Antenna arrays can be fabricated as patches on conductive transparent material over an appropriate transparent dielectric substrate with the appropriate transparent ground-plane. To keep the fabrication cost low, such antenna arrays have a planar design without cross-over of the feeding lines or 3D interconnects. To steer the antenna horizontally, patches need to be fed with incremental phase shifts relative to their left or right neighbors; such feeds require an appropriate network and RF switches, typically located in an adjacent non-transparent area such as a PCB. Fabricating and disposing transparent phase delay component on the transparent material reduces the size of the PCB, thereby increasing visible transparent area.

Telecommunications requirements in dense, urban areas are often substantial, due to a dense arrangement of business locations in multi-story buildings. Networking resources are typically wired, due to the speed and transmission reliability that such physical interconnections provide. Wireless based communication in urban areas is often hindered by the presence of dense structural materials such as concrete and steel. However, the dense arrangement of window area in substantially opposed orientation (such as across a thoroughfare or street) provides an opportunity for a mesh network of line-of-sight based communications, if the proximate sites are properly managed, as tenancy in such environments is usually widely varied.


A suspension thrust bearing device includes a rolling bearing provided with two races and with rolling elements arranged between the races, and two caps each in contact with one race, one of the caps including a circular flange and the other cap including an axial portion provided with hooks intended for latching onto the said flange, which hooks leave an axial space of height b remaining between the said hooks and the said flange, one of the caps including an operational part provided with a chamfer intended to facilitate latching with the other cap, with an axial surface of height a and of diameter D and with a radial retention surface, and the other cap including an operational part provided with a chamfer intended to facilitate latching, with an axial surface of height c and with a radial retention surface, the sum of the heights a+b+c being greater than 1.9% of the diameter D.

1. Field of the Invention
The present invention relates to the field of suspension thrust bearings used in particular in motor vehicles for the telescopic suspension struts of the steered wheels.
2. Description of the Relevant Art
A suspension thrust bearing generally includes an upper race and a lower race between which are arranged rolling elements in the form of balls or rollers. A suspension thrust bearing is generally arranged in the top of the suspension strut, between a suspension spring and an upper element secured to the body of the vehicle. The spring of the suspension device is installed around the rod of the damper piston, the end of which is secured to an elastic support block. The suspension thrust rolling bearing allows rotational movement between the support cup for the spring, which may rotate, and the elastic support block, which is fixed to the body of the vehicle. The relative angular movement between the support cup for the spring and the elastic block results from turning the steered wheel and/or from compression of the suspension spring. The suspension thrust bearing also allows axial forces to be transmitted between the spring and the body of the vehicle.
Thus Document FR-A-2 829 429 describes a suspension thrust bearing including a thrust rolling bearing, a support cup for a spring and an elastic support block. The rolling bearing includes an upper race arranged in an annular upper cap forming an interface between the upper race and the elastic block, and a lower race. Also provided is an annular lower cap forming an interface between the lower race and the support cup for the spring. One cap may include an elastic lip extending radially in the direction of a skirt of the other cap, forming a narrow passage and cooperating with a radial flange of the skirt, so as to allow axial movement in one direction while prohibiting reverse axial movement.
However, in many struts of recent design the springs have a complex shape and, after they have been fitted on the vehicle, exert an axial force which does not pass through the axis of the rolling bearing. The geometry of the spring is such that before it is preloaded and during the start of preloading, the end turns of the spring exert non-uniformly distributed and/or localized forces over a limited angular sector of the respective bearing points. This is therefore manifested at the upper end of the spring by the application of a non-uniformly distributed force on the lower cap of the thrust bearing. When the region on which the spring bears is situated radially outside the diameter over which the balls bear on the races, the concentration of the spring bearing forces on a region of the cap situated outside the bearing region of the balls may exert on the lower cap a tilting moment about the balls which causes partial unlatching of the two caps on the side diametrically opposite to the force application point.
The radial latching interference is in fact relatively small because it is only intended to provide axial retention for handling the caps. Since the caps are made of a relatively rigid synthetic material—often glass-fiber-reinforced nylon-6,6 polyamide—a large interference could cause unacceptable stresses on the material and local cracking or fractures.
When the final preload is exerted on the spring, the lower turn bears completely on the cup, which produces a modification of the orientation and of the distribution of the load exerted by the spring on the cap, which tends to close again.
After carrying out numerous tests, the Applicant noticed that when the two caps are disunited beyond a certain limit, the said caps do not generally return correctly into position, and local relative friction between the said caps subsequently occurs and this forms the basis of incorrect operation of the suspension thrust bearing with generation of noise and an excessive frictional torque.
The embodiments described herein aim to overcome these drawbacks.


One embodiment of the present invention comprises a pair of intermeshable fruit juice extraction peeler cups (100, 150) comprising respective blades (106, 156) that are arranged so as to intermesh to peel and extract juice from a fruit introduced into a space 107 there between during an extraction stroke. Considering one peeler cup (150), its blades' distal ends 158 collectively define a shape referred to as a Mendesaddle shape (160). The Mendesaddle shape (160) comprises a top opening (164) and a bottom opening (166) extending toward a rearward end (154) of the peeler cup (150). A fruit enters the space (107) through an open area (139) that comprises top opening (164) and a corresponding top opening (114) of the mated peeler cup (100). Also, considering the bottom openings (166, 116), a juice-extracted fruit core may drop through an open area (141) provided by these, wherein, nonetheless, the size of the open area (141) (and also of each of the bottom openings 166 and 116) is effective to retain the whole fruit upon entry of the whole fruit into the space 107. Various features of the invention provide for more reliability and fewer misfeeds of fruit.

For decades commercial-scale fruit juice extraction, such as the extraction of citrus fruits including oranges and grapefruit, largely has utilized fruit juice extraction devices that have a vertical orientation of interdigitating extractor cups. Examples of such technology are found in U.S. Pat. Nos. 2,649,730, 2,780,988, and later patents assigned to FMC Corporation. In essence, fruit introduced from a side port falls into a lower, fixed extractor cup, at the bottom of which is an entrance of a filter receiving tube, and an upper, moveable extractor cup lowers over this along a vertical axis, causing most fruit rind (or peel) to be ejected through an upper, centered, annular passageway while forcing juice-laden pulp, and plugs of peel at the top and bottom of the juice-laden pulp, into a lower strainer tube. These plugs are further compressed as they travel down the strainer tube, releasing peel oils. The oils from the rind are known to adversely affect flavor and shelf life. It is noted that these extraction devices also comprise a reciprocating orifice tube within the strainer tube which is reciprocated in a relationship with the upper, moveable extractor cup's movement. During the extraction cycle, the majority of the remaining peel is forced, by virtue of the shapes of the contacting surfaces of the interdigitating extractor cups, through the upper, centered annular passageway of the moveable upper extractor cup so that such peel exits near above this cup.
In U.S. Pat. No. 4,309,943, modifications of this vertical juice extraction approach were made to increase production rate. Also, a high speed feeding device for use with this extractor was described in U.S. Pat. No. 4,309,944. These patents identify a general interest in increasing production rates in commercial fruit juice extraction facilities. Also, U.S. Pat. No. 4,700,620, assigned to FMC Corporation, teaches an improvement to the above-referenced FMC extraction devices in which a cam controls movement of an orifice tube within the strainer tube, for the stated purpose of reducing contact of the extracted juice with the freshly cut surfaces of the fruit skin. U.S. Pat. No. 5,070,778, also assigned to FMC Corporation, teaches an approach to reduction of peel oil by introduction of a plurality of apertures in the annular cutter head adjacent the annular passageway through which the fruit rind is ejected during the juicing cycle of these units.
The present inventor previously invented, and received patents for, a fruit juice extraction device that in its depicted embodiments is oriented in a substantially horizontal manner, and that provides opposing peeler cups that are effective to press and shear the fruit peel into slivers during the extraction cycle. The latter is based on the configuration and arrangement of the opposing intermeshable peeler blades of the cups. U.S. Pat. Nos. 5,655,441, 5,720,218, 5,802,964, and 5,655,441 describe such device as exemplified in a small, single-cup-pair device. Also, various improvements have been made in the invention, including those directed to drive mechanisms for multi-cup commercial production extraction units. These are described in the publication of Canadian Patent number CA 2347814, and in U.S. Patent Application publication numbers 2005/0028690 and 2005/0199138. U.S. Patent Application publication number 2006/0201345, a continuation of the above referenced patents issued to Applicant, further claims aspects of the invention.
Embodiments of such exemplified horizontal extraction devices have been demonstrated to achieve a fruit extraction with substantially less peel oil in the juice compared to models of the noted vertically oriented interdigitating extractor cups. Notwithstanding these improvements, a need remains to improve the technology of the opposing peeler cups to provide for improved production rates whilst maintaining or improving the quality of the extracted juice. Such need is directed to an economic interest and value in achieving relatively higher production rates for commercial juice extraction units.

Opposing paired peeling cups for fruit juice extraction devices, and said devices comprising said cups


A parallel acting vehicle seat lift uses a single jack screw unit at the front and a passive linkage at the rear. The linkage is located such its inherent play or looseness is continually taken up by the constant weight force of the occupant acting downwardly at the rear of the seat cushion. The jack screw unit, which is inherently tight, is attached at the bottom to the vehicle floor and at the top to the seat cushion frame by close fitting pivots, so there is no perceptible looseness. The passively acting linkage uses two bell cranks, each centrally pivoted to the floor, the first of which is attached at one arm the seat cushion frame by a close fitting pivot. The second bell crank is attached to the rear of the seat cushion frame by a lost motion connection, and the two facing arms of the bell cranks are connected together by a second lost motion connection. The continually acting weight force of the seat occupant imposes opposed moments on the bell cranks about their central pivots, thereby taking the play out of the lost motion connections.

