According to one embodiment, an electronic device includes a request module, a transmission module, and a connection module. The request module requests a tethering start for a terminal equipped with a tethering feature. The transmission module transmits a password for tethering to the terminal. The connection module connects the electronic device to a network via a tethering terminal.

In recent years, there has been a growing demand for using the Internet outside the office by carrying a tablet terminal or a small-sized, lightweight PC. Usually, this type of tablet terminals and PCs are equipped with a wireless LAN feature, but not with a mobile telephone feature. It is therefore necessary to connect to an access point over wireless LAN (such as Wi-Fi and Bluetooth), in order to connect to a network outside the office.
Since an access point does not always exist nearby, it is not always possible to connect to a network.
Tethering is known as a technology for coping with such a situation. Tethering allows a PC or a tablet terminal (portable handset) not equipped with a mobile telephone feature to be connected to a network wirelessly using a device equipped with a mobile telephone feature, such as a smartphone, as an access point (base unit). The tethering feature, however, is not easy to use.

Electronic device, method, and computer-readable storage medium


An image forming apparatus is provided. The image forming apparatus includes an image former to change a transfer condition while printing a calibration chart in which patches of different colors are repeatedly arranged in a sub-scanning direction, a scanner to scan the printed calibration chart, and a processor to determine an image defect under each transfer condition using the scanned calibration chart, and to set a transfer condition of the image former based on the determined image defect.

In general, an image forming apparatus refers to an apparatus that prints printing data generated at a printing control terminal apparatus such as a computer on recording paper. Examples of such an image forming apparatus are a copier, a printer, a scanner, a facsimile machine, or a multi-function peripheral (MFP) complexly implementing the functions of the aforementioned devices through a single device.
The image forming apparatus may form an image in various methods. From among these, electrophotography is increasingly used. The electrophotography refers to a method that forms an image through a process that includes charging a surface of a photoconductor, forming a latent image through laser scanning, developing by covering the latent image with toners, transferring the developed toner to printing paper, and fusing the toner.

Calibration chart based image forming apparatus

Hewlett-Packard Development Company, L.P.


The present invention relates to liquid crystalline alkenes and liquid crystalline polysiloxanes prepared from these alkenes. More precisely, the present invention is related to the development of fused ring aromatic-containing side chain liquid crystal polysiloxanes (SCLCP). These liquids crystalline polysiloxanes are particularly useful as the stationary phase in column chromatography for the separation of various isomeric compounds, including polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated diberizofurans (PCDF), polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polysubstituted benzenes.

Very long capillary columns (i.e., >60 m) containing conventional stationary phases are useful for the separation of a large number of environmentally important compounds having different volatilities. Separation of various isomers of a compound, however, particularly isomers having similar volatilities, is very difficult using these capillary columns containing conventional stationary phases.
Liquid crystal compounds have shown particular selectivity and sensitivity as stationary phases for the separation of isomers having similar volatilities. Since the initial discovery of this property, research has been directed at the development of liquid crystalline compounds exhibiting broad liquid crystalline temperature ranges (i.e. broad phase transition temperature ranges), higher column operating temperatures, and lower bleed (i.e. loss of mobile phase).
Studies have also been undertaken to determine the correlation between the separation of positional isomers of a compound (e.g meta- and para-substituted benzene) and the structure of the liquid crystalline compounds used as the stationary phases. See K. Naikwadi et al., Can. J Chem., 65:970 (1987). These studies have shown that the separation factor for a particular pair of isomers is dependent on the chemical structure of the liquid crystalline compound used as stationary phase. This correlation between structure and separation provided very important clues for the development of specific liquid crystalline compounds to be used in chromatographic separation of isomers of a compound.
Although conventional stationary phases have proven unsatisfactory to date, the separation of isomers having similar volatilities can be achieved with capillary or packed column gas chromatography using stationary phases composed of liquid crystalline polymers (LCPs). For a LCP to be useful as the stationary phase in chromatography, the LCP must exhibit high thermal stability, broad liquid crystalline temperature range, and high upper transition temperature. Optimal performance depends on additional factors, such as the structure of the mesogenic group (i.e. the side chain of the LCP), the degree of polymerization, the packing of the side chains of the LCP, and the procedure used to prepare the columns.
Liquid crystal polymers known to be useful as stationary phases for chromatography are based on either a phenyl carboxylate ester or biphenyl carboxylate ester. The performance of these side chain liquid crystalline polysiloxanes (SCLCPs) as stationary phases, however, is not completely satisfactory. For example, known SCLCPs exhibit low column stability due to their volatility as well as longer retention times (and, concomitantly, lower efficiency) for polyaromatic hydrocarbon samples due to the low effective temperature limit of the columns. Thus, there is a need in the art for SCLCPs exhibiting a broad liquid crystalline temperature range for use in highly stable, efficient and selective capillary columns.
Moreover, the toxicity assessment of any environmental sample containing isomeric compounds requires separation of all the isomeric components thereof. For example, in polychlorinated dibenzo-p-dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (T.sub.4 CDD) is the most toxic isomer. The separation of 2,3,7,8-T.sub.4 CDD from the other 21 T.sub.4 CDD isomers is essential to determine the toxicity of a particular sample. Similarly, in the case of furans the separation of 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-T.sub.4 CDF) is required from the other 37 T.sub.4 CDF isomers. Limited success has been achieved using known polymeric liquid crystal columns (see, e.g., U.S. Pat. No. 4,909,935) to separate these various isomers. Thus, there is a need in the art for capillary columns useful in the separation of isomers of toxic compounds, particularly compounds such as PCDD and PCDF.

Liquid crystal stationary phases for chromatography


When either a command value or an actually measured value is appropriately selected as an angular velocity used for the frictional torque calculation, the frictional compensation can be made valid at all times in both the case in which a robot is actively operated according to an angular velocity command and the case in which the robot is passively operated being pushed by an external force. In the case where a motor rotating direction and a collision direction are reverse to each other after a collision has been detected, the control mode is switched from the positional control to the electric current control and a torque, the direction of which is reverse to the direction of the motor rotation is generated by the motor, so that the motor rotating speed can be reduced and the collision energy can be alleviated. After that, when the motor rotating speed is reduced to a value not more than the setting value, the control mode is switched to the compliance control and the distortion caused in a reduction gear is dissolved. On the other hand, in the case where the motor rotating direction and the collision direction are the same, the control mode is directly switched from the positional control to the compliance control without passing through the electric current control. When the robot is operated whole following a collision force, the collision force can be alleviated.

