A scroll compressor with two scrolls including respective scroll wraps to form a compression chamber therebetween so that a volume of the compression chamber is decreased to compress a fluid therein by an orbital motion between the scrolls around an axis, has a frame supporting the scrolls thereon, a drawing force generator generating a drawing force urging axially one of the scrolls toward another one thereof, and a contacting force limiter bearing at least a part of the drawing force to prevent the at least a part of the drawing force from being born by a contact between the scrolls, when an axial distance between the scrolls is not more than a predetermined axial distance.

The present invention relates to a scroll compressor in which a compression chamber is formed between two scrolls with respective scroll wraps and a volume of the compression chamber is decreased to compress a fluid therein by an orbital motion therebetween around an axis, and relates to an air conditioner including the scroll compressor.
JPA Hei-5-263776 discloses a structure for the scroll, in which an axial distance between an orbital scroll and a stationary scroll is increased by a force converting mechanism having a contact between an outer peripheral surface of the stationary scroll and a tapered guide surface of a frame to convert a radial thermal expansion force of the stationary scroll to an axial force urging the stationary scroll axially, when a temperature of the stationary scroll is increased.
JPA Hei-3-11102 discloses a scroll structure in which a pitch between the scroll wraps varies from an radially inside of the scrolls toward an radially outside thereof.


An electronic system and corresponding method for authenticating firmware stored in a memory element external to a processor. In one embodiment, an electronic system comprises a processor and a memory element. The memory element is used to contain firmware and a digital signature of the firmware signed by a signatory. Coupled to the memory element, the processor authenticates the firmware during a predetermined condition, which occurs prior to execution of the firmware, through use of a pre-stored public key of the signatory and a pre-stored digital signature function.

1. Field
This invention relates to the field of data security. More particularly, the invention relates to an apparatus and method for authenticating code that is stored off-chip.
2. Related Art
Normally, one of the most critical elements for an electronic device is its processor. In general, a processor is an embedded controller that comprises an integrated circuit (IC) including processing logic and on-chip memory. Memory is considered to be xe2x80x9con-chipxe2x80x9d if placed on a die forming the IC. For 32-bit Intel(copyright) microprocessor architectures (e.g., Intel(copyright) IA-32 processors), all architecture functionality is implemented on-chip using a combination of hardware and microcode stored in the on-chip memory.
With the development of 64-bit Intel(copyright) microprocessor architectures (e.g., Intel(copyright) IA-64 processors), some firmware code involving non-performance critical architecture functionality is being considered for off-chip implementation. The use of off-chip firmware code provides a number of advantages.
One advantage is that the current die size constraints associated with IA-32 processors can be maintained or even reduced for subsequent generation technologies. For instance, additional run-time services can be added without increasing the size of the on-chip memory, and hence, the die size of the processor. Another advantage is that the overall performance of the processor can be enhanced. This is due to the fact that a lesser amount of architecture functionality is required to be placed in on-chip memory so that more die area is available for processing logic.
However, the use of off-chip firmware code offers disadvantages as well. For instance, when moving architectural functionality off-chip, the firmware code is more susceptible to corruption and other malicious attacks.
Hence, it would be desirable to develop an electronic system and method of operation which ensure that the firmware code is free from corruption or unauthorized replacement. Also, the electronic system and method would ensure that the firmware code originated from a particular source.
Briefly, one embodiment of the invention relates to an electronic system comprising a memory element to contain firmware and a digital signature of the firmware signed by a signatory. The electronic system further comprises a processor, coupled to the memory element, to authenticate the firmware during a predetermined condition and prior to execution of the firmware through use of a pre-stored public key of the signatory and a pre-stored digital signature function.

System and method for authentication of off-chip processor firmware code


Methods, systems, and computer-readable storage media for authenticating a user and user input to a back-end system and for validating the user input. In some implementations, actions include receiving a unique user identifier and user input, generating a personalized image recognition challenge based on the unique user identifier and the user input, the personalized image recognition challenge including a plurality of images and a written message, the written message instructing a user to select a particular image of the plurality of images to validate the user input, transmitting the personalized image recognition challenge for display on a device, receiving a response to the personalized image recognition challenge, the response comprising a selection of an image from the plurality of images, and authenticating the user and the user input based on the response.

Devices are increasingly used to conduct interactions, such as e-commerce interactions, in which a front-end device communicates with a back-end system. For example, a legitimate user can communicate with a trusted back-end system using a device, e.g., a smartphone, a tablet computing device. In some instances, a device can become compromised, such that the device can be controlled by and/or sensitive information can be exposed to a malicious user, e.g., an attacker. Such instances can often occur in the bring-your-own-device and mobile cloud infrastructures. In such infrastructures, the user authenticates to the back-end system using something that the user knows, e.g. credentials a password or personal identification number (PIN). Once the user is authenticated, the user can control an application on the back-end system, and can provide user input to the back-end system using the device.
Authentication of a user that provides input and authentication of the provided input is hard to achieve, if the user (unknowingly) relies on a compromised device. For example, using a compromised device can result in authentication factors, e.g., credentials, and/or input being easily stolen. An attacker controlling a compromised device can use the stolen authentication factors to act as an authenticated party and submit false input to a back-end.

Input validation, user and data authentication on potentially compromised mobile devices


Group 2A metal greases having a dropping point in excess of 650.degree. F. are produced by a manufacturing process in which water is carefully controlled in the process while conversion to grease is occurring. It is necessary to complete the reaction and dehydrate the reaction mixture before finish oils and additives are added in order to obtain a reproducible grease with a high drop point and a low penetration value.

This invention is directed to an improved process for the preparation of over-based Group 2A metal sulfonate greases and thickened compositions. Greases and thickened compositions of the present invention are of the heretofore known thixotropic type which comprise a volatile and/or a nonvolatile liquid carrier of solvents such as mineral oil or mineral spirits or equivalent oil medium together with an oil soluble Group 2A metal sulfonate derived from oil soluble higher molecular weight sulfonic acids.
Thixotropic greases are thickened over-based Group 2A sulfonate compositions particularly calcium sulfonate compositions having corrosion inhibiting properties and having utility for a variety of uses such as automobile and truck body undercoatings, lubricants and various other purposes which are known in the art. Such greases are thickened compositions which have gone into quite widespread use either as lubricants or admixed with other ingredients to produce compositions for use in a variety of environments. Generally speaking, these materials are characterized by reasonably good anti-wear properties, reasonably good resistance to mechanical breakdown, salt spray and water corrosion, together with thermal stability at high temperatures.
These greases are normally prepared in either a one step or a two step process. In the two step process, there is initially prepared a Newtonian solution by admixing a normally liquid oil, commonly a mineral oil or a mineral oil and a non-mineral oil volatile organic solvent such as hexene, with a normally liquid sulfonic acid comprising or containing an aliphatic straight or branch chain having at least 12 carbon atoms and having a molecular weight of from about 300 to about 700. These materials are then added to a Group of 2A metal oxide or metal hydroxide (such as calcium oxide or calcium hydroxide) which together with a promoter serves to produce an over-based Group 2A metal sulfonate which commonly has a large degree of overbasing. The resultant mixture is a Newtonian solution containing the over-based metal sulfonate dissolved or dispersed in the mineral oil, which solution is filtered to form a clear solution. The resulting clear Newtonian solution is then subjected to treatment in a second step which involves generally vigorous mixing and heating in the presence of a converting agent which may be water or water soluble alcohols or glycol ethers such as methyl cellosolve (mono-methyl ether of ethylene glycol) or mixtures, of water and such alcohols, or water soluble acids such as acetic acid or propionic acid. The second step results in converting the Newtonian solution to a non-Newtonian dispersed system in the form of a grease or a thickened composition.
The prior art one step process of forming the greases or thickened compositions differs from the two step process in that essentially all of the ingredients are mixed and there is no separately formed or separately formed and recovered Newtonian solution of an over-based metal sulfonate dissolved or dispersed in mineral oil. From an economic viewpoint, the one step process has a definite advantage over the two step process.
However, in carrying out either of these processes, it becomes apparent that grease reproducibility and ability to meet certain specifications has been erratic at best. Commercial products suffer long periods of time when top quality grease is not produced, but rather a more inferior grease is produced, which while suitable for many or even most applications, it not suitable for certain high demand applications.
Consequently, it would be desirable to determine a method for making a consistently high quality grease, having a dropping point in excess of 650.degree. F. It is further desirable that these greases have a penetration values consistent with National Lubricating Grease Institute (NLGI) grades for most such purposes.
It is therefore an object of the present invention to provide a method for the preparation of an over-based metal sulfonate grease having a dropping point of at least 650.degree. F. Other objects will become apparent to those skilled in this art as the description proceeds.

