The present invention provides methods and materials for treating and preventing autoimmune diseases. In particular, the present invention relates to the discovery that small peptides are capable of interacting with CD40, thereby interfering with the ability of CD40 to interact with CD 154, which is important in inflammation. The present invention also relate to the use of such peptides in reducing the inflammatory response, and in particular, the autoimmune inflammatory response. The present invention also relates to the use of such short peptides to prevent or reverse autoimmune disease, and particular, diabetes, in individuals suffering from such disease. It also relates to methods and materials for detecting T-cells that express CD40 (Th40 cells). Also provided are kits for reducing inflammation, treating autoimmune diseases, or detecting Th40 cells.

Inflammation normally occurs in response to infection by invading micro-organisms. This inflammatory response is beneficial because it is an important part in localizing the infecting agent for removal by the immune system. However, in autoimmunity there is no infection, yet severe inflammation is present. The inflammation in this case, referred to as aseptic chronic inflammation, is detrimental since it destroys normal tissues. The results of this aseptic inflammation are life-altering and in some cases life-threatening. Moreover, as with acute inflammation, this process is mediated by immune cells, including T-cells.
A major concern for modern medicine is how to control aseptic, chronic inflammation (ACI) such as that which occurs during autoimmune diseases, as well as how to control acute inflammation resulting from trauma. Inflammation, both chronic and acute, leads to tissue degeneration and eventual loss of function of major organs. ACI is not limited to a single disease, but is instrumental in numerous autoimmune diseases including, but not limited to type 1 diabetes, multiple sclerosis, systemic lupus erythematosa, rheumatoid arthritis, Crohn's disease, inflammatory bowel disease, chronic obstructive pulmonary disease including types of autoimmune asthma, atherosclerosis, vasculitis, hypertension, thyroiditis including Hashimoto's and Graves diseases, primary biliary cirrhosis, Paget's disease, Addison's disease, acute respiratory distress syndrome, acute lung injury, and ACI associated with organ transplantation.
Autoimmune disorders are classified into two types: organ-specific (directed mainly at one organ) and non-organ-specific (widely spread throughout the body). Examples of organ-specific autoimmune disorders are insulin-dependent Type 1 diabetes which affects the pancreas; Hashimoto's thyroiditis and Graves' disease, which affect the thyroid gland; pernicious anemia, which affects the blood; Addison's disease, which affects the adrenal glands; chronic active hepatitis, which affects the live; myasthenia gravis which affects the muscle; and multiple sclerosis, which affects tissue of the nervous system. An example of a non-organ-specific autoimmune disorders is rheumatoid arthritis. Autoimmune diseases are often chronic, debilitating, and life-threatening. The National Institutes of Health (NIH) estimates that up to 23.5 million Americans suffer from autoimmune disease and that the prevalence is rising. It has been estimated that autoimmune diseases are among the ten leading causes of death among women in all age groups up to 65 years.
Acute inflammation, as observed during trauma or sepsis, is also immune cell mediated. While all of the molecular mediators in this process have not yet been identified, a prominent role for T cells, macrophages/monocytes, neutrophils etc., is strongly implicated. Therefore a means to modulate these cell types would necessarily control the inflammatory response.
A unique T cell subset has been shown to be instrumental in the development of autoimmune disease. These cells are phenotypically characterized as CD4loCD40+ (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34:1488; Vaitaitis, G. M., M. Poulin, R. J. Sanderson, K. J. Haskins, and D. H. Wagner Jr. 2003. Cutting Edge, J. Immunol. 170:3455; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins 2002. Proc Natl Acad Sci USA 99:3782; Wagner, D. H., Jr., E. Newell, R. Sanderson, J. H. Freed, and M. K. Newell. 1999. International Journal of Molecular Medicine 4:231), and are referred to as Th40 cells. CD40 expression typically is associated with antigen presenting cells and the majority of prior art describes CD40 as being expressed on B cells, macrophages, monocytes etc. However CD40 proteins are also expressed on T cells (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34/1488; Vaitaitis, G. M., M. Poulin, R. J. Sanderson, K. J. Haskins, and D. H. Wagner Jr. 2003. Cutting Edge, J. Immunol. 170-3455; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins 2002. Proc Natl Acad Sci USA 99:3782; Wagner, D. H., Jr., E. Newell, R. Sanderson, J. H. Freed, and M. K. Newell. 1999. International Journal of Molecular Medicine 4:231; Bourgeois, C., B. Rocha, and C. Tanchot. 2002. Science 297:2060; Fanslow, W. C., K. N. Clifford, M. Seaman, M. R. Alderson, M. K. Spriggs, R. J. Armitage, and F. Ramsdell. 1994. Journal of Immunology 152:4262; Ramsdell, F., M. S. Seaman, K. N. Clifford, and W. C. Fanslow. 1994. Journal of Immunology 152:2190; Grabstein, K. H., C. R. Maliszewski, K. Shanebeck, T. A. Sato, M. K. Spriggs, W. C. Fanslow, and R. J. Armitage. 1993. Journal of Immunology 150:3141; Armitage, R. J., C. R. Maliszewski, M. R. Alderson, K. H. Grabstein, M. K. Spriggs, and W. C. Fanslow. 1993. Seminars in Immunology 5:401; Cooper, C. J., G. L. Turk, M. Sun, A. G. Farr, and P. J. Fink. 2004. J Immunol 173:6532). While Th40 cells comprise a proportion of the peripheral CD4+ compartment in naïve, non-autoimmune mice (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34:1488; Wagner, D. H., Jr., E. Newell, R. Sanderson, J. H. Freed, and M. K. Newell. 1999. International Journal of Molecular Medicine 4:231), and in humans (Waid. D. M, R. J. Wagner, A. Putnam, G. M. Vaitaitis, N. D. Pennock, D. C. Calverley, P. Gottlieb, and D. H. Wagner, Jr. 2007. Clin Immunol 124:138), this proportion is drastically expanded to as much as 50% of the CD4+ compartment in autoimmune prone mice (Waid, D. M., G. M. Vaitaitis, and J. Wagner. 2004. European Journal of Immunology 34:1488; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins 2002. Proc Natl Acad Sci USA 99:3782; Wagner, D. H., Jr., E. Newell, R. Sanderson, J. H. Freed, and M. K. Newell. 1999. International Journal of Molecular Medicine 4:231) and humans (Waid. D. M, R. J. Wagner, A. Putnam, G. M. Vaitaitis, N. D. Pennock, D. C. Calverley, P. Gottlieb, and D. H. Wagner, Jr. 2007. Clin Immunol 124:138). These T cells do not express early activation markers and occur in the naïve phenotype of non-challenged mice. In diabetic NOD mice, Th40 cells occur at exaggerated levels in spleen, lymph nodes and the pancreas, even prior to diabetes onset (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34:1488; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins. 2002. Proc Natl Acad Sci USA 99:3782). An elevated number and percentage of these T cells is seen in peripheral blood of type 1 diabetic patients when compared to non-autoimmune controls and type 2 diabetic patients (Waid. D. M, R. J. Wagner, A. Putnam, G. M. Vaitaitis, N. D. Pennock, D. C. Calverley, P. Gottlieb, and D. H. Wagner, Jr. 2007. Clin Immunol 124:138).
The observed increase in Th40 cells could mean that those T cells are antigen responsive or that CD40 expression is activation induced. Furthermore, several diabetogenic T cell clones are CD40+
(Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins. 2002. Proc Natl Acad Sci USA 99:3782). Purified primary Th40 cells from diabetic NOD mice and from pre-diabetic NOD (12-weeks of age) mice successfully transfer type 1 diabetes to NOD.scid recipients, directly demonstrating pathogenicity of that T cell subset (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34:1488; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins. 2002. Proc Natl Acad Sci USA 99:3782). It has been shown that Th40 cells infiltrate islet beta cells destroying insulin production thus suggesting islet antigen specificity (Waid, D. M., G. M. Vaitaitis, and J. Wagner, D. H. 2004. European Journal of Immunology 34:1488; Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins 2002. Proc Natl Acad Sci USA 99:3782). It has also been shown that Th40 cells are required for diabetes transfer. Peripheral (spleen and regional lymph node) T cells that were CD40 depleted, then CD25, Treg, depleted were not capable of transferring diabetes to Scid recipients. Even though Tregs were removed, if the autoaggressive CD40+ T cells subset is absent, disease transfer does not occur.
While Th40 cells are important in the development of autoimmunity, another important factor is expression of the CD40-Ligand, CD154. CD154 is temporally induced on activated T cells in response to CD3/TCR stimulation (Lederman, S., M. Yellin, A. Krichevsky, J. Belko, J. Lee, and L. Chess. 1992. Journal of Experimental Medicine 175:1091). CD154 expression has also been demonstrated on platelets, monocytes, basophils, eosinophils, dendritic cells, fibroblasts, smooth muscle, and endothelial cells (Russo, S., B. Bussolati, I. Deambrosis, F. Mariano, and G. Camussi, 2003. J Immunol 171:5489; Stumpf, C., C. Lehner, S. Eskafi, D. Raaz, A. Yilmaz, S. Ropers, A. Schmeisser, J. Ludwig, W. G. Daniel, and C. D. Garlichs. 2003. Eur J Heart Fail 5:629; Schonbeck, U., and P. Libby. 2001. Cell Mol Life Sci 58:4). CD154 is a member of the tumor necrosis factor (TNF) super-family and a soluble form of CD154 (sCD154) has been described (Russo, S., B. Bussolati, I. Deambrosis, F. Mariano, and G. Camussi. 2003. J Immunol 171:5489; Stumpf, C., C. Lehner, S. Eskafi, D. Raaz, A. Yilmaz, S. Ropers, A. Schmeisser, J. Ludwig, W. G. Daniel, and C. D. Garlichs. 2003. Eur J Heart Fail 5:629; Toubi, E. and Y. Shoenfeld. 2004 Autoimmunity 37:457). Therefore, sCD154 may act like a cytokine (Stumpf, C., C. Lehner, S. Eskafi, D. Raaz, A. Yilmaz, S. Ropers, A. Schmeisser, J. Ludwig, W. G. Daniel, and C. D. Garlichs. 2003. Eur J Heart Fail 5:629). Even though CD154 has not been genetically linked in T1D studies, sCD154 is significantly elevated in T1D and may play a role in the disease process (Varo, N., D. Vicent, P. Libby, R. Nuzzo, A. L. Calle-Pascual, M. R. Bernal, A. Fernandez-Cruz, A. Veves, P. Jarolim, J. J. Varo, A. Goldfine, E. Horton, and U. Schonbeck. 2003. Circulation 107:2664; Cipollone, F., F. Chiarelli, G. Davi, C. Ferri, G. Desideri, M. Fazia, A. lezzi, F. Santilli, B. Pini, C. Cuccurullo, S. Tumini, A. Del Ponte, A. Santucci, F. Cuccurullo, and A. Mezzetti. 2005. Diabetologia 48:1216; Devaraj, S., N. Graser, S. Griffen, J. Wang-Polagruto, E. Miguelino, and I. halal. 2006. Diabetes 55:774). The importance of CD40-CD154 interaction in autoimmunity has been established (Wagner, D. H., Jr., G. Vaitaitis, R. Sanderson, M. Poulin, C. Dobbs, and K. Haskins. 2002. Proc Natl Acad Sci USA 99:3782; Kobata, T., M. Azuma, H. Yagita, and K. Okumura. 2000. Rev. Immunogenet 2:74; Homann, D., A. Jahreis, T. Wolfe, A. Hughes, B. Coon, M. J. van Stipdonk, K. R. Prilliman, S. P. Schoenberger, and M. G. von Herrath. 2002. Immunity 16:403; Goodnow, C. C. 2001. Lancet 357:2115; Balasa, B., T. Krahl, G. Patstone, J. Lee, R. Tisch, H. O. McDevitt, and N. Sarvetnick. 1997. Journal of Immunology 159:4620). Blocking CD40-CD154 interaction prevents collagen induced arthritis (Durie, F. H., R. A. Fava, T. M. Foy, A. Aruffo, J. A. Ledbetter, and R. J. Noelle. 1993. Science 281:1328) experimental autoimmune encephalitis (Howard, L. M., and S. D. Miller. 2004. Autoimmunity 37:411), prostatitis (Grossman, M. E., E. Davila, and E. Celis. 2001. J Immunother 24:237), and importantly type 1 diabetes in the NOD mouse model (Balasa, B., T. Krahl, G. Patstone, J. Lee, R. Tisch, H. O. McDevitt, and N. Sarvetnick. 1997. Journal of Immunology 159:4620). In the diabetes model it was essential to administer a CD154 blocking antibody to NOD mice at 3-weeks of age; at 9-weeks, blocking antibodies had no effect on diabetes prevention (Balasa, B., T. Krahl, G. Patstone, J. Lee, R. Tisch, H. O. McDevitt, and N. Sarvetnick. 1997. Journal of Immunology 159:4620).
Previous work has also demonstrated that the Th40 cell subset induces RAG1 and RAG2 transcription, translation and nuclear translocation (Vaitaitis, G. M., M. Poulin, R. J. Sanderson, K. J. Haskins, and D. H. Wagner Jr. 2003. Cutting Edge, J. Immunol. 170:3455) when CD40 is engaged. CD3 engagement does not induce RAG1 or RAG2 in T cells (Vaitaitis, G. M., M. Poulin, R. J. Sanderson, K. J. Haskins, and D. H. Wagner Jr. 2003. Cutting Edge, J. Immunol. 170:3455). Subsequent to RAG1/RAG2 induction, CD40-mediated TCR revision occurs in peripheral T cells (Vaitaitis, G. M., M. Poulin, R. J. Sanderson, K. J. Haskins, and D. H. Wagner Jr. 2003. Cutting Edge, J. Immunol. 170:3455). CD40 induction of TCR revision is RAG dependent. T cells isolated from a TCR-Tg mouse undergo TCR revision when CD40 engaged, but T cells from the TCR-Tg.RAG−/− mouse do not TCR revise when CD40 engaged (Wagner, D. H., Jr., E. Newell, R. Sanderson, J. H. Freed, and M. K. Newell. 1999. International Journal of Molecular Medicine 4:231).
Multiple treatment options have been put forward to address and control both chronic and acute inflammation. Many approaches use non-steroidal anti-inflammatory drugs (NSAIDS) that attack the production of leukotrienes and prostaglandins, cellular products that cause localized inflammation. Other approaches use more powerful immunosuppressant drugs such as cyclophosphamide, methotrexate and azathioprine that suppress the immune response and stop the progression of the disease. Still other treatments involve the use of monoclonal antibodies designed to alter the immune responses to self-tissues, as occurs during autoimmune diseases. However, all of these treatments often have severe, long-term side effects.
Thus, there exists a need in the art for safer and more effective methods for treatment and prevention of autoimmune diseases. The present invention addresses this need by describing a novel method for treatment of autoimmune diseases.

