The present application belongs to the field of chemical synthesis, and specifically relates to a six-membered ring-containing nucleoside compound and a preparation method thereof. The present application discloses a six-membered ring-containing nucleoside compound. The structural formula of the nucleoside compound 7 is:

Originally, coronavirus can infect the respiratory and digestive tracts of animals and humans. Normally, it causes only mild symptoms of infection in healthy people with normal immunity. However, in the SARS epidemic at the beginning of this century, it caused 8096 infections and claimed 774 lives in 27 countries around the world. Ten years later, the Middle East Respiratory Syndrome caused by MERS brought pain to 1,728 patients and took 624 lives. Coronaviruses can be divided into four categories based on genome and structure. Among them, α and β coronaviruses only infect mammals, while γ and σ coronaviruses mainly infect songbirds. Both SARS and MERS belong to beta coronaviruses. At the beginning of 2020, a certain number of pneumonia caused by coronavirus broke out in Wuhan, China. These coronaviruses bring considerable pain to human and even directly threaten life. Up to now, people still haven't found effective methods and vaccines against coronaviruses. Therefore, the development of new drugs against coronaviruses is of great significance.
In the past 30 years of clinical treatment for SARS and MERS, there is still no effective treatment. The patients are mainly treated by combining ribavirin with various interferons, sometimes using lopinavir and ritonavir which are drugs used for treating HIV, and even using broad-spectrum antibiotics. In the research of various antiviral drugs, small molecule nucleoside (TEAD) antiviral drugs (such as favipiravir and brincidofovir) have entered clinical trials in recent years. In particular, a nucleoside analog, Galidesivir, has also entered clinical development. Unfortunately, none of these existing treatments can treat acute infections or persistent viral infections and their sequelae. Therefore, it is of great significance to develop convenient and effective drugs for treating coronavirus diseases.
In recent years, research on nucleoside antitumor and antiviral drugs has been extremely active. Up to now, several nucleoside antitumor drugs have entered the market. For anti-viral drugs, many patents and documents have been reported (see WO 2015/069939 A1; WO 2017/184668 A1; ES 2 465 265 T3; CN 102015714 A). In particular, in recent years, a class of monophosphate amide prodrugs with anti-ebola virus (ebov) activity, represented by GS-5734 (shown in formula I) and GS-441524 (shown in formula II) have found favor in the eyes of pharmaceutical chemists (Nature 2016, 531, 381-385; J. Med. Chem. 2017, 60, 1648-1661; Veterinary Microbiology 2018, 219, 226-233). Unfortunately, most of the studies on the molecule of these nucleoside drugs and analogs are focused on five-membered sugar rings, and the vast majority of these nucleoside drugs have a disadvantage that they are difficult to dissolve in neutral water and most organic solvents (only soluble in dimethyl sulfoxide and N,N-dimethylformamide), which has brought much trouble for further purification of clinical chemical drugs and injection dosage research. However, there is no literature reporting nucleoside drugs containing six-membered sugar rings or relevant research. From the perspective of pharmaceutical chemistry research, the chair-like conformation of the six-membered ring structure may exhibit different pharmacological activities in vivo. Therefore, it is necessary to develop a six-membered ring-contained nucleoside drug with better solubility and higher in vivo activity.

Six-membered ring-containing nucleoside compound and preparation method thereof

Abstract: where R1 is selected from one of

Abstract: where R2 is hydroxyl or alkynyl.


A method and an arrangement are specified for setting up and clearing communications links via a private branch exchange. A number of types of communications device are driven via the same controller. New devices with a transport network for transporting the communications data can thus be integrated in a private branch exchange by using TDM-based devices. The central configuration of the controller allows already existing central interfaces and databases relating to subscribers to be used. If required, service feature controllers can still be used.

Owing to the increasing amount of communications traffic resulting from the increasing number of communications subscribers, and from the increasing requirements for the amount of data to be transmitted, transmitting devices, in particular private branch exchanges, are subject to increasingly severe requirements in terms of the amount of data to be transmitted by a communications link and the number of communications terminals which can be connected to one another.
Present-day devices are based, for example, on the TDM method (Time Division Multiplexing) in which communications data from different connections is transmitted in respectively defined time slots. A connection between different communications partners is produced by a switching matrix which, on the basis of control information, associates incoming time slots on an incoming connection with outgoing time slots on an outgoing connection. Such switching matrices generally have a fixed size and can produce only a defined number of connections, which often makes it harder to adapt switching systems to meet the requirements. Furthermore, the time slots have a restricted capability to accommodate data. For example, one switching matrix can produce 4096 connections, while a maximum of 64 kbits of data can be transmitted within one time slot.
An increase in the number of subscribers can thus be taken into account only in steps of 4096 connections. However, additional development efforts for matching the switching device to the greater number of subscribers is required in order to utilize these different extension levels. It is likewise impossible directly and flexibly to increase the transmission performance of each connection, and this can at best be done by setting up two or more communications links, that is to say in the form of steps of 64 kbits. However, this type of bandwidth multiplication has not been used in practice for transmission via ISDN (Integrated Services Digital Network) and scarcely any terminals are available for this purpose.
Although such existing communications systems have disadvantages which are intended to be overcome in the course of new developments for future communications devices, seamless integration of existing and new communications devices to form a homogeneous communications infrastructure is absolutely essential, at least during a transitional phase.
This is firstly because the investments that have already been made by the end users and communications network operators must be protected. Secondly, this is because it is technically essential to avoid individual communication islands, which the different systems would result in.

Method and system for setting up and/or clearing a communications link between two types of devices


An encasement device for a golf tee is cylindrically adhered to a shaft of golf tee. The encasement device is a cover with graduated markings, which allows the golfer to consistently set the tee at the golfer's desired depth. Each graduated marking is numerically related to other graduated markings and the ground penetration depth. The resulting multi-layer structure of the golf tee and the encasement device deters breakage of the golf tee and reinforces the shaft structure of the golf tee.

In the game of golf, the tee shot is one of the more important shots. Driving the ball off the tee consistently in terms of range and accuracy is generally a precursor to the golfer's score on the hole and on the course. Many factors contribute to a good tee shot, including proper placement of the feet with respect to the tee, follow through on the tee shot and keeping the head down at time of impact. All of these factors are difficult to master and require multiple rounds of golf and practice sessions.
One factor that should require no practice, is the setting of the golf tee in the ground. However, a drawback of prior art golf tees are that they are not designed to allow the golfer to place the golf tee in the ground at the same depth every time. As a consequence of these poorly designed prior art golf tees, the golfer can not maintain the same body position every time. The golfer has to adjust his or her hands up or down the golf shaft to compensate for the varying height of the golf tee. Unfortunately for the golfer, this inability to consistently place the golf tee at the same height, distracts away from the golfer's ability to concentrate on those factors mentioned above that require focus and practice. Importantly, lack of uniform depth placement of the golf tee prevents hitting the golf ball in the same manner each time, leading to loss of range and accuracy.
Although not solely a consequence of depth misplacement, a further disadvantage of prior art golf tees are there inability to withstand breakage upon impact by the golf club. Since golf tees are normally constructed from wood, golf club impact can result in splintering the golf tee, therefore making it unusable for future tee shots.
Accordingly, there is a need to provide a simple and effective device for a golf tee which provides consistent depth measurements when teeing up golf balls and helps deter the breakage of the golf tees upon impact by the golf club.


A method of and apparatus for changing the position of chains of sausages in sausage production processes with two endless conveying belts which convey the sausages of the chain of sausages over a first length in a first direction and which then deflect the chain of sausages into a second direction and convey it over a second length in said second direction, the distance between the conveying belts being chosen such that it is larger during transport in said second direction than during transport in said first direction, for use in transferring a chain of sausages from a twist-off station to a suspension station.

