Heaps' law

From formulasearchengine
Revision as of 18:27, 20 July 2013 by 89.233.191.216 (talk)
Jump to navigation Jump to search
Shows a region where a differential equation is valid and the associated boundary values

In mathematics, in the field of differential equations, a boundary value problem is a differential equation together with a set of additional restraints, called the boundary conditions. A solution to a boundary value problem is a solution to the differential equation which also satisfies the boundary conditions.

Boundary value problems arise in several branches of physics as any physical differential equation will have them. Problems involving the wave equation, such as the determination of normal modes, are often stated as boundary value problems. A large class of important boundary value problems are the Sturm–Liouville problems. The analysis of these problems involves the eigenfunctions of a differential operator.

To be useful in applications, a boundary value problem should be well posed. This means that given the input to the problem there exists a unique solution, which depends continuously on the input. Much theoretical work in the field of partial differential equations is devoted to proving that boundary value problems arising from scientific and engineering applications are in fact well-posed.

Among the earliest boundary value problems to be studied is the Dirichlet problem, of finding the harmonic functions (solutions to Laplace's equation); the solution was given by the Dirichlet's principle.

Explanation

Boundary value problems are similar to initial value problems. A boundary value problem has conditions specified at the extremes ("boundaries") of the independent variable in the equation whereas an initial value problem has all of the conditions specified at the same value of the independent variable (and that value is at the lower boundary of the domain, thus the term "initial" value).

For example, if the independent variable is time over the domain [0,1], a boundary value problem would specify values for at both and , whereas an initial value problem would specify a value of and at time .

Finding the temperature at all points of an iron bar with one end kept at absolute zero and the other end at the freezing point of water would be a boundary value problem.

If the problem is dependent on both space and time, one could specify the value of the problem at a given point for all time the data or at a given time for all space.

Concretely, an example of a boundary value (in one spatial dimension) is the problem

to be solved for the unknown function with the boundary conditions

Without the boundary conditions, the general solution to this equation is

From the boundary condition one obtains

which implies that From the boundary condition one finds

and so One sees that imposing boundary conditions allowed one to determine a unique solution, which in this case is

Types of boundary value problems

The boundary value problem for an idealised 2D rod

If the boundary gives a value to the normal derivative of the problem then it is a Neumann boundary condition. For example, if there is a heater at one end of an iron rod, then energy would be added at a constant rate but the actual temperature would not be known.

If the boundary gives a value to the problem then it is a Dirichlet boundary condition. For example, if one end of an iron rod is held at absolute zero, then the value of the problem would be known at that point in space.

If the boundary has the form of a curve or surface that gives a value to the normal derivative and the variable itself then it is a Cauchy boundary condition.

Aside from the boundary condition, boundary value problems are also classified according to the type of differential operator involved. For an elliptic operator, one discusses elliptic boundary value problems. For an hyperbolic operator, one discusses hyperbolic boundary value problems. These categories are further subdivided into linear and various nonlinear types.

See also

48 year-old Registered Nurse (Medical ) Rave from Pickering, enjoys to spend time individuals watching, new property for sale developers in singapore and cave diving. Finished a cruise liner experience that included passing by Chan Chan Archaeological Zone. Related mathematics:

40 year old Supply and Circulation Manager Courtney from Aberdeen, has several pursuits including bmx, property developers in new project launch singapore and actions. Finds travel a wonderful experience after visiting Central Sikhote-Alin. Physical applications:

40 year old Supply and Circulation Manager Courtney from Aberdeen, has several pursuits including bmx, property developers in new project launch singapore and actions. Finds travel a wonderful experience after visiting Central Sikhote-Alin. Numerical algorithms:

Trying to invest in Singapore Actual Property , or are you attempting to promote, hire, invest, buy buy a Singapore property ? Properly then, you may have come to the fitting place in your seek for Singapore properties. Here, we are going to aid you find your dream Singapore property from our market itemizing of 1000's of Singapore properties in our Singapore real property database.

