Unit root

A unit root is a feature of processes that evolve through time that can cause problems in statistical inference involving time series models.

A linear stochastic process has a unit root if 1 is a root of the process's characteristic equation. Such a process is non-stationary. If the other roots of the characteristic equation lie inside the unit circle—that is, have a modulus (absolute value) less than one—then the first difference of the process will be stationary.

Definition

Consider a discrete-time stochastic process , and suppose that it can be written as an autoregressive process of order p:

Here, is a serially uncorrelated, zero-mean stochastic process with constant variance . For convenience, assume . If is a root of the characteristic equation:

then the stochastic process has a unit root or, alternatively, is integrated of order one, denoted . If m = 1 is a root of multiplicity r, then the stochastic process is integrated of order r, denoted I(r).

Example

The first order autoregressive model, , has a unit root when . In this example, the characteristic equation is . The root of the equation is .

Root (disambiguation)

A root is the part of a plant that is below ground.

Root or roots may also refer to:

Mathematics

People

Places

Switzerland

United States

Art, entertainment, and media

Roots franchise

Root (surname)

Root is a surname, and may refer to:

People

Root (linguistics)

A root, or a root word, is a word that does not have a prefix (in front of the word) or a suffix (at the end of a word). The root word is the primary lexical unit of a word, and of a word family (root is then called base word), which carries the most significant aspects of semantic content and cannot be reduced into smaller constituents. Content words in nearly all languages contain, and may consist only of root morphemes. However, sometimes the term "root" is also used to describe the word minus its inflectional endings, but with its lexical endings in place. For example, chatters has the inflectional root or lemma chatter, but the lexical root chat. Inflectional roots are often called stems, and a root in the stricter sense may be thought of as a monomorphemic stem.

The traditional definition allows roots to be either free morphemes or bound morphemes. Root morphemes are essential for affixation and compounds. However, in polysynthetic languages with very high levels of inflectional morphology, the term "root" is generally synonymous with "free morpheme". Many such languages have a very restricted number of morphemes that can stand alone as a word: Yup'ik, for instance, has no more than two thousand.

Unité

Unité is a mobile network operator in Moldova. Working in CDMA, UMTS and LTE standards.

General information

Communication standard: Unité has a license to work in CDMA standard on frequency of 450 MHz as well as in UMTS standard on frequencies of 2100 MHz and 900 MHz.

Numbering resources:
Unité network codes are:

Internationally they have the form:

Network code:
For CDMA standard: 259 03, where 259 — Mobile Country Code (MCC) for Moldova, and 03 — Mobile Network Code (MNC) for Unité network.
For UMTS standard: 259 05, where 259 — Mobile Country Code (MCC) for Moldova, and 05 — Mobile Network Code (MNC) for Unité network.

History

Unité began its activity on March 1, 2007 as CDMA operator. On April 1, 2010 Unité launched its own 3.5G network.

Mobile Internet

Unité offers mobile internet services via CDMA standard under the brand of "Connect" with speeds up to 2.4 Mbit/s and via 3.5G under the brand of "3G Connect" with speeds up to 14.4 Mbit/s

Ownership

Moldtelecom is 100% shareholder of the operator.

Unit of alcohol

Units of alcohol are used in the United Kingdom (UK) as a measure to quantify the actual alcoholic content within a given volume of an alcoholic beverage, in order to provide guidance on total alcohol consumption.

A number of other countries (including Australia, Canada, New Zealand, and the US) use the concept of a "standard drink", the definition of which varies from country to country, for the same purpose. "Standard drinks" were referred to in the first UK guidelines (1984) that published "safe limits" for drinking, but these were replaced by references to "alcohol units" in the 1987 guidelines and the latter term has been used in all subsequent UK guidance.

One unit of alcohol (UK) is defined as 10 millilitres (8 grams) of pure alcohol. Typical drinks (i.e. typical quantities or servings of common alcoholic beverages) may contain 1–3 units of alcohol.

Containers of alcoholic beverages sold directly to UK consumers are normally labelled to indicate the number of units of alcohol in a typical serving of the beverage (optional) and in the full container (can or bottle), as well as information about responsible drinking. Additionally, the advent of smartphones has led to the creation of apps which report the number of units contained in an alcoholic drink.

Unit (Cristian Fleming)

Unit is an electronic musician based in New York City. Unit began releasing electronic music officially at the age of 25, although he had musical involvement for many years prior, playing bass guitar at 17, and began working on electronic music at the age of 18. Unit has toured at various venues in Europe .

Discography

Music Also Appears On: