A two stage reaction for the production of steel from iron carbide is carried out in two separate but interrelated reactors. In the first reactor, iron, carbide, with slag formers, is fed into a feed end and the reaction is well-mixed by the vessel geometry, the stirring action below-surface injection of oxygen and iron carbide feed, and the evolution of gases from the liquid metal bath. The product, containing about 0.5-2% carbon, is fed into the second reactor where it is refined with subsurface-injected oxygen. The second reaction is autogenous, and the evolved carbon monoxide is fed to the first reactor where it is burned with oxygen in a foamy slag, which, with post-combustion burning in the slag of CO evolved in the first reactor, and with iron carbide preheating with the sensible heat of the off-gas from the first reaction, makes that reaction also essentially autogenous.

1. Field of the Invention
This invention relates to apparatus and processes for the manufacture of steel from iron carbide in two tightly-coupled stages comprising a first stage reactor in which an iron-carbon alloy of intermediate carbon content is produced by combusting energy-rich gases, including such gases from a second stage reactor, in addition to energy-rich gas generated in the first reactor, and such iron-carbon alloy is used as feed to the second stage reactor in which steel of a final desired carbon content is produced.
2. Description of Related Prior Art
Stellung et al. U.S. Pat. No. 2,780,537 discloses a method of producing iron carbide and states that the product may be oxidized to iron in steel furnaces of known construction.
Kalling et al. U.S. Pat. No. 2,978,318 discloses continuous feeding of powdered material containing iron carbide into an inclined, rotary "Kaldo" type furnace for producing steel. The patent teaches that this feed material provides all the heat required for the reaction and does not introduce sulfur into the process.
Raquin et al. U.S. Pat. No. 3,486,882 teaches a process for the continuous production of steel that includes continuously introducing prereduced steel-forming material into a molten bath contained in a refining vessel and simultaneously introducing thermogenic material and gaseous oxygen into the vessel. The prereduced steel-forming material is iron ore which has been reduced between 40 and 100%. This material is introduced into the vessel at an elevated temperature and may contain carbon or other thermogenic elements in sufficient amount to provide necessary heat requirements for the process.
Rouanet U.S. Pat. No. 3,527,598 teaches carrying out a continuous steelmaking process in a reactor using carburized and non-carburized prereduced pellets. The total carbon content of the carburized and non-carburized pellets is such that the reaction with oxygen furnishes all of the heat required for carrying out the process.
Stephens Reissue U.S. Pat. No. 32,247 teaches a process for the production of iron carbide from iron ore by utilizing a fluid bed process. The iron carbide product then is fed into a steelmaking furnace, such as a basic oxygen furnace or an electric furnace, for the production of steel.
While the original Stephens patent, U.S. Pat. No. 4,053,301, describes the furnace as either a basic oxygen furnace or an electric furnace, the above Stephens reissue patent broadly claims a "steelmaking furnace." The Stephens reissue patent prosecution history also states that the type of furnace used in the steelmaking process of the invention is irrelevant to the primary novelty of the patent. Thus, the Stephens reissue patent prosecution history teaches that the Stephens process is not limited to a particular steelmaking furnace, but can include other prior art steelmaking furnaces such as, for example, a reactor vessel.
Additionally, the Stephens reissue patent teaches, at col. 2, lines 20-22, that the formation of iron carbide and its subsequent conversion to steel can be "one continuous operation." Stephens teaches, at col. 4, lines 16-21, that, when the hot iron carbide is added directly to the furnace, the process is "continuous and auto-thermal." Stephens also teaches that the off-gas from the furnace, which contains about 90% carbon monoxide, may be collected and combusted with oxygen to produce heat.
The concept of continuous production of steel, e.g. from iron ore, has been discussed by Queneau in "The QSL Reactor for Lead and its Prospects for Ni, Cu, Fe," Journal of Metals, December, 1989, pages 30-35, and also by Worner: WORCRA (Continuous) Steelmaking, Open Hearth Proceedings, 1969, pages 57-63, and Proceedings of the Savard/Lee International Symposium on Bath Smelting, Minerals, Metals & Materials Society, 1992, pages 83-101.
The Queneau or Queneau-Schuhmann process for continuous production of steel is similar in nature to the so-called "QSL" process for production of non-ferrous metals, e.g. lead and nickel. See, e.g. U.S. Pat. Nos. 3,941,587, 3,988,148 and 4,085,923 and the above-mentioned Journal of Metals article. This latter publication discloses an enclosed reactor vessel for direct and continuous production of steel from iron oxide ores. The QSL reactor is an enclosed system that is capable of limiting the ingress and egress of atmospheric gases and gaseous reaction products.
The WORCRA process and similar processes, such as that described by Rudziki et al. in Open Hearth Proceedings, 1969, pages 48-56, used top lance blowing of oxygen or combined top and bottom oxygen blowing to burn CO generated on top of the melt to generate additional heat for the process. Rudziki's process is used to decarburize liquid pig iron saturated with carbon.
In the so-called "IRSID" process, described by A. Berthet et al. at the International Conference of the Science and Technology of Iron and Steel, Tokyo, September, 1970, page 60 and following, hot metal, such as pig iron, is continuously charged into a reactor into which oxygen is top-blown onto a metal bath, causing formation of a slag/metal/gas emulsion wherein very rapid refining of the metal occurs. The refined steel then moves to a decanter vessel for slag/metal separation and tapping. Carbon content of the feed metal is 4-5% and there is no gradient of carbon level from the entry to the exit end of the reactor. This process also is described in French Patent No. 2,244,822.
Geiger U.S. Pat. No. 5,139,568 discloses a reactor vessel that receives solid mineral material feed. The mineral feed enters a molten metal bath that consists of a lower, denser iron-carbon alloy or metal layer and an upper, lighter slag layer (col. 6, lines 35-37). Oxygen is injected into the molten metal through submerged nozzles and reacts with carbon from the iron carbide to generate carbon monoxide. The carbon monoxide enters a vapor space above the molten bath (col. 6, lines 51-55), where it reacts with oxygen that is injected into the vapor space. The heat from the combustion of carbon monoxide in the vapor space is said to provide about 100% of the heat energy required for the continuation of the reaction in the reactor (col. 7, lines 11-22).
In the structure taught in the Geiger '568 patent, the amount of oxygen injected into the molten metal through the bottom of the reactor is varied along the length of the reactor (col. 9, lines 63-68). In this manner, a carbon content gradient is formed along the length of the reactor and a low carbon alloy is formed for removal at the removal end. Without forming a carbon content gradient, an iron-carbon alloy of sufficiently low carbon is not formed at the removal end of the reactor.
Additionally, in the reactor described in the Geiger '568 patent, the carbon monoxide reaction product passes into the vapor space and oxygen is injected into the vapor space for combustion with the carbon monoxide. The '568 patent teaches that the combustion of carbon monoxide occurs with the oxygen injected into the vapor space. Oxygen from the molten bath is a "highly unlikely" source of oxygen for combustion of the carbon monoxide. Significant amounts of carbon monoxide and oxygen must react in the vapor space to form sufficient heat to make the process self-sustaining or autothermal. Accordingly, all or substantially all of the carbon monoxide reaction product must enter the vapor space and be combusted there in order to generate sufficient heat to further drive the reaction and allow a self-sustaining or autothermal process.
Although the overall heat balance of the Geiger reaction may be substantially correct for his purpose, the problem with the single vessel and accompanying need for a carbon concentration gradient, is that the heat balance does not reflect where in the process there are energy deficits and energy excesses, and how to control and recover the energy release from the combustion of carbon monoxide to carbon dioxide--which is necessary to achieve the provision of energy at the location within the reactor where it is needed.
The Geiger '568 patent recognizes that, in order to operate such a single reactor continuously to achieve the desired low carbon content, a carbon concentration gradient must be maintained from the iron carbide feed end to the tap end of the reactor. The patent teaches that, for the process to be thermally autogeneous, oxygen must be introduced into the vapor space of the reactor to combust the CO generated in the molten metal bath, producing heat and CO.sub.2. The heat so generated is envisaged as being substantially transferred to the molten metal bath and this is a necessary condition for maintaining a thermally autogenous process. However, that disclosure shows serious deficiencies. In the iron carbide feed end of the reactor, the predominant chemical reactions are endothermic, hence external heat is required to keep those reactions going. In the same region, gas evolution volume is high, resulting in a high rate of turbulent diffusion in the metal bath, leading to a well-mixed reaction region. In the remaining portion of the reactor, the predominant chemical reaction is exothermic (decarburization) and is accompanied by the generation of carbon monoxide providing an energy-rich fuel when combusted to carbon dioxide. Due to the elongated geometry of the Geiger reactor, a significant amount of carbon monoxide will be released into the vapor space at locations not in the vicinity of the energy-deficient region where iron carbide is fed into the reactor. Hence, the greater part of the energy released by combustion of carbon monoxide at locations distant from the iron carbide feed region will not reach that region because the radiation heat transfer view factor between that region and the remaining surfaces of the reactor is low. (The radiation heat transfer view factor is used in the art of heat transfer to characterize the effectiveness of radiative heat transfer between surfaces and between gases and surfaces.) Therefore, and from the standpoint of utilizing the greater part of the carbon monoxide energy in the energy-deficient iron carbide feed region, in the method disclosed by Geiger it is not possible to achieve thermal autogeneity. Another problem with the Geiger patent is in respect to the efficiency of utilization of carbon monoxide combustion energy stemming from carbon monoxide generated directly within the iron carbide feed region of the reactor. Since, in the Geiger process, all of this carbon monoxide is combusted in the vapor space of the reactor, the heat of combustion released will tend to be transferred equally well to both the bath surface and the dome refractory walls of the reactor forming the vapor space. In this way, the reactor dome refractory walls will get very hot which, in practice, would require provisions for water cooling. But, since the dome walls contain more surface area than the surface of the molten bath, significant heat losses to the dome walls of the reactor would be experienced. Thus, the amount of energy reaching the bath from the combustion of directly generated carbon monoxide will be only a fraction of the total energy generated. This additional factor further illustrates the point that the process as described in the Geiger patent falls short of being autogenous.
Sohn et al., in Proceedings of the Savard/Lee International Symposium on Bath Smelting, Minerals, Metals & Materials Society, 1992, pages 377-412, provide information concerning relationships between dimensions of a bottom-blown continuous refining reactor to minimize backmixing.

