초록 ▼

A structure and method for absorbing and shielding sound from a source of sound are disclosed having at least four layers including a first panel layer 2, a sound absorbing material layer 3, a first air layer 4 and a second panel layer 6, which are located in a sequence from a source of sound. The s

A structure and method for absorbing and shielding sound from a source of sound are disclosed having at least four layers including a first panel layer 2, a sound absorbing material layer 3, a first air layer 4 and a second panel layer 6, which are located in a sequence from a source of sound. The sound absorbing material layer 3 has a ventilating property.

대표청구항 ▼

A structure and method for absorbing and shielding sound from a source of sound are disclosed having at least four layers including a first panel layer 2, a sound absorbing material layer 3, a first air layer 4 and a second panel layer 6, which are located in a sequence from a source of sound. The s

A structure and method for absorbing and shielding sound from a source of sound are disclosed having at least four layers including a first panel layer 2, a sound absorbing material layer 3, a first air layer 4 and a second panel layer 6, which are located in a sequence from a source of sound. The sound absorbing material layer 3 has a ventilating property. thickness as much as twice or more the diameter of the second curved tube. agnetic wave comprises using a range of frequencies above zero. 12. The method for determining the characteristics of a railroad track defined in claim 2 wherein the step of lowering the permeability of the track with an initial electromagnetic wave comprises using a DC wave for the initial electromagnetic wave. 13. The method for determining the characteristics of a railroad track defined in claim 2 wherein the step of lowering the permeability of the track with an initial electromagnetic wave comprises using an AC wave for the initial electromagnetic wave. 14. The method for determining the characteristics of a railroad track defined in claim 2 wherein the step of evaluating the received signal to determine the characteristics of the track comprises determining the resistivity of the track. 15. The method for determining the characteristics of a railroad track defined in claim 2 wherein the step of evaluating the received signal to determine the characteristics of the track comprises detecting interfaces in the track. 16. A method for determining the characteristics of a railroad track comprising the steps of: (a) lowering the permeability of the track with an initial electromagnetic wave, (b) creating a transmitted electromagnetic wave adjacent to the track having a frequency higher than the initial electromagnetic wave, (c) engaging the transmitted electromagnetic wave with the track for creating a resulting wave, and (d) making the resulting wave available for detection so as to create a received signal that has a nulled relationship to the transmitted wave for evaluating the characteristics of the track. 17. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of making the resulting wave available for detection so as to create a received signal that has a nulled relationship to the transmitted wave comprises geometrically nulling. 18. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of geometrically nulling comprises creating the transmitted wave so as to prevent coupling with the received signal. 19. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of making the resulting wave available for detection so as to create a received signal that has a nulled relationship to the transmitted wave comprises separation nulling. 20. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of making the resulting wave available for detection so as to create a received signal that has a nulled relationship to the transmitted wave comprises electronic nulling. 21. The method for determining the characteristics of a railroad track defined in claim 20 wherein the step of electronic nulling comprises nulling the transmitted electromagnetic wave and the received signal by degrees of phase. 22. The method for determining the characteristics of a railroad track defined in claim 20 wherein the step of electronic nulling comprises nulling the transmitted electromagnetic wave and the received signal by amplitude. 23. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of nulling comprises minimizing direct signal coupling between the transmitted electromagnetic wave and the received signal. 24. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of lowering the permeability of the track with an initial electromagnetic wave comprises using a range of frequencies of zero and above. 25. The method for determining the characteristics of a railroad track defined in claim 16 wherein the step of lowering the permeability of the track with an initial electromagnetic wave comprises using a DC wave for the initial electromagnetic wave. 26. The method for determining the characteristics of a railroad track defined in claim 16 wherein the s tep of lowering the permeability of the track with an initial electromagnetic wave comprises using an AC wave for the initial electromagnetic wave. 27. An apparatus for determining the characteristics of a railroad track, the apparatus comprising: (a) means for lowering the permeability of the track with an initial electromagnetic wave, (b) a transmitter for generating a transmitted electromagnetic wave and engaging the transmitted electromagnetic wave with the track for creating a resulting wave, (c) a receiver for detecting the resulting wave such that the receiver is nulled with respect to the transmitter, the receiver for creating a received signal, and (d) means for evaluating the received signal to determine the characteristics of the track.