The present invention offers an apparatus and associated method to detect a skip write error occurring during a data storage device write process. The capacitance between the read/write head and the disc surface, called the xe2x80x9cparasitic capacitance,xe2x80x9d is used to determine whether a skip write error has occurred. The amount of parasitic capacitance is determined by monitoring the frequency change at the input of an oscillator of test circuit. A change in the read/write head fly height causes a change in the parasitic capacitance and a corresponding change in the frequency. The parasitic capacitance is compared to a threshold limit to determine whether a skip write error has occurred. The write operation is suspended when a skip write error is detected and a rewrite procedure is instituted.

This application relates generally to the field of information storage and more particularly to a method and apparatus for verifying that data written on a storage disc can be reliably recovered during subsequent read operations.
The need for larger capacity data storage devices has become critical with the staggering pace of advances in computer technology. The most common data storage device used within computers today is the disc drive. The amount of data that can be stored on a disc drive has increased dramatically in recent years. Coupled with the need for larger storage capacity is a desire to increase the information throughput of the drive (i.e., increase the rate at which information is stored to and retrieved from the disc drive).
Most disc drives are composed of one or more magnetic media discs attached to a spindle. A spindle motor rotates the spindle and discs at a constant high speed. An actuator assembly adjacent to the disc(s) has actuator arms extending over the discs, each with one or more flexures extending from each actuator arm. A read/write head is mounted at the distal end of each of the flexures. The read/write head includes an air bearing slider enabling the head to xe2x80x9cflyxe2x80x9d in close proximity above the corresponding surface of the associated disc. The distance between the read/write head and the surface of the associated disc during disc drive operation is called the xe2x80x9cfly height.xe2x80x9d Information is stored on and retrieved from a disc via the read/write head.
Information is stored on the disc surface as a bit. A bit is represented by a xe2x80x9c1xe2x80x9d or xe2x80x9c0,xe2x80x9d which corresponds to a change or lack of change, respectively, in the orientation of adjacent magnetic domains on the disc surface. A domain""s magnetic orientation is changed using the disc drive""s write element. A write element is essentially an inductive coil. A magnetic field is generated around the write element by passing a current through the coil. The magnetic flux of the generated field, if strong enough, orients the magnetization direction of a magnetic domain located on the disc surface. The direction of the current in the write element dictates the direction of the magnetic flux of the generated field, and subsequently, the orientation direction of the magnetic domain.
As mentioned above, the strength of the magnetic field present at the disc surface must be strong enough to orient the magnetic domain. The strength of the magnetic field relative to the disc surface decreases as fly height increases. The magnetic field relative to the disc surface may not be strong enough to change the magnetic domain""s orientation if the fly height becomes too great. One solution is to increase the strength of the magnetic field. The strength of the magnetic field, however, must be limited to prevent changing the orientation of adjacent domains located on the disc surface. The fly height of the read/write head, therefore, is critical to insure that the generated magnetic field is sufficient to change the orientation of the desired magnetic domain without changing the orientation of adjacent magnetic domains.
Information is retrieved from the disc surface using the read element. The read element senses orientation changes of the magnetic domains on the disc surface. The changes in the magnetic domain orientations create an electrical signal in the read element. The read element must be very sensitive to detect the orientation changes of the small magnetic domains. The disc drive""s preamplifier is used to amplify the resulting signal before the signal is sent to the disc drive controller. Again, the fly height of the read/write head is critical to insure that the read element is close enough to the disc surface to detect the orientation changes in the magnetic domains such that an electrical signal is produced within the read element.
Each disc is radially divided into a finite number of concentric tracks to facilitate organization of the stored bits. Each track is a certain width and is separated from the adjacent tracks by a xe2x80x9cblank space.xe2x80x9d This blank space prevents information stored in one track from overlapping the information stored in an adjacent track. The number of tracks located on each disc surface is known as the xe2x80x9ctrack density.xe2x80x9d Each track is linearly subdivided into sections, called segments. Bits are written to and read from these segments by the read/write head. The linear density of bits stored within each segment is called the xe2x80x9cbit density.xe2x80x9d
The product of track density and bit density is known as xe2x80x9careal density.xe2x80x9d The recent trend being followed by disc drive manufacturers is to increase the recording media""s areal density so that the amount of data stored can be increased without increasing the physical size or the number of discs used in a drive. For example, the areal density of early disc drives was less than 1 gigabits per square inch (Gbits/sq. inch), whereas today, disc drives with areal densities greater than 40 Gbits/sq. inch are being tested. Manufacturers increase areal density by increasing both track density and bit density. Track density is increased by narrowing the track width and/or narrowing the width of the blank spaces between tracks. Bit density is usually increased by increasing the recording speed in order to record higher frequency bits. A higher frequency bit is smaller, and therefore, takes up less space on the disc surface.
An increase in areal density has a direct effect on the fly height of the read/write head. The write element must fly closer to the disc surface when writing information at higher areal density because the xe2x80x9cblank spacexe2x80x9d and track width become smaller. A decrease in fly height is necessary to insure that the magnetic field present at the disc surface is strong enough to change the desired domain""s orientation without overwriting information stored in an adjacent track. Likewise, the read element must fly closer to the disc surface when retrieving information from a disc with higher areal density because the smaller bits generate a smaller magnitude signal within the read element. The fly height, in summary, must become smaller in order for the read and write operations to be completed effectively as areal density increases.
The fly height in current disc drives has decreased to less than 1 microinch (xcexc-in). A small contaminate particle, vibration, external shock, or a disc surface defect, among others, can affect disc drive performance at such low flying heights. For example, a dust particle that hits the read/write head can cause the read/write head to xe2x80x9cbouncexe2x80x9d away from the surface of the disc. If this bounce occurs while information is being written to the disc, the magnetic field generated by the write element may not be strong enough, relative to the disc surface, to change the desired domain""s orientation and accurately record the information on the disc. This problem is known in the art as a xe2x80x9cskip writexe2x80x9d or xe2x80x9cskip write error.xe2x80x9d
Most disc drives are manufactured in a clean room environment in order to prevent the presence of contaminate particles in an assembled disc drive. Most clean rooms are Class 100 clean rooms. Class 100 means that 100 contaminate particles per-liter-of-air are present in the room. Class 100 clean rooms were adequate for older disc drives with higher fly heights, but current disc drives require Class 10 clean rooms. Class 10 means that only 10 contaminate particles per-liter-of-air are present in the room. The amount of filtering needed to reach and maintain Class 10 status dramatically increases the cost of the disc drive manufacturing process.
Disc drive manufacturers place filters within the disc drive to trap the contaminate particles introduced during the manufacturing process. The filters also trap contaminate particles emitted from the drive""s components during normal operation. The filters require between 100 and 200 hours of normal drive operation to effectively capture the contaminate particles. A brand new drive, however, is usually used by industry testing facilities during benchmark testing (i.e., performance testing); before the internal filters have had an opportunity to trap the contaminate particles. The likelihood that a contaminate particle will cause a skip write during benchmark testing is high. The detection and correction of a skip write error during benchmark testing adversely affects the disc drive""s performance rating. Any degradation of performance during benchmark testing can lead to a decrease in consumer demand for the particular disc drive being tested. Additionally, detection and correction of a skip write error during normal disc drive operation adversely affects the user""s computing efficiency.
Disc drive manufacturers address skip write problems by using read verification and/or fly height monitoring. Read verification consists of reading the information that was stored during the write operation and comparing the information actually stored to the information intended to be stored. If the information actually stored differs from the information intended to be stored beyond an acceptable level, a likely skip write error is detected. A subsequent write operation is completed when a skip write error is detected and another read verify operation is completed to insure that the subsequent write operation was successful. This process continues until a successful write operation is completed at that disc location, or the information may be stored at a different disc location after a predetermined number of write attempts have failed. The additional read, compare, and write steps of the read verify operation, however, take a large amount of time and adversely affect the performance rating of the disc drive.
A second method of determining whether a skip write error has occurred is fly height monitoring. For example, the fly height of the write element can be monitored during normal write operations by determining the ratio of the magnetic pulse area to the magnetic pulse peak. An increase in the flying height of the read/write head corresponds to an increase in the magnetic pulse area, and therefore, an increase in the measured ratio. The writing process can be suspended and recovery procedures can be instituted if the ratio between the magnetic pulse area and magnetic pulse peak indicates that an acceptable fly height has been exceeded. Such a method requires complicated computations to determine the magnetic pulse area, the magnetic pulse peak, and the ratio between the area and peak.
Accordingly, there is a need for an apparatus and associated method of detecting whether a successful write operation has been completed and of correcting for an unsuccessful write operation that does not require a read verification procedure or complicated fly height computations.
Against this backdrop, embodiments of the present invention have been developed to determine whether a successful write operation has been completed. Embodiments of the present invention offer an apparatus and associated method to monitor the fly height of the read/write head during a write operation. The fly height can be used as an indication of whether the write operation was completed successfully. Embodiments of the present invention can be used for various types of storage systems such as magnetic and optical disc drives among others, however, a magnetic disc drive has been used to illustrate an embodiment of the present invention.
Accordingly, a preferred embodiment of the present invention relates to an apparatus and associated method monitoring the fly height of a read/write head to determine whether a skip write error is occurring. The fly height is determined by monitoring the parasitic capacitance between the write element and the disc surface. The amount of parasitic capacitance corresponds to the distance between the write element and the disc (i.e., the fly height). A change in parasitic capacitance causes a frequency change in an oscillator of a test circuit. The amount of parasitic capacitance is determined and compared to a predetermined threshold level to ascertain whether the fly height remains within an acceptable range, or a skip write error is occurring. The write operation is suspended when a skip write error is detected and a rewrite procedure is instituted.
Thus, a preferred embodiment of the present invention relates to an apparatus and associated method for determining the fly height of a read/write head by monitoring the parasitic capacitance present between the read/write head and a disc surface. The apparatus includes a test circuit, connected to the closed-loop write circuit created by the write element and the write element electrical leads, to determine the parasitic capacitance and to compare the amount of parasitic capacitance to a predetermined threshold value. The test circuit includes an oscillator, a frequency modulation detector, a filter circuit, a sample-and-hold circuit having a time constant, a comparator, a threshold trigger level circuit, and various capacitive and inductive elements among others. The test circuit is sensitive to frequency changes caused by a change in the amount of parasitic capacitance between the write element and the disc surface. The test circuit uses the change in frequency to determine the amount of parasitic capacitance, and ultimately, the fly height of the write element. The test circuit compares the fly height of the write element to a predetermined threshold to determine whether a skip write error is occurring.
Embodiments of the present invention do not require a read verification step to be completed, nor do embodiments of the present invention require complicated computations to determine whether a skip write error has occurred. Therefore, embodiments of the present invention increase the disc throughput; in other words, the speed that data can be stored and retrieved from the disc. Furthermore, embodiments of the present invention immediately achieve the increase in throughput; eliminating the 100 to 200 hours of operation usually needed by the disc""s internal filters to trap contaminate particles. Therefore, the need for more stringent clean room filtering can be reduced because acceptable performance can be achieved even though higher contaminate levels might be present in the disc drive.
These and various other features as well as additional advantages which characterize embodiments of the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.


