The invention relates to a procedure and a device for measuring memory cell currents, in particular for non-volatile memory components, where the device has a current mirroring device for mirroring a current flowing through a memory cell when it is being read, and delivering an analog current signal generated during the mirroring, or an analog current signal derived from it, to an analog output pad of a memory component.

With conventional memory components, in particular conventional semi-conductor memory components, a distinction is made between so-called function memory components (e.g. PLAs, PALs, etc.), and so-called table memory components, e.g. ROM components (ROM=Read Only Memory and/or fixed-value memory)—in particular PROMs, EPROMs, EEPROMs, Flash memory, etc.—, and RAM-components (RAM=Random Access Memory and/or Read/Write memory), for instance DRAMs and SRAMs.
A RAM component is a memory device in which data can be stored after an address has been specified, and from which the data can later be read out again under this address.
Because a RAM component needs to be provided with as many storage cells as possible, it becomes important for the creation of these cells to be kept as simple as possible.
With SRAMs (SRAM=Static Random Access Memory) the individual memory cells for instance consist of a few, e.g. six, transistors, and with so-called DRAMs (DRAM=Dynamic Random Access Memory) usually of only a single suitably controlled capacitive element (e.g. the gate source capacitance of a MOSFET), with the capacitance of which one bit at a time can be stored in the form of charge.
In any event, this charge only persists for a short period, which means that a so-called "refresh" must be performed regularly, e.g. ca. every 64 ms.
In contrast to this, SRAMs do not need any "refresh" to be performed on them; i.e., the data stored in the memory cell persists for as long as the SRAM is provided with an appropriate voltage supply.
In non-volatile memory components (NVMs and/or non-volatile memories), e.g. ROMs, PROMs, EPROMs, EEPROMs, and flash memories in contrast the stored data persists even when the supply voltage is switched off.
In ROM memory components the data in question can be secured during the manufacture of a corresponding memory component (i.e. by the manufacturer) by means of appropriate masks, for instance by providing either a discontinuity or a contact at an appropriate location on a corresponding memory cell matrix. In NMOS-ROM memory components this is for instance done by furnishing the corresponding transistors with an oxide layer of a different thickness between the gate and substrate. An oxide layer of "normal" thickness creates a conductive channel (d=1), while a "thicker than normal" oxide layer will prevent this (d=0).
PROMs are read only memories programmable by the user. The respective memory cells can for instance contain appropriate fuses (for instance thin CrNi layers) that can be melted by the application of suitable currents, and that thereby—irreversibly—have the data bit d=0 written into them. Alternatively the respective memory cells can for instance also contain special Mosfets, in which an additional isolated "floating gate" has been provided. This gate is given a charge during the programming of a corresponding memory cell, whereby the threshold voltage of the respective Mosfet is shifted.
EPROMs are multi-programmable non-volatile read only memory components, i.e. fixed-value memory components, in which the respective programming can be reversed by the user by means of an appropriate erasing program. Mosfets with additional isolated "floating gates" that can be correspondingly charged for programming, are for instance—as with many PROMs—able to be used as memory cells. By means of irradiating the EPROM with UV light the floating gate charge of (all) Mosfets can be reset, whereby the programming (of the whole EPROM) is reversed again.
An EEPROM is understood to be a multi-programmable read only memory component, in which the respective programming can—in contrast with an (UV erasable) EPROM—be electrically reversed bit by bit, byte by byte or one page at a time.
A flash memory and/or flash EEPROM represents a hybrid between an EPROM and an EEPROM. A flash EEPROM is a multi-programmable read only memory component, which—similar to an EEPROM—is electrically erasable, not however bit by bit, or byte by bite, but rather—correspondingly similar to an EPROM—always in its entirety.
In order to program the corresponding memory cells of PROMs, EPROMs, EEPROMs, flash memories, etc. the corresponding memory cells must be charged with (programming) currents of a predetermined level and duration.
In order to read a corresponding memory cell (i.e. in order to determine whether a data bit d=0 or a data bit d=1 has been stored there) so-called reference currents can be used.
A read current resulting for instance from the reading of a memory cell can be compared with a reference current (for instance—in a flash memory—with a reference current at a level of for instance 15 μA (or for instance 5 μA or 20 μA)); depending on whether the corresponding read current is larger or smaller than the corresponding reference current (for instance—depending on the respective cell state—for instance ca. 0 μA (in particular for instance <5 μA), or for instance ca. 30 μA (in particular for instance >20 μA)), it can be determined whether a data bit d=1, or a data bit d=0 has been stored in the corresponding cell.
When testing a read only memory component, an attempt can be made to determine the exact level of the respective read current (for instance for fault finding, or for instance—in accordance with the respective test result—to correspondingly adjust the level and/or duration of the (programming) currents and/or voltages for the normal operation of the memory component, and/or the level of the reference current used in each case, etc., etc.).
The conventionally applied procedures for the testing of a read only memory component in order to measure memory cell currents, in particular read currents, are relatively inaccurate.

Device and procedure for measuring memory cell currents


Electrical contacts in the battery compartment of a device will permit a battery to be inserted with the “+” pole of the battery against either one of the two contacts, with the “−” pole of the battery positioned against the other contact. A polarity-sensing circuit detects the battery's orientation. If a first orientation is detected, i.e., the “+” pole of the battery is touching Contact “A” and the “−” pole of the battery is touching Contact “B”, the polarity-sensing circuit mode-of-operation 1 will be selected. If the second orientation is detected, i.e., the “+” pole of the battery is touching Contact “B” and the “−” pole of the battery is touching Contact “A”, mode-of-operation 2 will be selected. A bridge rectifier, downstream from the polarity sensor, can ensure that the other circuits in the device receive power that is polarized correctly regardless of battery orientation.

Battery polarity identification circuits are well known. For example, U.S. Pat. No. 5,838,143 is directed toward an automatic battery polarity identification circuit having a first electroplate and a second electroplate adapted for receiving two opposite ends of a battery. The circuit further comprises a capacitor having a first end and a second end, and at least one relay, each of the at least one relay having a coil, the coil having a first end connected to the first end of the capacitor and a second end, a second fixed contact and a third fixed contact connected between the first electroplate and the second end of the coil, the first fixed contact and a fourth fixed contact connected to the second electrode.

Using battery orientation to control mode of operation


A fastener for a wig having two approximately U-shape members, each configured of a comb teeth fixed piece, and two curved elastic leg portions which extend from both ends of the comb teeth fixed piece. The two approximately U-shape members are connected to each other at a plurality of connecting points located away from each other in a direction that each of the curved elastic leg portions extends under the condition that opening portions of the approximately U-shape members face each other and the curved elastic leg portions are overlapped each other. Accordingly, both members have both a high elastic deformation capability and a high integrity. Therefore, during the operation such that the fastener for a wig are reversed by fingers, if one of the approximately U-shape members is reversed, the other approximately U-shape member is always reversed at the same time, one reversing operation is always enough.

In the case that wearer's own hairs remain, for example, a fastener described in the Patent document 1 has been widely used, as a method for fixing a wig to the wearer's head. This type of fastener is provided with comb teeth which clamp and fix the own hairs at one longer side of a frame with inverting ability. The fastener is connected to a rear side of the wig such that the comb teeth are positioned in parallel to an extending direction of the own hairs. In this case, since the extending direction of the comb teeth is parallel to the extending direction of the own hairs, there is a problem such that a clamping strength of the comb teeth to clamp the own hairs is low, and a stable fixing strength cannot be obtained if enough amount of own hairs do not exist.
Further, if the head moves in the lateral direction to the extending direction of the comb teeth, the own hairs will easily slip from the comb teeth. On the contrary, if the head moves in parallel to the extending direction of the comb teeth, the own hairs may be pulled by the comb teeth, and the wearer tends to feel pain. Further, there is also a case such that hair loss progresses by using the fastener at the same position for a long time.
In order to improve the above-mentioned defects, there is disclosed a fastener for a wig which is provided with comb teeth at left and right shorter sides of a frame with inverting ability in Patent documents 2 and Patent documents 3.
In the fastener described in Patent document 2, 3, since the fastener is connected to a rear side of the wig such that the comb teeth are positioned in perpendicular to an extending direction of the own hairs, the pain caused due to the pulled hairs will be reduced compared to the case of Patent document 1. However, each of the fasteners of Patent documents 2, 3 has the following problems because it has a construction such that two framing portions forming the left and right shorter sides to which the comb teeth are attached are connected together and integrated at the center position thereof.
Thus, when a wig is removed from the head, it is necessary to reverse the frames of the fastener to release the condition that the comb teeth clamp the own hairs. At this moment, since the fastener has the construction such that two framing portions at left and right are connected at one central position, it is impossible to reverse both framing portions by one operation of reversing the frame, and thereby requiring at least two revering operations. Otherwise, in many cases, the comb teeth at the intended side do not open due to loading strength or the loading position of the framing portion. Therefore, the wearer tends to feel the attaching and removing operation of the wig to be troublesome (this issue will be explained in the description of embodiments with referring to FIG. 4).


An expandable and contractible cellular panel 10 comprises a plurality of parallel, aligned, elongated tubular sections 12 secured together at the median region of their adjacent longitudinal margins to form the panel 10. The adjacent tubular sections 12 of the panel 10 are made of a pair of substantially identical separate strips of sheet material from those forming the other adjacent tubular sections 12. The various adjacent pairs of strips are laminated together along their confronting longitudinal margins. Each strip is made of at least two separate flexible substrate sheets 18,20 having completely different appearances, and are secured together by welding together their longitudinal margins. The corresponding substrate sheets 18,20 of all the strips have corresponding positions in the panel 10, so that all the substrate sheets having one appearance are on one side of the panel 10 and those having a different appearance are on the other side of the panel 10, and the welded portions 28,28' are located in the laminated portion of the strips where they are hidden from view.

