A cover member of an ultrasonic sensor has a first engagement portion and a second engagement portion, which are respectively engaged with a third engagement portion and a fourth engagement portion of a sensor body. The engagement portions are arranged in such a manner that a force applied to the cover member due to an engagement between the first engagement portion and the third engagement portion and a force applied to the cover member due to an engagement between the second engagement portion and the fourth engagement portion respectively have opposite directions to be substantially countervailed when the sensor body is attached to the cover member. Thus, the cover member can be restricted from slanting when the sensor body is fixed to the cover member.

Generally, an ultrasonic sensor is provided with a sensor body, which has an ultrasonic transducer and is attached to a bumper of a vehicle. The ultrasonic transducer generates ultrasonic wave. By receiving reflection wave of the ultrasonic wave, an obstacle near the bumper is detected.
For example, with reference to JP-2003-9270A (U.S. Pat. No. 6,759,950), FIG. 12 is a partially sectional view showing a mounting construction for fixing a conventional ultrasonic sensor 100 to a bumper 101. As shown in FIG. 12, a sensor body 102 of the ultrasonic sensor 100 has a circular column shape. By inserting the sensor body 102 in a circular hole 101a arranged at the bumper 101 from the outside of the bumper 101, the sensor body 102 is fixed to the bumper 101.
Specifically, the sensor body 102 has a flange 102a which is positioned at the rear end thereof in the insertion direction of the sensor body 102 to the bumper 101. A V-shaped metal spring 103 is provided around the outer periphery of the sensor body 102.
Thus, when the sensor body 102 is inserted through the hole 101a of the bumper 101, the expanding force in the diameter direction of the sensor body 102 generated by the metal spring 103 is applied to the wall face constructing the hole 101a of the bumper 101, in such a state that movement in the insertion direction of the sensor body 102 is regulated by the flange 102a. Thus, the sensor body 102 is substantially fixed to the bumper 101.
In recent years, the ultrasonic sensor is becoming intelligent, and a circuit board on which not only the ultrasonic transducer but also a signal processing circuit and the like are arranged is being housed in the sensor body. Thus, the sensor body is enlarged, and there occurs a problem that the sensor body cannot be inserted through the hole of the bumper from the outside of the bumper. Therefore, it is necessary to fix the ultrasonic sensor to the bumper by a structure different from the conventional structure.
In order to solve the above-described problem, the following construction is considered by the inventors of the present invention. That is, with reference to FIG. 13, a bezel 4 (cover) which has a cylindrical shape and has a flange 4a at one end thereof is provided. The bezel 4 is inserted from the outside of a bumper 2 into a hole 2a of the bumper 2, to be fixed to the bumper 2. Thereafter, a circular column portion in which an ultrasonic transducer of the sensor body 3 is disposed is inserted in a hollow portion of the bezel 4 from the inside of the bumper (that is, in direction opposite to insertion direction of bezel 4 to hole 2a of bumper 2), so that the sensor body 3 is fixed to the bumper 2 via the bezel 4.
In this case, because it is necessary to hold the sensor body 3 having a large size at the bezel 4 which functions as a fixing member, the bezel 4 is to be firmly fixed to the bumper 2 and the sensor body 3 is to be firmly fixed to the cover member 4.
Therefore, as shown in FIG. 13, it is proposed by the inventors of the present invention to provide a snap fit 4b, a nail portion 3z, a lance 38 and a hole portion (not shown) which is engaged with a nail portion 38b of the lance 38 and positioned at the upper side (with respect to up-down direction of drawing of FIG. 13) of the bezel 4. In this case, the snap fit 4b has a hole portion (not shown) positioned at the lower side (with respect to up-down direction of drawing of FIG. 13) of the bezel 4. The nail portion 3z is engaged with a hole portion 4z of the snap fit 4b, and positioned at the lower side of the sensor body 3. The lance 38 which is provided with the nail portion 38b is positioned at the upper side of the sensor body 3.
In this case, when the sensor body 3 is fixed to the bezel 4, the nail portion 38b of the lance 38 contacts the outer surface of the side wall of the bezel 4 so that the lance 38 is elastically deformed. When the nail portion 38b of the lance 38 comes to the hole portion of the bezel 4, the shape of the lance 38 recovers so that the nail portion 38b enters into the hole portion. Thus, the nail portion 38b is engaged with the hole portion.
Similarly, the snap fit 4b is pressed by the nail portion 3z of the sensor body 3 to be elastically deformed. When the hole portion 4z of the snap fit 4b comes to the nail portion 3z, the shape of the snap fit 4b recovers so that the nail portion 3z enters the hole portion 4z. Thus, the nail portion 3z and the hole portion 4z are engaged with each other. Thus, the bezel 4 and the sensor body 3 can be further firmly fixed via the lance 38, the snap fit 4b and the like.
However, in the above-described construction, as indicated by the arrow in FIG. 13, an elastic reaction force of the lance 38 is applied to the bezel 4 in a direction facing the lower side, and a force pressing the snap fit 4b by the nail portion 3z is applied in a direction facing the lower side. Therefore, the two forces are applied to the bezel 4 in the same direction. Thus, the cover member 4 is susceptibly slanted.
Similarly, there also occurs the problem in the case where the ultrasonic sensor is mounted to a vehicle component other than the bumper.


A rotary seal (10) for a fluid handling machine comprising first circular body (12) with circumferential surface (28) and second circular body (16) with similar surface (27), such that the bodies when coaxially assembled, the circumferential surface (28) and similar surface (27) mate with each other forming a sealing surface contact. An internal end face (33) of rotary seal (10) is exposed to fluids with an inclination, such that the fluid pressure on internal end face (33) adds to contact force at sealing contact surface. The first circular body (12) is continuous and second circular body (16) with a split (17) has a spring characteristic such that two ends formed by the split (17), force away from each other, hence exerting a radial force on circumferential surface when assembled with first circular body (12) and compensating for circumferential wear during operation. The second circular body (16) exerts combination of axial, radial and tangential forces on circumferential surface (28) which results in force closure at sealing surface contact.

The usage of mechanical seals is well known in fluid handling machines like pumps, fluid motors etc., and the sealing is generally accomplished by contact pressure between two highly polished surfaces of, a seal stator fitted on machine casing and a seal rotor mounted on machine rotor or shaft. Sealing is achieved in these conventional mechanical seal in two directions namely—the radial direction perpendicular to the machine rotor or shaft axis and along the shaft surface in the axial direction. However the peripheral surface area of machine rotor or shaft, that faces the portion of casing thickness where the seal stator element is supported and the portion of the seal stator thickness which bears the rotor element of the seal, is exposed to fluid during operations. The fluid gets trapped at the clearance between the casing and the machine rotor in the area between 'casing inner end edge' and the 'contact sealing surface point'. The amount of fluid trapped depends on above mentioned clearance, surface area at mentioned clearance and the operating fluid pressure. The trapped fluid is thwarted from leaking to spaces outside the casing of the fluid handling machine by the mechanical seal, however the trapped fluid connects the fluid spaces entrapped between casing and rotor and segregated by the rotor body elements that characterizes rotary machine and project radial from the rotor body or are fitted on the rotor to work on or be worked upon by working fluid within the fluid handling machine during operation like gears teeth, vanes etc. These spaces are not effectively sealed from each other and hence reducing volumetric efficiency and reducing performance. These leakages also render loss in compression in rotary engines resulting in inability of engine to attain combustion. Generally the quantity of mentioned trapped fluid is reduced by the 'rotor body end surface' inside the casing/stator, that shrouds rotor/shaft peripheral surface clearance at the seal area to avoid direct exposure to internal fluid, for example in gear pumps the Dedendum circle is of greater diameter than the puncture in the casing at rotor penetration point where the mechanical seal is fitted. The greater diameter shrouds the casing penetration area and a very fine working clearance between 'rotor body end surface' and casing is maintained, which provides an effective end face barrier that reduces leak off to periphery surfaces of rotor at sealing areas in fluid handling machines. The requirement of shrouding of casing at the seal stator holding area, constraint's the volume maximisation of segregated fluid space volume that is desired for maximising fluid throughput in fluid handling machines of given size and volume. It also hinders reduction in rotor body material quantity, weight and size. These limitations and draw backs that detrimentally influence volumetric efficiency, compression, sustaining of combustion & fluid throughput. It limits the optimization of parameters like weight, size, volume and cost of material in fluid handling machines due to usage of conventional mechanical seals.
It is therefore advantageous to provide an improved means of sealing which overcomes the aforesaid problems, and/or provides various other benefits and advantageous.

3 directional rotary seal for fluid handling machines


A printed circuit board (PCB) includes a ground layer, a first layer, a second layer, a connector footprint, and a pair of differential signal lines. The connector footprint comprises first and second bonding pads. The PCB defines a first signal via in a central portion of a space bounded by the first bonding pad, and a second signal via in a central portion of a space bounded by the second bonding pad. A number of first ground vias on the first bonding pad and a number of second ground vias on the second bonding pad are electrically connected to the ground layer. First annular slots surrounding corresponding first ground via are defined in the ground layer. Second annular slots surrounding corresponding second ground vias are defined in the ground layer. Connection slots are defined in the ground layer and communicate between the first annular slots and the second annular slots.

1. Technical Field
The present disclosure relates to a printed circuit board.
2. Description of Related Art
Differential mode signals have a higher tolerance than common mode signals. Because of structural requirements of footprints of connectors, differential mode signal lines require a single-ended signal line, which may cause noise.
Therefore, there is room for improvement in the art.

ShenZhen Goldsun Network Intelligence Technology Co., Ltd.


