A multi input multi output (MIMO) transceiver having a channel estimation module being responsive to received samples including channel state information (CSI) and operative to generate time domain beamforming parameters, in accordance with an embodiment of the present invention. The multi input multi output (MIMO) transceiver further includes an adaptive beamforming parameters module coupled to receive said time domain beamforming parameters and operative to generate time domain adaptive beamforming parameters, said adaptive beamforming parameters module operative to process said time domain beamforming parameters to generate frequency domain adaptive beamforming parameters, a decoding module coupled to receive said frequency domain adaptive beamforming parameters and operative to generate data bits, a channel parameters module coupled to receive said data bits and operative to extract said time domain adaptive beamforming parameters, an encoding module coupled to receive said time domain adaptive beamforming parameters and operative to generate a data packet, said encoding module operative to encode said data packet to generate a modulated data stream, and a beamform matrices module coupled to receive said modulated data stream and operative to generate a beamformed data stream based on said frequency domain adaptive beamforming parameters, said MIMO transceiver operative to process said beamformed data stream to generate output signals and to transmit said output signals by forming beam patterns.

1. Field of the Invention
The present invention relates generally to the field of wireless communication systems and particularly to a method and apparatus for adaptive transmit beamforming with reduced overhead in multi input multi output (MIMO) communication systems.
2. Description of the Prior Art
Communication systems can be categorized as conforming to either wired or wireless standards. Implementations can range from local wireless networks in the home, to the national and international cell phone networks, to the worldwide Internet.
Each communication system deployed typically conforms to one or more of a number of existing standards. Wireless standards include the IEEE 802.11 wireless local area network (WLAN), the advanced mobile phone services (AMPS), Bluetooth, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution system (LMDS), multi-channel-multi-point distribution systems (MMDS), and various proprietary implementations of such standards.
Wireless devices in a network, such as a laptop computer, personal digital assistant, video projector, or WLAN phone, can communicate either directly or indirectly to other users or devices on the network. In direct communication systems, often referred to as point-to-point communication systems, the two devices are assigned one or more communication radio frequency (RF) channels, and the devices communicate directly over those channels. In indirect communication systems, the devices communicate through an intermediary device, such as an associated base station for cellular services, or an access point for home or office WLAN networking, on an assigned channel. To complete the connection, the access point or base station communicates with the pair directly, using the system controller, the Public switch telephone network (PSTN), the Internet, or some other wide area network.
Referring now to FIG. 1, a conventional WLAN home network is shown to include an access point (AP) or base station 200, a network interface hardware 204 and various electronic devices 206-214 that are used in a typical WLAN home network. The devices include a WiFi phone 206, a personal digital assistant (PDA)/WiFi camera 208, a laptop 210, a home audio system 212 and a high definition television (HDTV)/projector 214. The devices 206-214 communicate with each other through the AP 200 on assigned channels. The AP 200 has a beamforming capable transmission module 216 and a multi input multi output (MIMO) antenna 218. Each of the devices 206-214 also has a beamforming capable transmission module and an MIMO antenna. The AP 200 is connected to the Internet Wide area network (WAN) or LAN through the network interface hardware 204.
The commonly known architecture for a digital wireless device to receive data in one of these networks includes an antenna connected to an RF signal processing circuit. The antenna receives the RF signal and supplies it to the RF circuit, which filters out unwanted signal and noise from adjacent channels and in turn converts it to the baseband (i.e., centered at zero frequency, DC), or some intermediate frequency (IF). The analog RF output signal, at IF or baseband is converted to a digital stream and processed by the baseband module. The baseband module demodulates and decodes the baseband signal, thus recovering the original data.
Similarly, to send data over the network, the digital baseband encodes the bit stream, modulates the encoded stream, and if necessary converts it to an IF signal. The digital signal is converted to an analog signal using a digital to analog converter and sent to the RF circuit. The RF circuit converts the analog baseband output to an RF signal, using a carrier frequency corresponding to the channel assigned to the particular user, and sends the signal over the wireless channel using the RF antenna.
Traditional devices, particularly early (pre-2005) WLAN products adhering to the 802.11 standard, have used a single physical RF antenna, for both transmitting and receiving data. The antenna is shared by virtue of time-domain duplexing (TDD), whereby the transceiver only transmits or receives data at any given time, and does not do both simultaneously. Thus the antenna can be shared between the receiver and transmitter functions. When only one antenna is used at each end of the communication link, the channel established is referred to as a single-input/single-output channel, or SISO. More advanced systems based on this standard employ multiple antennae, for both receiving and transmitting data. A basic two-antenna device that switches between antennae automatically based on received signal quality is using antenna-switching diversity. If the two-antenna device transmits on both antennae simultaneously, the channel is referred to as multiple-input/single-output (MISO), if the receiver side of the link only has one receiver antenna. Conversely, if the transmitter uses a single antenna, and the receiver uses two antennae, the channel is called a SIMO (single-input/multiple-output) channel.
Currently entering the market are MIMO products (multiple-input/multiple-output) devices, aimed at very high performance in throughput, range and link reliability. These products are in advance of the published standard, as the Institute of Electrical and Electronic Engineers (IEEE) has only recently completed Draft 2.0 of the 802.11n standard that formalizes the operation of multiple antennae WLAN systems. In particular, the standard defines the protocols and techniques that enable multiple antenna systems to interoperate so that maximum beamforming benefits can be achieved. For example, systems with multiple antennae can transmit and receive more than one data stream simultaneously using a combination of either time or spatial encoding functions. This can effectively double or triple the throughput, depending on the number of parallel streams.
To improve signal reception quality, the Draft 2.0 standard also includes several beamforming modes of operation. Basically, beamforming is a technique where an array of antennae are "directed" at a desired target or source by adjusting the relative gain and phase of the array elements. By adjusting the relative gain and phase of the elements, the antenna pattern, or beam, can be made to point in a favored direction for receiving or transmitting data, or to attenuate other directions in order to reduce an interference source. Prior art publications describing these methods are: A Primer on Digital Beamforming by Toby Haynes, Spectrum Signal Processing 1998, Digital beamforming basics, by Hans Steyskal, Journal of Electronic Defense 1986. The foregoing references describe the basic mathematics associated with forming beam patterns in order to focus an antenna array to better receive or transmit RF signals.
In the 802.11n Draft 2.0 standard, there are several methods of beamforming detailed that pertain to the orthogonal frequency domain multiplexing (OFDM) type of modulation. The OFDM modulation is multi-carrier, utilizing the inverse fast Fourier transform (IFFT) process to convert N individual data symbols into a time-domain signal for transmission. At the receiver, the time domain signal is blocked up into symbols and demodulated back into a vector N individual frequency domain symbols. The received signal y on each subcarrier can be expressed as y=Hx+n, and x=Qs, where s is the sent symbol, Q is a pre-multiplier, H is the channel between the transmitter and receiver, and n is the effective noise. For an MIMO link, the channel H is a matrix. For example, in a two transmitter and three receiver (2T3R) system, the H matrix is 3×2, and the received signal equation can be written as:
            [                                                  y              1                                                                          y              2                                                                          y              3                                          ]        =                            [                                                                      h                  11                                                                              h                  12                                                                                h                  21                                                                              h                  22                                                                                h                  31                                                                              h                  32                                                              ]                                  [                                                                      x                  1                                                                                x                  2                                                              ]                    +              [                                                            n                1                                                                                n                2                                                                                n                3                                                    ]              ,and the sent signal is expressed as:
      [                                        x            1                                                            x            2                                ]    =                    [                                                            q                11                                                                    q                12                                                                                q                21                                                                    q                22                                                    ]                          [                                                            s                1                                                                                s                2                                                    ]              .
During the course of decoding the received data, the channel matrix H is estimated, using the preamble portion of the data packet. To implement one particular form of beamforming, the channel state information (CSI) based on H is processed by the receiver and sent back to the transmitter. The transmitter then formulates a beamforming matrix Q, based on the CSI, and uses Q to beamform subsequent packets to the corresponding receiver. This process, by which the CSI is sent back to the transmitter for beamforming, is referred to as explicit beamforming.
Explicit beamforming is one method described in the 802.11n standard. There are three associated feedback formats for the CSI information. The first implementation utilizes a scaled version of the H matrix, and is referred to as full CSI. The data required to send the full CSI as feedback can be prohibitive because much dynamic range is required to represent a channel that has any significant fading. To alleviate this, another method referred to a steering matrix feedback is implemented. In this case the channel matrix is first decomposed using the singular value decomposition (SVD), so thatH=UΣV*  Eq. (1)After the decomposition, the V matrix is sent back to the transmitter. The advantage is that the V matrix is unitary (all its columns have unity norm), so that less resolution is needed to represent the channel, and thus there is reduced overhead with the method. The problem with this method is that small variations in the channel condition could lead to large changes to the V matrix. Thus, this method may not be robust and suffers from sudden performance loss in both throughput and link stability.
To further reduce the amount of information required for beamforming feedback, a third protocol is spelled out in the standard that compresses the channel state information. This is accomplished using Givens rotation decomposition and polar coordinates to parameterize the steering matrix, and feeding this back to the transmitter instead. Prior art limitations include feeding back an incomplete CSI to the transmitter; thereby limiting the type of beamforming processing that can be used, and, because it relies on the V matrix, it too may be sensitive to channel variations, as mentioned with the compressed method discussed above.
Thus, there exists a need to provide a method and apparatus for explicit feedback transmit beamforming that allows full and accurate CSI that requires a low amount of overhead to implement.

