Abstract: Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log.

Abstract: Systems and methods for tracking changes and performing backups to a storage device are provided. For virtual disks of a virtual machine, changes are tracked from outside the virtual machine in the kernel of a virtualization layer. The changes can be tracked in a lightweight fashion with a bitmap, with a finer granularity stored and tracked at intermittent intervals in persistent storage. Multiple backup applications can be allowed to accurately and efficiently backup a storage device. Each backup application can determine which block of the storage device has been updated since the last backup of a respective application. This change log is efficiently stored as a counter value for each block, where the counter is incremented when a backup is performed. The change log can be maintained with little impact on I/O by using a coarse bitmap to update the finer grained change log.

Abstract: A method for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first vertical pathway. The optical fiber may then be routed through at least one fluid bearing thereby redirecting the optical fiber along a second vertical pathway. Thereafter, a thermoplastic coating may be applied to the optical fiber with a thermoplastic coating system. The optical fiber may then be wound onto a fiber storage spool with a fiber take-up system. The fiber take-up system may be space apart from the thermoplastic coating system such that the thermoplastic coating may be cooled before the optical fiber is wound onto the fiber storage spool.

Abstract: Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log.

Abstract: Methods for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first pathway and redirecting the optical fiber along a second, different pathway which is non-parallel with the first pathway. The optical fiber may be coated as it travels along the second pathway.

Abstract: A system for measuring fitness for duty which includes a) a visual stimulus display b) eye monitoring equipment for measuring eye and eyelid movements c) a central processing unit and data storage device to collect and store the data from the eye monitoring equipment d) a data analysis device programmed to calculate one or more of the measures of blink latency, measures of the relative velocity of upper eyelid closing and opening movements during blinks, the product of the amplitude to velocity ratio of eyelid closing and opening, the duration of blinks, the variability of eyelid movements during blinks, the failure to respond appropriately with a voluntary blink following each said brief visual stimulus e) said data analysis device programmed to place the values for said measures into an algorithm for measuring fitness for duty.

Abstract: Systems and methods for tracking changes and performing backups to a storage device are provided. For virtual disks of a virtual machine, changes are tracked from outside the virtual machine in the kernel of a virtualization layer. The changes can be tracked in a lightweight fashion with a bitmap, with a finer granularity stored and tracked at intermittent intervals in persistent storage. Multiple backup applications can be allowed to accurately and efficiently backup a storage device. Each backup application can determine which block of the storage device has been updated since the last backup of a respective application. This change log is efficiently stored as a counter value for each block, where the counter is incremented when a backup is performed. The change log can be maintained with little impact on I/O by using a coarse bitmap to update the finer grained change log.

Abstract: Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber in a treatment zone wherein the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Methods for producing optical fibers along nonlinear paths incorporating fluid bearings are also provided thereby allowing for increased vertical space for the fiber treatment zone.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a controlled reduced pressure or partial vacuum in the range of 0.01 to 0.8 atm. The treatment device cools the bare optical fiber as it cools to a temperature range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide linear centering of the optical fiber as it exits the treatment device.

Abstract: A method for producing an optical fiber that includes a method for producing an optical fiber, said method comprising: (i) drawing a bare optical fiber from a preform along a first pathway at a rate of at least 10 m/sec; (ii) contacting said bare optical fiber with a region of fluid in a fluid bearing and redirecting said bare optical fiber along a second pathway as said bare optical fiber is drawn across said region of fluid cushion; (iii) coating the bare optical fiber; and (iv) irradiating said coated fiber in at least one irradiation zone to at least partially cure said coating, while subjecting the optical fiber to UV light.

Abstract: A fault-tolerant virtualized computer system comprises a primary host executing a primary virtual machine (VM) and a backup host executing a backup VM. In one embodiment, each VM includes a virtual disk mapped to a shared disk image on physical disk accessible to both hosts. A virtual disk IO request is received by virtualization software executing on the backup host from a backup VM. When the virtual disk IO request is a read request, the virtual disk IO request is mapped to a physical read IO request of a virtual disk image stored on a physical disk, the physical read IO request is issued to the physical disk. However, when the virtual disk IO request is a write request, it is assumed to be completed without mapping the virtual disk IO request or issuing a mapped physical IO request to the physical disk.

Abstract: Systems and methods for tracking changes and performing backups to a storage device are provided. For virtual disks of a virtual machine, changes are tracked from outside the virtual machine in the kernel of a virtualization layer. The changes can be tracked in a lightweight fashion with a bitmap, with a finer granularity stored and tracked at intermittent intervals in persistent storage. Multiple backup applications can be allowed to accurately and efficiently backup a storage device. Each backup application can determine which block of the storage device has been updated since the last backup of a respective application. This change log is efficiently stored as a counter value for each block, where the counter is incremented when a backup is performed. The change log can be maintained with little impact on I/O by using a coarse bitmap to update the finer grained change log.

Abstract: A method for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first vertical pathway. The optical fiber may then be routed through at least one fluid bearing thereby redirecting the optical fiber along a second vertical pathway. Thereafter, a thermoplastic coating may be applied to the optical fiber with a thermoplastic coating system. The optical fiber may then be wound onto a fiber storage spool with a fiber take-up system. The fiber take-up system may be space apart from the thermoplastic coating system such that the thermoplastic coating may be cooled before the optical fiber is wound onto the fiber storage spool.

Abstract: Methods for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first pathway and redirecting the optical fiber along a second, different pathway which is non-parallel with the first pathway. The optical fiber may be coated as it travels along the second pathway.

Abstract: A method for producing an optical fiber that includes a method for producing an optical fiber, said method comprising: (i) drawing a bare optical fiber from a preform along a first pathway at a rate of at least 10 m/sec; (ii) contacting said bare optical fiber with a region of fluid in a fluid bearing and redirecting said bare optical fiber along a second pathway as said bare optical fiber is drawn across said region of fluid cushion; (iii) coating the bare optical fiber; and (iv) irradiating said coated fiber in at least one irradiation zone to at least partially cure said coating, while subjecting the optical fiber to UV light.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber in a treatment zone wherein the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Methods for producing optical fibers along nonlinear paths incorporating fluid bearings are also provided thereby allowing for increased vertical space for the fiber treatment zone.

Abstract: A fault-tolerant virtualized computer system comprises a primary host executing a primary virtual machine (VM) and a backup host executing a backup VM. In one embodiment, each VM includes a virtual disk mapped to a shared disk image on physical disk accessible to both hosts. A virtual disk IO request is received by virtualization software executing on the backup host from a backup VM. When the virtual disk IO request is a read request, the virtual disk IO request is mapped to a physical read IO request of a virtual disk image stored on a physical disk, the physical read IO request is issued to the physical disk. However, when the virtual disk IO request is a write request, it is assumed to be completed without mapping the virtual disk IO request or issuing a mapped physical IO request to the physical disk.

Abstract: Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log.

Abstract: In an exemplary apparatus for cooling an electronic component, a housing defines an inlet port and an exhaust port and a foam member is disposed within the housing. The foam member has a shape that conforms to a shape of at least one surface of an electronic component such that the foam member is receivable thereon in thermal communication. The foam member has a pore size of no more than around 50 micrometers and a porosity of at least around 80 percent. The foam member is arranged within the housing such that coolant is flowable through the foam member. Pore size may be around 35 micrometers and porosity may be around 90 percent. Foam may be a ceramic foam that includes silica, aluminum oxide, and aluminum borosilicate fibers. In an application, at least one exemplary apparatus may be received in thermal communication on an upper case of an electronic chip.