Abstract: Techniques and structures for tuning database queries. Actual statistics associated with data stored are retrieved from at least one memory device. The data is associated with one or more tenants of the multi-tenant database system. The actual statistics include at least one type of statistic maintained for the data. A subset of the actual statistics is selected based on a data trait targeted for optimization. A statistical value is calculated for each actual statistic from the subset of actual statistics across one or more tenants having the data trait targeted for optimization. An optimal query plan is determined based on the original query and the calculated statistical values.

Abstract: Techniques and structures for tuning database queries. Actual statistics associated with data stored are retrieved from at least one memory device. The data is associated with one or more tenants of the multi-tenant database system. The actual statistics include at least one type of statistic maintained for the data. A subset of the actual statistics is selected based on a data trait targeted for optimization. A statistical value is calculated for each actual statistic from the subset of actual statistics across one or more tenants having the data trait targeted for optimization. An optimal query plan is determined based on the original query and the calculated statistical values.

Abstract: In accordance with embodiments, there are provided methods and systems for providing multiple column custom indexes in a multi-tenant database environment. A method embodiment provides defining a multi-tenant data structure having a plurality of data columns data fields and a plurality of rows for each of multiple tenants, each row including a data column for a tenant identifier, defining a first data field for a tenant, the first data field having a first data type, defining a second data field for the tenant, the second field having a second data type, and defining an index table including a tenant identifier for the tenant, a copy of data from the first data field and the second data field, and a key to the corresponding rows of the multi-tenant data structure.

Abstract: Disclosed are methods and systems for adjusting a High Voltage Direct Current (HVDC) compensator output signal to an HVDC system to reduce control loop modulus due to excessive time delay of sensor measurements. Two different time windows, a Short-Time Variance Window (STVW) and an Extended-Time Variance Window (ETVW) may be examined for detection of increased energy. To detect increased energy the HVDC compensator output signal may be passed through a bandpass filter, then variances for the STVW and ETVW may be generated to produce corresponding test statistics. The STVW and ETVW test statistics may be compared to hypothesis test thresholds and have binary logic based on the hypothesis test comparisons used to generate a gain. The gain may then be multiplied times the original HVDC feedback compensator output such that the adjusted HVDC feedback compensator output reduces the control loop modulus when applied to the HVDC system.

Abstract: Disclosed are methods and systems for adjusting a High Voltage Direct Current (HVDC) compensator output signal to an HVDC system to reduce control loop modulus due to excessive time delay of sensor measurements. Two different time windows, a Short-Time Variance Window (STVW) and an Extended-Time Variance Window (ETVW) may be examined for detection of increased energy. To detect increased energy the HVDC compensator output signal may be passed through a bandpass filter, then variances for the STVW and ETVW may be generated to produce corresponding test statistics. The STVW and ETVW test statistics may be compared to hypothesis test thresholds and have binary logic based on the hypothesis test comparisons used to generate a gain. The gain may then be multiplied times the original HVDC feedback compensator output such that the adjusted HVDC feedback compensator output reduces the control loop modulus when applied to the HVDC system.

Abstract: Techniques and structures for tuning database queries. Actual statistics associated with data stored are retrieved from at least one memory device. The data is associated with one or more tenants of the multi-tenant database system. The actual statistics include at least one type of statistic maintained for the data. A subset of the actual statistics is selected based on a data trait targeted for optimization. A statistical value is calculated for each actual statistic from the subset of actual statistics across one or more tenants having the data trait targeted for optimization. An optimal query plan is determined based on the original query and the calculated statistical values.

Abstract: In some embodiments, a computer-implemented method for tuning queries for a multi-tenant database system is provided. A processor retrieves actual statistics associated with data stored on one or more servers in the multi-tenant database system. The data may be associated with one or more tenants of the multi-tenant database system. A subset of the actual statistics is selected, wherein the subset of the actual statistics is related to tenants having a data trait targeted for optimization. The processor determines synthetic statistics based on the subset of the actual statistics. An original query is received at the multi-tenant database system, wherein the original query operates upon data associated with a tenant that has the data trait targeted for optimization. The processor determines an optimal query plan based on the original query and synthetic statistics. Finally, the processor executes the original query based on the optimal query plan.

Abstract: A two degree-of-freedom parallel device for orienting or pointing an end effector with vibration suppression is described. The two end effector degrees-of-freedom are decoupled by connecting fast actuators to the effector by passive joints. The stiffness of the linkages and the high speed of the revolute and prismatic actuators employed permit the application of large feedback useful for disturbance rejection.

Abstract: A method for rudder roll stabilization having two-feedback-path nonlinear dynamic compensation (NDC) is described. The high-order, Nyquist-stable control system having NDC hereof is absolutely stable and will provide a 20%-40% improvement in performance over existing roll reduction designs when lower performance steering mechanisms are employed, and is superior to linear controllers. That is, the present invention will be effective rudder roll stabilization in commercial vessels having slower rudders as well as in vessels having steering machines representing the best performance currently available, such as military systems. Since no ship hardware modifications are required, the present roll control technology will be able to be economically implemented.

Abstract: A two degree-of-freedom parallel device for orienting or pointing an end effector with vibration suppression is described. The two end effector degrees-of-freedom are decoupled by connecting fast actuators to the effector by passive joints. The stiffness of the linkages and the high speed of the revolute and prismatic actuators employed permit the application of large feedback useful for disturbance rejection.