Process for the preparation of over-based group 2A metal sulfonate greases and thickened compositions


An image processing apparatus includes: an HDD for storing a plurality of pieces of transmission destination information in correspondence with a short-cut key for instructing image transmission; an operation unit displaying the short-cut key and detecting selection of the short-cut key; and a control unit displaying the plurality of transmission destinations stored in correspondence with the short-cut key if a prescribed condition is satisfied. The operation unit receives a selection operation of selecting a piece of transmission destination information from among the displayed plurality of pieces of transmission destination information, and the control unit determines the selected piece of transmission destination information to be the transmission destination of image transmission made by the selection of the short-cut key. Even if a plurality of transmission destinations are registered with the short-cut key, erroneous transmission to an unintended destination can be prevented.

1. Field of the Invention
The present invention relates to an image processing apparatus having a function of transmitting image data such as facsimile and electronic mails and, more specifically, to an image processing apparatus capable of multicasting, by registering information of a plurality of transmission destinations with a short-cut key.
2. Description of the Background Art
As a method of sending documents such as forms and estimate sheets to a recipient, facsimile (hereinafter also referred to as FAX) has been widely used. Recently, it has become common to attach electronic data of such a document to an electronic mail and to send to a recipient through a network. It has become possible to select the method of transmission in accordance with the device (personal facsimile, multifunctional peripheral, or a personal computer (hereinafter referred to as a PC) used by the recipient.
By way of example, as one type of image processing apparatus, a multi function peripheral (MFP) having a plurality of functions including copying, printing, facsimile and scanning has come to be widely used. An MFP is capable of forming an image on a sheet of recording paper based on digital data of a document read by the scanning function or digital data received through a transmission line and, in addition, capable of image processing of such digital data to transmit by facsimile or electronic mail.
The method of transmission using an MFP includes a so-called multicasting, by which one document is sent to a plurality of recipients. For multicasting, the user sets the document to be transmitted on the MFP, successively sets a plurality of recipients of transmission, and presses a button for executing transmission, such as a start key. The set document is read and subjected to image conversion (converted to facsimile data or to data to be attached to an electronic mail), and then, transmission to the set plurality of recipients of transmission takes place successively.
The following method has been known as a method of designating a recipient to whom a document is to be transmitted. For facsimile transmission, a facsimile number of the transmission destination is entered using ten-keys. For electronic mail transmission, electronic mail address (also simply referred to as mail address) of the transmission destination is entered using a keyboard (alphabetical keys). Here, an inputting error may possibly leads to a wrong transmission.
A technique of registering facsimile numbers and mail addresses of recipients of transmission in correspondence with recipient names in an address book (storing in a non-volatile memory or the like of the MFP) in order to prevent wrong transmission has been known. At the time of transmission, the user operates an operation unit of MFP to call the address book, and selects a recipient of transmission from the address book. A technique of registering a facsimile number or a mail address of a recipient of transmission with a key referred to as a "single-touch key" for higher operability has also been known. Simply by pressing the single-touch key, a call is made to the registered facsimile number and the document is transmitted. If an electronic mail address is registered with the single-touch key, the document is transmitted to the mail address.
A technique of registering a plurality of recipients of transmission in advance with a key referred to as a "group key" to make it easier to set multicast destinations has been known. When multicast transmission is desired, by simply pressing the group key, the registered recipients of transmission are set as the recipients of multicast transmission, and the document transmission can be executed.
In relation to the registration with the group key, other than directly registering the information of transmission destination (facsimile number or mail address), information specifying an already registered single-touch dial or abbreviated dial (single-touch number or abbreviated number) is often registered with the group key, as disclosed in Japanese Patent Laying-Open Nos. 11-150614 (hereinafter referred to as '614 Reference) and 2001-218012 (hereinafter referred to as '012 Reference). When the group key is pressed, the transmission destination information (facsimile number or mail address) is determined referring to the information of already registered single-touch dial or the abbreviation dial specified by the single-touch number or the abbreviated number registered with the group key. Thus, not only the transmission using group key but also individual transmission (single-touch dial or abbreviated dial) is possible, and an environment enabling document transmission in accordance with the situation and the user's intention is provided.
Since individuals having a plurality of terminals are increasing, it becomes a common practice to register a plurality of pieces of transmission destination information (facsimile number and mail address) for one recipient name in the address book. As to the single-touch key, it has been adopted to enable registration of a plurality of pieces of transmission destination information for one key, as in the address book. Therefore, though the single-touch key and the group key have different names, these keys realize similar functions. In the present specification, these keys will be generally referred to as "short-cut key."
When a document is to be transmitted using a single-touch key having a plurality of transmission destinations registered, due to the function of the key, it is possible that one document is sent to a plurality of transmission destinations including a terminal not intended by the user, though transmission to one destination only (only one facsimile or one mail account) is desired. For example, though it is desired to transmit to facsimile only, an electronic mail may also be sent inadvertently.
A solution to such a problem is proposed, for example, in Japanese Patent Laying-Open Nos. 2002-125088 (hereinafter referred to as '088 Reference) and 2003-152945 (hereinafter referred to as '945 Reference). Specifically, '088 and '945 References disclose a technique of determining the transmission mode (facsimile transmission or electronic mail transmission) from the pressed mode key at the time of document transmission and sending document data to the destination information corresponding to the determined mode (if it is the facsimile transmission mode, to the facsimile number and if it is the electronic mail transmission mode, to the mail address). Accordingly, if both facsimile number and mail address are registered for one transmission destination, appropriate transmission process in accordance with the user instruction can be executed.
According to the technique disclosed in '088 Reference, however, if a document is to be transmitted to a plurality of recipients as in the case of multicast transmission described above, it is necessary to set the transmission mode (press a key) for every destination, which results in low working efficiency.
Further, according to '945 Reference, if a piece of destination information (mail address/FAX number) corresponding to the set transmission mode (internet FAX/normal FAX) is not registered when the single-touch key is pressed, it is necessary to select the transmission destination again, which results in low working efficiency. Further, since an indication "not-registered" appears after the user presses the single-touch key, it may be disturbing for the user.


Various embodiments relate to a method of encoding data and a related device and non-transitory machine readable storage medium, including: determining a plurality of factors of a value, b, to be exponentiated; retrieving, from a lookup table, a plurality of lookup table entries associated with the plurality of factors; calculating a product of the plurality of lookup table entries; and calculating a residue of the product using a cryptographic key modulus, N, to produce an exponentiated value, s.

Digital signature schemes commonly apply encoding processes to data prior to signing a message to ensure that the data conforms to a pre-chosen alphabet to which the scheme applies. For example, a standard RSA algorithm using a key 3-tuple of <N, e, d>first converts each symbol to a corresponding value between 0 and N. Other encoding schemes may be used for different sets of input values to enable signature schemes that exploit various mathematical properties of the values in the input value set.
After encoding, the encoded values are used to create a signature for transmission. Some encryption algorithms, such as RSA, utilize a modular exponentiation function to create such a signature. As an example RSA processes an encoded value, b, using the private key pair <N, d>by computing bd mod N. RSA would then verify the signature value, s, using the public key pair <N, e>by first computing se mod N. A decoding function is then applied to the resulting value to retrieve the original value.

Modular exponentiation using look-up tables


To reduce the number of erroneous operations, on an operation apparatus conducting mutually different operations such as opening and closing operations, a concretized human pictogram indicating mutually different state changes such as state changes represented by use of a face with opened eyes and a face with closed eyes associated with operation signals assigned to a pair of operation switches and a pictogram in which the human pictogram is combined with an operation pictogram representing a state in which a door concretizing an operation target to operate in response to an operation signal is opened or is being completely closed are respectively attached to the operation switches disposed adjacent to each other.

