A detecting apparatus includes the following units. A pressure detecting unit detects in time series higher and lower static pressures and a differential pressure. Fluctuation calculating units calculate time series data sets of a differential pressure fluctuation, a higher static pressure fluctuation, and a lower static pressure fluctuation. Square sum calculating units calculate the square sum of the time series data sets of the differential pressure fluctuation, the square sum of the time series data sets of the higher static pressure fluctuation, and the square sum of the time series data sets of the lower static pressure fluctuation. A correlation coefficient calculating unit calculates first and second correlation coefficients. An intermediate variable calculating unit calculates an intermediate variable. A blockage rate calculating unit calculates a blockage rate. A determination unit determines a blockage of higher and lower pressure impulse lines with reference to the blockage rate.

1. Field of the Invention
The present invention generally relates to an apparatus and method for detecting blockage of impulse lines. More specifically, the present invention relates to an apparatus and method for detecting blockage of impulse lines that are coupled to a differential pressure transmitter, wherein the differential pressure transmitter is configured to measure the differential pressure of a fluid that flows through a tube.
Priority is claimed on Japanese Patent Application No. 2006-84524, filed Mar. 27, 2006, the content of which is incorporated herein by reference.
2. Description of the Related Art
All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains.
It is well-known to a person skilled in the art to which the invention pertains that a differential pressure transmitter can be used to detect the differential pressure between upstream and downstream of an orifice that is provided in a tube. The differential pressure transmitter is coupled to upstream and downstream impulse lines. These upstream and downstream impulse lines are further coupled to the tube at upstream and downstream positions thereof, respectively. The upstream and downstream positions are positioned upstream and downstream of the orifice, respectively. The fluid may have different pressures upstream and downstream of the orifice. The pressure of a fluid upstream of the orifice will hereinafter be referred to as an upstream pressure. The pressure of a fluid downstream of the orifice will hereinafter be referred to as a downstream pressure. In general, the upstream pressure is higher than the downstream pressure. Thus, the upstream and downstream impulse lines may also be referred to as higher and lower pressure impulse lines, respectively.
The upstream and downstream impulse lines are respectively configured to allow the upstream and downstream pressures to travel from the tube to the differential pressure transmitter. The differential pressure transmitter is configured to measure the traveled upstream and downstream pressures so as to detect the differential pressure based on the measured upstream and downstream pressures.
A blockage of the impulse line or impulse lines can prevent the differential pressure transmitter from accurately detecting the differential pressure. In view of monitoring the fluid in the tube, it is important to detect or diagnose that a blockage is present or absent in the impulse line or impulse lines.
A conventional method of detecting a blockage in the impulse line or impulse lines will be described. It is assumed that Dps(i) represents data sets that are related to differential pressure in the normal state in which the impulse lines are free from any blockage. These differential pressure data sets are obtainable in time series from the differential pressure transmitter. The differential pressure has fluctuations Fdps(i) that are given by the following equation (1), where Dps(i) is the current differential pressure data set that is currently obtained from the differential pressure transmitter, and Dps(i−1) is the last differential pressure data set that was last obtained from the differential pressure transmitter. The differential pressure fluctuations Fdps(i) have a variance Vas (root mean square) that is given by the following equation (2), where N is the total sample number of the differential pressure data sets Dps. The variance Vas that is previously found before the diagnosis is made will hereinafter be referred to as "standard fluctuation variance".Fdps(i)=Dps(i)−Dps(i−1)  (1)Vas=Σ{Fdps(i)2}/N  (2)
The differential pressure fluctuation Fdps(i) and the fluctuation variance Va are determined based on the differential pressure data sets Dps(i) every time the impulse lines are diagnosed during the actual operation of the plant. The above-mentioned equations (1) and (2) can be used to determine the differential pressure fluctuations Fdps(i) and the fluctuation variance Va, respectively.
The square root (D′(Va/Vas)) of a ratio of the fluctuation variance Va to the standard fluctuation variance Vas will be introduced. This value D′(Va/Vas) can be calculated, where the standard fluctuation variance Vas is previously obtained before the diagnosis is made, and the fluctuation variance Va is obtained at the time of diagnosing the impulse lines. The fluctuation variance Va depends on a blockage of the impulse line or impulse lines. This means that the value D′(Va/Vas) also depends on a blockage of the impulse line or impulse lines. Thus, a blockage of the impulse line or impulse lines can be detected by detecting the value D′(Va/Vas).
For example, if both the higher and lower pressure impulse lines have a blockage, then the fluctuation variance Va of the differential pressure becomes smaller than the standard fluctuation variance Vas and also the value D′(Va/Vas) becomes smaller than 1. If either the higher or lower pressure impulse line has a blockage, then the fluctuation variance Va becomes larger than the standard fluctuation variance Vas and also the value D′(Va/Vas) becomes larger than 1. If both the higher and lower pressure impulse lines are free of any blockage, then the fluctuation variance Va approaches the standard fluctuation variance Vas and the value D′(Va/Vas) approaches 1. By comparing the value D′(Va/Vas) to the predetermined threshold, for example, 1, it can be determined whether both or either one of the higher and lower pressure impulse lines have a blockage or the both lines are free of any blockage.
Instead of the above-mentioned equation (1), the following equation (3) can be used to find the differential pressure fluctuation. In case of using the above-described equation (1), the calculated differential pressure fluctuation may reflect a transitional variation component of the differential pressure. The transitional variation may be rising and dropping of the differential pressure.Fdps(i)=Dps(i)−2Dps(i−1)+Dps(i−2)  (3)
However, in case of using the last-mentioned equation (3), the calculated differential pressure fluctuation is free from the transitional variation component of the differential pressure.
Meanwhile, the variance of the differential pressure fluctuations may vary depending on not only blockage of the impulse lines but also the flow rate of a fluid in the tube. The above-described standard fluctuation variance Vas is an experimental value that is measured at a predetermined or fixed flow rate of the fluid in the tube. During the actual operation of the plant, variation in the flow rate of the fluid may cause variation of the above value D′(Va/Vas). However, this variation is independent of the blockage rate of the impulse line or impulse lines. This means that the above-described threshold and the standard fluctuation variance should be set by taking into account the flow rate of the fluid. In other words, to avoid a blockage misdiagnosis it is necessary to update the above-described threshold and the standard fluctuation variance based on variation in the flow rate of the fluid.
There has been developed another conventional technique to correctly detect or diagnose a blockage of the impulse line or impulse lines. This detection or diagnosis is made independently of the flow rate of the fluid. The higher static pressure fluctuations Fsph(i) are calculated in accordance with the following equation (4) by using data sets Sph(i) related to the higher static pressure of a fluid. The higher static pressure is the static pressure of a fluid upstream of the orifice. The higher static pressure data sets Sph(i) are obtainable in time series from the differential pressure transmitter. Also, the lower static pressure fluctuations Fspl(i) are calculated in accordance with the following equation (5) by using other data sets Spl(i) related to the lower static pressure. The lower static pressure is the static pressure of a fluid downstream of the orifice. The lower static pressure data sets Spl(i) are also obtainable in time series from the differential pressure transmitter.Fsph(i)=Sph(i)−Sph(i−1)  (4)Fspl(i)=Spl(i)−Spl(i−1)  (5)
Subsequently, the sum of squares (Ssph) of the higher static pressure fluctuations Fsph(i) is calculated in accordance with the following equation (6). The other sum of squares (Sspl) of the lower static pressure fluctuations Fspl(i) is calculated in accordance with the following equation (7).Ssph=Σ{Fsph(i)2}  (6)Sspl=Σ{Fspl(i)2}  (7)
There is hereby introduced a ratio (D=Ssph/Sspl) of the sum of squares (Ssph) of the higher static pressure fluctuations Fsph(i) to the sum of squares (Sspl) of the lower static pressure fluctuations Fspl(i). This ratio (D=Ssph/Sspl) depends on a blockage of the impulse line or impulse lines. Thus, a blockage of the impulse line or impulse lines can be detected by detecting the ratio (D=Ssph/Sspl).
If the higher pressure impulse line is completely blocked, then the calculated value (Ssph) shall theoretically be equal to zero, and the other calculated value (Sspl) shall theoretically be a predetermined threshold as a non-zero value. Thus, the ratio (D=Ssph/Sspl) shall also be equal to zero. Actually, however, the differential pressure transmitter generates a noise-containing output signal. The noise of the output signal may cause the ratio (D=Ssph/Sspl) to be a non-zero value, for example, approximately 0.05.
If the lower pressure impulse line is completely blocked, then the calculated value (Sspl) should theoretically be equal to zero, and the other calculated value (Ssph) shall theoretically be a predetermined threshold as a non-zero value. Thus, the ratio (D=Ssph/Sspl) shall theoretically be infinite. Actually, however, the output signal noise may cause the ratio (D=Ssph/Sspl) to be a non-infinite value, for example, approximately 20. If both the higher and lower pressure impulse lines are free of any blockage, then both the calculated values (Ssph) and (Sspl) are close to each other. Thus, the ratio (D=Ssph/Sspl) shall be close to 1. Accordingly, by detecting the ratio (D=Ssph/Sspl), it can be determined which impulse line is blocked or both the impulse lines are not blocked.
If the flow rate of a fluid in the tube is increased, then both the calculated values (Ssph) and (Sspl) are also increased together. Also, if the flow rate is decreased, then both the calculated values (Ssph) and (Sspl) are also decreased together. Thus, the ratio (D=Ssph/Sspl) is independent of the flow rate. It is possible to accurately detect or diagnose a blockage of the impulse line or impulse lines independently of the flow rate of the fluid in the tube. The higher and lower static pressure fluctuations Fsph(i) and Fspl(i) can be determined in the same manner as described above.
The above-described and other technical backgrounds are disclosed in Japanese Unexamined Patent Applications, First Publications, No. 2004-132817, No. 2004-294175, and No. 2005-274501.
As described above, the second conventional technique can be used to accurately detect or diagnose a blockage of the impulse line or impulse lines independently of the flow rate of a fluid in a tube. The second conventional technique makes it difficult to set a threshold that is compared to the ratio (D=Ssph/Sspl).
If the higher pressure impulse line is completely blocked, the actual ratio (D=Ssph/Sspl) is approximately 0.05. If the lower pressure impulse line is completely blocked, the actual ratio (D=Ssph/Sspl) is approximately 20. If both the higher pressure impulse lines are not blocked, then the actual ratio (D=Ssph/Sspl) is nearly equal to 1. Thus, the threshold can be set 1. In this case, if the actual ratio (D=Ssph/Sspl) is less than 1, then it is determined that the higher pressure impulse line is blocked while the lower pressure impulse line is not blocked. If the actual ratio (D=Ssph/Sspl) is more than 1, then it is determined that the lower pressure impulse line is blocked while the higher pressure impulse line is not blocked.
In other words, if the higher pressure impulse line is blocked, then the actual ratio (D=Ssph/Sspl) is in a wider range of 1<D≦20. If the lower pressure impulse line is blocked, then the actual ratio (D=Ssph/Sspl) is in a narrower range of 0.05≦D<1. The determination range indicating that the higher impulse line is blocked is different in width from the other determination range indicating that the lower impulse line is blocked. This makes it inconvenient and difficult for a user to set the threshold.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved apparatus and/or method. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.

