The diffusion of an innovation traditionally has been defined as the process by which that innovation is “communicated through certain channels over time among the members of a social system” (Rogers, 1983, p. 5). As such, the diffusion process consists of four key elements: innovation, communication channels, time, and the social system.

New Product Diffusion Models in Marketing: A Review and Directions for Research:

ln the last few decades matiy methods have become available for forecasting. As always, when alternatives exist, choices need to be made so that an appropriate forecasting method can be selected and used for the specific situation being considered. This paper reports the results of a forecasting competition that provides information to facilitate such choice. Seven experts in each of the 24 methods forecasted up to 1001 series for six up to eighteen time horizons. The results of the competition are presented in this paper whose purpose is to provide empirical evidence about differences found to exist among the various extrapolative (time series) methods used in the competition.

The accuracy of extrapolation (time series) methods: Results of a forecasting competition

An instrument for measurement of tissue blood flow based on the laser Doppler principle was evaluated using a fluid model. A unique and linear relationship between flowmeter response and flux of red cells was demonstrated with red cell velocities and volume fractions within the normal physiological range of the microcirculatory network of the skin. Different degrees of oxygenation proved to influence the Doppler signal only to a minor extent. The study also shows that the Doppler signal is formed essentially by heterodyne mixing of light beams backscattered in static structures and moving red cells.

Evaluation of a Laser Doppler Flowmeter for Measurement of Tissue Blood Flow

Electromagnetic waves from the lower radio frequencies up through the optical spectrum can generate a myriad of effects and responses in biological specimens. Some of these effects can be harmful to man at high radiation intensities, producing burns, cataracts, chemical changes, etc. Biological effects have been reported at lower radiation intensities, but it is not now known if low-level effects are harmful. Even behavioral changes have been reported. Most of the effects are not harmful under controlled conditions, and can thereby be used for therapeutic purposes and to make useful diagnostic measurements. The problem of microwave penetration into the body with resultant internal power absorption is approached from both the theoretical and the experimental viewpoints. The results are discussed in terms of therapeutic warming of tissues and possible hazards caused by internal "hot spots." The absorption and scattering effects of light in biological tissues are reviewed. Molecular absorption peaks in the optical spectrum are useful for making molecular concentration measurements by spectroscopy. Much of the related work in the literature is summarized, some new results are presented, and several useful applications of wave energy and medical instruments are discussed.

Nonionizing electromagnetic wave effects in biological materials and systems

Electrocardiogram (ECG) compression techniques are compared, and a unified view of these techniques is established. ECG data compression schemes are presented in two major groups: direct data compression and transformation methods. The direct data compression techniques are ECG differential pulse code modulation (DPCM) and entropy coding, AZTEC, Turning-point, CORTES, Fan and SAPA algorithms, peak-picking, and cycle-to-cycle compression methods. The transformation methods include Fourier, Walsh, and Karhunen-Loeve transforms. The theoretical bases behind the direct ECG data compression schemes are presented and classified into three categories: tolerance-comparison compression, DPCM, and entropy coding methods. A framework for evaluation and comparison of ECG compression schemes is presented. >

ECG data compression techniques-a unified approach

A set of equations derived to describe the optics of highly scattering materials are explained, extended, and applied to the problem of in vitro and in vivo measurement of the relative oxygen saturation of nonhemolyzed blood. Fundamental absorption and scattering coefficients are described and related to the absorption coefficient of hemolyzed blood. Diffusion equations for light photons are used to solve the scattering problem in a three-dimensional system that may be useful for in vivo oxyhemoglobin measurements. Crude application to published data from in vitro measurements on nonhemolyzed blood indicates that the scattering coefficient of whole blood is probably not very wavelength-dependent.

A Note on the Theory of Backscattering of Light by Living Tissue

Pressing changes are needed in the administration of real estate taxation that will not only ensure that all properties be assessed accurately and equitably, but will enable taxpayers to perceive that they are being treated fairly. In this paper, we examine what properties an automated mass appraisal system should exhibit so as to meet efficacy, equity and public acceptability criteria. A new automated system designed on the basis of these properties which utilizes feedback control and pattern recognition concepts is presented. Results of an empirical study using Pittsburgh data supports the feasibility of the proposed system.

A Feedback Model for Automated Real Estate Assessment

A general technique for the real-time extraction of a physiological signal in the presence of well-characterized noise is described using a noninvasive fetal ECG detection system as an example application.

Near-Orthogonal Basis Functions: A Real Time Fetal ECG Technique

The reliability of fetal heart rate (FHR) from external abdominal-lead electrocardiographic waveforms depends upon the R-wave detection capability of the monitoring device. Assuming that the maternal component of the ECG is canceiled by techniques described elsewhere [1]-[4], we are left with a fetal electrocardiogm (FECG) which may be conrupted by high noise levels. This paper describes several digital signal processing techniques by which the detection of fetal R-waves is improved. These techniques-narrow band-pass filtering, local peak differencing, autoregressive filtering, and matched filtering-are theoretically developed. The performance of each technique is measured and analyzed for two sample fetal ECG inputs.

Richard L. Longini

Papers

A Note on the Theory of Backscattering of Light by Living Tissue

A Feedback Model for Automated Real Estate Assessment

Near-Orthogonal Basis Functions: A Real Time Fetal ECG Technique

Abdominal-Lead Fetal Electrocardiographic R-Wave Enhancement for Heart Rate Determination

A new design for an impedance pneumograph