A transfer ratio varying apparatus includes: a steering shaft configured to transmit a steering angle, an actuator connected to the steering shaft and a damper disposed between the input shaft and the steering shaft and configured to absorb vibration caused by the actuator. The actuator includes: a housing, an input shaft configured to integrally rotate with the housing and connected to the steering shaft, a motor including a rotatable shaft, an output shaft configured to transmit an angle to a wheel assembly, and a gear mechanism between the rotatable shaft and the output shaft at the housing, configured to adjust a rotational angle of the rotatable shaft and to output the adjusted rotational angle to the output shaft.

1. Field of the Invention
This invention generally relates to a transfer ratio varying apparatus capable of varying a transfer ratio between a steering angle of a steering wheel and an angle of a wheel assembly, where the wheel assembly includes wheels and an axle connecting the wheels.
2. Description of the Related Art
Conventionally, a transfer ratio varying apparatus is described in Japanese patent Laid-Open Publication No. 2000-211541. The transfer ratio varying apparatus includes a steering shaft for transmitting a steering angle of a steering wheel, and an actuator connected to the steering shaft. The actuator includes a housing, an input shaft positioned for integral rotation with the housing and connected to the steering shaft, a motor fixed in the housing and including a shaft that is rotatable (hereafter "motor shaft"), an output shaft rotatably supported by the housing and transmitting an angle to a wheel assembly, where the wheel assembly includes wheels and an axle connecting the wheels, and a gear mechanism disposed between the motor shaft and the output shaft in the housing and increasing or decreasing a rotational angle of the motor shaft. The increased or decreased rotational angle of the rotary shaft is outputted to the output shaft.
Normally, the wheel assembly can receive the angle which was generated by a variable transfer ratio relative to the steering angle of the steering wheel. However, in times of emergency, such as a malfunction of an electronic control unit (ECU), the input shaft of the actuator and the motor shaft can lock up, thereby disabling variance of the transfer ratio.
In the meantime, another Japanese Patent Laid-Open Publication No. 2001-30921 describes a steering apparatus including a damper. This steering apparatus includes a flexible coupling, a first steering shaft connected to one side of the flexible coupling, a second steering shaft connected to an opposite side of the flexible coupling, and a stopper plate attached to the flexible coupling for restraining relative displacement in a torsion direction of the first and second steering shafts. The stopper plate is firmly fixed with a mass, which is a damper. The damper includes a solid metal body coated with a rubber outer layer.
According to the steering apparatus with the aforementioned structure, vibration, which may occur upon steering the steering wheel, can be absorbed by the damper, thereby leading to a reduction of in-vehicle noise. However, in the structure of Japanese Patent Laid-Open Publication No. 2001-30921, it is necessary to have two steering shafts, which is undesirable.
When the above-described transfer ratio varying apparatus was actually mounted on a vehicle, it became obvious that in-vehicle noise is caused due to vibration of the steering wheel. In order to overcome this drawback, it may be preferable that the transfer ratio varying apparatus possesses substantially similar structure as the above-described steering apparatus. That is, the steering shaft of the transfer ratio varying apparatus is divided between first and second steering shafts with a flexible coupling therebetween, where the damper can be firmly fixed with a stopper plate attached to the flexible coupling.
However, the inventors of the present invention experimentally verified that vibration of the steering wheel arises from the rotation of the motor shaft. More particularly, vibration along the motor shaft rotation becomes vibration of the actuator. The actuator vibration is transmitted to the steering wheel via the steering shaft. Therefore, even if the damper is disposed between the first and second steering shafts, the vibration caused due to the motor shaft rotation may be amplified via the first and second steering shafts, which are relatively long. As a result, still some concerns may remain that the in-vehicle noise is not sufficiently reduced.
In light of foregoing, a need thus exists for providing an improved transfer ratio varying apparatus capable of effectively reducing in-vehicle noise.


Dynamically allocating virtual or physical CPU cycles for use in processing a video stream. Video complexity information for two or more digital video streams actively being processed by one or more video encoders is determined at periodic intervals. Video complexity information describes the complexity of digital video carried by the digital video streams across a bounded number of consecutive digital frames which includes digital frames not yet processed by the one or more video encoders. A determination is made as to whether a number of CPU cycles allocated for processing a particular digital video stream should be adjusted based on the determined video complexity information. The number of CPU cycles allocated for processing the particular digital video stream may be dynamically adjusted by changing an amount of CPU cycles allocated to a virtual machine in which the stream is processed or by processing the stream in a different virtual machine.

A communication satellite's transponder is a series of interconnected units which form a communications channel between receiving and transmitting antennas. Most communication satellites carry dozens of transponders, each transponder having a bandwidth of tens of megahertz. Most transponders operate on a "bent pipe" principle by sending a received signal back to earth with minimal processing, e.g., a transponder might amplify a signal and shift the signal from an uplink frequency to a downlink frequency. Some communication satellites use a "regenerative" transponder whereby a received signal is also demodulated, decoded, re-encoded, and modulated aboard the satellite.
Two or more digital video services (such as a channel) may be supported by a single transponder. As each transponder has a fixed capacity, the determination of how many digital video services that a particular transponder supports is based on maximizing the limited resources of the transponder as best possible. To arrive at the number of digital video services a particular transponder should support, one could simply assign an equal, fixed-sized share of the total capacity of the transponder to each service carried by the transponder. For example, if the transponder is to support five services, then each service would be assigned a fixed 20% of the capacity of the transponder. In this fashion, the transponder could support additional services until the proportional share of the transponder capacity assigned to a particular service is less than the minimum amount of transponder capacity required to support the worst case scenario or high water mark use-case of that service.
In practice, the amount of transponder capacity required by any particular single digital video service fluctuates over time. To make better use of the transponder in view of the changing needs of the services it supports, an approach termed "statistical multiplexing" has been used to allocate transponder resources to digital video services. In statistical multiplexing, the capacity of the transponder is dynamically adjusted many times a second based on the complexity of the digital video carried by each channel supported by the transponder. The complexity of the digital video is a measure of how much data it takes to describe how to display the digital video. In this way, when a particular channel requires a larger portion of the transponder's capacity, additional transponder resources can be allocated to that channel from another channel which is not using all of its allocated transponder resources at the moment.
In computing, a virtual machine (also designated by the acronym VM) is an emulation of a particular computer system. Virtual machines operate based on the computer architecture and functions of a real or hypothetical computer, and their implementations may involve specialized hardware, software, or a combination of both.
Classification of virtual machines can be based on the degree to which they implement functionalities of targeted real machines. That way, system virtual machines (also known as full virtualization VMs) provide a complete substitute for the targeted real machine and a level of functionality required for the execution of a complete operating system.
The use of VMs provides a great flexibility in the handling of tasks to execute in parallel. Indeed, VMs can be created and deleted very easily to meet the needs of tasks processing that evolve in real time. Moreover, VMs provide a great flexibility for creating machines with the desired properties, since the actual characteristics of a VM are a combination of software characteristics and characteristics of the hardware machine on which the VM is executed.
This flexibility is especially useful in multimedia processing. Indeed, multimedia task are known to require significant resources, and the flexibility of allocation of resources to VMs permit to create machines having resources just sufficient to execute a multimedia task. In a multimedia head-end server, VMs can thus be created dynamically upon the request of clients to obtain a multimedia service. When creating a virtual machine, it is possible to adjust the parameters of the machine, for example its CPU, RAM, and/or bandwidth. The necessary resources are then reserved on the host hardware machine. For example, when creating a VM with 4 GB RAM, 4 GB of RAM will be reserved for this VM on the host hardware machine, in order to ensure that the VM will have enough RAM to operate. Thus, the sum of all resources reserved by the VMs on a host machine cannot exceed the resources of the host machine, and the reservation of resources for a VM mitigates the ability of a hardware machine to host additional VMs for performing further multimedia processing.
It is thus advantageous to dispatch the processing tasks to perform amongst the available machines in order that they have the least possible unused resources. To achieve this goal, it is desirable to obtain, for processing tasks to execute, an evaluation of the resources needed to perform a task, and for machines, an evaluation of the available resources.
This is especially true for multimedia processing, in which many tasks are computationally-intense tasks that have to be performed in real time with a target of quality. For example, it is possible to encode video content with different levels of quality. More resources are usually needed for higher levels of quality. Indeed, it is usually necessary to perform more complex video coding decisions to improve the quality of video at an equivalent bitrate. A VM thus needs a minimum amount of resources to perform video encoding in real time at a desired level of quality.
The usual method for defining the resources of a machine rely on an evaluation a priori of the resources necessary to perform a task. For example, if the CPU necessary to perform a task is known, the CPU of a VM being also known, it is straightforward to infer how many instances of a task may run in parallel on the machine.
Although this works for simple calculation tasks, it is almost impossible to calculate a priori the resources necessary to perform multimedia processing. Indeed, the ability to perform a task depends upon complex interactions between CPU, memory, and the like. Moreover, the ability to perform multimedia processing with a desired level of quality in real time is highly dependent on the content of the multimedia streams to be processed. For example, the resources necessary to encode a video scene increase with the resolution of the scene. But it is also dependent on the content of the scene. For example, video scenes comprising water and waves are known to be highly difficult to encode, both in terms of encoding time and compression levels. Other parameters such as the frame rate or encoding parameters have an impact on the resources necessary to encode a video, which renders an a priori evaluation of the performance of a machine even more difficult.
Another possible approach to overcome this issue consists in calculating, for a given multimedia task, the minimum required amount of resources, by running the task and observing the footprint of the execution of the task. However, this approach may only be used with machines with standardized configurations, and is not adapted to virtual machines, in which the combination of hardware and software machines produces much more flexibility in the creation of machines, while bringing uncertainty about the actual capacity of a VM to be created.
FIG. 1 displays an example of determination of available resources on a machine of the prior art. The prior art method consists in running a multimedia processing 130 on a target machine 120. The multimedia processing 130 takes multimedia data 110 as input, and outputs processed multimedia data 140. The execution of the multimedia processing 130 on the machine 120 allows the calculation of a minimal machine configuration 150 necessary to execute the processing 130. The calculation of the minimal machine configuration 150 can be performed by observing the minimum resources needed by the multimedia task 130 to run. The minimum resources comprise for example a minimum CPU, a minimum memory, a minimum bandwidth, and so on. For example, the minimum CPU resources to run the processing can be observed by observing the maximum CPU used by the processing 130 when run on the target machine.
This prior art method allows the determination of minimum resources necessary to run a multimedia processing. However, it is only applicable to a predefined, standard type of platform. Indeed, the execution of a processing is highly dependent of the fixed physical attributes, such as memory and CPU, of the type of machine performing the execution. This method is thus not applicable to virtual machines. Indeed, the flexibility of the creation of virtual machines induces the permanent creation of new types of machines. For example, even if a virtual machine is defined by, amongst other resources, a nominal CPU and a nominal amount of memory, the type and behavior of machine will be different depending on the physical machine on which the virtual machine is running.

