Numerical methods for linear least squaresNumerical methods for linear least squares entails the numerical analysis of linear least squares problems. A general approach to the least squares problem can be described as follows. Suppose that we can find an n by m matrix S such that XS is an orthogonal projection onto the image of X. Then a solution to our minimization problem is given by simply because is exactly a sought for orthogonal projection of onto an image of X (see the picture below and note that as explained in the next section the image of X is just a subspace generated by column vectors of X).
SignalIn signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The IEEE Transactions on Signal Processing includes audio, video, speech, , sonar, and radar as examples of signals. A signal may also be defined as observable change in a quantity over space or time (a time series), even if it does not carry information.
Linguistic distanceLinguistic distance is the measure of how different one language (or dialect) is from another. Although they lack a uniform approach to quantifying linguistic distance between languages, linguists apply the concept to a variety of linguistic contexts, such as second-language acquisition, historical linguistics, language-based conflicts, and the effects of language differences on trade. The proposed measures used for linguistic distance reflect varying understandings of the term itself.
Freedom of speech in the United StatesIn the United States, freedom of speech and expression is strongly protected from government restrictions by the First Amendment to the U.S. Constitution, many state constitutions, and state and federal laws. Freedom of speech, also called free speech, means the free and public expression of opinions without censorship, interference and restraint by the government. The term "freedom of speech" embedded in the First Amendment encompasses the decision what to say as well as what not to say.
Four FreedomsThe Four Freedoms were goals articulated by U.S. President Franklin D. Roosevelt on Monday, January 6, 1941. In an address known as the Four Freedoms speech (technically the 1941 State of the Union address), he proposed four fundamental freedoms that people "everywhere in the world" ought to enjoy: Freedom of speech Freedom of worship Freedom from want Freedom from fear Roosevelt delivered his speech 11 months before the surprise Japanese attack on Pearl Harbor that caused the United States to declare war on Japan, December 8, 1941.
