A system and method that addresses the issue of inducing and exploiting multi-user diversity in, e.g., a WLAN system in a fully distributed and opportunistic manner. In some embodiments, the system includes: an access point having a variable beamformer configured to fluctuate signal strength as perceived by stations within a range of the access point; and a plurality of stations having modified distributed-MAC protocol such as to be channel-aware and opportunistic.

1. Field of the Invention
The present application relates to wireless networking and, in some preferred embodiments, to systems and methods of performance enhancement of wireless local area networks and, in some preferred embodiments, to beamforming and opportunistic scheduling in wireless networks and/or the like.
2. General Background Discussion:
Networks and Internet Protocol
There are many types of computer networks, with the Internet having the most notoriety. The Internet is a worldwide network of computer networks. Today, the Internet is a public and self-sustaining network that is available to many millions of users. The Internet uses a set of communication protocols called TCP/IP (i.e., Transmission Control Protocol/Internet Protocol) to connect hosts. The Internet has a communications infrastructure known as the Internet backbone. Access to the Internet backbone is largely controlled by Internet Service Providers (ISPs) that resell access to corporations and individuals.
With respect to IP (Internet Protocol), this is a protocol by which data can be sent from one device (e.g., a phone, a PDA [Personal Digital Assistant], a computer, etc.) to another device on a network. There are a variety of versions of IP today, including, e.g., Ipv4, Ipv6, etc. Each host device on the network has at least one IP address that is its own unique identifier.
IP is a connectionless protocol. The connection between end points during a communication is not continuous. When a user sends or receives data or messages, the data or messages are divided into components known as packets. Every packet is treated as an independent unit of data.
In order to standardize the transmission between points over the Internet or the like networks, an OSI (Open Systems Interconnection) model was established. The OSI model separates the communications processes between two points in a network into seven stacked layers, with each layer adding its own set of functions. Each device handles a message so that there is a downward flow through each layer at a sending end point and an upward flow through the layers at a receiving end point. The programming and/or hardware that provides the seven layers of function is typically a combination of device operating systems, application software, TCP/IP and/or other transport and network protocols, and other software and hardware.
Typically, the top four layers are used when a message passes from or to a user and the bottom three layers are used when a message passes through a device (e.g., an IP host device). An IP host is any device on the network that is capable of transmitting and receiving IP packets, such as a server, a router or a workstation. Messages destined for some other host are not passed up to the upper layers but are forwarded to the other host. In the OSI and other similar models, IP is in Layer-3, the network layer.
Wireless Networks
Wireless networks can incorporate a variety of types of mobile devices, such as, e.g., cellular and wireless telephones, PCs (personal computers), laptop computers, wearable computers, cordless phones, pagers, headsets, printers, PDAs, etc. For example, mobile devices may include digital systems to secure fast wireless transmissions of voice and/or data. Typical mobile devices include some or all of the following components: a transceiver (i.e., a transmitter and a receiver, including, e.g., a single chip transceiver with an integrated transmitter, receiver and, if desired, other functions); an antenna; a processor; one or more audio transducers (for example, a speaker or a microphone as in devices for audio communications); electromagnetic data storage (such as, e.g., ROM, RAM, digital data storage, etc., such as in devices where data processing is provided); memory; flash memory; a full chip set or integrated circuit; interfaces (such as, e.g., USB, CODEC, UART, PCM, etc.); and/or the like.
Wireless LANs (WLANs) in which a mobile user can connect to a local area network (LAN) through a wireless connection may be employed for wireless communications. Wireless communications can include, e.g., communications that propagate via electromagnetic waves, such as light, infrared, radio, microwave. There are a variety of WLAN standards that currently exist, such as, e.g., Bluetooth, IEEE 802.11, and HomeRF.
By way of example, Bluetooth products may be used to provide links between mobile computers, mobile phones, portable handheld devices, personal digital assistants (PDAs), and other mobile devices and connectivity to the Internet. Bluetooth is a computing and telecommunications industry specification that details how mobile devices can easily interconnect with each other and with non-mobile devices using a short-range wireless connection. Bluetooth creates a digital wireless protocol to address end-user problems arising from the proliferation of various mobile devices that need to keep data synchronized and consistent from one device to another, thereby allowing equipment from different vendors to work seamlessly together. Bluetooth devices may be named according to a common naming concept. For example, a Bluetooth device may possess a Bluetooth Device Name (BDN) or a name associated with a unique Bluetooth Device Address (BDA). Bluetooth devices may also participate in an Internet Protocol (IP) network. If a Bluetooth device functions on an IP network, it may be provided with an IP address and an IP (network) name. Thus, a Bluetooth Device configured to participate on an IP network may contain, e.g., a BDN, a BDA, an IP address and an IP name. The term "IP name" refers to a name corresponding to an IP address of an interface.
An IEEE standard, IEEE 802.11, specifies technologies for wireless LANs and devices. Using 802.11, wireless networking may be accomplished with each single base station supporting several devices. In some examples, devices may come pre-equipped with wireless hardware or a user may install a separate piece of hardware, such as a card, that may include an antenna. By way of example, devices used in 802.11 typically include three notable elements, whether or not the device is an access point (AP), a mobile station (STA), a bridge, a PCMCIA card or another device: a radio transceiver; an antenna; and a MAC (Media Access Control) layer that controls packet flow between points in a network.
In addition, Multiple Interface Devices (MIDs) may be utilized in some wireless networks. MIDs may contain two independent network interfaces, such as a Bluetooth interface and an 802.11 interface, thus allowing the MID to participate on two separate networks as well as to interface with Bluetooth devices. The MID may have an IP address and a common IP (network) name associated with the IP address.
Wireless network devices may include, but are not limited to Bluetooth devices, Multiple Interface Devices (MIDs), 802.11x devices (IEEE 802.11 devices including, e.g., 802.11a, 802.11b and 802.11g devices), HomeRF (Home Radio Frequency) devices, Wi-Fi (Wireless Fidelity) devices, GPRS (General Packet Radio Service) devices, 3G cellular devices, 2.5G cellular devices, GSM (Global System for Mobile Communications) devices, EDGE (Enhanced Data for GSM Evolution) devices, TDMA type (Time Division Multiple Access) devices, or CDMA type (Code Division Multiple Access) devices, including CDMA2000. Each network device may contain addresses of varying types including but not limited to an IP address, a Bluetooth Device Address, a Bluetooth Common Name, a Bluetooth IP address, a Bluetooth IP Common Name, an 802.11 IP Address, an 802.11 IP common Name, or an IEEE MAC address.
Wireless networks can also involve methods and protocols found in, e.g., Mobile IP (Internet Protocol) systems, in PCS systems, and in other mobile network systems. With respect to Mobile IP, this involves a standard communications protocol created by the Internet Engineering Task Force (IETF). With Mobile IP, mobile device users can move across networks while maintaining their IP Address assigned once. See Request for Comments (RFC) 3344. NB: RFCs are formal documents of the Internet Engineering Task Force (IETF). Mobile IP enhances Internet Protocol (IP) and adds means to forward Internet traffic to mobile devices when connecting outside their home network. Mobile IP assigns each mobile node a home address on its home network and a care-of-address (CoA) that identifies the current location of the device within a network and its subnets. When a device is moved to a different network, it receives a new care-of address. A mobility agent on the home network can associate each home address with its care-of address. The mobile node can send the home agent a binding update each time it changes its care-of address using, e.g., Internet Control Message Protocol (ICMP).
In basic IP routing (i.e. outside mobile IP), typically, routing mechanisms rely on the assumptions that each network node always has a constant attachment point to, e.g., the Internet and that each node's IP address identifies the network link it is attached to. In this document, the terminology "node" includes a connection point, which can include, e.g., a redistribution point or an end point for data transmissions, and which can recognize, process and/or forward communications to other nodes. For example, Internet routers can look at, e.g., an IP address prefix or the like identifying a device's network. Then, at a network level, routers can look at, e.g., a set of bits identifying a particular subnet. Then, at a subnet level, routers can look at, e.g., a set of bits identifying a particular device. With typical mobile IP communications, if a user disconnects a mobile device from, e.g., the Internet and tries to reconnect it at a new subnet, then the device has to be reconfigured with a new IP address, a proper netmask and a default router. Otherwise, routing protocols would not be able to deliver the packets properly.
Limitations of Existing Systems
Existing systems have a variety of limitations, including, e.g., limitations due to the fixed amount of resources available, such as, e.g., limitations on bandwidth and power. A number of existing systems are described in the following three references, the disclosures of which are incorporated herein into this application in their entireties.
1) B. Sadeghi, V. Kanodia, A. Sabharwal, E. Knightly, OAR: An Opportunistic Auto-Rate Media Access Protocol For Ad Hoc Networks, ACM Mobicom 2002 (hereinafter Reference 1). In Reference 1, the authors propose a technique to send multiple packets back-to-back when channel conditions are good, which they call as Opportunistic Auto Rate (OAR). The authors claim that this scheme enables users to increase their throughput. The OAR scheme in Reference 1, however, gives any such throughput enhancement at the expense of favoring users with high data rates. The number of packets that can be transmitted back-to-back is inversely proportional to the current data rate, and this makes the system highly unfair from an individual throughput perspective.
2) J. Wang, H. Zhai, Y. Fang, Opportunistic Packet Scheduling For Media Access Control For Wlans And Multi-Hop Ad Hoc Networks, IEEE WCNC 2004 (hereinafter Reference 2). In Reference 2, the authors propose an Opportunistic packet scheduling and Media Access Control (OSMA) protocol to exploit the multiuser diversity gain in WLAN systems. If the MAC queue of the AP (or station in ad-hoc networks) contain packets destined for multiple stations, the OSMA protocol provides a method to select the next packet to be transmitted based on channel quality estimates and other QoS parameters. The OSMA scheme in Reference 2 addresses the issue only at those WLAN entities which have packets to transmit to multiple stations. The method does not apply to stations in a WLAN infrastructure system (which transmit packet only to the AP), and hence fails to give high throughput gains in an infrastructure mode system.
3) X. Qin, R. Berry, Exploiting Multiuser Diversity for Medium Access Control in Wireless Networks, IEEE Infocom 2003 (hereinafter Reference 3). In Reference 3 the authors propose a variation of the ALOHA protocol, the channel-aware ALOHA. With this protocol, users randomly transmit with a transmission probability that is based on their channel gain. This in effect leads to a distributed scheduling system that attempts to exploit the multiuser diversity effect of scheduling transmissions when the channel conditions are favorable. The work in Reference 3 focuses on an ALOHA based system and as such is not directly applicable to CSMA/CA based WLAN systems.
Other general background references, the entire disclosures of which are incorporated herein by reference, are listed below.
1. IEEE 802.11 standard: Wireless LAN MAC and PHY layer specifications, 1999;
2. Y. Xiao, J. Rosdahl, Throughput and Delay Limits of IEEE 802.11, IEEE Communication Letters, Vol. 6, Number 8, August 2002;
3. J. Jun, P. Peddabachagari, M. Sichitiu, Theoretical Maximum Throughput of IEEE 802.11 and its Applications, Proceeding of the 2nd IEEE International Symposium on Network Computing and Applications 2003 (NCA '03);
4. A. F. Molisch, D. Gu, J. Zhang, N. Mehta, Physical layer and Medium Access Control laver Proposal for IEEE 802.11 n, Sep. 1, 2004, IEEE 802.11 groups;
5. IEEE 802.11e, Wireless LAN Medium Access Control (MAC) and Physical Laver (PHY) Specifications: Medium Access Control (MAC) Enhancements for Quality of Service (QoS), Draft v9, IEEE, August 2004;
6. Official website of IEEE 802.11 [http://qrouper.ieee.orq/qroups/802/11/];
7. P. Vishwanath, D. N. Tse, R. Laroria, Opportunistic Beamforming Using Dumb Antennas, IEEE Transactions on Information Theory, 2002;
8. B. Sadeghi, V. Kanodia, A. Sabharwal, E. Knightly, OAR: An Opportunistic Auto-Rate Media Access Protocol for Ad Hoc Networks", ACM Mobicom 2002;
9. Z. Ji, et. al., Exploiting Medium Access Diversity in Rate-Adaptive WLANs, ACM Mobicom 2004;
10. X. Qin, R. Berry, Exploiting Multiuser Diversity for Medium Access Control in Wireless Networks, IEEE Infocom 2003;
11. J. Wang, H. Zhai, Y. Fang, Opportunistic Packet Scheduling for Media Access Control for WLANs and Multi-hop Ad Hoc networks, IEEE WCNC 2004;
12. R. Jain, W. Hawe, D. Chiu, A Quantitative Measure of Fairness and Discrimination for Resource Allocation in Shared Computer Systems, DEC-TR-301, September 1984.
While a variety of systems and methods are known, there remains a need for improved systems and methods that can best make use of a fixed amount of resources in WLANs and/or the like, such as, e.g., bandwidth and power.