This patent is subject to a terminal disclaimer.

Dynamic allocation of virtual and/or physical resources vis-a-vis virtual machines in video stream processing


Methods and apparatus for shaping pipes, tubes, liners, or casing at downhole locations in wells. Use is made of rollers bearing radially outwards against the inside wall of the pipe (etc.), the rollers being rolled around the pipe to cause outward plastic deformation which expands and shapes the pipe to a desired profile. Where one pipe is inside another, the two pipes can be joined without separate components (except optional seals). Landing nipples and liner hangers can be formed in situ. valves can be deployed to a selected downhole location and there sealed to the casing or liner without separate packers. Casing can be deployed downhole in reduced-diameter lengths and then expanded to case a well without requiring larger diameter bores and casing further uphole. The invention enables simplified downhole working, and enables a well to be drilled & produced with the minimum downhole bore throughout its depth, obviating the need for large bores. When expanding lengths of casing, the casing does not need to be anchored or made pressure-tight. The profiling/expansion tools of the invention can be deployed downhole on coiled tubing, and operated without high tensile loads on the coiled tubing.

Field of the Invention
This invention relates to procedures and equipment for profiling and jointing of pipes, and relates more particularly but not exclusively to methods and apparatus for the shaping and/or expansion and/or conjoining of tubular casings in wells.
In the hydrocarbon exploration and production industry there is a requirement to deploy tubular casings in relatively narrow-bore wells, and to expand the deployed casing in situ. The casing may require to be expanded throughout its length in order to line a bore drilled through geological material; the casing may additionally or alternatively require to be expanded at one end where it overlaps and lies concentrically within another length of previously deployed casing in order to form a swaged joint between the two lengths of casing. Proposals have been made that a slotted metal tube be expanded by mechanically pulling a mandrel through the tube, and that a solid-walled steel tube be expanded by hydraulically pushing a part-conical ceramic plunger through the tube. In both of these proposals, very high longitudinal forces would be exerted throughout the length of the tubing, which accordingly would require to be anchored at one end. Where mechanical pulling is to be employed, the pulling force would require to be exerted through a drillstring (in relatively large diameter wells) or through coiled tubing (in relatively small diameter wells). The necessary force would become harder to apply as the well became more deviated (i.e. more non-vertical), and in any event, coiled tubing may not tolerate high longitudinal forces. Where hydraulic pushing is to be employed, the required pressure may be hazardously high, and in any event the downhole system would require to be pressure-tight and substantially leak-free. (This would preclude the use of a hydraulically pushed mandrel for the expansion of slotted tubes). The use of a fixed-diameter mandrel or plug would make it impracticable or impossible to control or to vary post-deformation diameter after the start of the expansion procedure.
It is therefore an object of the invention to provide new and improved procedures and equipment for the profiling or jointing of pipes or other hollow tubular articles, which obviate or mitigate at least some of the disadvantages of the prior art.
In the following specification and claims, references to a "pipe" are to be taken as references to a hollow tubular pipe and to other forms of hollow tubular article, and references to "profiling" are to be taken as comprising alteration of shape and/or dimension(s) which alteration preferably takes place substantially without removal of material.

Procedures and equipment for profiling and jointing of pipes


A QD protecting material having high compatibility with a binder component in a luminescent layer. The luminescent layer contains, as a part of its chemical structure, a compound containing a moiety A having a sum atomic weight MA of 100 or more and quantum dots protected by a protecting material, the protecting material contains, as a part of its chemical structure, a linking group connected to a quantum dot surface and a moiety B that has a sum atomic weight MB of 100 or more, satisfies a relationship between MB and MA represented by |MA−MB|/MB (2, and satisfies the requirement that the sum atomic weight MB is larger than one-third of the molecular weight of the protecting material, and a solubility parameter SA of the moiety A and a solubility parameter SB of the moiety B satisfy a relationship represented by |SA (SB| (2.

Light emitting devices are expected to be developed into a wide range of fundamental light emitting devices and applications, for example, organic electroluminescent devices (hereinafter referred to as organic EL device) and inorganic-organic hybrid light emitting devices.
Organic EL devices are charge injection-type selfluminous devices utilizing luminescence produced upon recombination of electrons and holes arrived at the luminescent layer. Organic EL devices have been energetically developed since T. W. Tang et al. demonstrated in 1987 that a device with a thin film, composed of a fluorescent metal chelate complex and diamine-type molecules, stacked thereon exhibits luminescence with high brightness at low drive voltage.
Conventional organic fluorescent materials and organic phosphorescent materials as the luminescent material for the luminescent layer have a broader spectrum and a lower color purity as compared with inorganic fluorescent materials, and a color filter or a resonator structure should be used for color purity improvement purposes. The use of the color filter or the resonator structure poses problems, for example, lowered utilization efficiency of light produced by luminescence, dependency of luminescent color upon the viewing angle, and increased production cost.
In order to solve the above problems, the use of inorganic semiconductor crystals of nano size called quantum dots (QD) instead of conventional organic materials has been proposed (patent document 1: Japanese Translation of PCT Publication No. 522005/2005). QD is mixed with an organic host material (a binder component) in the luminescent layer and forms a luminescent matrix that is held between the electrodes and is formed within the luminescent layer. The quantum dots are divided into semiconductor fine particles of which the luminescent color is regulated by regulating the particle diameter and dopant-containing semiconductor fine particles. The former quantum dots, i.e., semiconductor fine particles, emit light at a wavelength determined by the size (particle diameter) thereof. On the other hand, the latter quantum dots, i.e, dopant-containing semiconductor fine particles, emit light having a luminescent color inherent in the dopant used. The semiconductor fine particles and the dopant-containing semiconductor fine particles each exhibit a spectrum having a narrow half-value width and a high color purity. In particular, in the former QD, the wavelength of light emitted from QD can be accurately and continuously regulated by regulating the particle diameter in the production of QD and can realize a wider range of color reproduction than the latter QD restricted by a luminescent color inherent in the dopant.

Light emitting device having quantum cut dots with a protecting material and prolonged drive lifetime and good color purity


A system and method for identifying a resource region including a plurality of symbols, allocating pilot signals to the resource region, identifying pilot-free symbols free of the pilot signals in the plurality of symbols, arranging sacrifice carriers for a first region of a group of symbols in the pilot-free symbols at a first density for a first communication station, and arranging sacrifice carriers for a second region of the group of symbols in the pilot-free symbols at a second density for a second communication station, the first communication station mobile with respect to an access communication station at a first relative speed and the second communication station is mobile with respect to the access communication station at a second relative speed, and wherein the first density of sacrifice carriers is greater than the second density of sacrifice carriers if the first relative speed is greater than the second relative speed.

The present invention generally relates to telecommunications and, more particularly, to methods and devices for allocating data in a wireless communication system.
In telecommunications systems, channel estimation may be performed for coherent detection to compensate for distortion or errors introduced due to channel fading. One technique for estimating a channel may include the use of pilot signals or pilot symbols. A transmitter or transmitting side may send pilot signals to a receiver or receiving side through predetermined sub-carriers. The receiver may be programmed with the pilot signals so that the pilot signals sent from the transmitter are "known" to the receiver. Upon receiving the pilot signals, the receiver may estimate the channel by comparing the transmission the receiver actually receives with the known symbols that the receiver ideally should have received. Pilot signals may be continually transmitted from a transmitter to a receiver because the channel may be constantly changing. Furthermore, pilot signals may be transmitted across a wide range of frequencies or sub-carriers because the channel may vary with frequency.
The use of pilot signals may be a trade-off between accurate channel estimation and data bandwidth. Specifically, when more pilot signals are used, more accurate channel estimation may be achieved and, however, more sub-carriers may be used to transmit the pilot signals rather than data. On the contrary, when less pilot signals are used, more sub-carriers may be used to transmit data and, however, a higher frame error rate may result. Therefore, it may be desirable to have methods and devices that are able to enable accurate channel estimation without adversely affecting the entire throughput. Furthermore, the characteristics of a channel may change as the relative speed between a transmitter and a receiver changes. Therefore, it may also be desirable to have methods and devices that are able to allocate pilot signals based on the relative speed between the transmitter and the receiver.