Recently, robots have been used for not only the industrial field but also the public consumer field. Therefore, it has become important to ensure the safety. However, according to a stoppage means for stopping a robot arm by detecting an external force, which is given to the robot at the time of collision, with a force sensor, the manufacturing cost and the weight are undesirably increased. Accordingly, it is desired to enhance the performance of compliance servo control including the collision detection, in which no sensors are used, and the control of stopping motion.
Concerning the method of realizing compliance servo control without using sensors, it is common to adopt a method in which even when a positional deviation is increased in the positional feed back control, an excessively high torque is not generated in a motor by suppressing the increase in the electric current command with respect to an increase in the positional deviation.
According to a quantity of suppression of the electric current command in the feedback control, an intensity of torque generated by the motor is also suppressed, so that the compliance can be enhanced.
A means for suppressing the electric current command in feedback control is disclosed in JP-A-09-179632 (U.S. Pat. No. 5,994,864) in which the electric current command is limited. A means for suppressing the electric current command in feedback control is also disclosed in JP-A-08-155868 in which the feedback gain is decreased.
As described above, in order to enhance the compliance of a robot arm, it is important to suppress the electric current command in feedback control. Unless the electric current is suppressed in feedback control, the compliance of a robot arm becomes close to the common servo rigidity. Therefore, the compliance of servo control is lowered.
However, in order to operate a robot arm, it is necessary to generate a drive torque by a motor in which consideration is given to the inertia torque, the friction torque and the gravity torque. Therefore, when the robot arm is operated only by feedback control, it is difficult to suppress an electric current command of the motor.
FIG. 3 is a block diagram showing a conventional method of controlling the friction compensation in which the actual velocity is used. In the drawing, reference numeral 1 is a motor rotary angle command θcom, reference numeral 2 is a feedback controller, reference numeral 3 is an electric current restricting means, reference numeral 4 is a feedback control electric current command Icom, reference numeral 5 is a motor current Im, reference numeral 6 is a range representing (motor+actual load), reference numeral 7 is a motor torque constant Kt, reference numeral 8 is a motor generation torque τmm, reference numeral 9 is an external force τμ+τdyn+τdis given to a motor, reference numeral 10 is a transfer function of motor inertia, reference numeral 11 is a motor rotation angle θfb, reference numeral 12 is a differential operator, reference numeral 13 is a motor angular velocity command ωcom, reference numeral 14 is a differential operator, reference numeral 15 is a motor angular acceleration command αcom, reference numeral 16 is a motor inertia (rotor+reduction gear primary side) J, reference numeral 17 is a motor electric current Iml necessary for the operation of a robot, reference numeral 18 is an inverse number 1/Kt of the motor torque constant, reference numeral 19 is a calculated value of dynamic torque τdyn, reference numeral 20 is a calculated value of friction τμ, reference numeral 21 is a friction calculation block, reference numeral 22 is a dynamic calculation block, reference numeral 23 is a motor angular velocity ωfb, reference numeral 24 is a differential operator, and reference numeral 25 is a rotary angle of the other axis.
The motor generation torque τm, which is generated at the time of operation of the robot, is expressed by the expression (1) when it is seen from the motor drive side. The motor generation torque cm is expressed by the expression (2) when it is seen from the load side.τmm=Kt*Im  (1)τml=J*α+τμ+τdyn+τdis  (2)In this case, reference marks used in the expressions (1) and (2) are defined as follows.
Kt: Motor torque constant
Im: Motor electric current
α: Motor angular acceleration
ω: Motor angular velocity
J: Motor inertia (rotor+primary side of reduction gear)
τμ: Friction torque (converted into motor shaft end)
τdyn: Dynamic torque (Dynamic torque is a sum of gravity torque, inertia force, Coriolis force and elastic force, which is converted into a motor shaft end.)
τdis: Disturbance torque (Disturbance torque is a contact torque given from the outside or a parameter error. Disturbance torque is converted into a motor shaft end.)
When the disturbance torque τdis=0 in the expression (2), it is possible to calculate the motor electric current Iml, which is necessary for the operation of the robot arm, by the expressions (1) and (2).Iml=J*α+τμ+τdyn)/Kt  (3)
As shown in FIG. 3, when Iml calculated by this expression (3) is added to the feedback electric current command Icom, if the disturbance torque τdis=0, even when the feedback electric current is 0, it becomes possible for the robot arm to follow to a target position.
In FIG. 3, the feedback electric current command Icom (4) can be found when the PID calculation is conducted by the feedback controller (2) from the rotary angle command θcom (1) and the actual motor rotary angle θfb and the electric restriction (3) is made. Concerning the means for restricting the electric current (3), there are provided a system in which the limit is set and a system in which the feedback gain is lowered.
On the other hand, Iml (17) calculated by the expression (3) can be obtained as follows. The angular acceleration θcom (15), which is obtained when the motor rotation command θcom (1) is subjected to the differential calculation (12) and (14) twice, is multiplied by the motor inertia J (16). The friction torque τμ (20) and the dynamic torque τdyn (19) are added to the thus obtained value. The obtained value is multiplied by the inverse number 1/Kt (18) of the motor torque constant, and Iml (17) calculated by the expression (3) can be obtained.
That is, when the motor electric current Iml necessary for the operation of a robot can be accurately calculated by the expression (3), it becomes possible to suppress an electric current command in feedback control. Therefore, the compliance of the robot can be enhanced.
However, actually, an error of calculation is caused by the parameter error of the expression (3). Therefore, when the electric current is intensely suppressed in feedback control, it becomes impossible to compensate the error, and the robot arm becomes out of control and the positional deviation can not be decreased, that is, there is a possibility that the robot arm runs away.
When the electric current command is made to be 0 in the feedback control, if the positional deviation is extended by the contact torque given from the outside, a force to return the robot arm to the initial position is not generated.
As explained above, how much the electric current command by feedback control can be suppressed depends on the calculation accuracy of the expression (3).
The friction torque τμ, which is one of the primary items of the motor electric current Iml calculated by the expression (3) and necessary for the operation of the robot, includes: the stationary friction torque τμs and the dynamic friction torque τμm which are determined by the acting direction of a force; and the viscous friction torque τμd (coefficient D of viscosity) which is proportional to the velocity.τμ=τμs+τμm+τμd  (4)
However, in the expression (4), each item is calculated as follows.
                              τ                                                              μ                                                              s                =                  τ                                                              μ                                                              s0          *                      sgn1                                      (              ω              )                                                          (        5        )                                          sgn1                                (            ω            )                          =                  {                                                    1                                                              (                                                            ω                      =                      0                                        ,                                                                  moving                                                                                direction                                            >                      0                                                        )                                                                                0                                                              (                                      ω                    ≠                    0                                    )                                                                                -                  1                                                                              (                                                            ω                      =                      0                                        ,                                                                  moving                                                                                direction                                            <                      0                                                        )                                                                                τ                                                              μ                                                              m                =                  τ                                                              μ                                                              m0          *                      sgn2                                      (              ω              )                                                          (        6        )                                          sgn2                                (            ω            )                          =                  {                                                                      -                  1                                                                              (                                      ω                    <                    0                                    )                                                                                0                                                              (                                      ω                    =                    0                                    )                                                                                1                                                              (                                      ω                    >                    0                                                                                τ                                                              μ                                                              d                =                  D          *          ω                                    (        7        )
As can be seen from the expressions (5) to (7), all friction torque is calculated depending upon the angular velocity ω.
Concerning the angular velocity ω used for the calculation of the friction torque, the angular velocity ωFB, which is subjected to feedback control, is used in the above conventional example (JP-A-9-179632). In another conventional example (JP-A-10-180663), the angular velocity command ωcom, which is obtained when the positional command θcom is differentiated, is used.
However, in the compliance control of the robot, there are provided two cases. One is a case in which the robot acts actively according to the positional command θcom. The other is a case in which the robot acts passively being pushed by an external force.
As shown in FIG. 3, when the actual angular velocity ωfb (23), which is obtained when the actual motor rotation angle θfb (11) is differentiated (24), is used as the angular velocity which is used when the friction torque τμ (20) is calculated by the expression (5) with the calculation block (21), a velocity fluctuation caused by the external force τdis, which is a portion of the disturbance torque (9) given to the motor, is reflected, so that the calculation accuracy of the friction torque τμ (20) can be enhanced.
However, when the robot is actively operated from a state in which the robot is completely stopped, the operating direction is unknown until the robot starts operating.
Therefore, it is impossible to calculate the stationary friction torque τμs.
Until the robot starts operating, the actual angular velocity ωFB is 0, and the dynamic friction torque τμm and the viscous friction torque τμd calculated by the expressions (6) and (7) are, of course, 0. Therefore, the friction torque τμ calculated by the expression (4) is 0, and no motor torque for operating the robot is generated at all.
In this state, when the torque caused by the electric current command Icom (4) of feedback control is suppressed to enhance the compliance and becomes lower than the actual stationary friction torque τμs, the robot is not moved even when the rotation angle command θcom (1) is generated.
On the other hand, as shown in FIG. 4, when the angular velocity command ωcom (13), which is obtained when the motor rotation angle command θcom (1) is differentiated, is used for the angular velocity ω which is used for the calculation (21) of the frictional torque τμ (20), these problems are solved. That is, even when the robot is not operated, when the friction torque τμ (20) is calculated (21) by the expression (4) with the angular velocity command ωcom (13) and added to the feedback electric current command Icom (4), the actual friction torque can be compensated. Even when the electric current command Icom (4) by feedback control is suppressed, the robot can be operated.
However, when the angular velocity command ωcom (13) is used for the angular velocity ω which is used for the calculation (21) of the frictional torque τμ (20), the robot can be actively operated according to the angular velocity command ωcom (13). However, in the case where an angular velocity fluctuation is caused by the disturbance torque τdis in the middle of the operation, a big error is caused between the angular velocity command ωcom (13) and the actual angular velocity ωfb (reference numeral 23 in FIG. 3). Accordingly, an error of calculation of the viscous friction torque τμd, which is calculated by the expression (7) is increased.
When the robot is pushed by an external force at the time of stoppage of the robot when the angular velocity command ωcom (13) is 0, and the robot is stopped, the frictional torque τμ calculated by the expression (4) is 0 at all times. Therefore, the actual friction torque can not be compensated at all.
Further, even when the robot is not pushed by an external force, a delay of follow is caused in the feedback control conducted by the feedback controller in the actual operation. Therefore, at the time of stoppage of the robot, before the actual angular velocity ωfb (reference numeral 23 in FIG. 3) becomes 0, the angular velocity command ωcom (13) becomes 0. Therefore, the frictional torque τ calculated by the expression (4) at this time also becomes 0, and no frictional compensation is made. That is, at the point of time when the angular velocity command ωcom (13) reaches 0, the robot is suddenly stopped and can not reach an objective position and further there is a possibility that vibration is caused.
In this case, in the case where the torque generated by the motor according to the electric current command Icom (4) of the feedback control is suppressed to be lower than the actual frictional torque, even when a positional deviation is increased by an external force, the robot is not operated, and it is impossible to reduce the positional deviation.
In other words, although the frictional compensation is being conducted, it is impossible to set the feedback electric current command to be lower than the actual frictional torque. Therefore, the robot compliance can not be enhanced.
As explained above, in the case where the frictional torque τμ is calculated by the expression (4), according to the method in which one of the actual angular velocity ωfb and the angular velocity command ωcom is used as the angular velocity, even when the electric current Iml, which is calculated by the expression (3) with the calculated frictional torque τμ, is added to the feedback control electric current, the actual frictional torque can not be compensated.