Overseas particular person who want to buy/ purchase a Restricted residential property in Sentosa Cove can acquire fast observe approval from Singapore Land Dealing Unit. Overseas particular person who want to purchase/ acquire a Restricted residential property in Sentosa Cove can apply for a long term social visit move underneath this Scheme to facilitate entry into Singapore. Foreign individual who want to apply for permanent residency in Singapore can contact SLA or MAS permitted institutions. The place you're shopping for property which is below development, the Singapore Academyof Regulation will maintain a portion of the acquisition monies as stakeholders till the expiryof the defects legal responsibility interval supplied in the Agreement/Contract. D19) Hougang / Punggol / Sengkang Condominium Common Room with Aircon

A international individual (any one who isn't a Singapore citizen, Singapore Company, Singapore restricted liability partnership or a Singapore society) will still want approval from the Singapore Land Authority (SLA) to purchase land-titled property such as houses, bungalows and vacant plots of land. Housing Improvement Board Properties SINGAPORE NON-PUBLIC RESIDENTIAL PROPERTIES Singapore firm; Singapore society. We provide invaluable services to expats who are considering relocation to Singapore For every kind of Singapore property related providers, we're there to obtain your name. You are positive to get one of the best Singapore properties with our help. RE/MAX Singapore Singapore Residential Business and Industrial Singapore citizen; Singapore Land Authority Thomson Highway, Singapore

Nevertheless, additionally it is a foul investment decision to go in too early. For instance you buy a property near one of the new MRT station location at the Thomson line. Because it takes 10 years to be accomplished, you might need difficulties renting that place out to pay off your mortgage payments. In addition, 10 years is a long time when something can occur including recession, new properties being introduced, modifications in interest rates etc. All these can have an adversarial impact on your property funding.

First, there are generally more rental transactions than gross sales transactions, to permit AV to be determined for every property based on comparable properties. Second, actions in sale costs are extra unstable than rentals. Therefore, using rental transactions to derive the AV helps to maintain property tax extra steady for property owners. If you are shopping for or trying to hire a property. It's tiring to call up individual property agent, prepare appointments, coordinate timing and to go for individual property viewing. What most individuals do is to have a property agent representing them who will organize and coordinate the viewings for all of the properties out there based mostly in your requirements & most well-liked timing. Rent Property District 12 Lease Property District thirteen

The brokers say that many Chinese language patrons are also investing abroad so they can personal property close to major instructional establishments. Some are buying houses close to top faculties — despite the fact that their youngsters are so little they can not walk but. Greater than 80 % of rich Chinese need to ship their children overseas to school, based on the Hurun Report, a Shanghai-based mostly publication. Chinese language patrons sometimes used to pick up properties within the $1 to $5 million vary in New York, typically shopping for two and three at a time for funding purposes, the brokers mentioned. Monika Tu, a dealer at high-end real estate agency Black Diamondz Property Concierge in Sydney, says that over the previous yr mainland Chinese language have develop into 80 % of her firm's business. WCEGA Plaza & Tower

An insurance coverage that covers the reinstatement worth or outstanding loan, whichever is decrease, within the event that the property search singapore (view site…) it insures is destroyed by fire. The coverage does not embody dwelling renovations, moveable household contents and personal belongings. Mortgage Insurance Credit bureau checks (e.g., Good payment data for bank cards / previous or existing loans, no previous blemishes corresponding to discharged bankrupts) A sign by the financial institution of the quantity of mortgage that you are eligible for. Nonetheless, an AIP doesn't constitute a binding loan offer. Additional checks and situations may be imposed by the financial institution, and the phrases of the formal supply will even rely upon the property that you simply intend to buy. Freehold / leasehold (999 years / 99 years)

References

  • A. D. Polyanin and V. F. Zaitsev, Handbook of Exact Solutions for Ordinary Differential Equations (2nd edition), Chapman & Hall/CRC Press, Boca Raton, 2003. ISBN 1-58488-297-2.
  • A. D. Polyanin, Handbook of Linear Partial Differential Equations for Engineers and Scientists, Chapman & Hall/CRC Press, Boca Raton, 2002. ISBN 1-58488-299-9.

External links

fr:Problème aux limites