Development of a speedometer based on the display from the Nokia 3310

Development of a speedometer based on the display from the Nokia 3310Recently, among the accessories for bicycles are widely used so-called digital velospidometers (bike computers). These devices are able to measure a variety of parameters, the main ones being speed and distance. The principle of speed measurement is based on calculating the period of the wheel's revolution, and the distance is calculated based on measuring the number of such revolutions. Often, a reed switch serves as a reed switch in conjunction with a spoke wheel magnet. Depending on the functionality, the price of such devices varies widely. The cheapest bicycle speedometer can be purchased ...
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Richard Hamming: Chapter 19. Modeling - II

"The purpose of this course is to prepare you for your technical future."
 
Richard Hamming: Chapter 19. Modeling - II Hello, Habr. Remember the awesome article "You and your work" (+21? 2442 in bookmarks, 389k of readings)?
 
 
So Hamming (yes, yes, self-controlling and self-correcting Hamming codes ) Is the whole book based on his lectures. We translate it, because the peasant is talking.
 
 
This book is not just about IT, it's a book about the thinking style of incredibly cool people. "This is not just a charge of positive thinking; it describes ...
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A review of gradient methods in problems of mathematical optimization

A review of gradient methods in problems of mathematical optimization

Foreword


 
In this article, we will talk about methods for solving mathematical optimization problems based on the use of the gradient of a function. The main goal is to collect in the article all the most important ideas that are somehow connected with this method and its various modifications.
 
 

Note from the author


 
At the time of writing, I defended my thesis, the task of which required me to have a deep understanding of theoretical fundamentally methods of mathematical optimization. Nevertheless, I still (like everyone else) have their eyes blown away from the terrible long formulas...[/h][/h]
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Determination of the ballistic-temporal characteristics of the motion of the center of mass of the paratrooper, dropped from the plane

Introduction


 
To determine the ballistic-temporal characteristics of the motion of the center of mass of the paratrooper, we must choose a simplified mathematical model, which is quite accessible for analytical research and at the same time preserves the most characteristic features of the initial object.
 
For the construction of simplified mathematical models of the parachutist movement, analysis, determination, and systematization of the permanent and temporal parameters are carried out.
 
There are no regular and sufficiently substantiated methods for constructing nonlinear mathematical ...[/h]
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Probabilistic programming and Bayesian method for hackers

Hello colleagues. Today we wanted to ask how useful you seem to be a slightly outdated book " " Bayesian Methods for Hackers ", Published in the original in 201? but not yet translated into Russian.
 
 
Probabilistic programming and Bayesian method for hackers
 
The book is positioned as applied, maximally disposed of mathematics and timeless.
 
 
Under the cut - a slightly abbreviated translation of the review of this book, laid out by the author on Github.
 
Please participate in voting
 
Prologue ...
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A simple controller based on fuzzy logic. Creating and configuring

Fuzzy logic for control


 
The text is based on the materials of the book Gostev VV. "Fuzzy regulators in systems of automatic modeling". Like all serious publications on the topic, this book is overloaded with mathematical calculations and is hard for an unprepared reader. Meanwhile, the very principles of creating and using fuzzy logic are quite simple and obvious. This text is an attempt to translate an example from a book from a mathematical language into an engineering one.
 
The possible sequence of controller design based on fuzzy logic is shown, by sequential complication of logical ...[/h]
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We calculate the probabilities for the article "Dishonest game, or how the organizers of the drawings deceive us"

We calculate the probabilities for the article "Dishonest game, or how the organizers of the drawings deceive us" Article with the analysis of the game of the well-known trading network has caused us in Cloud4Y lively interest. Here are a few excerpts to introduce you to the course:
 
One day, on a sunny spring morning, reading the city forum, I came across a link with a simple game from a well-known trading network. The game (action), dedicated to the World Cup, was an unpretentious field three to three, filled with soccer balls. Clicking on the ball, we opened the picture with this or that product. When opening three identical pictures, the participant was guaranteed a free receipt of the goods ...
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Information systems with conceptual models. Part One

Information systems with conceptual models. Part OneBy implementing modern information systems, large companies expect to make decisions faster, discover hidden reserves and opportunities for the business, analyze the accumulated experience and build forecasts based on the identified regularities. However, the real return on information systems is often much lower, and implementation time and costs are higher than expected. The reasons can be a great many, including those related to ineffective management, the human factor, the outdated infrastructure.
 
 
Essential shortcomings are also in the information systems themselves. In this article, I ...
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Information systems with conceptual models. Part Two

Information systems with conceptual models. Part TwoIn the first part of Article we started talking about a new class of high-level domain models called conceptual. Unlike other similar models in conceptual models, the links between concepts are concepts themselves, and the model is built on the basis of identifying and describing the abstractions that served as the formation (definition) of the concepts of the subject domain. This allows end users to build and update domain models through simple and natural operations of creating, modifying and removing concepts and their entities.
 
 
Here, in the second part, let's talk about how a fully ...
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Use of nuclear regression for forecasting demand in chain stores

Kind time of the day, dear Khabarovsk! In this publication, we will talk about a model for forecasting the demand for goods in chain stores and its implementation in C ++.
 
 

Statement of the problem


 
Suppose we have a chain of shops, each of which imports goods. Goods (for the forecast model) fall into each store in an arbitrary way. For a certain period of time we have statistics - how many in each store are sold those or other goods. It is required to forecast sales of goods for a period of time similar to the one chosen for all stores for all goods that were not imported.
 
 
Notes and ...[/h]
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