Most commercially available powered vehicle seat lifts provide for both vertical lifting and back and forth tilting of the seat cushion, as well as back and forth, lateral adjustment. These are typically referred to as six way adjusters, the six ways being up and down, back and forth tilt, and back and forth lateral adjustment. An example may be seen in co assigned U.S. Pat. No. 4,664,351 to Borlinghaus. Powered jack screw units beneath the front and back of the seat cushion frame are rigidly attached at their lower ends to a floor plate, and attached at their upper ends to the seat cushion frame through a so called lost motion pivot, consisting of a pin that moves in a substantially horizontal slot. The pins and slots allow vertical lift to be applied to the seat cushion frame as well as allowing the ends of the frame to swing in an arc having a horizontal component. The same allowance for compound motion can be provided through the use of an additional transfer link or links between the end of the jack screw and the seat cushion frame. Less common, though known, are parallel acting seat lift mechanisms, which remain substantially parallel to their previous positions as they are raised or lowered, but lack the ability to tilt back and forth independently. An example may be seen in co assigned U.S. Pat. No. 2,919,744 to Tanaka. Even with a parallel lift, allowance must be made for some horizontal motion concurrent with the vertical, through pin and slot connections or extra links. An inherent problem with any lift mechanism that uses pin and slot connections or extra links, especially when located beneath the front of the seat cushion frame, is that a rocking motion by the seat occupant can cause a perceptible up and down motion of the seat cushion frame, sometimes referred to as seat chuck. While the basic operation of the seat is not affected, a perceptible motion of the seat is thought to be undesirable in terms of quality, or at least the perception of quality. However, there was previously no known means of providing for the necessary compound motion of the seat frame without the kinds of lost motion connections that were inherently loose.
Recently, a seat lift design disclosed in co assigned U.S. Pat. No. 5,586,740 has provided a six way seat adjuster without the need for the lost motion connections. Powered jack screw units beneath the front and rear of the seat cushion frame have close fitting pivots at both the upper end, where they attach to the seat cushion frame, and the lower end, where they attach to the floor pan. In order to provide stability, a brace located between the two jack screw units is closely pivoted to both the floor pan and the seat cushion frame, running diagonally. Having only close fitting pivots, and no pin and slot connections or extra links, the seat cushion frame is able to move up, down, or tilt back and forth with essentially no perceptible play or chuck. A variation of the design is disclosed in co pending and co assigned application Ser. No. 08/548,892, filed Oct. 26, 1995. This design replaces the rear jack screw unit, which is essentially vertical, with a nearly horizontal jack screw unit, the moving end of which is pivoted to the seat cushion frame through an intermediate, single bell crank that is also centrally pivoted to the floor pan. The single bell crank acts both as a force transferring connection to the seat cushion frame, and as a stabilizing brace. As with the design in U.S. Pat. No. 5,586,740, the absence of pin-slot connections or multiple link connections provides a solid occupant feel with substantially imperceptible response of the seat cushion frame to a rocking motion. Both designs, however, require two jack screw units, and their attendant motors, drive shafts and transmissions, which are costly.

Vehicle parallel seat lift with stable linkage


A voltage generating circuit for a semiconductor memory device. The voltage generating circuit includes a multi-boosting unit for stepping up a power supply voltage, a transfer transistor connected to a final boosting node of the multi-boosting unit and an output node, and a charge-sharing element, electrically connected to the final boosting node and a gate node of the transfer transistor, enabled during at least a part of the period the power supply voltage is stepped-up by the multi-boosting unit and performing charge sharing between the final boosting node and the gate node of the transfer transistor.

1. Technical Field
The present disclosure relates to a voltage generating circuit, a semiconductor memory device comprising the same, and a voltage generating method. More particularly, the present invention relates to a voltage generating circuit, a semiconductor memory device comprising the same, and a voltage generating method, which can efficiently drive low voltages.
2. Discussion of the Related Art
Semiconductor memory devices utilize a voltage generating circuit according to the operational needs of their internal circuits. In particular, a boosted voltage (Vpp), which is higher than a power supply voltage (Vcc), is generally utilized in semiconductor memory devices to compensate for threshold voltage (Vth) loss of MOS transistors.
The boosted voltage Vpp is utilized in circuits such as word-line driver circuits, bit-line isolation circuits, data output buffer circuits, etc. In these types of circuits, Vpp must be higher than Vcc+Vth. In particular, the word-line driver circuits require Vpp to be much higher than Vcc+Vth.
While there are various methods of generating Vpp, a bootstrapping technique which does not require a large amount of power and can be utilized at high speeds is most commonly used. The bootstrapping technique generates Vpp by time-dependent repetition of precharging, boosting, and charge sharing.
Conventional voltage generating circuits include a transfer transistor, which outputs a several times boosted voltage from a boosting node. However, when the boosted voltage at the boosting node is output, the voltage level at a gate node of a transfer transistor is smaller than the boosted voltage level at the boosting node, which makes it difficult to maximize the transfer characteristics of the transfer transistor. This phenomenon becomes worse as Vcc decreases or as a target Vpp increases, thereby significantly reducing voltage generation efficiency. Therefore, there exists a need to improve the low-voltage driving efficiency of voltage generating circuits for semiconductor memory devices.

Voltage generating circuit, semiconductor memory device comprising the same, and voltage generating method


Compounds that provide for sustained systemic concentrations of GABA analogs following oral administration to animals are disclosed. Pharmaceutical compositions including, and methods using, such compounds are also disclosed.

1. Field of the Invention
This invention is directed to compounds that provide for sustained systemic concentrations of GABA analogs following administration to animals. This invention is also directed to pharmaceutical compositions including and methods using such compounds.
2. State of the Art
Rapid clearance of drugs from the systemic circulation represents a major impediment to effective clinical use of therapeutic and/or prophylactic compounds. Although multiple factors can influence the systemic concentrations of drugs achieved following administration (including drug solubility, dissolution rate, first-pass metabolism, p-glycoprotein and related efflux mechanisms, hepatic/renal elimination, etc), rapid systemic clearance is a particularly significant reason for suboptimal systemic exposure to many compounds. Rapid systemic clearance may require that large doses of drug be administered to achieve a therapeutic or prophylactic effect. Such larger doses of the drug, however, may result in greater variability in drug exposure, more frequent occurrence of side effects, or decrease in patient compliance. Frequent drug administration may also be required to maintain systemic drug levels above a minimum effective concentration. This problem is particularly significant for drugs that must be maintained in a well-defined concentration window to provide continuous therapeutic or prophylactic benefit while minimizing adverse effects (including for example, antibacterial agents, antiviral agents, anticancer agents, anticonvulsants, anticoagulants, etc.).
Conventional approaches to extend the systemic exposure of drugs with rapid clearance involve the use of formulation or device approaches that provide a slow or sustained release of drug within the intestinal lumen. These approaches are well known in the art and normally require that the drug be well absorbed from the large intestine, where such formulations are most likely to reside while releasing the drug. Drugs that are amenable to conventional sustained release approaches must be orally absorbed from the intestine and typically traverse this epithelial barrier by passive diffusion across the apical and basolateral membranes of the intestinal epithelial cells. The physicochemical features of a molecule that favor its passive uptake from the intestinal lumen into the systemic circulation include low molecular weight (e.g. <500 Da), adequate solubility, and a balance of hydrophobic and hydrophilic character (logP generally 1.5-4.0) (Navia and Chaturvedi, P. R. Drug Discovery Today 1996, 1, 179-189).
Polar or hydrophilic compounds are typically poorly absorbed through an animal's intestine as there is a substantial energetic penalty for passage of such compounds across the lipid bilayers that constitute cellular membranes. Many nutrients that result from the digestion of ingested foodstuffs in animals, such as amino acids, di- and tripeptides, monosaccharides, nucleosides and water-soluble vitamins, are polar compounds whose uptake is essential to the viability of the animal. For these substances there exist specific mechanisms for active transport of the solute molecules across the apical membrane of the intestinal epithelia. This transport is frequently energized by co-transport of ions down a concentration gradient. Solute transporter proteins are generally single sub-unit, multi-transmembrane spanning polypeptides, and upon binding of their substrates are believed to undergo conformational changes, which result in movement of the substrate(s) across the membrane.
Over the past 10-15 years, it has been found that a number of orally administered drugs are recognized as substrates by some of these transporter proteins, and that this active transport may largely account for the oral absorption of these molecules (Tsuji and Tamai, Pharm. Res. 1996, 13, 963-977). While in most instances the transporter substrate properties of these drugs were unanticipated discoveries made through retrospective analysis, it has been appreciated that, in principle, one might achieve good intestinal permeability for a drug by designing in recognition and uptake by a nutrient transport system. Drugs subject to active absorption in the small intestine are often unable to passively diffuse across epithelial cell membranes and are too large to pass through the tight junctions that exist between the intestinal cells. These drugs include many compounds structurally related to amino acids, dipeptides, sugars, nucleosides, etc. (for example, many cephalosporins, ACE inhibitors, AZT, etc).
Gamma ("γ")-aminobutyric acid ("GABA") is one of the major inhibitory transmitters in the central nervous system of mammals. GABA is not transported efficiently into the brain from the bloodstream (i.e., GABA does not effectively cross the blood-brain barrier). Consequently, brain cells provide virtually all of the GABA found in the brain (GABA is biosynthesized by decarboxylation of glutamic acid with pyridoxal phosphate).
GABA regulates neuronal excitability through binding to specific membrane proteins (i.e., GABAA receptors), which results in opening of an ion channel. The entry of chloride ion through the ion channel leads to hyperpolarization of the recipient cell, which consequently prevents transmission of nerve impulses to other cells. Low levels of GABA have been observed in individuals suffering from epileptic seizures, motion disorders (e.g., multiple sclerosis, action tremors, tardive dyskinesia), panic, anxiety, depression, alcoholism and manic behavior.
The implication of low GABA levels in a number of common disease states and/or common medical disorders has stimulated intensive interest in preparing GABA analogs, which have superior pharmaceutical properties in comparison to GABA (e.g. the ability to cross the blood brain barrier). Accordingly, a number of GABA analogs, with considerable pharmaceutical activity have been synthesized in the art (See, e.g., Satzinger et al, U.S. Pat. No. 4,024,175; Silverman et al., U.S. Pat. No. 5,563,175; Horwell et al., U.S. Pat. No. 6,020,370; Silverman et al., U.S. Pat. No. 6,028,214; Horwell et al., U.S. Pat. No. 6,103,932; Silverman et al., U.S. Pat. No. 6,117,906; Silverman, International Application No. WO 92/09560; Silverman et al., International Application No. WO 93/23383; Horwell et al., International Application No. WO 97/29101, Horwell et al., International Application No. WO 97/33858; Horwell et al., International Application No. WO 97/33859; Bryans et al., International Application No. WO 98/17627; Guglietta et al., International Application No. WO 99/08671; Bryans et al., International Application No. WO 99/21824; Bryans et al., International Application No. WO 99/31057; Belliotti et al., International Application No. WO 99/31074; Bryans et al., International Application No. WO 99/31075; Bryans et al., International Application No. WO 99/61424; Bryans et al., International Application No. WO 00/15611; Bryans, International Application No. WO 00/31020; Bryans et al., International Application No. WO 00/50027; and Bryans et al, International Application No. WO 02/00209).
Pharmaceutically important GABA analogs include, for example, gabapentin, pregabalin, vigabatrin and baclofen. Gabapentin is a lipophilic GABA analog that can pass through the blood-brain barrier, which has been used to clinically treat epilepsy since 1994. Gabapentin also has potentially useful therapeutic effects in chronic pain states (e.g., neuropathic pain, muscular and skeletal pain), psychiatric disorders (e.g., panic, anxiety, depression, alcoholism and manic behavior), movement disorders (e.g., multiple sclerosis, action tremors, tardive dyskinesia), etc. (Magnus, Epilepsia, 1999, 40:S66-S72). Currently, gabapentin is also used in the clinical management of neuropathic pain. Pregabalin, which possesses greater potency in pre-clinical models of pain and epilepsy than gabapentin is presently in Phase III clinical trials.
Rapid systemic clearance is a significant problem with many GABA analogs including gabapentin, which consequently require frequent dosing to maintain a therapeutic or prophylactic concentration in the systemic circulation (Bryans et al., Med. Res. Rev., 1999, 19, 149-177). For example, dosing regimens of 300-600 mg doses of gabapentin administered three times per day are typically used for anticonvulsive therapy. Higher doses (1800-3600 mg/day in divided doses) are typically used for the treatment of neuropathic pain states.
Sustained released formulations are a conventional solution to the problem of rapid systemic clearance, as is well known to those of skill in the art (See, e.g., "Remington's Pharmaceutical Sciences," Philadelphia College of Pharmacy and Science, 17th Edition, 1985). Osmotic delivery systems are also recognized methods for sustained drug delivery (See, e.g., Verma et al., Drug Dev Ind. Pharm., 2000,26:695-708). Many GABA analogs, including gabapentin and pregabalin, are not absorbed via the large intestine. Rather, these compounds are typically absorbed in the small intestine by the large neutral amino acid transporter ("LNAA") (Jezyk et al., Pharm. Res., 1999, 16, 519-526). The rapid passage of conventional dosage forms through the proximal absorptive region of the gastrointestinal tract has prevented the successful application of sustained release oral dosage technologies to GABA analogs. Thus, there is a significant need for effective sustained release versions of GABA analogs to minimize increased dosing frequency due to rapid systemic clearance of these compounds.
Another deficiency with some GABA analogs, including gabapentin, is their lack of dose-proportional oral bioavailability (see Radulovic et al, Drug Metab. Dispos. 1995, 23, 441-448; Gidal et al, Epilepsy Res. 2000, 40, 123-127; Gabapentin Supplementary Basis for Approval, Warner-Lambert, Inc.). Absorption of gabapentin in mammals is subject to saturation, since the large neutral amino acid transport system has limited substrate capacity and is localized to the upper part of the small intestine, creating an absorption window that restricts the ability of the drug to be taken up into the bloodstream. Thus in man, gabapentin oral bioavailability decreases from about 60% at a dose of 300 mg to about 35% at a dose of 1600 mg. This leads not only to inefficient use of the administered drug, but also to unpredictable and highly variable drug levels in patients, particularly at the higher doses associated with efficacy in the treatment of epilepsy and neuropathic pain (Gidal et al, Epilepsy Res. 1998, 31, 91-99). There is, therefore, a need for derivatives of gabapentin and other GABA analogs, which following oral administration to a patient in need of therapy provide therapeutically efficacious levels of the GABA analog in the plasma of a patient, where the concentration of the GABA analog in plasma of the patient over time provides a curve of concentration of the GABA analog in the plasma over time, the curve having an area under the curve (AUC) which is substantially more proportional to the dose of GABA analog administered, as compared to the proportionality achieved following oral administration of the GABA analog itself. There is similarly a need for derivatives of gabapentin and other GABA analogs, which following oral administration to a patient in need of therapy provide therapeutically efficacious levels of the GABA analog in the plasma of a patient, where the concentration of the GABA analog in plasma of the patient over time provides a curve of concentration of the GABA analog in the plasma over time, the curve having a maximum plasma concentration (Cmax) which is substantially more proportional to the dose of GABA analog administered, as compared to the proportionality achieved following oral administration of the GABA analog itself.
One pathway that might provide for the sustained delivery of drugs with rapid systemic clearance is the proton-coupled peptide transport system (Leibach and Ganapathy, Ann. Rev. Nutr. 1996, 16, 99-119). These transporters mediate the cellular uptake of small intact peptides consisting of two or three amino acids and are found primarily in the intestine and kidney. In the intestine, where small peptides are not well-absorbed by passive diffusion, the transporters act as a vehicle for their effective absorption. Transporters in the kidney actively reabsorb di- and tri-peptides from the glomerular filtrate, thereby increasing their half-life in the circulation.
Two proton-coupled peptide transporters that have been cloned and characterized are PEPT1 and PEPT2. PEPT1 is a low-affinity, high-capacity transporter found primarily in the intestine. The human PEPT1 consists of 708 amino acids and possesses 12 putative transmembrane domains. PEPT2, in contrast, is a high-affinity, low-capacity transporter found mostly in the kidney. It consists of 729 amino acids and is 50% identical to human intestinal PEPT1.
Studies of PEPT1 and PEPT2 have shown that the transporters account for the absorption and reabsorption of certain therapeutically active compounds. The compounds include both biologically active peptides (e.g., renin inhibitors) and zwitterionic antibiotics. Based on these observations, researchers have suggested that peptide transporters, in conjunction with cytosolic peptidases, could be exploited for systemic delivery of certain drugs in the form of peptide prodrugs (see Tsuji and Tamai, Pharm. Res. 1996, 13, 963-977). Dipeptide analogues of α-methyldopa, L-α-methyldopa-Phe and L-α-methyldopa-Pro, for example, are absorbed more efficiently in the intestine than α-methyldopa alone. Once across the intestinal membrane, the dipeptides are hydrolyzed by cytosolic peptidases to release α-methyldopa.
Gallop et al have provided evidence from transporter mRNA expression profiling studies that PEPT expression in rat and human extends broadly over the length of the intestine, including the colon (U.S. Patent Application Ser. No. 60/351,808 filed 24 Jan. 2002). They have suggested that sustained exposure to a substrate for a PEPT transporter could be achieved by formulating such a compound in an extended-release dosage form, which would gradually release the compound during transit of the formulation through the large intestine.
Peptide prodrug derivatives of gabapentin and other GABA analog drugs are contemplated by Bryans et al (see International Application No. WO 01/90052; U.K. Application GB 2,362,646; European Application EP 1,178,034). These workers have disclosed gabapentin derivatives wherein the amino group is blocked with particular α-aminoacyl or dipeptide moieties. More specifically, the α-amino acids comprising these peptide prodrug derivatives are the 20 naturally encoded α-amino acids, plus phenylglycine.
Prodrug derivatives of gabapentin and other GABA analog drugs are also disclosed by Gallop et al (see the co-pending International Applications WO 02/28881, WO 02/28883, WO 02/28411 and WO 02/32376). The compounds disclosed therein are bile acid conjugates of GABA analogs that are designed to be actively transported across the intestinal mucosa via interaction with the ileal bile acid transporter. These conjugates are further designed to undergo enterohepatic recirculation and to slowly release the parent GABA analog into the systemic circulation. Additional prodrug derivatives of gabapentin and other GABA analog drugs are disclosed by Gallop et al (see the co-pending International Application WO 02/42414). The compounds disclosed therein are α-aminoacyl and β-aminoacyl conjugates of GABA analogs that are designed to be actively absorbed across the intestinal mucosa via interaction with peptide transporters expressed in the intestine.

