5,690 research outputs found
Cost-Sensitive Decision Trees with Completion Time Requirements
Get PDFIn many classification tasks, managing costs and completion times are the main concerns. In this paper, we assume that the completion time for classifying an instance is determined by its class label, and that a late penalty cost is incurred if the deadline is not met. This time requirement enriches the classification problem but posts a challenge to developing a solution algorithm. We propose an innovative approach for the decision tree induction, which produces multiple candidate trees by allowing more than one splitting attribute at each node. The user can specify the maximum number of candidate trees to control the computational efforts required to produce the final solution. In the tree-induction process, an allocation scheme is used to dynamically distribute the given number of candidate trees to splitting attributes according to their estimated contributions to cost reduction. The algorithm finds the final tree by backtracking. An extensive experiment shows that the algorithm outperforms the top-down heuristic and can effectively obtain the optimal or near-optimal decision trees without an excessive computation time.classification, decision tree, cost and time sensitive learning, late penalty
Two Joshua Trees, [s.d.]
No full textPhotograph of two Joshua trees, [s.d]. Two trees with thick bark and branches stand rooted in sandy dirt while small shrubs cover the ground. Spiky round balls of leaves are attached to the ends of the branches while all the branches seem to drupe downwards. More Joshua trees can be seen in the distance. Photoprint reads: "This is what our paper money is made from"
Palm trees in Eastlake Park (later Lincoln Park), [s.d.]
No full textPhotograph of palm trees in Eastlake Park (later Lincoln Park), [s.d.]. About four park benches are situated between two palms a few yards away. The benches, three of them facing one, are spaced out to allow a walkway between them. The ground appears to be dry and littered with a few scattered leaves. Patches of grass (or weed?) sparsely cover the ground. Other trees are visible in the background.; "Lincoln Park (formerly East Lake Park), which was a major tourist destination, boasts a nearby zoo and an alligator farm in addition to boating and lavish gardens in the early part of the century. Today, the park is best known as the location of Plaza de la Raza, established in 1970 in response to a city plan to demolish the historic boathouse, the organization has become the leading multidisciplinary cultural arts center for Latinos in Los Angeles." -- unknown author
View of the flowers and palm trees in Eastlake Park (later known as Lincoln Park), [s.d.].
No full textPhotograph of a view of the flowers and palm trees in Eastlake Park (later known as Lincoln Park), [s.d.]. In the foreground is a beautiful garden of flowers surrounded by a short wire-mesh fence. A footpath circles around this garden and branches off into a straight path that leads to a bench in the distance. Nearby on the footpath are two benches facing each other. On the grass behind the benches and all the way down to the bench at the end of the footpath is a column of palm trees (one on each side of the footpath). Other trees are visible behind the column of palm trees as well as in the distance.; "Lincoln Park (formerly East Lake Park), which was a major tourist destination, boasts a nearby zoo and an alligator farm in addition to boating and lavish gardens in the early part of the century. Today, the park is best known as the location of Plaza de la Raza, established in 1970 in response to a city plan to demolish the historic boathouse, the organization has become the leading multidisciplinary cultural arts center for Latinos in Los Angeles." -- unknown author
Tall redwood trees (Sempervirous), Santa Cruz, ca.1900
No full textPhotograph of tall redwood trees (Sempervirous), Santa Cruz, ca.1900. A mat(?) is lied between two of the trees. A sign is posted on one of the trees (at left)
California club, showing person and trees near base of building, [s.d.]
No full textPhotograph of California club, showing person and trees near base of building, [s.d.]. In the extreme foreground at right, a utility pole and wires can be seen. In the background to the left, a group of trees can be seen near lampposts. Walking along a road near the trees, a person can be seen. Behind the trees at center, a large building can be seen. The base of the building is wide and rectangular. Two smaller rectangular sections can be seen placed upon the base. At the top of the building, four chimney stacks can be seen. Along the side of the building, numerous windows and small palm trees in vases are visible above the base. In the extreme background, more buildings can be seen. To the far right, a sign reads: "Consumers Credit Co. Auto Loans"
Line of palm trees in South Park, [s.d.]
No full textPhotograph of a line of palm trees in South Park, [s.d.]. A wall of large palm trees extends into the background from the right, cutting across a well-mown swath of grass. A small stretch of paved walkway is visible in the extreme foreground, surrounding a flower bed to the left. More trees are visible in the distance at center
Surface phytoplankton pigment distributions in the Atlantic Ocean: an assessment of basin scale variability between 50N and 50S
No full textWe present an overview of the spatial distributions of phytoplankton pigments along transects between the UK and the Falkland Islands. These studies, undertaken as a component of the UK Atlantic Meridional Transect (AMT) programme, provided the first post-launch validation data for the NASA SeaWiFS satellite. Pigment data are used to characterise basin-scale variations in phytoplankton biomass and community composition over 100° of latitude, and to compliment the definition of hydrographic oceanic provinces. A summary of the key pigment characteristics of each province is presented.Concentrations of total chlorophyll a (totCHLa = chlorophyll a, CHLa + divinyl CHLa, dvCHLa) were greatest in high latitude temperate waters (>37°N and >35°S), and in the Canary Current Upwelling system. In these regions, the total carotenoid (totCAR) budget was dominated by photosynthetic carotenoids (PSCs). High accessory pigment diversity was observed of which fucoxanthin (FUC), 19'–hexanoyloxyfucoxanthin (HEX), and diadinoxanthin (DIAD) were most abundant, indicating proliferation of large eukaryotes and nanoflagellates. In contrast, tropical and sub-tropical waters exhibited concentrations of totCHLa below 500 ng l?1, with the North Atlantic Sub-tropical East gyre (NASE, 26.7–35°N), South Equatorial Current (SeqC, 7–14.6°S) and South Atlantic tropical Gyre (SATG, 14.6–26°S) characterised by totCHLa of <100 ng?1. These waters exhibited relatively limited pigment diversity, and the totCAR budget was dominated by photoprotecting pigments (PPCs) of which zeaxanthin (ZEA), a marker of prokaryotes (cyanobacteria and prochlorophytes), was most abundant. DvCHLa, a marker of prochlorophytes was detected in waters at temperatures >15°C, and between the extremes of 48°N and 42°S. DvCHLa accounted for up to two-thirds of totCHLa in oligotrophic provinces demonstrating the importance of prochlorophytes to oceanic biomass.Overall, HEX was the dominant PSC, contributing up to 75% of totCAR. HEX always represented >2% of totCAR and was the only truly ubiquitous carotenoid. Since HEX is a chemotaxonomic marker of prymnesiophytes, this observation reflects the truly cosmopolitan distribution of this algal class. ZEA was found to be the most abundant PPC contributing more than one third of the total carotenoid budget in each transect.Greatest seasonality was observed in highly productive waters at high latitudes and in shallow continental shelf waters and attributed to proliferation of large eukaryotes during spring. Concentrations of the prokaryote pigments (ZEA + dvCHLa) also exhibited some seasonality, with elevated concentrations throughout most of the transect during Northern Hemisphere spring
Eucalyptus trees lining the dirt road on the corner of Gower Street and Melrose Avenue, Hollywood, [s.d.]
No full textPhotograph of Eucalyptus trees lining the dirt road on the corner of Gower Street and Melrose Avenue, Hollywood, [s.d.]. The dirt road is laced with tracks. Grass covers the surrounding areas. Fallen leaves from the trees are scattered around on the grass. Houses (or buildings) are visible at right.; "This group consists of more than 400, quick-growing, tender, evergreen trees and some shrubs native to Tasmania and Australia. These unique trees can grow to gigantic proportions; some species can reach heights over 400 feet in their native habitats and up to 200 feet in California. Eucalyptus trees, also popularly known as Gum trees because some species exude a gum, are fragrant and normally pest-resistant. These trees have leathery, smooth, lance-shaped leaves, which have a more rounded shape when young. Their puffball-like flowers may be red or orange and are very attractive to bees. They have no petals, but instead, numerous stamens arising from a capsule-like calyx, which give them their fluffy appearance. The attractive, colorful bark of the stems and trunks of the Eucalyptus may be dappled in gray, green, russet, or cream and may peel in sheets. Besides the decorative qualities of the trees, Eucalyptus are valued for their timber, the important oils of the leaves and shoots, tannin, which is taken from the bark of some varieties, and a resinous substance known as kino. E. parvifolia is a beautiful, medium-sized species that has beautifully colored, peeling bark. At maturity, the leaves are small, slender, and blue-green. This species tolerates alkaline soil. E. citriodora (Lemon-scented gum) is a large, quick-growing tree with smooth, white bark and lemon-scented leaves. E. coccifera (Tasmanian snow gum) is a large tree with bloomy (bloom is a powdery, waxy substance sometimes covering plants) leaves and stems, not evident in young plants. The bark peels to reveal a white trunk. E. ficifolia (Red flowering gum) is a medium-sized plant with clusters of beautiful, feathery, red flowers up to a foot long. E. pauciflora subsp. niphophila (Snow gum) is a small, fairly slow-growing tree that is covered in large, leathery, grayish-green leaves. The multi-colored trunk has been compared to the skin of a python with its green, gray, and cream bark."--unknown author
Historic tree at Mission Carmel (San Carlos Borromeo de Carmelo) in Monterey, ca.1888
No full textPhotograph of the historic tree at Mission Carmel (San Carlos Borromeo de Carmelo) in Monterey, ca.1888. The tree stands at center, growing from the slope of a hill that feeds into the dry ravine at left. In the background left, the gaurd rail of a bridge can be seen.; "Viscaino hung bell on this tree and held mass in 1602 and Father Juniper Serra utilized it for the same purpose June 3, 1770 when he first landed to establish a mission for Saint Charles. [Also the boat was tied here.] The tree fell early in 1900 and the trunk was removed to the garden at rear of San Carlos Mission in Monterey. Photo made by a Mr. Adams [a photographer of Monterey about 1890] abt. 1880 and [negative] purchased from him about 1895 by C.C. Pierce". -- Unknown author
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