The present invention relates to a method of marking an operation device with pictograms to be attached to the operation device which conducts mutually different operations of, for example, ON/OFF or Open/close and an operation device marked with such pictograms.
In general, an operation switch is provided with an identification letter and/or a pictorial symbol, i.e., pictogram for the user to recognize a function of the operation switch. To reduce erroneous operations, pictograms desirably have high visibility and identifiability.
Particularly, for a switch such as the ON/OFF or Open/close switch which causes either one of the mutually different operations depending on the user's operation, it is desired to reduce erroneous operations. For this purpose, it is required to make the user first detect a target switch, for example, the ON/OFF or Open/close switch and then identify which one of the constituent components of the switch is ON or OFF.
For example, almost everyone has an experience of erroneous operations in an elevator. That is, to hastily open the closing door of the elevator for a person who desires to take the elevator, a passenger in the elevator cage mistakenly operates the Open/close switch disposed in an operation panel to resultantly close the door. This takes place because although the passenger empirically knows the locations of the Open and Close switches, it is not possible for the passenger to hastily judge which one of the switches is the Open switch to be selected to open the door.
To remove this problem, it is effective to mark characters such as "" ("Open" in Japanese), "" ("Close" in Japanese), "OPEN", and "CLOSE" on the surface of the Open/close switch as shown in (a) and (b) of FIG. 28. In the globalized environment today, these characters or letters are available only for those who can read such characters or letters. Hence, in general, pictograms are primarily employed, for example, as (c) of FIG. 28 in which a central straight line and a pair of arrows respectively indicating the closing and opening directions are used to represent the closed and open states of the door. Also, to solve the problem, it has been proposed to form the Open switch and the Close switch in concave and convex shapes, respectively.
As above, the marking characters or letters of the Open/close switch are arranged on an operation panel or a console for the user to detect the Open/close switch. After the detection thereof, it is desired that the letters call the user's attention with identifiability thereof. According to recent brain studies, there exist neurons which are highly reactive upon being stimulated by particular patterns. For monkeys, a hand neuron highly sensitive to a hand pattern and a face neuron highly sensitive to a face pattern have been reported. According to an article, this effect is also the case with humans.
As confirmation of the effect, reference has been made to good results attained in examples in which a road sign and a pedestrian sign to which a notice and a human image are attached are employed in a pedestrian crossing as well as in an example in which a board on which a human hand and a notice are presented is installed at a place of illegal dumping.
For a headlight of a motorcycle, it has also been proposed to produce the headlight in a form like a human eye. This easily reminds one of a human face. Hence, when a driver of a car running before a motorcycle catches, by use of a rear view mirror, an image of the motorcycle with such headlight, the effect of the headlight calls attention of the driver to existence of the motorcycle.
These techniques are described in JP-A-8-73145, JP-A-2006-298045, JP-A-57-115232, JP-A-63-275323, and JP-A-9-98972.

Operation device and elevator apparatus with operation device


An accessory device for dissipating electrical energy from a surgical device is provided. The electrical energy is induced on the surgical device when a charge-inducing instrument, e.g. an unipolar electrocautery device, is energized in proximity thereto. The induced energy is dissipated by conveying the energy along an electrically conductive coating adhered to a housing of the device to an energy dissipation region.

1. Technical Field
The present invention relates to a device and method for dissipating electrical energy during a surgical procedure and, more particularly, to an energy dissipation device and method having application in endoscopic surgical procedures.
2. Description of the Related Art
Endoscopic procedures have been practiced for many years. Initially, endoscopic procedures were primarily diagnostic in nature, i.e., involving the introduction of laparoscopes and like devices to view internal organs. Laparoscopic sterilizations have also been performed for some time. More recently, surgeons have begun to perform complex and innovative endoscopic surgical procedures. For example, endoscopic cholecystectomy has become a preferred modality for gall bladder removal in just the last two years.
Endoscopic procedures are typically performed through trocar sleeves or cannulas. Prior to introducing the cannula through the body wall, the surgeon generally insufflates the body cavity with carbon dioxide, e.g., through a Verres needle or like device. Insufflation creates a free area between internal body organs and the body wall. The surgeon then introduces one or more trocars through the body wall into the insufflated body cavity.
Trocars are sharp pointed instruments which include a trocar shaft or obturator with a piercing tip located at the distal end thereof. The trocar is positioned within a cannula for introduction of both into the body cavity. After introduction, the trocar is removed from the cannula and endoscopic instrumentation may be introduced through the cannula to effect diagnostic and/or surgical procedures. The cannula is typically provided with an internal flapper or trumpet valve to prevent gas release from the body cavity and generally measures from 3 to 12 mm in diameter. Safety trocars which include a spring-loaded safety shield surrounding the obturator are also known. See U.S. Pat. No. 4,601,710 to Moll et at.
A wide range of accessory instrumentation finds application in endoscopic surgical procedures. For example, graspers, dissectors, clip appliers, lasers and electrocautery devices are routinely employed. It is also common to perform a cholangiogram by introducing a catheter into the cystic duct during an endoscopic cholecystectomy. To obtain high quality imaging, radiolucent (rather than stainless steel) cannulas are typically employed in the region of the cholangiogram. Tissue gripping devices have also been developed for deployment on the exterior of the cannula, either permanently or removably, to prevent the cannula from working out of the body wall as a result of instrument manipulation therethrough.
Surgeons have long employed cautery to destroy or vaporize tissue and to cut and coagulate vessels and tissue through the application of electricity, heat or corrosive chemicals. Electrocautery (or galvanocautery) is routinely used to achieve hemostasis, both in endoscopic (closed) and non-endoscopic (open) surgical procedures. Electrocautery operates by taking advantage of the resistance to the flow of electrical current through tissue, such resistance resulting in heat generation as current attempts to pass therethrough. The degree of resistance to electrical current flow for tissue depends primarily on its vascularity and water content, with bone and fat having a higher resistance to current flow than skin and muscle.
Electrocautery instrumentation is typically either unipolar or bipolar. In unipolar applications, electrical energy is supplied from a generator to the end of an electrical conductor, e.g., cauterization wire, which is pressed against or placed adjacent the desired surgical site. A grounding plate is typically located below the patient so that the electrical current delivered by the cauterization wire passes through the patient to the plate, thereby completing the electrocautery circuit. In bipolar electrocautery, by contrast, a grounding wire is pan of the instrumentation placed adjacent the surgical site and the electrical current passes directly from the cauterization wire, through the tissue at the surgical site, and to the grounding wire.
Electrical burns constitute the most common electrical hazard in the operating room, the majority of which are associated with the use of electrosurgery or cautery units. A radio frequency generator supplies alternating current to the active electrode tip at frequencies between 300 thousand and 2 million hertz (cycles/second). Higher frequency devices are preferred to minimize the likelihood of muscle and nerve stimulation, i.e. electrical shock. The total power output of such units typically ranges from 40 to 600 watts and the units supply up to 10,000 volts. The current density at the tip of the electrode is extremely high, allowing the surgeon to achieve local heating and coagulation. To minimize the risk of extraneous burns in endoscopic procedures, it has been suggested that low power electrosurgical units and bipolar gasping forceps be employed and that insulation of accessory instrumentation, the cannula and the laparoscope be undertaken. See "Principles and Hazards of Electrosurgery Including Laparoscopy," G. R. Neufield, Surgery, Gynecology & Obstetrics, November 1978.
It has been reported that conductive trocar sleeves (or cannulas) can result in internal bums, particularly where the operative portion of the electrocautery instrument is not advanced beyond the end of the cannula. The suggested solution to this risk is the use of non-conductive cannulas, e.g., by placing a polyolefin heat-shrinkable tubing on the exterior of a conductive, stainless steel cannula. See "A Method for Preventing Abdominal Bums Caused by Electrocautery during Laparoscopy," J. M. Esposito, Am. J. Obstetr. Gynecol., Vol. 114, No. 8, 1972, pages 1105-06.
It has also been reported that endoscopic use of electrocautery devices can induce an electrical charge in or on the endoscope through which the electrocautery device is operated, despite the insulation of the electrocautery device. It will thus appear that high frequency current is leaking through the insulation, when in fact no electrons are passing therethrough. This phenomenon has been described as "capacitive coupling." See "Endoscopic Applications of Electrosurgery: A Review of Basic Principles," D. E. Barlow, Gastrointestinal Endoscopy, Vol. 28, No. 2, 1982, pages 73-76; "Safeguards in Laparoscopy: Education, Equipment Care, and Electron Control," R. M. Soderstrom, Contemporary OB/GYN, Vol. 11, March 1978, pages 95-107.
The induction of electric charge has also been observed on the surface of nonconductive cannulas when used endoscopically with a unipolar cautery. The electrons passing through the unipolar cautery create an electromagnetic field which in turn creates an electric charge in the nearby cannula. The electric charge thus created is proportional to the frequency of the energy supplied to the cautery device. This electrical charge may be stored and released through a small area, such as the cannula touching the bowel, resulting in a bum. An electromagnetic field is not generally created when a bipolar cautery is used because electric currents run in both directions within the cannula, so that the net electromagnetic field is zero. In the case of unipolar cautery, unless this electrical energy is dissipated, contact between the "charged" cannula and an internal body organ or viscera may bum the organ or viscera.
Thus, means are needed to ensure that any electrical energy induced in or in any way conveyed on to surrounding structures by the use of electrosurgical devices is controllably dissipated in a safe manner.


The network system includes a command transmitting unit that transmits a command for requesting information required by the representative device for network management from the non-representative device, when the non-representative device has joined a network or when there is a change in a state of the non-representative device, and a command receiving unit that receives a command including the information sent from the non-representative device that has received the command.

