A method and apparatus for handling data error in a data transmission system including a relay station which receives a data from a transmission apparatus and transmits the data to a receiving apparatus is provided. A relay station which transmits, to a receiving apparatus, a data received from a transmission apparatus, the relay station including: a data receiver to receive the data from the transmission apparatus; an error detector to detect whether an error of the received data is generated; and a data transmitter to transmit the received data and an error generation indicator for the received data to the receiving apparatus when the error is generated. According to the present invention, it is possible to combine transmitted data with retransmitted data and decode error-free data by transmitting data including a generated error to a receiving apparatus when error is again generated in the retransmitted data.

1. Field of the Invention
Aspects of the present invention relate to a method and apparatus for handling a data error in a data transmission system including a relay station which receives data from a transmission apparatus and transmits the data to a receiving apparatus, and more particularly, to a method and apparatus for generating an error generation indicator for data including a generated error and transmitting the error generation indicator to a receiving apparatus when an error is generated in data received from a transmission apparatus.
2. Description of the Related Art
Since wireless communication technology has been developed, a wireless network, which can conventionally transmit only a voice signal, has become so developed that the wireless network may transmit data.
When the voice signal is transmitted, only some noise is generated in the voice signal even though an error is generated in a portion of the transmitted voice signal. When two calling persons can recognize each other's voices even though the noise is generated in the voice signal, the voice signal can be continuously transmitted.
Conversely, when the data is transmitted, even though an error is generated in only one bit of a data frame of a predetermined length when transmitting the data, all of the data included in the entire data frame cannot be used. As wireless data transmission increases, a technology of handling the error generated when transmitting the data has been increasingly regarded as important.
A technology of handling the error generated when transmitting the data can be generally classified into two schemes, that is, an Automatic Repeat Request (ARQ) and a Forward Error Correction (FEC).
A Hybrid ARQ (HARQ) is a technology of combining the ARQ with the FEC and handling the error. The HARQ detects an error generated in data using the FEC. When the error is generated in the data, the HARQ requests a transmission apparatus to retransmit the data including a generated error, combines the originally-transmitted data including a generated error with the retransmitted data in response to a retransmission request, and decodes error-free data.
The conventional HARQ is useful for directly transmitting the data from the transmission apparatus to a receiving apparatus. However, the HARQ is required to be respectively used between the transmission apparatus and a relay station, and between the relay station and the receiving apparatus in order to apply the HARQ to a system for transmitting the data from the transmission apparatus to the receiving apparatus via the relay station. Accordingly, when a number of relay stations increases, the system becomes complex, and a transmission efficiency decreases.
Accordingly, a method and apparatus for handling data error in a data transmission system including a relay station is needed.

Apparatus and method for handling data error in data transmission system including relay station


This invention relates to novel linear peptides and mixtures and chemical combinations thereof useful for detecting and quantifying HTLV-I and HTLV-II infections. These peptides are also useful in vaccines against HTLV-I and HTLV-II vital infections.

Human T-cell leukemia virus subgroup I (HTLV-I) is a retrovirus closely associated with adult T-cell leukemia/lymphoma (ATL) (Poiesz et al., 1980, Proc. Natl. Acad. Sci. U.S.A., 77, 7415-7419). It is also linked with neurological diseases designated as tropical spastic paraparesis and HTLV-I-associated myelopathy (HAM) (Gessain et al., 1985, Lancet ii, 407-410). Human T-cell leukemia virus subgroup II (HTLV-II) was first isolated from a patient with T-cell hairy cell leukemia (Kalyanaraman et al., 1982, Science, 218, 571-573). It is associated with a T-cell variant of hairy cell leukemia.
The HTLV-I and HTLV-II genomes exist as proviruses in the human chromosomal DNA of leukemia cells. Their complete nucleotide sequences have been elucidated (Seiki et al., 1983, Proc. Natl. Acad. Sci. U.S.A., 80, 3618-3622; Shimotohno et al., 1985, Ibid., 82, 3101-3105). Like other retroviruses, the HTLV-I and HTLV-II genomes are flanked by LTR (long-terminal-repeats) structures which are believed to play an essential role in the integration of the proviral DNA into the host chromosomal DNA. Four major genes have been identified and occupy the following relative positions in the genome: LTR-gag-pol-env-pX-LTR (Seiki et al.; Shaw et al., 1984, Proc. Natl. Acad. Sci., 81, 4544-4548). The gag gene codes for a 48,000-dalton-precursor protein (often referred to as p53) consisting of 429 amino acids (433 for HTLV-II). This precursor protein is cleaved into at least three smaller proteins (FIG. 2). The pol gene codes for the viral reverse transcriptase. The env gene presumably codes for a 54,000-dalton protein which is glycosylated and later cleaved into two glycoproteins named gp46 and gp21. (Slightly different molecular weights have been reported for what are most probably the same env gene protein products). The last coding region is called pX and is believed to code for four proteins (tax.sub.1, tax.sub.2, rex.sub.1, rex.sub.2) involved in gene expression and regulation.
As depicted in FIGS. 1 and 2, the env proteins and the gag proteins of HTLV-I and of HTLV-II share a high degree of amino acid sequence homology. Furthermore, serologic cross-reactivity has been reported between the proteins of HTLV-I and those of HTLV-II (Lee et al., 1984, Proc. Natl. Acad. Sci., 81, 7579-7583). Despite this structural resemblance and cross-reactivity, some regions of these env and gag proteins are recognized only by antibodies present in a patient infected by either the HTLV-I or the HTLV-II virus.
HTLV-I and HTLV-II both differ from the human immunodeficiency viruses (HIVs) in their morphologic and genetic structures. As a result, antibodies to the HIV proteins should not cross-react with HTLV-I and HTLV-II antigens. However, some serum samples taken from patients with AIDS have shown some degree of cross-reactivity with HTLV antigens (Essex et al., 1983, Science, 220, 859-862).
Adult T-cell leukemia/lymphoma (ATL) occurs mainly in Southwestern Japan, the Caribbean basin and parts of Central and South America. In those regions, seroprevalence varies between 5% and 15% in the general population and reaches 30% in older age groups. In the United States, HTLV-I/II infections are mainly present in intravenous drug users (IVDU). In a recent American Red Cross survey (Williams et al., 1988, Science, 240, 643-646), antibodies to HTLV-I could be detected in 10 of 39,898 random blood donors in eight U.S. cities; this represents a seroprevalence rate of 0.025%. A similar study involving 3158 individuals from Northern Egypt led to the identification of two carriers (prevalence rate of 0.06%) (El-Farrash et al., 1988, Microbiol. Immunol., 32, 981-984). In these two studies, distinction between infection with HTLV-I and HTLV-II was not clearly established. These data indicate that there is a need for a reliable test to screen all blood samples destined for blood banks in order to avoid the inadvertent spread of the virus to blood product recipients.
There have been several attempts in the prior art to develop such tests. None has been successful in detecting all serum and plasma samples that are part of a well characterized commercial panel of HTLV infected fluids. Furthermore, none is able to detect HTLV infection at very low levels, thereby, ensuring safety of the blood supply and prompt and early treatment of HTLV infections.
Saxinger et al. (1984, Science, 225, 1473-1476) has reported the use of the HTLV-I particle as the immunoadsorbent in an enzyme immunoassay (EIA) for the detection of antibodies to the virus. In an improvement to this first generation test, specific HTLV antigens have been used instead of viral particles as the immunoadsorbent. For example, Samuel et al. (1984, Science, 225, 1094-1097) refers to antigens obtained by recombinant DNA technology. These detected each of 11 sera shown to contain antibodies to HTLV-I by a whole viral lysate-based EIA similar to the one developed by Saxinger et al. Slamon et al. (PCT/US85/01803) refer to assays using polypeptides and fragments thereof associated with immunogenic sites present on proteins of the pX region of HTLV-I and HTLV-II. The reported accuracy of these assays ranged between 77% and 87%. Fukui et al. (European Patent Application 87116787) refers to assays using polypeptides encoded by a fused gene comprising all or a part of the gag gene and all or a part of the env gene. They reported a sensitivity of 100% (57/57 ) with no false-positives.
Although these results look impressive, they are likely not repeatable with sera, like those most usual in the United States, which are characterized by much lower antibody titers than the Japanese sera used to validate the above assays.
Assays which use peptides derived from HTLV-I or HTLV-II proteins have also been reported. For example, Palker et al. (1989, J. Immunol., 142, 971-978) reports that antibodies in sera from 28 out of 36 patients (78%) reacted with a peptide spanning amino acids 190 to 209 of the HTLV-I envelope (peptide 4a; env 190-209).* Ten of 35 sera samples (29%) reacted with peptide 6 (env 296-312) and 6 out of 33 (18%) bound to peptide 7 (env 374-392). Palker et al. (1986, J. Immunol., 136, 2393-2397) also refers to a peptide (SP-71; gag 120-130) that reacted with 16 out of 18 HTLV-I seropositive samples. FNT *In this application, the amino acid sequence and numbering published by Seiki et al. (supra.) and by Shimotohno et al. (supra.) for the HTLV-I and HTLV-II gene products are used (for ease of reference only).
A peptide (SP-70; env 296-306) has been reported by Copeland et al. (1986, J. Immunol., 137, 2945-2951) to recognize antibodies from 4 out of 12 individuals seropositive for HTLV-I.
Wang et al. (U.S. Pat. No. 4,833,071) refers to three overlapping linear peptides spanning regions of the transmembrane protein (gp21) of HTLV-I. These peptides (env 381-400, env 377-400 and env 378-393), when used in a mixture, detected 102 out of 102 serum samples from patients with ATL and 5 out of 30 patients with AIDS/ARC. No immunoreactivity was found against sera from 12 normal subjects or from 12 patients with autoimmune diseases.
Reyes (PCT/W089/06543) refers to a non-glycosylated, 41-amino acid recombinant peptide antigen derived from the gp46 of HTLV-I. This recombinant peptide, env(163-203), is reported to have been used in a solid-phase assay for the determination of serum antibodies in six patients with HTLV-I infection.
Vahlne (PCT/W089/08664) refers to four synthetic peptides, A, B, C and H, spanning env(381-404), env(273-293), env(223-242) and env(176-199) of the envelope protein of HTLV-I. From the examples provided, it appears that only peptide A was useful in an ELISA for the detection of specific antibodies to HTLV-I present in the samples tested.
None of the above-described assays has demonstrated the high specificity (no false positives) and high sensitivity (detection of all positives, even when the sera contains very low levels of HTLV antibodies) necessary to ensure that HTLV infected blood products do not enter blood banks and that infected individuals seek prompt and early treatment. The peptides of this invention remedy these failures.

