In time series problems, noise can be divided into two categories: dynamic noise which drives the process, and observational noise which is added in the measurement process, but does not influence future values of the system. In this framework, we show that empirical volatilities (the squared relative returns of prices) exhibit a significant amount of observational noise. To model and predict t...

Molecular diffusion in brain extracellular space (ECS) is primarily controlled by interactions with the geometry and the interstitial matrix. Both factors increase λ, the tortuosity, a measure of hindrance to diffusion where λ2 = D/D∗ with D the free diffusion coefficient and D∗ the effective diffusion coefficient in brain [1]. Geometry lengthens diffusion paths or creates holdup in local voids...

Top-level reliability models have been developed for several recent configurations of the Space Interferometry Mission (SIM) and the results used in the decision process for selecting viable configurations for further study. For one configuration, closed-form solutions were obtained. For three configurations, Excel-based Monte Carlo models were developed. The agreement between the closed form a...

xor Goal 1

forces and moments which are generated at the base of the ma-nipulator. Hence, diiect application of the analysis and control schemes for the fixed base robots to space robots is not possible. Fig. 2. In the first category, the position and orientation of the + for the development of dynamic models of space ;bots.

Sentence Similarity is the process of computing a similarity score between two sentences. Previous sentence similarity work finds that latent semantics approaches to the problem do not perform well due to insufficient information in single sentences. In this paper, we show that by carefully handling words that are not in the sentences (missing words), we can train a reliable latent variable mod...

Abstract As with a spatial variogram or spatial covariance, a principal purpose of estimating and modeling a space-time variogram is to quantify the spatial temporal dependence reflected in a data set. The resulting model might then be used for spatial interpolation and/or temporal prediction which might take several forms, e.g. kriging and Radial Basis functions. There are significant problems...

Effective Space Asset Management is one key to addressing the ever-growing issue of space congestion. It is imperative that agencies around the world have access to data regarding the numerous active assets and pieces of space junk currently tracked in orbit around the Earth. At the center of this issues is the effective management of data of many types related to orbiting objects. As the popul...

This paper represents an approach to creating global knowledge systems, using new philosophy and infrastructure of global distributed semantic network (frame knowledge representation system, FRS) based on the space-time database construction. The main idea of space-time database environment introduced in the paper is to bind a document (an information frame, a knowledge) to a special kind of en...