This invention relates to a rapid and efficient method for carrying out enzyme-linked immunosorbent assay for detection of minute quantities of biomolecules such as antigen, antibody etc. This invention particularly relates to microwave mediated immobilization of antigen or antibody on to the activated surface followed by performing subsequent steps of ELISA by controlled microwave irradiation. The invented procedure has dramatically reduced the total time required for ELISA to less than 10 minutes from hours to days. The invented ELISA procedure is rapid, economical, reproducible and simple and can be automated. The invented procedure is useful for carrying out ELISA in clinical diagnostics, molecular biology, agriculture, sericulture, food technology, environmental science, biomedical research and other related fields.

The invention relates to a rapid method for carrying out microwave mediated ELISA (MELISA). More particularly, this invention relates to a rapid and efficient method for microwave mediated ELISA (MELISA) wherein all the major steps of ELISA can be performed under microwave irradiation in short time. This method is useful in clinical diagnostics, molecular biology, agriculture, food technology, environmental science etc.
The invented ELISA method is simple, time saving and obviates the time consuming cumbersome procedure. This method has the potential for automation.
This method has the advantage over the existing methods for ELISA which take long time usually ranging from several hours to 2 days whereas the invented method takes less than 10 minutes. It is particularly useful for disease diagnosis where quick results are required.
Enzyme linked immunosorbent assay (ELISA) is a very sensitive technique used for semiquantitative or quantitative determination of the concentration of certain antigens and antibodies. ELISA has become a useful tool in disease diagnosis in both animals and plants. Apart from this, its other applications include screening of monoclonal antibodies during the course of their production (Douillard, J. Y. and Hoffman, T., 1983), pesticide residue detection in crop produce (Van Emon, J. M. and Lopez-Avila, V., 1992) and environmental samples like soil and water (Linde, D. G. and Goh, K. S., 1995), detection of apoptosis in tissue culture etc. (Salgame, P. et al, 1996). Polystyrene microtitre plate is used universally for carrying out ELISA, as it is transparent, cheap, easily available, can be moulded to any desired shape and has a property of binding proteins through adsorption. Conventional methods of ELISA are based on the immobilization of antigen or antibody onto the surface of the wells of a polystyrene microtitre plate through adsorption. This is attributed to the non-covalent interaction between the biomolecule and the polystyrene surface.
However, adsorption is usually too inefficient a process to give good yields and doesn""t always proceed in a dose dependent manner. To overcome the inefficiency of conventional methods covalent immobilization of biomolecules onto the microtitre plate has been carried out by many (Satoh, A. et al, 1999). Covalent binding of immunogens to grafted plastic surfaces has also been reported (Larsson, P. H. et al, 1987). Despite this, the conventional ELISA method requires very long time varying from several hours to 2 days for completion. This is the main drawback of different ELISA methods, either based on adsorption or covalent binding. In case of medical urgency precious time is lost in diagnosis before the patient could be given medication. In agriculture, ELISA is usefull for detecting pesticide residues in crop produce and environmental samples. Export and marketing of crop produce can be delayed as a consequence of this handicap in the ELISA method, which contributes to loss of valuable foreign exchange.
The applicants have developed a novel and unique method whereby ELISA can be carried out rapidly by the use of microwaves. Microwaves are known for accelerating immunohistochemistry for about a decade (Boon, M. E. and Kok, L. P., 1992; Boon, M. E. et al, 1989; Boon, M. E. et al, PCT patent application WO 89/ 03038; Chiu, K. Y. and Chan, K. W., 1987; Hjerpe, A. et al, 1988).
Covalent immobilization of antigen or antibody on to a polystyrene surface by microwave irradiation has not been reported so far. In fact, all the major steps of ELISA by microwave irradiation in such a short time to detect minute quantities of antigen or antibody by measuring optical density was not known in the prior art.
However, there are attempts for doing one of the steps of ELISA by microwave irradiation (Hierpe, A. et al, 1988) where polystyrene ELISA plates were coated first with rabbit anti-carcinoembryonic antigen by incubating over night at 4xc2x0 C., followed by incubation of the antigen (CEA). In the subsequent step i.e. after the addition of enzyme-linked antibodies the authors studied the effect of microwave irradiation on antigen-antibody reactions.
In another experiment by the same authors, ELISA plates were first coated with normal mouse serum by incubating over night at 4xc2x0 C., followed by overnight incubation with non-labeled rabbit anti-mouse Ig. In the subsequent step they added mouse PAP (peroxidase-antiperoxidase) complexes and determined the effect of microwave irradiation on the reactivity constants of reactions of this last step.
In third experiment Hjerpe et.al first coated the plates with non-specific mouse serum followed by incubation with biotinylated horse-anti-mouse IgG. The plates were then used to study the effect of microwaves upon the subsequent binding of biotin-avidin complexes.
The reaction yields in all the above experiments were smaller in samples subjected to microwave irradiation as compared to those processed without microwave stimulation. The experiments showed that the microwaves caused a major loss of reactivity and the total yields were approximately 10% to 15% compared to conventional one that was carried out outside the microwave oven. According to authors, the diminished value in the microwave technique may be due to too high temperatures in the wells, despite the fact that a water load (a beaker of water to absorb excess microwave energy) and chilled bottom plate were taken as a precautionary measure.
In further ELISA experiment authors (Koh and Boon, 1992) used a fiberoptic thermometer to restrict the temperature below 40xc2x0 C. Here also a water load of 200 ml tap water was taken. Besides, the fluid in the wells was stirred by slowly blowing air through the solution via thin plastic tips, which were inserted into the wells. In an experiment the authors carried out only two steps namely, antibody and conjugate binding steps by microwave irradiation for 6 minutes at 150 watts each.
In another experiment, antibody, antigen and conjugate binding steps were carried out in 15, 30 and 30 minutes respectively using 45-50% microwave power in each step.
Remaining steps in both the experiments were carried out by conventional procedure. But the ELISA values were found to be much less in the above experiments than the conventional method.
According to authors, the longer exposure time gave higher extinction value (ELISA value) but the time gain was not attractive. In fact there was no benefit when exposure time of 30 minutes or more were used. Too short exposure times led to extinction values which, were rather low and could not be used.
The reported methods of ELISA by microwave exposure has several drawbacks such as (1) the results (ELISA value) were much less than the conventional procedure, (2) the time gain was not attractive. It may be possible to get comparable results (ELISA value) by doing the ELISA out side microwave oven in the same time, (3) procedure required water load, (4) it required cooling system or chilled bottom plate, (5) it needed a stirring system in the well of the microtitre plate, (6) not all the steps were carried out by microwave energy and the reported ELISA procedure has little or no potential for automation.
The applicants in the present invention have overcome all the above drawbacks. In fact, like thermal energy microwave can also activate or inactivate a biomolecule. Without proper conditions the microwave may cause partial or total destruction of the biomolecule leading to low or undesirable ELISA value. In the invented procedure proper conditions were found, most of, which are contrary to the reported method, or not known in the prior art. In the invented method all the steps except color development are carried out by microwave stimulation. Blocking step was not carried out by microwave irradiation in the published procedure as it gave nonspecific binding, whereas the applicants have invented a method where blocking step is carried out in short time by microwave irradiation. Longer microwave exposure time gave higher ELISA value in the reported method whereas in the invented procedure, it leads to destruction of material or nonspecific binding. This may be because water load or the cooling system used in the reported method absorbed most of the microwave energy giving minimum microwave effect and a significant effect of time as in the conventional method. In contrast, the invented method does not require any water load, cooling system or stirring system. Moreover, in the invented method about 200 times less (excluding color development step) time requires for ELISA than the conventional one (which takes around 18 hours) with comparable or even better ELISA value. Hence, it also has a great potential for automation.
The reported ELISA was carried out on a microtitre plate that did not bind the biomolecule through covalent linkage. In fact, it is known that the microwaves may readily effect the integrity of the noncovalent secondary bonding, such as hydrogen bonds, hydrophobic interactions and Van der Waal""s interaction.
The main object of the present invention is to provide a rapid and efficient method for enzyme linked immunosorbent assay to detect minute quantities of antigen or antibody spectrophotometrically for rapid diagnosis of diseases.
Another object of the present invention is to provide a technique, which is simple, reproducible and does not require additional expertise or costly equipment.
Another object of the present invention is to provide a rapid technique, which has the potential for automation and which can minimize human error that usually varies from person to person.
With a view to achieve the objects and overcoming the disadvantage of known ELISA method, a rapid and efficient method is provided for microwave mediated ELISA (MELISA) which comprises the steps of (i) covalent immobilization of the antigen or antibody on to the activated solid surface by microwave irradiation, (ii) blocking the free surface with blocking agent by brief microwave irradiation, (iii) binding of antibody or antigen by controlled microwave irradiation (iv) binding of conjugate by controlled microwave irradiation, (v) adding dye-substrate to the wells and (vi) recording the absorbance value.
Microwave mediated ELISA (MELISA) procedure is carried out on an activated surface in a very short time (around 10 minutes) and with the same efficacy as in the conventional ELISA carried out at 37xc2x0 C., in 16-18 hours.
This invention has the potential of automation or semi automation of the ELISA procedure.
Microwaves are known to effect the integrity of the noncovalent secondary bonding, such as hydrogen bonds, hydrophobic interactions and Van der Waal""s interaction.
To overcome this problem the applicants activates the surface of the microtitre wells prior to use. The activated surface immobilizes the antigen through a covalent bond by a brief microwave exposure. This covalently immobilized antigen is stable enough to withstand repeated but brief microwave exposure, which were needed for performing the subsequent steps of ELISA. Subsequent steps of biomolecule binding in the ELISA procedure are through non covalent binding which are susceptible to microwave energy. These problems are overcome by controlling the time and energy of the microwave irradiation in each step.
Novelty of the present invention is that the ELISA is carried out on to an activated surface capable of forming covalent linkage with the proteinaceous ligand.
Microwave mediated covalent immobilization of biomolecule, more preferably antigen or antibody on to the activated surface is another novelty of this invention.
Controlled microwave irradiation in each step of ELISA procedure is another new approach.
In the invented procedure, all the steps of ELISA such as antigen binding, blocking, antibody and conjugate binding are carried out by microwave irradiation and only enzyme-substrate reaction is performed out side microwave oven at room temperature. The invented procedure of ELISA is very fast with comparable or even better ELISA value than the conventional method.
Another novelty of the present invention is that the invented ELISA procedure does not require any water load or stirring system.
Another novelty of the present invention is that the invented ELISA procedure can be fully or partially automated with the use of a specially designed device.
Another novelty of the present invention is that the invented procedure can be used for other immunoassays like radio immunoassay, radio-immunosorbent test, radio allergosorbent test, biotin- avidin /streptavidin immunoassay, immnunoblotting, immunostaining etc. apart from different types of ELISA such as direct ELISA, indirect ELISA, sandwich ELISA and alike.
The present invention provides a new approach for enzyme linked immunosorbent assay technique on an activated microtitre plate, module or well by microwave exposure. Activated surface immobilizes the antigen through covalent bonding by microwave irradiation. This covalently immobilized antigen is stable enough to withstand repeated but brief microwave exposure, which are needed for performing the subsequent steps of ELISA. ELISA is a multistep and delicate process where improper condition in any step may hamper the whole results.
In the invented procedure inert solid surface such as polystyrene is activated by photochemical reaction in dry condition using a photoactivable compound. Activation of the solid support is made by exposing the support coated with the photoactivable compound to UV radiation or bright sunlight. This activated support is used for microwave mediated ELISA (MELISA) and for control ELISA to detect antibodies, to example E.histolytica and Aspergillus fumigatus. When untreated support is used it failed to bind the biomolecule in such a short time by microwave irradiation.
Microwave irradiation is performed inside a domestic microwave oven (BPL-Sanyo, India), operating at a frequency of around 2450 MHz.
The amoebic antigen is obtained from the culture of E.histolytica as per published procedure (Sawhney, S., et al, 1980; Sharma, G. L, et al, 1984). The protein concentration of the antigens was 1.54 mg per ml as determined by the method of Lowry etal. (Lowry, O. H., et al, 1951). The antigen was diluted before performing ELISA and a concentration of 1.0 xcexcg per well was used for coating the wells.
