ECHO model

Moorer proposed a slightly different structure, shown in figure 3.7, where the late reverb is driven by the output of the early echo FIR filter [Moorer, 1979], Moorer described this as a way of increasing the echo density of the late reverberation. The delays D and D2 can be adjusted so that the first pulse output from the late reverberator corresponds with the last pulse output from the FIR section. The gain g serves to balance the amount of late reverberation with respect to the early echoes. An important feature of this structure, apart from the early echo modeling, is the control... 

There are different ways to look at outcomes. One method, the ECHO model, purports three basic types of outcomes economic, clinical, and humanistic (Kozma et al., 1993). Economic outcomes include direct costs and consequences, both medical and nonmedical, and indirect costs and consequences. For example, when assessing outcomes from a patient perspective, a medication copayment would be a direct medication cost, whereas gas money to pick up the medication from the pharmacy would represent a nonmedical direct cost. Lost wages from missed work could be regarded as an indirect cost. 

Many have proposed that evaluation of drug therapy and pharmacists value-added services should include assessments of economic, clinical, and humanistic outcomes. The economic, clinical, and humanistic outcomes (ECHO) model assumes that the outcomes of medical care can be classified along the three dimensions of economic, clinical, and humanistic outcomes (Kozma, Reeder, and Schultz, 1993). Clinical outcomes are defined as medical events that occur as a result of disease or treatment. Economic outcomes are defined as the direct, indirect, and intangible costs compared with the consequences of medical treatment alternatives. Humanistic outcomes are defined as the consequences of disease or treatment on patient functional status or quality of life. All three of these outcomes need to be balanced simultaneously to assess value. 

Milov, A. D., Ponomarev, A. B., and Tsvetkov, Y. D. (1984). Electron—electron double resonance in electron spin echo Model biradical systems and the sensitized photolysis of decalin. Chem. Phys. Lett. 110, 67—72. 

A more comprehensive conceptual framework, the ECHO model, places outcomes into three categories economic, clinical, and humanistic outcomes. The model covers the five D s within the clinical and humanistic outcomes and provides an added economic outcomes dimension. As described by Kozma and associates, clinical outcomes are the medical events that occur as a result of the condition or its treatment. Economic outcomes are the direct, indirect, and intangible costs compared with the consequences of a medical intervention. Along with patient satisfaction, an essential humanistic or patient-reported outcome is self-assessed function and wellbeing, or health-related quality of life (HRQOL). This chapter focuses on HRQOL as an outcome of pharmacotherapeutic interventions. 

Filters that output noncoherent detector statistics have, in our recent work [1], shown to be very powerful for grain noise suppression in ultrasonics. However, such filters require the operator to carefully specify a transient prototype as a model of the defect echoes which should be detected. Here a new approach is presented, based on the above ideas about perception, which eliminates the need for the operator to manually specify a defect prototype. 

In Lakestani (10) modelling work performed within the PISC III project is validated against experiments. Figure 1 shows the pulse echo response from the lower edge of a 10 mm vertical strip-like crack at centre depth 55 mm. The probe has the size 20 mm by 22 ram, is of SV type with angle 45 and has centre frequency 2.2 MHz and an assumed bandwidth of 2 MHz. The calibration is perfomed by a side-drilled hole of diameter 9.5 mm and centre depth 60 mm (the... 

Calmon, P., Lhemery, A., Lecoeur-TaVbi, 1., Champigny, F., "Modelling of echo responses from defects in complex UT configurations", Proc. 14th hit. Cotif. NDE Nucl. Pres. Ves. Ind., 1996, 609-612. 

Accurate modelling of the field radiated by ultrasonic transducers is an essential step forward considering the final goal of the complete simulation of pulse echo experiments. 

We first supposed that the field radiated into the piece by the transducer is known, thanks to the Champ-Sons model. Then, the main approximation used consists in making far field assumptions in the beam defect interaction area. In the case of a focused transducer we assume that the incident wavefronts on the defect are plane. This is equivalent to say that the defect is located in or near the transducer focal area and that a defect located outside this zone does not cause a significant echo. In the case of planar contact transducer, the incident wavefronts on the defect are assumed to be spherical The incident field on the defect is therefore approximated by the product of a spatial function gfp,0,z)describing the amplitude distribution in the beam and a time-delayed waveform < ) ft) representing the plane or spherical propagation in the beam. The incident field on the defect can therefore be approximated for ... 

The physics of ultrasound is well known and widely described in many publications. Recording amplitudes from model reflectors at different depths by Dr. Josef Krautkramer in 1959 led to the DGS-diagram Echo amplitudes from disk shaped reflectors of different sizes were... 

With the reference block method the distance law of a model reflector is established experimentally prior to each ultrasonic test. The reference reflectors, mostly bore holes, are drilled into the reference block at different distances, e.g. ASME block. Prior to the test, the reference reflectors are scanned, and their maximised echo amplitudes are marked on the screen of the flaw detector. Finally all amplitude points are connected by a curve. This Distance Amplitude Curve (DAC) serves as the registration level and exactly shows the amplitude-over-distance behaviour" of the reference reflector for the probe in use. Also the individual characteristics of the material are automatically considered. However, this curve may only be applied for defect evaluation, in case the reference block and the test object are made of the same material and have undergone the same heat treatment. As with the DGS-Method, the value of any defect evaluation does not consider the shape and orientation of the defect. The reference block method is safe and easy to apply, and the operator need not to have a deep understanding about the theory of distance laws. 

Fig.3 shows the defect position on the bonding interface and the model of the reflective echo. The defects are exists on each bonding surface as(ii) (iv), is no exist as (i). 

The electron-spm echo envelope modulation (ESEEM) phenomenon [37, 38] is of primary interest in pulsed EPR of solids, where anisotropic hyperfme and nuclear quadnipole interactions persist. The effect can be observed as modulations of the echo intensity in two-pulse and three-pulse experiments in which x or J is varied. In liquids the modulations are averaged to zero by rapid molecular tumbling. The physical origin of ESEEM can be understood in tenns of the four-level spin energy diagram for the S = I = model system... 

Fig. 11a and b. Decay of the alignment echo height as a function of the mixing time x2 for different motional mechanisms, a Tetrahedral jumps as a model for conformational changes b Diffusive motion, the solid lines correspond to unrestricted rotational diffusion, the dashed lines to diffusion restricted to an angular region of 8°. Note the strong dependence of the decay curves on the evolution time t, in case of diffusive motion... 

Obtaining an accurate and detailed depth-age relationship for an ice core is, of course, a necessary task for learning paleoclimate histories. Approximate time scales can be calculated using numerical models of ice and heat flow for the core site (Reeh, 1989), constrained by estimates of the modem accumulation rate and by measurements of ice thickness from radio-echo-sounding surveys. 

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