A high-Cr, high-Mo duplex stainless steel having excellent corrosion resistance as well as improved toughness and workability has a chemical composition which consists essentially, on a weight basis, of C: 0.03% or less, Si: 0.4% or less, Mn: 2.0% or less, Cr: 26.0-30.0%, Ni: 5.0-9.0%, Mo: 3.0 -4.5%, N: 0.10-0.35%, Al: 0.01-0.04%, optionally one or both of Cu and W in a total amount of 0.05-3.0% and/or one or more elements selected from Ca, B and Ce in a total amount of 0.001-0.01%, and a balance of Fe and incidental impurities, wherein the following inequality (1) is satisfied: EQU -1.5.ltoreq.PBI.ltoreq.1.5 (1) EQU where PBI=14.times.(Ni.sub.eq -0.61.times.CR.sub.eq +2.8)/(Cr.sub.eq -6) EQU Ni.sub.eq (%)=Ni+0.5.times.Mn+30.times.(C+N){+Cu} EQU Cr.sub.eq (%)=Cr+1.5.times.Si+Mo{+0.5.times.W}.. The steel is prepared by packing a gas-atomized powder of the steel composition into a metal container, sealing the metal container, and compacting and sintering the steel powder by applying hot working or a combination of hot working and cold working to the container.

The present invention relates to a duplex stainless steel having excellent corrosion resistance in a chloride-containing solution as well as improved toughness and workability, and a process for the production thereof.
Recent developments in the gas atomization process to prepare stainless steel powder and the powder compaction process to produce stainless steel products make it possible to produce those stainless steels which are difficult to manufacture by a conventional melting method which includes melting, casting and forging.
Duplex stainless steels are known to have high strength and excellent resistance to pitting corrosion, crevice corrosion, and stress-corrosion cracking, and they are nevertheless less expensive than austenitic stainless steels. Typical commercially-available duplex stainless steels contain 18 -26% Cr, 4 -8% Ni, and 1 -3% Mo. As the field of applications of duplex stainless steels is expanded, further improvements in their properties have been desired.
For example, it is possible to further improve the corrosion resistance of a duplex stainless steel by increasing the Cr and Mo contents thereof. However, when it is prepared by a conventional melting process, the formation of intermetallic compounds occurs inevitably, thereby causing a decrease in toughness of the steel.
Japanese Patent Applications Laid-Open Nos. 61-243149(1986) and 62-222043(1987) disclose the production of high-Cr, high-Mo duplex stainless steels by the powder metallurgy method, i.e., a combination of the above-described gas atomization and powder compaction processes, which eliminates embrittlement of the stainless steel products caused by precipitation of intermetallic compounds. The precipitation of intermetallic compounds during preparation of such stainless steels was thought to be unavoidable in a conventional melting process. In contrast, application of the powder metallurgy method makes it possible to realize an increase in the Cr and Mo contents of a duplex stainless steel, which is desired for such a steel, without precipitation of intermetallic compounds.
Japanese Patent Application Laid-Open No. 62-56556(1987) describes the preparation by the melting method of a high-Cr, high-Mo duplex stainless steel containing 23% -27% Cr and 3.5%-4.9% Mo by weight. However, the Cr content of suc virtually limited to 25% by weight or less in order to prevent the formation of chromium nitride and intermetallic compounds. Therefore, it is not ensured that the steel has fully improved corrosion resistance.
The production of stainless steel powder by the gas atomization process is normally conducted either (1) by merely remelting a previously-prepared master alloy in an inductionheating furnace to form a molten alloy, which is then forced through a small orifice by a rapid stream of an inert gas for atomization (remelting method), or (2) by melting individual alloying metals together in a similar furnace in which the proportions of the alloying metals are adjusted so as to form a molten alloy having the desired alloy composition, followed by atomization in the above manner (melting method).
In the case of a high-Cr, high-Mo duplex stainless steel, it is difficult to previously prepare a master alloy for remelting since it is brittle and difficult to work by forging or other means into a prescribed shape of a master alloy. Therefore, the above-described method (2) is solely employed in the preparation of a powder of such a duplex stainless steel.
According to this method, however, refining treatment such as desulfurization or deoxidation can normally not be performed on the resulting molten alloy during melting in an inductionheating furnace. Therefore, particularly in the preparation of a high-Cr, high-Mo stainless steel powder, this method tends to give a steel powder product having an increased oxygen content due to a high susceptibility of chromium to oxidation. As a result, the resulting powder has a decreased hot workability and therefore it is difficult to compact into a desired shape by means of hot working. In addition, the amount of inclusions formed in the resulting steel is so increased that the cleanness and hence the corrosion resistance of the steel are degraded. In order to produce a steel powder having a decreased oxygen content, it is necessary not only to control the surrounding atmosphere but also to use pure alloying metals as raw materials. However, unlike a laboratory experiment, it is difficult for industrial-scale production of stainless steel powders to meet such conditions.
Furthermore, although the use of the powder metallurgy method in the production of a high-Cr, high-Mo duplex stainless steel can produce a compacted body without embrittlement due to precipitation of intermetallic compounds, the subsequent cooling of the compacted body is accompanied by precipitation of intermetallic compounds. Therefore, in this method as well, the product is brittle and is difficult to transport and subject to cold working and machining.

Duplex stainless steel having improved corrosion resistance


An invention for polymerizing or crosslinking a prepolymer using a water soluble, thermal polymerization initiator is disclosed. The prepolymer mixed with the initiator is injected or placed into an animal's body, and heat is applied over the site of the injection to polymerize the polymer. This transdermal thermal polymerization system can be used for drug delivery of bioactive agents in tissue engineering applications in which living cells are delivered.

The present invention relates to a minimally invasive system to achieve transdermal crosslinking or polymerization of hydrogels or other polymers for use in drug delivery or tissue engineering.
Fabricating polymers in situ provides many advantages over using preformed polymers for a variety of biomedical applications including drug delivery and tissue engineering. Prepolymerized liquid solution or moldable putties can be placed in an exact location and/or molded into complex shapes. Subsequent polymerization of the prepolymer yields a polymer of exactly the required shape and dimensions in the desired location. However, the formation of polymers in situ presents many challenges. Polymerization reactions which frequently occur by free radical reactions are quite adverse to physiological conditions including a narrow range of acceptable temperatures, requirement for nontoxic monomers and/or solvents, moist and oxygen-rich environments, and the need for rapid processing and clinically suitable rates of polymerization (Elisseeffet al., Proc. Natl. Acad. Sci. USA 96:3104–3107, 1999).
In the field of drug delivery, the implantation of a drug delivery device often involves a surgical procedure to place a formed drug-laden implant into a recipient's body at a desired site. These devices are usually made of a polymer impregnated with a bioactive agent to be delivered and are formed into shapes such as a sphere, cylinder, fibers, slab, or oval. The formed nature of these devices can lead to local irritation and inflammation at the site of implantation. As the polymer of the formed implant is degraded, the agent is gradually released in a controlled manner over an extended period of time. However, with the increased demand to minimize hospitalization stays and decrease patient morbidity, a drug delivery system which would require only a small incision or eliminate the need for a surgical procedure altogether would be very useful.
In the field of tissue engineering, many reconstructive plastic surgical procedures to correct deformities, whether traumatic or congenital, require invasive surgical techniques to place alloplastic prostheses. Griffith-Cima et al. in WO 94/25080 describe the use of injectable polysaccharide-cell compositions for delivering isolated cells by injection, which then form new tissue that is effective as a bulking agent. Sims et al. (Plastic Reconstructive Surgery 98:845, 1996) reported the formation of new cartilage from injected polyethylene oxide-cell suspensions and suggested that this technology would be useful in plastic surgery. A prosthesis which is formed in situ would eliminate the need for invasive surgical techniques.
A method of forming polymers in situ using photopolymerizaton of polymers which form semi-interpenetrating or interpenetrating polymer networks was described in U.S. Patent Application U.S. Ser. No. 08/862,740 by Langer et al. According to this application, one injects into a recipient's body a prepolymer solution which can be crosslinked, and then light is applied externally to the skin to crosslink the injected polymer. With the aid of a photoinitiator, the polymer will crosslink with an amount of light equivalent to 1–3 mW/cm2 applied to the skin of nude mice. The polymer solution may consist of living cells for tissue engineering applications or may contain a bioactive agent for drug delivery applications. Disadvantages of using photopolymerization include exposing the patient and the living cells (in the case of tissue engineering) to potentially harmful ultraviolet rays and the difficulty of providing electromagnetic radiation to most sites within the body.
Other implantable delivery systems are known such as those disclosed by Dunn et al. in U.S. Pat. Nos. 5,739,176; 5,733,950; 5,340,849; 5,278,202; 5,278,201; and 4,938,763. In Dunn's system, a syringeable, in situ forming, solid biodegradable implant is formed in the recipient's body either by 1) the diffusion of a solvent, in which a polymer is dissolved, away from the polymer to produce the implant; or 2) the addition of a curing agent such as benzoyl peroxide or azobisisobutyronitrile to the prepolymer suspension prior to injection. A major drawback to this approach is the use of organic solvents such as N-methyl-2-pyrrolidone, dimethylformamide, and THF which can be toxic or irritating to body tissues. Another drawback is the rapid rate at which the curing agent polymerizes the implant even at room temperature. Therefore, the injection of the prepolymer suspension mixed with the curing agent must take place immediately after addition of the curing agent.
The instant invention avoids the use of organic solvents and ultraviolet radiation which can be harmful, and polymerization and formation of the implant does not take place at an appreciable rate until desired.


