Source symbol decisions in the presence of space and time varying shallow water acoustic response functions

2016 ◽  
Vol 139 (4) ◽  
pp. 2195-2195
Author(s):  
Paul J. Gendron ◽  
Kari Cannon ◽  
Graham Entwistle
Keyword(s):  
Shallow Water ◽  
Time Varying ◽  
Response Functions ◽  
Acoustic Response ◽  
Space And Time

Understanding Distressed Residential Transaction Discounts Across Price Segments and Market Conditions

2020 ◽  
Vol 42 (1) ◽  
pp. 151-182
Author(s):  
Ramya Rajajagadeesan Aroul ◽  
J. Andrew Hansz ◽  
Mauricio Rodriguez
Keyword(s):  
Transaction Costs ◽  
Time Varying ◽  
Market Segment ◽  
Market Conditions ◽  
Large Market ◽  
Space And Time ◽  
Wide Range ◽  
Time Periods ◽  
Market Areas

In the literature, there is a wide range of discounts associated with foreclosures. Comparisons across studies are difficult as they use different methodologies across large areas over different time periods. We employ a consistent methodology across space and time. We find modest discounts, within the range of typical transaction costs, in all but the highest priced market segment. Higher priced segments could explain prior findings of substantial discounts. We find that discounts are time-varying, with discounts increasing with market distress. A one-size-fits-all approach is not appropriate when estimating distressed transaction discounts across large market areas or under changing market conditions.

Oscillations of a string on an elastic foundation with space and time-varying rigidity

2016 ◽  
Vol 88 (1) ◽  
pp. 567-580 ◽  
Author(s):  
A. K. Abramian ◽  
W. T. van Horssen ◽  
S. A. Vakulenko
Keyword(s):  
Elastic Foundation ◽  
Time Varying ◽  
Space And Time

scholarly journals Time-Domain Substructure Transient Vibration Transfer Path Analysis Based on Time-Varying Frequency Response Functions under Operational Excitations

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Rong He ◽  
Hong Zhou
Keyword(s):  
Path Analysis ◽  
Frequency Response ◽  
Time Domain ◽  
Time Varying ◽  
Response Functions ◽  
Transient Vibration ◽  
Transfer Path ◽  
Time Varying Systems ◽  
Transfer Path Analysis ◽  
The Time Domain

The time-domain substructure inverse matrix method has become a popular method to detect and diagnose problems regarding vehicle noise, vibration, and harshness, especially for those impulse excitations caused by roads. However, owning to its reliance on frequency response functions (FRFs), the approach is effective only for time-invariable linear or weak nonlinear systems. This limitation prevents this method from being applied to a typical vehicle suspension substructure, which shows different nonlinear characteristics under different wheel transient loads. In this study, operational excitation was considered as a key factor and applied to calculate dynamic time-varying FRFs to perform accurate time-domain transient vibration transfer path analysis (TPA). The core idea of this novel method is to divide whole coupled substructural relationships into two parts: one involved time-invariable components; normal FRFs could be obtained through tests directly. The other involved numerical computations of the time-domain operational loads matrix and FRFs matrix in static conditions. This method focused on determining dynamic FRFs affected by operational loads, especially the severe transient ones; these loads are difficult to be considered in other classical TPA approaches, such as operational path analysis with exogenous inputs (OPAX) and operational transfer path analysis (OTPA). Experimental results showed that this new approach could overcome the limitations of the traditional time-domain substructure TPA in terms of its strict requirements within time-invariable systems. This is because in the new method, time-varying FRFs were calculated and used, which could make the FRFs at the system level directly adapt to time-varying systems from time to time. In summary, the modified method extends TPA objects studied in time-invariable systems to time-varying systems and, thus, makes a methodology and application innovation compared to traditional the time-domain substructure TPA.

Variability in normal-incidence acoustic response in shallow-water marine sediments

2015 ◽  
Vol 104 ◽  
pp. 92-103 ◽  
Author(s):  
Roger W. Meredith ◽  
Richard W. Faas ◽  
Douglas N. Lambert
Keyword(s):  
Shallow Water ◽  
Marine Sediments ◽  
Normal Incidence ◽  
Acoustic Response

scholarly journals LOCALIZATION OF RESPONSE FUNCTIONS OF SPIRAL WAVES IN THE FITZHUGH–NAGUMO SYSTEM

2006 ◽  
Vol 16 (05) ◽  
pp. 1547-1555 ◽  
Author(s):  
I. V. BIKTASHEVA ◽  
A. V. HOLDEN ◽  
V. N. BIKTASHEV
Keyword(s):  
External Force ◽  
Wave Solution ◽  
Spiral Wave ◽  
Spiral Waves ◽  
Two Dimensional ◽  
Response Functions ◽  
Space And Time ◽  
Wave Drift ◽  
Linearized Problem ◽  
Small Periodic

Dynamics of spiral waves in perturbed, e.g. slightly inhomogeneous or subject to a small periodic external force, two-dimensional autowave media can be described asymptotically in terms of Aristotelean dynamics, so that the velocities of the spiral wave drift in space and time are proportional to the forces caused by the perturbation. The forces are defined as a convolution of the perturbation with the spirals Response Functions, which are eigenfunctions of the adjoint linearized problem. In this paper we find numerically the Response Functions of a spiral wave solution in the classic excitable FitzHugh–Nagumo model, and show that they are effectively localized in the vicinity of the spiral core.

Variability in the acoustic response of shallow-water marine sediments determined by normal-incident 30-kHz and 50-kHz sound

2002 ◽  
Vol 182 (1-2) ◽  
pp. 179-208 ◽  
Author(s):  
Douglas N. Lambert ◽  
Maria T. Kalcic ◽  
Richard W. Faas
Keyword(s):  
Shallow Water ◽  
Marine Sediments ◽  
Acoustic Response

Geometric optics in space and time varying plasmas. II

1977 ◽  
Vol 20 (1) ◽  
pp. 116 ◽  
Author(s):  
Ira B. Bernstein ◽  
D. E. Baldwin
Keyword(s):  
Time Varying ◽  
Geometric Optics ◽  
Space And Time
Sign in / Sign up

Export Citation Format

Share Document