On: “Homomorphic deconvolution” by D. J. Jin and J. R. Rogers (GEOPHYSICS, 48, 1014–1016).

Geophysics ◽  
1984 ◽  
Vol 49 (9) ◽  
pp. 1559-1560
Author(s):  
Mark Lane ◽  
Tad Ulrych
Keyword(s):  
Standard Deviation ◽  
Relative Magnitude ◽  
Phase Unwrapping ◽  
Inverse Transform ◽  
Maximum Delay ◽  
Complex Cepstrum ◽  
Minimum Delay ◽  
Goertzel Algorithm ◽  
Noise Realization ◽  
Do So

The recent note by Jin and Rogers (1983) presented examples of the failure of the homomorphic transform to invert properly. Since this transform is not only of interest in geophysics, but has also found applications in other fields (Oppenheim and Schafer, 1975), these results are of concern. We consequently attempted to reproduce Jin and Rogers’ results. We failed to do so. In fact, in our experience, the transform has always inverted successfully. Our results using the first example of Jin and Rogers are shown in Figure 1. We used the algorithm of Tribolet (1977) with a modified Goertzel algorithm (Bonzanigo, 1978) for phase unwrapping. The figure is arranged as in Jin and Rogers’ paper. Figure 1a shows the input: impulses separated by 20 samples, of magnitude 2000 and 1999. Figure 1b shows its complex cepstrum. We have set the zero‐quefrency point to zero since this represents a scale factor and can dominate the plotting. Note the minimum delay cepstrum with a small amount of aliasing. The sequence returned by the inverse transform is shown in Figure 1c, demonstrating a successful inversion. The effect of noise is also shown. Noise with a standard deviation of 5 was added to the sequence of Figure 1a. This is shown in Figure 1d. Note that our noise realization is undoubtedly different from that of Jin and Rogers. The noise has changed the relative magnitude of the original spikes such that they are maximum delay. This is reflected in the cepstrum (Figure 1e). Figure 1f shows the returned sequence, again demonstrating the successful inversion.

scholarly journals Os consórcios empresariais portugueses: análise estatística da vertente económica

2017 ◽  
Vol 16 (2) ◽  
pp. 455-478
Author(s):  
Bruno José Machado de Almeida
Keyword(s):  
Organizational Change ◽  
Statistical Analysis ◽  
Standard Deviation ◽  
Legal Aspect ◽  
Economic Aspect ◽  
Basic Premise ◽  
Kolmogorov Smirnov ◽  
Do So

As relações de colaboração entre as empresas são frequentes, sendo o modelo de cooperação um dos fatores mais determinantes. O seu pressuposto básico é, sobretudo, económico e enfatiza a otimização das sinergias em projetos partilhados. No entanto, os consórcios empresariais analisados contratualizam exclusivamente a vertente jurídica e organizacional e ocultam a vertente económica subjacente às alianças. Desse modo, o objetivo com este trabalho está centrado na procura e explicitação das componentes da dimensão económica que as empresas melhor identificam quando adotam a figura jurídica do consórcio empresarial. Para isso, foi construído um inquérito em escala Likert e remetido a um conjunto de empresas com acordos de cooperação, no sentido de indagar o pensamento dos seus responsáveis. Em seguida, as respostas foram submetidas a uma análise estatística apropriada (média, desvio padrão, testes de Kolmogorov-Smirnov, Shapiro-Wilk e Alfa de Cronbach, etc.). Os resultados obtidos sugerem que a inovação e a sustentabilidade são os fatores mais bem percecionados pelos consorciados.Palavras-chave: Cooperação empresarial. Economia. Eficiência. Internacionalização. Portugal. Abstract The relations of collaboration between the companies are frequent, and the model of cooperation one of the most crucial. His basic premise is mainly economic and emphasizes the optimization of synergies in projects that are shared. However, the business consortiums analyzed exclusively hire the legal aspect and organizational change and hide the economic aspect behind the alliances. To do so, we created a questionnaire in Likert’s scale which was given to companies with cooperation agreements to find out their managers’ thought. Subsequently, the answers were submitted to an appropriate statistical analysis (mean, standard deviation, Kolmogorov-Smirnov, Shapiro-Wilk and Alfa de Cronbach tests, etc.). The result suggests that innovation and sustainability are the factors most identified by the partners.Keywords: Business cooperation. Economics. Efficiency. Internationalisation. Portugal. 

