Disclosed is a rotating media storage device (RMSD) that has at least one calibration track with unique calibration servo synch marks (SSMcs). The RMSD includes a disk that comprises a plurality of tracks including a calibration track having a plurality of normal servo wedges distributed around the calibration track. At least one of the normal servo wedges includes a normal servo synch mark (SSMN). Further, at least one calibration servo wedge is distributed between a pair of normal servo wedges. The calibration servo wedge includes a calibration servo synch mark (SSMC). The calibration SSMC includes a pattern that is different than the pattern associated with the normal SSMN.

1. Field of the Invention
The present invention relates to rotating media storage devices (RMSDs). More particularly, the present invention relates to an RMSD that has at least one calibration track with unique calibration servo synch marks (SSMCs).
2. Description of the Prior Art and Related Information
Computer systems rely on rotating media storage devices (RMSDs), which often employ a moveable head actuator to frequently access large amounts of data stored on the media. One example of an RMSD is a hard disk drive. A conventional hard disk drive has a head disk assembly ("HDA") including at least one magnetic disk ("disk"), a spindle motor for rapidly rotating the disk, and a head stack assembly ("HSA") that includes a head gimbal assembly (HGA) with a moveable transducer head for reading and writing data. The HSA forms part of a servo control system that positions the transducer head over a particular track on the disk to read or write information from and to that track, respectively.
With reference to FIG. 1, FIG. 1 shows an example of a prior art disk 10 having a plurality of concentric tracks 12. Each surface of each disk 10 conventionally contains a plurality of concentric data tracks 12 angularly divided into a plurality of data sectors 15. In addition, special servo information is provided on each disk to determine the position of the moveable transducer head. These tracks 12 are typically referred to as normal tracks.
The most popular form of servo is called "embedded servo" wherein the servo information is written in a plurality of servo wedges 14a, 14b, etc. that are angularly spaced from one another and are interspersed between data sectors 15 around each track of each disk.
Each "Full" servo wedge 14 typically includes a phase lock loop (PLL) field 20, a servo synch mark (SSM) field 22, a track identification (TKID) field 24, a wedge ID field 26 having a binary encoded wedge ID number to identify the wedge, and a group of servo bursts (e.g. ABCD 28—an alternating pattern of magnetic transitions) which the servo control system samples to align the moveable transducer head with or relative to a particular track. In some instances, the servo wedge 14 may only include servo bursts 28 and is referred to as a "Mini-Wedge." This allows for a smaller servo wedge and allows for more space on the track to be devoted to user data.
Typically, the servo control system moves the transducer head toward a desired track during a coarse "seek" mode using the TKID field as a control input. However, in processing information, it is necessary to ensure consistency in the detection of bits composing a block of bits. One common approach directed to ensuring such consistency employs multiple stored fields including a phase lock loop (PLL) field 20 to facilitate bit synchronization and a synch field to facilitate block synchronization. The synch mark field facilitates block synchronization by holding a special marker that is detected to "frame" data, i.e., to identify a boundary of a block. In contemporary hard disk drives employing embedded servos, it is well known to provide framing of servo data via a servo synch mark (SSM) field 22.
Generally, in hard disk drives, a servo synchronization signal based on the head reading a servo synchronization mark (SSM) results in a read/write channel of the disk drive establishing a precise timing reference point for read/write operations.
Once the transducer head is generally over the desired track, the servo control system uses the servo bursts (e.g. ABCD) 28 to keep the transducer head over the track in a fine "track follow" mode. During track following mode, the moveable transducer head repeatedly reads the wedge ID field 26 of each successive servo wedge 14 to obtain the binary encoded wedge ID number that identifies each wedge of the track. In this way, the servo control system continuously knows where the moveable head is relative to the disk.
In some systems, "Mini-Wedges" only having servo bursts 28 are utilized in addition to the "Full Wedges." For example, once the servo control system has acquired the requisite information needed for track following from the Full Wedges, track following can be maintained using the Mini-Wedges. Use of Mini-Wedges allows for a smaller servo wedge and for more space on the track to be devoted to user data, but requires more computationally intensive servo control.
In many of today's disk drives, diagnostic and calibration functions are performed with the aid of specialized calibration tracks. As shown in FIG. 1, typically calibration tracks are located at the outer diameter and the inner diameter of a disk, such as outer diameter calibration track 13A and inner diameter calibration track 13B. Particularly, the calibration tracks are utilized by the servo control system for diagnosis and calibration purposes.
Turning to FIG. 2, FIG. 2 illustrates an example of calibration tracks at the outer and/or inner diameter of a typical disk drive. Generally, a calibration track includes a plurality of normal servo wedges, which may be Full Wedges or Mini-Wedges, distributed around the calibration track. Further, a plurality of calibration wedges are distributed between the normal wedges. FIG. 2 only shows two calibration servo wedges 29, however, it should be appreciated that dependent upon design considerations, any number of calibration servo wedges may be utilized. Typically, during a calibration mode, the servo control system seeks and locks to the normal wedges 14, and then switches to a new sampling period to read both normal and calibration wedges in order to perform any needed diagnostic and calibration functions.
There are many problems associated with the previously described configuration of calibration tracks used in current disk drives. For example, when full wedges are utilized as the calibration servo wedges, the servo control system of the disk drive may accidentally lock onto one of the full calibration servo wedges 29 of one of the calibration tracks 13, instead of one of the full normal wedges 14 of a non-calibration track, resulting in a timing error and possibly causing the disk drive to fail. This is because there is no difference between the servo synch mark (SSM) utilized in the full calibration servo wedges of calibration tracks and the full normal servo wedges of non-calibration tracks. Further, when Mini-Wedges are utilized for the calibration servo wedges, the servo control that needs to be utilized to track along the Mini-Wedges is very computationally intensive.

Rotating media storage device having a calibration track with unique calibration servo synch marks


An object of the present invention is to provide a method of forming a hollow blow-molded foam and also provide such a hollow-molded foam, which are capable of improving a flow-rate efficiency of a fluid that flows through the inside of the hollow blow-molded foam. A foaming resin is sandwiched between molds so that a hollow blow-molded foam having a ventilation path is molded, and a fluid for use in cooling the hollow blow-molded foam is allowed to flow through the ventilation path so that the hollow blow-molded foam is cooled.

In recent years, there have been strong demands for automobiles to have a wider inner space for a high roof, wider sheets, and the like. Thus, ducts for automobiles are required to be compact and to smoothly flow air at a desired flow rate. Moreover, various ducts having different shapes are required for every type of automobiles.
In order to address these demands, related art ducts for automobiles have been made of a hollow molded product composed of high-density polyethylene, polypropylene and the like. The hollow molded product made from these materials can be easily formed into various shapes. In addition, the hollow molded product makes it possible to easily maintain a desired amount of air flow. Therefore, the hollow molded product is desirably used as ducts for automobiles.
However, noise generated by a compressor of an air conditioner and noise generated by an air flow passing through ducts are leaked out of a duct blowing outlet. In recent years, there have been demands for reducing these noises. However, the material for a related art molded product is a non-foaming resin such as a high-density polyethylene, and polypropylene. For this reason, the hollow molded product itself doesn't have a function for absorbing noise.
JP-A No. 2004-116959 has proposed a duct that can reduce noise generated by a compressor of an air conditioner and noise generated by an air flow passing through ducts. It is described that this duct has superior properties, such as a dew condensation preventive property, a heat-insulating property, a heat resistant property and a light weight property, as well as strength that is sufficient in practical use, and can be produced by using simple processes.
More specifically, the duct disclosed in that application is formed by using an intermediate blow-molded foam that has an apparent density in a range from 0.05 to 0.5 g/cm3, and a closed cell rate of 50% or more. Moreover, the inner surface of the hollow blow-molded foam has a surface hardness of 45 to 80 degrees.
As described in the '959 reference, the hollow blow-molded foam has an apparent density in a specific range and a closed cell rate in a specific range. Moreover, the hollow blow-molded foam has a surface hardness on its inner surface within a specific range. As a result, the duct made of such a hollow blow-mold foam has a superior sound absorbing property. Moreover, the duct makes it possible to reduce noise generated by a compressor of an air conditioner and noise generated by an air flow passing through ducts.
For example, a hollow blow-molded foam disclosed in the '959 reference is manufactured in the following method. As illustrated in FIG. 13, a foaming parison composed of a thermoplastic resin and a foaming agent is extruded from a die. The foaming parison is disposed in split mold blocks provided with a pressure-reducing pipe. Then, the foaming parison is sandwiched by the mold. While a gas such as air is being blown into the foaming parison, the split mold blocks are closed. As the split mold blocks are closed, the foaming parison is deformed along the shape of a cavity. Simultaneously, the foaming parison tightly adheres to the inner surfaces of the split mold blocks. When the split mold blocks are completely closed, a space (air passage) defined by walls of a hollow blow-molded foam is formed as illustrated in FIG. 14. In the closed state of the split mold blocks, the hollow blow-molded foam is cooled by using a cooling device not shown. The hollow blow-molded foam thus formed has an apparent density of 0.05 to 0.5 g/cm3 and a closed cell rate of 50% or more. The inner surface of the hollow blow-molded foam has a surface hardness of 45 to 80 degrees.
However, in some cases, a hollow blow-molded foam having a high expansion ratio (for example, an expansion ratio of 2.5 folds or more) and a high thickness (for example, thickness of 2.0 mm or more) is produced by using the above forming method. In this case, the thickness of the hollow blow-molded foam becomes thicker during the forming process.
However, in the case when the thickness of the hollow blow-molded foam becomes thicker during the forming process, the heat insulating property of the hollow blow-molded foam itself becomes higher. For this reason, upon cooling the hollow blow-molded foam, the cooling process sometimes fails to sufficiently cool the inside of each wall of the hollow blow-molded foam. In the case when the inside of each wall is not cooled sufficiently, withdrawing and warping tend to occur in the hollow blow-molded foam. As a result, the time required for cooling the hollow blow-molded foam needs to be prolonged. Moreover, after taking out the hollow blow-molded foam from the split mold blocks, the shape of the hollow blow-molded foam also needs to be corrected.
When the cooling process for the wall inside the hollow blow-molded foam is delayed, the inner cells of the wall are expanded to become bulky. As a result, cells are ruptured to sometimes cause a roughened inner surface of the wall. When the inner surface of the wall is roughened, a resistance to air (fluid) flowing through a space (air flow passage) defined by the walls increases. This causes a reduction in the flow-rate efficiency of a fluid that flows through the inside of the hollow blow-molded foam.