As shown in FIG. 3, when the frictional torque τμ is compensated by 100% by using the actual angular velocity ωfb (23) for the angular velocity which is used at the time of calculating (21) the frictional torque τμ (20) with the expression (5), the feedback characteristic of the control system can be subjected to frictional compensation. Therefore, the control system is operated as if there were no friction. Accordingly, although the compliance can be enhanced, the feedback system becomes vibrational.
On the other hand, as shown in FIG. 4, in the case where the angular velocity command ωcom (13) is used for the angular velocity ω which is used for calculating (21) the frictional torque τμ (20), the feedback characteristic of the control system is not affected. Therefore, in order to improve the target following characteristic, it is desirable that the compensation is made by 100%.
Next, the second conventional example will be explained below.
Concerning the method of finding a collision torque without using a sensor, the following method is commonly used. The motor generation torque is found when a loss of torque, which is generated in the motor and the reduction gear, is subtracted from the torque generated by the drive electric current of the motor. When the torque necessary for the output of the reduction gear, which is found by the dynamic calculation and referred to as a dynamic torque, is subtracted from the motor generation torque found before, the collision torque is found.
For example, the frictional torque corresponding to the loss of the torque generated by the motor is defined as a sum of the proportional item to the velocity (viscous friction torque) and the stationary item (Coulomb's frictional torque), and calculated. This is disclosed, for example, in JP-A-2002-283276.
According to JP-A-6-083403 (U.S. Pat. No. 6,298,283), the following technique is proposed. When the fluctuation of a parameter of the robot is calculated by the estimated algorithm and added to the torque (electric current) command, the fluctuation factor is canceled. In this conventional example, the frictional torque corresponding to a loss caused in the torque generated by the motor is defined as a sum of the proportional item to the velocity and the stationary item, and estimated by the estimation algorithm.
Accordingly, in the case where the collision torque is found without using a sensor when the dynamic torque of the robot is subtracted from the motor generation torque or in the case where the servo following characteristic by the feedforward control of dynamic torque is improved in order to exhibit the motor drive force at the maximum, it is required to accurately calculate the necessary torque by the motor generation torque and the reduction gear output of the robot.
The motor generation torque τm at the time of operation of the robot can be expressed by the expression (8) when it is viewed from the motor drive side. Further, the motor generation torque τm at the time of operation of the robot can be expressed by the expression (9) when it is viewed from the load side.τmm=Kt*Im−(J*α+D*ω+τμsgn(ω))  (8)τml=τdyn+τdis  (9)
In this connection, reference marks shown in the expressions (1) and (2) are defined as follows.
Kt: Motor torque constant
Im: Motor electric current
α: Motor angular acceleration
ω: Motor angular velocity
J: Motor inertia (rotor+primary side of reduction gear)
D: Viscous friction coefficient (converted into motor shaft end)
τμ: Frictional torque (converted into motor shaft end)
τg: Gravity torque (converted into motor shaft end)
τdyn: Dynamic torque (Dynamic torque is a sum of gravity torque, inertia force, Coriolis force and elastic force, which is converted into a motor shaft end.)
τdis: Disturbance torque (Disturbance torque is a collision torque or a parameter error. Disturbance torque is converted into a motor shaft end.)
      sgn              (      ω      )        =      {                            1                                      (                          ω              >              0                        )                                                0                                      (                          ω              ≠              0                        )                                                            -            1                                                (                          ω              <              0                        )
Since the motor and the robot arm are connected to each other through the reduction gear, the items in the expression (9) except for the item of the motor inertia J must be converted into the motor shaft end with a reduction ratio.
When it is assumed that τmm=ml in (8) and (9), the collision torque τdis can be found by the following deformed the expression (10).τdis=Kt*Im−(J*α+D*ω+τμ*sgn(ω)+τdyn)  (10)
In the conventional example, the dynamic friction item τμ in the expression (10) is calculated as a fixed value. However, when the dynamic friction torque item is calculated as a fixed value, in the case where the motor generation torque is high at the time of acceleration and deceleration, a big calculation error of about 10% of the motor generation torque is caused.
On the other hand, feedforward control, the object of which is to improve the servo control characteristic, can be realized as follows. The motor electric current Im is found by the expression (10) under the condition that the disturbance torque τids=0, that is, under the condition that the robot is not contacted with the outside and no parameter errors are caused. The thus found electric current is represented by Iff. When Iff is added to the electric current command, the feedforward control can be realized.Iff (J*α+D*ω+τμ*sgn(ω)+τdyn)/Kt  (11)
In the conventional example, the calculation of the expression (11) is not used but the dynamic frictional item τμ is estimated by the estimation algorithm. However, it is not a change with age but the frictional torque is greatly changed in a short period of time of acceleration and deceleration. Accordingly, by the estimation of the estimation algorithm, a delay of the phase is generated and it is impossible to completely conduct the compensation.
When the calculation is previously conducted not by the estimation algorithm but by the dynamic torque, the delay of the phase is not caused. However, when the calculation is conducted with the expression (11) while the dynamic frictional torque is set at a fixed value, in the case where the motor generation torque is high at the time of acceleration and deceleration, a big calculation error of about 10% of the motor generation torque is caused.
This error will be explained as follows.
FIG. 11 is a view showing the motor generation torque τmm (1), τml (2) and the velocity (3) which are calculated by the expressions (8) and (9) when the robot is made to conduct a reciprocating motion shown in FIG. 12.
In this case, the robot arm to be used is a six axes vertical type multiple joint robot, the portable mass of which is 6 kg and the total arm length of which is approximately 1.3 m. In FIG. 12, the three wrist axes are omitted and the three fundamental axes are shown. At the time of making a measurement, axis FA, which is the third axis, is operated.
In this case, the measurement is made under the condition that the disturbance torque τdis=0, that is, under the condition that the robot is not contacted with the outside and no parameter errors are caused.
As shown in FIG. 11, in τmm (1) and τml (2), the error (4) of about 4% of the peak torque is generated, that is, it can be understood that the expression (8) has an error factor.
When a comparison is made at the time of both the acceleration and the deceleration, the result is as follows.τmm>τml
In the acceleration and deceleration in the operating section, the angular acceleration and the angular deceleration are the same although the directions are reverse to each other. With respect to the gravity, the robot arm is operated by a symmetrical pattern.
Accordingly, in order to reduce the error by decreasing τdyn, the dynamic frictional torque τμ must be increased. However, when dynamic frictional torque τμ is increased while it is kept as a constant value, as shown in FIG. 13, although the error (4) at the time of peak torque is decreased, however, the error (5) at the time of a constant velocity is increased.
That is, when the dynamic frictional torque τμ is considered to a constant, the error factor caused by τμ can not be eliminated. Therefore, in the expressions (10) and (11) containing τμ, the same error is generated.
Therefore, in the sensorless collision torque detection, when the dynamic frictional torque τμ is considered to a constant, although the robot arm does not collide with an object at the time of acceleration or deceleration, the expression (11) outputs an electric current corresponding to the error as a collision torque. For the above reasons, in order to prevent the occurrence of an erroneous detection, the collision detecting sensitivity must be lowered.
On the other hand, in the case of feedforward control of torque necessary for the reduction gear output, when the dynamic frictional torque τμ is considered to a constant, the calculation error is increased, and there is a possibility that the feedforward compensation torque becomes insufficient. When the estimation algorithm is used so as to prevent the generation of the calculation error, it is difficult to estimate the frictional torque, which is suddenly changed at the time of acceleration or deceleration, without causing a delay of the phase. Accordingly, there is a possibility that the deterioration of the control performance can not be sufficiently prevented.
Next, explanations will be made into a method of stopping the robot arm after the collision detection. There are proposed a method in which the robot arm is returned to the position where the collision is detected (JP-A-2002-117618 (U.S. Pat. No. 6,429,617)), a method in which the velocity command is forcibly set at 0 so as to stop the robot arm (JP-A-2000-52286) and a method in which the robot arm is stopped by the maximum reverse motor torque which is reverse to the rotating direction of the motor (Japanese Patent No. 3212571 (U.S. Pat. No. 6,298,283)) and (Japanese Patent No. 2871993 (U.S. Pat. No. 5,418,440)).
According to the methods in which the robot arm is returned to the collision detecting position, the robot arm is returned to the initial position by the positional control. Therefore, the stopping time depends upon the responding property of the positional control. In general, the responding property of the positional control is several tens Hz at the highest. Therefore, the responding property is not so high at the time of stopping the collision, and the stopping time is extended and it is impossible to prevent the occurrence of damage caused by the collision.
According to the method in which the robot arm is stopped by forcibly setting the velocity command at 0, the stopping time depends upon the responding property of the velocity control. In this case, the responding property is several hundreds Hz, which is higher than the responding property in the case of the positional control. However, it is inferior to the responding property (several kHz) of the electric current control.
According to this method, since the positional control servo rigidity by the integration of the velocity control is high, the robot arm is stopped while the distortion caused by the collision is remaining. Therefore, according to JP-A-2000-052286, the positional control rigidity is softened when the velocity integration gain is made to be 0, so that the problem of the distortion, which is caused by the collision, can be solved. However, in order to enhance the compliance, it is necessary to reduce a gain proportional to the velocity, which deteriorates the velocity responding property and extends the stopping time. It is difficult to make the stopping time and the compliance compatible with each other.
According to the method in which the robot arm is stopped by the maximum reverse motor torque with respect to the rotating direction of the motor, the responding property of the electric current control for generating the reverse torque is so high that the responding property can be several kHz, that is, the responding property is excellent. However, according to the method disclosed in Japanese Patent No. 3212571, it is necessary to previously set the time at which the reverse torque is impressed. When this impressing time is short, it is impossible to sufficiently reduce the velocity, and the damage caused by the collision is increased. When this impressing time is long, a redundant motion is conducted in the reverse direction, and there is a possibility that the robot arm causes the collision again. According to the method disclosed in Japanese Patent No. 2871993, a method is proposed in which the maximum reverse torque is impressed until the motor is stopped. In this method, it is unnecessary to previously determine the impressing time to impress the reverse torque. Therefore, the aforementioned problems are solved. However, only when the motor is stopped, the problem of the distortion caused by the collision can not be solved. Since the generation of the maximum reverse torque itself is a state in which the control is generating the maximum output in an open loop, in the case where the velocity is so low that the robot can not be damaged even when it collides with an object, there is a higher risk of impressing the reverse torque.
In either system, in the axis, the colliding direction of which coincides with the rotating direction of the motor, when the robot arm is returned to the collision detecting position or suddenly stopped, an intensity of the collision force is increased.
FIG. 15 is a view showing this state in which two-axes robot is used for the explanation. In general, the common vertical type multiple joint robot is composed of 6 axes. However, in order to simplify the explanations, 2-axes model will be explained below.
In FIG. 15(a), axis UA (41) is operated in the direction of the angular velocity ωfb (1), and axis FA (42) is operated in the direction of the angular velocity ωfb′ (6). When the time passes and each arm operates in the direction shown in FIG. 15(b) and collides with an obstacle (43), the collision force (44) is generated, and axis UA (41) is given a force reverse to the rotating direction of the motor, that is, axis UA (41) is given a collision torque τdis (9) in the direction so that the velocity can be reduced. On the other hand, axis FA (42) is given a force in the same direction as the rotating direction of the motor, that is, axis FA (42) is given a collision torque τdis′ (10) in a direction so that the velocity can be increased.
After that, in order to return axis FA (42) to the collision detecting position or suddenly stop axis FA (42), it is necessary to generate torque by the motor so that the motor rotation can be reduced. However, this torque is directed reverse to the direction of the collision torque τdis′ (10). Therefore, an intensity of the collision torque is increased on the contrary.
According to the method of returning the robot arm to the collision detecting position, although the axis (axis UA in FIG. 15), the motor rotating direction of which is reverse to the colliding direction, is returned to the collision detecting position, the axis (axis FA in FIG. 15), the motor rotating direction of which is the same as that of the colliding direction, is not reversed and continues the operation which has been conducted until the collision. In this way, the aforementioned problems are solved.
However, in the case where the collision is detected without using a sensor, the collision torque is estimated from the pieces of information of the mechanical parameter, position, velocity, acceleration and electric current of the robot. Therefore, compared with the case in which the collision detecting sensor is provided, the detection error is increased. For the above reasons, in the case of an axis, the collision detecting torque of which is low, there is a possibility that the direction is mistakenly detected and the appropriate stopping means can not be selected.
In the case of an axis, the detected collision torque value of which is low, it is safer that the colliding detection is not detected and the motor rotating speed is reduced so as to decrease the kinetic energy. However, since the colliding direction is unknown, it is better not to reduce the motor rotating speed in some cases, that is, different from the method described in Japanese Patent No. 2871993, the reverse torque should not be impressed until the motor is stopped. In the case where the motor rotating speed is so low that the robot can not be damaged even when it collides with an obstacle, the reverse torque should not be impressed.
Further, in the case of a vertical type multiple joint robot, it is impossible to neglect an interference force given between the axes. Accordingly, there is a possibility that a velocity reducing force is given to an axis, the velocity of which should not be reduced, by an interference force given from an axis to which the reverse torque is impressed. In any case, the reverse torque should be impressed upon a necessary axis for a minimum period of time.