This patent is subject to a terminal disclaimer.

Amino acid conjugates providing for sustained systemic concentrations of GABA analogues


Methods and apparatus are provided for reducing disk seek time to improve the overall throughput by improving the scheduling of read requests. One or more requests to read data from one or more disks are scheduled by suspending one or more requests to read data from the disk for a predefined period of time. The read suspension can be initiated, for example, in response to a request to read data from the disk, such as a speculative read operation. The predefined period of time may be approximately equal, for example, to an expected duration of the read request operation, an expected seek time, a predefined recovery time or a time since a last request less a recovery time. The read suspension can be conditioned upon one or more predefined criteria, such as a disk bandwidth threshold being satisfied, a time since a last request threshold being satisfied and a condition that only a request for a different stream than a currently requested stream is suspended.

In order to read or write data to a hard disk, the disk micro-controller must first physically position the disk head at the appropriate place on the disk platter(s) where the data is to be read or written. During this time, no data transfer can happen, and seek time is essentially wasted time. Thus, the management of seek time is an important factor in the overall throughput of read and write operations to a hard disk.
A number of techniques have been proposed or suggested for the management of seek time. For example, the total amount of seek time can be minimized by ensuring that each read or write operation transfers a large amount of data. Although this technique reduces the number of disk seeks required, and improves overall throughput, it is often impractical. A number of hard disk controllers employ a cache memory to improve the performance of read and write operations. The goal of the cache memory is to hide the disk seek time by effectively re-ordering read and write operations so that consecutive operations require little or no seek time.
Data from incoming write operations are usually written to the cache first, and then written to the disk at an appropriate time. This allows the micro-controller to re-order the write operations and change the timing of the write operations to minimize the disk seek time and thereby improve the overall throughput. For example, operations that physically access "similar locations" on the disk should be grouped together.
The use of the cache for read operations is also important. Typically, the disk micro-controller will observe the pattern of read operations, predict likely future read requests, and then speculatively (and efficiently) read large chunks of data into the cache when the disk is otherwise idle. The cache is usually managed as a set of "segments," with each segment having a specific purpose and being managed independently.
This speculative read-ahead works especially well when a single stream of data is read from consecutive sectors on the disk. The disk seek time is minimized and the performance approaches the maximum theoretical disk bandwidth. If a second stream of consecutive sector reads is added, however, the performance often drops significantly, depending on the transfer size of each operation. For example, if a request for a first stream is received, the controller will move the head to read the data from the first stream and then read and return the data for the first stream. Thereafter, the controller is idle and will start a speculative read of data for the first stream. Meanwhile, assume that a request for a second stream is received during the speculative read of the first stream. The controller will abort the speculative request (since actual requests take precedence over speculative reads), move the head to read the data from the second stream and then read and return the data for the second stream.
The disk will keep moving the head from one position to another in this manner as it aborts speculative read operations in favor of actual requests. Thus, the aborted speculative read ahead operations will be ineffective towards minimizing disk seek time. In effect, the disk seek time will dominate and the benefit of the read cache is significantly impaired. A need therefore exists for methods and apparatus for reducing disk seek time to improve the overall throughput. A further need exists for methods and apparatus for scheduling read requests.

Method and apparatus for scheduling disk read requests


An apparatus for measuring volatile organic compounds in a gas includes a sensor chamber having a housing with a gas inlet, a gas outlet, and a gas flow path from the gas inlet to the gas outlet, a set of baffles within the housing and positioned in the gas flow path, and a set of sensors within the housing and positioned in the gas flow path. Each sensor has an electrically conductive polymer whose electrical properties are dependent upon the presence of specific volatile organic compounds in the gas flow. Desirably, the set of baffles and the set of sensors are cooperatively positioned such that the time for gas to flow from the gas inlet to each of the sensors is substantially the same. The apparatus further includes a pump that removes the gas from the gas outlet of the housing, and an electronic circuit that measures the electrical properties of each of the sensors.

This invention relates to the monitoring of gases to detect levels of volatile organic compounds, and, more particularly, to a sensor apparatus useful in such monitoring.
Volatile organic compounds (VOCs) are associated with many industrial processes. VOCs such as solvents (e.g., benzene, toluene, xylene, ketones, acetates, alcohols) are typically used in the processes in liquid form, but may evaporate into the process environment. Some of the VOCs are health hazards and/or contribute to the formation of atmospheric pollutants.
In one example, industrial painting operations utilize large amounts of VOC solvents as carriers for pigments. The solvents evaporate to some degree during the painting as a result of the use of mildly elevated temperatures and/or the use of techniques such as spray painting which utilize finely divided droplets containing the solvents. Great care is taken to confine the solvents to closed systems, but inevitably there is some leakage at joints in the apparatus, input/output ports, and other locations.
Measuring the presence and concentrations of VOCs is of importance in several ways. For example, regulators compare the concentrations of VOCs to regulatory standards to ensure compliance of industrial operations to the standards, and to determine whether certain operations may be allowed to continue. Process engineers use information on VOC production to select processes for implementation. VOC information is used to determine whether a process is operating properly, and to identify sources of inefficient operation. Medical personnel seek to correlate human health with VOC concentrations.
The VOCs are typically present in the range of parts per billion or parts per million of the process gas such as air. Instruments are available to make quantitative measurements of the gas for VOCs at such low levels. Examples of such instruments include flame ionization detectors, Fourier transform infrared spectrometers, and instruments using other wet or dry chemical analysis procedures. Such instruments tend to be relatively expensive and bulky, and require trained personnel to operate them. It is therefore not ordinarily possible to place the measurement instruments at all locations where information might be needed, such as at a plurality of different sampling locations around a paint line. Instead, individual gas samples may be transported, or samples may be piped, from the sampling locations to the central measurement instrument. These approaches are accompanied by concerns that the composition of the sample may change during transport, or that the sampling loses its real-time character. The latter is of particular concern for process engineers who use the sampling data to optimize the operation and performance of the industrial system.
There is a need for an improved practical approach to the sampling and measurement of VOCs in industrial and other environments. The present invention fulfills this need, and further provides related advantages.
The present invention provides an apparatus for measuring volatile organic compounds (VOCs) in a real-time manner with excellent sensitivity. The apparatus is relatively inexpensive, so that units may be placed at various locations around an industrial operation to assess production of VOCs in the industrial operation. The apparatus is suitable for measuring a wide variety of VOCs using the same basic structure, modified only as to the sensor selected for each particular VOC. A single instrument may analyze for a number of VOCs simultaneously.
In accordance with the invention, the apparatus for measuring volatile organic compounds in a gas comprises a sensor chamber, which includes a housing having a gas inlet, a gas outlet, and a gas flow path from the gas inlet to the gas outlet, a gas flow path control structure within the housing to alter the gas flow from the gas inlet to the gas outlet, and a set of sensors within the housing and positioned in the gas flow path. Each sensor has an associated sensor electrical output signal that is dependent upon the presence of a respective volatile organic compound in the gas flow. The apparatus optionally includes a pump that removes the gas from the gas outlet of the housing, and an electronic circuit that measures each of the sensor electrical output signals.
The gas flow path control structure is preferably a set of baffles that spread the gas flow through a volume and to the set of sensors. Desirably, the gas flow path control structure and the set of sensors are cooperatively positioned so that the time required for the gas to flow from the gas inlet to each of the sensors is substantially the same. The apparatus may also be provided with appropriate sensors of its conditions, such as temperature and humidity sensors. The conditions of the apparatus, such as its temperature, may be controlled, as with a heating element to control the temperature in a closed-loop fashion. A microcontroller controls and coordinates operation of the apparatus, including the electronics, pump (where present), sensors, heating elements, and the like.
The sensors preferably include electrically conductive polymers whose electrical properties depend upon the presence of the respective volatile organic compounds in the gas flow contacting the polymer. Various polymers whose electrical properties are sensitive to organic compounds, such as methyl isoamyl ketone, xylene, and butyl acetate, are known.
The present approach provides a compact apparatus for measuring VOCs. The apparatus is relatively compact and light, permitting it to be positioned at locations where measurements are required, or for a number of the apparatus units to be positioned at a number of locations where measurements are required. Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. The scope of the invention is not, however, limited to this preferred embodiment.

Sensor apparatus for measuring volatile organic compounds


A computer system is provided that includes at least one processor configured to execute a host virtual machine configured to host a session with at least one client computer device. The at least one processor is further configured to execute a web browser application configured to access media content from a remote media source, receive encoded media content from the remote media source in a media container format, and execute a multi-media redirection module configured to intercept the encoded media content from being processed by a decoding module of the web browser application. The multi-media redirection module is configured to redirect the encoded media content to the at least one client computer device.

In virtual environments, end users may use client devices to connect to a virtual machine running on server hardware, which may provide the end user with the benefits of added compute power, application compatibility, security and regulatory compliance, and a reduction in overall cost for the end user. Typically, these end users may consume media such as video streaming, which can potentially increase the workload placed on the server hardware and increase associated costs.