A method and apparatus wherein a plurality of functions are implemented on a multimedia presentation device. A user can access several of the functions by depressing a single button. A particular function is specified by the duration of the button depression. For one embodiment the functions affect a favorite program list and allow a user to access the list, update the list, and delete entries from the list depending upon button depression duration. For example, the user may depress button number (#) 3 of a remote control device. A brief depression (e.g., less than 1 second), results in the remote control interpreting this click as a digit for selecting a channel, and the system will tune to channel #3. A longer depression (e.g., between 1 and 2 seconds), results in the system recalling previously programmed selection #3. Likewise, other functions are implemented by depression the button for various durations.

Multimedia interactive presentation devices such as television viewing systems (e.g., Cable TV, digital TV, Satellite, and set top box) or personal video recorders (PVRs) typically provide limited functionality in some areas. Additionally, the functionality that is provided is often cumbersome difficult and/or time consuming to use.
For example, one problem facing viewers is how to peruse the vast number of available channels. A user might scroll through the hundreds of available channels to select a channel, but this may require an unacceptable amount of time (e.g., hours) just to complete one round of channel surfing.
Recent developments to aid searching for programs include an interactive program guide (IPG), which is now well known to those skilled in the art. Such IPGs may have features to aid the viewer in searches for programs of interest. Using an IPG, while somewhat more convenient, may require the viewer to go through multiple menu layers. The menus are provided by the system operator for searching future broadcasts. Typically a user may have to go through two or more menu layers to get to the point of searching. Then specific search information must be entered such as title, time, content, etc. This may require the user to input dozens of keystrokes. At this point the user may be several menu layers deeper. Not only may the user not wish to take the time and effort to do such complex navigation, but it often takes time to extricate oneself from the multiple layer menu.
FIG. 1 shows a typical channel line-up 100, as would be displayed in an IPG (not shown) on a TV screen or similar display (also not shown). In this example, channels 1 through 7, 12, and 13 are available, so when the viewer presses the channel up and channel down buttons, which define a linear navigation scroll space 101 with multiple possible modes, he navigates among those channels in a linear manner. In some cases, the navigation wraps around from the last channel back to the first channel. However, as the number of available channels extends into the hundreds or even thousands (some satellite TV systems have now gone to four-digits channels, because they have used up their three-digit options) such a method for channel selection becomes very unwieldy.
Also available as a feature on some remote controls is a favorite channels list. To implement this feature, the viewer can, by using a special button on the remote control while browsing or viewing programs, select channels to be added as favorites. Then the viewer can roam just within those listed favorite channels. However, this may require the user to navigate through the multiple menu levels and then check a box for each desired channel. Such a favorite channels feature may also include a "last channel" button to allow the user to return to the immediate previous favorite channel. For example, for a favorite channel list having ten preferred channels, if the user is at number 6 in their list, the last channel button will return them to favorite channel number 5. However to go back to favorite channel number 4, the user will typically have to move forward through the list of favorites (e.g., through numbers 7, 8, and 9,) and then progress from zero to number 4. Such limitations on functionality are time-consuming and annoying.
What is needed is an easier and more intuitive way for the viewer to access available functionality to navigate more efficiently among the multitude of channel and/or program selections.

Multimedia interactive device function selection based upon button depression duration


A distributed network of interactive agents is provided wherein remote agents interact with a central computer and with one another through an object based parallel modeling language and/or an aggregate modeling language using an open client-server architecture, which enables many users to control the behavior of individual objects or agents and to view the aggregated results on a central computer. This network of agents is integrated with a powerful suite of modeling, analysis and display tools that together give agents the capacity to “fly” the system in intuitive mode, to reflect on the emergent result of their simulation and, also, to encode their strategies as rules which the system can then run independently.

1. Technical Field
The present invention relates to the field of computer systems. In one aspect, the present invention relates to a network-based architecture for enabling individual agents to interactively model and simulate complex dynamic systems. The present invention can be beneficially applied in many applications, including enabling participatory simulations of complex dynamic systems to model emergent activities of the system.
2. Description of Related Art
Conventional participatory simulations are simulations whereby individual agents act out the roles of individual system elements and then see how the behavior of the system as a whole emerges from these individual behaviors. The emergent behavior of the system and its relation to individual participant actions and strategies can then become the object of collective discussion and analysis.
An early example of a participatory simulation that was used in the context of systems dynamics and systems learning was The Beer Game as developed by Jay Forrester and his systems dynamics group at MIT in the early 1960's. The game does much to highlight the ways in which costly unintended behaviors of a system (in this case beer inventory in a distribution system) can emerge from participants attempting to act rationally in their localized role (e.g., as beer retailer, wholesaler, distributor, or producer). A number of other participatory simulation applications were developed at this time, an example of which was FishBanks (Meadows, 1986), that was developed as an "interactive, role-playing simulation in which groups are asked to manage a fishing company." In FishBanks, students try to maximize their assets in a world with renewable natural resources and economic competition. These programs are examples of an aggregate modeling approach to participatory simulation.
More recently, new classes of so-called "object-based" simulation activities have been developed (Resnick & Wilensky, 1993; 1998; Wilensky & Resnick, 1995). In these so-called "StarPeople" activities, participants typically play the role of "ants" in an anthill simulation, moving around the room and exchanging "messages." After participating in these StarPeople activities, students observe the emergence of global patterns from their local interactions. These pattern become the objects of reflection and discussion.
Throughout much of the history of participatory simulations, computational technologies have played a central role. For example, a class of computational "flight simulators" were developed at MIT to be used by individuals and groups of managers to gain experience flying a complex dynamic system like a modern business. More recently, multi-player networked versions of the beer game have been implemented (Coakley et al, 1995) and it is now even possible to immerse oneself in a multi-player versions of the game on the Internet (Powersim Corporation, 1998). A multi-player calculator-based version of the beer game participatory simulation also has been implemented and used with both school-aged and adult learners (Wilensky & Stroup, 1998, 1999). Management trainers have argued that there is a need for a tighter coupling between computer simulations and user experience. In possibly the first known use of the term participatory simulations, Diehl (1990) constructed systems that gave users more control over and participation within the simulations by allowing users to input more real word decisions and view output of familiar reports. These simulations were modeled using "aggregate" finite-difference tools like STELLA.
In contrast to the "aggregate" finite-difference computer modeling tools used to analyze simulations like The Beer Game, object-based parallel computer modeling languages (OBPML), such as StarLogo and StarLogoT (Resnick, 1994; Wilensky, 1995; 1997b), have previously been developed. For example, Borovoy, Colella and fellow researchers at MIT (Colella et al, 1998; Borovoy et al, 1996; 1998) have developed wearable computational badges (or "thinking tags") that allow users to move freely while communicating information between badges. Colella (1998) developed, implemented and researched student learning with one of the first instances of a participatory simulation supported by a thin layer of computing technology. Disease propagation models have been implemented by a number of researchers and curriculum developers (Colella et al, 1998; Stor & Briggs, 1998).
Further limitations and disadvantages of conventional systems will become apparent to one of skill in the art after reviewing the remainder of the present application with reference to the drawings and detailed description which follow.

Distributed agent network using object based parallel modeling language to dynamically model agent activities


The present invention is directed to methods and apparatus that use electrostatic and/or electromagnetic fields to enhance the process of spray forming preforms or powders. The present invention also describes methods and apparatus for atomization and heat transfer with non-equilibrium plasmas. The present invention is also directed to articles, particularly for use in gas turbine engines, produced by the methods of the invention.

Spray forming is a process by which a stream of molten metal is atomized by a gas stream impinging upon it. The resulting atomized droplets are then directed to a target by the gas stream, or the resulting atomized droplets are cooled to form a powder. Producing powders by typical prior spray forming methods results in a yield loss of 10-15%, and much of the loss is associated with powder being trapped in various areas of the apparatus rather than being delivered to the collection vessel during the process. In producing solid workpieces, known as preforms, typical prior spray forming methods result in a yield loss of 25-40%, and a significant portion of the loss is usually caused by over-spray and particles bouncing off the surface due to their angular impact relative to the normal of the preform surface. Various methods have been described to recover and reuse overspray powder, such as, for example, U.S. Pat. No. 5,649,993, but these are not wholly satisfactory.
Because many powders and preforms are susceptible to damage to their chemical structure by air and oxygen, they are often produced in a shield gas environment of nitrogen or argon. The flow of shield gas, however, must be turned off to allow workers to enter the chamber for cleanup, changeover and maintenance. Thus, any powder or preform remaining in the chamber becomes contaminated and unusable when air and oxygen enter the spray forming apparatus after the flow of shield gas is turned off.
Previously, gas streams or jets have been used to direct the path of the particles involved in the spray forming process. The gas streams typically consist of argon or nitrogen as the means of directing the particles, and heat is removed from the workpiece through conduction or convection.
Current processes for making powder metal products, particularly in materials used for critical aerospace applications, use a conventional gas atomizing process. In this process, high-pressure gas is directed at a molten metal stream to break it into smaller droplets. The droplets solidify as powder. For critical applications, the resultant powder is then blended with batches of powder from other small melts. The blend is screened to a small mesh size (325 mesh), canned and consolidated by extrusion into product suitable for manufacture into an aircraft component. This method of manufacture is not efficient because several small melts are required for blending, melts are made in conventional ceramic lined furnaces and hence result in oxide contamination, several powder handling operations offer opportunity for contamination, and many steps in the process make the production operation costly.
Heat transfer using non-equilibrium plasmas has heretofore been poorly understood and often incorrectly or inefficiently applied. There is a need in the art for methods and apparatus that improve the yield and quality of powders and preforms produced by spray forming. The present invention is directed to these, as well as other, important ends.

This patent is subject to a terminal disclaimer.