In recent years, network supporting apparatus increase which include printers and home electronics. So, communication protocols for use between devices on a network, mechanisms for device discovery and installation, and specifications of printing services have been standardized.
Standard communication protocols for client PCs to utilize networking apparatuses more generically and/or services for facilitating use of devices have been standardized, e.g., Web Service for Devices (WSD), Universal Plug&Play (UPnP) (registered trademark), and Bonjour (Rendezvous) (registered trademark).
The WSD is a standard specification defined for accommodating demands for various services using devices. Basically, the WSD uses a Web service architecture, providing standardized communication protocols and a printing service.
Such a network system exists that includes a representative device to collect information on devices on a network, non-representative devices that are under management of the representative device, and a management apparatus to manage the network system based on device information collected by the representative device.
Japanese Patent Application Laid-Open No. 2003-186765 proposes a method for reducing load on a management apparatus and a network in such a network system by having the representative device collect device information which is broadcast by non-representative devices when the devices join the network system and transmit all collected information to the management apparatus.
In information managed by the representative apparatus, there may be past information that cannot be re-collected once lost, but that can be useful, such as individual users' printing history, performance log for network communication, and/or operational status of apparatuses, for example.
The conventional technique mentioned above, however, allows the representative device to maintain only information obtained when a non-representative device joins the network. Therefore, when a changeover between the representative device and a non-representative takes place on the network, past information on the non-representative apparatus cannot be inherited.
On the other hand, a method is possible that has the representative device collect information on a non-representative device after the non-representative device joins the network, by polling. This method, however, has a problem of heavy load being placed on the network because communication traffic is produced at all times.

This patent is subject to a terminal disclaimer.

Network system and management method therefor


A method and device for creating hanging drop cell aggregates. The method and device includes a plurality of pegs that allow for high throughput culture of aggregates. Also disclosed are means of transferring formed aggregates to various destinations, such as well plates, scaffolding, tissues, or wounds. Use of the device permits aggregates to be prepared or created in larger quantities than current methods, and allows for them to be transferred more efficiently.

The current method for creating hanging drop cell aggregates is to pipette individual cells onto a slide or a petri dish and invert the cells so that the force of gravity causes the cells to form into aggregates. Once the aggregates have formed, they typically then have to be pipetted again to transfer them to a storage destination, and then again to their ultimate destination for research, treatment, or some other purpose. Generally, this is a slow and inaccurate process, but, until recently, uses of cell aggregates have not required production in quantities large enough to merit improvements on this process. Recent discoveries, however, have led to the need for high-throughput solutions for the cell aggregate formation process.
Another current method involves forming the cell aggregates directly in the specially coated low-attachment well plates or in well plates pre-loaded with a special-purpose scaffolding for forming cell aggregates. A problem with these designs is that the cell aggregates form directly in well plates, and in order to be used, the cell aggregates still must be transferred manually to their next location (e.g. into tissue or into another cell culture chamber) in the time-intensive manner described above.
A further disadvantage is that these methods do not employ the hanging drop method to create cell aggregates. There may be circumstances in which the creating cell aggregates via the hanging drop method (i.e., under the force of gravity) is superior to the methods described above.

High-throughput culture and transfer device and method

University of Virginia Patent Foundation


An approach is provided for context recovery. A radio link failure condition of a wireless link employed by a mobile unit is detected. An identifier of the mobile unit is received. A determination is whether the mobile unit can re-use connection parameters that were established prior to the failure condition. The mobile unit is instructed to re-use the connection parameters based on the determination.

Radio communication systems, such as a wireless data networks (e.g., Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, spread spectrum systems (such as Code Division Multiple Access (CDMA) networks), Time Division Multiple Access (TDMA) networks, etc.), provide users with the convenience of nobility along with a rich set of services and features. This convenience has spawned significant adoption by an ever growing number of consumers as an accepted mode of communication for business and personal uses. To promote greater adoption, the telecommunication industry, from manufacturers to service providers, has agreed at great expense and effort to develop standards for communication protocols that underlie the various services and features. One area of effort involves efficient design of control signaling within the communication system, particularly during link failure and the subsequent recovery process.

Method and apparatus for providing context recovery


An optical transducer system for use with an optical transducer of the kind which produces a wavelength multiplexed optical output signal comprises a broadband optical source, and a tunable filter in the form of a Fabry-Perot interferometer connected to receive a broadband optical signal from the source. The interferometer is repeatedly swept through its pass band by a control signal of triangular or sawtooth waveform, producing a swept wavelength optical output signal for application to the transducer. In one embodiment, the optical output signal from the transducer is compared with the output signal from the interferometer to decode it, while in another embodiment, a control loop maintains the output amplitude (intensity) of the broadband source substantially constant over the range of wavelengths used by the transducer, enabling a reference channel provided in the transducer to be used for decoding purposes.

The present invention relates to optical transducer systems, and is more particularly concerned with optical transducer systems of the kind involving an optical transducer which produces a wavelength multiplexed output signal, such as the transducer described in our United Kingdom Patent Application No. 8720156 (Publication No. 2 209 101A).
A wavelength multiplexed optical position transducer is described in our aforementioned United Kingdom patent application No. This transducer uses a graded-index rod lens and a glass wedge grating assembly to disperse and recombine a broad spectrum optical signal generated by an LED. The dispersed light is reflected by a coded strip and the combination of wavelengths present in the recombined spectrum is a function of the position of the lens/grating assembly relative to the coded strip.
The recombined signal from a transducer is transmitted along a single optical fibre to a detector system. The detector system wavelength demultiplexes the received signal in a further wedge/grating assembly.
Typically a ten bit coded strip is used in the transducer to reflect the various wavelengths in the dispersed optical signal. A further channel is sued to provide a continuous ON signal for use as a reference channel. This reference channel is used to compensate for wavelength-independent variable system losses such as poor optical connections, bent fibres, and ageing of the LED's. However, there may be further, wavelength-dependent, variations in intensity caused by factors such as temperature variations of the LEDs. The LEDs could have their temperatures stabilized by using PELTIER coolers but this is not a practical solution in many applications due to the low lifetime of Peltier coolers at elevated temperatures (e.g. 10,000 hours at 125.degree. C.).
Another drawback with the prior detector system is the fact that eleven data channels have to be dealt with simultaneously. This means that each channel requires a separate photodiode, pre-amplifier and phase-sensitive detector, which makes it difficult to reduce the size and weight of the detector system for applications such as aerospace, where these are important factors.
It is an object of the present invention to alleviate at least some of the drawbacks of the prior optical transducer and its detector system.

Wavelength multiplexed optical transducer with a swept wavelength optical source


A device for detection of magnetic permeability (μ) or, alternatively, relative magnetic permeability (μr) or, alternatively relative magnetic susceptibility (μr-) of a sample is described. The device comprises a sample chamber having at least one opening for introduction of a sample or a sample container holding a sample and an electronic circuit. The device also comprises a coil surrounding said sample chamber, and also an electronic circuit adapted to measure the inductance of said coil. The sample chamber, coil and at least one component of the electronic circuit are placed in a temperature controlled zone. Said at least one component in said electronic circuit is/are selected from the group consisting of capacitors, sensors, precision voltage references, precision regulators, low pass and or high pass filters.

The annual world market for diagnostic equipment based on immunoassays has increased considerably in the last decades. The main reason for the success of immunoassays is that it is easy to adjust to various chemical analysis problems. By using different types of detection techniques in combination with immunoassays, a number of important chemical substances can be identified and quantified. Depending on the physical measuring principle, different types of detectors are suitable for different types of analysis problems. Since the introduction of immunoassays, many new detectors have been presented.
A number of magnetic technologies have been incorporated into devices for different quantitative measurement purposes. Examples of the technologies are magnetic permeability (μ), relative magnetic permeability (μr) and relative magnetic susceptibility (μr-1).
The temperature dependency of magnetic permeability (μ), relative magnetic permeability (μr) and relative magnetic susceptibility (μr-1) has been taken into account earlier when constructing devices bases on these technologies. In F. Ibraimi et al, Anal Bioanal Chem DOI 10.1007/s00216-013-7032-9, 1-7, 2013, an inductance coil for measurement of magnetic permeability maintained at a constant temperature (30° C.) is described.
U.S. Pat. No. 6,700,389 describes a device and a method wherein the temperature of an inductive coil is determined to adjust the inductance measured.
U.S. Pat. No. 7,910,063 describes a further approach to compensate for the changes in coil temperature. According to this document, a device and a process for measurement of magnetic permeability is described. Samples are placed in a measuring coil measuring the inductance of the sample, which thereafter is compared and compensated with a wellknown reference signal achieved by measurements at the same temperature conditions. This type of device allows measurements of the magnetic permeability for samples, but suffers from the drawback that two coils have to be used in the device.
All the above mentioned techniques further suffer from the drawback that the temperature-dependent drift of electrical components (other than the inductance coil) present in the electrical circuit limits the sensitivity (signal to noise ratio) of the detector.

