Questions on how to represent real-world or non computer science problems with computer science tools.

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How to mitigate the hierarchical error propagation in tree-structured classification

Suppose we have a multi-class classification problem, where the number of classes $K \geq 3$ We use a tree structure of multiple SVMs to divide and conquer the problem, with one example in the figure ...
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0answers
19 views

Middle ground between model-based and model-free approaches

In the context of the reinforcement learning domain, the dichotomy between model-based (learn a model and used it to determine a controller) and model-free (learn a controller without learning a ...
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2answers
66 views

Dynamic Shortest Path with Linear Programming

Consider a grid with $x=5$ columns, $y=5$ rows, and $T$ timesteps. There are $N=2$ agents in this grid, which can move vertically or horizontally. The positions of each agent $x$ at timestep $t$ ...
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0answers
54 views

Context-free grammar for DAGs?

I'm looking for a "safe" representation of DAGs. With "safe" representation I mean that it can be described by a context-free grammar. Ideally, this grammar would be suitable for a simple LR parser. ...
2
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1answer
41 views

Efficient formulation for binary integer linear programming

Problem: There are two types of balls, big (B) and small (S), which need to packed into boxes. One box can contain either: nothing, or 1 S, or 1 B, or 2 S, or 2 B, or 1 B and 2 S We are given the ...
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1answer
42 views

How does the Weibull distribution work as fault model in wireless sensor networks?

I am a little bit confused with the concept of using the Weibull distribution or other distribution for fault model. As I understand, in simulation this distribution is often used for modelling a ...
4
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1answer
34 views

Finding a method to classify pixels according to how drastic their intensity change

I am looking for a method to classify pixels into three groups: (1) Pixels which does not change their intensity much in general (the slight changes may be due to noise only), (2) Pixels which change ...
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3answers
83 views

Terminology needed for the computational solution to the Rubik's Cube

I apologize if this question is out of the guidelines of this forum. If it is please let me know and I will abstain from requesting definitions and terminology. Hello! I am currently writing a ...
2
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1answer
48 views

Why arrival process of packets at a switch is not a Poisson Process?

"Packet arrivals are not Poisson .... but some events are, such as web requests and new flow arrivals" I know since the network traffic is very bursty, they are not Poisson. But I am unable to ...
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0answers
60 views

Integer programming for the courier (goods delivery) scheduling problem

Model: Consider an undirected, weighted, complete graph $G = (V, E = V \times V, w: E \to \mathbb{N}^{+}, r: V \to \mathbb{N}^{+}, d: V \to \mathbb{N}^{+})$. $s \in V$ is a source vertex. $G$ ...
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0answers
16 views

A* orientation discretization

I have a space with obstacles I wish to find a path through. What I can do is discretize the space into a grid and use A* (or D* or whatever) to find a path through it. I wish to now add orientation ...
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2answers
150 views

How to impose Euclidean distance constraint in a constraint satisfaction problem without quadratic constraints?

Best reference I could find is this one. However, I could not quite understand this one since there is no numerical example. What I am trying to achieve with one sentence How can I answer the ...
2
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0answers
43 views

How to select a good window size in the Running Gaussian Average method for Selective Background Updating?

I have been studying the Selective Background Updating in Running Gaussian Average Method, as discussed in the Wikipedia (the Variant method). The details of the algorithm, as I understand, is as ...
2
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1answer
61 views

Selective Background Updating in Running Gaussian Average Method for Background Subtraction

I am studying the Running Gaussian Average Method for background subtraction. One alternative, as described in Wikipedia, also known as Selective Background Updating, is to only update the ...
0
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1answer
85 views

Please explain linear programming as seen for this load balancing problem

I have at hand a linear program related to load balancing. However I have no idea what this is and wikipedia gives me something too simplified/abstract to be useful. I wonder if someone can explain ...
1
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1answer
38 views

What is the reason of using Gaussian model for Background Modeling?

I am a new learner to Background Subtraction (Background Modeling) and I am reading a few previous works on how it is performed. Starting with Wikipedia (by searching "Background Subtraction"), I ...
2
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0answers
23 views

Calibrating a Markov Chain with little data

I am trying to calibrate a Markov Chain. Usually you would have the amount that "moves" from one state to the other and then the resulting value, with data at any given time with the following ...
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1answer
68 views

Data versioning in a relational database

I've been working on an industrial project where my job was to design a data model in-memory and in a relational database in such a way, that can capture the time-varying nature of the production ...
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1answer
58 views

Converting reality to Petri net

I'm autistic and I think a bit differently. I have superior memory and visual thinking, but I have a problem with converting real thing to abstract. I'd like to model reality processes with Petri ...
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1answer
88 views

Formalizing self-propagating behaviour

Since reading Ken Thompson's Reflections on Trusting Trust I am trying to formalize the idea of a program which mutates its own behaviour; specifically, a program that would be self-reproducing except ...
1
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1answer
56 views

Requiring at least one alldiff constraint to be satisfied converted to SAT

For generating certain hard puzzles, I am trying to model a problem (ultimately) in SAT. I don't know how to do that, so I am starting with CSP because it's more expressive. In CSP, there is a global ...
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0answers
52 views

How to convert a search solution to a path to be tracked?