Robot arm control method and control device

Matsushita Electric Industrial Co., Ltd.


A method and system for constant-power loading for asymmetric antenna configurations. The sounding packet, the sounding bit in HT-SIG field, and the HT-LTF field in the PLCP protocol data unit (PPDU) are used to determine the number of transmit antennas and the number of data streams, wherein if the number of transmission streams is the same as the number of data streams, then a first set of power loading level (fixed uneven power loading) is applied, otherwise a second set of power loading level is applied. Alternatively, one additional bit in the HT-SIG filed of PLCP protocol data unit (PPDU) signaling field is used to signal the set of power loading level used.

A multiple-input-multiple-output (MIMO) communication system employs multiple transmit antennas in a transmitter and multiple receive antennas in a receiver for data transmission. A MIMO channel formed by the transmit and receive antennas may be decomposed into independent channels, wherein each channel is a spatial sub-channel (or a transmission channel) of the MIMO channel and corresponds to a dimension. The MIMO system can provide improved performance (e.g., increased transmission capacity) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.
MIMO increases system link robustness and spectral efficiency. To optimize spectral efficiency for MIMO system, many efforts have been made, which can be broadly classified into two categorists: open-loop approaches and closed-loop approaches. The open-loop approaches include spatial multiplexing, space-time coding and the tradeoff therebetween them. The closed-loop approaches focus on maximizing the link capacity, which results in a "water-filling" solution, and on minimizing the weighted MMSE which provides an "inverse water-filling" solution.
In an open-loop MIMO system, the MIMO transmitter has no prior knowledge of the channel condition (i.e., channel state information). As such, space-time coding techniques are usually implemented in the transmitter to combat fading channels. In a closed-loop system, the channel state information (CSI) can be fed back to the transmitter from the receiver, wherein some pre-processing can be performed at the transmitter in order to separate the transmitted data streams at the receiver side.
Such techniques are referred to as beamforming techniques, which provide better performance in desired receiver's directions and suppress the transmit power in other directions. Beamforming techniques are considered for IEEE 802.11n (high throughput WLAN) standard. Closed-loop eigen-beamforming generally provides higher system capacity compared with the closed loop solution, assuming the transmitter knows the down-link channel. Singular value decomposition (SVD) based eigen-beamforming decomposes the correlated MIMO channel into multiple parallel pipes.
When applying the closed loop approach to MIMO-OFDM, the optimal solution requires a bit loading and power loading per OFDM subcarrier, i.e., adapting the transmitted signal x and the power loading matrix P simultaneously per subcarrier. In order to simplify the complexity, conventional approaches propose: (1) adapting coding/modulation and power level across all subcarriers (described in S. A. Mujtaba, "TGn Sync Proposal Technical Specification", a contribution to IEEE 802.11, 11-04-889rl, November 2004 (incorporated herein by reference)), (2) fixing coding/modulation for all data streams and only adjusting the power level, and (3) fixing coding/modulation and the power loading level (unequal) for all OFDM symbols. The first approach provides the highest throughput with the most implementation complexity. In the second approach above, different levels of power quantization with auto-detection have been evaluated, with 2 level quantization recommended. Such methods are robust for different antenna configurations, channel condition etc., but result in higher cost due to receiver complexity (auto-detection is required). In order to further simplify the receiver complexity, the third approach above proposes 1-bit (const) power loading has been utilized. Since constant power loading is used, no auto-detection is needed. However, such an approach only works well when transmitter and receiver antennas are symmetric. In case of asymmetric transmission, constant power loading leads to performance degradation.
An uneven power loading detection approach, wherein auto-detection at the receiver is not necessary with adaptive power loadings, has also been proposed. However, the receiver must implement an Upper-triangular Decomposition (UD) in addition to the MMSE MIMO detection. Therefore, this approach cannot be used for dummy receivers without beamforming capability. A dummy receiver is the receiver with minimum complexity and only support basics MIMO detection. For example, only general MMSE linear detection, not SVD or UD kind of particular matrix operation.

Methods and apparatus for constant-power loading asymmetric antenna configuration


Methods and apparatus are provided which solves the looping problem in structural documents, such as those defined by DOM, EDI and XML. The method and apparatus remove ambiguities by presenting a user with a hierarchical tree structure representation of the document allowing the user to select data grouping rules to be followed. The method and apparatus then automatically create a modified hierarchical tree structure based upon the user-defined rules. Rules can be input by the user using a rule table editor or by means of a graphical user interface.