Process and apparatus for the manufacture of steel


A flexible, ignition resistant, biregional fiber is disclosed, wherein the fiber is preferably derived from a single homogeneous polymeric precursor composition, said biregional fiber comprising an inner core region of a thermoplastic polymeric composition and a surrounding outer sheath region of a thermoset carbonaceous material. The biregional fiber is particularly characterized by having a ratio of the radius of the core region with respect to the total radius of the fiber (r:R) of from about 1:4 to about 1:1.05, an LOI value of greater than 40, a breaking twist angle of from 4 to 13 degrees, and a bending strain value of from greater than 0.01 to less than 50%. In a further embodiment of the invention, a biregional precursor fiber is disclosed, wherein the biregional precursor fiber is preferably derived from a single homogeneous polymeric composition, and wherein said precursor fiber comprises an inner core region of a thermoplastic polymeric composition and a surrounding outer sheath region of a oxidation stabilized, thermoplastic polymeric composition. The precursor fiber is particularly characterized by having a breaking twist angle of from 17 to 23 degrees. The invention further resides in a method of making the ignition resistant biregional fiber. Preferred end uses for the ignition resistant biregional fibers are disclosed including thermal insulation; flame resistant and fire blocking insulation; blends of the biregional fibers with other natural or polymeric fibers; coated fibers, composites of a polymeric matrix reinforced with the biregional fibers of the invention, electron conductive fibers for battery electrodes, and the like.

Resilient and flexible, linear and non-linear carbonaceous fibers are now well known in the art. Representative of non-linear carbonaceous fibers is U.S. Pat. No. 4,837,076, issued Jun. 6, 1989 to McCullough et al. The fibers are produced by melt or wet spinning fibers from a thermoplastic polymeric composition and then stabilizing the fibers by treating them in an oxygen containing atmosphere and at an elevated temperature for a predetermined period of time. The oxidation stabilization treatment of the fibers is carried out to the extent such that the entire polymeric composition of the fibers, when viewed in cross-section, is oxidized. Although the stabilization process, to some extent, depends on the diameter of the fibers, the composition of the polymeric precursor composition, the level of oxygen in the atmosphere, and the treatment temperature, the process is extremely time consuming and costly in order to achieve complete stabilization of the fibers throughout their cross section.
Traditionally, the stabilization treatment of polymeric fibers under oxygen extends over at least several hours to in excess of 24 hours to completely permeate the fibers with oxygen and to achieve sufficient stabilization of the fibers in preparation for subsequent carbonization of the stabilized fibers to produce carbonaceous fibers for commercial end uses. The Encyclopedia of Polymer Science and Engineering, Vol. 2, A Wiley-Interscience Publication, 1985, pp. 641-659, reports that "current standard processing technology requires from 1 to 2 hours for adequate stabilization" of fibers, p.658. No other method of processing suitable for large or "heavy" 320 k tows is disclosed. Also, in "High Performance Fibers II, published by Battelle, esp. the chapter entitled "Process Technology-Oxidation/Stabilization", page 149 et seq. it is reported that oxidation and cyclization takes place between 150.degree. C.-300.degree. C. and that "the reaction must take place throughout the fiber and not be confined to the fiber surface." Accordingly, the lengthy stabilization treatment employed in present standard procedures reduces the productive output of stabilized fibers, requires substantial capital investment, and is therefor extremely costly and a major deterrent in rendering the process desirable for greater commercial exploitation, i.e. extended commercial usage of the fibers at lower cost. It is also reported that if electrically heated oxidation chambers are used, the chambers must be substantially larger than the ovens used in a subsequent carbonization step, therefore resulting in a substantially higher capital cost.
It is further taught in U.S. Pat. No. 4,837,076 that the conventionally stabilized fibers (stabilized precursor fibers) are subsequently formed into a coil-like and/or sinusoidal shape by knitting or weaving a fiber tow into a fabric or cloth. The so formed knitted fabric is thereafter heat treated in a relaxed and unstressed condition and in a non-oxidizing atmosphere at a temperature of from 525.degree. C. to 750.degree. C. and for a period of time sufficient to produce a heat induced thermoset reaction wherein additional crosslinking and/or cross chain cyclization occurs between the original polymer chains. The carbonization treatment of the fibers is carried out to the extent such that the entire oxidation stabilized material of the precursor fibers, when viewed in cross-section, is carbonized. Specifically, no residual portion of the oxidation stabilized fiber material remains in a thermoplastic condition. In example 1 of U.S. Pat. No. 4,837,076, it is reported that portions of a stabilized knitted cloth were heat set at temperatures ranging from 550.degree. C. to 950.degree. C. over a 6 hour period. The most flexible fibers and fibers that are subject to the least fiber breakage due to brittleness when subjected to textile processing were obtained in those fibers that had been heat treated at a temperature of from 525.degree. C. to 750.degree. C. The resulting fiber tows, obtained by deknitting the cloth, and having the heat set, i.e. thermoset, non-linear structural configuration, can then be subjected to other methods of treatment known in the art to create an opening, a procedure in which a yam or the fiber tows of the cloth are separated into an entangled, wool-like fluffy material, in which the individual fibers retain their coil-like or sinusoidal configuration, yielding a fluff or batting-like body of considerable loft.
U.S. Pat. No. 4,837,076 also discloses that at a treatment temperature above 1000.degree. C. the stabilized precursor fibers become graphitic and highly electrically conductive to the point where they begin to approach the conductivity of a metallic conductor. These graphitic fibers find special utility in the manufacture of electrodes for energy storage devices. Since graphitization of the stabilized fibers is carried out at a temperature and for a period of time such that the entire stabilized polymeric material of the fiber, when viewed in cross-section, is graphitized, the process, especially at the higher temperatures, is extremely time and energy consuming and equipment intensive, and therefor very costly.
Graphitization of oxidation stabilized fibers is generally desired in order to produce higher tensile modulus properties in the fibers. However, it is reported in High Performance Fibers II, published by Battelle, Copyright 1987, esp. the chapter entitled "Process Technology-Graphitization", pages 158 and 159, that "breakage of the fibers is a problem that has not been solved" and that "the most serious disadvantage of these high tensile strength fibers is their low strain-to-failure ratio, which means that they are very brittle". Moreover, the process is also said to be expensive because of the "high capital cost of the equipment and the great amount of electrical energy required to achieve the necessary temperature for graphitization of the fibers (2000.degree. to 3000.degree. C.) throughout their entire cross-section.".
Fibers that are generally referred to as "bicomponent or composite fibers", "biconstituent fibers", "bilateral fibers" and "sheath-core fibers" are commonly known in the art. Definitions of these terms can be found in "Man-Made Fiber and Textile Dictionary", Hoechst Celanese Corporation, 1990, pp. 14, 15, 32, and 139. A bicomponent or composite fiber is defined as a fiber composed of two or more polymer types in a sheath-core or side by side (bilateral) relationship. Biconstituent fibers are defined as fibers that are extruded from a homogeneous mixture of two different polymers wherein such fibers combine the characteristics of the two polymers into a single fiber. Bilateral fibers are two generic fibers or variants of the same generic fiber extruded in a side by relationship. Sheath-core fibers are bicomponent fibers of either two polymer types or two variants of the same polymer. One polymer forms a core and the other polymer of a different composition surrounds it as a sheath.
Bicomponent fibers have also been generally disclosed in U.S. Pat. No. 4,643,931, issued Feb. 17, 1987 to F. P. McCullough et al. These fibers are blends of a small amount of conductive fibers into a yarn to act as an electrostatic dissipation element. Fiber manufacturers also routinely manufacture conductive fibers by incorporating into a hollow fiber a core of carbon or graphite containing thermoplastic composite or by coating a fiber with a sheath made of a thermoplastic composite containing carbon or graphite.
U.S. Pat. No. 5,260,124, issued Nov. 9, 1993 to J. R. Gaier, discloses a hybrid material comprising a fabric of high strength carbon or graphite fibers, a layer of a graphitized carbon disposed on the fibers, and an intercalate in the layer. In the process of manufacture, Gaier's fabric of high strength carbon or graphitic fibers is coated by vapor deposition with a porous graphite layer to form a two-dimensional fabric like structure. In contrast to Gaier, the fibers of the invention are "biregional" and are not carbonized or graphitized throughout to form a high strength fiber, nor are the ignition resistant biregional fibers of the invention coated with a layer of graphitized carbon, thereby forming a composite structure. The core region of the fiber of the invention always remains thermoplastic, while the sheath region of the fiber is oxidation stabilized and thermoplastic, or carbonaceous and thermoset Moreover, the ignition resistant biregional fiber of the invention does not require an intercalate treatment in the outer graphite layer.
Electrical energy storage devices, particularly batteries, which employ fibrous carbon or graphite electrodes and which operate in a nonaqueous electrolyte at ambient temperature are known from U.S. Pat. No. 4,865,931, issued Sep. 12, 1989 to F. P. McCullough et al. The patent generally discloses a secondary battery comprising a housing having at least one cell positioned in the housing, each cell comprising a pair of electrodes made of a multiplicity of electrically conductive carbon fibers, a foraminous electrode separator for electrically insulating the electrodes from contact with each other, and an electrolyte comprising an ionizable salt in a nonaqueous fluid in each cell.
A similar electrical storage device is disclosed in U.S. Pat. No. 4,830,938 to F. P. McCullough et al, issued May 16, 1989. This patent discloses a shared bipolar, carbonaceous fibrous, electrode which is capable of carrying a current from one cell to an adjacent cell without a current collector frame associated therewith. Neither of the aforementioned McCullough et al patents disclose the use of ignition resistant biregional fibers having an inner core region of a thermoplastic polymeric composition and a surrounding outer sheath region of a thermoset carbonaceous material. The biregional fibers of the invention are particularly suitable for use as electrodes in secondary energy storage devices primarily in view of their substantially greater flexibility and lower cost.
In general, the biregional fibers of the invention distinguish over the various types of fibers of the prior art in that the biregional fiber is preferably produced from a homogenous polymeric composition, i.e. a single polymeric composition, preferably an acrylic polymer, in which an outer region of the fiber is oxidation stabilized and then carbonized to form two visually distinct regions in the fiber, when viewed in cross section, i.e. typically a translucent or lightly colored inner core region and a black outer sheath region. In the case of a biregional precursor fiber, the fiber comprises a thermoplastic inner core and a thermoplastic stabilized outer sheath, while in the case of an ignition resistant biregional fiber, the inner core is thermoplastic and the outer sheath is thermoset and carbonized.
When the ignition resistant biregional fiber of the invention is manufactured from a homogeneous polymeric composition, preferably an acrylic polymer, there is no boundary or discontinuity between the inner core and the outer oxidation stabilized or carbonized sheath. The term "homogeneous polymeric composition" used herein includes homopolymers, copolymers and terpolymer and does not include fibers containing two or more polymers of different compositions and coefficients of crystallinity. In contrast discontinuities are produced in bilayered or bicomponent fibers in which two polymers of different compositions are used in a side by side or core-sheath relationship. Such discontinuities or boundaries occur between the layers of the different polymeric compositions due to their different coefficients of crystallinity. This also applies to different polymeric compositions which are intermixed with each other.
In the case of a core/sheath fiber, the outer sheath layer is formed much like a skin layer and is separate and distinct from the inner core thus forming a physical boundary or discontinuity between the inner core and the outer skin layer. More specifically, in viewing a cross sectional surface of a bilayered or sheath-core fiber (generally coextruded), inspection of the surface from an outer periphery to the center of the fiber surface, one would pass from one type of polymeric composition forming the outer sheath layer through a boundary layer or discontinuity into the core having another polymeric composition of different crystallinity. As previously indicated, polymers having different compositions also have different coefficients of crystallinity and melting points. For example, polyacrylonitrile will undergo a melting point transition at a temperature range of 320.degree. C.-330.degree. C. This represents a relatively high melting point for polymers and is characteristic of stiff chains. Both nylon 6,6 and PET fibers melt at 265.degree. C., and polyolefins such as polyethylene and polypropylene melt around 135.degree. C. and 165.degree. C., respectively. Accordingly, although the inner core and the outer sheath of the biregional fiber of the invention forms two visually distinct regions, when viewed in cross section, they do not form a physical boundary or discontinuity between the core and the sheath, i.e. the regions are continuous.
The single homogenous polymeric composition that is preferably employed in the manufacture of the ignition resistant biregional fiber of the invention is a standard acrylic polymer, i.e. homopolymer, copolymers and terpolymers of acrylonitrile, wherein the copolymers and terpolymers contain at least 85 mole percent acrylic units and up to 15 mole percent of one or more vinyl monomers copolymerized therewith, or optionally, a subacrylic polymer, as hereinafter disclosed.