Method of forming hollow blow-molded foam and such hollow blow-molded foam


An automatic cleaning assembly for an analytical furnace is detachable from the filter chamber above the combustion tube. The cleaning assembly includes a rotating brush which is lowered through the filter chamber and into the combustion tube while a vacuum is drawn through the lower seal of the combustion tube. This results in a higher vacuum pressure differential and improved flow rate for removing dust from the filter of the furnace and the combustion tube.

The present invention relates to a combustion furnace for an analyzer and particularly to an automatic cleaning system.
The combustion of inorganic solid samples using an induction furnace requires a pressurized oxygen-rich environment. A quartz combustion tube is typically used to maintain this pressurized environment. Additionally, a filter is typically positioned adjacent the combustion tube and in the analyte gas stream to eliminate combustion debris which could degrade downstream analytical components. In one furnace system, a specimen is placed in a crucible which is positioned within the combustion tube and heated by an induction coil for the combustion of the specimen. The gases emitted therefrom are subsequently analyzed for determining one or more constituent elements of the specimen. The combustion tube so used is capable of many cycles of operation; however, after each combustion, oxides and other contaminants typically expelled during the combustion process tend to coat the interior of the tube. Thus, through the analytical process, the combustion tube and filter become coated with dust and residue debris of combustion. Removal of these combustion byproducts is essential in maintaining quality analytical results, as well as extending sample throughput.
The cleaning of the combustion tube and an associated filter requires moving wire brushes through the internal surfaces of the combustion tube and filter. U.S. Pat. No. 4,234,541 issued Nov. 18, 1980, discloses an early design in which a manually manipulated brush was employed to loosen debris from the filter and combustion tube, which debris is subsequently collected.
In current designs, dust and combustion residue is collected on a vacuum dust door enclosing the lower end of the combustion tube when the crucible pedestal and lower seal assembly are lowered. In this prior art design, a manifold communicates with the combustion tube and is coupled to a vacuum source as a non-rotating cleaning brush is linearly extended through the filter and combustion tube. The debris is then transferred to a collection box. With this design, when cleaning is complete, the vacuum dust door swings open to allow for another analysis cycle. However, too often, a combustion crucible falls into the vacuum dust door and the door becomes jammed. If this occurs, the operator must partially disassemble and repair the system prior to continuing with additional analyses. Also, with the prior art design, the vacuum dust door and/or the lower seal cup can plug due to accumulation of combustion byproducts, requiring manual cleaning.
Accordingly, there exists a need for an improved analytical combustion furnace in which cleaning of the filter and tube are better managed.


Authentication in a public land mobile network, PLMN, having tenant slices is performed by a network element that has: a memory comprising program code; a communication circuitry for communication with entities in the PLMN; and a processing circuitry configured to execute the program code and according to the program code to cause: detecting a registration request from a mobile communication device, MCDt; detecting whether the registration request requests access to a network slice with one-tier authentication with the network slice, and: if yes, causing beginning of authenticating the MCDt with the network slice independently of any authentication between the MCDt and the PLMN.

This section illustrates useful background information without admission of any technique described herein representative of the state of the art.
Public Land Mobile Networks (PLMN) have greatly evolved during past decades from rudimentary voice communication enablers to mobile broadband Internet devices. Currently, a fifth generation of mobile networks is being designed e.g. by further developing the Long-Term Evolution (LTE). 5G networks also support wireless LAN (WLAN or IEEE 802.11) radio access.
Network slicing enables efficient sharing of network resources so that different users or types of uses employ the network resources with different requirements, such as Quality of Service.
In order to use a network slice produced by network slicing, a mobile device is first authenticated (primary authentication) based on a subscriber database of the PLMN. Depending on the subscription details and policies of the PLMN, the mobile is by this implicitly authorized to use certain resources in the PLMN. Typically, these resources support a connection to a data network (outside the PLMN), which could be the Internet, or, for example, a private data network of some third party company. A secondary authentication may be required by the data network, based on an own user data base in the data network. In case of a private data network, the secondary authentication is typically needed.
The third party is referred to as tenant, when it has rented resources of the PLMN, for example in form of a network slice. E.g., the PLMN operator creates a slice inside the PLMN for the third party, and the connections between the tenant's mobile devices and the data network use the resources of this slice. Then the third party is a tenant of the PLMN operator. Each time a tenant's mobile device attaches to the PLMN and is successfully authenticated using primary authentication, the PLMN authorizes it to use the tenant's slice to connect to the tenant's data network, but real access to the data network may only be granted by the tenant after successful secondary authentication.

Authentication in public land mobile networks comprising tenant slices


In a printer 1 which is an information processing apparatus of the present invention, after a password is accepted from a PC 2 together with image data and job information, the image data is encrypted and stored in a storage part 106, the job information is associated with the password and stored in a management part 104 as a job management table, and the process waits. In a case where a security program is executing, in case that a main power 110 is turned off, the operation of a backup part 105 to supply power to the management part 104 is inhibited, so that the job information table stored in the management part 104 is deleted. In a case where the security program is not executing, power is supplied to the management part 104 by the backup part, thereby maintaining the job management table stored in the management part 104.

Many printers in recent years are connected to a communication network and provided with a network printer function to receive image data from another apparatus such as a personal computer (PC) connected to the communication network and output an image. Further, multi-function apparatuses have been commercialized in which printers are provided with a plurality of functions such as a copying function to capture an image recorded on a sheet as image data by scanning it, form an image based on the captured image data and output the image, a facsimile function to transmit and receive image data to and from an external facsimile by use of facsimile communication, and a transmission function to transmit the captured image data to an external apparatus. In order to perform the image data processing in each function without stagnation, printers having such advanced multifunction are provided with storing means such as a hard disk for storing information such as image data and have a parallel processing function to successively store the accepted information while successively processing the information already stored in the storage image.
To the printers as described above, many PCs can be connected through the communication network, so that a plurality of users can provide an image output instruction. For this reason, there is a possibility that the images outputted onto recording sheets on instructions from a plurality of users are mixed together in the image discharge part and carried away by a wrong user by mistake. Therefore, a technology has been developed such that when receiving an image output job transmitted from a PC, the printer stores the job and waits without performing the image output and after the user inputs an output instruction by directly operating the printer, the printer outputs the image. Japanese Patent Application Laid-Open No. 60-25385 discloses a technology such that a password is transmitted together with image data from a PC to the printer, the printer stores the image data and waits, and in case that the user inputs the correct password by directly operating the printer, the printer outputs the image. Moreover, among such printers, products have been developed that have a function to back up information associated with the processing on standby in order that even when the power is turned off while the processing is on standby, the image output can be performed after the power is turned on again.
There are cases where information handled by printers includes confidential information such as documents including trade secrets, and security measures are necessary for the information stored in the storing means by the printer. In particular, in the case of a printer in which the image data is stored until the correct password is inputted as disclosed in Japanese Patent Application Laid-Open No. 60-25385, in case that the function to back up the information associated with the processing on standby is provided, the information is not deleted but is stored even after the power is turned off. For this reason, information such as image data can be taken out to the outside, for example, by reading out the information from an external apparatus or detaching the storing means, so that it is difficult to maintain the confidentiality of the information being handled.

Information processing device with attached security settings and security setting-dependent operation modes


Methods of processing a substrate include supplying process gas to a processing chamber including the substrate. Plasma is created in the processing chamber. After performing a first substrate processing step, the plasma is maintained in the processing chamber and at least one operating parameter is adjusted. The operating parameters may include RF bias to a pedestal, a plasma voltage bias, a gas admixture, a gas flow, a gas pressure, an etch to deposition (E/D) ratio and/or combinations thereof. One or more additional substrate processing steps are performed without an interruption in the plasma between the first substrate processing step and the one or more additional substrate processing steps.

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Ionized physical vapor deposition (iPVD) processes typically involve multiple, discrete processing steps. Some of the processing steps may involve the use of plasma that is operated with a different RF power and/or a different etch/deposition (E/D) ratio. Currently, the DC plasma is extinguished between each of the steps of an integration stack and re-ignited for a subsequent step.
At the beginning of a processing step, the plasma is struck and becomes stable after a predetermined period. Film that is deposited before the plasma is stable will have low quality, which lowers yield. The amount of time associated with the stabilization of the plasma also lowers substrate throughput.
Some advanced iPVD processes for copper utilize high density plasma to facilitate Cu reflow. Reflow provides high sidewall/bottom Cu coverage and low overhang with minimum or no deposition on the field.

Continuous plasma and RF bias to regulate damage in a substrate processing system


The invention concerns an arrangement for the adjustment of the position of a shearbar with respect to knives of a chopper assembly. The arrangement includes a first adjusting drive to position the first end of the shearbar at a predetermined first spacing from the knives and a second adjusting drive to position the second end of the shearbar with respect to the knives until a spacing measurement arrangement indicates that the spacing between the shearbar and the knives is less than a threshold value. An analogous procedure is applied to the first adjusting drive. On the basis of the measurement values the shearbar is brought into a position that corresponds to a desired gap between the shearbar and the knives. Each of the first spacing and the second spacing are greater than the desired gap between the shearbar and the knives.

1. Field of the Invention
The invention concerns an arrangement for the adjustment of the position of a shearbar with respect to the knives of a chopper assembly, for use in a harvesting machine, and a method of adjusting the arrangement.
2. Related Technology
In forage harvesters the spacing between the chopper knives and the shearbar is a significant value for the quality of the cut and the power required for the cutting operation. As a rule, shearbars of this type are arranged so that they can be adjusted with respect to the chopper drum by means of electric motors, where each end of the shearbar is associated with an electric motor. A spacing sensor, that as a rule is configured as a knock sensor or a magnetic spacing sensor, detects a signal that contains information regarding the spacing between the shearbar and the nearest knife of the knives on the chopper drum.
In the state of the art various procedures are known in order to bring the shearbar into the desired position relative to the chopper drum by an automatic control of the electric motors.
EP 0 291 216 A suggests initially moving both ends of the shearbar away from the chopper drum. Then one end of the shearbar is next moved towards the chopper drum, until a sensor detects a contact between the shearbar and the chopper drum. Then this particular end is moved away from the chopper drum by a first distance and the other end of the shearbar is moved towards the chopper drum, until a sensor detects a contact between the shearbar and the chopper drum. Then the other end is again withdrawn from the chopper drum by the first spacing. This procedure is performed successively until both motors bring about a contact between the shearbar and the chopper drum upon their activation. Then the shearbar is retracted from the chopper drum at both ends by a path of from approximately 0.127 to 0.254 mm.
EP 0 335 256 A describes an arrangement in which one end of the shearbar is moved in the direction of the chopper drum by a first motor until a contact exists. Then the shearbar is again retracted by the first motor until no contact exists. Then the other adjusting motor is activated until a contact exists and is activated in the opposite direction until the contact between the shearbar and the chopper drum disappears. This adjusting process is repeated once where after each of the last adjustment steps the desired gap on each side is adjusted by retracting the shearbar.
DE 100 21 659 A proposes that one end of the shearbar be moved at first in the direction of the chopper drum until a contact occurs and then retracting it by a spacing that corresponds to the desired gap. Then the other end is moved to the chopper drum until a contact occurs and then retracted again from the chopper drum by a spacing that corresponds to the desired gap. Alternatively the shearbar is at first brought into a parallel orientation to the chopper drum and then the final spacing is adjusted by moving both ends synchronously. For such an adjusting operation a very precisely-operating spacing sensor is required.
EP 1 080 630 A proposes that one end of the shearbar be moved at first to the chopper drum until an appropriate gap exists. Then the other end is moved to the desired spacing.
Thereby the known procedures for the adjustment of the shearbar relative to the chopper drum always include a step in which a first end of the shearbar is brought into the vicinity of the chopper drum. Following this, the other end of the shearbar is moved to the chopper drum. This procedure is based on the fundamental assumption that the chopper assembly is manufactured and ground as a cylinder or a concave shape. The end of the shearbar that was not moved in each case is located at a relatively small spacing from the chopper assembly, so that the assumption can be made that an approach or a contact between the shearbar and the chopper assembly occurs first at the end of the shearbar that was moved on the basis of the cylindrical or concave shape of the chopper drum. In each case the target position of the shearbar is then determined on the basis of the measured values.
This procedure is problematic if the shape of the chopper assembly is convex. This shape can result, for example, from higher wear in the outer region of the chopper assembly on the basis of greater amounts of crop due to non-uniform supply of crop, in that larger amounts of crop are supplied to the outside of the chopper assembly compared to the supply in the center, or on the basis of grinding processes in which the grinding stone operates for a longer time at the edge than in the center of the chopper assembly.
To illustrate this point, reference is made to FIG. 1. The chopper assembly 22 is convex, where the convexity "a" is shown to an exaggerated degree for purposes of illustration. In actual cases it may amount, for example, to 0.5 mm. at a width of the chopper assembly 22 of approximately 700 to 850 mm. and a diameter of the chopper assembly 22 of approximately 600 mm. Depending on the distance "b" of the end of the shearbar 38 that was not repositioned, the shearbar 38 comes into contact with the knives 48 further towards the edge or in the center of the chopper assembly 22. The spacing "b" between the chopper assembly and the end of the shearbar 38 that was not adjusted is relatively small, so that the contact between the shearbar 38 and the chopper assembly 22 occurs in the vicinity of its center.
In case the spacing "b" between the end of the shearbar 38 that was not repositioned and the chopper assembly 22 differs upon the approach of the other end of the shearbar to the chopper assembly the contact thereby occurs at various different axial positions. In a procedure in which the shearbar is moved towards the chopper assembly in successive alternating steps at both ends, the orientation between the enveloping circle described by the knives and the shearbar depends upon chance, and a parallel orientation is difficult to achieve.
The problem underlying the invention is seen in the need to provide an arrangement for the adjustment of a shearbar, in which a parallel adjustment between the shearbar and the enveloping circle described by the knives is possible even with convex chopper assemblies.

Arrangement for the adjustment of a shearbar with respect to a chopper assembly and a method of adjustment thereof


A sonar transducer assembly includes a housing mountable to a water craft capable of traversing a surface of a body of water. The sonar transducer assembly includes a linear downscan transmit/receive transducer element positioned within the housing, aimed downwardly, and configured to transmit sonar pulses in the form of a fan-shaped beam perpendicular to a plane of the surface of the water, and further configured to receive sonar returns from the sonar pulses and convert sound energy of the sonar returns into downscan sonar return data. The sonar transducer assembly also includes at least one sidescan receive-only transducer element positioned within the housing, aimed outwardly and downwardly, and configured to receive sonar returns from the sonar pulses and convert sound energy of the sonar returns into sidescan sonar return data.

Sonar (SOund Navigation And Ranging) has long been used to detect waterborne or underwater objects. For example, sonar devices may be used to determine depth and bottom topography, detect fish, locate wreckage, etc. In this regard, due to the extreme limits to visibility underwater, sonar is typically the most accurate way to locate objects underwater. Sonar transducer elements, or simply transducers, may convert electrical energy into sound or vibrations at a particular frequency. A sonar sound beam is transmitted into and through the water and is reflected from objects it encounters. The transducer may receive the reflected sound (the "sonar returns") and convert the sound energy into electrical energy. Based on the known speed of sound, it is possible to determine the distance to and/or location of the waterborne or underwater objects. The sonar return signals can also be processed to be displayed in graphical form on a display device, giving the user a "picture" of the underwater environment. The signal processor and display may be part of a unit known as a "sonar head" that is connected by a wire to the transducer mounted remotely from the sonar head. Alternatively, the sonar transducer may be an accessory for an integrated marine electronics system offering other features such as GPS, radar, etc.
Since the development of sonar, display technology has also been improved in order to enable better interpretation of sonar data. Strip chart recorders and other mechanical output devices have been replaced by, for example, digital displays such as LCDs (liquid crystal displays). Current display technologies continue to be improved in order to provide, for example, high quality sonar data on multi-color, high resolution displays having a more intuitive output than early sonar systems were capable of producing. Accordingly, it is desirable to provide improved sonar systems for better image quality.


A shift device is provided with a shift lever, a parking switch, and a neutral switch. A transmission is switched to a range, in which the transmission of driving force to driving wheels of a vehicle is started, by the shift lever being operated in two or more directions from a home position and arriving at a specific position. The transmission is switched to a range, in which the transmission of driving force to the driving wheels of the vehicle is interrupted, by the parking switch and the neutral switch being operated in one direction.

Over these recent years, automatic transmission vehicles have become popular in which automatic transmissions are installed to automatically switch gear ratios of the vehicle in accordance with the vehicle velocity, engine speed, or the like. The driver of an automatic transmission vehicle tilts a shift lever of the shift device to designate a shift mode of the automatic transmission.
For example, Patent Document 1 describes a shift device in which a shift lever is tiltable from a home position to a drive position (D position), a reverse position (R position), an upshift position (+ position), and a downshift position (− position). The mode designation positions are set toward the front, rear, left, and right of the home position. The shift lever is tilted from the home position to the front, rear, left, or right to switch the shift mode of the automatic transmission. The shift device further includes a push-type neutral switch and parking switch located toward the front from the shift lever at a location separated from the driver seat. By operating the neutral position or the parking switch, the automatic transmission is switched to a neutral mode or a parking mode.

KABUSHIKI KAISHA TOKAI RIKA DENKI SEISAKUSHO


A quantum computer may include topologically protected quantum gates and non-protected quantum gates, which may be applied to topological qubits. The non-protected quantum gates may be implemented with a partial interferometric device. The partial interferometric device may include a Fabry-Pérot double point contact interferometer configured to apply “partial” interferometry to a topological qubit.

Anyonic interferometry is a powerful tool for processing topological quantum information. Anyonic interferometry may be used to non-demolitionally measure the collective anyonic charge of a group of (non-Abelian) anyons, without decohering internal state of the anyons, and consequently, anyonic interferometry may be used to generate braiding operators, change between different qubit encoding, and generate entangling gates.
By utilizing braiding operations and conventional, or complete, anyonic interferometry measurements for Ising-type quasiparticles, only the Clifford group operations, which is not computationally universal and, in fact, can be efficiently simulated on a classical/digital computer, can be generated.
Topological quantum computers based on Ising-type quasiparticles using only braiding operations and conventional/complete anyonic interferometry measurements lack a computationally universal set of topologically protected gates that may be applied to topological qubits.

