An internal voltage generation circuit includes an internal reference voltage generation unit configured to generate first and second reference voltages, a core voltage generation unit configured to receive the first reference voltage and to generate a core voltage based on the first reference voltage, and a bit line pre-charge voltage generation unit configured to receive the second reference voltage and to generate a bit-line pre-charge voltage based on the second reference voltage.

Exemplary embodiments of the present invention relate to an internal voltage generation circuit and an integrated circuit including the same.
In general, semiconductor devices use an external power source voltage VDD_EX, which is supplied from the outside. Since the external power source voltage VDD_EX may have a change in level due to noise, the semiconductor devices are equipped with an internal voltage generation circuit for generating a stable internal voltage. Here, the internal voltage may include many different types of voltages, e.g., a core voltage VCORE which is used in a core region including a memory cell, a cell plate voltage VCP which is used as a plate voltage of a memory cell capacitor, and a bit line pre-charge voltage VBLP which is used for pre-charging a bit line. Here, the cell plate voltage VCP and the bit line pre-charge voltage VBLP are generated from the core voltage VCORE, and those are generated to have the level corresponding to a half of the core voltage VCORE in order to minimize power consumption. The cell plate voltage VCP and the bit line pre-charge voltage VBLP are generated through the same internal voltage generation unit. Hereafter, an example of the bit line pre-charge voltage VBLP is described.
FIG. 1 is a block diagram illustrating a conventional integrated circuit.
Referring to FIG. 1, the integrated circuit 100 includes a source reference voltage generation unit 110, a core reference voltage generation unit 120, a core voltage generation unit 130, a first internal circuit 140, an over-driving unit 150, a bit line pre-charge voltage generation unit 160, and a second internal circuit 170.
The source reference voltage generation unit 110 generates a source reference voltage VREF. The core reference voltage generation unit 120 generates a core reference voltage VREFC based on the source reference voltage VREF. The core voltage generation unit 130 generates a core voltage VCORE based on the core reference voltage VREFC.
The first internal circuit 140 performs a predetermined operation by receiving the core voltage VCORE. The over-driving unit 150 over-drives a core voltage VCORE terminal in response to an over-drive control signal ODP. The bit line pre-charge voltage generation unit 160 generates a bit line pre-charge voltage VBLP based on the core voltage VCORE. The second internal circuit 170 receives the bit line pre-charge voltage VBLP and performs a predetermined operation.
More specifically, the source reference voltage generation unit 110 generates the source reference voltage VREF based on an external power source voltage VDD_EX (not shown) and an external ground voltage VSS_EX (not shown), and the generated source reference voltage VREF is maintained at a stable level although the conditions of process, voltage and temperature (PVT) may be changed a bit. For example, the source reference voltage generation unit 110 may include a bandgap circuit or a Widlar circuit.
The over-driving unit 150 may operate to secure a fast sensing operation of a bit line sense amplifier (BLSA).
Hereafter, the operation of the integrated circuit 100 having the above structure is described.
The source reference voltage generation unit 110 receives the external power source voltage VDD_EX (not shown) and the external ground voltage VSS_EX (not shown), and generate the source reference voltage VREF. In particular, the source reference voltage generation unit 110 generates a stable source reference voltage VREF although the conditions of process, voltage and temperature (PVT) may be changed a bit.
The core reference voltage generation unit 120 generates the core reference voltage VREFC for generating the core voltage VCORE based on the source reference voltage VREF generated in the source reference voltage generation unit 110, and applies the generated core reference voltage VREFC to the core voltage generation unit 130. Here, the core reference voltage generation unit 120 may generate the core reference voltage VREFC through a down-conversion method.
The core voltage generation unit 130 generates the core voltage VCORE of a predetermined voltage level based on the core reference voltage VREFC and supplies the generated core voltage VCORE to the first internal circuit 140.
Here, the bit line pre-charge voltage generation unit 160 generates the bit line pre-charge voltage VBLP based on the core voltage VCORE and supplies the generated bit line pre-charge voltage VBLP to the second internal circuit 170. The bit line pre-charge voltage generation unit 160 may also generate the bit line pre-charge voltage VBLP through the down-conversion method, just as the core voltage generation unit 130.
Meanwhile, the over-driving unit 150 over-drives the core voltage VCORE terminal in response to the over-drive control signal ODP.
The conventional integrated circuit 100 of the above structure, however, may malfunction as follows.
FIG. 2 is a timing diagram describing the operation of the integrated circuit 100.
Referring to FIG. 2, the core voltage VCORE maintains a predetermined target level by the core voltage generation unit 130, and the bit line pre-charge voltage VBLP maintains a predetermined target level by the bit line pre-charge voltage generation unit 160. In this state, when the over-drive control signal ODP is enabled upon receipt of an active command ACT, the voltage level of the core voltage VCORE terminal is increased while the over-driving unit 150 performs an over-driving operation. The increased core voltage VCORE, however, is used as a reference voltage of the bit line pre-charge voltage generation unit 160. Therefore, the bit line pre-charge voltage VBLP generated in the bit line pre-charge voltage generation unit 160 is also increased during the time that the core voltage VCORE is increased. In this case, the second internal circuit 170 to which the increased bit line pre-charge voltage VBLP is supplied may malfunction.

Internal voltage generation circuit and integrated circuit including the same


The present disclosure includes: a creep control unit configured to perform a creep control including bringing one of a first clutch and a second clutch into a half-clutch state and bringing the other into a disengaged state, so as to transmit a predetermined torque from a drive source to a transmission mechanism via a clutch device; and a clutch switching control unit configured to, when a vehicle stops during the performing of the creep control, perform a clutch switching control including, on the basis of the heat-generating state of the one clutch that is maintained in the half-clutch state from the stop of the vehicle, switching the one clutch from the half-clutch state to the disengaged state and switching the other clutch from the disengaged state to the half-clutch state.

A dual clutch transmission in which a dual clutch device including two clutches is provided between an engine and a transmission mechanism, and a power transmission path from the engine to a vehicle drive system via the transmission mechanism is set into two lines, has been put into practical use.
In such a dual clutch transmission, during vehicle creeping, a creep control including bringing one of the clutches bringing into a half-engaged state (half-clutch state) so as to slightly transmit a torque to the vehicle drive system is performed (for example, see Patent Document 1).

Control device and control method for dual clutch transmission


A bearing part for a gas bearing comprising two bearing parts, said bearing part formed of a granite-like or metal substance with pores or gas leakage channels and means for injecting a gas between the bearing parts (2, 3) for forming a gap (7) therebetween. The pores (10) in the surfaces of the granite material of these bearing parts are sealed by a non-brittle, transparent, mechanically, machinable pore sealing material (9, 12) for forming gas bearing parts having a non-porous surface. Examples of pore sealing materials (9, 12) for sealing the pores of the bearing parts and bearing part material are polyurethanes, acrylic polymers, epoxy resins, silicone resins, polyvinylidenefluoride resins, aramide resins etc. Preferably the pore sealing material consists of a polymer being curable at low temperatures, particularly below 30.degree. C.

This invention relates to a bearing part for a gas or air bearing comprising at least two bearing parts movable with respect to each other, gas injection means being present between the two bearing parts working faces facing each other for injecting a gas in order to be able to maintain a gas gap between the bearing parts.
These air bearings comprising two bearing parts rotatable with respect to each other and made of ceramic material, 10 glass and/or metal are generally known. Such air bearings offer the great advantage that they operate without friction even in the case of large and heavy structures, without any lubricant being used.
To obtain a very thin air gap between the bearing parts, the latter may be provided with air conduction grooves through which ambient air is fed between the two working faces of the rotatable bearing parts to form a very thin air gap. The use of a very small air gap is necessary in order to obtain the desired stability of the air bearing.
A drawback of said known air bearings is that they are expensive because of the use of expensive bearing parts of the materials mentioned.
It has emerged, however, that although replacement of the ceramic material by, for example, natural stone, in particular granite, leads to considerable savings through the use of a much cheaper starting material for the bearing parts, such a large number of pores occurs in the surfaces of the working faces of the bearing parts which are formed in manufacturing the bearing parts from large blocks of natural stone that although the surface is flat, it is not impermeable to gases, as a result of which the gases leak away and an air gap of the desired constant thickness cannot be maintained. This results in the production of undesirable vibrations in the bearing.
The above drawback of the gases leaking away and the production of vibrations is made yet more severe by the fact that the porosity in the surfaces of the working faces of the bearing parts is not often the same everywhere, but varies from point to point.


The present disclosure relates to a receiving basket for a lifting device of a food processing machine, in particular a filling machine with a lifting device, whereby the receiving basket receives the meat trolley, as well as a respective method. The receiving basket or the meat trolley has a sealing element that enables a sealing point between the receiving basket and the meat trolley.