SEISMIC WAVE PROPAGATION IN LAYERED MEDIA IN TERMS OF COMMUNICATION THEORY

Geophysics ◽  
1966 ◽  
Vol 31 (1) ◽  
pp. 17-32 ◽  
Author(s):  
S. Treitel ◽  
E. A. Robinson
Keyword(s):  
Impulse Response ◽  
Communication Theory ◽  
Amplitude Spectrum ◽  
P Wave ◽  
Earth Model ◽  
Phase Lag ◽  
Elastic Plates ◽  
Pass System ◽  
Maximum Delay ◽  
Minimum Delay

The problem of a normally incident plane P wave propagating in a system of horizontally layered homogeneous perfectly elastic plates is reformulated in terms of concepts drawn from communication theory. We show how both the reflected and transmitted responses of such a system can be expressed as a z transform which is the ratio of two polynomials in z. Since this response must be stable, the denominators of the z transforms describing the reflected and transmitted motion are minimum delay (i.e., minimum‐phase lag). If the layered medium is bounded at depth by a perfect reflector, then the reflected impulse response recorded at the surface is in the form of a dispersive all‐pass z transform. A dispersive all‐pass system is one whose z transform is the ratio of the z transform of a maximum‐delay wavelet to that of its corresponding minimum‐delay wavelet; hence, the amplitude spectrum of a dispersive all‐pass system is unity for all frequencies. This means that the amplitude spectrum of the reflected response is identical to the amplitude spectrum of the input wavelet used to excite the system. More specifically, all the energy put in is returned with the same frequency content, but is differentially delayed. The phase‐lag spectrum of the reflected response lies everywhere above the phase‐lag spectrum of the input wavelet. Thus, the all‐pass situation implies that the layered earth model considered here, while not able to alter the amplitude of the frequency components of the input wavelet, will introduce differential time delays with certain properties into each such component. Finally, since the reflected impulse response is an all‐pass wavelet, its autocorrelation is a spike of unit magnitude at τ=0, and zero for all other lags.

Physical activity across the life-span: Does feeling physically younger help you to plan physical activities?

2016 ◽  
Vol 22 (3) ◽  
pp. 324-335 ◽  
Author(s):  
Julian Wienert ◽  
Paul Gellert ◽  
Sonia Lippke
Keyword(s):  
Physical Activity ◽  
Standard Deviation ◽  
Life Span ◽  
Standard Error ◽  
Good Health ◽  
Physical Activities ◽  
Subjective Age ◽  
Age Range ◽  
The Relationship ◽  
Do So

We tested whether the relationship between subjective physical age and physical activity is mediated by planning. Participants came from a broad age range (25–78 years, M = 39.57, standard deviation = 10.75) and reported relatively good health ( M = 3.36, standard deviation = 0.90). The model supported the suggested mediation ( β = −.01, standard error = .01, p = .042). Feeling physically younger is associated with higher planning to adopt higher levels of physical activity and more planning is associated with more subsequent physical activity. Results open avenues for interventions that help people to become more active by focusing on subjective age. One way to do so might be tailoring approaches for interventions.

scholarly journals Hubungan Jumlah Perenang dengan Sisa Klor di Kolam Renang Antasari Banjarbaru Tahun 2016