Methods and devices for allocating data in a wireless communication system

Industrial Technology Research Institute


In one embodiment, a method for forming an embedded trace substrate includes forming a conductive layer on a carrier. A dielectric film is provided on the conductive layer. Vias are formed in the dielectric film and extend to portions of the conductive layer. A conductive pattern is formed on the dielectric layer and is electrically connected to the conductive layer through the vias. The carrier is removed and portions of the conductive layer are selectively removed to provide a plurality of bumps pads configured to protrude outwardly from the dielectric layer.

The present invention relates, in general, to electronics, and more particularly, to semiconductor package substrates, embedded trace substrates, and methods of forming embedded trace substrates having a finer line trace width with relatively higher interfacial bonding strength at a relatively lower cost.
Recently, packaged integrated circuit (IC) structures for mobile applications have become a main driver of the semiconductor industry. Small form factor, thin profile, high performance, multi-function integration and low cost are important requirements for mobile applications and have generated numerous developments in the process, materials, and equipment sectors. Some package solutions have been developed to meet these requirements including embedded trace substrates, which can provide a cost-effective alternative compared with other existing solutions. Compared to traditional core substrates, embedded trace substrates can simplify the substrate fabrication process and enable a finer line width capability in a cost effective manner.
FIGS. 1A through 1E show cross-sectional views of an embedded trace substrate at various stages of fabrication in accordance with the related art.
Referring to FIG. 1A, metal bump patterns 106a, 106b are formed on each of separation films 104a, 104b of a carrier 102. The separation films 104a, 104b are formed on an upper portion and a lower portion of the carrier 102 respectively.
Referring to FIG. 1B, dielectric films 107a and 107b having vias are formed on each of the metal bump patterns 106a, 106b to provide metal patterns connected to each of the metal bump patterns 106a, 106b. Embedded trace substrates 108a, 108b are thus formed on the upper portion and the lower portion of the carrier 102 respectively.
Next, the two embedded trace substrates 108a, 108b including the metal bump patterns 106a, 106b are stripped away from the carrier 102 as shown in FIG. 1C.
Next, as shown in FIG. 1D, a blanket front etching process is used to globally and non-selectively remove portions of the metal bump pattern 106a of the embedded trace substrate 108a. The front etching process is carried out sequentially until the upper portion of the dielectric film 107a is exposed. As shown in FIG. 1E, after the front etching process, bump pads 106 for the embedded pattern are formed. In accordance with the related process, the bump pads 106 are recessed approximately 5-7 micrometers or more below the top surface of the dielectric film 107a due to over-etching, which is difficult to control. The formation of bump pads 106 in this recessed or over-etched manner is one problem with the related embedded trace substrate manufacturing process that can lead to reliability problems. For example, bonding problems between a semiconductor chip and the bond pads 106a can occur because the bonding area is too thin and/or too small. This bonding problem can lead to reliability issues with the bonding interface and can contribute to the deterioration of the mechanical and electrical properties of the packaged device.
Accordingly, it is desired to have an alternative structure and method for providing embedded trace substrates that overcome, among other things, the issues of the related art. Also, it would be beneficial for such a structure and method to be cost effective and compatible with existing manufacturing processes.
For simplicity and clarity of illustration, elements in the figures are not necessarily drawn to scale, and the same reference numbers in different figures denote generally the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. It will be appreciated by those skilled in the art that words, during, while, and when as used herein related to circuit operation are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as propagation delay, between the reaction that is initiated by the initial action. Additionally, the term while means a certain action occurs at least within some portion of a duration of the initiating action. The use of word approximately or substantially means a value of an element is expected to be close to a state value or position. However, as is well known in the art there are always minor variances preventing values or positions from being exactly stated. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that, although the terms first, second, etc. may be used herein to describe various members, elements, regions, layers and/or parts, these members, elements, regions, layers and/or parts are not be limited by these terms. These terms are only used to distinguish one member, element, region, layer and/or part from another member, element, region, layer and/or part. Thus, for example, a first member, element, region, layer and/or part discussed below could be termed a second member, element, region, layer and/or part without departing from the teachings of the present invention.

Embedded trace substrate and method of forming the same


A system and method for reallocating block in a checkpointing bitmapped-based file system is provided. The system and method enable blocks to be allocated or reallocated during checkpoints which permits various file system processes to proceed during the checkpointing process. An additional copy of the bitmap is created when the bitmap is being written to disk, thereby enabling these various file system processes to continue to operate on a bitmap during the checkpointing process.

A file server is a computer that provides file service relating to the organization of information on storage devices, such as disks. The file server or filer includes a storage operating system that implements a file system to logically organize the information as a hierarchical structure of directories and files on the disks. Each "on-disk" file may be implemented as a set of disk blocks configured to store information, such as text, whereas the directory may be implemented as a specially-formatted file in which information about other files and directories are stored. A filer may be configured to operate according to a client/server model of information delivery to thereby allow many clients to access files stored on a server, e.g., the filer. In this model, the client may comprise an application, such as a file system protocol, executing on a computer that "connects" to the filer over a computer network, such as a point-to-point link, shared local area network (LAN), wide area network (WAN), or virtual private network (VPN) implemented over a public network such as the Internet. Each client may request the services of the filer by issuing file system protocol messages (in the form of packets) to the filer over the network.
A common type of file system is a "write in-place" file system, an example of which is the conventional Berkeley fast file system. In a write in-place file system, the locations of the data structures, such as inodes and data blocks, on disk are typically fixed. An inode is a data structure used to store information, such as metadata, about a file, whereas the data blocks are structures used to store the actual data for the file. The information contained in an inode may include, e.g., ownership of the file, access permission for the file, size of the file, file type and references to locations on disk of the data blocks for the file. The references to the locations of the file data are provided by pointers, which may further reference indirect blocks that, in turn, reference the data blocks, depending upon the quantity of data in the file. Changes to the inodes and data blocks are made "in-place" in accordance with the write in-place file system. If an update to a file extends the quantity of data for the file, an additional data block is allocated and the appropriate inode is updated to reference that data block.
Another type of file system is a write-anywhere file system that does not overwrite data on disks. If a data block on disk is retrieved (read) from disk into memory and "dirtied" with new data, the data block is stored (written) to a new location on disk to thereby optimize write performance. A write-anywhere file system may initially assume an optimal layout such that the data is substantially contiguously arranged on disks. The optimal disk layout results in efficient access operations, particularly for sequential read operations, directed to the disks. A particular example of a write-anywhere file system that is configured to operate on a filer is the Write Anywhere File Layout (WAFL™) file system available from Network Appliance, Inc. of Sunnyvale, Calif. The WAFL file system is implemented within a microkernel as part of the overall protocol stack of the filer and associated disk storage. This microkernel is supplied as part of Network Appliance's Data ONTAP™ storage operating system, residing on the filer, that processes file-service requests from network-attached clients.
As used herein, the term "storage operating system" generally refers to the computer-executable code operable on a storage system manages data access and may, in case of a filer, implement file system semantics, such as the Data ONTAP™ storage operating system, implemented as a microkernel, and available from Network Appliance, Inc., of Sunnyvale, Calif., which implements a Write Anywhere File Layout (WAFL™) file system. The storage operating system can also be implemented as an application program operating over a general-purpose operating system, such as UNIX® or Windows NT®, or as a general-purpose operating system with configurable functionality, which is configured for storage applications as described herein.
Disk storage is typically implemented as one or more storage "volumes" that comprise physical storage disks, defining an overall logical arrangement of storage space. Currently available filer implementations can serve a large number of discrete volumes (150 or more, for example). Each volume is associated with its own file system and, for purposes hereof, volume and file system shall generally be used synonymously. The disks within a volume are typically organized as one or more groups of Redundant Array of Independent (or Inexpensive) Disks (RAID). RAID implementations enhance the reliability/integrity of data storage through the writing of data "stripes" across a given number of physical disks in the RAID group, and the appropriate caching of parity information with respect to the striped data. In the example of a WAFL-based file system, a RAID 4 implementation is advantageously employed. This implementation specifically entails the striping of data across a group of disks, and separate parity caching within a selected disk of the RAID group. As described herein, a volume typically comprises at least one data disk and one associated parity disk (or possibly data/parity) partitions in a single disk) arranged according to a RAID 4, or equivalent high-reliability, implementation.
File systems require a methodology to track the allocation status of the disk blocks within a file system. By "allocation status" it is meant whether a block has been allocated by a file or directory or whether the block is free to be allocated. File systems typically utilize a bitmap file wherein each bit is associated with a block the file system. If the bit is set (i.e. equal to 1) then the block has been allocated in the file system and is thereby associated with. Similarly, if the bit is not set (i.e. equal to 0) then the block has not been allocated in the file system and is free to be allocated.
However, in checkpointing systems, like the above-described WAFL file system, a free block cannot be allocated until the blocks' allocation status as free has been reflected in a checkpoint. Note that, in a checkpointing file system, a checkpoint of the file system is created, typically at regular time intervals. This "checkpoint" is a consistent and up-to-date version of the file system that is typically written to disk. Thus, in the event of a crash, only data written after the last checkpoint would be lost or corrupted. If a journalling file system is utilized, the stored operations can be replayed to bring the file system completely up to date after a crash other error condition. Thus, in a checkpointing system, the file system must track all of the blocks freed after the most recent checkpoint and not allocate any of those freed blocks until after the checkpoint is safely written to disk.
The newly freed blocks (post checkpoint) cannot be reused (i.e., allocated again) until after the data has been written to disk to avoid the possibility that a block could be freed and then reused before the status of the block has been written to disk. If, for example, a new checkpoint is interrupted while writing its changes (data) to disk by a server crash or other failure, the previous checkpoint could now contain data generated as part of the new checkpoint if a block that was in use in the previous checkpoint was freed after the previous checkpoint and allocated (reused) by the new checkpoint to store new data. Therefore, overwriting blocks that are known to be allocated at the time of the previous checkpoint compromises the integrity of that checkpoint and therefore the consistency and integrity of the file system itself in such situations.
In a known file server implementation, two copies of the bitmap are utilized. A "current copy" is utilized to track what has been allocated, while a "safe copy" tracks what can actually be used. Utilizing this two-copy methodology, a block can be allocated if it is marked free in the safe copy. After the checkpointing process, the current copy is moved to the safe copy and the old safe copy is freed, or otherwise disposed of. A noted disadvantage of this methodology is that the file system is not able to allocate a block while the bitmaps are being written to disk for example during a checkpoint operation. Allocation of blocks is, again, desirable at this time because various file system processes, such as restoring files from a snapshot or utilizing file folding techniques, described further below, can continue to operate during the time while the bitmaps are being written to disk. This added operating time permits these various file system processes to complete more quickly. During the writing process, the safe copy is locked or otherwise owned by a disk storage layer—for example a Redundant Array of Inexpensive (or "Independent") Disks (RAID) layer of a storage operating system.
Certain file systems include the capability to generate snapshots, described further below, of an active file system. In such file systems, a block may be incorporated into a snapshot and then deleted from the active file system. The block will then be marked as unallocated in the bitmap; however, if the snapshot and active file system share the same logical address space, the block is still physically resident on the storage device. A problem arises when a user desires to reallocate the block from the snapshot to the active file system as the bitmap describing those blocks in the active file system has the given block marked as unallocated.