Method and apparatus for adaptive reduced overhead transmit beamforming for wireless communication systems


The asphalt tamper includes a tamper plate connected to a reciprocating rod that oscillates inside of a protective sleeve, wherein the reciprocating rod abuts a cam that rotates about the output of a motor. The reciprocating rod has a shoulder that interacts with a spring that applies a biasing force ushering the reciprocating rod back and forth upon interaction with the rotating cam.

A. Field of the Invention
The present invention relates to the field of motorized tampers, more specifically, a hand-held tamper that has a variable speed control and is powered by an electric motor.
Manual or motorized tampers have been around for a long time, and provide a valuable service in compacting various types of ground. However, traditional motorized tampers are bulky and do not have variable speed control, or the option to be electrically powered. A variable speed control for a motorized tamper expands the range of different surfaces that require different tamping speeds. The present invention seeks to improve this field of prior art and overcome these limitation by providing a motorized tamper that is lightweight when compared to the prior art, has a variable speed control, and is electrically powered.
B. Discussion of the Prior Art
As a preliminary note, it should be stated that there is an ample amount of prior art that deals with motorized tampers. As will be discussed immediately below, no prior art discloses a lightweight motorized tamper that includes a variable speed control and an electric motor that is powered via a rechargeable battery.
The Grane Patent (U.S. Pat. No. 4,170,427) discloses a vibrating tamper with side-by-side engine section and tamper section connected by a suspension system including leaf springs. However, the vibrating tamper of Grane is big and bulky and not as lightweight as the asphalt tamper claimed below. Additionally, the asphalt tamper of Grane offers only a single tamping speed as opposed to a variable speed control that adjust the tamping speed, and requires the use of springs and an eccentrically-placed engine that is aligned with the tamping force generated.
The Pikuet Patent (U.S. Pat. No. 7,316,524) discloses a tamping device for tamping of asphalt or stone that includes a motor being coupled to a drive shaft that rotates off centered weights as opposed to an oscillating plate that tamps the surface and of which has a variable speed control. Though, the tamping device of Pikuet is not bulky, it relies upon off-centered rotating weights to provide the tamping force as opposed to a reciprocating tamping plate.
The Westbrook et al. Patent (U.S. Pat. No. 7,201,536) discloses an asphalt-patching machine that is mountable to a motor vehicle having a supply of asphalt patch material and tamper thereon. However, the tamper is a part of a patching machine that mounts to a motor vehicle, as opposed to a motorized tamper that is lightweight and can be hand-held.
The Gabriel, Jr. Patent (U.S. Pat. No. 4,215,949) discloses a self-contained asphalt patching apparatus that has a motorized tamper. Again, the motorized tamper is a part of asphalt patching machine and not a hand-held tamper that is lightweight in comparison with variable speed capabilities.
While the above-described devices fulfill their respective and particular objects and requirements, they do not describe a hand-held tamper that a variable speed control and of which is powered by an electrical motor and rechargeable battery. In this regard, the asphalt tamper departs from the conventional concepts and designs of the prior art.


In a transfer line for the metal-cutting machining of workpieces, the transfer line including a plurality of machining stations arranged one after the other substantially in one plane. The workpieces are arranged in hanging fashion in such a way that clamping devices are arranged above the workpieces, thereby providing a falling and collecting space for the cuttings under the workpieces. Removal of cuttings is thereby facilitated and it is not necessary to flush the cuttings away using large amounts of coolant.

The invention relates to a transfer line for the metal-cutting machining of workpieces, in which a plurality of machining stations comprising tools together with their drives and guides are arranged one after the other substantially in one plane and transfer devices convey the workpieces to the machining stations in which the workpieces are held by clamping devices during machining.
Transfer lines of the type described above are known. They serve, for example, for the fully automatic machining of workpieces of essentially the same kind, for example engine blocks. In the individual machining stations of the transfer line, the various machining operations are performed by suitable machining units and tools. When the machining operations are completed, the transfer devices move the workpieces in an operating cycle to the next machining station.
As a rule, liquid cooling lubricants are employed for the machining operations, the function of which is to lubricate and cool the tools and also to flush away the cut-off cuttings. For this purpose, there is arranged beneath the workpiece-conveying path a channel which receives the cuttings and the coolant. The channel may be arranged either in the machine bed or on the floor on which the machining stations also stand, or a suitable underfloor channel or drain is provided. In the channel or drain, there are then provided conveying devices for the cuttings, for example screw conveyors, band conveyors, scraper conveyors, flap conveyors or else flushing nozzles, which carry the cuttings away.
The use of the cooling lubricant is relatively expensive. On the one hand, a high delivery rate is required, and on the other hand appropriate devices for maintaining a supply of and for cleaning the cooling lubricant are required.
An object of the present invention is to avoid the use of cooling lubricant as far as possible, especially as the wetting of the cuttings by the cooling lubricant is also undesirable.


A method of operating a multiprocessor system having a predefined number of processing units for processing data, includes obtaining load information representing a loading of each of a number of randomly selected ones of the processing units. The number of randomly selected processing units is greater than 1 and substantially less than the predefined number of processing units. A least loaded of the randomly selected processing units is identified from the obtained load information. The data is directed to the identified least loaded randomly selected processing unit for processing.

Distributed computing systems, such as banks or networks of workstations or servers or mirrored sites on the World Wide Web, face the problem of using their resources effectively. If some hosts lie idle while others are heavily loaded, system performance can fall significantly. To prevent this, load balancing is used to distribute the workload, improving performance measures such as the expected time a task spends in the system. Although determining an effective load balancing strategy depends largely on the details of the underlying system, general models from both queueing theory and computer science often provide valuable insight and general rules of thumb.
In a system of n servers, incoming tasks must choose a server and wait for service. If an incoming task knows exactly the current number of tasks already queued at each server and can instantaneously be queued, it is usually best for the task to go to the server with the shortest queue. In many actual systems, however, it is unrealistic to assume that tasks will have access to up-to-date load information; global load information may be updated only periodically, or the time delay for a task to move to a server may be long enough that the load information is out of date by the time the task arrives. Unlike in systems in which up-to-date load information is available, the strategy of going to the shortest queue can lead to extremely bad behavior when load information is out-of-date. Systems which attempt to exploit global information to balance load too aggressively may suffer in performance, either by misusing it or by adding significant complexity. Hence, it is often not clear what the best load balancing strategy is.
If old information is utilized in selecting one of multiple servers for servicing a task, a phenomenon which can be characterized as "herding" may occur. More particularly, if multiple clients are directing tasks to particular servers based upon the stale information, numerous tasks may be directed to the server which the stale information indicates to be the least loaded but which, in fact, has a current loading which exceeds the current loading of other servers.
For example, if the available loading information is updated every T seconds, all tasks directed during the T second period will be directed to what appears to be the least loaded server. This may significantly increase the number of tasks queued for service at that server while the actual number of tasks queued for service at other servers is significantly less than that of the server to which the tasks are being directed. Hence, any delay in updating server loadings can result in herding, since tasks are directed to what appears to be the least loaded of the servers based upon stale loading information.
It will be recognized by those skilled in the art that this phenomena can occur whether the multiserver system is a homogeneous system, i.e., a system in which each of the servers is substantially similar and preferably all queues are equally loaded, or a heterogeneous system in which servers have different processor speeds, etc., and beneficially the server loadings are balanced in view of the differences in the respective server capabilities.
Various techniques have been proposed to balance the loading in multiserver environments. However, the proposed techniques have generally relied on complex algorithms and models which are difficult to implement and require substantial system overhead during operations. Accordingly, there remains a need for simple techniques for balancing the loadings of multiple processors servers in a client-server environment.