The present invention relates to a method and an apparatus for changing the position of chains of sausages in sausage production processes making use of two endless conveying belts which are arranged in parallel, and to the use of said method and apparatus for transferring chains of sausages from a twist-off station to a suspension station.
In sausage production processes, sausages are produced in the form of chains of sausages. The sausage meat is pressed into the sausage skin in a stuffing machine. The sausage skin is twisted off at predefined intervals so as to form individual sausages which are interconnected at the twist-off points after the fashion of a chain. Subsequent to the twist-off unit, the chains of sausages are introduced e.g. between two conveying belts which transport the chain of sausages away from the twist-off station at a defined speed. Due to the predefined speed, the length of a sausage between two twist-off points is defined. The chain of sausages can be transferred from the conveying belts to a suspension station where the chain of sausages is attached to suitable hooks at individual twist-off points thereof such that it takes up little space. With the aid of these hooks, the chain of sausages can then be transported away on suitable rails.
The chain of sausages must be knotted together at the sausage skin end. If the sausage skin tears or bursts, an operator must also be able to take action. This often necessitates that the operator works below the suspension hooks with a stoop.
The height above the floor at which the chain of sausages is discharged from the twist-off unit is predetermined by the structural design of the stuffing machine. This height should not be chosen too high so that the stuffing machine can still be filled easily. In addition, an excessively high level of support is not desirable for reasons of safety.
It is the object of the present invention to provide a method and an apparatus which permit improved handling of the machine.
In the case of the method according to the present invention, the chain of sausages is taken hold of by two endless conveying belts subsequent to the twist-off station; by means of these conveying belts the chain of sausages is transported away, initially without any change of direction. In a deflection area, the conveying belts are deflected into a second direction so as to convey the chain of sausages in a second direction at an oblique angle to a higher level. The distance between the conveying belts in the area of transport in said second direction is larger than the distance between the conveying belts in the area of transport in said first direction.
In the deflection area, the path of movement of one conveying belt is shorter than the path of movement of the other conveying belt. This has the effect that the conveying belts are longitudinally displaced relative to one another in the deflection area in the direction of movement. If a sausage portion is located between the conveying belts, friction may be caused by this longitudinal displacement, which may injure the sausage portion. By increasing the distance in the second area, in which the chain of sausages is conveyed in the second direction, the distance between the conveying belts will increase in the deflection area. Also this will contribute to a reduction of the friction acting on the sausage portions, whereby the risk of injuries will be reduced.
In the area in which transport takes place in the first direction, the distance between the conveying belts may correspond to the diameter of the sausage. If the distance in said area of transport in the first direction is, however, chosen such that it is smaller than the desired stuffing diameter, it will be guaranteed that the chain of sausages is safely held between the conveying belts during the twist-off process. In this way, the respective sausage is reliably taken hold of and transported. Reliable taking over of the chain of sausages by the conveying belts is guaranteed, when the chain of sausages is conveyed over a certain length in said first direction, i.e. when the transport path in said first direction is chosen such that also longer sausages can be taken hold of safely. In practice, a conveying length of at least 15 cm in said first direction proved to be suitable for all the conventional different sausage lengths.
The chain of sausages can be removed from the second area. According to an advantageous embodiment of the method, the area of transport in said second direction is followed by another deflection area in which the chain of sausages is deflected from said second direction into a third direction, which is parallel to said first direction. By means of this method, the chain of sausages is therefore displaced parallel to its original direction of transport. If the chain of sausages is e.g. horizontally introduced between the conveying belts, it can be raised to a higher level by said advantageous method, and it will be discharged from the conveying belts again in parallel.
For guaranteeing a reliable transfer to a subsequent station, it will be advantageous when the distance between the conveying belts is smaller in the area of transport in said third direction than in the area of transport in said second direction.
A careful transfer will be possible when the distance in the area of transport in said third direction is larger than or equal to the stuffing diameter of a sausage portion.
It will be advantageous when the transport length in said third direction is again chosen such that it will suffice for all conventional sausage lengths (also in this case at least approx. 15 cm) so as to permit transfer with the correct orientation.
An apparatus according to the present invention for carrying out the method according to the present invention comprises two parallel endless conveying belts comprising a first area for conveying the chain of sausages in a first direction, the conveying belts extending at a first distance from one another in said first area, a first deflection area in which the conveying belts are deflected parallel to one another from said first direction into a second direction, a second area for conveying said chain of sausages in a second direction, the conveying belts extending at a second distance from one another in said second area, said second distance being larger than said first distance.
The apparatus according to the present invention can be implemented such that it is adapted to convey sausages having a defined length and a defined diameter. It will, however, be advantageous to provide adjustment means with the aid of which the distances in the first area and in the second area and in the third area, respectively, can be adjusted so that sausage diameters of different dimensions can be processed.
The endless conveying belts can be driven by individual motors operating at matched speeds. A particularly simple embodiment is, however, an embodiment in the case of which the two conveying belts are driven with the aid of a suitable gear unit by the same motor. This will guarantee a synchronous movement.

Method and apparatus for changing the position of chains of sausages

Albert Handtmann Maschinenfabrik GmbH and Co. KG


A duplexer having dual coupled line characteristics is disclosed. With a small number of resonators and without using an external device such as a chip inductor or a chip capacitor, the signals of the receiving frequency can be improvingly damped. The diameters of the transmitting terminal dielectric filter resonators and the receiving terminal dielectric filter resonators are not same, but their diameters at an open terminal and at a short circuit terminal are made different from each other so as to differentiate a coupling amount at the short circuit terminal from that at the open terminal. Further, the transmitting terminal filter resonators and the receiving terminal dielectric filter resonator are provided in a form of grooves, and sizes of the grooves near the open terminal are made different from those of the grooves near the short circuit terminal so as to differentiate a coupling amount of the resonators at the short circuit terminal from those at the open terminal. The duplexer of the present invention is used in the transmission/receiving separate type filter of the mobile communication.

1. Field of the Invention
The present invention relates to a duplexer which is a transmitting/receiving separate type filter for use in UHF band mobile communication. In particular, the present invention relates to a duplexer having dual coupled line characteristics.
2. Description of the Prior Art
The duplexer which is used as a transmitting/receiving separate type filter in the UHF band mobile communications uses TEM mode dielectric coaxial resonators. The number of the coaxial resonators is decided depending on the filter requirement characteristics but generally, in order to increase the signal damping for the transmitting frequency at the band pass filter of the receiving terminal, the number of the resonators of the filter of receiving terminal is made larger than that of resonators of the band pass filter of the transmitting terminal.
FIG. 1 illustrates the constitution of a duplexer using the conventional dielectric. In this duplexer, an integrated type is provided in which a plurality of resonators are connected to a single dielectric block. That is, the duplexer includes: four resonators 2 of the transmitting terminal, five resonators 2' of the receiving terminal, and a resonator 3 used as a separating circuit for separating the transmitting/receiving signals.
In a dielectric block 1, the resonators 2, 2' and 3 having holes of the same size are formed from an upper face 1' of the dielectric block to its bottom. Further, the five faces of the dielectric block 1 excluding the upper face 1' are electroplated. Therefore, the resonators form short circuits connected from the bottom of the dielectric block to the ground. The upper face 1' functions as a 1/4 resonator which is an open end terminal. Further, the diameters of the resonators are uniform, and therefore, they are uniform impedance resonators in which the impedance of the open terminal is same as that of the short circuit terminal.
Further, in the first resonator and in the last resonator, there are inserted conductive rods 5 as input/output terminals. Further, dielectric sleeves are fitted to the input/output terminal conductive rods 5 for a capacitive coupling between the conductive rods 5 and the resonators 2. Further, resonator 3 is provided for the branching circuit so as to match the impedance between the transmitting terminal and the receiving terminal at an antenna terminal 5'. Therefore, input signals which are inputted into the transmitting filter are not transferred to the receiving filter, but are transmitted through the antenna terminal. The signals which are received through the antenna terminal are transferred to the transmitting filter but are transferred to the receiving terminal.
In this duplexer described above, the coupling between the resonators is done through a single coupling line in which the odd and even mode admittances of the open terminal and short circuit terminal are constant. Further, all the faces of the dielectric block except the upper face 1' are electroplated with a metal.
In the duplexer of FIG. 1, if an electric equivalent circuit is illustrated by using a coupling line for the transmitting filter, then it becomes as shown in FIG. 6. In FIG. 6, the equivalent circuit includes three resonators, and a UIR resonator is shown in the form of a short-circuited 1/4-wavelength resonator 19. Further, the coupling between the resonators is shown in the form of a distribution device 20 based on an induced coupling. Further, the coupling between the input/output conductive rods and the resonators is shown in the form of capacitance 21.
In this duplexer, if the insertion loss characteristics are illustrated for the band pass filters used in the transmitting terminal and the receiving terminal, then it becomes FIG. 9 in which the dampings at the frequencies higher or lower than the pass band are almost same.
However, in the mobile communication, in order to efficiently utilize the frequency, the transmitting band and the receiving band are closely positioned. Further, in order to make the damping of the adjacent frequency large, the transmitting band pass filter requires a more superior damping characteristic at a frequency higher than that of the pass band. Further, the band pass filter which is used at the receiving terminal requires a higher damping characteristic at a frequency lower than that of the pass band. In this band pass filter, in order to improve the damping characteristics, if the number of the resonators is increased, the damping characteristics are improved, but the insertion loss is increased, and the bulk of the filter is increased. Accordingly, there is required a pole filter having a blocking pole without transmitting the signals at a particular frequency, and without increasing the number of resonators.
FIG. 2 illustrates another conventional duplexer in which short-circuited 1/4-wavelength individual resonators 6 and a concentrated device are used, thereby providing a duplexer having a polarity. A transmitting filter includes three individual resonators, and a chip capacitor 9 is inserted into between a first resonator and input terminal 7. The coupling between the resonators is carried out in such a manner that an electrical pattern is connected on a PCB board 8, and that an external chip capacitor 9 is connected to it. In order to block the transmission of signals at a particular frequency, a separate chip inductor 10 is inserted into an open terminal of a second resonator. The resonance circuit is modified by connecting the chip inductor 10 to the open terminal of the second resonator so as to form a pole frequency. That is, at a frequency at which the impedance of the second resonance circuit becomes zero, the signals from the input side cannot be transferred, but flows through the resonance circuit to the ground, and therefore, there occurs a pole frequency. Such a pole frequency is generated at a frequency higher than the pass band of the transmitting filter, and therefore, the damping of the receiving signals can be increased. The filter of the receiving terminal includes four individual resonators, while a chip capacitor is inserted into between the last resonator and an output terminal. An equivalent circuit for this duplexer is illustrated in FIG. 7.
The equivalent circuit of FIG. 7 includes three resonators. The coupling between the resonators is done in such a manner that an electrical pattern is connected to a PCB board 8, and an external chip capacitor 9 is connected to it. In order to block the transfer of signals at a particular frequency, a separate chip capacitor 10' is disposed at an open terminal of a second resonator. Under this condition, the pole frequency occurs at a frequency lower than that of the pass band of the receiving frequency, and therefore, the damping of the transmitting frequency can be increased.
The frequency characteristics of this filter is illustrated in FIG. 10. In order to match the impedance of the filters of the antenna terminal 7', the transmitting terminal and the receiving terminal, there are used a chip inductor 11 and a chip capacitor 11'. Therefore, the signals which are inputted into the transmitting input terminal are not transmitted to the filter of the receiving terminal due to the impedance adjusting inductor, but are propagated through the antenna terminal to the external. The signals which are received to the antenna terminal are transmitted to the filter of the receiving terminal, thereby transferring energy.
In such a duplexer, a pole filter is formed, and therefore, the damping characteristics can be improved with a small number of resonators. However, external devices such as a chip capacitor or a chip inductor are used, and therefore, the bulk of the product is increased, as well as complicating the manufacturing process.
In the transmitting/receiving separate type filter of the mobile communication, a high damping characteristic is required, and owing to the compactness and light weight trend of the terminals, the filter and duplexer have to be miniaturized. Therefore, a duplexer which is small in size and superior in the damping characteristics is in demand. However, in the conventional duplexer, either the number of the resonators is increased, or an external device such as a chip capacitor or a chip inductor has to be used. Consequently, the size of the filter is increased, and the manufacturing process becomes complicated. Therefore, a duplexer which is superior in the damping characteristics and small in size is in demand.
Recently in the mobile communications, in order to efficiently utilize the frequency, the transmitting and receiving bands are closely approached, while the miniaturization and light weight of the terminals are progressing at a fast pace.

Duplexer having dual coupled line characteristics

Electronics and Telecommunications Research Institute


A digital-to-analog converter system has digital-to-analog converters, a common output, and a digital controller for transmitting first codes to one of the converters at a radio-frequency digital rate, and for transmitting second codes to another one of the converters at the same rate. The digital controller includes a timing system for operating each converter at the digital rate in a return-to-zero configuration, such that a signal from the first converter is transmitted to the common output while the second converter is reset, and vice versa. The digital-to-analog converter system can generate a radio-frequency analog signal having signals in first and second Nyquist zones simultaneously.

A digital-to-analog (D/A) converter (DAC) system is used to generate an analog signal based on a series of digital codes. A radio-frequency (RF) digital-to-analog converter system may be utilized in a variety of applications, including in a telecommunication system. A digital-to-analog converter system may also be used, if desired, in connection with a multi-step analog-to-digital (A/D) converter (ADC) system, a high-resolution display system, a waveform synthesis system, and an instrumentation device.

Radio-frequency digital-to-analog converter system


An improved structure for a reciprocating internal combustion engine or compressor piston fabricated from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small, flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variation in thermal expansion differences between the piston and the cylinder liner.

1. Field of the Invention
This invention relates to the lightweight design of an improved reciprocating piston for an internal combustion engine and/or compressor, and more specifically to improved structures for an integral ring piston fabricated from carbon-carbon composite materials.
2. Description of the Related Art
Internal combustion, reciprocating engines used in aerospace, military, and transportation applications and compressors should be lightweight and capable of operating at elevated temperatures.
Conventional internal combustion engines and compressors employ pistons fabricated from cast-iron, steel, or aluminum alloys. In many applications, aluminum alloy pistons have replaced steel and cast-iron pistons because they are lighter and their use has a dramatic effect on reducing total engine weight. However, aluminum alloy pistons used in high speed airplane engines and lightweight diesel engines frequently fail due to severe thermal loads at elevated engine operating temperatures, i.e. above 600 degrees Fahrenheit (F).
Additionally, the high thermal conductivity and high specific heat of cast-iron and steel pistons result in considerable "through-the-wall" heat loss. Such heat loss reduces engine and compressor operating efficiency, especially with diesel engines.
Further, conventional pistons fabricated from steel or aluminum alloy have relatively high coefficients of thermal expansion, i.e. they expand when heated. To account for thermal expansion, a small clearance between the piston and the cylinder liner is required. This clearance creates a gap through which compression gases "blow by" the piston thereby polluting the environment and reducing engine operating efficiency. To arrest "blow by," conventional pistons employ a plurality of piston rings to seal the gap.

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A hydraulic control system for a machine having a work implement is disclosed. The hydraulic control system has a fluid actuator configured to move the work implement. The control system also has an operator interface device configured to generate at least one signal in response to a movement of the operator interface device. The control system further has a valve assembly for controllably providing hydraulic fluid flow to the fluid actuator to affect movement of the fluid actuator. The hydraulic control system has a controller configured to communicate with the valve assembly and the operator interface device. The controller is also configured to receive a signal, determine a velocity input associated with the movement of the operator interface device based on the received signal, and determine a desired fluid actuator velocity based on the determined velocity input. The controller is further configured to generate a command signal corresponding to the desired fluid actuator velocity and to direct the command signal to the valve assembly.

Machines such as, for example, excavators, loaders, dozers, motor graders, and other types of heavy machinery use multiple hydraulic actuators to accomplish a variety of tasks. These actuators are typically velocity controlled to move a work tool at a speed based on an actuation position of an operator interface device. For example, an operator interface device such as a joystick, a pedal, or any other suitable operator interface device may be movable to a position to generate a signal corresponding to that position that is indicative of a desired velocity of an associated hydraulic actuator. When an operator moves the interface device to that specific position, the operator expects the hydraulic actuator to move at the corresponding predetermined velocity.
One example of this type of system is described in U.S. Pat. No. 5,899,008 (the '008 patent) issued to Cobo et al. on Apr. 4, 1999. The '008 patent describes an apparatus for controllably moving a work implement connected to a machine based on positional feedback. Specifically, the apparatus of the '008 patent includes an operator controlled joystick that generates an operator command signal in response to a moved position of the joystick. The signal is indicative of a desired velocity and initiates the controlled flow of hydraulic fluid to lift and tilt cylinders to move the cylinders in accordance with the desired velocity. Cylinder position sensors produce cylinder position signals in response to the position of the lift and tilt cylinders. A controller receives the operator command and cylinder position signals and responsively produces a pump command signal to change the displacement of a variable displacement pump, thereby regulating the movement speed of the hydraulic cylinders to match the desired velocity.
Although the '008 patent may provide predictable implement movement velocity, the apparatus of the '008 patent may be less responsive and less intuitive than desired by an operator of the machine. That is, there may be times when an operator desires only small movements of the lift and/or tilt cylinders, but at a high velocity. In this situation, a position only based control system may be unsatisfactory. Further, it may be more intuitive for the movement speed of the implement system to be at least partially based on the movement speed of the joystick.
The disclosed control system is directed to overcoming one or more of the problems set forth above.

Implement control system based on input position and velocity


The present invention is directed to a process for preparing Fluvastatin Sodium salt by basic hydrolysis of its alkyl ester. The reaction is performed in conditions suitable to allow a selective hydrolysis of the desired syn isomer, while the unwanted anti isomer is removed by extraction, thus reducing its content in the final product; this diastereomer is the main impurity of Fluvastatin sodium salt and its ester precursor.

Fluvastatin Sodium salt of formula I (relative stereochemistry) is marketed by Novartis under the trade name of Lescol and belongs to a class of anti-hyperlipidemic agents called statins. Such compounds are HMG-COA reductase inhibitors, i.e. inhibit the enzyme that reduces 3-hydroxy-3-methylglutaric acid to mevalonic acid, thus blocking the biosynthesis of cholesterol and lowering its level in the bloodstream. Most statins resemble mevalonic acid in the sense that they contain the 3,5-dihydroxy carboxylate function, fooling the enzyme to binding to the drug and therefore inhibiting it.

The product patent for Fluvastatin is EP 114027, in which several synthetic routes are described. The last 2 steps (reduction followed by saponification) of the preferred process are better described in the process patent EP 363934, in which the synthesis set forth in Scheme 1 (relative stereochemistry) is described; the drug substance is then obtained by lyophilization of its aqueous solution.

This patent claims a specific order of addition of the reactants in the stereoselective reduction from III to II, in order to achieve a high level of syn stereoselectivity and minimize the unwanted diastereomer, the so called anti isomer IV (relative stereochemistry).

This is well explained in the paper written by Novartis' process research and development group "The Story of Lescol: From Research to Production", Org. Process Res. Dev. 2001, 5, 519-527: in the introduction they report that the most difficult challenge was "to form the 3,5-diol exclusively in the syn configuration". This unwanted anti diastereomer is actually the main impurity of Fluvastatin Sodium salt and its ester precursors, as confirmed by the United States Pharmacopoeia monograph of Fluvastatin (Official Monographs, USP 28, First Supplement, USP-NF, 3234), which sets a limit of 0.8% (HPLC) for this impurity and a much lower limit of 0.1% for any other impurity. This high limit set by the USP, which is unusual for impurities in active pharmaceutical ingredients, must be due to the limited stability of Fluvastatin in stressed degradation studies; such limited stability is reported on page 9 of EP 907639, which uses the same HPLC method later adopted by the USP; clearly the anti isomer must be one of the main degradation products and this fact has been actually confirmed by our independent investigations. In conclusion, the content of anti isomer in the active pharmaceutical ingredient must be far below the above set limit to allow for the unavoidable degradation that takes place during storage (showed by the stability studies), i.e. the content of anti isomer must reasonably be below 0.4% and preferably below 0.2%.
Novartis apparently solved the problem of the purification of Fluvastatin Sodium from its anti isomer improving the stereoselectivity of the reduction of the carbonyl to the hydroxyl group, as claimed in EP 363934, affording an ester precursor of better quality. In "The Story of Lescol" is stated on page 526 that starting from the t-butyl ester (which is preferred over the methyl ester, since avoids a lactonization side process that causes isomerization to the anti isomer) such reduction affords a 99:1 selectivity, i.e. we must understand that the ester precursor contains about 1% of the unwanted anti isomer; this means that the ester precursor has to be recrystallized at least twice in order to achieve a reasonable degree of purity, with considerable yield loss. As a matter of fact, the authors of the paper carry on stating that: "only minimal purification occurs in the last step. The saponification leaves Fluvastatin Sodium salt in the aqueous layer, which is freeze-dried, to obtain the drug substance as a white powder".
As shown above, there is still need of an improved process for the preparation of Fluvastatin Sodium salt that allows minimizing the content of anti isomer, without resorting to several crystallizations of its t-butyl ester precursor, which cause considerable yield loss.