Methods and apparatus for spray forming, atomization and heat transfer


A flash memory device, such as a NAND flash, having an array of floating gate transistor memory cells arranged in a first and second addressable blocks. A voltage source to supply programming voltages to control gates of the floating gate transistor memory cells is provided. The voltage source supplies a pre-charge voltage to the control gates of the floating gate transistor memory cells located in the first addressable block when data is programmed in memory cells of the second addressable block. Methods for pre-charging word lines in unselected array blocks are included.

Flash memory is non-volatile, which means that it stores information on a semiconductor in a way that does not need power to maintain the information in the chip. Flash memory is based on the Floating-Gate Avalanche-Injection Metal Oxide Semiconductor (FAMOS transistor) which is essentially a Complimentary Metal Oxide Semiconductor (CMOS) Field Effect Transistor (FET) with an additional conductor suspended between the gate and source/drain terminals. Current flash memory devices are made in two forms: NOR flash and NAND flash. The names refer to the type of logic used in the storage cell array. Further, flash memory stores information in an array of transistors, called "cells", each of which traditionally stores one or more bits of information.
A flash cell is similar to a standard MOSFET transistor, except that it has two gates instead of just one. One gate is the control gate (CG) like in other MOS transistors, but the second is a floating gate (FG) that is insulated all around by an oxide layer. The FG is between the CG and the substrate. Because the FG is isolated by its insulating oxide layer, any electrons placed on it get trapped there and thus store the information.
When electrons are trapped on the FG, they modify (partially cancel out) an electric field coming from the CG, which modifies the threshold voltage (Vt) of the cell. Thus, when the cell is "read" by placing a specific voltage on the CG, electrical current will either flow or not flow between the cells source and drain connections, depending on the Vt of the cell. This presence or absence of current is sensed and translated into 1's and 0's, reproducing the stored data.
For reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need for methods and devices to program floating gate transistors.


A phased array includes a laminar substrate having both 1) a plurality of elements forming a patch phased array, and 2) a plurality of integrated circuits. Each integrated circuit is configured to control receipt and transmission of signals by the plurality of elements in the patch phased array. The integrated circuits also are configured to operate the phased array at one or more satellite frequencies—to transmit signals to and/or receive signals from a satellite. Each integrated circuit physically couples with one corresponding element so that incoming signals are received by the corresponding element in a first polarization, and outgoing signals are transmitted by the corresponding element in a second polarization. The phased array isolates the transmit signals from the receive signals by orienting the first and second polarizations differently.

Antennas that emit electronically steered beams are known in the art as "phased array antennas." Such antennas are used worldwide in a wide variety of commercial and radar applications. They typically are produced from many small radiating elements that are individually phase controlled to form a beam in the far field of the antenna.
Among other things, phased array antennas are popular due to their ability to rapidly steer beams without requiring moving parts. One problem, however, is their cost. They can cost on the order of $1000 per element. Thus, for a 1000 element array, the cost can reach or exceed $1,000,000.

Laminar phased array with polarization-isolated transmit/receive interfaces


There are provided a magnetic tunnel junction structure and a method of fabricating the same. The magnetic tunnel junction structure includes a lower electrode, a lower magnetic layer pattern and a tunnel layer pattern, which are sequentially formed on the lower electrode. The magnetic tunnel junction structure further includes an upper magnetic layer pattern, a buffer layer pattern, and an upper electrode, which are sequentially formed on a portion of the tunnel layer pattern. The sidewall of the upper magnetic layer pattern is surrounded by an oxidized upper magnetic layer, and the sidewall of the buffer layer pattern is surrounded by an oxidized buffer layer. The depletion of the upper magnetic layer pattern and the lower magnetic layer pattern in the magnetic tunnel junction region can be prevented by the oxidized buffer layer.

1. Field of the Invention
The present invention relates to a magnetic tunnel junction structure and a method of fabricating the same, and more particularly, to a magnetic tunnel junction structure having an oxidized buffer layer, and a method of fabricating the same.
2. Description of the Related Art
Semiconductor memory devices for storing information are normally classified into volatile memory devices and non-volatile memory devices. Whereas the volatile memory devices lose stored information therein when a power supply is shut off, the non-volatile memory devices still keep stored information even when a power supply is shut off. Such non-volatile memory devices including flash memory devices, ferroelectric random access memory (FeRAM) devices, and magnetic random access memory (MRAM) devices are typically used in memory cards, mobile phone communication terminals, and other electronics products in order to keep stored information therein, and to reduce power consumption.
The MRAM device includes a plurality of memory cells employing magnetic tunnel junction (MTJ) structures. The MTJ structure includes a lower magnetic layer pattern, a tunnel layer pattern and an upper magnetic layer pattern, which are stacked on a lower electrode. In accordance with the magnetization direction of the lower magnetic layer pattern and the upper magnetic layer pattern, there occurs a difference in the current amount flowing through the tunnel layer pattern. The MRAM device stores information by changing the magnetization direction or using the difference of the lower magnetic layer pattern and the upper magnetic layer pattern.
Conventionally, such an MTJ structure is fabricated by sequentially forming a lower conductive layer, a lower magnetic layer, a tunnel layer, an upper magnetic layer and an upper conductive layer on a semiconductor substrate, and then, sequentially patterning them using an photolithography and etching technique to form a lower electrode, a lower magnetic layer pattern, a tunnel layer pattern, an upper magnetic layer pattern and an upper electrode.
However, while sequentially etching the upper magnetic layer and the lower magnetic layer, etch residues may occur and cause a short circuit between the upper magnetic layer and the lower magnetic layer. Said short circuit results in a device failure in an MRAM device and must be avoided.
A method for avoiding a short circuit between the upper magnetic layer and the lower magnetic layer due to etch residues is taught by Chen et al. in U.S. Pat. No. 6,165,803 in the title of "MAGNETIC RANDOM ACCESS MEMORY AND FABRICATING METHOD THEREOF", and taught by Signorini in U.S. Pat. No. 6,485,989 in the title of "MRAM SENSE LAYER ISOLATION". However, the method disclosed in the U.S. Pat. No. 6,485,989 causes a reduction in etch process margin because the tunnel layer becomes thinner because the upper magnetic layer should be etched such that the etching stops on the tunnel layer.
The method disclosed in the U.S. Pat. No. 6,165,803 includes etching an upper conductive layer (or mask layer), but the etching stops on an upper magnetic layer. Then, the exposed upper magnetic layer is changed into an insulating layer as will be described below.
FIGS. 1 to 3 are cross-sectional views illustrating a method of fabricating a magnetic tunnel junction structure in accordance with the U.S. Pat. No. 6,165,803.
Referring to FIG. 1, a lower insulating layer 13 is formed on a semiconductor substrate 11. A transistor (not shown) and a digit line (not shown) are formed on the semiconductor substrate 11. The lower insulating layer 13 insulates the digit line and the magnetic tunnel junction structure. In addition, the lower insulating layer 13 has a contact hole (not shown) and a plug (not shown) to electrically connect the magnetic tunnel junction structure and the transistor.
A lower conductive layer 15, a lower magnetic layer 17, a tunnel layer 19, an upper magnetic layer 21, and an upper conductive layer 23 are sequentially formed on the lower insulating layer 13.
Referring to FIG. 2, the upper conductive layer 23, the upper magnetic layer 21, the tunnel layer 19, the lower magnetic layer 17, and the lower conductive layer 15 are sequentially patterned to form a lower electrode 15a, a lower magnetic layer pattern 17a, a tunnel layer pattern 19a, a preliminary upper magnetic layer pattern 21a and an upper conductive layer pattern, which are sequentially stacked on the lower insulating layer 13.
Next, a new mask pattern is formed on the upper conductive layer pattern. The upper conductive layer pattern is then etched using the new mask pattern as an etch mask to form an upper electrode 23a. As a result, the upper surface of the preliminary upper magnetic layer pattern 21a is exposed.
Referring to FIG. 3, the exposed portion of the preliminary upper magnetic layer pattern 21a is oxidized or nitrified to form an inactive portion 21c. As a result, a final upper magnetic layer pattern 21b is formed in a magnetic tunnel junction region, while its sidewall is surrounded by the inactive portion 21c. Next, an upper insulating layer 25 is formed on the resulting structure having the final upper magnetic layer pattern 21b, and finally a bit line 27 is formed, to be electrically connected to the upper electrode 23a.
The method disclosed in the U.S. Pat. No. 6,165,803 decreases the likelihood of a short circuit between the final upper magnetic layer pattern 21b and the lower magnetic layer pattern 17a by using the technique of oxidizing or nitrifying the exposed portion of the preliminary upper magnetic layer pattern 21a.
However, this technique does have some limitations. The process for oxidizing the exposed preliminary upper magnetic layer pattern 21a must be performed at a low temperature to protect the final upper magnetic layer pattern 21b in the magnetic tunnel region. Therefore, this technique results in an undesirable and restrictive temperature requirement during the oxidation process.
Further, when forming the upper electrode 23a using a photolithography and etching technique, the photoresist pattern must be removed. In the removal process, an ashing technique using an O2 plasma gas is used. However, ashing is performed at a relatively high temperature that may exceed the aforementioned temperature requirement and thus deteriorate the final upper magnetic layer pattern 21b.
Furthermore, to meet the temperature requirement, the upper insulating layer 25 must be formed using a low temperature process, typically lower than 300° C. However, it is difficult to adequately form the upper insulating layer with a desired high density while using this low temperature process because at the low temperature the upper insulating layer has a tendency to be formed porous. As a result of a porous formation, the oxygen atoms from the O2 plasma used in the ashing technique may be diffused through the upper insulating layer 25 thus reaching and deteriorating the final upper magnetic layer pattern.
Accordingly, it is difficult to ensure process margins after the oxidation process and a subsequent ashing process required by this conventional technique. Embodiments of the invention address these and other limitations in the prior art.