The present invention relates to cellular insulation panels. It has one of its most important applications as an insulating panel for covering windows or other openings. These panels most commonly comprise a plurality of tubular sections adhesively secured together. The panel can be oriented so that the tubular sections form a horizontally contractible and expandable panel which extends vertically, such as when covering a doorway or other similar openings. The panel more commonly is used with an orientation where the tubular sections form a vertically collapsible and expandable panel extending horizontally, such as when covering a window.
In window covering, the panel is mounted upon a headrail with pull cords extending down through holes in the panel to a bottom rail secured to the bottom of the panel. In some panel designs, each tubular section is a strip of usually thermoplastic woven or unwoven sheet material folded into an open-top tube. Each tube-forming strip is initially completely separate from the other tubular strips forming the panel and is laminated to the adjacent strips of the panel by bands of adhesive. The folds of each tubular section are usually sharp or set so that they appear as lines or bands which improve the aesthetic appearance of the panel. Such a panel is disclosed in Dutch Published Application No. 6706563 published Nov. 11, 1968 to Landa. In this Dutch publication, the cells have a rectangular, hexagonal or a pointed oval shape, depending on the width of the adhesive bands and the degree of expansion of the cells. If the adjacent tubular sections are secured together over wide securement bands and are fully expanded, the cells have a rectangular shape, as is shown in U.S. Pat. No. 4,019,554 granted on Apr. 26, 1977 to Rasmussen.
In another form of cellular panel construction, a pair of zig-zag shaped sheets of material are placed into confronting relation and secured together at the abutting fold points, to form diamond-shaped cells. This panel construction is disclosed in U.S. Pat. No. 2,201,356 granted Nov. 21, 1938 to Terrell.
The rear side of all these cellular panels, which interrupt the passage of light when covering a window, preferably have a color to reflect light. The front side of the panels, which face into the room involved, desirably have an appearance from a strictly aesthetic standpoint. In the panel design where each tubular section is made of a separate sheet of material folded into a tube, one half of the sheet may be printed or embossed before it is folded into a tubular shape, so that the portion of each sheet which faces the inside of the room is provided with the desired aesthetic appearance. The other half of each sheet, which faces towards the window has color to reflect light. If the initial sheet of material is already of a desired light color to reflect light, it can remain without any added coloring. If the sheet forming each tubular strip is made of an expensive material to give the front side of the panel an attractive appearance, the high cost of the portion of the same sheet which is to face the window is an undesired expense.
The panel design having diamond shaped cells, described previously, made from a pair of separate, confronting zig-zag shaped sheets does not have this problem as only the front sheet must be made of the more expensive material. However, this type of panel is less attractive to some purchasers than the panel having pointed oval, hexagonal or rectangular cells. Also, the method required for fabricating the panel made from zig-zag shaped sheets is less efficient and more difficult to control than the method used to make a panel of separate folded strips of material adhesively secured together.
The preferred cellular panel constructed and manufactured in accordance with the present invention overcomes these disadvantages. The panel can have cells of any desired shape, and can be made by a very efficient stacking process. In addition, only the front side of the panel requires a more expensive material, satisfying the aesthetic objectives of purchasers, and thus, the rear side can be made of a less expensive material, which is only required to reflect light, and aid in forming an insulating panel.
Many of the present features of the invention are applicable to another type of panel to be referred to as a light-controlling cellular panel, which is used to cover primarily windows. In this panel, the front vertical side of each horizontally extending cell is made of a sheer material, preferably of one mesh size, and the rear vertical side of each cell is made of a sheer material preferably of a different mesh size or mesh shape, to avoid a Moire effect. When the panel is in its light-passing state, the upper or lower horizontal wall of each cell is a horizontal opaque wall which, most desirably, is wider than the height of the cell. When one of the vertical sides of the panel is shifted upward or downward with respect to the other vertical side of the panel, the opaque walls are pivoted into substantially vertical positions where they completely overlap, to obstruct the passage of light through the panel.
Most of the methods previously used to fabricate this type of light-controlling panel did not permit the ready manufacture of any desired width of the panel. The commercial forms of this panel have been usually constructed from two horizontally spaced confronting unfolded vertical sheets of sheer material, which respectively formed the complete front and rear sides of the panel. Opaque strips of material are adhesively secured at spaced vertical points between the front and rear sheer sheets of the panel. The cells of this panel have a rectangular shape. As will later be described, the present invention provides a very efficient and effective means for manufacturing a panel having a similar appearance to this panel, but is constructed much differently. The present invention is made from a multiplicity of separate identical strips of material of any desired length, cut from a continuous web and laminated by an efficient strip stacking process where the panel can have any desired length. The panel can then be made into any width using a highly efficient stacking process.

Cellular panel and method and apparatus for making the same


Denture adhesive including a solvent-free, high molecular weight terpolymer of maleic anhydride, a C.sub.1 -C.sub.4 alkyl vinyl ether and isobutylene.

1. Field of the Invention
This invention relates to denture adhesives and particularly to formulations including a solvent-free, high molecular weight terpolymer of maleic anhydride (MAN), a C.sub.1 -C.sub.4 alkyl vinyl ether (AVE), and isobutylene (IB), for use as active materials in denture adhesive formulations.
2. Detailed Description of the Prior Art
U.S. Pat. No. 5,037,924 described the preparation of terpolymers of maleic anhydride, a C.sub.1 -C.sub.4 alkyl vinyl ether, and isobutylene, for use as denture adhesives in the form of their mixed salts. These terpolymers were made by precipitation polymerization in the presence of an added solvent, for example, a cosolvent system of ethyl acetate and cyclohexane. The resultant terpolymer had a low molecular weight of about 30,000 to 400,000, with relatively good performance, in the form of their mixed salts, as denture adhesives. Furthermore, the terpolymers and their salts made therein in U.S. Pat. No. 5,037,924 contain trace amounts of the ethyl acetate and cyclohexane solvents.
Accordingly, it is an object of this invention to provide solvent-free, high molecular weight terpolymers of MAN, an AVE and IB with molecular weights of at least about 1,500,000, which, in the form of their mixed salts, perform in an excellent manner as denture adhesives.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.


The link layer of the multi-root PCI (peripheral component interconnect) express device stores transaction layer packets (TLPs) sent from a transaction layer in a dedicated retry buffer dedicated to the virtual hierarchy (VH) associated with the TLP. The link layer of the multi-root device also stores information related to the TLP about the VH and an address of the TLP stored in the dedicated retry buffer in a sequence buffer. Upon receipt of a reset request for a VH, the link layer may purge the dedicated retry buffer associated with the VH. After purging, the multi-root device may send an ACK (acknowledge code) DLLP (data link layer packet), indicating that the VH has been successfully reset. By utilizing multiple retry buffers, the ACK DLLP response for a VH reset is sent as soon as the retry buffer pointers are reset to initial values.

PCI (peripheral component interconnect) express (PCIe) is a computer expansion card interface format. PCIe is structured around point-to-point full duplex serial links called lanes. PCIe enables PCIe components to be interconnected to a computing device. PCIe IOV (input/output virtualization) allows PCIe components to be utilized by more than one system image (a software component running on a virtual system to which specific virtual and physical devices may be assigned). In a PCIe single-root IOV topology, PCIe components may be utilized by multiple system images running on a single computing device under a single root complex. In a PCIe multiple-root IOV topology, PCIe components may be utilized by multiple system images running on multiple computer devices under multiple root complexes. A virtual hierarchy is the portion of a PCIe IOV topology assigned to a single PCIe domain hierarchy.

PCI express multi-root IOV endpoint retry buffer controller


A new variety of Chrysanthemum plant named ‘Mermaid Yellow Improved’, having a domed, round canopy of yellow decorative type flowers.

The present invention comprises a new and distinct cultivar of Chrysanthemum botanically known as Chrysanthemum morifolium, and referred to by the cultivar name 'Mermaid Yellow Improved'.
'Mermaid Yellow Improved' originated from a naturally occurring whole plant mutation grown in a controlled planting of the planting of the unpatented variety "Mermaid" in Chichester, West Sussex, United Kingdom.
The new variety 'Mermaid Yellow Improved' has been asexually reproduced by vegetative cuttings in Chichester, West Sussex, United Kingdom and the distinguishing characteristics are retained through successive generations of asexual reproduction.


Disclosed is a composition containing phosphatidylserine as an effective ingredient, and more particularly to a composition containing phosphatidylserine as an effective ingredient for protecting and improving a skin, reinforcing a skin barrier function, suppressing and alleviating an inflammatory response, treating and improving an atopic skin, activating PPAR-a promoting a differentiation of the skin, protecting the skin and preventing and improving skin aging and wrinkle. Accordingly, it is possible to protect and improve the skin from the injury due to the ultraviolet or the external stimulating material such as chemical material and to reinforce and strengthen the skin barrier function using the composition, thereby improving a general skin state.

The mammal skin comprises various kinds of cells, performs a variety of functions and includes diverse chemical compositions. A variety of lipids exist between the different skin layers in various concentrations. Specifically, the dermis of skin consists of fibroblasts that mainly produce collagen and other proteins and a small quantity of lipid. On the contrary, the epidermis includes keratinocytes that produce the lipid but does not substantially produce the collagen. The collagen produced by the fibroblasts endows the skin with an extension strength and the lipid produced by the keratinocytes forms an interruption layer between a living tissue and an external to perform a skin barrier function.
As lipid ingredients in the skin, there are phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, triglyceride, glucosylceramide, ceramide, cholesterol, cholesterol sulfate, free fatty acids and the like. Among them, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol and the like that are phospholipids are distributed in the dermis and the ceramide-based materials are mainly distributed in the epidermis. The distribution ratio of the compositions and the lipid amount contribute to a skin barrier maintenance homeostasis and provide a rapid restoration action against external physical and chemical injuries.
The epidermis lipid during the aging is generally reduced contrary to the otherwise epidermis tissue, so that the skin barrier function is decreased. In addition, an overall epidermis lipid is reduced to a degree of about 30% of the young people, but each content proportion of the lipids is maintained. This validates that the lipids of the skin keratin are produced through lipid biosynthesis and ceramide biosynthesis pathways. It has been reported that the lipids of the skin keratin are actually derived from the phospholipids and the free fatty acids of the dermis [Hamanaka et al., J. Invsti. Dermatol., 119, pp 416-423, 2002]. It has been also known that the skin proceeds to an aging skin as the ratio of the free fatty acids is changed [Rogers et al., Arch. Dermatol. Res. 288, pp 765-770, 1996].
The phosphatidylserine is a kind of the lipids present in the nature and a material consisting of serine group, phosphate group, glycerol and two fatty acid groups connected each other. A weight of lecithin occupies about a half of a dry weight of a human brain. Most of lecithin forms a nerve cell membrane. The phosphatidylserine is a kind of lecithin derivatives that are important ingredients of the cell membrane and present particularly in plenty in the brain. It seems that the phosphatidylserine is deeply concerned with function expressions of the nerve cells, for example energy flow for a life-support activity in the nerve cell membrane and information transfer such as neurotransmitter discharge or synapse activity. However, although the phosphatidylserine is present in plenty in the brain of an animal, it is present less than a concentration of 0.1% in the origin except the brain of the animal, so that it is difficult to obtain the phosphatidylserine in a large quantity from natural raw materials.
It has been recently known peroxisome proliferators activated receptors (PPAR) existing in skin constituting cells on the whole. It has been clarified that the PPAR plays an important role in expressions of the barrier restoration and inflammation healing processes of the skin.
Specifically, the PPAR is a factor of regulating the energy homeostasis. It has been known that the PPAR is concerned with the skin state regulation such as permeability regulation of the skin barrier, epidermis layer multiplication inhibition, differentiation induction of the epidermis layer and the like through various mechanism. Due to the properties, the PPAR acts as a core regulator of diverse skin diseases such as psoriasis, wound healing and acnes due to hyperplasia of the epidermis layer as well as inflammation related skin diseases.
Accordingly, although it has not been much known a specified signal transfer of a material contributing to the skin homeostasis, it is attempted a specific research on functions of the phospholipids related to the PPAR which has been recently known. It is known that the PPAR has three subtypes. Among them, it has been clarified that PPAR-a has a possibility of a receptor of the phosphatidylserine [Michalik et. al., The Journal of Cell Biology, 154, pp 799-814, 2001].
In actual fact, it has been clarified that when clofibrate, WY14643 and the like, which are already known-agonists of the PPAR-a, are applied to the skin, the inflammation due to the skin stimulating material is decreased [Sheu et. al., The Journal of Investigative Dermatology, 118, pp 94-101, 2002].
Up to date, materials such as glucocorticoid have been used as anti-inflammatory agent. However, if continuous administration or treatment thereof is conducted, a chronic side-effect is caused, so that an immunological reaction is mainly decreased and thus the treatment is limited. Thereby, it has been considered that the agonist of the PPAR-a is a local and efficient treatment method, compared to the glucocorticoid (Sigma, USA).
In addition, the skin aging is classified into a photo-aging observed in the skin that is exposed to the ultraviolet for a long time and an intrinsic aging (chronological aging) observed in the skin that is not exposed to the ultraviolet. In the photo-aging and intrinsic aging, the skin becomes thin clinically and there occurs a wrinkle in the skin due to a decreased elasticity of the skin. It is thought that deficiency of the matrix protein, which is produced from the cell in the dermis, is a main cause of the wrinkle. Of the matrix protein in the skin, the collagen occupies 90% or more and the elastin occupies about 3˜4%. In general, the wrinkles are closely related with the collagen reduction in the skin tissue and the expression increase of a matrix metalloproteinase (MMP) which is a kind of the protease, which are closely connected with an activity of the fibroblasts in the dermis tissue. Although there are many research results about the collagen reduction and the MMP increase due to the ultraviolet and mechanisms thereof, a correct mechanism thereof has not been known up to now. A mechanism that has been most known is an activation of AP-1 (activator protein) due to the ultraviolet and a competition of TGF-β/smad, which is important for the collagen synthesis, for p300. The AP-1 and smad binding element (SBE) require the p300 so as to act as transcription factors. Since an amount of the p300 existing in the cell is limited, if one transcription factor is activated, the other transcription factor is impeded. Accordingly, the activation of the AP-1 by the ultraviolet causes the expression of the MMP to be increased and thus the synthesis of the collagen is decreased due to the increase of the MMP. Thereby, it is expected that the increase of the collagen amount and the impediment of the MMP expression may suppress the skin aging.

Composition for protection and improvement of skin, or reinforcing skin barrier function comprising phosphatidylserine


A furniture joinery comprises a slide rail having a plurality of grooves, at least one slide block slidably disposed in the slide rail, the slide block having a plurality of slides for engaging the slide rail, at least one of the plurality of slides having a neck and a head, the grooves receiving the neck therein.

1. Field of the Invention
The present invention relates to a mounting assembly and more particularly to mounting assembly for use in a tent, for example, which is used during tailgating activities.
2. Description of the Related Art
Portable tents are utilized for various events such as tailgating and wedding receptions, outdoor dining and the like. At times, during unexpectedly hot weather, tents can become extremely warm rendering users therein uncomfortable. In order to alleviate this problem, it is preferable that, where the tent is tall enough to accommodate such device, a ceiling fan be used to move air within the tent. However, tents come in various sizes and shapes so mounting these air movers is difficult.
Likewise, lighting is sometimes a problem inside tents. A mounting assembly for positioning a luminaire is desirable, in addition to or independently of the fan assembly as described above.
Given the foregoing, it will be appreciated that a tent canopy mounting assembly is desired which may be used with various tent constructions and which allows for easy installations of suspended electrical equipment and which allows for connection of a power supply to operate the electrical equipment.


A filament having excellent incision resistance includes as a primary component a polyethylene filament having a weight-average molecular weight of 300,000 or less and a ratio of a weight-average molecular weight to a number-average molecular weight (Mw/Mn) of 4.0 or less as determined in the state of a filament as well as a modulus of 500 cN/dtex or more. This filament is useful to produce a fabric excellent in incision resistance, a fibrous material for reinforcing mortar or concrete, and a rope, each of which comprises the filament. The filament can be produced by drawing a non-drawn polyolefin filament which comprises a polyethylene having a weight-average molecular weight of 60,000-600,000, a ratio of a weight-average molecular weight to a number-average molecular weight (Mw/Mn) of 4.5 or less, and a rate of birefringence (Δn) of 0.008 or more, at a temperature not higher than the α-relaxation temperature of the non-drawn filament.

Conventionally, natural fibers (such as cotton) and the general organic fibers have been used as an incision-resistant material. Gloves made by knitting up those fibers etc. have been often used in the field which needs incision-resistant.
Then, knits, textiles, etc. which consist of spun filament of high strength filaments, such as an aramid fiber, for providing the incision-resistant function have been devised. However, there was dissatisfaction in the viewpoint of a hair omission or durability. Although trials which improve incision-resistance by on the other hand using metal fibers together with organic fibers or natural fibers as another means are performed, the drape of textures becomes hard by using metal fibers, and there is thus a problem that pliability is impaired.
For example, the fiber reinforced concrete which is made by kneading metal fibers, glass fibers, carbon fibers, polyvinyl alcohol fibers, or various olefin fibers to various cement mortar or concrete materials is developed as a method of improving the brittleness which is a defect in the structure material of cement mortar and concrete (for example, JP-B-58-18343, Japanese patent No. 2,510,671). However, although the reinforcing effect by adhesion with a concrete matrix is excellent, the fibers for these reinforcement, such as metal fibers represented by steel fibers, essentially have large specific gravity which results in a defect that a structure made thereof becomes heavy, and in addition, the strength of the structure is degraded due to generation of rust. Therefore, the fibers are unsuitable as structure material for such as harbor facilities or skyscrapers asked for a weight saving.
On the other hand, for inorganic fibers, glass fibers have an inferior in alkali resistance and carbon fibers have a problem in that the fibers become bended or cut during kneading. In addition, polyvinyl alcohol fibers or polyolefin fibers, especially polypropylene fibers which are organic fibers, are low in tenacity, and thus have a problem of reduction in slump due to a need to increase the incorporation of the fibers to a large extent for achieve a sufficient effect. Although polyethylene fibers with ultra-high molecular weight are excellent in strength or alkali resistance, the fibers have a problem in that stiffness of the fibers is low and they easily get twined with each other to become a lump during kneading due to the flatness of the cross section.
Conventionally, twists of synthetic filaments, such as vinylon, polyester filament, and nylon, have mainly been used for a rope. In recent years, although a monofilament of fluorocarbon or nylon, as well as the interlace of a nylon monofilament came to be used for the rope, the rope of the interlace structure of a nylon monofilament had an inadequate tensile strength and thus was sometimes broken in the ocean area especially with wild waves. In addition, an improvement was desired also in respect of wear resistance and durability. Further, since the tensile strength was not high enough, the rope itself should be thick inevitably and the nature for containment and handling were remarkably bad.
As a polyethylene filament with a high strength, there is known a filament which is produced from an ultra-high molecular weight polyethylene by a so-called "gel-spinning method and melt spinning" and which has such a high strength and such a high elastic modulus that any of conventional filaments has never possessed, as disclosed in JP-B-60-47922 and JP-A-62-257414 for example, and this filament has already come into industrially wide use.
A high strength polyolefin filament produced by melt spinning is disclosed in, for example, U.S. Pat. No. 4,228,118. According to this patent, the process for producing a high strength polyethylene filament disclosed comprises extruding a polyethylene having a number-average molecular weight of at least 20,000 and a weight-average molecular weight of less than 125,000 through a spinneret which is maintained at the temperature between 220 and 335° C., then taking over the polymer at the rate of at least 30 m/min. followed by drawing it at least 20 times at the temperature between 115 and 132° C. Thus the filament has a tenacity of at least 10.6 cN/dTex.
Moreover, JP-A-08-504891 discloses a high strength polyethylene filament which is produced by melt spinning polyethylene with high density through a spinneret, and then drawing the obtained fiber at the temperature of 50-150° C. The process for production is characterized in that the polyethylene provided for melt spinning is a homopolymer of ethylene which satisfies the conditions of having a weight-average molecular weight (Mw) of 125,000 to 175,000, a number-average molecular weight (Mn) of 26,000 to 33,000 and a polymer dispersibility (Mw/Mn) of less than five, as well as a density of larger than 0.955 g/cm3, and that the extent of draw ratio at the draw stage is at least 400%. This patent is characterized by controlling the polymer dispersibility and the density of polyethylene as a starting material to the above-mentioned value.
In addition, JP-A-11-269717 discloses a high strength polypropylene filament made from a crystalline polypropylene with a weight-average molecular weight of 200,000 to 450,000, although the tenacity of the high strength polypropylene filament obtained according to the patent is at most about 13 cN/dtex. This patent is characterized by blending two kinds of polypropylene as starting materials each of which has a different melt flow rate, performing melt spinning, and drawing said filament to 5 times or more under the draw temperature of 120-180° C., using a pressurized steam.
Production cost becomes very high from the industrial viewpoint since a mixture of a solvent and a polymer is used in gel-spinning and solution-spinning. That is, by the method currently disclosed in this patent, the concentration of polyethylene as a starting material is at most 50% or less, and thus is lacking in productivity. If a solvent is used, incidental facilities, such as an equipment for recovery/purification and the like, will certainly be needed, which is thus expensive. Additionally, it is not desirable in respect of environment.
Furthermore, with respect to a melt spinning, although some arts are known, a high strength of said filament is attained only by the very limited conditions for production.

Process of making a high strength polyolefin filament


The use of a two layer photoimageable, aqueous processable, resist with an amphoteric binder in the layer laminated directly to a printed circuit board provides a permanent coating with improved adhesion throughout the lamination process while maintaining other desirable properties such as storage stability and circuit encapsulation.

Photopolymerizable resist materials are known to form a resist layer on a substrate, such as a printed circuit board, to allow subsequent processing of the substrate such as selective etching, electroplating or treatment with solder. The use of a non-photopolymerizable secondary layer in combination with photosensitive materials, such as a photopolymerizable resist, is known to enhance particular properties of the photoresist such as surface hardness, phototool release and photosensitivity.
The use of a solvent developable multiple layer photoresist for use in the etching of printed circuit detail is known. U.S. Pat. No. 4,349,620 describes such a photoresist that has improved adhesion, without sacrifice in development time, and with reduced film thickness. The use of a two layer photoresist system is disclosed in U.S. Pat. No. 4,352,870. Improved resolution is achieved through the resist layer closer to the substrate having a greater photosensitivity.
Lamination of a photosensitive material onto a substrate employing an intermediate liquid layer is taught in several U.S. Pat. Nos. using various liquids and application techniques. U.S. Pat. No. 3,629,036 discloses application of a liquid adhering agent, preferably a solvent for a resist containing a small amount of dissolved resist, to a surface of a substrate followed by application of a photosensitive resist film. U.S. Pat. No. 4,069,076 discloses a process for applying a photoresist film to a preimaged pattern relief substrate after flooding the substrate with a solvent or a nonsolvent swelling agent to reduce air entrapment and improve resist conformation. U.S. Pat. No. 4,293,635 discloses application of a photosensitive composition containing an amphoteric interpolymer, for improved cold flow, to a copper surface wetted with a liquid such as ethanol-water solution. U.S. Pat. No. 4,698,294 discloses a process for lamination of a dry film with a lamination liquid, which is substantially all monomer and non-photosensitive, such that adequate conformation and adhesion of the dry film to the circuit board is obtained with no air entrapment.
U.S. Pat. No. 4,506,004 discloses various embodiments of obtaining printed circuit boards more cost effectively by means of a two layer composite coating. In one embodiment an adhesive photopolymer layer is applied to a printed wiring board in a liquid state displacing air from the printed wiring board surface. A dry film solder mask is temporarily adhered to the underside of a screen printing frame and applied onto the liquid layer prior to processing of the photopolymer layer. In another of the embodiments of the patent nonphotoimaging epoxy layers can be employed.
In the use of permanent coatings for printed circuit boards, a combination of storage stability and acceptable end-use properties such as high temperature (solder) resistance, chemical inertness, high electrical resistance, low electromigration and good adhesion to raised copper metal reliefs is difficult to achieve, particularly with the use of liquids alone or dry films alone. Photoimageable liquid permanent coatings are known to suffer from pin-holes and skips as well as insufficient mask thickness at the corner of raised copper metal reliefs. Dry film photoimageable permanent coatings will typically alleviate the drawbacks of liquids, but are more costly and do not conform as well to the raised copper reliefs as liquids. It would be useful to have a permanent coating with an acceptable balance of the required storage, application and performance properties and particularly useful for the coating to be aqueous processable.

Aqueous processable, multilayer, photoimageable permanent coatings for printed circuits


A lens driving mechanism for an image pickup apparatus capable of being reduced in size, and having excellent driving accuracy and tranquility is provided. The lens driving mechanism is characterized in that vibration of a piezoelectric vibration motor is used as a driving source, and the vibration is transmitted to a motor power transmission ring directly or via a gear structure, to rotationally drive a lens driving ring. In a first lens driving mechanism, the motor power transmission ring is rotated by rotating the first transmission gear by use of the vibration of the piezoelectric vibration motor. In a second lens driving mechanism, a thrust bearing is provided on a gear side for rotating the motor power transmission ring, and the gear is rotated by vertically pressing a vibrator of the piezoelectric vibration motor in an urged state against a plane of the gear. In a third lens driving mechanism, the lens driving ring is rotationally driven by directly pressing a vibrator of each of one or more piezoelectric vibration motors in an urged state against the outer periphery of the lens driving ring.

1. Field of the Invention
The present invention relates to a lens driving mechanism of an image pickup apparatus, and an image pickup apparatus using the lens driving mechanism
2. Description of the Related Art
In recent image pickup apparatuses such as cameras, auto-focus mechanisms capable of freely changing a focal length at the time of picking up images within a given range are employed. There is an increasing demand for the image pickup apparatuses to have a higher magnification and larger aperture. Generally, in the auto-focus mechanisms, at least either mechanical compensation in which movement of a focal plane is compensated for by nonlinear movement of a lens group using a cam, or optical compensation in which a focal plane is designed to remain constant even after zooming is effected by calculating an optical power balance is employed and is used in combination with electronic compensation in which movement of a focal plane is compensated for by using an auto-focus function of the image pickup apparatus. This is because the focal plane movement of a zoom lens having a high magnification and large aperture is difficult to compensate for to a sufficient level by using only the mechanical compensation or the optical compensation.
As shown in FIGS. 13 and 14, in a lens driving mechanism of a conventional image pickup apparatus, a driving force is transmitted from the end of a rotating shaft of a DC motor 61 to a first drive gear 62 via belt drive, and a rotor 70 connected to a motor power transmission ring 67 is rotated via multiple clutch gears 63. Accordingly, a lens driving ring 68 mounted on the inside of the motor power transmission ring 67 is rotationally driven.
For example, a lens frame driving apparatus disclosed in Japanese Patent Laid-Open No. 2006-71942 as a lens driving mechanism includes: at least one vibrator for generating elliptical vibration composed of bending standing-wave vibration and longitudinal vibration; an electrically-driven member linearly driven in an optical axis direction relative to the vibrator by the action of the elliptical vibration of the vibrator; a manually-driven member provided movably in the optical axis direction in accordance with manual operation; and a driven member in which a rolling element in pressure contact with the outer surface of the electrically-driven member and the inner surface of the manually-driven member to be rollable in the optical axis direction is disposed, and which is linearly moved in the optical axis direction along with the rolling element that rotates to move in response to the relative movement of the electrically-driven member and the manually-driven member in the optical axis direction.
In a vibration wave motor and a lens barrel disclosed in Japanese Patent Laid-Open No. 2006-158054, a lens in a lens barrel is drive-controlled by a vibration wave motor for bringing at least one vibrator including a driving element excited to perform elliptical vibration, and a node of vibration into frictional contact with a contact surface provided perpendicular to a rotation axis direction in a rotor supported to rotate about the rotation axis, and rotationally driving the rotor, the vibration wave motor including a support member, a guide support portion formed in the support member, the guide support portion supporting the vibrator substantially at the node of vibration while restricting movement of the vibrator in a direction perpendicular to the rotation axis and a circumferential direction and enabling linear movement of the vibrator along the rotation axis direction, and an urging member arranged in the support member, the urging member urging the vibrator in the rotation axis direction of the rotor so as to be in contact with the contact surface, wherein the vibrator, the rotor, the support member, and the urging member are integrated into a unit to form the vibration wave motor.
However, conventionally, in the lens driving mechanism as shown in FIGS. 13 and 14, multiple gears need to be arranged between the rotating shaft of the DC motor 61 and the motor power transmission ring 67. Thus, there is a limit in ensuring the driving accuracy and downsizing as the lens driving mechanism, and it is difficult to further reduce the size of the lens driving mechanism. The lens driving mechanism also has a disadvantage that it lacks tranquility with the driving sound of the gears at the time of rotation being loud since each gear of the multiple gears is set with a given reduction ratio.
A lens frame apparatus in which the lens frame driving apparatus disclosed in Japanese Patent Laid-Open No. 2006-71942 is incorporated includes an ultrasonic actuator mounted on a fixed frame via a mounting plate. A movable frame with which the vibrator of the ultrasonic actuator is in pressure contact is fitted to the outer peripheral portion of the fixed frame in a forward/backward movable manner. A driven frame is fitted to the outer peripheral portion of the movable frame, and an outer frame is fitted to the outer peripheral portion of the driven frame respectively in a forward/backward movable manner. A roller is incorporated in the driven frame in a state of pressure contact with the movable frame and the outer frame. When the movable frame is electrically driven by the actuator, the driven frame is forwardly/backwardly driven via the roller in accordance with the forward/backward movement of the movable frame. On the other hand, when the outer frame is forwardly/backwardly driven by manual operation, the driven frame is forwardly/backwardly driven via the roller in accordance with the forward/backward movement of the outer frame. The technique disclosed in Japanese Patent Laid-Open No. 2006-71942, however, has a problem that it is not possible to increase the aperture size of a lens incorporated within a lens frame, and reduce the size of the lens frame at the same time since the ultrasonic actuator is mounted inside the lens frame.
The vibration wave motor disclosed in Japanese Patent Laid-Open No. 2006-158054 includes a housing, a rotor, a bearing member, a vibrator serving as an actuator and having a support shaft and a driving element, and a leaf spring having a pressing protrusion. The vibrator is slidably disposed in an opening of the housing along the rotation axis direction with the support shaft being supported in a rotatable manner. The vibrator is held while being urged by the leaf spring and being in contact with the rotor. The vibrator is excited to generate supersonic vibration so that the rotor is rotated. Since the vibrator is movably supported by the housing in the rotation axis direction and the vibrator is urged by the leaf spring and is in contact with a friction contact surface of the rotor, the vibrator is evenly in contact with the rotor in a direction perpendicular to the friction contact surface so as to provide superior driving conditions of the vibration wave motor. That is, in the lens barrel of Japanese Patent Laid-Open No. 2006-158054, the vibrator is rotated in contact with the rotor as a plane perpendicular to an optical axis in the lens barrel, to thereby drive the lens barrel by use of the torque. The technique, however, has a problem that the driving accuracy is relatively low as compared with a case of directly driving the lens barrel since the lens barrel is driven via a predetermined power transmission mechanism.
Accordingly, there has been a demand for a lens driving mechanism for an image pickup apparatus capable of being reduced in size, and having excellent driving accuracy and tranquility.