Flexible ignition resistant biregional fiber, articles made from biregional fibers, and method of manufacture


The invention discloses an integrated tumor resection instrument and a simulation training system. The resection device comprises an imaging system, a minimally invasive incision, a processor, an operating device, a resection executing mechanism and a positioning control device. The operating device is connected to the input end of the processor, the resection actuating mechanism is provided with a resecting driver, and the positioning control device and the resecting driver are both connected to the output end of the processor; the simulation training system comprises the steps of designing a manikin; arranging the imaging system; integrated resection. The resection device can resect the whole tumor along the edge of the tumor, thereby avoiding the incomplete resection and even tumor recurrent caused by crushing in the process of resecting the tumor. The simulation training system can train an operator to quickly master the resection skill and operation of various positions.

Traditionally, the complete and integrated resection of a surface tumor requires the skin and subcutaneous tissues to be cut open to expose the subcutaneous mass, and then complete excision is accomplished. Although complete excision of the mass is possible, such an operation leaves a significant surgical scar larger than the diameter of the tumor on the skin after the incision has healed, which has a serious aesthetic impact. The extent of the aesthetic impact of breast surface scars is more pronounced and is more emphasized by patients.
Currently, there are minimally invasive surgery for breast tumors, but the excision method used to remove the tumor is a rotary cut. An ultrasound-guided vacuum-assisted breast biopsy procedure needs to rotate and cut the tumor into small strips of tissue and then the tumor is suctioned out of the body by using negative pressure. It is very easy to cause local shedding of cells and broken tissues during the cutting process, especially in the case of malignant tumors. Moreover, there is a possibility of local tumor implantation after leaving cells or tissues behind. The minimally invasive rotary technique destroys the integrity of the tumor and violates the of "tumor-free" surgical principle.
Therefore, it has become an insurmountable technical barrier to the surgical field to achieve a small incision with no residual tissues or cells left behind and with integrated resection of the tumor.

Integrated tumor resection instrument and simulation training system


A method for computing a human-machine hybrid ensemble prediction includes: receiving an individual forecasting question (IFP); classifying the IFP into one of a plurality of canonical question topics; identifying machine models associated with the canonical question topic; for each of the machine models: receiving, from one of a plurality of human participants: a first task input including a selection of sets of training data; a second task input including selections of portions of the selected sets of training data; and a third task input including model parameters to configure the machine model; training the machine model in accordance with the first, second, and third task inputs; and computing a machine model forecast based on the trained machine model; computing an aggregated forecast from machine model forecasts computed by the machine models; and sending an alert in response to determining that the aggregated forecast satisfies a threshold condition.

Predicting the timing or outcomes of future events is a common occurrence. For example: meteorologists predict the weather in various localities based on measurements of current conditions; sports analysts predict the outcomes of tournaments based on their assessments of the various teams; and political analysts predict the outcomes of elections based on polling data and the behavior of the candidates.
Predictions are often performed using various computer and/or mathematical models in machine-based forecasting systems. However, machine forecasting systems also exhibit what is called the "cold-start problem," in which the accuracy of the system is extremely limited or reduced when a new problem is introduced and remains low until the system has accumulated enough data to understand the problem. This contributes to the rigidity of machine-only forecasting systems by slowing down the rate at which the system can adapt to new problems and topic areas.

Systems and methods for forecast alerts with programmable human-machine hybrid ensemble learning


A rethermalization system for heating refrigerated food on trays, maintaining the food in a refrigerated condition until heated, and heating some of the food to a desired temperature at a serving time while maintaining the rest of the food in a refrigerated condition. The system has a cart which docks inside a refrigerator. The cart has shelves on which trays of food reside. In the shelves there are heaters. The operator programs the system using an intricate series of commands at an operator interface. A first controller interprets the commands and sends the program to a second controller. The second controller controls the heating cycle of the heaters. A current sensor is provided to sense whether there is current to the heaters. The second controller polls the current sensor and compares the findings to what is called for in the program. The second controller sends a status signal, based on the comparison, to the first controller, which provides a response, based on the comparison, to the operator interface.

The preparation and serving of large numbers of meals in an institutional setting has long posed a variety of problems. The ability to serve palatable meals with the various dishes being served at optimum temperature often conflicts with efforts to make service of the meals easier, more efficient and less manpower intensive.
The preparation, storage, rethermalization and service of a large number of meals has evolved through several stages. Initially, trays were filled with food from various hot or cold storage containers just prior to serving, and then transported to the individual serving areas, such as patient's rooms in a hospital. However, as facilities grew larger, the assembly of trays from a centralized area became very difficult if not impossible. Frequently in such a system, the time between tray assembly and service grew longer, which resulted in food spoiling or being served at an unpalatable temperature.
One solution has been a food service system of trays and carts using heating elements inside of a refrigerator. In this type of system, trays are pre-assembled and loaded into the carts. In the refrigerator, the food remains cold. At a desired time, the heating elements are activated to rethermalize and maintain some of the food in a heated condition, while not effecting the rest of the food which is to remain cold. After the food has reached the serving temperatures the carts are rolled to the service locations and the trays served.
However, even these systems have problems. Such systems rarely provide significant operator feedback relating to whether the carts are properly connected in the refrigerators and the overall functioning of the system. Even those systems that check for a voltage on the lines providing power to the heaters cannot determine if the drop is due to an open circuit or the resistance of the heater element.