In the food industry, lifting devices are used for feeding food processing machines, for example filling machines, in particular vacuum filling machines or cutters. These lifting devices are usually formed as arm-operated lifting devices or as mast lifting devices and can be installed on a machine, for example a filling machine or a cutter, or also be formed as an independent unit ("stand-alone unit"). These lifting devices are designed to receive partially standardized containers, i.e. so-called meat trolleys. The meat trolleys are equipped with rollers. In this, the meat trolley is typically inserted in the receiving unit of the lifting device in a way that it is locked securely against falling out, i.e. that it is held in a firm position and that it is brought upwards with the lifting unit through a filling funnel of a filling machine. There, the meat trolley will then be tilted and emptied into the filling funnel. Subsequently, the meat trolley is brought back into the starting position by means of the lifting device and taken back out by the operator through release of the lock on the lifting device. During feeding of cutters, the cutter bowl is fed accordingly.
During transport of the full meat trolley to the machine over a mostly wet floor, the wheels and an undertray of the trolley, may be covered with contaminated spray water from the floor. During the feeding process, the meat trolley is located upside down above the aperture of the filling funnel. Thereby, the spray water or condensate at the outer walls of the container on the undertray of the meat trolley and in the wheel area can flow down over the external walls of the meat trolley and enter the filling funnel and contaminate the content.
A lifting device with a cover device in form of a hinged hood to prevent impurities of the meat trolley from entering the funnel is already known from the DE 195 00 326 A1. The cover device has several folding plates that start on the upper meat trolley edge. Here, in particular the hygiene of the folding mechanism as well as the high workload and the high manufacturing costs are disadvantageous. Besides, there are additional risks due to the danger of body parts, e.g. fingers, getting caught/squeezed. In addition, each cover device is only suitable for a specific meat trolley type.
Starting from this, the present disclosure is based on the purpose of providing a receiving basket and/or a lifting device as well as a respective method that prevents contamination of the food product during the feeding process by the spray water from the floor in a simple, reliable and cost-efficient way.
According to the present disclosure, the receiving basket for a lifting device has a sealing element that can lay itself onto at least one external wall of the meat trolley. When the meat trolley is tilted in an upper position, the sealing element prevents spray water from the floor area or the edges of the meat trolley or condensate from flowing into the funnel in such a way that the food product can be filled into a filling funnel. The sealing element is installed on the receiving basket in a way that, when the meat trolley is received by the receiving basket and sealed mechanically, the sealing element can lay itself in a sealing way onto at least one external wall of the sealing trolley. Thereby, the sealing element presses onto the external wall of the meat trolley in a way that reliable sealing is ensured. According to the present disclosure, no extra step is required for sealing, but sealing occurs automatically during insertion and attachment and/or locking of the meat trolley. Hence, sufficient sealing against spray water flowing down is always ensured. A respective sealing element on the receiving basket can be provided simply and cost-efficiently. The sealing element can thereby be fastened in a simple manner on the side surface that faces the meat trolley and/or on the upper and/or the lower surface of the receiving basket.
It is particularly preferable when the sealing element is formed as a sealing strip. A respective longish sealing strip, i.e. a drip protection strip, can be manufactured and fastened on the receiving basket in a simple way. The sealing strip is thereby designed so as to extend over the total length of the meat trolley at least on a tilting side.
Preferably, the sealing strip is formed at least in part of a flexible material. The flexible material comes with the advantage that the meat trolley can put pressure on the sealing element whereby the sealing function is improved. The form and manufacturing tolerances as well as deformations of the meat trolley can be compensated thereby. Preferably, the flexible material of the sealing element can be one of the group of elastomers.
Particularly preferably, the sealing element has a flexible sealing lip that can press on the meat trolley in order to achieve a particularly good sealing effect.
The receiving basket is preferably formed as a U-shaped support structure, whereby the sealing element extends at least along one of the three sides of the support structure. Preferably at least along the tilting side. The tilting side is the side of the receiving basket that faces the machine and that is oriented in a downward direction during a tilting movement; here the side that is opposite to the open side of the U-shaped support structure. Embodiments also for instance exist in which the opening of the U points towards the operator side, in this case the tilting side adjoining the open side. If a sealing element, in particular a sealing strip, is provided at least along the tilting side, waste water can be prevented effectively from flowing from the floor and/or the rollers of the meat trolley into the funnel.
Advantageously, the sealing element extends along multiple sides of the support structure. The sealing element can thereby comprise either multiple individual sealing strips or also be formed as a continuous L- or U-shaped sealing strip.
Advantageously, the sealing strip is formed in a way that a gutter can be formed between the receiving basket and the meat trolley. Therefore, spray water can be collected in the gutter when the meat trolley is tilted for emptying. The spray water can for example be guided from the gutter behind the machine to the floor already during the tilting process. Due to the sealing element being located on the receiving basket, the gutter seal and/or gutter is implemented in the lower area, i.e. lower third of the meat trolley. If then, for example, a respective gutter is implemented on the tilting side by means of the sealing strip, this area will always be outside of the funnel so that drained spray water cannot flow into the funnel.
It can thereby be advantageous if the gutter is situated preferably at an angle to the longitudinal axis of the respective side of the receiving basket, i.e. at least sectionally. This means that, viewed for example in an initial position of the meat trolley, the sealing strip is situated at an angle α in relation to the horizontal line. In the inclined version of the sealing strip, the spray water can be drained out of the critical area even better.
It is also possible for the sealing strip to have lateral sealing elements that seal the gutter laterally. Thereby, the sealing strip can be sealed respectively on one side of the receiving basket, or rather the respective end pieces in case of L- or U-shaped sealing strips. Then, the collected spray water will only flow out of the gutter onto the floor if the emptied meat trolley is lowered, i.e. when the meat trolley is tilted back.
The sealing element is preferably installed in a replaceable way. This comes with the advantage that the sealing elements can be removed easily for cleaning purposes. However, it is also possible that different strips are to be provided for different applications and that they can be replaced accordingly. Therefore, there can for example be a simple adaptation to different meat trolley geometries.
According to the present disclosure, a lifting device for receiving, lifting and emptying of a meat trolley in a food processing machine comprises a drive, a lifting element, e.g. a lifting arm or lifting mast. The lifting device further has a receiving basket connected to the lifting element for receiving a meat trolley.
A filling machine according to the present disclosure for filling of a pasty substance has a funnel for filling the pasty mass, a conveyer system to convey the pasty mass and a filling organ, in particular a filling pipe. A relevant filling machine has the lifting device according to the present disclosure that was mentioned before.
To implement a sufficient seal between meat trolleys and the receiving basket, it is alternatively also possible that the sealing element, e.g. the sealing strip, is not fastened on the receiving basket but instead on the external wall of the meat trolley so that the sealing element can lay itself onto at least one side of a receiving basket of a lifting device of the food processing machine. Thereby, the sealing element is, just as in the preceding embodiments, disposed in the lower third of the meat trolley. Consequently, a sufficient sealing effect can be achieved as well in a simple way and automatically if the meat trolley is inserted and fastened and/or locked in the receiving basket.
The following steps are to be provided in the method according to the present disclosure for feeding a food processing machine, in particular a filling machine:
inserting and fastening of a meat trolley filled with pasty substance in a receiving basket of the lifting device, whereby a long sealing point is formed at least between an external wall of the meat trolley and a respective opposite side of the receiving basket. Thereby, a sealing element, in particular a sealing strip, can be provided, as described before, either on the receiving basket or rather on the meat trolley.
The meat trolley is subsequently lifted and emptied. Then, the meat trolley is lowered and removed, i.e. unlocked and moved away.
As a gutter is formed between the receiving basket and the meat trolley, the spray water can flow from the floor of the meat trolley into the gutter while the meat trolley is swiveled for the emptying process. Therefore, it is ensured that this spray water cannot flow into the funnel. The sealing element is installed on the receiving basket or the meat trolley in a way that a correct sealing function is ensured. In one example, a gutter extends at least along the total width of the meat trolley side on the tilting side.
As described before, the sealing element can be fastened either on the receiving basket or on the meat trolley for the implementation of the seal and/or the gutter. The special features described for the sealing element in connection with the receiving basket shall apply in the same way for the formation of the sealing element if it is fastened on the meat trolley. Both embodiments allow for the existence of a sealing point between the receiving basket and the meat trolley in the lower area of the meat trolley in order to prevent spray water from flowing into the funnel when the meat trolley is tilted. The embodiment in which the sealing element is fastened on the receiving basket may be advantageous, as only one measure will be necessary on the receiving basket and as not every single meat trolley will have to be equipped accordingly.
The gutter extends at least on the tilting side along the total width of the meat trolley. On the other sides, a respective gutter can also be formed in a slightly shorter way.
The receiving basket and/or the lifting device also has a latching device that locks and fastens the meat trolley in a way that the lateral surface of the container has a predefined distance from the surface of the receiving basket that faces the container, i.e. that it is located in a predefined position. Then, i.e. when the meat trolley is not installed, the sealing element has a width that is larger than this distance. This means that a pressure is applied on the sealing element in the installed state in a way that a sufficient sealing effect is ensured.
According to the present disclosure the sealing element can also be formed as an inflatable element. This is particularly advantageous as meat trolleys with different geometries can be used by different factories or meat trolleys, and this can have severe traces of use, i.e. they can be severely deformed. An inflatable sealing element can ideally adapt to the outer contour of the meat trolley and thereby ensure a reliable sealing. It is also possible that the sealing element is not fully inflated before inserting the meat trolley, and once the meat trolley is fully inserted, which can be detected for instance by a switch or a lock or sensor, it can be fully inflated.

Receiving basket for a lifting device as well as method for feeding a food processing machine

ALBERT HANDTMANN MASCHINENFABRIK GMBH & CO. KG


A Radio Frequency for Consumer Electronics (RF4CE)-based terminal and a system therefor are disclosed. The system includes a plurality of terminals each having an RF4CE communication module, and at least one gateway for storing unique Identifier (ID) information and other ID information about a plurality of terminals within a predetermined area in a table and periodically transmitting the table externally.

