We present a theoretical analysis of error of combinations of Monte Carlo estimators used in image synthesis. Importance sampling and multiple importance sampling are popular variance-reduction strategies. Unfortunately, neither strategy improves the rate of convergence of Monte Carlo integration. Jittered sampling (a type of stratified sampling), on the other hand is known to improve the conve...

Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used techniq...

Chain records is a new type of multidimensional record. We discuss how often the chain records occur when the background sampling is from the unit cube with uniform distribution (or, more generally, from an arbitrary continuous product distribution in d dimensions). Extensions are given for sampling from more general spaces with a self-similarity property.

background : a detailed study of hidden and hard to reach populations in order to identify their characteristics is essential because they endanger the health of the society by their dangerous behaviors. however, sampling in these populations through conventional sampling methods is impossible due to reasons such as being hidden and lacking a precise frame. methods: in this article, applicable ...

There are some experiences that researcher come across quite number of time for very large networks in the initial samples such that they cannot finish the sampling procedure. Two solutions have been proposed and used by marine biologists which we discuss in this article: i) Adaptive cluster sampling based on order statistics with a stopping rule, ii) Restricted adaptive cluster sampling. Until...

PURPOSE To evaluate the anatomy of the junction of the inferior petrosal sinus and the internal jugular vein. METHODS Using a previously described classification system, we prospectively classified venous anatomy bilaterally in 135 of 136 persons consecutively undergoing inferior petrosal sinus sampling. RESULTS Type IV anatomy, with no anastomosis between the inferior petrosal sinus and th...