Process for the preparation of Fluvastatin Sodium salt

F.I.S. Fabbrica Italiana Sintetici S.p.A.


Tank level and flow control systems wherein the presence of materials or solutions of known viscosity ranges in a tank or flow stream is detected by using viscosity detection devices. Automatic control devices are also incorporated into these systems to react to one or more signals from the viscosity detection devices and to control the operation of a pump and appropriate valves. One embodiment of the tank level and control system includes a viscosity detection system using a vertical three probe arrangement to report relative viscosities of materials in a storage tank, at predetermined levels in the tank, to the control device.

The pulp and paper industry is replete with instances where tank level and flow control systems are needed to ensure the proper control of, for example, material balances in the paper mill and to ensure against the environmental concerns of spills and inefficient blending of process materials. One such example of this need relates to the kraft papermaking operations around the world, and specifically to the byproduct operations in the kraft mill. In particular, the kraft papermaking process involves the production of a spent caustic solution (or weak black liquor) as a byproduct of the digester operation (where wood chips, for example, are broken down to cellulose fibers by the application of steam, pressure and chemicals). This spent caustic solution, after further concentration (to increase the percentage solids in the solution) and when stored in some tank arrangement, forms a precipitate called sulfate soap which, having a lower density than the weak black liquor, floats on the weak black liquor solution in the tank.
It is the flow and control of the sulfate soap and the weak black liquor which is the focus of the present invention. More specifically, the weak black liquor in a kraft papermill is usually processed further in the mill evaporators and used as a source of energy for the mill. If the mill evaporators are provided with a source of black liquor which has a high concentration of sulfate soap, the evaporator operation will be significantly less efficient than desired and in some instances may present serious environmental hazards.
The sulfate soap is also processed further, usually by acidulation, wherein the sulfate soap is blended with the appropriate amount of an acid, typically sulfuric acid, to produce a waste brine solution having a low pH, and a tall oil product. The presence of higher than optimal levels of weak black liquor in the sulfate soap may lead to higher costs for acidulation, unacidulated soap, and a host of environmental concerns related to the disposal of the higher levels of acid/brine solution.
In order to optimize the removal of the sulfate soap from the weak black liquor without removing an unnecessarily large amount of the weak black liquor along with the sulfate soap, tank level and flow controls for this portion of the papermill must be carefully controlled.
Referring to FIG. 1, representing a prior art storage tank arrangement for sulfate soap and weak black liquor, the mixture of weak black liquor and sulfate soap was sent to a tank where the sulfate soap would rise to the top of the mixture and the weak black liquor would become the lower layer in the tank. The creation of the mixture of weak black liquor and sulfate soap is the result of the reaction of the caustic pulping liquor solution with the wood chips in the digester. The separated sulfate soap phase must be first skimmed from the mixture (while still in one or more weak black liquor tanks) to remove the bulk of the precipitated sulfate soap. This skimming operation involves the removal of the precipitated sulfate soap and some of the weak black liquor. The "skimmed" portion of the weak black liquor tanks is then typically transferred to one or more sulfate soap storage tanks where the weak black liquor and the sulfate soap undergo further separation.
In reality, the separation of the components in the tank occurs in accordance with a density gradient with the lighter soap material rising to the top of the tank and the heavier weak black liquor material sinking to the bottom of the tank. It is normal for the sulfate soap in the top portion of the sulfate soap storage tank to contain a lower percentage of black liquor than the sulfate soap toward, for example, the middle of the tank. This separation of the weak black liquor and sulfate soap occurs because of the different densities of the two components of this mixture. In particular, the weak black liquor by itself, has a typical density range of 8.8 pounds per gallon to 9.3 pounds per gallon, while the sulfate soap, depending upon the amount of entrained air and weak black liquor, may have a typical density range of from 2 pounds per gallon to 8 pounds per gallon. Also, weak black liquor is a relatively free flowing, non-viscous material when compared to sulfate soap, which, depending upon the percentage of entrained weak black liquor, is a relatively viscous material. In fact, sulfate soap can typically have a viscosity range of approximately 2000 centipoise to 5000 centipoise, while weak black liquor, depending upon the amount of solids in the solution, has a typical viscosity range of 1 centipoise to 3 centipoise.
In the past, for example, and referring to FIG. 1, an operator would manually open a valve A at the bottom of the tank to remove the accumulated weak black liquor and either visually inspect the flow of material from the open valve, or approximate the amount of weak black liquor in the tank and keep the valve open for the correct amount of time to remove the weak black liquor. Other attempts at performing this operation included the use of temperature detection devices B and C, based on the differentials in the thermal conductivity characteristics of the weak black liquor and sulfate soap components. This procedure in particular has proven to be ineffective due to varying component composition and fouling of the temperature probes B and C in the weak black liquor and sulfate soap solutions, respectively, causing frequent cleanings and unreliable readings of tank levels.
Prior to the present invention, attempts to use viscosity detection as a means to determine the sulfate soap and weak black liquor interfaces in a tank failed because of the inability of such systems to accommodate the full range of flow conditions in the tank. Specifically, the former attempts failed to address the ever present process conditions relating to the high variability of process physical parameters and chemical composition.

Viscosity based tank level and flow control systems


A semiconductor fabrication method for forming an insulation film and a first anti-oxidation film sequentially on a substrate which is sectioned into each of a peri region and a cell region. An active pattern is formed in the cell region and a first field ion-implanted region in a first conductive well of the cell region. Side wall spacers are formed on each side wall of the active pattern in the cell region. An active pattern is formed in the peri region by selectively etching the first anti-oxidation film and the insulation film so as to expose a certain surface portion of the peri region substrate therethrough. A first field ion-implanting region is formed in a first conductive well of the peri region by ion-implanting highly concentrated first conductive impurities through the exposed substrate and a second field ion-implanted region in a second conductive well of the peri region. Lastly, a field oxide layer created using a field oxidation process after removing the first anti-oxidation film, the insulation film and the side wall spacers. The method beings by forming a semiconductor device which eliminates double hump phenomenon, decreases leakage current and lowers stand-by current to improve the operating properties of the device.