Magnetic tunnel junction structure having an oxidized buffer layer and method of fabricating the same


An elastic exercise apparatus is provided including an interconnection housing. Further provided is an elastic lower closed loop connected to the interconnection housing for receiving feet of a user. Also included is an elastic upper closed loop connected to the interconnection housing for being strung about a rear portion of a neck of a user. By this structure, the loops provide a resistive force upon the user extending legs thereof during exercise.

1. Field of the Invention
The present invention relates to an elastic exercise apparatus and more particularly pertains to allowing the exercise of an individual while in a prone position.
2. Description of the Prior Art
The use of exercise apparatuses is known in the prior art. More specifically, exercise apparatuses heretofore devised and utilized for the purpose of facilitating various exercises are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
By way of example, the prior art includes U.S. Pat. No. 5,318,494 to Santighian; U.S. Pat. No. 4,245,840 to van Housen; U.S. Pat. No. 4,121,827 to Weider; U.S. Pat. No. Des. 350,576 to Richardson; U.S. Pat. No. 4,033,580 to Paris; and U.S. Pat. No. 4,057,246 to Wilson.
In this respect, the elastic exercise apparatus according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of allowing the exercise of an individual while in a prone position.
Therefore, it can be appreciated that there exists a continuing need for a new and improved elastic exercise apparatus which can be used for allowing the exercise of an individual while in a prone position. In this regard, the present invention substantially fulfills this need.


A child seat and a method for monitoring installation of the child seat are provided. The child seat includes a child seat frame configured to receive a child occupant. The child seat frame is configured to receive a seat belt webbing for securing the child seat frame to a vehicle seat. The child seat further includes a first bladder configured to contact the seat belt webbing. The first bladder has a fluid therein. The child seat further includes a first pressure sensor fluidly communicating with the fluid in the first bladder. The first pressure sensor is configured to output a first signal indicative of an amount of pressure in the first bladder. The child seat further includes a controller coupled to the child seat frame configured to receive the first signal and to compute a first tension value based on the first signal. The controller is further configured to generate a second signal to induce a first device disposed on the child seat frame to indicate when the first tension value is less than a first predetermined tension value.

Child seats have been utilized to hold infants or children therein within vehicles. During installation of child seats in a vehicle, if a sufficient amount of tension is applied to the vehicle's seat belt webbing to secure the child seat, rotation of the child seat with respect to a vehicle seat is restricted which assists in protecting a child disposed in the child seat. However, if an insufficient amount of tension is applied to the seat belt webbing when securing the child seat, the child seat may rotate more than desired during a sudden stop.
Accordingly, the inventors herein have recognized a need for a child seat that can notify a person when a desired amount of tension is being applied to seat belt webbing when securing a child seat on a vehicle seat.

Child seat and method for monitoring installation of the child seat


A two-beam semiconductor laser device 10 includes: a two-beam semiconductor element LDC having a first and a second semiconductor laser elements LD1 and LD2 that can be driven independently and that are formed integrally on a substrate; and a submount 63 having, mounted on a front part thereof, the two-beam semiconductor laser element LDC with the light-emitting face thereof directed forward and having a first and a second electrode pads 64 and 65 connected to electrodes 61 and 62 of the first and second semiconductor laser element LD1 and LD2 by being kept in contact therewith. The first and second electrode pads 64 and 65 are formed to extend farther behind the two-beam semiconductor laser element LDC, and wires 14 and 16 are wire-bonded behind the two-beam semiconductor laser element LDC.

As optical recording media, there have been known, among others, compact discs (CDs), recordable compact discs (CD-Rs), rewritable compact discs (CD-RWs), and as those offering higher recording densities, digital versatile discs (DVDs) and recordable DVDs. To record and play back, among these recording media, at least DVDs, CDs, CD-Rs, and CD-RWs, it is necessary to use, as the light source for optical pickups, one capable of emitting laser light of wavelengths 650 nm and 780 nm.
The laser light of a wavelength of 650 nm is for playback of DVDs, and the laser light of a wavelength of 780 nm is for playback of CDs and for recording and playback of CD-Rs and CD-RWs. The laser light of a wavelength of 650 nm may be used for recording of recordable DVDs. On the other hand, the recent demands for faster recording have been requiring higher-output light sources.
As a light source for incorporation in an optical pickup, there has been known a two-beam semiconductor laser device that can emit a laser light of wavelengths 650 nm and 780 nm from a single package. By incorporating a two-beam semiconductor laser device into an optical pickup, it is possible to make the optical pickup compact and to simplify the assembly thereof.
FIG. 6 and FIG. 7 are a front view and a perspective view respectively, showing a substantial part of a conventional two-beam semiconductor laser device. The two-beam semiconductor laser device 50 has a two-beam semiconductor laser element LDC mounted on a submount 63. The two-beam laser element LDC is integrated on a single substrate 51, with a first semiconductor laser element LD1 and a second semiconductor laser element LD2 formed separately from each other.
The substrate 51 is formed of, for example, n-type GaAs. The first semiconductor laser element LD1 is formed of, for example, an AlGaInP semiconductor, and outputs laser light of a wavelength of 650 nm. The second semiconductor laser element LD2 is formed of, for example, an AlGaAs semiconductor and outputs a laser light of a wavelength of 780 nm. The specific details of the structures of the first, AlGaInP, semiconductor laser element LD1 and the second, AlGaAs, semiconductor laser element LD2 are disclosed in Patent Publications 1 and 2, and therefore, in this respect, only a brief description thereof will be given below.
The first, AlGaInP, semiconductor laser element LD1 has an n-type AlGaInP semiconductor layer 52 formed on the n-type GaAs substrate 51. On the n-type AlGaInP semiconductor layer 52, a p-type AlGaInP semiconductor layer 53 is formed with a first junction layer 54 laid in between. The first junction layer 54 contains a single-quantum-well (SQW) or multiple-quantum-well (MQW) structure, and has part thereof formed into a first light-emitting portion 55.
Likewise, the second, AlGaAs, semiconductor laser element LD2 has an n-type AlGaAs semiconductor layer 56 formed on the n-type GaAs substrate 51. On the n-type AlGaAs semiconductor layer 56, a p-type AlGaAs semiconductor layer 57 is formed with a second junction layer 58 laid in between. The second junction layer 58 contains the same structure as the first junction layer 54, and has part thereof formed into a second light-emitting portion 59.
On the back face of the substrate 51, an n-side common electrode 60 is formed. On the top face of the first semiconductor laser element LD1, a first p-side electrode 61 is formed. On the top face of the second semiconductor laser element LD2, a second p-side electrode 62 is formed.
On the face of the submount 63 to which the two-beam semiconductor laser element LDC is fixed, a first electrode pad 64 and a second electrode pad 65 are formed separate from each other by patterning. The first and second p-side electrodes 61 and 62 of the two-beam semiconductor laser element LDC are fixed to the first and second electrode pads 64 and 65, respectively. This configuration enables the first and second semiconductor laser elements LD1 and LD2 to be driven individually.
The two-beam semiconductor laser element LDC has a so-called junction-down structure; that is, it has the first and second junction layers 54 and 58 located close to the submount 63. This enables the first semiconductor laser element LD1 and the second semiconductor laser element LD2 to dissipate heat efficiently. Thus, the submount 63 serves as a heatsink, and thereby helps stabilize the operation of and increase the output of the two-beam semiconductor laser element LDC.
Behind the two-beam semiconductor laser element LDC on the submount 63, a photodetector 66 such as a photodiode is fitted. According to what is detected by the photodetector 66, the light emission output of the two-beam semiconductor laser element LDC is controlled.
The submount 63, on which the two-beam semiconductor laser element LDC is fixed, is fixed to a heatsink plate or a leadframe (not shown), and to the n-side common electrode 60 of the two-beam semiconductor laser element LDC, a wire 67 is connected at one end thereof. One end of a wire 68 and one end of a wire 69 are connected to the first electrode pad 64 and the second electrode pad 65, respectively. One end of a wire 70 is connected to the photodetector 66. The other ends of the wires 67 to 70 are connected to lead terminals (not shown). In this way, the two-beam semiconductor laser device 50 is fabricated.
In the two-beam semiconductor laser device 50 structured as described above, the first semiconductor laser element LD1 can be driven independently by passing a current between the first p-side electrode 61 and the n-side common electrode 60; the second semiconductor laser element LD2 can be driven independently by passing a current between the second p-side electrode 62 and the n-side common electrode 60. Thus by driving the first semiconductor laser element LD1, laser light of wavelength of 650 nm can be produced, and by driving the second semiconductor laser element LD2, laser light of wavelength of 780 nm can be produced.
Known semiconductor laser devices typically use can packages or frame packages. In a semiconductor laser device using a can package, leads are fitted one-by-one to a metal stem, and a laser element is mounted on the metal stem and is sealed with a cap. In a semiconductor laser device using a frame package, a semiconductor laser element is mounted on a metal frame, and these are then insert-molded. Semiconductor laser devices using frame packages have been attracting attention for their low cost and good mass productivity.
Compared with conventionally widely used semiconductor laser devices using can packages, however, semiconductor laser devices using frame packages offer poorer heat dissipation. For this reason, semiconductor laser devices using frame packages are now mostly used for infrared laser devices. Further improvements are required so as to make semiconductor laser devices using frame packages usable as high-output laser devices for use with CD-Rs and CD-RWs, red laser devices for use with DVDs, two-wavelength laser devices, or blue laser devices operating at high operating voltages.
Patent Publication 3 discloses a semiconductor laser device using a frame package in which such an improvement has been made. FIG. 8 and FIG. 9 are a perspective view and a front view, respectively, of this type of semiconductor laser device using a frame package. FIG. 10 is a sectional view taken along line X-X′ shown in FIG. 9.
In the semiconductor laser device 80, a submount 83 is arranged in a fixed position on the top face of a frame 82. A semiconductor laser element 84 is arranged in a fixed position on the top face of the submount 83. The frame 82 is formed of a metal having good thermal and electrical conductivity, such as copper, iron, or an alloy of either, and is formed into a plate. The frame 82 includes a main frame 86 on which the semiconductor laser element 84 is mounted and sub frames 87 and 88 for wiring that are independent of the main frame 86. The main frame 86 and the sub frames 87 and 88 are integrated into a frame package by being molded in a resin-molded member 85 that is electrically insulative.
The main frame 86 includes an element mount portion 86a, a lead portion 86b and wing portions 86c and 86d. On the element mount portion 86a, the submount 83 is mounted. The lead portion 86b serves as a current path. The wings 86c and 86d are formed to project to the left and right, respectively, for the purpose of heat dissipation and positioning. In the main frame 86, a thick-walled section 86e and a thin-walled section 86f are formed. The thick-walled section 86e is formed by thickening a front part of the element mount portion 86a and front parts of the wing portions 86c and 86d. The thin-walled section 86f is formed by thinning the lead portion 86b and rear parts of the wing portions 86c and 86d.
The sub frames 87 and 88 are formed to be thin-walled like the lead portion 86b. This enables the lead portion 86b and the sub frames 87 and 88 to be finely processed with ease when the frame 82 is punched out by pressing. Therefore, it is possible to make the semiconductor laser device 80 compact by keeping the intervals between the lead portion 86b and the sub frames 87 and 88 short.
The resin-molded member 85 is formed by insert molding in such a manner that it sandwiches the frame 82, from above the front face and below the back face of the frame 82. On the front face of the resin-molded member 85 is formed a laser output window 85a through which laser light is emitted, as well as an enclosure 85b that is U-shaped so as to be open frontward. Taper faces 85c are formed in front-end parts of left and right side portions of the enclosure 85b. The taper faces 85c permit the semiconductor laser device 80 to be inserted smoothly to be arranged in a predetermined position. The back face of the resin-molded member 85 is formed to be a flat surface 85d that covers the element mount portion 86a, and has substantially the same outer shape (hexagonal shape) as the enclosure 85b located on the front face of the resin-molded member 85.
The resin-molded member 85 does not cover the part of the element mount portion 86a of the main frame 86 in the enclosure 85b, nor does it cover the sub frames 87 and 88. Thus, in these locations, the surfaces of the main frame 86 and the sub frames 87 and 88 are exposed. On the exposed part of the element mount portion 86a, the semiconductor laser element 84 is arranged and fixed, with the submount 83 placed in between. Subsequently, the semiconductor laser element 84 is connected to the main frame 86 with a wire (not shown), and the submount 83 is connected to the sub frames 87 and 88 with wires (not shown).
The submount 83 is built as a light receiving element whose base material is Si. This makes it possible to monitor the light emitted from the rear face of the semiconductor laser element 84. Instead of Si, a ceramic or metal material that has high thermal conductivity may be used, such as AlN, SiC, or Cu. The submount 83 is fixed to the element mount portion 86a, for example, with a solder material such as Pb—Sn, Au—Sn, or Sn—Bi, or with Ag paste. The semiconductor laser element 84 is fixed to the submount 83, in a predetermined position thereon, for example, with a solder material such as Au—Sn or Pb—Sn, or with Ag paste.
Structured as described above, the semiconductor laser device 80 using a frame package offers the following advantages: since the surface of the semiconductor laser element 84 is exposed, it offers good heat dissipation; it has a simple structure, and is therefore suitable for mass production.    Patent Publication 1: JP-A-H11-186651 (Claims, paragraphs [0017] to [0023], FIG. 1)    Patent Publication 2: JP-A-2002-329934 (Claims, FIG. 1, FIG. 4)    Patent Publication 3: JP-A-2002-43679 (paragraphs [0010] to [0022], FIG. 1, FIG. 2, FIG. 4)