Apparatus and method for detecting blockage of impulse lines


An integrated circuit (IC) includes volatile memories, at least one non-volatile memory, at least one control circuit, and a configurable logic array. Each volatile memory has an associated interface including a respective first input and a respective second input. The control circuit is coupled to the volatile memories and the non-volatile memory. The control circuit stores respective contents from each volatile memory in the non-volatile memory responsive to the respective first input, and loads the respective contents into each volatile memory from the non-volatile memory responsive to the respective second input. The configurable logic array is coupled to the volatile memories and is configurable to control each first input and each second input.

A programmable logic device (PLD) that includes non-volatile memory may retain data without power. The data retained in the non-volatile memory may be used for various purposes. A portion of the retained data may be configuration data used to program the logic and routing resources of the PLD to perform a specific function. In addition, a portion of the retained data may be accessible by the programmed device. The retained data may also include operating state of the configured function preserved during power-down of the PLD.
Generally a specific protocol is required to be implemented in the configured function to gain access to the retained data in the non-volatile memory. Reformatting of the retained data may further be required to enable application reading and writing of the retained data. A developer of an application for a PLD may devote significant effort in implementing the specific protocol and the data reformatting in the configured function. That effort may discourage development of applications using retained data from a non-volatile memory included in the PLD.
The present invention may address one or more of the above issues.

Interface for access to non-volatile memory on an integrated circuit


A computing system includes an anonymizer server. The anonymizer server is communicatively coupled to a data repository configured to store a personal identification information (PII) data. The anonymizer server is configured to perform operations including receiving a repository configuration request comprising an anonymized data schema, and creating an anonymized data repository clone based on the anonymized data schema. The anonymizer server is also configured to perform operations including anonymizing the PII data to create an anonymized data by applying a one-way data masking, a one-way data morphing, or a combination thereof, and storing the anonymized data in the anonymized data repository clone.

The present disclosure relates generally to data repositories and, more particularly, to anonymized data repositories.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Cloud computing relates to the sharing of computing resources that are generally accessed via the Internet. In particular, a cloud computing infrastructure allows users, such as individuals and/or enterprises, to access a shared pool of computing resources, such as servers, storage devices, networks, applications, and/or other computing based services. By doing so, users are able to access computing resources on demand that are located at remote locations, which resources may be used to perform a variety computing functions (e.g., storing and/or processing large quantities of computing data). For enterprise and other organization users, cloud computing provides flexibility in accessing cloud computing resources without accruing large up-front costs, such as purchasing expensive network equipment or investing large amounts of time in establishing a private network infrastructure. Instead, by utilizing cloud computing resources, users are able redirect their resources to focus on their enterprise's core functions.
In modern communication networks, examples of cloud computing services a user may utilize include so-called software as a service (SaaS) and platform as a service (PaaS) technologies. SaaS is a delivery model that provides software as a service rather than an end product. Instead of utilizing a local network or individual software installations, software is typically licensed on a subscription basis, hosted on a remote machine, and accessed by client customers as needed. For example, users are generally able to access a variety of enterprise and/or information technology (IT)-related software via a web browser. PaaS acts an extension of SaaS that goes beyond providing software services by offering customizability and expandability features to meet a user's needs. For example, PaaS can provide a cloud-based developmental platform for users to develop, modify, and/or customize applications and/or automating enterprise operations without maintaining network infrastructure and/or allocating computing resources normally associated with these functions.
Within the context of cloud computing solutions for data repositories, users may be asked to deal with ever increasing amounts of data, e.g., including certain Personally Identifiable Information (PII) stored in the data repositories. In fact, the amount of cloud-based data collected and stored in today's cloud computing solutions, such as cloud-based repositories, may be orders of magnitude greater than what was historically collected and stored. Users tasked with automating and/or troubleshooting enterprise, IT, and/or other organization-related functions (e.g., incident tracking and/or help desk-related functions) navigate ever increasing amounts of data to properly and efficiently perform their job functions. In certain embodiments, cloned data repositories may be created. With this in mind, the following embodiments are directed to improving the manner in which PII data may be derived for certain data repositories, including cloned data repositories.

System and method for anonymized data repositories


The invention relates to screen fabric, fabric border constructions, and screen frames. The fabric border constructions and frame are of a size and shape so as to releaseably fit and lock together. The fabric is attached to the border constructions and is of a size and shape in relation to the frame so as to be stretched to a precalculated tension upon being acted upon by the placement of the border strips on the frame. The invention provides for the border constructions and fabric to be released from the frame and later reattached duplicating the tension and placement of all coordinates of the fabric in relation to coordinates of the frame.