Task processing optimization in a multiprocessor system


The present disclosure relates to applicators designed for controlled in situ delivery of therapeutic films or depots during a surgical procedure.

Technical Field
The present disclosure relates generally to applicators for use in surgical procedures, and more particularly, to applicators for use in surgical procedures to control and/or sustain the delivery of at least one therapeutic agent for extended efficacy.
Background of Related Art
Laparoscopic surgical insufflation systems allowing the use of trocar-enabled aerosolizing technologies have been disclosed by others (Power et al.; US 2011/0030678), and specifically as mechanical devices which may allow the passage/delivery of a fluid/therapeutic agent to a surgical site or body cavity (i.e. standard of care anesthetics, analgesics, etc. and in place of local injection/infusion). However, little has been reported in terms of means of extending the efficacy of such therapeutic agents, or preferred materials compositions or alternative uses, and/or methods of use outside of laparoscopic approaches.
As such, these inventions and related devices leave much room for improvement pertaining to controlling and sustaining therapeutic agent delivery (for preferably extending efficacy), as well as allowing both laparoscopic and open surgical use, given the majority of reported acute post-operative pain is associated with open approaches.

Applicators for controlled in situ delivery of therapeutic compositions and implants, methods of fabrication and use


An automatic wheel-driven generating device mainly includes a base fixedly mounted on a wheel around an axle thereof and provided with a centered hollow column and one or more radially extended hollow pipes for each receiving a light-emitting element therein; a winding reel enclosed between left and right magnetic poles and fixedly mounted on the hollow column; and a magnet holder having a cap screwed into a center thereof and being fixedly mounted on the axle. The magnet holder carries magnets and is associated with the winding reel and the magnetic poles without contact with them. When the wheel rotates, the winding reel and the magnetic poles on the base rotate along with the wheel relative to the magnet holder that is unmovably fixed on the axle, so that an induced current is produced to drive the light-emitting elements to emit light beams. Each of the light-emitting elements is associated with a light-guiding bar that is connected to the wheel and has an uneven outer surface, so that light emitted from the light-emitting element is reflected and refracted in the light-guiding bar, making the whole rotating wheel a bright light circle to ensure a rider""s safety.

The present invention relates to an automatic wheel-driven generating means and a lighting device thereof. The generating means mainly includes a base fixedly mounted on a wheel around an axle thereof and provided with a centered hollow column and one or more radially extended hollow pipes for each receiving a light-emitting element therein; a winding reel enclosed between left and right magnetic poles and fixedly mounted on the hollow column; and a magnet holder having a cap screwed into a center thereof and being fixed to and around the axle by extending the axle through an axle hole centered at the cap. The magnet holder carries magnets and is associated with the winding reel and the magnetic poles without contact with them. When the wheel rotates, the winding reel and the magnetic poles on the base rotate along with the wheel relative to the magnet holder that is unmovably fixed on the axle, so that an induced current is produced to drive the light-emitting elements to emit light beams. The lighting device includes one or more light-guiding bars that are connected to the wheel and separately associated with the light-emitting elements. The light-guiding bars have uneven outer surfaces, so that light beams emitted from the light-emitting elements are reflected and refracted in the light-guiding bars.
For a rider to ride a bicycle safely in dark places, a generating means is developed for mounting on an axle of a wheel to generate current when the wheel rotates. The generated current drives a light-emitting element connected to the generating means to emit light. Such conventional wheel-driven generating means is usually bulky and heavy and includes bearings that complicate the assembling of the generating means. The bearings also increase overall dimensions at the axle of the wheel to which the generating means is mounted, forming an unpleasant vision that reduces a consumer""s interest in buying the bicycle.
Meanwhile, the conventional wheel-driven generating means usually includes a lighting device that has complicate structure and provides only light beams of low brightness.
It is therefore tried by the inventor to develop an improved automatic wheel-driven generating means and a lighting device thereof to eliminate the drawbacks existing in the conventional wheel-driven generating means.
A primary object of the present invention is to provide an automatic wheel-driven generating means that is mounted on a wheel to generate electric currents without the need of bearings. The omission of the bearings enables the automatic wheel-driven generating means to be easily assembled and have reduced volume and weight. When the wheel rotates, the automatic wheel-driven generating means generates electric currents to drive light-emitting elements provided thereon to emit light beams.
Another object of the present invention is to provide a lighting device for the above-described automatic wheel-driven generating means. The lighting device includes one or more light-guiding bars that have specially designed uneven outer surface, so that light beams emitted from light-emitting elements on the generating means are reflected and refracted in the light-guiding bars to produce multiple light spots from one single light source. The multiple light spots on a rotating wheel make the wheel a bright light circle that is helpful in ensuring a rider""s safety.

Automatic wheel-driven generating means and lighting device thereof


A plasma torch is provided with a sharply converging nozzle which can prevent the lower end of the torch from making contact with a workpiece which has concavities and convexities during the cutting of the workpiece with the plasma torch. An upper portion (1a) of the nozzle (1) is provided with an outwardly directed flange (1h) so as to make close contact with a seat surface (2d) formed in the inner periphery of the lower portion of the cap (2), so as to ensure electrical conduction between the nozzle (1) and the cap (2) and to secure to a torch body (8) the nozzle (1) and components (3, 4, 5) contained in the nozzle (1). O-rings (6, 6a, 9) provide seals for the cooling water passage (7). The lower end of cylindrical portion (1a) of the nozzle (1) below the flange (1f), as well as the conical portion (1b), constitutes part of the exterior surface of the plasma torch, while the apex angle (.theta..sub.1) of the nozzle structure is made smaller so that the nozzle structure is more sharply tapered.

A nozzle structure attached to the lower end of a conventional plasma torch, as shown in FIG. 2, comprises a nozzle 10, an annular insulation member 30, an annular swirler 40, and an electrode 50. The nozzle 10 has an upper cylindrical portion, a frustoconical portion, a lower cylindrical portion and a projecting conical lower end portion with an end face, forming an interior chamber. The end face of the nozzle 10 has a hole therein in communication with the interior chamber of the nozzle 10 for confining a plasma jet. The swirler 40 is positioned within the interior chamber of the nozzle 10, resting on the shoulder between the upper cylindrical portion and the frustoconical portion of the nozzle 10. The electrode 50 is positioned by the swirler 40 and the insulation cylinder 30 to be coaxial with the nozzle 10. The swirler 40 jets working gas in the form of a swirl steam or an axial stream into an annular gap between the electrode 50 and the nozzle 10. A cap 20 has an upper cylindrical portion and a lower conical portion, with the lower conical portion having a hole centrally formed therein. The cap 20 is positioned about and coaxially with the nozzle 10 with the sides of the hole in the lower end of the cap 20 being in close contact with the conical surface of the lower conical portion of the nozzle 10, so that the outer surface of the nozzle 10 is encompassed by the cap 20, excepting only the lower end face of the nozzle 10. A space defined between the outer periphery of intermediate portions of the nozzle 10 and the inner periphery of the cap 20 serves as a passageway 70 for nozzle cooling water. The cylindrical portion of the cap 20 is secured to the cylindrical portion of the torch body 80 by suitable means.
The cap 20 serves the function of securing to the torch body 80 the nozzle 10 and the components fitted therein, as well as ensuring electrical conduction to the nozzle 10. In such a plasma torch in which the nozzle 10 is directly cooled by water, the cap 20 also serves the function of sealing the cooling water passageway 70 so as to prevent the cooling water flowing around the outer periphery of the nozzle 10 from leaking out of the torch.
In order to achieve these functions effectively, the cap 20 is made to have metal-to-metal contact with the nozzle 10 in the vicinity of the lower (front) end of the plasma torch, and the diameter of the cylindrical portion of the cap 20 and the apex angle .theta..sub.2 of the conical portion of the cap 20 are both made to be large. The large diameter of the cylindrical portion of the cap 20 and the large apex angle of the conical portion of the cap 20 readily accommodate the various components positioned in the vicinity of the front end of the plasma torch, e.g., the insulation cylinder 30 fitted on the outer periphery of the electrode 50, the swirler 40 attached to the lower end of the insulation cylinder 30, the nozzle 10 in which these components are fitted, and the like.
Such a plasma cutter can be used in two-dimensional cutting of a workpiece such as a flat plate, and can also be used in three dimensional cutting, e.g., for forming components of automobiles or the like by installing the plasma cutter onto a robot. However, the conventional plasma torch having a large diameter cap and a large apex angle .theta..sub.2 at the lower end of the torch has incurred the following problems.
(1) If the height of the plasma torch (the distance between the lower surface of the nozzle 10 and the cutting surface on the workpiece) is set to a predetermined desired value, the sides of the lower end of the torch can sometimes make contact with the workpiece when the cutting is being conducted in a trough-like recess in the workpiece. Accordingly, it is not always safe for the height of the torch to be maintained at the predetermined desired value. That is, the accessibility of the plasma torch is inferior due to the size and shape of the lower end of the nozzle structure. Where the cutting has to be made with a torch height greater than the predetermined desired height, the cutting quality at that location can be extremely poor, and in some cases no cutting can be made.
(2) During a robotic teaching work wherein cutting loci are being stored in memory in a robot, a marking line made on the workpiece to be cut can be hidden by the torch so that the teaching work becomes difficult.
(3) Since the portion of the cap 20 which contacts the nozzle 10 is in close proximity to the lower end of the nozzle 10, molten metal which splatters during a cutting operation can contact the cap 20 and adhere thereto. Thus, an abnormal electric discharge or a double arc point is likely to occur. Accordingly, damage to the cap 20 can occur, thereby causing leakage of cooling water through the metal-to-metal seal between the nozzle 10 and the cap 20.