Beamforming and distributed opportunistic scheduling in wireless networks


In processing system that includes a processing element communicatively coupled to a storage system for storage of database files (35) managed by a database management system (34) having a transaction management facility (36), file access operations from application processes are intercepted and checked to determine if the operation is from a non-transactional process, and if so, whether an automatic transaction should be started for the operation.

The present invention relates generally to data processing using transaction processing in which changes to a database are recorded in an audit file to provide recovery of the database in the face of a failure. More particularly, the invention is directed to a method of providing automatic transaction capability to programs not configured for transaction processing.
Real world commerce involves transactions. A transaction may involve some commercial activity, such as a deposit to a bank account, or a transfer of funds from one bank account or another, or a sale of a product. In order to maintain a record of the transaction, it will be recorded in a database, preferably in a consistent manner. For example, a transfer of funds from one account to another will require a database change that will reduce the one account by the amount of the transfer, and augment the other account by that same amount. If the change is effected properly, the database change is kept consistent. If, however, a failure occurs during the change, there is a question of whether the entire transaction was recorded, i.e., if the database was changed to reflect the reduction of one account, was the database also changed to reflect the increase of the other account.
To ensure that the database remains accurate after the changes/modifications, the paradigm of transaction processing was developed. A transaction itself is often defined as an explicitly delimited operation or set of operations that change or otherwise modify the content of a database from one consistent state to another. Changes or modifications are treated as a single unit in that all changes/modifications of a transaction are formed and made permanent (i.e., the transaction is "committed"), or none of the changes are made permanent (the transaction is "aborted"). Failure occurring during the execution of a transaction will result in the transaction being aborted, and whatever changes were made to a database are undone to return it to a consistent state. A transaction, then, is said to guarantee Atomicity, Consistency, Isolation, and Durability.
Before a transaction commits its changes to the database, audit information about the database change/modification is written to a so-called "audit log" (or "audit trail"). At a conceptual level, an audit log can be viewed as a history of changes to a database, and information from the audit log will allow the database to redo or undo update operations as required. The audit log information may also be used to reconstruct the database in the event of a catastrophic event that corrupts or otherwise destroys the database.
Databases that ate managed with transactions have some inherent advantages. Updates to the database are permanently recorded in the audit file on magnetic media. This permits the database manager to:
Recover files that are lost when a database storage device is permanently damaged,
Create and maintain a duplicate copy of the database in a remote location, and
Improve performance by eliminating I/O operations that can be recovered (in the event of a failure) from the audit log.
In order to use transactions, an application program must be able to issue the necessary instructions to the transaction manager to initiate and manage transactions. Those instructions often include:
A "BEGIN" instruction to initiate a transaction before locking or updating records. It is possible for a process to BEGIN multiple transactions and to associate each change/modification with a specific transaction.
A "COMMIT" instruction, which commits a transaction when a related set of database updates are complete; this will cause all database updates associated with that transaction to become permanent.
An "ABORT" instruction to terminate a transaction when it is discovered that some factor would preclude making a set of consistent database updates; this causes all updates associated with that transaction to be undone, as if they had never been made.
A "RESUME" instruction to choose between one or more active transactions, thus allowing a process to specify a particular transaction for each I/O operation.
A program that makes effective use of transactions is called a "transactional application."
There are many existing applications are able to modify a database of one sort or another, often composed of hundreds and thousands of programs, that for one reason or another are not transactional applications; that is, they were not initially designed and prepared to include the necessary transaction instructions and programming logic to manage transactions. Nevertheless, it will be evident that such applications would certainly benefit from the use of transactions. Unfortunately the cost and risk of reprogramming these applications in order to add the necessary instructions for transaction utilization is high, often too high to justify the effort.
Furthermore, there are also transactional applications that only use transactions for a subset of the database. In many cases, it may not be desirable to use the same transaction for certain files, such as error logs, because the ABORT operation would undo updates that should be preserved. It is sometimes desirable to use transactions to manage updates to these files, but only if the transactions are managed separately from the original transactions.
Thus, there exists a need for a way to provide those applications that are without the necessary programming logic for transaction use to still be able to still be able to do so without the risk and expense of adding the necessary programming code.


Mobile device advertising chains are described herein. Presenting a primary offer, comprising a first action, is caused on a mobile computing device. The first action is caused on the mobile computing device. An end of the first action is detected. Presenting a purchase offer, comprising a purchase action, is caused on the mobile computing device after the end of the first action. Data indicating that the purchase action was completed in connection with the mobile computing device based on the purchase offer is received. A sum of the value to confer in connection with the device for accepting both the primary offer and the purchase offer is determined. The sum of the values may be used in optimizing subsequent presentations of the primary offer to other mobile devices.

The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
Smartphones, such as the APPLE IPHONE device and ANDROID-based devices, support numerous applications or "apps" and mobile web sites, (collectively, "apps"), including those that present advertisements. In some cases, the advertisements consist of short videos that may be offered to a device user as a condition for obtaining a virtual reward, for example, the sort useful in a game or other app.


A motor control device includes a backup electrical angle detection circuit in which an inter-sensor error correction unit calculates an advance gain equal to or more than 1 with respect to input of a steering torque equal to or more than a predetermined torque value, and multiplies an output shaft angular velocity by the advance gain to calculate a post-advance steering angular velocity for correcting the estimated angle error of the direction delayed with respect to the steering direction. Then, an estimated angle calculation unit of the backup electrical angle detection circuit integrates the post-advance steering angular velocity, and, on the basis of a value of the integration, calculates a second motor electrical angle that is an estimated value of a motor electrical angle.

Conventionally, as backup technologies for when a motor position sensor has broken down that detects a motor electrical angle of an electric motor mounted in an electric power steering device, for example, there are technologies disclosed by PTL 1 to 2.
In the technology of PTL 1, an electric power steering device includes a steering angle sensor mounted on a column output shaft side, in which an estimated angle calculated from counter electromotive force information of an electric motor that generates a steering assist force and an estimated angle calculated from detection information of the steering angle sensor are used by being switched in accordance with steering velocity.
Here, usually, in an electric power steering device, a steering shaft is connected to an electric motor via a reduction gear. Thus, between output shaft steering angle information and motor electrical angle, there are error factor characteristics, such as mechanical compliance characteristics (such as backlash, nonlinear elasticity characteristics, and elastic deformation) of gears and the like and detection error characteristic of a steering angle sensor. Additionally, in the structure with the interposed reduction gear, when estimating a motor electrical angle is estimated using the output shaft steering angle information, influence due to an error of the steering angle sensor is multiplied by gear ratio, and therefore appears as a large motor angle calculation error. In addition, influence of an error due to an error factor such as the reduction gear or the steering angle sensor tends to more significantly appear in handling feeling, as the steering torque becomes larger.
In other words, in the conventional technology of PTL 1 described above, when a steering situation and an environmental situation occur in which an angle error due to the error factor appears, an error may occur in the estimated angle calculated from the output shaft steering angle, which may consequently cause behavior such as the loss of synchronism or the shortage of assist due to reduced torque generation efficiency.
Additionally, the technology of PTL 2 utilizes a correlation between the mechanical compliance characteristics and motor output torque, and when the motor position sensor is normal, learns a relationship between output torque-related information and an error characteristic between an estimated electrical angle obtained from the output shaft steering angle and an actual electrical angle. Then, when the motor position sensor becomes abnormal, the estimated angle is corrected by the error characteristic obtained from the output torque-related information, and the corrected estimated angle is used as an estimated electrical angle.

Motor control device and electric power steering device including the same


A USB system is capable of connecting, based on the function of constructing and connecting a virtual port by a virtual port constructing functional unit, a number of devices exceeding a prescribed number of tiers having a hub device in a connection topology of a host device—hub devices—a device of the USB system. When the host device addresses a device on its downstream side, the hub device acts as if it is a specified device by a proxy response functional unit including the hub device, and instantaneously performs a proxy response depending upon the situation that, for example, the device on its downstream side is not ready. This causes no problem associated with the turn-around time of the USB bus even if the prescribed number of tiers is exceeded.