Temperature controlled magnetic permeability detector


Providing a user with assurance that a networked computer is secure, typically before completion of the log-in operation. This can be accomplished by extending the local log-in process to perform a host assessment of the workstation prior to requesting the user's credentials. If the assessment finds a vulnerability, the log-in process can inform the user that the machine is or may be compromised, or repair the vulnerability, prior to completion of the log-in operation. By performing vulnerability assessment at the level of the workstation, a network server is able to determine whether the workstation is a “trusted” platform from which to accept authentication requests. If the vulnerability assessment shows that the workstation is compromised, or if the possibility of remote compromise is high, the network server can elect to fail the authentication on the grounds that the workstation cannot be trusted. Optionally, a vulnerability assessment tool may be able to repair the vulnerability of the workstation, and then allow the authentication to proceed.

As use of network services becomes more prevalent in distributed computer networks, secure authentication of a computer user increases in importance. Authentication is required to prevent unauthorized use and abuse of network services. Authentication services typically require the user to verify his or her identity to the network service provider to determine whether that user is authorized to use a computer to access the network.
An authorization mechanism defines who is allowed to do what on a computer. Two computer authorization mechanisms for typical operating systems are privileges and object access control. Users granted a specific privilege can perform an action that is denied to users who do not have the privilege. Typically, privileges are not evaluated on a per-object basis. Instead, a privilege is applied in general to an action for a user. For example, the root user in most UNIX operating systems has a set of privileges associated with authorized actions. The "WINDOWS NT" operating system supports the grant of a set of privileges on a per-user or user group basis.
When access control is required for a particular object, such as a file, a form of authorization other than a general privilege can be used to define a permission to access the object on a per user basis. Object access control can specify, for each object, different access permissions for different users. For example, on a UNIX system, the "chmod" command allows the user to specify read, write, and execute permissions for the owner, the group, and the world. The "WINDOWS NT" operating system uses a discretionary access list that grants control permissions for different users.
Both authorization methods support the control of computer actions based on the identity of the user. The user's identity establishes the privileges and the objects that she can access via a computer. Establishing the identity of the user is crucial to security and control in a computer network and is the role of the authentication process.
There are three branches of authentication technology in common use today to assist verification of the identity of the user. Shared secret (password) technology is one; public key technology is a second; and biometric technology is a third. Conventional authentication involves confirming the user's identity by (1) verifying a shared secret, such as a password, (2) using public/private key encryption and verifying that the user knows the private key, or (3) using unique biometric information about the user, such as fingerprints, retinal patterns, or voice prints. All three technologies revolve around the fundamental principle of credentials. A credential is information useful to establish the identity of a computer user. An authenticating service requests credentials from the user to support a decision about the identity of the user based on the credentials.
In many organizations and homes today, users operate a workstation, which makes requests for a network service available on a computer network. The workstation is important in authentication for two reasons. First, the workstation is a platform from which the user can access resources, including network services, on the network. Users authenticate and connect to network services from their workstations. Second, the workstation can be silently compromised by an unauthorized party. A "silent" compromise is one that the user cannot easily detect without the aid of external security auditing tools. Silent compromise is typically accomplished by installing a compromise tool called a "root kit" or a "backdoor" on the workstation. For example, current "hacker" software can be used to obtain the customer's password by logging keystrokes or browser screenshots can be taken to intercept SSL-protected HTTP traffic.
An intruder may compromise the integrity of a workstation, or a workstation may be misconfigured so that compromise is possible. The use of a network service may be compromised when a user accesses a network service from a compromised workstation. This subjects the network service to unauthorized use and abuse by the intruder on a valid user's workstation.
The effect of a compromised workstation is the potential violation of security mechanism that assumes the workstation is "trusted", including password-based authentication and some forms of biometric authentication. Smart card authentication implementations also can be subverted if the workstation's Trusted Computer Base is subverted. For example, a user's credentials, such as password and biometric credentials, can be stolen or rogue code can be executed that impersonates the logged-on user.
Host assessment and authentication is relevant to the Internet environment because most Web clients are currently desktop machines. These machines are capable of being compromised, and are frequent targets of compromising attacks. Some Web sites attempt to verify the security of the client host by performing a security assessment before allowing transactions from that host.
For example, online banking applications are typically implemented by Web sites that allow customers to view account balances and pay bills. Customers and insurers want assurances that only the customer can perform transactions, and that the transactions are confidential. Current techniques include password authentication to verify that only the customer has access to their account, and SSL or PCT encryption to verify that there is no "man in the middle" capable of intercepting the network traffic.
In view of the foregoing, there is a need for a way for verifying the integrity of the workstation prior to granting access to and determining the level of a network service. The present invention solves the security compromise problem by providing assurances to the Web site operator (and their insurer) that the user's workstation has not been compromised or is easily compromised. The invention can accomplish this desirable objective by scanning the user's workstation for evidence of compromise and vulnerabilities that could lead to compromise. For example, when a user signs on to a Web site, the scan can be completed as part of the authentication process.

Method and apparatus for network assessment and authentication

International Business Machines Corporation


A surgical system with irrigation and aspiration lines having different compliance or stiffness, with the irrigation line having a higher compliance than the aspiration line.

This invention relates generally to the field of phacoemulsification and more particularly to irrigation/aspiration ("I/A") systems used during phacoemulsification.
The human eye in its simplest terms functions to provide vision by transmitting light through a clear outer portion called the cornea, and focusing the image by way of the lens onto the retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and lens.
When age or disease causes the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. An accepted treatment for this condition is surgical removal of the lens and replacement of the lens function by an IOL.
In the United States, the majority of cataractous lenses are removed by a surgical technique called phacoemulsification. During this procedure, a thin phacoemulsification cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquefies or emulsifies the lens so that the lens may be aspirated out of the eye. The diseased lens, once removed, is replaced by an artificial lens.
A typical ultrasonic surgical device suitable for ophthalmic procedures consists of an ultrasonically driven handpiece, an attached cutting tip, and irrigating sleeve and an electronic control console. The handpiece assembly is attached to the control console by an electric cable and flexible tubings. Through the electric cable, the console varies the power level transmitted by the handpiece to the attached cutting tip and the flexible tubings supply irrigation fluid to and draw aspiration fluid from the eye through the handpiece assembly.
The operative part of the handpiece is a centrally located, hollow resonating bar or horn directly attached to a set of piezoelectric crystals. The crystals supply the required ultrasonic vibration needed to drive both the horn and the attached cutting tip during phacoemulsification and are controlled by the console. The crystal/horn assembly is suspended within the hollow body or shell of the handpiece by flexible mountings. The handpiece body terminates in a reduced diameter portion or nosecone at the body's distal end. The nosecone is externally threaded to accept the irrigation sleeve. Likewise, the horn bore is internally threaded at its distal end to receive the external threads of the cutting tip. The irrigation sleeve also has an internally threaded bore that is screwed onto the external threads of the nosecone. The cutting tip is adjusted so that the tip projects only a predetermined amount past the open end of the irrigating sleeve.
In use, the ends of the cutting tip and irrigating sleeve are inserted into a small incision of predetermined width in the cornea, sclera, or other location. The cutting tip is ultrasonically vibrated along its longitudinal axis within the irrigating sleeve by the crystal-driven ultrasonic horn, thereby emulsifying the selected tissue in situ. The hollow bore of the cutting tip communicates with the bore in the horn that in turn communicates with the aspiration line from the handpiece to the console. A reduced pressure or vacuum source in the console draws or aspirates the emulsified tissue from the eye through the open end of the cutting tip, the cutting tip and horn bores and the aspiration line and into a collection device. The aspiration of emulsified tissue is aided by a saline flushing solution or irrigant that is injected into the surgical site through the small annular gap between the inside surface of the irrigating sleeve and the cutting tip.
One possible complication associated with cataract surgery is anterior chamber collapse following an occlusion break. Occlusion of the phacoemulsification tip can occur when a piece of lens material fully covers the distal aspiration port. When an occlusion occurs, vacuum can build in the system aspiration line so that when the occlusion eventually breaks, a sudden surge occurs, drawing fluid and lens material out of the eye and into tip aspiration port. When fluid is draw out of the eye faster than it can be replaced, the eye can soften and collapse.
One way to reduce surge after an occlusion break is to reduce the compliance in the aspiration system. By reducing compliance, vacuum build-up during an occlusion is reduced. However, as flexible tubings are used to connect the handpiece to the surgical console, there will always be some compliance in the aspiration system.
Another prior art method involves increasing the size of the irrigation line. While not addressing the size of any post-occlusion fluid surge directly, a larger irrigation line allows for large irrigation fluid flows, so that any vacuum build-up in the eye is more easily quenched, thereby reducing the risk of anterior chamber collapse. Larger irrigation lines, however, can make the handpiece more difficult to hold and control.
Therefore, a need continues to exist for a simple and reliable irrigation/aspiration system that reduces fluid flow surges.