Quantum computers having partial interferometric quantum gates


A method and an apparatus for controlling noise of multiple wind turbines. The method includes: determining a noise-influencing sector of each of the multiple wind turbines, based on positions of the multiple wind turbines and a position of a noise-influencing site; acquiring a current wind direction; determining whether there is at least one wind turbine of the multiple wind turbine under the current wind direction operating in the noise-influencing sector; and limiting output power of the at least one wind turbine, in a case that the determination is positive.

In recent years, construction of wind farms is getting more and more close to residential areas with development of wind power industry. As a result, an impact of noise generated in operation of a wind turbine on residents cannot be ignored.
There are two main kinds of the noise generated in operation of wind turbine. One is mechanical noise generated in the operation of wind turbine, for example, yaw noise and cooling fan noise of a converter. The other is aerodynamic noise of blades of the wind turbine, that is, noise due to high-speed airflow around the blades in rotation. To deal with the above two kinds of noise generated by the wind turbine that has been built, following methods are generally utilized. For the mechanical noise, seal of the wind turbine is strengthened, a brake of the yaw system is reformed, or a silencer is installed on a cooling fan of a converter. For the aerodynamic noise of blades, a saw-tooth tailing edge may be installed on the blades, or output power of the wind turbine may be reduced from a control perspective.
The conventional method for controlling noise from the control perspective is inflexible, apt to result in a great loss in power generation, and hard to meet requirements on various customizations.

Method and apparatus for controlling noise of multiple wind turbines

BEIJING GOLDWIND SCIENCE & CREATION WINDPOWER EQUIPMENT CO., LTD.


A dental handpiece includes a drive shaft which is driven by a drive motor and which has two coaxial ring gears which can selectively be coupled to shafts passing through different tool carriers. Different angular speeds of the coaxial ring gears is achieved by the inner ring gear being directly connected to the drive shaft, whereas the outer ring gear is driven by the drive shaft by way of a planetary transmission.

The invention relates to a dental handpiece comprising a drive shaft which is driven by a drive motor and which has two coaxial ring gears which can be selectively coupled to shafts passing through different tool carriers.
Handpieces of such type afford the advantage that tool carriers for tools involving a different speed of rotation only have to be connected to the appropriate ring gear in order to arrive at different drive transmission ratios for the tools.
In that respect, it is provided in EP-B1-0 012 871 that two coaxial ring gears are disposed on a common shaft and thus rotate at the same angular speed. In such arrangement the desired step-up or step-down transmission ratio is acheived by the tool carriers engaging by way of a small spur gear with the outer ring gear of the drive shaft or by way of a large spur gear engaging with the inner ring gear of the drive shaft. In that arrangement it is necessary for the shaft leading to the tool to be fitted to the drive shaft in an inclined and eccentric relationship, which on the one hand restricts the design options with regard to the shape of the handpiece while on the other hand requires the tool carrier to be of a relatively large diameter.
On the other hand, a construction of the type outlined in the opening part of this specification is known from EP-B1-0 012 872 (FIG. 10), in which a shaft can be arranged centrally in the tool carrier and various output drive speeds are achieved by using output drive shafts of different lengths. In that arrangement a gear at the end of the output drive shaft of the tool carrier that is towards the coupling means has a predetermined number of teeth, so that transmission ratios can only differ in accordance with differing numbers of teeth on the ring gears of the drive shaft. Another disadvantage with such construction is that the two transmission ratios require different directions of rotation.
It is already known, for example from U.S. Pat. No. 4,121,342, for different tool carriers to be driven selectively directly by way of a drive shaft or by way of a planetary transmission which is disposed around the drive shaft. The arrangement of a multi-stage planetary transmission (see DE-C-27 17 013) has also already been proposed, in order to be able to drive the output drive shaft of different tool carriers at different transmission ratios. A disadvantage of those handpieces which are necessarily straight in the region of the coupling means is the necessity of also having to effect manipulation in the handpiece for the purpose of changing the transmission ratio, in addition to exchanging the tool carrier.

Dental handpiece having coaxial ring gears rotatable at different respective angular speeds

Imtec Innovative Medizintechnik Gesellschaft m.b.H.


To permit rapid assembly and disassembly of the water cycle so that, when disassembled, it can be stored or transported in minimum space. The cycle, which has at least three flotation bodies (2a, 2b, 2c), which are elongated or torpedo shaped, is formed of tubular frame elements which are coupled together by push-in connectors with spring-loaded pin locks (9, 30, 30', 33, 41) so that individual frame elements (6,7,8; 12,13,14; 24,25) of the cycle can be disassembled into the frame elements, or, selectively, snapped together. The flotation bodies are preferably inflatable and formed with a keel. A pedal and crank arrangement is coupled to a transmission which can drive a propeller or, directly via a chain, a paddle wheel. To prevent damage to the propeller if it meets an obstruction, a propeller attachment and a housing therefor is releasably mounted on a frame for pivoting movement upwardly and downwardly, with various positions of the propellers selectable by a spring loaded engagement hook engaging in recesses in a positioning disk; and, to permit lateral deflection, the housing is rotatable about an axis transverse to the direction of movement (A) of the cycle, and positioned in predetermined location by a spring-loaded claw clutch to permit release, in the lateral direction, if an obstruction is encountered.

Various types of water cycles are known which have bicycle-type pedals to move the water cycle, together with occupants, over a water surface. These water cycles are relatively heavy, cannot be folded, and take up substantial storage space. They cannot be readily transported in the trunk of a passenger car.
It has previously been proposed--See U.S. Pat. No. 4,077,351, Girona, to provide a water cycle which has three flotation elements in the form of tires; the flotation elements are located in a triangular configuration, with two transversely aligned rear elements and one front element, which, similar to a front wheel of a bicycle, can be steered. To move this structure, paddles are secured to the rear tires, and coupled to bicycle-type pedals by a chain drive.

Humanly operable, recreational, readily disassemblable water cycle


A preparing method of a reduced graphene oxide film, a reduced graphene oxide film prepared by the preparing method, a graphene electrode including the reduced graphene oxide film, an organic thin film transistor including the graphene electrode, and an antistatic film including the reduced graphene oxide film are provided. The method for preparing a reduced graphene oxide film comprises: coating a graphene oxide-dispersed solution on a substrate to form a graphene oxide thin film; and reducing the graphene oxide thin film using a chemical reduction method and a pressure-assisted thermal reduction method to form a reduced graphene oxide film.

As compared with other preparing methods, solution-based synthesis for producing graphene oxide (GO) through chemical exfoliation from graphite has attracted considerable attention since the graphene oxide can be mass-produced with low manufacturing cost through a solution process. A GO-based flexible transparent conductive film has been studied a lot as a transparent electrode with potential applications as a thin film transistor, a sensor, or an organic photocell device. In general, the GO should be converted into reduced graphene oxide (rGO) in order to restore high conductivity of graphene. So far, there have been a lot of study reports showing various reduction processes. Geng et al. reported a simple method for preparing a transparent conductive graphene film by adjusting chemical reduction of exfoliated GO. Bao et al. reported that a post-annealing process at a high temperature (>800° C.) is needed to obtain rGO having an excellent electrical property. Although it was reported that a conventional thermal reduction process is more effective than a chemical reduction process, since most of the conventional methods are carried out at a high temperature for a long time, it is difficult to apply such methods to a flexible substrate such as plastic. Further, rGO has limitation such as a high surface resistance and a low uniformity, resulting in a low-grade electrical property. Therefore, an alternative GO reduction technique which can be applied to a flexible plastic substrate, and can be carried out rapidly and efficiently with high cost efficiency at a low temperature is still demanded for application of an rGO-based thin film. Meanwhile, Korean Patent Publication No. 2012-0008902 describes that a manufacture method of a partially reduced graphene film by heating and a manufacture method of a counter electrode of a dye-sensitized solar cell, but also has the above-described shortcoming.

Preparing method of reduced graphene oxide film using a chemical reduction method and a pressure-assisted thermal reduction method, reduced graphene oxide film prepared by the same, and graphene electrode including the reduced graphene oxide film


A method of installing an expandable tubular assembly in a wellbore, the tubular assembly including a plurality of expandable tubular elements, comprising: installing a first tubular element in the wellbore; installing a second tubular element in the wellbore such that an end part of the second tubular element extends into an end part of the first tubular element, arranging a radially deformable body around the overlapping portion; and radially expanding the end part of the second tubular element against the end part of the first tubular element such that the end part of the first tubular element becomes radially expanded and the deformable body becomes radially deformed, wherein a body of cement is present between the first tubular element and the wellbore wall, and wherein the deformable body is a fluidic volume that is pumped between the first tubular element and the wellbore wall before hardening of the cement.

In conventional methods of wellbore drilling, tubular casing is installed in the wellbore at selected depth intervals. Each new casing to be installed must pass through the previously installed casing, therefore the new casing must be of smaller diameter than the previously installed casing. As a result of such procedure, the available internal diameter of the wellbore for fluid production becomes smaller with depth. For very deep wells, or for wells in which casing is to be installed at relatively short intervals, such conventional casing scheme may render the well uneconomical. In view thereof it has been proposed to radially expand casing/liner sections after installation at the desired depth.
EP-A-1044316 discloses a method whereby a first tubular element is installed in the wellbore, and a second tubular element is installed in the wellbore so that an upper part of the second tubular element extends into a lower part of the first tubular element so as to form an overlapping portion of the tubular elements. The upper part of the second tubular element is then radially expanded against the first tubular element such that as a result thereof said lower part of the first tubular element is radially expanded.
A drawback of the known method is that the expansion forces needed to expand the lower part of the first tubular element generally are extremely high.
It is therefore an object of the invention to provide an improved method of installing a tubular assembly in a wellbore, which overcomes the drawback of the known method.