The in-ground, or xe2x80x9cwell lightxe2x80x9d, fixture comprises a hollow cylindrical housing, a bezel and lens mounted at the upper end of the housing, and a lamp assembly comprising a watertight lamp enclosure containing a lamp and reflector. The lamp enclosure is secured by support brackets which extend downward from the bottom portion of the bezel to provide three-axis adjustability of the lamp. An optional mounting ring is attached at the upper end of the housing to form a flange to facilitate stable placement of the well light in the ground as well as providing an attractive frame around the fixture. The lens is retained at a shallow angle within the bezel to permit water and dirt to run off of the lens surface.

The present invention relates to lighting fixtures adapted for landscape and environmental lighting applications and, more particularly, to in-, or below-ground lighting fixtures.
The use of outdoor lighting fixtures has become increasingly popular for illuminating buildings, gardens, pathways and entrance ways as the nighttime play of light on the landscape and vegetation is aesthetically pleasing. Additionally, such lighting provides enhanced security by eliminating hiding places and unobserved entry points for intruders. Outdoor lighting systems include one or more lighting fixtures which are connected to either a 12 V transformer or a standard 120 VAC line. The lighting fixtures generally include a housing, a lamp assembly having a halogen or conventional bulb and a reflector, and a lens or window. Many configurations are known for providing a variety of different lighting effects.
Landscape lighting fixtures, most of which are mounted at or above ground level are generally considered to appear somewhat incongruous with the surrounding vegetation during daylight hours, when the illumination function is not in use. Further, because of the constant exposure to the elements, above ground lighting fixtures are generally required to be made of expensive, high quality materials, such as non-corrosive metal alloys, in order to provide durability and a reasonable resistance to damage so as not to appear cheap and unkempt.
As an alternative to the above-ground placement of landscape lighting fixtures, recessed, in-ground lighting fixtures, also known as xe2x80x9cwell lightsxe2x80x9d, have gained widespread acceptance. In certain applications, the use of below-ground landscape lighting is preferable over above-ground varieties, especially in areas surrounding walkways where an above-ground element could poses a tripping hazard or in lawn areas where the use of a lawn mower presents a risk of damage to the fixture.
Despite having a number of advantages over above-ground type fixtures for certain applications, in-ground light fixtures encounter problems not typically seen in lighting fixtures of other varieties. A significant problem is the intrusion of water or other electrically conductive fluids into the subterranean receptacle housing the lighting fixture. A number of sealing techniques have been employed in the prior art. In the in-ground light fixture of Wagner, et al., U.S. Pat. No. 5,481,443, a single sealing element between the lens and the fixture housing is relied upon to provide a barrier against moisture intrusion. The U.S. Pat. No. 5,003,441 of Crowe, et al., which discloses an in-ground pop-up light fixture, makes passing mention to xe2x80x9cthe lower housing is normally sealed watertightxe2x80x9d but fails to disclose the means by which the seal is created. The well light of Porter, et al., U.S. Pat. No. 5,230,559, makes no provision for ensuring water resistance of the lighting fixture and attached wiring. The need for water resistance is of additional importance to in-ground fixtures since the light emitting surface is usually horizontal, providing a place for water to pool and increasing the chance of water-related damage. In addition, in such fixtures, the water can xe2x80x9cwickxe2x80x9d up the field wire into the fixture housing, thus imposing the need for the fixture to be water-tight from all perspectives.
A second problem experienced with below-ground light fixtures is the need to control the direction of illumination with maximum efficiency and ease for the user. A significant limitation is that the lamp is located at or below ground surface, which limits the range of illumination and convenient access to the lamp. It would be an advantage to have an apparatus where the lamp is easily accessible to the user for adjustment of beam quality and direction without compromising the water tightness or weather resistant features of the fixture.
A third, seldom addressed problem is a means for cooling the in-ground lighting fixture. Halogen and incandescent filaments generate a significant amount of radiant heat when illuminated. Being placed in-ground, the lighting fixture has limited means for providing air circulation to dissipate heat build-up within the fixture which can potentially lead to failure of the fixture due to damaged or melted components and electrical wiring as well as accelerating corrosion due to the exposure to outdoor environments. Furthermore, minerals and other residue deposited on the lens as the result of irrigation and other environmental exposure are baked on by the heat generated by the lamp. The baked-on residue obscures light output and exacerbates the tendency for heat build-up.
It would be desirable to provide an in-ground lighting fixture that provides a watertight interior environment for electrical wiring and associated elements while allowing for adjustability of the light beam. An additional cooling means for the lighting element would also be desirable. These problems and deficiencies are clearly felt in the art and are solved by the present invention in the manner described below.
It is an advantage of the present invention to provide an in-ground lighting fixture that is water-tight.
It is a further advantage of the present invention to provide an in-ground lighting fixture that allows multi-axis adjustment of the beam.
Another advantage of the present invention is to provide an in-ground lighting fixture that has means for cooling and providing air circulation for the below-ground portion of the fixture.
Still another advantage of the invention is to provide an in-ground lighting fixture that minimizes build-up on the lens that can occur from exposure of the fixture to water and dirt.
In an exemplary embodiment, the in-ground, or xe2x80x9cwell lightxe2x80x9d, fixture comprises a hollow cylindrical housing, a bezel and lens mounted at the upper end of the housing, and a lamp assembly comprising a watertight lamp enclosure containing a lamp and reflector. The lamp enclosure is secured by support brackets which extend downward from the bottom portion of the bezel to provide three-axis adjustability of the lamp. An optional mounting ring is attached at the upper end of the housing to form a flange to facilitate stable placement of the well light in the ground as well as providing an attractive frame around the fixture. The lens is retained at a shallow angle within the bezel to permit water and dirt to run off of the lens surface.
The bezel comprises a circular plate that has top and bottom portions and an outside diameter that fits within the inside diameter of the mounting ring so that the bezel is supported on top of the upper end of the housing. The bottom portion of the bezel has a first inner diameter sized to fit within the inner diameter of the housing and a second inner diameter larger than the first inner diameter to create a lip adapted to fit over the top edge of the housing. When seated, the upper surface of the bezel is flush with the upper face of the mounting ring. The bezel has a plurality of openings therethrough, including a window opening that is generally rectangular to provide access to a transparent lens that is disposed at a shallow angle relative to horizontal to guide water and dirt away from the lamp assembly, allowing the water to run off the outer edge of the lens without pooling. A plurality of radially-arranged openings provide air circulation into and out of the interior of the housing, keeping the outer lens cool. Both the mounting ring and the bezel can be made from brass, anodized or powder-coated aluminum, or any other material that provides appropriate durability and weather-resistance as well as being aesthetically pleasing.
Retained within the housing is a lamp assembly comprising a shroud portion, a window, and a base portion which enclose a lamp and reflector. A pair of lamp support brackets are provided to mount the lamp assembly to the bottom portion of the bezel. Each bracket has a flanged portion for attachment to the bezel and a straight portion which attaches to the-lamp assembly. The brackets are disposed on opposite sides of the lamp base. Axial mounting screws are inserted from either side of the lamp base into threaded bores to hold the lamp assembly in place on the brackets while defining a pivot axis for tilting the lamp at a desired angle. The flanged portion of each bracket has an elongated slot formed therein through which the mounting screws are inserted, allowing the lamp assembly to be moved along a line parallel to the length of the window, then locked in place with the mounting screws. The straight portion of each bracket has an elongated slot formed therein to allow the lamp assembly to be adjusted closer to or farther away from the lens to alter the beam spread, then locked into position by tightening the axial mounting screws. The two sets of elongated slots and the axial mounting screws combine to provide a three-axis gimble mounting that provides maximum aiming flexibility, from near horizontal, e.g., for use in illuminating signs or walls, to vertical, for use lighting, e.g., flagpoles, trees, or overhead structures.
The base portion of the lamp assembly is generally cylindrical with a first end and a second end. A watertight electrical connector sleeve extends through the side of the second end for passing electrical wires from the outside to the interior of the base portion to connect to the socket that holds the lamp. Optional epoxy potting may be used to fill in the bottom interior spacing within the base to further provide stability for the socket and water-proofing for the electrical connectors. The outer surface of the second end has a plurality of annular cooling fins extending therefrom to function as a heat sink to dissipate heat generated by the lamp. The first end of the base is threaded with external ACME screw threads with an O-ring seat formed below the lowest thread. A large gauge O-ring is disposed within the O-ring seat so that the outer diameter of the O-ring is larger than the diameter of the screw threads. A second, smaller gauge O-ring is disposed below the first O-ring, closer to the second end of the base portion, and has an outer diameter that is greater than the outer diameter of the first O-ring.
The shroud portion of the lamp assembly is generally cylindrical with a window end and a base end. The interior of the base end has internal ACME screw threads for mating with the external threads on the base portion. A smooth inner sidewall below the threaded portion contacts the large O-ring to provide a tight fit, while the interior edge of the base end is chamfered to tightly fit against the second smaller O-ring, combining to create a watertight seal between the shroud portion and the base portion. The window end of the shroud portion has a recess formed for receiving the window, or lens, with the outer face of the window flush with the edge of the window end. The window is sealed within the shroud to create a watertight seal using a latex or RTV-silicone sealant or other appropriate sealant.
When an appropriate commercially-available lamp/reflector combination is plugged into the socket in the base portion, sufficient space remains between the upper extent of the reflector and the window to insert filters, diffusers or other optical elements to modify the beam, if desired. A bias spring can be used to provide an upward bias against the reflector to keep the lamp pressed against any optical elements that might be used.
The well light of the present invention provides a highly adjustable recessed fixture that is sufficiently watertight that it can actually be used in underwater applications such as swimming pools, decorative ponds and fountains.

In-ground lighting fixture with gimbaled lamp assembly


A method and apparatus are disclosed for automatically batching objects into portions, comprising conveying and weighing objects. An appropriate bin for each of the weighed objects is selected, wherein each bin is provided with a weighing means. Accordingly, the total portion weight is periodically registered. By means of comparing the potion weight with the summed object weight in that portions, an appropriate bin can be selected for forthcoming objects.

In various industries, basic objects are sold in batches satisfying various constraints. For example, many food objects, such as fresh or frozen fish portions, chicken portions or meat portions, are sold in prepackaged batches having a predetermined weight and/or number of pieces, within given tolerance. The tolerances may be quite strict in some industries.
In the contracts between sellers and purchasers for delivery of products must satisfy minimum weight or other requirements. It is important that none of the collections is below minimum weight, but exceeding the weight results in an economical loss for the manufacturer.
The typical way to build up portions of objects is to weight each object prior to selecting the appropriate portion that is building up this particular object, where the weight of each portion is simply the sum of each individual object In that portion. If all the portions are far from the final weight limit, it is not essential which of these portions will be chosen for this object. If however the weight of one or more portions is closed to the final weight limit, it is essential which portion, for this particular object, will be chosen.
GB A 2.115.630 describes system for portion weighing of material wherein an automatic feedback correction is Introduced to correct the weighing difference between continues weighing and stationary weighing. U.S. A 3,945,448 describe similar system. As discussed hereinafter there is the fundamental difference between those prior systems, which do not allow selection of objects to be directed into preferred bin according to its first weight as well as corrected weighing for prior items already directed to a plurality of bins.
The problem with prior art methods is the inaccuracy in the weight of each portion that is building up, which can change the precondition when selecting an appropriate objects into a portion, so that the overweight of that portion is minimized. Where the weight of one portion is based on the sum of each object in the portion, the error in the weight of the total portion is the sum of errors in of each individual object. This can be related to the resolution in the weighing means that are being used. As an example the resolution in a weighing means is 1 g. This means that the error in weighing a single object is up to 1 g. If the number of objects in one portion is 20, the maximum error is number of objects multiplied with the resolution (error) for one single object, or 20*2 g=40 g. However, by registering the weight of the total portion by a single weighing procedure this error is dramatically reduced, and would in this particular example be 1 *1 g=1 g.


An optical fiber amplifier capable of compensating dispersion and loss of an optical signal in transmission along an optical fiber includes an optical fiber doped with erbium ions and having a dispersion compensating function. The amplifier further includes an erbium pump for performing forward pumping to the optical fiber, and a Raman pump for performing backward pumping to the optical fiber which is forward-pumped by the erbium pump means. When an optical signal passes through the optical fiber which undergoes density inversion of erbium ions and Stimulated Raman Scattering (SRS), dispersion and loss of the optical signal is compensated.

1. Field of the Invention
The present invention relates to an optical fiber amplifier and an amplification method for compensating dispersion and loss of an optical signal, and more particularly, to an optical fiber amplifier capable of compensating dispersion and loss of an optical signal in transmission thereof and an amplification method for compensating dispersion and loss of an optical signal using the same.
2. Description of the Prior Art
Data traffic is exponentially increasing owing to the Internet, which is implemented in part with a high Wavelength Division Multiplexing (WDM) optical communication network to accommodate the increase. The latter may be accomplished by increasing the number of transmission channels or by raising the transmission rate per channel. When the transmission rate per channel of the optical signal reaches or exceeds a gigabit per second, the optical signal becomes especially sensitive to the effect of dispersion and may require compensation. One well known method utilizes a Dispersion Compensating Fiber (DCF) having negative dispersion to compensate for positive dispersion occurring in an optical signal.
Use of a DCF to compensate for dispersion of an optical signal results in a large amount of power loss and therefore requires implementation with an additional optical amplifier. The optical transmitter may include, for example, an Erbium-Doped Fiber Amplifier (EDFA). A Raman Amplifier is also widely used for this purpose.
The EDFA applies a pump signal, i.e., a pumped optical signal, to an optical fiber which is doped with the element erbium, in order to directly amplify a received optical signal without having to convert the optical signal into an electric signal. The Raman amplifier uses an optical fiber which serves as a nonlinear medium for generating a scattered pump signal from an incident non-chromatic pump signal to amplify an optical signal.
When the EDFA is used to compensate power loss of an optical signal owing to the DCF, more EDFAs are needed, in proportion to the transmission distance for the optical signal, thereby degrading the Optical Signal Noise Ratio (OSNR). Also, incorporating a DCF and a number of EDFAs into one module disadvantageously increases the volume of the module.
Although use of the Raman amplifier can improve OSNR, the efficiency of Raman amplification is lowered. As a result, a pump Laser Diode (LD) is required to input a high-power pump signal into the optical fiber to obtain a predetermined, suitable level of gain.

Optical fiber amplifier and amplification method capable of compensating dispersion and loss in transmission thereof


A method of providing hydrocarbons to an engine exhaust for regenerating a diesel particulate filter within an exhaust system of a diesel engine. A mass flow rate of exhaust gas within an exhaust system is determined. A mass flow rate of oxygen within the exhaust gas entering the diesel oxidation catalyst is determined. A set point indicative of an allowable mass flow rate of oxygen within the exhaust gas exiting the diesel oxidation catalyst is received. A hydrocarbon threshold that may be injected into the exhaust system is calculated. Hydrocarbons are injected into the exhaust system upstream of the diesel oxidation catalyst, wherein the injected hydrocarbons do not exceed the calculated threshold amount of hydrocarbons.

Many factors, including environmental responsibility efforts and modern environmental regulations on engine exhaust emissions, have reduced the allowable acceptable levels of certain pollutants that enter the atmosphere following the combustion of fossil fuels. Increasingly, more stringent emission standards may require greater control over either or both the combustion of fuel and post combustion treatment of the exhaust. For example, the allowable levels of nitrogen oxides (NOx) and particulate matter have been greatly reduced over the last several years. To address, among other issues, environmental concerns, many diesel engines now have a diesel oxidation catalyst (DOC) as well as a diesel particulate filter (DPF) within an exhaust system of the diesel engine purposed to reduce the amount of NOx and particulate matter released into the atmosphere.
In some diesel engine operating conditions it may be beneficial to provide hydrocarbons, typically in the form of diesel fuel but other fuels or hydrocarbon sources may be utilized, to the exhaust system of the engine at a location upstream of the DOC such that the hydrocarbons will combust and raise temperatures within the DPF to a point sufficient to allow regeneration of the DPF. In other diesel engine operating conditions, it may be beneficial to provide hydrocarbons in the form of an in-cylinder post injection such that the exhaust is sufficiently warm to allow regeneration of the DPF to occur. However, in still other diesel engine operating conditions it may be beneficial to provide hydrocarbons both directly into the exhaust system and via in-cylinder post injection. Some engines are equipped with an injector to provide hydrocarbons both directly to the exhaust system, or via in-cylinder post injection.
However, one drawback of existing systems that provide hydrocarbons for DPF regeneration is to ensure that only a limited amount of hydrocarbons pass through the DOC without combusting, a condition often referred to as hydrocarbon slip. Hydrocarbon slip can have many negative effects on an exhaust system, such as causing the DPF to reach too high a temperature and break, causing a temperature hysteresis across the DOC, or blocking catalyst sites on the DOC and limit the DOC's ability to function properly. Therefore, a maximum amount of hydrocarbons that may be injected into the exhaust system for DPF regeneration must be controlled. Current attempts to control the maximum amount of hydrocarbon injection utilize calibration tables, but these tables were developed during steady state engine operating conditions, and therefore do not account for transient engine operating conditions.
Therefore, a need exists for a system and method of providing hydrocarbons to be used to raise exhaust temperatures that allow regeneration of a DPF to occur that allows delivery of hydrocarbons upstream of a DOC, but that calculates a maximum amount of hydrocarbons that may be delivered without causing hydrocarbon slip to exceed a preset limit.

System and method of controlling maximum hydrocarbon injection for diesel particulate filter regeneration

International Engine Intellectual Property Company, LLC.


The present disclosure describes promoting roaming of a wireless terminal in a wireless local area network (WLAN). The AP obtains signal quality and/or data transmission quality of the wireless terminal periodically, and determines whether the obtained signal quality and/or data transmission quality of the wireless terminal satisfies a predetermined threshold. Upon determining that the predetermined threshold is not satisfied, the AP proactively sends a probe response frame to the wireless terminal. The probe response frame notifies the wireless terminal of a wireless signal strength of the AP to promote roaming to a neighboring AP.

WLAN is a distributed system with a relatively loose network architecture compared to wireless systems such as Global System for Mobile Communications (GSM) and third generation (3G). For example, wireless access points (APs) and wireless terminals in a WLAN operate relatively independent from each other. After exchanging messages and establishing a link, an AP does not control actions of a wireless terminal except for disconnecting the link to the terminal. Due to the nature of how WLAN is implemented, a wireless terminal in a WLAN generally handles different network environments differently, and different manufacturers have different implementations.

