Intermediate Transfer Functions Research Articles

Methods to homogenize electrochemical concentration cell (ECC) ozonesonde measurements across changes in sensing solution concentration or ozonesonde manufacturer

Abstract. Ozone plays a significant role in the chemical and radiative state of the atmosphere. For this reason there are many instruments used to measure ozone from the ground, from space, and from balloons. Balloon-borne electrochemical cell ozonesondes provide some of the best measurements of the ozone profile up to the mid-stratosphere, providing high vertical resolution, high precision, and a wide geographic distribution. From the mid-1990s to the late 2000s the consistency of long-term records from balloon-borne ozonesondes has been compromised by differences in manufacturers, Science Pump (SP) and ENSCI (EN), and differences in recommended sensor solution concentrations, 1.0 % potassium iodide (KI) and the one-half dilution: 0.5 %. To investigate these differences, a number of organizations have independently undertaken comparisons of the various ozonesonde types and solution concentrations, resulting in 197 ozonesonde comparison profiles. The goal of this study is to derive transfer functions to allow measurements outside of standard recommendations, for sensor composition and ozonesonde type, to be converted to a standard measurement and thus homogenize the data to the expected accuracy of 5 % (10 %) in the stratosphere (troposphere). Subsets of these data have been analyzed previously and intermediate transfer functions derived. Here all the comparison data are analyzed to compare (1) differences in sensor solution composition for a single ozonesonde type, (2) differences in ozonesonde type for a single sensor solution composition, and (3) the World Meteorological Organization's (WMO) and manufacturers' recommendations of 1.0 % KI solution for Science Pump and 0.5 % KI for ENSCI. From the recommendations it is clear that ENSCI ozonesondes and 1.0 % KI solution result in higher amounts of ozone sensed. The results indicate that differences in solution composition and in ozonesonde type display little pressure dependence at pressures ≥ 30 hPa, and thus the transfer function can be characterized as a simple ratio of the less sensitive to the more sensitive method. This ratio is 0.96 for both solution concentration and ozonesonde type. The ratios differ at pressures < 30 hPa such that OZ0. 5%/OZ1. 0 % = 0. 90 + 0. 041 ⋅ log10(p) and OZSciencePump/OZENSCI = 0. 764 + 0. 133 ⋅ log10(p) for p in units of hPa. For the manufacturer-recommended solution concentrations the dispersion of the ratio (SP-1.0 / EN-0.5 %), while significant, is generally within 3 % and centered near 1.0, such that no changes are recommended. For stations which have used multiple ozonesonde types with solution concentrations different from the WMO's and manufacturer's recommendations, this work suggests that a reasonably homogeneous data set can be created if the quantitative relationships specified above are applied to the non-standard measurements. This result is illustrated here in an application to the Nairobi data set.

A frequency-domain approach to frequency-weighted balanced realization

The Ho-Kalman/Kung algorithm for balanced realization by singular-value decomposition of the Hankel operator has a natural frequency-domain equivalent. The controllability operator and observability operator are represented by intermediate transfer functions, called the gain to states and noise gain respectively. The product of these, the Hankel operator, can be expressed in terms of the input-output transfer function using an identity which the author refers to as the dynamic-range limitation. This frequency-domain theory extends naturally to the frequency-weighted case, and further to non-integrator-based linear fractional systems. It also provides additional design insight into the filter dynamic-range problem.

The Expanding Role of Semi-Conductive Polyurethane in Electro-Photographic Systems

This paper explores the increasing use of semi-conductive polyurethane materials in dry toner Developer, Charging, Cleaning, Intermediate Transfer and Transfer functions, and Developer, Intermediate Transfer and Squeegee functions in liquid toner systems. If you design or specify semiconductive polymer materials for these functions, this paper will provide information on the important design characteristics to communicate to the polyurethane manufacturer. Also discussed is a common language for those specifications and for identifying testing and measurement methods for those characteristics. Testing and measuring methods of Volume Resistivity and Electrical characteristics are explored in detail. A common formula for specifying resistivity is explained and the effect of time, temperature and humidity on this measurement are discussed. Basic molding and machining processes used are reviewed briefly at the beginning of this paper, as are application descriptions. The major functional and quality characteristics to be determined and considered for these applications are:a) Electrical Properties; Volume Resistivity, Change in Volume Resistivity over time (and/or over total energy transmitted), Change in Volume Resistivity under differing temperature and humidity conditions, Other electrical properties such as R/C charge-decay time and Refresh rate and relation to nip residence time.b) Physical Properties: Compression Modulus and Durometer [JIS or Shore] (relation to nip width), Tensile, Tear, Shear and Cut Strength, Resilience, Compression Set, Wear and Abrasion Resistance, Surface Energy and release characteristics and COF. Chemical and ozone resistance, Surface roughness, Load and Dynamic properties (tan-δ, Hysteresis and balancing issues)c) Base Chemistry: Material class or base polymer group (i.e. Polyester or Polyether Polyurethane and how this relates to Chemical Resistance and Hydrolytic Stability.), and the use of differing conductive agents in these systems.d) Attribute Defect Criteria and Dimensional tolerance issues.

