FAQ Database Discussion Community


How to model a quiz-system in OOP? [closed]

java,oop,modeling,quiz-engine
I am just trying to make a quiz system for young people to learn road/traffic signs.The idea was also to make something in a way that i later can use the same system for other types of quizzes. I have just started out, and this is what i have planned...

How to understand use-cases in specific scenerio

drawing,uml,modeling,use-case
I am drawing a diagram of use-case using ArgoUML, I have a scenario in which user can update status but after sign in to the application , in that sense i need to extends update status after sign in or make it a new separate usecase or generalize it. Thank...

Event-B, formal modelling : How to affect all the elements of a set to a relation

modeling,event-b
I'm having quite a lot of troubles with Event-B.. I'd like to make a relation from a group of client to a client number each I have a relation of that type : cli(PERSON) = NAT1 (Person is a finite set) and in an event I have a subset of...

Mathematical modelling in Matlab

matlab,simulink,modeling,transfer-function
I am new to Matlab and I need to perform a simple task. I have an input function u(t)=2t-1 and an output function y(t)=(-4/45)e^3t+ (1/5)e^(-2t)-1/3t-1/9 I have to find the corresponding behavior model, defined via a transfer function and then simulate the behavior model in Matlab/Simulink. I am not sure...

Eclipse Model Tool - Two sided transformation ( model to code and code to model )

eclipse,modeling,papyrus,modelio
is there any tool that i want to generate model from code, and code from model? Especially i prefer this tool should be compatible with eclipse java project . When i update my code, model must be updated according to changes in code. Also when i update model, code must...

Ontologies, OWL, Sparql: Modelling that “something is not there” and performance considerations

performance,sparql,modeling,ontology,sesame
we want to model that "something is not there" as opposed to missing information, e.g. an explicit statement that "a patient did not get chemotherapy" or that "a patient does not have dyspnea" is different from missing information about whether a patient has dyspnea. We thought about several approaches, e.g....

R: unexpected behavior of the fdwm() function (evmix package)

r,distribution,modeling,mixture-model,weibull
I am trying to fit a dynamic mixture model (Weibull for the bulk, Pareto for the tail) using the fdwm() function from the evmix package: library(repmis) library(evmix) data=source_data("https://www.dropbox.com/s/r7i0ctl1czy481d/test.csv?dl=0")[,1] test=fdwm(data,c(0.9150062,75.4699181,quantile(data,0.98),11.21,87.41,0.05)) I am experiencing a weird behavior: the function first returns an error...: Error in integrate(rx, wshape, wscale, cmu = cmu, ctau...

Relation between a Object Diagram and a Class Digram in MOF Layer terms

uml,modeling,meta-object-facility
I want to express the relationship between object diagrams and class diagrams in terms of the MOF Layer Model. As an Object Diagram (OD) is an instance of a Class Diagram (CD), I conclude that an OD must be on a Layer below a CD (e.g. OD in M0 and...

laravel model best practice

postgresql,laravel,model-view-controller,eloquent,modeling
Hi I'm using laravel in my current project. I thought its recommended to create a model for each database table to get the best out of eloquent's Relationships somewhere in my Database I have this mapping table to map records from table A to table B (many to many) should...

Handling missing values in a database schema?

database-design,modeling,missing-data,representation
Suppose I have the following table schema MONTH VARCHAR(10) HASRAIN BOOLEAN YEAR INTEGER Now suppose for a particular year, I have values for 11 months, but no value for the the left over month (let's call it September). Is it more correct to: Put a record in with a zero...

How to modell contact information database

sql,database,modeling
I am trying to create a contact information system, but I am very stuck with the database modelling. What I am thinking about today is having a person table with the rudimentary information about a person (name, forename, surname, ssn, sex, date-of-birth etc.). Them I am thinking about creating new...

What underlying difference makes Node Instances appear different?

deployment,uml,modeling,enterprise-architect
I have two similar (if not identical) node instances that are appearing differently in a deployment diagram (and anywhere else that I use them). I may have done some odd things in the past while beating EA into submission. But, now ... by pulling every lever I can imagine, I...

Namespace for (DDD) entities cutting across domains

namespaces,domain-driven-design,modeling
I have a couple of business-related domains like Purchase, Marketing and Economy. Having the models arranged into a namespace* for each domain would be nice, but there are some entities cutting across domains, like an Item. How to organize those cross-cutting objects? * = As in C#/Java/Python namespaces....

Hadoop performance modeling

performance,hadoop,modeling
I am working on Hadoop performance modeling. Hadoop has 200+ parameters so setting them manually is not possible. So often we run our hadoop jobs with default parameter value(like using default value io.sort.mb, io.sort.record.percent, mapred.output.compress etc). But using default parameter value gives us sub optimal performance. There is some work...

Modeling Matlab Script with Adobe After Effects

matlab,import,modeling,after-effects
So I am looking for some general advice. For my final project in my Computational Physics class. I have to complete the following problem. (4.16 from Computation Physics 2nd Edition By Giordano and Nakanishi) -Carry out a true three-body simulation in which the motions of Earth, Jupiter, and the Sun...

How to set first column to a constant value of an empty np.zeros numPy matrix?

python,numpy,matrix,modeling
I'm working on setting some boundary conditions for a water table model, and I am able to set the entire first row to a constant value, but not the entire first column. I am using np.zeros((11,1001)) to make an empty matrix. Does anyone know why I am successful at defining...