A new and distinct cultivar of Peperomia plant named ‘EC-PEPE-1903’ is disclosed, characterized by large, velvety, oval-shaped leaves with greyed-orange petioles. The new variety is a Peperomia, typically used as an ornamental plant.

The new cultivar is a product of a planned breeding program. The new variety was selected as a seedling resulting from the crossing of two unnamed, unpatented varieties of Peperomia vestita. The crossing was made by the inventor, Obed J. Smit, a citizen of the Netherlands in 2014. 'EC-PEPE-1903' was selected by the inventor in 2017 at a commercial greenhouse in Sappemeer, the Netherlands.
Asexual reproduction of the new cultivar 'EC-PEPE-1903' by terminal cuttings was first performed in Sappemeer, the Netherlands at a commercial greenhouse in March 2017 and has shown that the unique features of this cultivar are stable and reproduced true to type through successive generations.


The invention is a method for producing a finished mail piece. The method allows a system user to select at a first node, a plurality of characteristics which define a mailing. These characteristics include selection of a document to be printed at a terminal node and a list of addresses to which the printed document will be sent. Once selections have been made, the print job is transmitted to a terminal node which comprises a data processor, an envelope printer, and a document printer among other elements. The document printer will print the document in accordance with the characteristics selected at the first node; and, the envelope printer will print addresses from the address list to corresponding envelopes. Once the document has been printed, it is inserted into the envelope by inserting means to form an unfinished mail piece. The unfinished mail piece is sealed and then franked with appropriate postage in order to form a finished mail piece. The mail piece is then placed into a mail stream for delivery to the destination address. A receipt indicative of the print job and delivery into the mail stream may be optionally generated by the terminal node and transmitted to the first node. Several nodal layers can be created such that the first node can transmit the print job to a second node which can further transfer the print job to subsequent nodes for printing and routing.

The expansion of computer networking, and both the hardware and software that support it, has allowed a proliferation of new services to become available to network users. And, as a better understanding of networking has evolved, so too have the opportunities that are the outgrowth of such technology as the InterNet and the World Wide Web. These technologies allow increased service capability by offering users a chance to participate in marketing and service ventures that they would not normally be able to access due to constraints from expense, equipment, or size.
Small businesses in particular can benefit from the ability to utilize the equipment of a centralized data center; equipment that the small business could never cost-justify if it had to be purchased directly. Direct mail or mass mailings are an example of how an excellent marketing tool can be cost-justified by firms that utilize the tool only once or twice a year. The limited usage does not justify the expense of maintaining the mailing, shipping or print equipment in-house; yet, through networks such as the InterNet and World Wide Web small businesses can create a mailing and then download the mailing parameters to a data center that can assemble the mailing and utilize efficient, high speed systems to produce a finished mail piece. Thus, the creation of the hybrid mail piece.
Hybrid mail is a creature of the evolution of technology and the mail stream. Where once a mail piece was created locally and then dropped into the closest available mailbox for eventual delivery to a remote location, now the entry points into the mail stream are virtually unlimited. One of the key elements to the importance hybrid mail is the ability of the user to get the finished mail piece to its intended destination not just more quickly, but also at a cheaper cost.
The prior art has been limited to the services available from print shops that produce the printed document, or fulfillment houses that assemble and mail documents, brochures, or direct mail pieces. Those few that have merged their services to form fulfillment services with printing and mailing capability, still required at the very best, that a document be downloaded for printing at the remote site from the network. But, the ability to define the parameters of the mailing, and include the parameters within the mailing data coming from the initiating site, simply do not exist. Thus, a disadvantage of the prior art is that there has not been an effective marriage of the various art forms required to adequately create a mailing and a corresponding address list, fully define the parameters of the mailing, remotely produce the mailing, and then prepare the mailing for delivery to the mail stream as a set of finished mail pieces.
Thus, an objective of the present invention is to define a mail piece remotely, download the defined mail piece to a terminal site, and then provide a cost effective means of producing and then delivering the finished mail piece to its ultimate destination.

Method and system for mail piece production utilizing a data center and inter-related communication networks


Modified neuropeptide Y receptors having deletions, replacements or additions in the third intracellular domain are identified and methods of making the modified receptors are provided. The invention includes the modified receptors, assays employing the modified receptors, cells expressing the modified receptors, compounds identified through the use of the modified receptors, including modulators of the receptors, and the use of the compounds to treat conditions, including obesity, diabetes, anxiety, hypertension, cocaine withdrawal, congestive heart failure, memory enhancement, cardiac and cerebral vasospasm, pheochromocytoma and ganglioneuroblastoma, and Huntington's, Alzheimer's and Parkinson's diseases.

Neuropeptide Y (NPY) is a 36 residue, amidated peptide. It is anatomically co-distributed and co-released with norepinephrine in and from sympathetic postganglionic neurons ([1], [2], [3], [4], [5], [6]). Stimulation of the sympathetic nervous system under physiological circumstances such as exercise ([7], [8]) or exposure to the cold ([9], [10]) promotes an elevation of both norepinephrine and NPY.
NPY is believed to act in the regulation of appetite control ([11], [12]) and vascular smooth muscle tone ([13], [14]) as well as regulation of blood pressure ([6], [15], [16], [17]). NPY also decreases cardiac contractility ([18], [19], [20], [21], [22]). Congestive heart failure and cardiogenic shock are associated with probable releases of NPY into the blood ([23], [24], [25]). Regulation of NPY levels may be beneficial to these disease states [26].
At the cellular level, neuropeptide Y binds to a G-protein coupled receptor ([27], [28], [29], [30]). Neuropeptide Y is involved in regulating eating behavior and is an extremely potent orixigenic agent ([11], [12], [31]). When administered intracerebroventricularly or injected into the hypothalamic paraventricular nucleus (PVN) it elicits eating in satiated rats ([32], [33], [34]) and intraventricular injection of antisera to NPY decreases eating ([11], [31]). It has been shown to stimulate appetite in a variety of species and at different stages of development ([12]). Other effects on energy metabolism include decreased thermogenesis, body temperature and uncoupling protein, and increased white fat storage and lipoprotein lipase activity ([9], [35], [36], [37], [38], [39]). NPY levels in the PVN increase upon fasting ([40], [41], [42], [43], [44]), before a scheduled meal ([31], [36], [40]), and in both streptozotocin-induced and spontaneous diabetes ([36], [45], [46], [47], [48], [49]). Also, NPY levels are increased in genetically obese and hyperphagic Zucker rats ([36], [50], [51]). Thus, a specific centrally acting antagonist for the appropriate NPY receptor subtype may be therapeutically useful for treating obesity and diabetes. Other disorders which might be targeted therapeutically include anxiety, hypertension, cocaine withdrawal, congestive heart failure, memory enhancement, cardiac and cerebral vasospasm, pheochromocytoma and ganglioneuroblastoma, and Huntington's, Alzheimer's and Parkinson's diseases ([26], [52]).
At least four receptor subtypes of the NPY family have been proposed based on pharmacological and physiological properties. The Y1 receptor is stimulated by NPY or PYY (peptide YY) and appears to be the major vascular receptor ([16], [53], [54], [55]). The Y2 receptor is stimulated by C-terminal fragments of NPY or PYY and is abundantly expressed both centrally and peripherally ([55], [56], [57], [58]). A third receptor (Y3) is exclusively responsive to NPY and is likely present in adrenal medulla, heart, and brain stem ([27], [59]). In addition, other subtypes of this receptor family are known to exist, based on pharmacological and physiological characterization ([60], [61], [62], [63]). The feeding behavior is stimulated potently by NPY, NPY.sub.2-36 and the Y1 agonist [Leu31, Pro34]NPY, but is not stimulated by the Y2 agonist NPY.sub.13-36 ([11], [64], [65], [66]). This pharmacology is not characteristic of the defined Y1, Y2 or Y3 receptors and can thus be attributed to a unique receptor, termed "atypical Y1" ([11], [65], [66]), that is responsible for evoking the feeding response. In addition, data indicate the existence of additional members of this receptor family including one subtype specific for peptide PP ([62], [63]), one with affinity for short C-terminal fragments of NPY which induce hypotension when administered systemically ([15], [17], [30], [67], [68]), and one associated with binding of NPY and PYY to brain sigma and phencyclidine binding sites ([61]).
The DNA encoding the Y 1 receptor has been cloned and shown to be a G protein coupled receptor ([53], [69], [70]). G-protein coupled receptors are well-known to share substantial sequence homology to each other (71). Recently, DNA encoding the Y4 receptor has been isolated using Y1 DNA probes [72]. In addition, DNA encoding the Y2 receptor has been isolated by expression cloning ([73], [74]). The cDNAs encoding these receptors are at least 45% identical at the DNA level and 30% at the protein level. Other NPY receptors have not been cloned.

