Questions tagged [modelling]
Questions on how to represent real-world or non computer science problems with computer science tools.
90
questions
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16 views
implementing a 802.15.4 math model based on a paper. How to verify it
I am implementing a mathematic model for predicting the congestion of 802.15.4 network based on the paper:
Performance analysis of IEEE 802.15.4 non-beacon mode with the unslotted CSMA/CA
Based on the ...
0
votes
0answers
18 views
Search algorithm for multidimensional space with custom topology
First, let's start with the description of the problem in dimension 1:
Let $T_0$ be a space with $n$ nodes organized in a tree structure, with $m$ of those nodes defined as target nodes. In this space,...
1
vote
1answer
17 views
Explanation of roofline model
I am currently studying the roofline model. Wikipedia [2] shows the following example graph:
The diagonal line shows $\beta * I$. But I do not understand why this line does not go through the zero ...
2
votes
0answers
28 views
How to specify mutated types mathematically?
Say I have an object which I pass to a method, and the method returns that same object, just mutated.
So it goes like this:
...
0
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0answers
14 views
modelling communication costs on a network
Consider a set of $N$ computers. Each computer needs to send some data to $K$ other computers, and each computer is receiving data from $K$ other computers (ie. the communication pattern can be ...
0
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0answers
17 views
Is MDP Considered as The Model-based Value Iteration in/of Reinforcement Learning?
Is MDP Considered as The Model-based Value Iteration in/of Reinforcement Learning?
If no, then Reinforcement Learning is all about being Model-free learning. Right?
3
votes
2answers
116 views
How do you have a type typed “Type” when implementing a programming language?
I am working on the base of a language model, and am wondering how to represent the base type, which is a type Type. I have heard of an "infinite chain of ...
2
votes
1answer
46 views
A voting scheme where votes are scriptable
I am looking for literature on mathematical models of (political) voting schemes. Concretely, I am interested in models that allow votes of the following form:
"I am voting for $X$, but only if $...
0
votes
2answers
48 views
Are objects appropriate for modeling the real world?
First of all, I know objects are not meant to model the real world, although they have been marketed as such and perhaps that was an intention at some point.
Here I say 'modeling the real world' in a ...
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0answers
25 views
Lectures and books for beginner to approach learning simulations
I'm an incoming undergrad with a math background up to single-variable calculus, but reasonably strong programming background through algorithms, data structures, web and mobile app development. ...
1
vote
1answer
44 views
Tools for modelling compilers
I'm a wannabe mathematician, whose master's thesis is (by the looks of it) going to focus on a certain "compiler", used to produce learning materials from a subset of $\LaTeX$, in the context of ...
1
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0answers
8 views
Is there a way to connect a deep language model output to input?
In models like GPT-2, TXL and Grover, is there a good way to know which input weights (tokens) resulted in each token of the output?
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146 views
Relational Database to Aggregate Data Model
Can any application currently using a relational database be rewritten to use an Aggregate Data Model, by Focusing on data modelling aspects only (ignoring other features like salability or ...
4
votes
1answer
37 views
How to model references in an ontology
I am interested in creating an ontology which will model arguments (among other things). For example, a triple in the ontology might be
...
1
vote
2answers
949 views
What is the difference between “information model” and “conceptual model”?
I am trying to figure out the difference between information and conceptual models. For me, both terms seem to mean be the same, but I cannot find a reference where this is established. They are never ...
0
votes
1answer
447 views
How to write an if then logical constraint given part of the input related to a decision variable?
I am trying to solve an assignment problem-like from a bi-objective persepctive where I have a marketplace of vendors proposing different machines with different types and specs. The goal is to select ...
0
votes
1answer
26 views
How to evaluate the learned prototypes for multivariate time-series (e.g. motion)?
Consider a method which finds prototypes for multivariate time-series (MTS) data, and is designed to find prototypes for each class of data.
For example, the {walking} class consists of some slightly ...
1
vote
0answers
1k views
Restriction for greater than constraint in linear programming
I have a model that considers real values and that uses a binary variable $x$. In this model, the following conditions should apply:
\begin{equation}
x=
\begin{cases}
0, & \text{if}\...
1
vote
1answer
45 views
What is a logical approach to developing an algorithm which can find the optimal parameters for a function which make it best fit a given data set?
Consider the highlighted columns in the following table:
Starting with 100,000 newborns, $l_{x+2}$ denotes the number of individuals in the sample still alive at age $x+2$. If we consider Makeham's ...
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0answers
95 views
How to model an ''affinity constraint'' in assignment problem
Working on an optimization problem formulated using the well known assignment problem. My decision variable is defined as follows :
$$\alpha _{x}^{r,u} = 1\begin{cases}
& \text{ 1 if } \mathbf{...
0
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0answers
28 views
How to define a generic evaluation metric
Given a system (S) that accepts a tuple of parameters ($\alpha, \beta, \gamma \dots$ etc). These parameters affect the performance of S in a different way. For instance, decreasing $\alpha$ would ...
3
votes
1answer
67 views
Develop a winning strategy for a game
Okay so I've been going crazy about this problem I was given. It is as follows:
Given a pile of N matches, 2 people take turns removing matches from the pile. When it is your turn you are allowed ...
3
votes
1answer
198 views
Is this problem just an application of traveling salesman? If not is it some other already “solved” problem?
Description of the problem in question:
Say I have a complete graph with positive weighted edges. 1 vertex is specified as the "end". A subset of the other vertices are designated as "start" vertices....
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0answers
50 views
DAGs and Equivalence Class of DAGs
I am learning DAGs and Equivalence Class of DAGs, I am reading the material by Prof. Campos Ibáñez here: https://www.cs.cmu.edu/afs/cs/project/jair/pub/volume18/acid03a-html/node2.html
However, I ...
