Radioactive decayRadioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay, all of which involve emitting particles. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force.
Lesson planA lesson plan is a teacher's detailed description of the course of instruction or "learning trajectory" for a lesson. A daily lesson plan is developed by a teacher to guide class learning. Details will vary depending on the preference of the teacher, subject being covered, and the needs of the students. There may be requirements mandated by the school system regarding the plan.
Video lessonA video lesson or lecture is a video which presents educational material for a topic which is to be learned. The format may vary. It might be a video of a teacher speaking to the camera, photographs and text about the topic or some mixture of these. The Khan Academy has been successful in teaching mathematics using notes written using Yahoo!'s doodle pad with a voiceover by Salman Khan (educator). These were then loaded onto YouTube where they have been popular and influential.
Lesson studyLesson study (or jugyō kenkyū) is a teaching improvement process that has origins in Japanese elementary education, where it is a widespread professional development practice. Working in a small group, teachers collaborate with one another, meeting to discuss learning goals, planning an actual classroom lesson (called a "research lesson"), observing how their ideas work in a live lessons with students, and then reporting on the results so that other teachers can benefit from it.
Fourier transformIn physics and mathematics, the Fourier transform (FT) is a transform that converts a function into a form that describes the frequencies present in the original function. The output of the transform is a complex-valued function of frequency. The term Fourier transform refers to both this complex-valued function and the mathematical operation. When a distinction needs to be made the Fourier transform is sometimes called the frequency domain representation of the original function.
Happy LessonHappy Lesson is a comedy manga, written by Mutsumi Sasaki and illustrated by Shinnosuke Mori, serialized in Dengeki G's Magazine from April 1999 to September 2002, featuring a high school student who is adopted by five of his teachers. It was adapted into a five-part OVA series in 2001; a thirteen-episode animated TV series in 2002; a sequel TV series, called Happy Lesson Advance, in 2003; and a second OVA series, Happy Lesson: The Final, in 2004. The series has also been adapted into a series of drama CDs and a Dreamcast game.
Three-part lessonA three-part lesson is an inquiry-based learning method used to teach mathematics in K–12 schools. The three-part lesson has been attributed to John A. Van de Walle, a mathematician at Virginia Commonwealth University. The purpose is to cognitively prepare students for the math lesson by having them think about a procedure, strategy or concept used in a prior lesson. Teachers determine what specific previous learning they wish students to recall, based on outcomes desired for that particular lesson.
Nine Lessons and CarolsNine Lessons and Carols, also known as the Festival of Nine Lessons and Carols and Service of Nine Lessons and Carols, is a service of Christian worship traditionally celebrated on or near Christmas Eve. The story of the fall of humanity, the promise of the Messiah, and the birth of Jesus is told in nine short Bible readings or lessons from Genesis, the prophetic books and the Gospels, interspersed with the singing of Christmas carols, hymns and choir anthems.
A Lesson in RomanticsA Lesson in Romantics is the debut studio album by American rock band Mayday Parade. The band resulted from a merger of two separate bands, Kid Named Chicago and Defining Moment. In June 2006 the band released an EP, Tales Told by Dead Friends, which they sold to people by following the 2006 edition of Warped Tour and offering copies; it eventually sold 10,000 copies. The band signed to Fearless Records in August. A Lesson in Romantics was recorded in early 2007 with producers Zack Odom and Kenneth Mount.
Swimming lessonsSwimming lessons are the process of learning to swim. In most countries there is a definition of a number of swimming levels that are reached in the process of the curriculum. The respective certificates of swimming tests are required for further training in aquatic abilities. Many countries have defined a minimum swimming level that children should reach by the end of primary education, in most cases with the help of school swimming classes being part of the normal curriculum.
ConvolutionIn mathematics (in particular, functional analysis), convolution is a mathematical operation on two functions (f and g) that produces a third function () that expresses how the shape of one is modified by the other. The term convolution refers to both the result function and to the process of computing it. It is defined as the integral of the product of the two functions after one is reflected about the y-axis and shifted. The choice of which function is reflected and shifted before the integral does not change the integral result (see commutativity).
Sine and cosine transformsIn mathematics, the Fourier sine and cosine transforms are forms of the Fourier transform that do not use complex numbers or require negative frequency. They are the forms originally used by Joseph Fourier and are still preferred in some applications, such as signal processing or statistics. The Fourier sine transform of f(t), sometimes denoted by either or , is If t means time, then ξ is frequency in cycles per unit time, but in the abstract, they can be any pair of variables which are dual to each other.
Economics in One LessonEconomics in One Lesson is an introduction to economics written by Henry Hazlitt and first published in 1946. It is based on Frédéric Bastiat's essay Ce qu'on voit et ce qu'on ne voit pas (English: "What is Seen and What is Not Seen"). The "One Lesson" is stated in Part One of the book: "The art of economics consists in looking not merely at the immediate but at the longer effects of any act or policy; it consists in tracing the consequences of that policy not merely for one group but for all groups.
Hilbert transformIn mathematics and signal processing, the Hilbert transform is a specific singular integral that takes a function, u(t) of a real variable and produces another function of a real variable H(u)(t). The Hilbert transform is given by the Cauchy principal value of the convolution with the function (see ). The Hilbert transform has a particularly simple representation in the frequency domain: It imparts a phase shift of ±90° ( radians) to every frequency component of a function, the sign of the shift depending on the sign of the frequency (see ).
Hartley transformIn mathematics, the Hartley transform (HT) is an integral transform closely related to the Fourier transform (FT), but which transforms real-valued functions to real-valued functions. It was proposed as an alternative to the Fourier transform by Ralph V. L. Hartley in 1942, and is one of many known Fourier-related transforms. Compared to the Fourier transform, the Hartley transform has the advantages of transforming real functions to real functions (as opposed to requiring complex numbers) and of being its own inverse.
Trigonometric functionsIn mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis.
Jacobi elliptic functionsIn mathematics, the Jacobi elliptic functions are a set of basic elliptic functions. They are found in the description of the motion of a pendulum (see also pendulum (mathematics)), as well as in the design of electronic elliptic filters. While trigonometric functions are defined with reference to a circle, the Jacobi elliptic functions are a generalization which refer to other conic sections, the ellipse in particular. The relation to trigonometric functions is contained in the notation, for example, by the matching notation for .
Integral transformIn mathematics, an integral transform maps a function from its original function space into another function space via integration, where some of the properties of the original function might be more easily characterized and manipulated than in the original function space. The transformed function can generally be mapped back to the original function space using the inverse transform. An integral transform is any transform of the following form: The input of this transform is a function , and the output is another function .
Decay chainIn nuclear science, the decay chain refers to a series of radioactive decays of different radioactive decay products as a sequential series of transformations. It is also known as a "radioactive cascade". The typical radioisotope does not decay directly to a stable state, but rather it decays to another radioisotope. Thus there is usually a series of decays until the atom has become a stable isotope, meaning that the nucleus of the atom has reached a stable state. Decay stages are referred to by their relationship to previous or subsequent stages.
Laplace transformIn mathematics, the 'Laplace transform, named after its discoverer Pierre-Simon Laplace (ləˈplɑ:s), is an integral transform that converts a function of a real variable (usually , in the time domain) to a function of a complex variable (in the complex frequency domain, also known as s-domain', or s-plane). The transform has many applications in science and engineering because it is a tool for solving differential equations. In particular, it transforms ordinary differential equations into algebraic equations and convolution into multiplication.