Pegylated CD154 peptides and methods of inhibiting CD40 interacations with CD154

The Regents of the University of Colorado, a body corporate


A torsional hinge structure for supporting a functional surface such as a mirror is disclosed. The structure includes at least one torsional hinge extending between a functional surface such as for example, a mirror and an anchor pad such that the torsional or the functional surface can pivot around the torsional hinge. The device may comprise two torsional hinges or a single torsional hinge. However, the single torsional hinge or one of the dual torsional hinges will be elongated and include a permanent magnet mounting area to which is bonded a permanent magnet. The structure defines a bobbin area or portion underneath the enlarged area for mounting the drive magnet. A conductor is wound around the drive bobbin for forming an electromagnet, which generates magnetic forces that interact with the permanent magnet mounted on the torsional hinge to cause pivoting motion of the mirror or other functional device.

The use of rotating polygon scanning mirrors in laser printers to provide a beam sweep or scan of the image of a modulated light source across a photoresistive medium such as a rotating drum is well known. More recently, there have been efforts to use a much less expensive flat mirror with a single reflective surface such as a mirror oscillating in resonance to provide the scanning beam. These scanning mirrors provide excellent performance at a very advantageous cost. However, because the permanent drive magnet is mounted on the resonant mirror itself, the mass balance of the magnet and other rotating elements have very close and critical tolerances. Robust mounting brackets typically have been used to mount the torsional hinge mirrors to a using device to help assure a stable platform. However, distortion of the bracket itself due to mounting stresses and/or different CTE (coefficient of thermal expansion) between a mirror and the bracket can also produce sufficient stress in the mirror bracket that will cause the resonant frequency of the scanning mirror to change beyond acceptable limits or even destroy the mirror.
Texas Instruments presently manufactures mirror MEMS devices fabricated out of a single piece of material (such as silicon, for example) typically having a thickness of about 100 to 115 microns using semiconductor manufacturing processes. The reflective surface of the mirror may have any suitable perimeter shape such as oval, elongated elliptical, rectangular, square or other. Single axis mirrors include the reflective surface portion and a pair of torsional or full hinges, which extend to a support frame or alternately the hinges may extend from the mirror portion itself to a pair of hinge anchors. Other mirror embodiments use a single torsional hinge to eliminate hinge stress.
U.S. Patent Application No. 2004/0027449 describes various techniques for creating the pivotal resonance of the mirror device about the torsional hinges. Thus, by designing the mirror hinges to resonate at a selected frequency, a scanning engine can be produced that provides a scanning beam sweep with only a small amount of energy required to maintain resonance.
In addition, the mass balance of the mirror further complicates the task of mounting the resonant frequency within acceptable tolerances. Magnetic drive mechanisms for the mirror typically depend on a permanent magnet mounted to the resonating mirror surface interacting with a drive coil located very close to the mirror. The critical mass balance of the mirror requires that the permanent magnet be designed with a size, thickness and mass having very close tolerances.
Therefore, since applications that use a pattern of light beam scans, such as laser printers and imaging projectors, as well as other uses, require a stable precise drive to maintain a constant scan velocity, the changes in the resonant frequency and scan velocity of a pivotally oscillating device due to temperature variations, careless placement of the magnet on the mirror or out of tolerance size and/or mass, can restrict or even preclude the use of the device in laser printers.
Therefore, it would be advantageous to provide an inexpensive and easily manufactured mirror package that does not require extremely close tolerance as to mounting position.