1. Field of the Invention
This invention relates in general to stretching fabric on frames and in particular to retensioning fabric on frames as used in screen printing.
2. Prior Art
Screen printing involves the use of stretched fabric that is attached to a frame. Desirable attributes of screens are 1) that the fabric is very tightly stretched to a consistent tension, 2) that the fabric is held in place on the frame, and 3) that the fabric after it is coated with emulsion and has had an art pattern exposed onto the emulsion can be released from the frame with the art pattern intact and put into storage to be later restretched on the frame so as to accurately duplicate the tension level previously attained and to accurately match the placement of the art pattern in relation to the coordinates of the frame with the position previously attained. It is also desirable that this process be achieved quickly and easily and that fabric is not wasted. The oldest method of stretching fabric is with clamps that are pulled by hand, pneumatic pressure, or mechanically. Tension meters are used to determine the tightness of the screen fabric and adjustments are made to either loosen or tighten the fabric in order to approach a prescribed tension level. Once the tension level is reached, the fabric is glued or stapled to the frame. Once this is done, the fabric cannot be released from the frame without destroying the fabric. These methods do not solve the problem of restretching the fabric or address efficient and convenient storage.
I have observed that in one field of screen printing, i.e., that of printing on glass cylinders, in which relatively loose fitting stainless steel fabric is used, the fabric has border strips of extruded plastic along one axis that cup over flanges on the outside of the frame thus holding the fabric in place on two sides only. The other two edges of the fabric have border strips of metal that are crimped on to the stainless steel fabric and bolted to the frame. This construction is specifically designed to allow electric current to flow through the screen and heat the screen to melt a thermoplastic printing ink. It was observed that there are no means in this construction to significantly tighten the fabric. The two edges of the fabric with the extruded plastic border strips can only be loosely pulled by hand and cupped over the frame flanges. The construction of the plastic borders does not provide a means for attaching a clamp or any type of stretching device to pull the fabric tight enough to meet the tension requirements of most screen printers. Also, there is no indexing of the extruded plastic border strips along the frame flanges which means that the plastic borders, which are shorter than the flange, could vary in their placement along the flanges. Along the other axis at the other two edges, the metal border strips were observed to be crimped onto the stainless steel fabric and had holes through which they were bolted to the frame. With more than just a minimal tension along this axis, the fabric would tear loose, especially polyester fabric.
This device allows the fabric to be loosely stretched, released, and loosely restretched with an art pattern only approximating its original position in relation to the coordinates of the frame.
Widely used today are draw bar frames U.S. Pat. Nos. 3,482,343 and 3,553,862 and roller frames U.S. Pat. Nos. 3,908,293 and 4,345,390. The draw bar frame incorporates pulling clamps as part of the frame and roller frames allow the fabric to be rolled tightly by means of rollers that form the four sides of a frame. These devices solved the problem of how to stretch fabric, release it for storage, and restretch the same fabric at a later time. However, it still required the trial and error method of reaching a prescribed tension level with the use of a tension meter and there still was no way of restretching an art pattern back to its original position in relation to the coordinates of the frame.
In U.S. Pat. No. 3,991,677 of 1976 by V. H. Barnes entitled "Printing Screen and Tensioning Means" is described a frame structure with a stretching mechanism incorporated into the frame structure. Also described is a screen with border strips that attach to tension bars of the stretching mechanism. In U.S. Pat. No. 3,211,089 of 1962 by Elmar Messerschmitt entitled "Screen Printing Screen" is described a frame structure with a stretching mechanism incorporated into the frame. The Messerschmitt invention uses a continuous border around the fabric which attaches to an element of the frame. The frame expands telescopically thereby stretching the fabric. U.S. Pat. No. 3,416,445 of 1965 by T. H. Krueger entitled "Screen Stencil with Separate Border Strips" describes various border strips, fabric, and frames. One embodiment of this invention has two adjacent sides of the fabric with border strips attached to a frame on studs whereas the other two opposite sides are pulled outward by flexible straps pinned to the border strips and wrapping around rotating crank shafts that are part of the frame. These flexible straps are all that hold these two border strips in place on this frame. Another embodiment of this invention features L shaped border strips. A third embodiment features a rigid continuous border that cannot be stretched and is fundamentally a frame attached to another frame.
The Barnes, Messerschmitt, and Krueger inventions require stretching mechanisms that are incorporated into the frames. The stretching mechanisms have moving parts which, like draw-bar frames and roller frames, are added expenses in the construction of the frames and add extra weight to the frames. These stretching mechanisms with their moving parts are exposed to the every day spraying, washing, and rinsing of the screens with water, cleaning compounds, solvents, and inks. They are subjected to the wear and tear of shop operations which usually includes a significant amount of mechanical shock. These parts, of course, depreciate under these severe conditions.
These three inventions do not utilize locking mechanisms that secure all four fabric edges into definite fixed positions on the frames. The Barne's invention does not have any pins, studs, abutments, etc. to fix the exact lateral location of the border strips on the tension bars. The Messerschmitt invention's continuous border is of a flexible material that stretches and is therefore unreliable as an aligning feature, particularly after repeated uses. The Krueger invention utilizes studs on two sides only to fix the locations of two unmoveable border strips. These two border strips do not at any time move to a more outward position on the frame. The other two border strips are attached to flexible straps which are unreliable as aligning features. Also, by only outwardly moving two border strips, the corner area between the stationary strips is under very little tension and the area between the two outwardly moved border strips is under extremely high tension. The tension throughout the fabric, because of the stretching method employed by this invention, is very inconsistent. This tension inconsistency in the fabric similarly exists in the L shaped border strips embodiment of this invention.
In none of the above cited references is there an inflexible aligning feature providing reliable alignment for a border strip that is moved to a more outward position. In none of the above cited references is there a discussion, object, or claim of controlling the stretch distances of the fabric along the X and Y axis by establishment of exact start and stop positions of the border strips so as to effect precalculated stretch distances for fabric of precalculated size and shape.
Whatever the precise merits, features, and advantages of the above cited references, none of them achieves or fulfills the purposes of the interlocking screen fabric, border strips and frames of the present invention.

Interlocking fabric, border constructions and frames


A marine lifesaving system is disclosed. A marine lifesaving system comprises an insulated container comprising a plurality of walls and a lid, at least one locking means to selectively and co-operatively secure said lid with said insulated container, at least one storage receptacle defined in one or more of the walls, or the lid, of the insulated container, at least one bladder system located in the at least one storage receptacle, at least one compressed gas canister connected to each of the at least one bladder systems, and an activation device for activating the at least one compressed gas canister, thereby inflating the at least one bladder system, wherein the activation device consists of a pull-string that extends exterior to the at least one storage receptacle.

Various marine lifesaving devices are commercially available, including floating devices of different shapes and sizes, life vests comprised of rigid foam or inflatable bladders, life rafts of varying shapes and personal watercraft. Many of the available marine lifesaving devices, however, have potential disadvantages. Floating devices, for example, may be ideal for victims who involuntarily fall over board, but if said victim is in an enclosed environment, such as a closed deck on a boat, wearing said device may be more dangerous than using no safety device at all, since the victim would be unable to swim underwater to escape the closed deck. Even a prolific swimmer would be incapable of escaping from a capsized vessel, if wearing a floating device when under a closed deck of the vessel. Therefore, many flotation devices that are made of foam materials are required to be located either on open decks or with direct access to an open environment. Similarly, life jackets are required to be onboard all water vessels but life jackets are not required to be worn by federal law (except for children under 13 or in states where a lifejacket law exists). Since they are not required to be worn, unlike a seatbelt in a car, life jackets are generally stowed in compartments and other locations on a vessel that are out of sight to prevent unnecessary wear and tear or from having them blown over board. Therefore, they are not easily accessible in time of emergency.
Life rafts are another means that are frequently used in lifesaving situations when someone involuntarily goes overboard a vessel, when a vessel capsizes or sinks or other emergency situations are encountered while on a vessel. However, most life rafts are large, expensive and not easily stowed onboard vessels. They are hard to access even in emergency situations when a vessel is capsizing or sinking, unless they are readily carried out in the open. Also, many of the commercially available life rafts are difficult to assemble and cannot be used in smaller vessels. Another problem with available lifesaving devices is that they can be large, bulky and cause visual clutter. In situations where visual aesthetics are important, such as on super-yachts and other high-end, luxury watercraft, large and bulky lifesaving devices can be unseemly and undesirable.
Consequently, a need exists to overcome the problems with the prior art, and particularly for a more efficient way of providing an onboard, readily accessible, lifesaving flotation system.

Supplemental lifesaving system integrated in an object


A fuse structure in an integrated circuit chip is described that includes an insulated semiconductor substrate; a fuse bank integral to the insulated semiconductor substrate consisting of a plurality of parallel co-planar fuse links; and voids interspersed between each pair of the fuse links, the voids extending beyond a plane defined by the co-planar fuse links. The voids surrounding the spot to be hit by a laser beam during fuse blow operation act as a crack stop to prevent damage to adjacent circuit elements or other fuse links present. By suitably shaping and positioning the voids, a tighter pitch between fuses may be obtained.