Lens driving mechanism and image pickup apparatus using the same


The control section can determine, on the basis of a detection signal from a detection device, whether operation of an element corresponding to the detection device has completed. The display device can display step sequence data and a three-dimensional model of a machine tool operated through simulation. When the abnormality detection section detects an abnormality of the machine tool, the control section extracts, from a ladder circuit corresponding to a step in which an abnormality has been detected, an element to be operated in response to completion of operation of a preceding element in the ladder circuit, or an element not having completed its operation. The control section then specifies a detection device corresponding to the extracted element or a moving part corresponding to the detection device, and displays the element or the moving part in the displayed three-dimensional model in a distinguishable manner.

1. Field of the Invention
The present invention relates to a machine tool control apparatus for controlling a machine tool; in particular, a machine tool equipped with a numerical controller and a safety device, etc. provided around the machine tool.
2. Description of the Related Art
Conventionally, a machine tool is provided with a numerical controller for controlling operation of the machine tool, and an operation panel including instruction input means and display means. The machine tool is configured to enable input of operation instruction from the operation panel and display of an abnormal condition on the operation panel.
In a conventional machine tool, an abnormal condition is typically displayed in the form of character data (including numerals). For example, when an abnormality occurs in a sensor A, a message "Sensor A is Abnormal" or an error code "123" is displayed. However, in the case where a workpiece is mounted on a jig with a slight positional deviation from the correct position, the machine tool may stop without displaying occurrence of an abnormality (hereinafter, such an abnormality will be referred to as "clam-up stop abnormality"). In such a case, even a skilled operator encounters difficulty in specifying a cause of stoppage of the machine tool.
In view of a foregoing, there has been proposed a facility monitor apparatus which displays on a touch-switch-type display unit a screen as shown in FIG. 5 (a ladder circuit corresponding to a step in which an abnormality has occurred (a circuit diagram showing the operation sequence of the step and the completion condition of the step)) when a machine tool has stopped because of occurrence of an abnormality (including clam-up stop abnormality), to thereby facilitate the operator's work for specifying the cause of the abnormality (see Japanese Patent Application Laid-Open (kokai) No. 2003-122427).
In recent years, an increasing number of companies have started operations in foreign countries where production cost is low so as to manufacture products or parts with high price competitiveness. In such a case, in general, skilled workers cannot be recruited in such foreign countries. Further, even in Japan, the number of skilled workers having mastered high-level techniques has decreased, and an increasing number of unskilled workers such as outsource workers tend to be found in production sites.
Although the conventional machine tool typically reports occurrence of an abnormality by use of "character data, " this is insufficient for unskilled workers. For example, even when a message "Sensor A is Abnormal" is displayed, an unskilled worker cannot cope with the abnormality, because he or she may not know the location where the sensor A is mounted to the machine tool. Further, even when the mounting position of the sensor A is found, the unskilled worker may not know how to repair or replace the sensor A. Moreover, when a clam-up abnormality has occurred, a very long time may be required to specify the cause of the abnormality, and a very long time may be required to resume the operation.
The conventional technique disclosed in the above-mentioned publication suffers the same problem as the conventional machine tool in that an unskilled worker may be unable to find the mounting location of a part (sensor A in the above-described example), which is the cause of an abnormality, and the unskilled worker may not know the steps of repairing or replacing the part. However, in the case of a clam-up abnormality, the disclosed technique facilitates the work of specifying the cause of an abnormality.
Specifically, in the case of a clam-up abnormality, a ladder circuit corresponding to a step in which the machine tool has stopped is displayed, thereby enabling the unskilled worker to successively investigate or check moving parts each corresponding to a sensor, switch, or the like contained in the ladder circuit. Since the range of investigation is automatically narrowed, the cause of an abnormality can be easily specified.
In the case of a ladder circuit as simple as the example shown in FIG. 5 (having six or so elements), sequentially investigating the displayed elements does not require a considerably long time. However, in the case where a worker or operator does not know the locations of moving parts corresponding to the elements to be investigated and/or the worker or operator does not know the shapes of the moving parts, sequentially investigating the moving parts may take a considerably long time.


A method to manage modification of encryption credentials for an encryption server. The encryption server is used to encrypt data uploaded by a user after provision of user encryption credentials associated with an encryption account. The data is encrypted by using a user encryption key stored in a cloud storage server.

Cloud storage service providers often store data encrypted by an encryption service provider. In such a case, the cloud storage service provider never has access to user data, only to the encrypted data.
The encryption service provider has access to the data only when credential for the cloud storage service is provided by the user. As the user holds the credential, he is in control of his/her data.
Traditionally, a user credential such as password is used to authenticate and authorize access to a service. This user credential is typically the basis for deriving an encryption credential (e.g. encryption key) which is used for encrypting the user data. The derivation features are out of scope of the invention and will thus not be addressed in details here.
According to such derivation features, the encryption credential is classically derived from the user's login credential at the encryption server. Typically, the 'secret' input to this derivation function is a user password. Without this 'secret', the server cannot generate the encryption key.
In the case of loss, a second factor of authentication, or an out-of-band mechanism is sufficient to reset the first credential. Once the credential is reset, it is however necessary to be able to recover all the data previously stored encrypted.
The need for non-traditional credential recovery method arises in the context of such credentials being used also to derive keys for encrypting data. In such context, it is not possible to recover the keys without the original credential. It is thus not possible to recover the previously stored data.
Further alternative and advantageous solutions would, accordingly, be desirable in the art.

Method to manage modification of encryption credentials


A support garment for diving equipment includes several subassemblies for providing comfortable support of diving equipment, such as a tank of pressurized breathing gas, a buoyancy compensating air cell and a ballast weight pocket assembly. A frame is adjustably secured to a shoulder support assembly that includes adjustment straps for accommodating various body sizes. A belt assembly is pivotally secured to the lower portion of the frame. A bust or chest panel extends between shoulder supports, providing a secure and comfortable fitting structure for divers of various body types, particularly women. Elements of the garment are secured to one another via rivets placed at predetermined locations, thereby facilitating assembly and servicing of the garment.