Modified human neuropeptide Y1 Receptors


There is disclosed an improved corrugated pallet having pallet legs attached at various points of attachment. The field of invention relates to a corrugated cardboard pallet of the type generally formed by a pair or more of pallet decks which are stacked atop one another, each of which has finger elements die cut therein radiating outwardly from a central circle and terminating on a circular score line of substantially the same diameter as the inner diameter of one of the leg elements. The die cut lines for the fingers radiate tangentially outwardly to create a substantially spiral pattern. The leg assembly is of the type formed by an outer leg, and an inner leg, with the radiating die cut fingers nested between the annulus created between the outer and inner leg and adhesively secured to the legs. The improvement consists of die cutting a series of linearly aligned perforations along the length of each finger, such that when the adhesive is applied to the outer and inner surfaces of the fingers, the adhesive is permitted to permeate the inner confines of the corrugated material forming the fingers thereby increasing the surface area of adhesive for securing the finger elements to the respective leg elements.

The present invention relates to corrugated pallets and in particular to the type of corrugated pallets which have been developed for the purpose of providing inexpensive and light weight pallets constructed of corrugated cardboard.
Pallets are of course widely utilized in all industries for the purpose of stacking and transporting various goods. It is well-known that in the past, pallets were formed of wood, in order to lend rigidity and strength to the pallet so that merchandise of great weight could be stacked and transported on the pallets. However, with the advent of conservation, and preservation of the natural resources, the use of woods for constructing pallets has been deemed to be undesirable, and even more important, it has now been determined by many countries in the world that wood is a nesting place for various types of bacteria and other undesirable germs, especially when the wood is wet or rotted. Just as importantly, it has been found in many countries that pest infestation has become a widespread problem, and it has been found that wood pallets have a tendency to introduce unwanted pests in different countries. Hence, in many countries of the world, wood pallets are not even permitted into the country unless they have been properly fumigated. This has caused a tremendous cost impact on those entities employing wood pallets for the purpose of shipping goods from place to place. The net result is that there has developed a strong tendency toward pallets constructed of alternate material.
In this connection, the art has gravitated to corrugated pallets which are made of corrugated paper and other materials which are relatively inexpensive, are capable of bearing weight, and are totally recyclable. Applicant has patented a certain pallet leg for a corrugated cardboard pallet under U.S. Pat. No. 4,487,136 which discloses and claims a corrugated pallet having leg elements which are installed onto the pallet deck, which yields a corrugated pallet having sufficient strength for virtually all applications in connection with the stacking and transport of goods placed thereon. Assignee's later U.S. Pat. No. 4,850,284 has further disclosed an improvement which relates to the cross-laminating of the cardboard pallet decks in order to further enhance the rigidity and strength of the subject pallet.
In both instances, the method of attaching the pallet leg to the pallet is by die cutting a plurality of finger members in a tangentially radiating manner in order to create a substantially spiral pattern with the fingers. The core legs are installed onto the pallet deck by twisting an inner leg in the direction of the spiral pattern of the finger elements, and nesting the inner leg within an outer leg having the fingers interposed in the annulus formed there between. Attachment is achieved by means of the use of an adhesive which is applied to the finger elements such that once the finger elements are nested within the annulus formed between the inner and outer leg elements, the cores forming the leg elements will become adhesively secured to the pallet deck via the finger elements.
It will be appreciated from the above description, that the method of attachment relates to the positioning of an adhesive such as a glue, on the outer as well as inner surfaces of the finger elements such that when the finger elements are interposed or nested within the annulus formed between the outer and inner leg elements, the finger elements will become adhesively secured on both surfaces to the respective core leg elements. It has been observed, however, that when the adhesive is applied in this manner, the adhesive merely spreads over the skin or surface of the outer surface and inner surface of the finger elements. Hence, the ability to secure the core legs to the deck is strictly a function of the securement which is achieved by the adhesive being interposed between the surface of the finger elements and the respective inner or outer leg element. While this has produced a pallet which has a high degree of strength and rigidity, and permits a great degree of weight to be stacked onto the pallet, and also provides a pallet having legs which are securely attached thereto, it has now been determined that the securement of the pallet legs to the pallet may be further enhanced by virtue of the present invention. Hence, the present invention is intended as a method of further enhancing the securement of the pallet legs to the pallet deck in order to further strengthen the pallet as a whole, and especially, to enhance the strength of the attachment or securement of the legs to the pallet deck. This feature has an impact since these pallets are utilized in connection with forklift vehicles which are employed for lifting and transporting the pallets from place to place. The use of such forklift vehicles is widespread and common knowledge, however, it is also known that the use of these types of vehicles, will often cause damage to the pallets where the tynes of the forklift strike the pallet legs when the operator attempts to position the forklift vehicle in a proper position to lift the pallet for transportation purposes. Hence, it is believed that the present invention, by providing a greater bond between the leg elements and the pallet deck, enhances the value of the pallet and further reduces the possibility of damage which occurs by the use of forklift vehicles.


In one aspect, the present disclosure relates to a method comprising: receiving, at a client device, information from a node manager about a plurality of nodes in a computer cluster, the information comprising a network address associated each of the plurality of nodes and sending, by the client device, a request to a load balancer to access a first node from the plurality of nodes, the request comprising a first URL including an encoded representation of the network address associated with the first node. The load balancer is configured to determine the request should be routed to a first network address based on decoding the URL, the first network address associated with a first node from the plurality of nodes and forward the request to the first node in response to the determining.

As is known in the art, a computer cluster is a set of loosely or tightly connected computers that work together so that, in many respects, they can be viewed as a single system. Clusters with hundreds of computers (or "nodes") may be used to perform complex distributed processing tasks such as deep neural network (DNN) machine learning. Clusters may be deployed to improve performance and availability while typically being much more cost-effective than single computers of comparable speed or availability. Cloud-based computing environments make it possible to allocate large clusters programmatically using Application Programming Interfaces (APIs) though which an administrator can instantiate and configure virtual machines (or "instances") as desired or necessary.
As is also known in the art, cloud-based clusters and other large server deployments may utilize load balancers to distribute network traffic across physical and/or virtual servers. A load balancer may be provided as a software program that listens on a network port where external clients connect. The load balancer may forward client requests to one of the "backend" servers, which processes the request and send a response back to the load balancer. Some load balancers may include routing capabilities. For example, existing load balancers may be configured to route certain types of requests to specific backend servers.
Traditionally, load balancers have had to maintain state information about the backend servers. For example, some existing load balancers maintain a lookup-table or prioritized list of backend servers. Processing a single request may involve iterating through long lists of rules in order to determine where to route the request. Moreover, before client requests can be routed to a particular backend server, the server must be registered with the load balancer. In cloud-based systems where the allocation of backend servers can change frequently, the load balancer must be updated often and can require complex rules to ensure proper routing of traffic. These problems are compounded when multiple load balancers are employed for redundancy or scalability.


An apparatus and method for detecting a voice activity period. The apparatus for detecting a voice activity period includes a domain conversion module that converts an input signal into a frequency domain signal in the unit of a frame obtained by dividing the input signal at predetermined intervals, a subtracted-spectrum-generation module that generates a spectral subtraction signal which is obtained by subtracting a predetermined noise spectrum from the converted frequency domain signal, a modeling module that applies the spectral subtraction signal to a predetermined probability distribution model, and a speech-detection module that determines whether a speech signal is present in a current frame through a probability distribution calculated by the modeling module.

1. Field of the Invention
The present invention relates to voice activity detection, and more particularly to an apparatus and method for detecting a speech signal period from an input signal by using spectral subtraction and a probability distribution model.
2. Description of Related Art
With the development of technology, various devices have been developed that can more conveniently maintain peoples' lifestyles. In particular, devices have been provided that can recognize speech and properly react to it. This capability is known as speech recognition.
The principal technologies of such speech recognition include a technology that detects a period where a speech signal is present in an input signal, and a technology that captures the content included in the detected speech signal.
Voice detection technology is required in speech recognition and speech compression. The core of this technology is to distinguish the speech and noise of an input signal.
A representative example of this technology includes the "Extended Advanced Front-end Feature Extraction Algorithm" (hereinafter, referred to as "first conventional art") which was selected by the European Telecommunication Standard Institute (ETSI) in November of 2003. According to this algorithm, a voice activity period is detected based on energy information in a speech frequency band by using a temporal change of a feature parameter with respect to a speech signal in which a noise is removed. However, when the noise level is high, performance may be deteriorated.
Also, Korean Patent No. 10-304666 (hereinafter, referred to as "second conventional art") discloses a method for detecting a voice activity period by estimating in real-time each component of a noise signal and a speech signal from a speech signal having noise using statistical modeling such as the complex Gaussian distribution. However, even in this case, when the magnitude of a noise signal becomes greater than the magnitude of a speech signal, a voice activity period may not be detected.
According to the above-described conventional art, a signal-to-noise ratio (hereinafter, referred to as "SNR") decreases, that is, the magnitude of noise increases, and thus it may not be easy to distinguish a speech period from a noise period, as shown in FIGS. 1A to 1D.
FIGS. 1A to 1D are histograms illustrating a distribution of a speech signal 110 having noise and a noise signal 120 according to a change in an SNR. Referring to FIGS. 1A to 1D, an x-X-axis represents the magnitude of band energy in a frequency band between 1 kHz and 1.03 kHz, and a y-axis represents a probability with respect thereto.
Also, FIG. 1A illustrates a histogram when an SNR is 20 dB, FIG. 1B illustrates a histogram when an SNR is 10 dB, FIG. 1C illustrates a histogram when an SNR is 5 dB, and FIG. 1D illustrates a histogram when an SNR is 0 dB.
Referring to FIGS. 1A to 1D, as the SNR value decreases, the speech signal 110 having noise is more concealed by the noise signal 120. Accordingly, the speech signal 110 having noise may not be distinguished from the noise signal 120.
Specifically, according to the conventional methods, a speech period and a noise period may not be easily distinguished from each other in an input signal having a low SNR value.

