A method and apparatus for client-side detection of network congestion in a best-effort packet network comprising streaming media traffic is disclosed. Said method and apparatus provide for quality streaming media services in a congested network with constrained bandwidth over the last-mile link. A client media buffer detects at least one level of congestion and signals a server to enact at least one error mechanism. Preferred error mechanisms include packet retransmissions, stream prioritization, stream acceleration, changes in media compression rate, and changes in media resolution. Said method and apparatus allow distributed management of network congestion for networks comprising multiple clients and carrying significant streaming media traffic.

1. Field of the Invention
The present invention relates generally to the field of computer networks, more particularly to the flow of audio/video/media data through packet networks, and still more particularly to congestion detection and flow control over packet networks.
2. Description of the Related Art
Media data, such as audio or video data, has traditionally been broadcast over dedicated bandwidth RF (radio frequency) channels to ensure quality delivery to the receiver. With the explosion of the Internet and the accompanying deployment of broadband packet networks, the opportunity has arisen to include entertainment or media services along with other data services on the broadband networks. However, delivering streaming media over broadband packet networks at a marketable quality with current technology is difficult.
Existing best-effort packet networks were not designed for high-bandwidth real-time data, such as streaming video. These networks were designed to accommodate the economic average of data traffic, so they often confront congestion in various nodes of the network when peaks in data traffic occur. Such congestion results in the loss or corruption of packets and thus interferes with the quality level of real-time data. In particular, such congestion can cause interruptions or delays in streaming media, resulting in a quality of service that is inferior to broadcast standards and thus not marketable to a broad customer base.
Much of the general Internet operates as a packet network with the TCP/IP stack of protocols for packet transmission. TCP (the "transmission control protocol") is responsible for breaking data into manageable pieces, reassembling and ordering the pieces at the other end, and retransmitting any pieces that are lost. IP (the "Internet protocol") determines a route for the data pieces between the transmitter and the receiver. Application-level data, such as streaming media data, is broken into pieces and each piece is given a transfer header by TCP. An IP header is then affixed to each piece, followed in some cases by a data link header providing information relevant to the actual data link over which the data will be transferred. At the receiving end, these headers are removed in inverse order until the original data is recovered.
An alternative to TCP called UDP (User Datagram Protocol) may be used at the transport layer. Unlike TCP, UDP does not guarantee delivery, but UDP does deliver packets at a specified rate. It is thus often used for real-time application data. UDP is responsible for packetization, multiplexing, and performing checksum operations to verify the correct packet size. A second protocol, RTP (Real-time Transport Protocol), may be used in concert with UDP to handle data identification, sequence numbering, timestamping, and delivery monitoring.
FIG. 1 illustrates the organization of packets in the TCP/IP configuration. A packet of application data 100 first has a TCP header 102 attached. In the case of data for a real-time application, the TCP header 102 may be replaced with UDP/RTP header information as discussed above. Then a network layer or IP header 104 is attached, and finally a link layer header 106 is appended. The resulting packet is transmitted 108. As the packet is received 110, the headers 106, 104, and 102 are removed in inverse order so that the original application data packet 100 is available to the receiver.
Regional broadband networks, such as networks providing digital subscriber line (DSL) service into residences over existing telecommunications copper wire infrastructure, are growing in popularity. Such networks provide opportunities to introduce higher quality streaming media because they provide greater ability for network engineering and flow control than for instance the general Internet. These networks typically communicate through the use of the asynchronous transfer mode (ATM) protocol with IP over ATM over SONET (Synchronous Optical Network) for the backbone link and with IP over ATM over DSL for the last-mile link. ATM provides potential quality of service control unlike the TCP/IP protocol family used for the general Internet, but due to the increase in costs associated with commissioning such service, existing telecommunications access networks using ATM are not currently enabled for QoS (quality of service). Packet networks with QoS can reserve the bandwidth necessary for quality media streaming, but the significant expense associated with implementing this specification has thwarted its widespread introduction.
A variety of DSL specifications exist for providing data service over existing copper-wire telephone lines. Asymmetric DSL, or ADSL, is the most popular specification for residential customers, and it is reaching increasing numbers of households. ADSL is capable of providing downstream bandwidth in the 6 Mbps range over shorter distances, but more typically it can provide on the order of 1.5 Mbps of downstream bandwidth and 384 kbps of upstream bandwidth to a broad customer base. The potential for video content delivery over the general Internet, and specifically over DSL networks, is great, but its realization has been constrained not only by network congestion issues but also by the excessive bandwidth required for most quality video data. However, recent video compression advances by the assignee of this invention and potential future research allow broadcast quality video to be provided at compression ratios that are consistent with the typical 1.5 Mbps bandwidth constraint of ADSL.
As improving compression ratios make streaming video over ADSL or other constrained bandwidth networks feasible, several problems with implementation arise. In the presence of network congestion and a constrained last-mile link with limited headroom for error recovery, means must be found for avoiding error due to congestion-induced packet loss so that a service provider can maintain delivery of a high quality media stream to the client subscriber. Furthermore, as streaming media, especially video, proliferates and consumes significant bandwidth network-wide, flow control techniques for managing network-wide congestion increase in importance.
Existing flow control strategies for streaming media are minimal. Such strategies typically rely on server-side detection of congestion. Servers can monitor NACK (negative acknowledgement) signals that indicate when a client has not received a complete packet, and they can also monitor RTT (return trip time) to find how long packet transmission has taken. In the case of streaming over TCP/IP networks, TCP can guarantee loss-less delivery of packets but not timely delivery. Servers can initiate flow control measures such as stream switching when they detect network congestion. Such measures typically result in pausing of the stream and rebuffering with relative frequency. This interruption of service is unacceptable for a streaming media provider who wishes to market competitive high quality entertainment services to customers.

Flow control method for quality streaming of audio/video/media over packet networks


In one embodiment, a computer-implemented method of autonomously parking an autonomous driving vehicle, includes generating environment descriptor data describing a driving environment surrounding the autonomous driving vehicle (ADV), including identifying a parking space and one or more obstacles within a predetermined proximity of the ADV, generating a parking trajectory of the ADV based on the environment descriptor data to autonomously park the ADV into the parking space, including optimizing the parking trajectory in view of the one or more obstacles, segmenting the parking trajectory into one or more trajectory segments based on a vehicle state of the ADV, and controlling the ADV according to the one or more trajectory segments of the parking trajectory to autonomously park the ADV into the parking space without collision with the one or more obstacles.

Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
Motion planning and control are critical operations in autonomous driving. One example of motion planning and control is in the area of autonomous parking. Autonomous vehicle parking involves heavy computation including trajectory generation and collision avoidance. What is needed is an efficient computational scheme to increase computation speed, robustness, and functional safety of an autonomous driving vehicle to control the vehicle while autonomously parking.

Segmenting a parking trajectory to control an autonomous driving vehicle to park


An electrowetting-on-dielectric (EWOD) microfluidic device comprises at least one integrated electrochemical sensor, the electrochemical sensor comprising: a reference electrode; a sensing electrode; and an analyte-selective layer positioned over the sensing electrode. In some embodiments, the electrochemical sensor measures a concentration of an analyte in a fluid sample exposed to the electrochemical sensor based on a potential difference between the reference electrode and the sensing electrode. The first analyte and the second analyte can be selected from a group consisting of K+, Na+, Ca2+, Cl−, HCO3−, Mg2+, H+, Ba2+, Pb2+, Cu2+, I−, NH4+, (SO4)2−.

In an electrowetting-on-dielectric (EWOD) digital microfluidic device (DMF), the formation and motion of individual droplets can be controlled by applying an external electric field to designated electrodes within the device. Intricate pump and/or valve systems are thus not needed in such devices to drive and regulate the flow of liquids. In addition, droplets can be individually created and controlled in an EWOD DMF device, thus permitting the multiplexing of many droplets on a two-dimensional surface. Due to these advantages, EWOD DMF devices have been proposed for a variety of applications. However, sensor design has been a limiting factor in creating usable and practical devices for some applications. These problems include immobilization of the sensor, integration of the sensor, reusability of the sensor, sensor size, sensor array design, and many other issues. Therefore, there is a need for improved EWOD DMF devices and sensors.

Microfluidic devices comprising electrochemical sensors

Board of Regents, The University of Texas System


Process and plant for the production of synthesis gas, hydrogen and/or reducing gas by means of a primary reformer heated on the shell side, used in conjunction with a pressure swing adsorption unit for purifying the product gas, the purpose of which is to find a solution to the problem of utilising the work potential of the fuel gas from the pressure swing adsorption unit, which is used to fire the primary gas reformer.