Promoting wireless local area network (WLAN) roaming

HEWLETT PACKARD ENTERPRISE DEVELOPMENT LP


A method for obtaining a mixture of heterogenous short double-stranded RNA molecules suitable for use in gene silencing (hsiRNA) by subjecting large double-stranded RNA to enzymatic cleavage under specified conditions. The resulting mixture consistently includes enhanced representation of fragments having a size of 21-22 nucleotides absent any fractionation step. The fragments contain sequences that collectively span the entire length of the large double-stranded RNA from which they are derived. Double-stranded RNA with sequences that individually represent segments of a target mRNA may be analyzed using the methods described herein to identify the most active subset of hsiRNA fragments or individual siRNA fragments for achieving gene silencing for any gene or transcribed sequences. A method is additionally provided for preparing and cloning DNA encoding selected siRNA, hsiRNA mixtures or hairpin sequences to provide a continuous supply of a gene silencing reagent derived from any long double-stranded RNA.

RNA interference (RNAi) employing short double-stranded RNA (siRNA) is a powerful tool for silencing gene expression in mammalian cells (see for example, U.S. Pat. No. 6,506,559, International Publication No. WO 01/29058, International Publication No. WO 01/68836, International Publication No. WO 01/75164, U.S. Publication No. 20020114784, U.S. Publication No. 20030125281, U.S. Publication No. 2002162126, U.S. Publication No. 20030108923, U.S. Publication No. 20020173478, Fire, et al. Nature 391:806-811 (1998); Yang, et al., Mol. Cell. Biol. 21:7807-7816 (2001), Elbashir, et al., Nature 411:494-498 (2001), Hammond et al. Nat. Rev. Genet 2:110-119 (2001), Sharp, Genes Dev. 15:485-490 (2001)).
A standard method for generating siRNA relies on an inherently expensive chemical synthesis of a pre-determined short sequence. Because not all parts of a target sequence are equally effective in silencing, it is necessary to generate libraries of chemically synthesized fragments to identify those sequences which are effective (Holen et al. Nucleic Acids Res. 30:1757-1766, 2002)).
An alternative method for generating siRNA relies on in vitro transcription (see for example, Donze and Picard, Nucleic Acids Res. 30:1757-1766 (2002) and Paddison et al. Genes and Dev. 16:948-958 (2002)). While this approach does not require chemical synthesis it remains necessary to choose and test individual short sequences to determine which are most effective.
Several enzymatic approaches have been reported for cleaving double-stranded RNA molecules into short fragments. An evolutionarily conserved enzyme which is believed to cleave large dsRNA to produce siRNA in vivo has been identified as DICER. (Bernstein, et al., Nature 409:363-366 (2001)). This enzyme contains a helicase motif, a PAZ (PIWI-ARGONAUT-ZWILLE) domain and a tandem repeat of a catalytic domain which is RNaseIII-like. Drosophila extracts presumably containing DICER mixed with large dsRNA in vitro produce short dsRNA in a range of sizes. The preferred size for RNAi applications in this mixture was determined by Tuschl et al. to be 21-23 nucleotides (International Publication No. WO 01/75164). Problems associated with using crude cell extracts containing a putative cleavage enzyme are for example, that it is unclear what proteins in the mixture of proteins are necessary and sufficient to generate the observed effect. In addition, the extract is relatively inefficient at cleaving large double-stranded RNA with only a relatively small amount of the starting material being cleaved to the desired size in vitro even under extended incubation times. (Paddison et al., Proc. Natl. Acad. Sci. 99:1443 (2002)).
More recently, mammalian Dicer has been obtained recombinantly from baculovirus cell expression systems. Lysates of recombinant DICER produced in baculovirus infected insect cell cultures are reported to generate short double-stranded RNA fragments from large double-stranded RNA in the presence of a magnesium buffer. The purified siRNA fragments were used for "silencing" the expression of cognate genes in cultured mammalian cell lines (Myers et al. Nature Biotechnology, 21:324-328 (2003)). Limitations of this approach include the cost of baculovirus expression systems, the incomplete digestion of double-stranded RNA starting material and the need for gel based or other purification step to eliminate precursor RNA prior to performing silencing experiments.
An alternative enzymatic approach for generating small double-stranded RNAs has been to use E. coli RNaseIII in the presence of magnesium ions to partially digest large double-stranded RNA. (Yang et al. Proc. Nat'l. Acad. Sci. USA 99:9942-9947 (2002)). Problems associated with this approach include low recovery amounts of the double-stranded fragments in a specific size range larger than about 15 nt and the associated inconvenience of titration to avoid over or under-digestion. Unless digestion is carefully monitored, RNaseIII in the presence of magnesium ions cleaves large double-stranded RNA into very small fragments that are generally considered to have no known use in RNAi. Careful titration and timing of the partial digest at best yielded a smear throughout a gel after which, a particular size fraction could be recovered for use in RNA silencing in cultured mammalian cells (Yang, et al., Proc. Nat'l. Acad. Sci. USA 99:9942-9947 (2002)). A problem with this approach is the lack of certainty with respect to (a) an end product where the end product relates to yield of a dsRNA having a particular size larger than about 15 nucleotides and (b) the extent of representation of the large double-strand RNA sequence in the cleavage products. The latter may be important since not all parts of the sequence of a long double-stranded RNA are thought to be equally effective in gene silencing and important sequences may be under-represented while unimportant sequences may be over-represented.
Because gene silencing has become a methodology of great importance in understanding molecular functions in cells and organisms, it is desirable to have a rapid, cost effective and reliable method for generating double-stranded RNA suitable for silencing of any gene.

Methods and compositions relating to gene silencing


The invention relates to a method of judging the thermostability of a protein, comprising the steps of calculating an analytical value specific to a test protein by a principal component analysis based on the amino acid composition of the protein calculated from the data of the amino acid sequence of the protein or the nucleotide sequence of the gene and comparing the analytical value with an analytical value of a protein which is retained by a thermostable organism and corresponds to the test protein, and further relates to a program for allowing a computer to execute processing for judging the thermostability of a protein by the method, and a computer readable recording medium having recorded the program thereon.

1. Field of the Invention
The present invention relates to a method of judging whether or not a protein has thermostability by focusing on a protein produced by an organism, and calculating a characteristic value related to thermostability from the data of the amino acid sequence or the nucleotide sequence of the protein. More particularly, the invention relates to a method of judging the thermostability of a protein, which judges whether or not a test protein has thermostability, comprising the steps of calculating an analytical value specific to the test protein by a principal component analysis based on the amino acid composition of the protein, and comparing the analytical value with an analytical value of a protein which is retained by a thermostable organism and corresponds to the test protein.
In addition, the invention relates to a program for judging whether or not the protein has thermostability by focusing on a protein produced by an organism, and calculating a characteristic value related to thermostability from the data of the amino acid sequence or the nucleotide sequence of the protein, and a recording medium having recorded the program thereon. More particularly, the invention relates to a program for allowing a computer to execute processing for judging the thermostability of a protein, which judges whether or not a test protein has thermostability by calculating an analytical value specific to the test protein by a principal component analysis based on the amino acid composition of the protein, and comparing the analytical value with an analytical value of a protein which is retained by a thermostable organism and corresponds to the test protein, and a computer readable recording medium having recorded the program thereon.
2. Background Art
Thermostable enzymes are widely used in the industrial world, research and development fields and the like as an enzyme that does not lose the enzymatic activity at a high temperature. Examples of the thermostable enzyme include, an enzyme used in an enzymatic reaction process for hydrolysis of a saccharide such as starch (see JP-T-10-506524 (the term "JP-T" as used herein means a published Japanese translation of a PCT patent application), and JP-A-2000-50870), an enzyme used in an enzymatic reaction in the disposal of food waste or in the production of a fertilizer from the food waste (see JP-A-2001-61474 and JP-A-2003-219864), an enzyme used in an enzymatic reaction in the production of a useful substance such as trehalose (see JP-A-08-336388 and JP-A-08-149980) and the like.
As described above, thermostable enzymes are very important in the industry. Recently, it has become important to develop a thermostable DNA polymerase to be used in the PCR method (see JP-B-04-67957), or in a replicative RNA-based amplification system (see JP-A-02-5864 and JP-A-02-500565), and a large number of thermostable DNA polymerases have been isolated mainly from thermophilic microorganisms. A DNA polymerase has become one of the important tools in genetic engineering techniques, and has become important as a tool not only for gene cloning or sequence determination, but also for detection or identification of a small amount of gene, namely, as an enzyme for gene amplification.
At present, thermostable DNA polymerases to be used mainly for these purposes are derived from the genus Thermus as Taq polymerase which is derived from T. aquaticus. The interest on the discovery of a novel polymerase with a more appropriate property and activity is growing, and as a DNA polymerase from other than the genus Thermus, for example, a method using a DNA polymerase from Anaerocellum thermophilum (see JP-T-2001-502169), a method using a DNA polymerase from a sulfur metabolism thermophilic archaebacterium Pyrococcus horikoshii (see JP-A-2000-41668) and the like have been reported.
In this way, the importance of thermostable enzymes is growing more and more, however, a search of such a thermostable enzyme often requires the steps of screening a bacterium producing a target enzyme from the natural world using thermophilic bacteria or thermostable bacteria as a target for screening, and confirming the thermostability of an enzyme produced by studying the culture conditions by performing a heat treatment one by one. Therefore, not only it required enormous time and effort, but also it depended on a coincidence in many cases. In addition, the subject of screening was limited to thermophilic bacteria, thermostable bacteria or mesophilic bacteria, and the thermophilic bacteria or thermostable bacteria was only limited species in light of numerous species of microorganisms, therefore the diversity of thermostable enzymes was limited.
Not only an accidental discovery is expected, but also the establishment of a systematic and saving method for searching a useful thermostable enzyme in industry was needed. Further, the development of a computer processable program, which is for conveniently executing the method was needed.

Method and computer program product for determining whether or not a test protein has thermostability

Japan Agency for Marine-Earth Science and Technology


A system that includes: (ii) at least one input port adapted to receive multiple addressable packets that include media content that belong to multiple media streams and to at least one duplicating media stream; (ii) at least one processor adapted to process the multiple addressable packets to determine media stream layer errors to control, and to participate in a replacement of addressable packets that include media content that belong to a defective media stream by addressable packets that belong to a corresponding duplicate stream. A method for providing a video stream over a network, the method includes: (i) receiving a first multi purpose communication protocol stream that includes multiple media streams and receiving at least one duplicate media stream; (ii) detecting a error in a media stream program; and replacing the defective media stream by a duplicate media stream.

Methods and systems for compressing and transmitting media signals are known in the art. Compressed digital video is largely becoming the preferred medium to transmit to video viewers everywhere. Parts of the Moving Pictures Experts Group (MPEG) specifications are standardized methods for compressing and transmitting video. Various audio compression techniques are also known in the art. In general, MPEG is used today for transmitting video over terrestrial, wireless, satellite and cable communication channels and also for storing digital video.
An audio stream is organized as an ordered sequence of frames. A video stream is usually organized as an ordered sequence of pictures; each picture includes a plurality of pixels. A video picture includes a plurality of slices, each slice including a plurality of macro blocks. The audio and video streams are provided to an audio encoder and to a video encoder respectively to generate compressed audio and video elementary streams, also referred to as elementary streams.
Elementary streams are packetized to produce PES packets. PES packets made up of elementary streams that form a program share a common time base. The PES packets may also include additional information. PES packets of distinct elementary streams can be arranged as either a Program Stream or a Transport Stream. At least one or more stream of PES packets having a common base time are usually combined to a Program Stream.
A Transport stream combines one or more programs with one or more independent time bases into a single stream. Transport streams include transport packets of 188 bytes. Transport stream packets start with a transport packet header. The header includes a packet ID (PID). Transport stream packets of one PID value carry data of a single elementary stream. Transport streams include Program Specific Information (PSI) tables. The PSI tables specify which PIDs and accordingly which elementary streams are associated to form each program.
Transport streams can include a single program of a multiplex of different programs. The latter is known as Multiple Program Transport Stream (MPTS).
Transport streams are designed to convey media (video and/or audio) signals. Other communication protocols can convey multiple information types that differ from video. These communication protocols are not tailored to carry only video and can carry video as well as other types of information. Such communication protocols are referred to as Multi Purpose Communication Protocols (MPCPs).
Usually, communication networks use a stack of communication protocols. The seven layer OSI model includes seven layers, while other commonly used protocol stacks include a different amount of layers.
MPCP protocols are usually the lower layer protocols of a protocol stack. They may include inter-network layer protocols, network interface layer protocols, and even transport layer communication protocols that differ from the MPEG transport stream.
Some commonly used MPCP protocols are ATM, IP, UDP, Ethernet, GigaEthernet, and the like.
One common protocol stack includes MPEG Transport stream, UDP, IP and Ethernet. Accordingly, an MPCP thread that conveys such an MPEG Transport stream includes MPEG Transport packets that are encapsulated within IP packets, UDP packets, Ethernet frames, and the like.
FIG. 1 illustrates a prior art Ethernet frame 90. Ethernet frame 90 includes an Ethernet header 91, an IP header 92, a UDP header 93, an Ethernet frame trailer 94 as well as multiple MPEG Transport packets 75. An exemplary transport packet (of a MPEG Transport) 75 includes transport stream payload (not shown) and a transport stream header. Various fields of the transport stream header are shown. Some are omitted for simplicity of explanation. The illustrated fields of the transport stream header include: a transport error indication bit 81, PID field 82, continuity counter field 83, discontinuity indicator field 85, and PCR field 87. The discontinuity indicator field 85 is a part of an adaptation field 84. The PCR field 87 is a part of optional fields 86.
A modern multiple purpose communication network includes multiple purpose components, such as routers, switches and the like. In order to improve the resilience of the multiple purpose communication network many components receive an MPCP thread and a duplicate MPCP thread.
Some of these multiple purpose communication network component are able to perform various MPCP operations. They are not capable of performing video related operations.
These MPCP operations may include processing MPCP information, performing error corrections based upon the MPCP information, requesting a re-transmission of certain MPCP packets, re-arrangement, assembling and fragmentation and the like.
For example, the MPCP processing may include retrieving or extracting an IP header, a UDP header and/or an Ethernet header or trailer, in order to detect IP layer failures, UDP layer failures, Ethernet layer failures and the like. These error can include Ethernet link loss, no IP relevant activity, no data on the relevant UDP port and the like.
Various well-known methods for providing redundancy are known in the art. U.S. Pat. No. 5,959,972 of Hamami, titled "method of port/link redundancy in an ATM switch"; U.S. Pat. No. 6,289,017 of Shami et al., titled "Method of providing redundancy and load sharing among multiple LECs in an asynchronous mode network"; U.S. Pat. No. 6,222,820 of Hamami, titled "method of VCC/VPC redundancy for asynchronous transfer mode networks"; U.S. patent application 20020076143 of Foltzer, titled "Multi-channel, multi-mode redundant optical loop having a bus topology"; U.S. patent application 20030110409 of Gale, et al. titled "method and apparatus for network fault correction via adaptive fault router", all being incorporated herein by reference, provide a brief view of some state of the art redundant networks a method for providing redundancy.
Typically, once a link fails the traffic that was conveyed over the link is re-directed—routed through another link. If the link conveyed bi-directional traffic, the bi-directional traffic is re-routed.
U.S. Pat. No. 5,959,972 describes a method for implementing redundancy of both links and ports between two switches, e.g., ATM switches. A redundant link connection between two ATM switches is constructed using two separate parallel communication links connected between separate ports on each of the switches. One communication link is termed the main link and the other is termed the backup link. Two virtual circuits are setup between the backup link ports. One is a direct virtual circuit directed over the backup link. The other is an indirect virtual circuit that is routed over the main link via the main link ports. A virtual circuit is also setup over the main link for regular data traffic. In addition, a standby virtual circuit is setup over the backup link but is placed in standby until the occurrence of a failure. Until a failure occurs, traffic normally proceeds over the main link while the backup link ports transmit keep alive messages to each other over the indirect virtual circuit that is routed over the main link. When the main link fails, either one or both of the backup link ports detects the failure. The data traffic is then switched from the main link to the backup link. The failure is detected by the failure of the backup link ports to receive keep alive messages.
U.S. patent application 20020076143 describes an optical local loop having a bus topology with a pair of optical fibers disposed among a plurality of Optical Network Units (ONUs). A Host Digital Terminal (HDT) is disposed at the head end of the optical local loop for concentrating optical signals for a network. Redundant transceiver banks are provided within the HDT for operating with the optical signals effectuated at a plurality of wavelengths which are multiplexed and de-multiplexed via a pair of Wavelength Division Multiplex (WDM) connecters disposed on corresponding optical fibers. During transmission, the ONUs excite both optical fibers and the received optical signals are monitored in the HDT for quality and integrity of the optical paths. A selectively actuatable mechanism is provided in the HDT to switch downstream transmission to the ONU nodes from one optical path to the other optical path of the local loop based on the path quality and integrity.
Once a MPCP failure is detected the multiple purpose communication network component switches from one MPCP thread to the secondary MPCP thread. Thus, it switches from one MPTS to another MPTS, such as a duplicate MPTS.
The switching between a first MPTS to a second MPTS may can cause temporary visual artifacts or otherwise temporarily reduce the quality of multiple programs, including programs that were properly conveyed over the multiple purpose communication network.
In addition, in cases that both MPCP threads are partially damaged, the transition can result in a replacement of one or more programs by one or more defective duplicate programs.
There is a need to provide systems and method for providing redundancy in a more efficient manner.

Method and system for program based redundancy


Systems and methods for power management in an information handling system are disclosed. A method may include determining a power requirement of resources configured to receive power from a plurality of power supply units including one or more online power supply units, one or more redundant power supply units, and one or more standby power supply units. The method may also include determining a power capacity of the one or more online power supply units. The method may additionally include determining if the power capacity of the one or more online power supply units exceeds the power requirement of the resources. The method may further include transitioning at least one of the power supply units based on such determining steps.

As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
With the advent of power-hungry information handling systems, power management has become more important. In the past, power conservation has often been a secondary consideration to speed and processor availability. However, due to the increased processing demands required by modern information handling systems, more information handling systems utilize multi-processor systems and/or multiple-blade systems that require more power to operate than single-processor computer systems. In addition, as processor designs continue to scale up in speed and density, corresponding power consumption can increase dramatically, requiring more efficient power management.
While processing demands and device consumption are often driving factors in the desire for managing and conserving power, other factors such as network failures, blackouts, and other device, system, or mechanical failures may also motivate a desire to reduce and efficiently manage power consumption. Current solutions often employ a power source management, sequencing, and conservation technique to handle inrush and steady state load demands, as well as redundancy and efficiency requirements of power sources.
In addition, in certain applications (e.g., Internet servers), multiple redundant power supplies are often employed to reduce or eliminate downtime in the event of a power supply failure. In many redundant power supply systems, all available power supplies are generally brought online and share the power requirements of the system. However, in many instances, each power supply may become more efficient as the power delivered from it increases. Thus, if many redundant power supplies are online and sharing a relatively small load, the individual redundant power supplies may be operating relatively inefficiently.

System and method for managing power supply units