The present invention relates generally to devices used by underwater divers for supporting equipment and for maintaining neutral buoyancy during dives. More particularly, the invention relates to an improved buoyancy compensator, particularly well suited for use by women, that more comfortably conforms to the divers body morphology and more effectively supports loads encountered both underwater during a dive and out of the water during preparation for and following a dive.
Various structures have been proposed and are currently available for supporting equipment used by underwater divers. Such structures often include a support harness and backpack for holding one or more pressurized diving tanks behind the divers back. A buoyancy compensating device, often referred to as a "BC," may be incorporated with the tank support structure, or may be provided as a separable unit. Such BC's typically include a sealed bladder or air cell that can be selectively inflated or vented by the diver as needed to maintain a neutral buoyancy during the dive, thus facilitating underwater activities and swimming. A weight system may be incorporated into the BC to allow the diver to insert and remove weights for additional buoyancy control.
Known BC structures are configured to fit snugly around the diver's torso, such as by adjustable straps wrapping around the diver's shoulders and waist. Where a tank supporting backpack is incorporated in the device, the position of the backpack may sometimes be made adjustable by means of the strap arrangement. Moreover, certain BC's may incorporate an integrated ballast weight system into a unitary structure. Where a weight system is not included in the BC, the diver will often opt to wear a separate weight belt below the tank support and BC structure.
While such BC devices have substantially improved the comfort and facility of underwater diving, they are not without drawbacks. For example, despite the adjustability of known BC and tank support systems, they are often uncomfortable or unwieldy for certain divers, such as women. Generally, with few exceptions, heretofore known tank supports and BC's have been designed similar to orienteering backpacks, having a pair of shoulder straps, a sternum strap and a waist belt, all designed for use by men of relatively standard size and morphology. As a result, such structures often provide insufficient adjustability for smaller persons. Moreover, the shoulder strap, backpack and sternum strap arrangements of conventional tank supports and BC's are not well suited to the upper body configuration of most women. While attempts have been made to improve or adapt such structures for women and other divers, these have provided only limited success.
There is a need, therefore, for a tank support and buoyancy compensating device that provides a greater degree of comfort and adjustability for a range of body morphologies, especially those of women. In particular, there is a need for an improved diving garment that will fit comfortably, yet securely over the bust and hip regions, without unduly limiting the diver's freedom of movement or compromising the effectiveness of the support. The device should advantageously provide for adequate and comfortable support of diving equipment, such as a pressurized air tank, a BC air cell and a weight system, both during underwater dives and out of water during transport, preparation and following dives.


Systems and methods are provided for detecting voiced and unvoiced speech in acoustic signals having varying levels of background noise. The systems receive acoustic signals at two microphones, and generate difference parameters between the acoustic signals received at each of the two microphones. The difference parameters are representative of the relative difference in signal gain between portions of the received acoustic signals. The systems identify information of the acoustic signals as unvoiced speech when the difference parameters exceed a first threshold, and identify information of the acoustic signals as voiced speech when the difference parameters exceed a second threshold. Further, embodiments of the systems include non-acoustic sensors that receive physiological information to aid in identifying voiced speech.

The ability to correctly identify voiced and unvoiced speech is critical to many speech applications including speech recognition, speaker verification, noise suppression, and many others. In a typical acoustic application, speech from a human speaker is captured and transmitted to a receiver in a different location. In the speaker's environment there may exist one or more noise sources that pollute the speech signal, or the signal of interest, with unwanted acoustic noise. This makes it difficult or impossible for the receiver, whether human or machine, to understand the user's speech.
Typical methods for classifying voiced and unvoiced speech have relied mainly on the acoustic content of microphone data, which is plagued by problems with noise and the corresponding uncertainties in signal content. This is especially problematic now with the proliferation of portable communication devices like cellular telephones and personal digital assistants because, in many cases, the quality of service provided by the device depends on the quality of the voice services offered by the device. There are methods known in the art for suppressing the noise present in the speech signals, but these methods demonstrate performance shortcomings that include unusually long computing time, requirements for cumbersome hardware to perform the signal processing, and distorting the signals of interest.
In the figures, the same reference numbers identify identical or substantially similar elements or acts.
Any headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

Detecting voiced and unvoiced speech using both acoustic and nonacoustic sensors


An optoelectronic sensor is attached to an optically transparent substrate, such as glass, and encapsulated to form an optoelectronic device. An optical assembly can be mounted opposite the optoelectronic sensor. Filters and refractive index matching materials may be included between the optoelectronic sensor and the optically transparent substrate.

Numerous electronic devices, such as digital cameras, personal digital assistants, and internet appliances, utilize optoelectronic sensors. Optoelectronic sensors are semiconductor chips that are capable of electronically capturing visual information by converting light to electronic signals so that this information can be processed or viewed electronically. Optoelectronic devices, such as image sensors, charge coupled devices (CCDs), or other light sensitive sensors, require the sensors to have a "line of sight" through the package housing the optoelectronic sensors.
A conventional optoelectronic device usually encapsulates a semiconductor chip onto which the sensor is mounted in a package with a non-transparent molded resin or ceramic material, which prevents the encapsulated semiconductor chip from chemical or physical reaction with the external atmosphere as well as providing mechanical protection to avoid damage to the semiconductor chip from external sources. Typical packages include plastic or ceramic leaded or leadless packages, ball grid array (BGA) packages, and dual in line packages (DIP). However, for optoelectronic devices, the structure of the package for the device regardless of the type of package includes a glass cover mounted on the package so the optoelectronic sensor mounted in the package is capable of detecting light passing into the device through the glass cover.
Conventional packages for optoelectronic devices therefore consist of two pieces, a carrier substrate for the optoelectronic sensor and the glass cover to allow light to reach the optoelectronic sensor after encapsulation of the carrier substrate by either plastic or ceramic material.
Using conventional semiconductor device packaging with glass covers has several disadvantages. For example, the glass covers can separate from the plastic or ceramic packaging material resulting in the optoelectronic sensor being exposed to the external environment thereby eventually destroying the device.
Another problem is that moisture can enter the package causing condensation on the inside of the glass cover thus degrading the image capturing ability and quality of the device.
Additionally, the finished package consists of two pieces requiring the device to pass through the normal semiconductor wire bonding process, a cleaning process, and an assembly process to install the glass cover making the production cost of the conventional device high as well as requiring extra processing steps.
Therefore, there is need for a package for optoelectronic devices having a single piece construction with improved moisture resistance, lower cost, and higher reliability.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.


A cache system may include a cache to store a plurality of cache lines in a write-back mode; dirty cache line counter circuitry to store a count of dirty cache lines in the cache, increment the count when a new dirty cache line is added to the cache, and decrement the count when an old dirty cache line is written-back from the cache; dirty cache line write-back tracking circuitry to store an ordering of the dirty cache lines in a write-back order; mapping circuitry to map the dirty lines into the ordering; and controller circuity to use the mapping circuity to identify an evicted dirty cache line in the ordering and remove the evicted dirty cache line from the ordering.

In a multi-processor system, having the ability to use non-volatile DIMM (NVDIMM) memory has many advantages. However, it can also push significant hold-up time requirements to the power supplies. As the cache memory sizes of the processor sockets grow, this power supply hold-up requirement can grow after system deployment with the introduction of upgraded non-volatile DIMMs into the system.

Hewlett Packard Enterprise Development LP


A method and apparatus for an ice detection system. The ice detection system includes a first sensor located on a leading edge of a vertical stabilizer on an aircraft, a second sensor located on a first side of the vertical stabilizer, and a third sensor located on a second side of the vertical stabilizer. The first sensor is configured to detect a first type of icing condition for the aircraft. The second sensor is configured to detect a second type of icing condition for the aircraft. The third sensor is configured to detect the second type of icing condition for the aircraft.

1. Field
The present disclosure relates generally to detecting icing conditions and, in particular, to icing conditions for an aircraft. Still more particularly, the present disclosure relates to detecting supercooled water drops, including supercooled large drops (SLD).
2. Background
In aviation, icing on an aircraft may occur when the atmospheric conditions lead to the formation of ice on the surfaces of the aircraft. Further, this ice also may occur within the engine. Ice forming on the surfaces of the aircraft, on inlets of an engine, and other locations are undesirable and potentially unsafe for operating the aircraft.
Icing conditions may occur when drops of supercooled liquid water are present. In these illustrative examples, water is considered to be supercooled when the water is cooled below the stated freezing point for water but is still in a liquid form. Icing conditions may be characterized by the size of the drops, the liquid water content, air temperature, and other parameters. These parameters may affect the rate and extent at which ice forms on an aircraft.
When icing occurs, the aircraft does not operate as desired. For example, ice on the wing of an aircraft will cause the aircraft to stall at a lower angle of attack and have an increased drag.
Aircraft may have mechanisms to prevent icing, remove ice, or some combination thereof to handle these icing conditions. For example, aircraft may include icing detection, prevention, and removal systems. Ice may be removed using deicing fluid, infrared heating, and other suitable mechanisms.
Aircraft may be certified for operating during different types of icing conditions. Some aircraft may be certified to operate in normal icing conditions but not those that include supercooled large drops. Currently used sensors are unable to differentiate between normal and supercooled large drop icing conditions. Therefore, it would be desirable to have a method and apparatus that takes into account one or more of the issues discussed above as well as possibly other issues.

Supercooled large drop icing condition detection system


A chip package includes a chip, an isolation layer, and a redistribution layer. The chip has a substrate, an electrical pad, and a protection layer. The substrate has a first surface and a second surface. The substrate has a through hole, and protection layer has a concave hole, such that the electrical pad is exposed through the concave hole and the through hole. The isolation layer is located on the second surface, the sidewall of the through hole, and the sidewall of the concave hole. The redistribution layer includes a connection portion and a passive element portion. The connection portion is located on isolation layer and in electrical contact with the electrical pad. The passive element portion is located on isolation layer that is on second surface, and an end of passive element portion is connected to connection portion that is on the second surface.

Field of Invention
The present invention relates to a chip package and a manufacturing method of the chip package.
Description of Related Art
A typical RF sensor includes a chip package and passive components. The passive components can be, for example, inductors. And the chip package is used as an active component. Both the chip package and the inductors are disposed on a printed circuit board, and the inductors are placed outside the chip package.
That is to say, after the chip package is manufactured, additional and independent inductors are required to be arranged on the printed circuit board to allow the RF sensor working properly. However, it leads to a lot of assembly time for the RF sensor, and makes it difficult to reduce the cost of the inductors. Moreover, additional space and circuits need to be reserved on the printed circuit board, thereby causing design inconvenience.