Provided are methods of detecting the presence or amount of NPY 1-36 or NPY 3-36 in a sample using mass spectrometry. Importantly, by methods of the invention, both NPY 1-36 and NPY 3-36 can be quantified simultaneously, separately, and independently in a sample that contains both peptides. The methods provide enhanced specificity, and excellent sensitivity with limits of quantitation (LOQ) of about 0.1 ng/mL, and are accomplished in less time and with less sample preparation than required in other assays for NPY. In certain embodiments, because the methods of the invention are specific for both NPY 1-36 and NPY 3-36, the methods provide a major advantage over existing immunoassays. Therefore, the methods may be used to obtain reliable concentration data in several important patient populations, such as patients with hypertension, heart disease, or cancer.

Neuropeptide Y (NPY) is a 36-amino acid peptide neurotransmitter found in the brain and autonomic nervous system; it is the most abundant neuropeptide in serum and plasma. NPY 1-36 has been associated with a number of physiological processes in the brain, including the regulation of energy balance, memory and learning, and epilepsy. The main effect of NPY is increased food intake and decreased physical activity. NPY 1-36 is secreted by the hypothalamus, and, in addition to increasing food intake, it increases the proportion of energy stored as fat and blocks nociceptive signals to the brain. Importantly, NPY 1-36 augments the vasoconstrictor effects of noradrenergic neurons. The full peptide is, therefore, an important diagnostic in patients suffering from hypertension, stress, and cardiovascular disease, for example.
NPY 1-36 is cleaved by dipeptidyl peptidase IV (DPPIV) into NPY 3-36, a 34-amino acid peptide fragment. NPY 3-36, however, has drastically different properties than its parent peptide; it has been shown to have an important role in cancer symptomatology. Importantly, NPY 3-36 has angiogenic properties and, therefore, may play a role in various cancer pathways, including, but not limited to, the formation and growth of solid tumors, and metastasis.
Enzyme-linked immunosorbent assay (ELISA), also known as an enzyme immunoassay (EIA), has been used to detect NPY. ELISA is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. In simple terms, in ELISA an unknown amount of antigen is affixed to a surface, and then a specific antibody is applied over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal.
Importantly, current immunoassays for NPY measure NPY 1-36 and NPY 3-36 simultaneously without distinguishing them. In addition, they cross-react with many other breakdown products of the two main NPYs. This result is suboptimal, as the properties of NPY 1-36 and NPY 3-36 are different.
Efficient mass spectrometric techniques for the independent quantitation of NPY 1-36 and NPY 3-36 at physiologically relevant concentrations have been likewise unavailable. While matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) has been recognized as an important tool in the study of neuropeptides due to the ability directly to detect ions at a specific mass-to-charge (m/z) ratio, even in complex biological mixtures, it has thus far been limited to determining the identity of peptide fragments produced by neuropeptide-processing, -converting, and-inactivating enzymes. Nilsson, C.; et al. "Processing of Neuropeptide Y and Somatostatin in Human Cerebrospinal Fluid as Monitored by Radioimmunoassay and Mass Spectrometry," Peptides 1998, 19(7), 1137-1146. Similarly, endogenous NPY has been qualitatively identified using a combination of chromatographic techniques and nanospray mass spectrometry. Stenfors, C.; et al. "Characterization of Endogenous Neuropeptide Y in Rat Hippocampus and Its Metabolism by Nanospray Mass Spectrometry," J. Biol. Chem. 2997, 272(9), 5747-5751.
Therefore, there exists a need for an efficient mass spectrometric technique for the independent and simultaneous quantitation of NPY 1-36 and NPY 3-36 in a sample at physiologically relevant concentrations.

Mass spectrometric methods for quantifying NPY 1-36 and NPY 3-36


A quick connect/disconnect coupling comprised of a male coupling adapted to mate with a female coupling, the female coupling forming a passageway to receive the male coupling, and locking means for retaining the male coupling in said female coupling. The locking means being comprised of a locking lever pivotably mounted to the female coupling and having a cooperating projection adapted to extend through the coupling into the passageway to engage an annular cavity of the male coupling to maintain the male coupling into a mating relationship with the female coupling when the locking lever is in a closed position. The male and female couplings are provided with a reinforced annular rim, the reinforced annular rim of the male coupling extends radially of the coupling at a mid-portion thereof. The reinforced annular rim of the female coupling extends radially of said coupling at the distal end thereof, such that when said male coupling is inserted and locked into said female coupling, the reinforced annular rims of the male and female couplings lie adjacent one another.

1. Field of the Invention
This invention relates to couplings and more particular to quick connect/disconnect couplings having a male and female member.
2. Description of the Prior Art
Quick connect/disconnect couplings are usually provided at the end of flexible hoses connected to large volume pumps, such as for emptying septic tanks or for pumping water from construction sites, etc. These are also used in the quick coupling of hoses for the handling toxic and acid liquids.
One of the problems associated with these couplings is that they are subject to a fair amount of abuse and the coupling eventually loses its "round".
In a quick disconnect coupling, a pair of levers is pivotably mounted on the female member for camming cooperation with the male member to quickly attach or detach the male member to the female member. In order to prevent accidental opening of the levers, the levers will be bet up so as to be flush-mounted with the coupling or flexible hose, such that if the coupling is dropped, the levers will not accidentally open. However, since the couplings are made to be quickly removed, the levers have to be easily handled by an operator. To facilitate the opening of the levers, pull rings have been provided in the past to locking levers to enable an operator to open the levers and release the coupling. Examples of such pull rings for operating levers of quick connect/disconnect coupling are shown in U.S. Pat. No. 3,439,942 and published Canadian application 2,117,115.
However, as indicated in Canadian patent application 2,117,115, the use of pull rings with locking levers can often interfere with the operation of the levers.