The extensible Markup Language (XML) is emerging as one of the most important formats for document and data representation and transmission. For example, business documents can be presented by XML for Internet transmission and World Wide Web access. More and more users and new applications are starting to require their input and output to be in XML format.
Details of XML are described in "Extensible Markup Language (XML) 1.0," W3C Recommendation Feb. 10, 1998, the disclosure of which is incorporated by reference herein. An XML document can be modeled as a tree, see "Document Object Model (DOM) Level 1 Specification, version 1.0," W3C Recommendation 1 Oct. 1998, the disclosure of which is incorporated by reference herein.
The Electronic Data Interchange (EDI) flat file format has been in use by the auto, health care, manufacturing and other industries, for more than 20 years. Due to the communication cost at the time the format was designed, data is highly compressed based on EDI maps and dictionaries.
The looping problem in structural documents, such as those defined by the Document Object Model (DOM) and extensible Markup Language (XML), can have a remarkable impact on application programming. The problem is that similar data items within a document may repeat several times, and that related data items are not properly grouped together. The problem is most severe in documents represented in flat file format, for example EDI, and there are few or no data grouping tags or position symbols to distinguish the occurrences of loops. Documents with poor data groupings may complicate the code structure of an application program that must read the document, as the programmers may need to write extra code to sort out the repeating data items and loops. In certain applications, such as XSL, the XML Stylesheet Language, "XSL Transformations (XSLT) 1.0," W3C Recommendation 16 Nov. 1999, this becomes difficult since the allowable structural construct and formatting style may be limited.

User controllable data grouping in structural document translation

International Business Machines Corporation


A cheek retraction device includes a base and a stem extending from the base, the stem for coupling to a vacuum line. Arms extend in opposed directions from the base to opposed grips flanking a working area configured to be disposed over an opened oral cavity. The grips have a plurality of ports coupled in fluid communication to the stem. A trunk extends from the base, between the arms, to in front of the working area. The has a plurality of intakes coupled in fluid communication to the stem.

Respiratory droplets are a primary vehicle for transmitting respiratory infections. Coughing and sneezing will rapidly disperse a large number of droplets into the air, potentially making airborne a sufficient volume of virus-carrying droplets to infect a person who inhales those droplets. However, even the act of talking and normal breathing will emit virus-carrying droplets, and with prolonged exposure to such talking or breathing, a person may inhale a sufficient number of droplets to become infected.
The above has been well known for some time but has become more acute in the year 2020 due to the pandemic created by the SARS-CoV-2 virus that causes the COVID illness. Governments and individuals, however, have recognized that transmission of this virus—and other viruses—can be mitigated significantly with the use of masks. If both infected and healthy individuals wear masks when close to each other, the spread of disease can be slowed.
Mask wearing is appropriate and practical in many situations, but not all. In the dental setting, a patient's mouth must be open and accessible to the dental staff. A dental hygienist cannot practically work on the mouth of a patient who is wearing a mask. So, dental patients do not wear masks, and this exposes the staff to a risk. Further, hygienists and dentists frequently need to be very close to the patient's mouth and are thus more likely to inhale more of the exhaled air. As such, the staff are even more likely to inhale a sufficient number of virus-carrying droplets to become infected with an illness. An improved method of providing dental services to a patient who may or may not be infected with a communicable respiratory illness is needed.


A spring damper device includes cylindrical outer coil springs and inner springs inserted in the outer coil springs, respectively. The cylindrical outer coil springs are held in the form of arcs of a circle at angular intervals therebetween by a retainer plate, whereas the inner springs have a length shorter than the outer coil springs so that the inner springs are actuated a predetermined angle later compared with their corresponding outer coil springs. Each of the inner springs has a diameter smaller at opposite end portions thereof than at a central portion thereof.

a) Field of the Invention
This invention relates to a spring damper device for use in a lockup clutch of a torque converter.
b) Description of the Related Art
FIG. 1 is a cross-sectional view showing a basic construction of a torque converter equipped with a lockup clutch. FIG. 2 is an illustration as viewed in the direction of arrows II--II of FIG. 1. In these drawings, there are shown a torque converter main body 10, a centering portion 1 of an engine power output shaft, a pump 2, a turbine 3, a stator 4, a turbine hub 5 of the torque converter, an axis 6, a power input casing 21 connecting the engine power output shaft and the pump 2 with each other, a piston 22 axially movable on the hub 5 and acting as a clutch plate, a retainer plate 23 fixed on the piston 22 by rivets 26, and tabs 24 located inside a spring 32 which is arranged on an inner peripheral side of an outer peripheral flange 28 of the piston 22. These tabs 24 have been formed by radially slitting a peripheral portion of the retainer plate 23 at predetermined angular intervals and bending out every second slitted peripheral portions. Designated at numeral 25 are spring end face support members which are located radially outside the retainer plate 23 and are bent into turned square U-shapes with the open faces of the Us rendered broader. Numeral 33 indicates caps in which end portions of the corresponding springs 32 are received, respectively. Numeral 27 indicates a friction member of the clutch.
A driven plate 31 is arranged opposite the end face supporting members 25. Incidentally, a portion indicated by sign 32A in an upper part of FIG. 2 indicates that the spring 32 has been compressed, its caps 33 have already been brought into contact with each other and the spring 32 cannot be compressed any further. On the other hand, at another portion indicated by sign 32B in a lower part of FIG. 2, the tab 24 is omitted, and the spring and its associated caps are shown in cross-section.
A description will next be made about the operation of the torque converter equipped with the lockup clutch. Now assume that a hydraulic pressure is applied on a right side of the piston 22. Then the piston 22 is moved leftwards and is brought into contact under pressure with the power input casing 21. Rotation of the piston 22 is hence transmitted to the turbine 3 via the end face supporting members 25, the caps 33, the springs 32 and the driven plate 31. As the turbine 3 is fixedly mounted on the turbine hub 5, a power output shaft (not shown) is rotated by way of an unillustrated power output hub.
Variations in torque are absorbed at the springs 32. Each spring 32 is positioned between its associated end face supporting members 25 and is also prevented from axial dislocation by the associated tab 24.
Further, as is illustrated in FIG. 3, it has also been contemplated to form each spring 32, which is arranged for the absorption of torque variations, as a double coil spring formed of an inner spring 32X and an outer spring 32Y and further to make the inner spring 32X shorter to delay its actuation, thereby providing the double coil spring with two-step damping characteristics. There is also a modification that linear cylindrical springs are set in the form of arcs of a circle to save a space for their arrangement.
In the case of double coil springs such that, as is shown in FIG. 3, each outer spring 32Y is inserted between spacers 34, which are in turn positioned between the associated two end face supporting members 25, and the corresponding shorter inner spring 32X is inserted in the outer spring 32Y, it is designed to hold each outer spring 32Y in a curved form or to allow each outer spring 32Y to flex into a curved form under a centrifugal force during rotation. In such a conventional device, however, an inconvenience arises as shown in FIG. 4 and FIG. 5 which is an enlarged view of a part A of FIG. 4. Namely, opposite end portions of each linear inner spring 32X may enter spaces between pitches of the associated outer spring 32Y during an operation so that the opposite end portions of the linear inner spring 32X may ride on the associated outer spring 32Y. This leads to unstable damping characteristics and hence to a shorter service life.

Spring damper device suitable for use in lockup clutch of torque converter


A transfer system including a frame having an upper end portion and a lower end portion, a transfer fixture connected to the upper end portion, the transfer fixture defining a channel and including an elongate transfer member positioned in the channel, the elongate transfer member including a web and a base flange connected to the web.

In the aircraft industry, elongate members, such as composite stringers, must be held in a desired position while being prepared for an adhesive bonding operation. During preparation for bonding, a film adhesive material is manually rolled out to the length of the stringer, which may be 90 feet or more, and a protective poly backer must then be removed from the film. The entire length of the film material is then flipped over by a team of workers in order to place the backside of the film adhesive on a base flange of the stringer. Workers then manually trim excess film material away from the edges of the base flange.
During the operations described above, the stringer may be hand held by several workers, while other workers roll out and apply the film adhesive to the stringer. The stringer may also be hand-held while workers trim away excess film adhesive. Hand holding and manipulation of the stringer may be tedious, time-consuming, labor intensive and may present the risk of damage to edges of the base flange.
Once the film application process is complete for one stringer, work may begin on another stringer. The process of transitioning work from one stringer to the next may be difficult and time consuming, particularly when heavy equipment is involved.
Accordingly, those skilled in the art continue with research and development efforts in the field of film material application.

Transfer system and method for applying a film material to an elongate member


A three-dimensional image is derived from two-dimensional images. At least one of the two-dimensional images has a predetermined number of pixels. Depth measurements are derived from the two-dimensional images. The number of derived depth measurements is substantially equal to the predetermined number of pixels. The three-dimensional image is derived from the two-dimensional digital images and the depth measurements.