Methods, systems, and computer readable media for predicting early onset glaucoma via structural parameters obtained via time and spectral-domain optical coherence tomography (SD-OCT) are disclosed. SD-OCT technology measures the thicknesses of the layers of the retina that contain the cells that die in glaucoma before there is any functional loss. A multivariable predictive model may be used for the diagnosis of early glaucoma using a combination of optic nerve head (ONH), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell-inner plexiform layer (GCIPL) parameters measured via SD-OCT. The model generates a glaucoma probability score for individual patient, which is valuable information in assisting clinicians in glaucoma diagnosis and treatment.

Glaucoma is the second leading cause of blindness in the world. [1] The loss in vision is irreversible, and recent estimates based on meta-analysis of population-based studies indicate that in 2010 there were 44.7 million people with open-angle glaucoma (OAG) worldwide, and 2.8 million people in the United States. [2] These numbers are projected to reach 58.6 million worldwide [2] and 3.4 million in the United States by 2020. [3]
The current standard for the diagnosis of glaucoma is based on the presence of typical structural changes with corresponding functional deficits. However, studies on early changes in glaucoma have shown that structural changes indicated by significant loss of retinal ganglion cells and their axons may precede detection of functional deficit by currently available standard automated perimetry (SAP) methods. [4, 5] In addition, SAP is subject to fluctuation even in clinically stable glaucoma.
Ophthalmoscopy and optic disc photography traditionally have been used as primary methods for structural assessment in glaucoma. However, substantial interobserver variability and low to medium interobserver agreement in detecting subtle changes makes ophthalmoscopy or fundus photography alone poor methods for detecting changes indicative of early glaucoma or glaucomatous progression. [6, 7]
In recent years, and with the advent and continuous improvement of imaging devices such as scanning laser ophthalmoscopy (SLO), scanning laser polarimetry (SLP), and time and spectral-domain optical coherence tomography (SD-OCT), a great deal of effort has been invested in identifying quantifiable parameters for objective assessment of structural glaucomatous damage. Of these devices, SD-OCT has rapidly become one of the most widely used technologies in daily clinic due to its high image resolution and measurement precision. The caveat, however, is that the clinician is presented with an array of quantitative information to mentally process as part of the diagnosis process. The multitude of parameters—most of which are highly correlated and are redundant to some extent—oftentimes renders the interpretation process difficult, particularly when structural changes conflict in their results.
For example, optic nerve head (ONH) parameters may appear normal but retinal nerve fiber layer (RNFL) measurements may appear abnormal. One way of circumventing this issue would be to use a multivariable model that reduces the number of structural parameters provided by the OCT output into a set of fewer parameters containing the most useful and relevant information from the original set while also explaining a majority of variability in the original dataset. Earlier studies have combined structural parameters measured by one or several of the devices listed above to assess the glaucoma diagnostic ability using various methods such as machine learning classifiers, linear discriminant functions (LDF), and principal component analysis (PCA). [8-12] In addition, three recent studies used linear discriminant analysis to assess diagnostic ability of combined structural parameters measured SD-OCT. One of these studies combined ONH and peripapillary RNFL parameters, [13] whereas the two others used a combination of ONH, peripapillary RNFL, and ganglion cell of complex (GCC) parameters, [14, 15] which is anatomically different from ganglion cell inner-plexiform layer (GCIPL). [16] In view of these studies however, a need still exists for predicting early onset glaucoma in patients.
In view of the existing glaucoma diagnosis methods and studies described above, it can be appreciated that the diagnosis of glaucoma in the early stages is challenging. One of the major obstacles in preventing glaucoma blindness is the failure to identify individuals with the condition in the early stages, when changes are not distinct. Waiting until significant visual function loss has occurred means that 30-50% of the cells have died and cannot be regenerated.
In view of the shortcomings of the existing glaucoma diagnosis methods and studies described above, and further in view of the high number of people affected by glaucoma, a need exists for methods, systems, and computer readable media for predicting early onset glaucoma using a combination of structural parameters measured via SD-OCT.

The University of North Carolina at Chapel Hill


A printer includes a file input section that receives an input PDF file that holds change history; a change history extraction section that extracts the change history from the input PDF file; and a print processing section that prints the extracted change history.

1. Technical Field
The present invention relates to a printer, a print data output device, a method, a computer readable medium, and a computer data signal.
2. Related Art
In relation to an electronic document, such as specifications, a manual, or the like, which is repeatedly modified/changed and to be distributed to a third party, the contents of a change from the previous version may be described for each version in the form of a history. In general, each version is given a unique file name and stored as a unique file.
Here, an electronic document such as specifications, a manual, or the like, as described above, is generally distributed with the main purpose of providing the latest version so that the user can refer to the content thereof. Therefore, many such documents are often distributed in a PDF (Portable Document Format) file; that is, a general purpose format depending on neither a platform nor an application.

System and method for processing a change history of a PDF file


A lighting unit according to the invention comprises a supply unit (1) and a low-pressure mercury discharge lamp (2). The low-pressure mercury discharge lamp has a light-transmitting discharge vessel (3) which is provided with a luminescent layer (3) on an inner surface and which encloses in a gastight manner a discharge space (4) which is provided with a filling comprising mercury and one or several rare gases. A first (5a) and a second electrode (5b) are arranged in the discharge space, each comprising a coiling of a metal wire coated with one or several electron-emitting metal oxides. Each electrode is electrically connected to a respective current supply conductor (6a, 6b) which extends to outside the discharge vessel (3). The current supply conductors are electrically connected to the supply unit outside the discharge vessel, the unit ignites the low-pressure mercury discharge lamp in the state upon switching-on. During nominal operation, at least a portion (5a*) of each electrode (5a, 5b) passes an electrode current Iel having an effective value Iel which is at least 1.8 times the minimum electrode current Ip4 required for thermal emission. The lighting unit according to the invention has a long switching life.