Apparatus and method for detecting voice activity period


Disclosed is a method for the installation of systems in an aeroplane fuselage, a device with a rails system for the execution of the method, and a freight loading system, which uses the rails system as a guidance system for cargo.

In aeroplane construction concepts for the installation of systems and concepts for freight loading systems are usually considered separately from one another. Thus in the concepts of known art no interfaces exist between systems installation and the freight loading systems, although in both cases individual elements are to be conveyed and accurately arranged in position in an aeroplane fuselage.
In a concept described in the applicant's patent application US 2008/0255026 A1 for the purpose of systems installation fuselage sections are each mounted on a conveyor vehicle and continuously moved in the transverse direction along a circuit from one build area to the next build area. A comparable concept with a cyclical movement of the conveyor vehicles is also of known art.
However, in these principles of assembly and/or installation of known art it is critical that the systems in question, such as runs and modules, also tools, accessories and small parts, must be individually moved into the fuselage by the assembly personnel to the installation site in question, which results in the expenditure of a large amount of time. In addition the larger systems and tools require a high level of physical effort from the assembly personnel.
Freight loading systems for cargo such as containers and items of luggage should enable the rapid loading and unloading of a freight compartment. Furthermore the freight loading systems should only have a low weight and should enable an almost total utilisation of the freight compartment.
A freight loading system of known art shown in DE 42 38 095 C2 envisages a conveyor belt extending in the longitudinal direction of the aeroplane, by means of which the cargo is conveyed into the freight compartment. This freight loading system allows good utilisation of the freight compartment, but a very powerful drive is required for movement of the conveyor belt.
Other freight loading systems envisage so-called roll mats, which are installed over a large surface area of the floor of the freight compartment. The roll mats are, however, relatively heavy, and are susceptible to contamination.
A freight loading system that can be compared with the roll mats is of known art from DE 603 11 544 T2. In this system a multiplicity of ball- and roller-type actuating drives, arranged next to one another in the longitudinal and transverse directions of the aeroplane, are envisaged for the movement of the cargo. The actuating drives are, however, susceptible to mechanical and electrical damage. Furthermore loading and unloading is time-intensive.
From the applicant's German patent application DE 199 23 529 A1 a freight loading system is of known art, in which the cargo is routed on rails extending in the longitudinal direction of the freight compartment. While the loading and unloading times or freight loading times are indeed reduced relative to the solutions described earlier, the cargo during loading must be scheduled in a previously defined sequence on the rails, since no repositioning of the cargo is possible within the freight compartment. Furthermore the cargo can only be introduced into the freight compartment through a front face side opening or rear face side opening, which limits the application of this freight loading system to freighter aeroplanes.
The object of the present invention is to create a method and a device for the installation of systems or system modules in an aeroplane fuselage, which remove the above-cited disadvantages and enable a rapid installation, also a freight loading system with reduced freight loading times, which has features of the device for the installation of systems.

Method and device for the installation of systems, and a freight loading system


The phase change memory device includes a plurality of memory banks, a plurality of local conductor lines connected to the plurality of memory banks, at least one global conductor line connected to the plurality of local conductor lines, and at least one repair control circuit configured to selectively replace at least one of the at least one global conductor line with at least one redundant global conductor line and configured to selectively replace at least one of the plurality of local conductor lines with at least one redundant local conductor line.

1. Technical Field
Example embodiments of the present invention relate to a semiconductor memory device, for example, to a phase change memory device.
2. Description of Related Art
A semiconductor memory device is a memory device that stores data and from which stored data may be read. The semiconductor memory device may be divided into a volatile memory device and a nonvolatile memory device.
The volatile memory device is a memory device in which retained data is erased when a power supply is cut off. Some examples of the volatile memory device are SRAM, DRAM and SDRAM. The nonvolatile memory device is a memory device in which retained data is not erased even when power supply is cut off. Some examples of the nonvolatile memory device are ROM, PROM, EPROM, EEPROM, flash memory device, PRAM, MRAM, RRAM, and FRAM.
A phase change memory (PRAM) is a memory device that stores data using a material of which a resistance varies with temperature, for example, chalcogenide. When a temperature higher than the melting point of chalcogenide is applied to the chalcogenide for a relatively shorter period of time, the chalcogenide becomes an amorphous state. When a temperature lower than the melting point of chalcogenide is applied to the chalcogenide for a longer period of time, the chalcogenide becomes a crystalline state. A resistance of the chalcogenide in the crystalline state is lower than a resistance of the chalcogenide in the amorphous state. Thus, the phase change memory device may store data by changing chalcogenide into a crystalline state or an amorphous state.


Molded parts having good frictional wear resistance are provided by a polyacetal composition containing 0.25-15 parts by weight of fine spherical ceramic powder of 1.0 .mu.m or smaller average grain size to 100 parts by weight of polyacetal resin.

1. Field of the Invention
This invention relates to a polyacetal composition which is suitable for molded parts of good wear-resistance that can be used suitably under the condition of repeated friction under high load, regardless of the material of the mating member, and its molded parts.
2. Description of the Related Art
Polyacetal resin has excellent mechanical properties and heat resistance, especially wear-resistance, and it is in wide use as sliding members. However, in case of its use for mechanical parts, such as gears, rollers, bearings, door parts, etc., under the condition of repeated friction under heavy load, improvement of wear-resistance against repeated operations is desired. Also, recently, members with which it comes into contact are becoming diversified, such as plastics, composite plastics or ceramic materials, in addition to conventional metallic materials.
Therefore, conventionally, for the purpose of further improvement of wear-resistance of polyacetal resins, inorganic solid lubricants, such as MoS.sub.2, graphite, etc.; liquid or semi-solid lubricants, such as petroleum, synthetic lubricants, aliphatic alcohols or their esters, etc., or addition of polyolefin fine powder of 500,000 or higher molecular weight are used.
However, wear-resistance of this material varies greatly depending on the material of the mating member and it can be wear-resistant to some mating members, but not wear-resistant to other mating members, therefore a lubricant must be selected depending on the material of the mating member.

Polyacetal composition and its molded parts


An optical scanning apparatus of the present invention is for optically scanning a medium. In the optical scanning apparatus, a light source receives image information and emits light beam modulated in accordance with the image information. A single optically imaging system is positioned in a single location for receiving the light beam from the light source and for focusing the light beam to be focused on the medium. A reflective mirror formed with a single reflective surface is provided for reflecting the light beam from the optically imaging system to direct the light beam to the medium. The reflective mirror is rotated by a motor at a fixed speed to allow the reflective surface to scan the light beam on the medium in a scanning sweep. Surfaces other than the reflective surface of the reflective mirror is prevented from directing the light beam to be focused on the medium.

1. Field of the Invention
The present invention relates to an optical scanning apparatus used for an electrophotographic type image recording apparatus.
2. Description of the Related Art
There has been known an electrophotographic type image recording apparatus for receiving image information from a computer and forming an image on an image receiving medium in accordance with the image information. The image recording apparatus is equipped with an optical scanner which receives the image information from the computer and modulates and deflects laser beam emitted from a laser source in accordance with the image information.
FIG. 1 shows a conventional optical scanner 31 employed in the electrophotographic type image recording apparatus. The optical scanner 31 receives the image information from the computer and optically scans a cylindrically-shaped photosensitive drum 33 in raster pattern to form a latent image thereon. As shown in FIG. 1, the optical scanner 31 is positioned to confront the photosensitive drum 33. All the components of the optical scanner 31 are encased in a casing 32. In the casing is installed a semiconductor laser 34 which faces a polygonal mirror 40. The polygonal mirror 40 is axially fixed to a rotating shaft of a constant-speed rotating motor 42. Installed between and justified with the semiconductor laser 34 and the polygonal mirror 40 are a collimating lens 35 and a cylindrical lens 36. Installed between the polygonal mirror 40 and the photosensitive drum 33 are a series of imaging lenses 43 including an f.theta. lens.
The laser 34 is electrically connected to a computer device and receives image signals from the computer. The laser 34 emits laser beam modulated in accordance with the image signals. The laser beam emitted from the laser 34 passes through the collimating lens 35 where it is converted into a parallel beam. The parallel beam then passes through the cylindrical lens 36 where it is focused to strike a surface of the polygon mirror 40 in an elliptic beam spot. Since the polygonal mirror 40 is rotated with a constant speed by the motor 42, the laser beam reflects off the polygon mirror 40 to be deflected therefrom at a constant angular velocity. The laser beam then passes through the imaging lenses 43 and strikes a peripheral surface of the photosensitive drum 33 where an electrostatic latent image is produced. The latent image is then developed through a well-known electrophotographic process and is transferred to be fixed on a hard copy medium such as a paper.
The above-described conventional optical scanner has a problem, however, in that the polygonal mirror 40 should be equiangular, which requires high-precision production, to prevent irregularities in spacings between scanning lines that will possibly appear if surfaces thereof are at varying angles with respect to the axis of the polygonal mirror 40.
Inclusion of the cylindrical lens 36 and the imaging lenses 43 is a well-known technique for reducing such irregularities. However, this technique creates additional problems wherein the number of parts and the complexity of the apparatus increase. It is noted that the imaging lenses 43 include a plurality of f.theta. lenses each of which has a complex shape. The increase in the number of the parts further requires an intricate positioning operation of the parts so that all the parts may be axially aligned with respect to an optical axis of the laser beam. More specifically to say, the semiconductor laser and the collimating lens should be positioned relative to each other so that the laser beam from the semiconductor laser may be reliably converted into the parallel beam. The cylindrical lens and the imaging lenses should be positioned relative to the polygon mirror so that the laser beam may be focused on the polygon mirror and may be focused on the photosensitive drum in a beam spot having a desired spot shape.
Furthermore, the polygon mirror should be symmetrical with respect to its axis so that it may be mounted on the motor rotating shaft in a balanced manner, to thereby prevent variations in the rotation speed of the motor. Accordingly, the polygon mirror should be produced with high accuracy.
High precision is also required for attaching the polygonal mirror 40 to the motor 42. If the two are not precisely axially aligned, the large mass and subsequent inertia of the polygonal mirror 40 cause large variations in rotation speed of the motor 43.
As described above, each of the parts employed in the conventional optical scanner has a complex shape. The number of the parts employed in the conventional optical scanner is large, and therefore positioning operations for the parts becomes intricate. Accordingly, the conventional optical scanner is expensive.


