Abstract: Blockchain technology is used to provide security of electronic systems. The disclosed technology allows for a dynamic bond of trust to be applied to the field of information security without the need for a single point of trust to first be established. The lines of trust between electronic systems or devices is established by distributing information among the systems or devices. This allows for easy identification of commonalities and/or decision making whereby policy(s)/action(s)/monitoring/etc. can be enforced when those commonalities align. Simultaneously, deviations from those commonalities can be identified and policy(s)/action(s)/monitoring/etc. may also be invoked. The use of blockchain technology enables investigative and responsive actions to detect and exploit a potential attacker on a network.

Abstract: Direct Image Lookup (DIL) metadata is used to perform differential operation for snapshots and linked targets. Each snapshot contains metadata to store “images” to perform direct lookup of user data for any part of any snapshot in the system. Metadata pages of DIL image data represent sets of tracks of data. Metadata pages of subsequent snapshots for the same sets of tracks are compared, and where there are no changes to a given metadata page for a given set of tracks between subsequent snapshot copies, the differential process is not run on the tracks associated with the metadata page. If a given metadata page associated with a set of tracks has changed between subsequent snapshots, the differential process is used to identify which tracks in the subsequent snapshot contain different data than the corresponding tracks of the previous snapshot. Similar differential processing also is implemented for relinked target devices.

Abstract: Memory management processes allocate and recycle pages of replication data pointer (RDP) metadata space in shared memory. When the RDP page currently allocated to an IO thread becomes full, that RDP page is released, and a new RDP page is allocated to the IO thread. The released page eventually becomes fragmented and is added to a list of RDP pages that are ranked based on partial fullness. An IO thread that needs a new RDP page is allocated a mostly empty RDP page from the ranked list, if such a page is available. Otherwise, a new completely empty RDP page is allocated to the IO thread. Use of the ranked lists reduces latency associated with allocation of new RDP pages. Contention between IO threads for RDP metadata space is reduced because each IO thread has exclusive rights to the free RDP metadata space in its currently allocated page.

Abstract: Systems and method of calibrating a range measurement system for a vehicle mounted on a guideway are disclosed. In some embodiments, a method includes: measuring a first time of transmission (TOT) between a first internal component of an on-board range measurement device and a second internal component of a wayside range measurement device. The first TOT is compared with a first pre-determined time. A health of the range measurement system is determined based on a difference between the first TOT and the first pre-determined time.

Abstract: Memory management processes allocate and recycle pages of replication data pointer (RDP) metadata space in shared memory. When the RDP page currently allocated to an IO thread becomes full, that RDP page is released, and a new RDP page is allocated to the IO thread. The released page eventually becomes fragmented and is added to a list of RDP pages that are ranked based on partial fullness. An IO thread that needs a new RDP page is allocated a mostly empty RDP page from the ranked list, if such a page is available. Otherwise, a new completely empty RDP page is allocated to the IO thread. Use of the ranked lists reduces latency associated with allocation of new RDP pages. Contention between IO threads for RDP metadata space is reduced because each IO thread has exclusive rights to the free RDP metadata space in its currently allocated page.

Abstract: Systems and methods of calibrating an Inertial Measurement Unit (IMU) on a vehicle are disclosed. In some embodiments, a first tilt angle of the IMU is measured with the IMU while the vehicle is stationary. A second tilt angle of the IMU is measured with an inclinometer or tilt sensor while the vehicle is stationary. The orientation of the IMU is corrected based on the first tilt angle and the second tilt angle.

Abstract: Nodes of the cluster receive workload tasks and use a striping algorithm to determine which node in the cluster should process the workload tasks. Workload task allocation within the cluster is dependent on the cluster membership at the time the striping algorithm is implemented. If a node leaves the cluster, the cluster membership is updated, and the striping algorithm is used to reallocate workload tasks assigned to the leaving node to other nodes within the cluster. If a node joins the cluster, cluster membership is updated, and any workload tasks previously assigned to the cluster nodes are allowed to complete before the joining node is able to begin working on workload tasks. Cluster membership changes are updated in a shared global memory, and locally synchronized in connection with particular events, to implement the distributed cluster join management process.

Abstract: Direct Image Lookup (DIL) metadata is used to perform differential operation for snapshots and linked targets. Each snapshot contains metadata to store “images” to perform direct lookup of user data for any part of any snapshot in the system. Metadata pages of DIL image data represent sets of tracks of data. Metadata pages of subsequent snapshots for the same sets of tracks are compared, and where there are no changes to a given metadata page for a given set of tracks between subsequent snapshot copies, the differential process is not run on the tracks associated with the metadata page. If a given metadata page associated with a set of tracks has changed between subsequent snapshots, the differential process is used to identify which tracks in the subsequent snapshot contain different data than the corresponding tracks of the previous snapshot. Similar differential processing also is implemented for relinked target devices.

Abstract: A method for determining rail vehicle location and identifying obstacles, which includes operations of transmitting, from at least two vehicle beacons on a first vehicle, a ranging signal to at least two external beacons; receiving, at the at least two vehicle beacons, a return signal from the at least two external beacons; and determining, based on the return signal from the at least two external beacons, a position of each of the external beacons with respect to the at least two vehicle beacons of the first vehicle.