The invention relates to a lighting unit comprising a supply unit and a low-pressure mercury discharge lamp, which low-pressure mercury discharge lamp has a light-transmitting discharge vessel which is provided with a luminescent layer on an inner surface and which encloses a discharge space in a gastight manner, the discharge space being provided with a filling comprising one or several rare gases in addition to mercury. In this discharge space a first and a second electrode are positioned, which electrodes each comprise a coiling of a metal wire coated with one or several metal oxides which emit electrons, and which electrodes are each electrically connected to a respective current supply conductor which extends to outside the discharge vessel and is electrically connected there to the supply unit, which unit ignites the low-pressure mercury discharge lamp in the cold state upon switching-on.
Lighting units with a low-pressure mercury discharge lamp, also referred to as "lamp" hereinafter, are widely used for general lighting purposes. They render possible a considerable energy saving owing to the high luminous efficacy in comparison with that of incandescent lamps.
A discharge is maintained with a discharge current between the electrodes during nominal operation of the lighting unit. The manner in which the lamp is ignited depends on the type of lighting unit.
In a lighting unit of the "hot start" type, the electrodes each have a further current supply conductor. Before an ignition voltage is applied between the electrodes, the latter are brought to a temperature required for nominal operation by means of an auxiliary current from the current supply conductor to the further current supply conductor. This method of igniting, however, leads to a comparatively long delay, called ignition delay hereinafter, between the moment of switching-on of the lighting unit and actual lamp ignition. This is a disadvantage. Moreover, the provisions required for this render such a lighting unit comparatively expensive.
In a lighting unit of the "rapid start" type, the electrodes also each have a further current supply conductor, and the electrodes are given a raised temperature by means of an auxiliary current. It is true that an ignition voltage is applied immediately after switching on in this type of lighting unit. An ignition delay is realized here, however, in that the ignition voltage is insufficiently high for igniting the lamp with its still cold electrodes. The lamp does not ignite until after the electrodes have assumed a sufficiently high temperature.
A lighting unit of the kind described in the opening paragraph, in which the lamp ignites in the cold state, is described in U.S. Pat. No. 5,341,067. In such a lighting unit, also referred to as "cold start" or "instant start", an ignition voltage is applied between the electrodes of a sufficient level for igniting the lamp practically immediately after switching-on, i.e. with an ignition delay of less than 100 ms. The electrodes only assume their nominal operational temperature after ignition. A further current supply conductor to the electrodes is not necessary in lighting units of this type. The electrodes are exclusively heated by the discharge arc applied thereto and by the discharge current during nominal operation in this case. If the electrodes have a further current supply conductor, an auxiliary current may contribute to maintaining the nominal operational temperature of the electrodes.
The lamps of the lighting units mentioned above in general have a long life in continuous operation. The life of lighting units in which the lamps are ignited in the cold state is limited in practice by the switching life of the lamp, i.e. the number of times the lamp can be switched on. It was in fact found that the ignition of the lamp whose electrodes are still cold causes comparatively much damage to the electrodes, so that the electrode becomes defective after a comparatively small number of switching operations. To reduce the switching frequency, the lamps are often operated continuously also in cases where the need for lighting is of short duration only. This strongly detracts from the energy saving which could be achieved in comparison with incandescent lamps.

Lighting unit, low-pressure mercury discharge lamp, supply unit, and combined packaging


A self-propelled tree pruning apparatus having a cutting tool with helical edges, such as a milling head. The pruning apparatus is comprised of a frame, at least one pair of driven wheels rotatably attached to the frame, a pair of hugger wheels rotatably held by support means, the support means being adjustably attached to the frame to permit the hugger wheels to be positioned a distance from the driven wheels sufficient to allow the trunk of a tree to be pruned to fit between the driven wheel and the hugger wheels, pneumatic means, such as air bags, for urging the hugger wheels toward the driven wheels, the cutting tool being attached to a drive shaft that is attached to the frame in a manner to allow the cutting tool to move along three axes, and a self-powered motor for driving the driven wheels and cutting tool. In operation, the pruning apparatus is mounted on the trunk of a tree to be pruned, with driven wheels on one side thereof and a pair of hugger wheels located on the other side of the trunk. The driven wheels cause the pruning apparatus to climb the trunk of the tree to be pruned to a desired height. The pruning apparatus follows a helical path around the trunk and upwardly, cutting limbs of all sizes as its rotating cutting tool comes into contact with them. Upon achieving the desired height up a tree trunk, the engine is throttled back to idling speed and the pressure in the air bags released, thereby permitting the apparatus to descend to the ground.

This invention relates to a self-propelled tree pruning apparatus.
Trees are pruned for many reasons. However, commercial pruning of forest trees, such as Douglas fir and ponderosa pine, is undertaken primarily to produce trees having knot-free clearwood in the pruned area of the tree. When the lower branches of young forest trees are properly removed, occlusion or covering over of the removed branch stub takes place as the tree grows, thereby providing knot-free clearwood in the pruned area when the mature tree is harvested. Effective pruning requires that all branches, regardless of size, be removed up to a height of about thirty feet from the ground. Factors affecting rapid occlusion include trim angle, closeness of cut, and cut quality (i.e., smoothness of cut).
Currently the standard pruning method involves manual pruning using saws and hand shears. Manual labor is unsatisfactory for a number of reasons, such as safety, cost, and use of incorrect pruning techniques by untrained workers.
A number of pruning machines have been suggested. Some, such as the "Tree Witch", are hydraulically powered; some, such as the "Tree Monkey", are gasoline powered. Some use shearing devices for pruning; some, such as the Tree Monkey, use chain saws. All of these devices are difficult to operate and maintain, and do not provide the same quality of cut as manual pruning.
It is an object of the present invention to provide a self-propelled tree pruning apparatus which is easy to use and maintain, prunes rapidly, and provides a cut equal or superior to that of mechanical pruning.


The invention relates to a process for the manufacture of thermoplastic resin parts, comprising the steps of:    a) introducing a thermoplastic material (2) in a cavity (11) of a mold (1);    b) closing the mold (1), compressing and distributing the thermoplastic material (2);    c) opening the mold (1) and removing the obtained product.            Step a) comprises the steps of        a1) depositing the thermoplastic material (2) on a carrier support (4);        a2) moving the carrier support towards the cavity of the mold;        a3) depositing the thermoplastic material (2) inside the cavity of the mold.