This invention relates to the fabrication of integrated circuits and, more particularly, to a method for protecting fuses from damage while at the same time increasing the fuse density (i.e., the number of fuses per unit area) when employing a laser beam to blow selected fuses forming a fuse bank.
Semiconductor integrated circuits (IC) and their manufacturing techniques are well known in the art. In typical integrated circuits, large number of semiconductor devices are fabricated on a silicon substrate. To achieve the desired functionality, a plurality of conductors are typically employed for coupling selected devices together. In some integrated circuits, some of the conductive links or wires may be coupled to fuses, which may be selectively programmed (i.e., blown) after fabrication using lasers. By way of example, in a dynamic random access memory (DRAM), fuses may be employed during manufacturing to protect from destruction some of the gate stacks of the transistors from inadvertent built-up charges. Once the fabrication of the IC is substantially complete, the fuses may be blown or cut to permit the DRAM circuit to function as if the protective current paths never existed. More commonly, fuses may be employed to set an enable bit and address bits of a redundant array element in a DRAM circuit or for repairing defects found in the DRAM by appropriate replacement of defective elements with redundancy replacement elements present within or without the chip.
To facilitate discussion, FIG. 1 illustrates a typical dynamic random access memory (DRAM) integrated circuit, including a main memory array 102. To allow the replacement of a defective main array element within main memory array 102, a redundancy replacement array 104 is provided as shown. A plurality of fuses in fuse array 106 are coupled to redundancy array 104 via a fuse latch array 108 and a fuse decoder circuit 110. In order to replace a defective main memory array element, individual fuses in fuse array 106 may be blown or cut by setting their values to either a binary 1 or 0 as dictated by the decoder circuit. During this operation, the values of the fuses in fuse array 106 are typically loaded into the fuse latch array 108 when power is turned on. These values are then decoded by fuse decoder circuit 110 during run time, thereby facilitating the replacement of selected defective memory array elements with specific redundancy elements which are part of the redundancy array 104. Techniques for replacing failed main memory array elements with redundant array elements are well known in the art and will not be discussed in great detail here for brevity sake.
As previously mentioned, the fuse links within fuse array 106 may be selectively blown or programmed with a laser beam. Once blown, the fuse changes from a highly conductive state to a highly resistive (i.e., non-conductive) state, since a programmed fuse inhibits current from flowing through it and represents an open circuit to the path taken by the current.
With reference to FIG. 2a, a fuse bank 200 is shown having a plurality of fuse links, such as 202, 204, 206, and 208, (represented in FIG. 1 as fuse array 106), are shown in their original unblown, i.e., conductive state.
In FIG. 2b, a laser beam has been employed to cut or blow fuse link 204, thereby inhibiting the flow of current therethrough. If the fuses are placed too closely together for a given laser wavelength and spot size, i.e., by deleting the fuse, an adjacent fuse link may inadvertently be blown or cut, rendering the IC defective or, at best, a possibility exists of causing damage to neighboring fuses during the fuse blow process. This is because the damage zone around a blown fuse is typically larger than the fuse itself in view of a number of factors, such as the laser spot size, thereby damaging the passivation layer over the fuses which extend outward from the fuses. Clearly many factors enter in determining the severity of the damage caused by laser beam, e.g., the amount of energy carried by the beam, its wavelength and the diameter of the beam.
In FIG. 3a, there is shown a typical fuse bank 300 consisting of fuses 302, 304, and 306. Additional structures, e.g., 308 and 310, are placed within the fuse bank and between the fuses. These structures, formed by barrier material, typically tungsten or molybdenum, act as crack stops when fuse 304 is blown by a laser beam (not shown). Further exhibited are cracks 320 propagating from fuse 304 and stopping at crack stop 308 and 310.
In another view of the same structure (FIG. 3b), a top view of the above structure built on a substrate 350 is illustrated. Only two fuses, i.e., 302 and 304, are exhibited. The crack stop is made up of several layers 330 through 340 which coincide with the several levels of wiring used in the fabrication process of the semiconductor chip. Once again, the cracks 320 are arrested by the crack stop, preferably made of portions of refractory metal.
Several other methods of protecting fuses have been advanced for protecting fuse elements to ensure that the fuse remains unaffected when the fuse blows open. In one example described in U.S. Pat. Nos. 5,420 455 and 5,523,253, both issued to Gilmour et al. on Mar. 31, 1994 and May 30, 1995, respectively, a deposition of metal having a melting point higher than the melting point of the fuses is interspersed between the fuses. Such metals include tungsten and molybdenum. These barriers are resistant to cracking and are designed to prevent any cracks from propagating to other adjacent fuses in the immediate neighborhood. The bodies of barrier material are positioned such that they extend from the top surface of the layer containing the fuse links to approximately half-way down to the mid-point of the thickness of the fuse link.
The structure described by Gilmour et al. suffers from a major drawback, in that it requires specialized metals, oftentimes undesired ones due to manufacturing process considerations and/or they suffer from unwanted characteristics which may adversely affect the integrity of the circuits making the integrated chip. Another drawback resides in the added requirement of process alterations necessitated by the presence of certain refractory metals which tend to increase the cost of the product, rendering them uneconomical. Yet a further drawback resides in the presence of conductive paths provided by the presence of portions of barrier metal which may, under certain circumstances, alter the electrical characteristics of the circuits forming the IC chip. Finally, the introduction of a metallic crack stop between fuse links as described by Gilmour et al. will also not work at tight pitches, since the crack stop itself will be ablated by the laser, causing damage to fuses or circuit elements next to it.
Accordingly, it is an object of the invention to provide an improved fuse structure and method for fabricating integrated circuits having laser fuse links.
It is another object of the invention to provide an improved fuse structure and a method therefor, which advantageously allows more fuses to be concentrated into a given space by reducing the distance (pitch) between adjacent fuses.
It is still another object to prevent either the energy inherent of a laser beam or the damage caused by the fuse blowing, to reach or affect any adjacent fuse links or circuit elements in the immediate vicinity of the fuse link being programmed.
It is a further object to protect fuse links which span over several wiring layers when at least some of the fuse links within the structure are programmed by a laser beam.
In one aspect of the invention, the damage done to areas surrounding fuses packed closely together is limited by creating material discontinuities in the form of voids between fuses which will act as crack arresting structures. These xe2x80x9ccrack stopsxe2x80x9d can then be used in various configurations to contain the extent of damage around a blown fuse.
In another aspect of the invention, an integrated circuit is designed to include additional structures characterized by the absence of material, and placed between fuses and parallel to the fuses. The laser fuse link is configured to be set by a laser beam during fabrication of the integrated circuit.
In yet another aspect of the invention, these crack stops are positioned immediately surrounding the region of the fuses blown on a fuse link.
In one embodiment of the invention, there is provided a fuse structure including: an insulated semiconductor substrate; a fuse bank integral to the insulated semiconductor substrate consisting of a plurality of parallel co-planar fuse links; and voids interspersed between each pair of the fuse links, the voids extending beyond a plane defined by the co-planar fuse links.
In another embodiment of the invention, there is provided a fuse structure integral to a semiconductor substrate including: a fuse bank integral to the semiconductor substrate and consisting of a plurality of co-planar fuse links, each of the fuse links being provided with a co-planar area extending beyond the width of the fuse link; and voids positioned within the semiconductor substrate and interspersed between each pair of the fuse links surrounding the co-planar areas.
In a third embodiment of the invention there is provided a fuse structure integral to a semiconductor substrate providing support to a plurality of stacked insulated wiring layers including: integral to a first one of the stacked insulated wiring layers, a fuse bank comprising at least two co-planar rows of fuse links; integral to a second one of the stacked insulated wiring layers, a conducting bus positioned in a direction transversal to the direction of at least the two rows of fuse links; and portions of conductive material placed between the at least two rows of fuse links and running in a direction parallel to the bus.
In another aspect of the invention, there is provided a method of forming a fuse structure integral to a semiconductor substrate supporting a plurality of stacked insulated wiring layers which includes the steps of: providing to a first one of the stacked insulated wiring layers a fuse bank comprising at least two co-planar rows of fuse links; providing to a second one of the stacked insulated wiring layers, a conducting bus positioned in a direction transversal to the direction of the at least two row of fuse links; and placing portions of conductive material between the at least two rows of fuse links and running in a direction parallel to the bus.

Crack stop between neighboring fuses for protection from fuse blow damage

International Business Machines Corporation


A laser radar (LADAR) system is provided with amplitude-weighted spatial coherent processing. An amplitude-weighted sum of time domain signals arising from several detectors within a detector array is formed and used for range doppler processing. Weighting coefficients are chosen to be proportional to the signal amplitude present for each of the separate signals from each detector within the array. The amplitude coefficients are determined using target returned energy arising from a continuous wave (CW) porch portion of the transmitted waveform. Amplitude-weighted spatial coherent processing improves the carrier-to-noise ratio (CNR).

Advanced missile threats emerging in the 21 st century require development of advanced laser radar (LADAR) sensing capabilities. The U.S. Army sponsored Discriminating Sensor Technology (DST) Program seeks to develop LADAR seeker technology to augment sensors of Exoatmospheric Kill Vehicle (ExoKV) seekers. Current ExoKV seekers can use three passive sensors (one visible and two infrared (IR)) for acquisition, tracking, limited discrimination, and aimpoint selection in the terminal homing phase. The visible sensor must rely on external illumination (sun, moon, stars, earthshine) and the IR sensors use emitted radiation to perform their tasks.
Advanced threats may include reentry vehicles (RVs) and identically shaped precision Lightweight Replica Decoys (LREPS) with RV-like motion as well as many Closely-Spaced Objects (CSOs) to degrade the discrimination performance of current non-imaging, passive ExoKV seekers. The increased traffic in future threat clusters, jammers, chaff, and radar-absorbing materials may degrade the acquisition and discrimination coordination between ground-based radars and passive ExoKV seekers. However, the presence of an DST Range-Resolved Doppler Imaging (RRDI) LADAR seeker onboard the ExoKV will substantially reduce coordination concerns.
The RRDI LADAR does not rely on external illumination or emitted radiation from the target. The RRDI LADAR illuminates each target to measure target range, velocity, and angular rates and form images that resolve the target in the range and cross-range (breadth) dimensions. The RRDI images substantially increase the number of target features measurable by the discrimination function of a LADAR-upgraded ExoKV seeker. The precision 4-dimensional (4-D) track of a RRDI LADAR seeker improves the quality of the guidance function, which reduces the amount of fuel needed to divert to the target. Each upgraded ExoKV passive sensor and the DST RRDI LADAR shares the same small telescope system.
DST uses a solid state laser transmitter to illuminate targets with coherent radiation. DST receiver optics collect and focus back-scattered Doppler-shifted radiation from the target onto a detector array where it is mixed (heterodyned) with a local oscillator signal derived from the transmitting laser. Heterodyning makes the signal detection process very sensitive to tiny, distant received signals and impervious to clutter noise sources. A modulated waveform is applied to the LADAR transmitted signal to permit the received signal to be processed to produce 4-D precision track (range, azimuth, elevation, and Doppler) measurements and RRDI images of each advanced target. These measurements locate the target and produce RRDI images that enhance in multiple ways the system discrimination function onboard an ExoKV.
Most RRDI images nominally have over ten range bins in the projected range dimension and many tens of Doppler bins in the crossrange dimension, even when targets are hundreds of kilometers from the LADAR seeker. These image changes yield features that permit advanced conical penetration aids to be discriminated on the basis of their body-centered motions that differ from that of an RV. Very sensitive Doppler measurement properties of the LADAR received signal magnify cross range measurement resolution by orders of magnitude beyond what is physically feasible by a passive seeker sharing the same aperture. These Doppler measurement properties of the RRDI LADAR map the relative velocities of tiny surface areas of RVs and decoys to extract motion feature differences that serve as discriminants.
The RRDI LADAR is not affected by radar jammers or chaff and can readily separate and discriminate objects that appear as CSOs to the ExoKV passive seeker. Adding an RRDI imaging seeker to an ExoKV improves CSO resolution, improves seeker discrimination quality against advanced replica decoy threats, increases lethality, reduces KV fuel and reduces missile defense system susceptibility to jammers and chaff.
Despite the advantages associated with the aforementioned advances in LADAR technology, and specifically RRDI LADAR, there remains room for significant improvements. For example, there exists an ongoing need for increased range acquisition. However, various applications such as missiles are not well-suited for the increased size and weight associated with higher power amplifiers used to improve range acquisition. In view of such disadvantages, there remains a strong need in the art for a LADAR system that provides improved performance without requiring increased size and weight.