2017 ◽  
Vol 14 (1) ◽  
pp. 375
Author(s):  
Fadila Harariet ◽  
Darmiah Darmiah ◽  
Imam Santoso
Keyword(s):  
Standard Deviation ◽  
Correlation Analysis ◽  
Swimming Pool ◽  
Residual Chlorine ◽  
Cross Sectional ◽  
The People ◽  
Relationship Of ◽  
The Relationship ◽  
Do So

Abstract: The relationship of total swimmers with residual chlorine in the swimming pool. The swimming pool as a means of public that usually visited by the people can potentially become vehicles for spreading germs through water contaminated media pool so that sanitation should always be considered. This study aims to determine the number of swimmers in the Swimming Pool Antasari Banjarbaru, determine residual chlorine in Swimming Pool. This type of research was analytic research with cross sectional approach. The population is all water swimming pool which used by swimmers and all swimmers in the pool by sampling as much as 5 spots, using correlation analysis. The results showed the number of swimmers on average were 151 swimmers with the lowest number were 113 swimmers and the highest were 223 swimmers. Residual chlorine inside the water of swimming pool was an average of 0.73 mg/L, the standard deviation was 0.71 mg/L with the lowest number was 0.01 mg/L and the highest number was 1.49 mg / L. The results of the analysis did not prove statistically no relationship with the rest of the swimmers amount of chlorine in Swimming Pool because H0 (p = 0.679> value α = 0.05) and the value of r was -0.218 so that the relationship can not be seen. Efforts to do so that residual chlorine water in Swimming Pool in accordance with the requirements is to conduct regular inspections both manager pool and the relevant agencies, maintain the quality of residual chlorine by adding chlorine stabilizer isocyanuric, and perform administration disinfection according to the dosage required to obtain results corresponding residual chlorine required pursuant Peraturan Menteri Kesehatan RI Nomor: 416/Menkes/Per/IX/1990. Keywords: Total swimmer; residual chlorine; swimming pool.

COVID-19 lockdown effects on gender inequality: the case of the Italian Astronomy & Astrphysics Community

2021 ◽  
Author(s):  
Laura Inno ◽  
Alessandra Rotundi ◽  
Arianna Piccialli
Keyword(s):  
Standard Deviation ◽  
Gender Inequality ◽  
Research Productivity ◽  
Male And Female ◽  
First Semester ◽  
Average Value ◽  
The World ◽  
Community Of Researchers ◽  
Astronomy And Astrophysics ◽  
Do So

<div> <p>Among European countries, Italy was the first to be heavily hit by the outbreak of COVID-19 and quickly decreed on 9 March 2020 that the entire national territory be locked down to prevent its further spread, establishing an unprecedented situation for its citizens, including researchers. Italy hosts a large (~2000) and lively community of researchers in the fields of Astronomy and Astrophysics, which contains the largest fraction of female researchers (~30%) among the world’s leading countries in astronomy (defined as the ones with IAU members >150). Therefore, the Italian community poses as an ideal testbed to investigate the consequences of the lockdown on research productivity, also by gender. </p> </div><div> <div> <p>In order to do so, we used the INAF and MIUR websites to compile a complete database of the Italian researchers, considered by gender, and matched it with the first authors of preprints posted on the largest preprint archive of natural science publications, arXiv, for each year from 2017 to 2020.</p> <p>The submission rate over the previous three years is about 38.6 ± 8.2 (one standard deviation, <em>σ</em>) papers per month,  with the fraction of papers published by women consistently close to 30%, which well reflects the percentage of women in the community. As expected, the overall production in the first semester of 2020  (i.e. during the first lockdown) was lower than the average value estimated above. But if we break down this difference by the assigned first-author gender, we find that the decrease only concerns the submissions by female researchers, while submissions by male researchers actually increased during the lockdown by up to 10% (or a difference of 3.5<em>σ</em>).  We discuss this difference in productivity between male and female researchers during the lockdown as a possible reflection of the unbalanced distribution of the unpaid workload at home between partners.</p> </div> </div>

scholarly journals Impact of crustal deformation detection by the DSI (difference of split-band interferograms) method with PALSAR-2 data: A case study on the 2016 Kumamoto Earthquake

