Tree (data structure)

In computer science, a tree is a widely used abstract data type (ADT)--or data structure implementing this ADT--that simulates a hierarchical tree structure, with a root value and subtrees of children with a parent node, represented as a set of linked nodes.

A tree data structure can be defined recursively (locally) as a collection of nodes (starting at a root node), where each node is a data structure consisting of a value, together with a list of references to nodes (the "children"), with the constraints that no reference is duplicated, and none points to the root.

Alternatively, a tree can be defined abstractly as a whole (globally) as an ordered tree, with a value assigned to each node. Both these perspectives are useful: while a tree can be analyzed mathematically as a whole, when actually represented as a data structure it is usually represented and worked with separately by node (rather than as a list of nodes and an adjacency list of edges between nodes, as one may represent a digraph, for instance). For example, looking at a tree as a whole, one can talk about "the parent node" of a given node, but in general as a data structure a given node only contains the list of its children, but does not contain a reference to its parent (if any).

Node

In general, a node is a localised swelling (a "knot") or a point of intersection (a vertex).

Node may refer to:

In mathematics

In computing and electronics

Freddie Wong

Freddie Wong (born September 13, 1985) is an American filmmaker, musician, VFX artist and competitive gamer. He is a major part of the YouTube channel RocketJump. He is the older brother of actor and YouTuber Jimmy Wong.

Early life

Wong attended Lakeside School in Seattle, Washington. He then attended and graduated from the University of Southern California School of Cinematic Arts. Wong owns and manages Overcrank Media, a Los Angeles-based media production company specializing in feature film and online video content, having produced an independent film titled Bear. Wong met his future collaborator Brandon Laatsch in college.

Career

Wong competed in the World Series of Video Games in Dallas in July 2007. He won first prize in the Guitar Hero 2 competition, playing the song "Less Talk More Rokk" by Freezepop.

During MTV's "Gamer's Week" celebration in November 2007, Freddie appeared as a guest on Total Request Live. Participating in the program with his newly formed band Hellanor Brozevelt, Wong was part of a country-wide search to find the best Rock Band ensemble. After receiving tutelage from well-known rockers Good Charlotte, Brozevelt performed at the Hard Rock Cafe in New York against Chicago-based Carrie Me Home.

Vertex (graph theory)

In mathematics, and more specifically in graph theory, a vertex (plural vertices) or node is the fundamental unit of which graphs are formed: an undirected graph consists of a set of vertices and a set of edges (unordered pairs of vertices), while a directed graph consists of a set of vertices and a set of arcs (ordered pairs of vertices). In a diagram of a graph, a vertex is usually represented by a circle with a label, and an edge is represented by a line or arrow extending from one vertex to another.

From the point of view of graph theory, vertices are treated as featureless and indivisible objects, although they may have additional structure depending on the application from which the graph arises; for instance, a semantic network is a graph in which the vertices represent concepts or classes of objects.

The two vertices forming an edge are said to be the endpoints of this edge, and the edge is said to be incident to the vertices. A vertex w is said to be adjacent to another vertex v if the graph contains an edge (v,w). The neighborhood of a vertex v is an induced subgraph of the graph, formed by all vertices adjacent to v.

Leaf

A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot.Foliage is a mass noun that refers to leaves collectively.

Typically a leaf is a thin, dorsiventrally flattened organ, borne above ground and specialized for photosynthesis. Most leaves have distinctive upper (adaxial) and lower (abaxial) surfaces that differ in colour, hairiness, the number of stomata (pores that intake and output gases) and other features. In most plant species, leaves are broad and flat. Such species are referred to as broad-leaved plants. Many gymnosperm species have thin needle-like leaves that can be advantageous in cold climates frequented by snow and frost. Leaves can also have other shapes and forms such as the scales in certain species of conifers. Some leaves are not above ground (such as bulb scales). Succulent plants often have thick juicy leaves, but some leaves are without major photosynthetic function and may be dead at maturity, as in some cataphylls, and spines). Furthermore, several kinds of leaf-like structures found in vascular plants are not totally homologous with them. Examples include flattened plant stems (called phylloclades and cladodes), and phyllodes (flattened leaf stems), both of which differ from leaves in their structure and origin. Many structures of non-vascular plants, and even of some lichens, which are not plants at all (in the sense of being members of the kingdom Plantae), look and function much like leaves. The primary site of photosynthesis in most leaves (palisade mesophyll) almost always occurs on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of Eucalyptus palisade occurs on both sides and the leaves are said to be isobilateral.

Nissan Leaf

The Nissan Leaf (also formatted "LEAF" as a backronym for leading environmentally-friendly affordable family car) is a compact five-door hatchback electric car manufactured by Nissan and introduced in Japan and the United States in December 2010, followed by various European countries and Canada in 2011. The U.S. Environmental Protection Agency (EPA) official range for the 2016 model year Leaf with the 30 kWh battery is 172 km (107 miles) on a full battery charge, while the trim with the smaller 24 kWh battery is 135 km (84 miles), the same as the 2014/15 model year.

As of December 2015, the Nissan Leaf is the world's all-time best selling highway-capable all-electric car. Leaf global sales passed the 200,000 unit milestone in December 2015, five years after its introduction. As of December 2015, the top markets for Leaf sales are the United States with over 89,000 units, followed by Japan with over 57,000 units, and Europe with over 49,000 Leafs. The European market is led by Norway with over 15,000 new units, and the U.K. with over 12,000 units registered.

Leaf (Israeli company)

Leaf, previously a division of Scitex and later Kodak, is now a subsidiary of Phase One. Leaf manufactures high end digital backs for medium format and large format cameras. In 1991, Leaf introduced the first medium format digital camera back, the Leaf DCB1, nicknamed ‘The Brick’, which had a resolution of 4 million pixels (4 megapixels). As of 2012, Leaf produces the Credo line of digital camera backs, ranging from 40 to 80 megapixels. Until 2010, Leaf also produced photography workflow software Leaf Capture.

Products

Digital camera backs

After Leaf's DCB, the digital backs evolved into two product lines, the Aptus and the (now discontinued) Valeo. The main difference is that the Aptus models have a 3.5-inch touchscreen, where the Valeos have no on-board display. The Valeos can still be used untethered by using the DP-67 software or the more recent WiView software on a Compaq iPAQ. The iPAQs are connected via Bluetooth with the digital backs. For untethered usage, you will need battery packs for both the Aptus and the Valeo, otherwise the back must be powered via a Firewire connection to a computer. The Valeo models need a Leaf Digital Magazine as well for untethered use, where the Aptus models have a Compact Flash slot.