1. Field of the Invention
The present invention relates to a Radio Frequency for Consumer Electronics (RF4CE)-based terminal and a communication system therefor, and more particularly, to local communication between terminals each having an RF4CE communication module, and communication between terminals each having an RF4CE communication module over an external communication network.
2. Description of the Related Art
The RF4CE Consortium, founded by major global home appliance manufacturers, agreed to work with the ZigBee alliance to jointly deliver a standardized specification for RF4CE in March, 2009. A core technology of future-generation home networking, RF4CE is designed to be deployed in a wide range of remotely-controlled audio/visual consumer electronics products, such as TVs, air conditioners, set-top boxes, and audio equipment. It is a protocol that allows for device-to-device communication and control in compliance with the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard.
Compared to conventional wireless communication technologies, RF4CE does not require any particular receiver and thus supports bi-directional wireless communication between a controller and a target device. Remote controls conforming to the RF4CE standard will replace IR remote controls and can operate devices freely from long distances regardless of obstacles, thereby overcoming the line-of-sight problem of IR remote controls. For example, the signal transmitter of a conventional IR remote control for a TV should be pointed towards the receiver of a TV in order to control the TV. In contrast, an RF4CE remote control conforming to IEEE 802.15.4 can control the operation of a TV in a living room from a bedroom because it offers non-line-of-sight operation.
One of big features of RF4CE is that one-to-one communication is possible without any base station or receiver. For example, RF4CE allows for bi-directional communication between home appliances like a TV and a refrigerator without the need for installing a base station between them.
Accordingly, research and development is underway in anticipation that a future remote control will have a plurality of device profiles registered inside such that a user may remotely control a plurality of devices using a single remote control and further, the remote control of the future will even act as a communication convergence device such as a mobile phone.
In communication systems that provide portable phone services, data communication such as Short Message Service (SMS) messages is always conducted through the servers of service providers and charged per message. For example, when an SMS message is transmitted to a mobile terminal using a portable phone service or a communication terminal using an Internet telephony system, a fixed fee should be paid per SMS message.

RF4CE-based terminal and communication system thereof

Sungkyunkwan University Foundation for Corporate Collaboration


A small boat comprising a helmseat positioned at the center of the forward half of the boat, and a control stick for steering the boat positioned at the front of this helmseat. Since the helmseat is positioned at the center of the forward half of the boat, the driver is located approximately equidistant from the left and right gunwales, which makes it easier to steer the boat. In addition, a control stick is positioned to the front of the helmseat, and, because this control stick can be used to steer the boat and also to change the direction of the boat, the amount of space required to steer the boat is less than that required in a design wherein steering is performed by turning a circular steering wheel, such as with the prior art already described. This is effective particularly for a small boat moving at a high speed.

This invention relates to a small engine driven boat.
In a typical prior art small boat, for example, as described in Japanese Patent Provisional Publication No. 55-2510, the steer seat or helmseat is located toward one of the sides or gunwales, a circular frame-like steering wheel is provided for steering the boat and a control box for operating the internal combustion engine are located to the front of this helmseat, and a passenger seat is located toward the other side or gunwale from the helmseat.
With this type of prior art, because the helmseat is located toward one of the gunwales, it is difficult to know the exact position of the other side of the boat while steering, and also operation of both the steering wheel and the control box is required.
In addition, not only is space required for the control box, but also, because the boat is steered by turning the circular steering wheel, a relatively large amount of space is required in which to operate the steering wheel. Moreover, in order to, for example, turn the rudder all the way in one direction, the steering wheel must be turned over a large angle, such as about two complete revolutions in one direction, and thus it is not easy to quickly turn the boat.
The general object of this invention is to provide a small boat in which the steering operation is made easy by the combination of the functions of both the steering wheel and the control box in a single control stick, and in which the amount of space required to perform the steering operation is reduced.


A novel and aesthetically pleasing head rail attachment which may be used in combination with vertical blind head rail assemblies to help reduce the amount of sunlight entering through the open sides of vertical blinds when they are mounted away from a wall and on the outside of a window frame. The head rail attachment affixes easily to the existing vertical blind head rail and gives a completed or framed look to the existing window.

Blinds have been known and used for many years. Venetian blinds were popular for a number of years; then vertical blinds emerged. Horizontal blinds; more specifically, horizontal mini-blinds have been very popular for the last several years and are available in an array of colors and sizes. However, many residential and commercial decorators and their clients still prefer vertical blinds for a variety of reasons. The majority of horizontal blinds are mounted on the inside of a given window frame whereas vertical blinds are mainly mounted on the outside of a given window frame. Because of window configurations, alarm systems and the like, it is not always possible to mount blinds on the inside of the window. The primary complaint, however, regarding vertical blinds, or blinds mounted on the outside of window frames, is streaks of sunlight through the space created between the wall and the blinds. These streaks of sunlight are not only annoying, but may cause furniture and carpet to fade prematurely and unevenly.
While many improvements have been made on the head rail assembly for venetian and other blinds, nothing was found that specifically attended to the problem of sunlight streaking.


A software implementation of a Reed-Solomon decoder placing a constant load on the processor of a computer. A Berlekamp-Massey Algorithm is used to calculate the coefficients of the error locator polynomial, a Chien Search is used to determine the roots of the error locator polynomial, and a Forney Algorithm is used to determine the magnitude of the errors in the received digital code word. Each step is divided into m small tasks where m is the number of computational blocks it takes to read in a code word and the processor can pipeline or parallel process one task from each step each time a block is read.