Method of installing a tubular assembly in a wellbore


The present invention relates to a molten steel refining method for refining molten steel, the carbon content of which is not more than 0.1 weight %, by blowing oxygen gas for decarburization at a blowing speed so that a cavity, the depth of which is 150 to 400 mm, can be formed on the surface of molten steel in a straight barrel type vacuum refining apparatus in which a straight barrel type vacuum vessel having no vessel bottom and a ladle are arranged. When necessary, the above decarburizing processing conducted by blowing oxygen gas is combined with: an Al heating process in which Al added into the vacuum vessel is burned by oxygen gas blown into the vacuum vessel at a blowing speed such that the cavity depth can be 50 to 400 mm; a degassing treatment conducted in a high vacuum condition; a desulfurizing treatment in which a desulfurizing agent is blown into the vacuum vessel; or a burner heating treatment in which a combustion improving agent is blown together with oxygen gas, wherein each treatment except for the high vacuum degassing treatment is conducted in a degree of vacuum of 100 to 400 Torr.

1. Field of the Invention
The present invention relates to a vacuum refining method for molten steel. More particularly, the present invention relates to a vacuum refining method for refining molten steel with a straight barrel type vacuum vessel having no vessel bottom.
2. Description of the Related Art
In a vacuum refining furnace, oxygen gas is blown onto molten steel to be refined by means of top-blowing. The objects of blowing oxygen gas by means of top-blowing are described as follows. The first object is "decarburization" in which oxygen gas is reacted with carbon contained in the molten steel when oxygen gas is blown. The second object is "Al heating" in which the temperature of molten steel is raised when Al added to molten steel is burned by oxygen gas blown onto the molten steel by means of top-blowing. The third object is "desulfurization" in which flux, such as lime, is added to molten steel together with carrier gas. The fourth object is "burner heating" in which oxygen gas and combustion improving gas of a hydrocarbon, such as LNG, are blown by means of top-blowing so as to heat a vacuum vessel and suppress the adhering metal.
Conventionally, DH is known as a vacuum refining furnace composed of a straight barrel type vacuum vessel and a dipping snorkel. However, in the case of DH, a vacuum vessel to circulate molten steel goes up and down, and no molten steel exists in the vacuum vessel when it is moved to the uppermost position. Accordingly, in the case of blowing oxygen gas by means of top-blow, oxygen gas directly collides with the bottom of the vacuum vessel. Therefore, refractory material of the vessel bottom is severely damaged by the colliding oxygen gas. For the above reason, a method of blowing oxygen gas from a top-blowing lance has not been adopted at all.
Although it is not a case of vacuum refining, a secondary refining furnace in which the top-blowing of oxygen gas is conducted with a straight barrel type dipping snorkel is described as "CAS-OB Method" in S1086 of vol. 71 of "Iron and Steel" published in 1985. The object of the above method is to raise the temperature of molten steel by burning Al. However, the following problems may be encountered according to the above method. In the above method, it is impossible to conduct pressure reduction processing. Accordingly, when it is necessary to conduct a very low carbon steel melting processing and a dehydrogenation processing together with "Al heating", it is necessary to provide another refining furnace, so that the equipment cost is increased. Since the operation is conducted under atmospheric pressure, molten steel can not be sufficiently agitated, and the heat transfer efficiency is low. In order to improve the heat transfer efficiency, it is necessary to extend the processing time.
In the decarburizing reaction treatment conducted for producing ultra low carbon steel by means of top blown oxygen in a region, the carbon concentration is not more than 0.1%. Since the carbon concentration is very low, oxygen gas which has been blown out by means of top-blowing temporarily generates an iron oxide on the surface of molten steel, and this iron oxide reacts with and is reduced by carbon contained in the molten steel. In order to facilitate the reducing reaction, it is necessary to raise the hot point so as to form an advantageous condition from the viewpoints of thermodynamics and reaction speed. Therefore, it is necessary to conduct a so called hard-blowing operation in which the top-blown oxygen is made to collide with the surface of molten steel at high jet intensity.
With regard to a molten steel refining method in which an RH type vacuum refining apparatus having a vessel bottom is used and a water-cooled type top-blowing lance inserted into a vacuum vessel from an upper portion blows out a jet stream of oxygen into the vacuum vessel for refining molten steel, an example is shown in Japanese Unexamined Patent Publication No. 2-54714. Therefore, this molten steel refining method is well known.
FIG. 8 is a schematic illustration showing a refining method of molten steel conducted by a conventional RH type vacuum degasifying apparatus. The operation will be explained below. There is provided a snorkel of up-leg 23 at the vessel bottom 22 of the vacuum vessel 21. Gas is blown into the vacuum vessel 21 from a lower end of the snorkel of up-leg 23, so that the molten steel 24 can be sucked up from a ladle 25 to the vacuum vessel 21. In the vacuum vessel 21, an oxygen jet 27 is blown out from a top-blowing lance 26 to the surface of the molten steel 24. In this way, the molten steel 24 is subjected to decarburizing processing and Al heating, and the thus processed molten steel 24 is returned to the ladle 25 via a snorkel of down-leg 28. When the molten steel 24 is circulated between the ladle 25 and the vacuum vessel 21 in this way, it is continuously processed.
However, when oxygen is fed from the top-blowing lance 26 in the RH type vacuum refining apparatus described above, since the vacuum vessel 21 has a vessel bottom 22, the operation is restricted in various ways, and the following problems may be encountered.
In the RH type vacuum refining apparatus, vacuum necessary for sucking up the molten steel 24 from the ladle 25 so as to make the molten steel 24 reach the vessel bottom 22 of the vacuum vessel 21 is usually not more than 200 Torr. In order to circulate the molten steel 24 after that, vacuum is further enhanced, and it becomes necessary to maintain a high vacuum of not more than 150 Torr. Further, when oxygen gas is blown out from the top-blowing lance 26 in a reduced pressure condition, it is necessary to maintain a high vacuum condition. Unless a high vacuum condition is maintained, an oxygen jet 27 collides with the vessel bottom 22, and the refractory material at the vessel bottom is damaged because the molten steel depth T is small. Accordingly, in the case of conducting the hard blowing operation, the following restrictions must be observed. In order to keep the depth L of a cavity 29, for example, it is necessary to keep a very high vacuum of about 10 Torr so that the head of molten steel can be raised to maintain the depth T of molten steel on the vessel bottom 22 in the vacuum vessel 21.
In the case where oxygen is blown out from the top-blowing lance at a low degree of vacuum, a quantity of molten steel to be sucked is small, so that the depth T of molten steel in the vacuum vessel 21 is small. Therefore, for the same reason as that described above, the oxygen jet 27 collides with the vessel bottom 22, and the refractory material at the vessel bottom is damaged. Therefore, the depth L of the cavity formed by the oxygen jet 27 is restricted. As a result, it is impossible to conduct the hard-blowing operation, and it is necessary to conduct a so called soft-blowing operation in which the top-blown oxygen is made to collide with the surface of molten steel at low jet intensity.
Consequently, in the RH type vacuum refining apparatus, the following problems may be encountered. When oxygen gas is blown out in a reduced pressure, it is restricted as described above. Since it is impossible to conduct a hard-blowing operation in a low degree of vacuum at the beginning of the treatment, the reduction of iron oxide is delayed and the decarburizing reaction speed is lowered. In addition to that, the jet speed of the oxygen gas is low. Therefore, after the lance has been discharged, oxygen in the periphery of the jet reacts with CO gas in the atmosphere, so that CO.sub.2 is generated. That is, the post combustion is actively conducted, for example, at a rate of post combustion that is not less than 20%. Accordingly, the temperature in the vessel is unnecessarily raised and the refractory material of the vacuum vessel is damaged.
On the other hand, when a vacuum refining apparatus, which will be referred to as a straight barrel type vacuum refining apparatus hereinafter, is used for refining, in which a lower portion of the straight barrel type vacuum vessel having no bottom is dipped in the molten steel in the ladle, it is possible to blow out oxygen even in a low degree of vacuum because there is provided no vessel bottom. When oxygen is blown out by means of top-blowing in the above refining apparatus, it is necessary to maintain the vacuum refining apparatus in a low degree of vacuum in order to facilitate the decarburizing reaction. The reason is that it is difficult for iron oxide to flow out from the vacuum vessel in the case of an unnecessarily high degree of vacuum, so that the decarburizing efficiency is lowered. To the contrary, when the degree of vacuum is too low, the circulation of molten steel is deteriorated, and molten steel can not be sufficiently mixed. Accordingly, the decarburizing efficiency is lowered.
Examples in which stainless steel is refined by means of top-blowing in the above straight barrel type vacuum refining apparatus are disclosed in Japanese Unexamined Patent Publication No. 1-156416, No. 61-37912, No. 5-105936 and No. 6-228629. In the above examples, the carbon concentration at which decarburization starts is in a high carbon concentration range of not less than 0.2%. Further, in the above patent publications, there is no specific description about the oxygen blowing condition.
In the decarburizing reaction conducted at the aforementioned high carbon concentration, the top-blown oxygen directly reacts with carbon in the molten steel since the carbon concentration is high. In the above circumstances, no iron oxide is generated. Accordingly, even if converter slag exists in the vacuum refining apparatus, no problems are caused. Also, since the carbon concentration is sufficiently high, the agitating and mixing characteristic and the decarburizing efficiency are not affected. Accordingly, in this case, the higher the vacuum in the vacuum refining apparatus is, the more effectively the decarburization can be conducted. In the above well-known documents, Japanese Unexamined Patent Publication No. 5-105936 discloses an example in which the degree of vacuum is maintained at 200 Torr, and Japanese Unexamined Patent Publications No. 1-156416, No. 61-037912 and No. 6-228629 disclose examples in which the degree of vacuum is kept at 100 Torr or 50 Torr.
In the case where the carbon concentration is high, from the viewpoint of the principle of decarburization, the higher the degree of vacuum is, the more advantageous the effect that can be provided. However, in order to keep the vacuum refining apparatus in a high vacuum condition, the investment in plant and equipment is necessarily increased for the vacuum pump system because a large quantity of CO gas is produced, and further molten steel splashes violently in the process. Therefore, it is necessary to increase the height of the apparatus for the prevention of splash. As a result, the investment in plant and equipment is increased. For the above reasons, in the above examples, the degree of vacuum is maintained at 100 Torr or 50 Torr. In the above well known documents, it is described that refining is continued until the carbon concentration becomes 0.01 to 0.02%. However, metallurgical effects are not shown when the carbon concentration is restricted to a value lower than 0.1%.
However, as described later, in a high vacuum condition in which the degree of vacuum is higher than 105 Torr, it is difficult for slag particles in the molten steel to flow out from the vessel, so that the decarburizing oxygen efficiency is low. Therefore, in the case of a degree of vacuum lower than 195 Torr, the agitating energy is reduced, and the molten steel can not be agitated and mixed sufficiently. For this reason, the decarburizing efficiency is lowered.