A microprocessor (10) and system implementing the same is disclosed, in which stack-based register address calculation is performed in a single add cycle for instructions involving a PUSH operation. The microprocessor (10) includes a floating-point unit (FPU) (31) having a register stack (52.sub.ST) and a stack pointer (FSP), for executing floating-point instructions containing relative register addresses (REG) based upon the contents (TOP) of the stack pointer (FSP). The instructions may involve PUSH operations, in which an operand is added to the stack of operands in the register stack (52.sub.ST). Register addressing circuitry (125, 125') includes an adder (122; 122') for generating the sum of the contents (TOP) of the stack pointer (FSP) and the relative register address (REG) of the instruction, and an adder/decrementer (120) for generating the sum of the contents (TOP) of the stack pointer (FSP) and the relative register address (REG) of the instruction minus one, to account for the PUSH. The adder (122; 122') and adder/decrementer (120) have their outputs coupled to a multiplexer (124) which is controlled according to whether or not the current instruction involves a PUSH operation. For the case where the contents (TOP) of the stack pointer (FSP) and the relative register address (REG), as well as the raw calculated register address, are each three-bit binary values, the adder/decrementer (120) may be constructed to perform the addition and subtraction of one with a single carry/borrow propagate add.

In the field of microprocessors, the way in which registers are addressed and accessed in retrieving or storing operands during the execution of an instruction is a distinguishing feature of the microprocessor architecture. For example, instructions executed by microprocessors of the accumulator architecture implicitly refer to an operand stored in the accumulator. In general-purpose register architecture microprocessors, both memory and register operands are explicitly addressed in the instructions. In microprocessors of the load/store register architecture, which has been widely adopted in recent years, register operands are directly addressed in the instructions, and memory operands are accessed only by execution of load and store instructions.
Another well-known microprocessor architecture is referred to as the stack architecture. In the stack architecture, as is well-known, operands are implicitly stored in an ordered sequence within a group of registers referred to as a stack. A separate register, referred to as a stack pointer, stores an address corresponding to the stack register from or to which the next instruction is to fetch or store an operand. Operations referred to as PUSH and POP are respectively used to store operands into, and retrieve operands from, the stack; the stack pointer is incremented or decremented accordingly. In modern microprocessors, stack architectures are used primarily for internal execution units, rather than for the main instruction pipelines. For example, modern microprocessors of the x86-architecture type commonly utilize stack architecture in their on-chip floating-point units (FPUs), while the main, or integer, pipelines are of load/store architecture.
In stack architecture processors, actual (raw) register addresses must be calculated for each instruction that involves an operand store or fetch from the stack. For example, a typical floating-point instruction in an x86-architecture microprocessor involves the calculation of a register address based upon the current stack pointer value (referred to in this architecture as the top-of-stack value TOP) and upon an explicit register address indicated in the instruction; the register address in the instruction is typically an offset address relative to the top-of-stack value TOP. The execution of certain instructions may also involve a PUSH operation, in which an operand is stored in the next register above the top of the stack. As is known in the art, a PUSH operation involves the pre-decrementing of the stack pointer, followed by the storage of the operand in the new pointed-to location; conversely, a POP operation involves the read of an operand from the top of the stack, followed by incrementing of the stack pointer.
Because the floating-point units in typical x86-architecture microprocessors of the so-called P5 or P6 class are pipelined, register address calculation must be performed prior to execution, for example in an instruction schedule stage of the pipeline. This early register mapping is necessary in order to detect register conflicts and dependencies that may arise from the multiple instructions in the pipeline. Especially in the case of floating-point instruction execution, therefore, the calculation of register addresses for instructions involving PUSH operations is performed for a high percentage of the executed instructions. The time required for calculation of register addresses affects the overall performance of the unit.
It is therefore desirable to calculate raw register addresses as rapidly as possible. Of course, as is well known in the art, the addition of two binary numbers, either with or without a carry-in bit, may be done by a simple single carry-propagate adder. Accordingly, in a stack architecture, the calculation of a register address by the addition of the stack pointer contents and a relative register address may be performed with a single add. However, the calculation of a register address for an instruction involving a PUSH operation requires both adding the stack pointer contents to the relative register address indicated in the instruction, and also subtracting one to account for the PUSH. As is well known in the art, however, subtraction of one may not be performed in combination with a sum operation in a conventional single carry-propagate adder, but instead requires a second carry-propagate addition of minus one (i.e., 2's complement of 1.sub.2) to the previous sum. The necessity for two carry-propagate adds to calculate register addresses has been observed to affect a large number of operations, particularly in modern pipelined floating-point sequences, and, since this calculation is in the critical performance path, limits the overall microprocessor performance.

Single carry/borrow propagate adder/decrementer for generating register stack addresses in a microprocessor


A monitoring system for driver's braking habits comprising a sensor connected to brakes of a vehicle provided to sense and evaluate the following levels of pressure being applied to the brakes by a driver: normal pressure, above normal pressure and an excessive pressure level. The sensor is adapted to activate a warning signal element connected to the sensor and is provided to warn the driver when the pressure level exceeds the above normal pressure level and the excessive pressure level which facilitates correction of bad driving habits of the driver and development of preventive driving techniques. The sensor comprises a first sensor adapted to sense and evaluate the above normal pressure level, and a second sensor adapted to sense and evaluate the excessive pressure level.

Thousands of vehicles are on the road every day, and most reported accidents involve cars, trucks, bikes and even pedestrians. Alcohol is sometimes the cause, but according to statistics, speed and bad driving by sober drivers are the main factors of road accidents. Bad driving happens when vehicles are going too fast, tail-gaiting, and drivers slam on the brakes.
Road safety is a major concern for government, companies and the general population. Often drivers acquire bad driving habits that turn out to be dangerous. These habits are amplified in magnitude when these people drive heavy trucks or buses. They eventually forget basic principles they learned in preventive driving, they go too fast and do not use any defensive techniques. This often translates in over-usage of the vehicle's brakes.
For large trucks, a variety of systems are available that provide additional information on the driver's performance. Whenever this information is downloaded, it provides data on speed, acceleration, deceleration, usage of brakes, shifting of gears, engine temperature, time that engine is left running on idle and other situations. The computer readings can advise drivers of faulty driving habits and even the exact location where it happened. The company can get a reading on a driver's habits over the past few hours, days or weeks. Correction of these driving habits and training can be the solution.
However, these monitoring computers are very expensive and thus inaccessible for all but the richest companies. Besides, companies that use this technology are sometimes overwhelmed by the amount of information being recorded, thus making the information useless and unmanageable. Most important of all, these systems do not offer much assistance to promote preventive driving because they provide such information after the fact.


Systems and method are provided for delivering notifications to user regarding use of their authentication information. The delivery of notifications involves ascertaining a device identifier associated with a request received from a user device to engage in a transaction using the authentication information and comparing this device identifier associated with the request to a plurality of known device identifiers previously associated with the authentication information. Thereafter, a notification for a user associated with the authentication information can be generated and delivered, if the device identifier is not among the plurality of known device identifiers. In the systems and methods, contact information for delivering the notification is based on contact information for at least one previous transaction that meets a selection criteria and that is associated with the authentication information.

Year after year, the number of electronic transactions performed via computing devices continues to increase. Additionally, the number of computing devices associated with a single user has also continued to increase over time. For example, it is not uncommon for a user to possess a personal computer and at least one of smartphone device or a tablet device. Further, many users utilize these multiple computing devices for performing electronic transactions with a same electronic entity or service. For example, many financial institutions and digital content providers offer access to their system via desktop or mobile devices to perform substantially the same types of electronic transactions. In another example, these devices may access a same storefront for downloading digital content to the various devices. Moreover, there are many instances in which the user may utilize someone else's computing device to perform such electronic transactions.
In general, such devices are allowed to complete transactions with an electronic entity based on verification of a username/password combination. That is, upon accessing a portal of the electronic entity, the user will typically be requested to supply a valid username/password combination to gain access or complete a transaction. Thereafter, the electronic entity's authentication systems can determine whether or not the combination is valid and allow access by the user if the combination is valid.
For some types of electronic entities, there can be additional safeguards implemented to protect the user from fraud or identity theft. In one example, an electronic entity can require the user to generate a user profile during a previous visit and the user can be required to answer additional questions associated with the user profile when performing certain tasks. Successfully answering such questions can result not only in providing user access, but can result in placement of a cookie or other piece of software on the device to "mark" the device as a known or trusted device during a future visit to avoid the need for such questions. Alternatively, the user can also adjust the user profile to specifically add the device to the account associated with the electronic entity to allow the electronic entity's authentication system to automatically recognize the device.
In general, when the above-mentioned authentication is successful, no further action is taken by the electronic entity's authentication systems. Some electronic entities do offer the option of providing an alert when a new device is added to the list of known or trusted devices in a user profile or when there are other changes in a user profile. This generally occurs via the directing of a pre-defined message via contact information retrieved from the user profile. However, this type of notification generally fails to consider how the user has been utilizing the authentication information. Accordingly, in many instances, authentication systems fail to detect fraudulent access by third parties in possession of the user's authentication information. Worst yet, the user may not be notified of such access by these third parties.