Amplitude-weighted spatial coherent processing for LADAR system


A wet chemical process tank, or a wet etch tank, that has improved fluid circulation and improved uniformity in the fluid concentration in the tank is disclosed. In a preferred embodiment, a tank body is provided which has a liquid dispenser positioned therein with a plurality of liquid outlets in a vertical surface of the dispenser each having a different diameter opening for compensating the different fluid pressure in the dispenser. A more uniform liquid concentration is thus achieved in the tank cavity to perform a more uniform chemical process on the plurality of wafers. The tank body is further provided with a second endwall which has a second distance from the plurality of wafers that is at least twice the first distance between a first endwall and the plurality of wafers. When the second endwall is at least 0.5 cm shorter than the first endwall, the larger second distance together with the shorter height of the second endwall induces a large volume of liquid to overflow the second endwall and to carry away any film residues or flakes, such as that of a photoresist material, from the tank cavity and thus preventing any possible redeposition of the film residues on the wafer surface and any contamination problems.

The present invention generally relates to a wet chemical process tank that has improved fluid circulation and more particularly, relates to a wet chemical process tank that has improved liquid flow such that flakes of film residues can be effectively carried away from the etch tank.
In semiconductor fabrication process, various techniques of etching resist-imaged photomasks, silicon wafers or other semiconductor materials have been used. A set etching technique conducted in an immersion tank is generally a practical high-throughput, flexible fabrication process. By properly selecting etchant chemicals, etch reactions with a target film are thermodynamically favored over reactions with other films. Desirable etch-rate ratios can be usually obtained.
A wet etching method is especially suitable for the blanket etching of materials such as polysilicon, oxide, nitride and metal. The method is capable of providing a desirable etch selectivity, a damage-free interface and particle-contamination-free wafers. In the more recently developed wet etching technology, automated robotic handling systems and ultra-pure chemicals are used to further improve particle control and process consistency. A well-controlled wet etching technique is therefore the choice of etching process in VLSI and ULSI fabrication techniques.
One of the key criteria in carrying out a set etching process is that the etch products must be soluble in the etchant solution and therefore, no contaminating particles are generated. In an immersion etching process, the volume of the etching tank should be large enough to create enough pressure on the wafer surface in order to ensure an accurate balance of the etchant components; to keep the concentration of the etchant relatively constant; and to minimize the number of times the etchant tank must be changed. An etchant bath change creates expensive down time and furthermore, the handling of highly hazardous corrosive materials creates potential safety problems.
Wet etching is a frequently used technique for stripping photoresist films from silicon wafers where the complete removal of resist images without adversely affecting the wafer surface is desired. The resist layer or images should be completely removed without leaving any residues, including contaminant particles that may have been present in the resist. The underlying surface of the photoresist layer should not be adversely affected, for instance, accidental etching of the metal or oxide surface should be avoided. Liquid etchant strippers should produce a reasonable bath yield in order to prevent redeposition of dissolved resist on the wafers. The etchant should completely dissolve the photoresist layer in a chemical reaction, and not just lifting or peeling so as to prevent redeposition. It is also desirable that the etching or stripping time be reasonably short in order to permit high wafer throughput.
Wet etchants such as sulfuric acid (H2SO4) and mixtures of H2SO4 with other oxidizing agents such as hydrogen peroxide (H2O2) are widely used in stripping photoresist or in cleaning a wafer surface after the photoresist has been stripped by other means. For instance, a frequently used mixture is seven parts H2SO4 to three parts 30% H2O2 or a mixture of 88% sulfuric acid and 12% nitric acid. Wafers to be stripped can be immersed in the mixture at a temperature between about 100xc2x0 C. and about 150xc2x0 C. for 5-10 minutes and then subjected to a thorough rinse of deionized water and dried in dry nitrogen. This type of inorganic resist strippers, such as the sulfuric acid mixtures, is very effective in the residual-free removal of highly postbaked resist. They are more effective than organic strippers and the longer the immersion time, the cleaner and more residue-free wafer surface can be obtained.
In a typical wet chemical process tank, in order to ensure a perfect mix of acid and other components or a good uniformity in the acid itself, constant stirring or agitation of the solution in the tank is desired. While mechanical stirring or agitation techniques have been used, the moving components of a stirrer or agitator frequently generate contaminant particles that are detrimental to the wafer surfaces. Furthermore, a mechanical stirrer or agitating device tends to work only in a localized area of the large chemical tank while leaving a large area of the tank unmixed. Since wafers are usually loaded into a wafer boat and positioned at or near the center of the tank, too vigorous stirring or agitation of the liquid in the tank may cause the wafers in the wafer boat to move and as a result, stick to each other. Such wafer sticking problems result in uneven and unsatisfactory etching on the wafer surfaces.
An improved mixing method for liquids in a wet chemical tank is to force a fluid to enter the wet chemical tank at the bottom of the tank and then forming gas bubbles to rise from the bottom to the top of the tank and thereby carrying out mixing function along the way. The fluid used is normally a substance that readily reacts with the liquid in the tank such that either a gas or a vapor is generated to form the bubbles. One of such suitable chemical reactions occurring between a liquid in a tank and a fluid pumped therein is an acid and water. For instance, when phosphoric acid (H3PO4) and ionized water are mixed in a tank, water reacts with the strong acid violently and immediately boils to form water vapor in bubbles and then the bubbles rise to the top of the liquid surface in the tank. During the process where the bubbles rise to the top of the liquid surface, the bubbles cause disturbance in the liquid and thus improve its uniformity by the agitation occurring in the liquid. A conventional system of a wet chemical process tank equipped with a fluid dispensing member, which is commonly called a spray bar, positioned at the bottom of the tank is shown in FIG. 1.
FIG. 1 shows a wet chemical process system 10 including a process tank 12 formed by a bottom wall 14 and four sidewalls 16 which are joined perpendicular to the bottom wall 14 forming a fluid-tight enclosure. The bottom wall 14 and the sidewall 16 can be constructed of a corrosion resistant material such as panels of stainless steel or steel panels coated with a corrosion resistant material such as Teflon. Due to the extreme corrosive nature of the processing liquids that are normally used in the wet chemical processing of semiconductor wafers, a securely sealed enclosure is a critical requirement for both maintenance and safety. The size of the tank 12 should be sufficiently large such that, for instance, two wafer boats (not shown) which are capable of holding twenty-four wafers each can be placed in the center of the tank while leaving an adequate space between the wafers and the walls such that a constant movement in the processing liquid can be achieved. Into the wet chemical process tank 12, a fluid dispensing member, or a spray bar 22, is positioned at the bottom of the tank. A plurality of openings 24 are formed on the top surface 26 of the dispensing member 22 for allowing a fluid to enter the tank.
An enlarged, cross-sectional view of the dispensing member 22 taken at an opening 24 is shown in FIG. 1A. An internal fluid passage 28 is provided in dispensing member 22 which is in fluid communication with conduit 32 through a connector 34 and an elbow section 36 in the dispensing members 22. A precision volumetric pump 42 is used to pump a fluid such as deionized water from an inlet 44 through conduit 32 into the fluid passage 28. Since the volume of the deionized water that enters the process tank for reaction with phosphoric acid must be precisely controlled such that just the right amount of bubbles are generated, the pump 42 utilized must be a high precision volumetric pump that is capable of precisely controlling the amount of liquid pumped there through. For instance, into a normal wet chemical process tank of 20-liter capacity that is filled with phosphoric acid, only 40 cubic cm of deionized water should be pumped into the tank per minute. At such precisely controlled flow rate, just the right amount of water vapor in bubbles can be generated to suitably mix the phosphoric acid containing in tank 12.
The fluid dispensing member 22, due to its extended exposure to strong acids when immersed in a tank, must be made of a corrosion-resistant material. A suitable material is Teflon which can be easily machined to provide the internal fluid passage 28 and the openings 24. The connector 34 and the conduit 32 should also be made by a corrosion resistant material due to their prolonged exposure to corrosive liquids.
