Abstract: A method for forming a sealed floating roof for a storage tank is disclosed. A plurality of roof panels are positioned adjacent to one another such that respective depressions of adjacent roof panels disposed adjacent to one another form a walled trough at interconnections of the plurality of roof panels. A self-propelled automatic welder is positioned and guided within the walled trough to make a weld joint at the walled trough, and thus forming the sealed floating roof.

Abstract: A sealed floating roof for a storage tank, comprising a frame and roof panels, in which the frame provides a guide for directing an automatic welder along said structure to allow for automated welding of the roof panels to the frame, and a method of forming such a roof.

Abstract: A sealed floating roof for a storage tank, comprising a frame and roof panels, in which the frame provides a guide for directing an automatic welder along said structure to allow for automated welding of the roof panels to the frame, and a method of forming such a roof.

Abstract: A sealed floating roof for a storage tank, comprising a frame and roof panels, in which the frame provides a guide for directing an automatic welder along said structure to allow for automated welding of the roof panels to the frame, and a method of forming such a roof.

Abstract: An apparatus and method for making fractional assignments of processing elements to processing nodes for stream-based applications in a distributed computer system includes determining an amount of processing power to give to each processing element. Based on a list of acceptable processing nodes, a determination of fractions of which processing nodes will work on each processing element is made. To update allocations of the amount of processing power and the fractions, the process is repeated.

Abstract: A method of choosing jobs to run in a stream based distributed computer system includes determining jobs to be run in a distributed stream-oriented system by deciding a priority threshold above which jobs will be accepted, below which jobs will be rejected. Overall importance is maximized relative to the priority threshold based on importance values assigned to all jobs. System constraints are applied to ensure jobs meet set criteria.

Abstract: A method for measuring performance of system. The method includes the steps of retrieving a metric definition from a declarative metrics specification, obtaining a list of computing nodes from a database that are currently assigned to the metric definition, obtaining resource data provided by the computing nodes in the list of computing nodes and determining the metric of system performance based on the metric definition and the resource data. The computing nodes in the list of computing nodes are nodes of a cluster of nodes having a dynamically varying node count.

Abstract: A method of choosing jobs to run in a stream based distributed computer system includes determining jobs to be run in a distributed stream-oriented system by deciding a priority threshold above which jobs will be accepted, below which jobs will be rejected. Overall importance is maximized relative to the priority threshold based on importance values assigned to all jobs. System constraints are applied to ensure jobs meet set criteria.

Abstract: A method of choosing jobs to run in a stream based distributed computer system includes determining jobs to be run in a distributed stream-oriented system by deciding a priority threshold above which jobs will be accepted, below which jobs will be rejected. Overall importance is maximized relative to the priority threshold based on importance values assigned to all jobs. System constraints are applied to ensure jobs meet set criteria.

Abstract: An apparatus and method for making fractional assignments of processing elements to processing nodes for stream-based applications in a distributed computer system includes determining an amount of processing power to give to each processing element. Based on a list of acceptable processing nodes, a determination of fractions of which processing nodes will work on each processing element is made. To update allocations of the amount of processing power and the fractions, the process is repeated.

Abstract: An apparatus and method for scheduling stream-based applications in a distributed computer system includes a scheduler configured to schedule work using three temporal levels. Each temporal level includes a method. A macro method is configured to schedule jobs that will run, in a highest temporal level, in accordance with a plurality of operation constraints to optimize importance of work. A micro method is configured to fractionally allocate, at a medium temporal level, processing elements to processing nodes in the system to react to changing importance of the work. A nano method is configured to revise, at a lowest temporal level, fractional allocations on a continual basis.

Abstract: In a system having a plurality of caches, a method for maintaining cached objects includes storing an object in a plurality of caches. In response to a request to update the object, a future invalidation time is determined when the object should be invalidated in caches currently storing the object. Updating of the object is delayed until the invalidation time has passed.

Abstract: A method of choosing jobs to run in a stream based distributed computer system includes determining jobs to be run in a distributed stream-oriented system by deciding a priority threshold above which jobs will be accepted, below which jobs will be rejected. Overall importance is maximized relative to the priority threshold based on importance values assigned to all jobs. System constraints are applied to ensure jobs meet set criteria.

Abstract: An apparatus and method for making fractional assignments of processing elements to processing nodes for stream-based applications in a distributed computer system includes determining an amount of processing power to give to each processing element. Based on a list of acceptable processing nodes, a determination of fractions of which processing nodes will work on each processing element is made. To update allocations of the amount of processing power and the fractions, the process is repeated.

Abstract: A system and method for maintaining consistency in a system where multiple copies of an object may exist is provided for maintaining consistent copies. Consistency is maintained using a plurality of consistency policies in which at least one consistency policy results in different performance than a second consistency policy. A consistency policy is selected from the plurality consistency policies for each object to improve system performance.

Abstract: A method of choosing jobs to run in a stream based distributed computer system includes determining jobs to be run in a distributed stream-oriented system by deciding a priority threshold above which jobs will be accepted, below which jobs will be rejected. Overall importance is maximized relative to the priority threshold based on importance values assigned to all jobs. System constraints are applied to ensure jobs meet set criteria.

Abstract: A method for measuring performance of system. The method includes the steps of retrieving a metric definition from a declarative metrics specification, obtaining a list of computing nodes from a database that are currently assigned to the metric definition, obtaining resource data provided by the computing nodes in the list of computing nodes and determining the metric of system performance based on the metric definition and the resource data. The computing nodes in the list of computing nodes are nodes of a cluster of nodes having a dynamically varying node count.

Abstract: A system and method for maintaining consistency in a system where multiple copies of an object may exist is provided for maintaining consistent copies. Consistency is maintained using a plurality of consistency policies in which at least one consistency policy results in different performance than a second consistency policy. A consistency policy is selected from the plurality consistency policies for each object to improve system performance.

Abstract: In a system having a plurality of caches, a method for maintaining cached objects includes storing an object in a plurality of caches. In response to a request to update the object, a future invalidation time is determined when the object should be invalidated in caches currently storing the object. Updating of the object is delayed until the invalidation time has passed.

Abstract: A device and method of making a full contact floating roof for use in covering fluid bodies, such as storage tanks containing hydrocarbon fluids, allowing ease of construction, high integrity, and low maintenance cost.