Abstract: Methods and apparatus for burst-mode admission control using token buckets are disclosed. A work request (such as a read or a write) directed to a work target is received. Based on a first criterion, a determination is made that the work target is in a burst mode of operation. A token population of a burst-mode token bucket is determined, and if the population meets a second criterion, the work request is accepted for execution.

Abstract: Methods and apparatus for compound token buckets usable for burst-mode admission control are disclosed. A peak burst rate and a sustained burst rate of work requests that are to be supported at a work target are determined. The maximum token populations of a peak-burst token bucket and a sustained-burst token bucket are configured, based on the peak burst rate and the sustained burst rate respectively. In response to receiving a work request directed at the work target, a determination to accept the work request for execution is made based at least in part on the token population of the peak-burst token bucket and/or the sustained-burst token bucket.

Abstract: Methods and apparatus for equitable distribution of excess shared-resource throughput capacity are disclosed. A first and a second work target are configured to access a shared resource to implement accepted work requests. Admission control is managed at the work targets using respective token buckets. A first metric indicative of the work request arrival rates at the work targets during a time interval, and a second metric associated with the provisioned capacities of the work targets are determined. A number of tokens determined based on a throughput limit of the shared resource is distributed among the work targets to be used for admission control during a subsequent time interval. The number of tokens distributed to each work target is based on the first metric and/or the second metric.

Abstract: Methods and apparatus for token-sharing mechanisms for burst-mode operations are disclosed. A first and a second token bucket are respectively configured for admission control at a first and a second work target. A number of tokens to be transferred between the first bucket and the second bucket, as well as the direction of the transfer, are determined, for example based on messages exchanged between the work targets. The token transfer is initiated, and admission control decisions at the work targets are made based on the token population resulting from the transfer.

Abstract: Methods and apparatus for token-based pricing policies for burst-mode operations are disclosed. A pricing policy to be applied to token population changes at a token bucket used for admission control during burst-mode operations at a work target is determined. Over a time period, changes to the token population of that bucket are recorded. A billing amount to be charged to a client is determined, based on the recorded changes in token population and an associated pricing amount indicated in the pricing policy.

Abstract: A database management system may be operated by a third-party provider that hosts the system in a datacenter and provides access to the system to end users on behalf of various entities. Limits on total capacity consumption may be imposed, but may result in service outages when capacity consumption exceeds those limits. Requests to perform operations on the system may be classified. The request classifications may be associated with policies for admitting or rejecting the request. One or more token buckets representative of capacity available to the request to perform the operation may be used to determine to admit the request and updated based on the cost of performing the operation.

Abstract: A security document (1) is provided having a substrate (4) and an integral security device (10) which includes an image layer (12) and a focussing layer (11). each formed from a radiation curable ink layer embossed with relief formations (13; 15). The first radiation curable layer embossed with relief formations (13) to form the image layer (12) is provided on a first surface of the document, and the second radiation curable layer (11) embossed with focussing element relief formations (15) is provided on a second surface of the document. The first and second surfaces are separated by a predetermined distance D to produce a visible optical effect when viewing the image layer (12) through the focussing layer (11). In preferred embodiments, at least one of the first and second radiation curable layers is embossed with diffractive relief structures and high refractive index or reflective coatings may be applied to the embossed relief formations in the image layer (12) and/or the focussing layer (11).

Abstract: A method and apparatus for inspection of a security article (10) is provided in which a substantially collimated light beam (15) from a point light source (14) is directed onto a diffractive optical projection element (DOE) (11). The light beam is transformed by the DOE (11) into a patterned beam (17) which is reconstructed to form a projected image at a particular position in space remote from the surface of the security article 910). An optical detection device 916) is located at which the patterned beam (17) is reconstructed to detect the projected image. The inspection method and apparatus may be used in equipment for handling, sorting, counting or otherwise processing security articles, in particular security documents such as banknotes. The apparatus may include a processor for generating a signal when the absence or poor quality of a DOE is detected and which is used to isolate or mark the security article.

Abstract: A method of protecting a security document from counterfeiting includes applying at least one security element containing a concealed Fourier pattern to the document. The concealed Fourier pattern is produced from a master Fourier profile, and is applied to the document by embossing, engraving, laser ablation or chemical etching, and/or by a cylinder or plate bearing the master Fourier profile. When a counterfeit security document produced without knowledge of the master Fourier profile is scanned or imaged and subjected to a Fourier transform, the resulting test Fourier pattern will differ from a master Fourier pattern corresponding to the master Fourier profile for the authentic security document. In a particular embodiment, the concealed Fourier pattern is applied to the document by rotogravure printing.

Abstract: A method and apparatus for inspection of a security article (10) is provided in which a substantially collimated light beam (15) from a point light source (14) is directed onto a diffractive optical projection element (DOE) (11). The light beam is transformed by the DOE (11) into a patterned beam (17) which is reconstructed to form a projected image at a particular position in space remote from the surface of the security article 910). An optical detection device 916) is located at which the patterned beam (17) is reconstructed to detect the projected image. The inspection method and apparatus may be used in equipment for handling, sorting, counting or otherwise processing security articles, in particular security documents such as banknotes. The apparatus may include a processor for generating a signal when the absence or poor quality of a DOE is detected and which is used to isolate or mark the security article.

Abstract: A method and apparatus for inspection of a security article (10) is provided in which a substantially collimated light beam (15) from a point light source (14) is directed onto a diffractive optical projection element (DOE) (11). The light beam is transformed by the DOE (11) into a patterned beam (17) which is reconstructed to form a projected image at a particular position in space remote from the surface of the security article 910). An optical detection device 916) is located at which the patterned beam (17) is reconstructed to detect the projected image. The inspection method and apparatus may be used in equipment for handling, sorting, counting or otherwise processing security articles, in particular security documents such as banknotes. The apparatus may include a processor for generating a signal when the absence or poor quality of a DOE is detected and which is used to isolate or mark the security article.