Abstract: In some embodiments, a computer-implemented method for tuning queries for a multi-tenant database system is provided. A processor retrieves actual statistics associated with data stored on one or more servers in the multi-tenant database system. The data may be associated with one or more tenants of the multi-tenant database system. A subset of the actual statistics is selected, wherein the subset of the actual statistics is related to tenants having a data trait targeted for optimization. The processor determines synthetic statistics based on the subset of the actual statistics. An original query is received at the multi-tenant database system, wherein the original query operates upon data associated with a tenant that has the data trait targeted for optimization. The processor determines an optimal query plan based on the original query and synthetic statistics. Finally, the processor executes the original query based on the optimal query plan.

Abstract: In accordance with embodiments, there are provided methods and systems for providing multiple column custom indexes in a multi-tenant database environment. A method embodiment provides defining a multi-tenant data structure having a plurality of data columns data fields and a plurality of rows for each of multiple tenants, each row including a data column for a tenant identifier, defining a first data field for a tenant, the first data field having a first data type, defining a second data field for the tenant, the second field having a second data type, and defining an index table including a tenant identifier for the tenant, a copy of data from the first data field and the second data field, and a key to the corresponding rows of the multi-tenant data structure.

Abstract: In accordance with embodiments, there are provided mechanisms and methods for validating queries. These mechanisms and methods for validating queries can enable embodiments to provide more reliable and faster execution of queries both in development and in production. In an embodiment and by way of example, a method for validating queries is provided. The method embodiment includes capturing a query that is directed to a multi-tenant database. A plan is determined by which the query will be applied to the database. The plan is statically analyzed for performance. Then a performance measure is applied to the query.

Abstract: The assembly includes a pair of heat exchangers, each including an upper and lower manifold, parallel and spaced relative to one another. Tubes extend between each set of upper and lower manifolds with fins disposed between each of the tubes. A valve system controls fluid flow between the upper manifolds and the lower manifolds. The valve system is movable between a maximum cooling mode with fluid flow form the first upper manifold through both of the tubes and to said first lower manifold. A temperate mode allows fluid to flow from the first upper manifold to the first lower manifold and from the second upper manifold to the second lower manifold to prevent flash fogging. A maximum cooling mode allows fluid to flow from the second upper manifold through both of the first and second tubes to the lower manifolds.

Abstract: A fuel cell assembly for using hydrogen gas and oxygen to produce electrical energy. The cathode of the fuel cell produces water vapor to define a flow of moist air including water vapor. A dehumidifier receives the flow of moist air including water vapor to produce purified liquid water and a flow of dehumidified air. The dehumidifier has an air inlet having a first cross-sectional area and an air outlet having a larger second cross-sectional area. The diffuser cavity of the dehumidifier progressively increases in size from the air inlet to the air outlet for depressurizing and cooling the flow of moist air including water vapor below the dew point of the moist air including water vapor to condense the water vapor on the housing of the dehumidifier.

Abstract: An SOFC stack module including an integral individual stack manifold containing all of the gas pathways necessary for supply and exhaust of fuel gas and cathode air to and from the stack chimneys. The stack is mounted and hermetically joined directly to the manifold without an intermediate base plate. Flanges at the inlet and outlet ports couple to system distributary manifolds via high temperature sealing joints. The manifold preferably is fabricated of a ferritic stainless steel, and may be formed in a one-piece casting, a combination of multiple castings and stamped plates metallurgically joined (brazed or welded together), or stamped from sheet metal stock. Preferably, the manifold includes fin structures extending into adjacent fuel gas and cathode air chambers to enhance balancing of temperatures by heat exchange therebetween. Heat exchange may be further improved by configuring the manifold to have a plurality of interleaved anode and cathode gas supply chambers.

Abstract: A method for rudder roll stabilization having two-feedback-path nonlinear dynamic compensation (NDC) is described. The high-order, Nyquist-stable control system having NDC hereof is absolutely stable and will provide a 20%-40% improvement in performance over existing roll reduction designs when lower performance steering mechanisms are employed, and is superior to linear controllers. That is, the present invention will be effective rudder roll stabilization in commercial vessels having slower rudders as well as in vessels having steering machines representing the best performance currently available, such as military systems. Since no ship hardware modifications are required, the present roll control technology will be able to be economically implemented.

Abstract: This document provides methods and materials related to rapid, quantitative determination of TPMT activity in biological samples. Also featured are compositions and kits useful for determination of TPMT activity in biological samples.

Abstract: The assembly includes a pair of heat exchangers, each including an upper and lower manifold, parallel and spaced relative to one another. Tubes extend between each set of upper and lower manifolds with fins disposed between each of the tubes. A valve system controls fluid flow between the upper manifolds and the lower manifolds. The valve system is movable between a maximum cooling mode with fluid flow form the first upper manifold through both of the tubes and to said first lower manifold. A temperate mode allows fluid to flow from the first upper manifold to the first lower manifold and from the second upper manifold to the second lower manifold to prevent flash fogging. A maximum cooling mode allows fluid to flow from the second upper manifold through both of the first and second tubes to the lower manifolds.

Abstract: A housing rotatably supports a desiccant wheel, Ambient air passes through one part of the housing and hot exhaust air passes through the other part. As the wheel rotates, it absorbs moisture from the ambient air in part of the housing and desorbs moisture into the exhaust air in the other part. A fuel cell system supplies the hot exhaust air directly to the desiccant wheel, The dry ambient air is directed to an evaporative cooler and divided between dry channels and wet channels, The air passing through the dry channels cools to be directed to a conditioned space. The air passing through the wet channels evaporates water in the channels facilitating heat transfer and adding moisture to that air. The air from the wet channels is optionally added back into the air from the dry channels to provide appropriate humidity.