A flush mounted presser assembly for a die cutting machine. The presser assembly includes a support member having an upper surface which defines a substantially horizontal plane, a presser movable vertically in a plane perpendicular to the horizontal plane of the support member between a first extended position spaced from the support member beneath the horizontal plane and a second retracted position also beneath the horizontal plane of the support member, and a mounting arrangement for mounting the presser to the support member wherein the mounting arrangement is disposed flush with or below the horizontal plane of the support member so that none of its components extend or project above the horizontal plane of the support member. The mounting arrangement comprises a base mounted on the support, a linkage assembly interconnecting the base and presser, and a spring for biasing the linkage assembly and presser toward its first extended position away from the support member.

The present invention relates to die cutting machines for making carton blanks, and more particularly to a presser assembly for supporting carton blanking scrap during a blanking operation in a die cutting machine.
In the manufacture of cartons, small sheets of paper material having specific profiles are cut out of larger sheets of paper material. These smaller sheets are known as carton blanks which, in turn, are formed into cartons and/or boxes. The blanks are formed during a process known as a blanking operation in a die cutting machine.
In a die cutting machine, the blanks are cut, but not removed from a large sheet of paper material. After the blanks have been cut, the sheet is moved downstream in the die cutting machine to a blanking station where the sheet is positioned over a frame for support. The frame includes large openings which correspond in size, in shape and in position to the profile of the carton blank previously cut. Below the frame is a mechanism for stacking the carton blanks.
At the blanking station, an upper tool is used in combination with the lower tool or frame to knock the carton blanks from the sheet of paper material while holding the scrap material that surrounds the blanks. The upper tool has a support board that moves vertically up and down in the die cutting machine, and the support board typically has a plurality of stand-offs depending therefrom that hold pushers spaced beneath the board which in turn are used to push the carton blanks from the sheet through the lower tool or frame. A plurality of presser assemblies are also mounted in the support board and depend therefrom to hold the scrap material against the lower tool or frame during the blanking operation so that the blanks may be pushed from the sheet. A presser assembly typically includes a presser rail which is biased downwardly away from the support board by a spring so that the rail is positioned slightly below the pushers. As the upper tool is lowered, the presser rail engages the sheet of paper material first such that a scrap portion of the large sheet of material is secured between the presser rail and the frame. The upper tool then continues to be lowered such that the pushers engage the carton blanks and knock the blanks out of the sheet of material. The carton blank then falls into a stacking mechanism below the frame where the blanks are stacked for further processing.
In order to securely hold the carton blank scrap, the present day presser rails are interconnected to the support board by a plurality of guide cylinders. Each guide cylinder biases the presser rail downwardly away from the support board, and are mounted to the support board such that their upper ends project upwardly from the board. However, it is desirable to eliminate any components projecting above the support board and instead provide flush mounted presser assemblies for at least two reasons. First, for tool storage purposes an upper tool having flush mounted pressers takes up less space. This is particularly advantageous in locations where storage space is at a premium. Secondly, many die cutting machines are built in such a manner that the upper tool slides into the blanking station of the machine. Any component projecting upwardly of the support board would interfere with such sliding action. Therefore, only flush mounted presser assemblies can be used with such systems.


A hat and scarf that is made from coordinating material. A band extends around the circumference of the bottom of the hat and secures it to one's head. A loop is secured to the top of the hat. Each end of the loop is stitched to the hat top, thereby creating a small opening between the hat and the loop. At the rear of the hat, a band is secured at both ends by means of a fastener. The fastener is preferably a button or snap, thereby allowing the band to be easily attached or detached from the hat. A strand of coordinating material extends along the rear of the hat. It is fitted through the loop at the hat top and is secured under the band, consequently leaving two ends of the strand dangling from the bottom of the hat. The scarf is made from a flexible material that drapes loosely over one's neck. It is made from the same material as the hat, thereby creating a matching set.

The invention relates to a head gear. More particularly, the invention relates to a hat, to be worn on one's head, and a matching scarf, to be draped around one's neck.
During the cooler months of the year, it is common to wear hats and scarves to protect one's head and neck from the cold weather. Since these articles are often necessary, it should be possible to coordinate the hat and scarf with one's other clothing, thereby creating fashion accessories.
U.S. Pat. No. 58,944 to Rosenberg discloses a unique design for a combined head and neck covering.
U.S. Pat. No. Des. 108,757 to Tannenbaum discloses a unique design for a combined cap and muffler.
U.S. Pat. No. 5,621,920 to Gorsuch et al. discloses a stocking cap with a tail that may be wrapped around one's neck. The end of the tail may then be attached to the cap in order to create either a scarf or a ski mask.
U.S. Pat. No. 2,735,283 to Schuessler discloses a knitted cap structure.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.


The focus of a laser machining apparatus is set by reading a program for setting the focus of the laser beam on a workpiece; irradiating the workpiece with the laser beam according to the program for setting the focus; moving a machining lens relative to the workpiece while keeping constant the distance between the machining head and the surface of the workpiece; detecting information regarding the relative distance between the machining lens and the workpiece; judging that the laser beam has focused on the workpiece when the detected relative distance information has exceeded a predetermined range and when a blue flame occurs; and storing the position information of the machining lens at the time when it is judged that the laser beam has focused on the workpiece.

