Wahyudin Syam (Page 4)

GNSS signal modelling considering channel impairments and spoofing interferences

Signals of global navigation satellite system (GNSS), such as the well-known GPS and GALILEO, are significantly affected by channel impairments and signal interferences.

GNSS

Low frequency radio navigation system for use in natural disaster situations

It is critical to have a navigation system for search and rescue of victims and important assets in a disaster situation.

Metrology

Coordinate measuring machine (CMM): Calibration, performance verification and measurement uncertainty estimation

Calibration, performance verification and measurement uncertainty estimation are important activities for coordinate measuring machine (CMM) machine and measurement.

Metrology

Error sources on coordinate measuring machine (CMM) measurements and environment control

A coordinate measuring machine (CMM) is a complex measuring instrument. Hence, there are many error sources that cause the degradation of a CMM measurement accuracy and the increase of the uncertainty of the CMM measurement results.

GNSS

Channel coding theory: An introduction and comparison of block, Convolutional, Turbo and low-density parity-check (LDPC) codes

In this post, a brief introduction about channel coding theory is presented. The comparison of convolutional, TURBO and LDPC codes for use in global navigation satellite system (GNSS) signals is also presented.

Metrology

Sampling strategy for coordinate measuring machine (CMM) measurements

In any CMM measurements, especially with a tactile-CMM, sampling strategy is very important. This Sampling strategy in CMM measurement affects not only measurement performance, but also measurement accuracy!

Metrology

Part-alignment procedure on coordinate measuring machine (CMM) for dimensional and geometrical measurements

Part-alignment is a compulsory process that needs to be performed for CMM measurements. This process is performed right after the qualification process of CMM probing system. Only after part-alignment is performed, dimensional and geometrical measurements by a CMM can be carried out.

Metrology

The probing system of tactile-CMM: Vector diagram and qualification process

In this post, the vector diagram and the mathematics behind the qualification process of a probing system are presented.

Metrology

The probing system of tactile-CMM: Important aspects to consider for probing system

In this post, important aspects regarding the probing system of tactile-CMM is discussed. By knowing these aspects, we can improve the efficiency and efficacy of dimensional and geometrical measurements with tactile-CMM.

Metrology

The probing system of tactile-CMM: The history, configuration and mechanism

Probing system in a tactile coordinate measuring machine (tactile-CMM) is a fundamental component that acts as sensor to detect whether a stylus tip has touched the surface of a measured part.

Metrology

General procedures to operate a tactile coordinate measuring machine (tactile-CMM)

There is a general procedure to operate a tactile coordinate measuring machine (tactile-CMM). In this post, we will discuss this general procedure that can be implemented to all types of tactile-CMM from various manufacturers.

GNSS

GNSS spoofing: a fatal attack on GNSS system that is difficult to detect

Global navigation satellite system (GNSS), such as the infamous global positioning system (GPS), can provide position, velocity and timing (PNT) solutions in global scale and is mostly free to use by people with, for example, a smartphone at hand or any low-cost GNSS receiver.

Metrology

Tactile CMM: The reference of dimensional and geometrical measuring machine in industry

Coordinate measuring machine (CMM), especially tactile CMM, is the industry standard for dimensional and geometrical measurement. The use and application of CMM in manufacturing industry, from automotive, aerospace until space industry, have been matured and well-accepted.

Research

Research is like a puzzle: Start from anywhere to reach a goal

Like a puzzle game, research is a unique and challenging but very rewarding activity. This metaphor is somehow valid, although may be not directly an 100% apple-to-apple comparison.

Applied programming

TUTORIAL: PYTHON for fitting Gaussian distribution on data

In this post, we will present a step-by-step tutorial on how to fit a Gaussian distribution curve on data by using Python programming language. This tutorial can be extended to fit other statistical distributions on data.

Applied programming

TUTORIAL: Visual Basic for Application (VBA) macro in Excel for Monte-Carlo Simulation

In this post, a hands-on tutorial of Visual Basic for Application (VBA) macro in Microsoft Excel for Monte-Carlo (MC) simulation is presented. MC simulation is a powerful tool to analyse and solve various scientific and engineering applications.

Metrology

Coordinate measuring machine (CMM): An introduction, types, considerations and applications

Coordinate measuring machines (CMMs) have been well accepted as universal instruments to perform various types of dimensional and geometrical measurements. The measurements are performed by capturing or probing 3D spatial coordinate points (XYZ–coordinates) on the surface of a measured part.

Metrology

Important aspects in micro-scale and Nano-scale measurements

Measuring dimension and geometry at micro-scale and Nano-scale is challenging. Because, at micro- and Nano-scale, there are additional effects that are not relevant at higher-scale measurements (than micro-scale measurement), but are very relevant at the micro- and Nano-scale.

Tolerancing

The economic benefits of tolerance stack-up analysis

Tolerance stack-up analysis has many advantages, especially from economical perspective.

Tolerancing

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.