In a conventional wet chemical process tank, the fluid dispensing member, as shown in FIG. 1, has fluid outlets facing upward for easier exit of the fluid. Since wafer boats are normally positioned at the center of the tank and therefore, directly above the fluid dispensing member and are in the path of the bubbles formed by water vapor exiting the openings in the dispensing member. This can cause various processing problems, for instance, the bubbles can sometimes stick to a wafer surface such that the specific surface area cannot be wetted by the etchant. This can lead to uneven etching of a wafer surface. The rising bubbles can also cause disturbance or movement of the wafers and thus causing the wafers to stick to each other. When the wafer sticking problem occurs, the wafer surfaces which are stuck together are not exposed to etchant solution and thus, poor etching occurs on the surfaces as a result.
An improved conventional system for wet etch that is equipped with an improved liquid dispensing member is shown in FIGS. 2Axcx9c2C. In the improved wet etch tank 30, a liquid dispenser member 38 that has fluid outlets 40 facing sideways for avoiding impacting the wafers with an acid flow that is fed through the dispenser 38. The acid flow is fed through an inlet port 46 that is situated at one end of the etch tank 30. A cross-sectional view of the improved wet etcher tank 30 is shown in FIG. 2A, while a plane view and an end view of the same are shown in FIGS. 2B and 2C, respectively.
While the improved wet etcher 30 avoids impacting the wafers directly with the acid flow 48, it does cause other processing difficulties. For instance, since all the fluid outlets, or apertures 40, are provided in the same dimension, i.e. in the same diameter, the flow velocity of acid from the outlets 40 along the longitudinal length of the dispenser 38 is not the same. The outlets 40 that are closer to the fluid inlet port 46 produce higher flow velocities of the acid flow and thus causing a solution concentration adjacent to those outlets higher than the remaining volume of the tank. At the end of the dispenser 38, the flow velocity becomes the smallest and thus produces the lowest concentration of the etch solution. The variation in the concentrations of the etchant solution at different locations in the tank leads to a large non-uniformity in the etch rates achieved on the wafers and a variation in the thicknesses of the material removed.
In the improved wet etching tank 30, the inner tank 50 overflows from flow outlets 52 provided along the top edge of the tank wall 54. The overflow from the inner tank 50 is received by the outer tank 56 which normally has a wall that is 5 cm away from the inner tank wall. However, due to a slow liquid flow rate at the plurality of fluid outlets 52, film contaminants such as flakes 58 of a photoresist film from a photoresist stripping process frequently cumulates at the fluid outlets 52 and cannot be expelled from the tank 30. When a large cumulation of the flakes 58 occurs in the wet etch tank 30, the flakes may redeposit on the wafer surface when the wafers are lifted out of the etch tank 30. This creates a serious contamination problem for the wafers.
It is therefore an object of the present invention to provide a wet chemical process tank with improved fluid circulation that does not have the drawbacks or shortcomings of the conventional wet etch tanks.
It is another object of the present invention to provide a wet chemical process tank that has improved fluid circulation for achieving a more uniform fluid concentration in the tank and a higher overflow rate such that film residues can be carried away from the etch tank.
It is a further object of the present invention to provide a wet chemical process tank that has improved fluid circulation such that redeposition of contaminating film residues on the wafers can be avoided.
It is another further object of the present invention to provide a wet chemical process tank that has improved fluid circulation such that an etchant solution of improved uniformity is achieved in the tank.
It is still another object of the present invention to provide a wet chemical process tank that utilizes a fluid dispenser equipped with outlet apertures having different diameters such that a flow rate differential between the outlets can be minimized.
It is yet another object of the present invention to provide a wet etch tank that has improved liquid flow properties in which a second endwall of the tank is spaced from the wafers at least twice the distance between a first endwall and the wafers for inducing a higher flow rate to carry away any contaminating film residues.
It is still another further object of the present invention to provide a wet etch tank that is equipped with a liquid dispenser that has outlet apertures with diameters that are different by at least 100%.
In accordance with the present invention, a wet chemical process tank that has improved fluid circulation, more uniform fluid concentration in the tank and a higher flow rate for discharging contaminating film residues is provided.
In a preferred embodiment, a wet chemical process tank that has improved fluid circulation is provided which includes a tank body that has a bottom wall and two sidewalls, a first endwall and a second endwall perpendicularly joined to the bottom wall forming a fluid tight cavity for holding a liquid therein; the cavity is adapted for holding a plurality of semiconductor wafers in an upright position; the first endwall and the two sidewalls are of the same height, while the second endwall is at least 0.5 cm shorter than the first endwall for inducing a liquid flow over the second endwall when liquid enters and overfills the cavity from a liquid inlet positioned juxtaposed to the first endwall; and a liquid dispenser positioned on and supported by the bottom wall of the tank body that has an elongated body and generally rectangular shaped cross-section connected on one end juxtaposed to the first endwall in fluid communication with the liquid inlet, the elongated body has a liquid passageway therein in fluid communication with a plurality of openings provided on a vertical side of the body allowing liquid to exit the body in a horizontal direction, the plurality of openings increases in size from a first opening adjacent to the first endwall to a second opening adjacent to the second endwall by at least 50%.
In the wet chemical process tank that has improved fluid circulation, the tank body may further include an outer tank for accepting an overflow from the cavity of the tank body and for recirculating the overflow into the tank body by a pump means. The liquid may be a diluted acid solution for conducting a wet etch process. The second endwall may be at least 1 cm shorter in height than the first endwall for inducing a liquid flow over the second endwall. The shorter height of the second endwall induces a liquid flow from the first endwall towards the second endwall. The second opening in the plurality of openings may be at least 100% larger than the first opening. A second distance between the second endwall and the plurality of semiconductor wafers may be at least 100% larger than a first distance between the first endwall and the plurality of semiconductor wafers. The bottom wall, the two sidewalls, and the first and second endwalls may be formed with a corrosion-resistant surface. The liquid dispenser may be formed of a corrosion-resistant material. The first opening may have a diameter of about 0.2 cm, while the second opening may have a diameter of about 0.6 cm.
The present invention is further directed to a wet etch tank that has improved liquid flow which includes a tank body that has a bottom wall and two sidewalls, a first endwall and a second endwall perpendicularly joined to the bottom wall forming a fluid-tight cavity for holding a liquid therein; the cavity is adapted for holding a plurality of semiconductor wafers held in an upright position therein; the first endwall and the two sidewalls are of the same height, while the second endwall is at least 0.5 cm shorter than the first endwall for inducing a liquid flow over the second endwall when liquid enters and overfills the cavity from a liquid inlet positioned juxtaposed to the first endwall; the first endwall may be spaced from the plurality of semiconductor wafers at a first distance, while the second endwall may be spaced from the plurality of semiconductor wafers at a second distance, the second distance being at least 2 times the first distance to facilitate the liquid flow over the second endwall and to carry away film residues; and a liquid dispenser positioned on and supported by the bottom wall of the tank body which has an elongated body and generally rectangular shaped cross-section connected on one end juxtaposed to the first endwall in fluid communication with the liquid inlet, the elongated body may have a liquid passageway therein in fluid communication with a plurality of openings provided on a vertical side of the body allowing liquid to exit the body in a horizontal direction, the plurality of openings increases in size from a first opening adjacent to the first endwall to a second opening adjacent to the second endwall by at least 50%.
In the wet etch tank that has improved liquid flow, the tank body may further include an outer tank for accepting an overflow from the cavity of the tank body and for recirculating the overflow into the tank body by a pump means. The liquid may be a diluted acid solution for conducting a wet etch process, or a photoresist stripping process. The second endwall may be at least 1 cm shorter in height than the first endwall for inducing a liquid flow over the second endwall. The shorter height of the second endwall further induces a liquid flow from the first endwall towards the second endwall. The second opening in the plurality of openings may be at least 100% larger than the first opening.
In the wet etch tank that has improved liquid flow, a second distance between the second endwall and the plurality of semiconductor wafers may be at least 3 times larger than a first distance between the first endwall and the plurality of semiconductor wafers. The bottom wall, the two sidewalls, the first endwall and the second endwall may be formed with a corrosion-resistant material, or with a corrosion-resistant surface. The liquid dispenser may be formed of a corrosion-resistant material, such as a corrosion-resistant polymeric material. The second opening may have a diameter that is at least 100% larger than the first opening in the liquid dispenser.

Wet chemical process tank with improved fluid circulation

Taiwan Semiconductor Manufacturing Co., Ltd.


