MULTILAYER FEEDFORWARD NETWORKS WITH NON-POLYNOMIAL ACTIVATION FUNCTIONS CAN APPROXIMATE ANY FUNCTION

Several researchers characterized the activation functions under which multilayer feedforward networks can act as universal approximators. We show that all the characterizations that were reported thus far in the literature ark special cases of the following general result: a standard multilayer feedforward network can approximate any continuous function to any degree of accuracy if and only if the network's activation functions are not polynomial. We also emphasize the important role of the threshold, asserting that without it the last theorem doesn't hold.Information Systems Working Papers Serie

A novel approach to error function minimization for feedforward neural networks

Feedforward neural networks with error backpropagation (FFBP) are widely applied to pattern recognition. One general problem encountered with this type of neural networks is the uncertainty, whether the minimization procedure has converged to a global minimum of the cost function. To overcome this problem a novel approach to minimize the error function is presented. It allows to monitor the approach to the global minimum and as an outcome several ambiguities related to the choice of free parameters of the minimization procedure are removed.Comment: 11 pages, latex, 3 figures appended as uuencoded fil

Bitcoin: An Impossibility Theorem for Proof-of-Work based Protocols

Bitcoin’s main innovation lies in allowing a decentralized system that relies on anonymous, profit driven miners who can freely join the system. We formalize these properties in three axioms: anonymity of miners, no incentives for miners to consolidate, and no incentive to assuming multiple fake identities. This novel axiomatic formalization allows us to characterize which other protocols are feasible: Every protocol with these properties must have the same reward scheme as Bitcoin. This implies an impossibility result for risk-averse miners: no protocol satisfies the aforementioned constraints simultaneously without giving miners a strict incentive to merge. Furthermore, any protocol either gives up on some degree of decentralization or its reward scheme is equivalent to Bitcoin’s

Bitcoin: An Impossibility Theorem for Proof-of-Work based Protocols

A key part of decentralized consensus protocols is a procedure for random selection, which is the source of the majority of miners cost and wasteful energy consumption in Bitcoin. We provide a simple economic model for random selection mechanism and show that any PoW protocol with natural desirable properties is outcome equivalent to the random selection mechanism used in Bitcoin

ROI Assessment on Using Information Technology in the Course of Admission Decisions in Myocardial Infarction Diagnosis

The healthcare sector has been investing heavily in health information technologies (HIT), with the aim of improvingdecision-making through improved medical processes, reduced costs and integration of medical data. However, the overallcontribution of HIT to the medical field is not obvious, especially, in high-stress environments such as the emergencydepartment (ED). The objective of this research is to explore whether investing in HIT in an ED is rewarding in evaluatingacute myocardial infarction diagnosis in EDs.We evaluated the overall profitability of certain integrative medical IS in a cost-effectiveness analysis using an experimentalstudy in the course of diagnosing an acute myocardial infarction. The results in the paper show that our specific medicalcases received a clear cost-effective reading since the results (ΔCosts/ΔQuality) were lower than the range of all commonthreshold values. Furthermore, the use of HIT in the ED also improved the quality of the medical care

ReLEx: Regularisation for Linear Extrapolation in Neural Networks with Rectified Linear Units

Despite the great success of neural networks in recent years, they are not providing useful extrapolation. In regression tasks, the popular Rectified Linear Units do enable unbounded linear extrapolation by neural networks, but their extrapolation behaviour varies widely and is largely independent of the training data. Our goal is instead to continue the local linear trend at the margin of the training data. Here we introduce ReLEx, a regularising method composed of a set of loss terms design to achieve this goal and reduce the variance of the extrapolation. We present a ReLEx implementation for single input, single output, and single hidden layer feed-forward networks. Our results demonstrate that ReLEx has little cost in terms of standard learning, i.e. interpolation, but enables controlled univariate linear extrapolation with ReLU neural networks

A RETURN ON INVESTMENT ANALYSIS OF USING HEALTH INFORMATION TECHNOLOGY IN THE COURSE OF ADMISSION DECISIONS

In light of the ever-growing importance and usability of medical information systems (IS), the healthcare sector has been investing heavily in these technologies in recent years, with the aim of improving decision-making through improved medical processes, reduced costs and integration of medical data. However, these systems are extremely costly. In addition, the overall contribution of these technologies to the medical field is not obvious, especially, in high-stress environments such as emergency departments (EDs). The objective of this research is to explore whether investing in health information technology (HIT) in an ED is financially rewarding in general, and specifically the circumstances under which such an investment is more rewarding and vice versa. A cost-effectiveness analysis served as the selected tool for return on investment (ROI) estimations of certain integrative medical IS that serves seven main hospitals in Israel. We evaluated the overall profitability of this medical IS, by balancing the quality gained from information (retrieved from medical IS) against the costs of providing this information. The results of the cost-effectiveness analysis show that our specific medical cases of chest pain received a clear cost-effective reading since the results (ΔQuality/ΔCosts) were lower than the range of all common threshold values. Furthermore, the use of HIT in the ED improved the quality units per patient for each chosen admission decisions The findings of this study may also contribute to policy makers in the healthcare sector regarding the advisability of investing in such systems

Normative Value of Information for Decision-Making in the Healthcare Environment

With their ever-growing importance and usability, the healthcare sector has been investing heavily in medical information systems (IS) in recent years, as part of the effort to improve medical decision-making and increase its efficiency. This research aims to evaluate the contribution of information technology (IT) to improving the medical decision-making processes and to evaluate the degree to which IT investments are worthwhile. The method included the assessment of normative value of information. A decision tree model was developed. The calculated tree results were summarized in a cost-effectiveness analysis and a return on investment (ROI) analysis. This research aim to contribute: Researchers - by providing insights regarding decision theory, value of information and medical informatics; Practitioners - by promoting the design of medical IS; Physicians - by enhancing efficient use of information resources; Patients - by improving healthcare services; Policy decision-makers - regarding the advisability of investing and managing medical IS

The Contribution of Information Technology to Emergency Medicine

Information systems have been adopted in many fields including the healthcare industry. Indeed, keeping abreast of theadvances of the technological age, many medical organizations have invested heavily in information technologies (IT),aiming at improving medical decision-making and increasing its efficiency. Despite their advantages, information systems donot always provide the vital medical information required for medical decision-making, and the decisions may result in adecreased level of quality of care and unnecessary costs.The objective of this research is to evaluate the contribution of IT to decision-makers (physicians) at the point of care ofemergency departments (EDs). We evaluate the contribution of the medical information to medical decisions by using twomethods: the track log-file analysis and an experimental study. Our results lead to the major conclusion that using ITcontributes to increasing the proportion of correct admission decisions