1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly to a semiconductor device fabrication method for realizing an isolation structure in a memory chip, by means of applying a memory cell region formation to an advanced local oxidation of silicon (LOCOS) process, and a peri region to a general step thereof.
2. Description of Conventional Art
A conventional semiconductor device fabrication method for fabricating a 64 MB dynamic random access memory (DRAM) using an advanced LOCOS technique is illustrated in FIGS. 1A-1 through 1I-2. There will be described the fabrication steps in accordance with the accompanying drawings wherein FIGS. 1A-1, 1B-1, . . . 1I-1 as shown on the left side thereof denote a peri region isolation structure and FIGS. 1A-2, 1B-2, . . . 1I-2 as shown on the right side illustrate a cell region isolation structure respectively.
As shown in FIGS. 1A-1 and 1A-2, the first step is to grow a base oxidation 8 as an insulation film on a substrate 1 which is sectioned into a peri region and a cell region. The peri region defines a substrate portion composed of each of a first conductive well (hereinafter, "P-well") and a second conductive well (hereinafter, "N-well"), and the cell region denotes a substrate portion composed of a P-well.
As shown in FIGS. 1B-1 and 1B-2, the second step is to deposit a first nitride film 9 as a first anti-oxidation film on the base oxidation film 8, and to form a pair of photoresist patterns 4 on active pattern regions of the first nitrate film 9 by a lithographic process.
As shown in FIGS. 1C-1 and 1C-2, the third step is to etch the first nitrate film 9 and the base oxidation film 8 using the photoresist 4 as a mask, to form active patterns composed of the oxidation film 8 and the nitride film 9 on the peri and cell regions of the substrate 1. Afterwards, the remaining photoresist 4 is removed.
As shown in FIGS. 1D-1 and 1D-2, the fourth step is, after removing the photoresist 4 includes the following. In the peri region another photoresist pattern 4' is formed that entirely covers the exposed active pattern formed on the second conductive well 5. Then, highly concentrated first conductive impurities (such as p+impurities) are implanted into the substrate 1 of the peri and cell regions using the photoresist 4' as a mask to form N-field ion-implanted regions 10 (such as p+regions) for serving as first field ion-implanted regions in the first conductive wells 7 of each of the peri and cell regions. The photoresist 4' is then removed.
As shown in FIGS. 1E-1 and 1E-2, the fifth step begins forming another photoresist 4" to entirely cover the exposed active pattern formed on the first conductive well 5. Highly concentrated second conductive impurities (such as n+impurities) are then implanted into the substrate 1 using the photoresist 4" as a mask to form P-field ion-implanted regions 11 (such as n+regions) for serving as first field ion-implanted regions in the second conductive well 5 of the peri region. The photoresist 4" is thereafter removed.
As shown in FIGS. 1F-1 and 1F-2, the sixth step is to perform a LOCOS annealing on the substrate 1 having the active patterns thereon, to deposit a second nitrate thin film 12 as a second anti-oxidation film on the annealed surface, and to form thereon a HLD (high temperature and low pressure dielectric) insulation film 13.
As shown in FIGS. 1G-1 and 1G-2, the seventh step is to form side wall spacers on each side wall of the active patterns and on selected surfaces of the substrate 1. The side wall spacers are formed by dry etching portions of the HLD insulation film 13 and a portion of the second nitride film 12. A silicon dry etching is performed with the side wall spacers and the active patterns acting as masks so that the exposed substrate 1 is etched to a defined depth of up to 500 .ANG.. Beginning with FIG. 1G-1, the first conductive well 7 and the second conductive well 5 will be shown without a step therebetween for convenience' sake.
As shown in FIGS. 1H-1 and 1H-2, the eighth step includes performing a field oxidation in the recesses formed during the seventh step so as to form a field oxidation film 14. The HLD insulation film 13 is removed from the side wall spacers. A field diffusion is then performed that results in an N-field 10' being formed in the P-well 7 in each of the peri and cell regions and a P-field 11' being formed in the N-well 5.
As shown in FIGS. 1I-1 and 1I-2, the ninth step is to remove the first nitrate film 9, the second nitrate film 12, and the base oxidation film 8, thus to complete the semiconductor device isolation structure fabrication.
Consequently, the conventional advanced LOCOS technology is focused on isolating the active regions and the device isolation regions from each other using each of the field oxidation film 14, N-field 10' and P-field 11'. Therefore, when a semiconductor device is manufactured using the advanced LOCOS technique, the field oxidation film 14 tends to be formed steeply at its bird's beak portion so that the active regions are less likely to be intruded into by the field oxidation film 14 and become decreased in size. As a result, the conventional technique remains advantageous for forming memory device regions being densely patterned such as a cell region.
However, the LOCOS technique can induce a double hump phenomenon in which a parasitic transistor initially turns on in active edge regions which will be in contact with gates during the device fabrication. The "double hump phenomenon" is illustrated in IEEE Electron Device Letters, Vol. 14, No. 8, August 1991, pp. 412-414 in the article entitled "The Current-Carrying Corner Inherent to Trench Isolation" and in IEEE Transactions on Electron Devices, Vol. Ed.-32, No. 2, February 1985, pp. 441-445 in the article entitled "Analysis of an Anomalous Subthreshold Current in a Fully Recessed Oxide MOSFET Using a Three-Dimensional Device Simulator." Therefore, the LOCOS technique has a disadvantage in that, because of the current leakage and increased stand-by current occurring in a peri region where memory operating circuits are congregated, the memory device operating characteristics can be adversely affected.


A Growing apparatus for cleansing air and watering plant, wherein the apparatus includes a modular panel constructed for either vertical or horizontal planting systems, including connecting couplers and end caps for directing water flow from upper to lower channels. Panel consist of 5 channels per section with opposing conical top and bottom set at 45 degree angles (FIG. 9-23) for both channeling water and accepting irrigation nozzle. System can also use a horizontal channel system while the orientation is different but function is the same. Panels stack nesting consecutively on top of each other to make larger systems.

Indoor green walls using plants have been increasingly popular for aesthetics, improved air quality, humidity and natural cooling. Planting system both horizontal and vertical systems have been developed for air cleaning using the microbes living around plant roots for air cleaning. These green structures can pose a number of problems for the owner, mold, algae, and health issues from dirty catch basin reservoir. Drip irrigation or "eb flow systems are the most common methods of irrigation for vertical systems. Because each plant tray drains into the next consecutive tray all the dirt/debris flows into catch basin that is open and exposed to the indoor environment. Poor air circulation creates mold and algae problems, and poor growing conditions for the plants. The plants ability to clean the air is inhibited by these issues and dramatically reduces the potential healthy effects green walls can have. Aeroponic systems like U.S. Pat. No. 850,523B2 Luebbers, Hensley, use spray methods for watering plants still resulting in a mixture of soil and debris in irrigation water which will frequently need to be cleaned. Drip vertical systems like patent #EP1416229A2 Darlington, use an air permeable sub-straight creating a similar problem of organic/dirt debris building up in containment reservoir. EP2654400A 1 Paleszezak discloses a series of pipes, with alternating prismatic shaped bins, for air circulation. W02011 019277 A2 Kluiver discloses a system where indoor pollution is captured on the leaves of a plant and washed into substrate. System W0201 0033423A 1 Wolverton/Middlemark, use beds with various sized substrate to and drip irrigation to process indoor air through. U.S. Pat. No. 6,477,80582 Ware uses similar drip methods, again mixing irrigation water directly with planting mediums and debris. Therefore it is the purpose of this invention to demonstrate an irrigation system that efficiently delivers water and air directly into planting substrate that does not need modification for air flow, while keeping irrigation water separate from living area. It is the purpose of this invention to use air movement to facilitate water movement over a modified wicking system into the soil, not using the capillary nature of the wick to do so as U.S. Pat. No. 4,741,125 Donald Pengorest where a bi expandable metal control device is used for control. Further U.S. Pat. No. 4,219,967 Hickerson, relies on a wick system as well. Capillary wicks are used in many growing devices however controlling the moister they deliver is not easily achieved, leaving soil saturated and unhealthy. There for it is the purpose of this invention to control air and moisture delivery through a specifically designed nozzle that removes the need for electronic equipment for regulating moisture levels.

Pressurized growing air system for vertical and horizontal planting systems


A magnetic field generating device used for MRI includes a pair of magnetic pole pieces to each other to provide a gap therebetween and generate a magnetic field in the gap, the magnetic pole pieces being formed by laminating and integrating a plurality of non-oriented silicon steel sheets. By using laminated non-oriented silicon sheets the eddy current generated in the magnetic pole pieces caused by the application of GC pulses can be reduced and phenomenon of the residual magnetism can also be reduced.

1. Field of the Invention
The present invention concerns a magnetic field generating device used, for example, in a magnetic resonance imaging apparatus (hereinafter referred to as MRI), particularly for medical use.
2. Description of the Prior Art
MRI is an apparatus adapted to obtain a tomographic image of a portion of a person and provide an image of his or her tissue.
In the magnetic field generating device used for the MRI, it is necessary that the provided gap have a space which is capable of partially or wholly accommodating the person to be diagnosed and it is also necessary to form a stable intense magnetic field, usually of 0.02 to 2.0 T and at an accuracy of less than 1.times.10.sup.-4 in an image pick-up view field in the gap, i.e., in order to obtain a clear tomographic image.
A known magnetic field generating device used for MRI has a construction as shown in FIGS. 12(a) and 12(b) in which a pair of components 1, 1 made of permanent magnets are opposed to each other as a magnetic field generating source, with one end of each of them being secured with a magnetic pole piece 2 and the other ends of them are connected by means of yokes 3, to generate a static magnetic field in a gap 4 defined between the magnetic pole pieces 2 and 2.
An annular protrusion 5 is disposed at the periphery of each of the magnetic pole pieces 2, 2 in order to improve the uniformity of the magnetic field distribution in the gap 4, and it is usually made of a plate-shaped bulk (one piece product) prepared by scraping from magnetic material, such as electromagnetic soft iron or pure iron (refer to Japanese Patent Laid Open Sho 60-88407).
Gardient magnetic field coils 6 disposed in the vicinity of each of the magnetic pole pieces 2, 2 usually comprise three sets of coil groups corresponding to three directions X, Y and Z for obtaining positional information in the gap 4, but they are described simply in the drawing.
When a pulse current is applied to the gradient magnetic field coils 6, a gradient magnetic field changing with time in a trapezoidal waveform can be generated in a desired direction.
When the pulse current is caused to flow in the gradient magnetic field coils 6, since the magnetic pole pieces 2 are composed of the plate-shaped bulk as described above, magnetic the field changes abruptly upon rising and falling of the current to induce an eddy current in the magnetic pole piece 2, 2.
Since the eddy current forms a magnetic field in a direction opposite to the magnetic field formed with the gradient magnetic field coils 6, it takes a long time for the gradient magnetic field to reach a predetermined intensity.
As a means for overcoming the foregoing problem, there has been proposed a magnetic field generating device using, as the magnetic pole piece, a plate-shaped lamination comprising soft magnetic thin films, such as permalloy steel sheets or amorphous steel sheets, which are laminated such that the plane of lamination is in perpendicular to the plane of the magnetic pole pieces, and arranged and integrated in two layers such that the laminating directions are different by about 90.degree. from each other (Japanese Patent Laid Open Sho 61-203605), or a magnetic field generating device using a magnetic powder of high specific resistivity (Japanese Patent Laid Open Sho 63-25907).
However, the construction described above, which is intended to reduce the eddy current, still involves a problem that the magnetic pole pieces are magnetized by the magnetic field formed with the gradient magnetic field coils (GC), and the uniformity of the magnetic field in the gap is distorted by the residual magnetism due to the magnetic hysteresis phenomenon (residual magnetism phenomenon) even after the interruption of the GC pulses due.