A successive approximation ADC is disclosed. A comparator receives and compares a sampled input signal and an output of a DAC. Non-binary successive approximation register (SAR) control logic controls sampling of the input signal and controls a sequence of comparisons based on comparison result of the comparator. The SAR control logic controls each comparison when signal or charge in the DAC has not been completely settled. A binary-error-tolerant corrector is then used to compensate the sampling error.

1. Field of the Invention
The present invention generally relates to analog-to-digital converters (ADCs), and more particularly to a successive approximation register (SAR) ADC with binary error tolerance.
2. Description of the Prior Art
Flash analog-to-digital converter (ADC), pipelined ADC, and successive approximation register (SAR) ADC schemes embody widely used ADC architectures that have respective advantages in specific applications. The SAR ADC requires less power consumption and silicon area (and thus cost) as compared to other ADC architectures. Nevertheless, the SAR ADC needs more cycles to obtain the digital output, and therefore is not a good fit for high speed applications.
The SAR DAC is subdivided into two methods: binary approximation and non-binary approximation. The binary approximation ADC was disclosed, for example, in "A 65-fJ/Conversion-step 0.9-V 200-KS/s Rail-to-Rail 8-bit Successive Approximation ADC," IEEE J. Solid-State Circuits, vol. 42, October 2007, pp. 2161-2168, by Hao-Chiao Hong and Guo-Ming Lee, the disclosure of which is hereby incorporated by reference. In this disclosure, a digital-to-analog (DAC) is used to successively approximate a sampled signal, which is then compared by a comparator to determine whether setting or resetting next bit. This binary search continues several times with each voltage difference inversely proportional to 2n, until the equivalent digital output is obtained. The binary approximation was also disclosed, for example, in "A 65fJ/Conversion-Step 0-to-50MS/s 0-to-0.7 mW 9b Charge-sharing SAR ADC in 90 nm Digital CMOS," ISSCC Dig. Tech. Papers, February 2007, pp. 246-247, by J. Craninckx and G. van der Plas, the disclosure of which is hereby incorporated by reference. This disclosure applies the same operation principle as that discussed above, but uses a comparator to compare the charge difference in order to determine whether adding or subtracting further charge. This binary search continues several times with each charge difference inversely proportional to 2n, until the equivalent digital output is obtained. In the operation, the speed of the ADC of this binary approximation method is limited, because the comparator in either disclosure should wait for complete settling time until the voltage or charge is within the accuracy of ½LSB (that is, ½N+1, where N is the resolution of the ADC), otherwise, sampling error incurs.
The non-binary method was disclosed, for example, in "A 1.2-V 10-b 20-Msample/s nonbinary successive approximation ADC in 0.13-m CMOS," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers, 2002, pp. 176-177, by F. Kuttner, the disclosure of which is hereby incorporated by reference. Contrary to the binary approximation, the voltage difference in the non-binary approximation method in not inversely proportional to 2n, but 1.85n. Owing to the capability of tolerating sampling error up to about 12.7%, this non-binary approximation method can sample an unstable signal, thereby reducing cycle time and data conversion time, however, at the cost of requiring additional and complex digital correction (e.g., logic circuit or read only memory (ROM)), and associated power consumption and silicon area.
For the reason that conventional approximation ADC architectures have respective disadvantages, a need has arisen to propose a novel ADC architecture that can maintain the advantages while avoid the disadvantages of conventional ADC architectures.

Successive approximation ADC with binary error tolerance mechanism

NCKU Research and Development Foundation


An integrated circuit module package includes a lead frame having a recessed area. A semiconductor die containing active electrical components is attached to the recessed area of the lead frame. An integrated passive device containing passive electrical components is vertically stacked with, and electrically coupled to, the semiconductor die. An optional heat sink is attached to the integrated passive device. The integrated passive device is connected to the lead frame by conductors to electrically couple the integrated passive device and the semiconductor die to circuitry external to the integrated circuit module package. A cap is then attached to the heat sink or the integrated passive device to protect the semiconductor die and the integrated passive device. The integrated circuit module package dissipates heat from the semiconductor die through the lead frame, and dissipates heat from the integrated passive device through the cap and optional heat sink.

1. Field of the Invention
The present invention relates generally to integrated circuit module packages and assembly methods thereof, and more particularly to radio-frequency (RF) module packages and assembly methods thereof.
2. Description of the Background Art
Mobile phone manufacturers are under competitive pressure to develop smaller, less expensive mobile phones. Accordingly, mobile phone designers may focus on reducing the size and cost of RF module packages in mobile phones. An RF module in a conventional mobile phone includes electronic circuitry for receiving, processing, and transmitting RF signals. The electronic circuitry of the RF module includes both active and passive components. Examples of active components in an RF module include a voltage controlled oscillator, a low noise amplifier, a filter, a mixer, and an antenna. Examples of passive components in an RF module include resistors, capacitors, and inductors.
Typically the active components as well as some smaller passive components of an RF module are integrated into a radio-frequency integrated circuit (RFIC) in the RF module. Generally, larger passive devices are not integrated into the RFIC because the larger passive devices would occupy large areas of the RFIC. In a conventional RF module, for example, an inductor is typically configured in the shape of a spiral in which a coil is wound several times within a defined area on a planar surface of the RFIC. Because the spiral inductor has an inductance proportional to the length of the coil, the number of windings of the coil, and other physical dimensions and geometric properties associated with the coil layout, the spiral inductor may occupy a large area in the RFIC.
An RFIC typically includes one or more power amplifiers that generate a large amount of heat, which may change transistor parameters and affect RF signal processing operation. If the heat generated by the RFIC is not effectively dissipated, electrical components of the RFIC may become damaged and rendered non-operational. Therefore, heat dissipation capacity is an important characteristic of an RF module package in additional to the size and thickness of the RF module package.
FIG. 1 depicts a conventional RF module 100. The conventional RF module 100 includes multiple RFICs 105, 120, and 130 mounted on a lead frame 135. The RFICs 105, 120, and 130 are electrically connected via bonding wires 110 to lead frame inductors 115, 125, and 140 formed on a surface of the lead frame 135. The lead frame inductors 115, 125, and 140 are serpentine inductors composed of the same conductive material as that of the lead frame 135 and are configured to match the impedances of the RFICs 105, 120, and 130. In one type of conventional RF module, the lead frame inductors 115, 125, and 140 may be formed on a printed circuit board (not shown) separate from the lead frame 135. The space occupied by the lead frame inductors 115, 125, and 140 largely determines the size and configuration of the conventional RF module and limits the ability to dissipate heat from the RFICs 105, 120 and 130.
FIG. 2 illustrates a cross-sectional view of the RFIC 105 (FIG. 1) packaged in a conventional plastic ball grid array (PBGA) package 200. As illustrated in FIG. 2, the RFIC 105 is mounted on the lead frame 135, which is attached to a package substrate 210. The package substrate 210 includes vias 215 (e.g., vias 215a-c) that are formed by drilling holes through the package substrate 210. Additionally, solder balls 220 (e.g., solder balls 220a-b) are mounted and electrically coupled to portions of the lead frame 135 near the vias 215. An electrode pad (not shown) of the RFIC 105 is electrically connected to the lead frame inductor 115 via the bonding wire 110a. The via 215c is filled with a conductive filler material, such as a metal, to establish an electrical connection between the lead frame inductor 115 and the portion of the lead frame 135 electrically coupled to the solder ball 220a.
The PBGA package 200 includes a plastic cap 205 formed over the RFIC 105. Because the lead frame 135 conducts heat much more effectively than the plastic cap 205 and the package substrate 210, heat generated by the RFIC 105 is substantially dissipated in one direction through the lead frame 135 to the ambient air environment of the PBGA package 200. Because the PBGA 200 dissipates heat from the RFIC 105 in substantially one direction, the heat dissipation capacity of the PBGA 200 is limited.
FIG. 3 illustrates a cross sectional-view of the RFIC 105 (FIG. 1) packaged in a thermally enhanced ball grid array (TEBGA) package 300. As illustrated in FIG. 3, the RFIC 105 is mounted on the lead frame 135 (FIG. 1). The lead frame 135 is attached to a front surface 320 of a heat sink plate 310. Electrode pads (not shown) of the RFIC 105 are electrically connected to electrode terminals 340 of a multi-layer printed circuit board (PCB) 325 via bonding wires 110. The electrode terminals 340 are electrically connected to various solder balls 335 through various metal-filled vias 330 in the PCB 325. A heat transfer gel 305 is attached to a back surface 315 of the heat sink plate 310 to facilitate heat transfer from the heat sink plate 310 to the ambient air environment of the TEBGA 300 package. Because heat generated by the RFIC 105 is dissipated in substantially one direction through the lead frame 135, the heat sink plate 310, and heat transfer gel 305, to the ambient air environment of the TEBGA package 300, the heat dissipation capacity of the TEBGA package 300 is limited.
The manufacturing process steps of assembling the multi-layer PCB 325 in the TEBGA package 300 are complex and may result in low product yield. Consequently, the manufacturing cost of a TEBGA package 300 may be higher than that of other types RF module packages. Moreover, the configuration of the multi-layer PCB 325 limits the ability to design a small, thin TEBGA package 300.
It light of the above, there exists a need for a small, thin, RF module package having a high heat dissipation capacity.