Electronic transaction notification system and method


A hybrid energy storage system includes at least one first energy store and at least a second energy store, each with a nominal energy flow at least in one direction, wherein the energy stores exchange electrical energy with one another and/or with at least one external energy source and/or energy sink via electro-physical energy flows, using at least one control circuit. The control circuit operates the energy sink using at least one boost converter, which has at least one electronic switch, and/or a buck converter in the event of a required energy flow of the energy sink which is higher than the nominal energy flow of the second energy store, with an energy flow of the first energy store, while the second energy store supplies an energy flow from zero up to a constant energy flow which corresponds at maximum to the nominal energy flow of the second energy store.

Hybrid energy storage units are used in a multiplicity of applications, for example in automotive applications, in the industrial sector, in uninterruptible power supplies (UPSs), in medical technology (e.g. defibrillators) and for electrical tools. These applications are distinguished by the fact that different states occur, in which different levels of energy and/or quantities of energy are required. For example, when a drilling machine is started up large quantities of energy or a high level of current is required, whereas, as operation of the drilling machine continues, as soon as the drilling machine is "up and running", at rated load substantially smaller quantities of energy or levels of current are required for operation. Moreover, dynamic mechanical loads cause currents to fluctuate widely. This applies similarly with electric drives that are used for example in electric vehicles, or vehicles with a hybrid drive system. However, since every energy storage unit has a so-called comfort zone in which the energy storage unit can be operated without being damaged, problems arise when the energy consumption varies or fluctuates. Operating the energy storage unit outside its comfort zone may result in damage to the energy storage unit or degradation and hence the gradual destruction of the energy storage unit, as a result of which among other things the cyclic stability of the energy storage unit deteriorates.
Hybrid energy storage systems comprising a plurality of energy storage units enable work to be divided up: whereas one energy storage unit constantly supplies energy for a continuous output in its comfort zone, the other energy storage unit undertakes to provide peak energy currents for brief periods so that each of the energy storage units can be operated in its comfort zone and so there is no damage to the energy storage units. In this way, the service life of the energy storage units and their cyclic stability can be improved.
DE 10 2012 013 413 A1 discloses an arrangement of electrochemical energy storage units that comprises a first electrochemical energy storage unit and a second electrochemical energy storage unit. The two energy storage units are connected to one another such that, by way of energy flows, the energy storage units can exchange energy with one another and with at least one external energy source and/or with at least one external energy sink. Further, a device for controlling the energy flows is provided such that damage or overloading of the first energy storage unit at the expense of damage to the second energy storage unit can be prevented or reduced. Although in this case damage to the one energy storage unit is reduced, it is only at the expense of damage to the other energy storage unit.
US 2011/0084648 A1 discloses a hybrid energy storage system and a method for operating a hybrid energy storage system. The hybrid energy storage system has an ultra-capacitor connected to a DC bus and an energy source connected to the DC bus via a switch. The ultra-capacitor and the current source are both connected to a DC voltage converter. The hybrid energy storage system operates in four modes. In a low-energy mode, the DC voltage converter supplies the required energy such that the ultra-capacitor is maintained at a higher voltage than the energy source. In a high-energy mode, the DC voltage converter is no longer able to supply the required energy, the voltage of the ultra-capacitor cannot be maintained, and the energy source is connected to the DC bus by way of the switch. In a peak energy mode, the ultra-capacitor is used to increase the energy from the energy source. In a controlled charging mode, energy generated by the application is used to charge the ultra-capacitor.
A potential converter device having a first storage capacitor, a second storage capacitor and a converter device is disclosed in DE 10 2008 021 875 A1. The first storage capacitor is supplied with energy by an energy source. The converter device makes it possible to transfer energy from the first to the second storage capacitor if the potential curve of the first capacitor reaches a first threshold value and until the potential curve of the second capacitor reaches a second threshold value which is greater than the first threshold value. Further, the first capacitor is charged with the aid of the energy source over a period such that, during this period, energy for a connected consumer can be drawn off from the second capacitor.
The publication "T. Nabeshima; T. Sato; K. Nishijima; S. Yoshida: A Novel Control Method of Boost and Buck-Boost Converters with a Hysteretic PWM Controller, in EPE 2005, Dresden, 2005, pages 1-6", discloses a method for a buck-boost converter using a hysteretic pulse width modulation controller. Using an RC circuit connected to an auxiliary winding of the inductor, a triangular voltage is generated, and this is superimposed on the output voltage of the buck-boost converter and supplied to a hysteretic comparator as a feedback signal. In this way no steady-state error voltage is produced at the output, and variations in the input voltage and the load current are compensated.
US 2009/0317696 A1 discloses a battery device having a lithium battery and a lead acid battery. A control circuit has a voltage detection device and a voltage boost converter device. The voltage in the lead acid battery is detected automatically and used as a reference point. Then, the voltage in the lithium battery is increased to the reference point, that is to the voltage of the lead acid battery. In this disclosure, although damage to the lead acid battery is reduced by the support of the lithium battery, this is achieved at the expense of the lithium battery.
WO 03/088373 A2 discloses a hybrid battery arrangement having a high-power device and a high-energy battery, wherein, with the aid of a microprocessor and depending on the current required by the load, the high-power device and/or the high-energy battery is/are connected up to the load via a switch. As the switch there is disclosed a field-effect transistor. Using a DC voltage converter, the high-energy battery is able to recharge the high-power device during a switch-off period. However, because of the way it is manufactured, a field-effect transistor has the property of conductivity in two directions, with the result that a boost procedure is not possible, since with every switching procedure the boosted voltage drains again as a result of current flowing back from the higher potential to the lower.


A system and method for compressing and decompressing datastreams with fractal coding is disclosed. The method includes the generation of an optimal data set transformation function corresponding to a representative datastream captured from a data source. The data set transformation function is determined by ordering the digits of the representative datastream to order the intervals of an attractor. The ordered intervals are then used to determine the mapping functions which define an optimal data set transformation function. The nodes or graphical representation of the data set transformation function are incorporated in a compressor/decompressor combination. The compressor receives data symbols from a data source and determines the next interval of an attractor using a composition operation. The address or a portion of the address is shifted out as a number representative of the data symbols. Preferably, the interval is renormalized so the interval may be represented in sixteen bits. The decompressor receives the number and determines the data symbol value that corresponds to the number in relation to an identified interval. The corresponding data symbol is shifted out and the mapping function corresponding to the data symbol is applied to the identified interval to determine a next interval. The mapping function is applied using a composition operation. The next interval and number are then preferably renormalized and used as the identified interval for the next number received from the compressor. The inventive system includes a buffer for capturing a representative datastream, a data symbol arranger to order strings of the captured datastream, a mapping function generator to generate the mapping functions of the transformation function and a compressor/decompressor combination.

Bandwidth limitations in various data transmitting media have led to the development of methods for "compressing" data. Compression generally refers to the representation of a set of data by using fewer elements than contained in the set to represent the set of data. If each data element within the set may be regenerated from the compressed representation then the method is commonly known as lossless. If the data representation regenerated from the compressed representation of the data set does not accurately represent each and every element within it, the method is known as lossy. Because the set of compressed data may represent all elements but contain fewer elements than the actual set represented, the transmission of the compressed data usually requires less time and fewer resources than if the original set of data was transmitted. Conversion of the transmitted compressed data set is called decompression and is usually performed by a receiver to obtain the original data set or a close approximation thereto. Thus, the compressed data must not only be capable of accurately representing the data set, but it must also contain sufficient information for the receiver to decompress the data representation.
One known method for compressing a data set uses a data set transformation function to represent a data set. The data set transformation function may be constructed out of projective, affine or complex mapping functions that, when applied to any data set in iterative fashion, converges to the same attractor. As a result, the coefficients of the data set transformation function may be used to represent a data set that is substantially the same as the attractor. This type of compression method is known as an iterated function system or IFS. This type of compression method is lossy as the attractor usually approximates the data set and does not exactly reproduce the data set.
One lossless compression method which uses iterated function systems is disclosed in Fractal Image Compression by Michael F. Barnsley and Lyman P. Hurd, AK Peters Ltd., 1992. The section entitled Arithmetic Compression and IFS Fractals discusses the use of iterated function systems to encode a datastream from a zero-order Markov source. To generate the mapping functions used to compress the data from such a source, a sample datastream is collected from the data source and the frequency of occurrence for each symbol in the datastream is computed. These frequencies are then used to find the coefficients for a mapping transformation having the general form: EQU w.sub.i (x)=p.sub.i x+t.sub.i for i =1,2, . . . ,n
where the p.sub.i for i=1,2, . . . ,n are independent probabilities for each of the symbols in the datastream. The mapping transformations computed from the representative datastream are then used to compress subsequent datastreams from the zero-order Markov source and the mapping transformations are utilized to construct a decompressor as well.
While the compressor/decompressor combination for this zero-order Markov process compresses datastreams for this type of source, it fails to efficiently compress data from higher order Markov sources or other stochastic processes in which the generation of the symbols are not truly independent. Specifically, most data communicated between systems today are not independently generated streams of the binary symbols 1 and 0. Rather, there is a long term correlation between the binary representation of the words, for example, in a word processing program as most of the documents generated by a particular word processing program are written in a particular language, say English. As a result, the output of that program would tend to have certain words reoccurring on a regular basis. Because the system described above views the generation of the symbols as being completely independent, the correlation between the frequency of occurrence of the symbols is not used to more efficiently compress the datastreams generated by such stochastic processes.
What is needed is a lossless method of compression using iterated function systems which efficiently encode and decode datastreams for stochastic processes in a way which incorporates the long term data correlation for such sources.

System and method for the fractal encoding of datastreams