683 results about "Self-tuning" patented technology

An adaptive replacement cache policy dynamically maintains two lists of pages, a recency list and a frequency list, in addition to a cache directory. The policy keeps these two lists to roughly the same size, the cache size c. Together, the two lists remember twice the number of pages that would fit in the cache. At any time, the policy selects a variable number of the most recent pages to exclude from the two lists. The policy adaptively decides in response to an evolving workload how many top pages from each list to maintain in the cache at any given time. It achieves such online, on-the-fly adaptation by using a learning rule that allows the policy to track a workload quickly and effectively. This allows the policy to balance between recency and frequency in an online and self-tuning fashion, in response to evolving and possibly changing access patterns. The policy is also scan-resistant. It allows one-time-only sequential read requests to pass through the cache without flushing pages that have temporal locality. The policy is extremely simple to implement and requires only constant-time overhead per request. The policy has negligible space overhead.

A proactive, resilient and self-tuning memory management system and method that result in actual and perceived performance improvements in memory management, by loading and maintaining data that is likely to be needed into memory, before the data is actually needed. The system includes mechanisms directed towards historical memory usage monitoring, memory usage analysis, refreshing memory with highly-valued (e.g., highly utilized) pages, I / O pre-fetching efficiency, and aggressive disk management. Based on the memory usage information, pages are prioritized with relative values, and mechanisms work to pre-fetch and / or maintain the more valuable pages in memory. Pages are pre-fetched and maintained in a prioritized standby page set that includes a number of subsets, by which more valuable pages remain in memory over less valuable pages. Valuable data that is paged out may be automatically brought back, in a resilient manner. Benefits include significantly reducing or even eliminating disk I / O due to memory page faults.

A self-tuning resonator for use in a transmitter apparatus for inducing alternating currents in a buried conductor. The resonator is dynamically tuned at frequencies below 500 kHz by exploiting the inherent voltage-variability of net capacitance in multilayer ceramic capacitors. The transmitter apparatus provides improved efficiency and induced output power suitable for use in a man-portable locator system, providing a very high magnetic field output from a physically small battery-powered resonator at frequencies under 500 kHz. The resonator exhibits a very low equivalent series resistance (ESR) and is adaptively returned to a predetermined resonant frequency responsive to any changes in resonance arising from phenomena such as component heating, thereby supporting very high tank circuit currents from battery-powered source to produce very high magnetic flux output.

Embodiments of the present invention concern a multiphase switch-mode power supply. The multiple phase switch-mode power supply can have at least one switch and a digital controller to control the switching of the at least one switch. During a calibration period, the digital controller can freeze the current of all of the multiple phases except for a phase being calibrated. This can be done by fixing the current reference of the phases except for the phase being calibrated.

An automatic tuning system for a stringed instrument is provided having a string adjustment assembly comprising a motor and gear assembly, wherein the motor and gear assembly is pivotable on a housing for the tuning system. The system can also include a vibrato arm in contact with the motor and gear assembly, and a vibrato return spring in contact with both the motor and gear assembly and the instrument, which is capable of reversibly changing the position of a string contact surface in the string adjustment assembly with respect to the string, thereby lowering the pitch of the string and then raising it to its original pitch. The system can also include an option board for wireless communication with remote components such as a remote footswitch or other type of control panel. Other remote devices may also be wirelessly connected to the tuning system, including other instruments, audio devices for receiving sound, and the like. The system comprises a processor that can be preprogrammed with generic instructions for motor movement to achieve specific pitch changes and can also be programmed to store the motor instructions required to achieve specific pitch changes each time the system performs an automatic tuning correction, and to utilize these instructions the next time the system is tuned. The system is capable of performing fine tuning corrections as well as of prompting a user to perform coarse-tuning corrections. It also allows a user to change tunings while playing.

A system and method for accessing a relational database and estimating the selectivity of a query (e.g., an SQL query) in order to better predict the number of qualifying records for simple and complex queries. A dataset is created based upon queries applied against the database by the user community. The dataset is populated with information related to query conditions and their respective combinations. A regression function reflecting correlations between query conditions is generated and used as a data mining model to calculate table-specific estimates for the cardinality of subsequent queries. An appropriate access method is then selected from a set of available access methods based upon the number of estimated query-qualifying records. By periodically updating the regression model with FIFO managed queries, a self-tuning mechanism is achieved resulting in better selectivity / result size estimates for use in selecting access methods used in compiling subsequent SQL queries applied against the database.