In a conventional injection molding process, the thermoplastic resin is injected at high temperature and high pressure in a closed mold, allowing complex shapes to be obtained. With these high pressure and temperature injection techniques, very compact and very rigid parts can be obtained, so many times reinforcing elements are not needed. These processes allow introducing inserts or decorative linings inside the mold.
Nevertheless, these injection processes have certain drawbacks, for example:                It is necessary to use high quality materials to reach the required mechanical and/or structural characteristics, as well as the desired external appearance. Many times it is not possible to use recycled or low quality materials.        It is necessary to closely control the temperature so that the material flows well. When plastic cools it contracts, so it is necessary to closely control the temperature, especially when trying to obtain complex shapes.        The high temperature involves enormous energy consumption. The required facility furthermore is more complex since it must be able to heat the material at that high temperature. In addition, when the use of inserts or reinforcements introduced in the mold is required or when the part to be obtained must incorporate a lining, it is necessary to take into account that not all the materials used to form inserts, reinforcements or linings can withstand these high temperatures.        The injection nozzle is in a specific area of the mold, therefore in order to reach the most distant areas and/or areas with complex shapes, the material has to flow very well. In order to obtain completely filling the mold and a good packing of the material (which allows improving the mechanical and structural behavior of the obtained part), it is necessary to use high pressures. These necessary high pressures make a more complex facility necessary.
In some cases (as in the case of roof panels or door panels for automotive vehicles), the plastic part must incorporate a lining layer on at least one of the two faces of the obtained part (generally arranged on the "visible face", i.e. on the face of the product that is visible to the user during conventional product use). In order for this lining layer to adhere to the plastic part, the lining layer is generally placed in the mold and then the thermoplastic material is injected. This has the drawback that it is not possible to use any lining material since many materials may degrade (for example due to burning or glares which deteriorate their appearance or involve the loss of their initial properties) due to the high temperatures of the injection. It is therefore occasionally necessary to use a complementary protection layer that is placed between the lining layer and the surface of the thermoplastic material and functions as insulation against the high temperature of the injection process, to prevent deterioration of the lining layer. However, this increases the complexity and increases the final cost of the process. Furthermore, the use of the complementary protection layer is sometimes not enough to completely solve these problems, which may require the use of special (and/or expensive) materials for the lining layer.
The high pressure of the injection may further break the lining material.
The movement of the plastic material flowing from the injection nozzle throughout the mold may furthermore cause the lining layer to move, wrinkle or become detached, dragged by the movement of the plastic material, possibly changing the final appearance of the part.
The injection processes can be carried out in a closed mold or in an open mold (in which case the injection is carried out in two steps: first part of the material is injected with the mold open, then the mold is closed and the injection is then finished).
Another technique that can be used for producing thermoplastic parts is called open mold compression. This technique is traditionally based on introducing the plastic material in an open mold, closing with the corresponding upper mold and applying a closing pressure. In this technique, the pressures are not as high as in injection molding processes, and the plastic material is usually at a lower temperature than the temperature used in injection processes.
These open mold compression techniques therefore have a series of advantages over injection processes, for example:
i) Open mold compression techniques allow the use of a wider variety of plastic materials than injection processes. Many non-suitable or completely inappropriate materials can be used for an injection process.
ii) They do not require cycle temperatures as high as in injection processes and, therefore, the energy consumption is lower, the required facilities are less complex and a much wider variety of materials can be used for inserts, reinforcements or lining layers.
iii) The plastic material is not as hot, therefore the stabilization of the part requires less time, which results in higher productivity. This also means that greater control over the quality of the parts is obtained or, in other words, for the same cycle time, the stabilization is greater and therefore better parts are obtained.
iv) Furthermore, due to the use of lower temperatures and pressures, the risk of defects in the lining is reduced. With high temperatures, the thermoplastic material can, for example, pass through the pores of the lining or cause tears in the lining in which the thermoplastic material could enter.
v) Many times it is not necessary to use a complementary protection layer.
vi) The facilities or tools used in these processes can be simpler and smaller than those used in injection processes.
vii) The use of lower temperatures can be useful for reducing cycle times.
Nevertheless, these open mold compression techniques have the drawback that the metering machine causing or generating the melted or softened thermoplastic material is usually a very large and heavy machine, which cannot be easily moved for pouring the plastic material into the cavity of the mold. It is certain that perhaps it is not necessary to move the entire machine: this type of machine can incorporate, for example, thermoplastic material feed hoppers, thermoplastic material heating means and other devices that do not have to be moved and, furthermore, an arm by means of which the thermoplastic material is introduced in the mold, which arm generally incorporates heating means to prevent the material from cooling down and a thermoplastic material driving system, for example a worm screw. However, this arm would have to move and would still be a very large and heavy element. Furthermore, the mold generally incorporates guiding columns making it difficult for the arm of the metering machine to access the cavity of the mold to be filled with the thermoplastic product (the columns are usually arranged between the lower part and the upper part of the mold so as to allow the guided movement of the upper part for the pressure closing of the mold).
These open mold techniques further have the drawback that the forming pressure is the closing pressure of the mold and the temperature of the thermoplastic material is lower than the temperature used in the injection process, therefore a poor filling of the mold may occur (for example, if the material is very cold, even though it exerts pressure, the material does not completely fill the mold) and the obtained part may be less packed than when using injection techniques and, therefore, have worse mechanical characteristics. This means that to obtain parts with similar features as those obtained by injection, the parts must incorporate reinforcing members.
These reinforcing members can consist of, for example, meshes or screens which are placed inside the open mold, then introducing the plastic material in the mold on the screen or mesh.
There are a number of publications reflecting processes for obtaining products comprising reinforcing members such as meshes or screens, for example, DE-A-19922202, DE-A-3642063, US-A-2002/0035796, EP-A-1529618, JP-A-2006-289651, JP-A-3-009836, US-A-5135694, JP-A-2003-039580, JP-A-56-078953 and JP-A-2001-301074.

Process for obtaining a thermoplastic material product, and the corresponding product


There is provided a computer implemented method for detecting anomalous behavior in a network, comprising: receiving data representing at least one network activity, each network activity representing a certain data access event involving certain network entities; extracting from the data the certain network entities involved in the respective network activity; retrieving at least one relevant diversity value from a network behavior model based on the extracted certain network entities, wherein the network behavior model includes at least one diversity value, wherein each respective diversity value represents a certain relationship between at least one network entity and at least one network entity type; calculating an abnormality score for the received network activity based on the retrieved relevant diversity values; and classifying the network activity as anomalous or normal based on the calculated abnormality score.

The present invention, in some embodiments thereof, relates to systems and methods for detection of anomalous behavior and, more specifically, but not exclusively, to systems and methods for detection of anomalous behavior based on network activity.
Different systems and methods have been developed to detect network security threats. The security threats can originate from activity of a human party, such as a hacker or a malicious insider, and/or from activities of malicious code.
One approach to network security threat detection is termed network behavior anomaly detection (NBAD). NBAD involves learning normal behavior patterns within the network, and continuously monitoring the network for unusual events that do not fit within the learned normal behavior patterns. Examples of network parameters that are monitored to detect abnormal behavior include, traffic volume, bandwidth use, and protocol use. The abnormal behavior is suspicious for malicious activity.

Systems and methods for detection of anomalous network behavior


An optical transmitter transmits a data signal developing a specific spectrum at a predetermined frequency, while an optical receiver detects amplitude information on the spectrum included in the data signal to control the received data signal to a constant amplitude on the basis of the detected amplitude information. This can provide an optical communication system and an optical receiver capable of functioning well even if the optical S/N is in a poor condition.

(1) Field of the Invention
The present invention relates to an optical communication system and an optical receiver.
(2) Description of Related Art
In the recent years, the employment of a large-scale integrated circuit (LSI) has permitted an error correction code to be used as a transmission code. At present, an LSI capable of correcting and reducing an error rate of 2×10−4 up to an error rate of approximately 10−15 has been put to practical use. And not only that, an LSI provided with an error correction code for making correction from 1×10−2 to 10−15 has been in development.
Naturally, in the case of the employment of such a high correction capability code, an optical receiver would be required to operate normally in poor S/N conditions causing an error rate of 1×10−2.
So far, the optical receiver has conducted an operation to make up an input to an identification unit to a constant amplitude for normal identification. As this approach, there has been employed a structural example in which a peak value of an equalized waveform signal after amplification is detected to give feedback (see FIG. 6) or a structural example in which an optical output power is made constant by an optical amplifier (see FIG. 7).
In FIG. 6, reference numeral 1 represents a light-receiving device (PD: PhotoDiode), numeral 2 represents a gain variable type preamplifier [AGC (Automatic Gain Controlled) amplifier], numeral 3 represents a low-pass filter (LPF), numeral 4 designates a band-pass filter (BPF), numeral 5 designates a differential amplifier, numeral 6 designates a flip-flop circuit (FF), numeral 7 depicts a peak value detecting circuit, numeral 8 depicts a limiter amplifier, numeral 9 depicts a signal identifying section, numeral 10 denotes a buffer amplifier, and numeral 18 denotes a clock extracting circuit.
In the optical receiver shown in FIG. 6, a PD 1 comprising a PIN photodiode or an avalanche photodiode receives light from an optical transmission line, and the preamplifier 2 amplifies the output of the PD 1. The output of the preamplifier 2 is inputted to the low-pass filter 2 and further to band-pass filter 4. The low-pass filter 3 is a filter having 3-dB down band corresponding to 0.7 to 0.8 of the bit rate of a received signal. The output of the low-pass filter 3 is inputted to the differential amplifier 5 and further to the peak value detecting circuit 7.
The peak value detecting circuit 7 is for detecting a peak value of a signal (received data signal) inputted to the differential amplifier 5 of the signal identifying section 9 and adjusting the gain of the preamplifier 2 to make constant the signal level inputted to the signal identifying section 9. The differential amplifier 5 of the signal identifying section 9 is for shaping a signal waveform in its amplitude direction by applying a value minimizing the error rate as a reference voltage Vref.
The band-pass filter 4 of the clock extracting circuit 18 is a filter for clock extraction, which detects a frequency (clock component) corresponding to the bit rate of a data signal. In this connection, the clock extracting circuit 18 shown in FIG. 6 has an arrangement for when the signal to be sent from the optical transmission line is an RZ (Return to Zero) signal. In the case of an NRZ (Non-Return to Zero), since a clock component does not exist in the signal spectrum unlike the RZ signal, there is a need to place a differentiating circuit for detecting an edge of a signal and a rectifying circuit for rectifying the output of the differentiating circuit in the former stage of the band-pass filter 4 to generate a clock for signal identification.
The output of the band-pass filter 4 is inputted to the limiter amplifier 8, and the limiter amplifier 8 cuts off both a peak level and bottom level of the output of the band-pass filter 4 and amplifies the received signal so that its upper limit and its lower limit assume predetermined values, respectively, for clock production. The clock thus shaped in the limiter amplifier 8 is inputted to the flip-flop circuit 6 of the signal identifying section 9. The flip-flop circuit 6 punches the output of the differential amplifier 5 with the output of the limiter amplifier 8 for outputting data subjected to signal identification. The buffer amplifier 10 is for setting up the circuit isolation.
On the other hand, in a configuration shown in FIG. 7, an optical amplifier 11, such as an EDF (Erbium Doped Fiber) amplifier, is provided at the final stage of an optical transmission line. In the FIG. 7 configuration, the same parts as those in FIG. 6 are marked with the same reference numerals. This optical amplifier 11 is designed to implement constant output control so that the signal power to be inputted to the PD 1 is made constant at all times.
Accordingly, a preamplifier 2′ at the latter stage is required to perform simple amplification only, and this eliminates the need for the feedback control based on the received signal peak value detection in the FIG. 6 configuration.
Meanwhile, the received waveform in the above-mentioned optical receiver varies, for example, as shown in FIGS. 8A to 8C according to optical S/N. FIG. 8A shows a received waveform (eye pattern) in a case in which the SIN is at 8 dB (error rate=1×10−1), FIG. 8B shows a received waveform in a case in which the SIN is at 17.5 dB (error rate=1×10−4), and FIG. 8C shows a received waveform in a case in which the S/N is at 21.5 dB (error rate=1×10−9).
For example, in the poor optical S/N condition shown in FIG. 8A, in an optical receiver with the configuration shown in FIG. 6, the peak value detecting circuit 7 detects a peak value of a noise instead of a peak value of the intended received signal (data signal), and the amplitude of the received signal (data signal) inputted to the signal identifying section 9 becomes lower than the proper amplitude. For this reason, the signal identification indeterminate factors increase so that the actual error rate is impaired as compared with the error rate based on the optical S/N. Moreover, since the amplitude inputted to the clock extracting circuit 18 decreases, it tends to be out of the dynamic range of the clock extracting circuit 18.
In the poorer optical S/N condition, the ASE (Amplified Spontaneous Emission) light increases, which decreases the optical signal component with respect to the entire light. With this fact, in the case of the FIG. 7 configuration of the optical receiver which implements the constant output control on the entire light in the optical amplifier 11, similarly, the amplitude of the received signal to be inputted to the signal identifying section 9 becomes lower and the amplitude to be inputted to the clock extracting circuit 18 also becomes lower, which creates the same problem as that of the optical receiver with the configuration shown in FIG. 6.
In addition, although the error correction code is capable of correcting an error of a data signal, it is helpless against a case in which a clock signal falls into a malfunctioning condition. Although simple clock extracting circuits using a PLL circuit have frequently been put to use, if the optical S/N is in a poor condition, since a large noise is introduced into a phase comparator constituting the PLL circuit, the phase jump of the clock occurs to cause the out-of-synchronization, thereby producing huge burst errors.
For these reasons, the conventional optical receivers shown in FIGS. 6 and 7 do not function normally when a received signal is in a low S/N condition.