Low cost torsional hinge mirror package with non-rotating magnetic drive


A system, method, and article of manufacture for supporting summary tables in a distributed database environment is disclosed. The system generally comprises a central program and a plurality of remote database systems that may be heterogeneous. The central program is configured to communicate with the database systems and to support summary tables (also referred to as materialized views) within the central program or within one or more of the database systems. The summary tables may contain summary data from one or more of the database systems. The central program may initiate the generation of summary tables, which may be populated local to the central program or local to one or more of the database systems. The central program may also maintain or coordinate maintenance of the summary tables. In addition, the central program may be configured to receive user queries on one or more of the database systems and to generate optimized query plans based upon the user queries, considering in so doing, the summary tables.

1. The Field of the Invention
The present invention relates to database systems and more specifically, to manners of utilizing summary tables in a distributed database environment.
2. The Relevant Technology
A summary table, otherwise known as a materialized view, is a pre-computed and stored result of a query. A standard view is a derived relation defined in terms of base relations. A view defines a function mapped from a set of base tables to a derived table. This function is typically recomputed every time the view is referenced. A view becomes a materialized view when the tuples generated by the view are stored in a database. Index structures can be built on the materialized view. Consequently, database accesses to the materialized view can be much faster than recomputing the view. A materialized view or summary table is thus like a cache, essentially embodying a copy of selected data that can be accessed quickly.
The data stored in a database is generally accessed using a query formatted in the SQL language native to most existing database systems. It is a primary objective in designing database systems to be able to service queries with the least cost, that is, in the lowest amount of time. One manner of decreasing query response time is with the use of summary tables. It is often the case that certain data can be accessed more quickly by accessing one or more summary tables in which copies of the data have been stored. Summary tables are generally quite small relative to the entire database, and scanning a summary table is much more efficient than scanning multiple relations of a database. Thus, one technique for speeding up query servicing is to maintain a plurality of summary tables and to selectively direct queries to the appropriate summary table for which the query can be most rapidly serviced. It would be advantageous to employ summary tables directed to the various heterogeneous database systems in query optimization.
As a further complication to the employment of summary tables in multiple database systems (MDBS), some database systems do not support summary tables. In order to provide more efficient query servicing, it is desirable to utilize summary tables in such an environment.
Additionally, it is considered by the inventors to be advantageous in some instances to be able to support the summary tables locally within the respective databases of an MDBS, rather than within a centralized database management program. The benefits of so doing include better performance for a class of queries that involve computation on large amounts of data but that yields relatively smaller result sets; the possibility for using the remote source""s replication utilities for maintaining the currency of the summary table; and the enablement of the remote database""s applications to take advantage of the summary table.
It would be further advantageous if a single central program could be employed to support and manage summary tables on a plurality of heterogeneous database systems, including where necessary, on databases that do not natively support summary tables.
Accordingly, a need exists for a distributed database system that capitalizes on the use of summary tables. To best utilize such a system, the capability should be provided to centrally generate, maintain, and query the summary tables. The system preferably makes provisions for communicating with database systems that do not support summary tables. Such a distributed database system and its method of use are disclosed herein.
The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available database management systems. Thus, it is an overall objective of the present invention to provide a distributed database apparatus, system, and article of manufacture that capitalizes on summary tables within a plurality of heterogeneous database tables.
To achieve the foregoing object, and in accordance with the invention as embodied and broadly described herein in the preferred embodiment, a distributed database system and method are provided. The distributed database system is preferably implemented with modules for execution by a processor. In one embodiment, the modules comprise a central program comprising a communication module configured to communicate with a plurality of databases and an identification module configured to identify as a summary table a relation containing therein summary data from the plurality of databases.
At least one of the databases may be remote to the central program, and the databases may be heterogeneous. Each database may comprise a database system having database storage and a database manager. In one embodiment, at least one of the database systems does not directly support summary tables.
In one embodiment, the identification module comprises a single catalog resident in the central program. A nickname corresponding to the relation containing therein summary data from one or more of the plurality of heterogeneous database systems may be stored in the catalog. A description of the relation containing therein summary data as a summary table may also be stored in the catalog in conjunction with the nickname.
The central program may also comprise a summary table creation module within the central program, the summary table creation module configured to initiate the generation of a relation containing therein summary data from one or more of the plurality of databases.
The summary table may be created within the central program or, alternatively, remotely within the database system. In embodiments where the database system does not support summary tables, the database system is unaware that a relation containing therein summary data is a summary table.
The central program preferably comprises a query processing module configured to receive a user query and process the query for submission to one or more of the database systems. In one embodiment, the query processing module, generates an optimized query plan, considering in so doing, a cost model and the contents of one or more summary tables within one or more of the database systems.
An attendant method of use of the distributed database system in one embodiment comprises communicating with a plurality of databases from a central location and identifying as a summary table a relation containing therein summary data from the plurality of heterogeneous database systems. The step of communicating with a plurality of databases from a central location may comprise communicating with at least one database remote to the central program.
In one embodiment, the step of identifying as a summary table a relation containing therein summary data from the plurality of databases further comprises placing information indicative of the relation containing therein summary data within a single catalog resident in the central program.
The step of placing information indicative of the relation containing therein summary data within a single catalog resident in the central program may comprise placing a nickname corresponding to the relation containing therein summary data from one or more of the plurality of databases in the catalog. Additionally, placing information indicative of the relation containing therein summary data within a single catalog resident in the central program may comprise placing a description of the relation containing therein summary data as a summary table in the catalog and linking the description with the nickname.
The step of communicating with a plurality of databases from a central location may comprise communicating with a plurality of database management systems, one of the database management systems local to each of the heterogeneous database systems, at least one of the database management systems not directly supporting summary tables.
The method may further comprise communicating with a plurality of database systems, in which at least one of the database management systems does not directly support summary tables. This may comprise creating a relation containing therein summary data within the database management system without informing the database management system that the relation containing therein summary data is a summary table.
The method may further comprise initiating the generation of a relation containing therein summary data from one or more of the plurality of heterogeneous database systems. The relation may be generated within the central program or within the one or more of the plurality of heterogeneous database systems.
The method may further comprise receiving a user query and in response, considering the usage of one or more summary tables within one or more of the heterogeneous database systems in generating an optimized query plan based upon the user query.
In yet another aspect of the invention, an article of manufacture comprises a program storage medium readable by a processor and embodying one or more instructions executable by the processor to perform the above-described method of use of a distributed database system.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

Support for summary tables in a heterogeneous database environment

International Business Machines Corporation


A pressurized oven is provided having a fully sealed cavity, reduces heat lost, shortens cooking time and saves energy of oven operation. The pressurized oven includes a cavity component, a door assembly, heating elements and a control system that includes a relief valve on top of the cavity. The relief valve includes a valve weight and a venting stub, wherein the valve weight sits on the top of the venting stub. The valve weight disposed on top of the venting stub remains closed and the gas is not released when the pressure is not sufficient to lift the valve weight. When the pressure inside the oven is sufficient to lift the valve weight, the valve weight block is lifted to open the valve, the gas is released and the pressure is decreased. Once the pressure becomes less than the valve weight, the valve closes and gas is no longer released.

1. Field of Invention
Aspects of the present invention relate to methods and systems for food preparation. More particularly, aspects of the current invention related to methods and systems for pressurized cooking.
2. Background
Food preparation generally involves raising the internal temperature of the food to a specified level. There are a variety of conventional methods for food preparation, such as on top of a flame (e.g., grilling, pan frying, boiling) and in an oven (e.g., baking, broiling). In all methods, the same concept of raising the temperature of the product is the ultimate goal. The manner in which that goal is accomplished affects the taste and the time involved in the cooking process. In a conventional oven, the heat migrates (by conduction) from the outside of the food toward the middle. There may also be dry, hot air on the outside of the food evaporating moisture on the surface of the food product. As a result, the surface of the food product dries out, becoming crispy and brown, while the inside of the food product remains moist.
In recent years, microwave ovens have become commonplace in the household. A microwave oven uses microwaves to heat food. In the case of microwave ovens, the commonly used radio wave (micro wave) frequency is roughly 2,500 megahertz (2.5 gigahertz). Radio waves in this frequency range can be absorbed by water, fats and sugars, and when are absorbed, the radio waves are converted directly into atomic motion, and thus into heat. Microwaves in this frequency range are also not absorbed by most plastics, glasses or ceramics. In microwave cooking, the radio waves penetrate the food product and excite water and fat molecules throughout the food product more evenly than in a conventional over. No heat conduction toward the interior occurs. However, there are drawbacks to microwave cooking, in that the radio waves penetrate unevenly in thick pieces of food and, as such, do not always reach the middle of the food product, and "hot spots" can be caused by wave interference inside the food product.
A method of cooking on a stove top involves the use of a pressure cooker, which is a pot for food preparation that is designed to maintain a pressure above atmospheric pressure. Water in an open pot boils at 100° C. at a standard atmosphere. As the water evaporates and becomes steam, the water remains at the same temperature. The only way to make the steam hotter (and/or to boil the water at a higher temperature) is to increase the pressure, which can be accomplished by a pressure cooker. The heat from the stovetop transfers through the metal pot to the contents (which generally include water and the items being cooked.) Since the pressure cooker is sealed, as the water inside the container expands to steam, the closed environment of the container causes the pressure inside the container to rise. The higher pressure, in turn, results in a higher temperature inside the vessel. For example, at higher pressures, the temperature at which water boils is higher than 100° C. The increased pressure inside the pot delays the water and/or other liquids inside the pot from boiling until the liquid reaches a much higher temperature. As a result, the cooking process is sped up considerably.
However, currently, cooking using an oven is performed at atmospheric pressure and generally takes a long time. As such, there is a need in the art for an improved oven for food preparation products that involves pressurized cooking in an oven.