Error-corrective coding is often needed to preserve the integrity of received data. The basic concept is to add redundancy to a message to eliminate the need for retransmission. Shannon's work showed that dramatic gains in performance could be achieved by intelligently adding redundancy to a transmitted message. This addition of redundancy to the message is called Forward Error-Correction (FEC).
There are many methods of adding redundancy, but one of the most efficient and popular methods is RS coding. FIG. 1 is a block diagram of a typical RS system.
The RS encoder takes a block of digital data and adds "redundant" bits (i.e., bits containing some of the same information already present). During transmission or storage of data, data errors may occur for a number of reasons, such as noise, interference, or scratches on a storage medium such as a CD. The RS decoder recovers the original data by processing each received block of data to correct any errors in the received block. The number and type of errors that the decoder can correct depends on the characteristics of the RS code.
Over the last 20 years, RS encoded data has become commonplace in all sorts of communications and computer channels, particularly those that have a potential for bursts of errors, which is where multiple errors tend to be close to each other. RS codes are typically used where the multiple bits in error (an error burst) fall within the frame of a single character and it can be assumed that most of the time only one character is erroneous within a data block.
RS codes are also concatenated with convolutional codes, which are typically used in cases where the transmitted data is a bit stream having an undefined length.
Many practical applications take advantage of the multiple-error-correcting capability of an RS code, including magnetic and optical storage systems, as well as all sorts of communications systems.
Overview of RS Codes
Although the mathematics underlying RS coding is complex, some basic terminology for describing RS codes is provided here. An RS code is described as an (n, k) code, where the code words each consist of n symbols, k of which are message symbols. The following parameters characterize RS codes:                b=the number of bits per symbol        n=the total number of symbols per code word        k=the number of symbols in the unencoded word        (n−k)=the number of check symbols per code word        t=(n−k)/2, the maximum number of erroneous symbols that can be corrected
FIG. 2 shows a typical RS code word broken into data and parity parts, which are further broken into symbols, which are further broken into bits. The RS code is a systematic code because the data is left unchanged and the parity symbols are appended to the data.
Designing an RS code is difficult, and knowledge of RS codes is highly specialized, and thus is typically outside the mainstream designers' domain of expertise. Specifically, RS codes operate over an algebraic finite field called a Galois Field (GF), and the encoding and decoding algorithms are complicated. Due to the complexity of the RS coding theory, this document does not discuss in detail all aspects of the RS algorithms, but focuses instead on the implementation of these algorithms. There are a large number of available coding algorithms and techniques for carrying out the finite field arithmetic.
Implemented RS Algorithms
Although there are a large number of RS algorithms to choose from, most of the RS algorithms used today are based on the Galois Field GF(256). However, algorithms based on GF(128), GF(512) and other Galois fields are used. Likewise, there are a multitude of generator polynomials, and primitive elements to choose from, though only a few are commonly used. See A Commonsense Approach to the Theory of Error Correcting Codes. pp. 193,194 in appendix A, by Benjamin Arazi for a formal treatment and definitions and explanations of generator polynomials and primitive elements.
Briefly, every GF(q) has a primitive element α such that every field element except 0 is expressed by some power of α (modulo q). Also, αq-1=1. That is, operations in the exponent of α are performed modulo q-1. Further, any polynomial g(x) of degree n, modulo on which the operations of the field GF(2n) are performed, is called a generating polynomial of the field.
If, for example, the RS code has symbol size b=8 (one byte or 8 bits per symbol), and the symbols are elements of the Galois Field GF(28)=GF(256), then the maximum code word length will be (28−1)=255 symbols. Further, an RS code with R=2t parity bytes has a generator function g(x)=(x−r0)(x−r1) . . . (x−rR-1), where r is a root of the binary primitive polynomial x8+x4+x3+x2+1.
A popular RS code designation is RS(n=255,k=223) with b=8 bit symbols. Each code word contains 255 code word symbols, which are each one byte long. So 223 symbols are data and 32 symbols are parity. That is, referring to FIG. 2 for this code n=255, k=223, b=8, 2t=32 and t=16. Therefore, this RS code word allows an RS decoder to correct any sixteen erroneous symbols in the code word; that is to correct errors in up to 16 bytes anywhere in the code word.
The amount of processing required to encode and decode RS codes is related to the number 2t of parity symbols per code word. A large t allows errors in a larger number of symbols to be corrected but requires more encoding/decoding processing power. Conversely, a small t allows errors in a fewer number of symbols n to be corrected but requires less encoding/decoding processing power.
RS Encoding Algorithm
Each RS code word consists of k message bytes (Mk-1,Mk-2, . . . , M0) and R=2t parity bytes (CR-1, CR-2, . . . , C0). The check polynomial C(x)=CR-1xR-1+CR-2xR-2+. . . +C0 is obtained as the remainder when the message polynomial M(x)=(Mk-1xk-1+Mk-2xk-2+ . . . +M0) *xR is divided by the generator function, g(x).
Referring to FIG. 3, the RS Encoder function takes an array of k data symbols as an input and returns an array of n symbols (an RS code word). For brevity, further details of RS encoding are omitted. See A Commonsense Approach to the Theory of Error Correcting Codes, pp. 145,146 by Benjamin Arazi for more information.
RS Decoding Algorithm
There is more than one algorithm that can be used to decode RS codes. Most common are Euclid's algorithm and the Berlekamp-Massey algorithm. The Berlekamp-Massey algorithm is used by an embodiment of the invention (described below) because it is iterative and less computationally intensive since it doesn't involve polynomial multiplication and division, but only sums.
Referring to FIG. 4, the RS Decoder function takes as its input 1 a received code word of n symbols and returns as an output 7 k decoded data symbols together with a count of the number of symbol errors corrected or a flag indicating that more than t errors were present. An RS decoding algorithm is typically divided into the following steps:                i) Calculation of the power sum symmetric functions 2;        ii) Generating the error locator and error evaluator (magnitude) polynomial 3;        iii) Using a search algorithm to search the polynomial roots 4;        iv) Calculating the error values 5 and correcting the errors 6.
Historically, these steps have been performed in hardware in a serial manner where there is no need to.have the time required to perform any given step be related to the time required for any other step.
There are several different ways to accomplish these steps. One is to generate a pipeline in which a separate piece of hardware is dedicated to each of the four steps and operates on one block of data at a time. Thus, the pipeline processes four different data blocks at one time and synchronizes the processing. This is hardware intensive, but it does allow for data to be processed at the rate at which it comes in as long as the time it takes to perform any step is less than the time it takes to input the next block of data. Another is to perform all the steps serially in software for a block of data and when the last step is completed read the next block. This has limited usefulness since the rate of arrival of the next block of data is a function of the transmitter and receiver, not the RS decoding processor. Therefore this process is typically limited to a relatively slow transmission rate.
The Peak-Load Issue
To implement a software RS decoder on a general processor, a block processing technique is typically used to reduce real-time sensitivity of the system.
When the block size is identical with the RS code word size, there is no peak-load issue. In every block, the following tasks need to be performed:                1. Read in a complete RS code word (you can read in a complete RS code word in a block because in this case the block size is exactly equal to code word length);        2. Perform all the steps i)-iv) of the RS decoding algorithm as discussed above one by one.
However, the block size of most systems is limited by system parameters, and therefore, the block size is usually smaller than the RS code length. This is what causes a peak-load issue to arise.
Assume the block size is half of the RS code length, meaning the decoding procedure described needs to be repeated every 2 blocks. It also means that each code word is two blocks in length.
In the first block, since only half of the RS code is available, the decoding procedure cannot be started, and nothing can be done after the read of the first half of the RS code word. Only after reading in the second block is a complete code word available, and then RS decoding can be performed. Since all the calculation is performed after reading in the second block, the processor load associated with the second block is very high, or peaked.
Referring to FIG. 5, where the load is plotted over time, the code word 51 takes two block cycles 50 to be completely read in to the system. No processing can be done during the first two cycles 47 and 48 while the first code word 51 is being read in. In FIG. 5, first letter abbreviations are used for functions. Input is 'I', syndrome is 'S', locator polynomial is 'L', root search is 'R', and error magnitude evaluation is 'M'. During input cycle I2,1 49, which is the first block cycle of the second code word, the syndrome calculation S1 42 is performed on the first code word. During the next block cycle 41, the second half of the second code word I2,2 is read in but no other work is or can be performed. Then, while the first half of the third code word is being read in I3,1, the syndrome calculation S2 46 of the second code word and the error locator polynomial L1 43, of the first code word are calculated. This is followed by block cycle 40 during which no calculation is performed while the system is reading in the second half of the third code word I3,2. A definite peak of load occurs in block cycle 44 when the first half of the fourth code word, I4,1, is read in and at the same time three calculations occur, the root search calculation R1 of the first code word, the error locator polynomial calculation L2 of the second code word, and the syndrome calculation S3 of the third code word. This peak cycle is followed by another cycle when no calculation is performed while the system is reading in the second half of the fourth code word, I4,2. During the following block cycle I5,1, the error magnitude evaluation calculation M1 45 of the first code word occurs during a peak along with all the calculations of block cycle 44 as previously noted. After this there is an alternating no-load cycle followed by a peak-load cycle as long as code words are read in. Therefore, approximately half of the available processing power is unused in this example.
If each code word is longer than two blocks, then the peak problem becomes worse because there are more blocks when nothing can be done but to read more of the code word in.
This means that most of the computation will be performed at those blocks containing the last symbol of an RS code word. The peak-load occurring in these blocks will cause a severely skewed computation load distribution over the whole decoding process, and therefore an obvious performance loss in many systems such as multi-line and multi-tasking systems.
To some systems where the block size is limited by the delay requirement of the receiver, the peak-load problem may become completely intolerable and may cause system collapse.


A cylindrical, chlorine-free synthetic quartz glass blank of a specific size obtained by homogenizing a synthetic quartz glass ingot having periodic striae along a direction of growth has (a) striae grades in the working and off-axis directions which meet grade A of U.S. military specification MIL-G-174B, (b) average hydroxyl group concentrations in the working and off-axis directions of 700 to 1,000 ppm each, (c) average fictive temperatures in the working and off-axis directions of 850 to 950xc2x0 C. each, and (d) a refractive index distribution for 633 nm wavelength light in the working direction of at most 1xc3x9710xe2x88x926. The blank has a good transmittance to laser light, undergoes little deterioration when irradiated with laser light, and is particularly suitable for ArF excimer laser-related applications.

