Parameterization in Grid Generation

The distribution of grid points for calculating the solution of partial differential equations is chosen so as to include consideration of truncation error, stability, and the resolution of the solution near boundary layers and shocks. It is important to specify the distribution of points along a grid line. The problem of distributing points along a curve is considered. It is assumed that the curve is defined parametrically. The objective is to select a set of parameter values so that the corresponding points on the curves are properly distributed. The distribution is based on some intrinsic property of the curve such as arc length or curvature

Fast carry accumulator design

Simple iterative accumulator combined with gated-carry, carry-completion detection, and skip-carry circuits produces three accumulators with decreased carry propagation times. Devices are used in machine control, measurement equipment, and computer applications to increase speed of binary addition. NAND gates are used in combining network

Application of three-dimensional Bezier patches in grid generation

Bezier and B-spline patches are popular tools in surface modeling. With these methods, a surface is represented by the tensor product of univariate approximations. The extension of this concept to three dimensions is obvious and can be applied to the problem of grid generation. This report will demonstrate how three dimensional patches can be used in solid modeling and in the generation of grids. Examples will be given demonstrating the ability to generate three dimensional grids directly from a wire frame without having to first set up the boundary surfaces. Many geometric grid properties can be imposed by the proper choice of the control net

Foster Care and Disconnected Youth: A Way Forward for New York

On December 1, 2011, the Community Service Society of New York and The Children's Aid Society convened over 200 local and national experts, policymakers, service providers, and advocates to discuss the issues faced by older youth in foster care and strategies to prevent and address their disconnection from anchor social institutions like school, work, and family. This report highlights and further develops the issues raised at the forum, recommends policy directions, and discusses successful program models that address the many challenges facing aging-out youth who become disconnected. Evidence suggests that after aging out of foster care, these young adults have particularly poor chances of becoming successful adults . Between the ages of 16 and 24, many have been homeless more than once . Many have experienced trauma and show signs of depression, behavior problems, and/or emotional difficulties. They are more likely than their peers to get pregnant or become parents. Those who are LGBTQ are often targets of discrimination . All are less likely to reach educational milestones, less likely to be employed, and more likely to rely on public benefit programs. Much can be done to prevent the hardships that aging out of foster care often brings, so that all are "connected by 25"—meaning they have achieved their educational objectives, established connections to employment, and have strong family relationships and stable housing, with the goal that every young person in foster care will develop and reach his or her full potential. These youth can be helped with effective programs that take a comprehensiveapproach, using a strategic combination of services, job training, and employment, along with alternative education options and skills training. Such programs exist, but there are not enough of them, and they lack funding, even though they demonstrate success and represent significant savings over the long-term

Kīlauea, Hawai’i, puts on a ‘once-in-a-century’ show

Kīlauea is the youngest of five basaltic shield volcanoes on the island of Hawai’i. It is located to the south-east of the much larger Mauna Loa volcano, and rose above sea level about 100 ka ago. Kīlauea is one of the most monitored, and arguably the best understood volcanoes on Earth, providing scientists with a good understanding of its current eruption, in which magma rises from depth and is stored beneath its 4 × 3.2 km summit caldera in an underground reservoir. The reservoir is connected to a lava lake within a crater called Halema’uma’u, which is situated on the floor of the caldera. When magma drains from the summit area it travels in underground conduits and emerges on the flanks of the volcano at a rift zone, where it erupts through fissures. The magma is sometimes stored in other reservoirs along the way. This link between summit magma storage and fissure eruptions on the flanks has occurred thousands of times at many Hawai’ian volcanoes. The current eruptive episode is, however, a ‘once-in-a-century’ show, because it is the first time since 1924 that fissure-fed lava flow eruptions have been accompanied by significant explosive eruptions within Halema’uma’u Crater. This gives scientists a unique opportunity to use modern methods to understand exactly how such hazardous explosions happen at Kīlauea, a volcano that receives about 2 million visitors a year

Errors in finite-difference computations on curvilinear coordinate systems

Curvilinear coordinate systems were used extensively to solve partial differential equations on arbitrary regions. An analysis of truncation error in the computation of derivatives revealed why numerical results may be erroneous. A more accurate method of computing derivatives is presented