Phosphate buffer saline (PBS), pH 7.2, 0.01 M is used as coating buffer.
Phosphate buffer saline (PBS), pH 7.2, 0.01 M together with 0.1% tween 20 (polyoxyethylene 20 sorbiton monolaurale is used as washing buffer.
Blocking solution is made by dissolving 2% BSA in 0.01 M PBS, pH 7.2.
Substrate solution is prepared by adding 0.067% of o-phenylenediamine and 0.043% of H2O2 in 0.1 M phosphate citrate buffer, pH 4.5).
Hyperimmune sera to E.histolytica is raised in Newzealand White rabbits as per the methods of Sawhney et al (Sawhney et. al, 1980). The antibody titres in the sera are checked by gel-diffusion test.
The antibody (+ve sera) is diluted before performing ELISA and 1:300 dilution in PBS is used for the experiments.
Rabbit is bled through the ear vein before giving the immunization dose of E.histolytica antigen to obtain negative control sera (xe2x88x92ve sera). 100 xcexcl of diluted (1:300) xe2x88x92ve sera is used for each well.
Horse radish peroxidase conjugated anti-rabbit IgG is purchased from Sigma as lyophilized powder.
After reconstitution, the optimum dilution is found to be 1:4000 as determined by checkerboard titration, which is used in the experiments.
ELISA is a 5-step procedure, namely antigen binding, blocking, antibody binding, conjugate binding and color development. Each step of MELISA is optimized by carrying out the subsequent steps by conventional ELISA procedure. Conventional ELISA is carried out by overnight coating the activated wells with antigen at 4xc2x0 C., blocking the wells in 2 hours at 37xc2x0 C. followed by antibody and conjugate binding at 37xc2x0 C. for 2 h each and color development that is enzyme-substrate reaction at room temperature for 5 minutes followed by reading absorbance.
In the invented procedure, the first step of ELISA is performed by covalent immobilization of the amoebic antigen onto the activated polystyrene microwell plate by microwave irradiation at 700 watts in different duration of time. Binding, is detectable even in 10 seconds which increases with the increase in time of irradiation (Table 1). At 90 seconds the antigen binding becomes more or less same as 70 seconds of microwave irradiation. Hence, optimum time for antigen immobilization is taken as 70 seconds. In control experiments carried out for the same duration that is 70 seconds at 37xc2x0 C., no binding of antigen to the activated polystyrene surface is observed.
In the second step of MELISA, blocking is carried out with 2% BSA in 10 seconds in the microwave oven at a power out put of 700 watts to block the free surface of the activated surface. Further increase in irradiation time showed non-specific binding (Table 2.)
In the third step of MELISA, antibody binding to the immobilized antigen is carried out at 155 watts for 100 seconds. This is a crucial step where harsh conditions such as excess time or higher power output leads to nonspecific binding as shown in Table-3. At 155 watts in 50 seconds and 100 seconds, no nonspecific binding is observed. Although the observed OD is very low in 50 seconds, 100 seconds is found to be excellent, giving high ratio of xe2x88x92ve to +ve sera. Increase in time to 150 seconds increases the nonspecific binding (table 4).
In the fourth step of MELISA, conjugate binding is carried out by microwave irradiation at 155 watts for different duration of time. Excellent result is obtained in 100 seconds (Table 6). Harsh condition such as excess time or higher energy such as 700 watts leads to nonspecific binding (Table 5).
In each step control experiment is carried out by doing the same experiment outside microwave oven for the same duration of time. In all this experiments negligible or undesirable ELISA value (nonspecific binding) is obtained.
After optimizing each step of MELISA, the applicants carried out all the steps with optimized conditions of microwave irradiation without damaging the biomolecules. To achieve it the applicants have immobilized antigen on to the activated well in 70 seconds, blocking in 10 seconds, antibody binding in 100 seconds and conjugate binding at 100 seconds of irradiation. The total time required for all these steps are 280 seconds only by the invented procedure whereas conventional ELISA is done in about 18 hours.
MELISA and ELISA to detect E.histolytica antibodies are repeated several times under similar experimental conditions and the results are found to be highly reproducible as shown in Table- 7.
MELISA procedure is further verified by detecting Aspergillus fumigatus antibody from patients sera. A. fumigatus antigen is obtained from static culture as per published procedure (Banerjee, B., et al, 1990).
The protein concentration of the antigens is found to be 12.5 mg per ml as determined by the method of Lowry et.al. (Lowry et.al., 1951). Immunoreactivity of the antigen is checked by using hyperimmune serum raised in Newzealand White rabbits.
Sera samples are obtained from 10 patients of allergic bronchopulmonary aspergillosis (ABPA). All these patients fulfill the clinical criteria of ABPA as described earlier (Rosenberg, M., et al, 1997).
Negative control sera samples are taken from 10 volunteers who are apparently healthy and do not have any respiratory or other disease.
Pooled positive and negative sera are taken as the controls for ELISA, which are found to be comparable in both MELISA and conventional ELISA.
Horse radish peroxidase conjugated with anti-human IgG is purchased from Sigma as lyophilized powder. After reconstitution, the optimum dilution of the conjugate is found to be 1:4000 as determined by checkerboard titration.
A.fumigatus antibody (present in patient sera) detected by the invented method is in agreement with the conventional ELISA procedure (Table. 8)
The results obtained in different experiments are given comparative grades as below:
Excellent=++++
Very good=+++
Good=++
Poor=+
Undesirable or no results=xe2x88x92
The total time required for MELISA is less than 10 minutes. However, time required in each step may vary depending on the biomolecules where excellent results can be obtained by minor modification of reaction conditions that is minor alternation in duration and energy of irradiation.
Accordingly the present invention provides a rapid method for microwave mediated enzyme-linked immunosorbent assay characterized in using an activated solid support wherein the said method comprises:
(a) providing an activated solid support,
(b) loading a biomolecule selected from an antigen or antibody by dissolving the said biomolecule in a coating buffer into the activated well of the said solid support and placing the said well inside a microwave oven followed by irradiating the said well with microwaves at a frequency ranging between 2300-2500 MHz with the power output ranging between 600-900 watts for a period ranging from 50-100 seconds followed by washing the well thoroughly with an appropriate washing buffer,
(c) blocking the free sites of the well with an immobilized biomolecule as obtained from step (b) as above by loading blocking solution into the said well and irradiating it inside the microwave oven at a frequency of from 2300-2500 MHz with a power out put ranging between 600-800 watts for a period ranging from 5-20 seconds and washing the said well with an appropriate washing buffer,
(d) loading the corresponding antibody or antigen dissolved in a buffer into the well immobilized with antigen or antibody as obtained from step (c) above followed by irradiation of said well inside the microwave oven at a frequency of from 2300-2500 MHz with a power output ranging from 50-200 watts for a period ranging from 90-200 seconds followed by washing with washing buffer,
(e) loading an appropriate enzyme- conjugate dissolved in a suitable buffer into the above said well obtained from step (d) and irradiating the said well inside a microwave oven at a frequency of from 2300-2500 MHz with a power output ranging from 100-300 watts for a period ranging from 50-150 seconds followed by washing with a washing buffer,
(f) adding a substrate-dye-buffer to the above well as obtained from step (e) as above and keeping it for a period ranging from 4 to 10 minutes in dark followed by addition of stop solution and measuring optical density of the solution by spectrophotometer at a suitable wavelength.
In an embodiment of the present invention the solid support used is selected from the group consisting of materials such as polystyrene, polypropylene, polyethylene, glass, cellulose, nitrocellulose, silicagel, polyvinyl chloride, polyaniline and alike.
In an embodiment of the present invention the preferred solid support used is polystyrene.
In yet another embodiment the solid support is selected from any shape, form and size such as sheets, plates, test particles such as beads and microspheres, test tubes, test sticks, test strips, well, ELISA plate, microwell plate or module.
In an embodiment of the present invention the solid support used for immobilizing biomolecules is selected from any support having at least one active functional group capable of binding ligand molecules by covalent means.
In yet another embodiment of the present invention the functional group is selected from halide, aldehyde, acetyl, epoxide, succinamide, isothiocyanate, acylazide and alike.
In yet another embodiment of the present invention the functional group may be present in the support itself or can be introduced by conventional chemical or photochemical or other methods known to prior art.
In yet another embodiment of the present invention the functional group is introduced on to the solid support by photochemical reaction in dry condition using a photoactivable compound which is selected from 4-fluoro-3-nitroazidobenzene, N-hydroxysulfo-succinimidyl 4-azidobenzoate, N-hydroxysulfo-succinimidyl 4-azidosalicyclic acid and alike.
In yet another embodiment of the present invention polystyrene surface is activated by coating with 1-flouro-2-nitro-azidobenzene and exposing the coated support in dry condition to UV radiation at 365 nm.
In yet another embodiment of the present invention the light source for photochemical reaction is selected from UV lamp, laser beam, bright sunlight or alike.
In yet another embodiment of the present invention time for photoreaction for activation of solid support is selected form 10 seconds to 10 hours.
In yet another embodiment microwave irradiation is performed in a microwave apparatus selected from domestic microwave oven, specially designed microwave oven or any apparatus or chamber in which microwave is generated and alike.
In yet another preferred embodiment of the invention, the first step of ELISA, is carried out by covalent binding of antigen or antibody onto the activated plate by microwave irradiation at a frequency of from 2300-2500 MHz with the power output ranging between 600-900 watts for a short period ranging from 50-100 seconds.
In yet another preferred embodiment of the invention the second step of ELISA, that is the blocking step is carried out by microwave irradiation at a microwave frequency of from 2300-2500 MHz with a power out put ranging between 600-800 watts for a short period ranging from 5-20.
In yet another preferred embodiment of the invention the third step of ELISA, that is corresponding antibody or antigen binding is carried out by microwave irradiation at the microwave frequency of from 2300 to 2500 MHz with power output of from 50 to 200 watts in a period ranging from 90 to 200 seconds.
In yet another preferred embodiment of the invention the fourth step of ELISA, that is enzyme-conjugate binding is carried out by microwave irradiation at the microwave frequency of from 2300 to 2500 MHz with power output of from 100 to 300 watts in a period ranging from 50 to 150 seconds.
In yet another preferred embodiment of the invention the total time for antigen binding, blocking, antibody binding and conjugate binding is ranging from 195 to 470 seconds wherein the total time for conventional method usually is ranging from 10 hours to 24 hours.
In another embodiment to the present invention, the antigen can be dissolved in a coating buffer of suitable composition having a pH, in the range of from 6.5 to 11 with molarity ranging from 0.005 M to 0.1 M compatible with the antigen such as carbonate buffer, phosphate buffer and alike.
In yet another preferred embodiment of the invention, washing buffer used is a mixture of phosphate buffer having a pH, in the range of from 6.5 to 11, with molarity ranging from 0.005 M to 0.1 M and tween 20 in the range between 0.05% to 3%.
In yet another preferred embodiment of the invention, blocking reagent is selected from bovine serum albumin, skimmed milk powder, gelatin and alike.
In another embodiment to the present invention biomolecule is selected from antigen or antibody. Antigen may be any, biomolecule, microorganism, substance etc. that elicits or has the potential to elicit an immune response.
In yet another preferred embodiment of this invention, antibody is selected from any biomolecule, which is produced by the host in response to inoculation with the specific antigen and has capabilities of binding to the antigen in a specific manner.
In yet another preferred embodiment of this invention, conjugate is a specific biomolecule having antibody or antigen conjugated with an enzyme selected from peroxidase or alkaline phosphatase.
In yet another preferred embodiment of this invention, enzyme may be replaced by a label selected from chromophore, fluorophore and alike which facilitates its assay.
In yet another preferred embodiment of this invention, the invented procedure can be used for other immunoassays like radio immunoassay, radio-immunosorbent test, radio allergosorbent test, biotin- avidin/streptavidin immunoassay, immnunoblotting, immunostaining etc. apart from different types of ELISA such as direct ELISA, indirect ELISA, sandwich ELISA and alike.
The invention further provides an apparatus for microwave mediated enzyme linked immunosorbent assay (MELISA) comprising (a) a loading chamber, for loading the samples or reagents from a specified bottle from a fine tube by a suitable pump onto the activated polystyrene plate/module automatically; (b) a reaction chamber consisting of magnetron, exhaust fan etc. for carrying out all the steps such as binding of the antigen, blocking, antibody binding and antibody enzyme conjugate binding by microwave irradiation and enzyme substrate reaction without microwave stimulation at ambient temperature in a pre-programmed time; (c) a washing cum drying chamber for washing and drying the said ELISA plate or module automatically by a pre-programmed command after each step of the MELISA procedure; (d) a detection chamber for calorimetric detection with the help of the spectrophotometer; (e) a moving platform is used for carrying the Elisa plate/modules from one chamber to another chamber (f) a microprocessor based computing means for controlling MELISA method through suitable hardware and software.
This invention is further explained with the help of the following examples and should not be construed to limit the scope of the invention.