1. Field of the Invention
The present invention relates to synthetic quartz glass blanks having a good transmittance and low deterioration during laser irradiation from which can be obtained optical elements such as lenses, prisms, mirrors and windows for use with excimer lasers, and particularly ArF excimer lasers.
2. Prior Art
Higher levels of integration in VLSI circuits have led to exposure patterns of increasingly small linewidth. This has created a need for exposure light sources of shorter wavelength in the lithography systems used to form circuit patterns on semiconductor wafers. The i-line (wavelength, 365 nm), once the light source of choice in lithography steppers, has been largely supplanted by the KrF excimer laser (248 nm), and today ArF excimer lasers (193 nm) are starting to see industrial use.
This trend toward shorter wavelength light sources has also created a need for higher precision in the optical components (e.g., lenses, windows, prisms) used in exposure tools. Some of the many important concerns that exist regarding such components, particularly when used with ArF excimer lasers, include refractive index homogeneity, improving the transmittance and reducing the scattering of laser light, and stability to excimer laser irradiation.
Of these concerns, the refractive index homogeneity xcex94n is the most critical and most difficult to achieve. The hydroxyl group concentration and its distribution have a large influence on the refractive index distribution in quartz glass. That is, a hydroxyl group concentration of 10 ppm reportedly narrows the refractive index distribution in quartz glass by 1xc3x9710xe2x88x926. It can readily be seen from this that a very high-homogeneity synthetic quartz glass body having a hydroxyl group concentration distribution of only 10 ppm would be needed to obtain a synthetic quartz glass blank in which xcex94n=1xc3x9710xe2x88x926.
Two methods are commonly used for making synthetic quartz glass: a direct method in which a silica-forming starting material is flame hydrolyzed, forming fine particles of silica which are then melted and deposited to effect growth; and a soot method in which a silica-forming starting material is flame hydrolyzed, forming fine particles of silica which are deposited to effect growth, then later vitrified to form a clear glass. However, obtaining a synthetic quartz glass body of such high homogeneity directly by either of these methods is technically very difficult. To obtain a synthetic quartz glass body of higher homogeneity, it is thus necessary to subject the synthetic glass ingot obtained by either method to homogenizing treatment.
The most efficient and effective way to homogenize quartz glass is to carry out the zone melting process disclosed in JP-A 7-267662 in the ingot growth direction and in a direction perpendicular thereto. This approach has a number of advantages. For example, the molten portion of the ingot is mechanically agitated, enabling efficient homogenization to be carried out and thus making it possible to narrow, for example, the distribution in the hydroxyl group concentration. In addition, during homogenization, the quartz glass ingot is treated without being brought into contact with anything other than the burner flame, minimizing the diffusion of external impurities to the ingot and thus holding down the decline in UV light transmittance.
Generally, when homogenizing treatment by a zone melting process is used to improve the uniformity of the hydroxyl group concentration, a wider variation in hydroxyl group concentration prior to such treatment results in less efficient homogenization. The efficiency of homogenization declines also with increasing hydroxyl group concentration. At higher hydroxyl group concentrations in particular, the variation in concentration is generally wider, detracting even further from the efficiency of homogenization. For this reason, a hydroxyl group concentration of 1,000 ppm or less is preferred in synthetic quartz glass ingots subjected to homogenization.
Other properties which, like the refractive index homogeneity xcex94n, are of critical importance in synthetic quartz glass blanks for optical elements used in ArF excimer laser exposure systems, are the transmittance of the glass to UV light and its stability to laser irradiation.
The most important transmittance to UV light is the transmittance to the 193 nm wavelength light used in an ArF excimer laser. The transmittance of quartz glass to light at this wavelength decreases as the content of impurities rises. Typical impurities include alkali metals such as sodium, and other metallic elements such as copper and iron. By using a silane or silicone starting material of very high purity to produce the synthetic quart glass, the concentration of such metallic impurities present within the quartz glass can be brought down to below the level of detection by a highly sensitive detector ( less than 1 ppb). However, because sodium and copper have relatively large coefficients of diffusion to quartz glass, the diffusion and admixture of such external impurities often occurs during homogenization and heat treatment. Special care must be taken to avoid such contamination during these treatment operations.
Stability of the quartz glass to excimer laser irradiation is a very important factor, particularly as an ArF excimer laser reportedly causes five times more damage than a KrF excimer laser.
When quartz glass is irradiated with ArF excimer laser light, one effect that arises is the cleavage of Sixe2x80x94Oxe2x80x94Si bonds by the very intense energy of the light, forming the paramagnetic defects commonly known as Exe2x80x2 centers which absorb 215 nm light. Another effect, commonly referred to as xe2x80x9claser compaction,xe2x80x9d is a rearrangement of the network structure of quartz glass that increases the density of the glass.
The former effect lowers the transmittance of the quartz glass to 193 nm light, and the latter effect raises the refractive index and increases the birefringence. All of these changes in optical characteristics are undesirable for an exposure system.
It is known that reducing the number of intrinsic defects in quartz glass and setting the hydrogen concentration in the glass to at least a certain level are both highly effective for improving the stability of the quartz glass to laser irradiation.
Intrinsic defects present in quartz glass include defects characterized by too much or too little oxygen for the Sixe2x80x94Oxe2x80x94Si structure making up the quartz glass. Well-known examples include oxygen deficient defects (Sixe2x80x94Si, which absorbs at 245 nm) and oxygen surplus defects (Sixe2x80x94Oxe2x80x94Oxe2x80x94Si, which absorbs at 177 nm). However, such defects, or at least those which are measurable by spectrophotometric means, are excluded from optical-grade synthetic quartz glass to begin with. Of greater concern are more subtle defects, such as those in which the Sixe2x80x94Oxe2x80x94Si bond angle falls outside the range of stability, as in the case of excessively stretched or compressed Sixe2x80x94Oxe2x80x94Si bonds.
To remove such unstable structures, JP-A 7-61823 discloses a process in which the growth rate of quartz glass produced by the direct method is held to a level of not more than 2 mm per hour.
Although this process does appear to work, because the growth rate is very slow, it has a poor productivity and is not very cost-effective. Moreover, with regard to the general production conditions, it is empirically known that a slow growth rate tends to increase the hydroxyl group concentration in the resulting quartz glass. Two examples are cited in JP-A 7-61823, but the synthetic quartz glass obtained in both had hydroxyl group concentrations of 1,200 ppm, which is considerably higher than 1,000 ppm.
Because, as noted above, hydroxyl groups have a large impact on the refractive index of quartz glass, a lower hydroxyl group concentration is preferred for obtaining a more uniform refractive index distribution. Homogenization of the resulting quartz glass body is not called for in the art disclosed in JP-A 7-61823. However, in cases where homogenizing treatment is subsequently carried out to increase the uniformity of the refractive index, it is preferable for the hydroxyl group concentration to be no higher than 1,000 ppm. At a concentration above 1,000 ppm, the efficiency of homogenization declines, lengthening the length of time required for treatment. A longer treatment time increases the diffusion of external impurities into the quartz glass, thus lowering the transmittance of the glass, and also reduces the hydrogen concentration.
The fact that hydrogen molecules in the quartz glass inhibit damage to the glass by excimer laser irradiation is well-known in the art and has been the subject of active investigation ever since it was revealed in JP-A 1-212247.
There are two ways to include an appropriate level of hydrogen molecules in quartz glass. One method is to introduce hydrogen molecules into the growing ingot by suitably adjusting the ratio of hydrogen, propane and oxygen used as the combustion gases during growth of the quartz glass ingot. This approach allows the amount of hydrogen molecules that dissolve in the growing ingot to be adjusted within a range of about 0 to 2xc3x971019 molecules/cm3.
The other method involves the thermal diffusion of hydrogen molecules by heat treating a quartz glass body within a hydrogen atmosphere. This method has the advantage of enabling strict control of the hydrogen molecule concentration. At the same time, it also has a number of significant disadvantages. Specifically, because it uses hydrogen gas, which is a highly flammable substance, there is a risk of explosion. Also, the associated equipment costs for safety and other purposes represent a substantial economic burden. In addition, heat treatment as in this case may allow impurities to diffuse into the quartz glass, which tends to lower the transmittance of the glass.
An important factor which affects the refractive index distribution of the quartz glass and governs the stability of the glass to ArF excimer laser irradiation is the xe2x80x9cfictive temperature.xe2x80x9d This is a concept particular to glass, and refers to the temperature at which glass in a molten state, as it cools, undergoes a loss in the freedom of the molecules and solidifies. The physical value to which the fictive temperature relates is the density of the quartz glass.
Because the fictive temperature distribution of quartz glass is also, like the hydroxyl group concentration distribution, a major determinant of the refractive index distribution in the quartz glass, methods for holding the refractive index distribution xcex94n in a quartz glass body to 1xc3x9710xe2x88x926 or less by suitably combining the hydroxyl group concentration distribution and the fictive temperature distribution have been disclosed in JP-A 2-102139 and JP-A 2-239127.
We have found from our own research that the fictive temperature has a large influence on changes in the transmittance of quartz glass when irradiated with ArF excimer laser light. It thus became clear to us that the intrinsic defects present in quartz glass, its hydrogen concentration, and its fictive temperature are all important factors for enhancing the laser durability of the quartz glass. This will be discussed more fully later in the specification.
JP-A 2-102139 and JP-A 2-239127 devote attention to planarizing the refractive index distribution, and thus cite suitable ranges for the fictive temperature distribution. Yet, because nothing was known at the time about how the fictive temperature interacts with laser durability, the fictive temperature itself is not discussed. Hence, these prior-art disclosures do not resolve the technical issue addressed by the present invention; namely, how to improve both the refractive index distribution and the laser durability of synthetic quartz glass blanks.
JP-A 5-58667 teaches that the resistance of quartz glass to damage from excimer laser irradiation is enhanced by controlling the fictive temperature of the glass within a range of 800 to 1,000xc2x0 C. However, as is apparent from the description given therein, JP-A 5-58667 is concerned with KrF excimer laser and not ArF excimer lasers. Hence, the fictive temperature range is broader. Quartz glass material intended for use in the production of optical elements for ArF excimer laser exposure systems must have an optimized fictive temperature.
It is therefore an object of the present invention to provide synthetic quartz glass blanks which have a good transmittance to laser light and minimal deterioration during laser irradiation, and are thus suitable for excimer laser-related applications, particularly ArF excimer laser-related applications.
We have discovered that synthetic quartz glass blanks endowed with characteristics (a) to (d) listed below provide optical elements which have a good transmittance and experience minimal deterioration, and can thus be used in excimer laser applications, particularly ArF excimer laser applications.
Accordingly, the invention provides a synthetic quartz glass blank which is obtained by homogenizing a synthetic quartz glass ingot having periodic striae in a direction of growth, has a generally cylindrical shape with a diameter of 150 to 380 mm and a thickness of 50 to 150 mm, and contains substantially no chlorine; wherein the blank has:
(a) striae grades in a working direction and an off-axis direction which meet grade A of U.S. military specification MIL-G-174B,
(b) a working direction hydroxyl group concentration averaged in the off-axis direction and an off-axis direction hydroxyl group concentration averaged in the working direction of 700 to 1,000 ppm each,
(c) a working direction fictive temperature averaged in the off-axis direction and an off-axis direction fictive temperature averaged in the working direction of 850 to 950xc2x0 C. each, and
(d) a refractive index distribution xcex94n for 633 nm wavelength light in the working direction of the synthetic quartz glass of at most 1xc3x9710xe2x88x926.
Preferably, the synthetic quartz glass blank of the invention, after irradiation with 30,000 pulses of ArF excimer laser light at an energy density per pulse of 2 mJ/cm2 and a frequency of 200 Hz, has a laser light transmittance that is at least 98.0% of the transmittance prior to laser irradiation and, after irradiation with 2xc3x97106 pulses of ArF excimer laser light under the same conditions, has a transmittance of at least 97.5%.
The inventive synthetic quartz glass blank typically has an average hydrogen molecule concentration in the working direction of 2xc3x971017 to 3xc3x971018 molecules/cm3.
It is advantageous for the striae on the ingot from which the synthetic quartz glass blank of the invention is obtained to be distributed periodically in the growth direction to a density of at least one striae per centimeter and to be located preferably at positions where feeding of a silica-forming starting compound is interrupted during growth of the ingot.
The ingot from which the inventive blank is obtained is generally repeatedly homogenized in the growth direction and in a direction perpendicular to the growth direction.