1. Field of the Invention
The present invention relates to the field of laser processing, and, in particular to a system in which a laser machining apparatus automatically performs focus position detection as a required preparatory operation to perform laser machining, stores detected data in a memory, and automatically performs focus position determination.
2. Description of the Background Art
A two-dimensional laser machining apparatus has been employed to cut a plate workpiece in contactless relation at a high speed and with a high accuracy. The two-dimensional laser machining apparatus controls a machining head along X, Y and Z axes, and cuts a workpiece using a laser beam which is introduced from a laser oscillator and outputted from the tip of the machining head. Usually, from a machining quality point of view, it is desirable that the laser beam be focused on the surface of the workpiece, so that when the workpiece is cut using the laser beam, it is necessary to perform a focus setting operation distinct from the actual machining operation. During actual machining, based on the height of the machining head determined by the focus setting operation, a height detecting sensor is mounted to the tip of the machining head, and machining is performed by following the outline of the workpiece so as to keep constant the distance from the tip to the workpiece by using the detecting sensor.
With reference to FIGS. 8 and 9, the general configuration of a two-dimensional laser machining apparatus will be explained hereinafter. Numeral 1 indicates a machining head which is mounted for movement along a Z axis 10. Numeral 2 indicates a distance sensor which functions as a focus detection means and is mounted on the tip of the machining head 1. Numeral 11 indicates a Z axis guide which guides the movement of the machining head 1 driven by the motor M3 in the direction of arrow Z; numeral 12 a Y axis guide which guides the movement of the machining head 1 driven by the motor M2 in the direction of arrow Y; and numeral 13 an X axis guide which guides the movement of the machining head 1 driven by the motor M1 in the direction of arrow X. The motors M1 through M3 are driven by a drive signal M from an NC (numerical control) control section 15, and controlled in such a manner that the spot of a laser beam L follows a machining line K according to a machine processor, while the distance from the machining head 1 to a workpiece W is kept constant. In order to keep constant the distance from the machining head 1 to the workpiece W, the distance sensor 2 mounted on the tip of the machining head 1 measures the distance between the workpiece W and the machining head 1, and feeds back a measuring signal to the NC control section 15, thereby finally controlling the spot of the laser beam L. Connected to a control section 16 is a local operation box 17 which is used at the time of focus position detecting and the like. Numeral 18 indicates a laser oscillator for outputting the laser beam; and numeral 19 a machining apparatus body comprising the three guides for the X, Y and Z axis directions.
Generally, the method used for focus detection is such that a weak laser beam irradiates the workpiece, and a blue flame, derived from a plasma state occurring when the focus of the laser beam is placed on the surface of the workpiece, is visually monitored. In that method, the machining head 1 is allowed to move back by manual operation to widen the distance between the tip of the machining head and the workpiece installed on a machining table so that the tip of the machining head 1 does not interfere with the workpiece during a focus position detecting operation. Thereafter with a focusing program, the machining head is moved relatively and parallel to the workpiece while the laser beam irradiates the workpiece, and an operator finely moves only a lens in the machining head in the plus and minus directions of the Z axis by using the local operation box 17, whereby the blue flame, produced by the plasma occurring near the focus position, is visually monitored.
By using the local operation box of the two-dimensional laser machining apparatus, the operator can input the lens height for which the blue flame is found, as the height of the lens when focused, thereby setting the focus position.
After the focus position has been set, the two-dimensional laser machining apparatus is operated, while keeping the just-focused lens position found by said monitoring and setting operations, and the height of the machining head is adjusted by manual operation so as to provide the proper distance between the machining head and the workpiece.
FIG. 10 is a flowchart showing the steps of a conventional blue flame monitoring operation. In order to perform the operation to monitor the blue flame, after moving back the machining head, the workpiece (or test piece) W is installed on the machining table 14 to determine a focus (S101); the distance between the tip of the machining head and the workpiece W is adjusted so that the tip of the machining head 1 does not interfere with the workpiece or test piece W during the focus position detecting operation (S102); and a program for determining focus is read in the control section 15 (S103). Thereafter, according to the program operation performed by the program for determining focus, the machining head is moved relatively to the workpiece while keeping a constant distance between them (S104); and the laser beam L is irradiated (S105); whereby, while moving the machining head in the Z axis using the local operation box 17 (S106), occurrence of the blue flame is monitored by the operator (S107).
FIG. 11 is a flowchart showing the steps of a conventional focus position setting operation. The blue flame is monitored (S201); whether the blue flame occurs properly is checked (S202); and the operator inputs the height of the current position, when the blue flame properly occurs, as the proper focus height of the machining head, into the control section 16 of the laser machining apparatus (S203). When a proper blue flame does not occur in S202, using the local operation box, the machining head is moved along the Z axis up and down (S204), and the operation beginning with S201 is repeated.
FIG. 12 is a flowchart showing a conventional focusing operation. After the distance between the machining head and the workpiece is widened in S101 shown in FIG. 10, the blue flame occurring is monitored by the operator (S301); whether the blue flame occurs properly is checked (S302); the operator inputs the height of the current position, as the height of the proper focus machining head, into the control section of the laser machining apparatus (S303); and the widened distance between the machining head and the workpiece is adjusted to a proper state (S304). Where a test piece has been used in the above focusing operation, the test piece on the machining table is replaced with the workpiece to start an actual machining operation. Where the above focusing operation has been performed using the workpiece, after completion of the above operation, an actual machining operation is started in that condition.
Conventionally, the distance between the machining head and the workpiece being cut is controlled by a contactless sensor mounted on the tip of the machining head as disclosed in Japanese Laid-Open Patents SHO64-78691 and SHO64-78692.
The former reference discloses a laser machining apparatus which includes a contactless gap sensor, sampling command/drive means and a sampling data storage circuit, wherein, while a machining head is moved away from a reference position from a workpiece in an increment of a specified amount by performing a sampling command with the command means, an output value of the gap sensor is stored in the data storage circuit, whereby the gap sensor output value is controlled in a manner to become the stored data value corresponding to the command gap from a control section.
The latter reference discloses a laser machining apparatus which includes machining head check means, reference output setting means and machining head good/bad judgment means, wherein a machining head is automatically positioned at a check reference position by being given a check command, and a sensor output is measured, whereby the position of the machining head is judged by whether the value is within a predetermined reference output or not. Another device, in which the tip of a machining head is provided with a contactless sensor, and which relates to the control that controls the distance between a workpiece and a machining head during teaching based on a height set in a control panel, is disclosed in Japanese Laid-Open Patent SHO61-165288.
None of the above-mentioned three conventional devices provide continuous monitoring and recording of blue flame, and processing of the data to calculate a focus position.
Although in the blue flame monitoring operation in conventional art a laser beam irradiates a workpiece, and an operator finely moves a machining head in the Z direction using a local operation box such that the workpiece and the machining head are allowed to move relatively to each other at a certain speed, whereby the operator visually monitors the occurrence of the blue flame produced by plasma occurring near the just-focused position, there has been a problem that the monitoring is too complex. Another problem is that the occurrence of the blue flame as detected by the monitoring operation cannot be continuously stored, so that the operator must frequently perform the focus position detection for each monitoring operation to input a current Z axis value through a control section.
Still another problem is that the conventional art focusing is performed by an operator, whereby the detected focus position depends on the degree of skillfulness of the operator, and also whereby the determination of focus position requires non-productive time not accompanied by actual machining. Another problem is that a proper focus position is difficult to determine, whereby a proper focusing cannot be performed, thereby providing a poor machining.

Laser machining apparatus and method of setting focus thereof


A preparation method of a SiC porous ceramic material and porous ceramic material manufactured by using the method, comprising: mixing a SiC aggregate, a sintering aid (zirconium oxide), a pore-forming agent (activated carbon) and a polymer binder with a reinforcing agent (SiC whiskers) according to a certain proportion, and obtaining a porous ceramic material via forming, drying and high-temperature sintering. The porous ceramic material has a high strength, a high porosity, a good thermal shock resistance and a low sintering temperature, and can server as a filter material of high-temperature flue gas and a carrier material in vehicle exhaust purification.