The invention relates to determining a depth.
Determining a depth or a distance, also known as range sensing, is important in, e.g., industrial applications such as measurement of solder paste volume in manufacturing surface-mounted electronic assemblies, digitization of three-dimensional (xe2x80x9c3-Dxe2x80x9d) clay models, and inspection of semiconductor packages for lead coplanarity.
Electronic devices that have traditional electrical terminals (e.g., dual in-line package leads) may be inspected in two dimensions using backlight. However, some devices that have other types of electrical terminals such as ball grid array balls cannot be effectively inspected using backlight. Instead these devices are inspected by an imaging system that can view the terminals in three dimensions to check for compliance with specifications for, e.g., height, volume, and shape.
Optical systems have been devised that allow 3-D images to be derived from two-dimensional (xe2x80x9c2-Dxe2x80x9d) images, by exploiting optical principles that relate the extent to which a surface is out-of-focus to a distance between the surface and an in-focus point. With such systems, resulting depth information in each of the derived 3-D images has only a fraction of the resolution of each of the 2-D images (e.g., only 512xc3x97512 points of depth information from 1024xc3x971024 2-D images). Thus, to derive depth information having only moderate resolution, such systems are compelled to use costly high-resolution cameras that can produce the necessary high-resolution 2-D images.
In general, in one aspect, the invention features a method for deriving a three-dimensional image from two-dimensional images, at least one of the two-dimensional images having a predetermined number of pixels. The method includes: deriving focus-based depth measurements from the two-dimensional images, the number of derived focus-based depth measurements being substantially equal to the predetermined number of pixels; and from the two-dimensional digital images and the depth measurements, deriving the three-dimensional image.
Implementations of the invention may include one or more of the following features. The method may further include deriving a focus measurement for each pixel in the predetermined number of pixels. The method may further include deriving each focus-based depth measurement from the focus measurements. The three-dimensional image may include information about a subject and each of the two-dimensional images may include different information about the subject. The method may further include imposing structured illumination on the subject and producing the two-dimensional images from the subject under the structured illumination. The method may further include, for each of the two-dimensional images, imposing different structured illumination on the subject. Each instance of imposed structured illumination may include a same pattern having a spatial period, and, for the instances of imposed structured illumination, the respective positions of the pattern relative to the subject may differ by a fraction of the spatial period. The fraction may include a multiple of a quarter of the spatial period. The subject may bear a contrast pattern, and the method may further include, in the derivation of the focus-based depth measurements, excluding at least some information about the contrast pattern.
In general, in another aspect, the invention features a method for use in determining a depth. The method includes taking three sample values of a characteristic of an area defined by a pixel, each sample value corresponding to a different position of structured illumination relative to the area.
Implementations of the invention may include one or more of the following features. The structured illumination may include a pattern having a spatial period, and each of the different positions may differ by a fraction of the spatial period. The method may further include, from the three sample values, deriving a computed value representing a result of illuminating the area with unstructured illumination. The method may further include, from the three sample values and the computed value, deriving normalized sample values representing respective results of illuminating the area with the structured illumination at positions differing by the fraction of the spatial period. The method may further include, from the normalized sample values, deriving a focus measure representing a relative distance. The spatial period may be at least as long as four times a length defined by the pixel.
In general, in another aspect, the invention features a method for use in processing a digital image. The method includes: imposing structured illumination on a subject, producing two-dimensional images from the subject under the structured illumination, at least one of the two-dimensional images having a predetermined resolution, each of the two-dimensional images including different information about the subject, from the two-dimensional digital images, deriving focus measurements, from the focus measurements, deriving depth measurements, and from the two-dimensional digital images and the depth measurements, deriving a three-dimensional image having the predetermined resolution.
In general, in another aspect, the invention features a method for use in determining a depth. The method includes: taking three sample values of a characteristic of an area defined by a pixel, each sample value corresponding to a different position of structured illumination relative to the area, the structured illumination including a pattern having a spatial period, each of the different positions differing by a fraction of the spatial period; from the three sample values, deriving a computed value representing a result of illuminating the area with unstructured illumination; from the three sample values and the computed value, deriving normalized sample values representing respective results of illuminating the area with the structured illumination at positions differing by the fraction of the spatial period; and from the normalized sample values, deriving a focus measure representing a relative distance.
Among the advantages of the invention are one or more of the following. A CCD sensor having a 512xc3x97512 pixel array can be used to produce a 512xc3x97512 depth image (i.e., 512xc3x97512 points of depth information). With little or no modification to hardware, some existing systems for producing depth images can be upgraded to produce higher-resolution depth images. A depth image can be created by using a simple patterned mask that changes sinusoidally from dark to light. Large groups of electrical terminals can be effectively inspected by using conventional CCD sensors.
Other advantages and features will become apparent from the following description and from the claims.


A method for working up antimony halide catalysts containing inactivating organic impurities having high boiling points, in which anhydrous antimony trichloride can be isolated in a technically simple manner. The antimony trichloride can be chlorinated to obtain antimony pentachloride which can be re-used as a catalyst in a fluorination process.

This invention relates to a method for working up inactive solutions containing antimony halide catalysts and organic impurities.
Fluorochlorohydrocarbons, fluorochlorocarbons, fluorohydrocarbons and fluorocarbons are used to a large extent as solvents and refrigerants. (For simplicity, the following description will refer only to hydrocarbon compounds, but this term is to be understood as including hydrogen-free compounds, perhaps more correctly called carbon compounds. Thus, as used herein, the term "fluorochlorohydrocarbon" should be understood as embracing halocarbons such as CFCl.sub.3 as well as hydrogen-containing compounds.) In most industrial production processes, a chlorine/fluorine exchange takes place, catalyzed by antimony halide. Antimony pentahalide, particularly antimony pentachloride, is used as the catalyst.
The life of these catalysts is limited. During production of fluorochlorohydrocarbons or fluorohydrocarbons, unwanted halogenated organic compounds, some of which have considerably higher boiling points than the desired products, are also formed in addition to the desired process products. These byproducts dilute the antimony halide catalyst, so that gradually solutions containing antimony halide catalysts and organic impurities and having increasingly diminishing activity form. When the diminishing activity of the catalysts falls below a given limit, the inactive catalyst solution has to be removed from the reactor and be replaced by fresh antimony halide catalyst.
The solutions contain pentavalent and usually also trivalent antimony in the form of the halides, namely predominantly in the form of chlorides, but also to a greater or lesser extent in the form of mixed chlorides/fluorides. Depending on the field of use of the catalyst solution, the fluoride content may also be very low. In addition to the inorganic constituents, halogenated hydrocarbons are also present in the solutions. Which particular halogenated hydrocarbons are present in each case will naturally depend on the respective fluorination process in which the catalyst solution has been used and the manner in which the process is performed.
It is desirable to work up the inactive solutions for economic reasons (recovery of the antimony content), and also particularly for ecological reasons.
Antimony pentahalides and the halogenated hydrocarbons of the inactive solution form a homogenous mixture. Since some of the organic constituents have a boiling point similar to antimony pentachloride, for example, it is not possible to work up the solutions by means of distillation. Due to the formation of homogenous phases and the similar boiling points of antimony halides and impurities, it is difficult to separate the antimony halides from the organic constituents during working up.
Methods for working up inactive solutions containing antimony halide catalysts and organic impurities are already known. One method provides an aqueous work-up procedure. According to the process of British Patent Application No. GB 1,531,799, in order to separate the antimony halide from the organic constituents, sufficient water or aqueous hydrochloric acid is added to the organic solution containing antimony halide catalysts so that two liquid phases form. One phase is formed by the organic constituents, the other, aqueous phase contains the portions of pentavalent antimony. The hydrated antimony compounds can then easily be separated from the organic constituents and reduced if desired. The conversion of the dissolved antimony compounds into anhydrous compounds, in particular into the anhydrous antimony halides, is certainly very involved. Therefore the aqueous antimony trihalide solutions which are obtained after reduction are used directly for producing lead chromate pigments.
Another method provides a non-aqueous work-up procedure. Such a process is described in U.S. Pat. No. 3,760,059. In this procedure an equal volume of trichloroethylene is added to the solution containing antimony halide catalyst and organic impurities, and the mixture is heated in an autoclave. The resulting antimony trichloride, which is crystalline and anhydrous, can be separated from the organic constituents by suction filtering, and if desired, can be processed to produce antimony pentachloride, which then can be re-used as a catalyst. However, the addition of a considerable quantity of trichloroethylene which is necessary in this process (other olefins, apart from perchloroethylene, have proved unusable) leads to a correspondingly higher occurrence of unwanted byproducts having high boiling points.

Method of working up antimony halide catalyst solutions


Briefly, in accordance with an embodiment of the invention, a method and apparatus to write back data is provided. The method may include setting a status corresponding to a block of data in response to a change in address mapping to indicate that the block of data is pending write back. The apparatus may include a storage area to store a status associated with a block of data to indicate that the block of data is pending write back and is not accessible with the current address mapping. Other embodiments are described and claimed.

Two methods for writing information in a multilevel memory hierarchy may include "write through" and "write back." Write through may refer to when information is written to both the cache memory and to a lower-level memory in the memory hierarchy. Write back may refer to when information is written only to the cache memory and may be written to the lower-level memory at a later point in time.
Determining when to write back the information to the lower-level memory may involve many factors and tradeoffs in terms of system performance.
Thus, there is a continuing need for alternate ways to write back data in a computing system.


An electronic apparatus includes: a front surface member that includes a concavity in which an insertion aperture is located, the insertion aperture for receiving an object to be inserted into the insertion aperture, a bottom surface of the concavity having a support; and a cover that removably fits into the concavity to cover the insertion aperture. The cover includes a slider having an arc-shaped cross section. In a state in which the cover is fitted in the concavity, the slider of the cover contacts the support provided at the bottom surface of the concavity. When a part of the cover is pushed, the cover rotates, while the slider slides along a surface of the support.