Optical communication system and optical receiver


Each of a base member and a rotational arm is circular. A ring member is fixed to a peripheral edge of the base member. A peripheral edge of the rotational arm is covered by the ring member and one end of a return spring is engaged with a hook portion formed in the ring member. The other end of the return spring is engaged with fixing members such as bolts, nuts and rivets and so on. A peripheral edge of the nuts as the fastening members is formed in a guide portion for the return spring.

The present invention relates to a vehicle seat and more specifically to a vehicle seat comprising a back and forth slide mechanism comprising a fixed rail and a movable rail for supporting a seat cushion and a reclining apparatus comprising a base member fixed to said seat cushion, a rotational arm swingably supported by said base member and fixed to a seat back, a lock mechanism encased between said base member and said rotational arm, an operating lever unlocking said lock mechanism, a lock spring urging said operating lever to a locking direction and a return spring inclining the seat back forward.
Hitherto, a construction adjusting back and forth movement of a seat cushion by a back and forth slide mechanism is well known. Two reclining apparatuses inclining a seat back forward and rearward are described in Japanese Unexamined (KOKAI) Patent Publication No. 9 (1997)-28496 and Japanese Unexamined (KOKAI) Patent Publication No. 9 (1997)-131237 suggested by the present applicant. Japanese Examined (KOKOKU) Patent Publication No. 63 (1988)-65327 discloses a hinge apparatus for a reclining backrest capable of locking according to an adjusting position. Japanese Unexamined (KOKAI) Patent Publication No. 7 (1995)-136032 discloses a construction in which a cam is moved along only a sliding direction (up and down direction) of a pole in order to avoid an inferior connection by a dimension error of the pole and the cam.
The Japanese Unexamined (KOKAI) Patent Publication No. 9 (1997)-28496 discloses two reclining apparatuses in which a bulging portion is provided with a first cam portion for unlocking the cam portion of an inner side and a second cam portion for locking respectively, at a time of lock-off and lock-on, the bulging portion is engaged with a groove for lock-off of teeth inner and an abutment for lock-on, engagement and disengagement with outer teeth of teeth inner and inner teeth of an arm fixed to a seat back side and lock-off and lock-on are performed prior to the outer side.
A return spring is mounted in order to incline a seat back forward, the return spring is mounted on a free hinge side of one side lock because installation positions are few when each of a base member and a rotational arm is circular.
As shown in FIGS. 5 and 6, a reclining apparatus 10 comprising a base member 11 fixed to a movable rail side, a rotational arm 12 swingably supported by the base member 11 and fixed to a seat back side, a lock mechanism (not shown in the drawing) encased between said base member 11 and said rotational arm 12, an operating lever 15 unlocking said lock mechanism, a lock spring 35 urging the operating lever 15 to a locking direction and a return spring 45 inclining the seat back forward is well known.
One end 45a of said return spring 45 is engaged with a hook portion 34 formed in the rotational arm 12, the other end 45b of the return spring 45 is engaged with a hook bracket 47 formed in said base member 11, the hook bracket 47 is curvedly extended and is formed in a guide portion 51 for said return spring 45. The guide portion 51 produces a resilient force efficiently so that a smooth operation is gained.
In this conventional example, however, when each of the base member and the rotational arm is circular, installation positions of the return spring are few and it is difficult for two reclining apparatuses to fix the return spring. Especially when each of the base member and the rotational arm is circular, when the rotational arm is fixed to a lower portion of the side frame of the seat back frame by stud bolts, the return spring is forced to be positioned outside in order to avoid engagement with the stud bolts and thereby the reclining apparatuses become thick and it is necessary to mount parts when the angle limiting portion of the front and rear inclination of the seat back is formed, it is necessary to mount the guide portion to a hook bracket in order to gain a smooth operation of the return spring and thereby the number of parts increases and the manufacturing cost becomes high.


A vehicle seat, particularly a motor vehicle seat, with a pair of runners (7) for longitudinal adjustment, a seat-back (3) which can be tilted forward after releasing a locking device, and a runner latching device (10), which is unlatched at release of the locking device to longitudinally displace the seat. A mechanical detection system (12) detects the distance of the momentary seat position from the initial position based on longitudinal displacement, and is active only at release of the locking device. A tracking and blocking device (13) cooperating with the detection system (12) is provided. The latter allows opening and closing of the runner latching device (10) and/or the locking device only at the zero position of the detection system (12).

Known motor vehicle seats of this type which allow sliding the seat to the front as well as tilting the seat-back forward for easy access to the back seats, are equipped with a locking device for return to the original position from which the seat has been slid forward. This locking device has a locking element which is normally coupled to the upper runner of a pair of seat runners, released from the upper runner when the seat back is unlatched for a forward tilt, and fastened to the associated lower runner. In addition, the runner latch is unlatched and held in the unlatched state until the seat reaches the locking element during a return to its initial position after it has been shifted forward. This system is not just costly but also has a relatively large space requirement, which is why it can only be located, as a rule, in the unprotected area beneath the seat. As a result, then, if the seat cannot be returned to its initial position any more because of, for example, loaded items placed behind the seat which was slid to the front, the seat latching device can no longer be latched. The loaded items must then be removed again in order to return the seat to its initial position before a new, initial position, further forward, can be chosen.


The invention relates to a sealing cap (11), for openings and containers. The valve arrangement (15) comprises an axiallly displaceable valve body (17), which is held in the direction of the container interior by means of a spring (22) against a first sealing seat (34), on the cap interior. The valve arrangement (15) comprises one single valve body (17), provided with a first axially effective sealing surface arrangement (20) and a second radially effective sealing surface arrangement (21). The axially effective sealing surface arrangement (20) co-ordinates with an axial seal seat (34), surrounding a defined opening (32), connecting to the container interior on the cap inner part (14). The radially effective sealing surface arrangement (21) co-ordinates with a first radial counter sealing surface (61, 62), comprising a bypass (39), for the first flow connection and a second radial counter sealing surface (61), comprising a safety relief opening (69), for the second flow connection.