A similar case search apparatus includes: a keyword extracting unit which extracts a keyword from an image interpretation report; a diagnosis tree analyzing unit which extracts, based on the keyword, one or more target diagnosis flows corresponding to the image interpretation report, by referring to a diagnosis tree storage unit storing diagnosis trees; a similar diagnosis flow extracting unit which extracts one or more diagnosis flows similar to the one or more target diagnosis flows from among the plurality of diagnosis flows included in the diagnosis trees stored in the diagnosis tree storage unit, based on the degree of difficulty regarding a diagnosis item or the degree of difficulty regarding a disease name; and a similar case searching unit which searches out one or more case data sets corresponding to the similar diagnosis flows from among a plurality of case data sets stored in a case data storage unit.

Recently, medical images previously interpreted to make diagnoses and information related to the results of the image interpretations and the results of the diagnoses are actively stored in databases for the purposes of helping radiologists to interpret medical images and helping clinicians to make diagnoses. Furthermore, similar case search systems have been proposed which are intended to search out, from the databases, medical images similar to target medical images to be interpreted by doctors to make diagnoses and the information related to the results of interpreting the medical images and the results of the diagnoses.
In such a conventional similar case search system, a database stores a large number of document data sets (hereinafter referred to as "image interpretation reports") related to the results of image interpretations and diagnoses. In this case, the database is searched for image interpretation reports including character strings (words) similar to character strings included in an image interpretation report (hereinafter referred to as a "current image interpretation report") input by a doctor. As a result, the searched-out similar image interpretation report and the medical images associated with the similar image interpretation report are output as the result of the search (see Non-patent Literature (NPL) 1).
In such a conventional case search system, the image interpretation report is searched out using a vector having, as an element, the total number of keywords included in the image interpretation report. More specifically, the degree of similarity of each image interpretation report in the database with respect to a current image interpretation report is calculated by calculating the distance between the vector of the image interpretation report in the database and the vector of the current image interpretation report. In the search, image interpretation reports found to have a higher similarity are preferentially searched out.

Similar case search apparatus and similar case search method

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.


An electromagnetic actuator wherein an annular supporting member secured to a stator and an oscillator member secured to a movable member are disposed in opposition in an axis-perpendicular direction and are elastically linked by a supporting rubber elastic body disposed therebetween. One axial face of the supporting rubber elastic body is furnished with an inside peripheral recessed portion and an outside peripheral protruding portion while another axial face is furnished with an inside peripheral protruding portion and an outside peripheral recessed portion so as to establish in the supporting rubber elastic body an elastic center axis that curves along a sinuous trajectory of an interconnected peak segment and valley segment situated between opposing faces of the annular supporting member and the oscillator member in the axis-perpendicular direction.

1. Field of the Invention
The present invention relates to an electromagnetic actuator adapted to utilize as actuating force magnetic attractive force produced by energizing a coil; and to a fluid-filled active vibration damping device employing the same.
2. Description of the Related Art
In the field of actuators utilized for example as actuating force generation sources in one class of vibration damping devices, namely fluid-filled active vibration damping devices, the use of electromagnetic actuators is known. An electromagnetic actuator includes a stator provided with a coil, and a movable member capable of displacement in the axial direction of the coil with respect to the stator; through the action of a magnetic field generated by energizing the coil, attractive force arises between the movable member and the stator, causing the movable member to experience relative displacement in the axial direction with respect to the stator. Additionally, an oscillator member attached to the movable member is linked by a supporting rubber elastic body to an annular support member attached to the stator, and when energization of the coil ceases and the attractive force disappears, the movable member is restored to its original position with respect to the stator by the recovery force of the supporting rubber elastic body. It is accordingly possible to bring about oscillatory displacement of the oscillator member through ON/OFF control of current through the coil. Such an arrangement is disclosed in Japanese Patent No. 4016343.
By providing a missing section in the magnetic path formed around the coil in order to define a magnetic pole defining portion, attractive force arising from the magnetic force acting between the movable member and the stator is exerted between this magnetic pole and the ferromagnetic movable member. Because the magnitude of the attractive force arising from magnetism in this way is inversely proportional to the square of the distance separating the magnetic pole defining portion and the movable member in the axial direction, the smaller the distance separating them, the more efficiently the actuating force will act on the movable member.
However, as noted earlier, because attractive force is inversely proportional to the square of the separation distance, if the separation distance is small, there is a risk that the movable member will become difficult to control owing to the sharply increased attractive force, causing problems such as the movable member striking against other components as a result of excessive displacement, and associated noise. It is therefore necessary to ensure a sufficiently large distance separating the movable member and the magnetic pole defining portion, and this made it difficult for actuating energy to be realized efficiently.

Electromagnetic actuator and fluid-filled active vibration damping device using the same


Systems and methods of providing power to high-voltage sensors in power-limited environments through environmental energy harvesting are disclosed. The systems and methods are configured to intermittently power high-voltage sensors by repeatedly releasing stored energy in bursts. An environmental energy harvesting device generates a low-voltage power supply and is coupled to one or more capacitors to charge the capacitors to a high-voltage threshold. After such high-voltage threshold has been reached, the capacitors are discharged to provide a high-voltage power burst to a high-voltage sensor configured to inspect a component and generate an inspection result signal. The inspection result signal is received by an output module, which may further store or transmit to an external receiver a data signal indicating the inspection results.

Nondestructive inspection sensors have been developed that are capable of detecting defects in components. Such sensors can be configured to operate constantly for long periods of time when supplied with electrical power. Although some environments allow easy access to stable high-voltage power sources, application of nondestructive inspection sensors in power-limited environments would be advantageous if sufficient power could be supplied to operate the sensors. As an example, piezoelectric sensors could be beneficially deployed to detect or monitor the growth of cracks, pits, or other defects in vehicle components (e.g., aircraft body surfaces or brakes on trains or automobiles), but power limitations currently prevent such deployment.

Burst energy release for read-write sensors


A water filling assembly for ice trays including a reservoir disposed in water delivering relation to each of a plurality of vertically stacked ice trays within a housing wherein the reservoir and trays are cooperatively structured to successively fill each of said trays from an uppermost one in the stacked array to a lower most one upon the selective passage of liquid from said reservoir to said trays.

1. Field of the Invention
This invention relates to an automatic water filling assembly for ice trays which eliminates the necessity for the removal of individual trays from a freezer or like reduced temperature environment for filling.
2. Description of the Prior Art
The use of ice trays to form ice cubes is of course well known and in wide use throughout the world. Typically, individual trays are placed in the freezer portion of a refrigerator once they are filled with water. Sufficient time is allowed to elapse with the result that ice cubes are formed in each of the forming cavities of the trays. Typically, after the ice has been used or removed from a given tray, it is removed from the refrigerator, carried to a spigot, sink or the like, filled and then returned to the refrigerator for freezing. Filling of ice trays is not only a tedious task but is also time consuming when one considers the care that has to be taken to avoid spillage when returning the filled ice tray from the sink to the refrigerator. These are probably some of the factors which account for many of the continually empty ice trays to be found in domestic refrigerators. While advancements in the prior art have, in some cases, eliminated the necessity of filling numerous ice trays, such solutions have generally led to the production and use of automatic, electrically powered ice makers. While functional, such ice makers are generally considered to be expensive and in certain instances plagued with maintenance problems.
Accordingly, there is a need for an automatic ice tray filling mechanism which will overcome the above set forth problems relating to the task of filling such trays and further wherein such a preferred automatic filling assembly can be positioned and maintained intact on the interior of the freezer portion of the refrigerator for prolonged and continued use. Such a mechanism should preferably be inexpensive for purchase by the consumer and effectively be maintenance free and further be capable of having a long operable life under what may be considered harsh operating conditions.
The prior art does include molding or forming containers for ice cubes. Such devices are represented in the following United States Patents.
Daenen, U.S. Pat. No. 4,372,526, discloses an ice cube making apparatus and serving system including a plurality of separate freezing compartments for forming ice cubes and incorporating a liquid drain arrangement so that excess water may be removed from the freezing compartments before the tray is transferred to the freezer.
Bowers, U.S. Pat. No. 1,229,873, discloses a multiple mold which may be filled successively through gravity flow from an uppermost molding chamber to a lower most molding chamber. While gravity flow and the automatic filling of multiple chambers are disclosed, such structure is not directed to the filling of ice trays.
Smith, U.S. Pat. No. 1,971,664, discloses an ice tray having a first and second depth of forming cavities separated by an apertured plate wherein the lower most plurality of forming chambers are filled first by applying a water supply to the uppermost series of chambers.
Price, U.S. Pat. No. 3,565,389, discloses an ice mold in the form of a closed chamber.
While the above set forth structures are representative of at least minimal attempts by the prior art to accomplish filling of ice forming devices in some unique fashion, such devices do not generally overcome the problems as set forth above.


Systems and methods of synchronizing the frequency of a slave clock to that of a master clock using time-stamps in transmissions from a master device having the master clock, determining an error signal, and adjusting the frequency of the slave clock based on said error signal.

Synchronization is critical for telecommunication system performance. Frequency and time (time-of-day or wall-clock) synchronization is crucial for mobile wireless networks because the radios used in these networks operate in very strict bands that need separation to avoid channel interference which reduces the call quality and network capacity. Poor synchronization has also negative impact for the handover between base stations.
Mobile handsets generally derive the accurate frequency that they transmit and receive from the base stations. If the transmission frequencies are not very closely matched between adjacent cell sites, then "clicks" can occur when the call is being handed over (that is, switches) between base stations. In the worst case, the call would drop because the mobile handset would not be able to immediately lock onto and acquire the new signal.
Failure to meet the timing requirements of the relevant standards would cause performance degradation for the radio access channels. In particular, this failure could compromise cell handover (especially for travelling mobile stations) and producing excess of dropped calls.
With increasing interest in packet networks as a common mode of communication, packet-based synchronization solutions are in high demand as alternative to PDH (plesiochronous digital hierarchy)/SDH (synchronous digital hierarchy) and GPS based solutions. Equipment vendors and telecom service providers are looking for new packet synchronization solutions with very high accuracies beyond those attainable using the traditional packet methods like Network Time Protocol (NTP) (see Mills, D., "Network Time Protocol (Version 3) Specification, Implementation and Analysis", IETF RFC 1305, March 1992).
It is desirable that such new solution are also be designed for applications (e.g., base stations) that cannot bear the cost of a GPS receiver at each node, or for which GPS signals are inaccessible (for example due to location).
The IEEE Standard 1588 Precision Time Protocol (PTP) (IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems, IEEE 1588-2008), is the latest addition in packet timing technology. Originally designed to provide precise timing for critical industrial automation applications it is now providing the highest level of accurate frequency and time to wireless backhaul networks. The backhaul portion of the network comprises the intermediate links between the core network, or backbone, of the network and the base stations. Currently standardized in 2008 as Version 2 (IEEE-1588v2, superseding IEEE 1588-2002), PTP is designed to overcome the Network Time Protocol (NTP) latency and jitter issues, providing accuracy in the nanosecond range.
Base stations have traditionally met synchronization requirements by locking their internal oscillators to a recovered clock from the T1/E1 TDM (time division multiplexing) backhaul connection. While Ethernet has proven to be a ubiquitous and inexpensive medium for connectivity, it has not been well-suited for applications requiring precise synchronization. When the backhaul transitions from TDM to Ethernet, the base station becomes isolated from its traditional network sync feed. New base station designs are incorporating IEEE 1588 PTP slave clocks to meet the 50 ppb (parts per billion) accuracy requirement. These PTP slave clocks in the base stations rely on access to a PTP grandmaster clock deployed in a mobile switching center (MSC). Sync and Follow_Up packets flow from the grandmaster clock to the slave clocks in the base stations.
IEEE 1588v2 PTP is fully compatible with all Ethernet and IP networks. Additionally, the protocol is designed to enable a properly designed network to deliver frequency and phase or time with precision rivalling a GPS receiver. An IEEE 1588v2 PTP Technique for Frequency Synchronization implementation can supply FDD (frequency division duplexing) and TDD (time division duplexing) radio systems and CES-based (circuit emulation services) transport systems with the synchronization signals they require as illustrated in FIG. 1. This greatly reduces the costs of clocking all wireless base station equipment using other means.
A primary reference is a source of time and or frequency that is traceable to international standards. A recognized standard time source is a source external to PTP that provides time and/or frequency as appropriate that is traceable to the international standards laboratories maintaining clocks that form the basis for the International Atomic Time (TAI) and Universal Coordinated Time (UTC) timescales. Examples of these are Global Positioning System (GPS), NTP, and National Institute of Standards and Technology (NIST) timeservers.
Although IEEE 1588v2 PTP systems add a small amount of additional traffic to the network load, they have several advantages. First, they work in the data path, and also benefit from the redundancy and resiliency mechanisms of the network, resulting in "always on" operation. Next, multiple transmission paths reduce redundant clock system costs. They also use a single synchronization session for all base station traffic. IEEE 1588v2 PTP supports any generic packet-based transport (such as IP, MPLS). The protocol also features configurable synchronization packet rates for network conditions to maintain accuracy.
The transmission of the clock information over a packet network eliminates the need for alternative mechanisms, such as GPS or prohibitively expensive oscillators placed at the receiving nodes. This provides significant cost savings in network equipment as well as in ongoing installation and maintenance. This synchronization solution transmits dedicated timing packets, which flow along the same paths with the data packets, reducing the cost of synchronization and simplifying implementation.
To ensure that packet technologies (Ethernet, IP, MPLS) have the necessary attributes to be truly carrier grade, operators and vendors are introducing several key technologies for the transport of timing and synchronization over packet networks. Of these IEEE 1588v2 PTP is perhaps the most important because it provides both frequency and time distribution.
The grandmaster is the root timing reference in a domain and transmits synchronization information to the clocks residing in its domain. In IEEE 1588v2 PTP messages are categorized into event and general messages. All IEEE 1588 PTP messages have a common header as shown in FIG. 2.
Event messages are timed messages in that an accurate timestamp is generated at both transmission and receipt of each message. Event messages have to be accurately timestamped since the accuracy in transmission and receipt timestamps directly affects clock distribution accuracy. A timestamp event is generated at the time of transmission and reception of any event message. General messages are not required to be timestamped. The set of event messages consists of Sync, Delay_Req (both of which have the format shown in FIG. 4), Pdelay_Req, and Pdelay_Resp. The set of general messages consists of Announce (which has the format shown in FIG. 3), Follow_Up (which has the format shown in FIG. 5), Delay_Resp (which has the format shown in FIG. 6), Pdelay_Resp_Follow_Up, Management, and Signalling.
The Sync, Delay_Req, Follow_Up, and Delay_Resp messages are used to generate and communicate the timing information needed to synchronize ordinary and boundary clocks using the delay request-response mechanism. A Sync message is transmitted by a master to its slaves and either contains the exact time of its transmission or is followed by a Follow_Up message containing this time. In a two-step ordinary or boundary clock, the Follow_Up message communicates the value of the departure timestamp for a particular Sync message.
A Delay_Req message is a request for the receiving node to return the time at which the Delay_Req message was received, using a Delay_Resp message.
The format of the PTP message timestamp fields is shown in FIG. 7. A timestamp is the current time of an event that is recorded by a device. IEEE 1588 PTP allows for two different types of timestamping methods, either one step or two-step. One-step clocks update time information within event messages (Sync and Delay-Req) on-the-fly, while two-step clocks convey the precise timestamps of packets in general messages (Follow_Up and Delay-Resp).
The basic pattern of synchronization message exchange is illustrated in FIG. 8. The message exchange pattern is as follows. The master 101 sends a Sync message (M101) to the slave 102 and notes the time T1 at which it was sent. The slave 102 receives the Sync message and notes the time of reception T2. The master 101 conveys to the slave 102 the timestamp T1 by one of two ways: 1) Embedding the timestamp T1 in the Sync message. This requires some sort of hardware processing (i.e., hardware timestamping) for highest accuracy and precision. 2) Embedding the timestamp T1 in a Follow_Up message (M102). Next, the slave 102 sends a Delay_Req message (M103) to the master 101 and notes the time T3 at which it was sent. The master 101 receives the Delay_Req message (M103) and notes the time of reception T4. The master 101 conveys to the slave 102 the timestamp T4 by embedding it in a Delay_Resp message (M104).
At the end of this PTP message exchange, the slave possesses all four timestamps {T1, T2, T3, T4}. These timestamps may be used to compute the offset of the slave's clock with respect to the master and the mean propagation time of messages between the two clocks. The computation of offset and propagation time assumes that the master-to-slave and slave-to-master propagation times are equal.
The IEEE 1588 PTP based frequency recovery technique described in Section 12.1 of IEEE 1588-2008 Standard requires estimation of the mean path delay between server (master) and client (slave) which may include accounting for path asymmetry. In order to accurately synchronize to their master, slave clocks must individually determine the network transit time of the PTP messages. The network transit time is determined indirectly by measuring round-trip time from each slave to its master.
Like all message-based time transfer protocols, PTP time accuracy is degraded by asymmetry in the paths taken by event messages. Any asymmetry in the forward and reverse path propagation times and introduces an error into the computed value of the link delay. Asymmetry can be introduced in the physical layer, e.g., via transmission media asymmetry, by bridges and routers, and in large systems by the forward and reverse paths traversed by event messages taking different routes through the network. Systems should be configured and components selected to minimize these effects guided by the required timing accuracy. In single subnet systems with distances of a few meters, asymmetry is not usually a concern for time accuracies above a few 10 s of ns. Asymmetry is not detectable by PTP; however, if known, PTP corrects for asymmetry. If two-step clocks are used, then the network has to be designed such that the general message takes the same path as the event message through a transparent clock. Failure to do this will result in a condition where the transparent clock does not calculate path delay properly. This condition is undetectable and may introduce additional jitter and wander, but it will not break the protocol.
Other IEEE 1588 based techniques (such as those discussed in T. Neagoe and M. Hamdi, "A Hardware IEEE-1588 Implementation with Processor Frequency Control," Arrow Electronics White Paper; T. Neagoe M. Hamdi and V. Cristea, "Frequency Compensated, Hardware IEEE-1588 Implementation," IEEE International Symposium on Industrial Electronics, 9-13 Jul. 2006, pp. 240-245 and S. Balasubramanian, K. R. Harris, A. Moldovansky, "A Frequency Compensate Clock for Precision Synchronization Using IEEE1588 and its Applications to Ethernet" IEEE-1588 Workshop, September 2003 assume that the PTP GrandMaster Clock (GMC) sends Sync messages at fixed intervals, an assumption which might not necessary hold true in practice. The above receiver clock recovery mechanisms are designed based on this assumption.
An object of the present invention is to provide a method and system for frequency synchronization that allows one or more receivers (slaves) to frequency synchronize to a transmitter (master). Other applications of frequency synchronization are in process and manufacturing industries like paper mills, printing presses, automation and robotic systems, test and measurement instruments and systems, etc.
Another object of the present invention is to provide a synchronization technique based on, for example, the IEEE 1588 Precision Time Protocol (PTP) that allows frequency to be distributed over a packet network from a PTP server (master) to synchronization clients (slaves).

Method and system for frequency synchronization

Khalifa University of Science, Technology and Research


An oxide superconducting thin film includes a substrate having a single crystal structure, the main face of the substrate and a crystal face of the single crystal structure having an angle therebetween; an intermediate layer formed on the main face of the substrate and having an axis oriented in a direction perpendicular to the crystal face; and a superconducting layer formed on the intermediate layer and containing, as a main component, an oxide superconductor having a c-axis oriented in a direction perpendicular to the surface of the intermediate layer. A superconducting fault current limiter and a method of manufacturing an oxide superconducting thin film are also provided.

There is a method of obtaining an oxide superconducting thin film by preparing a substrate and depositing an oxide superconductor on a substrate, which is a conventional technique for putting an oxide superconducting material to practical use.
For example, RE-based superconductors (RE: rare earth element), which exhibit a superconducting phenomenon at liquid nitrogen temperature (77 K) or higher, particularly yttrium-based superconductors (hereinafter referred to as "YBCO") represented by a composition formula of YBa2Cu3O7−δ, are often used as the oxide superconductor to be deposited.
Oxide superconducting thin films using the RE-based superconductors are expected to be applied to superconducting fault current limiters, cables, and superconducting magnetic energy storages (SMES), and RE-based superconductors and manufacturing methods thereof have drawn a lot of attention.
However, obstacles to practicalization of oxide superconducting materials, including the RE-based superconductors (particularly, oxide superconducting thin films that is formed in the form of a thin film), include difficulty in improving the critical current density characteristics (hereinafter simply referred to as "Jc characteristics").
For example, the practicalization of superconducting fault current limiters using oxide superconducting thin films requires that a largest possible electric current flow with a resistance of zero, which in turn requires that the Jc characteristics of the oxide superconducting thin films be improved.
Patent Document 1 (Japanese Patent Application Laid-Open (JP-A) No. 2005-290528) discloses a method of manufacturing an oxide superconducting thin film, in which a buffer layer (intermediate layer) formed of CeO2 or the like and a superconducting layer formed of an RE-based superconductor or the like are formed on a substrate obtained by cutting a sapphire single crystal at an angle several degrees different from the r-plane or a-plane thereof followed by grounding, whereby the Jc characteristics of the oxide superconducting thin film are improved.

Oxide superconductor thin film, superconducting fault current limiter, and method for manufacturing oxide superconductor thin film

NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY


A semiconductor storage device in which a gate bird's beak occurring under a floating gate is suppressed includes a side wall formed on the side face of a floating gate constructed by an HTO film, a nitride film, and an HTO film.

1. Field of the Invention
The present invention relates to a semiconductor storage device and, more particularly, to a semiconductor storage device provided with a non-volatile memory having a floating gate.
2. Description of the Related Art
In recent years, demand for a non-volatile memory in which stored data is held even after the power is turned off is increasing. Especially, demand on an EEPROM (Electrically Erasable Read-Only Memory) is increasing. A cell structure of a conventional EEPROM will be described with reference to FIGS. 7(a) to 7(c) and FIG. 8. The EEPROM comprises a source 12, a drain 11, a floating gate 3 for accumulating charges, a gate insulating film (tunnel oxide film) 5 formed between the floating gate and a well, an ONO film (insulating film) 4 which is a stacked layer of an oxide film--a nitride film--an oxide film formed between a control gate and the floating gate, and a side wall 13 covering the side faces of the floating gate and the control gate. As shown in a cross section of FIG. 8 taken along the line A-A', the side faces of the floating gate 3 and the control gate 5 are covered with a thermal oxide film 13-1 having a thickness of 100 angstroms or larger, the thermal oxide film 13-1 is covered with a hot thermal oxide (HTO) film 13-2, and the HTO film 13-2 is covered with a CVD oxide film 13-3 deposited by chemical vapor deposition (CVD). Since electrons in the floating gate 3 are leaked and the data holding characteristics deteriorate when only the HTO film 13-2 and the CVD oxide film 13-3 are used, the thermal oxide film is formed during heat treatment to improve the film quality of the HTO film 13-2 and to improve the data holding characteristics. The thermal oxide film is formed by diffusing oxygen into the floating and control gates via the HTO film 13-2.
The problems of the conventional EEPROM are as follows. A gate insulating film 2 under the floating gate 3 is also subjected to oxidization similarly due to the heat of thermal oxidation used to form the side wall 13. As a result, what is called a gate bird's beak such that a tunnel film as the gate oxide film 2 near the edge of the floating gate 3 becomes thick occurs. A Fowler-Nordhein current which becomes larger as the drain impurity concentration becomes higher and whose current density becomes higher as the tunnel film becomes thinner is not passed near the edge of the floating gate where the drain impurity concentration is high and the tunnel film is thin. The Fowler-Nordhein tunneling phenomenon (FN tunneling phenomenon) does not therefore contribute to writing. Consequently, a first problem such that the speed of electrons moving from the floating gate to the drain decreases occurs. A second problem is as follows. The FN tunneling current is not passed around the edge of the floating gate 3, the electrons are moved only from a part of the tunnel film, and the amount of electrons passing the tunnel film per unit area increases, so that tolerance to the number of rewriting times deteriorates. As a third problem, since the tunnel film near the edge at which the FN phenomenon that the electrons can be moved with a small amount of the writing current occurs becomes thicker, the interband tunneling current becomes dominant and the writing efficiency (FN current/current consumed at the occasion of writing) deteriorates.

Floating gate sidewall structure for the suppression of bird's beak


A graphical user interface (GUI) for a television set-top box which includes a web browser. The set-top box has an Internet data connection and is controlled from user inputs entered through a remote control device. The GUI generates menu screens that are superimposed over conventional television video images, so that the user can view browser graphics generated by the GUI while viewing television images in the background. The GUI further provides animated on-screen notifications of the presence of interactive content, such as hypertext links to World Wide Web pages, which may be associated with television content currently being received. The GUI can also provide animated on-screen notifications of other events, such as previously-specified dates and times or the end of a television commercial. A main menu screen includes function buttons which appear to slide back and forth. A two-state progress indicator indicates that a download is in progress and the degree of completeness of a download.

Two important areas of technology in modern society are computers and television. Computer technology is the basis of one of the most widely used information resources in the world, the World-Wide Web ("the Web"). The Web is a collection of formatted hypertext pages located on numerous computers around the world that are logically connected by the Internet. The Web has become a resource for information relating to almost any subject imaginable. Although advances in personal computers and web browser software have made the Web accessible to a large segment of the population, many people are uncomfortable using personal computers. In contrast, television is a technology with which most people are very familiar and comfortable. Therefore, it is desirable to enable people to receive information from the Internet, particularly the Web, on their television sets.
In addition, television broadcasters and sponsors may wish to notify viewers of when interactive content is available that is associated with a program or commercial (advertisement) they are currently viewing. For example, a sponsor may have a Web site from which viewers can obtain additional information on a product shown in a commercial they are watching. Accordingly, it is desirable to provide an entertaining yet relatively unobtrusive way of notifying users when a television material they are viewing has interactive (Web) content associated with it and a way for the viewer to easily and immediately access that information using their television sets. It is further desirable to provide such features so that the user experiences relatively seamless transitions between viewing conventional television content and interactive (Web) content.

Interactive graphical user interface for television set-top box


A fiber Chirped Pulse Amplification (CPA) laser system includes a photonics band gap (PBG) fiber to function as a compressor. The PBG fiber is spliced with a fiber end cap that has an core expander for increasing a mode area of the PBG fiber. With increased mode area, the laser system is enabled to sustain an increased damage threshold energy thus is capable of producing short pulse laser with higher pulse energy.

Even though current technologies of fiber laser have made significant progress toward achieving a compact and reliable fiber laser system providing high quality output laser with ever increasing output energy, however there are still technical difficulties in implementing an air core photonics band gap fiber (PBF) in a fiber compressor. For better understanding the function performed by a pulse compressor, a short pulse high energy fiber laser system as that shown in FIG. 1 is first described. Referring to FIG. 1 for a schematic diagram of a short pulse high-energy fiber laser system that includes a laser seed 15 having an oscillator for generating a fiber-based mode-locking laser with original pulse duration. The laser project from the oscillator of the seed laser 15 is projected into a single mode fiber (SMF) laser stretcher 20 to stretch the laser pulse. The stretcher 20 generates laser pulse with stretched pulse width is projected into a series of laser amplifiers 25 to amplify the laser into higher energy. The amplified laser is then projected into a pulse compressor 30 to re-compress the pulse width of the laser to output a laser with original pulse width. In order to provide compact and reliable fiber laser system, instead using grating lenses for pulse compression as that commonly used in a conventional system, it is desirable and very promising according to test results to implement a compressor with the air core photonics band gap (PBG) fiber. Specifically, the air core PBG fiber is very useful for high-energy fiber laser/amplifier for compressing the chirped pulses back to a couple of hundreds fs. Even though such configuration enables an all fiber system for generating short pulse-high energy lasers, however, due to a limitation in power handling of the end-face of the photonics band gap (PBG) fiber, the outputted laser is still limited to only tens of micro Joules. Laser output of higher energy is not yet feasible due to this limitation when a laser system is implemented with the PBG fiber
In order to further improve the energy handling, different configurations or processes may be implemented to prevent a surface damage of the end-faces of the PBG fiber. End cap of a piece of coreless fiber or glass can be attached to the PBG fiber to increase the mode area of output beam at the end facet. This will make possible to amplify ps to 100 fs pulse to the level of mJ. However, perfect treatment of the two surfaces of two separated pieces of material (PBG fiber with coreless fiber or glass plate) is difficult.
Therefore, a need still exists in the art of fiber laser design and manufacture to provide a new and improved configuration and method to provide fiber laser with new PBG fiber covered with end caps or with part of the air core and air holes filled with glass powder or liquid glass. The new and novel FBG fiber of this invention increases the mode area of the fiber to improve the energy absorptions and dissipation processes in laser transmission. With the improved FBG fiber to function as a compressor of the laser system, a short pulse high-energy laser system is enabled to provide laser output power up to millie-Joules (mJ) having ps to 100 fs pulse widths.

Method and configurations in achieving high energy operation for photonic band gap (PGB) fiber with end caps


A vehicle differential device having a differential case rotatably supported via a bearing by a housing and a drive shaft inserted into the differential case, including an oil sump member on the opposite side of the differential case to the bearing, the oil sump member including an insert hole into which the drive shaft is inserted, and an oil supply channel formed higher than the drive shaft in the vertical direction, wherein at least a portion of the insert hole is formed with a gap between the insertion hole and the drive shaft wider than that on the vertically lower side of the rotational axis of the drive shaft, the oil sump member includes a discharge hole allowing oil to flow out toward the differential case if an oil level of an oil chamber formed between the oil sump member and an oil seal exceeds a predetermined height.

A vehicle differential device (differential gear) including a differential case rotatably supported via a bearing by a housing and a drive shaft inserted into the differential case is used in a power transmission path of various vehicles. The differential device includes, for example, a ring gear having outer circumferential teeth and disposed in the housing; the differential case integrally disposed with the ring gear and rotating around one shaft center; a pinion gear rotatably supported around a shaft center orthogonal to the one shaft center by a pinion shaft fixed to the differential case within the differential case; and a pair of side gears facing each other with the pinion gear interposed therebetween and disposed rotatably relative to each other around the one shaft center within the differential case, and the differential device allocates a drive force to a pair of drive shafts (axles) corresponding to left and right drive wheels coupled to the pair of the side gears while allowing differential rotation.
The differential device as described above is required to supply sufficient oil to portions in need of lubrication. To implement the lubrication, for example, techniques have been proposed such as a lubricating structure of a differential device described in Patent Document 1. According to this technique, lubrication oil can stably be ensured from low rotation to high rotation to improve lubrication performance by introducing the oil into a chamber and guiding and supplying the oil dripping from an opening by an oil guide to rear surface portions of bearings to lubricate the bearings and an inboard portion (differential case).


A semiconductor device comprises a MOSFET of LDD structure, in which the gate electrode structure comprises an oxide film interposed between a poly-Si layer and a refractory metal layer or a metal silicide. The oxide film prevents the metal or metal silicide from being diffused into the gate oxide film during the heating step included in the process of manufacturing the semiconductor device. Also, a side wall spacer is formed of poly-Si to achieve an electrical connection between the poly-Si layer and the layer of the metal having a high melting point or of the metal silicide so as to constitute a part of the gate electrode.

1. Field of the Invention
The present invention relates to a semiconductor device including a MOSFET of an LDD (Lightly Doped Drain) structure, particularly, to a semiconductor device including a MOSFET of an LDD structure of a so-called "polycide gate electrode", which comprises a poly-Si layer and a refractory metal such as W, Ti or Ta or a metal silicide layer, and a method of manufacturing the same.
2. Description of the Related Art
FIG. 1 shows the conventional NMOSFET of an LDD structure. For manufacturing the MOSFET shown in the drawing, a gate oxide film 2 is deposited first on a p-type semiconductor substrate 1, followed by forming a poly-Si layer 3 on the gate oxide film 2. Then, As ions are implanted, followed by activating the implanted As ions by heat treatment and subsequently forming a metal silicide layer 4. Further, an anisotropic etching is applied so as to form a gate electrode structure. Then, impurity ions are implanted at a low concentration to form a diffusion layer 6 for the LDD structure, followed by forming a SiO.sub.2 layer by CVD. Further, anisotropic etching is applied to the CVD SiO.sub.2 layer so as to form a sidewall spacer 5 for the gate electrode, followed by ion implantation for forming source/drain regions 7. The problems summarized below are inherent in the conventional MOSFET shown in FIG. 1:
1. A heat treatment such as annealing is applied to a laminate structure consisting of the poly-Si 3 and the metal silicide layer 4 having a high melting point. During the heat treatment, the metal atoms within the metal silicide layer 4 are diffused into the gate oxide film 2 through the grain boundary within the poly-Si layer 3 so as to lower the breakdown voltage of the gate oxide film 2. The problem is serious in the case where the poly-Si layer 3 is made thin, leading to a serious defect in the case of flattening the surface morphology for miniaturizing the elements.
2. The LDD structure is effective for moderating the electric field around the drain region so as to improve the reliability of the MOSFET. In the conventional method in which the sidewall spacer 5 is formed of CVD.SiO.sub.2, hot electrons derived from stress are trapped in the CVD.SiO.sub.2 layer 5 positioned on the N.sup.- type region, leading to a high resistance at the boundary between the CVD.SiO.sub.2 layer 5 and the diffusion layer 6. This brings about the deterioration inherent in the LDD structure.


Systems and methods are directed to automated cleaning systems for vehicles. In one example, a vehicle is provided that includes a drive system, a passenger cabin, and a vehicle cleaning system. The vehicle cleaning system includes a vacuum unit and a robotic manipulator. The robotic manipulator includes an arm including a plurality of arm sections and a gripper unit positioned at a distal end of the arm. The robotic manipulator is connected to the vacuum unit such that the arm provides a vacuum path between the vacuum unit and the gripper unit.

An autonomous vehicle is a vehicle that is capable of sensing its environment and navigating with little to no human input. In particular, an autonomous vehicle can observe its surrounding environment using a variety of sensors and can attempt to comprehend the environment by performing various processing techniques on data collected by the sensors. This can allow an autonomous vehicle to navigate without human intervention and, in some cases, even omit the use of a human driver altogether.
When a vehicle is operated in a fully autonomous mode, there may not be a human driver present to monitor the state of the interior of the vehicle. For example, in a non-autonomous vehicle, a driver can determine if objects are left behind in the vehicle and can monitor when the vehicle interior needs to be cleaned to provide a desired standard of service to users. Without a human driver present in the vehicle, an autonomous vehicle may need to be taken out of service periodically to inspect the cleanliness of the vehicle interior and perform any necessary action to return the vehicle interior to the desired standard.

Automated cleaning systems for autonomous vehicles


The present disclosure relates to systems, non-transitory computer-readable media, and methods for generating and providing pose guides that are tailored to a context of a camera viewfinder stream. In particular, in one or more embodiments, the disclosed systems determine a context of the camera viewfinder stream and provide sample pose images that correspond with the determined context. In response to a selection of a sample pose image, the disclosed systems generate and display a pose guide that is customized to the proportions of a subject depicted in the camera viewfinder stream. The disclosed systems further iteratively modify portions of the generated pose guide to indicate that the subject depicted in the camera viewfinder stream is coming into alignment with the generated pose guide. The disclosed systems automatically capture a digital image when the subject is in total alignment with the generated pose guide.

Recent years have seen significant improvements with regard to imaging systems. For example, conventional imaging systems provide vivid camera viewfinder displays and capture colorful and detailed digital images via mobile devices. Specifically, conventional imaging systems provide imaging experiences that include utilizing a mobile device camera viewfinder to position a camera of the mobile device, and then capturing a digital image in response to a user interaction with a shutter function of the mobile device.
Often, users want to imitate (or to instruct others to imitate) interesting and engaging poses that they have seen in professional photographs or other media. In order to do so, conventional imaging systems often require users to access web browsers and other applications on their mobile device to find professional images including poses for imitation. Following this, conventional imaging systems further require users to navigate between and interact with these web browsers and other applications and the conventional imaging system to view and imitate (or to instruct others to imitate) the displayed poses. As such, conventional imaging systems are particularly inefficient when operating in connection with a client computing device with a small screen—such as a smart phone or table, where interacting with and switching between multiple applications to find and imitate professional photographic poses are difficult.
Moreover, by forcing users to estimate and guess with regard to pose imitation between applications, conventional imaging systems give rise to various system-level inefficiencies. For example, in forcing users to switch back-and-forth between applications to imitate professional and engaging poses, conventional imaging systems cause the overuse and eventual waste of system resources associated with generating graphical displays, storing user selections, maintaining application data, and capturing digital images. Additionally, given the guess-work involved in attempting to imitate poses between applications, conventional imaging systems waste additional system resources in capturing and deleting digital images that fail to turn out the way the user desires.
Even when conventional imaging systems provide a level of in-application pose guidance, such conventional imaging systems are generally inflexible and inaccurate. For example, in order to provide a level of pose guidance, conventional imaging systems are limited to static, outline-based overlays. To illustrate, a conventional imaging system may provide pose guidance as a generic human-shaped pose outline that is overlaid on a camera viewfinder of a client computing device.
This level of pose guidance provided by conventional imaging systems is inflexible. For example, as discussed, conventional imaging systems provide one-size-fits all pose guidance that is untethered from the proportions, characteristics, and attributes of the person who is posing. Thus, conventionally provided pose guidance is too rigid to be tailored to the body of any particular poser.
Furthermore, this conventionally provided pose guidance is extremely inaccurate. For example, conventional imaging systems provide pose guidance that is non-specific with regard to a posing user's context and position within the camera viewfinder. Accordingly, conventional imaging systems often inaccurately capture digital images where the posing user is in a pose that is not the same as indicated by the pose guidance and/or the posing user is in an inappropriate pose relative to the context of posing user.
These along with additional problems and issues exist with regard to conventional imaging systems.

Providing contextual augmented reality photo pose guidance


A cable containing at least one optical fiber and at least one material. The at least one optical fiber being at least partially embedded within the at least one material, and the at least one material forming a housing that protects the at least one optical fiber. The at least one material having a Shore A hardness of about 75 or less.

1. Field of the Invention
The present invention relates to communication cables having at least one light waveguide at least partially contacting and/or partially embedded within a soft housing.
2. Background of the Disclosure
Three general types of protective coatings have been recognized in the optical cable art: 1) loose tube buffers, 2) tight buffers and 3) composite buffers. See Mahlke, G. and Gossing, P., Fiber Optic Cables, John Wiley and Sons Limited, New York, 1987, pp. 96-108. Other specialized constructions have also been developed. See, for example, Saito et al., U.S. Pat. No. 4,770,489, which discusses the use of a grooved spacer core to carry a group of fibers, wherein the grooves are filled with a soft jelly-like material, the spacer is surrounded with a layer of aramid fiber, and the aramid fiber is surrounded by a plastic jacket. Filling compounds and flooding compounds are used within cables to block the flow of water therein but they are not wholly interchangeable. Filling compounds are suitable for contact with fibers and must not include a base composition or additives that result in unacceptable levels of optical performance changes.
Flooding compounds, on the other hand, typically include ingredients that render them unsuitable for contact with optical fibers. Generally filling compounds will be located in a tube having at least one optical fiber, and flooding compounds will be located exteriorly of the tube.
In the loose tube construction, one or more fibers are surrounded by a protective tube, typically referred to as a core or buffer tube, which is spaced from the fiber(s) by a distance sufficient to allow the fiber(s) to move within the core or buffer tube in response to applied stresses. By placing the fiber loosely in a tube, the fiber is substantially decoupled from the rest of the cable. Typically, the space between the fiber(s) and the loose tube is filled with a filling material, e.g., a grease or a thixotropic gel, so as to inhibit or prevent water migration in the tube and/or to protect the fiber(s) from water absorption.
Greveling, U.S. Pat. No. 4,763,982, discloses a cable comprising: 1) an outer jacket and 2) an inner tube composed of strength members, such as aramid fibers, embedded in resin carrier, the inner tube being filled with a thixotropic water blocking medium. Peacock, U.S. Pat. No. 4,822,133, discloses the use of water blocking grease used as a filling material in a tube. Other filling materials have included petroleum jelly mixed with a polymer, usually polyethylene, as described by Biskeborn et al, U.S. Pat. Nos. 3,607,487 and 3,717,716. Other filling materials have included a low viscosity oil thickened by a styrene-isoprene-styrene copolymer, again with polyethylene added to impart consistency and reduce slump; see, for example, Dobbin et al., U.S. Pat. No. 3,879,575.
Sabia, U.S. Pat. No. 4,464,013, describes the use of a mixture of (1) from 85 to 94 percent by weight of ASTM Type 103, 104A, or 104B, or mixtures thereof, naphthenic or paraffinic oil having a minimum specific gravity of 0.855; a minimum SUS viscosity at 210xc2x0 F. of 40; a maximum pour point ASTMD 97 of less than xe2x88x925xc2x0 F.; and a maximum of 5 percent aromatic oils; and (2) from 6 to 15 percent by weight of a styrene-ethylene butylene-styrene block copolymer having a styrene-rubber ratio of from approximately 0.2 to 0.5. These two ingredients comprise substantially 100 percent of the filling material, but with up to 1 weight percent of the filling material being stabilizer.
Patel, U.S. Pat. No. 4,497,538, proposes the use of a mixture of a block copolymer, petroleum and an additive. The block copolymer is a styrene-ethylene butylene-styrene (SEBS) having a styrene to rubber ratio of 0.39 to 0.41, and a specific gravity of approximately 0.91. The petroleum is a mixture of microcrystalline waxes and oil that contains a small amount of an antioxidant additive. The additive is a low molecular weight polyethylene having a molecular weight range from 1,000 to 10,000 and a specific gravity of at least 0.90.
A major component of the foregoing filling compositions is a petroleum based filling composition, for example, an oil, grease, or wax that has been mixed with minor amounts of one or more organic and/or inorganic compounds. Such petroleum based filling compositions are relatively expensive, require special blending and are not suitable for use with all cable components. For example, not all plastics commonly used for cable components are adequately resistant to the petroleum-based composition.
Another disadvantage of petroleum based filling compositions is that they may not be suitable in all environments. For example, a petroleum based composition may not form a network of molecular bonds that sufficiently reduces flow under normal cable use environments. As a result, petroleum based compositions are often messy, particularly for those working with the cable in the field. Moreover, known filling compositions are susceptible to dripping at high temperatures, and may cause undesirably high optical performance losses at lower operating temperatures.
It is an object of the invention to provide an alternative to the petroleum based filling materials conventionally used in the art by at least partially embedding an optical waveguide in a relatively soft material(s). In one embodiment of the present invention the material(s) comprises a three-dimensional molecular network that have bonded through crystallization, intermolecular hydrogen bonding and/or intermolecular polar attraction of functional groups and not necessarily through covalent crosslinking. The three dimensional network, optionally including various additives, desirably possesses suitable properties under service conditions such that temperature change does not cause undesirable strain on the fibers, desirably possesses a low modulus thereby minimizing the resulting strain on the optical fiber, inhibits dripping at high temperatures and is inexpensive.
It is a further object of the invention to provide an alternative to the petroleum based filling materials, which possesses other desirable characteristics. For example, the material(s) desirably does not slump excessively at elevated service temperatures, so that the material(s) will not migrate out of the end of the tube. Further, the material(s) is desirably not excessively oily or greasy, is not messy, and desirably has a soft rubber-like texture allowing for convenient handling during cable repair, fiber access, and other operations.
It is a further object of the invention to provide an alternative to the petroleum based filling materials incorporated in a tube. The material(s) desirably possesses a melt flow at temperatures over about 80xc2x0 C., preferably between about 90xc2x0 C. and about 125xc2x0 C., yet remains sufficiently soft at temperatures as low as about xe2x88x9250xc2x0 C. so as not to cause undesirable optical attenuation. By use of the material(s), slicing of the tube may be employed for optical fiber access without the ordinary dripping considerations.
It is a further object of the invention to provide material(s) with a three-dimensional network that may include controlled amounts of any or substantial amounts of petroleum based oils, greases and waxes, and can exclude additives often employed with the oils, greases and waxes. Additives that may be excluded from the material(s) of the invention include fumed silica and other silica products. However, superabsorbent materials such as hydrophilic polymers and other stabilizers often used with conventional petroleum based filling materials may be desirable for use with the present invention.
It is a further object of the invention to provide a three dimensional network of material(s) including a foam incorporated therein. For example, the foam may be created by injecting gas into the material(s), adding materials to the which split off a gas when heated, dissolving a gas in the material(s) under pressure, adding microspheres, as well as other mechanical and chemical means.

Communication cable having a soft housing


A method and apparatus for drying or curing rigid cylindrical and flexible belt substrates includes: a curing chamber defining a central axis; a support structure selectively receivable within the curing chamber and including a support for at least one substrate along the central axis which rotates the at least one substrate about the central axis; a curing mechanism surrounding the at least one substrate within the curing chamber for expelling temperature controlled low velocity air toward the at least one substrate as the at least one substrate rotates about the central axis without axial movement relative to the curing chamber; and inductive coils surrounding at least a portion of the at least one substrate within the curing chamber for indirectly heating the at least one substrate. Preferably, the at least one substrate is dried/cured by combination of indirect RF induction heating at the same time or prior to low velocity air impingement. By varying the frequency, power, coil diameter and spacing, heatup rates and temperatures can be very closely controlled and very rapid heatup rates can be achieved.

1. Field of the Invention
The invention relates to a method and apparatus for drying or curing rigid cylindrical and flexible belt substrates. More particularly, the invention relates to an efficient method and apparatus that is useful in drying or curing spray-coated photoreceptor substrates (metallic or conductive plastic rigid cylinders, metallic or conductive plastic flexible seamless belts, and the like) and, for that matter, any smooth surface object subject to strict cleanliness standards during manufacture.
2. Description of Related Art
A photoreceptor is a rigid cylinder or flexible belt device used in a xerographic apparatus. The photoreceptor substrate is coated with one or more layers of a photoconductive material, i.e., a material whose electrical conductivity changes upon illumination. In xerographic use, an electrical potential is applied across the photoconductive layer and then exposed to light from an image. The electrical potential of the photoconductive layer decays at the portion irradiated by the light from the image, leaving a distribution of electrostatic charge corresponding to the dark areas of the projected image. The electrostatic latent image is made visible by development with a suitable powder. Better control of the coating quality yields better imaging performance.
The coating of a substrate may be accomplished through an automated four step process, whereby the substrate to be coated is first loaded on a support arm structure (step 1) which then moves the substrate to successive processing stations. The substrate is first moved to the cleaning station (step 2) which includes a cleaning chamber for receiving the support arm bearing the substrate and having decontaminating means for removing contaminates from the substrate; and then on to a coating station (step 3) which includes a coating chamber for receiving the support arm bearing the substrate and having an applicator for applying a coating formulation onto the substrate. Finally, the substrate is moved to a curing station (step 4) which includes a curing chamber for receiving the support arm bearing the coated substrate and has curing means for curing the coating on the substrate. An apparatus and method for processing as described above, is detailed generally in U.S. Pat. No. 5,032,052 to Swain, 5,038,707 to Swain et al. and U.S. Pat. No. 5,079,854 to Hammond et al., which are incorporated herein by reference and referred to for purposes of describing a substrate coating and manufacturing process. In addition, as well known in the art, other suitable methods for coating photoconductive layers can be utilized, such as dip coating, vacuum deposition and the like.
The method and apparatus described herein is preferably adaptable for use with either an airless or air atomized spray coating system. However, in an air atomized spray coating system, an air assisted automatic spray gun using high velocity air to atomize the coating formulation is used to spray the coating onto the substrate. Due to high mass transfer rates intrinsic to the use of atomizing air, this method entails considerable evaporative loss of solvent from the spray droplets and requires the use of slow evaporating solvents to prevent excessive solvent loss before the droplets arrive at the substrate. It is difficult to use this method in a sealed environment, and thus difficult to control the solvent humidity surrounding the substrates prior to, during, or after the coating process. In addition, the air atomized spray method creates a considerable amount of overspray which results in higher material usage.

Method and apparatus for drying/curing rigid cylindrical and flexible belt substrates


The present invention provides compositions and methods of identifying a subject as having an increased risk of developing fragile X-associated tremor and ataxia syndrome (FXTAS) or identifying a subject having an increased risk of developing fragile X syndrome (FXS), comprising analyzing messenger RNA (mRNA) transcripts and/or translation products of the antisense gene ASFMR1.

The CGG repeat expansion in the 5′-UTR of the fragile X mental retardation gene (FMR1) has been implicated in the pathogenesis of two distinct disorders, fragile X syndrome (FXS), a neurodevelopmental disorder (1, 2), and fragile X-associated tremor and ataxia syndrome (FXTAS), a progressive neurodegenerative disease (3, 4). In the general population, the FMR1 5′-UTR contains 5 to 54 CGG repeats, while expansions of this trinucleotide repeat outside of the normal range fall into two distinct categories, the premutation range with 55 to 200 repeats and the full mutation range with greater than 200 and up to thousands of repeats (3, 5).
Full mutation expansions coupled with cytosine methylation result in transcriptional silencing of the FMR1 gene, loss of expression of FMR1 protein (FMRP), and FXS, the most common form of heritable X-linked mental retardation. The FXS phenotype is complex and highly variable, with mental impairment ranging from mild learning disabilities and emotional problems to severe mental retardation (1, 2). The severity of mental retardation is correlated with the degree of cytosine methylation of the FMR1 promoter and repeat region (6, 7).
Premutation alleles are associated with FXTAS, one of the most common single-gene forms of gait ataxia and tremor in older males (3, 4, 8, 9). While the full mutation alleles are transcriptionally silent, premutation alleles demonstrate a 2-10 fold increase in FMR1 mRNA levels (10) but normal or reduced amounts of FMRP(11-13). Since FXTAS is restricted to premutation carriers and not found in full mutation individuals, increased FMR1 transcript level rather than the reduced FMRP is thought to be the underlying cause of this disorder. Accordingly, post-mortem examination of the brains of FXTAS individuals revealed intranuclear inclusions containing the FMR1 transcript, ubiquitin, molecular chaperones, and components of the proteasome (14, 15). The current molecular model for FXTAS is that the transcript containing the expanded premutation size CGG repeat sequesters results in misfolding of cellular proteins, such as CGG-binding proteins, leading to the formation of intranuclear inclusions (16, 17). This model is consistent with the RNA gain-of-function model proposed for another trinucleotide-repeat associated disease, myotonic dystrophy (DM1), in which the CUG repeat in the 3′-UTR of DMPK sequesters RNA-binding proteins, such as the members of the muscleblind family (18, 19).
Although deregulation or mutations of FMR1 have been implicated in the pathogenesis of both FXS and FXTAS (1, 3, 20, 21), it is important to note that there have been individuals with phenotypic manifestation of FXS with no mutations found in the FMR1 gene (22, 23). In addition, only one-third of male premutation carriers develop FXTAS (9). These observations together with the wide variability of FXS and FXTAS phenotypes suggest that in addition to FMR1, there are other genes potentially involved in pathogenesis of these disorders.
The present invention provides the identification of a gene, ASFMR1, overlapping the CGG repeat region of the FMR1 gene in the antisense orientation. The ASFMR1 transcript is spliced, polyadenylated and exported to the cytoplasm. Similar to FMR1, the ASFMR1 transcript is elevated in lymphoblastoid cells and peripheral blood leukocytes of individuals with premutation alleles relative to normal and is not expressed from full mutation alleles. In addition, the ASFMR1 transcript exhibits premutation-specific alternative splicing, providing a qualitative molecular abnormality associated with FXTAS.
The present invention overcomes previous shortcomings in the art by providing methods and compositions for identifying subjects at increased risk of developing fragile X-associated tremor and ataxia syndrome (FXTAS) and identifying subjects at increased risk of developing fragile X syndrome (FXS).

Methods and compositions for identifying increased risk of developing fragile X-associated disorders

The Fred Hutchinson Cancer Research Center


An optical network includes an optical ring, a plurality of local nodes, and a data center node. The plurality of local nodes are coupled to the optical ring and each local node is capable of receiving traffic from a local client and associating a transmitter tag with the traffic. The transmitter tag identifies a virtual network of the local client. The local node is further capable of transmitting the traffic on the optical ring.

Telecommunication systems, cable television systems, and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical fibers comprise thin strands of glass capable of transmitting optical signals over long distances with very low loss of signal strength.
In recent years, optical networks have, to an increasing extent, replaced and/or been integrated with conventional, non-optical systems. Nonetheless, many functionalities provided by or techniques supported by non-optical systems are difficult to duplicate with optical networks and/or create unique problems when implemented using optical architectures. As a result, despite the advantages optical networks possess, their use may be limited in legacy systems that utilize protocols or functionality not easily or effectively replicated on optical networks.

Method and system for utilizing virtual local access network addressing in optical networks

Abstract: The data center node is also coupled to the optical ring and is capable of receiving traffic transmitted by one of the local nodes and determining a receiver tag for the traffic, based on the transmitter tag associated with the traffic and the local node that transmitted the traffic. The data center node is also capable of associating the selected receiver tag with the traffic and transmitting the traffic on the optical ring.