Wahyudin Syam (Page 5)

General benefits when the variation transformation chain of an assembly is known

This post will show general advantages if we have the tolerance stack-up model or the variation transformation chain of an assembly.

Tolerancing

Good practice guide for designing an assembly and its components

Assembly process should be carefully designed just as designing parts. A good design of assembly process will lead to a flexible, accurate and low-cost assembly process.

Applied programming

Common problems in numerical computation: from data overflow, rounding error, poor conditioning to memory leak

In many modern science and engineering fields, numerical computation has an essential role to perform meaningful analyses. In numerical computation, many unexpected results occur due to errors related to digital computation instead of errors due to logic or model or formula errors.

Research

Standard deviation and standard error: The fundamental and important differences

In statistical data analysis, the spread of data is mostly quantified with standard deviation. However, for scientific analysis, standard error (SE) (commonly also called, standard deviation of the mean) is more appropriate to use than standard deviation.

Research

Demystifying p-value in analysis of variance (ANOVA)

In analysis of variance (ANOVA), p-value is very often used to determine whether an initial hypothesis is accepted or rejected. However, many people still do not know what p-value is. In fact, there is a better parameter to use to accept to reject an initial hypothesis.

Metrology

Measurement system analysis: Gauge repeatability and reproducibility (Gauge R&R) test

This post will give a practical explanation about gauge repeatability and reproducibility (Gauge R&R or GR&R) test. Gauge R&R is one of measurement system analysis methods.

Metrology

The history and introduction of CMM: the inseparable relation between CMM and GD&T

The invention of coordinate measuring machine (CMM) is a direct consequence of the need to verify dimensional tolerances (GD&T). In this post, the history behind the invention of CMM as well as a brief introduction about CMM is presented.

Applied programming

The problematic aspect of number crunching in programming: Case study in GNSS calculations

In programming, especially for languages requiring explicit data type declarations, such as C/C++, FORTRAN and Java, the number of bits to represent numbers are very important.

Metrology

Measurement uncertainty estimation: Spreadsheets method

This post will discuss Spreadsheets method to estimate measurement uncertainties. This method is the most well-known and used method to estimate measurement uncertainties.

GNSS

Generating GPS L1 C/A pseudo-random noise (PRN) code with MATLAB and C/C++

In this post, C/A codes for GPS signals generation will be discussed. The C/A code implementation in MATLAB and C/C++ are presented as well.

Tolerancing

How BMW reduces their assembly cost by optimising assembly features and fixturing constraints

BMW reduces their total assembly cost by significantly reducing, if not completely eliminating, fixtures for assembly.

Research

Simplicity is the ultimate sophistication: The use of simple rules for successful research

Actually, to be successful in our research or jobs or other activities, we just need to follow and commit to few simple rules.

Research

Continuous and discrete statistical distributions: Probability density/mass function, cumulative distribution function and the central limit theorem

In real world, all variables are random and the randomness is modelled by statistical distributions. In this post, various type of statistical distributions for both continuous and discrete random variables are explained.

Applied programming

TUTORIAL: C/C++ implementation of circular buffer for FIR filter and GNU plotting on Linux

In this post, a tutorial for implementing the concept of circular buffer to a finite impulse response (FIR) filtering application of continuous data is presented. Also, the plotting of the filtered data with GNU plot application in Linux will be shown.

Applied programming

TUTORIAL: C/C++ programming with Qt framework, OpenCV and Eigen libraries for ellipse fitting from images

This post presents how to develop and deploy an application for ellipse fitting from white blobs on images. The development is on Windows operating system. In this application, C/C++ programming language will be used along with Qt framework, OpenCV and Eigen libraries.

GNSS

GPS (GNSS) signal processing chain from a received raw signal, signal acquisition, tracking to demodulation: An introduction

In this post, gentle explanations focusing on the evolution of GPS signals from a satellite to a receiver and the processing chains from the raw received signals, signal acquisition, tracking to demodulation are presented.

Tolerancing

Datum references, tolerance zone and material condition in GD&T

This post explains some fundamental elements of GD&T. The elements are datum reference (datum reference frame), tolerance zone and material condition.

Tolerancing

Examples on how to interpret GD&T: Form, orientation, location and run-out tolerances

This post presents and discusses real examples on how to interpret GD&T tolerancing symbols from technical drawings.

Metrology

The role of measurement uncertainty in quality inspection

In quality inspection, measurement uncertainty has a fundamental role in deciding the conformance and non-conformance of a part.

Metrology

Understanding measurement model, systematic error and random error

In this post, three important aspects in measurement are concisely discussed. The three aspects are measurement model, systematic error and random error.

Metrology

Measurement uncertainty estimations: Monte-Carlo simulation method

In this post, a method to estimate measurement uncertainties based on Monte-Carlo simulation is presented with examples.

Academic writing

12 fallacies that should be avoided when constructing arguments

In this post, 12 fallacies when writing arguments for scientific articles are presented with examples. Some of the presented fallacies seem to be very small and commonly used, but those fallacies completely change the meaning of arguments written in a scientific article.

Metrology

Measurement uncertainty estimations: GUM method

Any types of measurement results should be presented with their associated uncertainty. In this post, a method to estimate measurement uncertainties based on Guide to the expression of uncertainty in measurement (GUM) is presented with examples.

Academic writing

Five fundamental rules for scientific writing that are applicable for all fields

This post explains five important rules to write scientific articles. The rules can be applied to all types of research fields. The five rules are logical, clear, accurate, concise and audience-dependence.

Tolerancing

3D tolerance stack-up analysis with examples

In this post, 3D tolerance stack-up analysis will be explained with two examples. Both traditional “+/-” dimensional tolerance and geometrical tolerance (GD&T) are considered.