Howard Mark
Articles
Artificial Intelligence in Analytical Spectroscopy, Part I: Basic Concepts and Discussion
February 01, 2023
Are you intrigued by artificial intelligence, but unsure what it really means for analytical chemistry? Read on.
Decimal Versus Binary Representation of Numbers in Computers
October 01, 2022
The past decision to use binary representation in computer architectures affects the results of chemometric-based outputs, especially if different data values are used.
Data Transforms in Chemometric Calibrations: Simple Variations of MLR, Part 2
July 01, 2022
We examine variations of the multiple linear regression (MLR) algorithm confer special properties on the model that the algorithm produces and critique the use of derivatives in calibration models.
Data Transforms in Chemometric Calibrations: Application to Discrete-Wavelength Models, Part 1: The Effect of Intercorrelation of the Spectral Data
February 01, 2022
Raw data produced by an NIR instrument undergoes some sort of processing, or transformation, to make them easier to use. In this series, we explore options for that data transformation, starting with multiple linear regression (MLR).
Survey of Key Descriptive References for Chemometric Methods Used for Spectroscopy: Part II
October 01, 2021
The second in a two-part series highlighting key explanatory or tutorial references for each of 29 chemometric methods.
Survey of Key Descriptive References for Chemometric Methods Used for Spectroscopy: Part I
June 01, 2021
The carefully selected literature references in this curated set describe the application of 29 major chemometric methods used for analyzing molecular spectroscopy data.
2021 Review of New Spectroscopic Instrumentation
May 01, 2021
Our annual review of new products for atomic and molecular spectroscopy, including details by category and highlights of overarching trends.
Why Does -1 x -1 = 1?
February 01, 2021
Mathematics is a formal logic system, perhaps the ultimate formal logic system. Here we describe the elegance of the foundations of the mathematics that chemometrics is based on.
Classical Least Squares (CLS), Part 3: Expanding the Analysis to Include Concentration Information on Principal Component Regression (PCR) and Partial Least Squares (PLS) Algorithms
October 01, 2020
We explore how different algorithms and different numbers of factors affect the results.
A Survey of Chemometric Methods Used in Spectroscopy
August 01, 2020
We provide a scorecard of chemometric techniques used in spectroscopy. The tables and lists of reference sources given here provide an indispensable resource for anyone seeking guidance on understanding chemometric methods or choosing the most suitable approach for a given analysis problem.