1. Field of the Invention
The invention relates to a bus communication system, and in particular to a bus communication system in which a hub device is provided between a host and a bus device under the universal serial bus (USB) or USB-OTG (USB-On-The-Go) standard and communication is made between the host and the bus device over tiered hub devices. The invention relates also to a line-concentrating and switching device advantageously for use in a hub device, which is provided in tiers for transmitting data. This invention further relates to a host device to control the hub device and devices, which are interconnected in tiers to form a network.
Furthermore, the invention relates to a communication control method for a bus communication system, which is in keeping with the function and topology of hub and bus devices provided in tiers, and in particular to a communication control method advantageously applicable to a multi-stage connection of bus devices under the USB or USB-OTG standard. Finally, the invention relates to a communication control method of a network system composed of plural, interconnected networks under different standards, in which communication may be made from one network to a device connected in a lower layer of another network. The present invention may be applied with advantage to for example a communication control method in a network system where there co-exist networks of the USB-OTG and USB standards.
2. Description of the Background Art
Nowadays, USB devices have become widespread as a simplified peripheral of an personal computer, while the USB has come to be well-known as an interface which takes the place of, for example, the RS-232C (Recommended Standard-232C) which is a conventional serial interface standard. The USB standard was initially of the USB version 1.0 and later updated to the USB version 1.1. Still later, the USB standard has been updated to version 2.0, in which the transmission rate is raised from conventional 12 Mbit/sec to 480 Mbit/sec in keeping with the increasing operating speed of peripherals.
First, the USB is featured by a low cost. Second, the USB is featured by allowing for freedom in layout. Specifically, the USB is able to cope with the plug and play function, which automatically recognizes peripheral connected to allow for use without setting a driver. Additionally, the USB has a hot plug function, which allows plug-in and plug-out of a peripheral without turning off the power supply. In a layout aspect, the hub device may be applied for interconnecting a terminal device in the LAN (Local Area Network).
Japanese Patent Laid-Open Publication No. 2002-202835 proposes a peripheral electronic device, which is premised on a tree connection topology and may be directly connected to another peripheral electronic device similarly premised on a tree connection topology through the same connector. The proposed electronic device checks the state of connection resulting from the coupling of the connector to verify to which the connector is connected, in order to perform an operation accordingly.
Since the USB standard allocates seven bits to the address of a bus device, 127 USB devices at the maximum can be connected, in addition to a host device. However, hub devices and USB cables suffer from delay time. In consideration of delay time, the tree connection structure, with a host device located at an apex point, is limited to seven tiers. Specifically, if a host device presents in the first layer, the USB devices are of such a structure in which up to the seventh tier is allowed for the terminal USB device. However, the USB prescriptions lack for a statement that the connection structure is to be limited to seven tiers, and simply provide for delay time of USB devices, etc.
It is explicitly stated that delay time from the upstream to downstream end connector of a hub device shall be 70 nanosecond or less, and that a signal propagation delay in one direction shall be 30 nanosecond or less. In addition, it is explicitly stated that a cable used shall have attenuation characteristics of 5.8 dB or less per cable at a frequency of 400 MHz.
There is disclosed in Japanese Patent Laid-Open Publication No. 2000-194649 a method for connecting electronic equipment of a tree connection topology directly to each other without contravening the USB standard. In this connection method, a device of the USB standard is used in common by plural host devices satisfying the USB standard. The plural host devices are connected to plural high-end ports of a hub device, as a connection device for electronic equipment, to plural low-end ports to which devices of the USB standard are connected. One of the high-end ports and one of the low-end ports are selected to operate the host device and the device of the USB standard associated with the selection. There is no necessity for detaching and connecting again the cables, thus improving user friendliness.
There is also disclosed in Japanese Patent Laid-Open Publication No. 2002-288112 an interface system and an interface device in which the USB standard is satisfied and a free network system may be constructed in such a manner as to override the constraint imposed by the standard. In order to realize this, a semiconductor device for communication control is featured by host controlling means and function controlling means which manage communication control as a slave, with the host controlling means and the function controlling means mounted on a single semiconductor chip and being in operation simultaneously. The interface system includes a semiconductor device for communication control, a first connector connectable to host equipment, a second connector connectable to function equipment, and an external switching means connected between the first and second connectors and the transmitting/received data input and output terminals of the semiconductor device for communication control. The external switching means are controlled in an operatively interlocked relation to the switching means provided within the semiconductor device for communication control, in order to connect the host equipment or the function equipment at all times to the two connectors, whereby data may be transmitted and received between the devices without changing the cable connection.
It should be noted that the delay time such as encountered with the above-mentioned USB standard limits the turn-around time of a USB bus. The turn-around time is provided for preventing signal collision on the bus. Thus, until a device of the USB standard has received a packet from a host device and the turn-around time elapses, the device of the USB standard cannot send out a packet to the host device. This turn-around time is requested to secure when devices of the USB standard communicate with each other.
The USB standard provides that the cable length in general shall be five meters at the maximum. Thus, the total cable length from a host device to a terminal device of the USB standard in the lowermost layer amounts to 30 meter. However, the USB standard simply states that the length shall be limited by the aforementioned attenuation characteristics and the signal propagation time. Such USB prescriptions are presumably intended to provide for flexibility in order to take into account the possible future improvement in cables, etc. However, rather detailed prescriptions are provided in connection with connectors in view of securing the compatibility.
With USB devices, the bus topology takes a so-called star connection. Between a host device of the first tier and a USB device located at the lowermost layer or the seventh tier, there are five hub devices, that is, five tiers. If a number of USB devices corresponding to the connectable limit are connected to a sole hub device, the connection topology may be likened to that of placing many loads to a sole electrical outlet. In actual, if tiers are formed using one, or at most two, hub devices, with a personal computer, placed in a home, as a host, plural USB devices, such as a keyboard, a mouse, a printer, a scanner, a terminal adaptor (TA) or an external storage unit, are connected to the tiers in a disorderly fashion. Even granting that up to 127 USB devices can be connected under the USB standard, an extremely difficult condition emerges with the wiring necessary for the connection.
If, in order to improve the difficult condition, plural USB devices are connected in series and connection is made in such a manner as to override the seven-tier limitation, the result is a neat connection topology. If, for example, connection is made to a tier beyond the limitation on the number of tiers, the number of USB devices connected per tier may be reduced, such that the number of the ports of the topology may be made approximately equal to the number of the ports in the above-mentioned difficult condition. Specifically, the resulting connection is desirable for a case in which a large number of USB sensors are arranged in a wide area and measurement is made on the sensors by a personal computer operating as a host device. In this case, a portable USB device is desirably used as the USB sensor. However, in order to make connections in this topology and meet the aforementioned USB prescriptions, it is requested to solve the problem of the delay time of USB devices and/or the turn-around time of USB buses.
Recently, there is proposed the USB-OTG standard as an architecture of constructing a more flexible network using devices of the USB standard. This architecture, which employs an interface establishing peer-to-peer connection between USB devices without the mediation of a host device, is effective to moderate several difficult conditions.
The first difficulty is the increased load in adding a function owned by the host device to the aforementioned USB portable device. This increased load is caused by providing a USB portable device with a storage area for storing plural device drivers. The second difficulty is the necessity of supplying a large current to a USB portable device, specifically, the use of a high-efficiency power supply. The third difficulty is the physical load imposed by employing an "A" connector for the host device.
With the USB-OTG standard, the function as specified in connection with the first difficulty in communication between USB portable devices is not needed. Consequently, the standard that slightly complements the aforementioned standard of the USB Version 2.0 (On-The-Go Supplement to the USB 2.0 Specification) was formulated in the year of 2001.
The connection between the first and second networks under the USB-OTG standard will be described. Before this description, the connection topology of the first network in the case of using the USB standard will be described. In the first network, a PDA (personal digital assistant) working as a host device is connected by a USB cable to a hub device, which is connected through one of the ports owned by the hub device and a USB cable to a printer. It is now assumed that a personal computer as a host device is newly connected to the hub device and the printer is controlled from this personal computer in order to use the printer. The newly added personal computer is connected through a port of the hub device and four-conductor USB cable. However, the personal computer is unable to directly communicate with the printer, even though it is attempted to use the printer over a hub device. The reason is that the PDA is designed to supervise the network including the PDA, hub device and printer in accordance with the USB standard, in other words, that the first network in the state of art is not constructed in accordance with the USB-OTG standard.
The newly added personal computer is connected to the PDA as a constituent element of the second network. The USB-OTG standard is applied to the PDA and the personal computer used in the second network. The respective OTG ports of the PDA and the personal computer are connected to the five-conductor OTG cable. In this case, the communication is possible between the personal computer and the PDA on the network. However, the personal computer on the second network cannot utilize the printer in the first network. The reason is that, while the USB-OTG standard allows communication in the second network, specifically, communication between the personal computer and the PDA, the printer in the first network operating in the USB standard communicates only with the PDA of the host device.

Bus communication system by unrestrained connection and a communication control method therefor


The present invention includes a method for automatically reconstructing most of the power, ground and clock prerouting without significant user involvement. This enables several floorplans to be tried concurrently in a batch mode. The method automatically migrates many floorplans in increments to find the best result for each starting floorplan. The user is then free to select a floorplan that looks best from the candidates generated with all the special net routing patterns already considered and updated for each.

1. Field of the Invention
The present invention relates generally to automatic integrated-circuit placement and routing tools, and more particularly to symbolic constraint-based systems for preroute reconstruction following floorplan incrementing.
2. Description of the Prior Art
After the logic circuitry for a very large scale integrated (VLSI) circuit has been designed, placement "algorithms", really computer-implemented processes, are used to "place" each circuit macrocell of the VLSI circuit logic in the floorplan of an integrated circuit (IC) chip. Computer-implemented processes, called "routers", are used to interconnect the macrocells into wire networks, e.g., "nets". Local bundles of these connection networks have a measurable width and take up space on the integrated circuit. Too many connections may be attempted through a bundle that passes between macrocells, and this can stymie the automatic design by becoming congested.
Preferably, the locations selected for each macrocell and the wire routing choices have been optimal. An acceptable placement of component blocks occurs when the unused space between component blocks is at a minimum, and when the overall area used for the whole design is minimized.
Beyond the wire connection of functional networks that provide the various signal paths within an IC, it is also necessary to route special wire networks, e.g., ground, power and clocks. See, Andrew S. Moulton, "Laying the Power and Ground Wires on a VLSI Chip", 20th Design Automation Conference, IEEE, 1983, pp. 754-755; and, David W. Russell, "Hierarchical Routing of Single Layer Metal Trees in Compiled VLSI", ICCAD, IEEE, 1985, pp. 270-272. The special connections of power and ground are needed by just about all the active cells in a device, and their connection can sometimes compete with the required signal net connections.
Daniel R. Brasen describes, in U.S. Pat. No. 5,485,396, issued Jan. 16, 1996, a floorplan of component blocks of logical circuits, including the symbolic routing of major connection networks, which is produced as part of the process for laying out an integrated circuit on a chip. The floorplan is done before optimized placement and routing of the logical circuits within the individual component blocks of the VLSI circuit. The logical circuits are apportioned into component blocks. Then, an initial layout of the component blocks of the VLSI circuit is made. The major connection networks are routed between the component blocks so that the major connection networks are connected to connection areas within the component blocks. The initial layout of the component blocks is adjusted, as necessary, to take into account the addition of the major connection networks. Then, routing guidance information is generated as part of the floorplan. The routing guidance information indicates locations and sizes of each of the major connection networks.
Daniel R. Brasen also describes, in U.S. Pat. No. 5,349,542, issued Sep. 20, 1994, the calculating of segments within a power network of an integrated circuit using information generated during design and placement. The performance of logic blocks within the integrated circuit is simulated to obtain an estimated maximum current requirement for each logic block. After estimating the maximum current requirement for each logic block, the maximum current flow through each power net segment is obtained by summing the current requirements for each logic block which draws current through the power net segment. Based on this maximum current flow through each power segment, the width for each power net segment is calculated. A check may be made to assure that a predetermined electromigration limit is not exceeded. When the projected current flow through a power net segment exceeds the predetermined electromigration limit, the width of the power net segment is increased.
Steven L. Crain, et al., describes in U.S. Pat. No. 5,311,443, issued May 10, 1994, a rule-based floorplanner for a macrocell array comprising a plurality of predetermined macrocells. The floorplanner uses a net list, a macrocell list, and a list of design constraints and characteristics of the base array itself to derive an initial Burain score. A trial floorplan is attempted and checked against a list of theoretical rules and a list of empirical rules to determine a measured Burain score which accurately indicates the difficulty which can be expected when completing the design.
For the physical design of very large scale integration (VLSI) chips, Klein, et al., describes a method for implementing a high density master image of logic, e.g., in U.S. Pat. No. 4,890,238, issued Dec. 26, 1989. In a hierarchical top-down design methodology, the chip circuitry is logically divided into partitions that are manageable by the present automatic design systems and programs. Global wiring connection lines are included in the initial design of the different individual partitions and treated there in the same way as circuits in that area. The various partitions are designed in parallel. A floorplan is established that provides the different partitions shaped in such a way that they fit together without leaving any space between the different individual partitions.
Conventional design approaches begin with a fixed core area and place the various blocks (macrocells) within the floorplan. The rest of the core area is then used for the placement of standard cells. If the floorplan is not just right, local congestion of routing resources can lead to incomplete connections. Getting stuck this way necessitates re-running the placement and routing processes. Several such iterations may be required with intermediate fudging by the user before 100% routing completion is obtained. using core areas larger than actually required can solve the completion problem, but wastes considerable floorplan area.
Multiple place and route passes waste time. Each pass must necessarily redo all the special routing too, e.g., power, ground, and clock prerouting for each floorplan change. Since such prerouting usually needs considerable user intervention, especially when the design has several macrocell blocks, the turnaround time can be considerably extended for each additional pass. Ignoring the special prerouting before doing the floorplan is not possible, since the placement and routing are so greatly impacted.