2021 ◽  
Author(s):  
Taku Ozawa ◽  
Yuji Himematsu
Keyword(s):  
Standard Deviation ◽  
Spatial Resolution ◽  
Phase Unwrapping ◽  
Band Pass Filter ◽  
2016 Kumamoto Earthquake ◽  
Noise Component ◽  
Pass Filter ◽  
Kumamoto Earthquake ◽  
Surface Deformations ◽  
The 2016 Kumamoto Earthquake

Abstract Interferometric Synthetic Aperture Radar (InSAR) is a useful tool for detecting surface deformations at high spatial resolutions. When InSAR is applied to huge surface deformations, clear fringes with complicated phase gaps often appear in the interferograms. Although the surface deformations in such areas are important for understanding their mechanisms and for investigating disasters, it is difficult to convert the data on such fringes to surface deformation information because of difficulties associated with phase unwrapping. To resolve these difficulties, we created multiple SAR pairs with different frequencies using a band-pass filter and derived the difference of interferograms which are generated from these SAR pairs. Generally, its result corresponds to the result of SAR observations made with long-wavelength radar. Therefore, a phase wrap was less likely to occur, and phase unwrapping was easy to accomplish. We applied this method to the PALSAR-2 data pairs for the 2016 Kumamoto Earthquake and succeeded in identifying huge crustal deformations with complicated phase gaps in the vicinity of surface ruptures. Comparing these results with the crustal deformations observed from GNSS measurements, the root-mean-squares of the differences were found to be approximately 4 cm. Although this accuracy was poorer than that of conventional InSAR, it was nearly equivalent to that of the offsettracking method. Furthermore, its spatial resolution was significantly better than that of the offset-tracking method. However, the disadvantage of this method is that its detection accuracy is significantly degraded in zones with low coherence, due to noise amplification. The standard deviation of the noise component was approximately 2 cm for pixels with coherences above 0.7. However, for pixels with a coherence lower than 0.2, the standard deviation was greater than 10 cm, and the noise component occasionally exceeded 1 m. Despite the disadvantages of this method, it is effective for the detection of huge crustal deformations with high spatial resolution in areas where phase unwrapping methods for conventional InSAR are inappropriate.

MULTICHANNEL Z‐TRANSFORMS AND MINIMUM‐DELAY

Geophysics ◽  
1966 ◽  
Vol 31 (3) ◽  
pp. 482-500 ◽  
Author(s):  
Enders A. Robinson
Keyword(s):  
Digital Filter ◽  
Pulse Train ◽  
Digital Filters ◽  
Single Channel ◽  
Deterministic Model ◽  
Digital Data ◽  
Mixed Delay ◽  
Maximum Delay ◽  
Multichannel Filter ◽  
Minimum Delay