The present invention relates to (i) a reactive ink for ink jet printing comprising a two-component system, the first component comprising a polymerizable monomer, and the second component comprising a polymerization catalyst, wherein the monomer is able to form a polymeric film at low temperature within thirty minutes, preferably within ten minutes, from contacting the catalyst, (ii) a process of making an image on a non-porous substrate using such a reactive ink, and an ink jet print head including a two component ink-system.

Ink jet devices known in the art are divided in continuous stream devices and drop-on-demand devices.
In continuous stream devices, the ink is sprayed with a continuous stream of droplets through at least one nozzle. The droplets are electrostatically charged as they leave the nozzle and are deflected in flight by the application of high voltage pulses to a set of deflector plates. The trajectory of each drop, and then its contact position with the substrate to be printed, is accurately controlled.
In drop-on-demand devices, the ink is sprayed from a nozzle directly to a specific position of the substrate following the input of a digital system which positions the nozzle and provides the ejection of the droplets.
The present invention relates to an ink for drop-on-demand devices.
Drop-on-demand devices are mainly of three kinds. A first kind of device consists in a piezoelectric system which comprises a head fed with an ink which is ejected from a nozzle by a piezoelectric transducer which produces a pressure pulse. A second kind consists in an acoustic system employing the ability of a sound pulse of provoking the release of droplets from a liquid surface. A third kind consists in a thermal system which comprises a head equipped with a thermal resistance and fed with an ink. The thermal resistance causes the evaporation of the ink solvent (usually water) and the formation of a bubble, which in turn causes the ink ejection through the head nozzle.
In the field of printing on non-porous surfaces, like those of plastic, glass, metal, and composite materials, it is possible to use the above mentioned ink jet printing technologies.
The drop-on-demand ink jet printing technology shows some fundamental advantages in industrial printing, like a reduced ink consumption, a high image definition, and a low cost.
The fixing of the ink ejected by ink-jet technology on non-porous surfaces can be done with different methodologies. For example, the ink may be able to chemically attack the surface of the substrate so as to convey the colorant by means of a solvent within the substrate. Alternatively, the ink may comprise reactive components able to polymerise by thermal or photochemical treatments and to form a film which fixes and keeps the colorant on the surface of the substrate.
Both these techniques have drawbacks.
The first technique works only if the substrate to be printed is attacked by the ink solvent. Accordingly, the inks so formulated can be used only with plastic supports which are easily attacked by the ink solvents. In the case of printing on glass, metal or other surfaces with high chemical resistance it is necessary to resort to other techniques.
The second technique requires that the printed ink may be heated at high temperatures or exposed to UV-radiations to promote the polymerisation.
However, thermal polymerizable inks cannot be used with thermal ink-jet systems, as the temperature reached in the ejecting chamber would promote the polymerization of the ink components. Thermal polymerizable inks could be used with piezoelectric ink-jet systems, but still there are stability problems under storage which could result in the clogging of the printing head and require the storage at temperature below 0° C. Further, the use of high temperature for the polymerisation of the inks limits the type of substrates to be printed to those with high thermal stability.
The use of UV-polymerizable inks makes difficult the polymerisation of three-dimensional objects or surfaces which are not perfectly planar. Moreover, the total cost and the overall dimensions of a printer with a device for polymerisation is considerably higher. Besides that, reactive inks—where both reactive monomers or oligomers and polymerisation catalyst are mixed together in the same composition—are more likely to be unstable over time and to be more prone to clog the nozzles negatively affecting the printhead reliability.
Patents and patent applications disclosing reactive ink compositions having the above mentioned disadvantages are for example U.S. Pat. No. 5,380,769, U.S. Pat. No. 7,632,546, U.S. Pat. No. 7,563,489, US 2008/00384, and US 2008/0295731.
U.S. Pat. No. 7,632,546 discloses a radiation curable phase change ink preferably used in piezoelectric ink jet devices, comprising an ink vehicle that includes at least one gellant comprised of a curable polyamide-epoxy acrylate component and a polyamide component, and at least one colorant. U.S. Pat. No. 7,563,489 discloses radiation curable phase change ink preferably used in piezoelectric ink jet devices. The ink comprises an ink vehicle that includes at least one curable epoxy-polyamide gellant, and at least one colorant.
US 2008/00384 discloses a radiation curable phase change ink comprising an ink vehicle that includes at least one curable carrier, at least one gellant, at least one curable wax and at least one photoinitiator.
U.S. Pat. No. 5,380,769 discloses a reactive ink compositions comprising at least two reactive components, a base ink component and a curing component, that are applied to a receiving substrate separately. The base ink component includes an ink carrier, a compatible colorant, and a cross-linkable constituent, and the curing component is a cross-linking agent. Upon exposure of the base ink component to the curing component, at least a portion of the ink is cross-linked to provide a printed image that is durable and abrasion-resistant.
US 2008/0295731 discloses a reactive ink set including three mixtures of radically polymerizable monomers. A first mixture includes a peroxide, a second mixture includes a peroxide decomposition agent, and an optional third mixture that does not include a peroxide or a peroxide decomposition agent. The first mixture and the second mixture polymerize to form a solid ink on the substrate following jetting in the liquid state.

Bicomponent reactive ink for ink jet printing


A detector module is disclosed for an X-ray detector. In an embodiment, the detector module includes a number of sensor boards arranged adjacent to each other on a module support, each sensor board including, in a stack formation, a sensor layer having a sensor surface and a support ceramic by which the sensor layer is thermally coupled to the module support. A number of elements are arranged on the side of the support ceramic that faces the module support in a stack formation and at least one heating element is included which, in a plane of projection perpendicular to the stack formation, at least partially covers at least the area of the support ceramic that is free from the elements. An X-ray detector including a number of detector modules is also disclosed.

An X-ray detector, in particular a quanta-counting X-ray detector, is used in imaging applications. An X-ray detector of this kind is used by way of example therefore for computed tomography recordings in medical imaging to generate a spatial image of an examination region of a patient.
An X-ray detector, whose sensor layer is designed as a direct-converting semi-conductor layer, enables a quantitative and energy-selective detection of individual X-ray quanta. Pairs of electron holes, i.e. pairs of negative and positive charge carriers, are generated in the sensor layer on the penetration of X-ray radiation. The charge carriers are separated and move to the electrodes or surfaces of the sensor layer with the opposite charge respectively due to a voltage applied to the sensor layer or surface of the sensor layer. The current caused as a result, or a corresponding charge transfer, can be evaluated by an electronic sensor device connected downstream. Semi-conductor materials by way of example in the form of CdTe, CdZnTe, CdTeSe, CdZnTeSe, CdMnTe, GaAs, Si or Ge, which have a high absorption cross-section for X-ray radiation, are suitable for detection of the X-ray quanta.
Large-area X-ray detectors are required in particular for a computed tomograph, for which reason a plurality of comparatively small detector modules with the above-described construction is frequently arranged side by side. These detector modules typically have a sensor surface between 1 cm2 and 4 cm2. To achieve optimally high image quality the detector modules are also arranged with the smallest possible spacing from each other. The voltage applied to the sensor layer or to the sensor surface is fed to the detector modules of an X-ray detector by way of individual power supply channels of the HV supply and is adjusted to a predefined operating voltage.
In the case of direct-converting X-ray detectors, or detector modules with a corresponding construction, the electrical resistance of the sensor material changes with the X-ray flux. This leads to a change in the power loss. A change in the X-ray flux therefore causes a change in temperature in the sensor layer, whereby the energy resolution and the count rate of the X-ray detector are in turn affected. A temperature-dependent count rate drift is a miscount that cannot be corrected and leads to image errors and artifacts in the tomographic scans created from absorption data.
In addition to a change in the temperature of the sensor layer caused over time, the drift behavior of an X-ray detector is also affected by locally different temperatures of the sensor layer. Temperature gradients of this kind result in particular due to uneven heat dissipation in the sensor layer.
An undesirable temperature gradient can also result on the sensor board or in the sensor layer of the corresponding sensor board depending on the operating point of the sensor board. An elevated current through the sensor material which, even without penetrating X-ray radiation, can lead to a high power loss and therefore also to a temperature gradient in the sensor layer, can occur as a function of the respectively chosen setting of the operating parameters, such as the mean operating temperature of the detector module or of the sensor material or the applied supply voltage.
To avoid temperature gradients in the sensor layer, preferably all-over thermal coupling to a heat sink is desirable. In current detector modules cooling is implemented by way of example by cooling ribs in a module support to which the sensor layer can be coupled in a stack formation by way of a support ceramic. The sensor layer can therefore be uniformly heated with all-over coupling of the support ceramic to the module support.
However, all-over coupling is made difficult by components arranged on the bottom of the support ceramic, for example components such as passive elements or connectors for data transfer, and/or by other mechanical indentations used for connection to an electronic sensor device. Since these components impede uniform heat dissipation in the sensor layer the regions of the sensor layer, which are applied to the regions of the support ceramic provided with the components, have a slightly higher temperature during operation than the area that is free from the elements at which the support ceramic is coupled to the module support in a planar manner.
One possibility for avoiding this problem can be achieved by way of example by a change in the geometry of the support ceramic. A support ceramic can therefore be used by way of example which is only partially covered by the sensor layer. On account of its larger area the support ceramic then provides "free" regions to which the above-mentioned components can be attached.
An embodiment of this kind is not possible, however, by way of example in a detector module with a tiled modular construction, without restrictions. In the case of a tiled detector module a plurality of tiles, what are known as sensor boards, are arranged adjacent to each other on a shared module support at a spacing of about 100 μm, with the sensor layers of the sensor boards jointly forming the sensor surface of the detector module. A limitation of the spatial resolution must be accepted with a change in the geometry as described above. The number of sensor boards arranged side by side on a module support would also be reduced owing to the larger area.