Peptides and analogues and mixtures thereof for detecting antibodies to HTLV-I and HTLV-II viruses


This invention methods of etching an aluminum oxide comprising substrate, and methods of forming capacitors. In one implementation, a method of etching an aluminum oxide comprising substrate includes flowing water and ozone to aluminum oxide on the substrate, with at least one of the water and the ozone being at a temperature of at least 65° C. at the aluminum oxide effective to etch aluminum oxide from the substrate. In one implementation, aspects of the method are utilized in forming a capacitor.

One example chemistry for etching aluminum oxide is a base-buffered HF solution (for example 100 volume parts water to 1 volume part HF to 15 volume parts of a base) to provide the primary H2F2 etching species. This exemplary chemistry provides very good selectivity in etching aluminum oxides relative to titanium nitride, for example a selectivity of about 500:1. In the context of this document, selectivity in an etch for etching one material selectively to another requires removal/etching of the one relative to the other at a ratio of at least 2:1. Of course, often much higher selectivities are obtainable and desirable. The above exemplary chemistry has not produced desired degree of selectivity in etching aluminum oxide selectively relative to hafnium nitride and aluminum nitride. For example, using the above chemistry not only etches aluminum oxide but also etches aluminum nitride and hafnium nitride just as fast or faster.
One example chemistry for etching aluminum oxide is a base-buffered HF solution (for example 100 volume parts water to 1 volume part HF to 15 volume parts of a base) to provide the primary H2F2 etching species. This exemplary chemistry provides very good selectivity in etching aluminum oxides relative to titanium nitride, for example a selectivity of about 500:1. In the context of this document, selectivity in an etch for etching one material selectively to another requires removal/etching of the one relative to the other at a ratio of at least 2:1. Of course, often much higher selectivities are obtainable and desirable. The above exemplary chemistry has not produced desired degree of selectivity in etching aluminum oxide selectively relative to hafnium nitride and aluminum nitride. For example, using the above chemistry not only etches aluminum oxide but also etches aluminum nitride and hafnium nitride just as fast or faster.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. Rather, the invention is only limited by the accompanying claims as literally worded without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.

This patent is subject to a terminal disclaimer.

Methods of etching an aluminum oxide comprising substrate, and methods of forming a capacitor


An arrangement of divergently mounted acoustic transducers in a hemispherical air tight enclosure, the enclosure being sized with regard to the loading requirements of the acoustic transducers to produce a small size speaker system having an omnidirectional sound radiation pattern and a flat frequency response without the need of a crossover network. The hemispherical enclosure being comprised of six flat equal sided pentagonal plates, five triangular shaped flat gussets and a flat base plate all of which when assembled forms a half dodecahedron polyhedron shaped enclosure with a closed base, with the base serving as the enclosure mounting surface.

The present invention relates to sound reproduction but particularly to a plurality of speakers arranged in a divergent pattern to approximate a hemisphere in order to disperse sound equally in all directions.
Prior art has taken many forms in an effort to reproduce faithfully and to direct sound waves successfully to the listener where ever he may be in the listening area and to eliminate dead spots or areas of sound wave cancelation. From basic driver and horn combinations to cabinets with multiple drivers, special crossover networks and tuned ports with baffled internal structures the designer has attempted to create an infinite acoustic baffle around the speaker driver elements in order to extend frequency band width and to reduce distortion to a minimum. The introduction of the accoustic suspended speaker system in which the speaker is sealed in a cabinet without ports has proved to be superior to the ported types in bandwidth but is somewhat less efficient. All of the afore mentioned systems reproduce sound as a wave front which radiates from the speaker face and must be directed toward the listener. This directional effect can lead to wave front cancelations or dead spots in the listening area caused by reflections from walls and furniture.
Two speakers placed back to back in a sealed container and excited in phase as shown by manger in U.S. Pat. No. 4,268,719 create an infinite baffle which is in the form of a plane parallel to and located between the two speakers. The distribution of sound from this combination more closely resembles an omnidirectional wave pattern which is less subject to reflection problems. Taking this approach further, more speaker elements may be included into different patterns such as those described by glassco in U.S. Pat. No. 4,673,057 in which a number of similar speakers are arranged so that each maintains a common angle of divergence with its adjacent speakers. It is apparent that if the number of speakers continued to increase in this system eventualy a sphere would be formed which would have nearly perfect omnidirectional radiation qualities. In an effort to produce a speaker system which has the maximum frequency response and best omnidirectional pattern one is forced to use as big a speaker as possible for the low frequency response and to add tweeter units to extend the upper frequency response and to use as many speakers in the design as is economical. The tradeoffs all considered, the dodecahedron seems to be the closest to the desired shape. However, a system of this shape using twelve standard eight inch woofers and twelve small tweeters weighs in at about one hundred pounds. This is a considerable weight to hang from a ceiling and is an awkward form to transport from place to place. Use of such a speaker system in a car or van would be impossible or at least impractical and two are required for stereo sound. Bisecting the dodecahedron on its equatorial plane as described by glassco to produce a stereo system limits its installation in a listening room to the middle of the room or to the middle of the ceiling which is not always possible.


A water conservation device for use in toilet tanks which have a valve movable between an open and a closed position. The valve is connected to a flush linkage which draws the valve to the open position upon activation of a flushing lever. The water conservation device consists of an elongate body having a first end and a second end. The first end of the elongate body is indirectly linked to the valve. The second end of the elongate body is indirectly suspended within the toilet tank, such that the elongate body is disposed at an angle to the valve. As the elongate body pivots, the weight of the elongate body pulls the valve into the closed position.

Toilets are constructed with bowls to receive human excrement and tanks that hold water for the purpose of clearing the excrement from the bowl. They generally have a valve movable between an open and a closed position. The valve is connected to a flush linkage which draws the valve into the open position upon activation of a flushing lever. A standpipe is provided which serves to prevent the toilet tank from overflowing. It is generally accepted that when a toilet is flushed more water is released from the tank than is required to clear the bowl.
To address the problem of excess water usage, a plurality of water conservation devices have been developed. Examples of such water conservation devices are U.S. Pat. No. 4,748,699 which issued to Charles F. Stevens in 1988 and U.S. Pat. No. 4,945,578 which issued to Mohamed A. Jomha and Andrew Lazowski in 1990. These patents disclose floatation devices which travel up and down on the standpipe of the toilet and push the valve into the closed position.
Water conservation devices which "push" the valve into a closed position have a number of inherent problems. One problem is that they are relatively complex. Another problem is that they are difficult to install on some styles of toilets. A final problem is that the valve occasionally becomes jammed in a partially open position resulting in gallons of water flowing through the tank.

Water conservation device for use in toilet tanks


A host computer includes a host machine and a projector. The host machine has a keyboard. The projector is positioned about the keyboard and includes a projection lens. A using position of the projection lens is higher than a received position of the projection lens.