Examples of the present disclosure describe systems and methods relating to context rules in a graph or isolated collection. In an example, information in an isolated collection may be associated with one or more contexts. The information may be represented within the isolated collection based on one or more rules, and one or more of the rules may be associated with one or more contexts to which the information relates, thereby indicating a context association. A context association may indicate a positive, negative, or other relationship between one or more rules and one or more contexts. Based on the context association, information within the isolated collection may be adapted to generate different views of the isolated collection for different contexts. As such, relevant, useful, or actionable information may be included or emphasized, while information that is not as relevant, useful, or actionable may be omitted or deemphasized.

A graph or isolated collection may store information relating to a variety of domains, contexts, data types, users, tenants, divisions, teams, or other categories. While it may ultimately be useful to have a rich body of knowledge, such a diverse set of information may complicate accessing or identifying relevant information within the isolated collection.
It is with respect to these and other general considerations that the aspects disclosed herein have been made. Also, although relatively specific problems may be discussed, it should be understood that the examples should not be limited to solving the specific problems identified in the background or elsewhere in this disclosure.


A method and apparatus for filtering data packets in a shared-medium or point-to-multipoint communications network. A filter unit is sent a data packet carrying a filter tag value in a packet addressed to the filter unit. The value is stored in the filter unit and subsequently received packets not addressed to the filter unit itself are forwarded only if they carry the stored filter tag. An embodiment of particular interest applies the method to Ethemet frames over a telecommunications access network (including optical or wireless networks), and uses the VLAN tag field to carry the filter tag information.

There are many known examples of communications network architectures which make use of shared medium communication between a transmitter and multiple receivers. Architectures include for example point-to-multipoint optical networks and wireless networks, in particular for (but not limited to) telecommunications access networks. Whilst these architectures have many problems in common, they are described here in the context of Passive Optical Networks (PON's) in general and Gigabit Ethernet PON's (GEPON's) in particular.
GEPON's have been proposed as a means of cost effectively providing fibre access to homes and businesses. In such a network, downstream traffic is broadcast to all nodes whereas a Time Division Multiple Access (TDMA) protocol is used to multiplex the upstream traffic onto the PON without collisions.
One significant problem with a GEPON is that all downstream traffic is broadcast and hence visible to all end-nodes, which are likely to be unrelated home or business customers. A security mechanism is required which can filter traffic at the end node in order that each customer will only receive traffic destined for his end-node.
A second problem with a GEPON is that, unlike a conventional Ethernet Access system based on point-to-point links, there are multiple customers associated with a single physical port at the headend. Thus, the headend Access Router or switch can no longer use physical port association as a means of differentiating customer traffic in order to enforce policies such as security, bandwidth allocation, access to particular traffic types, etc. A different mechanism for differentiating customers' traffic is therefore required.
One known approach to filtering downstream traffic destined for a specific Optical Network Unit (ONU) is to filter by MAC address. If each ONU has a single MAC address, and all Ethernet frames for that ONU use this address, then this provides the headend with a sufficient means of differentiation traffic for different customers. There are however several disadvantages to this approach. First, it is likely that the customer will have several Customer Premises Equipment (CPE) devices connected to a local network, each Ethernet device having its own distinct MAC address. Simple layer 2 bridging of traffic destined for these different CPE devices (e.g. PCs, Set Top Boxes etc) cannot therefore be used, forcing the use of a more complex solution such as layer 3 switching via a router. This solution is not however suitable for multicast traffic, such as multicast video, which uses a different multicast MAC address.
A second known approach to tackling the problem is to allow the ONU to use several MAC addresses for its CPE devices, with the ONU bridging the traffic destined for these CPE devices. This however can create significant security problems, as a CPE device such as a PC on one ONU could relatively easily impersonate a device on another ONU and hence steal traffic destined for that ONU. In addition, a PC or Set Top Box could "tune-in" to multicast video traffic purchased by another customer on the PON. Furthermore, a mechanism is required by which the list of MAC addresses to be passed through an ONU can be populated. In any practical system, this mechanism must be automatic and therefore adds further complexity in the ONU.
Both of the above approaches can work successfully if routing or security and multicast functions are built into the ONU, which is then owned and managed by the network provider. In such arrangements the ONU becomes a "trusted" device performing filtering and policing functions, together with other functions such as routing, Network Address Translation (NAT) etc as necessary, under the control of the network operator. This is however an expensive solution, and does not fit the commercial and perhaps regulatory requirements of many operators who require a minimal-functionality ONU capable of providing an inexpensive, simple and clear demarcation point at the edge of their network.

Data stream filtering apparatus and method


An apparatus and method for reducing effects of spurs in a phased-locked loop having a sigma-delta modulator and digital circuits. The apparatus includes a clock dithering circuit coupled to each of the sigma-delta modulator and the digital circuits. Each clock dithering circuit is configured to dither flanks of a respective first and second clock input signal, and generate a dithered clock output signal, one for each of the sigma-delta modulator and digital circuits. A frequency of each dithered clock output signal follows a frequency of the respective first and second clock input signals, and a phase between each dithered clock output signal and the respective first and second clock input signal is shifted and constantly changing.

The present disclosure generally relates to frequency control devices, and more particularly to spur reduction in a Phase-Locked Loop (PLL).
A phase-locked loop (PLL) circuit, as is generally known in the art, finds application where circuit synchronization is needed. In modern digital receivers, the phase-locked loop circuit may not be a hardwired implementation, but may rather be software, or microprocessor based implementation. The phase-locked loop will generally include three basic components. A phase detector, a loop filter and a voltage-controlled oscillator. As the incoming signal and the generated signal change with respect to each other, the phase difference or error is used as a time-varying signal into the loop filter. The loop filter generally governs the response of the phase-locked loop to the variations in the error signal. A well designed phase-locked loop will be able to track changes in the phase of the incoming signal, but will not be overly responsive to noise in the receiver.
The purity of the frequency output of an integrated phase-locked loop is an important factor in many applications. The clock used in the digital logic can couple through parasitics and surges to other parts of the phase-locked loop. These disturbances can result in spurious tones at the output of the phase-locked loop, also referred to herein as RF "spurs."
Spurs are generally reduced through the careful selection of phase-locked loop parameters, such as loop bandwidth, layout and signal routing. Differential logic can also be employed to reduce the ripple on the power or voltage supply lines. Spur reduction can also be achieved by shielding. However, the amount or spur reduction typically resulting from shielding is minimal. Reductions in the loop bandwidth are not preferable, as reducing the bandwidth can increase the lock time of the phase-locked loop and make it harder to integrate the loop filter. The contribution of noise from the voltage controlled oscillator can also increase.
Accordingly, it would be desirable to provide a system that reduces coupling induced spurs and addresses at least some of the problems identified.


This invention relates to a novel formaldehyde dehydrogenase expressed by a formaldehyde dehydrogenase gene and having independent reduction activity for formic acid, a method of preparing the formaldehyde dehydrogenase from a strain transformed with a recombinant expression vector including the gene, and a method of producing formaldehyde from formic acid through a reduction reaction of the formaldehyde dehydrogenase.

The industrial use of biocatalytic reactions is rapidly growing with the advancement of biotechnology because various catalytic reactions, including reactions that have not conventionally been able to be carried out using conventional chemical catalysts, are performed under biocompatible conditions.
Such reactions are typically applied to the synthesis of chiral compounds, alcohols, aldehydes, amino acids and medical intermediates, the synthesis of polymers suitable for biodegradable or biometric applications, and the development of biosensors for assays and diagnosis. Furthermore, because of current problems attributable to an increase in the concentration of carbon dioxide and global warming resulting therefrom, thorough research into decreasing carbon dioxide emissions and producing a new type of energy through the reduction reaction of carbon dioxide is ongoing in academic and industrial fields. Specifically, carbon dioxide is converted into formic acid using a formate dehydrogenase, the produced formic acid is converted into formaldehyde by means of a formaldehyde dehydrogenase, and the formaldehyde is converted into methanol by means of an alcohol dehydrogenase. For this, the formaldehyde dehydrogenase must be essentially contained in a multi-enzyme system. Despite its potential importance and usability, there have been almost no reports on reduction reactions involving formaldehyde dehydrogenase, compared to oxidation reactions thereof. Since the oxidation reaction, rather than the reduction reaction, is carried out in a thermodynamically favorable and feasible manner due to the properties of typical dehydrogenase, formaldehyde dehydrogenase having independent reduction activity has not yet been reported.
Therefore, a novel formaldehyde dehydrogenase, having independent reducibility for converting formic acid into formaldehyde, needs to be reliably applicable to a multi-enzyme system so that methanol can be produced using carbon dioxide, and moreover, so that a variety of industrially important chemicals can be produced.

Formaldehyde dehydrogenase and method for preparing formaldehyde using same

Konkuk University Industrial Cooperation Corp.