System and method for reallocating blocks in checkpointing bitmap-based file systems


A plurality of projections and grooves are formed on a polishing member. The grooves are formed in grid pattern. A portion on which the grooves and the projections are formed (polishing portion) has a substantially circular shape in a plane view. Around the polishing portion, an outer peripheral portion having a fixed height is provided. The height of the outer peripheral portion is equal to the height of bottom portions of the grooves. Ends of each of the grooves extend to the outer peripheral portion, which allows slurry and the like entering the grooves to flow outside via the outer peripheral portion. When a polishing pad thus structured is to be bonded to a surface plate, adhesive is applied or a double-stick tape is affixed to a rear surface of a base member, and thereafter, the polishing pad is put in place on the surface plate. Next, the polishing portion is pressed to the surface plate from an upper side, and subsequently the outer peripheral portion is pressed to the surface plate from the upper side.

1. Field of the Invention
The present invention relates to a polishing pad suitable for chemical mechanical polishing (CMP), a polishing apparatus having the same, and a bonding apparatus.
2. Description of the Related Art
Conventionally, a semiconductor integrated circuit has been formed by depositing insulating layers, conductive layers, and so forth on a silicon wafer. Each layer is etched during the formation processes. As a result, steps are formed in each layer. With such steps, even the same layer has a highly conductive portion and a low conductive portion, so that a desired electrical characteristic cannot be obtained. Therefore, planarization by CMP is performed after etching when necessary.
For performing CMP, a polishing pad is bonded to a CMP apparatus. Polishing pads in various shapes are available, and for example, those having grooves arranged along the circumference, those having grooves arranged in grid pattern, and so on are available.
FIG. 6A and FIG. 6B are schematic views showing an example of a conventional polishing pad (first conventional example). Note that FIG. 6B shows a cross section taken along the I—I line in FIG. 6A. The first conventional example, which has a double-layer structure, is composed of a base member 101 to be bonded to a surface plate 10 and a polishing member 102 having irregularities formed on a front surface thereof. On the polishing member 102, a plurality of projections 102b and grooves 102a are formed. The grooves 102a are formed in grid pattern, each having a rectangular cross section. Ends of each of the grooves 102a extend to the outside of the polishing member 102 to allow slurry and the like entering the inside of the grooves 102a to flow outside. A polishing portion 103 covers the entire polishing pad in a plane view.
The first conventional example as described above, however, has a problem of poor bondability to the surface plate 10. This is because the grooves 102a are formed on the entire polishing pad, and portions in which the grooves 102a are formed in particular are poor in bondability. Consequently, small gaps are formed between the portions in which the grooves 102a are formed and the surface plate 10, and the slurry and the like enter the gaps. If the slurry and the like enter, adhesive strength further lowers, sometimes resulting in peeling of the polishing pad off the surface plate 10 during the polishing. This sometimes causes in the worst case the breakage of a silicon wafer. Another problem is that abrasive and the like contained in the slurry remain on the surface plate 10 when the polishing pad is peeled off after the polishing is finished. The residual abrasive and the like will obstruct ensuring high planarity when the polishing pad is bonded the next time, so that a wafer cannot be sufficiently planarized.
Therefore, a polishing pad with improved bondability has been proposed. FIG. 7A and FIG. 7B are schematic views showing another example of a conventional polishing pad (second conventional example). Note that FIG. 7B shows a cross section taken along the I—I line in FIG. 7A. In the second conventional example, a wall portion 104 is formed around a polishing portion 103. Further, grooves 102b have the same depth in a center portion but in areas close to the wall portion 104, the grooves 102b closer to the wall portion 104 have shallower depth.
According to the second conventional example as described above, since it is possible to inhibit the deterioration of bondability of the portions in which the shallow grooves 102a are formed, the aforesaid peeling and entering of slurry and the like can be inhibited. However, the existence of the wall portion 104 outside the grooves 102a makes it difficult to discharge the slurry and the like that have entered the inside of the grooves 102a. Consequently, an excessive amount of the slurry and the like may possibly stay in the polishing portion 103, which sometimes causes a scratch and the like on a wafer during the polishing.
A related art is described in Japanese Patent Application Laid-open No. 10-71561.

Polishing pad, polishing apparatus having the same, and bonding apparatus


The present invention may provide a switching power supply circuit for converting primary side direct-current voltage to secondary side direct-current voltage. The switching power supply circuit may include a choke coil, a converter transformer; a switching element, a primary side series resonant capacitor, a primary side parallel resonant capacitor, an oscillating and driving circuit, a secondary side rectifier circuit, and a control circuit. Resonance frequency of the primary side first series resonant circuit may be set at a frequency substantially twice resonance frequency of the primary side second series resonant circuit. Resonance frequency of the primary side parallel resonant circuit may be set at a frequency substantially equal to or higher than 1.5 times the resonance frequency of the primary side first series resonant circuit.