A composition and a method for generating clinically safe NK cells derived from non-fully differentiated stem cells are provided. The non-fully differentiated stem cells are co-cultured with endogenous NK cells isolated from adipocyte-containing tissue to generate a high percentage of clinically safe NK cells, where anti-tumor activity of the clinically safe NK cells in vitro is similar to that of endogenous NK cells. Optimized Production of the clinically safe autologous NK cells from stem cells provides platform for treating cancer patients by applying an effective adoptive immunotherapy ranging from the early to terminal stages.

The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
The American Cancer Society reports that more than 1.7 million new cancer cases will be diagnosed for 2019, and about 0.6 million Americans will have died of cancer in 2019. The funding for cancer research in America was more than 4 billion dollars in 2017 through the National Cancer Institute, and researchers are making endless efforts to develop effective cancer treatments.
Immunotherapy is a very exciting approach to developing anti-tumor treatments. As a part of its normal function, the immune system detects and destroys abnormal cancer cells, and immunotherapy helps the immune system to better act against cancer. One of these therapies is T-cell transfer therapy, which is a treatment that increases the natural ability of the patient's T cell to fight cancer. In this treatment, T cells are collected from a patient and engineered, such that engineered T cells are capable of detecting and binding to a specific antigen on the surface of cancer cells through the expression of an antigen-binding receptor on the surface of T cells. The engineered T cells are given back to the patient usually via a needle in the patient's vein(s). This therapy is called CAR (chimeric antigen receptor)-T cell therapy. CART cells can detect and bind cancer cells effectively and efficiently. As a result, CART cells can destroy cancer cells significantly more than the original T cells, and the anti-tumor activity of CART cells has been proven by many clinical trials.
Researchers have also experimented with generation of CARNK cells. There are some advantages of using NK cells rather than using T cells. First, unlike CART cells, CARNK cells retain an intrinsic capacity to detect and target cancer cells through their native receptors, so that it is less likely that cancer cells can escape from CAR cells by downregulating the CAR target antigen expression. Second, it is less likely that patients will suffer from cytokine release syndrome because CARNK cells do not undergo clonal expansion within days to weeks. Thus, the level of cytokines released from CARNK is maintained within the normal range. On the other hand, CART cells undergo clonal expansion, such that cytokine released from CART cells can reach a high level, and this high level of cytokines may cause increased inflammation throughout a patient body. This can result in organ failure or even death. Consequently, researchers have started to utilize NK cells to develop an effective anti-cancer treatment.
Because primary NK cells are difficult to isolate and purify, researchers have developed a protocol to generate NK cells using stem cells. These include induced pluripotent stem cells (iPSCs). An advantage of using iPSCs is that there is no immune rejection response from the patient. The iPSCs derived NK cells can be released back to an individual without concern for immune rejection because the iPSCs are obtained from the same individual. Additionally, there are already established protocols to differentiate iPSCs to NK cells, for example, shown in U.S. Pat. No. 9,260,696.
All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
However, there is at least one significant disadvantage using iPSCs. It is well known that undifferentiated iPSCs have intrinsically tumorigenic properties. On the other hand, differentiated cells derived from iPSCs lose tumorigenicity ("The tumourigenicity of iPSCs and their differentiated derivates", J. Cell. Mol. Med. Vol 17, No 6, P 782-791, 2013). When iPSC derived NK cells contaminated with undifferentiated iPSCs are introduced to a patient, the undifferentiated iPSC may differentiate into cancer cells in a body of the patient. Therefore, iPSC derived NK cells must be completely separated from undifferentiated iPSCs. Because the NK cells must be completely separated from undifferentiated iPSCs, a large amount of the NK cells are lost during separation of iPSCs from NK cells during the cell sorting process.
One way to reduce wasting large numbers of the generated NK cells is to increase the rate of the differentiation into NK cells. U.S. Pat. No. 9,260,696 teaches that, typically, only about half of stem cells (iPSCs and embryonic stem cells) are differentiated into NK cells in the presence of inactivated antigen presenting cells.
Qu el al. have used adipose-derived stem cells (ADSCs) that are differentiated into NK cells "conversion of adipose-derived stem cells into Natural Killer-like cells with anti-tumor activities in nude mice, PLos ONE, Vol 4, e106246, 2014". The efficiency of the ADSC differentiation to NK cells is not literally described, but in vitro results indicate that the efficiency is at least 90%.
There are two known ways to generate ADSC-derived NK cells. One is to use sphere clusters and the other way is to express E4BP (NK cell-specific transcription factor) in ADSCs. In vitro anti-tumor activity of NK cells developed from sphere clusters shows about 60% of the activity obtained from endogenous NK cells. On the other hand, in vitro anti-tumor activity of NK cells expressing E4BP is similar to the activity obtained from endogenous NK cells. This, in vitro anti-tumor activity of the NK cells expressed with E4BP is greater than the NK cell derived from sphere clusters. However, E4BP3 is expressed in ADSCs through lentivirus transduction of E4BP3 to ADSCs. There is a significant concern using such lentivirus exposed cells to treat cancer patients.
Thus, there is still a need for efficiently generating clinically safe NK cells from stem cells, having at least similar in vitro anti-tumor activity to the endogenous NK cells.

Enhancement of production of NK cells from stem cells


An outboard motor including a supercharged internal combustion engine. The supercharger is positioned on a side of the crankcase opposite from the cylinders of the engine and is driven by the crankshaft through any of a plurality of different forms of drive arrangements that permit axially adjustment to maintain alignment.

This invention relates to a two-cycle engine for an outboard motor and more particularly to an improved supercharger and drive arrangement for an internal combustion engine.
The use of superchargers to improve the performance of internal combustion engines is well known. Superchargers have particular utility with two-cycle internal combustion engines because they can not only improve the performance of the engine but also improve the scavenging of the engine. Superchargers have particular utility in outboard motors because of the power increase which they can obtain and this has considerable advantage in permitting a compact, high power outboard motor. However, because of the compactness required for outboard motors, the placement and drive arrangement for a supercharger can be particularly critical, particularly with this type of application.
The supercharger should be basically positioned relatively close to the crankshaft of the engine, from which it is driven In some types of applications, this is accomplished by placing the supercharger is a generally aligned relationship with the crankshaft so that it can be driven nearly directly off end the crankshaft and the supercharger extends beyond the front of the engine. However, when mounted in an outboard motor, this gives rise to considerable height of the engine and at the power head and this is not at all desirable.
It is, therefore, a principal object of this invention to provide an improved supercharger and drive arrangement for an internal combustion engine and particularly one which may be utilized in conjunction with an outboard motor.
It is a further object to this invention to provide an improved and compact supercharger, internal combustion engine arrangement.
In outboard motor applications, it is desirable to maintain a low center of gravity of the outboard motor. In addition, the outboard motor is frequently tilted up about a horizontally disposed axis and it is desirable to maintain the center of gravity as far forward as possible so as to assist in this tilting up operation.
It is, therefore, a still further object to this invention to provide an improved supercharger drive arrangement for an outboard motor wherein the supercharger can be positioned at the front of the outboard motor and will not extend vertically above the engine.


Described are processes for shaping age hardenable aluminum alloys, such as 2XXX, 6XXX and 7XXX aluminum alloys in T4 temper, or articles made of such alloys, including aluminum alloy sheets. The processes involve heating the sheet or article before and/or concurrently with a forming step. In some examples, the sheet is heated to a specified temperature in the range of about 100-600° C. at a specified heating rate within the range of about 3-600° C./s, for example about 3-90° C./s. Such a combination of temperature and heating rate results in an advantageous combination of sheet properties.

