFOR DELAY @WaitTime;  SELECT @LazyWrites2 = cntr_value  FROM sys.dm_os_performance_counters dopc WHERE (         dopc.counter_name LIKE 'Lazy writes/sec%' COLLATE SQL_Latin1_General_CP1_CI_AS     )     AND dopc.object_name = 'MSSQL$' + CONVERT(VARCHAR(255),                SERVERPROPERTY('InstanceName')) + ':Buffer Manager';  SELECT LazyWritesPerSecond = (@LazyWrites2 - @LazyWrites1) / @NumSeconds;   The above code assumes the server is under load during the 15 seconds it takes to run, otherwise it will report 0; which might be a misleading false-negative.  Should I also look at PAGELATCHIO_* wait stats or some other wait type as an indicator of memory pressure, or lack thereof?   My question is, how can I reliably determine a "good" target value for PLE and max server memory (mb)? Where do the bipolar jets of black holes come from? How are they formed? And why are they so bright? What is LookDev/Material Preview mode for in 2.8? When editing a post and using the image uploader, any unused link references are completely removed.  For example, this post has three image references, only one of which is used ([3]) in the body of the post:        After uploading a fourth image, references [1] and [2] are completely removed (and the remaining references are renumbered to become [1] and [2]):        I sometimes write link references before using them in the body of the post and sometimes remove images temporarily before reinserting them elsewhere in the post so this is inconvenient.  (Note: this also applies for the iOS app, having the same behavior) I'm having an issue with the following piece of (G)AWK script:  do {     ... } while (system("sleep 10"))   My intention is to break the loop when the user presses ^C during the sleep, but it's not working.  I believe the problem is that Bash exits with 0 when interrupted with ^C, at least when it's executed by AWK's system():  $ awk 'BEGIN { print "\n" system("sleep 2") }' (let the sleep complete) 0      $ awk 'BEGIN { print "\n" system("sleep 2") }' ^C 0   Why is it so?   Is this a bug in Bash or in (G)AWK?  Is there a simple solution that doesn't involve complicated Bash-specific syntax like trap?  The best I could come up with is this:  do {     ... } while (42 == system("sleep 10 &amp;&amp; exit 42"))   which still looks like a kludge to me. How should I determine how many lands of each different color to put in my deck? Animations about a young man pulled into a fantasy setting with dragons? I'm looking for an animation (more likely a film not a series) that I watched as a kid, watched early 90's I'm sure it contained a book loving male main character (wears glasses might have even had an amulet) who gets pulled into a fantasy via a magic book  Setting with dragons and an evil wizard, I remember it being on TV as I never had it on VHS.  Same sort of animation technique as visionaries or thundercats.  Thanks. Integration of the cardinal sine It is said that the integral of the cardinal sine is $1$. How do I integrate the cardinal sine? $$ \int_{-\infty}^{\infty} \frac{\sin(a)}{a} \, {\rm d} a $$ Could I have a hint for testing the convergence of the following series please?  $$\sum_{n=2}^\infty\frac{1}{(\ln n)^{\ln n}}$$  I am very appreciative for your help. $n$-th digit in the sequence of natural numbers What's the $n$-th digit in the sequence $S$ of numbers formed by the natural numbers, i.e.,  $n$-th digit in the sequence 1 2 3 4 5 6 7 8 9 10 11 12... ? For example 11th digit in the sequence is 0. Best way to save data in a Java application? How to prove the existence of $b$ in $Q$ such that $a<b^2<c$ in $Q$? Why is "women" pronounced the way it is? As far as I know, it is the only word where wo is pronounced as wee. What is the reason for this? Does it have to do with the origin of the word? Display error message if same record exist with combination of some fields? I have taken three fields from case object called AccountName, IntegrationTo__c and SfType__c (checkbox).  I have created one case record with a specific combination of three fields.  For the second time I create a record with that combination, then  display error message only if SfType__c is true in first record otherwise allow  for record creation.  trigger AvoidDuplicate on Case(before insert)  {          set&lt;string&gt; newNameSet = new set&lt;string&gt;();     newNameSet = new set&lt;string&gt;();      set&lt;string&gt; newEmailSet = new set&lt;string&gt;();      set&lt;string&gt; dbNameSet = new set&lt;string&gt;();      set&lt;string&gt; dbEmailSet = new set&lt;string&gt;();      for(Case newLead : trigger.new){          newNameSet.add(newLead.Account.Name);          newEmailSet.add(newLead.IntegrationTo__c);      }      for(Case dbLead : [select id, Case.Account.Name, IntegrationTo__c from Case where IntegrationTo__c IN: newEmailSet OR Case.Account.Name IN: newNameSet]){          dbNameSet.add(dbLead.Account.Name);          dbEmailSet.add(dbLead.IntegrationTo__c);      }      for(Case newLead : trigger.new){          if(dbNameSet.contains(newLead.Account.Name) &amp;&amp; dbEmailSet.Contains(newLead.IntegrationTo__c))              newLead.addError('You are inserting Duplicate Case');      }  }   i wrote this this not checking the account field name and integration__c values only with combination of account and integration__c shows error Does Thanos' plan apply to higher order beings? We know that Thanos' plan was to       instantly destroy half of all life in the universe    His plan doesn't appear to apply to lower or non sentient life forms      if it did half the trees in the final Wakanda scene would have disintegrated too   Does his plan apply to all beings more powerful than himself?