Field of the Invention
The invention relates to an electronic apparatus that includes an insertion aperture for insertion of an object.
Description of the Background Art
Generally, electronic apparatuses, such as car navigation apparatuses, include an insertion aperture for insertion of an object. Some among examples of such an insertion aperture are a slot for a memory card and a terminal for a cable. Conventionally, protective structures to protect such insertion apertures have been proposed.
For example, Japanese unexamined utility model application publication No. H1-59992 proposes a protective structure in which an insertion aperture is provided in a concavity formed on a front surface of an electronic apparatus and in which the insertion aperture is covered by a cover that is fitted in the concavity. In the protective structure, the cover includes, on a back surface thereof, a projection that contacts a bottom surface of the concavity in a state in which the cover is fitted in the concavity. A user pushes a portion of a front surface of the cover to remove the cover from the concavity. Thus, the cover rotates around an end of the projection, like a seesaw, and an opposite to the pushed portion of the front surface of the cover is moved up. Therefore, the user can remove the cover from the concavity.
In a case where the protective structure described above is used, it is recommended that the front surface of the cover fitted in the concavity be substantially level with a front surface of a surface member (front surface around the concave) of the electronic apparatus. Therefore, the deeper the concavity is, the greater a distance from the front surface of the cover to the end of the projection of the cover should be. Therefore, if a depth of the concavity is greater, a turning radius of rotation of the cover to be removed from the concavity is greater, and thus a range in which the cover moves during the rotation is larger. As a result, in order to avoid the cover from coming into contact with a side wall of the concavity, a gap between the cover and the side wall of the concavity needs to be greater.
However, it is not recommended from a viewpoint of protection of the insertion aperture and an aesthetic appearance of the electronic apparatus that the gap between the cover and the side wall of the concavity should be widen.


An external random access memory (RAM) module for increasing the RAM capacity of a computer system. The RAM module includes: a plurality of RAM slots for receiving removable memory modules; a memory addressing unit for addressing the removable memory modules in the external RAM module; and a connector for connecting the memory addressing unit to an external port of the computer system, wherein the external port is addressable by a processing unit in the computer system.

1. Technical Field
The present invention relates generally to systems for expanding random access memory (RAM) capabilities on a computer system, and more specifically relates to a portable RAM module that can be externally connected to a computer system to provide increased RAM capabilities.
2. Related Art
As the use of personal computers (i.e., desktops, laptops, workstations, PDA's, etc.) continues to flourish, the capabilities and deliverable expectations of software applications also continues to dramatically increase. In line with these increased capabilities, the hardware resources required to run these applications have also dramatically increased. Not long ago, 32 Megabytes (MB) of RAM would suffice for most processing needs. Over time, 64 MB, then 128 MB, then 256 MB, all came and went as sufficient processing configurations, and these days even 512 MB often does not suffice.
For an organization that uses thousands of desktops, the management of hardware upgrades is far more expensive and time consuming than associated software upgrades. The process of upgrading hardware can often have a huge impact on employee productivity—a developer could lose the whole morning while waiting for an upgrade to take place. Typically, these organizations have a "standard configuration" defined for a time period, which they try to upgrade with time, e.g., a standard configuration may comprise 256 MB of memory and a PENTIUM™ 3 processor. This standard configuration is reviewed and updated on a year to year basis.
More often than not, additional memory requirements are intermittent. That is, a user may require additional memory to carry out a part of his job for some period of time. For example, for a group of machines being used for application development and support, the processing power requirement spikes during the time of an application release, which could be three or four months of year. On other occasions, e.g., when a user needs to edit large files, such as a several gigabyte (GB) video file, or even huge worksheets, the user may need more memory. However, this requirement is often short-lived as the additional memory may not be required after the specific operation.
A common approach to handle this issue is to purchase and install additional RAM. Unfortunately, upgrading RAM is a relatively costly process as the memory upgrade process requires the computer chassis to be opened and the RAM module installed in each of the machines. This activity requires a level of hardware knowledge and cannot be carried out by a typical end user. Moreover, if the user has more than one machine that has intermittent RAM requirements from time to time, then all the machines will have to be upgraded, as there is no technology in place to share memory.
Another approach could be that the user procures RAM for one machine and then manually removes it and plugs it on other machines as required. As pointed out earlier, this requires a level of expertise and the RAM slots are likely to be damaged if the RAM is frequently removed and installed.
Furthermore, the price of the upgrade may be dictated by the number of free RAM slots in the machine. If the machine has only two RAM slots available, and it already has two memory modules of 128 MB each installed, then the user would need to buy a fresh 512 MB memory module or two memory modules of 256 MB each to upgrade to 512 MB. Even though the upgrade is from 256 MB to 512 MB, the user would end up paying for the entire 512 MBs.
At first look, "grid computing" seems to be a likely solution that could address the problem in future. A grid creates a virtual super computer out of existing workstations by knitting them together. This super computer can be used to host business applications at lightening speeds. A grid application can offload a quantum of its work to any other node that has free resources available. These new breed of applications are capable of harnessing the processing power of other free machines "On Demand."
Unfortunately, grid computing addresses a different, although very important, aspect of the problem. The applications that are supposed to run on the grid need to be specially written and deployed for that purpose. If an end user needs additional memory for editing a large video file, the user cannot use the grid unless that video editing software is grid enabled. Moreover, even if the application is grid enabled, the user would need to link with a grid provider and have that application deployed on the grid.
There is currently no technology that enables different workstations or laptops to share memory. There are some new technologies that would let applications share the processing power of other machines on the network, but the problem of additional memory requirements would continue to exist in the near future. Accordingly, a need exists for a cost effective solution for intermittently upgrading RAM on personal computers.


An improved multicarrier modulation system and method, which has the advantages of both isotropic orthogonal transfer algorithm orthogonal frequency division multiplexing (IOTA OFDM) and scalable advanced modulation (SAM), is introduced. The invention is root raised cosine (RRC) OFDM using the most spectrally efficient RRC filter without sacrificing the compact subchannel spacing of OFDM. The invention further provides an adjacent channel interference (ACI) suppression scheme and a modified RRC for better suppressing ACI of RRC OFDM. The ACI suppression scheme can also be applied to SAM with the modified RRC and to IOTA OFDM with a modified IOTA. The invention greatly improves a major problem of conventional OFDM namely ACI due to the use of a wide subchannel filter. Thus, the invention allows OFDM to meet even the strictest ACI requirements, which was not possible by using a conventional raised cosine windowing method.

As high-speed data transmission is required for multimedia communications, multi-carrier modulations such as orthogonal frequency division multiplexing (OFDM) or scalable advanced modulation (SAM) have been developed in order to accommodate these high-speed requirements. OFDM has been found to be an effective data transmission scheme for use with fading and multi-path transmission channels because it reduces inter-symbol interference (ISI) and makes equalization simple. The concept of using parallel data transmission and frequency division multiplexing (FDM) was first published as early as the mid 1960s. These schemes are adopted to avoid the use of high-speed equalization and to combat impulsive noise and multi-path distortion as well as to use the available bandwidth efficiently. In the early 1970s, the application of discrete Fourier transform (DFT) on FDM was discovered to eliminate arrays of sinusoidal generators and coherent demodulation making implementation of OFDM cost-effective. More recently, International Mobile Telecommunications-2000 (IMT-2000) chose MC-CDMA, which is an OFDM application, as a future code division multiple access (CDMA) standard, making the popularity of OFDM grow even more rapidly.
One of the problems associated with OFDM is adjacent channel interference (ACI). The ACI of OFDM is problematic in that the pulse shape of OFDM is rectangular and the spectrum of the pulse is a sum of a sinc function whose sidelobe fades very slowly. Therefore, although the −3 dB bandwidth of an OFDM signal is 10 kHz, its −40 dB bandwidth should be 100 kHz not to interfere with an adjacent channel signal. This problem has been solved generally by using a raised cosine window on the high sidelobe spectrum. However, the raised cosine window cannot reduce the ACI completely with reasonable nonlinear distortion. The ACI problem is not as serious when the number of subcarriers is very large (i.e. >˜1024). However, the ACI problem is very serious when the number of subcarriers is small (i.e. <˜128). The expanded bandwidth by the ACI is relatively large when the number of subcarriers is small and relatively small when the number of subcarriers is large, i.e. the percentage increase of bandwidth depends on the number of subcarriers. That is because the amount of the expanded bandwidth by the ACI is fixed for a given symbol rate. Thus, the seriousness of the ACI problem depends on the number of subcarriers.
The ACI problem is solved dramatically with an isotropic orthogonal transfer algorithm (IOTA) OFDM technique. The IOTA functions, which are the pulse shapes of IOTA OFDM, are not orthogonal to each other when they are spaced by 1/Ts in the frequency domain, as the rectangular pulses, which are the pulse shapes of OFDM, are orthogonal in regular OFDM. However, the IOTA functions are orthogonal to each other when they have real and imaginary data symbol alternations both in time domain and frequency domain as the pulse shapes of Offset QPSK are orthogonal to each other when they have real and imaginary data symbol alternations in time domain. Therefore, IOTA OFDM is a form of OFDM with an offset structure in time and frequency domain. The ACI problem of IOTA OFDM is not so serious because the spectrum of an IOTA function, which is the same with IOTA function in time domain, fades much faster than the spectrum of a rectangular pulse, which is a sinc function. However, its ACI still can be problematic when the number of subcarriers is very small (i.e. <˜32) such as in a wideband radio protocol. To avoid ACI, the signal requires wide edge margins at both sides, which reduces the spectral efficiency of the signal. Therefore, the spectral efficiency of the IOTA OFDM can be worse than SAM because of the problem handling ACI.
SAM is merely an assembly of single-carrier modulations with a root raised cosine (RRC) pulse, which are overlapped slightly in frequency. SAM is spectrally less dense than IOTA OFDM because the RRC is not orthogonal when the subchannels are spaced by 1/Ts in frequency. The subchannel frequency spacing of SAM is (1+α−β)/Ts where α is a roll-off factor of RRC and β is an overlapped amount (α>β). However, a sidelobe of RRC spectrum fades faster than any other pulses. Therefore, SAM has better spectral efficiency than IOTA OFDM when the number of subcarriers is small because its ACI is minimal. But SAM is spectrally less efficient when the number of subcarriers is large because of the wider subcarrier spacing.
Thus, the ACI problem of OFDM that is not solved completely by IOTA OFDM and SAM may be solved by the inventions as discussed herein. The need exists for a new form of OFDM that has the both spectral advantages of IOTA OFDM and SAM while still offering the best spectral efficiency regardless of the number of subcarriers. A new ACI suppression scheme is needed to solve the ACI problem of these multicarrier modulation techniques by reducing the sidelobe without a considerable cost. The new invention should provide an ACI suppression method that uses a modified RRC pulse for a first form of multicarrier modulation and/or a modified IOTA pulse for a second form of multicarrier modulation. The modified RRC also can be applied to reduce the ACI of the single carrier signal as well as that of the multicarrier signal.