A coating system includes a coating source and a planetary manipulator assembly that includes a first driveshaft capable of receiving rotational input, a sun gear rotationally fixed to the first driveshaft, a planetary gear engaged with the sun gear, a second driveshaft rotationally fixed to the planetary gear such that torque is transmitted from the sun gear to the planetary gear, a support shaft operatively engaged with the second driveshaft, a carrier body supporting the planetary gear relative to the sun gear, a third driveshaft capable of receiving rotational input, and a drive gear rotationally fixed to the third driveshaft. The support shaft is arranged substantially perpendicular to the second driveshaft. The carrier body is rotatable by the drive gear about a common axis with the sun gear, and rotation of the carrier body rotates the planetary gear and the second driveshaft about the sun gear.

The present invention relates to coating systems for applying coatings to workpieces, and more particularly to coating systems that include a manipulator having planetary gearing.
In order to apply coatings to workpieces with desirable coating distribution, manipulators can be used to move the workpiece within a stream, plume or cloud of coating material. Such manipulators allow more even coating thickness distribution on various surfaces of workpieces, especially workpieces with relatively complex geometries and hard-to-reach (e.g., non-line-of-sight) areas. Gear-driven manipulators exist, including those with gear-driven arms that rotate and move upward and downward at up to +/−45° in a "butterfly" movement to provide one complete axis of rotation and one partial axis of rotation.
Gas turbine engines include numerous components with a variety of coatings. For example, gas turbine engines often include vane segments, such as "doublets" with a pair of airfoils extending between inner and outer platforms. Such doublets can include thermal barrier coatings (TBCs) made of ceramics or other materials, as well as environmental or other coatings. The configuration of typical vane doublets with highly contoured end walls can make coating uniform coating distribution difficult, including in the throat area between the airfoils.
Therefore, it is desired to provide an alternative coating system having an alternative workpiece manipulator.


The invention relates to a bloom retarding fat composition comprising a component A and a component B. Component A is present in an amount of 40-95% (w/w) of said bloom retarding fat composition, and component B is present in an amount of 5-60% (w/w) of said bloom retarding fat composition. Component A comprises a fat composition having a content of SatOSat TAGs of 60% (w/w) or higher. Component B comprises a fat composition having a content of saturated fatty acids of 30% (w/w) or less. In component B the total content of Sat2U TAGs of 18% (w/w) or less, and a content Sat3 TAGs of 8% (w/w) or less. Further in component B the content of SatSatU TAGs in Sat2U of component B is 1% (w/w) or more. Also the molar ratio of SatSatU:SatUSat TAGs is 1 or higher in component B and wherein Sat is a C16-20 saturated fatty acid, and wherein O stands for oleic acids; U stands for unsaturated fatty acids, including oleic acid. The invention relates to various applications of such a bloom retarding fat composition.

Chocolate is throughout the world regarded as being one of the finest types of confectionary and various types and shapes of chocolate confectionary have been developed over the years. The innovation within the field of chocolate has been much focused on sensory aspects, such as taste, and mouth feel. However, also the visual appearance is an important aspect in the consumer's overall perception of the quality of a chocolate confectionary. Accordingly, the visual appearance of a chocolate confectionary plays a key role for the chocolate manufacturer because a less attractive appearance of the confectionary will easily be judged by the consumer to relate to a confectionary of inferior quality.
An important problem relating to the visual appearance of a chocolate confectionary is the bloom effect which might take place in the coating of the chocolate confectionary. Such bloom effect is easily recognisable on the surface of that coating because in case a blooming has occurred, the coating of the confectionary will have a rather dull appearance having less gloss and often having clearly visible bloom crystals on the surface. The appearance of bloom, if any, typically takes place after weeks or months of storage.
Chocolate generally comprises cocoa butter, cocoa solids and sugar. Milk fat and/or milk proteins, emulsifies and other ingredients may be present in chocolate composition as well.
In the manufacturing process of chocolate, the ingredients are mixed refined and conched to a mixture. The mixture is subjected to a tempering process in a tempering apparatus in which the chocolate is subjected to a carefully pre-programmed temperature profile. Subsequently, the chocolate is used for making the chocolate confectionary (e.g. as a coating, a filling, a layer in a chocolate bar etc.) and the resulting confectionary is cooled following a predetermined cooling program.
The tempering process serves the purpose of making a sufficient amount of a desired type of seed crystals of the solid fats present in the chocolate, which in turns is responsible for obtaining a rather stable chocolate product which is less prone to changes in the crystal composition of the solid fats. The desired seed crystals are of the crystal form Form V. It is believed that the bloom effect occurring in chocolate confectionary is occasioned by polymorph transformation of fat crystals present in the chocolate.
Of the ingredients used for making chocolate, cocoa butter is by far the most expensive. For this reason, chocolate manufacturers have developed less expensive cocoa butter equivalents (CBE for short) which are compatible with cocoa butter in all ratios.
The general perception is that, mixing cocoa butter and/or cocoa butter equivalents with soft oils like soy oil, rapeseed oil, sunflower oil etc in a relative high content, may result in decrease in shelf life. It should be noted though, that bloom may also occur in a chocolate product in case the chocolate composition has been poorly tempered.
The bloom in chocolate coatings is a well studied phenomenon and among chocolate manufactures it is agreed that the bloom effect is inter alia occasioned by solid fat crystals transforming from the Form V to the Form VI crystal phase. Such recrystallisation into Form VI crystals may then accordingly result in bloom on the surface of the chocolate confectionary.
In the prior art various ways of avoiding the bloom effect in chocolates have been suggested. Such suggestions for avoiding bloom formation relate inter alia to optimising tempering conditions, adding high-melting milk fat fractions or sorbitan tristearate to the chocolate.
However, also specifically altering the TAG composition of a chocolate may lead to reduced bloom.
U.S. Pat. No. 5,524,090 accordingly discloses an anti-bloom agent comprising not less than 40% by weight of triglycerides of the form SatSatU, wherein Sat is a saturated fatty acid and wherein U is an unsaturated fatty acid, and wherein not less than 75% of all the Sat fatty acids are selected from the group comprising stearic acid and palmitic acid. In another embodiment, the content of the SatSatU triglycerides in the anti-bloom agent is not less than 20% by weight. The anti-bloom agent disclosed in U.S. Pat. No. 5,524,090 is intended for being added to a hard butter or a hard butter product, such as raw fats and oils, e.g. a cocoa butter product, such as chocolate in an amount that increases the content of SatSatU triglycerides in that product by 2-25%.
Addition of the anti-bloom agent according to U.S. Pat. No. 5,524,090 results in delayed formation of Form VI-crystals. A raise in the SatSatU content of cocoa butter by adding an anti-bloom agent according to U.S. Pat. No. 5,524,090 in an amount increasing the SatSatU content by 16% thus resulted in an decrease to 1.06 in the ratio of the x ray powder diffraction intensity of Form VI/Form V after 7 months storage, compared to cocoa butter having no such anti-bloom agent added, in respect of which the corresponding ratio was 1.63.
In an article of K. V. Smith et al. in Food Chemistry 102 (2007) 656-663 an investigation of the effect of formation of Form VI crystals by adding hazel nut oil to cocoa butter was published. The investigation reveals that adding hazel nut oil to cocoa butter significantly increases the rate of formation of Form VI crystals, even if the hazel nut oil was added in only minute amounts. Hazel nut oil in amounts of 0, 1, 2, 5, 10, 20% respectively were mixed with cocoa butter at 60° C. Thereafter, the mixtures were tempered and stores at 15, 20 and 25° C. X-ray diffraction was used to determine the progression of Form VI crystal formation. The results in the Smith article shows that after five weeks at 25° C., cocoa butter without hazel nut oil showed 28.3% Form VI, whereas cocoa butter comprising 20% hazel nut oil exhibited almost full transformation from Form V to Form VI. Even addition of 5% hazel nut oil in cocoa butter was able to lead to almost full transformation into form Form VI after ten weeks storage at 25° C.
Accordingly, the Smith article shows that even very small amounts of hazel nut oil in cocoa butter leads to considerable increased transformation from crystal Form V to Form VI.
Accordingly, in the art of chocolate manufacture there still exists a need for a fat composition which in a chocolate composition will act bloom retarding on the one hand, and which on the other hand will allow for cost savings in respect of the TAGs to be used in the chocolate composition.
It is the object of the present invention to provide such a bloom retarding fat composition.


An apparatus for automatically compensating for the deflection of electron beam in a cathode ray tube display by the earth's magnetic field (EMF) detects the EMF at the installation site of the cathode ray tube display by the EMF detector comprising a plurality of magnetic sensors for sensing the x, y, z component of magnetic field. A pulse generator and a counter transform each detected component of the EMF into a predetermined gate signal and then output the gate signal to the microcomputer. The microcomputer compares the gate signal indicative of the detected EMF with a reference signal stored in the internal memory to obtain a compensation value. The microcomputer further outputs the compensation value to a processor, which automatically compensates for the deflection of electron beam in a cathode ray tube.