The present invention relates to host computers and, more particularly, to a host computer with a projector.
With the development of technology, notebook computers and projectors are now in widespread use. Electronic products are prone to be smaller and thinner in design. Consequently, the functions of a notebook computer and a projector are generally independent. Thus, a transmission line is needed to connect the notebook computer and the projector, so that information in the notebook computer can be shown via the projector. As for users, if a user makes a report in a customer's company or a supplier's company, he/she has to take with transmission line besides a notebook computer and peripheral devices of the notebook computer. It is very inconvenient.
In addition, projectors in the market can only transmit an image onto a target screen in front. If the projector is fixed to an immovable thing, such as a table, the projecting direction of the projector cannot be changed. In other words, the projecting direction of the projector can be adjusted only if the projector is moved or rotated. However, a distance between the notebook computer and the projector is limited by the length of the transmission line. Furthermore, when the user needs to make a report away from his/her seat, another person is required to switch pages of the report. Otherwise, the user not only needs to leave his/her seat but also needs to switch pages by himself/herself, thereby causing the meeting running not smoothly. Moreover, the meeting is unable to be held if the customer does not provide a projector, which may make a bad impression on the customer and cause a loss of working performance.


Among other things, an information retrieval process that optimizes the retrieval of highly relevant information across dissimilar documents; information retrieval is based on information understanding, using contextual word disambiguation and sentence parsing to determine well-formed sentences, storing information according to syntactical structures; the information retrieval process finds the target of the search in the subject, subject complement, or direct object and returns maximally informative factual sentences; this search method alters the traditional user experience by presenting facts about the search topic with a link to the source document sentence, rather than presenting brief snippets of text containing the search string.

This description relates to generating and communicating curated information interactively in response to a query from one party to a database. Searching for information, such as by querying a database using keywords or searching for documents or web pages using a search engine, can be inefficient and may not return desired results, particularly if the keywords are not well chosen. Given this long-felt unmet need, better systems and methods for searching for information in databases are desirable.
The World Wide Web encompasses 4.49 billion pages of which approximately 50% are in English. Often relevant information about a topic is distributed across several documents. The prior art does not contain adequate solutions for finding relevant information given this situation.

Information retrieval based on semantics


A high efficiency filter and method for its production. An array of tube-type sleeves, each sleeve composed of a filtering medium and joined longitudinally along its exterior surface to the adjacent sleeve, is expandably fixed into a framework and all margins of the array are sealed to the framework in order that a fluid passing orthogonally through the plane of the array and its frame must pass through at least two filtering surfaces. The process and machine used to make the aforementioned product start with a relatively narrow roll of filtration media and, through a series of steps, form, cut and glue the media so as to form the requisite sleeve structure and then by means of controlled curing, affix a predetermined number of the sleeves in to the desired array.

The present invention relates generally to high efficiency filters and filtering processes and more particularly to filtering of fine particles from fluid streams. It relates also to the form of the high efficiency filters and to the manner of their manufacture.
The design of filters to remove particulate material from gases is known to depend on the temperature and compositions of the gases containing the particles and on the size and character of the particles to be removed.
The removal of fine particles of coal, carbon and ash from hot gas entering a gas turbine through use of ceramic filters to prevent damage to turbine blades is taught in U S. Pat. No. 4,343,631. Numerous other patents teach specific filter structures useful in separating designated materials from specified fluid streams. Such patents include U.S. Pat. Nos. 3,880,620; 4,530,418; 4,734,195; 3,707,831; 3,031,827; 3,766,629; 4,363,644; 4,689,059; 3,491,891; 4,640,779; 3,502,596; 2,076,304; 3,330,101; 4,613,438; 3,883,331; 2,885,026; 3,594,989; 4,639,261; 4,584,005; 4,685,944; 4,233,044 and 2,980,208. A number of these patents disclose a filter structure involving a honeycomb like array of filter elements or filter channels. However in essentially all such filter elements the design of the filter is for a fluid flow parallel to the axis of the honeycomb. The subject application deals with a filtering structure and filtering operation in which the filtering occurs in a direction perpendicular to the axis of the cells of a cellular structure such as a honeycomb.
A set of standards has been established for the operation of filters in removing finer and finer particles from gas. This standard has been set with respect to clearing the air for so-called clean room operations. The standard is known as Federal Standard 209B and it is entitled "Clean Room and Clean Work Station Requirements, Controlled Environment". The standard was established partly in connection with clean room operations used in forming microelectronic chips because of the negative impact of air borne dust particles on the manufacture and on the operation of such chips. The standard contains a number of criteria. Some of these criteria have to do with the number and size of particles which must be removed from air and conversely the number and size of particles which may remain in the air of a "clean room." Recently there have been a number of studies and proposals relating to the modification of the standard and a new standard, FED-STD-209D dated June 1988 has been published. A copy of the standard, amounting to some 41 Pages, was published in the Journal of Environmental Science of Sept/Oct 1988.
Some of the filters which are used in connection with establishing a clean room atmosphere are known as HEPA (or High Efficiency Particulate Air) filters. There are carefully drawn criteria about how such filters are to be operated and the ability which they must display for removing particles of prescribed sizes from air. One of these criteria is that the resistance to airflow of the filters at prescribed airflow should not be more than 1.0 inch of water except for filters which have an efficiency of 99.999% and for these latter filters the pressure drop is established by agreement of buyer and seller.
A HEPA filter is defined by the standard as a throw-away extended-media dry-type filter in a rigid frame having minimum particle collection efficiency of 99.97% for 0.3 micrometer thermally-generated dioctyl phthalate (DOP) particles, and a maximum clean-filter pressure drop of 1.0 in. water gage, when tested at rated air-flow capacity.
Another type of filter is known as an ASRAE filter and still another is known as a UPLA (Ultra Low Particle Air) filter. Another filter is known as the ULPA filter (or Ultralow Penetration Air Filter). Each of these filters has well defined and well recognized characteristics which are well known in the trade.
One characteristic which is shared by all of these filters is that each such filter has just one filter media layer. The subject invention concerns a new and unique multilayer filter media system for the above applications which has two or more layers of filter media.


The invention comprises an improvement in the process wherein a polysilicon layer, which is formed over a step on an integrated circuit structure and masked with a photoresist, is anisotropically etched to remove the exposed portions of the polysilicon layer leaving residues of polysilicon adjacent to the step and residues of a polymerized silicon/oxide-containing material adjacent the sidewalls of the masked portions of the polysilicon layer. The improvement comprises treating the integrated circuit substrate with a dilute hydroxide solution to remove both the polysilicon residues and the residues of polymerized silicon/oxide-containing material.