Japanese Unexamined Patent Publication No. 7-179930 discloses an example in which plain carbon steel was refined under the condition that the degree of vacuum was maintained at 200 Torr and oxygen was blown by means of top-blowing so that the carbon concentration was in a range from 0.03% to 0.001%. In this case, the post combustion rate was not less than 78%, and the decarburizing oxygen efficiency was very low. The reason was that the cavity depth, which was found by calculation using the expression described later, was only 52 mm. That is, the oxygen gas collided with the molten steel in the manner of soft blowing. Also, it can be considered that the degree of vacuum was too low, so that the molten steel was not agitated and mixed sufficiently and the decarburizing efficiency was further deteriorated. Japanese Unexamined Patent Publication No. 6-116627 discloses a method in which the molten steel, the carbon concentration of which is 0.03 to 1.0%, is subjected to a top-blown oxygen, and the vacuum P is controlled in accordance with the equation of P (Torr)=a+980.times.%C! (a=170 to 370). The object of this method is nitrogen removal. Although there is no description about the decarburizing efficiency, the degree of vacuum is 199 to 399 Torr when the carbon concentration is 0.03% which is the lowest value. In the low degree of vacuum described above, the stirring energy is lowered. Therefore, the molten steel can not be stirring and mixed sufficiently, and the decarburizing efficiency is deteriorated. Further, there is no description about the manner of blowing of oxygen, which is an important factor to enhance the decarburizing efficiency, in the above patent publication. That is, there is no description of whether the hard blowing operation or the soft blowing operation is conducted.
Japanese Unexamined Patent Publication No. 6-116626 discloses a technique in which molten steel is refined in a degree of vacuum of 760 to 100 Torr while a mixing ratio of top blown oxygen gas and Ar gas is changed in accordance with the degree of vacuum. There is a description that the carbon concentration at the start of decarburization is 1.0 to 0.1%. This operation is mainly conducted at a high carbon concentration. Even in this case, there is no description about the manner of blowing of oxygen, which is an important factor to enhance the decarburizing efficiency, in the above patent publication. That is, there is no description of whether the hard blow operation or the soft blow operation is conducted. Further, there is no description about the effective decarburizing condition when pure oxygen gas is used.
In the prior art in which the straight barrel type vacuum refining apparatus is used, examples are shown in the case of a region in which the carbon concentration is high and also in the case in which the degree of vacuum is too low, wherein the decarburizing principles are quite different from each other. Concerning the oxygen blowing condition, it is only recognized that the soft blow operation is required in the example, and no technical investigation has been made into the appropriate oxygen blowing condition.
In the straight barrel type vacuum refining apparatus, the following operation is effective. Before blowing oxygen gas into the vacuum vessel for the purpose of decarburization, in order to raise the temperature of molten steel in the vacuum vessel of the refining apparatus, Al alloy is added to the molten steel. Top blown oxygen is fed onto the surface of the molten steel, so that Al is burned to raise the temperature of the molten steel. The aforementioned Al heating is a technique in which Al alloy is continuously added to the molten steel or Al alloy is added to the molten steel all at once, and during the above Al alloy adding operation, oxygen is top-blown to the molten metal, so that Al is oxidized and the temperature of molten steel is raised by the heat generated by the oxidization of Al. In this case, when carbon contained in the molten steel is oxidized, the amount of oxygen used for oxidizing Al is reduced. Therefore, it is not preferable to oxidize carbon contained in the molten steel. It is necessary to react the top-blown oxygen with Al at a high efficiency. Also, it is necessary to add the thus generated heat to the molten steel at a high efficiency. From the viewpoint of thermodynamics, carbon and Al are respectively oxidized as follows. When the partial pressure of CO is high, that is, when the vacuum is low, the oxidization of Al occurs prior to the oxidization of carbon. However, when the partial pressure of CO is low, that is, when the vacuum is high, the oxidization of carbon occurs prior to the oxidization of Al. Consequently, the appropriate degree of vacuum has not been known in the actual operation for the following reasons. Although a low vacuum is necessary for suppressing the oxidization of carbon, in a free surface region in which the reaction occurs, the temperature is raised by the reaction, and the partial pressure of CO is not same as the degree of vacuum.
Further, it is necessary to effectively discharge Al.sub.2 O.sub.3 produced in the reaction outside the vacuum vessel. The reason is described below. When a large amount of Al.sub.2 O.sub.3 is suspended on the surface of the vacuum vessel, since the heat conduction of Al.sub.2 O.sub.3, which is an oxide, is low, Al.sub.2 O.sub.3 becomes a resistance to heat transfer. Accordingly, the coefficient of heat transfer on the surface region of the vacuum vessel is deteriorated, so that heat transfer efficiency is lowered. In order to discharge slag from the vacuum vessel, it is necessary to keep the vacuum vessel in a low degree of vacuum. The reason why the vacuum vessel is kept in a low degree of vacuum condition is described as follows. When the vacuum vessel is kept in a high degree of vacuum, an interval between the lower end of the dipping portion and the surface of the molten steel in the vacuum vessel is increased, and slag particles in the molten steel are moved in a stream flowing downward. However, very few of the particles of slag arrive at the lower end of the dipping portion, and most slag particles are circulating in the vacuum vessel. The above slag flow rises to a bubble activating surface being carried by a rising stream. Therefore, an amount of Al.sub.2 O.sub.3 suspended in the surface region is accumulated, so that the heat transfer efficiency is lowered.
An effective means for discharging Al.sub.2 O.sub.3 from the straight barrel type vacuum refining apparatus has not been found.
In order to effectively transfer the generated heat to the entire molten steel, it is necessary that an amount of circulating molten steel is sufficiently large. In this case, the amount of circulating molten steel may be smaller than that in the case of blowing oxygen performed for the purpose of decarburization. The reason is that not only convection heat transmission conducted by a circulating molten steel flow but also conduction heat transmission caused by a difference in temperature contributes to the heat transfer. However, in the case where the degree of vacuum is too low, gas blown into the molten steel expands greatly when it rises to the surface. Accordingly, the stirring energy is reduced and the molten steel is not agitated and mixed sufficiently. As a result, the heat transfer efficiency is lowered. Therefore, it is necessary that the degree of vacuum is maintained at the most appropriate value.
It is described in Japanese Unexamined Patent Publication No. 58-9914 that desulfurization is conducted after the high vacuum treatment of decarburization or hydrogen removal in the refining method of molten steel performed at a reduced pressure. In the above patent publication, a method is disclosed in which powder for refining is blown onto molten steel in a reduced pressure at a sufficiently high speed so that the powder can get into the molten steel. According to the above method, a flow speed of gas to be blown to the molten steel must be not lower than Mach 1, that is, when the flow speed of gas is higher than Mach 1, the powder for refining can get into the molten steel sufficiently.
According to the above method, the flow speed of gas to be blown to the molten steel is very high as described above. Accordingly, the molten steel splashes, and a lance and refractory material in the vessel are damaged, and further the metal adheres to the inside of the vessel. In order to remove the adhering metal, it takes time and labor. In order to blow the gas at a high flow speed of not less than Mach 1, it is necessary to reduce the nozzle diameter of the lance. Therefore, when a refining agent is blown into the vacuum vessel by the top-blowing lance inserted into it, in addition to the usual oxygen blowing hole, it is necessary to form a new blowing hole exclusively used for blowing the refining agent, which causes a problem with respect to the apparatus. On the other hand, when the refining agent is blown by the oxygen blowing lance, it is necessary to feed a large amount of carrier gas to ensure the blowing speed. As a result, the temperature is lowered, and further the utility cost is increased.
Japanese Unexamined Patent Publications No. 5-287357 and No. 5-171253 disclose a method in which an RH type vacuum refining apparatus having a vessel bottom is used and powder used for refining is blown from a water-cooled top-blowing lance inserted into a vacuum vessel so as to refine molten steel.
In the above patent publications, the following are described. In order to enhance the powder trapping efficiency, it is preferable to conduct a hard blow operation. When the hard blow operation is conducted in an RH vacuum refining apparatus, it is necessary to prevent the oxygen jet from colliding with the vessel bottom. Therefore, when oxygen gas is blown into the vacuum vessel from the top-blowing lance, it is necessary to ensure a head of molten steel in accordance with the depth of a cavity formed on the molten steel surface. For this reason, when powder for refining is blown into the vacuum vessel, a high degree of vacuum of not more than 100 Torr must be maintained. However, when the vacuum vessel is maintained in a high degree of vacuum condition, the amount of powder which is exhausted with the exhaust gas is increased. As a result, the powder trapping efficiency with respect to molten steel is lowered, and the reaction efficiency is deteriorated. In order to enhance the powder trapping efficiency, the blowing speed must be increased.
Concerning the circulating speed of molten steel in the vessel or ladle of the conventional vacuum refining apparatus, the renewal speed of molten steel is not high, so that a high blowing speed is required. However, when a jet speed of carrier gas is increased for the purpose of increasing the blowing speed of powder used for refining, the amount of flowing gas is increased and also spitting is increased. Therefore, it is not preferable to increase the jet speed of carrier gas. As is conventionally known, the speed of powder is a half of the speed of carrier gas at most, and further it is reported that the depth of intrusion of powder is constant irrespective of an amount of flowing carrier gas. For the above reasons, it is not advantageous that the speed of carrier gas is increased.
An example in which a desulfurizing agent is blown to molten steel in a straight barrel type vacuum refining apparatus is disclosed in Japanese Unexamined Patent Publication No. 6-212241. However, in the above patent publication, there is no description about the vacuum and flow speed which are important factors to determined the efficiency.
As described above, there is no disclosure of the condition in which the desulfurizing agent is added to molten steel in the straight barrel type vacuum refining apparatus.
In the refining method of molten steel conducted in a reduced pressure, when the composition of molten steel is adjusted after the process of decarburization or the processing in a high degree of vacuum, the temperature in the vacuum vessel is raised to suppress the adhering metal. In order to accomplish the above object, the molten steel is subjected to burner heating by using a top-blowing lance, so that the temperature of molten steel can be raised.
In the above case, since the pressure in the vacuum vessel is reduced, the length of a combustion flame blown out from the top-blowing lance tends to extend. However, when the flame reaches the surface of molten steel, a combustion improver of hydrocarbon, which has not burned yet, reacts with the molten steel, so that the concentrations of carbon and hydrogen in the molten steel are increased, which causes a serious problem. In order to solve the above problem, the degree of vacuum may be lowered so as to shorten the length of the flame, or an interval between the lance and the molten steel surface may be increased. In the case of RH, in order to circulate the molten steel, the molten steel must be sucked up into the vacuum vessel. Therefore, it is impossible to reduce the degree of vacuum. Accordingly, only one method of increasing the lance height can be adopted. However, according to this method, an interval between the average flame region and the molten steel surface is increased. Therefore, the heat transfer efficiency is lowered.
With regard to the burner heating conducted in a straight barrel type vacuum refining apparatus, there is no specific disclosure.


