What is claimed is:
1. A mine stopping installed in a mine passageway comprises:
a rigid wall extending across the passageway to close the passageway, said wall comprising a first wall section extending from one side of the passageway at a first angle and a second wall section extending from an opposite side of the passageway at an oblique angle relative to the opposite side such that the wall sections are arranged in a non-coplanar, non-parallel relationship with respect to one another.
2. A mine stopping as set forth in claim 1 wherein each of said first and second sections includes at least one elongate extensible panel extending vertically from a floor to a roof of the passageway.
3. A mine stopping as set forth in claim 1 further comprising a door installed in an opening in the wall for swinging between a closed position for inhibiting the passage of air therethrough and an open position moved away from said closed position.
4. A method of installing a stopping in a mine wherein the stopping comprises a plurality of elongate extensible panels adapted to extend from a floor to a roof of a passageway in the mine, each panel comprising a lower panel member adapted for engagement of its lower end with the floor and an upper panel member adapted for engagement of its upper end with the roof, the method comprising:
positioning a first of said extensible panels at a first angle relative to sides of the passageway,
positioning a second of said extensible panels at a second angle relative to sides of the passageway,
forcing the upper end of the upper panel member of said panels into engagement with the roof and the lower end of the lower panel member of said panels into engagement with the floor,
wherein at least one of said first and second angles is oblique with respect to the sides of the passageway.
5. A method as set forth in claim 4 wherein the forcing step includes engaging an end of an extensible member of a jack with the upper end of the upper panel member and extending the extensible member to effect relative telescopic extension of the upper and lower panel members thereby to force the upper end of the upper panel member into pressure engagement with the roof.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for optimizing the transmission of data from a server located on a server computer to a client located on a client computer the method comprising steps for:
a) upon a client request for response data hosted by the server located on a server computer to a client proxy, determining if a prior version of said response data exists in a client proxy cache, if so computing client proxy meta-data from said prior version of said response data to identify said prior version;
b) if at step a) said prior version of said response data does not exist in said client proxy cache, sending a request for said response data to said server proxy;
c) upon computing client proxy meta-data in step a), determining if said prior version of said response data is current by comparing said client proxy meta-data with server proxy meta-data computed from the response data requested, if said prior version of said response data is current, informing said client proxy of this, if not then fetching the current response data from said server, returning current response data and computing new server proxy meta-data from said current response data to identify a current server version;
d) upon receipt of a request from step b), fetching current response data from said server and computing server proxy meta-data from said current response data to identify the current server version;
e) after fetching the current response data in step d), computing said client proxy meta-data from said current response data to identify a current client version; and
f) based on the preceding steps, forwarding said prior version of said response data or said current response data from said client proxy to said client located on the client computer.
2. The method of claim 1, wherein the server is an HTTP server having a URL and the meta-data comprises meta-data other than the last-modified timedate andor the expiration timedate as specified in the response data fetched previously from the HTTP server for the same URL.
3. The method of claim 2, wherein said client proxy meta-data and said server proxy meta-data comprise at least a hash value.
4. The method of claim 1, wherein the client proxy and the server proxy store meta-data indexed or keyed to a requested URL.
5. The method of claim 1, wherein the response data is indicated as uncacheable.
6. The method of claim 5, wherein the response data is indicated as uncacheable by HTTP headers selected from the group of \u201cCache-Control: private\u201d and \u201cCache-Control: no-cache\u201d.
7. A method for ascertaining the validity of cached response data on a HTTP client located on a computer for a given URL, the method comprising steps for:
a) receiving at a client proxy, a client request for response data hosted by an HTTP server located on a server computer;
b) determining if a client proxy version of the response data exists in a client proxy cache;
c) sending a request comprising client proxy meta-data computed from the client proxy version of the response data to a server proxy if it is determined in step b) that the client proxy version of the response data exists in the client proxy cache;
d) sending a request to the server proxy for the response data if it is determined at step b) that the client proxy version of the response data does not exist in the client proxy cache;
e) if a server proxy version of the requested response data is not found, receiving current response data retrieved from the HTTP server at the server proxy and computing server proxy meta-data from the retrieved current response data;
f) receiving a notification from a processor that the client proxy version of the response data is current when a comparison is made, by the processor, of the client proxy meta-data and the server proxy meta-data, computed from the server proxy version of the response data, and the processor determines that the client proxy version of the response data is current, otherwise, receiving the retrieved current response data from the server proxy at the client proxy;
g) computing client proxy meta-data from the received current response data independently of the server proxy meta-data; and
h) forwarding the prior version of the data or the retrieved current response data from the client proxy to the client located on the client computer.
8. The method of claim 7, wherein the meta-data is other than last-modified timedate andor expiration timedate as specified in the response data fetched previously from the HTTP server for the same URL.
9. The method of claim 8, wherein the client proxy meta-data and the server proxy meta-data comprise at least a hash value.