Magnetic field generating device used for MRI


A method and apparatus for keeping information included in routing tables consistent throughout a wireless network are provided. The method includes enabling a mesh access point to generate data and transmit the data, gathering a plurality of pieces of information about a plurality of stations associated with the mesh access point, classifying the plurality of pieces of information into a plurality of blocks, generating a checksum for each of the blocks, and transmitting the checksum.

1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a wireless network, and more particularly, to a method and apparatus for keeping information in routing tables consistent throughout a wireless network.
2. Description of the Related Art
With the spread of Internet networks and the great increase in the amount of multimedia data transmitted via networks, the demand for high-speed communication networks has steadily increased. Regarding high-speed communication networks, a local area network (LAN) was developed in the late 1980s to have a transmission speed of 1-4 Mbps. A 100 Mbps Ethernet which is implemented based on a recent LAN standard is widely used. Recently, research has been vigorously conducted to develop a gigabit Ethernet. Various attempts to wirelessly access a network and carry out wireless network communication have expedited the research and development of wireless local area networks (WLAN), and thus, WLANs are now widespread. A WLAN provides lower data transmission rates and lower stability than a wired LAN. However, it is more convenient to establish a WLAN than to establish a wired LAN because a WLAN does not need wires, and a WLAN offers higher mobility than a wired LAN. Therefore, the demand for WLANs has steadily increased.
With the growing demand for increasing the amount of data transmitted over networks and recent developments in wireless data transmission technology, various improved versions of the IEEE 802.11 standard, such as the IEEE 802.11a, 802.11b, 802.11g, 802.11n, and 802.11s standards, have already been ratified or are expected to be ratified in the near future through standardization processes.
A device called an access point is used in a WLAN environment to provide LAN services to a wireless terminal. An access point performs almost the same functions as a hub in a wired LAN environment. The IEEE 802.11s standard defines a WLAN mesh, which is a LAN constituted by a plurality of access points, and enables the access points to wirelessly communicate with one another.
FIG. 1A is a diagram of a related wired LAN environment in which a plurality of access points are connected with one another by wires, and FIG. 1B is a diagram of a WLAN mesh environment which is established by a plurality of access points according to the 802.11s standard. In both the related wired LAN environment and the WLAN mesh environment, stations are wirelessly connected to an access point. However, in the related wired LAN environment of FIG. 1A, a plurality of access points AP1 through AP4 are connected to one another in a wired manner. Thus, routing information specifying which of the access points AP1 through AP4 each station is associated with is transmitted via wire. Therefore, the routing information is unlikely to be lost while being transmitted.
On the other hand, in the WLAN mesh environment of FIG. 1B, a plurality of access points AP1 through AP4 wirelessly communicate with one another. Each of the access points AP1 through AP4 transmits, via a wireless medium, information about a plurality of stations associated with the corresponding access point. For example, the access point AP1 may transmit its routing information to the access points AP2 and AP3, and the access point AP3 may transmit the routing information of the access point AP1 to the access point AP4. This type of data transmission among a plurality of access points is referred to as a multi-hop method. In the multi-hop method, if an intermediate access point between a sending access point and a receiving access point does not function correctly, it may not be able to receive data from the sending access point. For example, if the access point AP3 fails to receive the routing information of the access point AP1 due to instability of the wireless medium, the access point AP4 also may not be able to receive the routing information of the access point AP1. Therefore, it is more difficult to share a routing table in the WLAN mesh environment of FIG. 1B than in the wired LAN environment of FIG. 1A.
In short, a WLAN mesh environment is the same as a typical wireless network environment in that a plurality of wireless terminals are within the communication range of an access point and are thus controlled by the access point. However, in the WLAN mesh environment, unlike in the typical wired network environment, a plurality of access points wirelessly communicate with one another in a multi-hop manner. In order for a plurality of access points to wirelessly communicate with one another in a multi-hop manner, a wireless mesh routing protocol must be executed on Layer 2, i.e., on a link layer, and data paths to wireless terminals where the wireless mesh routing protocol cannot be executed must be secured while satisfying all the requirements prescribed in the IEEE 802.11 standard. Therefore, it is necessary to effectively transmit information about wireless terminals not having the wireless mesh routing protocol, i.e., legacy stations, over a network established between access points in a multi-hop method and to efficiently maintain the consistency of all station information stored in the access points. In particular, given that a wireless network environment is generally unstable and broadcast techniques used for distributing information over a wireless network are yet to be sufficiently reliable, some access points are highly likely to fail to receive information transmitted thereto. Therefore, it is necessary to develop a mechanism for detecting data loss during transmission of data between access points in a wireless network environment and updating data that is believed to be lost.

Method and apparatus for keeping information in routing tables consistent throughout wireless network


A system for a vehicle, comprising: a tank pressure control valve coupled in a first conduit between a fuel tank and a fuel vapor canister; a refueling valve coupled in a second, different, conduit between the fuel tank and the fuel vapor canister, the second conduit in parallel to the first conduit. In this way, two smaller, less complex valves may be utilized to control fuel tank vapor purging and fuel tank depressurization during refueling. This in turn may lower system cost and increase system functionality.

Vehicle fuel systems include evaporative emission control systems designed to reduce the release of fuel vapors to the atmosphere. For example, vaporized hydrocarbons (HCs) from a fuel tank may be stored in a fuel vapor canister packed with an adsorbent which adsorbs and stores the vapors. At a later time, when the engine is in operation, the evaporative emission control system allows the vapors to be purged into the engine intake manifold for use as fuel.
Previously disclosed systems place a single fuel tank isolation valve (FTIV) between the fuel tank and the fuel vapor canister. The FTIV may be a solenoid valve under control of a pulse-width modulated signal. The FTIV may be partially opened to regulate fuel tank pressure during engine-on conditions, and fully opened to prepare the fuel tank for refueling.
However, combining tank pressure control with a refueling valve presents numerous potential issues. Opening the FTIV completely when a significant pressure exists within the fuel tank may result in the corking of other fuel tank valves such as a grade vent valve and/or a fill limit vent valve, rendering them unusable. Opening the FTIV in this fashion could also lead to an abundance of hydrocarbons entering the engine intake system, altering the air/fuel ratio, and potentially leading to engine stalling. Additionally, any delays or imprecision in control of an FTIV may increase release of hydrocarbons or degraded air-fuel ratio control during purging.
The inventors herein have recognized the above issues, and have developed systems and methods to at least partially address these issues. In one example, a system for a vehicle, comprising: a tank pressure control valve coupled in a first conduit between a fuel tank and a fuel vapor canister; a refueling valve coupled in a second, different, conduit between the fuel tank and the fuel vapor canister, the second conduit in parallel to the first conduit. In this way, two smaller, less complex valves may be utilized to control fuel tank vapor purging and fuel tank depressurization during refueling. This in turn may lower system cost and increase system functionality.
In another example, a method for a hybrid-electric vehicle, comprising: in response to a refueling request: opening a tank pressure control valve while maintaining a refueling valve closed; allowing a fuel tank pressure to decrease below a first threshold; and opening the refueling valve. In this way, fuel tank depressurization may be controlled during refueling such that fuel tank vent valves are not exposed to rapid pressure changes during refueling events which may cork the valves, rendering them unusable for future fuel tank venting events.
In yet another example, a system for a hybrid-electric vehicle, comprising: a tank pressure control valve coupled in a first conduit between a fuel tank and a fuel vapor canister; a refueling valve coupled in a second conduit between the fuel tank and the fuel vapor canister, the second conduit in parallel to the first conduit; a controller configured with instructions stored in non-transitory memory and executable by a processor to: in response to a refueling request: opening a tank pressure control valve while maintaining a refueling valve closed; allowing a fuel tank pressure to decrease below a first threshold; and opening the refueling valve. In this way, that fuel tank vent valves are not exposed to significant pressure differentials during refueling events which may close the valves, and thus may prevent adequate refueling.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

Systems and methods for a two-valve non-integrated refueling canister only system


In an embodiment of the method of handling mobile station identifiers, at least one network element that used entire mobile station identifiers in performing packet data session handling functions is programmed to use less than the entire mobile station identifiers.

