Modern computer graphics systems are able to render sophisticated 3D scenes consisting of millions of polygons. For most camera positions only a small collection of these polygons is visible. We address the problem of occlusion culling, i.e., determine hidden primitives. Aila, Miettinen, and Nordlund suggested to implement a FIFO buffer on graphics cards which is able to delay the polygons befo...

A computer application that renders a virtual environment, for example an architectural model for use in a walkthrough scenario, can suffer from low performance due to the complexity of the environment. Visibility algorithms are concerned with determining the part of the environment that is visible and therefore necessary to render while discarding the rest, thereby reducing the workload of the...

In two articles in this issue (Fundam. Appl. Toxicol. 37, 2 -6 and 7-22), we present something new: two papers on the opposite sides of an argument. In this case, the argument regards culling of litters. For many scientists performing breeding studies in a regulatory context, the culling of litters to a standard size shortly after birth (generally 3-5/gender/ litter) is an accepted practice. Wh...

We analyze the performance of a genetic algorithm (GA) we call Culling, and a variety of other algorithms, on a problem we refer to as the Additive Search Problem (ASP). We show that the problem of learning the Ising perceptron is reducible to a noisy version of ASP. Noisy ASP is the first problem we are aware of where a genetic-type algorithm bests all known competitors. We generalize ASP to k...

Sows that fail to establish and maintain pregnancy fail to cover costs associated with their daily maintenance and housing. Pregnancy diagnosis can help to: 1) minimize costs associated with nonproductive days (NPDs), 2) maintain correct number of sows for farrowing crates, 3) identify open females for rebreeding or culling, 4) prevent unintended culling of pregnant sows, 5) identify the timing...

Records on 3092 pregnancies distributed over a period of 24 years (1986 to 2010) were used to estimate genetic and non genetic parameters of threshold traits in Holstein Friesian. Parity, season and year of calving were included in the model to estimate their effect on replacement traits. A total of 105 sires' records were used to study the genetic component of the characters. The overall avera...

Control measures for canine rabies include vaccination and reducing population density through culling or sterilization. Despite the evidence that culling fails to control canine rabies, efforts to reduce canine population density continue in many parts of the world. The rationale for reducing population density is that rabies transmission is density-dependent, with disease incidence increasing...

Highly pathogenic avian influenza (HPAI) is often controlled through culling of poultry. Compensating farmers for culled chickens or ducks facilitates effective culling and control of HPAI. However, ensuing price shifts can create incentives that alter the disease dynamics of HPAI. Farmers control certain aspects of the dynamics by setting a farm size, implementing infection control measures, a...

From-region visibility culling is considered significantly harder than from-point visibility culling, since it is inherently 4dimensional. We present a conservative occlusion culling method based on factorizing the 4D visibility problem into horizontal and vertical components. The visibility of the two components is solved asymmetrically: the horizontal component is based on a novel parameteriz...