1. Field of the Invention
This invention relates to an improved process for etching a polysilicon layer on an integrated circuit structure wherein the improvement comprises using an additional etching step to selectively remove residues not removed during the anisotropic etching of the polysilicon layer.
2. Description of the Related Art
During the construction of an integrated circuit structure, a polysilicon layer may be formed which covers a raised portion or step on the integrated circuit structure. Such a step might, for example, comprise an oxide portion such as an isolation oxide or an oxide-covered polysilicon line, e.g., a poly 1 layer. Subsequent masking and anisotropic etching of this polysilicon layer, for example, to form another polysilicon line, can result in undesirable residues being left behind on the integrated circuit structure after the anisotropic etching step.
FIG. 1 shows such a polysilicon layer formed on an integrated circuit substrate, while FIGS. 2 and 3 show the structure of FIG. 1 respectively after first and second stages of an anisotropic etch of the polysilicon layer. In FIG. 1, polysilicon layer 20 is formed over silicon substrate 2 on which was previously formed a gate oxide layer 4 and raised steps 10 comprising polysilicon lines 12 covered by a oxide portion 14. A photoresist mask has been applied and patterned leaving photoresist portion 32 over a portion of polysilicon layer 20 where a line is to be formed from polysilicon layer 20. It will also be noted that a native oxide layer 16, of usually less than about 30 Angstroms thickness, is present over polysilicon layer 20.
Conventionally, polysilicon layer 20 is anisotropically etched (to avoid undercutting of the polysilicon beneath mask 32) by, for example, an RIE etch, using Cl.sub.2, HCl, and HBr gases to remove the exposed portions of polysilicon layer 20 down to the level of oxide portion 14 and gate oxide 4, as shown in FIG. 2, while observing the emission from the plasma with optical emission spectroscopy to monitor increases in the intensity of the Cl.sub.2 line indicative that the Cl.sub.2 is not being used to line indicati etch polysilicon. This first portion of the RIE etch process leaves polysilicon shoulders 22 and oxide portions 18, representing the inverted corners of oxide layer 16 over polysilicon layer 20 where polysilicon layer 20 begins to cross over each step 10, remaining on the sides of step 10 due to the greater thickness of polysilicon layer 20 at these points as shown in FIG. 2.
The structure is then subjected to a further RIE etch or overetch to remove the remaining portions of polysilicon layer 20 on the sides of step 10, as shown in FIG. 3, by changing the chemistry of the RIE etch to provide a higher concentration of O.sub.2 or HBr gas and a lower concentration of Cl.sub.2 gas, as well as a reduction in power density from, e.g., about 250-350 watts down to about 50-120 watts for a 4" wafer, to make the etch more selective in the etching of polysilicon, which will reduce or eliminate inadvertant etching of gate oxide layer 4.
However, as can be seen in FIG. 3, completion of the RIE etch leaves polysilicon spikes or residues 24 adjacent step 10 as well as polymeric silicon/oxide-containing materials comprising sidewalls 26 on the sides of polysilicon line 28 and photoresist 32. The formation of the polysilicon residues 24 shown in FIG. 3 is apparently due to the presence of portions 18 of native oxide layer 16 which remain on the surfaces of polysilicon layer 20 over the corners of step 10 after the initial RIE etch, as shown in FIG. 2.
Conventionally, in the prior art, such residues of polymeric silicon/oxide-containing materials forming sidewalls 26 were removed by dipping the integrated circuit structure in HF. However, the HF will also etch the gate oxide and, therefore, unless the wet etch conditions are very carefully controlled, the gate oxide will also be removed, exposing the underlying silicon substrate.
Furthermore, the polysilicon spikes which form on the integrated circuit structure adjacent the raised step cannot be removed in this manner so attempts were made in the past to prevent the occurence of such spikes by treating the structure with HF to remove oxide portions 16 prior to the RIE etch. However, such attempts have not always resulted in elimination of the subsequent formation of the polysilicon spikes on the structure.
It would, therefore, be desirable to provide an improved process for the selective etching of a polysilicon layer wherein residues left adjacent steps and masked portions of the polysilicon layer after an anisotropic etching step could be selectively removed with minimum damage to oxide portions in or on the integrated circuit structure such as gate oxide over the silicon substrate.

Process for etching polysilicon layer in formation of integrated circuit structure


The distributed index of refraction type optical element consists of an element composing a glass forming oxide and a cation composing a glass modifying oxide, and has therein a distributed index of refraction imparted by a gradient of density of the element and a distributed index of refraction imparted by a gradient of density of the cation which are completely independent of each other. This optical element permits controlling chromatic aberration in various ways and has various favorable optical characteristics. The method of making the optical element comprises a first step for imparting a first distributed index of refraction to a glass body material by forming a gradient of density of the element and a second step for imparting a second distributed index of refraction to the glass body material by forming a gradient of density of the cation.

Field of the Invention
The present invention relates to a distributed index of refraction type optical element and a method of making the same.
Description of the Prior Art
As optical elements indispensable for optical systems to be developed in the next generation, distributed index of refraction type optical elements are now attracting wide attention due to their excellent ability for correcting aberration.
A large number of enterprises and research institutes are studying and developing various distributed index of refraction type optical elements, not to speak of SELFOC (registered trade mark) and Slab lenses which have already been offered for sale.
The distributed index of refraction type optical element has a refractive power of its medium proper which is imparted by the index of refraction distributed in the medium. The power is determined dependently on the distributed index of refraction and enhanced by increasing a difference between gradients of the indices of refraction (herein after referred to as .DELTA.n). Accordingly, an important task now imposed on researchers of distributed index of refraction type optical elements is to increase .DELTA.n and investigations are being made by many researchers to try to increase .DELTA.n.
Under the present circumstances, most approaches are made in the area of developing distributed index of refraction type optical elements having increased .DELTA.'s and large outside diameters, whereas attempts to reduce chromatic aberration in optical elements are retarded. Moreover, the distributed index of refraction type optical elements posses the possibility of remarkably reducing the number of lens elements owing to the excellent capability for correction of aberration, but such produces a contradiction in that the correction of chromatic aberration becomes more difficult as the number of lens elements is reduced. In order to compose a lens system comprising a distributed index of refraction type optical elements and having sufficiently corrected chromatic aberration, it may therefore be necessary to adopt a means such as use of an achromatic lens, thereby reducing the merit of the distributed index of refraction type optical elements. In order to compose a lens system in which the chromatic aberration is corrected with a small number of lens elements, it is impotant to reduce the chromatic aberration to be produced by each of the lens elements. For this purpose, the distributed index of refraction type optical element must be made of a medium having a characteristic ranging from the high index of refraction-low dispersion region to the low index of refraction-high dispersion region. In case of a radially distributed index of refraction type optical element, the index of refraction of the medium is varied and rays are refracted differently dependenting on height of rays (distance from the optical axis). Assuming now that a medium has a constant Abbe's number (.nu..sub.d =(n.sub.d -l)/(n.sub.F -n.sub.c)), the portion having a high index of refraction refracts a ray more largely than the portion having a low index of refraction, thereby allowing the ray to be dispersed more largely due to the difference in wavelength as illustrated in FIG. 1A. In other words, the chromatic aberration (n.sub.F -n.sub.c) becomes more remarkable as index of refraction n.sub.d is higher when Abbe's number is kept constant. In order to reduce the chromatic aberration (n.sub.F -n.sub.c ), it is therefore desirable that Abbe's number .nu..sub.d is large for the portion having the high index of refraction as shown in FIG. 1B. That is to say, it is desirable that a meduim has a charateristic varying from the high index of refraction-low dispersion region to the low index of refraction-high dispersion region. In case of the axially distributed index of refraction type optical element, on the other hand, it is considered that the conclusion obtained for the general achromatic cemented lens (doublet) shown in FIG. 2A or FIG. 2B is applicable. Since the cementing between the lens made of a medium having the high index of refraction and the lens made of a medium having the low index of refraction is realized by distributing index of refraction in a medium of a single lens as illustrated in FIG. 2C or FIG. 2D, it is desirable that the axially distributed index of refraction type optical element, like the radially distributed index of refraction type optical element, has a characteristic varing from the high index of refraction-low dispersion region to the low index of refraction-high dispersion region. Describing this characteristic with reference to the n.sub.d -.nu..sub.d graph illustrated in FIG. 3, the optical characteristic varying in the direction A is more excellent for correction of chromatic aberration than the characteristic varying in the direction B (See Japanese Patent Preliminary Publication No. Sho 60-218614). Further, as the distribution in the direction A in FIG. 3 has an indication closer to the horizontal direction, the chromatic aberration is not only reduced but also produced in the negative side. This is a phenomenon which cannot be observed in the ordinary glass material and an optical element exhibiting this phenomenon has an excellent capability to cancel the chromatic aberration produced by the other lenses. It is also possible, needless to say, to make an optical element which produces no chromatic aberration by properly setting the inclination.
However, most of the distributed index of refraction type optical elements now available are designed for increased .DELTA.n's and have smaller Abbe's number at the portion having higher indices of refraction. That is to say, most of the distributed index of refraction type optical elements have the characteristic varying in the direction B shown in FIG. 3. Speaking concretely of the ion-exchange method, for example, which imparts a gradient of density or concentration by ion-exchange between Tl.sup.+, a univalent ion adopted into glass as a component to compose a glass modifying oxide (having no direct relation to formation of glass) for increasing .DELTA.n, and Na.sup.+ or K.sup.+, the use of Tl.sup.+ allows an increase .DELTA.n but makes the Abbe's number have a characteristic varying from the high index of refraction-high dispersion region to the low index of refraction-low dispersion region, thereby allowing chromatic aberration to be produced remarkably. Further, ion-exchange between Ag.sup.+ and Na.sup.+ increases .DELTA.n but allows chromatic aberration to be produced remarkably. Furthermore, certain examples remarkably improve the correction of chromatic aberration by utilizing Li.sup.+ but decrease .DELTA.n on the other hand and do not exhibit the effects thereof sufficiently. Speaking more concretely, enhancement in content of Li.sup.+ is effective to increase .DELTA.n but have not attained to levels yet to exhibit sufficient effects in practice since enhancement in content of Li.sup.+ is allowable only within a limited range from the viewpoint of the chemical resistance of glass body materials and due to technical difficulty to dissolve a volatile alkali component stably into glass body materials. Since the ion-exchange method allows bivalent and higher-valent ions to be exchanged at very slow speeds and is substantially usable for imparting gradients of density of univalent cation only, the method allows the gradients of ion density, or concentration for imparting distributed indices of refraction to be varied only within a strictly limited range and does not permit obtaining a distributed index of refraction type optical element having a large .DELTA.n and producing little chromatic aberration. Moreover, distributed index of refraction type optical elements are being developed by the sol-gel method. There is a method to impart a gradient of density, or concentration by eluting a metal element such as Ti, Ge or Zr which enhances index of refraction and composes a glass forming oxide (a substance originally contained for forming glass) from a wet gel by using an acid or a similar chemical. Though this method permits obtaining .DELTA.n which is large to a certain extent, the distributed index of refraction type optical element prepared by this method has an Abbe's number characteristic varying from the high index of refraction-high dispersion region to the low index of refraction-low dispersion, and allows remarkable production of chromatic aberration, which is similar to the characteristic of the distributed index of refraction type optical element obtained by the Tl.sup.+ .revreaction.Na.sup.+ type ion-exchange.