A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

1. Field of the Invention
This invention relates to piezoelectric actuators. More specifically, the invention relates to cylindrically-shaped and telescopically-extending piezoelectric fiber composite actuator assemblies.
2. Description of the Related Art
Piezoelectric fiber composite actuators are flexible, planar actuators that can be bonded to a structure and then operated to generate and control or detect deflections/strain of the structure. A conventional piezoelectric fiber composite actuator has the following structural features:
(i) a layer of individual piezoelectric fibers (e.g., round, square, etc.) arrayed side-by-side and typically encased in a polymer matrix material; and
(ii) interdigitated electrodes etched or deposited onto one or two polymer film layers with the resulting layers sandwiching the layer of piezoelectric fibers.
The layer of individual piezoelectric fibers can be assembled from individually-extruded piezoelectric fibers or can be formed from a macro sheet of polymer-backed piezoelectric material that has been processed (e.g., piezoelectric material that has been mechanically diced or etched, laser etched, etc.) to yield parallel rows of piezoelectric material "fibers" attached to the polymer backing. A piezoelectric fiber composite actuator constructed in this fashion is also known as a macro-fiber composite actuator. A complete description of such an actuator is disclosed in U.S. Pat. No. 6,629,341, the contents of which are hereby incorporated by reference.
The piezoelectric fiber/macro-fiber composite actuator is a flat device that is lighter and smaller than hydraulic or gas piston-cylinder actuators/assemblies as well as piezoelectric "stack" actuators/assemblies. However, when not bonded to a structure, piezoelectric fiber/macro-fiber composite actuators tend to buckle when used to generate or detect a strain, displacement or force in the plane of the actuator.

Telescoping cylindrical piezoelectric fiber composite actuator assemblies

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A member-store functional unit transfers the name of a member store and the title of a campaign to an ID-assigning functional unit which assigns IDs to the title of the campaign and the name of the member store. The ID-assigning functional unit then transmits the IDs to an encoding functional unit. A broadcasting functional unit broadcasts the IDs, encoded by the encoding functional unit, by multiplexing the IDs in an audio signal. A reception functional unit receives the IDs whereas a decoding functional unit extracts and decodes the IDs. The decoding functional unit then outputs the IDs to a customer-number-assigning functional unit with a receiver ID. The customer-number-assigning functional unit forms a judgment on validity of the member-store ID, the campaign ID and the receiver ID, and assigns a customer number to the receiver ID if the member-store ID, the campaign ID and the receiver ID are found valid. An anonymous-customer management functional unit sends the customer number to a member-store functional unit so as to make a request for a transmission of a service identified by the campaign ID to the reception functional unit by way of an anonymous-service management functional unit.

The present invention relates to an information processing apparatus, an information processing method, an information processing system and a recording medium. More particularly, the present invention relates to an information processing apparatus, an information processing method, an information processing system and a recording medium that allow customers to be managed with ease at a low cost.
In recent years, the number of department stores and relatively large stores issuing the store's own card called a house card to each member customer has been increasing. By using a house card in a store issuing the card, a customer gets a discount to a certain degree and can make a payment through a money withdrawal from a bank account of the customer for a purchased commodity or service even if the customer does not bring cash.
By the way, when a department store or a retailer issues a house card to a customer, the store or the retailer obtains information on the customer such as the customers' address and name, which are filled in on an application form. Thus, in a sales campaign or the like, the department store or the retailer can notify the customer of the season, prompting the customer to purchase new commodities and services.
In such a conventional system, however, the store must prepare application forms each having a serial number, raising a problem of a higher cost.
In addition, a customer must fill in personal information such as the customer's address and name on an application form in order to obtain a house card. There is thus raised a problem of cumbersome work to fill in such personal information repeatedly to obtain several house cards from stores.

Method, apparatus and computer program product for managing customer information


A system and method for allocating physical memory in a distributed, shared memory system and for maintaining interaction with the memory using a reservation protocol is disclosed. In various embodiments, a processor node may broadcast a memory request message to a first subset of nodes connected to it via a communication network. If none of these nodes is able to satisfy the request, the processor node may broadcast the request message to additional subsets of nodes until a positive response is received. The reservation protocol may include a four-way handshake between the requesting processor node and a memory node that can fulfill the request. The method may include creation of a reservation structure on the requesting processor and on one or more responding memory nodes. The reservation protocol may facilitate the use of a proximity-based search methodology for memory allocation in a system having an unreliable underlying transport layer.

1. Field of the Invention
This invention relates to computing systems and more particularly to memory allocation within a distributed shared memory system having unreliable packet transport.
2. Description of the Relevant Art
Computer systems that include one or more banks of memory may use different architectures to organize and access that memory. Some computer systems may include a single, dedicated bank of memory for each of one or more processors and accessible only by that processor. In these distributed configurations, memory access times may be highly predictable, as the dedicated memory bank may respond according to uniform memory access times. In such configurations, no other processors (or their processes) may be able to access the dedicated bank of memory, so the local processor may have complete control over the memory accesses for its processes. Such configurations may not provide flexibility in terms of the amount of memory available for any one process, if the processor can only access its own local memory.
Other computer systems are configured to include a single memory space that is shared between two or more processors. While this configuration may allow flexibility for each processor to address different amounts of memory for different processes, it may not efficiently scale to large systems. For example, in a computer system including two processors, if both processors need to access the shared memory at the same time, one processor may sit idle while waiting for a turn to access data, negatively impacting system performance. The problem may be compounded when more processors are included in the system.
Some computer systems are configured to include features of both a shared memory architecture and a dedicated memory architecture, in what is called a Distributed Shared Memory (DSM) system. In DSM systems, a separate (local) memory may be provided for each processor, but each of the processors may also be able to access non-local memory, such as a shared block of main memory. Some DSM systems are page-based systems, in which a linear memory space is distributed between processors based on one or more fixed memory partitions, such as a page size. Other DSM systems are object-based systems, in which processes on multiple machines share an abstract memory space filled with shared objects.
Some DSM systems employ a non-uniform memory access or non-uniform memory architecture (NUMA). Under NUMA, the memory access time for any given access depends on the location of the accessed memory relative to the processor. In such systems, the processor can typically access its own local memory, such as its own cache memory, faster than non-local memory. In these systems, non-local memory may include one or more banks of memory shared between processors and/or memory that is local to another processor.
In a NUMA shared memory multiprocessor computer system, each processor, on behalf of some process, may from time to time need to allocate some memory. If sufficient local memory is available, the processor may allocate local memory to the process. If not, the processor may need to allocate non-local memory. In general, if the processor is able to allocate nearby memory, according to the system configuration, the latency of accesses to that memory may be reduced and the performance of the system may be increased. In conventional systems a centralized scheme, in which a single processor is responsible for memory allocations for all processors, may be used to allocate nearby non-local memory to a processor, but such a scheme may lack the ability to efficiently scale to large systems. In addition, prior art memory allocation schemes often assume that packet transport is reliable, and may not be suitable for use in systems having an underlying transport layer that is unreliable.

Resource reservation protocol over unreliable packet transport


A fuel cell system and a method for controlling the fuel cell system are provided. The method includes detecting an output characteristic value of the fuel cell system and controlling the fuel cell system to respectively operate in at least two of a first mode, a second mode and a third mode at different time points according to the detected output characteristic value. Accordingly, the fuel cell system is capable of stably generating electric power, and is adapted to different operation environments.

Field of the Invention
The invention relates to a fuel cell system and a method for controlling the same. Particularly, the invention relates to a fuel cell system capable of stably outputting electric power and a method for controlling the same.
Description of Related Art
Development and application of energy have always been indispensable conditions of human life, however, the development and application of energy may cause increasing damage to the environment. Energy generated through a fuel cell technique has advantages of high efficiency, low noise and pollution-free, etc. which is an energy technology in line with a trend of the times. Types of the fuel cells are diversified, and the commonly used fuel cells are direct methanol fuel cells (DMFC) and proton exchange membrane fuel cells (PEMFC). However, both of the DMFC and the PEMFC generate power through fuel reaction, and fuel quantity and a speed of the fuel reaction may influence performance and stability of the whole fuel cell.
Taking the PEMFC as an example, the PEMFC is composed of a proton exchange membrane, an anode, and a cathode. The anode takes hydrogen as a fuel, and the hydrogen is transported to a flow channel of the anode through a pump and a flux control valve. When the hydrogen is reacted with a catalyst in the anode, heat is produced. The fuel of the anode is reacted with the catalyst to produce hydrogen ions and electrons, and a chemical formula thereof is:2H2→4H++4e−
The electrons generated during the anode reaction move to the cathode through a circuit, and the hydrogen ions move to the cathode by penetrating through the proton exchange membrane, and are further reacted with the electrons and oxygen to generate water, and a chemical formula thereof is:4H++4e−+O2→2H2O
The water generated at the cathode is recycled through a condensation system. On the other hand, since a flow rate of the hydrogen supplied to the anode is required to be stable during the reaction, a complicated valve and a pump are generally required to implement a flux control of the hydrogen.
The hydrogen serving as the fuel could be produced by a general hydrogen producing method and a chemical hydrogen storage technology is widely used in portable electronic devices. The chemical hydrogen storage technology generally produces hydrogen through reaction of a solid-state reactant and a liquid reactant. The solid-state reactant could be metal hydride or metal, for example, NaBH4, MgH2, CaH2 or Al. The liquid reactant includes liquid water, malic acid, citric acid, H2SO4, NaHCO3, CaCO3, etc. For example, water could be added to sodium borohydride for chemical reaction, so as to produce hydrogen. Then, the produced hydrogen is introduced to the fuel cell to react to generate electric power. Regarding the reaction of the sodium borohydride and water, the water could be added to the sodium borohydride or the sodium borohydride could be added to the water for reaction, and a chemical formula thereof is:NaBH4+2H2O→NaBO2+4H2
According to the above chemical formula, it is known that the hydrogen could be continually produced in one chemical reaction until the chemical reaction between the solid-state reactant and the liquid reactant is completed. Since the hydrogen generated through the chemical reaction is unstable in flux, a flux control valve is generally used to stably output the hydrogen.
Moreover, when the water is added to the solid-state reactant, a large amount of the hydrogen is released. When the fuel cell receives a large amount of the hydrogen in a short time, an output voltage thereof is increased and a temperature thereof is sharply increased, which causes difficulty in the system control.
Presently, a valve is used to control the output of the hydrogen in order to achieve a precise control, though the valve is quite expansive. Moreover, if the output of the hydrogen is controlled without the valve, following problems are encountered:                1. It is unable to be operated at different ambient temperatures. In case of a low ambient temperature, a large amount of chemical reactions is required to produce hydrogen and maintain the temperature, and in case of a high ambient temperature, logic for controlling the flux of the hydrogen is different due to better reactivity. On the other hand, if the temperature is excessively high, the system is hard to decrease the temperature to an optimal temperature for the fuel cell.        2. The flux of the hydrogen cannot be controlled. A large amount of hydrogen may cause sharp increase of the voltage and temperature, and a small amount of hydrogen results in a low voltage. If there is no good controlling method for the flux of the hydrogen, a service life of the fuel cell is quickly decreased.        3. According to a general control mode, the temperature range of the fuel cell is enlarged, which may cause an excessively high or low temperature. Since the temperature directly influences the performance of the fuel cell in outputting the electric power, a fuel usage rate of the fuel cell is decreased.
Moreover, U.S. Patent Publication No. 20090214904 discloses an integrated fuel and a fuel cell, in which a rate for introducing water or vapor to a solid fuel is controlled by controlling an aperture size and using a film material. Moreover, Taiwan Publication No. 201004018 discloses a fuel supplying method of a fuel cell. In addition, U.S. Patent No. 20070196700 discloses a controlling method for fuel supply.

Fuel cell system and method for controlling the same


A computed tomography (CT) reconstruction method includes implementing an iterative image reconstruction process for CT metrology of an object, wherein the iterative reconstruction process utilizes accurate forward projection. During each of a plurality of iterations, a reconstructed image is constrained by utilizing prior outer edge information obtained from a modality in addition to CT, and then transformed to a projection domain so as to generate a calculated sinogram. A correction image is determined based on the calculated sinogram and a measured sinogram.

The present disclosure relates generally to computed tomography (CT) imaging and inspection systems and, more particularly, to a method for iterative CT reconstruction using multi-modal edge information.
In present date industrial inspection processes, different types of measurement systems are available such as computed tomography (CT), coordinate measuring machines (CMM), laser-based profilometry, etc. Each inspection modality has its own advantages and disadvantages associated therewith. Modalities such as CMM and laser-based profilometry can measure external surfaces with high accuracy, but cannot measure internal features unless the part is cut open. To date, CT is the most versatile of the measurement/inspection systems for revealing both the internal and external structures of industrial parts in a non-destructive manner. The potential industrial applications of CT include reverse engineering, rapid prototyping, casting simulation & validation, tire development, first article inspection, ceramic porosity inspection, process validation, parts qualification and defect detection, to name a few. However, the low inspection accuracy of CT inhibits widespread applications thereof.
For example, in the area of reverse engineering, CT is a poor choice for capturing detailed external surface features, which can be crucial for capturing the design intent. The factors affecting CT accuracy in this regard include (among other aspects) beam-hardening, partial volume effect, scattering and off-focal radiation. Thus, in order to improve CT inspection accuracy, more effective methods are needed for removing the effects of these artifacts. In the area of CT image reconstruction, filtered backprojection (FBP) is a common technique because of its fast computation and ease of implementation. However, because FBP oversimplifies the CT data acquisition into an ideal Radon transform (i.e., Fan Beam transform, cone beam transform or any other transform depending on the particular acquisition geometry), the reconstructed image suffers from artifacts such as beam hardening and partial volume as discussed above, contributing to degraded image quality and inspection accuracy. Precorrection of the data prior to performing an FBP reconstruction is generally not capable of fully correcting for the artifacts due to these effects.
Another type of CT image reconstruction methodology is what is referred to as iterative reconstruction. These techniques are based on different mathematical principles, such as the statistical approach of maximum likelihood, and the least squares approach, for example. Iterative methods allow for the incorporation of a dedicated forward model of the data acquisition. On the other hand, because the computation associated with iterative reconstruction is highly intensive, iterative methods are not yet widely used in CT. As such, in present inspection processes, CT images are typically reconstructed using the FBP method where both external and internal features are extracted from the CT images. In the event a more accurate measurement of internal features is desired, the part is generally cut open and inspected by CMM. Thereafter, the CT measurement is calibrated using the CMM measurement, so as to compensate for any possible bias. Unfortunately, this procedure is both time-consuming and expensive.
Accordingly, it is desirable to be able to provide an improved inspection method that accurately captures both the internal and external features of an object to be inspected, but in a time efficient and inexpensive manner.

Iterative CT reconstruction method using multi-modal edge information


A combustor liner for a gas turbine includes a body having a plurality of angled strips on an outside surface of the combustor liner. The plurality of angled strips are arranged in an array about the outside surface. A space is disposed between each of said plurality of angled strips so as to create vortices in a cooling air flowing in a longitudinal direction across said outside surface of said combustor liner. A method of fabricating a combustor liner includes forming a plurality of angled strips on an outside surface of the combustor liner and arranged in an array about the outside surface, each of the angled strips is disposed so as to be spaced apart to create vortices in a cooling air flowing across the outside surface of the combustor liner.

This invention relates generally to turbine components and more particularly to a combustor liner.
Conventional gas turbine combustors use diffusion (i.e., non-premixed) combustion in which fuel and air enter the combustion chamber separately. The process of mixing and burning produces flame temperatures that can exceed 3900 degrees F. Since conventional combustors and/or transition pieces having liners are generally capable of withstanding for about ten thousand hours (10,000 hrs.), a maximum temperature on the order of about 1500 degrees F., steps to protect the combustor and/or transition piece must be taken. This has typically been done by film-cooling which involves introducing relatively cool compressor air into a plenum formed by the compressor discharge case surrounding the outside of the combustor. In this prior arrangement, the air from the plenum passes through louvers in the combustor liner and then passes as a film over the inner surface of the liner, thereby maintaining combustor liner temperature at an acceptable level.
Because diatomic nitrogen rapidly disassociates at temperatures exceeding about 3000° F. (about 1650° C.) and reacts readily with oxygen at such temperatures, the high temperatures of diffusion combustion result in relatively high NOx emissions. One approach to reducing NOx emissions has been to premix the maximum possible amount of compressor air with fuel. The resulting lean premixed combustion produces cooler flame temperatures and thus lower NOx emissions. Although lean premixed combustion is cooler than diffusion combustion, the flame temperature is still too hot for prior conventional combustor components to withstand without some type of active cooling.
Furthermore, because the advanced combustors premix the maximum possible amount of air with the fuel for NOx reduction, little or no cooling air is available, making film-cooling of the combustor liner and transition piece impractical. Nevertheless, combustor liners require cooling to maintain material temperatures below limits. In dry low NOx (DLN) emission systems, this cooling can only be supplied as cold side convection. Such cooling must be performed within the acceptable limits of thermal gradients and pressure loss. Thus, means such as thermal barrier coatings in conjunction with "backside" cooling have been utilized to protect the combustor liner and transition piece from destruction by such high heat. Backside cooling involves passing the compressor air over the outer surface of the combustor liner and transition piece prior to premixing the air with the fuel.
There are currently three forms of prior art for the convective cooling of combustor chambers. First, a series of longitudinal or axially spaced horizontal turbulators, which appear as straight lines across the surface of the liner, are used in practice to disrupt the thermal boundary layer and provide enhanced heat transfer for cooling. These turbulators are either machined in the metal surface, or applied as tack-welded strips of material to the metal. Second, convective cooling is provided by a series of impingement jets supplied by the external combustor chamber cooling flow sleeve. Typically, it is not possible to provide such impingement cooling over the entire extent of the chamber, and so some mixture of impingement and surface turbulators is employed. Third, an array of surface indentations, also known as dimples or hemispherical concavities, is made in the liner surface to create flow vortices that act to enhance heat transfer. The various known techniques enhance heat transfer but with varying effects on thermal gradients and pressure losses.

Combustor cooling with angled segmented surfaces