Kernel-based system identification from noisy and incomplete input-output data

In this contribution, we propose a kernel-based method for the identification of linear systems from noisy and incomplete input-output datasets. We model the impulse response of the system as a Gaussian process whose covariance matrix is given by the recently introduced stable spline kernel. We adopt an empirical Bayes approach to estimate the posterior distribution of the impulse response given the data. The noiseless and missing data samples, together with the kernel hyperparameters, are estimated maximizing the joint marginal likelihood of the input and output measurements. To compute the marginal-likelihood maximizer, we build a solution scheme based on the Expectation-Maximization method. Simulations on a benchmark dataset show the effectiveness of the method.Comment: 16 pages, submitted to IEEE Conference on Decision and Control 201

Impact of HEIs on the Scottish economy: new evidence from an HEI-disaggregated input-output approach

This paper measures the regional demand impacts on output and employment of Scottish Higher Education Institutions (HEIs) based on Input-Output tables for the year 2006. The HEI disaggregated table was developed from existing Input-Output tables using supplementary data from HESA and purchasing data for Scottish universities. We calculate direct, indirect and induced impacts. Most of the existing literature focuses on individual institutions by employing Keynesian Multiplier or Input-Output analysis. This paper adds to the literature by providing the first systematic study of all individual HEIs using a common framework of analysis. The results suggest that HEIs may have substantial regional economic impacts both in terms of output and employment. Furthermore analysis of the HEIs' income sources suggests they are more export intensive than is commonly acknowledged, which motivates a re-evaluation of the appropriate counterfactual in regional impact studies of HEIs. Keywords: HEIs, University Impact, Input-Output

I/O Considered Harmful (At least for the first few weeks)

One of the major difficulties with teaching the first programming course is input/output. It is desirable to show students how to input data and output results early in the course in order to motivate the students and so that they can see the results of their programs. Output is also a useful tool for testing programs. However, in most programming languages input and output are esoteric and the techniques for performing input and output must be learnt by the students at an early stage, precisely when they are trying to understand the basics of programming. We argue that input/output operations need not be taught in the early stages of a course if the language environment provides appropriate tools for testing programs. This assertion is demonstrated by reference to the Blue objectoriented language and environment

Compilation of input-output data from the national accounts

In this paper, a new method is presented to derive an input-output table from a system of make and use tables. The method, which we call 'activity technology', is mathematically equivalent to the well-known commodity technology, but chooses another unit, i.e. the activity. We will argue that, in the activity technology model, negatives can only arise from causes such as heterogeneity and errors in the data. To apply the activity technology, very detailed make and use matrices are required, as well as additional data on the input structures of certain activities. We will describe a method that can incorporate this additional data within the activity technology framework. Statistics Netherlands has adopted the method

Revised stochastic analysis of an input-output model

A main difficulty of regional analysis is the inaccuracy of regional input-output data. A natural framework for investigation is stochastic input-output analysis. In his study of Central Queensland, West (1986) assumes that input coefficients are normally distributed and derives formulas for the approximation of input-output multipliers means and variances. In his normality framework, these moments do not exits, however. Moreover, an inconsistency in the derivation will be exposed. We remedy these shortcomings by respecification of the stochastic structure and by direct evaluation of the moments through Monte Carlo calculations. West's formulas are quite accurate for an aggregated version of his data set. The leading terms of the formulas can be shown to be first order approximations to the means and the variances

On Reduced Input-Output Dynamic Mode Decomposition

The identification of reduced-order models from high-dimensional data is a challenging task, and even more so if the identified system should not only be suitable for a certain data set, but generally approximate the input-output behavior of the data source. In this work, we consider the input-output dynamic mode decomposition method for system identification. We compare excitation approaches for the data-driven identification process and describe an optimization-based stabilization strategy for the identified systems

A COMPARISON OF ECONOMIC IMPACT ESTIMATES FOR CHANGES IN THE FEDERAL GRAZING FEE: SECONDARY VS. PRIMARY DATA I/O MODELS

This paper compares estimates of local personal income impacts that could result from increases in the federal grazing fee, using secondary data input/output models (U.S. Forest Service IMPLAN) and five primary data input/output models. The results show that the impacts estimated by the IMPLAN models are usually higher than those estimate by primary data models.Livestock Production/Industries,

Data reduction complex analog-to-digital data processing requirements for onsite test facilities

The analog to digital processing requirements of onsite test facilities are described. The source and medium of all input data to the Data Reduction Complex (DRC) and the destination and medium of all output products of the analog-to-digital processing are identified. Additionally, preliminary input and output data formats are presented along with the planned use of the output products