The present disclosure provides lamination transfer films and use of the lamination transfer films, particular in the fabrication of architectural glass elements, such as those used in Insulated Glass Units (IGUs). The lamination transfer films may be used to transfer functional layers and structures. The lamination transfer films may include a support film that can be removed during the transfer process, and the transferred materials are primarily inorganic. The resulting transferred structures on glass generally have high photo- and thermal-stability, and therefore can successfully be applied to the glass surfaces that are interior to the cavity within an IGU. The lamination transfer films can also be patterned such that macroscopic patterns of microoptical elements can be applied on a glass surface.

Insulated Glazing Units (IGUs) are used to reduce thermal loss through architectural exterior wall windows. A typical IGU includes two panes, a spacer frame, and a cavity formed by these three elements. Microoptical elements integrated into an IGU can be used to redirect some of the sunlight passing through the IGU to an interior ceiling, to augment conventional interior lighting, thereby increasing the energy efficiency of buildings. In many cases, it can be convenient to integrate the microoptical elements directly on the glass of the window, e.g., by applying refractive or diffractive optical structures to the surface of the glass. Microoptics applied to the outside surface of an IGU can be adversely impacted by several factors, including soiling and abrasion. It would be advantageous to apply microoptics to the glass surfaces within the cavity of an IGU; however, such structures must exhibit photo- and thermal-stability so that the clean environment within the IGU is maintained.


The apparatus for testing the characteristics of waterproofness and breathability of fabrics includes a demonstration unit, a base unit, and a fluid conduit and valve. The demonstration unit has a transparent wall and a support plate/gasket combination to retain and support the test fabric specimen. The flexible fluid conduit runs between the demonstration unit and the base unit, and a valve is positioned in the conduit. To test a fabric's waterproofness: the demonstration unit is assembled; the base unit is filled with water; the demonstration unit is placed lower than the base unit, and thus, water flows into the demonstration unit; and the demonstration unit is positioned to expose and view the fabric. To show the fabric's breathability: the demonstration unit, filled with water, is positioned higher than the base unit; the valve is opened causing the water to flow out of the demonstration unit; and air is drawn through a breathable fabric and is visible as bubbles rising from the fabric into the water contained in the demonstration unit.

A variety of techniques have been developed to test both the waterproofness and breathability of fabrics and articles of clothing. Waterproofness is the capacity of a specimen to keep liquid water from penetrating. One way to test for waterproofness is to fill the test specimen with water and then check for the presence of leaks, or liquid water on the test specimen's outer surface. Breathability is the capacity of a specimen to allow gas to penetrate. When testing a specimen's breathability, the test specimen is typically inflated with gas at a pressure above atmospheric pressure. The test specimen's capacity to allow gas to penetrate is detected by loss of inflation pressure or air bubbles.
One common test of a specimen's waterproofness is to inflate the article and then immerse the inflated article in water. The absence of bubbles escaping from the inflated test specimen is used to demonstrate that the specimen is waterproof. Leaks occur when either a liquid or a gas penetrates a test specimen, whether through the fabric, at the seams, or through material defects. A water leak indicates that the specimen is not waterproof; a gas leak indicates that the test specimen allows gas to penetrate. Thus, the presence of bubbles would indicate that the test specimen has a gas leak.
U.S. Pat. No. 4,799,384 to Casali discloses an apparatus and method for testing for gas leaks in order to demonstrate the waterproofness of footwear articles. In operation, the footwear article is inflated using compressed gas, the top of the article is gripped in such a manner that the gas cannot escape, the article is then immersed in a liquid reservoir which has at least one transparent side. The test article is observed for gas leaks as indicated by the presence of rising bubbles.
U.S. Pat. No. 3,166,439 to Dennhofer discloses an apparatus for examining surgical gloves for gas leaks. Dennhofer pressurizes the gloves with compressed gas while the gloves are under water and inspects for the presence of bubbles.
U.S. Pat. No. 2,054,204 to McDonald also discloses a device wherein surgical gloves can be tested for gas leaks. The sealed glove is placed in a mesh frame to prevent the glove from bulging when pressurized. A small hand pump is used to pressurize the sealed glove, and the pressurized glove within the mesh frame is immersed in a reservoir of water. Bubbles rising from the glove signal the presence of gas leaks.
U.S. Pat. No. 4,776,209 to Patchel discloses a gas leak detector for testing waterproofness wherein a glove or other article may be gas leak tested without getting the article wet. The article is positioned within a testing chamber and both the article and the test chamber are sealed. Gas at a controlled pressure is introduced into the sealed article. A tube fluidly connects the lower end of the test chamber with a reservoir of liquid. If gas leaks from the article into the test chamber, after the initial period of article inflation, then the gas inside the test chamber will exit through the tube into the liquid reservoir, and bubbles will visibly indicate this leakage.
Prior art references thus teach the presence of bubbles as indicative of a gas leak. However, such prior art references use gas pressure greater than ambient to generate bubbles. Furthermore, in such prior art devices a single test may be used to prove that a test specimen is both air tight and waterproof, i.e. if the test specimen does not leak air, it will not leak water.
Also known in the art are techniques for testing a specimen's moisture vapor transmissibility. For instance, U.S. Pat. No. 4,581,921 to Gillespie discloses a moisture vapor transmission test cell, having upper and lower enclosures with a test specimen positioned between the enclosures. Moisture vapor transmissibility is the capacity of a test specimen to allow air and water molecules to penetrate the specimen. Since water molecules are larger than air molecules, there is not an identical correspondence between breathability and moisture vapor transmissibility. A test specimen might let air penetrate, but not let the larger water molecules penetrate.
In Gillespie the upper enclosure contains flowing conditioned air; the lower enclosure contains a fluid/vapor reservoir. During operation, conditioned air flows parallel to the upper surface of a test specimen, while the lower surface of the test specimen is exposed to vapor of a test liquid contained in a reservoir. Vapor is drawn through the test specimen due to the flow of the conditioned air over the surface of the test specimen for a known period of time. At the end of a test cycle, the amount of fluid remaining in the reservoir is a measure of the moisture vapor transmissibility of the test specimen. Gillespie does not test or demonstrate the waterproofness of the test specimen, nor is there any visual display of the test specimen's breathability characteristics.

Apparatus and method for testing waterproofness and breathing fabrics


An archery combination involving an archery bow and a bow sight. The bow sight uses a brace secured to the bow with at least two sighting pins which extend at right angles to the archer's line of sighting. A protective guard is secured to the brace and, is moveable between a protective position around the sighting pins to a position which exposes the pins. When the protective guard is in position to expose the sighting pins, the pins are released or “unlocked” from the brace allowing the sighting pins to be easily removed from the brace for repositioning; when the protective guard is in the protective position, the pins are “locked” and cannot be removed from the bow sight.

