The field of Home Automation is expanding rapidly as electronic technologies converge. The home network encompasses communications, entertainment, security, convenience and information systems. This category holds sites of broad scope on the topic.

Ecology is a branch of science dealing with the interrelationships of organisms with one another and with their nonliving environment.

These relationships include physiological responses of individuals, structure and dynamics of populations, interactions among species, organization of biological communities, and processing of energy and matter in ecosystems.

This category is related to the business of design in the construction and maintenance industry. It is divided into subcategories related to specific disciplines. Please do not submit to the Design category, but rather to one of the subcategories below.

Information and consulting resources on how to maximize employee relations. For additional information on potential and current conflict issues - see the conflict resolution sub-category

Electrochemistry is the study of the exchange of electrons between an ion/molecule and an electrode, or another ion/molecule. Application areas include batteries, plating or electrodeposition, corrosion, analytical electrochemistry, as well as the study of any chemical reaction involving oxidation or reduction.

Number theory addresses problems about integer and rational numbers. It includes congruences, divisibility, primes, and Fermat's Last Theorem.

In this category are included any equation or set of equations where the unknowns must be integer numbers. It includes Fermat Last Theorem as a special case.

Pi = 3.1415926535... An irrational number, a never ending yet never repeating decimal, Pi has been calculated and explored throughout history from the ancient times to the present.

Geophysics involves the application of physical theories and measurements to discover the properties of the earth. The discipline dates to antiquity, mainly as a scientific approach to earthquake prediction (a problem still unsolved), but major progress began in the late 1500s with initial work in such areas as magnetism and gravity. Tremendous improvements in instrumentation in the early years of the 20th century generated rapid progress in geophysics and ultimately led, in the 1960s, to the theory of plate tectonics. Plate tectonics, the study of the interior structure of the earth, and such related areas as global and regional processes are known collectively as solid earth geophysics. The subdiscipline known as exploration geophysics involves the use of geophysical theory and instrumentation to locate petroleum and other mineral sources. Unlike solid earth geophysics, exploration geophysics generally concentrates on finding lateral heterogeneities in a relatively small part of the earth's crust. Geophysics is considered by some to be a branch of geology, by others to be of equal rank. It is distinguished from the other earth sciences largely by its use of instruments to make direct or indirect measurements of the parts of the Earth being studied, in contrast to the more direct observations which are typical of geology. The following definitions are from Robert E. Sheriff's Encyclopedic Dictionary of Applied Geophysics. 1. The study of the earth by quantitative physical method, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. 2. The application of physical principles to studies of the earth. Includes the branches of (a) seismology (earthquakes and elastic waves); (b) geothermometry (heating of the earth, heat flow, volcanology, and hot springs); (c) hydrology (ground and surface water, sometimes including glaciology); (d) physical oceanography; (e) meteorology; (f) gravity and geodesy (the earth's gravitational field and the size and form of the earth); (g) atmospheric electricity and terrestrial magnetism (including ionosphere, Van Allen belts, telluric currents, etc.); (h) tectonophysics (geological processes in the earth); and (i) exploration and engineering geophysics. Geochronology (the dating of earth history) and geocosmogony (the origin of the earth) are sometimes added to the foregoing list. 3. Often refers to solid-earth geophysics only, thus excluding (c), (d), (e), and portions of other subjects from the above list. 4. Exploration geophysics is the use of seismic, gravity, magnetic, electrical, electromagnetic, etc., methods in the search for oil, gas, minerals, water, etc., with the objective of economic exploitation.

Geodesy is the study of the size and shape of the Earth's surface and the creation of theoretical mathematical models of the surface that best fits the physical data.

This category is concerned with NMR, EPR, MRI and NQR. There are categories for user guides, commercial vendors of NMR systems and supplies, NMR theory, magnet safety, shimming, in short nearly everything to do with the use, repair and operation of a NMR, EPR, MRI or NQR system. 07/23/00

Organizations providing independent testing, laboratory, calibration, and instrument repair services.

A selection of sites containing online versions of the periodic table of elements. Sites are classified according to the number of properties they display:

• Very Basic: less than eight properties.
• Basic: 9 - 16 properties.
• Detailed: 17 - 24 properties.
• Comprehensive: 25 - 32 properties.
• Very comprehensive: more than 32 properties.

There are also notes when special software or browser features such as JavaScript are required.

History, Proof, and Conjectures related to Fermat's Last Theorem

The physics which describes subatomic systems and interactions of elementary particles.

Businesses that are devoted to the training or education of the human resources industry.

Please also see http://dmoz.org/Business/Human_Resources/Training_and_Safety .

Companies that provide consultancy services on a fee basis. They do not supply products with technical support. All sites are investigated and references sort.

Legal organizations focused on protecting civil liberties. Civil liberties are freedoms guaranteed to citizens in the constitution of the country or state. For instance, in the United States, the Bill of Rights guarantees certain freedoms to its citizens. The organizations in this category seek to protect these guaranteed freedoms.

Description Proposed systems for determining governance and/or policy which differ from and are offered as potential replacements for existing political systems.

This category is for any site related to actuarial science and the actuarial profession, members of whom are called actuaries. What is an actuary? Consider the following description from BeAnActuary.com: "Actuaries put a price tag on future risks. They have been called financial architects and social mathematicians because their unique combination of analytical and business skills is helping to solve a growing variety of financial and social problems. Actuaries make financial sense of the future. How? An actuary applies mathematical models to problems of insurance and finance. To be more specific, actuaries improve financial decision making by developing models to evaluate the current financial implications of uncertain future events. If you've never met an actuary, that's not unusual. The actuarial profession numbers only about 19,000 people in North America. But don't let that small number fool you. Actuaries put their special problem-solving skills to work in many different business situations, and their work has had an influence on people's lives for more than a century. Actuaries make a difference. Their calculations and projections are the backbone of the insurance and financial security industries. Actuarial work involves lots of math, but actuaries must also be up-to-date on business issues and trends, social science, law, and economics. In other words, actuaries have a well-rounded business approach to problem solving. And they must be good communicators to explain things to nonactuaries. Actuaries are key players on a company's management team. They are well paid, and they like what they do for a living."

Phi is the Greek letter representing the golden ratio, also called the golden mean or the golden proportion. Break a line segment into two such that the ratio of the whole to the longest segment is the same as the ratio of the two segments, that ratio is the golden ratio. Phi = 1.618034...

Fibonacci numbers, named after Italian mathematician Leonardo Fibonacci, are the numbers in the Fibonacci sequence 0, 1, 1, 2, 3, 5, 8, 13, 21, . . . , each of which, after the second is the sum of the two previous ones.

Benford's Law is related to statistics and may also be called "The first Digit Law" . It states that the first digits of a natural set of numbers follow a certain trend, example; The "% frequency" of number "1" as the first digit or leding digit is "%30.10" ; number "2" is "%17,61"....etc.

A Magic Square of order n is an arrangement of the numbers from 1 to n^2 (n-squared) in an n by n matrix. The sum of any row, any column, or any main diagonal must be the same. The smallest non-trivial case is of order 3.

The same idea can be extended to other shapes such as stars, cubes, circles, and so on. These are called Magic objects.