1
vote
0answers
10 views
B2B integration modelling tools and standard suggestions
This question might be too broad, but I really need help with this. I am required to choose a standard or notation to model an integration between two business processes, one of which is external.
...
1
vote
1answer
78 views
How to convert two conflicting objective functions into a single objective function
I have two objective functions say f1 where I have to minimize (X+Y) and another function f2 where I have to maximize (A-B). The two functions are conflicting.
I need to convert them into a ...
2
votes
2answers
186 views
How can union-find algorithm be used with “real” data
In the beginning of the Princeton algorithms course the Dynamic connectivity problem is presented (quick-find, quick-union). Here is how it's described:
The input is a sequence of pairs of integers,...
0
votes
2answers
263 views
Modeling tiling problems as SAT problems
I read that tiling problems can be modeled as satisfiability problems (2-SAT?), but the author did not explain how. Is this true? What would be an example?
By a "tiling problem" I mean you have a ...
0
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0answers
74 views
Applying Ford-Fulkerson to settle a business lunch
I want to organize a business lunch with two societies $E_1$ (mine) and $E_2$. Each society is made of four people from the Executive management and 6 of the Financial Management. I want to organize ...
2
votes
3answers
200 views
Integer linear programming formulation of formula in DNF
I have multiple sets, e.g.,
$$\{1, 2\}, \{2, 3, 4\}, \{1, 4\}$$
Each variable $1, 2, 3, 4$ is binary. I need to represent the following condition without additional variables
$$(1 \land 2) \lor (2 \...
3
votes
2answers
294 views
Matching two people. One has 7% in common with the other. The other has 70% in common. What's a fair match score?
I am exploring some ideas around dating site matching, and I can do with some ideas as to which is the better solution
Senario: We have a boy and girl, the boy has completed his profile/bio ...
2
votes
1answer
283 views
Expressing a logical constraint in integer programming
Let $x$ be an integer such that $x \in [ - 10,10]$ and $b$ a binary variable. Apply integer programming to express $b = 1 \leftrightarrow x \ge3$
My work:
\begin{equation}
\begin{cases}
\...
1
vote
1answer
328 views
Set Cover and additional constraints
Consider the following bipartite graph:
Each node in red color represents a warehouse $w = \{ 1,2,3\} $. For this example we have three warehouses located at different locations. Each warehouse has a ...
3
votes
3answers
201 views
How to Determine Places, Transitions and Tokens in a Scenario when Modeling with Petri Nets?
When modeling a scenario with Petri nets how should I determine the places, transitions and tokens?
Example:
There are two exam assistants in an exam hall observing the exam. They stand in front of ...
3
votes
2answers
1k views
Linear programming formulation for the single-source shortest path problem
In this course lecture; section 5.1, single-source shortest path (SSSP) is formulated as the following linear program (LP):
\begin{align}
\max &\sum d_u \\
\text{subject to} & \\
d_v &\le ...
2
votes
0answers
281 views
The meaning of ontology in computer science
I am reading a paper and ran into this word Ontology-based, What does it really mean? I did searching about it but still ambiguous to me, can someone elaborate this ...
0
votes
1answer
45 views
How to conceptually represent attributes (characteristics) of an object in logics?
I am reading about/working on the knowledge representation using OpenCog framework http://wiki.opencog.org/w/OpenCog_Framework which essentially is special kind of probabilistic logic (s.c. PLN - ...
1
vote
1answer
128 views
Ambiguity in choosing the best ER model
I am actually little bit confused when I am reading through the text - Database system concepts by Henry F. Korth and others
I won't be able to understand one thing, which one of the following models ...
1
vote
0answers
46 views
Modelling belonging of a real variable to an interval by a boolean variable
In the context of a MILP, I have variables $x_{t} \in \mathbb{R}$ which have a lower bound $x^{min}$ and an upper bound $x^{max}$.
Let $I_{1} = [x^{min},a_{1}], I_{2} = ]a_{1}, a_{2}], ..., I_{n} = ]...
0
votes
1answer
39 views
How to simulate systems' unavailability?
I am simulating a system where the clients' unavailability is one big issue to the systems behavior.
I gathered the real system logs to analyze the unavailability of the clients in the deployment ...
7
votes
2answers
112 views
CNF form of variable assignment problem
There are n variables $x_1$, $x_2$,..., $x_n$ and each one of them takes values from 1 to k (k>= n) and all are distinct. How can I represent this in the CNF form? (I tried the trivial way of trying ...
2
votes
0answers
56 views
An alternative to the object paradigm
I've been playing around with an alternative to the standard object-oriented paradigm for modeling data, and I would like to know if there is any research or already existing systems along the same ...
1
vote
1answer
364 views
Scheduling N variable-time interdependent tasks across M workers
I have N tasks, each of them requires some time to complete. Time to complete is not the same for all tasks. Each task may depend on a number of other tasks (assume, that no dependency cycles are ...
-1
votes
1answer
975 views
Stereotype in UML
What is a Stereotype in Unified modelling language?And What are the primary class stereotypes?.I need clear explanation using diagrams or real world scenario.
0
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0answers
46 views
choosing right neural network architecture and input features
As a short example suppose we have a kind of pollution sensor and a jet fan in a tunnel.
Jet fan turn on/off according to the automatic scenario based on pollution sensor value.
Pollution itself ...
2
votes
2answers
190 views
Modelling a dependency of multiple transitions on data in one place
We are modeling our process using a colored Petri net. One of the limitations we have is that when multiple transitions depend on one place, only one of those transitions will fire because then the ...
1
vote
0answers
68 views
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 ...
1
vote
0answers
39 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 model)...
4
votes
2answers
481 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 $t$ is ...
3
votes
0answers
279 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.
...