The invention relates to a process and a plant for the production of synthesis gas, hydrogen and/or reducing gas by means of the use of a primary reformer heated on the shell side, which is used together with a pressure swing adsorption unit to purify the product gas.
In a primary reformer steam and a feed gas containing carbon, such as methane, react on the tube side according to the linearly dependent equations (1, 2, 3) to yield carbon monoxide, carbon dioxide and hydrogen:
CH4+H2Oxe2x86x923H2+CO+205 kJ/molxe2x80x83xe2x80x83(1)
CH4+2H2Oxe2x86x924H2+CO2+164 kJ/molxe2x80x83xe2x80x83(2)
CO+H2Oxe2x86x92H2+CO2xe2x88x9241 kJ/molxe2x80x83xe2x80x83(3)
Whereas reactions (1) and (2) are highly endothermic, reaction (3) is mildly exothermic; thus together they are endothermic. Therefore it is necessary to heat the tubes of the shell side of the primary reformer in order to equalize the energy balance. The fuel gas used for firing the primary reformer can be natural gas or a highly calorific residual gas from another plant section or a mixture of the two gases.
The firing has to be regulated in order keep the temperature constant at all times. The fuel gas used for firing is therefore usually divided into a large portion, which is used for the majority of the firing duty and essentially should remain constant, and a small portion used to control the heating.
Whilst the tube-side synthesis gas reactions usually take place at high pressure (approximately 30 bar in hydrogen production plants and approximately 5 bar in reducing-gas plants), the shell-side heating of the primary reformer is usually performed at a pressure that is just below atmospheric pressure in order to prevent the risk of any emission of flue gas in case of leakages.
The major portion of the fuel gas used for firing must be slightly higher in pressure than that on the shell side, in order to overcome the pressure drop in the jet assembly feeding the gas to the combustion chamber and thus to thoroughly distribute the gas within the combustion chamber. The required inlet pressure is normally approximately 0.3 bar above the pressure level prevailing on the shell side in the combustion chamber and is thus approximately 1.3 bar absolute.
The fuel gas portion provided for control must have a slightly higher inlet pressure in order to overcome the pressure drop in the flow control valve. The necessary inlet pressure is usually around 1 bar above the pressure prevailing on the shell side of the combustion chamber and is thus around 2 bar absolute.
In order to adjust these pressure levels, the fuel gas, for example natural gas, which often has a supply pressure of 5 to 60 bar, this being considerably higher than the above mentioned pressures, is depressurised by throttling down to pressures of approximately 1.3 bar and 2 bar absolute. The intention of this invention is to employ an ejector to utilise the work obtainable of the fuel gas resulting from said pressure reduction and which is usually not used at all.
The raw synthesis gas formed by the reaction on the tube side of the primary reformer contains a large amount of carbon monoxide CO which, when producing hydrogen H2 as product gas reacts further in the downstream CO conversion reactor at a high temperature, the reaction (3) being exothermal, as mentioned above. After separation of the process condensate, the synthesis gas essentially consists of hydrogen H2, carbon dioxide CO2, as well as minor residual quantities of the feed gas and traces of side reaction products.
Depending on the intended use of the product gas and the relevant purity requirements, a gas separation process takes place in a downstream unit, in which undesired components of the product gas are separated and removed.
This gas separation process is usually performed in a pressure swing adsorption unit. Such a pressure swing adsorption unit consists of several adsorbers operated cyclically, numerous modes of operation being known from literature relating to the sequence of the cycles.
Patent EP-0 015 413-B1 describes a pressure swing adsorption process for fractionating or purifying gas mixtures, said process permitting the use of a part-stream of said gas mixture as motive gas. It is pointed out that patents DE-33 37 078-A1 and DE-33 29 435-A1 also reflect the state of the art.
All these concepts have in common that each adsorber is initially loaded under pressure with the gas component to be separated, while the product component flows through the adsorber and leaves it through a product line. Thereafter, depressurisation takes place, whereby the adsorbed gas component is desorbed, separated and disposed of separately through a waste gas line. Following this, or alternatively even during the expansion, purging takes place using the product gas for regenerating the adsorbent, the purge gas being usually admixed to the waste gas. After this, the adsorber is repressurised and ready for a new cycle.
The technological differences in the various pressure swing adsorption processes lie primarily in the ways several adsorbers can be coupled in order to attain the smoothest product flow possible, as well as in the method of regulating and monitoring the process and in selecting the pressure level and the purge times.
In plants for the production of hydrogen H2, the pressure level chosen for the desorption and purging is usually that of the major portion of fuel gas used in the primary reformer. This is because the desorbed gas and, in particular, the purge gas are high in calorific value and are suitable for firing on the shell side of the primary reformer and only need to be enriched with some supplementary fuel. Further desorption by vacuum appeared uneconomic to specialists because the use of a vacuum machine was too expensive and consumed too much energy.
In the production of reducing gas, the synthesis gas produced in the primary reformer is usually fed directly to the plant section in which the desired reduction is to take place. The tail gas from the reduction unit is very rich in combustible and recyclable components, but also contains large amounts of water vapour H2O, carbon dioxide CO2 and pollutants, which must be removed. When a pressure swing adsorption unit is used to deplete the carbon dioxide CO2 content of this tail gas, it is common, however, to use a vacuum machine to generate vacuum pressure in order to achieve an adequate desorption effect.
The aim of the invention is to create a solution for utilising the obtainable work of the fuel gas from the pressure swing adsorption unit and which is used to fire the primary reformer.
With a process of the type described above, this aim is met according to the present invention by feeding the waste desorption gas from the pressure swing adsorption unit to the suction inlet side of an ejector which is driven by part of the fuel gas used in the primary reformer, the waste desorption gas being admixed to the main fuel gas stream or to a regulating gas stream, depending on the particular mode of operation.
With the invention, the obtainable work of the fuel gas to be applied can be used to create a vacuum pressure by means of an ejector, making it possible to mix the gas obtained by desorption and that by purging the pressure swing adsorption unit and to utilise this in accordance with the invention. As a result, the total amount of fuel gas necessary for the operation of the primary reformer will not be increased.
In the production of hydrogen, the reason for this is that although the obtainable work of the fuel gas is utilized, the energy required on the firing side with regard to the amount of additional fuel gas for the operation of the primary reformer will only increase by the amount lost because less product gas of high calorific value, i.e. pure hydrogen H2, has to be taken from the product stream for purging and regeneration in the pressure swing adsorption unit under vacuum.
There is a substantial difference between the procedure described in this document and the state of the art mentioned previously, particularly in EP-0 015 413, said difference consisting in the fact that no gas stream obtained in the course of the pressure swing adsorption process is used as motive gas, but reformer gas usually available at higher pressures from a combined process, involving the upstream steam reformer, is exploited. A sufficient quantity of this fuel gas is available and is burnt in the reformer together with the pressure swing adsorption exhaust gas.
The obtainable work of said fuel gas, which is under high pressure, is often neglected; natural gas of, for example, 35 bar available at battery limit is usually depressurised by adiabatic throttling to obtain the burner inlet pressure (about 1.2 to 5 bar). When compared with the known processes it becomes evident that there are considerable advantages which, for example, consist in the fact that the motive gas need not be collected in buffer vessels, which have no operating cycle but which usually operate under a stationary vacuum.
A further advantage of the process in accordance with the invention is that neither inlet gas fed to process unit nor withdrawn product gases are being utilised as motive gas so that in these cases, the product yield is not diminished and thus undergoes a distinct improvement. The quality and amount of the product gases to be withdrawn are the only criterion crucial for the evaluation of hydrogen and synthesis gas production plants, which evidently leads to particular advantages of the invention.
A further advantage of the invention is that no relieved gases are being used as motive gas so that even pressure swing adsorption applications can efficiently desorb under vacuum at low adsorption pressure as, for example, in reduction gas units.
Another advantage is the fact that, for example, the loss in calorific value of the exhaust gas obtained in the pressure swing adsorption plant, which results from admitting additional fuel gas to compensate this loss, is faced with an improved product gas yield so that, when referred to the quantity of product gas produced, one even obtains a depressurisation of additional fuel gas and feed gas, thus permitting a cut in the primary reformer investment costs.
This loss of calorific value in the waste gas from the pressure swing adsorption unit, which must be compensated by additional fuel gas, is relatively small considering the much larger gain in product gas, as a result of which even a saving of additional fuel and feed gas can be achieved in relation to the product gas generated, thus also lowering the investment costs for the primary reformer, these constituting advantages of the invention.
In the production of reduction gas, the reason for this is that the fuel gas stream admixed to the waste gas in the ejector is in any case required to heat the primary reformer and, therefore, only makes a detour on its way to the firing system. In this case the advantage achieved by the invention consists of the elimination of a conventional vacuum compressor with rotating parts, which is clearly more expensive than an ejector and which requires a large amount of electrical power for its operation.
Further embodiments of the invention can be derived from the sub-claims, e.g. one plant for performing the task according to the invention being characterised by an ejector driven by fuel gas with a suction inlet side connection for admixing desorption gas.
It is expedient that the ejector be used to meet both the process and plant requirements in order to raise the pressure of the low-pressure desorption gas to the pressure level of the fuel gas feed tank and/or the regulating fuel-gas.
The invention further provides for both the generation of at least two levels of vacuum pressure and for the usage of those ensuing pressure levels in the desorption step of the pressure swing adsorption unit. At first, only part of the adsorbing components are desorbed by a weak vacuum pressure and subsequently the vacuum is increased in order to perform further desorption.
This step-wise reduction of pressure as well as the use of the vacuum to increase the desorption effect can be performed in several (at least two) stages. The trick is, when examining the flow rates of the ejector streams, that the more powerful the vacuum is desired to be, the higher the volume of ejector motive streams will have to be in order to desorb a certain amount of gas. As the amount of the ejector motive streams is determined by the heat requirements in the primary reformer, the provision of multiple stages instead of a continuous lowering of the vacuum approaches the desired aim more closely, the number of stages as well as the number of pressure levels prevailing in individual cases can be optimised according to economic criteria.