Distributed index of refraction type optical element and method of making the same


In a universal mobile telecommunications system, a radio access network includes multiple base stations for communicating with user equipment. The radio access network is configured to send the user equipment a measurement control message which includes configuration information and a location reporting indicator. The user equipment is configured to perform a minimization of drive test according to the configuration information, and provide location information along with the recorded measurement result according to the location reporting indicator.

1. Field of the Invention
The present invention is related to a method of operating a user equipment, and more particularly to a method of operating a user equipment for providing a measurement report in a UMTS.
2. Description of the Prior Art
The 3rd Generation Partnership Project (3GPP) has developed a universal mobile telecommunications system (UMTS) which adopts a wideband code division multiple access (WCDMA) technology capable of providing high frequency spectrum utilization, universal coverage, and high-speed/quality multimedia data transmission. In the UMTS, a radio access network known as a universal terrestrial radio access network (UTRAN) includes multiple base stations (Node-B, NB) for communicating with multiple mobile stations (user equipment, UE).
NBs of the wireless communication system must be deployed properly in order to provide seamless, high quality and large signal coverage without experiencing call drops or signal degradation. However, planning and optimizing the deployment of the NBs are based on signal quality measurements which may be time- and effort-consuming for an operator of the wireless communication system. Common methods of performing the measurements include measuring the signal strength or quality at different time and geographical locations of interest. Therefore, it is more economical for a UE of the wireless communication system to perform the measurements and send the measurement report to an NB. Based on the measurement reports received from multiple UEs, the deployment of the NBs may be planned and optimized accordingly without spending many human and material resources.
In a minimization of drive test (MDT) proposed in current 3GPP specifications associated with UMTS (such as 3GPP TS 25.331), the UE is configured to measure radio channels and report the radio channel measurement information to the NB periodically at an interval, immediately in response to a specific event, or after a predetermined time has elapsed from the time when the radio channel measurement information has been recorded. The UE sends the measurement report after the completion of channel measurement. The NB may then use the MDT measurement report received from the UE for coverage optimization, mobility optimization, capacity optimization and Quality of Service (QoS) verification. Therefore, there is a need to improve the efficiency of the NB when performing the above-mentioned optimizations or verifications.

Method of operating user equipment for providing measurement report in UMTS


A guide wire for advancing a medical device such as a catheter through a patient's body lumen which has an elongated core with proximal and distal core section, a flexible tubular member such as a coil on the distal end. The wire core includes surface textures that are translated into the overlying coating. Alternatively, the coating has its own surface texture. The surface textures include randomly or non-randomly spaced bumps, divots, ridges, helical grooves, longitudinal grooves, undulations, etc.

This present invention relates to the field of guide wires used for advancing intravascular devices such as stent delivery catheters, balloon dilatation catheters, and atherectomy catheters within a body lumen. More specifically, the present invention relates to a guide wire with a polymer coating having a textured surface.
Conventional guide wires for angioplasty, stent delivery, atherectomy and other vascular procedures usually comprise an elongated core with one or more tapered sections near the distal end thereof and a flexible body such as a helical coil or a tubular body of polymeric material disposed about the distal portion of the elongated core. A shapable member, which may be the distal extremity of the elongated core or a separate shaping ribbon which is secured to the distal extremity of the elongated core, extends through the flexible body and is secured to the distal end of the flexible body by soldering, brazing, or welding, which forms a rounded distal tip. Torquing means are provided on the proximal end of the elongated core to rotate, and thereby steer, the guide wire while it is being advanced through a patient's vascular system.
Further details of guide wires and devices associated therewith for various interventional procedures can be found in, for example, U.S. Pat. Nos. 4,748,986 (Morrison et al.); 4,538,622 (Samson et al.); 5,135,503 (Abrams), 5,341,818 (Abrams et al.), and 5,345,945 (Hodgson et al.), which are hereby incorporated herein in their entirety by reference thereto.
In a typical coronary procedure using a guide wire, a guiding catheter having a preformed distal tip is percutaneously introduced into a patient's peripheral artery, e.g., femoral or brachial artery, by means of a conventional Seldinger technique and advanced and steered therein until the distal tip of the guiding catheter is seated in the ostium of a desired coronary artery.
There are two basic techniques for advancing a guide wire into the desired location within the patient's coronary anatomy through the in-place guiding catheter. The first is a preload technique which is used primarily for over-the-wire (OTW) devices, and the second is the bare wire technique which is used primarily for rail type systems.
With the preload technique, a guide wire is positioned within an inner lumen of an OTW device such as a dilatation catheter or stent delivery catheter with the distal tip of the guide wire just proximal to the distal tip of the catheter and then both are advanced through the guiding catheter to the distal end thereof. The guide wire is first advanced out of the distal end of the guiding catheter into the patient's coronary vasculature until the distal end of the guide wire crosses the arterial location where the interventional procedure is to be performed, e.g., a lesion to be dilated or a dilated region where a stent is to be deployed. The catheter, which is slidably mounted onto the guide wire, is advanced out of the guiding catheter into the patient's coronary anatomy over the previously introduced guide wire until the operative portion of the intravascular device, e.g., the balloon of a dilatation or a stent delivery catheter, is properly positioned across the arterial location. Once the catheter is in position with the operative means located within the desired arterial location, the interventional procedure is performed. The catheter can then be removed from the patient over the guide wire. Usually, the guide wire is left in place for a period of time after the procedure is completed to ensure reaccess to the arterial location if it is necessary. For example, in the event of arterial blockage due to dissected lining collapse, a rapid exchange type perfusion balloon catheter such as described and claimed in U.S. Pat. No. 5,516,336 (McInnes et al.), can be advanced over the in-place guide wire so that the balloon can be inflated to open up the arterial passageway and allow blood to perfuse through the distal section of the catheter to a distal location until the dissection is reattached to the arterial wall by natural healing.
With the bare wire technique, the guide wire is first advanced by itself through the guiding catheter until the distal tip of the guide wire extends beyond the arterial location where the procedure is to be performed. Then a rail type catheter, such as described in U.S. Pat. No. 5,061,273 (Yock) and the previously discussed McInnes et al., which are incorporated herein by reference, is mounted onto the proximal portion of the guide wire which extends out of the proximal end of the guiding catheter outside of the patient. The catheter is advanced over the catheter, while the position of the guide wire is fixed until the operative means on the rail type catheter is disposed within the arterial location where the procedure is to be performed. After the procedure, the intravascular device may be withdrawn from the patient over the guide wire or the guide wire advanced farther within the coronary anatomy for an additional procedure.
There has been an interest in creating different surface profiles for the guide wire core. The interest arose primarily to address the issue of friction between the contact surface of the guide wire and the catheter lumen through which it passes or the body lumen of the patient. One attempt is the use of a sleeve at the distal portion of the core as seen in, for example, U.S. Pat. No. 5,404,887 (Prather). Another approach to reducing the surface contact between the guide wire and a catheter lumen or body lumen is shown in U.S. Pat. No. 6,296,616 (McMahon).

Textured polymer coated guide wire and method of manufacture


Provided are a booting apparatus and method using a snapshot image. A snapshot image may be divided into a plurality of blocks. Each of the blocks may be stored in a nonvolatile memory in a compressed or non-compressed format. The snapshot image may be incrementally loaded in units of the blocks during booting. The loading and decompression of the blocks may be performed in parallel.

1. Field
The following description relates to a technique for reducing the amount of time it takes to boot a system.
2. Description of the Related Art
With recent improvements in the performance of embedded devices, the use of rich operating systems (OSs) such as WINDOWS® Phone OS, IPHONE® OS, and ANDROID®/LINUX®, have become widespread.
As the functions supported by rich operating systems have diversified, the size of the operating system kernels and software platforms have increased. Large-size OS kernels and software platforms cause delays in system booting because they require a great amount of initialization routines and file loadings.
In order to address this problem, various methods such as hibernation and suspend-to-disk have been suggested. Hibernation and suspend-to-disk methods enable a quick system boot by storing random access memory (RAM) state information and CPU/device state information in a non-volatile storage medium such as a disk or a flash memory when powering off the system and the stored state information may be restored to its original location in a memory in response to the system being rebooted. The stored state information is also referred to as a snapshot image.