System and method for generating a spectral efficient root raised cosine (RRC) pulse for increasing spectral efficiency


A system and method for providing content from a source to a vehicle is disclosed. The content is restricted by associating the content with at least one requirement for vehicle information from a vehicle to which the content is provided. When restricted content is requested, a vehicle system obtains vehicle related information from the vehicle. The vehicle information is transferred to the vehicle system from the source, and the restricted content is transferred from the source to the vehicle system. The vehicle system, the source, or both determine whether the vehicle information meets the at least one requirement restricting the content. As long as the requirement for vehicle information is met, processing of the restricted content is allowed.

Vehicles can have several types of devices for processing content. Some examples of devices include conventional radios, satellite radios, audio systems, video systems, entertainment systems, Telematics systems, and navigations systems. The devices can be installed in the vehicle when manufactured or can be aftermarket units added later in the vehicle. The devices can handle various forms of content, such as media, audio, video, radio broadcast, satellite broadcast, television broadcast, Global Position System (GPS) data, and navigation data. To deliver the content to a passenger in the vehicle, the devices have certain processing capabilities, such as storing, rendering, encoding, decoding, transcoding, parsing, encrypting, decrypting, streaming, communicating, and playing capabilities.
Providers of digital media, such as music and videos, use several techniques to restrict or control the acquisition, storage, transfer, and/or processing of the digital media. These restrictive techniques can be referred to as Digital Rights Management (DRM) schemes. Some examples of restrictive techniques include Serial Copy Management System (SCMS), Macrovision, Helix DRM, Steam, iTunes™ (which incorporates Apple's FairPlay DRM for content downloaded through the iTunes™ Music Store), Windows Media DRM (WMDRM) that protects Windows Media Audio or Video content and is implemented in Windows Media Player, OMA DRM system used by the Open Mobile Alliance, Real Networks, Sony's DRM technology OpenMG, MMK Secure Stream, Digital Transmission Content Protection (DTCP), Content Protection for Recordable Media (CPRM), High-Bandwidth Digital Content Protection (HDCP), and Digital Transmission Copy Protection over Internet Protocol (DTCP-IP).
While the subject matter of the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. The figures and written description are not intended to limit the scope of the inventive concepts in any manner. Rather, the figures and written description are provided to illustrate the inventive concepts to a person skilled in the art by reference to particular embodiments, as required by 35 U.S.C. §112.

System and method for providing content to vehicles in exchange for vehicle information


Provided are an apparatus and method for calibrating an extreme ultraviolet (EUV) spectrometer in which a wavelength of a spectrum of EUV light used for EUV lithography and mask inspection technology can be measured accurately.

1. Field of the Invention
The present invention relates to an apparatus and method for calibrating an extreme ultraviolet (EUV) spectrometer, and more particularly, to an apparatus and method for calibrating an EUV spectrometer to accurately measure a wavelength of a spectrum of EUV light used for EUV lithography and mask inspection technology.
2. Discussion of Related Art
In general, an EUV beam, for example, electromagnetic radiation (also known as soft X-rays) having a wavelength of about 124 nm or less, which includes light having a wavelength of 13.5 nm, can be used in a photolithography process to form a very small pitch on a substrate, for example, a silicon wafer.
That is, EUV light and X-rays are located in a shorter wavelength region than visible light, and thus can enhance measurement resolution according to a diffraction limit which limits sizes of wavelengths in precision measurement using light, and can be used for fine measurement or nondestructive testing involved in biotechnology using a good transmission characteristic by extending to the X-ray region.
Particularly, if a good coherent light can be generated at the same time, various applications using interference and diffraction phenomena of light are possible. Because a repetition rate of an incident femtosecond laser can be maintained, it can be used for precision spectroscopy or frequency standard measurement, and so on in EUV and X-ray regions.
One of various methods of generating EUV light and X-rays is a method using a synchrotron. When EUV light and X-rays are generated using a synchrotron, there are advantages in that a large amount of light of good quality can be obtained and various wavelength bands can be obtained at the same time, however, because a facility itself is very enormous and expensive, there is a problem in that it cannot be simply configured in a laboratory stage.
As a method of overcoming this problem, recently, a high-order harmonic generation (HHG) method using a high power femtosecond pulse laser has been proposed, and thus coherent EUV light and soft X-rays can be generated with a relatively small experimental device.
In the HHG method, electrons are ionized, move along a track and are recombined by applying a high time-varying electric field to an inert gas such as, for example, argon (Ar), neon (Ne), xenon (Xe), and so on, and the energy corresponding to the sum of the ionization energy and kinetic energy of the electrons generates light of the EUV and X-ray band.
HHG has typically been designed or made by injecting an inert gas into a gas cell, with the used inert gas leaving the gas cell naturally.
Alternatively, lithium (Li), tin (Sn) and a semiconductor device are also able to generate EUV light in addition to inert gases such as Ar, Ne, Xe, and so on, and inert gases are used to generate EUV light in current HHG technology using a gas cell only because HHG using a gas cell uses a gas as a medium. Thus, there is no specific limitation to inert gases, and EUV light can be generated using other methods.
Meanwhile, because ultra-refinement of a semiconductor process for high integration is required, light sources used for lithography including G-line (436 nm), I-line (365 nm), krypton fluoride (KrF) (248 nm) and argon fluoride (ArF) (193 nm) have been developed.
However, new lithography technology extending resolution in semiconductor processes of 90 nm or less was still required, for which ArF immersion lithography and double-patterning lithography were developed, and thus dynamic random access memories (DRAMs) and NAND flash memories have recently been successfully mass-produced in 23 nm and 20 nm processes, respectively.
Among various techniques being studied to surpass the ArF lithography as next generation lithography, EUV lithography has reached a stage of trial production in major semiconductor companies, and research and development thereof are being actively conducted worldwide.
Meanwhile, in order to inspect defects of mask made by EUV lithography, EUV light is also needed. Particularly, a technique of inspecting defects of a mask with the same wavelength as used in lithography is called an actinic mask inspection technique. In order to generate EUV light with the same EUV wavelength as used in lithography, the HHG method is needed. In order to check whether EUV light generated by the HHG method matches a desired wavelength, a spectrum should be measured using an EUV spectrometer. In this case, calibration of the spectrometer is necessary in order to accurately measure the spectrum. As a calibration method of EUV light, there is a method using an atomic line which has been used for some time. Each inert gas has unique fluorescence lines known as atomic lines. Because wavelength values of atomic line spectra have been studied and widely known since decades ago, EUV light can be calibrated based on a position and a wavelength value of an atomic line spectrum.
However, in order to acquire a degree of strength that a charge-coupled device (CCD) camera of the spectrometer is able to measure, energy several times greater than energy of a laser used for HHG is needed. Therefore, there is a problem in that a laser light source that outputs energy greater than that of a laser for generating EUV high-order harmonics is necessary.

Apparatus and method for calibrating extreme ultraviolet spectrometer

KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY