How to estimate the complexity of sequential algorithm given that we know the complexity of each step?

First case: I was stumble upon a two step sequential algorithm where the big O complexity of each step is O(N^9).

Second case: Also if the algorithm have three steps where the complexity of step 1 is O(N^2), the complexity of step 2 is O(N^3) and the complexity of step 3 is O(N^9)

What would be the complexity of the first case and second case ?

Computability of sequential cubic-order algorithms

I have a cubic-order algorithm which must be executed sequentially; there appears to be no way of making it parallel.

I need to come up with an estimate of maximum input size that can be solved using today’s technology. So, the essential problem seems to be how to relate the cost of a single step to execution time on a “typical” hardware. Is there a gold-standard way of doing this, e.g. something an attentive peer-reviewer would like to see being done in a manuscript?

Making aysnchronous sequential circuits hazard free

The problem I am stuck at requires me design a hazard free asynchronous sequential circuit for a given problem description. I have followed the routine steps as follows:

  • I have obtained the primitive flow table from the problem description
  • I have reduced the flow table using state minimisation routines of incompletely specified FSM
  • I have assigned the output symbol preventing glitches
  • I have done the state assignments of the reduced flow table

Let us assume that I require three secondary variables $ y_1,y_2 ,y_2 $ for the state encoding.

Now I have the resulting flow table. I am stuck at how I should proceed for hazard checking. I know the general procedure of checking and removing static and dynamic hazards, given a function and some transitions.

In this problem,

  • For static hazards, I guess, I should check the KMap for each $ y_1 ,y_2,y_3 $ and thereby check for adjacent $ 1’s$ . Am I right?
  • For dynamic hazards , I really have no clue how to proceed.Descriptive answers would be very helpful

Thank you in advance for all your answers.

Name of ‘smart brute force’ attack against sequential cipher lock [duplicate]

I remember learning about an attack against sequential cipher locks – ones that don’t have a ‘reset’ or ‘enter’, you just enter digits and as soon as the last n consecutive entries match, the lock opens. So, if the code is ‘1234’, the sequence ‘32431234’ will work just fine.

The attack depends on a specific sequence that appends such digits that the resulting ‘tail’ of the string is as new as possible.

Let’s take for example a 3-digit binary lock. The possible codes are 000, 001, 010, 011, 100, 101, 110, 111. To try all 8 codes in standard brute force attack, you’d enter 24 digits total.

But instead, entering sequence 0001110100, 10 digits total, you cover all combinations and unlock the lock – generating sequences: 000, 001, 011, 111, 110, 101, 010, 100, each new digit past first 2 generating a new code.

For the good of me, I can’t recall the name of the sequence used for this sort of attack.

SQL – Return most recent batch of sequential rows

What i’m trying to accomplish here is pull in all the rows where there is a break of less than lets say 40 days between the next row.

So in the first example there is an uninterrupted break every month or roughly so is accounted for, so I would like the query to pull in all records here.

Example 1

ID          DATE(INT)      190402      20200205 190401      20200103 177904      20191205 177903      20191108 177902      20191001 177901      20190905 147512      20190802 147511      20190703 147510      20190603 147509      20190529 147508      20190429 147507      20190402 147506      20190306 147505      20190205 147504      20190110 147503      20181211 147502      20181115 147501      20181022 

In example two there is a gap greater than 40 days between Sep 25 2019 and January 29 2020. So I would like the query to just pull in the most recent subsequent block. In this case it would just be the top record.

Example 2

ID          DATE 189101      20200129 164705      20190925 164704      20190904 164703      20190802 164702      20190703 164701      20190605 

I have started down this road, and was looking at using LEAD to calculate the number of days between the current and previous rows. I realize I probably need to break the years out to account for the case when moving to a new year or convert it to a real date so that I can use some sql functions to calculate the difference in days for me.

After that I wasn’t sure how to go about only returning the most recent consecutive block. Thought I would ask here to see if anyone had any insight on how I to accomplish this.

Sequential Menu (Drill down) or Accordion

I have 3 levels in my information architecture for my desktop dashboard. In the vertical navigation which measures H:500px W:200px I have;

  • Top level: 8 items
  • Second level: 9 items in total (one of my top level item has 7 second levels)
  • Third level: 12 items

Would you use an accordion style (which will make the menu long when expanded) or a sequential drill down menu? and why?

Cheers,

Chris

Does gnome files support copy queue in sequential mode?

When dragging/dropping files one by one from one “gnome files” window to another they will be copied in parallel. This leads to a large and not needed workload without speeding up the transfer of any single file.

Does anyone know how to force “gnome files” to use the file copy queue in sequential mode (one file after another)?

Thanks in advance Best Regards Stefan

Solving sequential multi-knapsack problem

Suppose I have $ n$ items, each with value $ v(j)$ and weight $ w(j)$ , and $ m$ knapsacks each with capacity $ c(i)$ . If I make the assumption that $ w(j-1)$ evenly divides $ w(j)$ , then there’s a nice optimal packing algorithm outlined in Detti, A polynomial algorithm for the multiple knapsack problem with divisible item sizes.

I have a slight variant to this problem, where the value depends on the knapsack I put the item in: $ v(j,i)$ . Is there any paper or book detailing an exact optimal solution to this problem? In my case $ v(j,i)$ takes at most 2 distinct values, but I’m not sure if that matters.