1. Field of the Invention
The present invention relates to a switching power supply circuit.
2. Description of the Related Art
As so-called soft-switching power supply of a resonant type, a voltage resonant converter formed by a single-ended system with one switching element as in Japanese Patent Laid-Open No. 2000-134925, for example, is known.
FIG. 22 shows one example of configuration of a switching power supply circuit including a voltage resonant converter formed by such a single-ended system.
The switching power supply circuit shown in FIG. 22 rectifies and smoothes an alternating voltage VAC from a commercial alternating-current power supply AC by a rectifying and smoothing circuit composed of a bridge rectifier circuit Di and a smoothing capacitor Ci, and thereby generates a rectified and smoothed voltage Ei as voltage across the smoothing capacitor Ci. Incidentally, a noise filter, which is composed of one set of common mode choke coils CMC and two across capacitors CL, for eliminating common mode noise is provided in the line of the commercial alternating-current power supply AC.
This rectified and smoothed voltage Ei is input as direct-current input voltage to the voltage resonant converter. This voltage resonant converter has a configuration of a single-ended system having one switching element Q1. The voltage resonant converter in this case is externally excited, and thus a MOS-FET as the switching element Q1 is switching-driven by an oscillating and driving circuit 2.
A body diode DD of the MOS-FET is connected in parallel with the switching element Q1. In addition, a primary side parallel resonant capacitor Cr is connected in parallel with the drain and source of the switching element Q1.
A primary side parallel resonant circuit (voltage resonant circuit) whose resonance frequency is governed by the primary side parallel resonant capacitor Cr and a leakage inductance L1 produced by the primary winding N1 of a converter transformer PIT is formed. A voltage resonant operation as switching operation of the switching element Q1 is obtained by the primary side parallel resonant circuit. The resonance frequency is determined mainly by the leakage inductance L1 of the primary winding N1 and the capacitance of the primary side parallel resonant capacitor Cr.
The oscillating and driving circuit 2 applies a gate voltage as a drive signal to the gate of the switching element Q1 to switching-drive the switching element Q1. Thereby the switching element Q1 performs switching operation at a switching frequency corresponding to the cycle of the drive signal.
The converter transformer PIT transmits the switching output of the switching element Q1 to a secondary side. The structure of the converter transformer PIT has for example an EE-shaped core formed by combining E-shaped cores of ferrite material with each other. A winding part is divided between the primary winding N1 and a secondary winding N2, and the primary winding N1 and the secondary winding N2 are wound on a bobbin around a central magnetic leg of the EE-shaped core. Also, a gap of 0.8 mm to 1 mm, for example, is formed in the central magnetic leg of the EE-shaped core of the converter transformer PIT. Thereby k=about 0.80 to 0.85 is obtained as the value of a coupling coefficient k between the primary side and the secondary side. The coupling coefficient k at this level represents a degree of coupling that may be considered to be loose coupling. Lowering the value of the coupling coefficient k makes the converter transformer saturated less easily. In addition, the leakage inductance L1 is produced in the primary winding N1 on a condition that the value of the coupling coefficient k is lower than one.
One end of the primary winding N1 of the converter transformer PIT is inserted between the switching device Q1 and the positive electrode terminal of the smoothing capacitor Ci. Thereby, the switching output of the switching device Q1 is transmitted to the primary winding N1. An alternating voltage induced by the primary winding N1 occurs in the secondary winding N2 of the converter transformer PIT.
In this case, a secondary side series resonant capacitor C5 is connected in series with one end of the secondary winding N2. Thereby a secondary side series resonant circuit (current resonant circuit) whose resonance frequency is governed by the leakage inductance L2 of the secondary winding N2 and the capacitance of the secondary side series resonant capacitor C5 is formed. The resonance frequency is determined mainly by the leakage inductance L2 of the secondary winding N2 and the capacitance of the secondary side series resonant capacitor C5.
In addition, rectifier diodes Do1 and Do2 and a smoothing capacitor Co are connected to the secondary side series resonant circuit as shown in FIG. 22, whereby a voltage doubler half-wave rectifier circuit is formed. This voltage doubler half-wave rectifier circuit generates a secondary side direct-current output voltage Eo having a level corresponding to twice an alternating voltage V22 induced in the secondary winding N2 as voltage across the smoothing capacitor Co. The secondary side direct-current output voltage Eo is supplied to a load, and is input to a control circuit 1 as detection voltage for constant-voltage control.
The control circuit 1 inputs a detection output obtained by detecting the level of the secondary side direct-current output voltage Eo input as detection voltage to the oscillating and driving circuit 2. The oscillating and driving circuit 2 outputs a drive signal varied in frequency and the like according to the level of the secondary side direct-current output voltage Eo which level is indicated by the detection output input to the oscillating and driving circuit 2. The oscillating and driving circuit 2 thereby controls the switching operation of the switching element Q1 so as to make the secondary side direct-current output voltage Eo constant at a predetermined level. Thereby control for stabilizing the secondary side direct-current output voltage Eo is performed.
FIGS. 23A, 23B, and 23C and FIG. 24 show results of experiments on the power supply circuit having the configuration shown in FIG. 22 described above. Incidentally, in the experiments that provided the results of FIGS. 23A, 23B, and 23C and FIG. 24, principal parts of the power supply circuit of FIG. 22 is set as follows.
For the converter transformer PIT, an EER-35 is selected as a core material, and the gap of the central magnetic leg is set to a gap length of 1 mm. As for the numbers T of turns of the primary winding N1 and the secondary winding N2, N1=39 T and N2=23 T, respectively. The level of a voltage induced per turn (T) of the secondary winding N2 is set to 3 V/T. The coupling coefficient k of the converter transformer PIT is set to k=0.81.
The capacitance of the primary side parallel resonant capacitor Cr is selected to be Cr=3900 pF, and the capacitance of the secondary side series resonant capacitor C5 is selected to be C5=0.1 μF. Accordingly, the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit is set at 230 kHz, and the secondary side series resonance frequency fo2s of the secondary side series resonant circuit is set to 82 kHz. In this case, relative relation between the primary side parallel resonance frequency fo1p and the secondary side series resonance frequency fo2s is expressed by fo1p≈2.6×fo2s.
The rated level of the secondary side direct-current output voltage Eo is 135 V. Load power is supplied in a range of maximum load power Pomax=200 W to minimum load power Pomin=0 W.
FIGS. 23A, 23B, and 23C are waveform charts showing operations of principal parts in the power supply circuit shown in FIG. 22 on the basis of switching cycles of the switching element Q1. FIG. 23A shows a voltage V1, a switching current IQ1, a primary winding current I21, a secondary winding current I22, and secondary side rectified currents ID1 and ID2 when the maximum load power Pomax=200 W. FIG. 23B shows the voltage V1, the switching current IQ1, the primary winding current I21, and the secondary winding current I22 when medium load power Po=120 W. FIG. 23C shows the voltage V1 and the switching current IQ1 when the minimum load power Pomin=0 W.
The voltage V1 is obtained across the switching device Q1. The voltage V1 is at a zero level in a period TON in which the switching device Q1 is on, and forms a sinusoidal resonant pulse in a period TOFF in which the switching device Q1 is off. The resonant pulse waveform of the voltage V1 indicates that the operation of the primary side switching converter is voltage resonant operation.
The switching current IQ1 flows through the switching device Q1 and the body diode DD. The switching current IQ1 flows with waveforms shown in the figures during the period TON, and is at a zero level during the period TOFF. The primary winding current I21 flowing through the primary winding N1 is obtained by combining a current component flowing as the switching current IQ1 during the period TON with a current flowing through the primary side parallel resonant capacitor Cr during the period TOFF.
The rectified currents ID1 and ID2 shown in FIG. 23A flowing through the rectifier diodes Do1 and Do2 forming a secondary side rectifier circuit, each flows sinusoidally, as shown in the figure. In this case, the resonant operation of the secondary side series resonant circuit appears in the waveform of the rectified current ID1 more dominantly than in the rectified current ID2.
The secondary winding current I22 flowing through the secondary winding N2 has a waveform obtained by combining the rectified currents ID1 and ID2 with each other.
FIG. 24 shows switching frequency fs, the on period TON and the off period TOFF of the switching element Q1, and AC-to-DC power conversion efficiency (ηAC→DC) of the power supply circuit shown in FIG. 22 with respect to load variation.
First, looking at the AC-to-DC power conversion efficiency (ηAC→DC), high efficiencies of 90% or more are obtained over a wide range of load power Po=50 W to 200 W. The inventor of the present application has previously confirmed by experiment that such a characteristic is obtained when a secondary side series resonant circuit is combined with a voltage resonant converter of a single-ended type.
The switching frequency fs, the on period TON, and the off period TOFF in FIG. 24 indicate the switching operation of the power supply circuit shown in FIG. 22 as a characteristic of constant-voltage control dealing with load variation. In this case, the switching frequency fs is substantially constant with respect to load variation. On the other hand, the on period TON and the off period TOFF linearly change in manners opposite to each other as shown in FIG. 24. This indicates that the switching operation is controlled by holding the switching frequency substantially constant while the secondary side direct-current output voltage Eo is varied, and changing a time ratio between the on period and the off period. Such control can be regarded as PWM (Pulse Width Modulation) control that changes the on period and the off period within one cycle. The power supply circuit shown in FIG. 22 stabilizes the secondary side direct-current output voltage Eo by this PWM control.
FIG. 25 schematically shows the constant-voltage control characteristic of the power supply circuit shown in FIG. 22 by relation between the switching frequency fs (kHz) and the secondary side direct-current output voltage Eo. The power supply circuit shown in FIG. 22 has the primary side parallel resonant circuit and the secondary side series resonant circuit. Therefore the power supply circuit shown in FIG. 22 has, in a composite manner, two resonant impedance characteristics, that is, a resonant impedance characteristic corresponding to the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit and the secondary side series resonance frequency fo2s of the secondary side series resonant circuit. Since the power supply circuit shown in FIG. 22 has the relation fo1p≈2.8×fo2s, the secondary side series resonance frequency fo2s is lower than the primary side parallel resonance frequency fo1p, as shown in FIG. 25.
As for constant-voltage control characteristics with respect to the switching frequency fs under a condition of a constant alternating input voltage VAC, as shown in FIG. 25, constant-voltage control characteristics at the maximum load power Pomax and the minimum load power Pomin under the resonant impedance corresponding to the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit are represented by characteristic curves A and B, respectively, and constant-voltage control characteristics at the maximum load power Pomax and the minimum load power Pomin under the resonant impedance corresponding to the secondary side series resonance frequency fo2s of the secondary side series resonant circuit are represented by characteristic curves C and D, respectively. When constant-voltage control is to be performed at tg, which is a rated level of the secondary side direct-current output voltage Eo, under the characteristics shown in FIG. 25, the variable range (necessary control range) of the switching frequency fs necessary for the constant-voltage control can be represented as a section denoted by Δfs.
The variable range Δfs shown in FIG. 25 as a necessary frequency control range extends from the characteristic curve C, which corresponds to the secondary side series resonance frequency fo2s of the secondary side series resonant circuit at the maximum load power Pomax, to the characteristic curve B, which corresponds to the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit, at the minimum load power Pomin. Crossed between the characteristic curve C at the maximum load power Pomax and the characteristic curve B at the minimum load power Pomin are the characteristic curve D, which corresponds to the secondary side series resonance frequency fo2s of the secondary side series resonant circuit, at the minimum load power Pomin and the characteristic curve A, which corresponds to the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit, at the maximum load power Pomax. Thus, as the constant-voltage control operation of the power supply circuit shown in FIG. 22, switching-driving control is performed by PWM control that holds the switching frequency fs substantially fixed, and which changes the time ratio between the periods TON and TOFF in one switching period. Incidentally, this is indicated by the fact that the period length of one switching period (TOFF+TON) shown at the times of the maximum load power Pomax=200 W, load power=100 W, and the minimum load power Pomin=0 W in FIGS. 23A, 23B, and 23C is substantially constant, while the widths of the period TOFF and the period TON are changed.
Such an operation is obtained by making a transition between a state in which the resonant impedance (capacitive impedance) at the primary side parallel resonance frequency fo1p of the primary side parallel resonant circuit is dominant and a state in which the resonant impedance (inductive impedance) at the secondary side series resonance frequency fo2s of the secondary side series resonant circuit is dominant, as resonant impedance characteristics according to load variation in the power supply circuit, in the narrow variable range (Δfs) of the switching frequency.
The power supply circuit shown in FIG. 22 has the following problems. The switching current IQ1 at the maximum load power Pomax shown in FIG. 23A among the waveform charts of FIGS. 23A, 23B, and 23C described above is at a zero level until an end of the off period TOFF as turn-on timing. When the on period TON arrives, the switching current IQ1 operates such that the switching current IQ1 first flows as a current of negative polarity through the body diode DD1 and is then inverted to flow between the drain and the source of the switching element Q1. Such an operation indicates that ZVS (Zero Voltage Switching) is performed properly.
On the other hand, the switching current IQ1 shown in FIG. 23B when Po=120 W corresponding to a medium load operates so as to flow as noise before the end of the off period TOFF as turn-on timing. This operation is an abnormal operation in which ZVS is not properly performed. That is, it is known that a voltage resonant converter provided with a secondary side series resonant circuit as shown in FIG. 22 causes the abnormal operation in which ZVS is not properly performed at the time of the medium load. It is confirmed that an actual power supply circuit as shown in FIG. 22 causes such an abnormal operation in a load variation range as the section A shown in FIG. 24, for example.
As described earlier, a voltage resonant converter provided with a secondary side series resonant circuit inherently has, as a tendency thereof, a characteristic of being able to maintain high efficiency in an excellent manner as the load is varied. However, as shown by the switching current IQ1 in FIG. 23B, a considerable peak current flows at the time of turning on the switching element Q1, thereby inviting an increase in switching loss and constituting a factor in lowering power conversion efficiency. At any rate, the abnormal operation as described above causes a shift in phase-gain characteristics of a constant-voltage control circuit system, for example, thus resulting in a switching operation in a state of abnormal oscillation. Thus, in the present situation, there is a strong recognition that it is difficult to put the power supply circuit of FIG. 22 to practical use in actuality.
In order to remedy this, a so-called class E switching converter shown in FIG. 26 has been put to practical use as a converter combining a voltage resonant converter and a current resonant converter. The class E switching converter shown in FIG. 26 has a switching element Q1. The switching element Q1 in this case is a MOS-FET. A body diode DD is formed so as to be connected in parallel with the drain and source of the switching element Q1 as MOS-FET. A forward direction of the body diode DD in this case is from the source to the drain.
A primary side parallel resonant capacitor Cr is connected in parallel with the drain and source of the same switching element Q1. The drain of the switching element Q1 is connected to the positive electrode terminal of a direct-current input voltage Ein via a series connection of a choke coil L10. The source of the switching element Q1 is connected to the negative electrode terminal of the direct-current input voltage Ein.
One terminal of a choke coil L11 is connected to the drain of the switching element Q1, and a series resonant capacitor C11 is connected in series with another terminal of the choke coil L11. An impedance Z as a load is inserted between the series resonant capacitor C11 and the negative electrode terminal of the direct-current input voltage Ein. Concrete examples of the impedance Z include a piezoelectric transformer, a fluorescent lamp ready for high frequencies, and the like.
Incidentally, since the inductance of the choke coil L10 is set considerably higher than the inductance of the choke coil L11, the class E switching converter of such a configuration can be considered one form of a complex resonant converter including a parallel resonant circuit formed by the inductance of the choke coil L10 and the capacitance of the primary side parallel resonant capacitor Cr and a series resonant circuit formed by the inductance of the choke coil L11 and the capacitance of the series resonant capacitor C11. In addition, the class E switching converter can be said to be the same as a voltage resonant converter of a single-ended type in that the class E switching converter is formed with only one switching element.
FIG. 27 shows operations of principal parts of the class E switching converter having the configuration shown in FIG. 26 described above. A switching voltage V1 is obtained across the switching element Q1. The switching voltage V1 is at a zero level during a period TON during which the switching element Q1 is on, and has a sinusoidal pulse waveform during a period TOFF during which the switching element Q1 is off. This switching pulse waveform is obtained as a result of the resonant operation (voltage resonant operation) of the above-described parallel resonant circuit.
A switching current IQ1 flows through the switching element Q1 and the body diode DD. The switching current IQ1 is at a zero level during the period TOFF. In the period TON, the switching current IQ1 first flows through the body diode DD and is thus of negative polarity for a certain period from a starting time point of the period TON, and is thereafter inverted to be of positive polarity and flows from the drain to the source of the switching element Q1.
A current I2 flowing through a transformer of the class E switching converter is obtained by combining the switching current IQ1 flowing through the switching element Q1 (and the body diode DD) with a current flowing through the primary side parallel resonant capacitor Cr. The current I2 has a waveform including a sinusoidal wave component.
Relation between the switching current IQ1 and the switching voltage V1 described above indicates that the operation of a ZVS characteristic is obtained in turn-off timing of the switching element Q1 and that the operation of the ZVS characteristic and a ZCS (Zero Current Switching) characteristic is obtained in turn-on timing.
A current I1 flowing from the positive electrode terminal of the direct-current input voltage Ei through the choke coil L10 into the class E switching converter forms a pulsating current waveform having a predetermined average level as shown in FIG. 27 with a relation of L10>L11 set for the inductances of the choke coils L10 and L11. Such a pulsating current waveform can be considered approximate to a direct current.


