Questions tagged [modelling]
Questions on how to represent real-world or non computer science problems with computer science tools.
83
questions
0
votes
2answers
44 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 ...
0
votes
0answers
19 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. ...
0
votes
0answers
17 views
How to create a database of meta-model transformations with real data?
I am currently working on meta-model transformation and the coevolution of models. I have already done some kind of a state of the art, and the next step in my research would be to collect some (...
1
vote
1answer
42 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
vote
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?
0
votes
0answers
136 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
34 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
591 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
386 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
964 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
40 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 ...
0
votes
0answers
88 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
votes
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
63 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
196 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....
1
vote
0answers
48 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
74 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
177 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
235 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
votes
0answers
73 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
177 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
270 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
277 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
249 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
164 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
1answer
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
278 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
116 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
38 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
105 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
55 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
345 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
927 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
votes
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
170 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
66 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
439 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
248 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
votes
1answer
332 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 ...
2
votes
1answer
111 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 ...
3
votes
1answer
52 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 ...
5
votes
3answers
165 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
votes
1answer
281 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 ...
1
vote
0answers
214 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.
$G$ ...
2
votes
0answers
25 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 ...