Chip package and manufacturing method thereof


In the case where a subject is captured with a high-luminance light, such as sunlight, for a background, a phenomenon that a portion of the high-luminance subject is detected as a no-signal level is prevented. The solid-state imaging device includes: a photoelectric transducer PD which converts incident light to charges; a voltage level detection circuit 50 in which pixel units 10an1 and 10bn1, each having a voltage conversion amplifying transistor Q13a which outputs a voltage by converting the charges accumulated in the photoelectric transducer PD, are arranged one-dimensionally or two-dimensionally, and which detects a pixel output voltage outputted from each of the pixel units to the common column signal line Ln; and a column signal processing circuit 80 which receives a logic output voltage of the voltage level detection circuit 50 and the pixel output voltage and which outputs a voltage to a horizontal output circuit 90. The column signal processing circuit 80 outputs either a voltage identical to the pixel output voltage or a fixed voltage, depending on the logic output voltage.

MOS solid-state imaging devices can be broadly divided into two types, an AMI type and a floating diffusion amplifier type (may be referred to as an "FDA type" hereinafter), according to the circuit configuration and the timing when charges accumulated in a pixel unit of a photoelectric transducer PD are detected.
FIG.1 is a diagram showing a configuration of the AMI type solid-state imaging device.
As shown in FIG. 1, a solid-state imaging device 900 includes; plural pixel units 10an1 and 10an2 which are arranged two-dimensionally (two units in the diagram); plural common column signal lines Lns respectively arranged per column (a line in the diagram); a load transistor Q2la connected to each common column signal line Ln; a sample hold transistor Q31 provided for each common column signal line Ln; plural noise signal elimination circuits 40 which are respectively arranged per column (a circuit in the diagram); and the like.
Each of the pixel units 10an1 and 10an2 includes: a photoelectric transducer PD which converts incident light to charges; a reset transistor Q12 which resets a cathode of the photoelectric transducer PD to a power supply voltage VDD using a RESET pulse; a voltage conversion amplifying transistor Q13a which detects a voltage corresponding to charges of the photoelectric transducer PD; and a row selection transistor Q14 which transfers, to each of the common column signal lines Lns per row, a voltage outputted from the voltage conversion amplifying transistor Q13 using a VSEL pulse.
The sample hold transistor Q31 samples and holds the voltage outputted to the common column signal line Ln using an SH pulse.
The noise signal elimination circuit 40 includes a clamp transistor Q42, a clamp capacitor C41, and a sample hold capacitor C42, and detects a signal component in which a noise component is eliminated, by obtaining a difference between: a reset voltage of the photoelectric transducer PD to be detected in each of the pixel unit 10an1 and 10an2; and a voltage to be detected depending on the charges corresponding to the amount of light.
Next, a charge detection operation of the solid-state imaging device 900 is described. Note that the charge detection operation in the pixel unit 10an1 is described in particular.
FIG. 2 is a diagram showing drive timing of the solid-state imaging device 900 shown in FIG. 1.
At the time t0, all pulses are off.
Next, the VSE pulse turns on the row selection transistor Q14 at the time t0, the SH pulse turns on the sample hold transistor Q31 at the time t2, and a CP pulse turns on the clamp transistor Q42 in the noise signal elimination circuit 40 from the time t3 to t4.
From the time t4 when the CP pulse is turned off to the time t5 when the RESET pulse in the pixel unit 10an1 is turned on, the sample hold capacitor C42 in the noise signal elimination circuit 40 holds the accumulated charges of the photoelectric transducer PD of the pixel unit 10an1 via the voltage conversion amplifying transistor Q13a of the pixel unit 10an1.
A holding signal in this case is assumed to be a voltage A.
From the time t5 to the time t6, after the RESET pulse turns on the reset transistor Q12 and then the photoelectric transducer PD is reset to a power supply voltage VDD level, until the time when the SH pulse turns off the sample hold transistor Q31 at the time t7, the sample hold capacitor C42 of the noise signal elimination circuit 40 again hold the reset level of the photoelectric transducer PD via the voltage conversion amplifying transistor Q13a. The holding signal at this time is assumed to be a voltage B. In the noise signal elimination circuit 40, by obtaining a difference between the previously held voltage A and the subsequently held voltage B, an accumulation signal component is detected which is in a two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated. Next, at the time t8, the VSEL pulse turns off the row selection transistor Q14. With this, the charge detection operation for a row of the photoelectric transducer PD set in the two-dimensional imaging region ends.
FIG.3 is a diagram showing the configuration of an FDA-type solid-state imaging device.
In this case, a solid-state imaging device 950 includes pixel units 10bn1 and 10bn2 as a replacement for the pixel units 10an1 and 10an2.
Each of the pixel units 10bn1 and 10bn2 further includes a transfer transistor Q11 which reads charges from the photoelectric transducer PD and a floating diffusion FD which temporarily accumulates charges, in addition to the components provided for the pixel units 10an1 and 10an2. In this case, the reset transistor Q12a resets the floating diffusion FD to the power supply voltage VDD, and the voltage conversion amplifying transistor Q13a detects a voltage corresponding to the accumulated charges of the floating diffusion FD.
Next, the charge detection operation of the solid-state imaging device 950 is described. Note that the charge detection operation in the pixel unit 10bn1 is described in particular.
FIG. 4 is a diagram showing drive timing of the solid-state imaging device 950.
At the time t0, all pulses are OFF. Next, the VSEL pulse turns on the row selection transistor Q14 of the pixel unit 10bn1 at the time t1, and the SH pulse turns on the sample hold transistor Q31 at the time t2. From the time t3 to t4, the RESET pulse turns on the reset transistor Q12a. With this, after the floating diffusion FD is reset to the power supply voltage VDD level, from the time t4 when the RESET pulse is turned off to the time t5 when the TRANS pulse turns on the transfer transistor Q11, the sample hold capacitor C42 of the noise signal elimination circuit 40 holds the reset level of the floating diffusion FD via the voltage conversion amplifying transistor Q13a. The holding signal at this time is assumed to be a voltage C.
Next, from the time t5 to the time t6, the TRANS pulse turns on the transfer transistor Q11, and after the accumulated charges of the photoelectric transducer PD are transferred to the floating diffusion FD, until the time t7 when the SH pulse turns off the sample hold transistor Q31, the sample hold capacitor C42 of the noise signal elimination circuit 40 holds the charges accumulated in the floating diffusion FD of the pixel unit 10bn1 via the voltage conversion amplifying transistor Q13a. The holding signal at this time is assumed to be a voltage D. In the noise signal elimination circuit 40, by obtaining a difference between the previously held voltage C and the subsequently held voltage D, an accumulation signal component is detected which is in the two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated. Next, at the time t8, the VSEL pulse turns off the row selection transistor Q14. With this, the charge detection operation for a row of the photoelectric transducer PD set in the two-dimensional imaging region ends.
However, when a subject is captured with a high-luminance light, such as sunlight, for a background, a phenomenon occurs that the aforementioned MOS solid-state imaging device detects a portion of the high-luminance subject not as a saturation signal level but as a no-signal level.
The occurrence mechanism of this phenomenon is described with reference to FIGS. 5 to 9. The pixel unit 10an1 loans used in FIG. 5 and FIG. 6 is categorized as an AMI type. FIG. 5 shows a case where the amount of incident light is reference amount of light, and normal charge detection is performed. FIG. 6 shows a case where the amount of incident light is equal to or more than 200 thousand times as much as the reference amount of light, and abnormal charge detection is performed.
FIG. 5(a) shows a potential diagram of the pixel unit 10an1 from the time t3 to the time t5 shown in FIG. 2.
The noise signal elimination circuit 40 holds the accumulated charges of the photoelectric transducer PD via an voltage conversion amplifier of the pixel unit 10an1. The holding signal at this time is assumed to be the voltage A.
FIG. 5(b) shows a potential diagram of the pixel unit 10an1 from the time t5 to the time t6 shown in FIG. 2. Here, the photoelectric transducer PD is reset to the power supply voltage VDD level.
FIG. 5(c) shows a potential diagram of the pixel unit 10an1 from the time t6 to the time t7 shown in FIG. 2. Here, the level of the photoelectric transducer PD which has been reset to the power supply voltage VDD level is maintained, and is held by the noise signal elimination circuit 40 via the voltage conversion amplifier of the pixel unit 10an1. The holding signal at this time is assumed to be the voltage B. In the noise signal elimination circuit 40, by obtaining a difference between the previously held voltage A and the subsequently held voltage B, an accumulation signal component can be detected which is in the two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated.
FIG. 6(a) shows a potential diagram of the pixel unit 10an1 from the time t3 to the time t5 shown in FIG. 2. Here, the noise signal elimination circuit 40 holds the accumulated charges of the photoelectric transducer PD via a voltage conversion amplifier of the pixel unit 10an1, The holding signal at this time is assumed to be the voltage A.
FIG. 6(b) shows a potential diagram of the pixel unit 10an1 from the time t5 to the time t6 shown in FIG. 2. Here, the photoelectric transducer PD is reset to the power supply voltage VDD level.
FIG. 6(c) shows a potential diagram of the pixel unit 10an1 from the time t6 to the time t7 shown in FIG. 2. Here, the level of the photoelectric transducer PD which has been reset to the power supply voltage VDD level can not be maintained. In the case where the amount of incident light is equal to or more than 200 thousand times as much as the reference amount of light, immediately after the photoelectric transducer PD is reset to the power supply voltage VDD level, in other words, immediately after the time t6 when the RESET pulse of the pixel unit 10an1 is turned off, the large amount of charges is accumulated in the photoelectric transducer PD. Thus, the voltage level identical to the level when the accumulated charges become saturated is held by the noise signal elimination circuit 40 via the voltage conversion amplifier of the pixel unit 10an1. In this case, assuming that the holding signal is the voltage B, a difference between the previously held voltage A and the subsequently held voltage B becomes 0 or minus in the noise signal elimination circuit 40. As a result, the accumulation signal component can not be detected which is in the two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated.
The pixel unit 10bn1 described in FIG. 7 and FIG. 8 is categorized as an FDA type. FIG. 7 shows a case where the amount of incident light is the reference amount of light, and the normal charge detection is performed. FIG. 8 shows a case where the amount of incident light is equal to or more than 200 thousand times as much as the reference amount of light intensity, and the abnormal charge detection is performed.
FIG. 7(a) shows a potential diagram of the pixel unit 10bn1 from the time t3 to the time t5 shown in FIG. 4. Here, the RESET pulse of the pixel unit 10bn1 turns on the reset transistor Q12a. With this, a charge detection unit (floating diffusion) of the pixel unit 10bn1 is reset to the power supply voltage VDD level.
FIG. 7(b) shows a potential diagram of the pixel unit 10bn1 from the time t4 to the time t5 shown in FIG. 4. Here, the charge detection unit (floating diffusion) of the pixel unit 10bn1 which has been reset to the power supply voltage VDD level is maintained, and is held by the noise signal elimination circuit 40 via the voltage conversion amplifying transistor Q13a of the pixel unit 10bn1. The holding signal at this time is assumed to be the voltage C.
FIG. 7(c) shows a potential diagram of the pixel unit 10bn1 from the time t5 to the time t7 shown in FIG. 4.
After the accumulated charges of the photoelectric transducer PD are transferred to the charge detection unit (floating diffusion), the level is maintained. Until the time t7 when the SH pulse turns off the sample hold transistor Q31, the noise signal elimination circuit 40 holds the charges accumulated in the charge detection unit (floating diffusion) of the pixel unit 10bn1 via the voltage conversion amplifying transistor Q13a. The holding signal at this time is assumed to be the voltage D.
In the noise signal elimination circuit 40, by obtaining a difference between the previously held voltage C and the subsequently held voltage D, the accumulation signal component can be detected which is in the two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated.
FIG. 8(a) shows a potential diagram of the pixel unit 10bn1 from the time t3 to the time t4 shown in FIG. 4. Here, the RESET pulse turns on the reset transistor Q12a. With this, the charge detection unit (floating diffusion) of the pixel unit 10bn1 is reset to the power supply voltage VDD level.
FIG. 8(b) shows a potential diagram of the pixel unit 10bn1 from the time t4 to the time t5 shown in FIG. 4. Here, the charge detection unit (floating diffusion) of the pixel unit 10bn1 which has been reset to the power supply voltage VDD level can not be maintained. In the case where the amount of incident light is equal to or more than 200 thousand times as much as the reference amount of light, with the parasitic NPN configuration as shown in FIG. 9, the potential in the photoelectric transducer PD region is significantly lowered, and a path where a current flows is generated from the charge detection unit (floating diffusion). With this, even when the TRANS pulse is turned off, the potential is lowered in the charge detection unit (floating diffusion) of the pixel unit 10bn1, and consequently, the noise signal elimination circuit 40 holds, via the voltage conversion amplifying transistor Q13a, the voltage level equal to or more than the level when the accumulated charges become saturated. The holding signal at this time is assumed to be the voltage C.
FIG. 8(c) shows a potential diagram of the pixel unit 10bn1 from the time t5 to the time t7 shown in FIG. 4. Here, even when the TRANS pulse of the pixel unit 10bn1 turns on the transfer transistor Q11, since the accumulated charges, equal to or more than the level when the accumulated charges become saturated, have flown from the photoelectric transducer PD in advance, the voltage level of the charge detection unit (floating diffusion) of the pixel unit 10bn1 is lowered. Consequently, the noise signal elimination circuit 40 holds this voltage level via the voltage conversion amplifying transistor Q13a of the pixel unit 10bn1. Assuming that this holding signal is the voltage D, a difference between the previously held voltage C and the subsequently held voltage D becomes 0 or minus. As a result, the accumulation signal component can not be detected which is in the two-dimensional imaging region of the pixel units and in which the noise signal component is eliminated (refer to Patent Reference 1).
As a method of solving this phenomenon, a method which detects a pixel output signal in a signal processing circuit and corrects it is suggested (refer to Patent Reference 2).
When a subject is captured with a high-luminance light, such as sunlight, for a background, a conventionally suggested correction method is to temporarily transfer an output signal generated immediately after a photoelectric transducer PD or a charge detection unit is reset to a comparator in a signal processing circuit and then to judge whether or not high-luminance light is entered using the voltage.    Patent Reference 1: Japanese Laid-Open Patent Application No. 2003-46865 (Pages 1-8, FIG. 1)    Patent Reference 2: Japanese Laid-Open Patent Application No. 2000-287131 (Pages 1-16, FIG. 1)