Disclosed are methods and compositions for removing, inhibiting, or preventing corrosion on metal surfaces within water channels in salt-water cooled internal combustion engines. These methods comprise contacting the metal surfaces with an aqueous mixture of a di- lower alkyl fatty acid amide.

1. Field of the Invention
This invention relates to methods, compositions, and apparatus for use in preventing or inhibiting corrosion within internal combustion marine outboard and/or inboard engines. More specifically, this invention relates to preventing or inhibiting corrosion within water channels in salt-water cooled internal combustion marine outboard and/or inboard engines.
2. Description of the Related Art
Water-cooled marine outboard/inboard engines used in salt-water environments experience rapid mineral deposit buildup (scales) resulting in substantial amounts of corrosion within the engine internal water cooling channels. Such deposits and corrosion reduce the efficiency of the engine cooling system and reduce engine life. Therefore, outboard and inboard engines used in salt-water environments typically require various treatments to remove these mineral deposit buildups (scales) and corrosive deposits.
However, frequent removal of the deposits and corrosion is inconvenient, difficult and costly since the deposits and corrosion are generally located in portions of the engine that are difficult to reach. Further, removal of these deposits and corrosion is very time consuming. Accordingly, need exists for methods and compositions suitable for removing the buildup quickly and efficiently as well as for preventing subsequent development of corrosion on the metal surfaces within the water channels.

Methods and compositions for preventing corrosion within salt-water cooled internal combustion engines


The invention relates to a heat compression molding process for the manufacturing of composite material articles, the process comprising the steps of i) providing a mold (20) in which the negative shape (31, 32) of an article (30) to be manufactured is formed; ii) inserting into said mold (20) an SMC semi-finished product (10) comprising one or more sheets of composite material comprising a matrix of a heat-hardening resin and carbon fibers, the mold being pre-heated at a temperature suitable to allow the cure of said heat-hardening resin; iii) closing the mold (20) and carrying out a compression cycle in an autoclave according to a predefined time-pressure law; and iv) extracting the article (30), wherein the amount of SMC semi-finished product (10) inserted in the mold (20) is calculated by weighing on the basis of the volume of the article (30) to be manufactured. The size of the surfaces of the SMC semi-finished product (10) intended to contact the surfaces of the shape (31, 32) are calculated so as to cover said surfaces in a percentage comprised between 70 to 99%, in particular higher than 80% and less than or equal to 99%. Thanks to these characteristics it is possible to obtain manufactured articles substantially free from surface defects and suitable for both structural and aesthetic uses.

