A method for enabling access to a data resource, which is held on a file server (25) on a first local area network (LAN) (21a), by a client (28) on a second LAN (21b). A proxy receiver (48) on the second LAN (21b) intercepts a request for the data resource submitted by the client (28) and transmits a message via a wide area network (WAN) (29) to a proxy transmitter (52) on the first LAN (21a), requesting the data resource. The proxy transmitter (52) retrieves a replica of the data resource from the file server (25) and conveys the replica of the data resource over the WAN (29) to the proxy receiver (48), which serves the replica of the data resource from the proxy receiver (48) to the client (28) over the second LAN (21b).

Geographically dispersed enterprises often deploy distributed computer systems in order to enable information sharing throughout the enterprise. Such distributed systems generally comprise a number of local area networks (LANs) that are connected into one or more wide area networks (WANs). Enterprises have commonly used dedicated leased lines or permanent virtual circuits, such as frame relay links, to connect their LANs and WAN end-points. While providing generally predictable bandwidth and quality of service, such interconnections are often expensive and represent fixed costs for an enterprise. More recently, with the development of the Internet, many enterprises have begun to use virtual private networks (VPNs) operating over the public Internet, at least for a portion of their data traffic. Although VPNs are typically less expensive than dedicated lines, bandwidth and latency are often unpredictable, particularly when transmitting large files over long distances.
Many LANs include one or more dedicated file servers that receive data from other processors on the LAN via the network for storage on the file servers' hard disks, and supply data from the file servers' hard disks to the other processors via the network. Data stored on file servers is often accessed using a distributed file system, the most prevalent of which are Network File System (NFS), primarily used for UNIX clients, and Common Internet File System (CIFS, formerly SMB), used for Windows® clients.
Because these network file systems were primarily designed for use with high-bandwidth LANs, file access over WANs is often slow, particularly when interconnection is over a VPN. Numerous and frequent accesses to remote file servers are often necessary for most file operations, which sometimes result in noticeably poor performance of the client application.
In an attempt to improve response time, techniques of replication and caching are often used. Replication entails maintaining multiple identical copies of data, such as files and directory structures, in distributed locations throughout the network. Clients access, either manually or automatically, the local or topologically closest replica. The principal drawback of replication is that it often requires high bandwidth to maintain replicas up-to-date and ensure a certain amount of consistency between the replicas. Additionally, strong consistency is often very difficult to guarantee as the number of replicas increases with network size and complexity.
In standard cache implementations, clients maintain files accessed from the network file system in local memory or on local disk. Subsequent accesses to the cached data are performed locally until it is determined that the cached data is no longer current, in which case a fresh copy is fetched. While caching does not necessarily require high bandwidth, access to large non-cached files (such as for each first access) is sometimes unacceptably slow, particularly if using a VPN characterized by variable bandwidth and latency. Maintaining consistency is complex and often requires numerous remote validation calls while a file is being accessed.
U.S. Pat. No. 5,611,049 to Pitts, which is incorporated herein by reference, describes a distributed caching system for accessing a named dataset stored at a server connected to a network. Some of the computers on the network function as cache sites, and the named dataset is distributed over one or more such cache sites. When a client workstation presents a request for the named dataset to a cache site, the cache site first determines whether it has the dataset cached in its buffers. If the cache does not have the dataset, it relays the request to another cache site topologically closer to the server wherein the dataset is stored. This relaying may occur more than once. Once a copy of the dataset is found, either at an intermediary cache site or on the server, the dataset is sent to the requesting client workstation, where it may be either read or written by the workstation. The cache sites maintain absolute consistency between the source dataset and its copies at all cache sites. The cache sites accumulate profiling data from the dataset requests. The cache sites use this profiling data to anticipate future requests to access datasets, and, whenever possible, prevent any delay to client workstations in accessing data by asynchronously pre-fetching the data in advance of receiving a request from a client workstation.
U.S. Pat. No. 6,085,234 to Pitts et al., which is incorporated herein by reference, describes a network-infrastructure cache that transparently provides proxy file services to a plurality of client workstations concurrently requesting access to file data stored on a server. A file-request service-module of the network-infrastructure cache receives and responds to network-file-services-protocol requests from workstations. A cache included in the network-infrastructure cache stores data that is transmitted back to the workstations. A file-request generation-module, also included in the network-infrastructure cache, transmits requests for data to the server, and receives responses from the server that include data missing from the cache.
While providing an improvement in network file system performance, caching introduces potential file inconsistencies between different cached file copies. A data file is considered to have strong consistency if the changes to the data are reconciled simultaneously to all clients of the same data file. Weak consistency allows the copies of the data file to be moderately, yet tolerably, inconsistent at various times. File systems can ensure strong consistency by employing single-copy semantics between clients of the same data file. This approach typically utilizes some form of concurrency control, such as locking, to regulate shared access to files. Because achieving single copy semantics incurs a high overhead in a distributed file systems, many file systems opt for weaker consistency guarantees in order to achieve higher performance.
Cache consistency can be achieved through either client-driven protocols, in which clients send messages to origin servers to determine the validity of cached resources, or server-driven protocols, in which servers notify clients when data changes. Protocols using client-driven consistency, such as NFS (Versions 1, 2 and 3) and HTTP 1.x, either poll the server on each access to cache data in order to ensure consistent data, thereby increasing both latency and load, or poll the server periodically, which incurs a lower overhead on both the server and client but risks supplying inconsistent data. Server-driven consistency protocols, such as Coda and AFS, described below, improve client response time by allowing clients to access data without contacting the origin server, but introduce challenges of their own, mostly with respect to server load and maintaining consistency despite network or process failures.
When client-driven protocols are used in an environment requiring strong consistency, they incur high validation traffic from clients to servers. This is undesirable in high-latency networks, as each read operation must suffer a round trip delay to validate the cached data. HTTP proxy caches have traded reduced consistency for improved access performance, a rational design choice for most Web content. Each resource is associated with an expiry timestamp, often derived by some heuristic from its modification and access times. The timestamp is used to compute the resource's freshness. A cache proxy may serve any non-expired resource without first consulting the origin HTTP server. For requests targeting expired resources, the proxy must first revalidate its cached copy with the origin site before replying to the client. It is important to note that HTTP uses heuristics that reduce the chance of inconsistencies, but no hard guarantees can be made regarding actual resource validity between validations because the server may freely modify the resource while it is cached by clients.
Server-driven protocols rely on the server to notify clients of changes in the attributes or content of the resource. Each server maintains a list of clients possessing a cached copy of a resource. When a cached resource is modified by a client, the server notifies all clients possessing a cached copy, forcing them to revalidate their copies before allowing further access to cached data. The server accomplishes this notification by making a callback to each client. (A callback is a remote procedure call from a server to a client.) The guaranteed notification relieves clients of having to continuously poll the server to determine validity, resulting in lower client, server and network loads, when changes are relatively infrequent compared with the overall access. However, the use of callbacks increases the burden of managing the server state (to maintain all client callbacks) and decreases system failure resilience (as the server is required to contact possibly-failed clients). CIFS and NFS Version 4 are stateful protocols. Some hybrid server-/client-driven protocols use leases for lock management. Leases grant control of a resource to a client for a server-specified fixed amount of time, and are renewable by the client. While the lease is in effect, the server may not grant conflicting control to another client. Therefore, during a lease, a client can locally use the resource for reading or writing without repeatedly checking the status of the resource with the file server. The NFS Version 4 protocol implements leases for both locks and delegation. This feature is described by Pawlowski et al., in "The NFS Version 4 protocol," published at the System Administration and Networking (SANE) Conference (May 22–25, 2000 MECC, Maastricht, The Netherlands), which is incorporated herein by reference. This paper is available at www.nluug.nl/events/sane2000/papers/pawlowski.pdf. Leases or token-based state management also exists in several other distributed file systems.
NFS has implemented several techniques designed to improve file access performance over a WAN. NFS clients often pre-fetch data from a file server into the client cache, by asynchronously reading ahead when NFS detects that the client is accessing a file sequentially. NFS clients also asynchronously delay writing to the file server modified data in the client's cache, in order to maintain the client's access to the cached data while the client is waiting for confirmation from the file server that the modified data has been received. Additionally, NFS uses a cache for directories of files present on the file server, and a cache for attributes of files present on the file server.
A number of other distributed file systems, less widely-used than NFS and CIFS, have been developed in an attempt to overcome the performance issues encountered when using distributed file systems over WANs. These file systems use client caching, replication of information, and optimistic assumptions (local read, local write). These file systems also typically require the installation of a custom client and a customer server implementation. They do not generally support the standard file systems, such as NFS and CIFS.
For example, the Andrew File System (AFS), which is now an IBM product, is a location-independent file system that uses a local cache to reduce the workload and increase the performance of a distributed computing environment. The system was specifically designed to provide very good scalability. AFS caches complete files from the file server into the clients, which are required to have local hard disk drives. AFS has a global name space and security architecture that allows clients to connect to many separate file servers using a WAN.
Coda is an advanced networked file system developed at Carnegie Mellon University. Coda's design is based on AFS, with added support for mobile computing and additional robustness when the system experiences network problems and server failures. Coda attempts to achieve high performance through client-side persistent caching. The system was also designed to achieve good scalability.
InterMezzo is an Open Source (GPL) project included in the Linux kernel. InterMezzo's development began at Carnegie Mellon University, and was inspired by Coda. When several clients are connected to a file server, InterMezzo decides which client is permitted to write using a mechanism called a "write lease" or "write token." Only one client can hold a write lease or token to a file at any given time, eliminating update conflicts. In InterMezzo, all clients are immediately notified of any updates to any directories to which they are connected. As a result, exported directories on all clients are always kept synchronized so long as all clients are connected to the network. Coda and InterMezzo are described by Braam et al., in "Removing bottlenecks in distributed filesystems: Coda & InterMezzo as examples," published in the Proceedings of Linux Expo 1999 (May 1999), which is incorporated herein by reference. This paper is available at www-2.cs.cmu.edu/afs/cs/project/coda-www/ResearchWebPages/docdir/linuxexpo99.pdf.
Ficus, developed at the University of California Los Angeles, is a replicated general filing environment for UNIX, which is intended to scale to very large networks. The system employs an optimistic "one copy availability" model in which conflicting updates to the file system's directory information are automatically reconciled, while conflicting file updates are reliably detected and reported. The system architecture is based on a stackable layers methodology. Unlike AFS, Coda, and InterMezzo, which employ client-server models, Ficus employs a peer-to-peer model. Ficus is discussed by Guy et al., in "Implementation of the Ficus replicated file system," Proceeding of the Summer USENIX Conference (Anaheim, Calif., June 1990), 63–71, and by Page et al., in "Perspectives on optimistically replicated, peer-to-peer filing," Software: Practice and Experience 28(2) (1998), 155–180, which are incorporated herein by reference.


The present invention relates to a toner for electrophotography containing a resin binder, a colorant, and a clay-organic complex obtained by intercalating into a smectite clay a quaternary ammonium salt represented by the formula (A):[(R1)3(R2)N]+.X−  (A)wherein R1 and R2 are not identical; R1 is an alkyl group, alkenyl group, or alkynyl group, each having 4 to 24 carbon atoms; R2 is an alkyl group, alkenyl group, or alkynyl group, each having 1 to 10 carbon atoms; and X− is an anion. The toner for electrophotography of the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

One of the important factors desired for a toner used for an electrophotographic system includes triboelectric charging property, especially initial rise of triboelectric charges. When initial rise of triboelectric charges is poor, homogeneous image quality cannot be obtained and there are disadvantages such as background fog. Conventionally, it has been attempted to improve initial rise of triboelectric charges by using a charge control agent or the like. However, since dispersibility of the charge control agent in a toner is insufficient, initial rise has not been sufficiently exhibited. Therefore, it has been attempted that a specified clay-organic complex is used as a charge control agent, whereby dispersibility of the charge control agent is increased to improve the initial rise (see Patent Publications 1 and 2).
However, with the advancement of higher image qualities and higher speed of machine in the recent years, in order to provide a toner with a high added value, various toners containing a large amount of wax and a crystalline polyester have been developed, and development of a toner having not only initial rise of triboelectric charges but also high saturation triboelectric charges has been desired.    Patent Publication 1: JP-A-2004-117651    Patent Publication 2: JP-A-Hei 8-6295


The present invention is an online methodology for end point detection for use in a chemical mechanical planarization process which is both robust and inexpensive while overcoming some of the drawbacks of the existing end point detection approaches currently known in the art. The present invention provides a system and method for identifying a significant event in a chemical mechanical planarization process including the steps of decomposing coefficient of friction data acquired from a chemical mechanical planarization process using wavelet-based multiresolution analysis, and applying a sequential probability ratio test for variance on the decomposed data to identify a significant event in the chemical mechanical planarization process.

Wafer polishing using chemical mechanical planarization (CMP), as shown with reference to FIG. 1, is a key nanoscale manufacturing process that can significantly impact critical requirements facing the semiconductor device manufacturing procedure. Some of these requirements for nanoscale manufacturing include continual feature size reduction, introduction of new materials for higher processing speeds and improved reliability, multilevel metallization (MLM) or interconnections, and increased productivity through larger wafer sizes. The CMP task has been made more challenging in recent years by complex wafer topographies, and the introduction of copper, as a substitute for aluminum, and low-k dielectrics. Some of the difficult manufacturing challenges of CMP include defects identification, such as delamination, dishing, and erosion, end point detection (EPD) and process control.
End point detection (EPD) is the determination of the end of polishing in a chemical mechanical planarization (CMP) process. FIG. 2 illustrates the CMP process and its associated end point as known in the art. If the end point is not detected properly, a defect in the chemical mechanical planarization process for metals, oxides, or dielectrics, known as over and underpolishing, may result. One primary reason for this defect may be the change in material removal rate (MRR) often caused by normal polish pad life cycle, variations in the slurry, variations in the polishing pad, and conditioning issues of pads. Other reasons for over and under polishing may include approximations of empirical MRR calculations and fluctuations in incoming oxide or metal layer thickness. Accordingly, EPD of CMP is a critical operational issue.
Literature in the field of EPD and CMP cites the need for accurate end point detection of a chemical mechanical planarization process involved in three different processes of wafer fabrication, including copper damascene, shallow trench isolation (STI), and interlevel dielectrics (ILD). Some of the challenges known in the art for EPD include: 1) inaccessibility to the entire wafer surface for measurements during polishing; 2) high cost of metrology; 3) difficulty in implementing online methodologies; 4) inaccurate interpretation of in-situ sensor data; and 5) lack of robustness of the detection methodology. Current approaches to EPD are include the analysis of both offline and in-situ sensor data. Offline methods are referred to as dry methods, and include processes in which the wafer is inspected under a microscope to determine its polishing status. Though this method has the advantage of a thorough microscopic level analysis, it is not conducive to higher productivity because the planarization process must be stopped to evaluate the wafer. Additionally, offline methods are expensive due to their cost of ownership.
The in-situ sensor methods known in the art, also referred to as wet methods, include optical, thermal, electric, electrochemical and acoustic emission sensor systems. Optical sensor-based methods known in the art employ interferometry, reflectance and spectral reflectivity, and ellipsometry to acquire thickness measurements. In these methods, a beam of light is passed through the wafer and the wavelength of light emitted from the wafer surface is measured. The wavelength is then used to evaluate the thickness of the wafer and, in turn, detect the end point of polishing. This method becomes inefficient, especially with metal CMP, as the wafer thickness grows. Cu, for example, is optically transparent to only about 30 nm. On patterned ILD wafers, optical methods present additional challenges, such as diffraction, which significantly affects the spectral analysis. Environmental factors such as sensing through air, slurry, and glass during in-situ measurements also affects the performance of optical methods for end point detection currently known in the art.
Thermal systems for end point detection in CMP utilize infrared temperature measurements and changes in temperature to detect an end point. In these thermal systems known in the art, a change in temperature can result from either the change in friction of the wear mechanisms or in the underlying chemical reactions. The major disadvantage of thermal methods for EPD is difficulty in implementation. Implementation is difficult because the infrared sensors have to be fixed onto a transparent pad or be positioned to rotate with the carrier to be able to accurately detect the temperature change. This configuration is difficult to implement in the manufacturing process. Additionally, small changes in temperature values that are difficult to detect, such as those often caused by the presence of thermally diffusive materials, present a significant challenge to thermal EPD detection systems.
Friction based methods for EPD in CMP use motor-current sensing techniques. These techniques are also highly dependent on process parameters and consumables, and become inefficient for polishing ILD, in which there is no transition to an underlying layer with a different coefficient of friction.
Monitoring the material removal rate (MRR) in the CPD process is another alternative for EPD. In this method, an x-ray beam is directed on the downstream slurry and a detector monitors the induced fluorescence. The fluorescence indicates the density of abrasive in the slurry, which is then used in MRR calculations. Though in principal this method works, it has been proven to be ineffective.
Electrochemical methods for EPD measure the electrochemical potential between a measurement electrode, which is either the surface being polished or a probe inserted into the slurry near the wafer, and the reference electrode.
Another approach to EPD in CMP is chemical EPD, which is suitable for polishing wafers with nitride in the second layer. The detection procedure relies on measuring the concentration of nitrous oxide emitted when the end point is reached.
Acoustic emission (AE) and coefficient of friction (CoF) sensors are known in the art to be used in process monitoring for EPD by measuring various properties including the amplitude of the emitted signal, and the frequency of the spectral peaks. Since these properties differ between materials, they can be used to detect transitions from one layer to another during CMP. The presence of noise and the need for advanced signal processing has kept these approaches from being commercially implemented.
Efficient EPD in CMP has been an open research issue since the introduction of CMP to the wafer fabrication process. Several approaches have been proposed in the literature of which only a few rely upon the signals (AE and CoF) obtained directly from the molecular interactions of the polishing process. However, these signals by themselves cannot characterize important process events, like end point. Accordingly, what is needed in the art is an improved end point detection methodology for CMP that is robust and efficient and also capable of real-time implementation.

System and method for online end point detection for use in chemical mechanical planarization


A cautery hook includes a proximal portion, a shank portion, and a distal hook portion. The shank portion is connected to the proximal portion at a bent knee protruding generally on a front side of the cautery hook. The distal hook portion is connected to the shank portion at an ankle protruding generally on a rear side of the cautery hook opposite from the front side of the cautery hook. The distal hook portion includes a distal hook tip generally on the front side of the cautery hook. The bent knee, ankle, and distal hook tip are the three most likely locations of contact between the cautery hook and a cannula sleeve when the cautery hook is passed through the cannular sleeve between an internal surgical site and the outside. Each contact tends to self-align the cautery hook to allow the hook to pass through the cannula sleeve without getting stuck or damaged.

Advances in minimally invasive surgical technology could dramatically increase the number of surgeries performed in a minimally invasive manner. Minimally invasive medical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. The average length of a hospital stay for a standard surgery may also be shortened significantly using minimally invasive surgical techniques. Thus, an increased adoption of minimally invasive techniques could save millions of hospital days, and millions of dollars annually in hospital residency costs alone. Patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.
The most common form of minimally invasive surgery may be endoscopy. Probably the most common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient""s abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately xc2xd inch) incisions to provide entry ports for laparoscopic surgical instruments. The laparoscopic surgical instruments generally include a laparoscope (for viewing the surgical field) and working tools. The working tools are similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube. As used herein, the term xe2x80x9cend effectorxe2x80x9d means the actual working part of the surgical instrument and can include clamps, graspers, scissors, staplers, and needle holders, for example. To perform surgical procedures, the surgeon passes these working tools or instruments through the cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon monitors the procedure by means of a monitor that displays an image of the surgical site taken from the laparoscope. Similar endoscopic techniques are employed in, e.g., arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy and the like.
Minimally invasive telesurgical robotic systems are being developed to increase a surgeon""s dexterity when working within an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location. In a telesurgery system, the surgeon is often provided with an image of the surgical site at a computer workstation. While viewing a three-dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the workstation. The master controls the motion of a servomechanically operated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors such as, e.g., tissue graspers, needle drivers, or the like, that perform various functions for the surgeon, e.g., holding or driving a needle, grasping a blood vessel, or dissecting tissue, or the like, in response to manipulation of the master control devices.
An electrosurgical instrument is an end effector for coagulating ruptured blood vessels or the like. The instrument typically includes an electrode that applies current to living tissue at a surgical site. As the tissue current is conducted through the tissue, the tissue temperature rises, ultimately causing desiccation, cutting, and/or coagulation of the target tissue or vessel. Some cautery instruments include a J-shaped or L-shaped distal hook conveniently configured to snag or capture anatomical tissue such as a blood vessel for cauterization. The J-shaped or L-shaped hook often includes a distal hook portion connected to a substantially straight shank portion. The lateral dimension of the hook portion typically is substantially larger than that of the shank portion. When the cautery hook is passed through a cannula sleeve between the internal surgical site and the outside, the hook portion may get caught at an edge of the cannula sleeve or become stuck in the sleeve, particularly if the hook portion includes a sharp tip. In some cases, the hook portion may even break off when passing through the cannula sleeve.
The present invention is generally directed to robotic surgery methods, devices, and systems. The invention provides a cautery hook that is configured to substantially avoid being caught inside a cannula sleeve and being damaged or broken when the cautery hook is passed through the cannula sleeve.
In accordance with an aspect of the present invention, a cautery hook includes a proximal portion having a proximal end. A shank portion is connected to the proximal portion at a bent knee protruding generally on a front side of the cautery hook. A distal hook portion includes a distal hook tip generally on the front side of the cautery hook. The distal hook portion is connected to the shank portion at an ankle protruding generally on a rear side of the cautery hook opposite from the front side of the cautery hook.
In use, the bent knee, ankle, and distal hook tip are the three most likely locations of contact between the cautery hook and a cannula sleeve when the cautery hook is passed through the cannular sleeve between an internal surgical site and the outside. Each location of contact tends to self-align the cautery hook to allow the hook to pass through the cannula sleeve without getting stuck or damaged.
In some preferred embodiments, a proximal portion line extending generally between the proximal end and the bent knee is angularly spaced from a shank portion line extending generally between the bent knee and the ankle by a bent knee angle generally on the front side of the cautery hook. The bent knee angle is greater than 180xc2x0 and no greater than about 270xc2x0. In a specific embodiment, the bent knee angle is between about 200xc2x0 and about 250xc2x0.
In some preferred embodiments, the distal hook tip coincides with, or is disposed rearward of, a proximal portion plane which extends from the proximal end toward the bent knee and which is generally transverse to a distal hook plane on which the distal hook portion lies.
In some preferred embodiments, a distal hook tip tangent which is generally tangential to the distal hook portion at the distal hook tip is angularly spaced by a master angle from a proximal portion line extending between the proximal end and the bent knee. The master angle is disposed generally on the front side of the cautery hook, and is greater than 90xc2x0, preferably between about 110xc2x0 and about 180xc2x0, and more preferably between about 120xc2x0 and about 150xc2x0.
In a preferred embodiment, a rear support is disposed rearward of the bent knee and extends generally between the proximal end and the ankle.
In another preferred embodiment, the bent knee is spaced from the ankle by a shank portion length and the ankle is spaced from the distal hook tip by a distal hook portion length. The shank portion length is approximately equal to or greater than the distal hook portion length.
In specific embodiments, the distal hook portion is generally linear. The proximal portion, the shank portion, and the distal hook portion are generally planar and generally coplanar with each other. The proximal portion includes an engagement base at the proximal end for coupling the cautery hook to a support shaft.
In accordance with another aspect of the invention, a cautery hook includes a generally linear proximal portion. A generally linear shank portion is connected to the proximal portion at a bent knee. The shank portion is generally coplanar with the proximal portion. A generally linear distal hook portion includes a distal hook tip and is connected to the shank portion at an ankle. The distal hook portion is generally coplanar with the shank portion. The distal hook tip and the bent knee are disposed generally on a front side of the cautery hook and the ankle is disposed generally on a rear side of the cautery hook which is opposite from the front side.
In some preferred embodiment, the distal hook portion is angularly spaced by a master angle from the proximal portion. The master angle is disposed generally on the front side of the cautery hook, and is greater than 90xc2x0.
In accordance with another aspect of the invention, a cautery hook configured to self-align when passed through a cannula sleeve includes a distal hook portion having a distal hook tip disposed generally on a front side of the cautery hook. The cautery hook further includes a proximal end. A protruding portion is formed between the proximal end and the distal hook portion. The protruding portion includes a protruding surface generally on the front side of the cautery hook.
In some preferred embodiments, the bent knee generally coincides with, or protrudes generally forward of, a plane extending between the proximal end and the distal hook tip. The cautery hook further includes an ankle formed between the bent knee and the distal hook tip. The ankle protrudes generally on the rear side of the cautery hook. The protruding portion is formed between a proximal portion extending from the protruding portion to the proximal end and a shank portion extending from the protruding portion to the ankle.
Another aspect of the invention is directed to a system for cauterizing a target tissue in an internal surgical site of a patient body. The system includes a cannula sleeve having a proximal end, a distal end, and a lumen therebetween. The distal end is insertable into the patient body for accessing the internal surgical site through the lumen. A tool extends into the lumen of the cannula sleeve. The tool includes a cautery hook coupled with a shaft by a joint. The cautery hook has a tip supported by a bend so that the tip extends in a forward direction. A surface of the cautery hook is disposed proximally of the bend and extends forward sufficiently that sliding engagement between the proximal hook surface and the lumen of the cannula sleeve aligns the cautery hook with the shaft so as to inhibit interference between the tip and the distal end of the cannula sleeve when the cautery hook moves proximally into the cannula sleeve. The tool may be a robotic tool.
In some preferred embodiments, the bend of the cautery hook is generally planar. The cautery hook is rotatable generally on a plane of rotation relative to the shaft at a pivotal connection with the bend lying generally on the plane of rotation. The proximal hook surface generally coincides with, or extends generally forward of, a plane which is perpendicular to the plane of rotation and extends between the pivotal connection and the tip.

Minimally invasive surgical hook apparatus and method for using same


An online commerce system facilitates online commerce over a public network using an online commerce card. The "card" does not exist in physical form, but instead exists in digital form. It is assigned a customer account number that includes digits for a prefix number for bank-handling information, digits for a customer identification number, digits reserved for an embedded code number, and a digit for check sum. The bank also gives the customer a private key. During an online transaction, the customer computer retrieves the private key and customer account number from storage. The customer computer generates a code number as a function of the private key, customer-specific data (e.g, card-holder's name, account number, etc.) and transaction-specific data (e.g., transaction amount, merchant ID, goods ID, time, transaction date, etc.). The customer computer embeds the code number in the reserved digits of the customer account number to create a transaction number specific to the transaction. The customer submits that transaction number to the merchant as a proxy for a regular card number. When the merchant submits the number for approval, the issuing institution recognizes it as a proxy transaction number, indexes the customer account record, and looks up the associated private key and customer-specific data. The institution computes a test code number using the same function and input parameters as the customer computer. The issuing institution compares the test code number with the code number embedded in the transaction number. If the two numbers match, the issuing institution accepts the transaction number as valid.

Online commerce is experiencing dramatic growth in recent years. More merchants are developing sites on the World Wide Web (or simply "WWW" or "Web") that consumers can access and order goods and/or services. It is fairly common for a consumer to browse a merchant's catalog, select a product, place an order for the product, and pay for the product all electronically over the Internet.
Typically, the consumer pays for the goods and/or services ordered over the Internet with a credit card. During the online transaction, the merchant sends an order form and requests the consumer to enter personal data (e.g., name, address, and telephone number) and credit card information (e.g., account number and expiration date). The consumer returns the completed order form containing the credit card information to the merchant over the Internet. The merchant verifies that the credit card number is valid and can be charged the payment amount. The card verification is usually conducted on a well-established card network, such as the VisaNet.RTM. network or the Veriphone.RTM. network.
One problem with this traditional online commerce model concerns the security of the credit card data as it travels over the Internet. The credit card information can be intercepted in route, copied into a database, and used to make unauthorized purchases. In an automated environment, an imposter can repeatedly use the stolen credit card data to conduct many online transactions before the consumer ever becomes aware that the credit card data has been stolen.
Another concern is that dishonest merchants may re-use or re-distribute an individual's credit card information.
It would be desirable to develop a new online commerce model that reduces or eliminates the incentive for stealing credit card data. Ideally, a secure online commerce model would render the credit card data hard to steal, and if stolen, worthless to the thief.
A further concern is that any new online commerce model should integrate well with existing proprietary card network systems. There are well-established systems that verify credit card purchases and subsequently settle accounts. These systems and associated protocols are entrenched in the merchant and banking communities and experience a high level of acceptance and trust. A new online commerce model should not usurp these systems, nor require merchants to change their existing practices to implement completely different systems and protocols.
The inventors have developed a card-based online commerce system that improves security and integrates with existing card verification and settlement systems.

Electronic online commerce card with customer generated transaction proxy number for online transactions


A technique for impeding the formation of mechanical bonds between workpieces, such as semiconductor wafers, and a carrier or susceptor on which they are supported during a deposition or layer formation process, such as in epitaxial processing. In the formation of relatively thick films, greater than approximately 50 microns (50 .mu.m) thick, wafers can become mechanically bonded to the susceptor on which they are supported, and are subject to damage caused by thermal stresses during a cooldown phase of processing. In the disclosed method, the speed or direction of rotation of a rotatable susceptor is abruptly changed at least once, or periodically during processing. Slight movement of the wafers with respect to the susceptor during each rotation speed change or reversal tends to break any bonds before they can develop strength, and production yields of acceptable wafers are significantly improved.

This invention relates generally to epitaxial growth in semiconductor fabrication processes and, more particularly, to the fabrication of thick films, greater than approximately 50 microns (50 .mu.m) thick. Probably the most significant problem in very thick film growth is stress-induced breakage of semiconductor wafers being processed. It is with this problem that the present invention is concerned.
In epitaxial processing, layers of various materials, usually silicon-based, are grown by a deposition process in a processing chamber. Typically, semiconductor silicon wafers are first loaded onto the outer surfaces of a silicon carbide coated graphite support, called a susceptor. The susceptor has multiple flat external surfaces to accommodate a number of large wafers, and the entire susceptor is lowered into a quartz processing jar, into which appropriate gases are admitted to effect formation of a layer of material on the silicon wafers. To ensure uniformity of deposition of the film, the susceptor is rotated at a uniform speed, about its vertical axis. Without the rotation, the thickness profile would tend to vary depending on a number of factors, such as the relative location of processing gas inlet ports.
After an appropriate time, the susceptor rotation is stopped, the susceptor and wafers are cooled down, the susceptor is lifted from the quartz jar, and the wafers are removed from the susceptor. For films in excess of 50 microns (50 .mu.m), cooldown often results in bending and breakage, sometimes referred to as microcracking, of some of the wafers. Prior to this invention, there has been no effective technique for minimizing or eliminating this wafer damage problem.

Processing method for growing thick films


The electrically motorized wheel assembly comprises a hollow shaft having a first opening at one end thereof and a second opening, the first opening receiving conductors from outside of the assembly; a stator coaxial with and fixedly attached to the shaft, the stator being provided with a hollow portion and coils; a rotor coaxial with the stator and mounted for rotation about the stator; and converting system for converting an input electrical current to a variable AC electrical current, the converting system including power electronics fixedly mounted within the hollow portion, input terminals for receiving the input electrical current and output terminals for delivering the variable AC electrical current; whereby, to provide the variable AC current to the coils of the stator.

Known in the art, there is the U.S. Pat. No. 4,913,258 of Hiroshi SAKURAI et al, granted on Apr. 3, 1990, in which there is described an outer-rotor type motor wheel, comprising a knuckle, a hub coaxially interlocked with the knuckle, a wheel disc rotatably attached to the periphery of the hub, a wheel secured to the periphery of the wheel disc, a rotor fastened to an outer side of the wheel disc from the direction of the outer side, and a stator coaxial to and spaced from the rotor by a small gap and fastened to the hub from the direction of the outer side. One drawback with this outer-rotor type motor wheel, is that in order to provide a powerful motor wheel having a high torque, high current has to be injected to the power line to energize the coil of the armature core even at zero speed. With this outer-rotor type motor wheel, a converter has to be provided. This converter is mounted inside the vehicule and can be very cumbersome. Such high current circulating through the power line produces heat which is energy loss and also requires a power line which can be quite heavy.
Also known in the art, there is the U.S. Pat. No. 754,802 of Ferdinand PORSCHE et al, granted on Mar. 15, 1904, in which there is described the combination of the axle, the wheel, the hollow journal for the wheel, the end of the axle projecting to the journal, and a pivotal connection between the axle and journal having its axial line disposed acutely to the plane of the wheel. Again, to produce a powerful motor-wheel, the current supplied to the sliding brushes, brought from outside of the motor-wheel has to be a high current. This high current will have to be brought through large diameter cables or wires to reduce energy loss.
Also known in the art, there is the U.S. Pat. No. 2,348,053 of J.E. BOWKER, granted on May 2, 1944, in which there is described an electrically-operated motor vehicle improvements comprising a plurality of wheels arranged to be driven, a dynamotot forming an integral part of each such wheel, and electrical circuit connections between switch banks and dynamotots and batteries to control the operation of the dynamotots as motors according to the position of a selector switch. Again, the armature windings will have to be .energized with a high current in order to produce a powerful motor, such high current will require large diameter cables to bring the energy from the batteries of the vehicle to the windings of the armature. As well known, such large diameter cables or wires are rigid, cumbersome and incovenient.
Also known in the art, there are the following U.S. Pat. Nos. that describe different kinds of motor-wheels 638,643; 643,854; 2,506,146; 2,514,460; 2,581,551; 2,608,598; 3,566,165; 3,704,759; 3,792,742; 3,812,928; 3,892,300; 3,897,843; 4,021,690; 4,346,777; 4,389,586; 1,709,255; 2,335,398; 3,548,965.
None of the above-mentioned patents shows the necessary means for reducing the diameter of the wires of the power line between the motorized wheel assembly and the power supply when a powerful motorized wheel assembly is needed.
It is an object of the present invention to provide an electrically motorized wheel assembly wherein a variable AC current can be provided to coils of the stator of the assembly, and wherein relatively small diameter flexible and less cumbersome wires or cables can be used to supply electrical energy to the assembly even when a powerful motorized wheel assembly is needed.
It is also a further object obtained by a preferred embodiment of the present invention to provide a motorized wheel assembly having a ratio R.sub.1 /R.sub.2 as close as possible to 1 where R.sub.1 is the distance between the air gap of the motorized assembly and the axis of rotation of the assembly, and R.sub.2 is the distance between the surface of a rim fixed onto the assembly, adapted to receive a tire, and the axis of rotation of the assembly.
It is also a further object of the present invention to provide a motorized wheel assembly that reduces heat production and energy loss.
It is also a further object of the present invention obtained by a preferred embodiment of the present invention to provide a motorized wheel assembly that is provided with means for cooling down the assembly when it is operating.
It is a further object obtained by a preferred embodiment of the present invention to provide a motorized wheel assembly having a reduced weight while being compatible with standard braking system, suspension system and steering system.
It is a further object obtained by a preferred embodiment of the present invention to provide a motorized wheel assembly which is detachable from a suspension arm.


An industrial waste byproduct from a titanium metal or a titanium dioxide production process can be utilized as a partial cement replacement. In some embodiments, the byproduct can comprise a byproduct from the production of titanium dioxide pigment from a sulphate process or from a chloride process. The cement can be used to make concrete and other cementitious material products for structural and non-structural uses, for example, grout, mortar, gunite, stucco, masonry, decorative stonework, bricks, blocks, roof tiles, floor tiles, cobblestones, pavers, combinations thereof, and the like.

The present state of the art in concrete research has demonstrated the benefits of utilizing byproduct industrial waste materials as partial cement replacements. The byproduct industrial waste material, also known as mineral admixtures, such as fly ash, slag, and silica fume, can be used as partial cement replacements to change the characteristics and increase the performance of concrete. The use of byproduct material conserves energy, and has additional environmental benefits because of the reduced production and use of cement which can be associated with high carbon dioxide emissions. Byproduct materials, such as fly ash, slag, and silica fume, however, are not always readily available in all areas of the world. These materials are often imported, which increases the cost of concrete production.
In the production of titanium metal, waste byproducts are produced that are generally expensive to store and dispose of, and that are typically not useful. A need exists for an economical and environmentally friendly technique for putting such byproducts to good use.
Producing pigment grade titanium dioxide (TiO2) involves chemical processes. Two processes for the manufacture of TiO2 pigment are the sulphate process and the chloride process. In the sulphate process, titanium slag or ilmenite (FeTiO3) is digested with strong sulphuric acid to solubilize titanium, which is later hydrolyzed and precipitated to form TiO2. In the chloride process, rutile (crystalline polymorphic TiO2) or high purity ilmenite is chlorinated to form gaseous titanium tetrachloride (TiCl4), which is purified and oxidized to form TiO2. Both processes generate large amounts of industrial waste byproducts that must be stored and disposed of properly, involving significant costs and energy use. A need exists for an economical and environmentally friendly technique for putting such byproducts to good use.
Furthermore, a need exists for economical and environmentally friendly cement replacements and methods of making concrete compositions.

Titanium production waste byproduct as partial cement replacement

The National Titanium Dioxide, Co., Ltd. (CRISTAL)


A communication device (104) includes two housings (108, 110), each containing circuitry (114, 115, 116, 117, 118, 122, 123) for operating the communication device (104) in different modes (700, 702, 704, 706, 730, 732). The communication device (104) includes a latch (112) for detachably coupling the two housings (108, 110) and rotating one housing (110/108) with respect to the other (108/110). The communication device (104) switches between the different modes (700, 702, 704, 706, 730, 732) based on the attachment or detachment and the relative position of the housings (108, 110).

Recently, there has been an increased demand in the marketplace for multi-mode communication devices. In response, manufacturers have proposed giving traditional audio telephones video capability. Traditional audio telephones, such as portable radiotelephones, include a user interface carried on a single housing. The user interface comprises a speaker, a microphone, a display, and a data input device, such as a keypad. These telephones are typically used to initiate a call to another user via the keypad. Once the call is initiated, the user positions the telephone in close proximity to his or her ear and mouth so as to listen to the speaker and speak into the microphone, i.e., communicate audibly, with the other user. During use, the telephone is positioned such that the user is unable to view or utilize the display.
To accommodate the video capability, it has been proposed to replace the display of the traditional audio telephone with a larger display, such as a color liquid crystal display, and mount a camera, such as a charge coupled device (CCD) camera, on the single housing in proximity to the display. It has been further proposed to enhance the microphone and speaker of the traditional audio telephone with speakerphone capability. The resulting multi-mode communication device allows the user to hold the communication device away from his or her head and communicate with another user both audibly via the enhanced microphone and speaker and visually via the larger display and camera. Unfortunately, such a device must have a single surface that is at least large enough to carry the larger display, camera, and enhanced speaker and microphone. This results in a dimensionally larger device. Also, the speakerphone enhancement prevents the user from positioning the device in close proximity to his or her ear and mouth to, for example, communicate in privacy or in the presence of loud ambient noise.
Other proposed multi-mode communication devices combine a portable radiotelephone with a personal digital assistant. In a first mode of operation, the device operates as a conventional radiotelephone. In a second mode of operation, a personal digital assistant mode, the device permits the user to, for example, write and store notes, view previously stored notes, fax a note, send a note via electronic mail, and/or access the Internet. In an overlapping mode, while viewing a stored note in the personal digital assistant mode, a user can place a radiotelephone call and view the note during the call. However, this device employs at least two displays and two keypads--one display and keypad for use primarily in the radiotelephone mode and the other display and keypad for use primarily in the personal digital assistant mode. Such redundancy adds sufficient size and cost to the device.
Therefore, what is needed is a multi-mode communication device that permits a user to communicate in privacy and employs a single user interface having components carried on multiple surfaces of the device so as to minimize the size and cost of the device.

Hand-held radiotelephone having a detachable display


A mesh belt is stretched in an annealing lehr and a plurality of fine mesh elements, which constitute a fine mesh having gas-permeability and elasticity, formed by weaving a heat-resistant wire, are fixed onto the mesh belt so as to be arranged along the moving direction of the mesh belt with predetermined spaces in the direction of the width of the mesh belt whereby a flaw which may be produced in a glass product to be annealed when it is placed on the mesh belt in the annealing lehr, is prevented.

1. Field of the Invention
The present invention relates to a method of annealing a glass product by transferring a glass product of high temperature on a conveyor constituted by a wire mesh belt having gas-permeability in an annealing lehr. In particular, the present invention relates to an annealing apparatus for annealing a glass product, which can minimize a flaw which may occur in the glass product of high temperature due to the contact with a metallic material and a thermal factor when the glass product is placed on a wire mesh belt, or a flaw which may occur by a shock when the glass product is placed on the mesh belt or a flaw which may occur due to a mechanical factor such as fine vibrations when the glass product on the mesh belt is passed in an annealing lehr.
2. Discussion of Background
Generally, a glass product obtained by molding molten glass is annealed to normal temperature or room temperature with use of an annealing lehr so that a stress produced in a cooling step is reduced. In the annealing lehr, a conveyor of a wire mesh belt is used to successively transfer glass products in the annealing lehr. The mesh belt is generally constituted by a wire net formed by weaving a heat-resistant wire of 2.0-4.0 mm in diameter so as to provide a mechanical strength which is durable to the weight of the glass products and a tension during the transferring of the products.
When a glass product of high temperature is placed on such mesh belt, there may cause a flaw in the glass product due to a temperature difference between the wire and the glass product or a flaw in the glass product at the position in contact with the mesh belt due to a mechanical shock when the glass product is brought to contact with the mesh belt. Or there may cause the adhesion of rust on the wire to the contacting surface of the glass product. Further, as a factor of resulting the flaw in the surface of the glass product, it is considered vibrations in the mesh belt which are produced during the transfer of the glass product in the annealing lehr. When such flaw is produced in the glass product, an amount of work to remove the flaw in a polishing process is very large and efficiency of production is reduced. As a method of preventing the occurrence of a flaw in a glass product, there is a method wherein stands for mounting thereon glass products of high temperature are provided on the mesh belt (for example, JP-A-55-32773). In this method, however, a large burden is required to mount and remove the stands when a large number of glass products are successively produced. Namely, in order to conduct the provision and remove of the stands in a mechanical manner, a complicated equipment for providing and removing the stands is required. When such operations are to be conducted manually, a much labor is required.

Method of annealing a glass product and annealing apparatus for a glass product


A communication system for vehicle management includes a vehicle, a vehicle management system disposed in the vehicle outputting first data to control substantially a function of the vehicle and recording second data substantially analogous to an operating parameter of the vehicle, a base station substantially remote from the vehicle and having a second transceiver, a first transceiver disposed in the vehicle and connected communicably to the vehicle management system to receive third data from the second transceiver and send the second data to the second transceiver, the third data updating the vehicle management system.

1. Field of the Invention
The invention relates to communication systems for vehicle management, and in particular, to wireless data modems in vehicles.
2. Description of the Related Art
Vehicles, such as over-the-road trucks, are often operated in fleets. Such vehicles may be equipped with computerized controls for their engines or transmissions. These controls may control various operating parameters, such as fuel flow and exhaust gas recirculation. These controls may collect information about vehicle operation as well. All vehicles of a particular type in a fleet may be equipped similarly. Owners or managers of such fleets may desire information about the operating status of each individual member of the fleet in order to manage the fleet efficiently. Since a vehicle such as an over-the-road truck may be away from a base of operations for a considerable periods of time it may be difficult to maintain information that is current. It may also be difficult to schedule the vehicle for maintenance to the control system, such as software upgrades, that entail bringing the vehicle back into a shop.

Communication system for vehicle management


A transmission probe and a reception probe for transmitting and receiving a wideband ultrasonic wave are provided. Each time when the locations of the probes and are moved, a received wave Gj(t) is obtained. Based on a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrowband spectrum FAj(f) is found by inverse Fourier transformation. A longitudinal wave primary resonance frequency f1 having a relationship with a thickness W (mm) of an inspection target and a primary resonance frequency fS1 of a transverse wave generated by mode conversion are calculated. A comparative display of the component waves GAj(t) is presented using f1, fS1 and sizing coefficients ns1, ns2, ns3 and ns4 for high precision inspection. Based on the measurement point which shows a wave generation in the comparative screen of the component waves GAj(t), it is determined that there is a flaw Z at a certain position inside the inspection target immediately below a line segment connecting the transmission probe and the reception probe.

When a conventional ultrasonic inspection method is applied to a nuclear reactor piping system as shown in FIG. 15, the following two problems occur.
1) As shown in FIG. 15, a reactor container contains pipes of a primary piping system, and a turbine building contains pipes of a secondary piping system. As shown here, many reactor pipes are installed in both piping systems, and the total length thereof is gigantic.
The conventional ultrasonic inspection method, which is performed by repeating inspections at local sites, has a problem that a huge number of steps of the inspection work is necessary.
2) With the conventional ultrasonic inspection method, the technological determination criteria required for analysis vary depending on the person who performs measurement and analysis. Therefore, the conventional ultrasonic inspection method has a problem that an error may occur in the evaluation on the development of a tiny flaw caused by an over-time change thereof.
In order to solve the problems (1) and (2), the present applicant has already filed a patent application on an invention relating to "Ultrasonic inspection method and apparatus utilizing resonance phenomenon" (PCT/JP2004/16982).
The prior invention made by the present application relates to an ultrasonic inspection method for extracting a narrowband component wave from a wideband received wave with frequencies n·f1 and n·fs1 (n is an integer of 1 or greater) using resonance frequencies f1=VP/2W and fs1=γ1·f1 (γ1 is a sonic speed ratio of transverse wave and longitudinal wave).
Specifically, in order to inspect presence/absence of a flaw in a thickness immediately below a line segment connecting a pair of probes distanced by an interval of "a", which are a transmission probe and a reception probe, the following is performed. Using one method of moving the probes, the pair of probes are moved by a defined distance in a direction perpendicular to the line segment connecting the pair of probes while the interval between the pair of probes is maintained. Each time when the probes are thus moved, a wideband ultrasonic wave is input from the transmission probe and a wideband ultrasonic wave is received by the reception probe. Based on the wideband received waves Gj(t) (j is the measurement point number) obtained at many measurement points, narrowband component waves GAj(t) are extracted with a sizing coefficient ns4 at the frequencies n·f1 and n·fS1. A comparative display of the component waves GAj(t) is presented with the sizing coefficient ns1, ns2 and ns3. Based on the generation state of the component waves GAj(t) thus displayed in comparison, the presence/absence of a flaw immediately below the line segment connecting the pair of probes is inspected for each j.
According to the prior invention made by the present applicant, the transmission probe and the reception probe are translated by a predetermined distance in a direction perpendicular to the line segment connecting the centers of the probes, so that flaws in an inspection target immediately below the line segment can be inspected all at once. Therefore, as compared with the conventional ultrasonic inspection method, the number of measurement points can be reduced to one several tenth or even to one several hundredth and thus the number of steps of the inspectionwork can be significantly reduced. This can contribute to the solution of the problem (1) above.
However, the above-described ultrasonic inspection method still has the following problem.
3) Due to the variety of locations and manners of movement of the probes, the method still has difficulties in terms of automatic measurement.
According to the prior invention made by the present applicant, even where different operators perform the measurements, as long as the analysis is performed with the same conditions of the sizing coefficients used for realizing higher precision of the inspection, the difference in the sizing result caused due to the varying capability of the measuring operators can be eliminated. Therefore, an accurate evaluation on the development of a tiny flaw caused by an over-time change thereof is made possible. This can contribute to the solution of the problem (2) above.
However, even with the above-described ultrasonic inspection method, there is still the following problem.
4) As a premise of the evaluation, the required received wave Gj(t) needs to be obtained at exactly the same position as in the immediately previous measurement. However, due to the variety of locations and manners of movement of the probes at the time of the measurement, it is difficult to locate and move the probes in the same manner as in the immediately previous measurement.

Ultrasonic inspection method utilizing resonant phenomena


A chuck comprises: a chuck body attached to a spindle of a machine tool; master jaws attached to the chuck body along the normal of the chuck body and formed with T-shaped grooves extending along the length thereof; T nuts having tops and trunks, the tops being slidably fitted in the T-shaped grooves of the master jaws; gripping claws having work holding surfaces and grooves for engagement with the trunks of the T nuts; and eccentric shafts inserted into holes formed across the T nuts and the gripping claws and used for attaching the gripping claws to the T nuts. The holes extend across the T nuts and the gripping claws which are engaged with one another. The gripping claws have large reshaping margins at work holding surfaces thereof.

1. Field of the Invention
The present invention relates to a chuck used to hold a work on a machine tool.
2. Description of the Related Art
A chuck is usually used in order to hold a work on a spindle of a machine tool such as a lathe.
Referring to FIGS. 27 and 28 of the accompanying drawings, a chuck 100 of the related art comprises: a chuck body 1 attached to a spindle of a machine tool; master jaws 2 fixedly positioned in the chuck body 1 along the normal of the chuck body 1 and having T-shaped grooves 2a extending along the length thereof; T nuts 3 having heads 3a and trunks 3b, the heads 3a being slidable in the T-shaped grooves 2a along the normal of the chuck body 1; gripping claws 4 having work holding surfaces 4a and grooves 4b engageable with the trunks 3b of the T nuts 3; and claw attaching members 5 inserted into holes 3c and 4c extending across the T nuts 3 and the gripping claws 4 which are engaged with one another. In this case, the claw attaching members 5 are bolts.
In this chuck 100, the gripping claws 4 usually have their work holding surfaces 4a shaped in order to reliably grip the work.
Therefore, the work holding surfaces 4a of the gripping claws 4 are re-shaped each time they are applied to works having different shapes. Further, even if works of the same shape are to be held, the work holding surfaces 4a have to be reshaped in order to reliably grip the works each time a machining process is changed. The work holding surfaces 4a gradually wear out, so that they should have large reshaping margins as possible.
With the chuck 100 of the related art, the holes 3c and 4c vertically extend through the T nuts 3 and the gripping claws 4 where the claw attaching members 5 are inserted are in parallel with the spindle 0 of the chuck 100, as shown in FIGS. 27 and 28.
With the related art, the holes 3c and 4c occupy a large portion of each gripping claw 4, which means that reshaping margins of the work holding surfaces 4a of the gripping claws 4 are reduced. This would lead to shorter life of the gripping claws 4, which is uneconomical.
Bolts are used as the claw attaching members in the related art, so that it is troublesome to attach the gripping claws to the T nuts. Further, since the bolts are inserted into threaded holes in the T nuts, it is time consuming to make such threaded holes. Sometimes, chips may remain in the threaded holes, which would lead to damages on the threaded holes and threads on the bolts.
The present invention has been contemplated in order to overcome the foregoing problems of the related art, and is intended to provide a chuck in which gripping claws have a little space for holes into which claw attaching members are inserted, and have sufficient reshaping margins of work holding surfaces. The invention further provides gripping claws for such a chuck.
Another object of the invention is to provide a chuck in which gripping claws can be easily attached to T nuts, and to provide gripping claws for such a chuck.
According to a first feature of the invention, there is provided a chuck comprising: a chuck body attached to a spindle of a machine tool; master jaws attached to the chuck body along the normal of the chuck body and formed with T-shaped grooves extending along the length thereof; T nuts having tops and trunks, the tops being slidably fitted in the T-shaped grooves of the master jaws; gripping claws having work holding surfaces and grooves for engagement with the trunks of the T nuts; and claw attaching members inserted into holes in the T nuts and the gripping claws and used for attaching the gripping claws to the T nuts. In the chuck, the holes are formed across the T nuts and the gripping claws which are engaged with one another. This structure is effective in increasing reshaping margins of the wok holding surfaces of the gripping claws, improving the life of the gripping claws, and reducing the running cost of the chuck.
The claw attaching members are constituted by eccentric shafts which have eccentric cams, are rotated and relatively move the T nuts and the gripping claws. The holes in the T nuts and the gripping claws are provided with cam parts with which the cams of the eccentric shafts come into contact.
The gripping claws can be easily attached to the T nuts by slightly turning the eccentric shafts. The holes into which the eccentric shafts are inserted can be formed with ease. Chips remaining in these holes would not extensively damage them.
The holes in the T nuts have cam parts with which cam parts of the eccentric shafts come into contact.
The eccentric shafts have cylindrical stems which are inserted into the holes of the gripping claws. The cams of the eccentric shafts inserted into the holes of the T nuts are thinner than the cylindrical stems, which is effective in preventing chips from getting to the cams of the eccentric shafts, and improving the life of the chuck.
In accordance with a second feature of the invention, there is provided a gripping claw for the foregoing chuck. The gripping claw has a groove for engagement with the trunk of the T nut, and has holes into which the claw attaching members are inserted for attachment of the gripping claw to the T nut, and the holes extend across the T nut and the gripping claw which are engaged.


An adaptive filter or equalizer for digital data communication includes, a first cascade circuit connected to operate as a digital finite-impulse-response (FIR) filter, the first cascade circuit having a respective first single input for receiving samples of complex input data, a respective second input composed of a first plurality of input taps for receiving filter weighting signals, and a respective output for producing samples of filtered data. An error signal generator responds to samples supplied from the output of first cascade circuit to generate samples of an error signal. A second cascade circuit, which includes the form of an FIR filter of inverse canonical form, a respective first single input for receiving said delayed samples of complex input data, a respective second input composed of a second plurality of input taps for consecutively receiving said samples of said error signal from error signal generator, a third single input, and a respective output, which supplies samples fed back to the third input for yielding a succession of weighting signals. Storage registers at the inputs of the first and second cascade circuits are updated by weighting signals and by error signal samples, respectively, serving to multiplex application of single inputs to multiple cascade stages.

Adaptive equalizers are used in modem electrical communication to equalize (i.e., compensate for) linear amplitude and phase distortions which naturally tend to occur within the useful frequency band of practical transmission circuits. If these distortions are compensated, as is well known in the art, a given circuit is capable of correctly receiving transmission of information at substantially higher rates and over virtually unlimited transmission distances. In particular, the current invention relates to dynamically adaptive equalizers, which employ the signals transmitted through a communication circuit or channel for measurement of its distortion. Such circuits alter their amplitude and phase characteristics with time to minimize the measured error at the receiving end of the circuit. Adaptive equalizers are required for use in connection with circuits the distortion properties of which are unknown at the time transmission is initiated, or which for any reason may change during transmission. Representative circuits include those having variable multiple paths, radio transmissions carrying digital voice, data and other signals, and switched telephone lines. In typical adaptive equalizer operation, communication may be established using a repeated signal carrying no information. The equalizer adjusts rapidly to compensate for the transmission circuit distortion. After information transmission is begun, the information signals are then used continuously for iterative dynamic correction of the filter characteristics.
Digitally operating adaptive equalizers are well known in the electrical communications art. All equalizers are, basically considered, electrical filters; and adaptive equalizers are based on electrically adaptable filters, typically taking the form of finite impulse response filters, some forms of which are described by Watanabe in U.S. Pat. No. 4,771,395 issued Sep. 13, 1988 and entitled FIR Digital Filter.
In addition to an dynamically adaptable electrical filter, an adaptive equalizer requires a means to produce the series of control inputs (termed "weights") which define the filtered output in time when responding to a single input pulse of known amplitude. This means is conventionally referred to as a "weight generator", and its outputs as "weights", though they are actually measures of the response of the filter to a pulse input supplied at evenly spaced time intervals.
The weight generator, in turn, uses as its input an error signal which is derived by comparing the output of the filter with expected value(s) of the output. Since these circuits are used in digital data transmission, the desired output signals have a very limited number of values.
Some prior art adaptive equalizers use identical circuits for the FIR filter and weight generator (WG) functions. An example of such adaptive equalizer is found in the Mobile Link 1/2 Receiver Program (MLRP) receiver, a product of Stanford Telecommunications, Inc., of Sunnyvale Calif., which uses the Zoran 891 FIR filter chip for both the FIR and weight generator functions of its adaptive equalizer. The Zoran chip is second-sourced by Harris as the HSP43891 and employs the canonical structure, which utilizes output weighting.
Currivan and Ohlson in U.S. Pat. No. 5,416,799 issued May 16, 1995 and entitled Dynamically Adaptive Equalizer System and Method describe the use of the inverse canonical structure, which employs input weighting, for the FIR filter and weight generator functions. A stated objective of their invention is to provide an adaptive digital filter (equalizer) the design of which makes use of similar inverse canonical structure circuits for the digital elements of the greatest complexity, i.e. the FIR filter and the weight generator. The practical benefits are reduced design time and reduced production cost for the equalizer. These benefits apply to adaptive filters having both filter and weight generator on a single semiconductor chip, as well as to adaptive filters in which filter and weight generator comprise separate chips or collections of chips and other components. Another stated objective of their invention is to minimize the number of additional integrated circuits required ("glue chips") to construct a family of adaptive equalizers from a multiplicity of integrated circuits of the same design. Another objective of their invention is to employ low-cost integrated digital circuits capable of operation at significantly higher speeds than are required to handle information signals, and through multiplex use of their outputs achieve significant reduction in cost and complexity of an adaptive filter for those information signals.
To secure their objectives Currivan and Ohlson rely on a weight generator that in effect reverses the direction of time for data samples. As a result, the updating of filter weights in an FIR filter with inverse canonical structure is done by Currivan and Ohlson in such order that error signals are generated from kernels that are only partially updated.
Laud in U.S. Pat. No. 5,392,315 issued Feb. 21, 1995 and entitled FIR Filter Coefficient Updating System points out that it is desirable to update the filter weights in an FIR filter with inverse canonical structure in such order that error signals are generated from kernels that are completely updated. To implement such updating of filter weights, a weight generator is required which operates on principles different from those known to the prior art.

Dynamically adaptive equalizer system and method


This invention relates to a capacitive switching network for producing signals of opposite polarity. In one embodiment of the invention, a first signal (V1) is applied to the first plate of a first capacitor (C1) and a second signal (V2) is applied to the first plate of a second capacitor (C2). The first plates of the first and second capacitors are then shorted together to produce a combined voltage (Vc). The generation of Vc causes an AC voltage equal to (Vc-V1) to be produced at the second plate of C1 and an AC voltage equal to (Vc-V2) to be produced at the second plate of C2. By way of example, for C1 equal to C2, there is produced a Vc equal to (V1+V2)/2. Furthermore, if V1 is greater than V2, a negative going AC signal equal to (VC-V1) is produced at the second plate of C1, and a positive going AC signal equal to (Vc-V2) is produced at the second plate of C2. The capacitive network of the invention is highly suited for use in high speed differential comparators.

A wide variety of applications arise where an unknown voltage must be compared to a standard voltage within certain preset voltage limits, or two separate voltages must be compared to determine, for example, which is the greater of the two. Such comparisons are used in, for example, feedback circuits, digital voltmeters, counters, etc.
Differential comparator circuits are commonly used for comparing or sensing the difference in levels (e.g., voltages) of a pair of input electrical signals. The differential comparator provides an indication of which of the two electrical input signal is larger.
U.S. Pat. No. 4,374,334 (W. E. Engler) which issued on Feb. 15, 1983 discloses a comparator comprising a first surface charge transistor and a second surface charge transistor which are provided in a common substrate. During a first phase of a cycle of operation, a first voltage signal is applied to a transfer gate of the first transistor and a second voltage signal is applied to a transfer gate of the second transistor. Additionally, during the first phase, the source region and the transfer gate of each of the transistors are equilibrated. The receiver regions or nodes of each of the transistors are precharged and then floated or isolated. During a second phase of the cycle of operation, the first voltage signal is applied to the transfer gate of the second transistor and the second voltage signal is applied to the transfer gate of the first transistor. Additionally, during the second phase, the receiver nodes accumulate an amount of charge proportional to the change of voltage resulting from the switching of the input signals. Such charge is received, however, only if a transfer gate becomes more positive (for n-channel transistors). The receiver node associated with the more positive signal in the first phase of operation will, therefore, remain charged while the receiver node associated with the more negative signal will be discharged, by transfer of charge, to ground. The extent of the potential change is proportional to the difference between the two voltage signals and the gain of the surface charge transistors.
A differential voltage comparator is disclosed in the book entitled "Electronic Circuit Design Handbook" by the editors of EEE magazine, published by Tab Books, revised 4th Edition, 1971, at pages 135 to 136. The disclosed differential voltage comparator provides a "go-no-go" indication when two input signals are compared. If the two input signals are within a preset differential voltage, then an output relay is not actuated and a "go" indication is provided. However, when the two input signals differ by more than the preset differential voltage, then the output relay is actuated and a "no-go" indication is provided.
The prior art differential comparator described hereinabove includes many transistors, diodes, resistors, thermal resistors, and a relay and, therefore, is a complicated circuit. Accordingly, it is desirable to have a comparator which operates at relatively high speeds and has relatively few components.


Aspects of the present disclosure involve systems, methods, computer program products, and the like, for utilizing multiple anycast addresses within a domain name system (DNS) architecture of a CDN. one or more DNS servers of the architecture may announce a plurality of anycast addresses for receiving DNS requests from requesting devices. The group of addresses may be dispersed (and/or announced by) the DNS servers of the architecture such that each server announces a subset of the available addresses. The number and identity of the subset of available anycast addresses utilized may vary from server to server of the DNS architecture and may be determined based on groups of servers, configurations of metros or gateways of the DNS architecture, or performance metrics of one or more servers.

The Internet and the World Wide Web (the "Web") are ubiquitous and easily accessible using numerous possible wired or wireless computing devices. Content providers (publishers) now use the Internet (and, particularly, the Web) to provide all kinds of content to numerous users throughout the world through any number of platforms. In order to offload the job of serving some or all of its content, many content providers now operate or subscribe to content delivery networks (CDNs). Provider content can be served to clients from the CDN (i.e., from one or more content servers in the CDN) instead of from the content provider's server(s). In a caching CDN, content may also be cached on some or all of the CDN servers, either before being served or in response to specific requests for that content. Having content cached enhances the performance of the CDN because the content does not have to be retrieved from origin servers or other locations, which are less efficient than edge servers in providing content.
Numerous forms of content may be served from the CDN. For example, television shows and movies may now be accessed from any number of Web sites, and the shows and movies may be served from the CDN. Print newspapers have migrated to the Web and provide portals through which clients operating some form of computing device (e.g., PC, smart phone, or tablet), with a browser may access numerous forms of content, such as short video clips, articles, images, and audio tracks. Software updates and patches, once provided on disc and mailed to recipients, are now routinely distributed to devices from a CDN through one or more network connections and devices.
CDNs typically include a domain name server (DNS) architecture to support the distribution of content from the CDN to a requesting device or user. In general, the DNS architecture includes multiple DNS servers that, in response to a request, return an Internet Protocol (IP) address or other device address at which requested content may be downloaded. In some instances, the DNS architecture may return several delegated DNS server addresses (or nameservers) from which more information to resolve the DNS request may be provided. However, the quantity of nameservers that may be returned in response to the DNS request may push the limits of scalability within standard internet DNS capabilities. As a result, new approaches for DNS network traffic management and DNS request handling have been developed, including utilizing load balancing and anycast techniques in an effort to reduce the size of results provided by the DNS system.
It is with these observations in mind, among many others, that aspects of the present disclosure were conceived and developed.

Systems and methods for utilization of anycast techniques in a DNS architecture


Disclosed is an apparatus including a memory system. The memory system includes a controller that assigns a first PEC to a first metablock based on a first number of structures of a memory across which the first metablock is distributed. The controller assigns a second PEC to a second metablock based on a second number of the structures of the memory across which the second metablock is distributed. The controller selects one of the first metablock or the second metablock to be used based on the first PEC and the second PEC.

The following description is provided to assist the understanding of the reader. None of the information provided is admitted to be prior art.
Non-volatile data storage devices, such as embedded memory devices (e.g., embedded MultiMedia Card (eMMC) devices) and removable memory devices (e.g., removable universal serial bus (USB) flash memory devices and other removable storage cards), have allowed for increased portability of data and software applications. Users of non-volatile data storage devices increasingly rely on the non-volatile storage devices to store and provide rapid access to a large amount of data.
In some examples, a number of physical blocks of the non-volatile data storage devices may be grouped together to form a metablock, sometimes referred to as a superblock. Using metablocks may improve the reliability of the non-volatile data storage device because the physical blocks of the metablock may be distributed across one or more physical structures of the non-volatile data storage device such as, for example, dies and/or planes. Read and/or write speeds of the non-volatile data storage device may also be improved with metablocks because the physical block(s) on each physical structure may be read and/or written in parallel with the block(s) of the metablock on the other physical structures. However, the blocks of different metablocks may be distributed across respective different numbers of physical structures, which may cause an imbalanced performance among different metablocks.

Systems and methods to optimally select metablocks


A gas regulator has a has an internal gas chamber and a solenoid valve that controls gas flow into the clamber. A pressure monitor monitors the pressure in the chamber and controls the operation of the solenoid valve to produce a desired pressure in the chamber. The solenoid control signal is a pulsed signal with a variable pulse width, frequency or both. The pressure maintained in the chamber may itself be varied by altering the set point pressure, for example according to the operating parameters of an engine.

In the preferred applications the final control of the gas flow to an engine is typically by a venturi (carburation system) or a solenoid valve (fuel injection system). Both of these require precise and accurate control of the input pressure to the device. In automotive use the pressure in the fuel storage container may range from 0.6 MPa to over 30 MPa (90 to 4500 psig) necessitating the use of sophisticated regulation systems to achieve a constant output pressure with the requisite variable mass flow rate.
The known regulators are mechanical. These regulators are preset by the manufacturer and may be difficult to adjust correctly after installation. Recent automotive regulations in many countries prohibit adjustment to a regulator after installation as tampering with the emission system. This requires that the regulator remains in tolerance for long periods, normally amounting to a number of years or a representative cumulative distance.
Existing natural gas vehicle (NGV) regulators for fuel injection applications are mechanical systems with either one or two stages of pressure regulation. Three or four stages of pressure regulation are used in conventional carburetor-mixer NGV fuel systems. Mechanical regulators can be designed to address many of the problems, but this may increase the number of moving parts, which in turn may affect reliability and cost. Although these systems have demonstrated good performance in many applications, there are problems associated with their use.
Droop: One difficulty with mechanical regulators is that the output pressure decreases or droops, when the fuel flow rate is increased significantly, which frequently happens in automotive applications. Typically, the fuel flow rate increases by a factor of 30 on acceleration from idle to maximum engine speed at wide open throttle. This can cause pressure droop between 70 and 140 kPa (10 to 20 psig) for mechanical regulators. Pressure droop complicates the calibration of fuel injected engines because there must be compensation for the pressure reduction in the calibration tables to maintain a proper air fuel ratio. Systems with droop require sophisticated and expensive compensation systems.
Resonance: The spring and diaphragm arrangement in a mechanical regulator may be sensitive to resonance. The flow dynamics of the manifold that connects the fuel injectors to the regulator can be prone to pressure resonances of 70 to 210 kPa (10 to 30 psig).
Hysteresis: The spring and diaphragm arrangement in a mechanical regulator may be sensitive to hysteresis which can result in a pressure reduction of 70 kPa (10 psig).
Temperature: The spring and diaphragm arrangement in a mechanical regulator may be sensitive to temperature effects. Elastomeric diaphragms are less flexible in cold weather, which decreases the ability of the fueling system to respond to changes in vehicle operation.
Transient response:
Mechanically regulated systems cannot compensate for the inertial lag from injectors on fuel injected natural gas vehicles. Current injectors have an opening time of up to 4 milliseconds, which is a significant portion of their pulse width operation.
The present invention aims at a system that ameliorates the problems with the mechanical regulators of the prior art.