Because of its low density as well as excellent corrosion resistance, high-temperature resistance, high-temperature oxidation resistance and thermal shock resistance, porous SiC ceramic material can be widely used in molten metal filters, catalyst carriers, water purifiers, thermal insulation and sound absorbing materials, gas combustion chamber media and high-temperature gas filters.
The preparation of high-strength porous SiC ceramic material generally requires a very high sintering temperature, usually above 1,800° C. The production process of such material can cause high energy consumption. Reducing the sintering temperature has been a research focus. Currently, there are two widely used low-temperature sintering technologies: one is to add inorganic metal oxides to react with SiC aggregate to form a new phase to strengthen the neck link of the particles, thereby enhancing the strength of SiC ceramic material; the other is to use polycarbonate silane as the precursor to prepare porous SiC ceramics at lower temperatures, but this method is costly and is difficult to produce and use on a large scale. Zircon is a chemically inert substance and has a strong corrosion resistance, and it is also difficult to react with molten metal and has a high stability in the high-temperature exhaust gas. Because zircon and SiC have very close thermal expansion coefficient, they can be well combined and have excellent high-temperature thermal shock resistance and is one of high-temperature dustproof ceramic materials with broad application prospects. However, there are many problems in the preparation of zircon-SiC porous ceramics. For example, porous ceramics prepared with SiC having a small particle size and the pore-forming agent have insufficient pore connectivity, small pore size and other defects, resulting in low gas permeability. This can't meet the high gas permeability required for high-temperature gas filtration and dust removal. Zircon is usually formed by letting zirconia and SiC react in the aerobic atmosphere. If SiC aggregate having a size of more than 100 microns is used to make zircon ceramics, a problem will also occur, that is, only a small part of the surface of SiC particles can be exposed to air, so the SiC particles can't be completely oxidized and a little zircon can form only in the neck surface of the particles. The porous ceramic prepared this way has very small strength and can't meet the needs of industrial production and can't be used as a high-temperature gas dust removal material. SiC whiskers have excellent mechanical properties, heat resistance, corrosion resistance and high-temperature oxidation resistance and have become one of the main reinforcing agents for a variety of high-performance composite materials.
For example, the Chinese patent application file (Publication No. CN102161594A) discloses a SiC whiskers-reinforced SiC ceramic matrix composite material, whose highest flexural strength was found to reach up to 500 MPa. The composite material has excellent comprehensive properties. Another example is that the Chinese patent application file (Publication No. CN100545127C) discloses a SiC whiskers-toughened titanium carbonitride-based cermet cutting blade which has high strength, high toughness and better abrasion resistance and heat resistance. However, the above patents are all related to the field of functional ceramics, and there are few studies on the use of SiC whiskers to reinforce the porous ceramic materials. In particular, there have not yet been published studies about the use of SiC whiskers for the preparation of SiC porous ceramic materials.
For porous SiC ceramic materials used for high-temperature flue gas purification, the flexural strength, porosity and average pore size are very important indicators, because the strength can withstand the impact of airflow, thus extending the service life of the materials; porosity and the average pore size mean a higher gas flux. In the existing technologies, large particles of SiC are difficult to oxidize, resulting in a small amount of zircon produced, so the flexural strength of the resulted ceramic material is not high, making it difficult to realize large-scale applications. Therefore, it is of great significance to use SiC whiskers to reinforce porous SiC materials to meet the requirements of high-temperature flue gas purification.
The purpose of the invention is to improve the strength and porosity of SiC porous ceramics at the same time to obtain a type of SiC porous ceramic material for high-temperature filtration.
The inventors of the invention have found that the addition of certain SiC whiskers into the mixture using SiC as aggregate can significantly improve the flexural strength of SiC porous ceramics, and the finally obtained SiC porous ceramics still have high porosity and good heat shock resistance and can meet the application requirements.
In order to achieve the above objective, the technical scheme used by the invention is:
A method for preparing a type of whisker-reinforced SiC porous ceramic material was proposed. Raw materials for preparing such material include large-particle SiC aggregate, a sintering aid, a pore-forming agent, and a type of macromolecular polymer for bonding, and another type of macromolecular polymer used for reducing the mold-release resistance. The feature of the method lies in that the blending materials also include a type of reinforcing agent, that is, SiC whiskers.
The method described in the invention is characterized by that the said sintering aid is zirconia, the said pore-forming agent is activated carbon, the said macromolecular polymer for bonding is polyvinyl alcohol (PVA), and the said macromolecular polymer used for reducing the mold-release resistance is liquid paraffin.
The method described in the invention is characterized by that the steps of preparing SiC porous ceramic material are:    (1) SiC aggregate, zirconia, activated carbon and SiC whiskers are mixed and then mechanically ground via ball milling to obtain a mixed powder a;    (2) Add PVA and liquid paraffin into the mixed powder a and mix them evenly, and then make the mixture into SiC porous ceramic green body through the dry pressing or extrusion method, and then dry the green body in the oven to get green body b;    (3) Green body b is placed in a high-temperature furnace to sinter. After natural cooling, a type of porous ceramic material can be obtained.
The method described in the invention is characterized by that the milling time in step (1) is 2-10 h until powder a is mixed evenly.
The method described in the invention is characterized by that the drying temperature of step (2) is 60 to 90° C. and the drying time is 2 to 4 hours.
The method described in the invention is characterized by that the sintering process mentioned in step (3) uses the following steps: first raise the temperature to 200° C. at a rate of 1-2° C./min; then raise the temperature to 500° C. at a rate of 2-3° C./min; keep the temperature at 500° C. for 0.5˜1 h to remove the activated carbon; finally raise the temperature to 1,450˜1,650° C. at a rate of 3˜3.5° C./min and keep the temperature at the point for 2˜6 h.
The method described in the invention is characterized by that the shapes of the said green bodies include plate, tube and honeycomb.
The method described in the invention is characterized by that the said SiC aggregate has an average particle size of 20-300 μm; the said ZrO2 has an average particle size of 1-5 μm and a purity of more than 99%; the said SiC whiskers have a crystal form of β and L/D>20, wherein L is a length of a SiC whisker and D is a diameter of the SiC whisker; the said activated carbon has a particle size of 8-50 μm; the said PVA is 1-10% PVA aqueous solution; and the ratio (mass ratio) of the said mixture is: zirconia occupies 5-20%, SiC whiskers 1-10%, activated carbon 5-15%, PVA 5%, and the remaining is SiC aggregate.
The method described in the invention is characterized by that a type of porous ceramic membrane material is obtained according to the method.
The method described in the invention is characterized by that the resulted porous ceramic membrane material is applied in the high-temperature flue gas dust removal and vehicle exhaust purification. The principle of the method described in the invention is as follows: the porous structure is obtained by the accumulation of particles and the addition of the pore-forming agent; the sintering aid is added into the mixture to enhance the bonding between the particles by means of the reactive sintering technology; for the problem that large SiC particles are difficult to oxidize at high temperature and this results in the too low strength of the prepared ceramic sample, SiC whiskers are added into the mixture to react with ZrO2 to produce zircon to reinforce the neck connection among SiC particles, thereby enhancing the ceramic strength.
The main content of the invention is to prepare a type of whisker-reinforced SiC porous ceramics, a type of zircon-SiC porous ceramics having a high flexural strength, and to use it in high-temperature flue gas filtration, especially in large thermal power plants, steel plants and other industries where coal is massively consumed.
In the invention, various parameters are determined with the following methods:    1. The porosity is tested with the Archimedes principle, with deionized water as the soaking medium. For the specific steps, please refer to relevant literature (reference: Physical Testing and Chemical Analysis-Part A: Physical Testing: Methods for determining the density and porosity of ceramic materials. (2006): 42(6): 289-291).    2. The flexural strength is tested with the flexural strength tester to measure the average flexural strength value of three points, with a span of 40 mm and a loading speed of 0.5 mm/min. As for the specific test steps, please refer to the national standard GB/T1965-1996 (reference: the national standard of the People's Republic of China: Test method for the flexural strength of porous ceramics (GB/T1965-1996), released on Sep. 13, 1996 and implemented on Apr. 1, 1997).    3. The pore size is tested with the gas bubble pressure method, with deionized water as the wetting agent. As for the specific test steps, refer to the relevant literature (reference: Inorganic Membrane Separation Technology and Application, by Xu Nanping, Xing Weihong and Zhao Yijiang, Chemical Industry Press, 2003, 21-22).    4. The test method of the gas permeation performance is to test the gas flow at the infiltration side under different pressures, using a gas-solid separation device made by the lab (reference: Preparation and Characterization of Porous Materials, by Chen Yong, China University of Science and Technology Press, 2010, 249-250).
In comparison with the existing preparation techniques, the zircon-SiC porous ceramics prepared in the invention has the following positive effects:    (1) Improve the strength of porous ceramics to ensure its application in the actual process.    (2) Provide a method for the preparation of high-strength porous ceramics, and provide an idea for the preparation of other porous ceramic materials.    (3) Prepare high-porosity new-type SiC porous ceramic materials, improve their gas permeability and expand their practical applications.

Preparation method of SiC porous ceramic material and porous ceramic material manufactured by using same


A wireless mesh access point receives a first notification of firmware download availability. In response to the first notification, the wireless mesh access point downloads a firmware file from a peer from which the first notification was received. The wireless mesh access point loads the downloaded firmware file into a firmware memory associated with operation of a processor. The wireless mesh access point then transmits a second notification of firmware download availability to one or more other peers.

A wireless network is a digital communications network that allows a wireless network device to communicate with or access a computer network via a radio communication link. For a number of years, the most common type of wireless network has been that which is commonly referred to as "WiFi" or "802.11," the latter term in reference to the IEEE 802.11 set of standards that govern such networks. Such an 802.11 network comprises one or more access points (APs) that are each connected by a wired connection with a router or similar networking device. The router or other such networking device allows a client device, such as a portable computer, smartphone, etc., to communicate with or access a computer network. It is common for the networking device to provide the client device with a connection to the Internet.
A wireless mesh network is a digital communications network comprising APs organized in a mesh topology, where each AP can communicate via radio communication links in a peer-to-peer manner with other such APs in the network. Each AP can receive a message from another (peer) AP and forward or relay the message to still another (peer) AP. The message reaches its ultimate destination via one or more such relays or "hops" as they are commonly referred to in the art. In a client-server computing system, the source and destination of a message is generally a client device or a server device. Wireless mesh networks provide numerous benefits over other types of wireless networks, including redundancy. For example, if a wireless mesh AP is removed from operation in the network, it may still be possible for messages that would have been routed via that AP to reach their destinations via alternative routes. A route through the wireless mesh network between an AP and the controller via one or more hops can be referred to as an uplink. Wireless mesh networks can employ radio technology and protocols that are similar to those employed in non-mesh wireless networks, such as those governed by IEEE 802.11. A set of standards known as IEEE 802.11s relates more specifically to wireless mesh networks and is an extension of the IEEE 802.11 set of standards.
A subset of the wireless mesh APs in a network may also be wireless mesh portal APs. A wireless mesh portal AP not only can communicate via wireless communication links with peers but also can communicate via wired connections with management systems or gateways to other networks, such as the Internet.
A wireless mesh AP includes a processing system that operates under control of firmware stored in a non-volatile memory. From time to time, system administrators may wish to update the firmware of the wireless mesh APs in the network. Using a management system, the system administrator can transmit a notification to each wireless mesh AP in the network that indicates a firmware update is available for download. In response to this notification message, each wireless mesh AP initiates a process in which the firmware is downloaded from the management system to the AP memory. The firmware image or file may take multiple hops through intermediary APs before reaching the destination AP that initiated the download and that stores the firmware image in its memory. A given intermediary AP may, in some instances, relay the same firmware image multiple times in association with downloads initiated by different APs.
The above-described method by which firmware updates are performed in a wireless mesh network may be inefficient and uneconomical. For example, contention among wireless mesh APs for wireless communication link bandwidth can slow the process. Also, for example, in some instances an owner or operator of the wireless mesh network may incur a monetary cost (e.g., a bandwidth usage charge) each time a firmware image is downloaded from a source via the Internet. It would be desirable to provide firmware updates in a manner that may be more efficient and economical.

Wireless mesh network firmware upgrade system and method