Rapid method for enzyme-linked immunosorbent assay

Council of Scientific and Industrial Research


An electrical card connector (1) for receiving an electrical card (100) includes a longitudinal insulative housing (10) and a plurality of conductive contacts (20) received in the insulative housing. Each contact includes a contact portion (204) projecting beyond the insulative housing. The electrical card is pressed to contact with the conductive contacts. A holding piece (30) is received in a rear portion of the insulative housing and provided for holding the electrical card.

1. Field of the Invention
This invention generally relates to an electrical card connector, and more particularly to one provided with simplified structure.
2. Description of the Prior Art
Conventional electrical card connector used in portable electronic devices for connecting an electrical card to a printed circuit board includes an insulative housing, a plurality of electrodes or contacts exposed in the housing for electrically connecting with circuit traces of the card and a holding device permitting the card to insert and remove therefrom.
U.S. Patent application publication No. 2005/0106921 A1 discloses such an electrical card connector for receiving mini SD card. The conventional electrical card connector includes an insulative housing and a plurality of conductive contacts. The insulative housing includes a pair of clamping arms which define a pair of retaining ribs for fastening the mini SD card. Since the conventional electrical card connector provides the retaining rib additionally to retain the mini SD card, thereby exceed the longitudinal length of the electrical card connector. In addition, it is not conventional to push the electrical card out of the electrical card connector.
Hence, an improved electrical card connector having a simplified structure is needed to solve the above problems.


A pulse laser oscillator (11) outputs a first laser beam, a beam splitter splitting the first laser beam into split beams, optical paths (12, 13, 14, 15, 16) propagating light of split beams split, respectively, taking different times for light propagation thereof, a condenser superimposing light of split beams propagated through the optical paths, respectively, on an identical spot of a measuring material (100), for irradiation therewith, a laser interferometer (30) irradiating the measuring material (100) with light of a second laser beam, having light intensity variations resulted from interferences between reference light and light of the second laser beam reflected or scattered, as bases to detect ultrasonic waves energized by light of the first laser beam and transmitted in the measuring material (100), a waveform analyzer (32) calculating a metallic microstructure or a material property of the measuring material (100) based on ultrasonic waves.

There has been a wide-spread use of ultrasonic wave for measurements of metallic microstructures or material properties. For instance, in the PTL 1 below, there is disclosed a grain size measuring apparatus for measuring grain sizes in a steel plate, using the principle that energized ultrasonic waves, transmitted through a steel plate, have different attenuation characteristics depending on grain sizes in the steel plate.
It is known that grain sizes, attenuated ultrasonic waves, and ultrasonic frequencies generally follow a scatter law to be defined (by expression 1), such that:
                    [                  Math                                                              1                ]                                                            D        =                              (                                          K                                  -                  1                                            ·              α              ·                              f                                  -                  n                                                      )                                1                          n              -              1                                                          (                  expression                                                              1                )
Here, denoted by a is an attenuation rate (dB/mm) of an ultrasonic wave, D is a grain size (mm), f is a frequency (MHz) of the ultrasonic wave, and n is a coefficient representing a scatter mode, typically within 1 to 4 or near.
In other words for ultrasonic waves scattered at crystal grains, the attenuation due to the scattering is promoted as the frequency becomes high. This tendency has an increased significance as the grain size increases. Accordingly, resultant differences in the attenuation rate can be based on to measure qualities of a metallic material, including the grain size, for instance.
For use to energize ultrasonic waves in a material to be measured, there are available known methods including a method employing a piezoelectric vibrator (as a first method), a method employing electromagnetic forces (as a second method), and a method employing a pulse laser beam (as a third method). Among them, the first method needs to closely attach the piezoelectric vibrator to the material to be measured, with an intervening medium (liquid) having a matched acoustic characteristic. Moreover, energized ultrasonic waves need to have frequencies typically about a few MHz or less. The second method permits ultrasonic waves to be energized in a non-contact manner, with a limited spacing (a stand-off distance) typically about a few mm from the material to be measured. Besides, this measuring material has to be a magnetic body. Namely, the second method is inapplicable to inspections such as that of a carbon steel (having a hot austenite structure) in a hot processing, that is a non-magnetic body, or of a stainless steel that also is a non-magnetic body.
In comparison with them, the third method is wide-spread because of advantages permitting non-contact measurements, large standoff distances (several 100 mm), and measurements of non-magnetic bodies.

Measuring apparatus and measuring method for metallic microstructures or material properties

TOSHIBA MITSUBISHI-ELECTRIC  INDUSTRIAL SYSTEMS CORPORATION


A system and method are provided which dynamically adapts to a changing economic environment by selecting or synthesizing an economic model from a set of economic models based on the selected model's ability to make accurate predictions about an actual economic market. The method and system each forms a space of different economic models, forms a behavioral landscape by extracting observables from executions of the economic models, and performs model selection and composite model synthesis through optimization over the behavioral landscape.

The stock market and non financial markets are complex systems in which one or more stocks, goods, services, or their derivatives are sold or bought. Many techniques exist that attempt to analyze expected behavior of these markets, including predictions of price and volatility for a forward time series from any given date. Among these methods are those concerning prediction of volatility based on Black Scholes, and implied volatility given prices of options and the assumptions of Gaussian random walks in prices that are used to back estimate the volatility implied by actual option prices. In addition, procedures exist which posit some mathematical form for a feature such as volatility, such as truncated Levy, or Levy, or other distributions, then attempts to fit observed volatility distributions using these assumed underlying distributions and appropriate weighting of coefficients in the given mathematical form.
Still other attempts to predict expected volatility uses Black Scholes formalism but treats variance in price as itself a random variable which changes over time, then attempts to estimate the rate of change of this random variable. Still other efforts to predict volatility are based on causal models of various kinds. For example, some workers postulate a "herding" effect in which clusters of traders of various sizes form and trade in much the same way, causing small and large fluctuations in price, hence in volatility. Other attempts are based on Langevain equations which represent displacement of buy and sell orders at a moment from "equilibrium", then seek stochastic equations describing the change of this displacement as a function of drift terms, price momentum terms, penalties for price variance, and volatility growth terms. Still other efforts are based on local linear models which embed a single stock's price series, or sometimes several price series, in a multidimensional space of the past N periods and attempts to locally fit the next price move of one or several prices.
The predictive capability of each of these economic model can vary with the economic environment. Specifically, an economic model may exhibit a good predictive capability for one set of economic circumstances and a poor predictive capability for another set of economic circumstances. Since the economic environment changes with time, the utility of each economic model also changes with time.
A great many researchers in economics, finance, and related areas have investigated different aspects of financial markets or markets in general. Topics of interest to the researchers and of relevance to our project have included diffusion of information in markets (Kyle, Albert S. (1985): "Continuous Auctions and Insider Trading," Econometrica, v. 57, 1315-35, Grossman, Sanford J., and Joseph E. Stiglitz (1980): "On the Impossibility of Informationally Efficient Markets," The American Economic Review, v. 70, 393-408), efficiency and statistical modeling of markets (Foley (1982)), speculation and bubble formation (Tirole, Jean (1982): "On the Possibility of Speculation Under Rational Expectations," Econometrica, v. 50, 1163-81.), and many others.
Other existing work in market microstructure theory (O′Hara Blackwell, Maureen, Market Microstructure Theory, Cambridge, Mass., 1995.) suffers from a lack of means for experimental verification (with some important exceptions, such as (Rust, John, John Miner, and Richard Palmer (1993): "Behavior of Trading Automata in a computerized Double Auction Market", in The Double Auction Market). For example, Glosten-Milgrom (GM) model examines the relationship between Dealer spreads and the proportion of informed Investors in the market. But it is very difficult to quantify the fundamental concept of "proportion of informed investors in the market" Ideally, one would prefer a numerical and experimental framework in which one could examine the regions of validity of analytic models like the GM.
Another important shortcoming of the existing literature is the static nature of most of the models, i.e., results even for dynamic models are usually derived using some type of equilibrium assumptions. Such assumptions greatly limit one's ability to investigate dynamic, potentially non-equilibrium behavior of the system, and also one's ability to model realistically the market participants and as the result the market itself.
Accordingly, there exists a need for a broad encompassing algorithmic framework to develop effective and routinely improvable models and predictions of economic markets including stock markets and non-securities markets. In addition, there exists a need for a broad and improvable algorithmic framework to seek means to price securities such as options and other derivatives.
There exists a further need for a system for performing analysis and making predictions in a securities market using an agent-based models of the dealers and investors.

System and method for the analysis and prediction of economic markets


A method and system for reducing power consumption of a wireless transmit/receive unit (WTRU), (i.e., mobile station), are disclosed. A first WTRU measures a predetermined parameter and determines whether the measured predetermined parameter exceeds a threshold. If so, the first WTRU sends a sleep frame to a second WTRU. The sleep frame indicates sleep duration. The second WTRU receives the sleep frame and enters a sleep state for the sleep duration. The predetermined parameter may be an inactivity time of wireless medium. The second WTRU may or may not be allowed to send transmission to the first WTRU during the sleep duration. The sleep frame may be a control frame, a management frame, a data frame or an action frame. One of a multiple receiver aggregate (MRA) multi-poll frame, a power saving aggregation descriptor frame, or a power save multi-poll frame may be used as the sleep frame.

FIG. 1 shows a conventional infrastructure mode wireless local area network (WLAN) 100. The WLAN 100 includes at least one access point (AP) 102 which is associated with at least one WTRU 104. The AP 102 is responsible for servicing the communication needs of its associated WTRUs 104. The WTRU 104 sends uplink traffic to the AP 102, and the AP 102 sends downlink traffic to the WTRU 104. In an independent basic service set (IBSS), WTRUs 104 talk directly to each other in an ad-hoc manner without the need for an AP 102 to be present.
In IEEE 802.11 WLAN systems, a WTRU 104 continuously listens to, (i.e., monitors), the wireless medium to determine if there are frames being transmitted. If there are frames being transmitted on the wireless medium, the WTRU 104 receives and decodes such frames in order to determine whether such frames are destined, (i.e., addressed), to itself or not. Listening or receiving and decoding frames consume significant power of the WTRU 104 as summarized in Table 1. Table 1 describes different states of the WTRU 104 and its power consumption level in each state.
TABLE 1approximate averagepower consumptionStateGeneric description(peak consumption = 100%)Active TxDevice in the process of80%transmitting a burstActive RxDevice in the process of50%receiving a burstListenDevice actively listening to30%the mediumStandbyDevice ignoring the medium, 5%but capable of Active Tx,Active Rx, and Listen withina short time span(typically <10 μs)SleepDevice substantially turned<0.1%   off, with change time to adifferent state in the orderof >1 ms
The problem with the conventional WLAN 100 is that a WTRU 104 may spend a lot of time in a listen state only to find out that there are few or no frames being transmitted on the wireless medium, and may spend a lot of time in an active receive state only to find out that the frames it received, (i.e., demodulated and decoded), are not destined to the WTRU 104.
Conventional power saving schemes attempt to reduce the amount of time that a WTRU 104 spends in the active receive or listen states and to increase the amount of time that the WTRU 104 spends in the standby or sleep states. One example is automatic power save delivery (APSD) defined in IEEE 802.11e. IEEE 802.11e defines scheduled APSD (S-APSD) and unscheduled APSD (U-APSD).
In S-APSD, an AP 102 and a WTRU 104 agree on scheduled intervals during which the AP 102 will deliver data that is destined to the WTRU 104. Since the WTRU 104 has agreed with the AP 102 on specific time intervals for scheduling its data, the WTRU 104 may go into a sleep state, (i.e., the WTRU 104 does not listen to, receive or decode frames), during all other times except for its scheduled service interval that it agreed upon with the AP 102. Doing so provides high power savings for the WTRU 104, because the WTRU 104 can spend more time in the sleep or standby states.
However, a drawback of the S-APSD scheme is complexity and lack of flexibility. The S-APSD scheme is complex due to its pre-scheduled nature, where both the AP 102 and the WTRU 104 have to agree upon, and meet, tight timing constraints. For example, the WTRU 104 has to wake up at strict times, and the AP 102 has to schedule data for the WTRU 104 during such strict times. In addition, the S-APSD scheme is not efficiently scalable from the AP's perspective, since the AP 102 has to store the scheduling intervals that the AP 102 agreed upon with each WTRU 104. As the number of WTRUs 104 grows, the AP 102 memory requirements will also grow. Additionally, because the AP 102 cannot send the data for the WTRU 104 immediately when the medium is available, but has to wait for that WTRU's scheduled interval, a delay and delay variation may be higher when using the S-APSD scheme.
On the other hand, in a U-APSD, the WTRU 104 may sleep, and wake up on its own to send a trigger frame to the AP 102. In reaction to the trigger frame, the AP 102 may send data to the WTRU 104. Drawbacks of the U-APSD are that when a WTRU 104 wakes up to send a trigger frame, it effectively consumes more power since the active transmit state consumes the most power. In addition, the U-APSD scheme may potentially waste the wireless medium, because the AP 102 may not have any data to send to the WTRU 104 in response to the trigger frame. Another problem with the U-APSD scheme is that the WTRU 104 may cause a collision since the WTRU 104 may not detect the channel as busy.
To enhance throughput in the new IEEE 802.1 in standard, several frame aggregation mechanisms have been introduced, such as medium access control (MAC) protocol data unit (MPDU) aggregation, physical layer (PHY) PDU (PPDU) aggregation, and PPDU bursting. Since such mechanisms generally aggregate multiple frames, new mechanisms such as multiple receiver aggregate (MRA) multi-poll (MMP) and power saving aggregation descriptor (PSAD) have been proposed in order to improve power saving performance.
The basic idea underlying the MMP and PSAD is that since an aggregated frame may be quite long, instead of having a WTRU 104 receive the entire aggregated frame only to find out that it does not have data within it, the AP 102 first sends an MMP or PSAD frame to describe which WTRUs' addresses are included in the subsequent aggregated frame. The AP 102 first sends a frame to preannounce the destinations and transmission times of the upcoming sequence of data. WTRUs 104 which have data in the upcoming sequence can sleep and only start listening or receiving their data at the scheduled (pre-announced) times. WTRUs 104 that do not have data within the upcoming sequence can also save power by sleeping during the upcoming data sequence.
FIG. 2 shows a conventional MMP frame 200. The MMP frame 200 is used to define multiple response periods in combination with multiple-receiver aggregation. The MMP frame 200 includes a frame control/duration field 202, a receiver address field 204, a transmitter address field 206, an N STA field 208, receiver information fields 210 and a cyclic redundancy check (CRC) field 212. The N STA field 208 indicates the number of receivers for which MPDUs are included inside the MRA aggregate. The receiver information fields 210 indicate each receiver address in the MRA aggregate. Each receiver information field 210 includes a receive offset field 214, a receive duration field 216, a transmit offset field 218 and a transmit duration field 220. The receive offset field 214 defines the start of the first symbol containing downlink data for the WTRU relative to the start of the PPDU carrying the MMP. The receive duration field 216 defines the length of the downlink data. The transmit offset field 218 defines the time when transmissions by this WTRU may start. The transmit duration field 220 defines the limit of transmission duration.
FIG. 3 shows a conventional process for the MMP frame exchange between an AP 102 and plurality of WTRUs 104. The AP 102 sends an MMP frame 302 to the WTRUs 104. The MMP frame 302 includes the uplink and downlink transmission schedule. After a short inter-frame spacing (SIFS), the AP 102 sends downlink data to the WTRUs 104 which are scheduled by the receive offset and receive duration for each recipient WTRU 104 in the MMP frame 302. FIG. 3 shows transmission of downlink frame to five (5) WTRUs 104 which are sent in two MRA frames 304,306 separated by the SIFS. Each WTRU 104 sends an uplink transmission in a scheduled period by the transmit offset and transmit duration. The receive offset and the transmit offset are set with reference to the completion of the transmission of MMP frame 302.
FIG. 4 shows a conventional PSAD frame 400. The PSAD frame 400 includes a frame control/duration field 402, a receiver address field 404, a transmitter address field 406, a basic service set identity (BSSID) field 408, a PSAD parameter field 410, a receiver information field 412 and a CRC field 414. The PSAD parameter field 410 is used to describe power save aggregation (PSA) access phase (PAP) which immediately follows the PSAD frame 400. The duration field 402 indicates the total time duration of all of the downlink and uplink transmission opportunities (TXOPs) which are described in the receiver information fields 412. The PSAD parameter field 410 includes a descriptor end field 416, which indicates the duration of the PAP which is described by the PSAD frame 400.
According to the IEEE 802.11n joint proposal specification and the enhanced wireless consortium (EWC) specification, a power save multi-poll (PSMP) feature has been introduced. A PSMP frame is a MAC management action frame with destination address set to broadcast that provides a time schedule for downlink transmission (DLT) and uplink transmission (ULT) to be used by the PSMP transmitter and PSMP receivers. The scheduled time begins immediately subsequent to the transmission of the PSMP frame. The DLT is a period of time described by the PSMP frame and which is intended to be used for the reception of frames by PSMP receivers. The ULT is a period of time described by the PSMP frame and which is intended to be used for the transmission of frames by a PSMP receiver.
FIGS. 5A-5C show a format of the PSMP frame 500, a PSMP parameter set field 502 of the PSMP frame 500 and STA Info field 504 of the PSMP frame 500. The PSMP parameter set field 502 includes N_STA field 506 and a PSMP sequence duration field 508. The N_STA field 506 indicates the number of STA Info fields present. The PSMP sequence duration field 508 indicates the duration of the current PSMP exchange which is described by the PSMP frame relative to the end of the PSMP frame. Each STA info field 504 includes a DLT start offset field 510, a DLT duration field 512, a ULT start offset field 514 and a ULT duration field 516 to schedule the DLT and the ULT.
The MMP, PSAD and PSMP schemes achieve their power savings basically by converting most of the time that WTRUs 104 unnecessarily spend in the active receive state into time in either the sleep or standby states, through pre-identifying which WTRUs or groups of WTRUs are targeted by the upcoming transmissions on the wireless medium.
The drawbacks with the MMP, PSAD and PSMP schemes are that they require some form of pre-scheduling, albeit on a smaller scale and more short-term than IEEE 802.11e APSD scheduling. MMP, PSAD and PSMP frames also have significant overhead, and hence are not very efficient in using the wireless medium. The MMP, PSAD and PSMP schemes provide power savings only when there are frames being transmitted, (i.e., when the wireless medium is being utilized), and do not provide power savings when the wireless medium is idle.

Method and system for reducing power consumption of a wireless transmit/receive unit


An enclosure for an optical communications device having a lid portion and a base portion. Alignment members adapted to interface with an optical connector are formed on the lid portion. The lid portion is affixed to the base portion with a portion of the communications components therebetween. Multiple base portions formed in a unitary piece of material and multiple lid portions formed in another unitary piece of material can be affixed to one another, and then separated into individual devices to minimize time spent aligning each base and lid portion.

1. Technical Field of the Invention
The present invention relates to optical communication devices, and more particularly enclosures for optical communications devices that provide alignment between the optical communications device and an optical cable.
2. Description of Related Art
An optical interconnect module is an optical-electrical device that enables an interface between optical communications systems and electrical communications systems. One or multiple optical fibers, bundled in an optic cable, are connected to the interconnect module to communicate with optical-electrical components of the interconnect module. The optical-electrical components interface data transmitted on the optical fibers to electrical communication systems or interface electrical communications systems to optical communications systems.
An optical cable may need to be repeatedly connected and disconnected from the optical interconnect module. Because the optical fibers are generally very small, the alignment tolerance required to ensure that the fibers align with their respective optical and optical-electrical components is a few microns or less. The alignment tolerance must be reliably and repeatable achieved each time the optical fiber is reconnected to the optical interconnect module.
Referring to FIG. 1, an optical interconnect module 10 typically has a lid portion 12 and a base portion 14 which form the enclosure. The lid 12 joins with the base 14 to enclose and protect optical and optical-electrical components 22 (eg. an electro-optical transducer) from the exterior surrounding environment. Focusing elements 24 reside on the lid 12 to focus light from each optical fiber onto optical-electrical components 22 or light from the optical-electrical components 22 into an optical fiber. A ferrule 17 on the end of the optical cable 16 secures the optical cable to the lid 12 and aligns the optical fibers with their respective focusing elements 24. Thus, the ferrule 17 must be precisely positioned on the lid 12 so that the optical fibers align with their respective focusing elements 24, and the lid 12 must be precisely aligned with the base 14 so that focusing elements 24 are aligned with their respective optical-electrical components 22.
In one prior art interconnect module 10, guide pins 26 are received in pin retaining receptacles 28 of the base 14. The pin retaining receptacles 28 are positioned in precise relation to the optical-electrical components 22. The lid 12 has corresponding alignment apertures 30 through which pins 26 pass as the lid 12 is placed on base 14. The corresponding alignment apertures 30 are positioned in precise relation to focusing elements 24, so that focusing elements 24 are aligned with the optical-electrical components 22 when the lid 12 is placed on the base 14. The ferrule 17 has alignment receptacles 19 which closely receive the pins 26 to secure and align the optical cable 16 onto the lid 12.
To achieve the high connection tolerances required in the interconnect module 10, the components must each be fabricated with very high precision. Thus, the pins 26 are precision machined to fit closely within the alignment receptacles 19 of the ferrule 17. The retaining receptacles 28 are fabricated in the base 14 in precise relation to the optical-electrical components 22 and precisely spaced to match the spacing of the alignment receptacles 19 of the ferrule 17. The retaining receptacles 28 must also be precision registered with the pins 26. Finally, the alignment apertures 30 are fabricated in the lid 12 and in relation to the focusing elements 24, and then precision registered with the pins 26. This multi-step machining process is costly and time consuming, and is repeatedly performed for each lid and base. Extreme care must be taken to avoid a tolerance stack-up leaving the optical interconnect module out of tolerance.
It is desirable to reduce the time and expense involved in manufacturing optical interconnect modules. Thus, there is a need for lower cost optical interconnect module and a method of manufacturing the same with fewer high precision manufacturing steps.

Optical device, enclosure and method of fabricating

Avago Technologies Fiber IP (Singapore) Pte. Ltd.


A communication method and apparatus of an electronic device in a mobile communication system is provided. The method includes performing data communication through a cellular communication network, determining whether a service type of the data communication matches one of predetermined service types, and switching, when the service type of the data communication matches one of the predetermined service types, from the cellular communication network to a Wireless Local Area Network (WLAN) of an Access Point (AP) for which its beacon signal is received with a signal strength greater than or equal to a first threshold value.

1. Field of the Invention
The present invention relates generally to an electronic device and more particularly, to a communication method of and apparatus for an electronic device selectively using a cellular communication network and a Wireless Local Area Network (WLAN).
2. Description of the Related Art
Recently, there is a growing tendency for electronic devices to evolve as multimedia devices capable of supporting diverse supplementary services such as a digital organizer function, a game function, and a schedule management function. With the diversification of multimedia services supported by an electronic device, there is a need for a method of facilitating communication and managing the supplementary services efficiently.
Currently, a WLAN function-equipped electronic device stays in a Wireless Fidelity (Wi-Fi) on/off state according to a user setting whether or not a WLAN (Wi-Fi) Access Point (AP) is available.
If a Wi-Fi module of an electronic device is turned on in an area without an available Wi-Fi AP, electrical current is unnecessary wasted. In addition, if the user manually powers on/off a Wi-Fi module or if the electronic device is configured to always use a cellular communication network for communication regardless of the availability of a Wi-Fi connection, excessive communication costs are likely to result.

Communication method and apparatus for electronic device in mobile communication system


There is described a packaging assembly configured to form and seal a plurality of packs for containing a pourable food product starting from a tube of packaging material; the packaging assembly comprises a pair of tracks and at least a pair of moving elements, which are cyclically movable along the tracks, respectively; each moving element comprises one forming unit configured to cooperate with the tube so as to surround a portion of the tube destined to form a main portion of one respective pack; and one sealing unit configured to cooperate with the tube to sequentially seal the tube at predetermined consecutive cross sections, each pair of consecutive cross sections forming opposite sealing bands of one respective pack; each forming unit is mounted onto the respective moving element in a linearly movable manner towards and away from the sealing unit mounted onto the same moving element.

As it is generally known, many pourable food products, such as fruit juice, UHT (ultra-high temperature-treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.
A typical example is the parallelepiped-shaped package for pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated web of packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. made of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material, e.g. an aluminum foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.
Such packages are normally produced on fully automatic packaging assemblies, on which a continuous tube is formed from a web of packaging material fed to such unit. The web of packaging material is sterilized on the packaging assembly, e.g. by applying a chemical sterilizing agent, such as hydrogen peroxide solution, which, once sterilization is completed, is removed from the surfaces of the packaging material, e.g. evaporated by heating. The web so sterilized is then maintained in a closed, sterile environment, and is folded and sealed longitudinally to form the tube, which is fed to the packaging assembly, along a vertical advancing direction.
In order to complete the forming operations, the tube is filled with the sterilized food product and is sealed and subsequently cut along equally spaced transversal cross sections.
Pillow packs are obtained thereby, which present a longitudinal sealing band and a pair of top and bottom transversal sealing bands.
WO00/64741 discloses a packaging assembly, which comprises two conveyors provided with:
a first track and a second track, which are arranged on respective opposite lateral sides of the tube; and
a plurality of first carts configured to move on the first track, and a plurality of corresponding second carts configured to move on the second track.
In particular, the first track and second track define respective endless paths, comprising:
respective operative branches, substantially parallel and facing each other, and between which the tube of packaging material is fed, so that the first and the second carts cooperate with the tube; and
respective return branches, along which the first carts and the second carts are spaced apart from the tube.
The first carts are movable independently from one another along the first path, and the second carts are movable independently from one another along the second path. For achieving the independent movement of the carts, linear motors are used: each track is equipped with electric coils, which, in a well-known manner, independently control the movement of each cart, the latter being equipped with corresponding permanent magnets.
Each first cart is provided with a forming unit and a sealing unit, and each corresponding second cart is provided with a forming unit and a counter-sealing unit.
Each forming unit comprises a half-shell, and each sealing unit comprises a cutting element or, in the case of the second carts, a counter-knife element.
In particular, the half-shell and the sealing unit of each first cart and the corresponding half-shell and counter-sealing unit of each second cart are cyclically movable between:
an open position, in which they are detached from the tube; and
a closed position, in which they contact the tube to define and control the volume of the packs being formed, and to seal each pack at equally spaced, consecutive transversal cross sections.
In greater detail, when the carts are moving along the return branches, the half-shells and the sealing units are in open positions, and when the carts are moving along the operative branches the half-shells and the sealing units move from open positions to closed positions and vice-versa.
To this end, the half-shells are forced to stay in the open positions by respective springs, and carry respective cam followers configured to cooperate with respective cams to move the half-shells towards the closed positions. This occurs as each cart starts to advance along the respective operative branch.
Similarly, the sealing units are forced to stay in the open positions by respective springs, and carry respective cam followers configured to cooperate with respective cams to move the sealing units towards the closed positions. This occurs as each cart starts to advance along the respective operative branch.
The profiles of the cams are, thus, designed to control the smoothest transition between the open position and the closed position assumed by each half-shell and each sealing/counter-sealing unit during the forming and sealing operations, further preventing undesired stress on the materials.
Each half-shell carried by the respective cart has a C-shaped cross section and comprises, integrally: a main wall, and two parallel lateral flaps projecting towards the direction of the tube of packaging material from respective opposite end edges of the main wall.
In their closed positions, the two half-shells, cooperating with the same portion of the tube, are configured to completely surround such portion so as to control the volume of the tube and the volume of the pack being formed. More specifically, in the closed positions, the main walls of such half-shells are located on opposite sides of the tube and are parallel to each other.
However, the packaging assembly shown in WO00/64741 presents the following drawback. In particular, each cart carries one forming unit and one sealing unit together, and so the control of the volume of the package being formed is not optimized, due to such a rigid configuration of the structure. In other words, the movement of each single cart influences the movements of the forming unit and sealing unit carried by the cart itself.
This problem is solved by EP-A-3053835, which discloses a packaging assembly of the linear-motor type, wherein the forming units (thus, the half-shells) and the sealing/counter-sealing units moving on each track are carried separately by different and independent carts. Therefore, each forming unit can move independently with respect to the adjacent sealing/counter-sealing unit.
However, such configuration provides a large number of carts.

Packaging assembly for forming and sealing a plurality of packs containing a pourable food product


In one aspect, an apparatus includes a memory repair controller coupled to a memory. The memory repair controller may be configured to provide repair information to cause the memory to disable one or more faulty locations in the memory, and the memory repair controller can be disabled after providing the repair information.

In semiconductor devices having on-chip memory, there are often defects that arise in manufacturing. To provide protection, redundant memory locations are formed, and can be used in place of faulty locations. To realize this protection, a device typically includes a memory repair controller that initiates a power-on repair upon bootup. This controller is provided with power to maintain the state of the memory repair operation throughout the complete operation of the chip. Often this leads to an increase in both static and dynamic power consumption since a clock to the controller is available from bootup, and the controller is always powered on. For low power battery-operated memory intensive devices that are often in sleep mode and are active mostly on demand, this situation can lead to reduction in battery life of the chip. Also, by always keeping the clock to the repair controller running, an illegal/re-triggering of a state transition may occur, leading to an undesired re-bootup.

Optimizing power consumption of memory repair of a device


A tuner circuit and a method of designing a tuner circuit for removing a buffer circuit for video drive for increasing drive current capacitance added to an output terminal is provided, unlike a buffer for small-current drive installed in a tuner circuit. The method of designing a tuner circuit has a buffer installed in an integrated circuit (IC) of small-current drive in a video output terminal, and includes an RF converting portion, a tuning portion and a demodulation portion, in which a video output signal of the buffer in IC is input to an input circuit for processing a signal without an external buffer for drive, and the amount of attenuation of a signal at high frequency due to small drive current is measured to improve a frequency characteristic of a video signal in the tuner circuit in proportion to the amount of attenuation. Thus, an additional buffer for drive is not required, so that the number of devices is reduced, to thereby lower the material costs.

This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C xc2xa7 119 from an application entitled Method Of Designing Tuner Circuit earlier filed in the Korean Industrial Property Office on the day of Sep. 5th, 1998, and there duly assigned Ser. No. 98-36625 by that Office.
1. Field of the Invention
The present invention generally relates to image signal processing and image signal circuits, and, more particularly, to tuning signal processing and tuning circuits with small output drive currents exhibiting increased drive current capacitance at an output terminal.
2. Description of the Related Art
Typically, a tuning circuit in a video tape recorder (i.e., a VCR) includes an radio frequency converter, a tuner and a demodulator. A broadcasting signal received by an antenna is output to a radio frequency amplifier and an output mode switch through a distributor. The RF converter includes the distributor, an output switch, and a modulator. The tuner includes the RF amplifier, a mixer, and a local oscillator while the demodulator includes a surface acoustic wave (i.e., a SAW) filter, a demodulator, an output buffer, and frequently, an external buffer that is often necessary to provide a current necessary to drive some external appliances that is larger than can be obtained with the output buffer included in the integrated circuit.
In the operation of a typical tuning circuit constructed as an integrated circuit, a broadcast signal is amplified at its radio frequency, mixed with a local oscillation frequency signal of a channel predetermined by the local oscillator in order to convert the broadcast signal into an intermediate frequency. The intermediate frequency is then demodulated. The demodulated video signal is applied through the internal output buffer that provides a small drive current of between approximately 0.5xcx9c1 milli-Amperes. A selection switch selects a video signal to apply to a video signal processor from between the video signal from the tuner circuit or a video input signal applied to an input video jack. When the tuner circuit is constructed as an integrated circuit, an externally connected circuit can be driven with a driving current of approximately 0.5xcx9c1 milli-Amperes; this range of amplitudes is common in integrated circuits. I have noticed that if a circuit connected to the integrated tuner circuit should happen to require a driving current of 10 milli-Amperes or more however, an external buffer must be incorporated into the tuner circuit between the output buffer in order to obtain a sufficiently large driving current from the integrated circuit. I have found that absent the external buffer, the ability of the integrated tuning circuit deteriorates to the point that attenuation occurs in the high frequency signal components of the video signal, thereby markedly reduces the gain of the higher frequency characteristics of the video signal.
It is therefore, an object of the present invention to provide an improved tuning process and video image signal tuning circuit.
It is another object to provide tuning signal processing and tuning circuits able to increase drive current capacitance at an output terminal.
It is still another object to provide a process and tuning circuit able to increase drive current capacitance at an output terminal without resort to an external buffer circuit.
It is yet another object to provide a process and tuning circuit able to increase drive current capacitance at an output terminal without resort to an external buffer circuit.
It is still yet another object to provide a process and integrated tuning circuit able to reduce attenuation of the gain of the higher frequency components of a video signal.
It is a further object to provide a tuning signal process and tuning circuit having a small output drive current, that exhibits increased drive current capacitance at an output terminal.
It is a still further object to provide a process and integrated tuning circuit using a buffer that produces a small driving current while minimizing the attenuation of the higher frequency characteristics of video signals.
These and other objects may be attained with a tuning circuit and process that uses a buffer installed within an integrated circuit (IC) providing small-current drive at a video output terminal. The tuning circuit has an RF converter, a tuner and a demodulator. A video output signal from the buffer in the integrated circuit is input to an input circuit for processing a signal without an external buffer, and the amount of attenuation of the gain of the higher frequency components of the video signal due to the low amplitude of the small drive current improves the frequency characteristic of a video signal in the tuner circuit in proportion to the amount of attenuation.


A database system with methodology for automated determination and selection of optimal indexes is described. In one embodiment, for example, in a database system, a method of the present invention is described for recommending database indexes to be created for optimizing system performance, the method comprises steps of: capturing a workload representative of database queries employed during system use; creating virtual indexes for optimizing system performance during execution of the database queries captured in the workload; computing cost benefits for different combinations of the virtual indexes; and recommending physical indexes to be created based on virtual indexes that have favorable cost benefits for the captured workload.

1. Field of the Invention
The present invention relates generally to data processing environments and, more particularly, to the automated determination of optimal indexes to use for a given workload environment.
2. Description of the Background Art
Computers are very powerful tools for storing and providing access to vast amounts of information. Computer databases are a common mechanism for storing information on computer systems while providing easy access to users. A typical database is an organized collection of related information stored as "records" having "fields" of information. As an example, a database of employees may have a record for each employee where each record contains fields designating specifics about the employee, such as name, home address, salary, and the like.
Between the actual physical database itself (i.e., the data actually stored on a storage device) and the users of the system, a database management system or DBMS is typically provided as a software cushion or layer. In essence, the DBMS shields the database user from knowing or even caring about the underlying hardware-level details. Typically, all requests from users for access to the data are processed by the DBMS. For example, information may be added or removed from data files, information retrieved from or updated in such files, and so forth, all without user knowledge of the underlying system implementation. In this manner, the DBMS provides users with a conceptual view of the database that is removed from the hardware level. The general construction and operation of database management systems is well known in the art. See e.g., Date, C., "An Introduction to Database Systems, Seventh Edition", Addison Wesley, 2000.
For enhancing the storage, retrieval, and processing of data records, database systems typically maintain one or more indexes on database tables. A variety of indexes may exist or be created in a database system. For example, an index may be created on a table to support a primary key. Additionally, secondary indexes may be employed for various reasons, such as to improve performance of the database on a particular type of query. For instance, an index created on columns or groups of columns in a table may enable the page containing rows that match a certain condition imposed on the index columns to be located without requiring the database engine to scan all pages in a table to find matching rows.
One of the primary purposes of database systems is to provide information in response to requests submitted by users in the form of database queries. Database systems are typically used to answer both known queries and ad hoc queries. A known query is a query that is frequently run on the system (e.g., on a daily, weekly, or monthly basis). An ad hoc query is a one-time or infrequently run query which usually seeks information not provided by available known queries or reports. During query execution, whether for a known query or a totally ad hoc query, a database system's optimizer must decide at some point which index or indexes (if any) are available for expediting processing of the query.
The benefit of having indexes available is that the optimizer may use them to improve performance for certain types of queries. Over the years, various techniques have been developed to improve an optimizer's ability to select one or more indexes for query processing. There are two main ways that an optimizer may use an existing index to improve processing of a query. The optimizer may use an index to satisfy some ordering or grouping property of the query, or it may use the index to satisfy some predicate(s) that are on the query. With a modern database system, one can safely assume that if an index exists, then the system's optimizer is at least smart enough to check whether it can use that index to its advantage.
Indexes however are not without disadvantages. For example, indexes take up disk space (which can be rather substantial for large databases). Also, indexes incur a maintenance penalty, due to the fact that the indexes must correctly reflect any changes to the underlying table data that they are indexing. Therefore, for a table having a lot of new rows inserted or rows deleted, the database system must incur cycles to maintain the corresponding indexes as rows are inserted and/or deleted.
The ability to "fine tune" a database system has existed for many years. Database systems have provided statistics that allow database administrators to tune or adjust system configuration, in order to achieve better performance. More recently, database vendors have added some degree of automation to the process. For example, Microsoft provides a utility that can recommend indexes. However, that utility runs external to the database engine and typically must perform a substantial number of passes/iterations before reaching a useful recommendation.
IBM has an approach that uses the notion of a virtual index. As the core task, a tool must decide whether to create an index with a given signature. In IBM's system, a virtual index is created inside the database engine, which appears to the system's optimizer as an index available for use. However, the structure is virtual, not real, meaning that it only contains enough in-memory information for the optimizer; it is not a physical structure that must be stored on disk.
The IBM approach has disadvantages, however. The way the IBM system generates virtual indexes relies on a limited series of fixed permutations of the elements of a given query. This can cause very good indexes to be missed and may potentially require a huge number of candidate indexes to be considered. As a result, the performance of the IBM approach is suboptimal.
The IBM approach has an additional problem. In the task of selecting indexes, there is a notion of "separability." This means that some indexes may be useful only if other indexes exist. Therefore, a system cannot achieve optimal results by simply recommending a list of indexes and then indicating that top performing ones should be picked. Here, the removal of some of the indexes (i.e., removal from consideration) may cause some of the better performing ones to also be unavailable for use. This can happen because the optimizer may require certain combinations of indexes to be present in order to use them.
IBM attempted to solve this problem with their implementation as follows. The IBM system creates a set of indexes in the database engine, and then the system attempts to pare down the list of indexes to meet the size constraint specified. Once a recommendation satisfying the given constraints has been made, the system tries to improve upon it by replacing small numbers of indexes in the proposed solution, accepting the modified solution if it appears better. As combinations are tried, the IBM system re-evaluates the benefit (e.g., cost benefit) provided by each index. It will continue considering perturbations of the solution until the user instructs it to stop. However, that approach does not adequately capture the notion of separability, since the cost model employed in selecting the base solution is not updated to take into account indexes that have been removed from the set until this final stage of trying permutations.
What is needed is an approach that recommends a set of indexes providing the best performance value, both in terms of storage (disk space) costs and maintenance costs (as data is updated). Further, the approach desired is one that supplies recommendations faster than currently-available solutions and gives better recommendations. The present invention fulfills these and other needs.

Database system with methodology for automated determination and selection of optimal indexes


Methods and apparatus for maintaining a quality of a Raman medium in a Raman conversion cell. In various examples, a flow velocity of the Raman medium is tailored based on a spatial nonuniformity of heat deposition resulting from the Raman conversion in the cell. In particular, in one example, the flow velocity of the Raman medium may be tailored to be higher where the heat deposition/temperature rise is larger and smaller elsewhere in the cell. This type of flow velocity profile reduces the overall required volumetric flow of the Raman medium in the cell without significantly affecting a quality of the Raman medium.

Stimulated Raman scattering, or Raman conversion, is a process that amplifies radiation at a "Stokes" wavelength λS at the expense of radiation at a shorter "laser" wavelength λL in the presence of a Raman medium. In particular, in Raman conversion, a single photon of wavelength λS is created for each photon of wavelength λL that is annihilated in the Raman medium. The energy difference between these two photons appears as excitation of the Raman medium, whose molecules or atoms are excited by this process from a lower to a higher energy state. As the excitation is thermalized, the excitation energy is transformed into heat.
In Raman conversion, the conversion rate from λL to λS in the Raman medium is proportional to the product of the laser and Stokes radiation beam intensities (each measured, for example, in W/cm2). Therefore, the heating rate at any given point in the Raman medium is also proportional to the product of these two intensities, being small where the intensity product of the beams is small and, conversely, large where the intensity product of the beams is large. Since the heating typically is not uniform, it may cause deleterious effects such as thermal lensing of the radiation beams.


An inflatable baby pacifier and a method of operating same, the inflatable baby pacifier comprising a two-sided skin contacting plate that supports a gas pump, a valve, and an adjustable pneumatic nipple; the gas pump being supported on one side of the two-sided skin plate; the adjustable pneumatic nipple forming a hollow interior, the adjustable pneumatic nipple being supported on an other side of the two-sided skin plate; the valve connects the gas pump to the hollow interior; wherein the gas pump is capable of sending a gas through the valve into the hollow interior.

Infant or baby oral pacifiers can be seen as a form of an artificial nipple upon which an infant may suckle. The suckling action upon the nipple (generally fluids generally do not pass through the pacifiers) is thought to provide a soothing or calming means to the baby. Further during the teething process, a burning and itching sensation can be felt the infant's gums. The infant's chewing action upon the nipple may provide a temporary alleviation of such sensations.
The pacifier could be seen as having three (3) recognizable parts: the nipple that is placed in the infant's mouth; a skin contacting plate or shield that generally limits the depth of insertion of the nipple within the infant's mouth; and a ring or other protrusion substantially allowing the pacifier to be gripped (e.g., by the infant.) The nipple in many such instances is an elongated member descending from the middle of the plate. The nipple could be hollow and made from a suitable pliable or resilient polymer. The nipple could have a hollow interior that could be sealed off to give the nipple an overall balloon-like construction, which allows the nipple to be suitably deformed by the baby's suckling action but will go back to its original shape when removed from the baby's mouth.
One possible issue for such pacifiers is that their nipples can be seen as not taking into account the change or growth that a baby undergoes during the early stages of its life. As a newborn, the baby, lacking teeth, may utilize the pacifier as soothing instrument so that the nipple can fulfill this function by being merely soft and supple. As the baby leaves the newborn stage and begins its teething stages, where the baby's teeth begin to emerge from the gum line. The nipple, in order to continue its soothing mission, needs to be more resilient to provide a to harder surface for the baby to chew upon during the teething process. Generally, the present pacifier with its non-changing nipple capacity may not being able to meet the change of the baby's suckling needs as the baby goes from newborn to teething infant.
What could be needed is a pacifier having an adjustable nipple that can be altered to meet the changes in the suckling/teething needs of the baby as it ages. One such possible solution to this issue could be the present invention of an inflatable baby pacifier with an adjustable pneumatic nipple. A gas pump connected to the adjustable pneumatic nipple can be used to insert an amount of gas (e.g., air) past a valve and into a hollow interior of an adjustable pneumatic nipple. This and other valves connected to the adjustable pneumatic nipple can further suitably alter the amount of gas within the adjustable pneumatic nipple to change the nipple's operational characteristics (e.g., suppleness/flaccidity for soothing suckling action to more resilience or hardness for chewing/teething action.)
In at least one invention embodiment, gas is pumped from the environment outside the invention into the adjustable pneumatic nipple and as needed or when needed gas could be then released from the hollow back out to the outside environment. In another embodiments, the gas may be fully self-contained within the pacifier itself and is moved through valve(s) between a containment area (e.g., gas pump) and the nipple's hollow interior.
Various embodiments of the invention could only have one valve is used to control passage of gas both into and out of the hollow interior. Other various embodiments of the invention, a first valve or set of first valves could control the movement of gas into the hollow interior wherein a second valve or set of second valves could control of the movement of gas out of the hollow interior. In still yet further embodiments of the invention an additional set of third valve(s) are used as relief valve(s) to prevent pressure in the hollow interior from exceeding a preset level.


A hot-forming line and a method for operating the hot-forming line is disclosed having a temperature-control station and a hot-forming and press-hardening tool. A linear conveyor system for conveying the metal blank or the formed steel-sheet products, respectively, through the hot-forming line is provided.

Manufacturing steel-sheet products by means of hot-forming and press-hardening is known from the prior art. To this end, a metal blank form a hardenable steel alloy is heated at least in regions to a temperature above the austenitizing temperature. Subsequent to heating, the metal blank in this warm state is placed into a hot-forming tool and hot-formed. Upon termination of the hot-forming process, the formed component in the hot-forming tool is rapidly cooled in such a manner that hardening of the material microstructure is initiated. This is referred to as a press-hardening procedure.
Consequently, a heating station, also referred to as a temperature-control station, and a hot-forming and press-hardening tool are required for carrying out such a production procedure. Manipulators, in most instances in the form of industrial robots, are employed between the individual stations or tools, respectively, in order for the blank or the components, respectively, to be transferred from one station to the next.
Such a hot-forming line is known, for example, from DE 10 2009 014 670 B4.

Hot-forming line for manufacturing hot-formed and press-hardened steel-sheet products, and method for operating said hot-forming line


An image (e.g., a sprite) having at least three textures is compressed by generating a map which represents boundaries separating regions in the image, and generating pointers that associate each of the regions with one of the textures. The resulting data structure may be used in decompressing the image.

This invention relates to image compressing.
Multimedia programs and games often display animation on a computer screen by the use of transparent bitmaps or "sprites". Each sprite may include regions each exhibiting its own color. Like animation cells in cartoon animation, a series of sprites is overlaid on a background to create the illusion of motion. Most computer animation titles start with an artist drawing black and white line drawings on paper, scanning them into a computer, and then colorizing the image.
MultiMedia animation sequences can be made up of many different sprites, some moving more than others, with as many as one-hundred or more bitmaps being displayed per second. A typical Windows MultiMedia bitmap takes one byte per pixel, so that a 640×480 pixel screen takes 300,000 bytes. A sprite that measures 100×100 pixels takes 10,000 bytes ( 1/30th of the screen size).
Sprites are stored, along with the computer animation program, on a hard disk drive or CD-ROM. Because sprites occupy a large amount of disk space, a customer's hard disk drive could be filled by a single multimedia title. In a CD-ROM drive, which is slower than a hard disk drive, it is difficult to pull the large sprites from the CD-ROM drive quickly enough to create a convincing illusion of motion.
Sometimes the sprites are compressed for storage and decompressed for display on the screen. Compression ratios of 2:1 have been achieved for complex multi-color images. Higher compression ratios are possible using sprites having only simple solid color patterns, or slower decompression algorithms, or lossy compression.
Some titles such as "Freddie Fish and the Missing Kelp Seeds" use simple coloring schemes. Titles built from Macromedia's Director tool, such as "Barbie and Her Magical House", slow down the animation rate and use transitions rather than animation. Broderbund's Living Books titles use small sprites and animate only one object at a time.
Some game systems, such as Nintendo or Sega, store a few generic sprites, and re-use them as much as possible. For example, to make Mario run, "Mario Brothers" needs just three or four sprites showing Mario in different stages of running. A whole title can be built out of about a hundred sprites.
Most DOS-based titles use 320×200 resolution. For example, "DOOM" uses the 320×200 mode and small sprites (maybe 20×20 pixels) that are scaled up in size. "7th Guest" crops off the top and bottom of the screen for a "letterbox" style format that is about 600×200.

Hewlett-Packard Development Company, L.P.


A technique includes providing a plurality of local oscillator signals such that each of the local oscillator signals has a different phase. The technique includes providing scaling units to scale the input signal pursuant to different scaling factors to generate scaled input signals. The scaling factors are selected on a periodic function of the phases. The technique also includes providing mixing circuits to mix the local oscillator signals with the scaled input signals to generate mixed signals and providing an adder to combine the mixed signals to generate an output signal.

The invention generally relates to a harmonic rejection mixer.
A conventional wireless receiver system may include at least one mixer, for purposes of downconverting the frequency of the incoming wireless signal. More specifically, the mixer typically multiplies the incoming wireless signal with a local oscillator signal to produce a signal, which has spectral energy that is distributed at sums and differences of the local oscillator and incoming signals' frequencies. If the local oscillator signal is a pure sinusoid that has its spectral energy concentrated at a fundamental frequency, then ideally, it is relatively easy to filter out unwanted spectral energy so that the spectral energy of the filtered signal is generally located at the desired intermediate frequency. However, for certain mixing applications, the local oscillator signal may be a non-sinusoidal, such as a square wave signal, which contains spectral energy that is located at a fundamental frequency and additional spectral energy that is located at harmonic frequencies. Mixing the incoming signal with such a local oscillator signal typically results in undesired spectral energy being located close enough to the desired spectral energy to make the undesired spectral energy relatively difficult to remove by filtering.
Thus, there exists a continuing need for a mixer that rejects harmonic frequencies that may be introduced by a local oscillator signal that is not a pure sinusoid.