This patent is subject to a terminal disclaimer.

Integrated circuit module package and assembly method thereof

Avago Technologies Wireless IP (Singapore) Pte. Ltd.


The present invention relates to a method of producing a (shaped) ceramic or glass-ceramic article, involving the steps of: (a) providing a powder or a powder mixture comprising ceramic or glass-ceramic material, (b) depositing a layer of said powder or powder mixture on a surface, (d) heating at least one region of said layer by means of an energy beam or a plurality of energy beams to a maximum temperature such that at least a part of said ceramic or glass-ceramic material in said at least one region is melted and (e) cooling said at least one region of said layer so that at least part of the material melted in step (d) is solidified, such that the layer is joined with said surface in said at least one region. The invention also relates to ceramic or glass-ceramic articles and their use.

Methods of producing ceramic or glass-ceramic articles are well known. The economies associated with conventional part production generally favor the production of large quantities of identical parts. Corresponding methods most of the time require complex processes involving the production of molds or the like. For commercial reasons, these production methods are generally unacceptable for small quantities. For prototyping, the production of small series of ceramic or glass-ceramic articles or the production of a plurality of articles each having different shape, only few economically viable methods are know. Mostly such methods involve a subtractive machining method. In such subtractive machining methods material is cut away from a starting block of material to produce a more complex part. Examples of such methods include: milling, drilling, grinding, lathe cutting, flame cutting, use of an electrical discharge machine etc. The problems associated with these production methods are large initial investment, waste of material and tool wear. The latter is costly and reduces accuracy of the articles produced. One method to produce shaped ceramic or glass-ceramic articles is computer controlled milling of shaped bodies out of the solid ceramic or glass-ceramic material, which inevitably leads to considerable waste that has to be reprocessed at great effort and expense. Also, complicated shapes with deep hollows are not accessible by the aforementioned methods or require complex procedures.
In order to solve these problem free form fabrication methods (solid free form fabrication methods) have been developed. This term relates to a collection of methods that have been successfully applied to produce articles from materials such as metals, plastics, ceramics, and the like. Typical examples are (i) electron beam melting, which involves melting of metal powder and produces substantially void free articles without pores, (ii) laser engineered net shaping, wherein a laser is used to melt metal powder and to deposit it on a substrate and (iii) selective laser sintering (SLS) or selective laser melting (SLM), which uses a laser to fuse powdered nylon, elastomer, metal or ceramic material. SLM usually requires additional processing to produce fully dense parts. For a typical example of a freeform fabrication method see also Griffith et al. "Free form fabrication of metallic components using laser engineered net shapings", Solid free form fabrication symposium, Austin, Tex., Aug. 12-14, 1996.
The automatic construction of physical objects using free form fabrication is called rapid prototyping. Rapid prototyping takes virtual designs from computer aided design (CAD) or animation modeling software or other data that describe the shape of physical objects, transforms them into data of thin, virtual, horizontal cross-sections of said physical objects and builds a new physical object on the basis of the data of the cross-sections.
An apparatus lays down successive layers of liquid, powder, or sheet material, and in this way builds up the new object from a series of said cross-sections. Selective laser melting (SLM) is a special type of rapid prototyping, wherein layers of material (in particular layers of powdered material) are molten and joined by subsequent crystallization. Aspects of rapid prototyping have for example been described in D. T. Pham, S. S. Dimov, Rapid manufacturing, Springer-Verlag, 2001, ISBN 1-85233-360-X.
U.S. Pat. No. 4,863,538 discloses a method of producing an article from plastic, metal or ceramic material by a free form sintering method, i.e. by sequentially sintering a plurality of powder layers to build the desired part in a layer-by-layer fashion. Heating is effected by means of a laser. EP 0 946 325 B1 discloses "Selective Laser Melting" (SLM). Various other publications have been published concerning this type of technology. However, ceramic or glass-ceramic articles produced by such known methods often have a fairly large amount of cracks, fissures and other imperfections, and therefore have inferior properties, especially inferior mechanical properties, inferior biocompatibility, high porosity and the like and are therefore not suited for sophisticated applications, e.g. as dental article or in certain applications in the electronic industry.
The often inferior properties of ceramic or glass-ceramic articles produced by such methods are primarily a result of the very high melting points of ceramic materials. These melting points make rapid rates of heating and cooling of the material necessary and result in large temperature differences among different parts of the articles produced during the production process. This leads to high stresses inside the ceramic or glass-ceramic articles which in turn lead to cracks, fissures and other defects.
Various means to improve the properties of ceramic or glass-ceramic articles have been proposed. U.S. Pat. No. 5,508,489 proposes the use of at least two laser beams to heat the powder, wherein one laser is used to sinter the powder and a defocused laser is used to provide a predetermined temperature gradient between the sintering location and the surrounding powder. This method reduces curling of the produced layers.
U.S. Pat. No. 7,452,500 describes a method, wherein a high-energy beam irradiates predetermined positions of a powder layer a plurality of times, wherein each position is first at least once heated to a temperature below the melting point of the powder material and during the second or a later irradiation heated to a temperature above the melting temperature. In SLM a layer of material is usually heated by means of laser irradiation on only one side of the layer, the side of the layer facing away from the beam is heated solely by heat transfer within the layer, which may be slow compared to the heating rate. A high temperature gradient between the two sides of the layer is the result. This may lead to evaporation, in particular explosive evaporation, on the side of the layer heated by the beam, while the side of the layer facing away from the beam may not even be molten.
U.S. Pat. No. 7,452,500 solves this problem by heating during a plurality of intervals. During the waiting period between two intervals the temperature gradient between the two sides of the layer is reduced by heat transfer, while the beam heats other regions of the layer. Thus the method avoids large temperature differences between the two sides of the layer to be melted, which avoids the risk of evaporation or even explosive evaporation of layer material due to overheating and reduces the time required to make an article. It also leads to reduced stress. An apparatus for free form fabrication is also disclosed in U.S. Pat. No. 7,452,500.
Reference is further made to the following documents:    U.S. Pat. No. 4,814,575 AUS 2006/119017 A1    EP 1 561 839 A1    U.S. Pat. No. 5,393,482 A    U.S. Pat. No. 6,767,499 B1    JP 2003 001368 A    DE 10 2004 041 633 A1    U.S. Pat. No. 4,863,538 A1    WO 2005/095304 A1    WO 0 240 744    EP 0 129 188    EP1 772 210    WO 2004/089 851    DE 10 2005 048 314    SHISHKOVSKY ET AL: "Alumina-zirconium ceramics synthesis by selective laser sintering/melting" APPLIED SURFACE SCIENCE, ELSEVIER, AMSTERDAM, NL, Vol. 254, No. 4, 23. Nov. 2007, Pages 966-970,    MERINO ET AL: "Ionic conductivity in directionally solidified Al2O3-ZrO2(3% mol Y2O3) near eutectic composites" SOLID STATE IONICS, NORTH HOLLAND PUB. COMPANY. AMSTERDAM, NL, Vol. 178, No. 3-4, 6. Mar. 2007, Pages 239-247    WANG A H ET AL: "Microstructural characteristics of Al2O3-based refractory containing ZrO2 induced by CO2 laser melting" APPLIED SURFACE SCIENCE ELSEVIER NETHERLANDS, Vol. 221, No. 1-4, 15. Jan. 2004, Pages 293-301    BOURBAN ET AL: "Solidification microstructure of laser remelted Al2O3-ZrO2 eutectic" ACTA MATERIALIA, ELSEVIER, OXFORD, GB, Vol. 45, No. 12, 1. Dec. 1997, Pages 5069-5075    LARREA A ET AL: "ZrO2-Al2O3 eutectic plates produced by laser zone melting" JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, ELSEVIER SCIENCE PUBLISHERS, BARKING, ESSEX, GB, Vol. 22, No. 2, 1. Feb. 2002, Pages 191-198,    LLorca et al: Progress in Materials Science 51 (2006) Pages 711-809.
However, until to date no method of free form fabrication is known for the preparation of ceramic or glass-ceramic articles with similar or even better material properties than those produced by the above mentioned subtractive machining methods.

Ceramic or glass-ceramic article and methods for producing such article

BEGO BREMER GOLDSCHLAEGEREI WILH, HERBST GMBH & CO. KG

NEDERLANDSE ORGANISATIE VOOR TOEGEPAST NATUURWETENSCHAPPELIJK ONDERZOEK TNO INNALOX BV

FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNGE E.V.