Symbolic constraint-based system for preroute reconstruction following floorplan incrementing


A heat dissipating device includes a semiconductor packaging structure having a stator set and a semiconductor element provided therein, a fan wheel set pivotally connected to the semiconductor packaging structure, and a guiding structure having a guiding channel. The guiding structure receives the semiconductor packaging structure and the fan wheel set. The fan wheel set includes a plurality of blades located above the surface of the semiconductor packaging structure. The stator set and the semiconductor element controls the first blades. The blades extend beyond side surfaces the semiconductor packaging structure and have their sizes increased, such that the airflow volume can be increased without changing the size of the semiconductor packaging structure.

A circuit board, such as a main board or a mother board, typically has a plurality of electronic components, such as a central processing unit or a graphic card, provided thereon, and conductive circuits that electrically connect the electronic components. The electronic components generate heat during operations, and if the heat generated is not dissipated from an electronic product in which the circuit board is provided, the electronic components may be overheated and fail. Such a problem becomes more prominent in the face of increasing demands for functions and processing speeds, because enhancement in the functions and processing speeds of the circuit boards means that the electronic components integrated on the circuit boards will need to be more or higher end. More or higher end electronic devices generate more heat. Therefore, effectively dissipating the heat generated from the circuit board is a necessary design consideration.
One of the approaches to dissipate heat that is commonly used in the industry involves installing a cooling fan on the main board or the mother board to dissipate the heat generated by the electronic devices. This kind of cooling fan can be seen in U.S. Pat. Nos. 6,799,282, 7,215,548, 7,286,357 and 7,568,517, for example.
As an example, a conventional heat dissipating device 1 shown in FIG. 1A is installed on a predetermined location of a circuit board, and comprises a printed circuit board 11, a housing 12 and a fan wheel set 13. The housing 12 has a base 120, a shaft sleeve 122 and a stator set 121 disposed around the shaft sleeve 122. The fan wheel set 13 has a hub 130, a magnet 131 located on an inner side of the hub 130, a plurality of blades 132 disposed around a periphery of the hub 130, and an shaft member 133 pivotally connected to the hub 130 and pivotally disposed in the shaft sleeve 122. The printed circuit board 11 has at least one control chip 110 and a plurality of passive elements 112 provided thereon. The printed circuit board 11 is disposed on the base 12 of the housing 120 to control the rotation of the fan wheel set 13 via the control chip 110, so that the rotation of the fan wheel set 13 can drive airflow.
The control chip 110 used in the conventional heat dissipating device 1 shown in FIG. 1A is a heat source. If heat generated by the control chip 10 cannot escape, it may lead to overheating and failing of the chip itself, which in turn will lead to the standstill of the fan wheel set 13. Thus, the heat generated by the electronic components on the main board of the electronic product cannot be dissipated effectively, resulting in failing or even damage of the electronic product. The control chip 110 is located just in a gap between the base 120 of the housing 12 and the hub 130 of the fan wheel set 13. The narrow gap often results in ineffective dissipation of the heat generated by the control chip 110, leading to overheating and damage of the control chip 110. The heat dissipating device 1 is a relative cheap component among the various components of the electronic product. However, if the heat dissipating device 1 cannot operate properly, it will damage the more expensive core component (the main board) of the electronic product, so its importance cannot be measured in terms of its price.
In addition, the provision of the control chip 110 will influence the size of the gap between the hub 130 of the fan wheel set 13 and the base 120 of the housing 12. An increase in the thickness of the control chip 110 very often requires an increase in the width of the gap, which is detrimental to the reduction of the overall height of the heat dissipating device 1. Moreover, the provision of the control chip 110 increases the footprint of the printed circuit board 11. If the area of the printed circuit board 11 is increased without increasing the cross-sectional area of this type of conventional heat dissipating device 1, then the area of the blades 132 will need to be reduced. However, a reduction in the area of the blades 132 will influence the airflow output. A lack of airflow output will affect the desired effect of heat dissipation.
In order to solve the problems, U.S. Pat. No. 7,345,884 proposed an improved cooling fan. As shown in FIG. 1B, the structure of a cooling fan 1′ described in U.S. Pat. No. 7,345,884 is substantially the same as the structure of the prior art mentioned above. The difference is in that the printed circuit board 11′ is formed with an extending part 11a that extends outwardly to allow the control chip 110′ to be provided thereon, such that the control chip 110′ is located entirely or partially outside the gap between the base 120′ of the housing 12′ and the hub 130′ of the fan wheel set 13′. As such, the heat generated by the control chip 110′ can be effectively removed by the airflow driven by the fan wheel set 13′.
However, the formation of the above outward extending part 11a of the printed circuit board 11′ will interfere the airflow driven by the rotation of the fan wheel set 13′. Interfered airflow will generate noise, which in turn degrades the quality of the electronic product equipped with such kind of cooling fan 1′. Meanwhile, due to the outward extension of the extending part 11a, certain interval has to be kept between the blades 132′ and the control chip 110′. This is also unfavorable to the reduction of the overall height of the conventional cooling fan 1′, therefore failing to satisfy the needs for thinner electronic products.
Furthermore, the conventional cooling fan 1′ still requires the printed circuit board 11′ to be provided between the hub 130′ of the fan wheel set 13′ and the base 120′ of the housing 12′, so the thickness of the printed circuit board 11′ will still affect the overall height of the cooling fan 1′, which makes further thinning of the cooling fan 1′ more difficult.
Therefore, overcoming aforementioned prior art problems is the current objective to be addressed.


An apparatus and method are disclosed of providing position indicating signals to a GNSS receiver in an area of poor reception of satellite signals from the GNSS or when a dedicated system under local control is required. The method includes the steps of disposing a plurality of stationary transceivers proximate the area of poor reception and calculating a global position of each stationary transceiver based upon information contained within signals received from at least some satellites of the GNSS. The method further includes the steps of transmitting a local global positioning signal from each of the stationary transceivers to the GNSS receiver in the area of poor reception, such local global positioning signals including at least the global position of the transmitting stationary transceiver.

Global position systems, such as the American NAVSTAR GPS and Russian GLONASS, are known. The NAVSTAR GPS developed by the U.S. Defense Department is a satellite-based radio navigation system which transmits information from which extremely accurate navigational calculations can be made in three-dimensional space anywhere on or near the Earth. Three-dimensional velocity can be determined with equal precision. The GPS uses 18 satellites evenly dispersed in three, inclined, 12 hour circular orbits chosen to ensure continuous 24 hour coverage world-wide. Each satellite uses extremely accurate cesium and rubidium vapor atomic clocks for generating a time base. Each satellite is provided with clock correction and orbit information by Earth-based monitoring stations.
Each satellite transmits a pair of L-band signals. The pair of signals includes an L1 signal at a frequency of 1575.42 MHZ and an L2 signal at a frequency of 1227.6 MHZ. The L1 and L2 signals are bi-phase modulated by pseudo-random noise (PRN) codes and an information signal (i.e., navigation data) encoded at 50 Hz. The PRN codes facilitate multiple access through the use of a different PRN code by each satellite.
Upon detecting and synchronizing with a PRN code, a receiver decodes the PRN encoded signal to recover the navigation data, including ephemeris data. The ephemeris data is used in conjunction with a set of Keplerian equations to precisely determine the location of each satellite. The receiver measures a phase difference (i.e., time of arrival) of signals from at least four satellites. The time differences are then used to solve a matrix of four equations. The result is a precise determination of location of the receiver in three-dimensional space.
Velocity of the receiver may be determined by a precise measurement of the L1 and L2 frequencies. The measured frequencies are used to determine Doppler frequency shifts caused by differences in velocity. The measured differences are used to solve another set of equations to determine velocity based upon the Doppler phase shift of the received signal.
A Russian GLONASS system operates in a similar manner except that each satellite transmits on a unique set of frequencies instead of a unique set of PRN codes.
While the GPS performs relatively well, there are still situations where receivers cannot detect satellite signals. For instance, where a receiver is located in a deep valley, a receiver cannot detect a sufficient number of satellite signals to accurately determine position. Accordingly, a need exists for a means of providing more powerful signals to receivers in suboptimum environments.

GNSS local constellation/acquisition aiding system


A lightweight motorcycle frame is made with sufficient rigidity to minimize or avoid the occurrence of frame cracks, due to impacts on the frame caused by a harsh landing after a vehicle jump or the like. The motorcycle frame includes a head pipe, a pair of main frames extending rearwardly from the head pipe, and a down tube extending downwardly from a lower portion of the head pipe. The frame may include a forged reinforcing body for connecting the head pipe and the down tube, and the other frame components may be formed by casting. In this case, the other frame components include a portion of the head pipe, the main frames, the down tube, and the reinforcing frame, which may be integrally molded by aluminum casting. Where used, the reinforcing body may be secured to a front portion of an integrally cast frame body.

1. Field of the Invention
The present invention relates to a motorcycle frame that is reinforced so as to be sufficiently rigid for use in extreme conditions, while being light in weight.
2. Description of the Background Art
In general, it is known to provide a motorcycle having frame components which include main frames and a down tube, where the main frames extend from a head pipe in a rearward direction of a body, and the down tube extends under this main frame and extends from the head pipe in a downward direction of the body.
For motorcycles having such frame components, it has been proposed that frame components, including a head pipe, a main frame, a down tube and the like, are integrally cast using light metal materials such as magnesium alloy in order to minimize vehicle body weight. Such a motorcycle is disclosed, for example, in Japanese Laid-open Patent Application No. Sho 60-176876.
In a motorcycle trial race, since there may be an event where a motorcycle drops, for example, through a distance of 10 meters in height, the motorcycle used for a motorcycle trial race is required to have enough strength to sustain impacts caused by such falls.
However, when a motorcycle is designed according to the convention of minimizing the weight of the motorcycle body, and when such a motorcycle is used for trial racing, it is necessary to stiffen respective frame components in the body portion to which a load is applied.
The present invention was made in consideration of the above described problem, and an object thereof is to provide a motorcycle frame, the rigidity of which is secured while maintaining a light frame weight.


A lumbo-sacral orthopedic brace apparatus is formed of flexible materials to fit over a patient's torso and has a front flexible section shaped to fit over the front of a patient's torso and covered with a VELCRO hook and loop fastener loop material. A plurality of flexible straps are attached to the brace front section on either side thereof by being attached to a hook and loop fastener hook strap which is attached to the brace front section loop material. A rear flexible section is shaped to fit over the rear of a patient's torso and has a plurality of loops attached to each side thereof by being attached to a hook and loop hook strap which is attached to the brace rear section loop material. The hook straps are able to be attached to the front or the back at any angle at any point across the entire front or back, respectively, rapidly altering the orthosis to accommodate a broad range of figure types. The straps on the front flexible section are looped through the loops on the rear section and are connected in groups to common flexible straps. Pulling one common strap pulls a plurality of straps through the loops. Each common strap has hook material attached thereto so that the common strap can be attached to the front section loop material in different positions and angles to adjust the stress of the rear flexible member on the rear of a patient's torso.

The present invention relates to an orthopedic brace and especially to a soft flexible orthopedic brace providing for multiple and rapid adjustment.
Although body jackets have been known and used for many years in the treatment and rehabilitation of the spine, elderly, injured, and handicapped persons have experienced difficulty in putting on rigid and soft flexible orthoses and generally require assistance. It is known to use corset lacings and corset buckles in combination with soft, flexible orthoses to provide even adjustment and an easy release. For example, the buckle taught by Camp in U.S. Pat No. 2,053,600 has improved the adjustment of nonrigid orthoses. Using the Camp buckle, corset lacings threaded through the buckle are adjusted with the orthosis on the patient. The buckle straps are attached to the orthosis with snaps, permitting ease of removal and reinstallation.
In the past, rigid orthoses have used corset lacing on one side to secure the anterior section to the posterior section and once adjusted, remains permanently fixed. The other side may be attached by two straps, resulting in a body jacket that is difficult to put on. When the straps are tightened, the opposing side may rotate or twist toward the last adjusted strap. For many patients, this design requires two people to properly position the orthosis. Thus, many elderly and handicapped patients are unable to don the jacket.
A rigid body jacket is also shown in U.S. Pat. No. 4,202,327 having a number of straps for connecting right and left sections with the straps secured to the jacket with hook and loop strips. The necessity for adjusting straps both front and rear prevents use by many patients without assistance in doffing and donning the orthosis.
In my prior U.S. Pat. No. 4,508,110, a body jacket-type orthoses limits motion in thoracic or lumbo-sacral areas and uses a rigid orthoses design for ease of adjustment by a patient and which can be adjusted by the patient by pulling on a plurality of laces, each attached to a short strap having VELCRO thereon which is used to attach the straps to predetermined positions on the rigid brace members.
Other prior art U.S. patents for orthoses can be seen in the Brooks et al. U.S. Pat. No. 4,475,543, for a lumbo-sacral brace using an elastic belt fastened with a pouch in combination with a semi-wrap-around polyurethane foam splint cured in place in the pouch. In the Kendrick patent, U.S. Pat. No. 2,100,964, a surgical belt is illustrated in which a plurality of laces are interconnected to a single strap on either side thereof. In the Spiro patent, U.S. Pat. No. 3,926,183, a dorsal lumbo sacral support combines elastic and non-elastic straps in a support device for a person's back, thoracic or pelvic areas. The Wax patent, U.S. Pat. No. 3,927,665, is for a lumbo-sacral support having an elastic body encircling band and inelastic tensioning system. The Miller patent, U.S. Pat. No. 5,074,288, illustrates a soft body brace attached to a patient with a plurality of straps. The Saunders patent is a back support system with interchangeable and positionally adjustable orthotic support. The Rosenberg patent, U.S. Pat. No. 4,175,553, is also a lumbo-sacral orthosis orthopedic support for encircling the torso and has a plurality of straps. The Lewis, Jr. patent, U.S. Pat. No. 4,459,979 is an orthopedic appliance made of resilient material conforming to the lower back of a person and uses a plurality of adjustable straps. The Varn patent, U.S. Pat. No. 5,362,304 is a thoracic lumbar sacral orthosis device formed as a jacket and has support plates which can attach thereto. The Peters patent, U.S. Pat. No. 5,188,585 is a lumbo-sacral orthopedic support which encircles the torso of a patient and has adjustable strap portions. The Batard et al. patent, U.S. Pat. No. 4,559,933, is an orthopedic lumbo-sacral corset using semi-rigid elements and inflatable pads.
There is a need for a soft flexible glove-like body jacket orthosis which can be adjusted on the patient and then easily removed and replaced by the patient.
The present invention is directed towards a flexible lumbo-sacral orthopedic brace which fits in a glove-like fashion and can be easily attached and tightened in a wide variety of positions for a wide variety of body shapes and provides for optional side splints and lightweight splints removably attachable thereto.