A wireless network in which wireless terminals associate with particular access points maintains information about the positions and associations of the terminals and calculates loads on access points. To provide increased bandwidth at a heavily loaded access point, terminals associated with adjacent access points are handed over to more distant access points, so that the adjacent access points become less active and generate less interference. The hand-over is initiated and carried out by the access points concerned, rather than by the terminal that is handed off. Loads can accordingly be balanced promptly and interference can be reduced.

1. Field of the Invention
The present invention relates to a wireless communication network, and in particular to a method and system for redistributing loads among the access points of a wireless communication network so as to reduce interference.
2. Description of the Related Art
The terminals of a wireless communication network generally receive control signals such as beacon signals from access points, select the strongest signal, and associate with the access point from which that signal was received. Technology of this type for connecting access points with wireless terminals is disclosed in, for example, Japanese Patent Application Publication No. 2003-249935. In the disclosed technology, communication takes place on a plurality of channels, using a carrier sensing function. A wireless terminal measures the electric field strength of the signal received from its associated access point. If the received electric field strength falls below a threshold value, the terminal may re-associate with a different access point.
In wireless networks using the above technology, an access point cannot choose the wireless terminals that will associate with it; it is the wireless terminal that decides which access point to associate with, mainly on the basis of received signal strength. This terminal-centered association strategy does not necessarily produce a well-balanced pattern of associations in the network as a whole, and can lead to unnecessary interference between wireless signals. This problem cannot be avoided by the prior art.
Interference reduces the amount of communication the network can carry, referred to as the bandwidth of the network. An example will be described with reference to FIG. 1.
The wireless network 1 in FIG. 1 is a so-called extended service set (ESS) network comprising a backbone network 3 with five access points (APs) 10-1 to 10-5 mutually interconnected by, for example, wired communication lines. Four mobile stations or wireless terminals 2-1 to 2-4 are currently present in the network area.
The fan-shaped sector depicted under each access point indicates its signal range, in which communication with wireless terminals can take place. In the areas of sector overlap, a wireless terminal can communicate with either of two adjacent access points. All wireless communications are assumed to take place on a single common channel, which simplifies the wireless connection procedure when the wireless terminals move from one access point to another. Each of access points 10-1 to 10-5 is out of the range of the adjacent access points; the access points do not communicate with each other on the common wireless channel.
In FIG. 1, two wireless terminals 2-1, 2-2 are within communication range of access point 10-2. Wireless terminal 2-1 is currently associated with access point 10-2, as indicated by the solid arrows, and is communicating with access point 10-2. Access point 10-2 and wireless terminal 2-1 form a so-called basic service set (BSS) network.
Similarly, two wireless terminals 2-2, 2-3 are within communication range of access point 10-3. Both wireless terminals 2-2, 2-3 are currently associated with access point 10-3, forming another BSS network.
Similarly, two wireless terminals 2-3, 2-4 are within communication range of access point 10-4. Wireless terminal 2-4 is currently associated with access point 10-4, forming yet another BSS network.
Under these conditions, interference may occur at access point 10-2. Access point 10-2 is communicating only with wireless terminal 2-1, but wireless terminal 2-2 is also within its signal range. If wireless terminal 2-2 begins communicating with access point 10-3, then as indicated by the dotted arrow, the signals transmitted by wireless terminal 2-2 will also be received by access point 10-2, where they may collide with signals transmitted by wireless terminal 2-1. Access point 10-2 will then be unable to receive information from wireless terminal 2-1 correctly, and will fail to transmit a reply to wireless terminal 2-1, forcing wireless terminal 2-1 to retransmit the same information. In other words, the bandwidth of the link between access point 10-2 and wireless terminal 2-1 will be reduced by an amount corresponding to the amount of traffic between wireless terminal 2-2 and access point 10-3.
For similar reasons, access point 10-4 and wireless terminal 2-4 may also find their bandwidth reduced.
Bandwidth may also be reduced on the links between access point 10-3 and wireless terminals 2-2 and 2-3.
Although no signal collisions occur at access point 10-3, which communicates with wireless terminals 2-2 and 2-3 in different time slots, signals sent from access point 10-3 to wireless terminal 2-2 may collide with signals sent from the adjacent access point 10-2 to wireless terminal 2-1, which are also received at wireless terminal 2-2. Wireless terminal 2-2 will then be unable to receive information from access point 10-3 correctly, and access point 10-3 may have to retransmit the same information to wireless terminal 2-2.
Similarly, signals transmitted from access point 10-3 to wireless terminal 2-3 may collide with interfering signals transmitted by access point 10-4, intended for wireless terminal 2-4.
In other words, the bandwidth of the links between access point 10-3 and its associated wireless terminals 2-2, 2-3 will be reduced whenever the adjacent access points 10-2, 10-4 communicate with wireless terminals 2-1 and 2-4. In the network as a whole, on the average, bandwidth is reduced in proportion to the amount of overlap between signal ranges.

Load redistribution method and system for reducing interference in a wireless network