1. Field of the Invention
The present invention relates to telecommunications, and more particularly, to wireless telecommunications.
2. Description of Related Art
In the field of wireless telecommunications, a system typically includes a plurality of base transceiver stations distributed within an area to be serviced by the system. Various users within the area, fixed or mobile, may then access the system, and, thus, other interconnected telecommunications systems, via one or more of the base transceiver stations. Typically, a mobile device maintains communication with the system as the mobile device passes through an area by communicating with one and then another base transceiver station, as the user moves. The mobile device may communicate with the closest base transceiver station, the base transceiver station with the strongest signal, the base transceiver station with a capacity sufficient to accept communications, etc.
Circuit and packet data communication with a wireless subscriber are handled and routed by way of the mobile station identification ("MSID"). The MSID may typically be characterized as either a 10-digit mobile identification number ("MIN") or a 15-digit International Mobile Subscriber Identifier ("IMSI"). All references to MIN in this document also include the International Roaming MIN [IRM] assigned to service providers outside North America. The MIN is a 10-digit number typically formatted like a dialable 10-digit Mobile Directory Number (MDN). However, MIN is not defined as a dialable number. The IMSI is a 15-digit non-dialable number based on ITU-T Recommendation E.212, and therefore, is not interchangeable with a 10-digit MDN. The format of the IMSI is given below:
IMSI (15 digits)=MCC (3 digits)+MNC (up to 3 digits)+MSIN (all remaining digits)
The mobile country code (MCC) forms the first three digits of the IMSI and identifies the country in which the home system is located. Together with the mobile network code (MNC), which consists of no more than the next 3 digits, the MCC+MNC forms a home system code identifying the home system. The Mobile Subscriber Identification Number (MSIN) uniquely identifies the mobile subscriber within the home system. The IMSI is used in various standards around the world. The IMSI may be programmed into a wireless unit or a Subscriber Identity Module ("SIM") card by the service provider with whom the wireless unit user has entered into a service agreement.
While MIN and IMSI are not interchangeable, standards have defined a MIN-based IMSI (MBI) to assist in the migration from MIN to IMSI as a subscriber identifier. The MBI is formatted like an IMSI except the first five digits are not assigned to a service provider and, therefore, are not carrier specific for network addressing, routing, billing or settlement purposes. The last 10-digits of the MBI consist of the MIN
Typically, the IMSI as defined by ITU-T Recommendation E.212 is referred to as the true-IMSI or IMSI_T to contrast this IMSI format with the MIN-based-IMSI (also referred to as IMSI_M and MBI).
Unfortunately, due to a lack of clarity in the standards, there is a lack of consistency between service providers, such as CDMA service providers, in their programming and use of MBI and true-IMSI as subscriber identifiers. While each identifier and its use are defined as separate and unique identifiers, they serve similar if not identical functions. However, according to current standards, they are non-interchangeable or interoperable, and this may result in inefficient handling of subscribers roaming across such systems. This problem is being addressed in this invention.

Method of handling mobile station identifiers


An automatic focus detecting telescope which offers easy maintenance and which, when applied to a surveying instrument such as an auto-level, provides easy detachment and attachment of an optical horizontal compensation system. Even if the optical horizontal compensation system is detached, no readjustments are required for the automatic focusing apparatus and the eyepiece optical system.

1. Field of the Invention
The present invention relates to a telescope including an automatic focus detecting apparatus which can be applied to a surveying instrument such as an auto-level, etc.
2. Description of the Related Art
The surveying instrument basically comprises a collimating telescope. The collimating telescope is provided with a focusing lens group in order to view a clear object image regardless of the distance of the aiming object. The telescope is provided, in order from the object side, with an objective lens system (which includes the focusing lens group), and an eyepiece lens group system. The position of the focusing lens group is adjusted according to the distance from the object, so that an image of the object may be formed on a focusing plate. The operator may thus observe the image superimposed on the focusing plate via the eyepiece lens group system.
For example, provided that the range of the object distance is between 2 m-infinity, and that the focusing lens group is a concave lens, the approximate amount of movement of the focusing lens is about 30 mm. The focusing lens group is normally driven through an operation of a rotation knob. If the amount of movement of the object image (i.e., the amount of movement of the focusing lens group) is set smaller in regard to the rotating angle of the rotation knob, the object image remains on the focusing plate longer due to the smaller amount of movement of the object image when compared with the rotating angle, but it is time-consuming to move such a lens. On the other hand, if the amount of movement of the object image is set larger with respect to the rotating angle of the rotation knob, the amount of movement of the object image becomes too large when compared with the rotative angle, and the object image remains on the focusing plate for a shorter time. Consequently, the operator may sometimes pass by the focal point (in-focus condition) without noticing the coincidence of the object image with the focusing plate and the focal point, leading to extra time taken for refocusing.
Additionally, if the object is positioned far from the telescope, focusing is easily performed through only a slight operation of the rotation knob in the rotating direction, since the amount of movement of the object image is larger when compared with the rotative angle of the rotative knob. On the other hand, if the object is positioned relatively close to the focusing lens, the amount of movement of the object image is smaller when compared with the amount of rotation of the rotation knob, and it is difficult to move the object image on the focusing plate despite more rotation of the rotation knob. In such a case, it is difficult to determine whether the aiming object is in a front focus or a rear focus position, which may lead the operator to rotate the rotation knob in the wrong direction with respect to the focal point. In any event, the conventional surveying instrument suffers from the fact that it takes too much time for focusing.
An auto-level basically comprises a collimating telescope and an optical horizontal compensation system. The collimating telescope is substantially set, with respect to the horizon, then a reference object is observed. At that time, if an optical axis of the telescope is not perfectly horizontally set, the horizontal compensation system coincides the collimation line with a horizontal line. The telescope is then pivotally rotated around a vertical axis perpendicular to the optical axis, and when an operator views any collimation point, the viewed collimation point is positioned with the imaginary horizontal surface that includes the reference point (the set horizon).
In order to overcome the above-mentioned problem, an auto-level is provided, to which a TTL (through-the-lens) type of automatic focus detecting apparatus is mounted. As is well known, however, the auto-level requires a regular readjustment of the optical horizontal compensation system in order to maintain horizontal accuracy. The optical horizontal compensation system is decoupled from the auto-level during readjustment, and is coupled again after the readjustment ends. Therefore, when the automatic focus detecting system is mounted to the auto-level, easy decoupling and coupling of the optical horizontal compensation system is desired.

Focus detecting apparatus for a telescope system


A power control device may include a first power-supply voltage source configured to generate a first power-supply voltage, and a second power-supply voltage source configured to generate a second power-supply voltage having a voltage level different from that of the first power-supply voltage. The power control device may include a power driver configured to provide an internal power source in response to the second power-supply voltage, irrespective of the first power-supply voltage source and the second power-supply voltage source, during an initial power-up period.

1. Technical Field
Embodiments of the present invention generally relate to a power control device, and more particularly to a technology for cutting off an unnecessary leakage current path when power of an integrated circuit (IC) having heterogeneous power is ramped up.
2. Related Art
Generally, a power-up signal generation circuit of a semiconductor device indicates a circuit for initializing a semiconductor device. In order to operate the semiconductor device, the power-up signal generation circuit receives an external voltage (VDD) from an external part. The voltage level of the external voltage (VDD) starts from 0V and increases up to a target voltage level at a predetermined slope.
In this case, when all circuits of the semiconductor device directly receive the external voltage (VDD), the circuits need to initialize a specific node as well as to provide stable power. As a result, the semiconductor device includes a power-up signal generation circuit. The power-up signal generation circuit is used to enable a power-up signal, so that the external voltage (VDD) reaching a stable power level can be applied to respective circuits. The semiconductor device is initialized by the power-up operation.
FIG. 1 is a conceptual diagram illustrating a ramp-up operation of the external voltage (VDD) for use in a conventional integrated circuit (IC).
Referring to FIG. 1, the conventional IC has heterogeneous power-supply voltages (VDD1, VDD2). In this case, the external power-supply voltage VDD1 is higher than the external power-supply voltage VDD2.
During a predetermined period T1 of the ramp-up operation, the power-supply voltage VDD1 increases with a predetermined slope, reaches a target level, and is maintained at a predetermined voltage level. After lapse of the period T1, the power-supply voltage VDD2 increases with a predetermined slope. After lapse of a predetermined period T2, the power-supply voltage VDD2 reaches a target level, and is maintained at a predetermined voltage level.
However, before the power-supply voltage VDD1 is ramped up and the power-supply VDD2 is ramped up, an undesired leakage current occurs. That is, if the ramp-up time of the power-supply voltage VDD1 is different from the ramp-up time of the power-supply voltage VDD2, an unnecessary leakage current occurs. As described above, the power-supply voltage VDD2 is maintained at 0V before the power-supply voltages (VDD1, VDD2) are ramped up, so that an internal leakage current unavoidably occurs.


A method of reliably communicating via a computer network by identifying hub nodes in the network, identifying leaf nodes in the network, communicating from hub nodes to corresponding leaf nodes, reporting from leaf nodes to corresponding hub nodes, communicating between hub nodes, re-designating a leaf node as a hub node if the leaf node identifies a region of the network not known by a hub node, re-designating a hub node as a leaf node if the hub node becomes redundant, re-designating a leaf node as a hub node if the leaf node loses connectivity to its hub node, and returning to the third step for additional processing.