Known processes for manufacturing articles in composite materials use the technology of heat compression molding, in which measured quantities of materials comprising a heat-hardening matrix reinforced with fibers of rigid materials are inserted into molds made of steel or aluminum suitable to a confer a predetermined shape to the article. This technology, created for molding articles reinforced with glass fibers but today increasingly used also for articles reinforced with carbon fibers, allows to obtain components characterized by low weight and excellent mechanical properties, as well as good dimensional tolerances.
The heat compression molding technology is very suitable for the manufacture of articles substantially free from undercut details, obtainable with molds made up of two overlapping parts inside which the shape of the article is formed in negative and in two portions.
In a typical process of heat compression molding for articles of composite material based on carbon fibers, semi-finished products made of heat-hardening resins and carbon fibers are used. These semi-finished products, manufactured in processes separate from the compression molding process, are in the form of pre-impregnated sheets known in the industry with the English acronym "SMC" (Sheet Molding Compound).
The SMC semi-finished products generally comprise a plurality of pre-impregnated sheets superimposed so as to form a single block. Before being loaded into the mold, an SMC semi-finished products can be advantageously subjected to a heating treatment, for example by means of infrared rays, which facilitates its arrangement in the mold and allows to reduce the curing time of the heat-hardening resin.
In order to control features such as the dimensional shrinkage during the hot crosslinking phase, the surface finishing, the ease of detachment from the molds and the behavior in fire, the heat-hardening resins are usually charged with mineral charges, lubricants, release agents, flame retardants and the like. Calcium carbonate, kaolin, stearates, oxides and hydrates of calcium, magnesium, aluminum are some of the most used additives.
Thanks to the low weights and the high mechanical characteristics, the articles in composite materials with carbon fibers made with the heat compression molding technology starting from SMC semi-finished products have been used for some years in the automotive industry for the production of structural components such as, for example, supports for lights, windscreen frames and supporting elements of bodywork parts.
Nevertheless, these articles are not generally used for the manufacture of aesthetic elements of a vehicle, such as, for example, bodywork parts and details of the passenger compartment, due to their rather coarse surface finishing. In particular, an article of composite material made starting from SMC semi-finished products has surface defects such as, for example, porosity and undulations that are even visible to the naked eye and that therefore, despite the excellent mechanical characteristics, make it unsuitable for a use also or exclusively aesthetic.
U.S. Pat. No. 4,855,097 describes a method for making an exterior automotive body panel by compression molding in which a charge containing a curable resin covers from 40% to 80% of the surface area of the molding surface. According to this known document coverages higher than 80% do not permit sufficient flow of charge necessary to provide a slight movement of the same.

Process for manufacturing articles in carbon fiber and article manufactured with this process


A system includes a back up wall and a veneer wall spaced from the back up wall. An anchor shaft has a first end secured to the back up wall, and a second free end of the shaft projects into a space between the back up wall and the veneer wall. A wing nut has a central barrel disposed on the shaft proximate the free end. The wing nut is spaced apart from a surface of the back up wall. A first generally planar side wing extends laterally from the central barrel of the wing nut. A second generally planar side wing extends laterally from the central barrel. The first side wing includes a first opening for receipt of a first wire tie leg, and the second side wing includes a second opening for receipt of a second wire tie leg. The wing nut is independently rotatable relative to the shaft to angularly orient the wings and thus the openings as desired.

1. Field of the Invention
The present invention relates generally to apparatus for transferring horizontal loads between a back up wall and a veneer wall, and, more particularly, to a wing nut connecting an anchor shaft extending from the back up wall or other building support to a wire tie extending from a veneer wall.
2. Description of the Background of the Invention
Various patents disclose apparatus for connecting a back up wall to a veneer wall for transferring horizontal loads therebetween.
Reinwall et al. U.S. Pat. No. 4,764,069 discloses a threaded stud drilled into a supportive metal stud wall. The stud has an elongate barrel integral with a driving head. The barrel may include cutting elements for cutting through an insulation layer and any sheeting on the supportive wall. The stud is driven until the barrel abuts the supportive wall. The driving head of the stud/barrel includes an elongate eye for receipt of a wire tie that extends from a mortar bed of a veneer wall. The driving head also includes a circumferential flange disposed between the barrel and the eye and sized larger than the barrel. The flange seals against the insulation layer.
Lopez U.S. Pat. No. 4,473,984 discloses a threaded stud having a fastener barrel rigidly secured on an end of the threaded stud. The fastener barrel includes a slot through which a wire tie is looped. The stud is driven into the back up wall by rotating the fastener barrel, typically with a drill having a chuck that fits around a portion of the fastener barrel. The fastener barrel may include teeth for cutting through insulation and any backup wall sheeting as the threaded stud is driven through insulation and the back up wall.
Various patents show fastening apparatus. Holaday U.S. Pat. No. 1,289,450 shows a pressure screw having a shaft and a handle. The handle has first and second wings, and each of the wings has an opening.
Larava U.S. Pat. No. 1,044,791 shows a thumb nut formed of sheet metal. The thumb nut has first and second wings with an opening in each wing.
Schmidt et al. U.S. Design Pat. No. 123,423 discloses a wing nut having a fastening portion and a handle portion. Similarly, Bethea U.S. Design Pat. No. 286,979 and Bethea U.S. Design Pat. No. 286,744 show nuts having fastening and handle portions.
Roerig U.S. Pat. No. 2,576,643 shows a wing nut, each wing having an opening therethrough.

Double-wing wing nut anchor system and method


There is provided a medical camera head including an imaging board integrally including an imaging element mounting section where an imaging element is mounted, a plurality of first flexible portions whose one ends connected to the imaging element mounting section are led out of the imaging element mounting section in different directions, and a connection section connected to the other end sides of the plurality of first flexible portions.

The present disclosure relates to medical camera heads and medical camera apparatuses.
In the medical field, camera apparatuses such as endoscope apparatuses have been used to observe an observation target in related art. Used in such a camera apparatus is a medical camera head (hereinafter also simply called a camera head) that images an observation target by an internal imaging element, such as an endoscope camera head connected to a rigid endoscope. The camera head outputs an image signal obtained by the imaging to other equipment. Then, an image of the observation target obtained by the camera apparatus is recorded, or displayed on a display apparatus to be observed by a plurality of persons during surgery. The camera head is used with a user grasping it for the purpose of moving the camera head in order to move its position in the observation target, or pressing a switch provided on the camera head in order to perform various operations of the camera head. To improve the operability of such a camera head, for example, there have been proposed technologies for reducing a camera head in size.
For example, JP 2012-195931A discloses a technology of placing a flexible board connected to an image sensor on a surface that is not provided with an imaging element, out of inner surfaces of a casing, in order to effectively use the space inside the casing.
In addition, for example, JP 2004-261362A discloses a technology of providing an external cover that is integrally molded using an elastomer material in order to reduce the number of components.

Medical camera head and medical camera apparatus


A method for contention-free access and management of shared timers in a multiprocessing environment allocates at least two timers, which are used by all subject threads in a "ping-pong" manner. Each thread uses a local variable to determine which of the two timers to use for blocking. At initialization, the first timer tracks a first specified time duration and the second timer tracks a second specified time duration after the first specified time duration. When the first timer expires, it is reset by the master thread to expire at a third specified time duration after the second specified time duration. Similarly, when the second timer expires, it is reset by the master thread to expire at a fourth specified time duration after the third specified time duration. This process repeats itself, so that a timer is always active in the system. Following timer expiration, the non-master threads and the master thread perform processing tasks, and then block on a timer without contention or additional synchronization.

1. Field of the Invention.
The present invention generally relates to contention-free access and management in multiprocessing software environments. In particular, the invention provides contention-free access to timer objects in a multiprocessing environment.
2. Description of Related Art.
A common operation in computer software is the scheduling of work to be performed at some time in the future, such as 10 milliseconds from the current time. Typically, this is accomplished by the use of a timer object. The operating system provides the timer object and the timer object schedules work by keeping track of elapsed time.
In the general case, the software using the timer performs a sequence of steps. The software first requests a timer object from the operating system. The software initializes the timer object, specifying the duration before the timer expires. The software then waits, or "blocks", on the timer object until the time duration has elapsed. When the operating system determines that the specified duration has elapsed, the previously blocked software performs its defined tasks.
In multithreaded, multiprocessing, or multiprogrammed environments, it often happens that there is a need to schedule work to be performed by a plurality of threads, processes, or jobs at some time in the future. If the threads are intended to block for the same duration of time, the threads may block on the same timer object, thereby reducing resource consumption and processing overhead. However, management of the shared timer may be costly, since ordinarily each thread will contend for access to the timer object and re-initialize it for the next timer interval. Notably, many of the traditional shared-timer management techniques are costly, including the "mutex and master thread" approach; the "mutex: first thread in initializes the timer" approach; and the "spinlock" approach (in multiprocessing systems).
In the "mutex and master thread" approach, a mutex is a synchronization object that ensures exclusive access to a resource. Other threads requesting the mutex have to wait until the mutex is signaled. The master thread is responsible for initializing the timer.
The master thread follows the procedure outlined below. First, it initializes the timer with the next duration and signals the operating system mutex, allowing all threads to run. The non-master threads may now block on the timer. After all non-master threads have gotten through the mutex, then the master thread resets the mutex so that any further waiting threads will block. If a thread is not a master thread, then it skips the above procedure and waits on the mutex.
In the "mutex: first thread in initializes the timer" approach, the first thread has the responsibility for setting the timer. The first thread acquires the operating system mutex and determines whether the timer is already set. If the timer is set, the first thread releases the mutex. Otherwise, the first thread initializes the timer and then releases the mutex. In either case, the thread subsequently blocks on the timer.
In the "spinlock" approach (in multiprocessing systems), a spinlock variable is associated with the timer. A thread attempts to acquire the spinlock variable, using an interlocked test and set operation . After acquiring the spinlock variable, the thread then determines whether the timer has been set. If the timer has not been set, the thread initializes the timer and releases the spinlock variable. In either case, it blocks on the timer object.
One problem with these traditional approaches is that they require a large amount of processing overhead because each thread must contend for exclusive to the timer. Additionally, these methods increase the elapsed time of the operation, since each thread must wait (either spinning or blocking) until it acquires exclusive access to the timer object.
Thus, because of the processing overhead of traditional methods, there is a need for an invention that eliminates the contention for timer-objects and the need for synchronization mechanisms and subsequent wait times.