In the standard deterministic model of water reverberation generation, the reverberation pulse‐train resulting from a deep reflection is minimum‐delay. Even in the more complex physical situations encountered in the field, there is evidence that in many cases the reverberation pulse‐train waveforms are minimum‐delay, or at least approximately so. The reason for this minimum‐delay property is that a pulse‐train waveform results from multiple reflections and transmissions within the layered earth; because reflection coefficients are less than unity in magnitude, the concentration of energy in a pulse‐train must appear at its beginning rather than its end; this early concentration of energy is the condition that pulse‐train waveform be minimum‐delay. Each deep reflection horizon contributes a minimum‐delay reverberation pulse‐train waveform to a seismic trace. If we let a spike series represent the deep horizons in the sense that the timing of a spike represents the direct arrival time of a reflection and the amplitude of the spike represents the strength of the reflection, then the seismic trace may be considered as the convolution of the spike series with the reverberation pulse‐train waveform. Because the reverberation pulse‐train waveform is minimum‐delay, and because at least approximately the deep horizon spike series represents a statistically uncorrelated series, the two conditions required for the application of the method of predictive deconvolution (Robinson, 1954, 1957) are met, and hence this method can be used as a practical digital data processing method to eliminate water reverberations on field seismic traces. The concept of minimum‐delay therefore is an important link in chaining together the deterministic approach and the statistical approach to seismic record analysis in the single‐channel case. The concept of minimum‐delay can be extended to the multichannel case. The theory of multichannel digital filters can be regarded as the matrix‐valued counterpart of single‐channel digital filter theory. A reflection seismogram consists of many traces; these traces are interrelated. A multichannel filter operates simultaneously on all these traces, and thus it can take advantage of the seismogram structure between traces as well as along a single trace. An important objective of seismogram analysis is to increase the resolution of overlapping waveforms by deconvolution. This goal can be accomplished through the use of inverse multichannel digital filters. Without proper design, an inverse multichannel filter can have the undesirable property that its impulse response function is unstable. In the case when there is the same number of input channels as output channels, then each of the coefficients of a multichannel digital filter may be regarded as a square matrix, and the z‐transform of the filter coefficients is a matrix‐valued polynomial in z. The determinant of its matrix‐valued z‐transform plays a central role in the classification of the delay properties of such a multichannel filter. This determinant is a scalar‐valued polynomial in z. If the coefficients of this polynomial represents a single‐channel minimum‐delay filter, then the original multichannel filter is also minimum‐delay; if they represent a single‐channel maximum‐delay filter, then the multichannel filter is also maximum‐delay; if they represent a single‐channel mixed‐delay filter, then the multichannel filter is also mixed‐delay. A minimum‐delay multichannel digital filter has an inverse which is a stable memory function. On the other hand, a maximum‐delay multichannel digital filter has an inverse that consists of a stable anticipation function. A mixed‐delay multichannel digital filter has a stable inverse, this inverse being made up of a memory component and an anticipation component.

scholarly journals NPV Sensitivity Analysis: A Dynamic Excel Approach

2017 ◽  
Vol 10 (3) ◽  
pp. 113-126
Author(s):  
George A. Mangiero ◽  
Michael Kraten
Keyword(s):  
Sensitivity Analysis ◽  
Standard Deviation ◽  
Financial Analysts ◽  
Business Case ◽  
Potential Range ◽  
Probability Estimate ◽  
Global Energy ◽  
Sales Revenue ◽  
Range Of Values ◽  
Do So

Financial analysts generally create static formulas for the computation of NPV.  When they do so, however, it is not readily apparent how sensitive the value of NPV is to changes in multiple interdependent and interrelated variables. It is the aim of this paper to analyze this variability by employing a dynamic, visually graphic presentation using Excel.  Our approach illustrates how these variables, when increased or decreased to reflect the potential range of values in a business case, change the value of NPV, and hence affect the decision about whether to proceed with the project or to reject it. Furthermore, since sales revenue is one of the least certain elements in the business case, the presentation includes a probability estimate of whether NPV will be positive or negative, assuming that sales revenue is normally distributed with a known mean and standard deviation. The business case we have chosen for illustrative purposes is a global energy project. Nevertheless, financial analysts in any industry should be able to apply our dynamic spreadsheet approach to their projects as well.

Holding replication studies to mainstream standards of evidence

2018 ◽  
Vol 41 ◽  
Author(s):  
Duane T. Wegener ◽  
Leandre R. Fabrigar
Keyword(s):  
Replication Studies ◽  
Replication Research ◽  
Standards Of Evidence ◽  
Do So

AbstractReplications can make theoretical contributions, but are unlikely to do so if their findings are open to multiple interpretations (especially violations of psychometric invariance). Thus, just as studies demonstrating novel effects are often expected to empirically evaluate competing explanations, replications should be held to similar standards. Unfortunately, this is rarely done, thereby undermining the value of replication research.

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