Selectively compressing blocks of a bootable snapshot image during booting


In a specific state where the raising operation of a boom 25 and the swing operation of an upperstructure 21 are performed at the same time to supply a hydraulic oil from a first pump 2 to a cylinder 7a through a first valve 6a, and to supply the same from a second pump 3 to a motor 7b through a second valve 6b, a controller 10 outputs the command current for opening a valve 13, and supplies a part of the hydraulic oil supplied to the motor 7b from the second pump 3 to the cylinder 7a through the third valve 6c when the motor 7b does not reach a steady swing state, and outputs a command current for closing the valve 13 when the motor 7b is in the steady swing state.

In a working machine provided with a front working device, there is a hydraulic drive device for supplying a sufficient amount of hydraulic oil to a boom cylinder while inhibiting a wasteful consumption of energy when a boom raising operation and a swing operation are performed at the same time. For example, Patent Literature 1 discloses a hydraulic drive device for a working machine "which includes a first hydraulic pump and a second hydraulic pump whose tilting angles can be adjusted independent of each other, a swing control valve for controlling the supply of a hydraulic oil to a swing motor, and a boom main control valve and a boom auxiliary control valve for controlling the supply of the hydraulic oil to a boom cylinder, and the swing control valve and the boom auxiliary control valve are disposed on a first bleed line, the boom main control valve is disposed on a second bleed line. A pilot pressure is output to swing control valve from the swing control valve, and the pilot pressure is output to the boom main control valve from the boom control valve. When the swing operation and the boom raising operation are performed at the same time, the boom side control valve does not output the pilot pressure to the boom auxiliary control valve (abstract excerpt)."

Hitachi Construction Machinery Co., Ltd.


A method for removing noise from a pixel of a digital image channel includes the steps of: storing an original value of the pixel of interest and using the value of the pixel of interest and neighboring contiguous pixels to determine a variable shape neighborhood region of cleaning pixels. The method further includes using the neighborhood region of cleaning pixels and the value of the pixel of interest to replace the original value of the pixel of interest with a noise cleaned pixel value.

The present invention relates to providing filtered digital images with reduced noise.
Many noise reduction algorithms can be classified as non-linear spatial filters image processing algorithms. Most often these algorithms involve using the pixel values in a small local surrounding neighborhood to the pixel of interest combined with some form of non-linear weighting and/or statistical conditions applied to derive a noise free estimate. The small local surrounding neighborhood is usually centered on the pixel of interest. For this class of noise reduction algorithm the filter size is fixed, meaning that all image pixels are processed with the same size local surrounding neighborhood size.
An example of a fixed size noise reduction algorithm is the Sigma Filter, described by Jon Son Lee in the journal article Digital Image Smoothing and the Sigma Filter, Computer Vision, Graphics, and Image Processing Vol 24, p. 255-269, 1983. This is a noise reduction filter that uses a non-linear pixel averaging technique sampled from a rectangular window about the center pixel. Pixels in the local neighborhood are either included or excluded from the numerical average on the basis of the difference between the pixel and the center pixel. Mathematically, the Sigma Filter can be represented as
xe2x80x83qmn=xcexa3ijaijpij/xcexa3ijaij
and
aij=1 if |pijxe2x88x92pmn| less than =xcex5
aij=0 if |pijxe2x88x92pmn| greater than xcex5
where pij represents the pixels in the local surround about the center pixel pmn, qmn represents the noise cleaned pixel, and e represents a numerical constant usually set to two times the expected noise standard deviation.
The Sigma Filter was designed for image processing applications for which the dominant noise source is Gaussian additive noise. Signal dependent noise sources can easily be incorporated by making the e parameter a function of the signal strength. However, for both signal independent and signal dependent noise cases the expected noise standard deviation must be known to obtain optimal results. The Sigma Filter performs well on highly structured areas due to the fact that most of the image pixels in the local neighborhood are excluded from the averaging process. This leaves high signal strength regions nearly unaltered. The filter also works well in large uniform areas devoid of image signal structure due to the fact that most of the local pixels are included in the averaging process. For these regions, the Sigma Filter behaves nearly as a low pass spatial filter.
Regions in images characterized by low amplitude signal modulation, or low signal strength, are not served well by the Sigma Filter. For these regions, most of the local pixel values are included in the averaging process thus resulting in a loss of signal modulation. Setting the threshold of the filter to a lower value does reduce the loss of signal, however, the noise is left mostly the same.
Another example of a fixed size non-linear noise filter was reported by Arce and McLoughlin in the journal article Theoretical Analysis of the Max/Median Filter, IEEE Transactions Acoustical and Speech Signal; Processing, ASSP-35(1), p. 60-69, 1987 they named the Max/Median Filter. This filter separated the local surround region into four overlapping regionsxe2x80x94horizontal, vertical, and two diagonal pixels with each region containing the center pixel. A pixel estimate was calculated for each region separately by applying a taking the statistical median pixel value, sampled from the regions"" pixel values. Of these four pixel estimates, the maximum valued estimate was chosen as the noise cleaned pixel. Mathematically the Max/Median Filter can be represented as
qij=maximum of {Z1, Z2, Z3, Z4}
Z1=median of {pi,jxe2x88x92w, . . . pi,j, . . . , pi,j+w}
Z2=median of {pixe2x88x92w,j, . . . pi,j, . . . , pi+w,j}
Z3=median of {pi+w,jxe2x88x92w, . . . pi,j, . . . , pixe2x88x92w,j+w}
Z4=median of {pixe2x88x92w,jxe2x88x92w, . . . pi,j, . . . , pi+w,j+w}
Where qij represents the noise cleaned pixel, Z1, Z2, Z3, and Z4 represent the four pixel estimates, and pij represents the local pixel values. The Max/Median Filter also reduces the noise present while preserving edges. For Gaussian additive noise, the statistical median value does not reduce the noise by as great a factor as numerical averaging. However, this filter does work well on non-Gaussian additive noise such as spurious noise.
Noise is most visible and objectionable in images containing areas with little signal structure, e.g. blue sky regions with little or no clouds. The Sigma filter can produce a blotchy, or mottled, effect when applied image regions characterized by low signal content. This is largely due to the rectangular geometric sampling of local pixels strategy. The radial region sampling strategy employed by the Max/Median Filter produces noise reduced images will less objectionable artifacts in image regions characterized by low signal content. For images with high noise content, the artifacts produced by radial region sampling strategy have a structured appearance.
U.S. Pat. No. 5,671,264 describes a variation of the Sigma Filter and Max/Median Filter. This algorithm borrows the technique of radial spatial sampling and multiple pixel estimates from the Max/Median Filter. However, the algorithm expands the number of radial line segment to include configurations with more than four segments. The algorithm uses combinations of Sigma and Median filters to form the individual region pixel estimates. These pixel estimates derived from the N regions are then combined by numerical averaging or taking the statistical median value to form the noise cleaned pixel value. A key component of this algorithm is the randomization of one of the three essential region parameters: length, orientation, and number of regions. The randomization of the filter parameters is performed on a pixel to pixel basis thus changing the inherent characteristics with pixel location. It is claimed that the randomization feature reduces the induced structured artifacts produced by the radial region geometry sampling method. The algorithm described in U.S. Pat. No. 5,671,264 can be categorized as a variable size non-linear noise filter.
In commonly-assigned U.S. Pat. No. 6,104,839, Cok, Gray, and Matreaszek describe a method of correcting defect pixels in digital images. Although this algorithm was not intended for the reduction of noise of digital images, it employed a pixel region growing technique, that is relevant for noise reduction algorithms. In this algorithm, a defect pixel (the original pixel value has been lost by a scratch or other defect) is replaced by an estimate formed from the surrounding non-defect pixels. A pixel estimate is formed from applying a structural model to the non-defect pixel values contained in a line segment passing through the defect pixel location. Each line segment is grown in a radial direction away from the defect pixel until a statistical condition is satisfied. The line segments comprising the filter are of variable length based on the image pixel values. Multiple line segments are used and the corresponding multiple pixel estimates are used to form a defect-corrected pixel value. Unlike noise reduction algorithms, the pixel defect correction algorithm is only applied to a small collection of defect pixels. The purpose of this algorithm is the reconstruction of lost pixel or corrupted pixels.
A. Lev, S. W. Zucker, and A. Rosenfeld, described two noise reduction algorithms in their journal article Iterative Enhancement of Noisy Images, IEEE Trans. Sysst. Man and Cybem. SCM-7, p. 435-441, 1977. Both these algorithms were based on edge sensitive local weighted averaging techniques. In the first algorithm, local pixel weights are assigned based on the presence or non-presence of edges produced with an edge detection algorithm. Pixels located on edges do not effect the local averaging process. Additionally, non-edge pixels separated from the center pixel by an edge pixel are also excluded (given a weight of zero). In this regard, only the region of non-edge pixels surrounding the center pixel is used to form the noise free pixel estimate. The second algorithm involved a generalization of the edge detection logic that formed the local pixel weights by combining the coefficients derived from four directional gradients filters, i.e. a horizontal, vertical and two diagonal gradient filters. The output of the directional gradient filters were transformed with an exponential function and combined in a multiplicative model to form the final 3 by 3 spatial filter. This filter is actually a filter of filtered responses. Both of the Lev et. al. filters reduce noise in images but must be applied iteratively to have much effect due to small filter size (3xc3x973). Although these filters used a fixed size local surrounding neighborhood, they did incorporate the concept of confining the pixels of consideration to a local domain about the center pixel based on a detected feature. However, the detection of that feature required the algorithm to have knowledge of pixels outside the local domain.
Fixed local surround size noise reduction filters suffer from two main problems. Algorithms employing small filter sizes take less computation time and preserve desirable low amplitude modulation signals but are also less affective at removing noise in unstructured regions. Algorithms employing large filter sizes take more computation time and are more affective at removing noise in unstructured regions but also destroy desirable low amplitude modulation signals. Radial region based noise reduction algorithms are affective at removing noise in unstructured regions but produce unwanted structured patterns in the noise cleaned images. Varying the size of the radial regions randomly can reduce the objectionability of the unwanted structured patterns but does not impact the computation time required.
It is an object of the present invention to provide a noise reduction algorithm which combines the elements of variable filter size based on image pixel data with a radial regions.
The present invention provides a noise reduction method that uses a variable shape and size filter by region growing a local neighborhood region of cleaning pixels, contiguous with the pixel of interest, based on the digital image pixel values.
This object is achieved with a method for removing noise from a pixel of a digital image channel comprising the steps of:
(a) storing an original value of the pixel of interest;
(b) using the value of the pixel of interest and neighboring contiguous pixels to determine a variable shape neighborhood region of cleaning pixels; and
(c) using the neighborhood region of cleaning pixels and the value of the pixel of interest to replace the original value of the pixel of interest with a noise cleaned pixel value.
The present invention overcomes the limitation of fixed filter size algorithms by growing a region of contiguous pixels about the pixel of interest. Since the variable size and shape of the neighborhood region of cleaning pixels is based on the supplied pixel values, low amplitude image detail is preserved while minimizing the effect of induced structured artifacts. In addition, in highly structured regions of digital images, the present invention reduces the number of evaluated pixels thus reducing the computation time.