Process for the production of synthesis gas in conjunction with a pressure swing adsorption unit

Abstract: This is achieved by supplying the waste desorption gas from the pressure swing adsorption unit to the inlet side of an ejector, which is driven by a part stream of the fuel gas for the primary reformer, the waste desorption gas being admixed to a main fuel gas stream and/or a regulating gas stream, depending on the particular mode of operation.


Disclosed herein are synthetic methods and compounds related to the compounds that are useful as or in the production of biologically active compounds. Stereoselective and stereospecific synthetic methods are disclosed to produce compounds, such as, for example, γ,δ-unsaturated-β-hydroxyesters and aminated derivatives thereof, at high yields with desired stereochemistry. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Ceramide (Cer) is involved in regulation of anti-proliferative and apoptotic responses in various cancer cells (Hannun and Obeid, Journal of Biological Chemistry 2002, 277, 25847; Ogretmen and Hannun, Nature Reviews Cancer 2004, 4, 604). In the sphingolipid metabolism cascade, Cer can be formed from the hydrolysis of sphingomyelin (SM), catalyzed by acid and neutral sphingomyelinase (SMase), or synthesized de novo from serine and palmitoyl-CoA (Perry et al., Journal of Biological Chemistry 2000, 275, 9078). Reciprocally, Cer levels can be decreased by conversion into other interconnected bioactive sphingolipid species, which in turn reduces the apoptotic effectiveness of Cer. Cer can be broken down by one of many ceramidases (CDase), leading to the formation of sphingosine (SP). SP is then either acylated back to Cer via Ceramide synthase (CS) or phosphorylated to S1P by sphingosine kinase (SK), of which there are two isoforms, SK1 and SK2 (Hannun and Obeid, Nat Rev Mol Cell Biol 2008, 9, 139). According to the Cer-SP-S1P rheostat model, both Cer and sphingosine are apoptosis-induced lipids, whereas S1P leads to cell proliferation and inflammation and is referred to as a tumor-promoting lipid (Pyne and Pyne, Nat Rev Cancer 2010, 10, 489; Spiegel and Milstien, Nat Rev Mol Cell Bio 2003, 4, 397; Milstien and Spiegel, Cancer Cell 2006, 9, 148; Wymann and Schneiter, Nat Rev Mol Cell Biol 2008, 9, 162). Cer can also be phosphorylated into ceramide 1-phospate (Cer1P) by ceramide kinase (CK), antagonizing the pro-apoptotic action of ceramide and promoting inflammation (Wymann and Schneiter, Nat Rev Mol Cell Biol 2008, 9, 162), or glycosylated to glucosylceramide (GluCer) mediated by glucosylceramide synthase (GCS). The latter results in the development of multidrug resistance in many cancer cells (Ogretmen and Hannun, Nature Reviews Cancer 2004, 4, 604; Reynolds et al., Cancer Letters 2004, 206, 169).
Different strategies have been developed to enhance the level of Cer. For example, many anticancer drugs and stress-induced agonists have been used to increase endogenous Cer levels through de novo synthesis of Cer or the hydrolysis of SM. In addition, treating cancer cells in vitro with more easily dispersed short-chain Cers (C2 to C8-Cer) almost always produces apoptosis and cell-cycle arrest, and those exogenous Cers compete metabolically with natural Cers and their metabolites (Radin, Biochem J 2003, 371, 243). Currently, a number of anticancer agents in clinical trials act to increase Cer levels via inhibition of the conversion of GluCer and Cer1P from Cer, or by blocking the hydrolysis of Cer to S1P (Radin, Biochem J 2003, 371, 243). Sphingosine analogs that serve as pharmacological inhibitors of SK have been developed, including DMS (N,N-dimethylsphingosine) (Edsall et al., Biochemistry-Us 1998, 37, 12892; Yatomi et al., Biochemistry-Us 1996, 35, 626) and sphingamine (D, L-threo-dihydrosphingosine) (Ahn et al., Experimental Biology and Medicine 2006, 231, 1664; Ahn and Schroeder, Anticancer Res 2010, 30, 2881). FTY720 (fingolimod) has also been known to directly inhibit SK1 activity, reduce tumor metastasis and increase apoptosis (Lim et al., Journal of Biological Chemistry 2011, 286, 18633). In addition, aromatic sphingosine analogs have been assessed as stronger sphingosine kinase inhibitors (Murakami et al., Bioorg Med Chem Lett 2005, 15, 1115; Moreno et al., Organic Letters 2011, 13, 5184; Lim et al., Bioorg Med Chem Lett 2004, 14, 2499). For example, water soluble sphingosine analog BML-258 (FIG. 1) is an SK1 selective inhibitor and is efficacious both in vitro and in vivo (Paugh et al., Blood 2008, 112, 1382; Pyne et al., Cancer research 2011, 71, 6576).
Accordingly, disclosed herein are synthetic methods and compounds related to the synthesis of bioactive compounds. The synthetic methods and compounds provide useful routes and efficient synthesis of the enantiomers of sphingosine derivatives with high diastereomeric excess.

Synthetic methods and compounds related thereto


A hand-protection sporting accessory includes a flexible hand attachment for connection about a wearer""s hand, and a slide pad extending from the hand. The flexible hand attachment includes a thumb loop through which the wearer""s thumb can extend so as to maintain the slide pad adjacent to the palm of the hand unless deliberately released from the thumb. The accessory is particularly useful in competitive skateboarding where the slide pad can be positioned out of the way for quick race starts where the participant needs good grip with the starting gate. A quick xe2x80x9cflickxe2x80x9d of the hand can be made after the race start, whereby the loop lassoes the thumb to thereby place the slide pad across the palm.

The present invention relates to a hand-protection accessory. More particularly, although not exclusively, the invention relates to an accessory for a sports glove, a sports glove incorporating an accessory, or a standalone accessory, for use in extreme sporting activities such as competitive skateboarding, to protect a participant""s hands.
Competition skateboarding and rollerblading are regarded by many as extreme sporting activities, having associated dangers. Participants wear knee pads, elbow pads, shoulder pads, helmets and other protective gear. The competitors also wear hand-protective gloves to protect their hands in the event of an accident. Hand injuries can be particularly bad in a fall where the participant""s palm makes sliding contact with the ground surface.
Protective gloves however, can present a burden to the participant, when handshaking, holding a drink bottle, signing an autograph, reaching into a pocket, and particularly at the commencement of a race. Moreover, to attain a good start, participants grasp the starting gate or post and pull themselves forward. Gloves having good protective and sliding capabilities in the event of an accident display exactly those properties which are undesirable in attaining good grip on the starting gate or post at race commencement.
It is an object of the present invention to overcome or substantially ameliorate the above disadvantage and/or more generally to provide improved hand-protection accessory.
There is disclosed herein a hand-protection accessory comprising:
a flexible hand attachment for connection about a wearer""s hand,
a pad extending from the hand attachment and including a thumb loop through which the wearer""s thumb can extend so as to maintain the pad adjacent the palm of said hand unless deliberately released from the thumb.
Preferably the hand attachment includes a pair of strap segments extending about the hand.
Preferably each strap segment extends from a respective attachment area, which attachment area is attached to one another in the back of said hand.
Preferably a pad strap segment extends between the pad and the hand attachment.
Preferably the pad strap segment extends from one of the attachment areas in between said strap segments.
Preferably a pad foundation portion extends between the thumb loop and the pad strap.
Preferably the pad is a replaceable piece attached to the pad foundation portion.
Preferably the pad is a slide pad having a low dynamic coefficient of friction.
Alternatively, the pad can be a grip pad having a high static coefficient of friction.
Such an accessory might be worn upon a bare hand or outside of a glove.
As an alternative, the flexible hand attachment might be formed integrally with a glove.
Although an accessory as disclosed herein would have a primary application in the sporting activities as discussed earlier, there is also application in the workshop for example where it would be very useful as a tool holder, or in the kitchen or other places. Often, in the workshop, extra grip is required on say the handle of a screwdriver, a standing block or scrubbing brush/burnishers etc. To this end, instead of having a xe2x80x9cslide padxe2x80x9d having a low dynamic coefficient of friction, this feature could be replaced with a xe2x80x9cgrip padxe2x80x9d having a high static coefficient of friction for achieving good grip.


The present invention includes an improvement to the existing method of steam reforming of hydrocarbon, wherein the improvement comprises: the flowing is at a rate providing a residence time less than about 0.1 sec resulting in obtaining product formation yield or amount that is the same or greater compared to product formation at a longer residence time. Another improvement of the present invention is operation at a steam to carbon ratio that is substantially stoichiometric and maintaining activity of the supported catalyst. The present invention also includes a catalyst structure for steam reforming of a hydrocarbon.

The present invention is a method and catalyst structure for steam reforming of a hydrocarbon.
Steam reforming of hydrocarbons is commonly used for feedstock production for carbon-monoxide hydrogenation (Fischer-Tropsch synthesis), methanol synthesis and hydrogen production. Steam reforming is done commercially by flowing a mixture of steam and the hydrocarbon past a supported catalyst having an alumina support and a catalyst metal thereon, and reacting the mixture at a temperature from about 600xc2x0 C. to about 1000xc2x0 C., forming at least one product. Research has been done with the catalyst metal on a spinel support. Residence times are typically on the order of seconds and steam to carbon ratio greater than about 2.5. For steam to carbon ratio less than 2.5, catalyst activity is generally degraded after hours to days due to coke formation and the supported catalyst must be refreshed or replaced.
The rate of supported catalyst activity degradation has been reduced by use of excess steam (steam to carbon ratio greater than 2.5). Excess steam, however, requires excess thermal energy and results in large system pressure drop. Using less steam results in faster degradation of catalyst activity because of coking from the hydrocarbon(s).
Hence, there is a need for a method of steam reforming of a hydrocarbon that provides greater product yield and permits using less steam and maintaining catalytic activity of the catalyst.
The present invention includes an improvement to the existing method of steam reforming of hydrocarbon, wherein the improvement comprises:
the flowing is at a rate providing a residence time less than about 0.1 sec resulting in obtaining product formation yield or amount that is the same or greater compared to product formation at a longer residence time. Another improvement of the present invention is operation at a steam to carbon ratio that is substantially stoichiometric and maintaining activity of the supported catalyst.
The present invention also includes a catalyst structure for steam reforming of a hydrocarbon. The catalyst structure has
(a) a first porous structure with a first pore surface area and a first pore size of at least about 0.1 xcexcm;
(b) a porous interfacial layer that is a spinel with a second pore surface area and a second pore size less than the first pore size, the porous interfacial layer having a thickness less than 4 mm placed upon the first pore surface area;
(c) a steam reforming catalyst selected from the group consisting of rhodium, iridium, nickel, palladium, platinum, carbide of group Vlb and combinations thereof placed upon the second pore surface area.
It is an object of the present invention to provide a method of steam reforming of hydrogen with a residence time of less than about 0.1 sec.
It is an object of the present invention to provide a catalyst structure with a porous interfacial layer of spinel.
The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.

Method and catalyst structure for steam reforming of a hydrocarbon


A rotary cutter for cutting grass, brush, shrubs, bushes, trees, and other vegetation, and a method of using the same. The cutter includes a bi-fold door proximate to an open front portion of the cutter's deck, which defines an open cutting area. The bi-fold door moves between a closed position where it shields the cutting area and an open position where it exposes the cutting area. The bi-fold door includes a front cover rotatably coupled to a rear cover via the first hinge, with the rear cover being rotatably coupled to the deck via the second hinge. The cutter also includes a first ramp and second ramp flanking the open front portion of the deck. Protrusions of the bi-fold door slide along inclined surfaces of the ramps as the bi-fold door moves between the closed position and the open position.

Rotary cutters, such as brush cutters and lawnmowers, are used to cut and clear grass, brush, shrubs, bushes, and even trees from the land. These rotary cutters typically include a blade pan with one or more blades attached thereto. The blade pan is attached to a gearbox, hydraulic motor, or the like, which in turn is operatively connected to a user-driven machine such as a skidsteer or tractor. For example, a cutter's gearbox may be operatively connected to a power take-off (PTO) of a tractor, or a cutter's hydraulic motor may be operatively connected to a hydraulic supply and return line extending from a hydraulic pump of a skidsteer or other user-operated machine.
Cutters typically include a molded or welded deck substantially surrounding the blades to prevent inadvertent contact with the spinning blades, and further to shield clippings from being flung from the cutter causing damage or injury. But these decks limit what types and sizes of vegetation that the cutter may be used to cut. More particularly, because the deck substantially surrounds the spinning blades, the only vegetation that can encounter the blades is that which can fit underneath the margins of the deck. Thus, the cutter may be ill-suited for trimming shrubs, bushes, trees, and other types of tall vegetation that is too large to easily fit underneath an edge of the deck.
Some cutters include a movable guard to expose part of the blade path to cut large shrubs, bushes, trees, and the like. But these cutters require complex linkages and other actuating mechanisms to move the guard out of the way of the vegetation. Moreover, many movable guards require that an operator move the cutter deck in a certain fashion to actuate the movable guard. For example, an operator may be required to raise the cutter and then lower the device against the tall vegetation to push the guard vertically up and out of the way. This process is time consuming and disruptive to the normal travel of the cutter.
Thus, there remains a need for a rotary cutter that includes a deck that suitably shields the cutting path during use, but which allows the cutter to be used to trim bushes, shrubs, trees, and other tall vegetation that otherwise could not fit below the outer edges of the deck, and one that can do so during a typical cutting operation (i.e., forward movement of the cutter) without requiring an operator to lift the cutter or otherwise move the cutter to actuate the movable guard.


The present invention provides a thermoresponsive nanoparticle useful for the stabilization of enzymes in environments having a temperature greater than thirty degrees Centigrade. The thermoresponsive nanoparticle has (a) a functionalized enzyme conjugate having one or more enzymes or biological catalysts, the enzymes or biological catalysts are modified with palmitic acid N-hydroxysuccinimide ester and acryclic acid N-hydroxysuccinimide ester, and (b) a thermally responsive polymer, wherein the functionalized enzyme conjugate is encapsulated within the thermally responsive polymer. A nanocatalyst is provided that has one or more proteins. The proteins are covalently immobilized and encapsulated within a thermally responsive polymer shell. The proteins are one or more enzymes or biological catalysts. A method for protecting the proteins is also set forth.

Enzymes are biological proteins that speed up chemical reactions by lowering the energy barrier for them to occur more easily. Enzymes demonstrate a high degree of utility due to their speed of reaction, specificity for certain analytes, and ability to be engineered and chemically modified. Enzymes are used in many industries including food processing, detergents and cleaning products, clinical diagnostics, fuel production and decontamination of chemical agents. The major problem associated with the practical utility of enzymes is the inability to sufficiently stabilize their tertiary structure in harsh environmental conditions, such as high temperatures, extreme pH, high salinity and solvents; free enzymes are susceptible to damage and will incur partial or total activity loss in the presence of such conditions. As a result, applications of free enzymes for large scale commercial use, especially for continuous use, are extremely limited. The ability to stabilize enzymes in harsh conditions is an area of immense interest; retention of activity in non optimized environments, such as elevated temperatures, will improve catalytic performance and be beneficial for countless applications.
Various approaches for stabilizing enzymes have been demonstrated from enzyme adsorption and modification to recombinant protein engineering; these methods only provide a moderate improvement in enzyme stability. Stability of enzymes adsorbed onto nanoparticles is highly dependant on nanoparticle size and adsorption pattern. Protein and nanoparticle interactions during adsorption can cause conformational changes to an enzyme's native structure, rendering it inactive. Entrapment of enzymes has been demonstrated to improve the stability by restricting their ability to unfold. Entrapment of oxidase enzymes within inorganic silica nanogels were shown to improve the stability over the native form by up to 200-fold. To date, the optimal method for enhancing the stability of enzymes has been three-dimensional covalent immobilization of enzymes. LeJeune and Russell demonstrated that hydrolase enzymes which detoxify chemical warfare agents could be immobilized within polyurethane foams. The surface lysine residues participate in the crosslinking reaction by condensing with the isocyanate groups on the polyurethane backbone, resulting in a foam material that contains active enzymes which retain superior stability over the native enzyme [see, LeJeune, K. E., "Covalent binding of a nerve agent hydrolyzing enzyme within polyurethane foams", Biotechnology and Bioengineering, Vol. 51, pages 450-457 (1996), and LeJeune, K. E., "Dramatically stabilized phosphotriesterase-polymers for nerve agent degradation", Biotechnology and Bioengineering, Vol. 54, pages 105-114 (1997)]. This work has been extended to numerous enzymes which have been utilized to make colorimetric sensor pens that have shelf-lives of years and can withstand harsh environmental conditions such as heat and solvents (see also U.S. Pat. Nos. 6,291,200; 6,673,565; 6,762,213; and 6,759,220).
Recently, there has been a large focus on nanoparticle development in many fields including: optics and coatings, clinical diagnostics, drug-delivery, and also in the development of novel materials such as self-healing and highly-porous plastics. Stabilization of covalently-immobilized enzymes within porous, hydrophilic nanogels has been demonstrated by several groups. Polymers which respond to specific stimuli, such as temperature and the presence of other molecules in solution are frequently utilized in particle development. Nanoparticles composed of such polymers have the capability to shrink and swell via changes in Gibbs free energy in the presence of the proper stimulus. Responsive nanoparticles are currently used for drug delivery, bioimaging and therapeutics. The present invention provides three-dimensional immobilization of enzymes at the nanoscale within thermally responsive polymer materials which will protect the enzyme by providing a responsive barrier material that will respond to environmental stimuli to provide structural support under conditions that would otherwise denature the enzyme.
Enzymes have been functionalized and coupled with N-isopropylacrylamide (NiPAAm) with N-hydroxysuccinimide (NHS) [Chen, G., "Preparation and properties of thermoreversible, phase-separating enzymes-oligo (N-isopropylacrylamide) conjugates", Bioconjugate Chemistry, Vol. 4, pages 509-514 (1993)]. NiPAAm is a thermo-responsive polymer that which undergoes avolume transition at temperatures above its lower critical solution temperature (LCST) approximately 32° C. Coupling NiPAAm to an enzyme allows it to be used for separation, recovery, and recycling of an enzyme simply by applying small temperature changes to the reaction medium. The growing NiPAAm enzyme chains have also shown moderate improvements in stability compared to native enzyme. However, heretofore, no one has cross-linked an enzyme or encapsulating an enzyme within thermally responsive (thermoresponsive) nanoparticles, as set forth in the present invention.
Incorporation of functional enzymes into nanoparticles is difficult for several reasons. Bottle-in approaches have limited utility because diffusion of enzymes into polymer particles, on a short time scale, is difficult due to small pore size and high polymer concentration on the outer particle shell. Harsh conditions during nanoparticle fabrication such as solvents, surfactants and high temperatures can be detrimental to the tertiary structure of the enzyme. The present invention provides an enzyme-friendly methodology for covalently immobilizing and encapsulating enzymes within stimulus responsive nanoparticles using standard oil-in-water emulsion polymerization protocols, such emulsion polymerization protocols are known by those persons skilled in the art. Essentially, hydrophobic graft-modified enzymes can be used as seeds in micelle systems for growth of nanoparticles. Incorporating functional enzymes into nanoparticles which are constructed from responsive polymers will further stabilize enzymes in harsh environments (for example, elevated temperature, chemicals, unfavorable pH, physical forces—all stressful).
Enzymes modified with NiPAAm polymers have shown an increased thermal stability over native enzymes. Through encapsulating and immobilizing an enzyme within responsive NiPAAm nanoparticles, the stability will be greatly improved at elevated temperatures; leading to a drastic improvement in both pot life (aqueous state) and shelf life (dry state) stability. The contraction of the particles supports the enzyme's tertiary structure, leaving the enzyme highly folded and active at elevated temperatures; free enzymes which are unencapsulated will unfold at these temperatures and become inactive.
The resulting functionalized enzyme conjugate-nanoparticle systems of the present invention have numerous applications. Enzymes generally demonstrate immense utility for a variety of industrial catalysis reactions; however the byproducts or intense environmental conditions limit the efficiency of using enzymes. The nanocatalysts and nanoparticles of the present invention stabilize enzymes to survive such intense environmental conditions including, such as for example but not limited to, temperature extremes. The nanocatalysts and nanoparticles of the present invention have high degree of utility for decontamination, chemical remediation, drug delivery, wound healing, protein therapy and a host of other applications.

Dynamic thermoresponsive nanoparticles for stabilization of enzymes at high temperatures


A vehicle control system is provided that includes a storage module including a capacitor module configured to store electrical energy and a storage controller operatively connected to the capacitor module. The storage controller is configured to provide the capacitor module electrical energy when the stored electrical energy of the capacitor module is less than a stored electrical energy threshold. The vehicle control system also includes a computer operatively connected to the storage controller, wherein the computer is configured to determine when a supplied voltage is less than a voltage threshold and initiate a shift-by-wire actuator when the supplied voltage is less than voltage threshold using the stored electrical energy in the capacitor module to actuate the shift-by-wire actuator.

The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Generally, vehicles having an automatic transmission or electric vehicles that do not have a gearbox are provided with a park lock function adapted to lock the output shaft of the automatic transmission or the output shaft of the electric motor to restrict the vehicle from moving in any direction. A parking pawl prevents the transmission from rotating, which prevents the vehicle from moving.


A circuit board including an electronic circuit unit and electronic adjusting units is disposed in a case. A signal transmitting member connected to the circuit board is mounted in a mount hole of a cover member. Operation holes corresponding to a plurality of operable portions of the electronic adjusting units are provided to the cover member. A cap member including a plurality of cap bodies and a connection portion connecting the cap bodies is attached to the cover member to close the operation holes. The operation holes for adjusting the electronic adjusting units are thus covered/uncovered by the simple cap member. The operation holes are reliably waterproofed by the cap member.

Physical quantity measuring devices include: a pressure transmitter including a detector that detects a physical quantity; and a circuit board that receives the detection signal from the detector and outputs a signal to an external device.
A typical example of the pressure transmitter is a pressure sensor including a housing, a pressure transducer housed in the housing, an electric circuit, and a connector terminal, the pressure transducer outputting a signal to an external device through the electric circuit and the connector terminal (see Patent Literature 1: Japanese Utility Model Registration No. 2540967).
In the typical device of Patent Literature 1, the connector terminal is provided to a connector body, and an electronic circuit board provided with the electric circuit is disposed in a space defined by the connector body and the housing. A trimmer or the like is adjusted by operating a variable resistor, which is provided to the electric circuit, with a tool such as a driver. The connector body includes a cylindrical portion covering the connector terminal, the cylindrical portion being provided therein with a plurality of adjustment holes required for the operation with the driver. The adjustment holes are each closed with a rubber stopper and sealed with a sealing material.
Another typical example of the pressure transmitter is a pressure detector including: a base; an upper cover; a circuit board disposed in a space defined between the base and the upper cover; and a pressure detector provided to the circuit board, the pressure detector outputting a detection signal to an external device through the circuit board and a lead wire (see Patent Literature 2: JP-A-11-118647).
In the typical device of Patent Literature 2, the circuit board is provided with a trimmer for adjusting a preset pressure of the pressure detector, the trimmer being operable when a trimmer cover provided to the upper cover is removed. One side of the trimmer cover is rotatably attached to the upper cover with a rotation shaft.
In the typical device of Patent Literature 1, when the electric circuit is adjusted, the adjustment holes are each closed with the rubber stopper and then sealed. Thus, once the adjustment holes are each closed by the rubber stopper, the electric circuit cannot be adjusted again. Even if the rubber stopper is removed, the driver cannot be inserted into the adjustment holes provided in the cylindrical portion, after the tip end of the connector terminal is connected to a connection member.
Therefore, in the typical device of Patent Literature 1, after device assembly is completed, it is difficult to adjust the electric circuit.
In the typical device of Patent Literature 2, since the trimmer cover is rotatably attached to the upper cover with the rotation shaft, the trimmer is adjustable when the trimmer cover is removed even after device assembly is completed.
However, the typical device of Patent Literature 2 employs a complicated arrangement where the trimmer cover is attached to the upper cover with the rotation shaft, which results in high production costs of the device.

Physical quantity measuring device and method of manufacturing the same


Apparatus, systems, and methods for providing high voltage to memory devices are provided. One apparatus includes a low voltage input and a two-rail level shifting. The two-rail level shifting is configured to increase the low voltage or to decrease the low voltage to an amount that is less than or equal to a ground potential based on the amount of the low voltage. A system includes a low voltage input for receiving a voltage and a two-rail level shifting coupled to the low voltage input. The two-rail level shifting is configured to increase the voltage to a positive voltage if the voltage is equal to a ground potential and decrease the voltage to a negative voltage if the voltage is greater than the ground potential. One method includes receiving a voltage, modifying the voltage to generate one of a plurality of output voltages, and providing the output voltage to a memory device.

1. Field of the Invention
The present invention relates generally to memory devices, and more particularly to, systems and methods for providing high voltage to memory devices.
2. Description of the Related Art
Previous memory systems use Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) devices as Non-Volatile (NV) storage elements in the NV EEPROM or Flash Memories. These prior memory systems rely on the usage of SONOS devices with thicker gate oxide layers (e.g., 110A) for the high voltage operations related to programming and erasing of the NV Flash Macro.
Some prior memory devices have a voltage gate oxide (Vgox) maximum of 7.3 volts and a junction voltage (Vjunc) of 10.5 volts. Other prior memory devices have a maximum Vgox of 8.1 volts and a Vjunc of 7.6 volts. To make these memory devices compatible with high voltage levels, these memory devices had to be laid out as ring transistors.
More recent memory devices have a maximum Vgox of 6.9 volts and a Vjunc of 11.3 volts, while some other memory devices have a maximum Vgox of 7.7 volts and a Vjunc of 11.3 volts. While the supply voltage levels are decreasing in newer technologies, the NV memory devices still require relatively high voltage for NV operations. In other words, these voltages are still too high to be directly supported by memory devices with thinner gate oxide thicknesses (e.g., gate oxide thicknesses of 55 A) since memory devices with thinner gate oxide thicknesses can typically only handle low voltage. For example, memory devices with a gate oxide thickness of 55 A typically can handle a maximum of 2.5 volts. Thus, prior memory systems do not utilize memory devices with a gate oxide thickness of 55 A for high voltage applications.
Furthermore, as the interest for smaller and faster devices has increased, interest in SONOS device scale down has increased as well. However, the aforementioned high voltage signals used on devices with thicker gate oxides may cause stresses on the devices with thinner gate oxides. Although additional devices can be employed to mitigate such stresses, inclusion of such devices may increase costs and complicate circuit fabrication.

This patent is subject to a terminal disclaimer.

Systems and methods for providing high voltage to memory devices


Techniques for scheduling operations for a task graph on a processing device are provided. The techniques include receiving a task graph that specifies one or more passes, one or more resources, and one or more directed edges between passes and resources; identifying independent passes and dependent passes of the task graph; based on performance criteria of the processing device, scheduling commands to execute the passes; and transmitting scheduled commands to the processing device for execution as scheduled.

Three-dimensional ("3D") graphics processing pipelines perform a series of steps to convert input geometry into a two-dimensional ("2D") image for display on a screen. In some examples, these steps are specified as commands by a host such as a central processing unit running an application. Many rendering workloads require large sequences of commands, and thus generating and processing these sequences is a complex task.

Task graph scheduling for workload processing


A computerized assessment grading method comprises creating a syntax tree for a received equation-based response to at least one assessment question and a syntax tree for at least one solution to the at least one question, comparing the syntax trees, and grading the response based on the results of the comparison.

Participant response systems for enabling participants of an event to enter responses to posed questions, motions or the like are well known in the art and have wide applicability. For example, during a conference, seminar or the like, participants can be provided with handsets that enable the participants to respond to questions, or to vote on motions raised during the conference or seminar. In the entertainment field, audience members can be provided with handsets that enable the audience members to vote for entertainment programmes or sports events. These participant response systems are also applicable in the field of education. Participants can be provided with handsets that enable the participants to answer questions posed during lessons, tests or quizzes. Of significant advantage, these participant response systems provide immediate feedback to presenters, facilitators, entertainment programme producers, or event organizers. With respect to the field of education, research shows that facilitators teach better and participants learn better when there is rapid feedback concerning the state of participants' comprehension or understanding. It is therefore not surprising that such participant response systems are gaining wide acceptance in the field of education.
Participant response systems fall generally into two categories, namely wired and wireless participant response systems. In wired participant response systems, the response devices used by participants to respond to posed questions or to vote on motions are typically physically connected to a local area network and communicate with a base or host computer. In wireless participant response systems, the response devices used by participants to respond to posed questions or to vote on motions communicate with the host computer via wireless communication links. Whether wired or wireless, many different types of participant response systems have been considered.
U.S. Pat. No. 4,247,908 to Lockhart, Jr et al. discloses a two-way communication system for use with a host computer that includes a control unit, a base station and multiple, hand-held, portable radio/data terminal units. The control unit interfaces directly with the host computer but uses a radio link to interface with the portable radio/data terminal units. Each portable radio/data terminal unit includes a two-way radio and a data terminal. The data terminal includes a keyboard for data entry and an LED display for readout of either received data or locally generated data. The host computer initiates communication through polling and/or selection of portable radio/data terminal units via the control unit. The control unit, in response to a "poll" from the host computer, answers by sending either a previously received message from a portable radio/data terminal unit, or if no message has been received, a "no message" response. Polling by the control unit is an invitation to the portable radio/data terminal units to send data to the control unit to be stored, grouped if necessary and sent on to the host computer. The control unit polls the portable radio/data terminal units by address in a particular sequence. The control unit transmits acknowledgements to the portable radio/data terminal units for received data on the next polling cycle.
U.S. Pat. No. 5,002,491 to Abrahamson et al. discloses an interactive electronic classroom system for enabling facilitators to teach participants concepts and to receive immediate feedback regarding how well the participants have learned the taught concepts. Structure is provided for enabling participants to proceed in lockstep or at their own pace through exercises and quizzes, responding electronically to questions asked, the facilitator being able to receive the responses, and to interpret a readout, in histogram or other graphic display form, of participant responses. The electronic classroom comprises a central computer and a plurality of participant computers, which range from simple devices to full fledged personal computers, connected to the central computer over a network. Optional peripheral hardware, such as video cassette recorders (VCRs) or other recording/reproducing devices, may be used to provide lessons to participants in association with the computer network.
U.S. Pat. No. 6,790,045 to Drimmer discloses a method and system for analyzing participant performance by classifying participant performance into discrete performance classifications associated with corresponding activities related to an electronic course. An observed participant performance level for at least one of the performance classifications is measured. A benchmark performance level or range is established for one or more of the performance classifications. It is then determined whether the observed participant performance level is compliant with the established benchmark performance level for the at least one performance classification. Instructive feedback is determined for the observed participant based upon any material deviation of the observed participant performance from at least one benchmark.
U.S. Patent Application Publication No. 2004/0072136 to Roschelle et al. discloses a method and system for assessing a participant's understanding of a process that may unfold over time and space. The system comprises thin client devices in the form of wireless, hand-held, palm-sized computers that communicate with a host workstation. The system provides a sophisticated approach of directing participants to perform self-explanation, and enables instructors to enhance the value of this pedagogical process by providing meaningful and rapid feedback in a classroom setting.
U.S. Pat. No. 6,381,444 to Aggarwal et al. describes a system for implementing a virtual class and distance education via a computer network. The process carried out by the system involves receiving signals from one or more instructor entities, the signals including lesson material designated as belonging to one or more interest groups. The lesson material is sent in advance to student entities listed in one or more of the interest groups to which the lesson material is designated as belonging. Signals from one or more student entities are received requesting admission to a particular class and instructions are sent to student entities to control the display and execution of the lesson material.
Current commercial response systems such as the ActivExpression™ produced by Promethean Limited of Blackburn, Lancashire, UK and CPSPulse™ produced by eInstruction of Denton, Tex., USA allow questions to be administered, the solutions to which are equations that must be entered as strings of text. Unfortunately, the grading engine that assesses the solutions to these questions performs simple string comparison. As a result, these systems require perfect matching of the entered solution to the instructor's solution potentially resulting in the errors in grading of the assessments.
A research paper presented at the 2nd International Conference on Digital Information Management (ICDIM'07) held Oct. 28-31, 2007 entitled "Equivalence Detection Using Parse-tree Normalization for Math Search" authored by Shatnawi et al. describes a technique for searching for mathematical equations on the World Wide Web. The research paper describes the difficult challenge of determining mathematical equivalence between a search term and what may be presented on the Web. The research relates to implementing a technique that transforms a user's mathematical search query into a unique normalized form. Normalization is conducted in two ways, algebraic and structural.
Although prior art participant response systems allow questionnaires to be administered to participants and response data gathered, these participant response systems typically have limited functionality for grading equation-based assessments in a quick, automated manner. Grading of equation-based assessments can be prone to errors, as an equation-based question may have more than one correct solution. For example, the equation y=2x2−2 may be correctly factored either as 2(x+1)(x−1) or as 2(x−1)(x+1). However, if a facilitator of a participant group defines the solution as 2(x+1)(x−1) and a participant enters a response of 2(x−1)(x+1), the participant's response may be graded as incorrect. Still other correct solutions to this question exist, which may also not be graded as correct when submitted as responses.
It is therefore an object of the present invention to provide a novel equation-based assessment grading method and a novel participant response system employing the method.

Equation-based assessment grading method and participant response system employing same


A device for generating a pseudorandom sequence of numbers includes a feedforward coupler, which has a plurality of memory units, and a feedback coupler connected between an input and an output of the feedforward coupler. The feedback coupler includes a changeable feedback characteristic and is embodied to change the feedback characteristic depending on a state of a memory unit of the plurality of memory units of the feedforward coupler.

1. Field of the Invention
The present invention relates to number generators, and in particular to number generators for generating a pseudorandom sequence of numbers.
2. Description of Related Art
Such a well-known random number generator is illustrated in FIG. 5. The pseudorandom number generator of FIG. 5, which is also referred to as a linear feedback shift register, includes a plurality of memory elements 51, 52, 53, 54, which in FIG. 5 are numbered from 0 to n. The memory cells can be initialized to a starting value via initializing means 55. The memory cells 51 to 54, as a whole, form feedforward means, while the linear shift register formed by the memory cells 51 to 54 is fed back by feedback means coupled between an output 56 of the circuit and the memory cell n. In detail, the feedback means includes one or several combining means 54, 58 fed by respective feedback branches 59a, 59b, 59c, as is exemplarily illustrated in FIG. 5. The output value of the last combining means 58 is fed into the memory cell n indicated by 54 in FIG. 5.
The linear feedback shift register shown in FIG. 5 is operated by a clock such that the occupancy of the memory cells, referring to FIG. 5, is shifted by one step to the left in each clock cycle so that the state stored in the memory means 51 is output as a number in each clock cycle, while at the same time the value at the output of the last combining means 58 is fed into the first memory unit n of the sequence of memory units. The linear feedback register illustrated in FIG. 5 thus provides a sequence of numbers responsive to a sequence of clock cycles. The sequence of numbers obtained at the output 56 depends on the starting state set up by the initializing means 55 before starting the shift register. The starting value input by the initializing means 55 is also referred to as a seed, which is why such arrangements illustrated in FIG. 5 are also referred to as seed generators.
The sequence of numbers obtained at the output 56 is referred to as a pseudorandom sequence of numbers, since the numbers seem to follow one another in a random way, but, as a whole, are periodic even though the period duration is large. In addition, the sequence of numbers can be repeated uniquely and thus has a pseudorandom nature if the initializing value fed to the memory elements by the initializing means 54 is known. Such shift registers are, for example, employed as key stream generators to provide a stream of encrypting/decrypting keys depending on a special initializing value (seed).
Such shift registers illustrated in FIG. 5 have the disadvantage of a small linear complexity. Thus, 2 n bits of the output sequence suffice in an n bit LFSR (linear feedback shift register) to calculate the entire sequence. The advantage of such well-known LFSRs illustrated in FIG. 5, however, is that the hardware expenditure is very small.
In addition, there are irregularly clocked LFSRs. They have a somewhat increased hardware expenditure with an almost always lower period. The linear complexity can, however, be considerably higher. A disadvantage of such irregularly clocked devices, however, is the fact that, due to the irregular clocking, the output sequence could be deducted in principle by current measurements in an SPA (simple power analysis). By employing shift register devices as parts of key generators which generate data to be kept secret inherently, that is key data, it is of especial importance that they be protected from any kind of cryptographic attack.
On the other hand, there is the requirement for such devices, in particular when they are to be accommodated on chip cards, that the hardware expenditure be small. Put differently, the chip area such devices occupy needs to be as small as possible. This is due to the fact that, in semiconductor manufacturing, the chip area of an entire device in the end determines the price and thus the profit margin of the chip manufacturer. In addition, especially in chip cards, a specification is usually such that a customer says that a processor chip can have a maximum area in square millimeters, on which most various functionalities must be accommodated. Thus, it is up to the circuit manufacturer to distribute this precious area to the individual components. As regards cryptographic algorithms, which are becoming increasingly complex, efforts of the chip manufacturer are directed to the chip having as much memory as possible to be able to calculate even operating memory-intense algorithms in an acceptable time. The chip area for key generators and other such components thus needs to be kept as small as possible to be able to accommodate more memory on a given chip area.
The general requirement to key generators and devices for generating a pseudorandom sequence of numbers, respectively, thus is, on the one hand, to be safe and, on the other hand, to require as little space as possible, that is to have the smallest hardware expenditure possible.
In principle, linear shift registers have different applications in coding theory, cryptography and other electro-technological areas. The output sequences of linear shift registers comprise useful structural characteristics which can be divided into algebraic characteristics and distribution characteristics.
It is well-known that an output sequence of an n step linear shift register, as has been explained, is periodic. The length of the period can be quite large and is, with regard to n, that is the number of memory elements, often exponential. The length of the period, in particular, is 2n−1, when the shift register is based on a primitive feedback polynomial.
The linear complexity of such a sequence, however, is at most n. The linear complexity of a periodic sequence, according to the definition, equals the number of cells of the smallest possible shift register which can generate the sequence considered.
Due to this fact, it can be shown that, as has been discussed, 2 n subsequent expressions of the sequence suffice to predict all the remaining expressions of the sequence. In addition, there is an efficient algorithm, the so-called Berlekamp-Massey algorithm, to calculate the parameters required to obtain the entire sequence. Thus, sequences of linear shift registers, despite their potentially large periods and their statistically good distributing characteristics, are not suitable directly as key sequences in so-called current ciphers. In addition, there are other applications in which the comparably low linear complexity of a sequence generated by a linear shift register must be seen as a disadvantage.
Usually, linear shift registers are described by their characteristic polynomial. The degree of the characteristic polynomial equals the number of delay elements, usually embodied as flip-flops, of the shift register considered. The exponents of the terms of f(x), except for the leading term, correspond to the shift elements of the shift register contributing to a feedback. The linear shift register illustrated in FIG. 5 would thus have a characteristic polynomial of the following kind:F(x)=xn+1+xn+ . . . +x+1
If such linear shift registers, as are exemplarily illustrated in FIG. 5, are loaded with an initializing state by the initializing means 55, wherein this state is also referred to as a starting state vector, they will typically output a periodic sequence having a certain pre-period and a subsequent period, depending on the implementation. Linear shift registers are always periodic. In technological applications, it is often strived for that the output sequence have both a large period length and a high linear complexity.

Device and method for generating a pseudorandom sequence of numbers


A method of object identification comprising, for an image in which an object is to be identified, determining for each of a set of location in the direction in which the gradient of intensity change to an adjacent location is greatest together with the magnitude of that gradient, modifying the gradient magnitude using a nonlinear function, the modified gradient and the associated direction for the set of location providing a vector representative of the image, and comparing the vector with a previously generated statistical model which provides identification of the object.

1. Technical Field
Statistical models of appearance are widely used in computer vision and have many applications, including interpreting medical images and interpreting images containing faces.
2. Related Art
Conventionally, a statistical model is built which represents intensity (greyscale or colour) variation across an image or part of an image. In the case of a facial appearance model, images of many faces are used to generate the model, these images being known as training images. The intensity variation that is likely to be seen in any given face will tend to include similar patterns, and the statistical model represents these patterns. Once the statistical model has been built it may be used to determine whether a new image includes a face, by determining whether the new image contains the facial intensity patterns. The identity of the face in the image may be determined by comparing the intensity patterns found in the image with identity patterns of known faces. A positive identification is given if a suitable error measure, such as a sum of squared error metric, is below a predetermined threshold value.
There are several known methods of generating statistical appearance models, and using the models to identify and/or recognize faces or other objects in images. Two known models, the Active Shape Model (ASM) [3,4] and the Active Appearance Model (AAM) [2] were developed at the Victoria University of Marichester, United Kingdom and have been widely used. Both of these models are based upon the use of normalized intensity values. The ASM and the AAM are both generalizations of eigen-face models [6]. Eigen-face models are also based upon the use of intensity values and have also been widely used.
A disadvantage of statistical appearance models that are based upon intensity variation information is that these models are prone to function incorrectly in the presence of changing lighting effects. For example, a face illuminated from an angle different to the illumination which was used when generating the model may cause an error.
It is Known to generate an ASM using images to which a non-linear filter has been applied. One such filter is arranged to locate edges in a given image, and then set to zero the intensity of everything that is not an edge (this is known as the Canny Edge Operator). The same filter is applied to a new image when the ASM is used to identify and/or recognise an object in the image the output of the filter is a pair of images, one of which represents the directions of edges of the image, and the other represents the magnitude of the edges. This method suffers from two disadvantages. The first disadvantage is that the resulting images are binary images, each edge being represented by 'on' values, with the result that a significant amount of information relating to the image is lost. In particular, information relating to structure close to the edges is lost. The second disadvantage of the method is that the filter parameters remain the same for every area of each image, and remain the same for every image. Although it is possible to adjust the filter parameters, tile method does not provide any measurement upon which to base any adjustment.


The present disclosure relates to managing concurrent recovery operations. Operation state may be stored in a repository managed by a service. The service may query the repository as requests come in, and take appropriate actions based on an identified state.

Individuals and organizations rely on information stored on their computer systems. This information may be stored locally or remotely, and loss of the data may lead to stress and significant expense. To protect against data loss, individuals and organizations often create data backups. These data backups may be used to restore data to a system in the event of data loss.
Restoring data to a system may require a recovery operation. There is a need, therefore, for an improved system and process for managing concurrent recovery operations.

Concurrent recovery operation management


A turbine blade is disclosed. The turbine blade includes a platform, an airfoil extending from one side of the platform, a root extending radially from another side of the platform, and a pocket located beneath the platform. The pocket is defined by a plurality of walls, and a pad is disposed in a corner of the pocket. The pad includes three pad corners and three sides connecting the three pad corners, wherein each side extends along a different one of the plurality of walls.

GTEs produce power by extracting energy from a flow of hot gas produced by combustion of fuel in a stream of compressed air. In general, turbine engines have an upstream air compressor coupled to a downstream turbine with a combustion chamber ("combustor") in between. Energy is released when a mixture of compressed air and fuel is burned in the combustor. The resulting hot gases are directed over blades of the turbine to spin the turbine and produce mechanical power.
Turbine blades and other components of GTEs are subject to high temperatures and high local stresses during operation. Components which undergo these high temperatures and stresses may be subject to mechanical failure, either from component breakage due to a reduced cross section of the component as a result of plastic deformation, or rupture where cracks initiate and propagate until the component is broken. For turbine blades, high local stresses may contribute to platform cracks and failures.
U.S. Patent Application Publication No. 2010/0232975 ("the '975 publication") describes a turbine blade assembly including a root connected to a platform, and an airfoil extending upwards from the platform. The '975 publication notes that the platform may experience stresses from rotation of the turbine blade assembly, and may fail due to plastic deformation caused by a combination of heat and stress. Accordingly, the turbine blade assembly of the '975 publication includes a number of ribs that are designed to increase the stiffness of the blade platform. Each rib, which can taper along the turbine blade root, extends outwardly towards a lateral edge of the platform.


An image reading system that reads long-type film images and displays the images on a monitor screen. The image reading system includes a display method having the capability to effectively utilize, on the monitor screen, all of the image information that is on the film, and which allows easy imaging capability of the final image when changes have been made to the original image. The image reading system creates first image data corresponding to roughly the entire body of the image storage region based on the image signal, and creates second image data corresponding to the image of the image storage region that has been trimmed based on trimming-related information included in the image signal and magnetic information. The image reading system displays the first image corresponding to the first image data and the second image corresponding to the second image data on the display.

1. Field of Invention
The present invention relates to an image reading and readout system that reads the image of each frame of a long-type film, displays the image on a monitor screen, and provides a method of trimming the image.
2. Description of Related Art
The image reading system is composed of a film image reading device, or film scanner. The film scanner, under the control of a host computer, reads the image of a film negative or reverse film. The host computer collects image data and controls the display of the image on the monitor screen.
In recent years, new types of film have been proposed. One of these is a long type of film (referred to below as "roll film") which is left in a film cartridge even after development. The roll film is equipped with a magnetic storage region in each frame. In each magnetic storage region, a photographic item is recorded when photography is performed. Print sizes C, H, and P are included in the photographic item.
The C size is called the classic size, and has an aspect ratio of 3:2. The H size is called the high-vision size, and has an aspect ratio of 16:9. The P size is called the panorama size, and has an aspect ratio of 3:1.
In addition to reading the image of each frame, the film image reading device also reads the magnetic information of each magnetic storage region. The host computer executes trimming processing of image data received from each frame, according to the aspect ratio determined by the print size included in the magnetic information, and then displays the image on the monitor screen.
Accordingly, in a conventional image reading system that handles roll film, not all of the image information of the frame read by the film image reading device is displayed on the monitor screen. Only the trimmed frame image, which was automatically trimmed according to the aspect ratio determined by the print size included in the magnetic information, is displayed on the monitor screen.
Sometimes the user sees the frame image displayed on the monitor screen and wants to add changes to the is print size set. during photography. However, a conventional display method ignores part of the image information on the film, as explained above.
Accordingly, the user cannot freely select, on the monitor screen, all of the image information for the film. Instead, the user can only change the frame image displayed according to the aspect ratio determined by the print size set during photography. Therefore, it is difficult to obtain a frame image of a satisfactory size.
Further, in a conventional display method, the frame image is displayed on the monitor screen based on the aspect ratio determined by the print size. Because the print size is only set during photography, when the user changes the image size, the user must do so without knowing what the print size was originally set to. This also points out why it is difficult in a conventional display method to obtain a frame image of a satisfactory size.


A dual spark plug may include: a metal body made of metal material, an insulating body provided inside of the metal body and made of an insulating material, a pair of central electrodes provided inside of the insulating body and electrically connected with an ignition coil, and a pair of ground electrodes respectively extended from both ends the metal body, and spaced apart from ends of the pair of central electrodes by a predetermined distance.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In gasoline vehicles, a mixture of air and fuel is ignited by a spark generated by a spark plug, and combustion is performed. In other words, the mixture injected into a combustion chamber during a compression stroke is ignited by the discharge phenomenon of the spark plug, and energy required for the vehicle's driving is generated while going through an expansion stroke of high temperature and high pressure.
The spark plug provided in the gasoline vehicle plays a role of igniting the compressed mixture by spark discharge due to high voltage current generated from an ignition coil.
In the case of a general gasoline engine, it is mainly operated to combust with a theoretical air/fuel ratio (14.7:1, λ=1).
However, in the case of an engine to implement lean burn combustion, the air/fuel ratio is approximately 30:1 (λ=2). In this case, the mixture in the combustion chamber has very little injected fuel compared to the amount of air, so even if spark discharge occurs by the spark plug, the mixture does not ignite (e.g., misfire), or an incomplete combustion occurs.
Therefore, it has been required research and development on spark plugs to implement lean combustion.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure, and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.


A wheel carrier for a vehicle suspension, intended for the rotatable mounting of a wheel, having a wheel carrier body made of metal is adapted to provide a stable, weight-optimized wheel suspension. The wheel carrier includes a wheel-attachment section and an extension projecting upwardly therefrom with means at its upper end for attaching an inboard-projecting control arm. A portion of the extension is offset inboard relative to the upper end and includes a hybrid section in which the wheel carrier body is reinforced in sections by a reinforcing element made of a fiber composite material.

In motor vehicles, the wheels are normally rotatably mounted on wheel carriers, which are themselves connected to the vehicle structure. The wheel carrier thus essentially forms a stable receiver for the axle of the respective wheel. The connection between the wheel carrier and the vehicle structure can be affected via various control arms (also commonly referred to in the pertinent art as links), which are movably connected between the wheel carrier and the chassis or a subframe, for example. The nature and the number of the control arms per wheel carrier can be different, or, for example, one or more transverse arms and longitudinal arms and/or semi-trailing arms can be provided. The function of the control arms involves guiding the wheel carrier, and thus the wheel, as well as a movable connection with the vehicle structure. The wheel carrier is normally part of the unsprung mass, whereas the vehicle structure is part of the sprung mass. Spring elements and dampers can be attached between the vehicle structure and either the wheel carrier itself or one of the arms.
In many cases, both the arms and the wheel carrier consist of metal, for example steel, grey cast iron or aluminum. In addition, composite materials such as fiber-reinforced plastic are also used to some extent. The choice of material is generally arrived at in such a way that the stability required for safety and travelling comfort is assured. On the other hand, there has been an increased requirement, in particular in more recent times, for a reduction in the weight of all vehicle components in order to save fuel and to reduce CO2 emissions.
DE 10 2009 002 939 A1 discloses a suspension having components which are fabricated to include fiber composite material.
In the light of the outlined prior art, the provision of a wheel suspension, which is optimized in respect of its weight and as such possesses adequate stability, still leaves room for improvement.


A detachable combination tool includes a first body, a second body, two locking blocks, and an elastic member. Thus, the second body can be detached from the first body easily and conveniently, so that the second body and the first body can be used independently, thereby facilitating the user operating the combination tool. In addition, the detachable combination tool can withstand a larger torque or force during operation.

1. Field of the Invention
The present invention relates to a detachable combination tool that can withstand a larger torque or force during operation.
2. Description of the Related Art
A conventional combination tool comprises a first tool and a second combined with each other. The first tool has a female snap formed with a concave portion, and the second tool has a male snap formed with a convex portion inserted into the concave portion of the female snap of the first tool, thereby combining the first tool with the second tool. However, the first tool is easily detached from the second tool, thereby causing inconvenience to the user during operation.
The primary objective of the present invention is to provide a detachable combination tool that can withstand a larger torque or force during operation.
Another objective of the present invention is to provide a detachable combination tool, wherein the second body can be mounted on and detached from the first body easily and conveniently by pressing the two locking blocks, thereby facilitating the user assembling and disassembling the combination tool.
A further objective of the present invention is to provide a detachable combination tool, wherein the second body can be detached from the first body easily and conveniently, so that the second body and the first body can be used individually and independently, thereby facilitating the user operating the combination tool.
In accordance with the present invention, there is provided a detachable combination tool, comprising a first body, a second body, and two locking blocks, wherein:
the first body has an inside formed with a receiving chamber;
the receiving chamber of the first body has two sides each formed with a snap recess;
the second body is detachably mounted on the first body and has a bottom provided with a protruding block received in the receiving chamber of the first body;
the protruding block of the second body has two sides each formed with a through hole aligning with the respective snap recess of the first body; and
each of the two locking blocks is movably mounted on the second body and has a bottom provided with a protruding locking portion extended through the respective through hole of the protruding block of the second body and detachably locked in the respective snap recess of the first body, so that the second body is detachably fixed to the first body by the two locking blocks.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.


A controller is provided that is configured to receive a timing value for a static timing model and a timing value for an extracted timing model. The controller is further configured to determine whether the timing value for the extracted timing model falls within a permissible range of deviation from the timing value for the static timing model.

The present invention is directed to a system for testing integrated circuit designs and more particualrly, to a system for determining whether the deviation between a timing value for an extracted model representation of a circuit design falls within a permissible range from a timing value for a static model of the same circuit design.
In the design of integrated circuits, static timing tools such as Prime Time(copyright) by Synopsys(copyright) are commonly used to evaluate static timing models of a circuit prior to actual fabrication of the circuit in semiconductor material. As a part of pre-fabrication evaluation of a circuit design, a timing value for a static timing model representation of the circuit is determined and subsequently a timing value for an extracted model of the same circuit is determined. These timing values are then manually evaluated to determine whether or not the timing value of the extracted model falls within a predetermined range of the timing value for the static model of the circuit.
As a typical integrated circuit design incorporates tens of thousands to millions of gates and wiring traces, the process of analyzing an integrated circuit design using these typical techniques can be very time consuming as each signal path of the circuitry must be modeled and evaluated. Further, a great deal of manual intervention is required to compare the timing values and operation of the extracted timing model with the timing value and operation of the static timing model to determine whether or not the circuit design is successful
Other features and advantages of the present invention will become apparent from the following description, drawings and claims. The present invention provides a system and method for testing abstracted timing models. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows.
A controller is provided that is configured by software instructions stored on memory. This controller is configured to receive a static model timing value and to receive an extracted model timing value. The controller is further configured to determine the difference between the static model timing value and the extracted model timing value and then to determine whether the difference is within a predetermined permissible range. If so, the controller outputs an indication of success if said difference falls within said predetermined permissible range.
The present invention can also be viewed as providing methods for testing abstracted timing models. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: receiving a static model timing value. Receiving an extracted model timing value and determining the difference between the static model timing value and the extracted model timing value. A determination is made as to whether the difference is within a predetermined permissible range. If the difference does fall within the predetermined permissible range, an indication of success/qualification is output.
Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.

System and method for testing abstracted timing models


Described is an interchangeable earring kit, an interchangeable necklace kit, a combination interchangeable earring and necklace kit and a system of add-on decorative elements for all of the kits. These kits can be used to create a jewelry wardrobe from interchangeable parts. The kits exist as single or combination systems for do-it-yourself jewelry design wear. The kits are contained in compartmentalized boxes to allow for separation of the components.

Earrings and necklaces are typically provided to the user as finished products giving the user minimal choice as to how to wear the accessory. There have been some attempts at user modifiable jewelry. Golove (U.S. Pat. No. 7,222,503) provides a ring with a removable and changeable stone. Erickson (U.S. Pat. No. 4,781,036) describes an earring in which one can unscrew a front and replace it with other designs that screw on. Francis (U.S. Pat. No. 4,753,828) describes a similar earring with a removable backing that one can paint on a desired image. Green (U.S. Pat. No. 5,927,104) describes again an earring with fronts that are unscrewed to replace with other designed fronts. These inventions are difficult to use and limited in the variety that one can obtain. They are also not organized.

Interchangeable earring and necklace kits and methods for their storage and use