Abstract: Systems and methods of calibrating an Inertial Measurement Unit (IMU) on a vehicle are disclosed. In some embodiments, a first tilt angle of the IMU is measured with the IMU while the vehicle is stationary. A second tilt angle of the IMU is measured with an inclinometer or tilt sensor while the vehicle is stationary. The orientation of the IMU is corrected based on the first tilt angle and the second tilt angle.

Abstract: Systems and method of calibrating a range measurement system for a vehicle mounted on a guideway are disclosed. In some embodiments, a method includes: measuring a first time of transmission (TOT) between a first internal component of an on-board range measurement device and a second internal component of a wayside range measurement device. The first TOT is compared with a first pre-determined time. A health of the range measurement system is determined based on a difference between the first TOT and the first pre-determined time.

Abstract: Blockchain technology is used to provide security of electronic systems. The disclosed technology allows for a dynamic bond of trust to be applied to the field of information security without the need for a single point of trust to first be established. The lines of trust between electronic systems or devices is established by distributing information among the systems or devices. This allows for easy identification of commonalities and/or decision making whereby policy(s)/action(s)/monitoring/etc. can be enforced when those commonalities align. Simultaneously, deviations from those commonalities can be identified and policy(s)/action(s)/monitoring/etc. may also be invoked. The use of blockchain technology enables investigative and responsive actions to detect and exploit a potential attacker on a network.

Abstract: Techniques for obtaining metadata may include: receiving, by a director, an I/O operation directed to a target offset of a logical device, wherein the director is located on a board including a local page table used by components on the board; querying the local page table for a global memory address of first metadata for the target offset of the logical device; and responsive to the local page table not having the global memory address of the first metadata for the target offset of the logical device, using at least a first indirection layer to obtain the global memory address of the first metadata. The global memory may be a distributed global memory including memory segments from multiple different boards each including its own local page table. Compare and swap operations may be used to perform atomic operations to ensure synchronized access when updating the distributed global memory.

Abstract: Sector signature patterns with sector signature values and sector signature parity values are embedded with data slices. A new pattern is embedded with a slice each time the slice data is updated. The patterns are selected in order such that every sector signature value and sector signature parity value changes when a new pattern is embedded. A separate metadata record such as a key is maintained to indicate which pattern has been embedded with the slice. A data integrity check is performed by comparing the embedded sector signature parity values with the metadata record and/or performing a pattern-to-key lookup.

Abstract: Blockchain technology is used to provide security of electronic systems. The disclosed technology allows for a dynamic bond of trust to be applied to the field of information security without the need for a single point of trust to first be established. The lines of trust between electronic systems or devices is established by distributing information among the systems or devices. This allows for easy identification of commonalities and/or decision making whereby policy(s)/action(s)/monitoring/etc. can be enforced when those commonalities align. Simultaneously, deviations from those commonalities can be identified and policy(s)/action(s)/monitoring/etc. may also be invoked.

Abstract: Sector signature patterns with sector signature values and sector signature parity values are embedded with data slices. A new pattern is embedded with a slice each time the slice data is updated. The patterns are selected in order such that every sector signature value and sector signature parity value changes when a new pattern is embedded. A separate metadata record such as a key is maintained to indicate which pattern has been embedded with the slice. A data integrity check is performed by comparing the embedded sector signature parity values with the metadata record and/or performing a pattern-to-key lookup.

Abstract: A method for determining rail vehicle location and identifying obstacles, which includes operations of transmitting, from at least two vehicle beacons on a first vehicle, a ranging signal to at least two external beacons; receiving, at the at least two vehicle beacons, a return signal from the at least two external beacons; and determining, based on the return signal from the at least two external beacons, a position of each of the external beacons with respect to the at least two vehicle beacons of the first vehicle.

Abstract: Techniques for obtaining metadata may include: receiving, by a director, an I/O operation directed to a target offset of a logical device, wherein the director is located on a board including a local page table used by components on the board; querying the local page table for a global memory address of first metadata for the target offset of the logical device; and responsive to the local page table not having the global memory address of the first metadata for the target offset of the logical device, using at least a first indirection layer to obtain the global memory address of the first metadata. The global memory may be a distributed global memory including memory segments from multiple different boards each including its own local page table. Compare and swap operations may be used to perform atomic operations to ensure synchronized access when updating the distributed global memory.

Abstract: Techniques for obtaining metadata may include: receiving, by a director, an I/O operation directed to a target offset of a logical device, wherein the director is located on a board including a local page table used by components on the board; querying the local page table for a global memory address of first metadata for the target offset of the logical device; and responsive to the local page table not having the global memory address of the first metadata for the target offset of the logical device, using at least a first indirection layer to obtain the global memory address of the first metadata. The global memory may be a distributed global memory including memory segments from multiple different boards each including its own local page table. Compare and swap operations may be used to perform atomic operations to ensure synchronized access when updating the distributed global memory.

Abstract: Blockchain technology is used to provide security of electronic systems. The disclosed technology allows for a dynamic bond of trust to be applied to the field of information security without the need for a single point of trust to first be established. The lines of trust between electronic systems or devices is established by distributing information among the systems or devices. This allows for easy identification of commonalities and/or decision making whereby policy(s)/action(s)/monitoring/etc. can be enforced when those commonalities align. Simultaneously, deviations from those commonalities can be identified and policy(s)/action(s)/monitoring/etc. may also be invoked.