Region growing based noise reduction method for digital images


There is provided a heating furnace comprising a furnace body, a cylindrical zone heater in the furnace body, a muffle tube installed through the furnace body for thermally treating a porous preform made of high purity quartz glass by moving the preform vertically therethrough and a partition means in the portion of the muffle tube projecting above the furnace body to divide an interior space of the muffle tube into an upper space and a lower one.

1. Field of the Invention
The present invention relates to a furnace for producing a high purity quartz glass preform for an optical fiber. More particularly, it relates to a heating furnace for thermal treatment such as dehydration, doping or sintering of a porous glass preform consisting of fine particles of quartz glass in order to obtain a high purity quartz glass preform for fabricating the optical fiber.
2. Description of the Related Art
In a heating furnace for producing a glass preform for use in the fabrication of an optical fiber, use of a quartz glass muffle tube is described in, for example, Japanese Patent Kokoku Publication Nos. 42136/1983 and 58299/1983 and Japanese Patent Kokai Publication No. 86049/1985. However, the quartz glass tube has a serious disadvantage in that it tends to deform at a high temperature. In practice, when the heating furnace is operated at a temperature greater than 1500.degree. C., the quartz glass tube deforms so that the furnace cannot be used again, unless a pressure difference between the outside and the inside of the muffle tube and a means for supporting the muffle tube are both accurately controlled. Further, when the furnace is used at a temperature greater than 1150.degree. C. over an extended period of time, the quartz glass tube is devitrified or crystallized. Since the thermal coefficient of expansion of the glass layer is different from that of the devitrification layer, the muffle tube is destroyed by the strain resulting from such a difference.
The inventors have found that a carbon tube is suitable for a muffle tube and overcomes the above problems (see, for example, PCT International Publication No. WO 88/06145). The carbon tube not only has an excellent heat resistance since it is stable at a temperature greater than 2000.degree. C., but also is easily purified to a high purity level with an ash content less than 20 ppm. In addition, it advantageously does not react with a reactive gas (for example, Cl.sub.2, CCl.sub.4, SiF.sub.4, SF.sub.6 and CCl.sub.2 F.sub.2) which is useful for the thermal treatment of the glass preform for the optical fiber. The carbon tube can be fabricated precisely so that it may be made in an assembly type to reduce the production cost thereof. Further, in order to improve gas tightness of the carbon tube, it is possible to coat the outer surface thereof with a SiC layer or a further carbon layer whereby the glass preform for the optical fiber having an excellent quality can be produced.
FIG. 1 shows one example of the conventional heating furnace wherein the thermal treatment of a glass soot preform 1 is carried out with a cylindrical zone heater. A carbon heater 4 and a muffle tube 3 are provided in a furnace body 5. This heating furnace comprises an inlet 6 for introducing nitrogen gas for purging the furnace body interior, an inlet 7 for introducing an atmosphere gas to the muffle tube and a supporting rod 2 for the preform 1 which is placed inside the heating furnace. The muffle tube 3 consists of an upper member 34, a middle member 35 and a lower member 36 and at least the middle member 35 is made of carbon, on the surface of which a SiC or carbon coating may be provided.
Since the conventional heating furnace is constituted as shown in FIG. 1, an amount of air around the furnace (an atmosphere in the operation room) flows in the muffle tube when the glass preform enters or leaves the tube. FIG. 2 schematically shows an equipment which is used in measurement of an amount of the air inflow into the muffle tube. This equipment comprises a muffle tube 101, an inlet 102 for purging gas, a gas sampling tube 103, a device 104 for measuring an oxygen concentration and a pump 105, and additionally a zone heater (not shown) around the muffle tube 101. An inner diameter of the muffle tube 101 is 150 mm, and the front end of the gas sampling tube 103 is fixed at a point 1 m below from the upper edge of the muffle tube. The results are shown in FIG. 3. These results indicate that the air flows into the muffle tube, and such air inflow cannot be prevented by increase of the amount of purging nitrogen gas.
Inflow of the air will cause various problems. Firstly, the interior space of the muffle tube is contaminated by dust in the air. The dust comprise SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and the like. Among them, Al.sub.2 O.sub.3 will cause devitrification of the preform, and Fe.sub.2 O.sub.3 will cause increase of transmission loss of the optical fiber. Secondly, the inner surface of the carbon muffle tube is oxidized. During oxidation of the sintered body of carbon, it is known that tar or pitch which is used as a binder is firstly oxidized. Therefore, the remaining graphite particles are dropped or splashed and float in the furnace. Since said particles adhere to the surface of the sintered glass preform, the optical fiber fabricated from such the glass preform has many parts with low strength. As a natural consequence, the lifetime of the carbon muffle tube is extremely shortened.
The first measure to prevent such oxidation of the muffle tube is to reduce the temperature to 400.degree. C. or lower at which the carbon is not oxidized during the insertion and removal of a glass preform. However, at such the low temperature, the operation rate of the furnace is greatly decreased. In addition, once the muffle tube is exposed to the air, a considerable amount of oxygen and moisture in the air is adsorbed on the muffle tube since the carbon muffle tube is porous. Then, the oxidation cannot be prevented completely.
As the second measure, a method is described in PCT International Publication No. WO 88/06145. The method comprises once disposing the porous glass preform in a front chamber on the top of the muffle tube and inserting the glass preform into the muffle tube after gas replacement of the atmosphere in the front chamber with an inert gas. The muffle tube equipped with the front chamber is shown in FIG. 4.
The carbon heater 4 and the carbon made muffle tube 3 are provided in the furnace body 5 as shown in FIG. 4. The heating furnace comprises an inlet 6 for introducing a purging nitrogen to the furnace body, an inlet 7 for introducing an atmosphere gas to the muffle tube, supporting rod 2 for the glass preform, the front chamber 11, an exit 14 for exhausting the gas from the front chamber and a partition 16. The glass preform 1 is inserted into the heating furnace.
The insertion of the porous glass preform into the heating furnace shown in FIG. 4 is carried out as follows:
(1) To a rotatable and vertically movable chuck, the porous glass preform 1 is attached through the supporting rod 2. PA1 (2) An upper cover of the front chamber 11 is opened, and the porous preform 1 is lowered into the front chamber 11. PA1 (3) The upper cover is closed, and the interior space of the front chamber is purged with an inert gas (e.g. nitrogen or helium). PA1 (4) The partition 16 which separates the front chamber 11 from the heating atmosphere is opened, and the porous preform 1 is introduced in the heating atmosphere which has been kept at a temperature at which the preform should be thermally treated. PA1 (5) The partition 16 is closed. PA1 (1) The partition 16 is opened. PA1 (2) The preform 1 which has been thermally treated is pulled up from the heating atmosphere to the front chamber 11. In this step, the temperature of the heating atmosphere is not necessarily lowered. PA1 (3) The partition 16 is closed. PA1 (4) The upper cover of the front chamber 11 is opened, and the preform is removed from the chamber 11. PA1 (1) The partition 16 consists of three members so that it takes a considerable time to close or open the partition; PA1 (2) The structure of the partition 16 is rather complicated. In particular, it is difficult to confirm the perfect closing of the split members. Then, there is a great possibility to open the front chamber to the air with an insufficient sealing; and PA1 (3) It takes a long time to replace the interior atmosphere of the front chamber with the inert gas since the volume of the partition portion increases due to the complicated structure of the partition.
The removal of the glass preform from the heating furnace is carried out as follows:
Though the above furnace is superior in preventing oxidation of the muffle tube, an overall length of the heating apparatus is too long and the structure of the partition 16 is complicated. FIG. 5 shows an example of the heating apparatus for thermal treatment of a porous glass preform having an overall length of 800 mm and a seed rod length of 200 mm. In this case, the length from the lower end of the muffle tube to the lower end of the chuck is 6760 mm and the overall length of the apparatus reaches nearly 8000 mm by taking account of spaces for operation and design.
Further, since the partition 16 should be adaptable to both cases where the supporting rod is and is not through the partition, totally three members should be used, two of which are split members each having an partly cut off portion for the supporting rod, and one of which is a member to close an aperture through which the rod is passed.
Then, the procedures for operating the partition 16 is hereinafter described with reference to FIGS. 6 to 8.
FIG. 6 shows a cross-sectional view of the partition in detail when the glass preform 1 is disposed in the front chamber 11, FIG. 7 shows when the glass preform 1 is being inserted into the heating atmosphere of the muffle tube through the partition 16 after the atmosphere in the front chamber is replaced with an inert gas and the partition 16 is opened, and FIG. 8 shows when the glass preform is thermally treated.
To carry out the above three operations, three members, that is, the covering member 72 for covering an aperture and two split members 71 which are operated with two sliding rods 73 should be used.
Then, some problems arise as follows:

