Background: Aging is a major challenge not only for high-income countries but also for middle- and low-income countries. The length of stay (LOS) in hospitals is one of the major concerns of elderly patients, which should be taken into consideration. We aimed to investigate the factors affecting LOS of elderly patients admitted to a referral hospital of northeast of Iran.    Methods: A rel...

Consider the task of summarizing the data in Figure 1. A common technique for performing this task is to use a statistical model known as a mixture model. Relative to many other models for estimating densities, mixture models have a number of advantages. First, mixture models can summarize data that contain multiple modes. In this sense, they are more powerful than distributions from the expone...

In this article we implement the well-known Ho-Lee Model of the term structure of interest rates and describe the algorithm behind this model. After a brief discussion of interest rates and bonds we construct a binomial tree and show how to replicate any fixed income type security. This allows us to value any interest rate contingent claim by means of the replicating portfolio. We also discuss ...

We show how to value a real option on a commodity using an implied binomial tree (IBT) that is calibrated using commodity futures options prices. Until now it has been assumed that spot options are required to be traded on the underlying asset in order to use an IBT; this requirement is, however, typically not met with commodities. We make two major contributions: First, by showing how to imple...

It is a common belief that the standard binomial algorithm of Cox-Ross-Rubinstein (CRR) cannot be used to deal with barrier options with multiple or time-varying boundaries. We propose an extension of the CRR model to evaluate options with exponential boundaries. The essence of the extended binomial model relies upon the construction of a binomial tree for the underlying asset price dynamics, c...

In its Exposure Draft, "Accounting for Stock-based Compensation," FASB proposes that either the Black-Scholes or binomial option pricing model be used to expense employee stock options, and that the value of these options be measured on their grant date with typically modest ex-post adjustment. This brings the accounting profession squarely up against the Scylla of imposing too narrow a set rul...

In this paper, we develop a decision model of a firm’s optimal strategy for investment in security process innovations (SPIs) when confronted with a sequence of malicious attacks. The model incorporates real options as a methodology to capture the flexibility embed ded in such investment decisions. SPIs, when seamlessly integrated with the organization’s overall business dynamics, induce organi...

In this paper, a new bivariate negative binomial regression (BNBR) model allowing any type of correlation is defined and studied. The marginal means of the bivariate model are functions of the explanatory variables. The parameters of the bivariate regression model are estimated by using the maximum likelihood method. Some test statistics including goodness-of-fit are discussed. Two numerical da...

This paper introduces the notion of option pricing in the context of financial markets. The discrete time, one-period binomial model is explored and generalized to the multi-period binomial model. The multi-period model is then redeveloped using the sophisticated tools of martingale theory. The paper concludes with a brief extension of the results to continuous time, giving a heuristic derivati...

In this paper we study Binomial Models with random time steps. We explain, how calculating values for European and American Call and Put options is straightforward for the Random{Time Binomial Model. We present the conditions to ensure weak{convergence to the Black{Scholes setup and convergence of the values for European and American put options. Di erently to the CRR{model the convergence beha...