Method for contention-free access and management of timers in multiprocessing environments


A method for manufacturing products using a mold having at least one mold cavity which is at least partly defined by at least two movable wall parts, wherein the mold is closed and the at least two movable wall parts (35A, 35B) are brought to a retracted position relative to the mold cavity, so that the volume of the mold cavity is enlarged relative to the volume required for a product to be formed, wherein at least partly molten material is introduced into the mold cavity and then in a first step a first one (35A) of the at least two movable wall parts is set into motion in the direction of a forwardly moved position and in a second step a second one (35B) of the at least two movable wall parts is set into motion in the direction of a forwardly moved position, wherein the movable wall parts are moved into said forwardly moved position for the formation of the product.

The invention relates to a method for manufacturing products. The invention relates in particular to a method for manufacturing products using a mold.
Mold-forming products provides the advantage that products can be manufactured relatively simply and reproducibly. Use can then be made, for instance, of injection molding technique. A disadvantage of this is that relatively high injection pressures are necessary to make the material spread throughout the mold cavity. Moreover, the injection temperature should be relatively high in order to prevent the material solidifying before the whole mold cavity has been filled. As a consequence, particularly high closing forces need to be applied to the mold, and stresses develop in the material and the product to be molded, which lead to an undesirably high degree of inaccuracy.
It has previously been proposed to make use of movable wall parts in the mold, so that flow paths for the material can be enlarged in cross section at least locally. As a consequence, the injection pressure can be lowered, as well as the injection temperature. In this technique, however, the control of the movable wall parts has to date been difficult.
An object of the invention is to provide a method for forming products using a mold with movable wall parts. In particular, an object of the invention is to provide a method for injection molding products, in which wall parts can be moved accurately and reproducibly.


The invention concerns a process for the preparation of soft magnetic composite products comprising the steps of providing particles of an iron based soft magnetic material with an electrically insulating layer; optionally mixing the dry powder with a lubricant; compacting the powder and heating the obtained component at an elevated temperature in the presence of water vapour. The invention also comprises the iron powder compact subjected to this treatment.

This invention relates to soft magnetic composites. More particularly, the invention relates to soft magnetic composites having improved strength. These composites which combine good soft magnetic properties with high strength are particularly useful as components in electrical machines.
Currently used components of soft magnetic composites prepared from pressure compacted coated iron powder have a relatively low compressive strength. This is due to the fact that these materials cannot be subjected to the usual method of improving the strength, i.e. sintering, since the high temperature required for sintering damages the insulating coating around the powder particles. Today soft magnetic composites are heat treated at a temperature below the sintering temperature in order to improve the magnetic characteristics. Also, the compressive strength of the component can be somewhat improved by such a heat treatment. WO95/29490 discloses a method of making a component having improved magnetic properties by compacting or die-pressing a powder composition of insulated particles of an atomised or sponge iron powder optionally in combination with a lubricant and in some cases a binder and subsequently subjecting the compacted composition to heat treatment in air at a temperature preferably not more than 50-500xc2x0 C. The strength of components prepared according to this patent is in the range 50-100 MPa, the higher strength being achieved at the cost of poorer magnetic properties. This strength is comparatively low and insufficient for certain applications.
Japanese Patent Publication 51-43007 discloses a method of manufacturing iron-based machine parts whereby an iron powder is pressure-compacted to obtain a green compact and the green compact is heated under an oxidising atmosphere including vapour at 400-700xc2x0 C. The purpose of this known method is to form iron oxide onto the surface of each iron grain. This procedure replaces the two steps involving dewaxing, i.e. the removal of lubricant, which usually is carried out at a temperature of at least 400xc2x0 C., and sintering, which is carried out at a temperature of at least 1100xc2x0 C. to form bonds between the metal particles. The Japanese publication also teaches that sizing of the body can be avoided because of the fact that the compacted and heat treated parts have high dimensional accuracy. The Japanese publication does not concern magnetic materials.
It has now been found that if uncoated iron powder particles, i.e. iron particles which are not provided with an insulating layer, are compacted and subsequently treated with vapour the strength of the material will increase but the energy loss in the material will be unacceptably large. When it comes to the coated iron powder particles used for magnetic applications it was found that the energy loss in coated material increases with increasing frequency and this tendency is even larger for vapour treated material than for coated material heated in air. During extensive studies it was however found that for frequencies less than 1000, preferably less than 300 Hz, it is possible to prepare soft magnetic composites having improved strength and a low energy loss.
The invention provides a process for the preparation of soft magnetic composites comprising the following steps: a) providing a low carbon powder of a soft magnetic material selected from the group consisting of an atomized or sponge powder of essentially pure iron or an iron-based prealloyed powder containing Si, Ni, Al or Co, b) providing the particles of the powder with an electrically insulating layer, c) compacting the powder to a composite body, and d) heating the composite body at a temperature between 400 to 700xc2x0 C. in the presence of vapor.
The invention also provides a composite body of compacted electrically insulated particles of a soft magnetic material, the compacted body having been heat treated in the presence of water vapour. The compacted body is useful in AC applications below 1000 Hz and preferably below 300 Hz.

Process for preparation of soft magnetic composites and the composites prepared


An air conditioning unit for a combined refrigeration plant and heat pump mode of operation for vehicles is disclosed, wherein the air conditioning unit includes a primary circuit and a secondary passage, and a power consumption required by the air conditioning unit to heat the passenger compartment is minimized.

To condition air to be supplied to a passenger compartment, prior art air conditioning systems include a refrigeration plant for cooling the air and a glycol-air heat exchanger for heating the air. These systems also typically include glycol-air heat pumps and air-air heat pumps.
Air conditioning units having glycol-air heat exchangers are disadvantageous in that when ambient air temperatures fall below 10° C., cooling water, as well as a glycol temperature cannot reach the temperature level required for comfortably heating the passenger compartment. Against a backdrop of increasing employment of vehicle drive systems which release a minimal amount of heat, such as electric or fuel cell drives, use of additional heaters is necessary.
It is inherent in glycol-air heat pumps that the cooling water of the internal combustion engine is utilized as heat source. However, heat extraction from the cooling water leads to the engine being operated at low temperatures for longer periods of time, which is undesirable.
If air-air heat pumps are used as heaters, ice builds up at a gas cooler or condensator at certain temperatures. Control of the system can prevent icing, but can also result in a minimization of heat output from the heat pump. If ice build-up at the gas cooler or condensator is permitted, the heat pump can be actively defrosted by operating the refrigerant circuit as an A/C-plant for a short time. However, this may result in a minimization of mean heat output of the heat pump.
Frequently, heat pump systems cannot dehumidify and heat the air to be fed into the passenger compartment at the same time. Therefore the systems cannot be operated with recirculated air from the passenger compartment, which may lead to undesired fogging of the windows. Additionally, heat pump systems delivering output to the engine cooling circuit frequently are insufficiently dynamic and efficient.
An air conditioning unit for vehicles is disclosed in DE 101 63 607 A1, hereby incorporated herein by reference in its entirety, having an integrated heat pump for cooling air and heating air, wherein refrigerant is circulated in a circuit and heat transmission is facilitated to air flowing into a passenger compartment. In this process, energy is fed directly into the air flowing into the passenger compartment by use of the integrated heat pump. This is facilitated by use of refrigerant-passed heat exchangers disposed in the vehicle's air conditioning box by cooling and optionally condensing the refrigerant for heating and evaporating the refrigerant for cooling. Next, the integrated heat pump energy is fed into the air flowing into the passenger compartment indirectly over heat carrier liquids. This is facilitated by use of liquid/air heat exchangers disposed in the vehicle's air conditioning box, by cooling the secondary refrigerant for heating the air and by heating the secondary refrigerant for cooling the air. It is a disadvantage of this invention that in heat pump mode of operation, the internal heat exchanger is not passed on the high-pressure side and a great number of components are required.
DE 101 26 257 A1, hereby incorporated herein by reference in its entirety, discloses a heating/cooling circuit for vehicles, whereby the heating/cooling circuit comprises an evaporator for cooling air to be fed to an interior, a heating heat exchanger for heating the air to be fed to the interior, an external heat exchanger with a compressor for discharging a refrigerant, a first expansion element allocated to the evaporator, a second expansion element allocated to the external heat exchanger, and refrigerant conduits connecting the components to each other. The invention provides means to adjust the pressure of the refrigerant in the external heat exchanger between highest and lowest system pressures to establish an effective, energy-saving, demand-oriented dehumidification of the air in cooling, heating and reheating modes of operation. Loading of the external heat exchanger with medium pressure, however, results in minimized performance of the external heat exchanger and a minimized efficiency of the heating/cooling circuit.
It would be desirable to produce an air conditioning unit for a combined refrigeration plant and heat pump mode of operation for vehicles, wherein a power consumption required to heat/cool the passenger compartment is minimized and a heating/cooling facilitated thereby is maximized.

Air conditioning unit for vehicles and method of operating the same

Halla Visteon Climate Control Corporation