2-D adaptive state-space filters based on the Fornasini-Marchesini second model

Based on the Fornasini-Marchesini second model, a technique is developed for implementing two-dimensional (2-D) adaptive state-space filters. First, the relationship between the coefficient sensitivities and the intermediate transfer functions is investigated for the Fornasini-Marchesini second model. A least mean square (LMS) adaptive algorithm is then presented by using new systems that generate the gradient signals. Finally, a 2-D adaptive line enhancer is constructed by using the 2-D adaptive state-space filter to illustrate the utility of the proposed technique.

A transfer function computational algorithm for linear control systems

The problem of computing the closed loop transfer function of a linear system represented by its block diagram or by its flow graph is of importance in CAD programs designed for the analysis of linear systems. Mason's rule (1953) is one of the available techniques to perform such calculations, but it requires searching into the graph for different paths and loops and becomes slow as system complexity increases. In this paper, a method is developed to efficiently compute the closed loop transfer function and intermediate transfer functions of a linear system. >

Engineering for the Customer: Combining Preference and Physical System Models. Part I—Theory

SUMMARY Engineering products for the customer is difficult. The criteria may be subjective, and often quality and cost are competing objectives which must be balanced. This paper proposes a model which structures the design process, and a methodology to engineer for customer preference. The model links design variables—tangible features of the design concept which can be manipulated by the designer—to multi-attribute value, a number indicating customer preference. Intermediate transfer functions within the model link design variables to system responses, and link specific system responses to value. Thus, customer expectations can be met more effectively, as design variables are related to customer preference in a quantitative way. An iterative design improvement method is considered in which a current design and a new design are compared. The comparison is made by mapping the designs into customer value space, and applying a measure of overall customer preference which considers both cost and a quality at...

A generalization of intermediate transfer function analysis to arbitrary linear networks

Consideration is given to the generalization of the intermediate-transfer-function analysis method for state-space filter circuits to arbitrary linear networks. This analysis technique involves the calculation of a set of intermediate transfer functions that can in turn be used to compute any desired transfer function, various sensitivity functions, output noise power, harmonic and intermodulation distortion product levels when the network contains quasilinear elements and various other linear network attributes. >

Two‐dimensional adaptive state‐space filters using LMS method

AbstractThis paper considers the construction of two‐dimensional (2‐D) adaptive state‐space filters using the least mean squares (LMS) method. The approach is based on the Roesser local state‐space model. First, the relation between the coefficient sensitivities and the intermediate transfer functions is investigated. Then, after introducing new systems for generating the gradient vectors, an adaptive algorithm is developed using the LMS method.Next, a 2‐D adaptive state‐space filter with separable denominator is introduced to reduce the amount of computation in the adaptive process. Finally, a numerical example is given in which the 2‐D adaptive state‐space filters are used to design 2‐D digital filters in the spatial domain.

A Comparison of HDTV and Film — Overall Light Transfer Characteristics

This article discusses the ways in which the technical processes involved in HDTV and film imaging systems can be modeled with a succession of transfer functions that determine the overall visual characteristics of these systems. The overall transfer characteristic shows how the original scene is reproduced by a display. A theoretical analysis of the intermediate transfer functions provides insight into the reproduction of the scene. In addition, the viewing environment affects the choice of an overall, aesthetically pleasing transfer characteristic. Film, for example, is usually viewed in a dark room while television has traditionally been assumed to be viewed in brighter surroundings. Actual photometric measurements of both HDTV and film show that in a dark environment the two transfer characteristics are strikingly similar.

Synthesis and analysis of state-space active filters using intermediate transfer functions

This paper is concerned with the realization of a given arbitrary filter transfer function as a network of resistively interconnected integrators. These state-space realizations are synthesized using a new technique called intermediate function (IF) synthesis. The technique is based on the selection of a set of functions to serve as either the transfer functions from the filter input to the integrator outputs or the transfer functions from the integrator inputs to the filter output. Relationships between the filter sensitivity and dynamic range and the intermediate functions are derived. A number of results are also given to aid in the selection of a set of IF's that yields structures with optimum performance.