A refractory composite structure is formed which comprises a ductile refractory metallic layer with a roughened surface which is tightly bonded to a refractory composite structural shell. The roughened surface is preferably dendritic in form and produced by chemical vapor deposition techniques. The refractory composite structural shell is preferably a carbon-carbon composite formed by applying a carbon filament preform to the roughened surface, infiltrating the preform with a carbon matrix precursor, and carbonizing the precursor.

1. Field of the Invention
This invention relates to high strength, high temperature corrosion and erosion resistant structures and their processes of preparation. More particularly, this invention relates to cost effective, low heat capacity, lightweight composite structures with tailored thermal conductivity which are capable of sustaining heavy loads and withstanding highly corrosive and erosive environments at greatly elevated temperatures and pressures for hours or days or even more.
2. Description of the Prior Art
Previously considerable difficulty had been experienced in providing efficient structures which retain their structural integrity at temperatures in excess of 1,500 degrees centigrade while sustaining substantial structural loads in harsh chemical environments. Previous solutions have included that proposed in Tuffias et al U.S. Pat. No. 4,917,968, wherein a structure composed of metallurgically bonded layers of a platinum group metal such as ductile iridium and a refractory metal such as ductile rhenium possesses both the high temperature corrosion resistance and the high temperature structural strength for high stress, high temperature applications. When additional strength was required, according to previous teachings, it was generally believed necessary to increase the thickness of the structure, particularly the thickness of the refractory metal layer. Increasing the strength of the structure by increasing its thickness increased the weight, the heat capacity, the cost and the difficulty of manufacturing it. These limitations are undesirable in a number of fields including, for example, that of rocketry. Rocket thrust chamber assemblies, for example, could be improved by the availability of lightweight, low cost, high strength, low heat capacity refractory materials. Further, the ability to selectively tailor the strength, heat capacity and thermal conductivity of various parts of the rocket thrust chamber assemblies would permit greater efficiencies and design flexibility.
As described, for example, in Tuffias et al U.S. Pat. No. 4,917,968, chemical vapor deposition procedures are utilized to form successive layers of a structure under conditions such that the layers are bonded together by an interlayer which is an admixture of the two adjacent layers. A first corrosion resistant layer is provided which is capable of withstanding highly corrosive environments at temperatures in excess of 1,500 degrees centigrade, and preferably, in excess of 2,000 or 2,200 degrees centigrade. The corrosion resistant layer is bonded through an interlayer to a high strength layer. The high strength layer exhibits tensile strengths in excess of 5,000, and preferably, 15,000 pounds per square inch at temperatures in excess of 1,500, and preferably, in excess of 2,000 degrees centigrade. In general, the metallic layers in such structures are composed of platinum group metals such as, for example, iridium, and refractory materials, preferably metals such as, for example, rhenium. The hot sides or normally interior sides of the structures may, if desired, be coated with high temperature ceramic materials such as, for example, hafnium dioxide or zirconium dioxide, to improve their corrosion resistance.
When rocket thrusters are operated at the optimum oxidizer/fuel ratio, the temperature of the combustion products may be as high as 2,000 to 3,000 degrees centigrade. This is the condition at which the highest efficiency is achieved. Thrusters must be cycled on and off many times over their useful lives. The thrusters may cool between cycles to very low temperatures. Further, thrusters must withstand the forces imposed on space vehicles during launch and in use. The materials from which thrusters are constructed must withstand both structural and thermal shock. Brittle materials tend to fail rapidly because of an inability to withstand this shock. Premature failure because of cracking under shock or thermochemical failure greatly limits the useful life and reliability of the thruster. Very few materials or material combinations are capable of withstanding the shock loads, the structural loads, and the catastrophically corrosive conditions which are imposed on, for example, a rocket thrust chamber assembly. The metallurgically bonded Iridium-Rhenium structure described in Tuffias et al U. S. Pat. No. 4,917,968 is capable of fulfilling these requirements except that increasing the mass of the structure to accommodate particularly robust applications produces some undesired results.
Increasing the volume of the metallic parts of the rocket motor in an attempt to increase strength and durability is generally self defeating. The cost of operating a spacecraft with heavier components escalates rapidly, and efficiency degenerates rapidly to unacceptable levels. The cost and difficulty of manufacturing high quality parts escalates quickly as the volume and weight of metal increases, particularly where the structure has a high degree of concavity. When operating out of the atmosphere, rocket motors are cooled by radiation. Under these conditions high heat capacity structures are undesirable because the heat retained in the structure of the rocket motor flows back into the adjacent structures and electronics, including the fuel system components, especially during shut down. This may cause the fuel system or other components to fail or, at the worst, it may cause the fuel to ignite outside of the rocket motor chamber with catastrophic results. In general, the heat in the rocket motor should be dissipated from the skirt region by radiation. Preferably, thermal conductivity between the skirt region and the rest of the rocket motor should be enhanced. These objectives are generally incompatible with increasing the strength of the motor by increasing the thickness of its refractory metal walls.
Propulsion systems incorporating thrust chamber assemblies are used in space for the maneuvering of satellites and otherwise, in air for aircraft intercept systems, ground based intercept systems, and the like. Improving the efficiency of the thruster and extending its life provides a substantial number of new alternatives in these and other applications. The same thrust can be obtained with less fuel and thus less weight. The savings in weight can be distributed between additional fuel and additional payload. Extending the life of the thruster and the number of cycles which it can withstand prolongs the useful life of the satellite or vehicle upon which it is mounted. Increasing the effective fuel capacity of the vehicle also extends its useful life.
Many applications exist outside of the space field for lightweight, relatively inexpensive structures which are capable of withstanding shock, and high structural loads in highly corrosive high temperature environments. The absence of such structures limits or precludes the use of some reactions in the chemical process industry. Such structures find application in propulsion systems and prime movers other than rockets. Other fields such as nuclear, metallurgical, waste disposal, emissions reduction, and the like, also require such structures to optimize or make possible various operations.
Chemical vapor deposition procedures are known and have been used for the better part of a century for forming various coatings. In general it is a method of plating on an atom by atom basis in which a gaseous compound, or compounds, of the material to be deposited is flowed over or through a heated substrate, resulting in the thermal decomposition or reduction of the compounds and the subsequent deposition of the material onto an exterior or interior surface of the heated substrate. The parameters which must be controlled for successful reliable operation include the choice of gaseous compounds, the concentration of the compounds in the gas, the gas flow rate, the gas pressure, the nature of the substrate material, the geometry of the substrate, the temperature of the substrate, and the geometry of the reaction chamber. The nature of the deposit may be controlled by controlling these parameters. The crystal form may, for example, sometimes be changed by changing the gaseous compounds. The degree of adherence to the substrate may be controlled, for example, by adjusting the temperature of the substrate. The deposits formed by chemical vapor deposition are generally very pure. Materials may be codeposited depending upon the composition of the gas which is supplied to the reactor. Both metallic and non-metallic materials may be deposited using these techniques and they may even be codeposited. In general, the preferred method of construction of hollow structures is that whereby successive layers are formed on a mandrel which is later removed, for example, by chemical leaching. The structure is thus formed inside out, thereby reflecting the outer surface of the mandrel.
For the sake of convenience in describing and defining the process and the structure, the cross-section of the structure has been referred to as comprising various layers of materials. If desired, however, it is possible with chemical vapor deposition techniques to provide a continuous variation in the composition of the structure from one pure material at one outer surface to another pure material at the opposed outer surface. Also, the variation in the composition need not be continuous. If ceramics are used on one outer surface it is possible to provide such a continuous variation in composition across three or more materials, not all of which are metallic. Such graded deposits have no discontinuity and thus no stress concentration due to a mismatch of thermal expansion rates. Graded deposits are produced by varying the composition of the reactive gas as the deposit builds up. The description and definition of the process and structure is intended to include such graded deposits.
In general the chemical vapor deposition operation which is utilized to form the structure is controlled so that the first deposit is not necessarily chemically or metallurgically bonded to the mandrel. Subsequent deposits are bonded very tightly to one another through interlayers. Adjustment of the temperature of the substrate and the period of time during which the substrate is subjected to elevated temperatures permit control of the extent and nature of the bond. The preferred temperatures should be determined for each specific situation, and may vary considerably from one application to another.
Less preferred alternative coating methods may be used, if desired, in the formation of part or all of the structures described. Such methods include, but are not limited to, for example, electrolytic, electroless, physical vapor deposition (PVD), plasma spray techniques, and the like.
The requirement that the structure be possessed of shock resistance and high strength at very high temperatures severely limits the choice of refractory materials for the high strength barrier or layer. Materials which have tensile strengths in excess of 5,000 pounds per square inch at 2,000 degrees centigrade include, for example, carbon-carbon, tungsten, Ta-10W, Mo-50Re, rhenium, and thoriated tungsten (W-1ThO.sub.2). Of these-materials, only carbon-carbon, W-1ThO.sub.2, rhenium and Mo-50Re have tensile strengths approximately in excess of 10,000 pounds per square inch at 2,000 degrees centigrade. Alloys, admixtures, and composites of these materials with each other and with other materials are also suitable for use as the structural barrier.
The requirement that the corrosion resistant layer or barrier withstand shock and catastrophically corrosive conditions at temperatures in excess of 1,500 and preferably in excess of 2,000 or 2,200 degrees centigrade for several hours severely limits the choice of materials for this layer or barrier. The platinum group metals and their alloys are candidates for this barrier. Iridium and rhodium and their alloys with each other and with, for example, platinum, rhenium and osmium, are suitable candidates. The addition, for example, of approximately 30 percent platinum or rhodium to iridium reduces the melting point of the alloy to approximately 2,200 degrees centigrade but substantially increases the resistance of the material to oxidation.
Iridium structures, and certain iridium alloy structures, which have been carefully prepared by chemical vapor deposition procedures are inherently ductile. This permits the structural layer to deform somewhat under applied loads without destroying the integrity of the corrosion barrier.
Where it is desired to protect exposed surfaces of the structure, and particularly the exposed surface of the corrosion barrier, with a ceramic material there are a number of possible suitable materials. Hafnium dioxide and zirconium dioxide are very suitable, particularly when stabilized with an inversion inhibitor. Yttria, for example, has been used to inhibit the crystalline inversion of hafnium dioxide. Crystalline inversion occurs with hafnium dioxide at approximately 1,600 degrees centigrade and causes cracking and spalling of hafnia coatings. Other borides, carbides and nitrides from which suitable materials may be selected include, for example, hafnium, tantalum, zirconium, tungsten, silicon, and boron carbides, tantalum, hafnium, boron, zirconium, titanium, and niobium nitrides, and hafnium, zirconium, tantalum, niobium, and titanium borides. The ceramic layer, if used, is very thin and is not intended to provide the primary corrosion protection for the structural layer. The purpose of the ceramic barrier is to reduce the recession rate of the primary corrosion barrier. The ceramic and/or primary corrosion barrier may be applied to all of the exposed surfaces of the structure if desired. The thickness of the ceramic layer is generally three mils or less. This may be varied as conditions may require.
Carbon fiber reinforced carbon matrix composites are known to be lightweight, high strength, refractory, structural materials whose strength increases with temperature, even at temperatures well in excess of 2,000 degrees Centigrade. Well known limitations on the use of carbon-carbon composites include the facts that they rapidly oxidize catastrophically at temperatures well below 1,000 degrees Centigrade, and generally exhibit some degree of porosity. These composites must, therefore, be protected from oxidation, and are generally not satisfactory where an impermeable structure is required. In the preparation of carbon-carbon composite structures, the carbon fibers and filaments are generally formed into a construct or preform of the desired configuration by winding, weaving, knitting, braiding, or wrapping over a suitably formed support or mandrel. The carbon matrix is generally formed by infiltrating the preform with resin, which is then pyrolyzed, or by chemical vapor deposition techniques, or both, whereby carbon is deposited in the construct. The characteristics of the completed composite are determined by the nature of the starting materials and the processing. The thermal and mechanical properties of carbon-carbon composites are highly tailorable.