This invention relates generally to archery equipment and more particularly to archery bow sights.
The modern competitive archery bow bears little resemblance to the bows of the middle ages. Composite materials are now used instead of birch wood; extreme balance is established and maintained through adjustable counter balances instead of relying on the carving skills of the bow-maker; and, complex and adjustable sights providing for differing ranges are now used instead of sighting along the arrow.
Competitive archery has developed in an extraordinary way and most of this progress has occurred in the last fifty years. Perhaps the most dramatic development relating to archery has been the sighting mechanisms themselves.
These sighting mechanisms originally were crude mechanisms, not much more than markings made on tape along the bow itself; and now include sights which allow the archer to not only adjust for the range, but also to provide sighting pins which extend into the archer's natural line of sighting to create a comfortable shooting experience.
One such archery bow sight is described in U.S. Pat. No. 4,984,373, issued on Jan. 15, 1991, to Forrest and entitled, "Archery Bow Sight", incorporated hereinto by reference.
Within the Forrest patent, each sighting pin is removable and can be placed within any of a variety of pin holes, allowing the pins to be placed to meet the specific archer's requirements. The pins though are left exposed, allowing them to be bent during normal use. Once properly positioned, the pins are "locked" into the bow sight to keep them from being jarred or mis-aligned.
It is clear there is a need for improved archery sights.


Disclosed are a method and device for determining an icon position. The method includes: detecting a target object in a target image and determining the reference position of the target object in the target image, and detecting a salient position in the target image, thereby obtaining the reference position of a key target or object in the target image, and a salient position possibly requiring more attention in the target image; and selecting, according to the distance between the reference position or salient position and preset candidate positions, an icon position from the candidate positions.

At present, the icons such as title text and watermark in an image or a video are generally placed in the middle, top or bottom of the image or video frame image. The inventors found that these icons may overlay key objects in the image, affect the display effect of the image, and cause interference to the users watching the picture in many cases.

Method and apparatus for determining an icon position

Beijing Dajia Internet Information Technology Co., Ltd.


An emulator for emulating a wireless network comprised of a plurality of RF nodes is comprised of a programmable controller for emulating the movements of the plurality of RF nodes within an emulated space. The controller provides both information and control signals based on the emulated movements. A programmable logic core receives a plurality of signals from the plurality of RF nodes and emulates signal propagation based on the information from the controller. A plurality of signal generation and conversion cards are interposed between the programmable logic core and the RF nodes. The signal generation and conversion cards are responsive to the control signals. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

The present disclosure is directed generally to emulators and, more particularly, to emulators used for wireless-network environments
As wireless network deployment and use become ubiquitous, it is increasingly important to make efficient use of the finite bandwidth provided. Unfortunately, research aimed at evaluating and improving wireless network protocols is hindered by the inability to perform repeatable and realistic experiments.
Techniques that have proven successful for analyzing wired networks are inadequate for analyzing wireless networks since they are fundamentally different. While the physical layer can frequently be ignored in wired networks, in wireless networks the physical layer fundamentally affects operation at all layers of the protocol stack in complex ways. Links are no longer constant, reliable, and physically isolated from each other, but are variable, error-prone, and share a single medium with each other and with external uncontrolled sources. As a result, traditional methods of experimentation have difficulty satisfying the needs of wireless researchers.
An ideal method of wireless experimentation would possess the following properties: repeatability and experimental control, layer 1-4 realism, the ability to run real applications, configurability, the ability to modify wireless device behavior, automation and remote management, support for a large number of nodes, isolation from production networks, and integration with wired networks and testbeds. We now discuss how alternative methods of experimentation fare with respect to this list of desirable properties.
The most direct method of addressing realism is to conduct experiments using real hardware and software in various real world environments. Unfortunately, this approach faces serious repeatability issues because the behavior of the physical layer is tightly coupled to the physical environment and precise conditions under which an experiment is conducted. The mobility of uncontrolled radio sources, physical objects, and people makes these conditions nearly impossible to reproduce. It is also difficult to avoid affecting co-located production networks. Moreover, configurability and management of even a small number of mobile nodes distributed in three dimensions is cumbersome; this lack of manageability also makes integration with external networks problematic.
For these reasons, many researchers have understandably embraced simulation as a means of evaluation. This approach solves the problem of repeatability, configurability, manageability, modifiability, and (potentially) integration with external networks, but faces formidable obstacles in terms of realism. Wireless simulators are confronted with the difficult task of recreating the operation of a system at all layers of the network protocol stack as well as the interaction of the system in the physical environment. To make the problem tractable, simplifications are typically made throughout the implementation of the simulator. Even fundamental tasks such as deciding what a received frame looks like diverge greatly from the operation of real hardware. See Takai et al. "Effects of Wireless Physical Layer Modeling in Mobile Ad Hoc Networks", Proc. of MobiHoc 2001, October 2001.
In addition, while wireless technology is undergoing rapid advances, wireless simulators, in particular open source wireless simulators, have lagged significantly behind these advances as discussed below. For several years now, ns-2 has been the de facto standard means of experimental evaluation for the wireless networking community. See, S. McCanne and S. Floyd. UCB/LBNL/VINT Network Simulator—ns (version 2), April 1999. Yet ns-2's wireless support has not kept pace with current technology, and is targeted towards the original 802.11 standard developed in 1997. Even this support, however, is inexact as ns-2 does not support automatic rate selection, uses a non-standard preamble, and contains an incorrect value for 802.11 ACK timeout value. In addition, ns-2's physical layer is particularly simple. See Takai, et al, supra. As a result, some researchers are opting to use commercial simulators such as QualNet [Scalable Network Tech. Qualnet] and OpNet [OPNET Tech. Opnet] because they claim better support for current standards. Despite these claims, however, it is unclear how well these simulators reflect actual hardware.
The aforementioned issues with simulators, and a desire to avoid long simulation times, have caused some researchers to adopt emulation as a means of evaluation. Emulation retains simulation's advantages of repeatability and manageability, while potentially mitigating the issue of realism. Unfortunately, as discussed below, with the exception of a few very small-scale emulators, and emulators hardwired to a particular physical location, these emulators have typically adopted extremely simplified MAC and physical layers. As the operation of these layers is fundamental to the operation of a wireless network, it is unclear that these emulators gain any realism over existing simulators.
Emulation has proven to be a useful technique in wired networking research, and it has an even larger potential in the wireless domain. See, B. White, J. Lepreau, L. Stoller, R. Ricci, S. Guruprasad, M. Newbold, M. Hibler, C. Barb, and A. Joglekar. An integrated experimental environment for distributed systems and networks. Proc. of OSDI 2002, December 2002; A. Vahdat, K. Yocum, K. Walsh, P. Mahadevan, D. Kostic, J. Chase, and D. Becker. "scalability and accuracy in a large-scale network emulator". Proc. of OSDI 2002, December 2002.
A common approach that has been taken for wireless emulation is to capture the behavior of a wireless network in terms of parameters such as capacity and error rates and then use a wired network to emulate this behavior. This has the advantage of allowing the use of real endpoints running real applications in real time. The wireless MAC and physical layers, however, are only very crudely simulated. For this reason, it is unclear whether or not this approach can obtain more realistic results than pure simulation. See, B. Noble, M. Satyanarayanan, G. Nguyen, and R. Katz. Trace-based mobile network emulation. Proc. of SIGCOMM 1997, September 1997; P Mahadevan, K. Yocum, and A. Vahdat. Emulating large-scale wireless networks using modelnet. Poster and Abstract Mobicom 2002, September 2002; T. Lin, S. Midkiff, and J. Park. A dynamic topology switch for the emulation of wireless mobile ad hoc networks. Proc. of the 27th Annual IEEE Conference on Local Computer Networks (LCN'02), November 2002.
More recently efforts have been made to develop RF emulators that accurately emulate down to the physical layer. RAMON [E. Hernandez and S. Helal. "ramon: Rapid mobility network emulator". Proc. of the 27th IEEE Conference on Local Computer Networks (LCN'02), November 2002. ] uses three programmable attenuators to allow emulation of the signals between a single mobile node and two base stations. While useful for the intended application of mobile IP roaming investigation, the inability to independently control all signal paths and the cost of programmable attenuators severely limits this approach.
B. White, J. Lepreau, and S. Guruprasad. Lowering the barrier to wireless and mobile experimentation. Proc. of HotNets-I, October 2002, proposes extending Emulab into the wireless domain using either fixed wireless nodes scattered in a building or passive carriers to carry wireless nodes. Clearly this approach can achieve a high degree of realism, but has serious obstacles in terms of control and repeatability (because this is essentially a wireless testbed). As there can be significant uncontrolled interference, this approach can only hope to achieve what the authors term "coarse repeatability". In contrast, our approach allows for far greater control and repeatability.
The most functionally similar approach to the wireless emulator that we have developed is provided by commercial channel emulators. See, PROPSim. Propsim c8 wideband multichannel simulator, Spirent Communications. Tas4500 flex5 rf channel emulator. The goal of these emulators, however, is quite different. Rather than supporting emulation of all channels in a wireless network (hundreds of channels may be required), commercial channel emulators are designed to support very fine-grained emulation of the wireless channel between either a pair of devices or between a small number of base stations and a small number of mobile devices (with the total of both being less than the maximum number of channels which is typically no more than eight). Moreover, channel emulators require the addition of external components to support half-duplex transceivers that are common in wireless data networks. Although channel emulators are useful for equipment vendors evaluating a new device, the limited scale, lack of support for complete interaction between all nodes, and lack of support for half-node duplex nodes make commercial channel emulators an unattractive option for wireless network emulation.

Device and method for programmable wideband network emulation