Aluminum alloys combine low density with structural strength and crash resistance, which makes them attractive for production of structural and body parts in the motor vehicle industry. However, aluminum alloys have lower formability compared to draw-quality steel. In some cases, relatively low formability of the aluminum alloys can lead to difficulties in obtaining good part designs and can create problems with failure due to fracture or wrinkling. Warm forming of aluminum alloy sheets is used in the motor vehicle industry to overcome these challenges since the aluminum alloys exhibit increased formability at elevated temperatures. Generally, warm forming is the process of deforming metal at an elevated temperature. Warm forming can maximize the metal's malleability but creates its own challenges. In some cases, heating may negatively affect mechanical properties of an aluminum alloy sheet. Heated aluminum alloy sheets may exhibit decreased strength during the stamping operations and the decreased strength characteristics may persist after cooling of the alloy sheet. Heating of the aluminum alloy sheets also can lead to increased thinning of the aluminum alloy parts during stamping operations. The aluminum alloy sheet or part may also experience an undesirable change in its metallurgical state.
Heat treatable, age hardenable aluminum alloys, such as 2XXX, 6XXX and 7XXX aluminum alloys, which are often used for the production of panels in motor vehicles, are typically provided to the manufacturer in the form of an aluminum sheet in a ductile T4 temper, in order to enable the manufacturer to produce desired automotive panels by stamping or pressing. To produce functional motor vehicle parts meeting the required strength specifications, parts produced from an aluminum alloy in T4 temper are typically heat treated post-production and subsequently age hardened, resulting in a part or sheet in T6 temper. Elevating the temperature of a heat treatable, age hardenable aluminum alloy during a warm forming step may prematurely convert the aluminum alloy part or sheet into a T6 temper, leading not only to decreased formability which could negatively affect subsequent forming steps, but also detrimentally affecting the manufacturer's ability to harden the parts during post production heat treatment and/or aging.
Accordingly, the manufacturers of aluminum alloy parts are in need of improved warm forming processes to produce the aluminum they use for making parts.

Process for warm forming an age hardenable aluminum alloy in T4 temper


A keyboard includes a substrate, a plurality of key structures, and an air pump. Each key structure includes a keycap disposed on the substrate, an air bag between the keycap and the substrate, and an electrical contact point between the keycap and the substrate. The airbag deformed when the keycap moves towards the substrate, applying a reaction force onto the substrate, and returns to an original state when the keycap is released. The air pump can adjust an air pressure in the airbag by charging or allowing discharge of air, so as to adjust the force applied by the deformed airbag to the substrate, thereby adjusting a tactile feedback to user for pressing the keycap.

Since different keycaps of a keyboard have a same structure, the strengths for pressing down the keycaps are almost the same. However, different fingers of one hand may have different strengths (for example, an index finger has a maximal strength, and a little finger has a minimal strength) when operating the keyboard. Even a single finger may have different strengths when pressing the keyboard from different directions. The little finger for example may not be able to type by fast pressing on the keycaps.
Therefore, there is a room for improvement in the art.

Keyboard containing airbag and method for adjusting tactile feedback to user operating the keyboard

Fu Tai Hua Industry (Shenzhen) Co., Ltd.


A method of navigating an electronic network includes steps of reading a list of at least one resource in an electronic network, displaying at least a portion of the list, receiving a user-initiated selection of a resource from the list, linking to the resource upon receiving the user-initiated selection, removing the resource from the list. An article of manufacture directs a system for navigating an electronic network to perform the above-listed steps.

The introductory chapter of Discover the World Wide Web with Your Sportster, Second Edition, provides a perceptive commentary on the present state of the Internet and the World Wide Web. Here, it is stated that the Internet is in need of an application which will transform the "much-hyped but difficult-to-use linking of computers around the world to being a highly informative, highly usable database and communications tool." It is further stated that the various available Web browsers (e.g. Mosaic and Netscape Navigator) all have difficulties and limitations which make them insufficient to handle the complexity of the Internet.
Part of the problem is in the complexity of addressing a resource on the World Wide Web. The World Wide Web uses an addressing system known as a URL (Uniform Resource Locator) that defines the location of a resource on the Internet. URLs are comprised of up to four parts: a protocol, a domain name, a path, and a filename. The combination of these four parts can produce a complex address for a resource. For example, the address for information on two-way pagers on the Motorola home page is: http://www.mot.com/MIMS/MSPG/Products /Two-way/tango/desc.html.
The popularity of the Internet and the World Wide Web has spawned a number of Web-related periodicals. One such periodical is Yahoo| Internet Life, which provides reviews of Web sites. This periodical includes a tear-out address guide having URLs for the reviewed Web sites. To link to a Web site of interest, an end user types into his/her computer a URL printed on the guide. Scientific American is another example of a periodical having a page of URLs. The aforementioned complexity of addressing on the World Wide Web can result in the end user typing a lengthy URL to navigate to a Web site of interest.
The end user may read all or a portion of the periodical before linking to any Web site of his/her interest. For example, the end user may read the periodical at a location distant from a computer or a like network navigation apparatus with which to link to the Web stite of interest. Further, an end user may find from the periodical a plurality of Web sites of his/her interest. In these cases, the end user, when located at the computer, can link to a first Web site of interest by manually entering a first URL from the guide. Thereafter, the end user can link to a second Web site of interest by manually entering a second URL from thief guide. This step can be repeated for other Web sites of his/her interest from the guide.

Method, system, and article of manufacture for navigating to a resource in an electronic network


A method and apparatus for managing a wireless local area network are disclosed. The network includes one or more wireless access points, each including a radio frequency assembly having a variable power output, and an antenna assembly for transmitting and receiving wireless signals. A microcontroller is included for sending a transmission characteristics signal to the wireless local area network. A network manager is included for receiving the transmission characteristics signal and selectively controlling the variable power output of the radio frequency assembly to a predetermined power level.

The present system is generally directed to the field of wireless communications. The present system has particular applicability in a wireless access point (AP) or wireless bridge (BR) of the type used in a wireless local area network (WLAN) and employing an antenna system for exchanging wireless signals.
As shown in FIG. 1, a managed wireless local area network (WLAN) 10 includes a network backbone 12, preferably an Ethernet network, and at least one wireless access point (AP) 14 (e.g., AP1, AP2 . . . APN, as indicated). Each access point 14 wirelessly communicates over radio frequencies with a plurality of wireless clients 16. The operation and performance of the wireless local area network 10 is typically handled by a network manager or network management entity (NME) 18. A network manager or network management entity 18 is used to calculate and determine a suitable coverage area that an access point can provide as will be shown and described hereinafter.
Management of an access point is also useful in instances where an access point is used in a stand alone configuration or mode and still needs to meet radiated power limitations imposed by regulation. Use of the present invention allows an access point to maximize output power with a particular antenna while complying with the regulations.
Referring also to FIG. 2, a typical layout for wireless local area network 10 is based on a floor plan 20 of an operating area, e.g. an office or other work area. Each access point 14 has a range, so as to establish a respective coverage area 22 associated with each access point 14. The coverage areas 22 can be selected to cover the anticipated wireless throughput requirements in a given area based on the expected locations of wireless clients within the areas 22. The size of the coverage areas 22 are based on the transmitted power, the antenna gain, and the various obstructions, e.g., metal building components that would interfere with the wireless signals. In the typical management of wireless local area network 10, the access points 14 are configured to transmit at the highest power possible, i.e., powered up to high power, and signals are exchanged. The network manager or network management entity 18 observes the strength of the received signals and uses this information to generate a "path loss vector," which is an indication of the amount of attenuation in the signal between access points 14. The network manager or network management entity 18 uses this information to calculate the actual range of each access point 14, in order to determine a practical coverage area 22 for each access point 14 that services wireless clients 16 without interfering with other access points. The path loss PL can be determined by the following expression:PL=PRAD−RSSI where
PRAD equals radiated power (measured in dBm); and
RSSI equals a received signal strength indicator (measured in dBm).
The radiated power PRAD itself equals the transmitter power PTx plus the antenna gain GANT so that the path loss can be expressed as:PL=PTx+GANT−RSSI
However, it can be difficult in practice to isolate these variables and thereby properly establish coverage areas 22. For instance, various access points have different power-output capabilities and different external antennas have different antenna gains. Further, an antenna may be connected to a respective access point using a long coaxial cable. Consequently, there may be a power loss associated with the cable length that complicates the path loss calculation. As a result of these variables, a network manager, e.g., network management entity 18, can only make assumptions about antenna gain from the measured quantities. These factors can also vary across different wireless channels and/or bands, thereby making it difficult to determine suitable coverage areas for a set of access points in a wireless local area network.
In previous systems, the antenna gain is entered manually and the antenna is considered to be an omni-directional antenna. A dipole, for example, is an omni-directional antenna with 2.2 dBi of antenna gain. Other types of omni-directional antenna can provide additional antenna gains, but all share a round radiation pattern when looking at a floor plan or map, such as floor 20 shown in FIG. 2. Either a bad assumption or incorrect knowledge of the antenna gain and/or type will cause invalid results by the network management entity 18 regarding network coverage.
Other types of antennas provide additional gain but with different types of radiation patterns. For example, "Yagi" antennas have higher gain and offer a narrow, long radiation pattern. These are typically used for bridging applications, but are also used here as an example. If an access point were to have a Yagi antenna installed, previous systems would not identify the antenna as such, and would likely assume the Yagi antenna to be a omni-directional antenna having less antenna gain.
Moreover, in previous systems, signal strength is simply measured and reported to the network manager, and only inferences can be made about the antenna gain. This uncertainty in antenna gain contributes to the problems of locating clients within a wireless local area network. In a typical system, the location of a client is based on knowing the relative signal strength of the client at different access points. But if the actual antenna gain is different than that assumed, the values used in the calculations will be different than the actual values, and, thus, the path loss calculation will not be correct, resulting in faulty distance determinations. This results in uncertainty in locating clients, since a client's location can only be estimated within an area of potential locations. Also, since variance in signal strength may be the result of other environmental factors, such as internal reflections from metallic construction elements in the building, this contributes further to the uncertainty.
Additionally, current wireless local area network capabilities create problems from a regulatory standpoint. The Federal Communications Commission (FCC) and other national regulatory agencies worldwide place various restrictions on transmitting radio antennas, such as establishing maximum radiated power limits. For wireless local area network devices, the transmit power is limited to 27 dBm or about 500 milliwatts (mW) without the support of transmit power control (TPC), which is part of the European Union (EU) European Telecommunications Standards Institute (ETSI) Broad Band Radio Access Network (BRAN) regulations. Generally, transmit power control requires that an access point transmit at the lowest power possible. These power limitations are necessary to avoid interference with other sources, particularly military radar, that share the same 5 GHz band with the wireless local area network channels in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11(a) protocol. However, this requirement is easily circumvented since it possible to obtain "off the shelf" external antennas that have higher antenna gains than can permissibly be used with a particular access point. For example, it is possible to operate a 20 dBm antenna with a 17 dBm access point for an illegal output of 37 dBm.
Previous-type solutions are known to the problem of connecting non-compliant antennas to access points. For example, it is known to use a "reverse TNC connector." This type of connector was originally developed for wireless local area network use as a unique connector that was not readily available, thus preventing non-compliant antennas from being used with wireless local area network products. However, after-market adapters are now available that allow non-compliant antennas to be used.

Wireless network management with antenna control


A structure adapted to be loaded onto a vehicle provided with a hydraulic lifting arm type handling mechanism including two longitudinal bottom rails adapted to cooperate with guide rollers at the rear of the vehicle, and means for moving the rails between a deployed position, in which the rails cooperate with the guide rollers, and a retracted position, in which each rail is withdrawn into a housing in the bottom of the structure.

1. Field of the Invention
The invention concerns a structure, such as a container or a mobile shelter, designed to be loaded onto a vehicle provided with a hydraulic lifting arm type handling mechanism.
2. Description of the Prior Art
These structures are built around a framework whose lower part embodies two longitudinal rails which cross below cross-members and cooperate with guide rollers at the rear of the vehicle chassis. These longitudinal rails are usually connected at the front part of the structure, to uprights, between which a bail bar is provided at a certain height. The lifting arm of the handling mechanism (described for example in French patent 2,109,109) is in the form of a telescopic boom articulated to a subframe which is connected to the chassis of the vehicle. To load a structure the boom is activated and the arm is swung towards the rear of the vehicle, a hook, carried by the free end of the boom engages the bail bar and the arm is then swung towards the front of the vehicle, during which maneuver the front of the structure is lifted and drawn towards the vehicle in an inclined position until its two bottom rails come into contact with the rollers mounted at the rear of the longitudinal rails of the vehicle. The structure's bottom rails then roll on the rollers while the structure continues to move forward, returning to the horizontal position, whereupon the boom is extended. At the end of the maneuver the structure rests on the rollers and is supported at the front by the hook connected to the free end of the lifting arm, the horizontal part of which is accommodated between the rails.
The configuration of the bottom of the structure (cross-members below which the longitudinal rails project) sometimes causes problems, especially if the structure must travel on a roller or rollerball type of the kind installed on aircraft. These types of handling decks can only cooperate with a flat and continuous surface, which means that the structure must be put on a pallet whose lower surface has these characteristics.

Structure such as a container or mobile shelter


Society of Motion Picture and Television Engineers (SMPTE) video data is separated into first data and second data. A first signal is formed based on the first data. A second signal is formed based on the second data. The first signal is transported via a first Optical Carrier 3 (OC-3) channel. The second signal is transported via a second OC-3 channel.

The video industry has adopted the Society of Motion Picture and Television Engineers (SMPTE) 259M (level C) standard almost exclusively for high quality video in studio and production applications. In some applications, a SMPTE 259M signal is to be transported to a remote location, which may be several miles away for example. Current methods of transporting SMPTE 259M signals or other professional quality video signals to remote locations use either dark fiber overlay networks or proprietary methods over very high bandwidth pipes. For example, an OC-12 channel may be used to transport an SMPTE 259M signal.

Method and system to transport high-quality video signals


In summary, therefore, this invention is directed to a thermal growth detector and compensator for detecting and compensating for relative movement between a work holder of a machine tool and a tool holder, that includes an elongated rod made of a material having a coefficient of thermal expansion of substantially zero that is attached at one end thereof to a part of a machine tool, and is attached at another end thereof to a part of a work holder on the machine tool. There is an element disposed at one end of the elongated rod for detecting movement of the rod, and an automatic compensation means is operatively connected to the movement detection element for automatically moving a tool holder relative to the work holder as a function of the movement of the rod detected by the movement detection element to compensate for movement of the work holder relative to the machine tool, whereby any movement of the work holder relative to the tool holder is detected and compensated for by moving the tool holder to compensate for movement of the work holder relative to another part of the machine tool.

Those in the high precision machine tool industry are continually searching for better ways of detecting and compensating for errors in the production of parts in the ranges of thousandths and millionths of an inch. Machines are known which automatically compensate for the wear of the cutting tools themselves, for minor deflections of the cutting tools under pressure that introduce errors, and for so-called "thermal growth" of one part of a machine tool relative to another part of the machine tool.
The detection of thermal growth and the compensation therefor has heretofore been somewhat of an art, given that thermal growth is a less predictable error than other types of machining errors, such as tool wear. Past efforts at compensating for thermal growth include the warming up of a machine tool prior to use, so that the majority of the thermal growth occurs prior to using a machine tool for producing parts, and the continuous running of a machine tool in the hope that a constant, stabilized running temperature had been reached. However, it has been found that there is no such thing as a perfect stabilized running temperature, owing to the vagaries of individual machine tools, and to the fluctuations of the environmental temperature of the area in which the machine tool is used. Furthermore, it is time consuming, wearing on machine components, and expensive to idle a machine tool for thirty minutes to an hour prior to use.
An early device for temperature compensation is disclosed in U.S. Pat. No. 2,956,344 to Rantsch, which device required two separate, spaced apart rods exhibiting small thermal expansion, each rod having measuring marks, and a device for detecting the relative displacement of the measuring marks.
In U.S. Pat. No. 2,664,787, a control rod of steel, invar metal, quartz or other material having minimum temperature sensitivity as respects expansion or contraction under normal operating conditions was essentially used as a lever for actuating switches to energize a motor in one of two rotational directions in order to compensate for thermal growth.
U.S. Pat. No. 4,530,626 to Sabbioni discloses a bar made of material of a very low coefficient of thermal expansion that uses a scale or reference element in its detection device so as to measure the distance from a tool to a piece of material to be cut in a gear cutter.
A recent high production machining device is disclosed in U.S. Pat. No. 5,005,452 to Wood, III, in which each of two slides of a machine tool has an associated rod of material such as In-var.TM. (Ryerson Steel of Cincinnati, Ohio) having a coefficient of linear expansion of only 0.000001 per unit length per .degree.C. An etched glass slide is attached to a reference surface of an upper one of the slides, an optical reading head is utilized to provide a linear position signal to the machine's control unit, and the thermally inert rod of In-var.TM. is attached to the other one of the slides. One or both of the slides has a linear scale on the low thermal expansion material attached to the reference surface.

Method and apparatus for detecting and compensating thermal growth in machine tools


An optical disc device includes a recording power acquiring unit that finds an optimum recording power when data is written in a data area by writing data for calibration in a power calibration area, and a data writing unit that writes data in a data area to be written by using an optimum recording power found by the recording power acquiring unit. A method for acquiring an optimum recording power used by the recording power acquiring unit when an area to be written is a not-yet-recorded area is different from a method for an already recorded area. When an area to be written is a not-yet-recorded area, the recording power acquiring unit finds an optimum recording power. When an area to be written is an already recorded area, the recording power acquiring unit writes preliminary data in a power calibration area and finds an optimum recording power.

1. Field of the Invention
The present invention relates to an optical disc device that finds an optimum recording power when data is written in a data area by writing data for calibration to the power calibration area of an optical disc, and in more detail, to an optical disc device in which a method for acquiring an optimum recording power when an area to be written is a not-yet-recorded area is different from a method for acquiring an optimum recording power when an area to be written is an already recorded area.
2. Description of the Related Art
When data is written to a rewritable optical disc such as a DVD-RW, an optimum recording power at the time of recording data is found before writing data. That is, data is written for calibration to a power calibration area (PCA) while changing laser power and an optimum recording power used for recording data is found from the reproducing signal of data written for calibration. However, an optimum recording power is different between a case where an area in which data is to be written is an area in which data has not yet recorded and a case where an area in which data is to be written is an area in which data has been already written. Then, in a case where an area in which data is to be written is an area in which data has been already written, an optimum recording power is also different depending on the intensity of laser power used for writing data. For this reason, there has been proposed the technology to be described below.
That is, in this technology, it is checked whether an area in which data is to be recorded is a not-yet-recorded area or an already recorded area in which data has been already recorded. Then, when an area in which data is to be recorded is a not-yet-recorded area, data is written for calibration to a power calibration area while changing the intensity of a recording laser power stepwise and finds an optimum recording power from the waveform of the reproducing signal of data written for calibration and then records data by using the found optimum recording power, whereas when an area in which data is to be recorded is an already recorded area, just as with the case of the not-yet-recorded area, an optimum recording power is found by using a power calibration area and the already recorded area is reproduced and the demodulation degree Mopt of the already recorded area is found from a reproducing signal at that time and then the found modulation degree Mopt is compared with a modulation degree Mtarget that has been previously set for each device.
As a result of comparison, when it is determined that the modulation degree Mopt of the already recorded area is larger than the modulation degree Mtarget that has been previously set for the device, data is written by using a laser power a little smaller than an optimum recording power found by using a power calibration area. Meanwhile, when it is determined that the modulation degree Mopt of the already recorded area is equal to the modulation degree Mtarget that has been previously set for the device, data is written by using the optimum recording power found by using a power calibration area. Then, when it is determined that the modulation degree Mopt of the already recorded area is smaller than the modulation degree Mtarget that has been previously set for the device, data is written by using a laser power a little larger than the optimum recording power found by using a power calibration area.
In other words, when date is overwritten in an already recorded area, a laser power when data has been written in the already recorded area is detected as a modulation degree. Then, the optimum recording power found by using a power calibration area is corrected on the basis of a detected laser power and data is overwritten in the already recorded area by using the corrected optimum recording power. That is, the laser power when data has been overwritten in the already recorded area is corrected according to the state of the already recorded area. For this reason, it is possible to prevent a laser power from being insufficient at the time of writing data or from being unnecessarily intensive. Hence, there is provided an advantage that the reliability of writing data can be improved without damaging the durability of an optical disc (refer to, for example, JP-A-2003-99933 (paragraph No. 0015)).
However, there have been raised problems shown below at the time of using the above-mentioned conventional technology. That is, even if laser power for writing is finely adjusted according to a comparison result between the modulation degree of an already recorded area and a modulation degree previously set for each device, the finely adjusted laser power becomes only a value considered to be optimum from previously obtained experimental data. That is, the finely adjusted laser power does not become a laser power corresponding to the state at that time of the already recorded area of an optical disc to which data is to be written or the state at that time of an optical pickup (ambient temperature and the like). For this reason, there is a case where laser power used for writing data to an already recorded area and having its intensity finely adjusted is deviated from an optimum value and hence there are sometimes presented the problem of reducing the reliability of written data and the problem of causing the life of the optical disc to be unnecessarily short.
The present invention has been made to solve the above problems. An object of the present invention is to provide an optical disc device that can record data by using a recording laser power to make an actually reproduced signal an optimum signal in both cases of a case where an area to be written is a not-yet-recorded area and a case where an area to be written is an already recorded area, and can make a recording laser power an optimum value for each data area even when an area to be written includes areas in which data has been written by recording laser powers that are different from each other, and can eliminate the need for additionally providing the function of causing the device to be more complex such as storing means for storing much laser power information and managing means for managing laser power information, and can write data continuously without interruption even when an area to be written includes areas in which data has been written by using recording laser powers that are different from each other and recording laser powers are made optimum values for the respective areas.
Moreover, another object of the present invention is to provide an optical disc device that finds an optimum recording power by using a not-yet-used power calibration area in a case where an area to be written, which is an area in which data is to be written, is a not-yet-recorded area, and writes preliminary data to a power calibration area by using a recording laser power used for writing data to an area to be written and then finds an optimum recording power by using a power calibration area in which preliminary data has been written in a case where an area to be written is an already recorded area, thereby being able to record data by using a recording laser power to make an actually reproduced signal an optimum signal in both cases of the case where an area to be written is a not-yet-recorded area and the case where an area to be written is an already recorded area.
Then, in addition to the above-mentioned object, still another object of the present invention is to provide an optical disc device that writes data by using an optimum recording power corresponding to each data area in which data is to be written when an area to be written includes data areas in which data has been written by using recording laser powers that are different from each other, thereby being able to make a recording laser power an optimum value for each data area even when an area to be written includes data areas in which data has been written by using recording laser powers that are different from each other.
Then, in addition to the above-mentioned object, still another object of the present invention is to provide an optical disc device that records laser power information, which is information that makes a recording laser power when data is written in a data area correspond to the data area, in a specified area of an optical disc to eliminate the need for providing storing means for storing laser power information for each optical disc in a device, thereby being able to eliminate the need for additionally providing the functions of making the device more complex such as storing means for storing much laser power information and managing means for managing laser power information.


A wiring substrate is provided. The wiring substrate includes: a core layer in which a gap is formed; and a lamination layer which includes an insulating layer and a wiring layer and which is formed on at least one surface of the core layer. The lamination layer has a thermal expansion coefficient different from that of the core layer. A plurality of mounting regions on which an electronic component is to be mounted are provided on the lamination layer to be spaced from each other. The gap in the core layer is filled with an insulating member having the same material as the insulating layer and surrounds each of the plurality of mounting regions or each of mounting region groups including one or more of the mounting regions.

1. Technical Field
The present disclosure relates to a wiring substrate and a method of manufacturing the same. More particularly, the present disclosure relates to a wiring substrate having a multi-layer structure capable of preventing deformation or reducing a deformation amount, and a method of manufacturing the same.
2. Related Art
Recently, a high integration, an increase in number of pins, and a decrease in size of a semiconductor device have been promoted with an increase in performance and a decrease in size of an electronic device using the semiconductor device such as a semiconductor chip. As a substrate on which the multi-pin and miniaturized semiconductor device is mounted, a multi-layer wiring substrate using a build-up method is used.
In this kind of multi-layer wiring substrate, a core layer is a reinforcement member such as glass fabric copper-clad lamination, and an insulating layer and a wiring layer are alternatively formed on both surfaces of the core layer (see e.g., JP-A-2000-261147). FIG. 11 is a cross sectional view showing a schematic configuration of a multi-layer wiring substrate 110. As shown in the same drawing, the multi-layer wiring substrate 110 has a configuration in which an insulating layer 113 and a wiring layer 114 are layered on both surfaces of a core substrate 111 having a through-hole 112 formed therein. The wiring layer 114 formed on the upper and lower portions of the core substrate 111 are electrically connected to each other via the through-hole 112.
Incidentally, since the rigidity reduces due to a decrease in thickness of the multi-layer wiring substrate used as the mounting substrate, the elastic characteristics of the electronic component and the multi-layer wiring substrate are combined with each other when the electronic component such as the semiconductor device is mounted onto the mounting substrate. As a result, deformation is generated in the wiring substrate on which the electronic component is mounted.
Particularly, when deformation such as warpage is generated in the wiring substrate, the deformation may cause an error of a carrying operation or breakage of the substrate during an automatic substrate carrying operation of an electronic component mounting process in the facility. Since a semiconductor package has been required to be further decreased in size nowadays, an error is generated frequently with a decrease in thickness of the wiring substrate. For this reason, it is difficult to improve electric performance and to reduce package cost due to a decrease in thickness of the substrate.

Wiring substrate and method of manufacturing the same


A suspension frame assembly of a magnetic levitation vehicle, includes multiple suspension frames which are sequentially connected; and each suspension frame includes two longitudinal beam bodies arranged in parallel. A supporting wheel and a holding arm are fixedly provided on both ends of each longitudinal beam body; and two anti-rolling devices mounted between mounting frames of two of the supporting wheels at a same end of the two longitudinal beam bodies; and the two longitudinal beam bodies of one of the suspension frames are respectively hingedly connected to the two longitudinal beam bodies of an adjacent suspension frame; an air-spring arm beam is provided at a hinged part of the two suspension frames, and is mounted on the holding arm of one of the two longitudinal beam bodies which are hingedly connected.

As a new type of vehicle, a low and intermediate speed magnetic levitation vehicle has the advantages of low noise, strong accelerating and braking capability, strong climbing capability, small turning radius, small vibration and good comfort and the like. As one of important members of the magnetic levitation vehicle, a suspension frame assembly affects the running performance of the magnetic levitation vehicle.
The carrying capacity of the low and intermediate speed magnetic levitation vehicle is limited by the performance of the suspension magnet and the factors affecting the suspension condition. Therefore, how to minimize the self-weight and improve the suspension capacity has become a technical problem to be solved by those skilled in the art at present.

Suspension frame assembly of magnetic levitation vehicle


A method is provided that decides whether a region of data storage units in a data storage system should be scanned for defective data. A current region of data storage units affected by a write operation is determined and which select transducing head of the data storage system that corresponds with the current region is also determined. A scalar value that corresponds with the select transducing head is retrieved. The scalar value related to a condition of the select transducing head based on previously conducted performance tests. An incremented write count of the affected region is scaled by the scalar value to obtain a new increment write count. A defective data scan is performed on the affected region if the new increment write count exceeds a default write count threshold.

Adjacent Track Interference (ATI) and Side Track Erasure (STE) are the inadvertent erasing or affecting of data that are adjacent to or near a recording head during a write operation in a data storage system. These two similar, yet different problems are head-dependent. Therefore, before factory heads are implemented into a data storage system, they are tested for ATI and STE performance. Heads that depict high levels of ATI and STE can be discarded.
One way to remedy the affects of heads that demonstrate characteristics of ATI and STE is to perform periodic scans of the media and rewrite data to eliminate defects. However, the frequency of these periodic scans are fixed. In other words, data units scanned that are affected by heads with high levels of ATI and STE will be scanned the same number of times as those data units that are not affected by erasure. In other words, fixed periodic scans might not provide enough protection to data units affected by high levels of ATI and STE or provide too much protection to data units that are not affected by erasure. Such issues affect performance efficiency of the data storage system.
Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.

Data recovery scan based on head performance