A stratified sampling method for the efficient repeated computation of dose-volume histograms (DVHs) in brachytherapy is presented as used for anatomy based brachytherapy optimization methods. The aim of the method is to reduce the number of sampling points required for the calculation of DVHs for the body and the PTV. From the DVHs are derived the quantities such as Conformity Index COIN and C...

Recent studies (e.g., Kuhn and Tatler, 2005) have suggested that magic tricks can provide a powerful and compelling domain for the study of attention and perception. In particular, many stage illusions involve attentional misdirection, guiding the observer's gaze to a salient object or event, while another critical action, such as sleight of hand, is taking place. Even if the critical action ta...

von Neumann’s trick for generating an absolutely unbiased coin from a biased one is this: 1. Toss the biased coin twice, getting 00, 01, 10, or 11. 2. If 00 or 11 occur, go back to step 1; else 3. Call 10 a H, 01 a T. Since p[H] = p[l]*p[O] = p[T], the output is unbiased. Example: 00 10 11 01 01 + H T T. Peter Elias gives an algorithm to generate an independent unbiased sequence of Hs and Ts th...

Visual, multisensory and cognitive illusions in magic performances provide new windows into the psychological and neural principles of perception, attention, and cognition. We investigated a magic effect consisting of a coin "vanish" (i.e., the perceptual disappearance of a coin after a simulated toss from hand to hand). Previous research has shown that magicians can use joint attention cues su...

In the coin problem, one is given n independent flips of a coin that has bias β > 0 towards either Head or Tail. The goal is to decide which side the coin is biased towards, with high confidence. An optimal strategy for solving the coin problem is to apply the majority function on the n samples. This simple strategy works as long as β > Ω(1/ √ n). However, computing majority is an impossible ta...

We suggest a rigorous theory of how objective single-case transition probabilities fit into our world. The theory combines indeterminism and relativity in the ‘‘branching space–times’’ pattern, and relies on the existing theory of causae causantes (originating causes). Its fundamental suggestion is that (at least in simple cases) the probabilities of all transitions can be computed from the bas...

Though the counterfeit coin problem is well known as a fascinating puzzle it claims great importance in Computer science, Game theory, and Mathematics. In terms of the puzzle the objective is to detect the counterfeit coins which are identical in appearance but different in weight. The word counterfeit not only describes forgeries of currency or documents, but can also be applied to software, p...

BACKGROUND The choice among endoscopy, Foley catheter, and bougienage techniques for pediatric esophageal coin removal currently depends on local or personal preferences. This reflects a lack of prospective comparisons of cost and effectiveness in the literature. METHODS A computerized decision analytic model was used to determine the expected costs of each method of esophageal coin removal. ...

A substantial number of micropayment schemes in the literature are based on distributing the cost of a digital signature over several successive micropayments (e.g. Payword). Thus, a stable relationship between user and merchant is assumed: the micropayments validated by the same signature must take place between the same user and merchant. This stability is ill-suited for surfing on the web, a...

Little is known about whether people make good choices when facing important decisions. This paper reports on a large-scale randomized field experiment in which research subjects having difficulty making a decision flipped a coin to help determine their choice. For important decisions (e.g. quitting a job or ending a relationship), those who make a change (regardless of the outcome of the coin ...