1. Field of the Invention
The present invention relates to an automatic magnetic field compensator for a cathode ray tube, and more particularly to an apparatus for automatically compensating for the changes generated in a display with a cathode ray tube in effect of the earth's magnetic field by using magnetic sensors detecting the earth's magnetic field.
2. Description of Background Art
Usually, a display with a cathode ray tube (CRT) has a problem that both sides of a screen tilt upward or downward in response to the effect of the earth's magnetic field (hereinafter: `earth's magnetic field` is abbreviated as `EMF`.) according to the installation direction, i.e. north, south, east or west. Accordingly, the effects of the EMF must be eliminated to realize a stabilized picture on a screen. More particularly, a tilt of screen is compensated for by flowing direct current (DC) with variable flowing direction and variable current intensity through a compensation coil for EMF wound around the neck of a CRT, around which a deflection yoke is also wound.
An apparatus for compensating for the deflection of electron beam in a CRT display is described in the Korean patent application No. 94-1310 (its Korean examined publication No. 96-13551).
The above-mentioned automatic magnetic field compensator, which is set forth in FIG. 1, comprises a compensation value determining unit 10 for generating compensation values respectively corresponding to each directional magnetic field, and a direction detect and select unit 20 for receiving the compensation values from the compensation value determining unit 10 and sensing the direction of a CRT to selectively output one of the received compensation values. This automatic magnetic field compensator further comprises a deflection compensating unit 30, coupled to the direction detect and select unit 20, for receiving the selected compensation values from the direction detect and select unit 20 and compensating for deflection of electron beam emanating from an electron gun in a CRT.
In FIG. 1, the direction detect and select unit 20 comprises a directional sensor (not shown) and an output select switch (not shown), thereby detecting the direction of a CRT to control the output of output select switch in response to the detection result. A compensation value of the east is set to be a reference voltage and VA indicates a compensation value of the west. VB indicates a compensation value of the south and VC indicates a compensation value of the north.
To explain the automatic magnetic field compensator referring to FIG. 1, the directional sensor in the direction detect and select unit 20 detects the present direction of a CRT. The direction detect and select unit 20 controls the output select switch to input the compensation values from the compensation value determining unit 10, which corresponds to the direction of a CRT, to the deflection compensate unit 30. The deflection compensate unit 30 compensates for the deflection of electron beam in a CRT in response to the input compensation values, thereby compensating for picture distortion, screen tilt, and color convergence to display a normal picture on a CRT screen.
The conventional automatic magnetic field apparatus described above, however, has a disadvantage that a display with a cathode ray tube must apply a predetermined voltage to the magnetic field compensator continuously in order to compensate for picture distortion and color convergence and therefore the display consumes power excessively.

Automatic magnetic field compensator for a CRT


In an arrangement for simultaneously exchanging digital symbols between terminals over a bidirectional transmission path, near term interference in the signal received from the transmission path is canceled by storing the sequence of successive digital symbols 1, 2, . . . , N applied to the transmission path, forming a replica of the interference from the stored digital symbols and subtracting the replica from the received signal. A signal representative of a replica of the interference occurring subsequent to the Nth digital symbol of the successive digital symbols 1, 2, . . . , N is then generated and combined with the signal having the interference corresponding to the stored symbol sequence removed to cancel the subsequent interference in the received signal. The signal representing the interference subsequent to the Nth digital symbol is generated by modifying the Nth stored symbol by an adaptive gain signal corresponding to the correlation of the subsequent interference replica signal with the signal having the interference removed, and recursively altering the modified Nth stored digital symbol with a prescribed impulse response representative of the characteristics of the bidirectional transmission path subsequent to the time periods of the sequence of successive digital symbols 1, 2, . . . , N.

Subscriber loop transceivers used in baseband data transmission systems such as the integrated services digital network (ISDN) share a single transmission medium over which terminals may simultaneously transmit and receive data signals. In order to maintain simultaneous transmission and reception, it is necessary to remove interference due to signals being transmitted appearing at the input of the receiver and intersymbol disturbances so that the received signal may be detected. Decision feedback equalizers have been used to compensate for intersymbol interference in the received signal as a result of the frequency dependent attenuation characteristics of the transmission line and echo cancelers are used to remove the transmitted signal reflected back to the receiver input.
Generally, both decision feedback equalizers and echo cancelers have been of the adaptive transversal filter type. As is well known in the art, such transversal filters span a finite time period and can only compensate for an impulse response of finite duration. The finite duration response, however, is only an approximation to the actual response of the transmission channel for both the path of an echo and the path of the received signal whereby compensation is only effective for near term interference. The far term interference or tails of the echo path or received signal path impulse responses are beyond the span of the transversal filter and cannot be canceled. Consequently, there is a degradation of system performance.
Recursive type filters such as disclosed in U.S. Pat. Nos. 3,646,480 issued Feb. 29, 1972 to D. A. Spaulding and 3,798,560 Mar. 19, 1974 issued to M. G. Taylor describe arrangements using recursive filter structures for equalization which may also be used for echo cancellation. Such recursive filters, however, are more difficult to adapt than nonrecursive filters using the transversal structure since the gradient adaptation method for transversal type filters is unstable when applied to recursive type filters. Adaptation methods such as disclosed in U.S. Pat. No. 4,057,696 issued to R. D. Gitlin et al Nov. 8, 1977 overcome the instability problem but are complex and are best suited for voiceband echo cancelers or modems where the low sampling rate allows multiplexing of hardware.
At the high data rates used in ISDN transceivers, hardware requirements necessitate a simpler adaptation method. The article "Mixed Recursive Echo Canceller (MREC)" by C. Mogavero et al appearing in the Proceedings of the 1986 Global Communications Conference (GLOBECOM) at pages 44-48 and U.S. Pat. No. 4,755,984 issued to R. Ambrosio et al Jul. 5, 1988 describe a tail canceler structure in which a nonrecursive filter exhibits a finite impulse response of the "boxcar integrator" type. This canceler structure adapts its gain using a modified version of the gradient method. Such adaptation has a sufficient length to approximate cancellation but the impulse response is finite whereby the degree of cancellation is limited.
The article "Architecture for Fully Integrated Echo Canceller LSI Based on Digital Signal Processing" by Hiroshi Takatori et al appearing in Proceedings of 1987 International Communications Conference at pp. 601 through 605 discloses an arrangement in which the aforementioned "boxcar integrator" is replaced by an ideal integrator having a step function impulse response which is used in combination with a vector quantization technique to adapt the filter gain. As is well known, the response of a transmission line for the tail component is primarily dependent on the parameters of the transformer used to couple the transceiver to the line and is largely independent of the line characteristics. The infinite impulse response selected to simplify the hardware needed for implementation by Takatori et al, however, is a relatively poor approximation to this transmission line response resulting in incomplete cancellation. It is an object of the invention to provide improved echo and intersymbol interference cancellation with higher accuracy removal of the tail portion components thereof.

Arrangement for canceling interference in transmission systems


A tandem axle suspension wherein alignment of one axle relative to the other may be adjusted. The suspension includes a pair of spring hangers attached to each side of the chassis frame and a leaf spring assembly interconnecting each pair of spring hangers. Each leaf spring assembly includes a leaf with a spring eye at one end and a spring pin extending through the spring eye and through a transverse aperture in an aperture-providing insert rotatably mounted in the spring hanger to which the end of the leaf spring with the spring eye is interconnected. The spring hanger in which the insert is mounted has an upper portion by which it is attached to the vehicle chassis frame and depending portion having a transverse opening in which the insert is rotatably mounted. The depending portion is transversely bifurcated by a slot extending upwrdly into the transverse opening. A horizontal bolt-receiving opening extends fore-and-aft through the depending portion and fore-and-aft through an upwardly extending fore-and-aft slot in the lower portion of the insert. A clamping bolt extends through the bolt-receiving opening. The fore-and-aft slot in the insert straddles the calmping bolt with sufficient upward clearance to permit the insert to be rotated through a substantial angle. The outboard side of the insert has a tool-engageable formation thereon. Since the aperture in the insert is eccentrically located fore-and-aft adjustment between the leaf spring and the chassis may be obtained by rotating the insert.

Known tandem drive vehicles, for example, use suspensions incorporating equalizing beams and leaf springs to cushion road shocks and to distribute weight between the tandem drive axles, thereby improving traction. The springs are generally mounted on saddle assemblies above the equalizing beams and connected at the front ends to front spring hangers with spring eye pins or spindles (hereinafter called "spring pins") through the spring eyes. The rear ends of the springs need have no rigid attachment to the rear spring hangers and may be free to move forward and backward to accommodate spring deflection. The rear hangers may be provided with cam surfaces which allow for this movement of the spring. Spring hangers may be affixed to the frame or chassis of the vehicle by conventional fixing means such as bolts, washers and nuts.
It is generally seen advantageous the tandem drive axles be parallel to each other and properly aligned with respect to the longitudinal axis of the truck frame or chassis. Prior suspension systems have been found wanting in satisfactory means for adjustment of the alignment of the axle with respect to the vehicle frame of chassis. The need for such adjustment has arisen in the last 2-3 years as a result of improvements in alignment measurement techniques, especially as a result of using laser-based equipment. If the axles and the wheels are properly aligned with the longitudinal axis of the vehicle frame, tire wear may be minimized and significant savings in fuel comsumption may also be achieved.
Two methods have been developed in an effort to provide some form of alignment adjustment. Those methods have related on the one hand to altering the position of the saddle assembly with respect to the leaf spring assembly and on the other hand, to fitting an eccentric adaptor at the ends of the equalizing beams where they are attached to the vehicle axles. The former method can be time consuming and arduous as it usually involves disassembling the saddle assembly and the leaf spring assembly.