T-model

The T-model is a formula that states the returns earned by holders of a company's stock in terms of accounting variables obtainable from its financial statements. Specifically, it says that:

where T = total return from the stock over a period (appreciation + "distribution yield" — see below);

g = the growth rate of the company's book value during the period;

PB = the ratio of price / book value at the beginning of the period.

ROE = the company's return on equity, i.e. earnings during the period / book value;

The T-model connects fundamentals with investment return, allowing an analyst to make projections of financial performance and turn those projections into an expected return that can be used in investment selection.

When ex post values for growth, price/book, etc. are plugged in, the T-Model gives a close approximation of actually realized stock returns. Unlike some proposed valuation formulas, it has the advantage of being correct in a mathematical sense (see derivation); however, this by no means guarantees that it will be a successful stock-picking tool.

Ford Model T

The Ford Model T (colloquially known as the Tin Lizzie, T‑Model Ford, Model T, or T) is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, the car that opened travel to the common middle-class American; some of this was because of Ford's efficient fabrication, including assembly line production instead of individual hand crafting.

The Ford Model T was named the most influential car of the 20th century in the 1999 Car of the Century competition, ahead of the BMC Mini, Citroën DS, and Volkswagen Type 1, and with 16.5 million sold it still makes the top ten list of most sold cars of all time (ranked eighth) as of 2012.

Although automobiles had already existed for decades, their adoption had been limited, and they were still mostly scarce and expensive. Automobiles were considered extreme luxury for the common man until the Model T. The Model T set 1908 as the historic year that the automobile became popular for the mass market. The Model T was a complete success among the population; in a matter of days after after the release, 15,000 orders were placed. The first production Model T was produced on August 12, 1908 and left the factory on September 27, 1908, at the Ford Piquette Avenue Plant in Detroit, Michigan. On May 26, 1927, Henry Ford watched the 15 millionth Model T Ford roll off the assembly line at his factory in Highland Park, Michigan.

Substitution model

In biology, a substitution model describes the process from which a sequence of characters changes into another set of traits. For example, in cladistics, each position in the sequence might correspond to a property of a species which can either be present or absent. The alphabet could then consist of "0" for absence and "1" for presence. Then the sequence 00110 could mean, for example, that a species does not have feathers or lay eggs, does have fur, is warm-blooded, and cannot breathe underwater. Another sequence 11010 would mean that a species has feathers, lays eggs, does not have fur, is warm-blooded, and cannot breathe underwater. In phylogenetics, sequences are often obtained by firstly obtaining a nucleotide or protein sequence alignment, and then taking the bases or amino acids at corresponding positions in the alignment as the characters. Sequences achieved by this might look like AGCGGAGCTTA and GCCGTAGACGC.

Substitution models are used for a number of things: