A virtual tape controller is provided between a changer using DVD media as recording media and a host computer. The virtual tape controller receives commands from the host computer through a magnetic tape interface that emulates the interface to magnetic tape apparatus. Request translation means interprets the commands from the host computer, and generates commands for controlling drives within the changer on the basis of information for indicating the data positions on virtual tapes held at access positions and the positions of the heads of data recorded on virtual tapes on the media held in conversion table holding means.

The present invention generally relates to information storage apparatus in a computer system, and particularly to a storage system using detachable disk-like recording media and which can emulate storage apparatus using tape-like recording media.
The storage media for use in a computer system or the like have been developed to have a higher density and capacity year after year. For example, the storage capacity of the 3.5-inch floppy disk used so far has been increased as 360 KB, 720 KB, 1440 KB, and 2880 KB. In addition, the DVD-RAM (Digital Versatile Disc Random Access Memory) that began to be marketed from 1998 has initially a capacity of 2.6 GB, and thereafter its capacity is planned to increase to 4.7 GB and 15 GB. The merit of increasing the capacity of the storage media is to make it possible to increase the recording capacity per installation area of the storage apparatus. This greatly affects the maintenance and management cost of the digital data held by companies.
On the other hand, in the field of large-scale computers, magnetic tapes have been used as recording media for a long time. The magnetic tape has also been improved in its recording density and storage capacity year after year. Therefore, the past assets were stored in low-density magnetic tapes of, for example, 200 MB per cartridge of tape. If the past assets stored in the low-density recording tapes can be transferred to the present high-density magnetic tapes, it is possible to greatly increase the recording density per installation area. Use of, for example, a tape of 50 GB per cartridge will enable data of 250 cartridges of 200-MB magnetic tape to be all transferred to a cartridge of that magnetic tape. If it is simply assumed that the size of a cartridge of high-density magnetic tape is equivalent to that of low-density magnetic tape, the recording capacity per installation area can be increased 250 times. Here, let us consider that information of T1 to T250 (T1, T2 . . . T250 respectively represent a cartridge of conventional magnetic tape) are stored as tape units in a cartridge of the present high-density tape A. In this case, the recording capacity per installation area can be increased as described above. However, if data of T10 and T240 stored on the cartridge of tape A are ordered to read at substantially the same time, the magnetic tape is fast forwarded or rewound, so that the performance of read (access time) of the storage apparatus is greatly reduced. In other words, a cartridge of tape fundamentally cannot respond to the order to read a plurality of times at substantially the same time because of the long latency of the tape-like recording media.
A technique of xe2x80x9cvirtual tapexe2x80x9d as disclosed in, for example, xe2x80x9cVirtual Tape: What It Is And Its Performance Considerationsxe2x80x9d (Kuntal G.Rawal, Steven A. Johnson, CMG97) was contrived to solve this problem and improve the recording capacity per installation area of the storage apparatus. This example describes a method in which a magnetic disk unit is used as a buffer for a plurality of requests to read. Specifically, in the previously given example, when a host computer orders a tape for T10 to be mounted, a virtual tape apparatus mounts magnetic tape A that includes data of T10. Then, a tape label is read from the mounted magnetic tape A, and data position of T10 is obtained. The virtual tape apparatus controls the magnetic tape A to be fast forwarded (or rewound) on the basis of this data position, and the data of T10 to be written in the magnetic disk unit. The host computer orders the data of T10 to be read from the magnetic disk unit in which the data of T10 was written. Then, when a request to read T240 of the same magnetic tape A occurs, the data of T240 is written in the magnetic disk unit. Because the access time of the magnetic disk unit is as extraordinarily fast as 10 ms or below as compared with the magnetic tape, the T10 and T240 can be read in parallel, or at the same time with an appropriate speed for operation even though requests to read the data of T10 and T240 occur at substantially the same time.
In the conventional virtual tape apparatus, the magnetic disk unit is required for the case where data of low-capacity magnetic tapes stored at different positions on a large-capacity magnetic tape are simultaneously read from that large-capacity tape. This results in the increase of the cost of the storage system. In addition, before desired data is read from the magnetic tape, the data is required to be transferred from the magnetic tape to the magnetic disk unit where it is written. Thus, it takes a long time to reach the desired data (the access time is long).
Accordingly, it is an object of the invention to reduce the system cost by removing the necessity of the magnetic disk unit in the conventional virtual tape apparatus.
In addition, it is another object of the invention to reduce the access time of the virtual tape apparatus.
In order to achieve the above objects, according to the invention, there is provided a virtual tape storage system including a control unit connected to a host computer, and a storage unit that is controlled by this control unit to write on or read from removable disk-like recording media in which data positions can be randomly accessed. The control unit has a magnetic tape interface that emulates an interface between the magnetic tape apparatus and the host computer, request translation means for interpreting the command received from the host computer through the magnetic tape interface and generating a command for controlling the storage unit, and controlling means for controlling the storage unit by use of the command generated by the request translation means.
In the preferred embodiments of the invention, a changer is used as the storage unit. The changer has a plurality of cells for holding the removable disk-like recording media, drives for loading the removable disk-like recording media and accessing data on the media according to the order from the control unit, and carrying means for transporting the removable disk-like recording media between the storage housings and the drives. The removable disk-like recording media each have a plurality of recording regions corresponding to the recording media recognized by the host computer and an index region for holding management information that makes identification information of recording media specified by the host computer be associated with the recording regions. The control unit also has a direct interface that receives from the host computer a command for directly accessing the removable disk-like recording media, so that the command from the host computer can be received by either one of the magnetic tape interface and the direct interface in accordance with the selection order from the host computer.


In providing product reviews relevant to a specific user, a server determines that a user is viewing a current product on a website. The website includes a plurality of product reviews for the current product. In response, the server automatically collects criteria specifically for the user, where the criteria describe the current and past website browsing behavior of the user. The server applies weights to one or more of the criteria, where the weights are specific to the user. The server ranks the plurality of product reviews based on the weighted criteria and sends the rankings of the plurality of product reviews to a web server hosting the website. The plurality of product reviews is displayed on the website according to the rankings. The relevancy rankings can vary between users and thus the display of the most relevant product reviews can vary between users.

Product reviews are critical for online shoppers and influence the purchasing decisions of visitors to a website or application. When viewing product details as part of a browsing experience on a website/application, users are typically given the same view of the product details with some static mechanism for displaying product reviews. Some products have numerous reviews, numbering in the hundreds and even thousands. These reviews are typically sorted by most recent. Some websites/applications allow product reviews to be marked "helpful" by users, and the reviews collectively rated most helpful are then sorted and displayed at the top of the list of reviews. Some websites/applications provide basic sorting options that can be set by the user. However, none of these websites rank product reviews for a specific user who is currently browsing the website/application. Therefore, the user may have difficulty finding reviews that are actually helpful to them.

Cognitive system and method to provide most relevant product reviews to specific customer within product browse experience

International Business Machines Corporation


An enzyme is re-engineered to be a zymogen, an enzyme precursor which is converted into an enzyme by protease cleavage. In the example described here, an RNase A enzyme is converted into a zymogen by adding to the enzyme a bridge of amino acids linking the amino and carboxyl termini of the enzyme. The bridge has built in it a protease cleavage site for a specific protease, for example the protease plasmepsin II, produced by the malaria parasite. Since RNase A can be made cytotoxic, this permits a cytotoxic enzyme to be made in the form of a zymogen that becomes active only when it is acted on by a protease only present in a particular target cell such as a pathogen.

The simplest definition of enzymes is that enzymes are proteins which can act as catalysts for a chemical reaction. As with all proteins, the amino acid sequence and the three-dimensional structure of enzymes are both important to the proper biological functioning of enzymes. Some enzymes are not functional as enzymes in the normal form in which they are synthesized originally in living cells. Instead, these enzymes are expressed as an enzyme precursor known as a zymogen. A zymogen is acted on by some other enzymatic process in or out of the cell to convert the zymogen into the enzymatically active form of the protein. Typically enzymes which could cause damage to cellular biochemical processes, like proteases, are produced as zymogens, thus permitting their activity to be controlled more precisely. Zymogens are inactive as expressed, and thus can be stored or transported safely and then activated by proteolytic activity only when needed.
In living cells, biological polymers such as proteins and nucleic acids must continually be digested into their monomers which can then be recycled for use in making new proteins or nucleic acids. Proteases digest proteins and nucleases digest nucleic acids. Among the best studied of nucleases are the ribonucleases which are adapted to digesting RNA molecules. In particular, the sequence, the three-dimensional structure, and many aspects of the functioning of ribonuclease A (RNase A) have been characterized, particularly with regard to bovine pancreatic ribonuclease A. RNase A exists in cells in balance with a ribonuclease inhibitor (RI), which binds to RNase A to inhibit its activity. It has already been found that adding a moiety to RNase A that acts to provide a steric barrier to binding between RI and RNase A causes the RNase to be uncontrolled by the RI and therefore cytotoxic, presumably by digesting needed RNA species in the cell.
It is a characteristic of proteases that they have specific amino acid sequences in target proteins that they recognize to digest a specific peptide bond. Many types of cells or organisms have specific proteases that recognize specific amino acid sequences for their target cleavage site. It is thus possible to design proteins which will be enzymatically cleaved only by proteases present in a select group, type or species of target cells.
Other objects, features and advantages of the invention will become apparent upon consideration of the following detailed description.


A method for reducing loads of a wind turbine includes determining a wind speed at the wind turbine. Further, the method includes determining an operational state of the wind turbine. The method also includes determining whether a rotor of the wind turbine is imbalanced beyond a predetermined threshold when the operational state corresponds to a predetermined operational state as a rotor imbalance beyond the predetermined threshold is indicative of a pitch fault in one or more of the rotor blades. In addition, the method includes yawing a nacelle of the wind turbine to a predetermined angular position when the wind speed exceeds a predetermined speed threshold and the rotor is imbalanced beyond the predetermined threshold.

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor including one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
During operation, the direction of the wind which powers the wind turbine may change. The wind turbine may thus adjust the nacelle through, for example, a yaw adjustment about a longitudinal axis of the tower to maintain alignment with the wind direction. In addition, when the wind turbine is parked or idling, conventional control strategies include actively tracking the wind direction to provide better alignment to the wind direction so as to minimize start-up delays when the wind speed increases or decreases back into the operating range.
However, in a situation where the wind turbine is idling and the rotor is imbalanced, there are limited benefits to tracking the wind as repair is needed before restarting the wind turbine. In addition, in such situations, the wind turbine can experience increased loads.
Accordingly, improved systems and methods for reducing loads during an idling or parked state of a wind turbine would be desired. In particular, the present disclosure is directed to systems and methods which actively yaw the nacelle of the wind turbine to a predetermined benign yawing/azimuth position when the wind turbine is idling or parked and the rotor is imbalanced so as to reduce loads during this scenario.

System and method for reducing wind turbine loads by yawing the nacelle to a predetermined position based on rotor imbalance


A failure-recovery-information storing unit stores failure-recovery information in which a working path is associated with a backup path. A failure-occurrence-notification receiving unit receives a failure-occurrence notification indicating that a failure has occurred in the working path. A backup-path searching unit searches for a backup path corresponding to the working path on which the failure has occurred, based on the failure-recovery information. A path-switch processing unit carries out a path-switch process, in such a manner that the data to be transferred using the working path in which the failure has occurred is transferred using the backup path.

1. Field of the Invention
The present invention relates to a data relay apparatus and a data relay method to relay data in a network, which carries out a failure recovery, when a failure occurs at any point on a working path that is being used as a path through which data is transferred via a plurality of data relay apparatuses, by switching the path to a backup path to make a detour to avoid the failure point, and more particularly to a data relay apparatus and a data relay method that can reduce the number of path used to recover the failure by increasing the number of working paths that can be handled by a single path used to recover the failure, such as a monitor path.
2. Description of the Related Art
The generalized multi-protocol label switching (GMPLS)/MPLS is a technology to transfer data according to label information. The label information includes a fixed-length label that is attached to a head of a packet, a time slot in a time division transmission, and an optical wavelength in an optical-multiplexed transmission. In particular, a network in which data is transferred using the fixed-length label that is attached to a head of a packet is referred to as the MPLS. In addition, the GMPLS network uses a single piece or a plurality of pieces of information including the fixed-length label used in the MPLS network.
For example, in a packet transmission using the fixed-length label, a relay node (a label switch router (LSR)) holds a label table that represents a relation of an output label and an output interface (IF) with respect to an input label and an input IF. At a time of packet relay, an output IF is determined according to a label attached to a packet received, instead of an address. Then, the label attached to the packet is rewritten into the output label to be relayed. By repeating this procedure, the packet is transmitted to a destination. A relay node (start-point node) of the MPLS network attaches the label at the beginning. The MPLS is such kind of high-speed packet relay technology.
FIG. 34 is a schematic diagram for explaining a packet transmission using the fixed-length label. The figure illustrates an example of transferring a packet from LSR1 to LSR4. First of all, the LSR1 attaches a label a to the packet to be transferred. An LSR2 receives the packet having the label a from an IF#1, searches for a label table, and acquires an output IF and an output label. After that, the LSR2 rewrites the label of the packet into an output label, and outputs the packet to an output IF. The MPLS transfers the packet to the LSR4 of an end-point by repeating such kind of process at each of the LSRs.
In this manner, the MPLS can enhance the speed of the packet relay by transferring the packet according to the fixed-length label. In addition, the MPLS can assure a bandwidth for each of the packet flows by associating a bandwidth control in the relay node with each of the labels.
Furthermore, in the time division transmission, each of the nodes holds a label table that represents a relation of an output label and an output IF with respect to an input label and an input IF. Then, each of the nodes determines an output IF and an output time slot according to a reception IF and a reception time slot, and outputs data to the output time slot of the output IF. By repeating this procedure, the data is transmitted to a destination.
Moreover, in the optical-multiplexed transmission, each of the nodes holds a label table that represents a relation of an output optical wavelength and an output IF with respect to an input optical wavelength and an input IF. Then, each of the nodes determines an output IF and an output optical wavelength according to a reception IF and a reception optical wavelength, converts the reception optical wavelength into the output optical wavelength, and outputs the output optical wavelength to the output IF. By repeating this procedure, the data is transmitted to a destination.
The GMPLS is a technology to carry out a data transfer in the same mechanism by handling the fixed-length label, the time slot, and the optical wavelength as a label.
In the GMPLS/MPLS, it is necessary to build a label table at each of the nodes, and a path-establishing signal protocol (such as CR-LDP/RSVP-TE) is used for building the label table. The following is an explanation of an operation for a path establishment with the RSVP-TE as an example.
FIG. 35 is a schematic diagram for explaining an operation of the path-establishing signal protocol (RSVP-TE). As shown in the figure, a start-point node that requests a path establishment transmits a request message for the path establishment (Path message) to an end-point node of the path by Hop-by-Hop. In the schematic diagram shown in FIG. 35, information on a relay node to be routed through is inserted in the Path message, for designating a path explicitly.
The end-point node that receives the Path message returns a path-establishment response message (Resv message) to carry out an assignment of the label to the start-point node along the path through which the Path message is transmitted. At this moment, a label table for transferring data is built by registering a label stored in the Resv message to the label table. A path ID is stored in both of the Path message and the Resv message, and the path ID is also registered to the label table accordingly.
In the path-establishment signal protocol, a PathErr/ResvTear/Notify message is used as a failure message for notifying that a failure has occurred in a path established, in addition to the Path message indicating a request for a path establishment and the Resv message that is a response to the Path message.
FIG. 36 is a schematic diagram for illustrating a transfer of a failure message using a PathErr/ResvTear message. As shown in the figure, the PathErr/ResvTear message is transferred to the start-point node by Hop-by-Hop along the path. On the other hand, a Notify message is directly transferred to the start-point node that is a destination for a message. For this reason, the Notify message may also arrives at the start-point node along a route that is different from the path. In the failure message, the same path ID as the path ID stored in the Path/Resv message, so that it is possible to carry out an association between the failure and the path.
In the GMPLS/MPLS, when a failure occurs in a working path for transferring data, the transfer of the data is carried out using a backup path that makes a detour around the working path. For example, in the MPLS, the working path is monitored using a monitoring path, and when a failure occurs in the working path, a failure recovery process is carried out by switching the working path to a backup path (see, for example, Japanese Patent Application Laid-Open Publication No. 2003-338831).
FIG. 37 is a schematic diagram for explaining a failure recovery method using a monitoring path. As shown in the figure, in the failure recovery using the monitoring path, a working path and a backup path for making a traffic on the working path take a detour at a time of a failure occurrence, using the path-establishment signaling protocol. At this moment, the backup path is established between the same start-point node and end-point node as those of the working path.
Furthermore, a monitoring path for monitoring a status of the working path is established using the path-establishment signaling protocol. The monitoring path includes, as shown in FIG. 37, two paths in both a downstream direction and an upstream direction along the working path. A monitoring packet is reciprocated on the two monitoring paths periodically. This monitoring packet is a labeled packet because it is transmitted on the monitoring path.
When there is a failure on the working path, the start-point node "LSR1" detects the failure by one of the following methods. One of the methods is to detect the failure by a fact that the monitoring packet that is supposed to be transmitted and received periodically does not arrive within a predetermined time. Another method is to detect the failure by a relay node on the upstream, and to transfer a failure notification packet with a labeled packet by the relay node.
Upon recognizing that a failure has occurred by one of the above two methods, the start-point node transmits the traffic that was being transmitted to the working path to the backup path to make a detour around the failure. One monitoring path can be established for a plurality of working paths that is established on the same route, as shown in FIG. 37. This will decrease a total number of the monitoring paths.
However, in the conventional technology described above, since the backup path is limited to a plurality of paths having the same route only, it is not possible to increase the number of the working paths that can be handled with one monitoring path. For this reason, the number of the monitoring paths is inevitably increased.
Furthermore, the fact that it is necessary to establish two monitoring paths for one sector is another factor for increasing the number of the monitoring paths. In consequence, the number of the monitoring paths to be managed on a network is increased, resulting in an increase of a management load.
Moreover, since it is necessary to transmit and receive the monitoring packet periodically, the monitoring packet consumes a bandwidth even for a normal time. In addition, since the notification packet for notifying the failure is inserted from the relay node, not from an entrance node of the path, it is necessary to install a function for inserting a packet from a relay node of the path.
It is an object of the present invention to solve the above problems in the conventional technology and to provide a data relay apparatus and a data relay method that can reduce the number of paths for a recovery of a failure by increasing the number of working paths that can be handled by a single path for the recovery of the failure, such as a monitoring path.
As a failure recovery method, there are several methods disclosed so far, such as a path detour method using an error message of the signaling protocol, a fast rerouting method explored by IETF (Internet Draft: draft-iert-mpls-rsvp-lsp-fastreroute-07.txt), and a path detour method using a multiple addressing of failure information (Yasuki fujii, Keiji Miyazaki, Kohei Iseda, "Review of preplan-type failure recovery method", Singakugiho TM2000-60, pp. 67-72, November 2000).
However, the path detour method using the signaling protocol has a problem that, when a failure that affects a plurality of paths occurs, a number of message are generated, which increases a network load. The fast rerouting method has a problem of increasing the number of backup paths because it is necessary to establish the same number of backup paths as the number of links through which the working path passes. The path detour method using the multiple addressing of the failure information has a problem that a packet to an unrelated node is generated because a multiple-address packet is used.

Data relay apparatus and data relay method


A compound represented by the formula (I) [R1 represents hydrogen atom or a substituent; R2, R3, R6, and R7 represent hydrogen atom, an alkyl group, a halogen atom, or a hydrophilic substituent; R4 and R5 represent an alkyl group or an aryl group; R8 and R9 represent a group cleaved by contact with an object substance for measurement; and X represents silicon atom, germanium atom, or tin atom] or a salt thereof, which is useful as a fluorescent probe that emits red fluorescence by contact with an object substance for measurement.

Fluorescein is a molecule reported in 1871, and has been widely used as a pH indicator or a labeling dye because of the high water solubility and high fluorescence quantum yield thereof. Since a calcium probe containing fluorescein as a mother nucleus was developed, there have been provided a large number of highly sensitive fluorescent off/on type probes utilizing intramolecular photoinduced electron transfer (PET), decyclization or cyclization of spiro ring, and the like. However, plural dyes containing fluorescein as a parent compound cannot be simultaneously used in molecular imaging, since fluorescence wavelengths thereof overlap with each other. Moreover, the probes utilizing the intramolecular photoinduced electron transfer suffer from a problem that such probes require precise design of the oxidation potential of the benzene ring, and therefore modification of the chemical structure is strictly limited.
A compound corresponding to the basic structure of rhodamine, pyronin Y (PY), of which oxygen atom is replaced with silicon atom (TMDHS) and application of this compound as a fluorescent probe have already been reported (Best, Q et al., Pacifichem 2010, subject number 2335, Dec. 19, 2010; Yuichiro KOIDE et al., Fourth Convention of The Japanese Society for Molecular Imaging, subject number P8-9, May 14, 2009). Further, there have recently been reported compounds usable as a mother nucleus of a red fluorescent probe, which correspond to fluorescein of which 10-oxygen atom of the xanthene ring is structurally modified (Chemical Communications, 47, pp. 4162-4164, 2011).


The programmable modem for digital data of the present invention provides a highly programmable, digital modem implemented in an integrated circuit which can be customized to specific applications. The programmable modem uses spread spectrum techniques and is specifically programmable to alter the parameters of the modem to improve performance. The present invention also provides a systematic method and development kit to provide rapid customization of a modem for a particular application or for rapid specification of a high-performance application specific integrated circuit mode.

1. Field of the Invention
The present invention involves a programmable modem for digital data, a method of using the modem, and a manner in which to design an appropriate modem. More specifically, the present invention relates to a programmable digital modem using spread spectrum techniques and being specifically programmable to alter the parameters of the modem to improve performance.
2. Description of Related Art
There are a number of systems and methods for communicating information using spread spectrum communication techniques. The direct sequence spread spectrum technique is a digital modulation technique in which a digital signal is spread over a wide frequency band so that it has a noise-like spectrum. This is done by breaking up each data bit into multiple sub-bits (commonly called chips, and referred to in this application as PN code bits or chips (Pseudo Noise code bits)) that are then modulated and up-converted to a carrier frequency. By using orthogonal codes for different communication links, the same frequency band can be used for different simultaneous links. Using the same PN code as the transmitter, the receiver can correlate and collapse the received, spread signal back to the data signal, while other receivers that use other codes or other transmission techniques cannot. Advantages of using spread spectrum communication techniques include robustness with respect to interference caused by other signal sources, the possibility of sharing the same frequency band for different co-existing applications, a potential for high effective data rates and a guarantee on message privacy. These advantages make spread spectrum techniques a preferred technology in order to realize communication systems for use on noisy network media where robustness of the link is crucial, like in wireless local area networks or in industrial environments with high and unpredictable interference levels or in home or indoor office environments.
Systems employing spread spectrum communication methods are well-known.
U.S. Pat. No. 5,359,625 discloses an apparatus and method for transmitting and receiving data on a communication channel making use of spread spectrum communication techniques using direct sequences that approximate a swept frequency waveform.
U.S. Pat. No. 5,022,047 discloses an apparatus for decoding received spread spectrum signals modulated with a PN code.
U.S. Pat. No. 5,309,474 discloses a direct sequence spread spectrum modulator with a signal orthogonalizer. Exemplary embodiments are shown wherein signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals.
U.S. Pat. No. 5,357,541 discloses a transceiver for transmitting and receiving digital data using direct sequence spread spectrum communication techniques. The transceiver also includes circuit means for selecting different PN code bit sequences to provide multiple communication channels on a single transmission medium. Additional means for providing selectable carrier frequencies are also disclosed. The means provide a limited programmability of the transceiver.
U.S. Pat. No. 5,235,615 discloses a method for establishing and communicating synchronous, code division multiple access communications between a base station and a plurality of remote units.
U.S. Pat. No. 5,375,140 discloses a wireless direct sequence spread spectrum digital cellular telephone system. Orthogonal CDMA techniques are used.
U.S. Pat. No. 5,363,401 describes a mechanism for extracting hybrid frequency-hopping/direct sequence signals within a multi-signal type environment.
U.S. Pat. No. 5,414,728 discloses a method and apparatus for bifurcating signal transmission over an in-phase and quadrature-phase spread spectrum communication channel using orthogonal codes on the in-phase and quadrature-phase branch. Both transmitter and receiver are described.
In the article "Silicon Synthesis of a Flexible CDMA/QPSK Mobile Communication Modem," DSP Applications, February 1994, by L. Philips et al., parts of the architecture of a flexible modem chip ("chips" herein to be understood as an integrated circuit) that can be used in a broad class of satellite transceivers is disclosed. This modem chip is called the Programmable Mobile Communication Modem (PMCM) and is programmable to a large extent. The chip is realized as an integrated circuit with a hardware core that is reusable, and therefore adapted for programming for different applications. The PMCM chip is used as one part of a chip set, the other part being any commercially available DSP chip.
A modem is a device that is designed to optimally transmit data over a particular, specified channel. There exists many types of channels. Hence, there exist many types of modems.
This is also true for the particular case of direct sequence spread spectrum (DSSS) modems. From the characteristics of the channel, and the required performance of the modem for that particular channel, the structure of the modem and a large number of modem parameters are selected. There is no systematic way to make these selections in the prior art. It is rather the art of the modem designer that makes a good modem design.
There are a number of methods and tools for supporting the design of large and complex electronic systems such as digital multi-processor systems. These systems comprise many parts which are very different, such as control dominated parts, reactive parts, data flow parts, and structurally described parts. Such systems are referred to as heterogeneous systems. The methods and tools propose a unifying specification paradigm to capture a behavioral specification of a large and complex, heterogeneous digital or mixed digital/analog electronic systems. These methods and tools propose a simulator concept to cope with all aspects of the various parts of the specified system. The methods and tools propose a single implementation target for heterogeneous systems. Examples are named Ptolemy, by the University of Berkeley, Calif., COSSAP by the RWTH Aachen, Germany (now commercialized by CADDIS, a subsidiary from Synopsys) or GRAPE by the University of Leuven, Belgium.

Programmable modem apparatus for transmitting and receiving digital data, design method and use method for said modem


A buffering device includes a cylindrical casing and a piston module movably mounted in the cylindrical casing. The cylindrical casing includes a base plate and a shielding piece pivotally attached to the base plate. An air inlet and an air outlet are defined in the base plate. A diameter of the air inlet is greater than that of the air outlet. When the piston module is moving towards the base plate, the shielding piece is rotated to a closed position to shield the air inlet by air pressure above the shielding piece. When the piston module is moving away from the base plate, the shielding piece is rotated to an open position to expose the air inlet by environmental air pressure.

1. Technical Field
The present disclosure relates to a buffering device.
2. Description of Related Art
A vending machine includes a cabinet and a door pivotably attached to the cabinet. A buffering device is attached to the door. When the door is rotating to a closed position, the buffering device provides resistance to slow down a rotation speed of the door. However, the buffering device includes resilient members which easily become invalid because of mechanical fatigue.
Therefore, there is room for improvement within the art.

HONG FU JIN PRECISION INDUSTRY (WuHan) CO., LTD.


A process is provided for producing a dental restoration piece that has a frame with first and second portions and a blended synthetic material covering a first portion of the frame, the heat expansion coefficient of the blended synthetic material being different than the heat expansion coefficient of the frame material. Prior to a thermal treatment of the dental restoration piece, at least the second portion of the frame is covered with a heat protection paste, whereby the heat protection paste limits the increase in temperature of the frame resulting from thermal treatment of the dental restorative piece to effect curing of the blended synthetic material to a lesser temperature value than if the heat protection paste had not been applied onto the dental restorative piece. Also disclosed is a kit for practicing the process.

A dental restoration piece-producing process typically provides for the use of two materials. Frequently, blended synthetic materials are applied to metal frames in order to make possible an aesthetically satisfactory dental restoration piece and to increase the biological compatibility of the dental restoration piece.
Blended synthetic materials are typically cured or hardened into a cured condition via irradiation thereof with light or heat or via a combination of light and heat. This results in an increase in temperature of the material. Problems then arise due to the difference between the heat expansion coefficients of the blended synthetic materials which have been applied onto metal frames and the heat expansion coefficient of the metal of the metal frames. While the blended synthetic material is typically still soft during the heating up phase—namely, in connection with a positive temperature gradient, the blended synthetic material hardens during the cooling off phase, whereupon stresses occur for the reason that the synthetic material contracts more than the metal during the cooling off phase.
Since the heat expansion coefficient of blended synthetic material is greater, hairline cracking occurs in the blended synthetic material either immediately after the polymerization, after the completion of production, or, possibly, also occasionally after the passage of a certain amount of time following production. Such cracking can lead to the accumulation of bacteria in usage.
Aside from the adverse hygienic considerations, another problem is that the collective securement of the blended synthetic material on the dental restoration piece is degraded by such stress cracking so that the danger exists that a portion of the blended synthetic material comes loose. Typically, the stress relief occurs as well at the thinnest locations of the dental restoration piece—for example, at interdental locations.
It has already been suggested, in order to prevent such problems, to accommodate or align the heat expansion coefficient of the synthetic material to the greatest extent possible to that of the deployed metal coatings. This approach, however, is subject to physical limitations as well as the functional requirement that polymeric synthetic materials must typically be deployed of the type which are curable via light and/or heat irradiation.
It has been suggested, in fact, to apply a compensation layer on the metal frame before the blended synthetic material is applied thereunto with the objective that the compensation layer will elastically or resiliently yield such that the occurrence of stress cracking in the contracting blended synthetic material will be avoided.
Such solutions are, however, technically problematical to realize in practice, are expensive, and, moreover, are apt to degrade the securement or attachment of the blended synthetic materials.

Process and kit for producing a dental restoration piece


A Hall effect device (60) is exposed to a magnetic field having flux lines extending in a first direction relative to the Hall effect device (60) if a seat belt tongue (16) is not locked in a seat belt buckle (12). The Hall effect device (60) is exposed to a magnetic field having flux lines extending in a second, opposite direction relative to the Hall effect device if the tongue (16) is locked in the buckle (12). The output of the Hall effect device (60) indicates whether or not the tongue (16) is locked in the buckle (12).

A seat belt system for restraining a vehicle occupant typically includes seat belt webbing, a seat belt locking tongue on the webbing, and a seat belt buckle. The tongue on the webbing is inserted in the buckle when the webbing has been placed about a vehicle occupant. A latch mechanism in the buckle interlocks with the tongue to secure the webbing about the occupant. Such a seat belt system may also include a buckle switch for indicating whether or not the tongue is locked in the buckle.

Method and apparatus for indicating the locked or unlocked condition of a seat belt buckle


The image forming apparatus comprises: a plurality of ejection ports through which liquid is ejected toward a prescribed recording medium; a plurality of pressure chambers which are respectively connected to the plurality of ejection ports; a plurality of first actuators which respectively change volume of the plurality of pressure chambers; a common liquid chamber which is connected to the plurality of pressure chambers; a second actuator which changes volume of the common liquid chamber; and a drive unit which supplies drive signals to the first actuators and the second actuator, such that the first actuators cause the volume of the pressure chambers to contract to eject the liquid through the ejection ports and subsequently to expand the volume of the pressure chambers, and causes the second actuator to contract the volume of the common liquid chamber after the volume of the pressure chambers has been expanded.

1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which an image is formed on a recording medium by ejecting liquid from ejection ports toward a recording medium such as paper by changing the volume of pressure chambers connected to the ejection ports.
2. Description of the Related Art
There is known an image forming apparatus in the related art, which forms an image on a recording medium, such as paper, by ejecting ink from a plurality of nozzles toward the recording medium, while moving a liquid ejection head having an arrangement of the nozzles and the recording medium, relatively with respect to each other.
A known liquid ejection head mounted in the image forming apparatus is, for example, a piezo-type liquid ejection head, in which ink is supplied to pressure chambers connected to nozzles, and the volume of the pressure chambers is changed, thereby causing the ink inside the pressure chambers to be ejected from the nozzles, by applying a drive signal corresponding to the image data to piezoelectric elements that are installed through a diaphragm plate on the outer side of the pressure chambers.
In the image forming apparatus having the inkjet head, in order to be able to form an image at high speed by shortening the ink ejection cycle, it is necessary to improve the refill speed of the liquid into the pressure chambers.
Japanese Patent Application Publication No. 4-45947 (and in particular, FIGS. 1, 2 and 3) discloses that the inkjet head is provided with drive elements (individual drive piezoelectric elements) for changing the volume of the pressure chambers, and another drive element (common liquid chamber driving piezoelectric element) for changing the volume of the common liquid chamber which supplies liquid to the pressure chambers, in such a manner that a pulse waveform is applied to the common liquid chamber driving piezoelectric element immediately after the meniscus cut-off time.
However, there is difficulty in refilling ink without causing disturbance to ink ejection.
More specifically, if a pulse waveform is applied to the common liquid chamber driving piezoelectric element immediately after the meniscus cut-off time, as in Japanese Patent Application Publication No. 4-45947, then as shown in FIG. 9A, immediately after the meniscus cut-off time there is a state in which the desired ink droplet 82 has separated and left a liquid column 81 that still projects from the nozzle 51, and if the common liquid chamber is pressurized in this state, then as shown in FIG. 9B, there is probability that a relatively small ink droplet 89 (a so-called "satellite ink droplet") is also propelled from the remaining liquid column 81 in addition to the desired ink droplet 82 that has been ejected previously. In general, it is difficult to apply a pulse waveform to the common liquid chamber driving piezoelectric element at a level that does not cause ink to be ejected from the nozzles, and consequently, this may cause detrimental effects to image quality.
Furthermore, there is a difficulty in adjusting the drive timings of the ink ejection and the ink refilling.
For example, in the inkjet head disclosed in Japanese Patent Application Publication No. 4-45947, it is necessary to apply a pulse waveform to the common liquid chamber driving piezoelectric element momentarily, immediately after the meniscus cut-off time, and in order to apply the pulse waveform to the common liquid chamber driving piezoelectric element at this strict timing, generally, it is necessary to adjust the timing at each ejection operation.


A measuring arrangement includes forming first and second pairs of light beams each having a low frequency light beam and a high frequency light beam. Both pairs of light beams generate beat signals of the same frequency. The low frequency light beam of either pair and the high frequency of the other pair pass through a predetermined optical path to cause phase changes in the same direction. Beat signals are generated by superposing the first and second beam pair to provide measurement information on the phase changes.

1. Field of the Invention
The present invention relates to a measuring method and apparatus and more particularly, the present invention is suitable for use in optical heterodyne interference arrangements, for example, a very small displacement measuring apparatus, an alignment apparatus, a brazing registration evaluation apparatus, a length measuring instrument, or an apparatus which measures a very small displacement of an object by using a diffraction means, such as a diffraction grating.
2. Description of the Related Art
Hitherto, a heterodyne interference method capable of detecting information on the phase of light which is in a linear relationship with displacement by phase detection has been widely used for the high-precision measurement of a very small displacement. In the heterodyne interference method, measurements are performed in such a way that interference fringes which change in relation to time and are formed by two light beams whose frequencies are slightly different from each other are photoelectrically detected, and the phase of the interference fringes is converted into the phase of an electrical signal.
FIG. 1 shows a conventional embodiment, which is a very small displacement measuring apparatus which uses a Zeeman laser 301 for a light source and utilizes linearly polarized light beams 302 and 303 intersecting at right angles with each other, frequencies thereof being slightly different from each other, and which constitutes an interferometer. The light 302 is P polarized light having a frequency f.sub.1, the electrical vector of which is light within the diagram. The light 303 is S polarized light having a frequency f.sub.2, the electrical vector of which is light perpendicular to the diagram. Complex amplitude displays E.sub.1 and E.sub.2 of respective lights 302 and 303 emitted from the Zeeman laser 301 can be expressed as follows when their respective initial phases are denoted as .phi..sub.1 and .phi..sub.2 : EQU E.sub.1 =A.sub.0 exp {i (w.sub.1 t+.phi..sub.1)} (1) EQU E.sub.2 =B.sub.0 exp {i (w.sub.2 t+.phi..sub.1)} (2)
where A.sub.0 and B.sub.0 are amplitudes, w.sub.1 and w.sub.2 are angular frequencies, w.sub.1 =2.pi. f.sub.1 and w.sub.2 =2.pi. f.sub.2. Lights 302 and 303 are each amplitude-divided by a beam splitter 304. Either one of light 302 or 303 becomes reference light 306 or 307, and either one of light 302 or 303 becomes signal light 315 or 316 which enter an interferometer.
At this time, the polarization directions of the reference lights 306 and 307 are aligned by a polarization plate 305 (a polarizer for extracting polarization components which are inclined by 45.degree. in their respective polarization directions) and are detected by a photoelectric detector 317. Complex amplitude displays E.sub.1R (the complex amplitude of light 307) and E.sub.2R (the complex amplitude of reference light 306) of the reference light beams 307 and 306 at this time are as shown below if L.sub.S and L.sub.0 denote respectively an optical path length from the light source 301 to the beam splitter 304 and an optical path length from the beam splitter 304 to the photoelectric detector 317, as shown in FIG. 1, and A.sub.1 and B.sub.1 denote the respective amplitudes of these displays E.sub.1R and E.sub.2R : EQU E.sub.1R =A.sub.1 exp [i {(w.sub.1 t+.phi..sub.1 -k.sub.1 (L.sub.S +L.sub.0)}] (3) EQU E.sub.2R =B.sub.1 exp [i {(w.sub.2 t+.phi..sub.2 -k.sub.2 (L.sub.S +L.sub.0)}] (4)
where k.sub.1 and k.sub.2 represent the number of waves. If c denotes a light velocity, the following relations are satisfied: ##EQU1## The polarization direction of the reference light beams 306 and 307 are aligned by the polarization plate 305 so that light beams 306 and 307 interfere with each other. When this interference light is photoelectrically detected by the photoelectric detector 317, a detection signal I.sub.R is: EQU I.sub.R =A.sup.2.sub.1 +B.sup.2.sub.1 +2A.sub.1 B.sub.1 COS {(w.sub.1 -w.sub.2) t+(.phi..sub.1 -.phi..sub.2)+(k.sub.2 -k.sub.1) (L.sub.S +L.sub.0)} (5)
This detection signal is a beat signal having an angular frequency of w.sub.1 -w.sub.2, i.e., a frequency of f.sub.1 -f.sub.2, and a phase of .phi..sub.R =(.phi..sub.1 -.phi..sub.2)+(k.sub.2 -k.sub.1) (L.sub.S +L.sub.0). In contrast, light which is transmitted through the beam splitter 304 enters a polarization beam splitter 308. Light beam 315 of S polarization is reflected thereby, is reflected by a mirror 310, and travels again toward the polarization beam splitter 308. At this time, the polarization direction is rotated by .pi./2 as a result of the light beam 315 passing two times through a .lambda./4 plate 309 disposed in the optical path. Because the light has become light of P polarization, it is transmitted through the beam splitter 308. Light beam 316 of P polarization is transmitted through the polarization beam splitter 308 and is reflected by an object 312 to be measured. The light beam 316 travels again toward the polarization beam splitter 308. In the same manner as described above, the polarization direction is rotated by .pi./2 as a result of light beam 316 passing two times through a .lambda./4 plate 311 disposed in this optical path. Because the light beam has become light of S polarization, it is reflected by the polarization beam splitter 308. Thereafter, the polarization directions of signal light beam 316 of S polarization and signal light beam 315 of P (5) and (8) is measured by using a lock-in amplifier 319 as a synchronization wave detector.
The difference .DELTA..phi. between the phases of the beat signals shown in equations (5) and (8) is determined as shown in the following equation: EQU .DELTA..phi.=(k.sub.2 -k.sub.1) (L.sub.0 -L.sub.1)-2k.sub.1 .DELTA.L.
By rearranging this, it follows that: ##EQU2## If .DELTA..phi..sub.0 when .DELTA.L=0 is measured beforehand, L.sub.0 -L.sub.1=.DELTA..phi..sub.0 /(k.sub.2 -k.sub.1). Since k.sub.1 and k.sub.2 are known, L.sub.0 -L.sub.1 can be determined.
Thereafter, if the difference .DELTA..phi. between the phases of the two beat signals shown in equations (5) and (8) is measured, a displacement .DELTA.L of an object to be measured can be determined on the basis of equation (9).
However, the resolution of such a heterodyne interference measurement depends upon the resolution of a phase measuring apparatus which measures the phase difference between two beat signals. To increase the measurement resolution, the resolution of a phase measuring apparatus must be increased. However, there is a technical limitation regarding this.
Hitherto, a so-called optical encoder which measures a movement amount or a rotation amount of an object by using an optical scale has been used in the field of mechanical control. A conventional optical encoder has been disclosed in, for example, Japanese Patent Laid-Open No. 58-191907. In this optical encoder, coherent light from a light source is made to enter a diffraction grating which is a reference scale through a mirror or the like. .+-.N-th-order diffracted light emitted from this diffraction grating is reflected by a corner cube to its original direction and is also made to enter the diffraction grating. Then, two diffracted light beams of .+-.N-th order are diffracted in the same direction to interfere with each other. The intensity of the resulting interference light is detected by an optical sensor.
Since such an apparatus is small and can achieve a high resolution, it has been used for various purposes and for a variety of applications.
As machining and control have become more precise and fine, it has been required that such a measuring apparatus have a higher resolution than ever before.

Measuring method and measuring apparatus


A snowmobile steering mechanism adapted to place higher pressure on the outside ski than on the inside ski when the snowmobile enters and exits turns, said steering mechanism being adapted to include the suspension in the steering action of the snowmobile causing the snowmobile to automatically lean into a turn improving the ability of the snowmobile to enter and exit turns in comparison to a snowmobile without the inclusion of the suspension in the steering action of the snowmobile.

Snowmobiles are well known and have been used for many years. Improvements have been made to snowmobiles through various innovations as described in the patent literature. Improvements to steering and suspension have also been realized. Negotiating turns for snowmobile operators is always a concern as the snowmobile sled might be over turned if the turn is negotiated at a higher speed, particular if the operator has not learned to lean into the turn which is dependent on ones physical dexterity.
Applicant is aware of the following literature which as been reviewed in view of the present invention which is considered as prior art.
U.S. Pat. No. 3,827,516 issued Aug. 6, 1974 to Lucia describes a mechanism for combining steering and tilt control of the skis, when the turning movement of the skis is provided through the rotation of two substantially vertical king pins as shown in the illustrations.
U.S. Pat. No. 3,613,812 issued Oct. 19, 1971 to Hetteen describes a snowmobile which includes a spindle connected to each ski through a spring mechanism including springs and a shock absorber as seen in FIG. 4.
U.S. Pat. No. 3,724,578 permits a ski to be rotated on a horizontal plane to guide the snowmobile, about pin 24 in an essentially vertically plane to compensate for terrain irregularities. The patent includes the leaf spring arrangement to provide for terrain irregularities.
U.S. Pat. No. 5,029,664 issued Jul. 9, 1991 to Zulawski teaches a suspension system for skis of a snowmobile which includes an arrangement for controlling movement of steering point of each respective ski.
U.S. Pat. No. 3,835,947 describes and teaches an anti-roll torsion bar stabilizing system for a snowmobile.
U.S. Patent application 2002/0175013 published Nov. 28, 2002 describes a complex suspension system for a snowmobile assembly.
U.S. Pat. No. 3,664,446 issued May 23, 1972 to Burtis teaches an articulating snowmobile vehicle.
U.S. Pat. No. 3,809,172 issued May 7, 1974 to Hendrickson purports to teach mounting of a shock absorber arrangement.
U.S. Pat. No. 3,734,219 issued May 22, 1973 to Christenscen teaches a steering system for a snowmobile to lessen the stabilizing forces acting ahead of the center of gravity of such snowmobile.
U.S. Pat. No. 4,671,521 teaches a snowmobile ski suspension including the steering arrangement for skis.
U.S. Pat. No. 6,260,648 issued Jul. 13, 2001 to Sette teaches a system for engaging the steering rod to a steering gear in a steerable vehicle or a snowmobile.
U.S. Pat. No. 6,234,262 issued May 27, 2001 to Moore teaches a snowmobile steering and suspension mechanism as seen in relation to FIG. 2 which incorporates as best seen in FIG. 8 with the use of a trailing brace arm, which includes a frame and shock absorbers and fixed length tie rods to trailing brace arms extending between the snowmobile frame and a pair of skis and the conventional steering spindle on each set of skis for effecting the steering action of the handle bar. The shock absorbers are connected between the frame and the trailing brace arms, which causes the skis in turn to shift the weight of the snowmobile towards the inside of a turn. The teachings of this reference therefore point in an opposite direction with respect to applicant's invention. The purpose of applicants invention is to impart a higher force on the outside ski when negotiating a turn.
Nowhere in the prior art is there found, within the patent literature to the best of applicant's knowledge a snowmobile assembly or a kit of components to convert the steering action of a snowmobile assembly to allow for increased pressure on the outside ski when negotiating turn.
However, in spite of the general discussions in the above-mentioned patent literature there is no discussion of the present problems facing the snowmobile enthusiast when negotiating turns.
It is therefore a primary object of this invention to provide improvements in snowmobile steering resulting in performance enhancement of the snowmobile when negotiating turns.
It is a further object of this invention to provide a kit of components which may be installed on existing snowmobiles to realize the improvement in turning performance of the steering and suspension thereof.
Further and other objects of the invention may become apparent to those skilled in the art when considering the following summary of the invention and a more detailed description of the preferred embodiments illustrated herein.

Snowmobile steering and suspension for improved performance in turns


The present disclosure contemplates a variety of improved methods and systems for providing professionals and organizations tools to improve productivity and efficiency. The present disclosure includes a process for discovering and validating entity objectives. In an embodiment, the method and system receive communications from multiple data sources (e.g., email, calendar, contacts), find correlations between the communications, identify communications that appear to be important to a user, and provide relevant resources.

People often fail to make use of resources (e.g., news articles, research reports, marketing materials, and knowledgeable colleagues) that could help achieve goals, because people are unaware that such resources exist, are unable to find them, or are too busy to search for them. Furthermore, people are often inundated with meeting invitations, phone calls, and electronic messages, particularly, though not exclusively, in the workplace. The information overload can be difficult to manage. Information overload can be especially difficult for professionals who are faced with daily challenges and changing business goals. People use sticky notes, "to do" lists, and email flags to help with productivity and efficiency. These traditional approaches are static, inflexible and time consuming, and often yield an imperfect solution.


A band of a plurality of link sets is provided wherein each link set comprises a link wherein a first side of such link is bent to form a spring lock, a link wherein a second side of such link is bent to form a spring clip, and a pin extending through the spring lock. The link sets are joined together by inserting the spring lock of one link set into the spring clip of a proximate link set. The band is wrapped around a pipe, the pipe is placed against a second pipe in an orientation in which the pipes are to be joined, the pins are extended from the band to make contact with the second pipe, the band is slid along the length of the pipe until the pins lay above the surface of the pipe, and the contour is marked on the pipe.

1. Field of the Invention
The invention relates to systems and tools related to pipe layout during the pipe fitting process.
2. Description of the Related Art
During the course of pipe fitting, two pieces of pipe are cut and joined together. This joining is typically accomplished by way of welding. The pipes may be easily cut if the desired joint is a butt weld or two pipes being welded together at the ends of each piece to form either a straight piece or an angle with use of modern fabrication equipment. Layout and cutting of the pipes becomes more difficult when dealing with joints that are not straight cuts or straight miters, but are saddle-type joints, branch-type joints, or pipes of differing diameters or cross section shapes.
Methods exist in the prior art for measuring pipe and determining how pipes should be cut prior to welding.
One method which may be employed includes utilizing template sheets which have been preconfigured for particular pipe sizes and angles between the pipes to be joined. These templates may be printed on paper or other medium suitable to act as a stencil, wrapped around the pipe to be cut, and used to transfer the contour of the cut to the pipe. Once the contour is marked on the pipe, the pipe may be cut to the appropriate contour for welding. While this method may work for standard pipe sizes and joint angles, it cannot easily be applied to non-standard pipe sizes or joint angles.
Another method is to employ a computer-aided design (CAD) system to calculate the contour resulting from the joining of two pipes. A contour template may then be printed and applied to the pipe as with the template sheets described above. Once the contour has been transferred to the pipe, the pipe may be cut to the appropriate contour for welding. While this method allows the contour for any joint to be generated and applied, it is time consuming to create the contour in the CAD system and print a single use template. A pipefitter likewise may not have access to a CAD system while working on a particular piping system, making adjustments to the templates impracticable.
Other systems include utilizing a fixed ring fitted with a plurality of pins oriented parallel to the central axis of the ring. The pipefitter places the ring around a first pipe and manually orients the first pipe with a second pipe in the desired configuration for the joint. Once the pipes are oriented, the pipefitter extends the pins from the ring to meet the surface of the second pipe. Upon making contact with the second pipe, the pins form the contour of the joint. The ring may then be raised along the body of the first pipe and used to transfer the contour to the first pipe. Once the contour has been transferred to the pipe, the pipe may be cut to the appropriate contour for welding. While this allows the pipefitter to create contours quickly while on the job site, it is limited in that the ring is fixed in diameter and will fit only a single size of pipe. A pipefitter must utilize multiple tools to fit differing sizes of pipe, and may not be able to utilize this type of tool for pipes of a non-standard cross section.
A solution is needed to address one or more of these shortcomings in the prior art.


A new and distinct Gaura lindheimeri plant with red-purple colored flowers, attractive variegated foliage, and a long blooming season.

The present invention comprises a new and distinct cultivar of Gaura lindheimeri known by the varietal name 'Gauheha'. The new variety was discovered and isolated in Niigata, Japan in May of 2002 as a naturally occurring branch mutation of Gaura lindheimeri 'Gauchebra' (U.S. Plant Pat. No. 14,581). The new variety exhibits similar flower color and flower habit to 'Gauchebra', but is different from 'Gauchebra' in the coloring of the foliage. The flower color, plant habit and foliage color of 'Gauheha' differ from other Gaura lindheimeri varieties known to the breeder. The new variety was first asexually reproduced by terminal cuttings in Niigata, Japan. The new variety has been trial and field tested and has been found to retain its distinctive characteristics and remain true to type through successive asexual propagations.

Gaura lindheimerii plant named ‘Gauheha’


The present disclosure relates to a technology of estimating rack force using force that is transmitted from a steering motor of a Steer-By-Wire (SBW) system to a rack bar. The present disclosure provides a method for estimating rack force of an SBW system, the method calculating restoring force that is applied to a reducer on the basis of the difference between position values of the rack bar that are obtained at the front end and the rear end of the reducer when the position of the rack bar is changed by operation of a steering motor; and calculating rack force by reflecting the restoring force to a motion equation including inertia force of the SBW system.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A Steer-By-Wire (SBW) system, which is a steering system mechanically disconnecting a steering wheel and driving wheels of a vehicle from each other, can steer a vehicle by receiving a turn signal of the steering wheel through an Electronic Control Unit (ECU) and operating a steering assist motor (hereafter, referred to as a "steering motor") connected to the driving wheels on the basis of the input turn signal.
Since the SBW system does not have the mechanical connection structure that existing steering systems have, it is possible to more freely configure the layout of a steering system, improve fuel efficiency, and remove disturbance that is input back from wheels.
We have discovered that it is possible to monitor transverse force that is applied to tires (force that is applied to a rack bar=rack force) in terms of transverse control of a vehicle and steering response control because it has an influence on control of not only the vehicle, but the steering response.
In particular, since the SBW system does not provide physical connection between a rack bar and a driver, it may be desirable to let the driver recognize the information about road surfaces by measuring and estimating the rack force.
As a method of estimating rack force, there is transverse force estimation that uses an automotive kinetic model and rack force estimation that uses a steering system model. As a measuring method, there is a method of directly measuring force using a rod cell on a tie rod.
However, according to the rack force estimation method that uses an automotive kinetic model, there are differences in accuracy, depending on the models of tires, and the accuracy may be particularly low at low vehicle speeds.
Further, the case that uses a steering system model uses values obtained through a torque sensor on a column physically connected to a gear box may not be compatible with an SBW system because there is no physical connection, so it may be desirable to accurately know the force that is transmitted from the motor of a tire steering system to a rack.
The description provided above is solely for helping understanding the background of the present disclosure and should not necessarily be construed as being included in the related art known by those skilled in the art.

Method for estimating rack force of steer by wire system


A switchable voltage generator is provided on-chip together with circuitry including transistors formed in accordance with several different technologies and optimized for operation at different voltages. Provision of a voltage generator on the chip avoids the need for dedicated connections for the lower voltage or voltages. To provide similar levels of burn-in voltage to the different transistor types, a bypass or shunt is provided across the regulator of the voltage generator. The on-chip voltage generator avoids the requirement for a large number of chip or module power connections for each supply voltage required in order to meet current requirements of different portions of chip circuitry. The use of a mode select receiver also avoids the requirement of additional connections to the chip. The combination of one or more switchable voltage generators with a mode select receiver allows economical and efficient electrically stressed testing of the chip at different levels of manufacture.

1. Field of the Invention
The present invention generally relates to the design and manufacture of integrated circuit devices and, more particularly, to the electrical stress testing of integrated circuit devices, especially those containing transistors of different types.
2. Description of the Prior Art
The change of electrical characteristics of electrical components due to thermal and electrical stress during use is well-recognized. In some applications, particularly involving semiconductor devices, therefore, it is a common practice to operate a device for a sufficient period of time to stabilize the electrical characteristics of the device or component before placing it in service. This process can often be accelerated by operation of the device or component under adverse conditions of elevated temperature and/or increased operating voltages. Such operation is commonly referred to as burn-in.
In semiconductor devices and integrated circuits, in particular, burn-in is especially useful since latent defects such as improperly formed conductors which could cause unexpected failure during field operation will often fail during burn-in. Also, further diffusion of impurities, given a predetermined distribution in portions of the device, could be redistributed under adverse thermal or electrical conditions to drastically alter the electrical characteristics or cause failure of the device.
This latter consideration has become of major importance as transistor sizes have been reduced in integrated circuit devices. This is particularly true of field-effect transistors (FET's as channel lengths have been reduced below one micron. However, as improvements in technology have reduced the sizes of individual elements in integrated circuits, the electrical conditions under which such elements are optimally operated have become more critical. The same is true for burn-in operation. For example, in integrated circuit devices containing both bipolar transistors and CMOS transistors, the bipolar transistors are often optimized for operation at 3.6 volts while CMOS FET's, commonly integrated on the same chip with such bipolar devices are optimized for operation at 2.5 volts due to channel length and gate oxide thickness constraints. Likewise, optimum burn-in voltages differ between the two technologies (e.g. bipolar and CMOS) due to breakdown considerations. For example, during burn-in, bipolar devices are preferably electrically stressed at up to 1.1 times the optimum operating voltage while CMOS FET's are preferably stressed at up to 1.5 times the optimum operating voltage. This difference is at least in part due to the difference in conduction phenomena between the two devices since conduction occurs across a junction in a bipolar device but not in FET's, where conduction is controlled by the extent of a depletion region within a junctionless channel.
Burn-in has virtually become an indispensable requirement in the manufacture of integrated circuits having highly miniaturized transistors in order to assure an acceptable level of reliability. Therefore, arrangements for conducting such burn-in and testing operations have become an integral part of the design of such integrated circuits. However, all such arrangements, to date, have imposed some requirement on device design or manufacturing process which is at least expensive or time-consuming or requires substantial structure to be fabricated integrally with the device which is not thereafter usable. For example, U.S. Pat. No. 5,030,908 to Miyoshi et al. uses an electron beam to place a charge on a predetermined area of an integrated circuit and discharge is observed over time to determine the electrical characteristics of the device. U.S. Pat. No. 4,821,238 to Tatematsu teaches the provision of an on-chip test pattern generator. U.S. Pat. No. 4,855,672 to Shreeve discloses the provision of on-chip test circuitry usable in combination with a continuous lead-frame structure in the form of a tape which allows a plurality of integrated circuits to be wound on reels and thermally stressed while being simultaneously tested. U.S. Pat. No. 4,967,146 to Morgan et al teaches the provision of grooves on a wafer which facilitates burn-in and location of contacts for testing and later disassembly of the wafer into individual chips.
Another approach involves the use of a separate burn-in power supply lead which is not thereafter used. This approach requires an additional power plane in the integrated circuit and/or module carrying the integrated circuit and a pin which is either floated (if the two normal operating voltages are provided on-chip from the same power supply) or tied to the Vcc power plane (if on-chip voltage conversion is not provided) during normal operation. This requires some modification of the physical and electrical environment in which the integrated circuit is to be used as well as significant additional structure within the integrated circuit device, itself U.S. Pat. No. 4,336,495 to Hapke teaches the provision of on-chip switching for the purpose of testing which involves the application of a voltage which is outside the normal operating range of the device, such as a voltage of opposite polarity to normal operating voltage, in order to avoid the provision of an additional module pin. However, such an approach is not applicable to either electrical stressing of the circuit or the selective provision of a particular burn-in supply voltage to selected transistors of an integrated circuit. Similarly, U.S. Pat. No. 4,625,129 to Ueno teaches on-chip power supply switching for the purpose of removing power from selected portions of an integrated circuit which is similarly inapplicable to the provision of separate burn-in power supply voltages. Horiguchi U.S. Pat. No. 4,944,688, presents a very detailed description of the design of a fixed reference voltage generating circuit and is exemplary of the complexities which may be encountered for powering large integrated circuits even in the case of voltage generators which are not switchable and do not provide burn-in voltage generation capability. Distribution of V.sub.L circuits among the memory cell arrays powered thereby is shown in FIG. 4 of Horiguchi et al. This approach increases overall power consumption and consumes additional chip space.
A BICMOS logic converter for the purpose of burn-in operation of a bipolar emitter coupled logic (ECL) circuit is taught in IBM Technical Disclosure Bulletin, Vol. 33, No. 10B, published in March 1991. The purpose of this circuit is to allow operability of the bipolar ECL circuit when V.sub.DD is raised under burn-in operation conditions. In this circuit, a field effect transistor is used to alter a load resistance of an amplifier circuit which receives an input from a reference voltage source. The change of load resistance boosts the gain of the amplifier and raises the output voltage swing.

Voltage burn-in scheme for BICMOS circuits

International Business Machines Corporation


A data-holding subsystem holding instructions executable by a logic subsystem is provided. The instructions are configured to receive one or more touch-input messages reporting touch contacts recognized by a touch input device, if a touch contact reported by the one or more touch-input messages satisfies a first criterion, initiating a virtual mouse input mode, in the virtual mouse input mode, outputting a cursor position corresponding to a position of the touch contact that satisfies the first criterion, if no touch contacts reported by the one or more touch-input messages satisfy the first criterion, and one or more touch contacts reported by the one or more touch-input messages satisfies a second criterion, initiating a multi-touch input mode, and in the multi-touch input mode, outputting a multi-touch gesture command corresponding to the one or more touch contacts that satisfy the second criterion.

Computing devices, such as desktops and mobile computing platforms, may be designed to support one or more peripheral devices such as trackpads, thumbpads, trackballs, isometric joysticks, pen tablets, touch pads, touch screens, mouse devices, etc. The aforementioned peripheral devices may be referred to as spatial input and control (SIC) devices. An SIC device allows the user to provide directional input to the system and applications, access arbitrary locations in the user interface, and issue control commands. Each SIC device and host computer combination defines a range of user functions, actions and modalities an interaction model, or method that affords the user spatial input and control over the system. Each SIC method has distinct advantages for specific activities. Many computing devices feature a single dedicated SIC method, and their applications are therefore designed for a limited range of interactions.
Many of the aforementioned SIC devices have various drawbacks. For example, touch screen devices may require a user to interact via a multi-touch surface in an extended, unsupported posture. The user's hand, wrist, arm, and shoulder may become fatigued after interacting with a touch input device for an extended period of time. As a result, a user's interaction with the device may become increasingly uncomfortable and imprecise. Moreover, direct touch interaction may visually occlude a portion of the graphics presented on a touch screen. These problems may be exacerbated when a dense user interface is utilized.


A no-exposed-pad ball grid array (BGA) packaging structure includes a metal substrate, a first die coupled to a top surface of the metal substrate, and a plurality of outer leads formed on the metal substrate and extending to the proximity of the die. A metal layer that contains a plurality of inner leads corresponding to the plurality of outer leads and extending to the proximity of the die is formed on the metal substrate by a multi-layer electrical plating process such that a lead pitch of the plurality of inner leads is significantly reduced. Furthermore, the die and the plurality of inner leads are connected by metal wires, and a plurality of solder balls is attached to a back surface of the plurality of outer leads and a die pad. The die, the plurality of inner leads, and the metal wires are sealed with a molding compound.

1. Field of the Invention
The invention relates to the field of semiconductor assembly or packaging and, more particularly, to ball grid array (BGA) packaging technologies.
2. Description of the Related Art
There are mainly two types of conventional lead frame structures used in semiconductor packaging processes. For the first type, as shown in FIG. 49, after performing chemical etching and electrical plating (or simply plating) on the metal substrate, a layer of high-temperature resistant film is affixed on the back surface of the metal substrate to form the lead frame carrier to be used in the packaging process.
For the second type, as shown in FIG. 51, chemical half etching is first performed on the back surface of the metal substrate, and the chemically half etched areas are sealed with encapsulation material. Further, chemical half etching for inner leads is performed on the top surface of the metal substrate and followed by plating on the surface of inner leads of the lead frame so as to complete the lead frame.
However, both of these two types of lead frames may have certain disadvantages in the packaging process. For example, for the first type, the issues may include:                1) Because an expensive high-temperature film must be affixed on the back surface of the metal substrate, the manufacturing cost is directly increased;        2) In the die attaching process of the packaging process, also because a high-temperature resistant film must be affixed on the back surface of the metal substrate, only epoxy may be used in the die attaching process, and certain techniques such as the eutectic process or soft solder technique cannot be used, which greatly limits choices of available products;        3) In the wire bonding process of the packaging process, also because a high-temperature resistant film must be affixed on the back surface of the metal substrate and the high-temperature resistant film is a kind of soft material, the wire bonding parameters may become unstable, which seriously impacts on the quality of wire bonding and the reliability and stability of the product; and        4) In the molding process, also because a high-temperature resistant film must be affixed on the back surface of the metal substrate, the molding pressure during the molding process may cause certain mold bleeding between the lead frame and the high-temperature resistant film, which may change a conductive metal lead into an insulated lead, as shown in FIG. 50 (certain metal leads on the left side of the drawing are insulated by bleeding material).
For the second type conventional lead frame structure, the issues may include:                1) Because the etching process was carried out twice, manufacturing cost may be increased;        2) Because the composition of the lead frame is metal material and compound, when operated in a high and low temperature environment, the lead frame may be warping due to the different expansion and shrinkage stress of the different materials;        3) The warpage of the lead frame may impact the accuracy of die attaching process and may also affect the production yield due to the impact on the smooth transferring of the warping lead frames in the die attaching process;        4) The warpage of the lead frame may also impact the alignment accuracy of the wire bonding and may also affect the production yield due to the impact on the smooth transferring of the warping lead frames in the wire bonding process; and        5) Because the inner leads on the top surface of the lead frame are formed using etching technique, the width of the inner leads might have to be greater than 100 μm and the distance between two adjacent inner leads also must have to be greater than 100 μm. Thus, it may be difficult to achieve high density for the inner leads.

No-exposed-pad ball grid array (BGA) packaging structures and method for manufacturing the same

JIANGSU CHANGJIANG ELECTRONICS TECHNOLOGY CO., LTD.


A developing device develops a latent image formed on a latent image carrier by supplying a developer to the latent image carrier. The developer comprises a carrier liquid and a toner dispersed in the carrier liquid. A gelling agent adding device adds a gelling agent to the developer remaining in the developing device so as to gel the developer.

1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer or the like. In detail, the present invention relates to an image forming apparatus in which a latent image formed on a latent image carrier through electrophotography, electrostatic recording, iongraphy or the like is visualized with liquid developer which is a liquid developing agent. Then, the developed image on the latent image carrier is transferred to a transfer body. Further, in order to use the latent image carrier repeatedly, after the developed image has been transferred, the residual developer is removed from and thus cleans the surface of the latent image carrier.
2. Description of the Related Art
In such a kind of a wet type image forming apparatus, a developing device is used which develops an electrostatic latent image, formed on a latent image carrier such as a photoconductor, using a toner which includes electrically charged particles. Further, in order to clean the latent image carrier, a cleaning liquid is supplied to the latent image carrier at a portion to be cleaned. There are a device which uses the developer which is contained in the developer tank of the developing device as the cleaning liquid, and a device which uses a special cleaning liquid contained in a cleaning liquid tank. In each of the devices, after the cleaning liquid has been supplied to the latent image carrier and used for cleaning, the cleaning liquid including the residual toner is collected in the above-mentioned developer tank or the above-mentioned cleaning liquid tank, and is used repeatedly.
In the device in which the developer is also used as the cleaning liquid, paper powder adhered on the latent image carrier, lumps of the toner adhered to a cleaning blade and so forth gradually mix with the developer. Then, after image forming has been performed tens of thousands of times, the physical properties of the developer change and thus come to be unsuitable for developing. Accordingly, such an old developer, the physical properties of which have changed, is removed from the developing device and is replaced with a new developer. As a method of treating such an old developer, a method of treating developer for electrostatic photography has been proposed (Japanese Patent Publication No.7-36085). In this method, after an oil coagulating agent is added to the old developer and thus, the old developer is coagulated, the coagulated material is compressed so that a developer solvent is collected therefrom, and the residue is treated as industrial waste. In this method, when the oil coagulating agent is added to the old developer, it is necessary to heat the developer to approximately 80.degree. C. so as to coagulate the developer. A method of treating such an old developer, in which, in addition to the oil coagulating agent, a coagulation facilitating agent is added to the old developer so that heating of the old developer is not needed, has been proposed (Japanese Laid-Open Patent Application No.5-313500).
A cleaning device has been proposed (Japanese Laid-Open Patent Application No.62-145273). In this device, after being used in the cleaning process, the special cleaning liquid is collected in the cleaning liquid tank and is used repeatedly. In the device, in order to maintain the cleaning liquid as a clean liquid, means for detecting the concentration of the toner in the cleaning liquid and means for removing and collecting the toner from the cleaning liquid through electrodeposition are provided. Then, the toner removing and collecting means is operated when the concentration of the toner exceeds a predetermined value.
Further, in order to miniaturize the developing device, use of a high concentration, high viscosity developer has been proposed (see Japanese Laid-Open Patent Application Nos.7-209922, 7-152254, 7-239615). In such a method, the concentration of the toner in the developer, which consists of an insulating liquid with the toner dispersed therein, is set to a high level. For example, in Japanese Laid-Open Patent Application No.7-209922, a method for liquid-developing the latent image formed on the latent image carrier with the toner as visualizing particles, which method is provided with a developing process of supplying the liquid developer to the latent image surface of the photoconductor by bringing the liquid developer having a high viscosity of 100 to 10000 mPa.s with the dispersed toner in high concentration in insulating liquid applied to a developing roller into contact with the photoconductor, has been proposed.
Further, in Japanese Laid-Open Patent Application No.7-209922, a liquid-developing method has been also proposed. In the method, prior to the developing process, a prewetting process is performed. In the prewetting process, a prewetting liquid is coated on the latent image carrier. The prewetting liquid has mold release characteristics and is a chemically inert dielectric liquid. In the prewetting process, a prewetting liquid layer separates the layer of the liquid developer supplied to the latent image carrier from the surface of the latent image carrier. Thereby, unnecessary adhesion of the toner on the latent image carrier is prevented, and thus, image degradation due to adhesion of the toner to non-image portions on the photoconductor is prevented.
However, in the treatment of the old developer in the method in which the developer is also used as the cleaning liquid, when a serviceman removes the old developer from the developing device, adds the oil coagulating agent to the old developer so as to coagulate the old developer, and compresses the coagulated material so as to collect the developer solvent therefrom, manually, a long time is required for replacing the developer.
Further, in the method in which the toner is collected through electrodeposition from the special cleaning liquid contained in the cleaning liquid tank so that the cleaning liquid is maintained to be clean, the rate of collection of the toner from the cleaning liquid through the electrodeposition is in proportion to the size of the electrode and the time of the toner collection. Accordingly, in order to increase the rate of collection of the toner, the device is enlarged and/or the time of the toner collection is elongated.
Also, a filter can be used instead of using electrodeposition. The filter is used to trap only the toner and cause the developing solvent to pass therethrough. Thus, the toner is collected from the cleaning liquid. However, similar to the method using electrodeposition, the rate of collection of the toner is in proportion to the size of the filter and the time for the toner collection. Accordingly, in order to increase the rate of collection of the toner, the device is enlarged and/or the time for the toner collection is increased.
Further, when the liquid-developing method provided with the prewetting process is performed in the transfer type electrophotographic apparatus, the developer and also the prewetting liquid remain on the photoconductor after the transfer process. This residual prewetting liquid is then collected in the cleaning process together with the developer. Therefore, when the developer in the developer tank of the developing device is used as the cleaning liquid, and the developer which has been used as the cleaning liquid is returned to the developer tank, the amount of prewetting liquid in the developer tank increases gradually. When the kind of prewetting liquid is different from the kind of developer solvent of the developer, the characteristics of the developer change and thereby the developer may not be used for developing. Specifically, when the liquids of different kinds are mixed together, the electric resistance or the like of the developer changes and the developing characteristics may change. Further, when the liquids of different viscosities are mixed together, the viscosity of the developer changes, and thereby, in the device in which a developing belt or a developing roller is used for conveying the developer and the rate of supply of the developer to the latent image carrier depends on the viscosity of the developer, the rate of supply of the developer to the latent image carrier may change and thereby the developing tone may change.
Further, in such a developing device which uses the liquid developer, generally speaking, a drain (drainage hole) is provided at the bottom plate or a side wall near the bottom of the developing device. The drain is used for the old developer to flow therethrough. The drain is usually closed by a rubber plug or the like when the developing device operates. The drain is opened as a result of the rubber plug or the like being removed when the developer is caused to flow out from the developing device, for example, when the developer is replaced.
However, in an image forming apparatus provided with such a developing device, the developing device may be inclined when the drain is opened and the developer flows out therethrough. In such a case, all of the developer in the developing device may not flow out and some amount of the developer may remain in the developing device. In such a case, when the developing device is detached from the apparatus body or the developing device detached from the apparatus is carried, the residual developer may spill from the developing device through the drain.


A method and apparatus are provided for installing control lines and pipe into a well. The pipe-holding spider that is normally mounted on the rig floor is adapted for easy disassembly and reassembly when the pipe slips within the spider are not engaged with the outer surface of the pipe string so that upon disassembly, a control line guide becomes vertically movable. The control line guide is adapted for being controllably elevated to a distance above the rig floor, thereby providing personnel access to a portion of the length of the pipe string below the elevated control line guide and above the rig floor for securing control line to the pipe string using a fastener.

This application is a continuation-in-part of U.S. patent application Ser. No. 10/995,905 filed on Nov. 24, 2004, now U.S. Pat. No. 7,222,677 issued on May 29, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 10/315,617 filed Dec. 10, 2002, now U.S. Pat. No. 6,920,931, issued on Jul. 26, 2005. This application is also a continuation-in-part of U.S. patent application Ser. No. 10/995,907 filed on Nov. 24, 2004, now U.S. Pat. No. 7,216,716 issued on May 15, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 10/315,617 filed Dec. 10, 2002, now U.S. Pat. No. 6,920,931, issued on Jul. 26, 2005.

Manipulatable spider components adapted for cooperation with a vertically reciprocating control line guide

Frank's Casing Crew and Rental Tools, Inc.


Techniques are disclosed for protecting a computer environment. The technique comprises providing an index; comparing a first event with the index; determining whether the first event is unusual; and determining whether a security incident associated with the first event has occurred.

Network security is an important issue in modern computer environments. In computer environments such as computer networks, activities and events are sometimes monitored using products such as firewalls and intrusion detection systems (IDS). Network administrators may be alerted when suspicious events or security incidents occur so that they may take appropriate actions.
Monitored systems often generate large volumes of network events such as traffic sessions, logins, probes, etc. The amount of data available sometimes makes it difficult to identify events that pose risks to the system. Sifting through the events to identify the security incidents is typically resource intensive, therefore the systems that support incident identification tend to be slow and expensive. It would be useful to have a technique that would more efficiently and accurately identify security incidents. The present invention addresses such needs

Security incident identification and prioritization


A three wheeled vehicle that has an improved dual front wheel steering system that allows the vehicle to be maneuvered by a combination of arm and leg steering movements coupled with front end leaning that shifts the center of mass of the vehicle down and toward the inside wheel. This transfer of mass counteracts a conventional cornering vehicle's tendency to fling its mass to the outside wheel and lift the inner wheel off the ground as well as changing the angle of the line of force exerted through the tires, and enhancing the vehicles's grip on the ground. The vehicle has a reduced amount of sliding and potential of flipping when turning sharply. The steering system is compatible with traditional ACKERMAN steering geometry wherein the inner wheel turns in a smaller diameter circle than the outer wheel.

The present invention relates to a vehicle with two front wheels that have an improved steering system. More particularly, to a dual front wheel steering system that turns or leans in unison or independently and can be steered with the arms, legs or both.
Prior art three wheeled vehicles exist with ACKERMAN steering geometry, but none that utilize matched upper and lower A frame tilt arms, configured so as to have neutral steering and to shift the vehicle's mass lower and toward the inner turning wheel when cornering. This is accomplished in part by aligning the main steering pivot point of the upper A frame tilt arm with the outer pivot points of the lower A frame tilt arm in a vehicle frame having a 7 degree positive castor angle.
The three wheeled vehicle's steering system fulfills a long felt need in the field of dual front wheel steering systems on three and four wheeled vehicles, powered or otherwise. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the prior art problems of vehicle rollover or skidding when making sharp or high speed turns.