In one such sealing cap, known from German Patent Disclosure DE 197 53 592 A1, the valve arrangement has two valve bodies, of which, in the position of repose, the first valve body rests directly on a sealing seat of an inner cap part under spring loading, and the second valve body is pressed against a further compression spring by the spring-loaded first valve body. The two-stage opening and closing of the flow connections is achieved by providing that the first valve body is lifted by means of the second valve body from its sealing seat on the inner cap part if the first limit value is exceeded; that when the second limit value is reached, the second valve body presses against a further sealing seat of the inner cap part and thus closes the first flow connection again; and that for the safety stage, an intermediate valve body disposed between the first and second valve bodies lifts with its sealing seat from a sealing face of the second valve body.
In terms of its valve arrangement, a sealing cap of this kind is complicated structurally, in terms of production, and in terms of assembly because of the many components.
From German Patent DE 41 07 525 C1, a sealing cap is also known that provides for a two-stage pressure equalization of the close container that may become necessary. In this sealing cap, the valve arrangement also has two valve bodies, which are internested in one another; the second valve body is pressed against a sealing seat on the inner cap part by the spring loading of the first valve body. In this arrangement, when the first limit value of the internal container pressure is exceeded, the second valve body lifts, carrying the first valve body with it, from its sealing seat on the inner cap part, and when the second limit value is reached presses against an opposed sealing face of the inner cap part again. In the safety stage, the first valve body is lifted from the second valve body.
In the valve arrangement of this known sealing cap, the same disadvantages arise as in the sealing cap described earlier above, and furthermore there is the problem that the sealing seats and sealing faces of the two valve bodies and of the inner cap part, along with the axial travel of the second valve body, must be adapted to one another within narrow tolerances.
From German Patent Disclosure DE 197 32 885 A1, a sealing cap with safety locking for openings of containers is also known. This safety locking makes it possible, when overpressure prevails in the container, to prevent the sealing cap from coming unscrewed, specifically by providing that the sealing cap is blocked nonrotatably relative to the fill nozzle on the container. This known safety locking uses an axially movable insert, which surrounds the inner cap part or its valve arrangement and is as a result exposed directly to the overpressure prevailing in the container, because its inner bottom is located in the opening of the fill nozzle. This axially movable insert is axially movable but is retained nonrotatably in a tubular supplementary inner part which is seated nonrotatably in the fill nozzle of the container and relative to which the sealing cap is rotatable. When overpressure occurs in the container, the insert is moved axially in the direction of the sealing cap and engages it nonrotatably. The result is a blockage of rotation of the sealing cap via the insert and the supplementary inner part with the fill opening of the container.
The provisions in this reference for torsion prevention or safety locking are complicated both structurally and because of the number of components to be used. Moreover, the axially movable insert and the tubular supplementary inner part not only increase the diameter of the inner cap part of the sealing cap but also reduce the effective area of the valve arrangement of the sealing cap, with adverse effects on the response behavior of the valve arrangement.


A semiconductor device which comprises a semiconductive substrate having thereon a plurality of source/drain regions arranged parallel to each other and a plurality of gate electrodes which extend perpendicularly to and above the source/drain regions through a gate oxide film, wherein at least one of a specific pair of source and drain regions corresponding to any desired at least one of the gate electrodes is provided with an offsetting stepped portion extending in the direction of depth of the substrate, and the offsetting stepped portion is filled up with an insulating film for filling up the stepped portion, so that the specific source/drain region provided with the offsetting stepped portion is disposed with respect to the corresponding gate electrode through a step of the offsetting stepped portion.

1. Field of the Invention
The invention relates to a semiconductor device and a preparing method therefor and more particularly to a NOR-type mask ROM (Read Only Memory) provided with a memory cell function memorizing 2 bit information and a preparing method for the NOR-type mask ROM.
2. Description of the Related Art
A conventional NOR-type mask ROM (provided by previously forming source/drain regions followed by formation of gate electrodes) is exemplified in FIGS. 6 (a), 6 (b) and 6 (c). The sectional views of FIGS. 6(b) and 6(c) are taken from the lines A--A' and B--B', respectively of the plan view of FIG. 6(a).
Inside the top surface of a semiconductive substrate 51 of a first conductivity type are disposed a plurality of parallel, strip-like shaped source/drain regions 52 of a second conductivity type. A plurality of strip-like shaped gate electrodes 54 are formed above the source/drain regions 52 to extend perpendicularly thereto and be spaced with each other at a fixed interval, having a gate oxide film 53 between the gate electrodes 54 and the source/drain regions 52. Information is written in such manner that any impurity ion is selectively implanted in a channel region of memory cell transistors to form thereat a high doped region 55 of an impurity of the first conductivity type, so that threshold voltage is changed. The memory cell merely allows each transistor to memorize information only of 1 bit.
A memory cell for a mask ROM memorizing 2 bit information may be achieved, as shown in FIG. 5, by that a source/drain region and a gate electrode in MOS transistors have offset with each other, thereby allowing the transistors to have orientation in conductivity properties.
As shown in FIG. 5(a), on the surface of a semiconductive substrate 61 of a first conductivity type are formed impurity regions 62a (62c) and 62b (62d) of a second conductivity type constituting source/drain regions. A gate electrode 64 is disposed on the substrate between the specific two source/drain regions through a gate oxide film 63. The gate electrode 64 is adapted to overlap with one source/drain region 62a and be spaced at a predetermined interval "1" away from the other source/drain region 62b.
When using, as shown in FIG. 5(b), the region 62a as source and that 62b as the drain in the transistor constructed above, the offset region F provided between the gate electrode 64 and the drain region 62b is applied with high electric field to have a depletion layer 66, thereby causing a channel region 67 and the drain 62b to electrically communicate with each other.
In case that the region 62c is used as drain and that 62d as source as shown in FIG. 5(c), the depletion layer 66 is not formed at the offset region F, so that the source region 62d does not communicate electrically with the channel region 67.
This technique may be adopted to allow MOS transistors to have orientation in conductivity properties and be capable of exhibiting the following four states.
i) Every source and drain regions in transistors overlap with gate electrodes, thereby enabling electrical communication in both of normal and reverse directions.
ii) Only source regions overlap with gate electrodes, so that there causes electrical communication in a normal direction but not so in a reverse direction.
iii) Only drain regions overlap with gate electrodes, so that there is no electrical communication in the normal direction but is in the reverse direction.
iv) Each of source and drain regions are kept away from gate electrodes, so that there causes no electrical communication in either direction.
Accordingly, information is read out of each memory cell transistor two times in the normal and reverse directions, thereby enabling reading of 2 bit information.
The conventional NOR-type mask ROM as shown in FIG. 6(b) is so constructed that gate electrodes 54 completely overlap with the source/drain regions 52, so that the mask ROM can not be applied with a function for a memory cell transistor memorizing 2 bit information as shown in FIG. 5, thereby being hindered from developing into a larger scale device.

Semiconductor device and preparing method therefor


The invention provides mouthwash formulations having improved taste, coupled with good whitening efficacy, which comprise a whitening agent such as hydrogen peroxide together with a combination of a first acid such as citric acid and a second acid such as phosphoric acid. In further embodiments, the mouthwashes may comprise a sucralose and saccharin combination, an acidic polymer, one or more anticalculus agents, e.g., alkali pyrophosphate salts, copolymers of maleic anhydride and methyl vinyl ether and other ingredients.

Whitening agents such as hydrogen peroxide (H2O2) provides whitening benefit in mouthwash, but peroxide-based mouth rinses are often associated with a bitter off-taste. Saccharin, commonly used as a sweetener in mouthwashes, may have a strong bitter after taste that is particularly noticeable in formulations comprising H2O2. Moreover, H2O2 is especially prone to degradation at high pH, and to minimize the peroxide degradation, a mouthwash formula with H2O2 is generally formulated below pH 5.5, the pH often being adjusted by the addition of an acid, which may give an unpleasantly sour taste.
There is a need for a mouthwash that provides whitening benefits, but also is palatable and has a pleasant taste.