Computers are increasingly being relied upon as the preferred method of communication. Therefore, it is becoming increasingly important that computer communication be reliable. Interruptions in data delivery, due to the lack of availability or bandwidth in a channel, can seriously impact communications. Therefore, there is a need for a method of efficiently routing computer communications.
U.S. Pat. No. 6,411,946, entitled "ROUTE OPTIMIZATION AND TRAFFIC MANAGEMENT IN AN ATM NETWORK USING NEURAL COMPUTING," discloses a method of optimizing routing selection and managing traffic by monitoring link data traffic, obtaining traffic history data, training an autoregressive backpropagation neural network, obtaining predicted traffic profiles, selecting predicted traffic links, and using quality-of-service factors to select an optimal route. The present invention does not monitor link data traffic; obtain traffic history data, train an autoregressive backpropagation neural network, obtain predicted traffic profiles, select predicted traffic links, and use quality-of-service factors to select an optimal route as does U.S. Pat. No. 6,411,946. U.S. Pat. No. 6,411,946 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 7,054,934, entitled "TAILORABLE OPTIMIZATION USING MODEL DESCRIPTIONS OF SERVICES AND SERVERS IN A COMPUTING ENVIRONMENT," discloses a device for and method of optimizing the allocation of computer resources between server and service models by allowing a user to select one of a plurality of optimization methods then employing the selected method to generate an optimal mapping of the server and service models. The present invention does not allow a user to select one of a plurality of optimization methods and employ the selected method to generate an optimal mapping of server and service models as does U.S. Pat. No. 7,054,934. U.S. Pat. No. 7,054,934 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 7,075,892, entitled "TOPOLOGICAL DESIGN OF SURVIVABLE MESH-BASED TRANSPORT NETWORKS," discloses a method of designing a telecommunication network by finding an initial topology of spans between nodes, minimizing the cost of these spans, finding additional spans that ensure restorability, minimizing the cost of the additional spans, and finding a final topology. The present invention does not find additional spans that ensure restorability as does U.S. Pat. No. 7,075,892. U.S. Pat. No. 7,075,892 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 7,092,378, entitled "SYSTEM FOR UTILIZING A GENETIC ALGORITHM TO PROVIDE CONSTRAINT-BASED ROUTING OF PACKETS IN A COMMUNICATION NETWORK," discloses a device for and method of using a genetic algorithm to assign flows to paths. The present invention discloses more than does U.S. Pat. No. 7,092,378. U.S. Pat. No. 7,092,378 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. Appl. No. 20020026342, entitled "MULTI-LAYER ENGINE USING GENERIC CONTROLS FOR OPTIMAL ROUTING SCHEME," discloses a device for and method of generating an optimal allocation schedule by using a generic multi-layering scheduling mechanism employing a heuristic algorithm. The present invention discloses more than does U.S. Pat. Appl. No. 20020026342. U.S. Pat. Appl. No. 20020026342 is hereby incorporated by reference into the specification of the present invention.

Method of reliably communicating via computer network

The United States of America as represented by the Director of the National Security Agency


Fiber optic devices are manufactured in an automated environment using a combination of clamps to secure the optical fibers and movable gripping devices that transport the optical fiber during the fabrication process while maintaining control of the ends of the optical fibers. An optical fiber from a spool is removed by a despooling arm having a gripping device, and moveable grippers thread the optical fiber into a set of clamps and place the end of the optical fiber in a clamp designed to splice the fiber optic end to a lead of a testing device. The fiber optic device is formed by dynamically controlling the heating and pulling process based on detected coupling ratios, and hermetically sealed while secured within the clamps. The sealed fiber optic device is moved for testing or packaging using a transport arm having a series of clamps to maintain the position of the fiber optic device and the ends of the leads of the fiber optic device.

Fiber optic couplers are used as optical beam splitters between two or more fibers. Fused biconical tapered couplers are formed generally by placing two bare single mode fibers in contact with each other, adding tension to the fibers, and heating the fibers using a heat source, for example a flame. As the fibers soften, they fuse together to form the fused biconical tapered coupler.
The conventional manufacture of fiber optic devices such as the fused biconical tapered coupler suffer from the fundamental problem that manual handling by technicians or operators introduces variations to the manufacturing process. Depending on the fiber optic device being formed, a considerable amount of error may be introduced by the handling of an optical fiber by an operator or technician. For example, conventional formation of a coupler includes removing of an outer coating from two or more optical fibers and placing the exposed optical fibers in contact with each other. The fibers may be twisted together, depending on the particular technique used to manufacture the coupler. The fibers are then fused together by heat, as the fibers are placed under tension by slowly and carefully pulling them apart at a predetermined rate. Given the delicate nature of optical fibers, the manufacture of optical fiber couplers requires highly skilled and trained technicians.
An additional problem with conventional manufacturing techniques is that the optical characteristics of the fiber optic devices during manufacture are uncontrollable. Skilled technicians with experience from trial and error have been needed to anticipate the optical characteristics of a fiber optic device during manufacture. For example, technicians making fused biconical tapered couplers would recognize that a jump in the detected coupling ratio occurs when a heat source is suddenly removed from the heated optical fibers. Technicians would attempt to anticipate the jump in the detected coupling ratio such that the heat source, when removed, would cause the detected coupling ratio to jump to the desired level. Hence, the yield of the manufacturing process would be unpredictable and entirely dependent on the individual technician's expertise.
U.S. Pat. No. 5,386,490 to Pen et al., incorporated in its entirety herein by reference, discloses a workstation for manufacturing a coupler between at least two optical fibers. A technician threads an optical fiber from an optical fiber spool into the clamping assembly. The technician is also needed to terminate the bare fiber into a bare fiber adaptor, used to hold the end of the optical fiber relative to a photodiode. Hence, the arrangement disclosed by Pen et al. still requires an operator to thread the optical fiber from a spool to the clamping assembly and mount the end of the optical fiber into a termination point. Further, operator intervention is still required for subsequent manufacturing operations, including hermetic sealing, testing, and packaging. Consequently, variations due to operator handling still exist.
Hence, the conventional manufacturing process suffers an inherent degree of variability due to manual handling by the skilled technicians. In addition, the necessity of skilled technicians greatly increases the manufacturing costs for the fiber optic devices. Finally, use of skilled technicians limits the production capacity, since technicians are subject to fatigue.

Arrangement for automated fabrication of fiber optic devices


An HCU (37) includes a battery low temperature reducing output calculating section (71A) that determines, when it is determined that an electricity storage device (31) is in a low temperature state by a battery temperature Tb, a battery low temperature reducing output PbL that is made to a larger value as the battery temperature Tb is lower, a hydraulic oil low temperature reducing output calculating section (71B) that determines, when it is determined that hydraulic oil is in a low temperature state by a hydraulic oil temperature To, a hydraulic oil low temperature reducing output PoL that is made to a larger value as the hydraulic oil temperature To is lower, and an output command calculating section (80) that controls a vehicle body operation based upon a sum of the battery low temperature reducing output PbL and the hydraulic oil low temperature reducing output PoL.

In general, there is known a hybrid construction machine provided with a motor generator that is jointed mechanically to an engine and a hydraulic pump, and an electricity storage device such as a lithium ion battery (for example, refer to Patent Document 1 and Patent Document 2). In this hybrid construction machine, the motor generator plays a role of charging power generated by a driving force of the engine in the electricity storage device or assisting in the engine by a power running operation using power of the electricity storage device. Many hybrid construction machines are provided with an electric motor separated from the motor generator, and the electric motor acts for or assists in an operation of a hydraulic actuator. For example, at the time of performing a revolving operation by the electric motor, the electric motor performs or assists in the revolving operation of an upper revolving structure by power supply to the electric motor, and braking energy at a revolving stop is regenerated to perform charge of the electricity storage device.
In this hydraulic construction machine, it is possible to enhance a reduction effect of a fuel consumption by increasing the output of the motor generator or revolving electric motor. However, when the output of the motor generator or the like is made large, there are some cases where the electricity storage device cannot supply sufficient power due to the limitations of a discharge capability, a capacitance, a temperature and the like of the electricity storage device. In this case, continuation of the power supply from the electricity storage device leads to hard use of the electricity storage device, accelerating degradation of the electricity storage device.
In the electricity storage device using a chemical reaction, such as the lithium ion battery, the output is lower in a low temperature state as compared to a normal temperature state. Even when charge and discharge are repeatedly performed within a range of the lowered output in such a low temperature state, it leads to hard use of the electricity storage device, causing large performance degradation in the electricity storage device.
There is known a control device configured in consideration of the above problems. For example, Patent Document 1 discloses the configuration that a maximum value of charge/discharge power that can be outputted in accordance with a temperature of the electricity storage device is calculated and the electricity storage device is used within a range of the calculated value.
Patent Document 2 discloses the configuration that, for suppressing degradation of the electricity storage device, when a current square integrated value exceeds a specified value, a discharge amount of the electricity storage device is limited according to the increasing amount. At this time, the current square integrated value shows a use amount of the electricity storage device for a constant time from the present to the past.

Hitachi Construction Machinery Co., Ltd.


A disk drive includes a light source configured to emit light indicative of a disk drive status. A disk drive status light guide system for a disk drive also includes a first light pipe configured and dimensioned to mechanically couple to the disk drive and configured to directly receive and guide light emitted by the light source, and a second light pipe separate from the first light pipe, the second light pipe configured to receive and guide light from the first light pipe to a status lens visible to a user.

Both external and internal disk drives are typically associated with at least one disk drive status light, often used to provide an indication of disk drive read/write activity. In some disk drives, an external electrical connector couples the disk drive to a separate disk drive status light incorporated into a computer case or external disk drive case. The disk drive may then drive the status light during operation.
In other disk drives, the disk drive status light is formed integrally with the disk drive, and light emitted by the status light may be guided outside an external case holding the disk drive (e.g., via one or more holes in the external case). Unfortunately, when the disk drive status light is a component of the disk drive, the location of the status light may not be ideal for viewing by a user, due to space and configuration constraints on the disk drive. As a result, relatively complex light guides may be formed between the disk drive status light and a lens visible to the user. Since the lens is typically coupled to an external case of the disk drive, as the disk drive moves relative to the external case, stresses may be introduced into the physical components of the light guide system coupling the disk drive status light to the lens.
There is therefore a need for an improved light guide system between a disk drive status light and a lens.