Method of forming a composite structure such as a rocket combustion chamber


A tip turbine engine (10) according to the present invention includes an engine support structure (12) for cantilevering a load bearing shaft from an engine support plane (P). An engine support structure (12) defines the engine support plane (P), which is perpendicular to an engine centerline (A). The shaft (60) is rotationally fixed, coaxial with the engine centerline (A), and structurally supported by the engine support structure (12) such that a load borne by the shaft (60) is transferred along the engine support plane.

The present invention relates to a tip turbine engine, and more particularly to an assembly with a load bearing support shaft cantilevered from a single engine support plane.
An aircraft gas turbine engine of the conventional turbofan type generally includes a forward bypass fan and a low pressure compressor, a middle core engine including a combustor, and an aft low pressure turbine all located along a common longitudinal axis. Although highly efficient, conventional turbofan engines operate in a axial flow relationship. The serial flow relationship results in a relatively complicated elongated engine structure and, therefore, requires multiple mounting planes to mount the engine and bear the loads of the elongated structure. Utilizing multiple mounting planes may complicate the mounting process and make assembly laborious and expensive.
A recent development in gas turbine engines is the more longitudinally compact tip turbine engine. Tip turbine engines locate an axial compressor forward of a bypass fan, which includes hollow fan blades that receive airflow from the axial compressor therethrough such that the hollow fan blades operate as a centrifugal compressor. Compressed core airflow from the hollow fan blades is mixed with fuel in an annular combustor located radially outward from the fan. The combustor ignites the fuel mixture to form a high energy gas stream which drives turbine blades that are integrated onto the tips of the hollow bypass fan blades for rotation therewith as disclosed in U.S. Patent Application Publication Nos.: 2003192303; 20030192304; and 20040025490. The tip turbine engine provides a thrust to weight ratio equivalent to conventional turbofan engines of the same class within a package of significantly shorter longitudinal length.
Accordingly and because of the unique architecture and shorter length of the tip turbine engine, it is desirable to cantilever the length of the engine from a sole engine support plane.


An organic light emitting diode display includes a display substrate including a display region having an organic light emitting diode; an encapsulation substrate facing the display substrate and covering the display region; a first sealing material between the display substrate and the encapsulation substrate, the first sealing material sealing the display region; a second sealing material in contact with an external exposed surface of the first sealing material and sealing the first sealing material; and a molding portion surrounding a lateral surface and an external corner of each of the display substrate and the encapsulation substrate and surrounding an external exposed surface of the second sealing material.

1. Field
Embodiments relate to an organic light emitting diode display and a method of manufacturing the same.
2. Description of the Related Art
An organic light emitting diode display is a self-luminance type display device including a hole injection electrode, an electron injection electrode, and an organic emission layer formed therebetween. The organic light emitting diode display emits light by recombining holes injected from an anode and electrons injected from a cathode in the organic emission layer and dissipating the holes and the electrons. Further, the organic light emitting diode display exhibits high quality characteristics such as low power consumption, high luminance, and high reaction speed. Accordingly, the organic light emitting diode display receives attention as a next generation display device of a portable electronic device.
The organic light emitting diode display includes an organic light emitting display panel including a display substrate on which a thin film transistor and an organic light emitting diode (OLED) are formed. The organic light emitting diode includes an anode, a cathode, and an organic emission layer. Holes and electrons injected from the anode and the cathode, respectively, form an exciton, and light is emitted while the exciton is transferred to a bottom state.

Organic light emitting diode display and method of manufacturing the same