Let's say I have a space with obstacles and I'm trying to control a robot's movement while avoiding obstacles. I also have a start state and a goal state. I use a search algorithm to find the shortest ...
3
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1answer
395 views

Set the parameters of a Erdos-Renyi graph generator to get a specific mean degree

I'm trying to reproduce the synthetic networks (graphs) described in some papers. The topic is the same as a previous question of mine, but with a different focus. It is stated that the Erdos-Renyi ...
3
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1answer
110 views

Mathematical model for a webpage layout?

Getting layout right (even if only a structure is considered) with HTML5/CSS3 is still more like an art or black magic. On the other hand, there are other GUI systems (like wxWindows and Tcl/Tk) and ...
4
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0answers
69 views

Solving an Interlacing Cords puzzle inside a Truncated Octahedron

My friend got me this really interesting puzzle Each node can be slided or docked around the Truncated Octahedron, creating knots and tangles in the middle of the puzzle. The idea is to move the ...
3
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1answer
170 views

Boat riddle as a combinatorial optimization problem?

I remember a riddle about a bunch of people on a river bank, and a boat with limited capacity (lets say the boat can transport 2 people at a time). There are various relations between the people like: ...
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1answer
224 views

How to represent circles in x-y coordinates [closed]

I would like to be able to represent circles in x-y coordinates. Each circle contains an x and y coordinates and radius in double data type. My goal is to compare circles with each other whether ...
4
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2answers
435 views

Is $a^n b^n$ an artificial language or does it occur in the real world?

The classic example of a context-free grammar is $a^nb^n$. That is, $n$ occurrences of $a$ followed by an equal number of occurrences of $b$. Do such forms occur in the real world? Can you provide an ...
6
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2answers
179 views

Peer grading design - choosing a graph, to get accurate rankings/ratings

Background. I am writing some code for semi-automated grading, using peer grading as part of the grading process. Students are given pairs of essays at a time, and the students have a slider to choose ...
17
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8answers
1k views

What randomness really is

I'm a Computer Science student and am currently enrolled in System Simulation & Modelling course. It involves dealing with everyday systems around us and simulating them in different scenarios by ...
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0answers
25 views

Predict binary occupancy vector from history of vectors

I have a set of binary vectors where each vector represents one day of occupancy in a house and consists of 48 elements (each element for 30 minutes of the day). Each element can be 1 meaning that ...
6
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2answers
160 views

Building probability distribution functions from observation

There are N players and M objects, each of the objects has a value. Each player has a strategy in choosing an object. Each round a player will choose an object, many players can choose the same ...
4
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1answer
106 views

What are the rudimentary types of information connectivity i.e. model types?

I am looking at a modelling tool and are trying to determine all the types of ways that you can model (at a rudimentary level) I remember seeing a list of ways in which you can connect or categorise ...
6
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1answer
132 views

How to represent the interests of a Facebook user

I'm trying to figure out a way I could represent a Facebook user as a vector. I decided to go with stacking the different attributes/parameters of the user into one big vector (i.e. age is a vector of ...
6
votes
1answer
99 views

How to score a given arrangement of windows on a screen to produce good layouts

(this is related to my other question, see here) I would like to write a function that scores a given arrangement of windows on a screen. The purpose of this function is to determine whether a ...
7
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1answer
112 views

Efficient queriable data structure to represent a screen with windows on it

(this is related to my other question, see here) Imagine a screen, with 3 windows on it: I'd like to find an efficient data structure to represent this, while supporting these actions: return a ...
2
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1answer
54 views

How can I measure the usability of a catalogue?

This question might seems vague but heres the context: When we are focusing on HCI we would most likely be interested on knowing first how the user usually deals with a certain object. We then try to ...
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4answers
2k views

How to devise an algorithm that suggests feasible cooking recipes?

I once had a veteran in my course that created an algorithm that would suggest cooking recipes. At first, all sort of crazy recipes would come out. Then, she would train the cooking algorithm with ...
3
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1answer
129 views

Is it viable to use an HMM to evaluate how well a catalogue is used?

I was interested on evaluating a catalogue that students would be using to observe how is it being used probabilistically. The catalogue works by choosing cells in a temporal sequence, so for ...
2
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1answer
137 views

Pattern classification: what goes into the sample?

I am trying to compare the performance of a classification result with Bayes classifier, K-NN, Piece wise component analysis (PCA). I have doubts regarding the following (please excuse my lack of ...
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1answer
431 views

Clustering of Songs (The Joe Walsh Problem)

The Eagles are a rock supergroup from the 70s and 80s, responsible for such classics as Hotel California. They have two quite distinctive sounds, one where guitarist Joe Walsh is present (for example, ...
11
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2answers
181 views

CCS process for a drink dispenser with two different prices

A drink dispenser requires the user to insert a coin ($\bar c$), then press one of three buttons: $\bar d_{\text{tea}}$ requests a cup of tea $e_{\text{tea}}$, ditto for coffee, and $\bar r$ requests ...
24
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4answers
3k views

How to determine likely connections in a social network?

I am curious in determining an approach to tackling a "suggested friends" algorithm. Facebook has a feature in which it will recommended individuals to you which it thinks you may be acquainted with. ...
15
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1answer
598 views

Efficient encoding of sudoku puzzles

Specifying any arbitrary 9x9 grid requires giving the position and value of each square. A naïve encoding for this might give 81 (x, y, value) triplets, requiring 4 bits for each x, y, and value (1-9 ...