Furnace for producing high purity quartz glass preform


An optoelectronic module. In some embodiments, the module includes: a housing, a substantially planar subcarrier, a photonic integrated circuit, and an analog electronic integrated circuit. The subcarrier has a thermal conductivity greater than 10 W/m/K. The photonic integrated circuit and the analog electronic integrated circuit are secured to a first side of the subcarrier, and the subcarrier is secured to a first wall of the housing. A second side of the subcarrier, opposite the first side of the subcarrier, is parallel to, secured to, and in thermal contact with, an interior side of the first wall of the housing.

Pluggable transceivers which include (i) one or more transmitters to convert electrical signals carrying data to optical signals carrying the same data and (ii) one or more receivers to convert optical signals to electrical signals may be used, for example, in switching systems. The design of a pluggable module may pose various challenges, including respecting space constraints, and keeping components in the module within acceptable temperature ranges.

Module with transmit and receive optical subassemblies with specific pic cooling architecture


An optical transmission device includes: a variable dispersion compensator to give chromatic dispersion and output an input light, a branching unit to branch the light output from the variable dispersion compensator to a first part and a second part, a reproduction unit to reproduce an electric signal from the first part of the input light, a monitor unit to perform reproducing processing on the electric signal from the second part of the input light, control the variable dispersion compensator based on a result of the reproducing processing, and has a sensitivity to a variation of the chromatic dispersion which is higher than the sensitivity to the variation of the chromatic dispersion of the reproduction unit.

Conventionally, an optical transmission system using light as a signal medium has been used to perform high-speed and long-distance communication. In the above-described optical transmission system, a waveform of an optical signal is deteriorated by chromatic dispersion due to characteristics of the optical transmission path. When the wavelength of the optical signal is deteriorated, there is a high possibility that a transmission error occurs with respect to an original signal included in the optical signal. Therefore, for the optical transmission system, a technique has been developed to compensate for chromatic dispersion generated on the optical transmission path by a variable dispersion compensator located in a receiving unit of an optical transmission device that transmits and receives the optical signal.
For example, a dispersion compensation device that controls a dispersion compensation amount of the variable dispersion compensator has been developed based on code error information of a signal that is output through an optical reception path from the variable dispersion compensator. Moreover, a dispersion compensation method for controlling the dispersion compensation amount of the variable dispersion compensator according to the code error information in accordance to a code type in a data signal obtained by receiving a dispersion-compensated optical signal has been developed.
The conventional techniques are disclosed in Japanese Laid-open Patent Publication No. 2002-208892 and Japanese Laid-open Patent Publication No. 2005-286382.

Optical transmission device, transmission and reception module, optical transmission system, and wavelength dispersion compensation method in optical transmission device


There is disclosed a refractory baffle for use in a fireplace which dispenses, via apertures provided therein, preheated combustion air over the central combustion zone of the fireplace. The refractory material substantially avoids warpage, flame quenching and other limitations associated with metal baffles.

Generally speaking, hollow baffle structures are used in wood stoves and fireplaces to provide preheated combustion air. This provision reduces emissions and enhances combustion of the products within the stove or fireplace.
Presently, metal baffles are used in the art. Although baffles composed of metal have utility, they are susceptible to warping from the heat and are believed to quench the flames which may cause an increased in emissions.
The cost of replacement of an ineffective baffle as well as the potential for combustion product deposit within the chimney of a stove or fireplace indicate that a more effective arrangement is required.
The prior art has provided several baffle structures, typical of which is illustrated in Canadian Patent Application Serial No. 2,001,309. This reference teaches a generally triangular hollow baffle composed of metal. Apertures are provided in a localized area of the baffle for directing preheated combustion air over the flames in the combustion area. There is no discussion or contemplation for the use of a refractory composition for the baffle.
Canadian Patent Application Serial No. 2,004,553 discloses the use of a ceramic material of which the baffle is made. The combustion air is not preheated and dispensed through the baffle. The baffle is devoid of openings over its surface and thus cannot enhance combustion by the use of preheated air.
Canadian Patent Application Serial No. 2,008,981 teaches a primarily mechanical arrangement for introducing preheated air into the path of solid fuel combustion residues. The arrangement includes metal parts and accordingly, may be susceptible to warpage.
Further, Canadian Patent Application Serial No. 2,040,556 teaches a baffle including a heat exchanger, primarily composed of metal. The arrangement provides a tiered structure having an opening therein for the passage of preheated air. The unit may be susceptible to overheating the air to the point where the air is expanded too much to be effective.


In an embodiment, a combining write buffer is configured to maintain one or more flush metrics to determine when to transmit write operations from buffer entries. The combining write buffer may be configured to dynamically modify the flush metrics in response to activity in the write buffer, modifying the conditions under which write operations are transmitted from the write buffer to the next lower level of memory. For example, in one implementation, the flush metrics may include categorizing write buffer entries as “collapsed.” A collapsed write buffer entry, and the collapsed write operations therein, may include at least one write operation that has overwritten data that was written by a previous write operation in the buffer entry. In another implementation, the combining write buffer may maintain the threshold of buffer fullness as a flush metric and may adjust it over time based on the actual buffer fullness.

1. Field of the Invention
This invention is related to the field of processors and, more particularly, to combining write buffers in caches.
2. Description of the Related Art
Processors often implement combining write buffers to capture write operations that have been written to a higher level write-through cache (e.g. an L1 cache), to buffer those writes prior to updating a lower level cache (e.g. an L2 cache). The combining write buffer combines two or more write operations that target data within the same cache block, and thus present fewer writes to the L2 cache.
The combining write buffer can accumulate write operations for some time. Determining when to flush write operations from one or more combining write buffer entries is a tradeoff between bandwidth and performance. Buffering write operations in the combining write buffer can lead to better bandwidth efficiency. On the other hand, if data is buffered for too long, the performance may suffer as data that needs to be pushed to lower level caches or memory remains in the combining write buffer.

Combining write buffer with dynamically adjustable flush metrics